Phosphatidylinositol transfer proteins (PITPs) facilitate the transport and presentation of phosphatidylinositol (PI) between the endoplasmic reticulum (ER) and target membranes, thereby regulating phosphoinositide metabolism. However, the tissue distribution of PITPs in C. elegans remains largely unknown. Here, we generated an endogenous GFP knock-in reporter to characterize the worm PITPs ortholog Y71G12B.17. GFP::Y71G12B.17 was prominently expressed in the excretory system, and was also detected in the hypodermis, sperm, sperm-associated residual bodies, developing vulva, and the pseudocoelom. These findings establish the endogenous expression pattern of Y71G12B.17 and identify candidate tissues for dissecting its roles in lipid transfer, homeostasis, and cellular signaling.
","acknowledgements":"We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
","authors":[{"affiliations":["University of Florida, Gainesville, FL, United States"],"departments":["Biology"],"credit":["validation","writing_originalDraft","writing_reviewEditing"],"email":"graycen.horne@ufl.edu","firstName":"Graycen","lastName":"Horne","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":null},{"affiliations":["University of Florida, Gainesville, Florida, United States","National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD"],"departments":["Biology","Laboratory of Biochemistry and Genetics",""],"credit":["conceptualization","dataCuration","formalAnalysis","investigation","methodology","writing_originalDraft","writing_reviewEditing"],"email":"baixiaofei@ufl.edu","firstName":"Xiaofei ","lastName":"Bai","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":true,"WBId":null,"orcid":"0000-0001-8179-8162"}],"awards":[],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":{"url":null},"extendedData":[],"funding":"This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","image":{"url":"https://portal.micropublication.org/uploads/68d680734322548eb7f9af959b2f0702.png"},"imageCaption":"(A) Schematic representation of the endogenous GFP::Y71G12B.17 reporter locus with an N-terminal GFP tag immediately upstream of the Y71G12B.17 coding sequence. (B–B″) Representative images showing GFP::Y71G12B.17 (green in B'') in the anterior excretory region near the pharynx, co-localization with FASN-1::RFP (magenta in B''). Monochromatic images show GFP::Y71G12B.17 (B) and FASN-1::RFP (B'). Yellow arrows highlight representative areas of the spatial overlap. (C–C″) Co-expression of GFP::Y71G12B.17 (C) and FASN-1::RFP (C') in hypodermal cells. with the merged image shown in (C''). Yellow arrows indicate hypodermal nuclei. (D) GFP::Y71G12B.17 signal in the pseudocoelomic region (yellow arrow) and residual-body-associated structures (red arrow). (E) GFP::Y71G12B.17 expression in sperm; the yellow arrow points to a representative GFP-positive sperm cell. (F) GFP::Y71G12B.17 expression in the developing vulval (yellow arrow). Scale bars are indicated in each panel.
","imageTitle":"Endogenous expression of GFP::Y71G12B.17 in multiple C. elegans tissues
","methods":"Microscopy
All fluorescence imaging was performed using a spinning-disk confocal system equipped with a Nikon 60× 1.2 NA water-immersion objective, a Hamamatsu C15440 ORCA-Fusion BT Digital camera, and a Yokogawa CSU-X1 confocal scanner unit. Imaging acquisition was controlled by Nikon's NIS-Element software. Image processing and channel merging were conducted using the ImageJ/FIJI Bio-Formats plugin (National Institutes of Health) [11, 12].
Generation of CRISPR knock-in strains.
CRISPR/Cas9 editing was performed using the Bristol N2 strain as the wild type. Synthetic crRNAs and tracrRNA were purchased from Horizon Discovery. Repair templates and single-stranded DNA oligos were synthesized by Integrated DNA Technologies (IDT). Approximately 20-30 young adult hermaphrodites were injected with the CRISPR/Cas9 injection mix.
GFP::Y71G12B.17 CRISPR information:
Guide RNA: 5' CGAAAAAAACATGATTGTAA”
Repair template primer F1: 5' tttcaaaacaacttcattacttcgaaaaaaacATG agtaaaggagaagaattgttc 3'
Repair template primer R1: 5' tcttccaatatcaaaaaataactcacCTTTACAAT cgatgctcctgaggctcccgatgctcc CTTGTAGAGCTCGTCCATTC 3'
Genotype Primer F1: 5' ccccctttgaaaactcacattt 3'
Genotype Primer R1: 5' gggttttaggccatctgtgga 3'
","reagents":"C. elegans strains used in this study:
XFB7 fasn-1(xmb13[fasn-1::rfp]) I.
XFB143 Y71G12B.17(xmb11[GFP::Y71G12B.17]) I
","patternDescription":"Description:
Phosphatidylinositol transfer proteins (PITPs) are conserved lipid-binding proteins that support phosphatidylinositol (PI) metabolism and phosphoinositide-dependent cellular processes. PI is synthesized primarily in the endoplasmic reticulum (ER), whereas its phosphorylated derivatives are enriched at distinct cellular membranes, such as PI4P at the Golgi complex and PI(4,5)P2 at the plasma membrane [1]. Class I PIPTs, including mammalian PITPNA and PITPNB, specifically bind PI and phosphatidylcholine (PC) to facilitate PI phosphoinositide synthesis across distinct membrane compartments [1, 2]. Consequently, PIPTs play essential roles in membrane trafficking, secretion, and intracellular signaling [1]. In mammals, PITPNA performs critical physiological functions in secretory tissues. For example, loss of PITPNA in pancreatic beta cells disrupts PI4P production, leading to hyperglycemia and reduced glucose-stimulated insulin secretion, highlighting its potential as a therapeutic target for type 2 diabetes [3].
The C. elegans genome encodes two predicted class I PIPTs, Y54F10AR.1 and Y71G12B.17, as well as the class II PITP PITP-1 [4]. PITP-1 has been characterized in sensory neurons, where it regulates phosphoinositide-dependent neurotransmission and behavioral plasticity [4]. More recently, reduction of pitp-1 gene expression was also shown to extend lifespan through insulin/IGF-1 and TOR signaling pathways [5]. In contrast, relatively little is known about the anatomical distribution or physiological functions of class I PITPs in C. elegans.
To determine the endogenous expression pattern of PIPTs, we generated an N-terminal GFP knock-in reporter at the endogenous locus of Y71G12B.17 using CRISPR/Cas9 genome editing (Figure A). GFP::Y71G12B.17 was broadly detected across several somatic and reproductive tissues, known for active lipid metabolism. Prominent expression was observed in the anterior excretory system (Figure B-B'), a structure functionally analogous to the mammalian renal system that serves as a hub for fluid balance and metabolic waste elimination. This system relies heavily on phospholipids, such as PI, and their metabolic derivatives to maintain its unique architecture and support intracellular transport pathways [6].
To further confirm this expression pattern, we co-expressed GFP::Y71G12B.17 with FASN-1::RFP, an endogenous reporter for the C. elegans fatty acid synthase required for de novo fatty acid synthesis [7, 8]. Endogenous GFP-tagged FASN-1 is broadly expressed in somatic tissues, with prominent expression in the hypodermis, excretory duct, and developing vulva, and serves as a key marker for lipid-enriched cellular compartments [7]. GFP::Y71G12B.17 showed marked co-localization with FASN-1::RFP within several regions surrounding the pharynx and the excretory cell body (Figure B-B''). Strong GFP signal was also observed along the lateral body wall in areas corresponding to the hypodermis (Figure C-C''), where it co-localized with FASN-1::RFP. These observations demonstrate that Y71G12B.17 is prominently expressed in the C. elegans excretory system and hypodermis, sharing a tissue-level distribution with key metabolic enzymes such as FASN-1.
Beyond the excretory system, GFP::Y71G12B.17 was detected in several reproductive and reproduction-associated tissues (Figure D-F). Fluorescent signals were present in the pseudocoelomic region adjacent to the germline and within structures associated with the residual body (Figure D) as well as in mature sperm (Figure E). Because the pseudocoelomic cavity functions as a key site for lipid transport and exchange between somatic sheath cells and the germline [9], this localization suggests potential roles for Y71G12B.17 in reproductive lipid transport.
Finally, GFP::Y71G12B.17 fluorescent signal was observed in the developing vulva (Figure F), another tissue where FASN-1 is known to function [7, 8]. Vulval morphogenesis requires coordinated cell-cell signaling, extensive membrane remodeling, and active membrane trafficking [10]. The presence of Y71G12B.17 in this tissue suggests that this class I PITP participates in membrane dynamics during organogenesis and C. elegans vulvar morphogenesis.
In summary, our endogenous tag reveals the tissue-specific distribution of the previously uncharacterized class I PITP Y71G12B.17 in C. elegans. Its expression in the excretory system, hypodermis, reproductive structures, and developing vulva—combined with its spatial overlap with FASN-1—provides an anatomical framework for future investigations into its functional roles in phosphoinositide metabolism, membrane trafficking, and organismal lipid homeostasis.
","references":[{"reference":"Ashlin TG, Blunsom NJ, Cockcroft S. 2021. Courier service for phosphatidylinositol: PITPs deliver on demand. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1866: 158985.
","pubmedId":"","doi":"ARTN 158985 10.1016/j.bbalip.2021.158985"},{"reference":"Grabon A, Khan D, Bankaitis VA. 2015. Phosphatidylinositol transfer proteins and instructive regulation of lipid kinase biology. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1851: 724-735.
","pubmedId":"","doi":"10.1016/j.bbalip.2014.12.011"},{"reference":"Yeh YT, Sona C, Yan X, Li Y, Pathak A, McDermott MI, et al., Poy. 2023. Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction. Nature Communications 14: 10.1038/s41467-023-39978-1.
","pubmedId":"","doi":"10.1038/s41467-023-39978-1"},{"reference":"Iwata R, Oda S, Kunitomo H, Iino Y. 2011. Roles for class IIA phosphatidylinositol transfer protein in neurotransmission and behavioral plasticity at the sensory neuron synapses of\n Caenorhabditis elegans. Proceedings of the National Academy of Sciences 108: 7589-7594.
","pubmedId":"","doi":"10.1073/pnas.1016232108"},{"reference":"Lin YH, Liao YH, Liao SB, Lin TY, Shanmugam MM, Hsu PJ, et al., Wang. 2026. Phosphatidylinositol transfer protein-1 integrates insulin/IGF-1 and TOR signaling to negatively regulate lifespan and healthspan in Caenorhabditis elegans. Journal of Biomedical Science 33: 10.1186/s12929-026-01246-x.
","pubmedId":"","doi":"ARTN 42 10.1186/s12929-026-01246-x"},{"reference":"Sundaram MV, Buechner M. 2016. The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity. Genetics 203: 35-63.
","pubmedId":"","doi":"10.1534/genetics.116.189357"},{"reference":"Starich TA, Bai X, Greenstein D. 2020. Gap junctions deliver malonyl-CoA from soma to germline to support embryogenesis in Caenorhabditis elegans. eLife 9: 10.7554/elife.58619.
","pubmedId":"","doi":"ARTN e58619 10.7554/eLife.58619"},{"reference":"Wang Y, Rincon Paz M, Fan X, Smith HE, Roure R, Patil A, et al., Bai. 2026. Loss of\n ptr-6\n restores eggshell integrity and embryonic viability in\n Caenorhabditis elegans\n fatty acid synthase mutants. G3: Genes, Genomes, Genetics : 10.1093/g3journal/jkag182.
","pubmedId":"","doi":"10.1093/g3journal/jkag182"},{"reference":"Perez MF, Lehner B. 2019. Vitellogenins - Yolk Gene Function and Regulation in Caenorhabditis elegans. Frontiers in Physiology 10: 10.3389/fphys.2019.01067.
","pubmedId":"","doi":"ARTN 1067 10.3389/fphys.2019.01067"},{"reference":"Sternberg PW. 2005. Vulval development. WormBook : 10.1895/wormbook.1.6.1.
","pubmedId":"","doi":"10.1895/wormbook.1.6.1"},{"reference":"Linkert M, Rueden CT, Allan C, Burel JM, Moore W, Patterson A, et al., Swedlow. 2010. Metadata matters: access to image data in the real world. Journal of Cell Biology 189: 777-782.
","pubmedId":"","doi":"10.1083/jcb.201004104"},{"reference":"Schindelin J, Arganda-Carreras I, Frise E, Kaynig V, Longair M, Pietzsch T, et al., Cardona. 2012. Fiji: an open-source platform for biological-image analysis. Nature Methods 9: 676-682.
","pubmedId":"","doi":"10.1038/Nmeth.2019"}],"title":"Endogenous Expression of the Class I Phosphatidylinositol Transfer Protein Y71G12B.17 in Caenorhabditis elegans
","reviews":[{"reviewer":{"displayName":"Jennifer Heppert"},"openAcknowledgement":false,"status":{"submitted":true}}],"curatorReviews":[{"curator":{"displayName":"Daniela Raciti"},"openAcknowledgement":false,"submitted":null},{"curator":{"displayName":"KJ Yook"},"openAcknowledgement":false,"submitted":null}]},{"id":"0b5f8acd-f6c9-4a18-ae5f-b8eaed5114c2","decision":"revise","abstract":"
Phosphatidylinositol transfer proteins (PITPs) facilitate the transport and presentation of phosphatidylinositol (PI) between the endoplasmic reticulum (ER) and target membranes, such as the Golgi and plasma membrane, thereby regulating PI and phosphoinositide metabolism. However, the tissue distribution and cellular expression patterns of class I PITPs in C. elegans remain largely unknown. Here, we generated an endogenous GFP knock-in reporter to characterize Y71G12B.17, renamed as PPIT-2 (phosphatidylinositol transfer protein alpha and beta 2), a conserved homolog of the human class I PITPs, PITPNA, and PITPNB. GFP::PPIT-2 was prominently expressed in the excretory system, including the excretory canals, and was also detected in the hypodermis, sperm, sperm-associated residual bodies, developing vulva, and the pseudocoelomic region adjacent to the germline. Notably, its tissue distribution overlaps with that of the fatty acid synthase FASN-1 in the excretory system and hypodermis. These findings establish the endogenous expression pattern of PPIT-2 and identify candidate tissues for dissecting its roles in PI transfer, cellular signaling, membrane trafficking, and lipid homeostasis.
","acknowledgements":"We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
","authors":[{"affiliations":["University of Florida, Gainesville, FL, United States"],"departments":["Biology"],"credit":["validation","writing_originalDraft","writing_reviewEditing"],"email":"graycen.horne@ufl.edu","firstName":"Graycen","lastName":"Horne","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":null},{"affiliations":["University of Florida, Gainesville, Florida, United States","University of Florida, Gainesvill, Florida, United States"],"departments":["Biology","Genetics Institute",""],"credit":["conceptualization","dataCuration","formalAnalysis","investigation","methodology","writing_originalDraft","writing_reviewEditing"],"email":"baixiaofei@ufl.edu","firstName":"Xiaofei ","lastName":"Bai","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":true,"WBId":null,"orcid":"0000-0001-8179-8162"}],"awards":[],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":{"url":null},"extendedData":[],"funding":"This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","image":{"url":"https://portal.micropublication.org/uploads/3b0543a4f88d16e69fbd4e235f6e7408.png"},"imageCaption":"(A) Schematic representation of the endogenous GFP::PPIT-2 reporter locus with an N-terminal GFP tag immediately upstream of the PPIT-2 coding sequence. (B–B″) Representative images showing GFP::PPIT-2 (green in B’’) in the anterior excretory region near the pharynx, co-localization with FASN-1::RFP (magenta in B’’). Monochromatic images show GFP::PPIT-2 (B) and FASN-1::RFP (B’). Yellow arrows highlight representative areas of the spatial overlap. (C–C″) Co-expression of GFP::PPIT-2 (C) and FASN-1::RFP (C’) in hypodermal cells. with the merged image shown in (C’’). Yellow arrows indicate hypodermal nuclei. (D) GFP::PPIT-2 signal in the pseudocoelomic region (yellow arrow) and residual-body-associated structures (red arrow). (E) GFP::PPIT-2 expression in sperm; the yellow arrow points to a representative GFP-positive sperm cell. (F) GFP::PPIT-2 expression in the developing vulval (yellow arrow). Scale bars are indicated in each panel.
","imageTitle":"Endogenous expression of GFP::PPIT-2 in multiple C. elegans tissues
","methods":"Microscopy
All fluorescence imaging was performed using a spinning-disk confocal system equipped with a Nikon 60× 1.2 NA water-immersion objective, a Hamamatsu C15440 ORCA-Fusion BT Digital camera, and a Yokogawa CSU-X1 confocal scanner unit. Imaging acquisition was controlled by Nikon's NIS-Element software (Version 6.10). Image processing and channel merging were conducted using the ImageJ/FIJI Bio-Formats plugin (Fiji/ImageJ: ImageJ version 1.54f; Bio-Formats plugin: version 7.0.0) (National Institutes of Health) (Linkert et al., 2010; Schindelin et al., 2012).
Mounting C. elegans for imaging
Animals were mounted on 7% agarose pads in M9 buffer containing 7.5 mM levamisole and covered with a coverslip. The synchronized mid or late L4 animals were used for imaging in panels B–C’’, and young adult hermaphrodites were imaged in panels D-F.
Generation of CRISPR knock-in strains
CRISPR/Cas9 editing was performed using the Bristol N2 strain as the wild type. Synthetic crRNAs and tracrRNA were purchased from Horizon Discovery. Repair templates and single-stranded DNA oligos were synthesized by Integrated DNA Technologies (IDT). Approximately 20-30 young adult hermaphrodites were injected with the CRISPR/Cas9 injection mix. The N-terminal tag was amplified from the plasmid pDD282, which contains C. elegans codon-optimized GFP-C1. F1 roller progeny of injected animals were initially selected based on visible GFP expression and subsequently screened by single-worm PCR across the insertion boundaries. Candidate insertions were validated by Sanger sequencing of both the 5′ and 3′ genomic junctions. All GFP::PPIT-2 lines used for imaging were established as homozygous knock-in stocks before imaging.
GFP::PPIT-2 CRISPR information:
Guide RNA: 5’ CGAAAAAAACATGATTGTAA”
Repair template primer F1: 5’ tttcaaaacaacttcattacttcgaaaaaaacATG agtaaaggagaagaattgttc 3’
Repair template primer R1: 5’ tcttccaatatcaaaaaataactcacCTTTACAAT cgatgctcctgaggctcccgatgctcc CTTGTAGAGCTCGTCCATTC 3’
Genotype Primer F1: 5’ ccccctttgaaaactcacattt 3’
Genotype Primer R1: 5’ gggttttaggccatctgtgga 3’
C. elegans strains used in this study:
Strain Name | Genotype | Source |
N2 | Bristol wild-type | CGC |
XFB7 | fasn-1(xmb13[fasn-1::rfp]) I. | This study |
XFB143 | PPIT-2(xmb11[GFP::PPIT-2]) I | This study |
Acknowledgments:
We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
Funding:
This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","reagents":"C. elegans strains used in this study:
N2, Bristol wild-type.
XFB7 fasn-1(xmb13[fasn-1::rfp]) I.
XFB143 Y71G12B.17(xmb11[GFP::Y71G12B.17]) I
","patternDescription":"Description:
Phosphatidylinositol transfer proteins (PITPs) are conserved lipid-binding proteins that support phosphatidylinositol (PI) metabolism and phosphoinositide-dependent cellular processes. PI is synthesized primarily in the endoplasmic reticulum (ER), whereas its phosphorylated derivatives are enriched at distinct cellular membranes, such as PI4P at the Golgi complex and PI(4,5)P2 at the plasma membrane (Ashlin, Blunsom, & Cockcroft, 2021). Class I PITPs, including mammalian PITPNA and PITPNB, specifically bind PI and phosphatidylcholine (PC) to facilitate PI phosphoinositide synthesis across distinct membrane compartments (Ashlin, Blunsom, & Cockcroft, 2021; Grabon, Khan, & Bankaitis, 2015). Consequently, PITPs play essential roles in membrane trafficking, secretion, and intracellular signaling (Ashlin, Blunsom, & Cockcroft, 2021). In mammals, PITPNA performs critical physiological functions in secretory tissues. For example, loss of PITPNA in pancreatic beta cells disrupts PI4P production, leading to hyperglycemia and reduced glucose-stimulated insulin secretion, highlighting its potential as a therapeutic target for type 2 diabetes (Yeh et al., 2023).
The C. elegans genome encodes two predicted class I PITPs, Y54F10AR.1 and PPIT-2, as well as the class II PITP PITP-1 (Iwata et al., 2011). PITP-1 has been characterized in sensory neurons, where it regulates phosphoinositide-dependent neurotransmission and behavioral plasticity (Iwata et al., 2011). More recently, reduction of pitp-1 gene expression was also shown to extend lifespan through insulin/IGF-1 and TOR signaling pathways (Lin et al., 2026). In contrast, relatively little is known about the anatomical distribution or physiological functions of class I PITPs in C. elegans.
To determine the endogenous expression pattern of PITPs, we generated an N-terminal GFP knock-in reporter at the endogenous locus of PPIT-2 using CRISPR/Cas9 genome editing (Figure A). GFP::PPIT-2 was detected in the excretory cell body and canals, the hypodermis, mature sperm, sperm-associated residual bodies, and the developing vulva, all of which are known for active lipid metabolism. Prominent expression was observed in the anterior excretory system (Figure B-B’), a structure functionally analogous to the mammalian renal system that serves as a hub for fluid balance and metabolic waste elimination. This system relies heavily on phospholipids, such as PI, and their metabolic derivatives to maintain its unique architecture and support intracellular transport pathways (Sundaram & Buechner, 2016).
Given the roles of class I PITPs in lipid transport and phosphoinositide signaling, we asked whether PPIT-2 is expressed in tissues that also express the lipogenic enzyme FASN-1. We therefore examined GFP::PPIT-2 in animals that also express FASN-1::RFP, an endogenous reporter of the C. elegans fatty acid synthase required for de novo fatty acid synthesis (Starich, Bai, & Greenstein, 2020; Wang et al., 2026). Endogenous GFP-tagged FASN-1 is broadly expressed in somatic tissues, with prominent expression in the hypodermis, excretory duct, and developing vulva, and serves as a key marker for lipid-enriched cellular compartments (Starich, Bai, & Greenstein, 2020). GFP::PPIT-2 showed marked co-localization with FASN-1::RFP within several regions surrounding the pharynx and the excretory cell body (Figure B-B’’). Strong GFP::PPIT-2 signal was also observed along the lateral body wall in areas corresponding to the hypodermis (Figure C-C’’), where it co-localized with FASN-1::RFP. These observations, GFP::PPIT-2 and FASN-1::RFP signals, were both detected in the examined excretory and hypodermal regions, indicating tissue-level overlap in these regions.
Beyond the excretory system, GFP::PPIT-2 was detected in several reproductive and reproduction-associated tissues (Figure D-F). Fluorescent signals were present in the pseudocoelomic region adjacent to the germline and within structures associated with the residual body (Figure D) as well as in mature sperm (Figure E). Because the pseudocoelomic cavity functions as a key site for lipid transport and exchange between somatic sheath cells and the germline (Perez & Lehner, 2019), this localization suggests potential roles for PPIT-2 in reproductive lipid transport.
Finally, GFP::PPIT-2 fluorescent signal was observed in the developing vulva (Figure F), another tissue where FASN-1 is known to function (Starich, Bai, & Greenstein, 2020; Wang et al., 2026). Vulval morphogenesis requires coordinated cell-cell signaling, extensive membrane remodeling, and active membrane trafficking (Sternberg, 2005). The presence of PPIT-2 in this tissue suggests that this class I PITP might participate in membrane dynamics during organogenesis and C. elegans vulvar morphogenesis.
In summary, our endogenous tag reveals the tissue-specific distribution of the previously uncharacterized class I PITP PPIT-2 in C. elegans. Its expression in the excretory system, hypodermis, reproductive structures, and developing vulva—combined with its spatial overlap with FASN-1—provides an anatomical framework for future investigations into its functional roles in phosphoinositide metabolism, membrane trafficking, and organismal lipid homeostasis.
","references":[{"reference":"Ashlin TG, Blunsom NJ, Cockcroft S. 2021. Courier service for phosphatidylinositol: PITPs deliver on demand. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1866: 158985.
","pubmedId":"","doi":"ARTN 158985 10.1016/j.bbalip.2021.158985"},{"reference":"Grabon A, Khan D, Bankaitis VA. 2015. Phosphatidylinositol transfer proteins and instructive regulation of lipid kinase biology. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1851: 724-735.
","pubmedId":"","doi":"10.1016/j.bbalip.2014.12.011"},{"reference":"Iwata R, Oda S, Kunitomo H, Iino Y. 2011. Roles for class IIA phosphatidylinositol transfer protein in neurotransmission and behavioral plasticity at the sensory neuron synapses of\n Caenorhabditis elegans. Proceedings of the National Academy of Sciences 108: 7589-7594.
","pubmedId":"","doi":"10.1073/pnas.1016232108"},{"reference":"Lin YH, Liao YH, Liao SB, Lin TY, Shanmugam MM, Hsu PJ, et al., Wang. 2026. Phosphatidylinositol transfer protein-1 integrates insulin/IGF-1 and TOR signaling to negatively regulate lifespan and healthspan in Caenorhabditis elegans. Journal of Biomedical Science 33: 10.1186/s12929-026-01246-x.
","pubmedId":"","doi":"ARTN 42 10.1186/s12929-026-01246-x"},{"reference":"Linkert M, Rueden CT, Allan C, Burel JM, Moore W, Patterson A, et al., Swedlow. 2010. Metadata matters: access to image data in the real world. Journal of Cell Biology 189: 777-782.
","pubmedId":"","doi":"10.1083/jcb.201004104"},{"reference":"Perez MF, Lehner B. 2019. Vitellogenins - Yolk Gene Function and Regulation in Caenorhabditis elegans. Frontiers in Physiology 10: 10.3389/fphys.2019.01067.
","pubmedId":"","doi":"ARTN 1067 10.3389/fphys.2019.01067"},{"reference":"Schindelin J, Arganda-Carreras I, Frise E, Kaynig V, Longair M, Pietzsch T, et al., Cardona. 2012. Fiji: an open-source platform for biological-image analysis. Nature Methods 9: 676-682.
","pubmedId":"","doi":"10.1038/Nmeth.2019"},{"reference":"Starich TA, Bai X, Greenstein D. 2020. Gap junctions deliver malonyl-CoA from soma to germline to support embryogenesis in Caenorhabditis elegans. eLife 9: 10.7554/elife.58619.
","pubmedId":"","doi":"ARTN e58619 10.7554/eLife.58619"},{"reference":"Sternberg PW. 2005. Vulval development. WormBook : 10.1895/wormbook.1.6.1.
","pubmedId":"","doi":"10.1895/wormbook.1.6.1"},{"reference":"Sundaram MV, Buechner M. 2016. The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity. Genetics 203: 35-63.
","pubmedId":"","doi":"10.1534/genetics.116.189357"},{"reference":"Wang Y, Rincon Paz M, Fan X, Smith HE, Roure R, Patil A, et al., Bai. 2026. Loss of\n ptr-6\n restores eggshell integrity and embryonic viability in\n Caenorhabditis elegans\n fatty acid synthase mutants. G3: Genes, Genomes, Genetics : 10.1093/g3journal/jkag182.
","pubmedId":"","doi":"10.1093/g3journal/jkag182"},{"reference":"Yeh YT, Sona C, Yan X, Li Y, Pathak A, McDermott MI, et al., Poy. 2023. Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction. Nature Communications 14: 10.1038/s41467-023-39978-1.
","pubmedId":"","doi":"10.1038/s41467-023-39978-1"}],"title":"Endogenous Expression of the Class I Phosphatidylinositol Transfer Protein PPIT-2 in Caenorhabditis elegans
","reviews":[],"curatorReviews":[{"curator":{"displayName":"Daniela Raciti"},"openAcknowledgement":false,"submitted":null},{"curator":{"displayName":"KJ Yook"},"openAcknowledgement":false,"submitted":null}]},{"id":"55bb2d46-742e-4294-bc09-d45b27d82b42","decision":"accept","abstract":"
Phosphatidylinositol transfer proteins (PITPs) facilitate the transport and presentation of phosphatidylinositol (PI) between the endoplasmic reticulum (ER) and target membranes, such as the Golgi and plasma membrane, thereby regulating PI and phosphoinositide metabolism. However, the tissue distribution and cellular expression patterns of class I PITPs in C. elegans remain largely unknown. Here, we generated an endogenous GFP knock-in reporter to characterize Y71G12B.17, renamed as PPIT-2 (phosphatidylinositol transfer protein alpha and beta 2), a conserved homolog of the human class I PITPs, PITPNA, and PITPNB. GFP::PPIT-2 was prominently expressed in the excretory system, including the excretory canals, and was also detected in the hypodermis, sperm, sperm-associated residual bodies, developing vulva, and the pseudocoelomic region adjacent to the germline. Notably, its tissue distribution overlaps with that of the fatty acid synthase FASN-1 in the excretory system and hypodermis. These findings establish the endogenous expression pattern of PPIT-2 and identify candidate tissues for dissecting its roles in PI transfer, cellular signaling, membrane trafficking, and lipid homeostasis.
","acknowledgements":"We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
","authors":[{"affiliations":["Department of Biology, University of Florida, Gainesville, FL, United States"],"departments":[""],"credit":["validation","writing_originalDraft","writing_reviewEditing"],"email":"graycen.horne@ufl.edu","firstName":"Graycen","lastName":"Horne","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":null},{"affiliations":["Department of Biology, University of Florida, Gainesville, FL, United States","Genetics Institute, University of Florida, Gainesville, Florida, United States"],"departments":["","",""],"credit":["conceptualization","dataCuration","formalAnalysis","investigation","methodology","writing_originalDraft","writing_reviewEditing"],"email":"baixiaofei@ufl.edu","firstName":"Xiaofei ","lastName":"Bai","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":true,"WBId":null,"orcid":"0000-0001-8179-8162"}],"awards":[],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":{"url":null},"extendedData":[],"funding":"This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","image":{"url":"https://portal.micropublication.org/uploads/3b0543a4f88d16e69fbd4e235f6e7408.png"},"imageCaption":"(A) Schematic representation of the endogenous GFP::PPIT-2 reporter locus with an N-terminal GFP tag immediately upstream of the PPIT-2 coding sequence. (B–B″) Representative images showing GFP::PPIT-2 (green in B'') in the anterior excretory region near the pharynx, co-localization with FASN-1::RFP (magenta in B''). Monochromatic images show GFP::PPIT-2 (B) and FASN-1::RFP (B'). Yellow arrows highlight representative areas of the spatial overlap. (C–C″) Co-expression of GFP::PPIT-2 (C) and FASN-1::RFP (C') in hypodermal cells. with the merged image shown in (C''). Yellow arrows indicate hypodermal nuclei. (D) GFP::PPIT-2 signal in the pseudocoelomic region (yellow arrow) and residual-body-associated structures (red arrow). (E) GFP::PPIT-2 expression in sperm; the yellow arrow points to a representative GFP-positive sperm cell. (F) GFP::PPIT-2 expression in the developing vulval (yellow arrow). Scale bars are indicated in each panel.
","imageTitle":"Endogenous expression of GFP::PPIT-2 in multiple C. elegans tissues
","methods":"Microscopy
All fluorescence imaging was performed using a spinning-disk confocal system equipped with a Nikon 60× 1.2 NA water-immersion objective, a Hamamatsu C15440 ORCA-Fusion BT Digital camera, and a Yokogawa CSU-X1 confocal scanner unit. Imaging acquisition was controlled by Nikon's NIS-Element software (Version 6.10). Image processing and channel merging were conducted using the ImageJ/FIJI Bio-Formats plugin (Fiji/ImageJ: ImageJ version 1.54f; Bio-Formats plugin: version 7.0.0) (National Institutes of Health) (Linkert et al., 2010; Schindelin et al., 2012).
Mounting C. elegans for imaging
Animals were mounted on 7% agarose pads in M9 buffer containing 7.5 mM levamisole and covered with a coverslip. The synchronized mid or late L4 animals were used for imaging in panels B–C'', and young adult hermaphrodites were imaged in panels D-F.
Generation of CRISPR knock-in strains
CRISPR/Cas9 editing was performed using the Bristol N2 strain as the wild type. Synthetic crRNAs and tracrRNA were purchased from Horizon Discovery. Repair templates and single-stranded DNA oligos were synthesized by Integrated DNA Technologies (IDT). Approximately 20-30 young adult hermaphrodites were injected with the CRISPR/Cas9 injection mix. The N-terminal tag was amplified from the plasmid pDD282, which contains C. elegans codon-optimized eGFP. We co-injected the dpy-10(cn64) roller marker with the GFP::PPIT-2 injection reagent (Arribere et al., 2014). The sequences for the dpy-10(cn64) crRNA and single-stranded repair template (ssODN) have been added to the Reagents section/table. F1 roller progeny of injected animals were initially selected based on visible GFP expression and subsequently screened by single-worm PCR across the insertion boundaries using the primers: Forward 5' ccccctttgaaaactcacattt 3' and Reverse 5' gggttttaggccatctgtgga 3'. The amplification sequence is listed below:
ccccctttgaaaactcacatttataaattttgatttttggaaatgaattaattaatttctaatttgaactttcagctttattttgaaattttttttttaataatcgttaaaggtcaaattacgtataacagttggaattggtcaaatttttcaaaacaacttcattacttcgaaaaaaacATGagtaaaggagaagaattgttcactggagttgtcccaatcctcgtcgagctcgacggagacgtcaacggacacaagttctccgtctccggagagggagagggagacgccacctacggaaagctcaccctcaagttcatctgcaccaccggaaagctcccagtcccatggccaaccctcgtcaccaccttctgctacggagtccaatgcttctcccgttacccagaccacatgaagcgtcacgacttcttcaagtccgccatgccagagggatacgtccaagagcgtaccatcttcttcaaggtaagtttaaacatatatatactaactactgattatttaaattttcaggacgacggaaactacaagacccgtgccgaggtcaagttcgagggagacaccctcgtcaaccgtatcgagctcaaggtaagtttaaacagttcggtactaactaaccatacatatttaaattttcagggaatcgacttcaaggaggacggaaacatcctcggacacaagctcgagtacaactacaactcccacaacgtctacatcatggccgacaagcaaaagaacggaatcaaggtcaacttcaaggtaagtttaaacatgattttactaactaactaatctgatttaaattttcagatccgtcacaacatcgaggacggatccgtccaactcgccgaccactaccaacaaaacaccccaatcggagacggaccagtcctcctcccagacaaccactacctctccacccaatccgccctctccaaggacccaaacgagaagcgtgaccacatggtcctcctcgagttcgtcaccgccgccggaatcacccacggaatggacgagctctacaagggagcatcgggagcctcaggagcatcgATTGTAAAGgtgagttattttttgatattggaagatggccgaagaattctatggtggcctaggaatccacagatggcctaaaaccc
Candidate insertions were validated by Sanger sequencing of both the 5′ and 3′ genomic junctions. All GFP::PPIT-2 lines used for imaging were established as homozygous knock-in stocks before imaging.
GFP::PPIT-2 CRISPR information:
Guide RNA: 5' CGAAAAAAACATGATTGTAA”
Repair template primer F1: 5' tttcaaaacaacttcattacttcgaaaaaaacATG agtaaaggagaagaattgttc 3'
Repair template primer R1: 5' tcttccaatatcaaaaaataactcacCTTTACAAT cgatgctcctgaggctcccgatgctcc CTTGTAGAGCTCGTCCATTC 3'
Genotype Primer F1: 5' ccccctttgaaaactcacattt 3'
Genotype Primer R1: 5' gggttttaggccatctgtgga 3'
dpy-10(cn64) CRISPR information:
Guide RNA: 5' GCTACCATAGGCACCACGAG”
Repair template: 5' CACTTGAACTTCAATACGGCAAGATGAGAATGACTGGAAACCGTACCGCATGCGGTGCCTATGGTAGCGGAGCTTCACATGGCTTCAGACCAACAGCCTAT 3'
C. elegans strains used in this study:
Strain Name | Genotype | Source |
Bristol wild-type | CGC | |
This study | ||
This study |
Acknowledgments:
We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
Funding:
This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","reagents":"C. elegans strains used in this study:
N2, Bristol wild-type.
XFB7 fasn-1(xmb13[fasn-1::rfp]) I.
XFB143 Y71G12B.17(xmb11[GFP::Y71G12B.17]) I
","patternDescription":"Description:
Phosphatidylinositol transfer proteins (PITPs) are conserved lipid-binding proteins that support phosphatidylinositol (PI) metabolism and phosphoinositide-dependent cellular processes. PI is synthesized primarily in the endoplasmic reticulum (ER), whereas its phosphorylated derivatives are enriched at distinct cellular membranes, such as PI4P at the Golgi complex and PI(4,5)P2 at the plasma membrane (Ashlin, Blunsom, & Cockcroft, 2021). Class I PITPs, including mammalian PITPNA and PITPNB, specifically bind PI and phosphatidylcholine (PC) to facilitate PI phosphoinositide synthesis across distinct membrane compartments (Ashlin, Blunsom, & Cockcroft, 2021; Grabon, Khan, & Bankaitis, 2015). Consequently, PITPs play essential roles in membrane trafficking, secretion, and intracellular signaling (Ashlin, Blunsom, & Cockcroft, 2021). In mammals, PITPNA performs critical physiological functions in secretory tissues. For example, loss of PITPNA in pancreatic beta cells disrupts PI4P production, leading to hyperglycemia and reduced glucose-stimulated insulin secretion, highlighting its potential as a therapeutic target for type 2 diabetes (Yeh et al., 2023).
The C. elegans genome encodes two predicted class I PITPs, Y54F10AR.1 and PPIT-2, as well as the class II PITP PITP-1 (Iwata et al., 2011). PITP-1 has been characterized in sensory neurons, where it regulates phosphoinositide-dependent neurotransmission and behavioral plasticity (Iwata et al., 2011). More recently, reduction of pitp-1 gene expression was also shown to extend lifespan through insulin/IGF-1 and TOR signaling pathways (Lin et al., 2026). In contrast, relatively little is known about the anatomical distribution or physiological functions of class I PITPs in C. elegans.
To determine the endogenous expression pattern of PITPs, we generated an N-terminal GFP knock-in reporter at the endogenous locus of PPIT-2 using CRISPR/Cas9 genome editing (Figure A). GFP::PPIT-2 was detected in the excretory cell body and canals, the hypodermis, mature sperm, sperm-associated residual bodies, and the developing vulva, all of which are known for active lipid metabolism. Prominent expression was observed in the anterior excretory system (Figure B-B'), a structure functionally analogous to the mammalian renal system that serves as a hub for fluid balance and metabolic waste elimination. This system relies heavily on phospholipids, such as PI, and their metabolic derivatives to maintain its unique architecture and support intracellular transport pathways (Sundaram & Buechner, 2016).
Given the roles of class I PITPs in lipid transport and phosphoinositide signaling, we asked whether PPIT-2 is expressed in tissues that also express the lipogenic enzyme FASN-1. We therefore examined GFP::PPIT-2 in animals that also express FASN-1::RFP, an endogenous reporter of the C. elegans fatty acid synthase required for de novo fatty acid synthesis (Starich, Bai, & Greenstein, 2020; Wang et al., 2026). Endogenous GFP-tagged FASN-1 is broadly expressed in somatic tissues, with prominent expression in the hypodermis, excretory duct, and developing vulva, and serves as a key marker for lipid-enriched cellular compartments (Starich, Bai, & Greenstein, 2020). GFP::PPIT-2 showed marked co-localization with FASN-1::RFP within several regions surrounding the pharynx and the excretory cell body (Figure B-B''). Strong GFP::PPIT-2 signal was also observed along the lateral body wall in areas corresponding to the hypodermis (Figure C-C''), where it co-localized with FASN-1::RFP. These observations, GFP::PPIT-2 and FASN-1::RFP signals, were both detected in the examined excretory and hypodermal regions, indicating tissue-level overlap in these regions.
Beyond the excretory system, GFP::PPIT-2 was detected in several reproductive and reproduction-associated tissues (Figure D-F). Fluorescent signals were present in the pseudocoelomic region adjacent to the germline and within structures associated with the residual body (Figure D) as well as in mature sperm (Figure E). Because the pseudocoelomic cavity functions as a key site for lipid transport and exchange between somatic sheath cells and the germline (Perez & Lehner, 2019), this localization suggests potential roles for PPIT-2 in reproductive lipid transport.
Finally, GFP::PPIT-2 fluorescent signal was observed in the developing vulva (Figure F), another tissue where FASN-1 is known to function (Starich, Bai, & Greenstein, 2020; Wang et al., 2026). Vulval morphogenesis requires coordinated cell-cell signaling, extensive membrane remodeling, and active membrane trafficking (Sternberg, 2005). The presence of PPIT-2 in this tissue suggests that this class I PITP might participate in membrane dynamics during organogenesis and C. elegans vulvar morphogenesis.
In summary, our endogenous tag reveals the tissue-specific distribution of the previously uncharacterized class I PITP PPIT-2 in C. elegans. Its expression in the excretory system, hypodermis, reproductive structures, and developing vulva—combined with its spatial overlap with FASN-1—provides an anatomical framework for future investigations into its functional roles in phosphoinositide metabolism, membrane trafficking, and organismal lipid homeostasis.
","references":[{"reference":"Ashlin TG, Blunsom NJ, Cockcroft S. 2021. Courier service for phosphatidylinositol: PITPs deliver on demand. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1866: 158985.
","pubmedId":"","doi":"ARTN 158985 10.1016/j.bbalip.2021.158985"},{"reference":"Grabon A, Khan D, Bankaitis VA. 2015. Phosphatidylinositol transfer proteins and instructive regulation of lipid kinase biology. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1851: 724-735.
","pubmedId":"","doi":"10.1016/j.bbalip.2014.12.011"},{"reference":"Iwata R, Oda S, Kunitomo H, Iino Y. 2011. Roles for class IIA phosphatidylinositol transfer protein in neurotransmission and behavioral plasticity at the sensory neuron synapses of\n Caenorhabditis elegans. Proceedings of the National Academy of Sciences 108: 7589-7594.
","pubmedId":"","doi":"10.1073/pnas.1016232108"},{"reference":"Lin YH, Liao YH, Liao SB, Lin TY, Shanmugam MM, Hsu PJ, et al., Wang. 2026. Phosphatidylinositol transfer protein-1 integrates insulin/IGF-1 and TOR signaling to negatively regulate lifespan and healthspan in Caenorhabditis elegans. Journal of Biomedical Science 33: 10.1186/s12929-026-01246-x.
","pubmedId":"","doi":"ARTN 42 10.1186/s12929-026-01246-x"},{"reference":"Linkert M, Rueden CT, Allan C, Burel JM, Moore W, Patterson A, et al., Swedlow. 2010. Metadata matters: access to image data in the real world. Journal of Cell Biology 189: 777-782.
","pubmedId":"","doi":"10.1083/jcb.201004104"},{"reference":"Perez MF, Lehner B. 2019. Vitellogenins - Yolk Gene Function and Regulation in Caenorhabditis elegans. Frontiers in Physiology 10: 10.3389/fphys.2019.01067.
","pubmedId":"","doi":"ARTN 1067 10.3389/fphys.2019.01067"},{"reference":"Schindelin J, Arganda-Carreras I, Frise E, Kaynig V, Longair M, Pietzsch T, et al., Cardona. 2012. Fiji: an open-source platform for biological-image analysis. Nature Methods 9: 676-682.
","pubmedId":"","doi":"10.1038/Nmeth.2019"},{"reference":"Starich TA, Bai X, Greenstein D. 2020. Gap junctions deliver malonyl-CoA from soma to germline to support embryogenesis in Caenorhabditis elegans. eLife 9: 10.7554/elife.58619.
","pubmedId":"","doi":"ARTN e58619 10.7554/eLife.58619"},{"reference":"Sternberg PW. 2005. Vulval development. WormBook : 10.1895/wormbook.1.6.1.
","pubmedId":"","doi":"10.1895/wormbook.1.6.1"},{"reference":"Sundaram MV, Buechner M. 2016. The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity. Genetics 203: 35-63.
","pubmedId":"","doi":"10.1534/genetics.116.189357"},{"reference":"Wang Y, Rincon Paz M, Fan X, Smith HE, Roure R, Patil A, et al., Bai. 2026. Loss of\n ptr-6\n restores eggshell integrity and embryonic viability in\n Caenorhabditis elegans\n fatty acid synthase mutants. G3: Genes, Genomes, Genetics : 10.1093/g3journal/jkag182.
","pubmedId":"","doi":"10.1093/g3journal/jkag182"},{"reference":"Yeh YT, Sona C, Yan X, Li Y, Pathak A, McDermott MI, et al., Poy. 2023. Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction. Nature Communications 14: 10.1038/s41467-023-39978-1.
","pubmedId":"","doi":"10.1038/s41467-023-39978-1"},{"reference":"Arribere JA, Bell RT, Fu BX, Artiles KL, Hartman PS, Fire AZ. 2014. Efficient marker-free recovery of custom genetic modifications with CRISPR/Cas9 in Caenorhabditis elegans. Genetics 198(3): 837-46.
","pubmedId":"25161212","doi":""}],"title":"Endogenous Expression of the Class I Phosphatidylinositol Transfer Protein PPIT-2 in Caenorhabditis elegans
","reviews":[],"curatorReviews":[{"curator":{"displayName":"Daniela Raciti"},"openAcknowledgement":true,"submitted":"1790083011827"},{"curator":{"displayName":"Daniela Raciti"},"openAcknowledgement":false,"submitted":null},{"curator":{"displayName":"KJ Yook"},"openAcknowledgement":false,"submitted":"1790218186291"}]},{"id":"5363b85c-c613-428f-b54c-e06dfb72122d","decision":"publish","abstract":"
Phosphatidylinositol transfer proteins (PITPs) transfer phosphatidylinositol (PI) between the ER and target membranes to regulate phosphoinositide metabolism. However, the expression patterns of class I PITPs in C. elegans remain largely uncharacterized. Here, we generated an endogenous GFP knock-in reporter for PPIT-2 (formerly Y71G12B.17), a conserved homolog of human PITPNA and PITPNB. GFP::PPIT-2 was prominently expressed in the excretory system and canals, with additional expression in the hypodermis, sperm, developing vulva, and germline-adjacent pseudocoelom. PPIT-2 expression notably overlaps with fatty acid synthase FASN-1, establishing candidate tissues to investigate its roles in PI transfer, membrane trafficking, and lipid homeostasis.
","acknowledgements":"We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
","authors":[{"affiliations":["Department of Biology, University of Florida, Gainesville, FL, United States"],"departments":[""],"credit":["validation","writing_originalDraft","writing_reviewEditing"],"email":"graycen.horne@ufl.edu","firstName":"Graycen","lastName":"Horne","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":null},{"affiliations":["Department of Biology, University of Florida, Gainesville, FL, United States","Genetics Institute, University of Florida, Gainesville, Florida, United States"],"departments":["","",""],"credit":["conceptualization","dataCuration","formalAnalysis","investigation","methodology","writing_originalDraft","writing_reviewEditing"],"email":"baixiaofei@ufl.edu","firstName":"Xiaofei ","lastName":"Bai","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":true,"WBId":null,"orcid":"0000-0001-8179-8162"}],"awards":[],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":{"url":null},"extendedData":[],"funding":"This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","image":{"url":"https://portal.micropublication.org/uploads/3b0543a4f88d16e69fbd4e235f6e7408.png"},"imageCaption":"(A) Schematic representation of the endogenous GFP::PPIT-2 reporter locus with an N-terminal GFP tag immediately upstream of the PPIT-2 coding sequence. (B–B″) Representative images showing GFP::PPIT-2 (green in B'') in the anterior excretory region near the pharynx, co-localization with FASN-1::RFP (magenta in B''). Monochromatic images show GFP::PPIT-2 (B) and FASN-1::RFP (B'). Yellow arrows highlight representative areas of the spatial overlap. (C–C″) Co-expression of GFP::PPIT-2 (C) and FASN-1::RFP (C') in hypodermal cells. with the merged image shown in (C''). Yellow arrows indicate hypodermal nuclei. (D) GFP::PPIT-2 signal in the pseudocoelomic region (yellow arrow) and residual-body-associated structures (red arrow). (E) GFP::PPIT-2 expression in sperm; the yellow arrow points to a representative GFP-positive sperm cell. (F) GFP::PPIT-2 expression in the developing vulval (yellow arrow). Scale bars are indicated in each panel.
","imageTitle":"Endogenous expression of GFP::PPIT-2 in multiple C. elegans tissues
","methods":"Microscopy
All fluorescence imaging was performed using a spinning-disk confocal system equipped with a Nikon 60× 1.2 NA water-immersion objective, a Hamamatsu C15440 ORCA-Fusion BT Digital camera, and a Yokogawa CSU-X1 confocal scanner unit. Imaging acquisition was controlled by Nikon's NIS-Element software (Version 6.10). Image processing and channel merging were conducted using the ImageJ/FIJI Bio-Formats plugin (Fiji/ImageJ: ImageJ version 1.54f; Bio-Formats plugin: version 7.0.0) (National Institutes of Health) (Linkert et al., 2010; Schindelin et al., 2012).
Mounting C. elegans for imaging
Animals were mounted on 7% agarose pads in M9 buffer containing 7.5 mM levamisole and covered with a coverslip. The synchronized mid or late L4 animals were used for imaging in panels B–C'', and young adult hermaphrodites were imaged in panels D-F.
Generation of CRISPR knock-in strains
CRISPR/Cas9 editing was performed using the Bristol N2 strain as the wild type. Synthetic crRNAs and tracrRNA were purchased from Horizon Discovery. Repair templates and single-stranded DNA oligos were synthesized by Integrated DNA Technologies (IDT). Approximately 20-30 young adult hermaphrodites were injected with the CRISPR/Cas9 injection mix. The N-terminal tag was amplified from the plasmid pDD282, which contains C. elegans codon-optimized eGFP. We co-injected the dpy-10(cn64) roller marker with the GFP::PPIT-2 injection reagent (Arribere et al., 2014). The sequences for the dpy-10(cn64) crRNA and single-stranded repair template (ssODN) have been added to the Reagents section/table. F1 roller progeny of injected animals were initially selected based on visible GFP expression and subsequently screened by single-worm PCR across the insertion boundaries using the primers: Forward 5' ccccctttgaaaactcacattt 3' and Reverse 5' gggttttaggccatctgtgga 3'. The amplification sequence is listed below:
ccccctttgaaaactcacatttataaattttgatttttggaaatgaattaattaatttctaatttgaactttcagctttattttgaaattttttttttaataatcgttaaaggtcaaattacgtataacagttggaattggtcaaatttttcaaaacaacttcattacttcgaaaaaaacATGagtaaaggagaagaattgttcactggagttgtcccaatcctcgtcgagctcgacggagacgtcaacggacacaagttctccgtctccggagagggagagggagacgccacctacggaaagctcaccctcaagttcatctgcaccaccggaaagctcccagtcccatggccaaccctcgtcaccaccttctgctacggagtccaatgcttctcccgttacccagaccacatgaagcgtcacgacttcttcaagtccgccatgccagagggatacgtccaagagcgtaccatcttcttcaaggtaagtttaaacatatatatactaactactgattatttaaattttcaggacgacggaaactacaagacccgtgccgaggtcaagttcgagggagacaccctcgtcaaccgtatcgagctcaaggtaagtttaaacagttcggtactaactaaccatacatatttaaattttcagggaatcgacttcaaggaggacggaaacatcctcggacacaagctcgagtacaactacaactcccacaacgtctacatcatggccgacaagcaaaagaacggaatcaaggtcaacttcaaggtaagtttaaacatgattttactaactaactaatctgatttaaattttcagatccgtcacaacatcgaggacggatccgtccaactcgccgaccactaccaacaaaacaccccaatcggagacggaccagtcctcctcccagacaaccactacctctccacccaatccgccctctccaaggacccaaacgagaagcgtgaccacatggtcctcctcgagttcgtcaccgccgccggaatcacccacggaatggacgagctctacaagggagcatcgggagcctcaggagcatcgATTGTAAAGgtgagttattttttgatattggaagatggccgaagaattctatggtggcctaggaatccacagatggcctaaaaccc
Candidate insertions were validated by Sanger sequencing of both the 5′ and 3′ genomic junctions. All GFP::PPIT-2 lines used for imaging were established as homozygous knock-in stocks before imaging.
GFP::PPIT-2 CRISPR information:
Guide RNA: 5' CGAAAAAAACATGATTGTAA”
Repair template primer F1: 5' tttcaaaacaacttcattacttcgaaaaaaacATG agtaaaggagaagaattgttc 3'
Repair template primer R1: 5' tcttccaatatcaaaaaataactcacCTTTACAAT cgatgctcctgaggctcccgatgctcc CTTGTAGAGCTCGTCCATTC 3'
Genotype Primer F1: 5' ccccctttgaaaactcacattt 3'
Genotype Primer R1: 5' gggttttaggccatctgtgga 3'
dpy-10(cn64) CRISPR information:
Guide RNA: 5' GCTACCATAGGCACCACGAG”
Repair template: 5' CACTTGAACTTCAATACGGCAAGATGAGAATGACTGGAAACCGTACCGCATGCGGTGCCTATGGTAGCGGAGCTTCACATGGCTTCAGACCAACAGCCTAT 3'
C. elegans strains used in this study:
Strain Name | Genotype | Source |
Bristol wild-type | CGC | |
This study | ||
This study |
Acknowledgments:
We thank the Caenorhabditis Genetics Center (CGC), which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40OD010440), for providing strains for this study. We also thank members of the UF Worm community for insightful feedback and discussion.
Funding:
This work was supported by the National Institute of General Medical Sciences/National Institutes of Health under Awards Numbers R00GM145224 and R35GM162564-01 to X.F.B. and G.H., as well as startup funds from the University of Florida to the Bai laboratory.
","reagents":"","patternDescription":"Phosphatidylinositol transfer proteins (PITPs) are conserved lipid-binding proteins that support phosphatidylinositol (PI) metabolism and phosphoinositide-dependent cellular processes. PI is synthesized primarily in the endoplasmic reticulum (ER), whereas its phosphorylated derivatives are enriched at distinct cellular membranes, such as PI4P at the Golgi complex and PI(4,5)P2 at the plasma membrane (Ashlin, Blunsom, & Cockcroft, 2021). Class I PITPs, including mammalian PITPNA and PITPNB, specifically bind PI and phosphatidylcholine (PC) to facilitate PI phosphoinositide synthesis across distinct membrane compartments (Ashlin, Blunsom, & Cockcroft, 2021; Grabon, Khan, & Bankaitis, 2015). Consequently, PITPs play essential roles in membrane trafficking, secretion, and intracellular signaling (Ashlin, Blunsom, & Cockcroft, 2021). In mammals, PITPNA performs critical physiological functions in secretory tissues. For example, loss of PITPNA in pancreatic beta cells disrupts PI4P production, leading to hyperglycemia and reduced glucose-stimulated insulin secretion, highlighting its potential as a therapeutic target for type 2 diabetes (Yeh et al., 2023).
The C. elegans genome encodes two predicted class I PITPs, Y54F10AR.1 and PPIT-2, as well as the class II PITP PITP-1 (Iwata et al., 2011). PITP-1 has been characterized in sensory neurons, where it regulates phosphoinositide-dependent neurotransmission and behavioral plasticity (Iwata et al., 2011). More recently, reduction of pitp-1 gene expression was also shown to extend lifespan through insulin/IGF-1 and TOR signaling pathways (Lin et al., 2026). In contrast, relatively little is known about the anatomical distribution or physiological functions of class I PITPs in C. elegans.
To determine the endogenous expression pattern of PITPs, we generated an N-terminal GFP knock-in reporter at the endogenous locus of PPIT-2 using CRISPR/Cas9 genome editing (Figure A). GFP::PPIT-2 was detected in the excretory cell body and canals, the hypodermis, mature sperm, sperm-associated residual bodies, and the developing vulva, all of which are known for active lipid metabolism. Prominent expression was observed in the anterior excretory system (Figure B-B'), a structure functionally analogous to the mammalian renal system that serves as a hub for fluid balance and metabolic waste elimination. This system relies heavily on phospholipids, such as PI, and their metabolic derivatives to maintain its unique architecture and support intracellular transport pathways (Sundaram & Buechner, 2016).
Given the roles of class I PITPs in lipid transport and phosphoinositide signaling, we asked whether PPIT-2 is expressed in tissues that also express the lipogenic enzyme FASN-1. We therefore examined GFP::PPIT-2 in animals that also express FASN-1::RFP, an endogenous reporter of the C. elegans fatty acid synthase required for de novo fatty acid synthesis (Starich, Bai, & Greenstein, 2020; Wang et al., 2026). Endogenous GFP-tagged FASN-1 is broadly expressed in somatic tissues, with prominent expression in the hypodermis, excretory duct, and developing vulva, and serves as a key marker for lipid-enriched cellular compartments (Starich, Bai, & Greenstein, 2020). GFP::PPIT-2 showed marked co-localization with FASN-1::RFP within several regions surrounding the pharynx and the excretory cell body (Figure B-B''). Strong GFP::PPIT-2 signal was also observed along the lateral body wall in areas corresponding to the hypodermis (Figure C-C''), where it co-localized with FASN-1::RFP. These observations, GFP::PPIT-2 and FASN-1::RFP signals, were both detected in the examined excretory and hypodermal regions, indicating tissue-level overlap in these regions.
Beyond the excretory system, GFP::PPIT-2 was detected in several reproductive and reproduction-associated tissues (Figure D-F). Fluorescent signals were present in the pseudocoelomic region adjacent to the germline and within structures associated with the residual body (Figure D) as well as in mature sperm (Figure E). Because the pseudocoelomic cavity functions as a key site for lipid transport and exchange between somatic sheath cells and the germline (Perez & Lehner, 2019), this localization suggests potential roles for PPIT-2 in reproductive lipid transport.
Finally, GFP::PPIT-2 fluorescent signal was observed in the developing vulva (Figure F), another tissue where FASN-1 is known to function (Starich, Bai, & Greenstein, 2020; Wang et al., 2026). Vulval morphogenesis requires coordinated cell-cell signaling, extensive membrane remodeling, and active membrane trafficking (Sternberg, 2005). The presence of PPIT-2 in this tissue suggests that this class I PITP might participate in membrane dynamics during organogenesis and C. elegans vulvar morphogenesis.
In summary, our endogenous tag reveals the tissue-specific distribution of the previously uncharacterized class I PITP PPIT-2 in C. elegans. Its expression in the excretory system, hypodermis, reproductive structures, and developing vulva—combined with its spatial overlap with FASN-1—provides an anatomical framework for future investigations into its functional roles in phosphoinositide metabolism, membrane trafficking, and organismal lipid homeostasis.
","references":[{"reference":"Arribere JA, Bell RT, Fu BX, Artiles KL, Hartman PS, Fire AZ. 2014. Efficient marker-free recovery of custom genetic modifications with CRISPR/Cas9 in Caenorhabditis elegans. Genetics 198(3): 837-46.
","pubmedId":"25161212","doi":""},{"reference":"Ashlin TG, Blunsom NJ, Cockcroft S. 2021. Courier service for phosphatidylinositol: PITPs deliver on demand. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1866: 158985.
","pubmedId":"","doi":"ARTN 158985 10.1016/j.bbalip.2021.158985"},{"reference":"Grabon A, Khan D, Bankaitis VA. 2015. Phosphatidylinositol transfer proteins and instructive regulation of lipid kinase biology. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1851: 724-735.
","pubmedId":"","doi":"10.1016/j.bbalip.2014.12.011"},{"reference":"Iwata R, Oda S, Kunitomo H, Iino Y. 2011. Roles for class IIA phosphatidylinositol transfer protein in neurotransmission and behavioral plasticity at the sensory neuron synapses of\n Caenorhabditis elegans. Proceedings of the National Academy of Sciences 108: 7589-7594.
","pubmedId":"","doi":"10.1073/pnas.1016232108"},{"reference":"Lin YH, Liao YH, Liao SB, Lin TY, Shanmugam MM, Hsu PJ, et al., Wang. 2026. Phosphatidylinositol transfer protein-1 integrates insulin/IGF-1 and TOR signaling to negatively regulate lifespan and healthspan in Caenorhabditis elegans. Journal of Biomedical Science 33: 10.1186/s12929-026-01246-x.
","pubmedId":"","doi":"ARTN 42 10.1186/s12929-026-01246-x"},{"reference":"Linkert M, Rueden CT, Allan C, Burel JM, Moore W, Patterson A, et al., Swedlow. 2010. Metadata matters: access to image data in the real world. Journal of Cell Biology 189: 777-782.
","pubmedId":"","doi":"10.1083/jcb.201004104"},{"reference":"Perez MF, Lehner B. 2019. Vitellogenins - Yolk Gene Function and Regulation in Caenorhabditis elegans. Frontiers in Physiology 10: 10.3389/fphys.2019.01067.
","pubmedId":"","doi":"ARTN 1067 10.3389/fphys.2019.01067"},{"reference":"Schindelin J, Arganda-Carreras I, Frise E, Kaynig V, Longair M, Pietzsch T, et al., Cardona. 2012. Fiji: an open-source platform for biological-image analysis. Nature Methods 9: 676-682.
","pubmedId":"","doi":"10.1038/Nmeth.2019"},{"reference":"Starich TA, Bai X, Greenstein D. 2020. Gap junctions deliver malonyl-CoA from soma to germline to support embryogenesis in Caenorhabditis elegans. eLife 9: 10.7554/elife.58619.
","pubmedId":"","doi":"ARTN e58619 10.7554/eLife.58619"},{"reference":"Sternberg PW. 2005. Vulval development. WormBook : 10.1895/wormbook.1.6.1.
","pubmedId":"","doi":"10.1895/wormbook.1.6.1"},{"reference":"Sundaram MV, Buechner M. 2016. The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity. Genetics 203: 35-63.
","pubmedId":"","doi":"10.1534/genetics.116.189357"},{"reference":"Wang Y, Rincon Paz M, Fan X, Smith HE, Roure R, Patil A, et al., Bai. 2026. Loss of\n ptr-6\n restores eggshell integrity and embryonic viability in\n Caenorhabditis elegans\n fatty acid synthase mutants. G3: Genes, Genomes, Genetics : 10.1093/g3journal/jkag182.
","pubmedId":"","doi":"10.1093/g3journal/jkag182"},{"reference":"Yeh YT, Sona C, Yan X, Li Y, Pathak A, McDermott MI, et al., Poy. 2023. Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction. Nature Communications 14: 10.1038/s41467-023-39978-1.
","pubmedId":"","doi":"10.1038/s41467-023-39978-1"}],"title":"Endogenous Expression of the Class I Phosphatidylinositol Transfer Protein PPIT-2 in Caenorhabditis elegans
","reviews":[],"curatorReviews":[{"curator":{"displayName":"KJ Yook"},"openAcknowledgement":false,"submitted":null},{"curator":{"displayName":"Daniela Raciti"},"openAcknowledgement":false,"submitted":null}]}]}},"species":{"species":[{"value":"acer saccharum","label":"Acer saccharum","imageSrc":"","imageAlt":"","mod":"TreeGenes","modLink":"https://treegenesdb.org","linkVariable":""},{"value":"achillea millefolium","label":"Achillea millefolium","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"acinetobacter baylyi","label":"Acinetobacter baylyi","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"actinobacteria bacterium","label":"Actinobacteria bacterium","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"adelges tsugae","label":"Adelges tsugae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"adenocaulon chilense","label":"Adenocaulon chilense","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"aedes japonicus","label":"Aedes japonicus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"aegorhinus vitulus","label":"Aegorhinus vitulus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"aerococcus","label":"Aerococcus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"alaimidae","label":"Alaimidae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"allobates femoralis","label":"Allobates femoralis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"alnus glutinosa","label":"Alnus glutinosa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"alosa aestivalis","label":"Alosa aestivalis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"alosa pseudoharengus","label":"Alosa pseudoharengus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"alternaria alternata","label":"Alternaria alternata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"amynthas agrestis","label":"Amynthas Agrestis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ancylostoma caninum","label":"Ancylostoma caninum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ancylostoma ceylanicum","label":"Ancylostoma ceylanicum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"anemone multifida","label":"Anemone multifida","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"anguilla rostrata","label":"Anguilla rostrata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"anisakis simplex","label":"Anisakis simplex","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"anomala albopilosa","label":"Anomala albopilosa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"anthomyiidae sp","label":"Anthomyiidae sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"anthomyiidae sp","label":"Anthomyiidae sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"arabidopsis","label":"Arabidopsis","imageSrc":"arabidopsis.png","imageAlt":"Arabidopsis graphic by Zoe Zorn CC BY 4.0","mod":"TAIR","modLink":"https://arabidopsis.org","linkVariable":""},{"value":"architeuthis dux","label":"Architeuthis dux","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"arion vulgaris","label":"Arion vulgaris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"armeria","label":"Armeria","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"artemia","label":"Artemia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"arthrobacter sp.","label":"Arthrobacter sp.","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ascaridia","label":"Ascaridia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ascaridia galli","label":"Ascaridia galli","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"asparagopsis taxiformis","label":"Asparagopsis taxiformis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"astatotilapia burtoni","label":"Astatotilapia burtoni","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"avena sativa","label":"Avena sativa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"aves","label":"Aves","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus","label":"Bacillus (firmicutes)","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus cereus","label":"Bacillus cereus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus mycoides","label":"Bacillus mycoides","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus subtilis","label":"Bacillus subtilis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus thuringiensis","label":"Bacillus thuringiensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus toyonensis","label":"Bacillus toyonensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacillus wiedmannii","label":"Bacillus wiedmannii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacteria","label":"Bacteria","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bacteriophage","label":"Bacteriophage","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bactrocera","label":"Bactrocera sp.","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"batrachospermum gelatinosum","label":"Batrachospermum gelatinosum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"betula lenta","label":"Betula lenta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"betula nigra","label":"Betula nigra","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bombus dahlbohmii","label":"Bombus dahlbohmii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bombus terrestris","label":"Bombus terrestris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bombyx mori","label":"Bombyx mori","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bos taurus","label":"Bos Taurus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"brachygobius doriae","label":"Brachygobius doriae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"brassica oleracea","label":"Brassica oleracea","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"brassica rapa","label":"Brassica rapa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"brugia malayi","label":"Brugia malayi","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"burkholderia thailandensis","label":"Burkholderia thailandensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"buttiauxella","label":"Buttiauxella","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"caenorhabditis brenneri","label":"Caenorhabditis brenneri","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"caenorhabditis briggsae","label":"Caenorhabditis briggsae","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"c. elegans","label":"Caenorhabditis elegans","imageSrc":"c-elegans.jpg","imageAlt":"C. elegans graphic by Zoe Zorn CC BY 4.0","mod":"WormBase","modLink":"https://wormbase.org","linkVariable":""},{"value":"caenorhabditis inopinata","label":"Caenorhabditis inopinata","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"caenorhabditis japonica","label":"Caenorhabditis japonica","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"caenorhabditis nigoni","label":"Caenorhabditis nigoni","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"caenorhabditis remanei","label":"Caenorhabditis remanei","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"caenorhabditis tropicalis","label":"Caenorhabditis tropicalis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"calidifontibacillus","label":"Calidifontibacillus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"calidifontibacillus erzuremensis","label":"Calidifontibacillus erzuremensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"calliphora sp","label":"Calliphora sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"caltha sagittata","label":"Caltha sagittata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cambarus latimanus","label":"Cambarus latimanus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"candida albicans","label":"Candida albicans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"canis familiaris","label":"Canis familiaris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cannabis sativa","label":"Cannabis sativa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"caretta caretta","label":"Caretta caretta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cassiopea xamachana","label":"Cassiopea xamachana","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"caulobacter vibrioides","label":"Caulobacter vibrioides","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cephalopods","label":"Cephalopoda","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cerastium arvense","label":"Cerastium arvense","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ceriodaphnia","label":"Ceriodaphnia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ceroglossus suturalis","label":"Ceroglossus suturalis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chaetoceros","label":"Chaetoceros","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chamaecrista fasciculata","label":"Chamaecrista fasciculata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chilicola chalcidiformis","label":"Chilicola chalcidiformis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chitinimonas","label":"Chitinimonas","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chlamydomonas reinhardtii","label":"Chlamydomonas reinhardtii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chromobacterium","label":"Chromobacterium","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chrysemys picta","label":"Chrysemys picta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"chrysoperla rufilabris","label":"Chrysoperla rufilabris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"citrus","label":"Citrus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"clavibacter sp.","label":"Clavibacter sp.","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"colinus virginianus","label":"Colinus virginianus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"crassostrea virginica","label":"Crassostrea virginica","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"crithidia fasciculata","label":"Crithidia fasciculata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cutibacterium acnes","label":"Cutibacterium acnes","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"cyanobacteria","label":"Cyanobacteria","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"daphnia","label":"Daphnia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"daphnia pulex","label":"Daphnia pulex","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"dermacoccus nishinomiyaensis","label":"Dermacoccus nishinomiyaensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"diabrotica virgifera","label":"Diabrotica virgifera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"diabrotica virgifera virgifera virus 1","label":"Diabrotica virgifera virgifera virus 1","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"d. discoideum","label":"Dictyostelium discoideum","imageSrc":"dicty.png","imageAlt":"D. discoideum","mod":"dictyBase","modLink":"http://dictybase.org","linkVariable":""},{"value":"diptera","label":"Diptera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"dotocryptus bellicosus","label":"Dotocryptus bellicosus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"drechmeria coniospora","label":"Drechmeria coniospora","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"drosophila","label":"Drosophila","imageSrc":"drosophila.png","imageAlt":"Drosophila graphic by Zoe Zorn CC BY 4.0","mod":"FlyBase","modLink":"https://flybase.org/doi/","linkVariable":"doi"},{"value":"dryopteris campyloptera","label":"Dryopteris campyloptera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"dryopteris expansa","label":"Dryopteris expansa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"dryopteris intermedia","label":"Dryopteris intermedia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"dugesia dorotocephala","label":"Dugesia dorotocephala","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"elasmobranchii","label":"Elasmobranchii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"embryophyta","label":"Embryophyta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"enoploteuthis chunii","label":"Enoploteuthis chunii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"enterobacter aerogenes","label":"Enterobacter aerogenes","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"enterococcus raffinosus","label":"Enterococcus raffinosus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"epichloë coenophiala","label":"Epichloë coenophiala","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"equus caballus","label":"Equus caballus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"erigeron sp","label":"Erigeron sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"eristalis","label":"Eristalis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"eruca vesicaria","label":"Eruca vesicaria","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"erwinia carotovora","label":"Erwinia carotovora","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"erythronium americanum","label":"Erythronium americanum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"escherichia coli","label":"Escherichia coli","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"eukaryota","label":"Eukaryotes","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"felis catus","label":"Felis catus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"francisella novicida","label":"Francisella novicida","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"francisella tularensis","label":"Francisella tularensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"fraxinus americana","label":"Fraxinus americana","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"fucus distichus","label":"Fucus distichus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"fungi","label":"Fungi","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"gasteropelecus sp.","label":"Gasteropelecus sp.","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"geranium sp","label":"Geranium sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"girardia","label":"Girardia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"glaucomys volans","label":"Glaucomys volans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"glycine max","label":"Glycine max","imageSrc":"","imageAlt":"","mod":"Soybase","modLink":"https://soybase.org","linkVariable":""},{"value":"glyptemys insculpta","label":"Glyptemys insculpta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"gossypium hirsutum","label":"Gossypium hirsutum","imageSrc":"","imageAlt":"","mod":"CottonGen","modLink":"https://www.cottongen.org/","linkVariable":""},{"value":"gromphadorhina portentosa","label":"Gromphadorhina portentosa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"gryllodes sigillatus","label":"Gryllodes sigillatus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"haliotis rufescens","label":"Haliotis rufescens","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"hepacivirus hominis","label":"Hepatitis C Virus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"herpes simplex virus type 1","label":"Herpes simplex virus type 1","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"human","label":"Human","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"human coronavirus oc43","label":"Human coronavirus OC43","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"hydra vulgaris","label":"Hydra vulgaris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"hydropsyche sp","label":"Hydropsyche sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"hymenoptera","label":"Hymenoptera","imageSrc":"","imageAlt":"","mod":"Hymenoptera Genome Database","modLink":"https://hymenoptera.elsiklab.missouri.edu/","linkVariable":""},{"value":"hypochaeris radicata","label":"Hypochaeris radicata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"hypodynerus vespiformis","label":"Hypodynerus vespiformis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"iflaviridae","label":"Iflaviridae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"iflavuris","label":"Iflavirus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ipomoea hederacea","label":"Ipomoea hederacea","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ischnomera","label":"Ischnomera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ischnomera ruficollis","label":"Ischnomera ruficollis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"julidochromis marlieri","label":"Julidochromis marlieri","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"juniperus virginiana","label":"Juniperus virginiana","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"kluyveromyces marxianus","label":"Kluyveromyces marxianus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"l. casei","label":"L. casei","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lacticaseibacillus casei","label":"Lacticaseibacillus casei","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lactobacillus","label":"Lactobacillus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"larentiinae sp","label":"Larentiinae sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"laurus nobilis","label":"Laurus nobilis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lepidoptera","label":"Lepidoptera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"leucanthemum vulgare","label":"Leucanthemum vulgare","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ligilactobacillus","label":"Ligilactobacillus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ligilactobacillus salivarius","label":"Ligilactobacillus salivarius","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"limosilactobacillus","label":"Limosilactobacillus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"linepithema humile","label":"Linepithema humile","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"liometopum occidentale","label":"Liometopum occidentale","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lolium arundinaceum","label":"Lolium arundinaceum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lontra longicaudis","label":"Lontra longicaudis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lumbriculus variegatus","label":"Lumbriculus variegatus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lumbricus terrestris","label":"Lumbricus terrestris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lupinus polyphyllus","label":"Lupinus polyphyllus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lycorma delicatula","label":"Lycorma delicatula","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"lynx rufus","label":"Lynx rufus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"magnaporthe oryzae","label":"Magnaporthe oryzae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"mammalia","label":"Mammalia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"manihot esculenta","label":"Manihot esculenta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"medicago lupulina","label":"Medicago lupulina","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"meloidogyne","label":"Meloidogyne","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"mimus polyglottos","label":"Mimus polyglottos","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"bryophyta","label":"Mosses","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"mouse","label":"Mouse","imageSrc":"","imageAlt":"","mod":"MGI","modLink":"https://informatics.jax.org","linkVariable":""},{"value":"m. minutoides","label":"Mus minutoides","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"mycobacterium smegmatis","label":"Mycobacterium smegmatis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"nakaseomyces glabratus","label":"Nakaseomyces glabratus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"nauphoeta cinerea","label":"Nauphoeta cinerea","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"neurospora","label":"Neurospora","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"n. benthamiana","label":"Nicotiana benthamiana","imageSrc":"","imageAlt":"","mod":"Solgenomics Network","modLink":"https://solgenomics.net/organism/Nicotiana_benthamiana/genome","linkVariable":""},{"value":"nicotiana tabacum","label":"Nicotiana tabacum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"noctuidae","label":"Noctuidae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"noctuidae sp","label":"Noctuidae sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"nothobranchius furzeri","label":"Nothobranchius furzeri","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"onchocerca volvulus","label":"Onchocerca volvulus","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"orconectes virilis","label":"Orconectes virilis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ormia ochracea","label":"Ormia ochracea","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"o. sativa","label":"Oryza sativa","imageSrc":"","imageAlt":"","mod":"Gramene","modLink":"https://www.gramene.org/","linkVariable":""},{"value":"other","label":"Other","imageSrc":"","imageAlt":"","mod":null,"modLink":null,"linkVariable":null},{"value":"oxalis enneaphylla","label":"Oxalis enneaphylla","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"paenarthrobacter nicotinovorans","label":"Paenarthrobacter nicotinovorans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"paenarthrobacter nicotinovorans","label":"Paenarthrobacter nicotinovorans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pantoea","label":"Pantoea","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pantoea agglomerans","label":"Pantoea agglomerans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"papaver sp","label":"Papaver sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"paramecium bursaria","label":"Paramecium bursaria","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"partitiviridae","label":"Partitiviridae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pelodiscus sinensis","label":"Pelodiscus sinensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"perezia recurvata","label":"Perezia recurvata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"petromyzon marinus","label":"Petromyzon marinus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"photinus pyralis","label":"Photinus pyralis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"photinus pyralis associated partiti-like virus","label":"Photinus pyralis associated partiti-like virus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"photinus pyralis iflavirus 1","label":"Photinus pyralis iflavirus 1","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"physcomitrium patens","label":"Physcomitrium patens","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pinus strobus","label":"Pinus strobus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pinus taeda","label":"Pinus taeda","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"platycheirus","label":"Platycheirus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"plectus sambesii","label":"Plectus sambesii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pogonomyrmex occidentalis","label":"Pogonomyrmex occidentalis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"poncirus trifoliata","label":"Poncirus trifoliata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"populus deltoides","label":"Populus deltoides","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"potato virus y","label":"Potato virus Y","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"primula magellanica","label":"Primula magellanica","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pristionchus pacificus","label":"Pristionchus pacificus","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"prunus persica","label":"Prunus persica","imageSrc":"","imageAlt":"","mod":"Genome Database for Rosaceae","modLink":"https://www.rosaceae.org/","linkVariable":""},{"value":"psalmopoeus iriminia","label":"Psalmopoeus iriminia","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pseudanabaena sp.","label":"Pseudanabaena sp.","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pseudomonas","label":"Pseudomonas","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pseudomonas aeruginosa","label":"Pseudomonas aeruginosa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pseudomonas glycinae","label":"Pseudomonas glycinae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pseudomonas putida","label":"Pseudomonas putida","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pseudomonas syringae","label":"Pseudomonas syringae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"pterophyllum scalare","label":"Pterophyllum scalare","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"python regius","label":"Python regius","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"quercus macrocarpa","label":"Quercus macrocarpa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ralstonia solanacearum","label":"Ralstonia solanacearum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ranitomeya imitator","label":"Ranitomeya imitator","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ranunculus peduncularis","label":"Ranunculus peduncularis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"rat","label":"Rat","imageSrc":"","imageAlt":"","mod":"RGD","modLink":"https://rgd.mcw.edu","linkVariable":""},{"value":"rheinheimera","label":"Rheinheimera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ribes rubrum","label":"Ribes rubrum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"sars-cov-2","label":"SARS-CoV-2","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"s. cerevisiae","label":"Saccharomyces cerevisiae","imageSrc":"yeast.png","imageAlt":"Yeast graphic by Zoe Zorn CC BY 4.0","mod":"SGD","modLink":"https://yeastgenome.org","linkVariable":""},{"value":"saccharomyces paradoxus","label":"Saccharomyces paradoxus ","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"s. uvarum","label":"Saccharomyces uvarum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"schistosoma","label":"Schistosoma","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"schizosaccharomyces japonicus","label":"Schizosaccharomyces japonicus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"s. pombe","label":"Schizosaccharomyces pombe","imageSrc":"pombe.png","imageAlt":"Pombe graphic by Zoe Zorn © Caltech","mod":"PomBase","modLink":"https://www.pombase.org/reference/PMID:","linkVariable":"pmId"},{"value":"schmidtea mediterranea","label":"Schmidtea mediterranea","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"senecio sp","label":"Senecio sp","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"simocephalus","label":"Simocephalus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"siraitia grosvenorii","label":"Siraitia grosvenorii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"solanum lycopersicum","label":"Solanum lycopersicum","imageSrc":"","imageAlt":"","mod":"Solgenomics Network","modLink":"https://solgenomics.net/organism/1/view/","linkVariable":""},{"value":"sorghum","label":"Sorghum","imageSrc":"","imageAlt":"","mod":"SorghumBase","modLink":"https://www.sorghumbase.org","linkVariable":""},{"value":"spiroplasma eriocheiris","label":"Spiroplasma eriocheiris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"staphylococcus aureus","label":"Staphylococcus aureus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"staphylococcus epidermidis","label":"Staphylococcus epidermidis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"steinernema carpocapsae","label":"Steinernema carpocapsae","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"https://wormbase.org","linkVariable":""},{"value":"steinernema hermaphroditum","label":"Steinernema hermaphroditum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"stenotrophomonas geniculata","label":"Stenotrophomonas geniculata","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"stewartia floidana","label":"Stewartia floridana","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"streptococcus gordonii ","label":"Streptococcus gordonii ","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"streptococcus mutans","label":"Streptococcus mutans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":" streptococcus pneumoniae","label":"Streptococcus pneumoniae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"s. purpuratus","label":"Strongylocentrotus purpuratus","imageSrc":"","imageAlt":"","mod":"Echinobase","modLink":"https://www.echinobase.org","linkVariable":""},{"value":"strongyloides ratti","label":"Strongyloides ratti","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"sulfolobus","label":"Sulfolobus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"symphoricarpos albus","label":"Symphoricarpos albus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"syncirsodes","label":"Syncirsodes","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"synechococcus elongatus","label":"Synechococcus elongatus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"syrphidae","label":"Syrphidae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tarantobelus jeffdanielsi","label":"Tarantobelus jeffdanielsi","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"taraxacum officinale","label":"Taraxacum officinale","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tatochila theodice","label":"Tatochila theodice","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tetrahymena","label":"Tetrahymena","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tetramorium immigrans","label":"Tetramorium immigrans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tomato brown rugose fruit virus","label":"ToBRFV","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"trachemys scripta","label":"Trachemys scripta","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tribolium castaneum","label":"Tribolium castaneum","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"trichoptera","label":"Trichoptera","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"trichuris muris","label":"Trichuris muris","imageSrc":"","imageAlt":"","mod":"WormBase","modLink":"www.wormbase.org","linkVariable":""},{"value":"trifolium repens","label":"Trifolium repens","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"trypoxylus dichotomus","label":"Trypoxylus dichotomus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"tsuga canadensis","label":"Tsuga canadensis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"ulva expansa","label":"Ulva expansa","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"universal","label":"Universal","imageSrc":"","imageAlt":"","mod":null,"modLink":null,"linkVariable":null},{"value":"vargula hilgendorfii","label":"Vargula hilgendorfii","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"vespula vulgaris","label":"Vespula vulgaris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"virus","label":"Virus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"watasenia scintillans","label":"Watasenia scintillans","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"wolbachia pipientis","label":"Wolbachia pipientis","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"xenopus","label":"Xenopus","imageSrc":"xenopus.png","imageAlt":"Xenopus graphic by Zoe Zorn CC BY 4.0","mod":"XenBase","modLink":"https://xenbase.org","linkVariable":""},{"value":"xenorhabdus griffiniae","label":"Xenorhabdus griffiniae","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"yramea cytheris","label":"Yramea cytheris","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"zaprionus indianus","label":"Zaprionus indianus","imageSrc":"","imageAlt":"","mod":"","modLink":"","linkVariable":""},{"value":"zea mays","label":"Zea mays","imageSrc":"","imageAlt":"","mod":"MaizeGDB","modLink":"https://www.maizegdb.org","linkVariable":""},{"value":"zebrafish","label":"Zebrafish","imageSrc":"zebrafish.png","imageAlt":"Zebrafish graphic by Zoe Zorn CC BY 4.0","mod":"ZFIN","modLink":"https://zfin.org","linkVariable":""}]}},"pageContext":{"id":"d7a0b38e-a913-46f3-9a45-f5c6513809a7","citedBy":[],"parsedCsv":{"csvHeader":[],"csvData":[]}}}, "staticQueryHashes": ["2114697108"]}