Tetraspanins are unique yet highly conserved four-pass transmembrane proteins that play important roles in diverse biological processes. The C. elegans tetraspanin protein TSP-12 is localized both at the cell surface and in multiple intracellular compartments, including different endosomal vesicles and the Golgi. In this study, we found that mutating key residues in the short C-terminal intracellular domain of TSP-12 (ILxxxxxWYY) led to an increase of cell surface localization of TSP-12 without affecting its localization in the ER or Golgi. These observations suggest that the ILxxxxxWYY motif in TSP-12 represents a potential internalization or endocytic compartment-targeting signal.
","acknowledgements":"We thank Scott Emr, Chris Fromme, and the rest of the Liu lab for discussions, Ken Sato for the mCherry::RER-1 strain, GCG (which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440)) for the CGC1 strain, and WormBase (grant U24HG002223) for providing genetic data and annotation services. The confocal imaging data was acquired through the Cornell University Biotechnology Resource Center, with NYSTEM (CO29155) and NIH (S10OD018516) funding for the shared Zeiss LSM880 confocal/multiphoton microscope.
","authors":[{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["writing_reviewEditing","writing_originalDraft","visualization","investigation","formalAnalysis"],"email":"ZL93@cornell.edu","firstName":"Zhiyu","lastName":"Liu","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0003-3527-1815"},{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["investigation","writing_reviewEditing"],"email":"BW28@cornell.edu","firstName":"Byron","lastName":"Williams","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0002-1517-931X"},{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["conceptualization","fundingAcquisition","writing_reviewEditing","writing_originalDraft","supervision","project"],"email":"kelly.jun.liu@cornell.edu","firstName":"Jun","lastName":"Liu","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0001-7815-4075"}],"awards":[{"awardId":"R35 GM130351 ","funderName":"National Institutes of Health (United States)","awardRecipient":"Jun Liu"}],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":null,"extendedData":[],"funding":"This work was supported by the National Institutes of Health R35 GM130351 grant to J.L.
","image":{"url":"https://portal.micropublication.org/uploads/44ff1185c9a4a3d1f45ea8309493b301.jpg"},"imageCaption":"A) Predicted structure of TSP-12 by AlphaFold3. Both the N- (green) and C- (yellow) termini of TSP-12 are localized to the cytoplasmic side. Two extracellular domains, LEL (large extracellular loop) and SEL (small extracellular loop), are shown in orange and dark blue, respectively. Four transmembrane (TM) α-helices are colored in royal blue. The putative sorting signals in the C-terminus are labeled in red (arrows). B) The amino acid sequence of TSP-12 with the transmembrane domains shown in royal blue and the 5 amino acids, IL and WYY, shown in red. C) The C-terminal tail amino acid sequence of TSP-12 showing mutation of IL and WYY in wild-type (WT) to AA and AAA (red) in TSP-12(5A mut). D-K) Airyscan confocal images showing localization of GFP::TSP-12 (D-G), SUP-17::GFP (H-K), with the ER and cis-Golgi marker mCherry::RER-1 (D'-K') in early embryos (D-E, H-I) and proximal oocytes (F-G, J-K). Scale bar, 10μm. L-S) Quantification of normalized cell surface over cytoplasmic localization of TSP-12 (L, N) and SUP-17 (P, R), with the respective wild-type value set as 1.00, and the colocalization of TSP-12 (M, O) or SUP-17 (Q, S) with RER-1. Pearson's coefficients indicate the correlated relationship between GFP::TSP-12 or SUP-17::GFP and mCherry::RER-1. Manders' M1 indicates the fraction of GFP::TSP-12 or SUP-17::GFP that is colocalized with mCherry::RER-1. Manders' M2 indicates the fraction of mCherry::RER-1 that is colocalized with GFP::TSP-12 or SUP-17::GFP. Manders' Colocalization Coefficients (M1 and M2) were determined by specifically quantifying the punctate signal of mCherry::RER-1, which labels the cis-Golgi. Statistical analysis was conducted using R by comparing 5A mutant embryos/germlines with WT embryos/germlines using ANOVA followed by Tukey HSD. ***P < 0.001; * 0.01< P < 0.05; n.s., no significant difference. (T) Western blot showing GFP::TSP-12 protein and GFP::TSP-12(5A mut) protein probed with anti-GFP antibodies. CGC1 worms do not expresse GFP::TSP-12 and are used as a negative control. 40 μg total protein (equivalent to ~200 young adult hermaphrodites) are used in each lane. * marks non-specific, anti-GFP antibody cross-reacting band. Actin is used as the protein loading control. Compared to WT, the amount of the ~55kDa band is decreased while levels of ~60kDa bands are increased for GFP::TSP-12 in tsp-12(5A mut) mutant.
","imageTitle":"Imaging and western blotting results showing that mutations in the C-terminal tail of TSP-12 lead to increased cell surface localization of TSP-12.
","methods":"All C. elegans strains used in this study were derived from CGC1 (Ichikawa et al., 2025), and were maintained at 20°C (unless otherwise noted). C. elegans strains used and generated in this study are summarized under Reagents.
CRISPR/Cas9 experiments
CRISPR/Cas9 experiments were conducted by following the protocol described in (Liu et al., 2026). The genotypes of the final strains were confirmed through Sanger sequencing. Oligonucleotides used in this study are summarized under Reagents.
Live imaging and image analysis
Imaging experiments and subsequent image analysis were conducted by following the protocol described in (Liu et al., 2026).
Western blot analysis
Western blot experiments were conducted by following the protocol described in (Liu et al., 2026). Goat anti-GFP (Rockland Immunochemicals, Item No. 600-101-215) (1:3,000), mouse anti-actin IgM (JLA20, Developmental Studies Hybridoma Bank) (1:2,000), HRP-conjugated donkey anti-goat IgG (Jackson Immunoresearch) (1:10,000), and IRdye 800CW-conjugated goat anti-mouse IgM (Licor) (1:10,000) were used.
","reagents":"Strains used in this study:
STRAIN | GENOTYPE |
dkIs91(pie-1p::mCherry::RER-1) [Gift from Ken Sato (Sakaguchi et al., 2015)] | |
sup-17(jj98[SUP-17::GFP]); dkIs91(pie-1p::mCherry::RER-1) isolate #1 | |
sup-17(jj98[SUP-17::GFP]); dkIs91(pie-1p::mCherry::RER-1) isolate #2 | |
sup-17(jj98[SUP-17::GFP]); tsp-12(jj551[5A mut]); dkIs91(pie-1p::mCherry::RER-1) | |
sup-17(jj98[SUP-17::GFP]); tsp-12(jj552[5A mut]); dkIs91(pie-1p::mCherry::RER-1) | |
tsp-12(jj181[GFP::3xFLAG::TSP-12]); dkIs91(pie-1p::mCherry::RER-1) isolate #1 | |
tsp-12(jj181[GFP::3xFLAG::TSP-12]); dkIs91(pie-1p::mCherry::RER-1) isolate #2 | |
tsp-12(jj181 jj553[GFP::3xFLAG::TSP-12 (5A mut]]); dkIs91(pie-1p::mCherry::RER-1) | |
tsp-12(jj181 jj554[GFP::3xFLAG::TSP-12 (5A mut]); dkIs91(pie-1p::mCherry::RER-1) |
Oligonucleotides used in this study:
Oligonucleotides used for genotyping | |
LW27 (ATCCAGGATCAGCAGCTGTA, R) | |
| LW30 (AAGTGTTGCGCTGTACACAC, F) |
| JKL-269 (AAGCGTTCAACTAGCAGACC, F) |
ZL431 (GGAGAATCTGTACTTTCAATCCGG, F) | |
| ZL374 (CCCTCTGCTGTGCTCTGTGTTGC, R) |
| ZL375 (CTGAAGGGGAACATTTCTTTCCTGG, F) |
Genotyping | ZL1045 (GTGACCGGCATAGGCTGTG, R) |
| ZL1046 (GTAGCCGTTTCGATGGTTATTATTGC, F) |
| ZL1060 (TCAACGGGCAAAATGGTATTAT, F) |
Sequencing | ZL1024 (CAATAGAAGCCAGAGAAGTGGC, F) |
| ZL1045 (GTGACCGGCATAGGCTGTG, R) |
| followed by sequencing using ZL1024 |
Oligonucleotides used for generating tsp-12(5A mut) using CRISPR-Cas9 | |
sgRNA (ZL1043) | ATCGGACATACTCGCTCAAC |
Repair template (ZL1042) | AGGTTCTCGGTATCTGTTTCGCTCAAAATCTCAAATCTGATGCTGCCGCCCAGCGTGCAAAAGCTGCCGCTACCCATTAATCAATCAAATAATCAATTAATCAACG |
Transmembrane proteins targeted for the secretory pathway, cell surface, or endosomal compartments involve precise sorting mechanisms. Nascent cargo proteins undergo quality control within the endoplasmic reticulum (ER) to ensure correct folding and modification. Following this, export-competent proteins accumulate at ER export sites (ERES) and traverse the ER-Golgi interface via coat protein complex II (COPII)-coated vesicles (Farhan et al., 2025; Watson et al., 2025). The cargo proteins then undergo anterograde transport through the Golgi, being further modified via glycosylation before reaching the trans-Golgi network (TGN). As the primary sorting hub, the TGN distributes cargo proteins to the plasma membrane, secretory granules, or the endolysosomal system. Meanwhile, retrograde trafficking retrieves escaped ER proteins or recycles Golgi-resident proteins (Dancourt and Barlowe 2010; Downes and Zanetti 2025). A number of targeting signals on cargo proteins have been identified to serve either as export signals, retention or retrieval motifs, or internalization and/or endolysosomal sorting signals (Dell et al., 2019). For example, cytosolic export signals, such as di-acidic [e.g., (D/E)x(D/E), x stands for any amino acid], di-hydrophobic(e.g., LL, IL), or di-aromatic motifs (e.g., FF, YY, LxxLE), are known to recruit the Sec23/Sec24 subunits of the COPII complex at ER export sites for efficient ER exit of cargo proteins (Barlowe 2003; Malhotra 2024). Conversely, cytosolic KKxx motifs (which recruit COPI for ER retrieval), luminal KDEL motifs (which are recognized by the KDEL receptor), and Golgi-retention signals such as the Vps74/GOLPH3-binding motif [(F/L)(L/I/V)xx(R/K)] (Gomez-Navarro and Miller 2016; Tu et al., 2008), serve as retention or retrieval signals for maintaining ER or Golgi localization of cargo proteins (Watson et al., 2025). Additionally, transmembrane proteins can be recycled through a cycle of endocytosis, sorting in early endosomes, and recycling back to the cell surface via either recycling endosomes or the retromer pathways. Motifs such as NPxY, YxxØ (Ø: an amino acid with a bulky hydrophobic side chain), [DE]xxxL[LI], and DxxLL have been found to serve either as internalization or endolysosomal targeting signals (Bonifacino and Traub 2003; Hsu et al., 2012; Kelly and Owen 2011).
We have been studying a highly conserved tetraspanin protein TSP-12 in C. elegans (Figure 1A). TSP-12 and its paralog TSP-14 function redundantly to regulate both Notch signaling and BMP signaling (Dunn et al., 2010; Liu et al., 2020; Wang et al., 2017). Our previous work has shown that TSP-12 is localized to multiple cellular compartments, including the cell surface, the Golgi, and early, late and recycling endosomes (Liu et al., 2020; Liu et al., 2026; Wang et al., 2017). When analyzing the protein sequence of TSP-12, we found two putative COPII (ER to Golgi) sorting motifs in the C-terminal tail of TSP-12, IL and WYY (ILxxxxxWYY, Figure 1B). To test the importance of these motifs for the localization and function of TSP-12, we first used CRISPR/Cas9 to change the IL and the WYY residues to alanines in an endogenous GFP::TSP-12 background, generating the \"5A mutant\" (abbreviated 5A mut; Figure 1C). The “5A mutant” animals do not have any detectable phenotypes. To our surprise, in both early embryos and proximal oocytes, GFP::TSP-12(5A mut) does not appear to accumulate in either the ER or the cis-Golgi compared to wild-type (WT) GFP::TSP-12. Instead, there is increased localization of GFP::TSP-12(5A mut) at the cell surface (Figure 1D-O). These observations suggest that the ILxxxxxWYY motif is unlikely to be a sorting motif for the ER-to-Golgi trafficking of TSP-12.
TSP-12 and SUP-17/ADAM10 are known to exhibit cell type-specific interdependence in their trafficking through the Golgi (Liu et al., 2026). To determine whether increased cell surface localization of TSP-12(5A mut) affects SUP-17 localization, we next generated TSP-12(5A mut) mutation in the untagged TSP-12 background and examined SUP-17::GFP localization. As shown in Figure 1H-S, the TSP-12(5A mut) mutation did not significantly alter the cell surface or intracellular localization of SUP-17::GFP in either embryos or proximal oocytes.
We have previously shown that on western blots, WT GFP::TSP-12 can be detected as two major bands at around 60kDa, representing both glycosylated and un-glycosylated forms of GFP::TSP-12, as well as a band near 55kDa (Liu et al., 2026). As shown in Figure 1T, we observed a decrease in the amount of the ~55kDa band and an increase in the amount and a downward mobility shift of the 60kDa bands in the GFP::TSP-12(5A mut) lane compared to the WT GFP::TSP-12 lane. The downward mobility shift may indicate differential glycosylation in the 5A mut, or may be simply due to the amino acid changes altering migration of the mutant protein in the gel. Because the ~55kDa band is absent in sup-17(ts) mutants at the restrictive temperature when GFP::TSP-12 protein is accumulated in the ER, we speculated previously that the ~55kDa band may represent a cleaved form of GFP::TSP-12 produced after the protein has trafficked past the Golgi, possibly due to endocytic processing (Liu et al., 2026). The reduced amount of this ~55kDa band, along with increased level and cell surface localization of GFP::TSP-12(5A mut) is consistent with this hypothesis, suggesting that the increased cell surface GFP::TSP-12(5A mut) protein might be a consequence of the GFP::TSP-12(5A mut) mutant protein unable to be internalized or unable to be sorted to various endosomal compartments.
In summary, we have identified a putative internalization or endocytic compartment-targeting signal in the C-terminal tail of the tetraspanin protein TSP-12. The ILxxxxxWYY motif has similarities to, but is not identical to, previously identified internalization or endolysosomal targeting motifs (NPxY, YxxØ, [DE]xxxL[LI], and DxxLL). Future work will be needed to identify the specific coat protein complexes that mediate TSP-12 internalization or targeting to the endocytic compartment.
","references":[{"reference":"Barlowe C. 2003. Signals for COPII-dependent export from the ER: what's the ticket out?. Trends in Cell Biology. 13: 295-300. 6.","pubmedId":"","doi":"https://doi.org/10.1016/S0962-8924(03)00082-5"},{"reference":"Bonifacino JS, Traub LM. 2003. Signals for sorting of transmembrane proteins to endosomes and lysosomes. Annu Rev Biochem. 72: 395-447. 11.","pubmedId":"12651740","doi":"10.1146/annurev.biochem.72.121801.161800"},{"reference":"Dancourt J, Barlowe C. 2010. Protein Sorting Receptors in the Early Secretory Pathway. Annual Review of Biochemistry. 79: 777-802. 3.","pubmedId":"","doi":"https://doi.org/10.1146/annurev-biochem-061608-091319"},{"reference":"Dell, Apos, Angelica EC, Bonifacino JS. 2019. Coatopathies: Genetic Disorders of Protein Coats. Annual Review of Cell and Developmental Biology. 35: 131-168. 5.","pubmedId":"","doi":"https://doi.org/10.1146/annurev-cellbio-100818-125234"},{"reference":"Downes KW, Zanetti G. 2025. Mechanisms of COPII coat assembly and cargo recognition in the secretory pathway. Nature Reviews Molecular Cell Biology. 26: 910-925. 4.","pubmedId":"","doi":"10.1038/s41580-025-00839-y"},{"reference":"Dunn CD, Sulis ML, Ferrando AA, Greenwald I. 2010. A conserved tetraspanin subfamily promotes Notch signaling in Caenorhabditis elegans and in human cells. Proceedings of the National Academy of Sciences. 107: 5907-5912. 13.","pubmedId":"","doi":"doi:10.1073/pnas.1001647107"},{"reference":"Farhan H, Raote I, Campelo F, Ge L, Hirschberg K, Forrester A, et al., Malhotra V. 2025. Towards a unified framework for the function of endoplasmic reticulum exit sites. Nature Reviews Molecular Cell Biology. 26: 957-969. 1.","pubmedId":"","doi":"10.1038/s41580-025-00899-0"},{"reference":"Gomez Navarro N, Miller E. 2016. Protein sorting at the ER–Golgi interface. Journal of Cell Biology. 215: 769-778. 9.","pubmedId":"","doi":"10.1083/jcb.201610031"},{"reference":"Hsu VW, Bai M, Li J. 2012. Getting active: protein sorting in endocytic recycling. Nature Reviews Molecular Cell Biology. 13: 323-328. 10.","pubmedId":"","doi":"10.1038/nrm3332"},{"reference":"Ichikawa K, Shoura MJ, Artiles KL, Jeong DE, Owa C, Kobayashi H, et al., Morishita S. 2025. CGC1, a new reference genome for Caenorhabditis elegans. Genome Res. 35: 1902-1918. 17.","pubmedId":"40664475","doi":"10.1101/gr.280274.124"},{"reference":"Kelly BT, Owen DJ. 2011. Endocytic sorting of transmembrane protein cargo. Current Opinion in Cell Biology. 23: 404-412. 12.","pubmedId":"","doi":"https://doi.org/10.1016/j.ceb.2011.03.004"},{"reference":"Liu Z, Shi H, Nzessi AK, Norris A, Grant BD, Liu J. 2020. Tetraspanins TSP-12 and TSP-14 function redundantly to regulate the trafficking of the type II BMP receptor in Caenorhabditis elegans. Proceedings of the National Academy of Sciences. 117: 2968-2977. 14.","pubmedId":"","doi":"doi:10.1073/pnas.1918807117"},{"reference":"Liu Z, Williams B, Wang L, Clark FK, Vignogna RC, Fromme JC, Liu J. 2026. Tetraspanin TSP-12 and SUP-17/ADAM10 exhibit cell type-specific codependence for trafficking through the Golgi. Proc Natl Acad Sci U S A. 123: e2524916123. 16.","pubmedId":"41481460","doi":"10.1073/pnas.2524916123"},{"reference":"Malhotra V. 2024. Tailored assemblies of COPII proteins in secretion. Journal of Cell Biology. 223 7.","pubmedId":"","doi":"10.1083/jcb.202404013"},{"reference":"Sakaguchi A, Sato M, Sato K, Gengyo Ando K, Yorimitsu T, Nakai J, et al., Sato K. 2015. REI-1 Is a Guanine Nucleotide Exchange Factor Regulating RAB-11 Localization and Function in C. elegans Embryos. Developmental Cell. 35: 211-221. 18.","pubmedId":"","doi":"https://doi.org/10.1016/j.devcel.2015.09.013"},{"reference":"Tu L, Tai WCS, Chen L, Banfield DK. 2008. Signal-Mediated Dynamic Retention of Glycosyltransferases in the Golgi. Science. 321: 404-407. 8.","pubmedId":"","doi":"doi:10.1126/science.1159411"},{"reference":"Wang L, Liu Z, Shi H, Liu J. 2017. Two Paralogous Tetraspanins TSP-12 and TSP-14 Function with the ADAM10 Metalloprotease SUP-17 to Promote BMP Signaling in Caenorhabditis elegans. PLoS Genet. 13: e1006568. 15.","pubmedId":"28068334","doi":"10.1371/journal.pgen.1006568"},{"reference":"Watson ET, Wegeng WR, Aravani S, Ernst AM, Von Blume J. 2025. Mechanistic insights into cargo sorting and export from the Golgi apparatus. Nature Reviews Molecular Cell Biology. 26: 940-956. 2.","pubmedId":"","doi":"10.1038/s41580-025-00907-3"}],"title":"Identification of a potential internalization or endocytic compartment-targeting signal in the C-terminal tail of the tetraspanin protein TSP-12
","reviews":[{"reviewer":{"displayName":"Barth Grant"},"openAcknowledgement":false,"status":{"submitted":true}}],"curatorReviews":[{"curator":{"displayName":"KJ Yook"},"openAcknowledgement":false,"submitted":null}]},{"id":"7c3f3dd3-8179-4571-a34c-b2b92242b9cf","decision":"accept","abstract":"Tetraspanins are unique yet highly conserved four-pass transmembrane proteins that play important roles in diverse biological processes. The C. elegans tetraspanin protein TSP-12 is localized both at the cell surface and in multiple intracellular compartments, including different endosomal vesicles and the Golgi. In this study, we found that mutating key residues in the short C-terminal intracellular domain of TSP-12 (ILxxxxxWYY) led to an increase of cell surface localization of TSP-12 without affecting its localization in the ER or Golgi. These observations suggest that the ILxxxxxWYY motif in TSP-12 represents a potential internalization or endocytic compartment-targeting signal.
","acknowledgements":"We thank Scott Emr, Chris Fromme, and the rest of the Liu lab for discussions, Ken Sato for the mCherry::RER-1 strain, CGC (which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440)) for the CGC1 strain, and WormBase (grant U24HG002223) for providing genetic data and annotation services. The confocal imaging data was acquired through the Cornell University Biotechnology Resource Center, with NYSTEM (CO29155) and NIH (S10OD018516) funding for the shared Zeiss LSM880 confocal/multiphoton microscope.
","authors":[{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["writing_reviewEditing","writing_originalDraft","visualization","investigation","formalAnalysis"],"email":"ZL93@cornell.edu","firstName":"Zhiyu","lastName":"Liu","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0003-3527-1815"},{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["investigation","writing_reviewEditing"],"email":"BW28@cornell.edu","firstName":"Byron","lastName":"Williams","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0002-1517-931X"},{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["conceptualization","fundingAcquisition","writing_reviewEditing","writing_originalDraft","supervision","project"],"email":"kelly.jun.liu@cornell.edu","firstName":"Jun","lastName":"Liu","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0001-7815-4075"}],"awards":[{"awardId":"R35 GM130351 ","funderName":"National Institutes of Health (United States)","awardRecipient":"Jun Liu"}],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":{"url":null},"extendedData":[],"funding":"This work was supported by the National Institutes of Health R35 GM130351 grant to J.L.
","image":{"url":"https://portal.micropublication.org/uploads/96056f8d3f9e5cc98356dda3413e0296.jpg"},"imageCaption":"A) Predicted structure of TSP-12 by AlphaFold3. Both the N- (green) and C- (yellow) termini of TSP-12 are localized to the cytoplasmic side. Two extracellular domains, LEL (large extracellular loop) and SEL (small extracellular loop), are shown in orange and dark blue, respectively. Four transmembrane (TM) α-helices are colored in royal blue. The putative sorting signals in the C-terminus are labeled in red (arrows). B) The amino acid sequence of TSP-12 with the transmembrane domains shown in royal blue and the 5 amino acids, IL and WYY, shown in red. C) The C-terminal tail amino acid sequence of TSP-12 showing mutation of IL and WYY in wild-type (WT) to AA and AAA (red) in TSP-12(5A mut). D) Western blot showing GFP::TSP-12 protein and GFP::TSP-12(5A mut) protein probed with anti-GFP antibodies. CGC1 worms do not express GFP::TSP-12 and are used as a negative control. 40 μg total protein (equivalent to ~200 young adult hermaphrodites) are used in each lane. Samples of each genotype were run in duplicate lanes. * marks non-specific, anti-GFP antibody cross-reacting band. MW, molecular weight ladder. Actin is used as the protein loading control. Compared to WT, the amount of the ~55kDa band is decreased while levels of ~60kDa bands are increased for GFP::TSP-12 in tsp-12(5A mut) mutant. In addition, the GFP::TSP-12(5A mut) protein migrates slightly faster than the wild-type protein, as compared to the mobility of the non-specific (*) and actin bands. E-H) and M-P) Airyscan confocal images showing localization of GFP::TSP-12 (E-H), SUP-17::GFP (M-P), with the ER and cis-Golgi marker mCherry::RER-1 (E'-P') in early embryos (E-F, M-N) and proximal oocytes (G-H, O-P). Scale bar, 10μm. M-T) Quantification of normalized cell surface over cytoplasmic localization of TSP-12 (I, K) and SUP-17 (Q, S), with the respective wild-type value set as 1.00, and the colocalization of TSP-12 (J, L) or SUP-17 (R, T) with RER-1. Pearson's coefficients indicate the correlated relationship between GFP::TSP-12 or SUP-17::GFP and mCherry::RER-1. Manders' M1 indicates the fraction of GFP::TSP-12 or SUP-17::GFP that is colocalized with mCherry::RER-1. Manders' M2 indicates the fraction of mCherry::RER-1 that is colocalized with GFP::TSP-12 or SUP-17::GFP. Manders' Colocalization Coefficients (M1 and M2) were determined by specifically quantifying the punctate signal of mCherry::RER-1, which labels the cis-Golgi. Statistical analysis was conducted using R by comparing 5A mutant embryos/germlines with WT embryos/germlines using ANOVA followed by Tukey HSD. ***P < 0.001; * 0.01< P < 0.05; n.s., no significant difference.
","imageTitle":"Imaging and western blotting results showing that mutations in the C-terminal tail of TSP-12 lead to increased localization of TSP-12 at or near the cell surface
","methods":"All C. elegans strains used in this study were derived from CGC1 (Ichikawa et al., 2025), and were maintained at 20°C (unless otherwise noted). C. elegans strains used and generated in this study are summarized under Reagents.
CRISPR/Cas9 experiments
CRISPR/Cas9 experiments were conducted by following the protocol described in (Liu et al., 2026). The genotypes of the final strains were confirmed through Sanger sequencing. Oligonucleotides used in this study are summarized under Reagents.
Live imaging and image analysis
Imaging experiments and subsequent image analysis were conducted by following the protocol described in (Liu et al., 2026).
Western blot analysis
Western blot experiments were conducted by following the protocol described in (Liu et al., 2026). Goat anti-GFP (Rockland Immunochemicals, Item No. 600-101-215) (1:3,000), mouse anti-actin IgM (JLA20, Developmental Studies Hybridoma Bank) (1:2,000), HRP-conjugated donkey anti-goat IgG (Jackson Immunoresearch) (1:10,000), and IRdye 800CW-conjugated goat anti-mouse IgM (Licor) (1:10,000) were used.
","reagents":"Strains used in this study:
STRAIN | GENOTYPE |
dkIs91(pie-1p::mCherry::RER-1) [Gift from Ken Sato (Sakaguchi et al., 2015)] | |
sup-17(jj98[SUP-17::GFP]); dkIs91(pie-1p::mCherry::RER-1) isolate #1 | |
sup-17(jj98[SUP-17::GFP]); dkIs91(pie-1p::mCherry::RER-1) isolate #2 | |
sup-17(jj98[SUP-17::GFP]); tsp-12(jj551[5A mut]); dkIs91(pie-1p::mCherry::RER-1) | |
sup-17(jj98[SUP-17::GFP]); tsp-12(jj552[5A mut]); dkIs91(pie-1p::mCherry::RER-1) | |
tsp-12(jj181[GFP::3xFLAG::TSP-12]); dkIs91(pie-1p::mCherry::RER-1) isolate #1 | |
tsp-12(jj181[GFP::3xFLAG::TSP-12]); dkIs91(pie-1p::mCherry::RER-1) isolate #2 | |
tsp-12(jj181 jj553[GFP::3xFLAG::TSP-12 (5A mut]]); dkIs91(pie-1p::mCherry::RER-1) | |
tsp-12(jj181 jj554[GFP::3xFLAG::TSP-12 (5A mut]); dkIs91(pie-1p::mCherry::RER-1) |
Oligonucleotides used in this study:
Oligonucleotides used for genotyping | |
LW27 (ATCCAGGATCAGCAGCTGTA, R) | |
| LW30 (AAGTGTTGCGCTGTACACAC, F) |
| JKL-269 (AAGCGTTCAACTAGCAGACC, F) |
ZL431 (GGAGAATCTGTACTTTCAATCCGG, F) | |
| ZL374 (CCCTCTGCTGTGCTCTGTGTTGC, R) |
| ZL375 (CTGAAGGGGAACATTTCTTTCCTGG, F) |
Genotyping | ZL1045 (GTGACCGGCATAGGCTGTG, R) |
| ZL1046 (GTAGCCGTTTCGATGGTTATTATTGC, F) |
| ZL1060 (TCAACGGGCAAAATGGTATTAT, F) |
Sequencing | ZL1024 (CAATAGAAGCCAGAGAAGTGGC, F) |
| ZL1045 (GTGACCGGCATAGGCTGTG, R) |
| followed by sequencing using ZL1024 |
Oligonucleotides used for generating tsp-12(5A mut) using CRISPR-Cas9 | |
sgRNA (ZL1043) | ATCGGACATACTCGCTCAAC |
Repair template (ZL1042) | AGGTTCTCGGTATCTGTTTCGCTCAAAATCTCAAATCTGATGCTGCCGCCCAGCGTGCAAAAGCTGCCGCTACCCATTAATCAATCAAATAATCAATTAATCAACG |
Transmembrane proteins targeted for the secretory pathway, cell surface, or endosomal compartments involve precise sorting mechanisms. Nascent cargo proteins undergo quality control within the endoplasmic reticulum (ER) to ensure correct folding and modification. Following this, export-competent proteins accumulate at ER export sites (ERES) and traverse the ER-Golgi interface via coat protein complex II (COPII)-coated vesicles (Farhan et al., 2025; Watson et al., 2025). The cargo proteins then undergo anterograde transport through the Golgi, being further modified via glycosylation before reaching the trans-Golgi network (TGN). As the primary sorting hub, the TGN distributes cargo proteins to the plasma membrane, secretory granules, or the endolysosomal system. Meanwhile, retrograde trafficking retrieves escaped ER proteins or recycles Golgi-resident proteins (Dancourt and Barlowe 2010; Downes and Zanetti 2025). A number of targeting signals on cargo proteins have been identified to serve either as export signals, retention or retrieval motifs, or internalization and/or endolysosomal sorting signals (Dell et al., 2019). For example, cytosolic export signals, such as di-acidic [e.g., (D/E)x(D/E), x stands for any amino acid], di-hydrophobic(e.g., LL, IL), or di-aromatic motifs (e.g., FF, YY, LxxLE), are known to recruit the Sec23/Sec24 subunits of the COPII complex at ER export sites for efficient ER exit of cargo proteins (Barlowe 2003; Malhotra 2024). Conversely, cytosolic KKxx motifs (which recruit COPI for ER retrieval), luminal KDEL motifs (which are recognized by the KDEL receptor), and Golgi-retention signals such as the Vps74/GOLPH3-binding motif [(F/L)(L/I/V)xx(R/K)] (Gomez-Navarro and Miller 2016; Tu et al., 2008), serve as retention or retrieval signals for maintaining ER or Golgi localization of cargo proteins (Watson et al., 2025). Additionally, transmembrane proteins can be recycled through a cycle of endocytosis, sorting in early endosomes, and recycling back to the cell surface via either recycling endosomes or the retromer pathways. Motifs such as NPxY, YxxØ (Ø: an amino acid with a bulky hydrophobic side chain), [DE]xxxL[LI], and DxxLL have been found to serve either as internalization or endolysosomal targeting signals (Bonifacino and Traub 2003; Hsu et al., 2012; Kelly and Owen 2011).
We have been studying a highly conserved tetraspanin protein TSP-12 in C. elegans (Figure 1A). TSP-12 and its paralog TSP-14 function redundantly to regulate both Notch signaling and BMP signaling (Dunn et al., 2010; Liu et al., 2020; Wang et al., 2017). Our previous work has shown that TSP-12 is localized to multiple cellular compartments, including the cell surface, the Golgi, and early, late and recycling endosomes (Liu et al., 2020; Liu et al., 2026; Wang et al., 2017). When analyzing the protein sequence of TSP-12, we found two putative COPII (ER to Golgi) sorting motifs in the C-terminal tail of TSP-12, IL and WYY (ILxxxxxWYY, Figure 1B). To test the importance of these motifs for the localization and function of TSP-12, we first used CRISPR/Cas9 to change the IL and the WYY residues to alanines in an endogenous GFP::TSP-12 background, generating the \"5A mutant\" (abbreviated 5A mut; Figure 1C). The “5A mutant” animals do not have any detectable phenotypes. To our surprise, in both early embryos and proximal oocytes, GFP::TSP-12(5A mut) does not appear to accumulate in either the ER or the cis-Golgi compared to wild-type (WT) GFP::TSP-12. Instead, there is increased localization of GFP::TSP-12(5A mut) at or near the cell surface (Figure1E-L). These observations suggest that the ILxxxxxWYY motif is unlikely to be a sorting motif for the ER-to-Golgi trafficking of TSP-12.
We have previously shown that on western blots, WT GFP::TSP-12 can be detected as two major bands at around 60kDa, representing both glycosylated and un-glycosylated forms of GFP::TSP-12, as well as a band near 55kDa (Liu et al., 2026). As shown in Figure 1D, we observed a decrease in the amount of the ~55kDa band and an increase in the amount and a downward mobility shift of the 60kDa bands in the GFP::TSP-12(5A mut) lane compared to the WT GFP::TSP-12 lane. The downward mobility shift may indicate differential glycosylation in the 5A mut, or may be simply due to the amino acid changes altering migration of the mutant protein in the gel. Because the ~55kDa band is absent in sup-17(ts) mutants at the restrictive temperature when GFP::TSP-12 protein is accumulated in the ER, we speculated previously that the ~55kDa band may represent a cleaved form of GFP::TSP-12 produced after the protein has trafficked past the Golgi, possibly due to endocytic processing (Liu et al., 2026). The reduced amount of this ~55kDa band, along with increased level and near cell surface localization of GFP::TSP-12(5A mut) is consistent with this hypothesis, suggesting that the increased GFP::TSP-12(5A mut) protein near the cell surface might be a consequence of the GFP::TSP-12(5A mut) mutant protein unable to be internalized or unable to be sorted to various endosomal compartments.
TSP-12 and SUP-17/ADAM10 are known to exhibit cell type-specific interdependence in their trafficking through the Golgi (Liu et al., 2026). To determine whether increased localization of TSP-12(5A mut) near the cell surface affects SUP-17 localization, we next generated TSP-12(5A mut) mutation in the untagged TSP-12 background and examined SUP-17::GFP localization. As shown in Figure 1(M-T), the TSP-12(5A mut) mutation did not significantly alter the cell surface or intracellular localization of SUP-17::GFP in either embryos or proximal oocytes.
In summary, we have identified a putative internalization or endocytic compartment-targeting signal in the C-terminal tail of the tetraspanin protein TSP-12. The ILxxxxxWYY motif has similarities to, but is not identical to, previously identified internalization or endolysosomal targeting motifs (NPxY, YxxØ, [DE]xxxL[LI], and DxxLL). Future work will be needed to identify the specific coat protein complexes that mediate TSP-12 internalization or targeting to the endocytic compartment.
","references":[{"reference":"Barlowe C. 2003. Signals for COPII-dependent export from the ER: what's the ticket out?. Trends in Cell Biology. 13: 295-300. 6.","pubmedId":"","doi":"https://doi.org/10.1016/S0962-8924(03)00082-5"},{"reference":"Bonifacino JS, Traub LM. 2003. Signals for sorting of transmembrane proteins to endosomes and lysosomes. Annu Rev Biochem. 72: 395-447. 11.","pubmedId":"12651740","doi":"10.1146/annurev.biochem.72.121801.161800"},{"reference":"Dancourt J, Barlowe C. 2010. Protein Sorting Receptors in the Early Secretory Pathway. Annual Review of Biochemistry. 79: 777-802. 3.","pubmedId":"","doi":"https://doi.org/10.1146/annurev-biochem-061608-091319"},{"reference":"Dell, Apos, Angelica EC, Bonifacino JS. 2019. Coatopathies: Genetic Disorders of Protein Coats. Annual Review of Cell and Developmental Biology. 35: 131-168. 5.","pubmedId":"","doi":"https://doi.org/10.1146/annurev-cellbio-100818-125234"},{"reference":"Downes KW, Zanetti G. 2025. Mechanisms of COPII coat assembly and cargo recognition in the secretory pathway. Nature Reviews Molecular Cell Biology. 26: 910-925. 4.","pubmedId":"","doi":"10.1038/s41580-025-00839-y"},{"reference":"Dunn CD, Sulis ML, Ferrando AA, Greenwald I. 2010. A conserved tetraspanin subfamily promotes Notch signaling in Caenorhabditis elegans and in human cells. Proceedings of the National Academy of Sciences. 107: 5907-5912. 13.","pubmedId":"","doi":"doi:10.1073/pnas.1001647107"},{"reference":"Farhan H, Raote I, Campelo F, Ge L, Hirschberg K, Forrester A, et al., Malhotra V. 2025. Towards a unified framework for the function of endoplasmic reticulum exit sites. Nature Reviews Molecular Cell Biology. 26: 957-969. 1.","pubmedId":"","doi":"10.1038/s41580-025-00899-0"},{"reference":"Gomez Navarro N, Miller E. 2016. Protein sorting at the ER–Golgi interface. Journal of Cell Biology. 215: 769-778. 9.","pubmedId":"","doi":"10.1083/jcb.201610031"},{"reference":"Hsu VW, Bai M, Li J. 2012. Getting active: protein sorting in endocytic recycling. Nature Reviews Molecular Cell Biology. 13: 323-328. 10.","pubmedId":"","doi":"10.1038/nrm3332"},{"reference":"Ichikawa K, Shoura MJ, Artiles KL, Jeong DE, Owa C, Kobayashi H, et al., Morishita S. 2025. CGC1, a new reference genome for Caenorhabditis elegans. Genome Res. 35: 1902-1918. 17.","pubmedId":"40664475","doi":"10.1101/gr.280274.124"},{"reference":"Kelly BT, Owen DJ. 2011. Endocytic sorting of transmembrane protein cargo. Current Opinion in Cell Biology. 23: 404-412. 12.","pubmedId":"","doi":"https://doi.org/10.1016/j.ceb.2011.03.004"},{"reference":"Liu Z, Shi H, Nzessi AK, Norris A, Grant BD, Liu J. 2020. Tetraspanins TSP-12 and TSP-14 function redundantly to regulate the trafficking of the type II BMP receptor in Caenorhabditis elegans. Proceedings of the National Academy of Sciences. 117: 2968-2977. 14.","pubmedId":"","doi":"doi:10.1073/pnas.1918807117"},{"reference":"Liu Z, Williams B, Wang L, Clark FK, Vignogna RC, Fromme JC, Liu J. 2026. Tetraspanin TSP-12 and SUP-17/ADAM10 exhibit cell type-specific codependence for trafficking through the Golgi. Proc Natl Acad Sci U S A. 123: e2524916123. 16.","pubmedId":"41481460","doi":"10.1073/pnas.2524916123"},{"reference":"Malhotra V. 2024. Tailored assemblies of COPII proteins in secretion. Journal of Cell Biology. 223 7.","pubmedId":"","doi":"10.1083/jcb.202404013"},{"reference":"Sakaguchi A, Sato M, Sato K, Gengyo Ando K, Yorimitsu T, Nakai J, et al., Sato K. 2015. REI-1 Is a Guanine Nucleotide Exchange Factor Regulating RAB-11 Localization and Function in C. elegans Embryos. Developmental Cell. 35: 211-221. 18.","pubmedId":"","doi":"https://doi.org/10.1016/j.devcel.2015.09.013"},{"reference":"Tu L, Tai WCS, Chen L, Banfield DK. 2008. Signal-Mediated Dynamic Retention of Glycosyltransferases in the Golgi. Science. 321: 404-407. 8.","pubmedId":"","doi":"doi:10.1126/science.1159411"},{"reference":"Wang L, Liu Z, Shi H, Liu J. 2017. Two Paralogous Tetraspanins TSP-12 and TSP-14 Function with the ADAM10 Metalloprotease SUP-17 to Promote BMP Signaling in Caenorhabditis elegans. PLoS Genet. 13: e1006568. 15.","pubmedId":"28068334","doi":"10.1371/journal.pgen.1006568"},{"reference":"Watson ET, Wegeng WR, Aravani S, Ernst AM, Von Blume J. 2025. Mechanistic insights into cargo sorting and export from the Golgi apparatus. Nature Reviews Molecular Cell Biology. 26: 940-956. 2.","pubmedId":"","doi":"10.1038/s41580-025-00907-3"}],"title":"Identification of a potential internalization or endocytic compartment-targeting signal in the C-terminal tail of the tetraspanin protein TSP-12
","reviews":[],"curatorReviews":[{"curator":{"displayName":"KJ Yook"},"openAcknowledgement":false,"submitted":"1776975881274"}]},{"id":"f9458b69-72fa-4482-9e3d-4e1bdb24e161","decision":"publish","abstract":"Tetraspanins are unique yet highly conserved four-pass transmembrane proteins that play important roles in diverse biological processes. The C. elegans tetraspanin protein TSP-12 is localized both at the cell surface and in multiple intracellular compartments, including different endosomal vesicles and the Golgi. In this study, we found that mutating key residues in the short C-terminal intracellular domain of TSP-12 (ILxxxxxWYY) led to an increase of cell surface localization of TSP-12 without affecting its localization in the ER or Golgi. These observations suggest that the ILxxxxxWYY motif in TSP-12 represents a potential internalization or endocytic compartment-targeting signal.
","acknowledgements":"We thank Scott Emr, Chris Fromme, and the rest of the Liu lab for discussions, Ken Sato for the mCherry::RER-1 strain, CGC (which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440)) for the CGC1 strain, and WormBase (grant U24HG002223) for providing genetic data and annotation services. The confocal imaging data was acquired through the Cornell University Biotechnology Resource Center, with NYSTEM (CO29155) and NIH (S10OD018516) funding for the shared Zeiss LSM880 confocal/multiphoton microscope.
","authors":[{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["writing_reviewEditing","writing_originalDraft","visualization","investigation","formalAnalysis"],"email":"ZL93@cornell.edu","firstName":"Zhiyu","lastName":"Liu","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0003-3527-1815"},{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["investigation","writing_reviewEditing"],"email":"BW28@cornell.edu","firstName":"Byron","lastName":"Williams","submittingAuthor":false,"correspondingAuthor":false,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0002-1517-931X"},{"affiliations":["Cornell University"],"departments":["Department of Molecular Biology and Genetics"],"credit":["conceptualization","fundingAcquisition","writing_reviewEditing","writing_originalDraft","supervision","project"],"email":"kelly.jun.liu@cornell.edu","firstName":"Jun","lastName":"Liu","submittingAuthor":true,"correspondingAuthor":true,"equalContribution":false,"WBId":null,"orcid":"https://orcid.org/0000-0001-7815-4075"}],"awards":[{"awardId":"R35 GM130351 ","funderName":"National Institutes of Health (United States)","awardRecipient":"Jun Liu"}],"conflictsOfInterest":"The authors declare that there are no conflicts of interest present.
","dataTable":{"url":null},"extendedData":[],"funding":"This work was supported by the National Institutes of Health R35 GM130351 grant to J.L.
","image":{"url":"https://portal.micropublication.org/uploads/96056f8d3f9e5cc98356dda3413e0296.jpg"},"imageCaption":"A) Predicted structure of TSP-12 by AlphaFold3. Both the N- (green) and C- (yellow) termini of TSP-12 are localized to the cytoplasmic side. Two extracellular domains, LEL (large extracellular loop) and SEL (small extracellular loop), are shown in orange and dark blue, respectively. Four transmembrane (TM) α-helices are colored in royal blue. The putative sorting signals in the C-terminus are labeled in red (arrows). B) The amino acid sequence of TSP-12 with the transmembrane domains shown in royal blue and the 5 amino acids, IL and WYY, shown in red. C) The C-terminal tail amino acid sequence of TSP-12 showing mutation of IL and WYY in wild-type (WT) to AA and AAA (red) in TSP-12(5A mut). D) Western blot showing GFP::TSP-12 protein and GFP::TSP-12(5A mut) protein probed with anti-GFP antibodies. CGC1 worms do not express GFP::TSP-12 and are used as a negative control. 40 μg total protein (equivalent to ~200 young adult hermaphrodites) are used in each lane. Samples of each genotype were run in duplicate lanes. * marks non-specific, anti-GFP antibody cross-reacting band. MW, molecular weight ladder. Actin is used as the protein loading control. Compared to WT, the amount of the ~55kDa band is decreased while levels of ~60kDa bands are increased for GFP::TSP-12 in tsp-12(5A mut) mutant. In addition, the GFP::TSP-12(5A mut) protein migrates slightly faster than the wild-type protein, as compared to the mobility of the non-specific (*) and actin bands. E-H) and M-P) Airyscan confocal images showing localization of GFP::TSP-12 (E-H), SUP-17::GFP (M-P), with the ER and cis-Golgi marker mCherry::RER-1 (E'-P') in early embryos (E-F, M-N) and proximal oocytes (G-H, O-P). Scale bar, 10μm. I-L) and Q-T) Quantification of normalized cell surface over cytoplasmic localization of TSP-12 (I, K) and SUP-17 (Q, S), with the respective wild-type value set as 1.00, and the colocalization of TSP-12 (J, L) or SUP-17 (R, T) with RER-1. Pearson's coefficients indicate the correlated relationship between GFP::TSP-12 or SUP-17::GFP and mCherry::RER-1. Manders' M1 indicates the fraction of GFP::TSP-12 or SUP-17::GFP that is colocalized with mCherry::RER-1. Manders' M2 indicates the fraction of mCherry::RER-1 that is colocalized with GFP::TSP-12 or SUP-17::GFP. Manders' Colocalization Coefficients (M1 and M2) were determined by specifically quantifying the punctate signal of mCherry::RER-1, which labels the cis-Golgi. Statistical analysis was conducted using R by comparing 5A mutant embryos/germlines with WT embryos/germlines using ANOVA followed by Tukey HSD. ***P < 0.001; * 0.01< P < 0.05; n.s., no significant difference.
","imageTitle":"Imaging and western blotting results showing that mutations in the C-terminal tail of TSP-12 lead to increased localization of TSP-12 at or near the cell surface
","methods":"All C. elegans strains used in this study were derived from CGC1 (Ichikawa et al., 2025), and were maintained at 20°C (unless otherwise noted). C. elegans strains used and generated in this study are summarized under Reagents.
CRISPR/Cas9 experiments
CRISPR/Cas9 experiments were conducted by following the protocol described in (Liu et al., 2026). The genotypes of the final strains were confirmed through Sanger sequencing. Oligonucleotides used in this study are summarized under Reagents.
Live imaging and image analysis
Imaging experiments and subsequent image analysis were conducted by following the protocol described in (Liu et al., 2026).
Western blot analysis
Western blot experiments were conducted by following the protocol described in (Liu et al., 2026). Goat anti-GFP (Rockland Immunochemicals, Item No. 600-101-215) (1:3,000), mouse anti-actin IgM (JLA20, Developmental Studies Hybridoma Bank) (1:2,000), HRP-conjugated donkey anti-goat IgG (Jackson Immunoresearch) (1:10,000), and IRdye 800CW-conjugated goat anti-mouse IgM (Licor) (1:10,000) were used.
","reagents":"Strains used in this study:
STRAIN | GENOTYPE |
dkIs91(pie-1p::mCherry::RER-1) [Gift from Ken Sato (Sakaguchi et al., 2015)] | |
sup-17(jj98[SUP-17::GFP]); dkIs91(pie-1p::mCherry::RER-1) isolate #1 | |
sup-17(jj98[SUP-17::GFP]); dkIs91(pie-1p::mCherry::RER-1) isolate #2 | |
sup-17(jj98[SUP-17::GFP]); tsp-12(jj551[5A mut]); dkIs91(pie-1p::mCherry::RER-1) | |
sup-17(jj98[SUP-17::GFP]); tsp-12(jj552[5A mut]); dkIs91(pie-1p::mCherry::RER-1) | |
tsp-12(jj181[GFP::3xFLAG::TSP-12]); dkIs91(pie-1p::mCherry::RER-1) isolate #1 | |
tsp-12(jj181[GFP::3xFLAG::TSP-12]); dkIs91(pie-1p::mCherry::RER-1) isolate #2 | |
tsp-12(jj181 jj553[GFP::3xFLAG::TSP-12 (5A mut]]); dkIs91(pie-1p::mCherry::RER-1) | |
tsp-12(jj181 jj554[GFP::3xFLAG::TSP-12 (5A mut]); dkIs91(pie-1p::mCherry::RER-1) |
Oligonucleotides used in this study:
Oligonucleotides used for genotyping | |
LW27 (ATCCAGGATCAGCAGCTGTA, R) | |
| LW30 (AAGTGTTGCGCTGTACACAC, F) |
| JKL-269 (AAGCGTTCAACTAGCAGACC, F) |
ZL431 (GGAGAATCTGTACTTTCAATCCGG, F) | |
| ZL374 (CCCTCTGCTGTGCTCTGTGTTGC, R) |
| ZL375 (CTGAAGGGGAACATTTCTTTCCTGG, F) |
Genotyping | ZL1045 (GTGACCGGCATAGGCTGTG, R) |
| ZL1046 (GTAGCCGTTTCGATGGTTATTATTGC, F) |
| ZL1060 (TCAACGGGCAAAATGGTATTAT, F) |
Sequencing | ZL1024 (CAATAGAAGCCAGAGAAGTGGC, F) |
| ZL1045 (GTGACCGGCATAGGCTGTG, R) |
| followed by sequencing using ZL1024 |
Oligonucleotides used for generating tsp-12(5A mut) using CRISPR-Cas9 | |
sgRNA (ZL1043) | ATCGGACATACTCGCTCAAC |
Repair template (ZL1042) | AGGTTCTCGGTATCTGTTTCGCTCAAAATCTCAAATCTGATGCTGCCGCCCAGCGTGCAAAAGCTGCCGCTACCCATTAATCAATCAAATAATCAATTAATCAACG |
Transmembrane proteins targeted for the secretory pathway, cell surface, or endosomal compartments involve precise sorting mechanisms. Nascent cargo proteins undergo quality control within the endoplasmic reticulum (ER) to ensure correct folding and modification. Following this, export-competent proteins accumulate at ER export sites (ERES) and traverse the ER-Golgi interface via coat protein complex II (COPII)-coated vesicles (Farhan et al., 2025; Watson et al., 2025). The cargo proteins then undergo anterograde transport through the Golgi, being further modified via glycosylation before reaching the trans-Golgi network (TGN). As the primary sorting hub, the TGN distributes cargo proteins to the plasma membrane, secretory granules, or the endolysosomal system. Meanwhile, retrograde trafficking retrieves escaped ER proteins or recycles Golgi-resident proteins (Dancourt and Barlowe 2010; Downes and Zanetti 2025). A number of targeting signals on cargo proteins have been identified to serve either as export signals, retention or retrieval motifs, or internalization and/or endolysosomal sorting signals (Dell et al., 2019). For example, cytosolic export signals, such as di-acidic [e.g., (D/E)x(D/E), x stands for any amino acid], di-hydrophobic(e.g., LL, IL), or di-aromatic motifs (e.g., FF, YY, LxxLE), are known to recruit the Sec23/Sec24 subunits of the COPII complex at ER export sites for efficient ER exit of cargo proteins (Barlowe 2003; Malhotra 2024). Conversely, cytosolic KKxx motifs (which recruit COPI for ER retrieval), luminal KDEL motifs (which are recognized by the KDEL receptor), and Golgi-retention signals such as the Vps74/GOLPH3-binding motif [(F/L)(L/I/V)xx(R/K)] (Gomez-Navarro and Miller 2016; Tu et al., 2008), serve as retention or retrieval signals for maintaining ER or Golgi localization of cargo proteins (Watson et al., 2025). Additionally, transmembrane proteins can be recycled through a cycle of endocytosis, sorting in early endosomes, and recycling back to the cell surface via either recycling endosomes or the retromer pathways. Motifs such as NPxY, YxxØ (Ø: an amino acid with a bulky hydrophobic side chain), [DE]xxxL[LI], and DxxLL have been found to serve either as internalization or endolysosomal targeting signals (Bonifacino and Traub 2003; Hsu et al., 2012; Kelly and Owen 2011).
We have been studying a highly conserved tetraspanin protein TSP-12 in C. elegans (Figure 1A). TSP-12 and its paralog TSP-14 function redundantly to regulate both Notch signaling and BMP signaling (Dunn et al., 2010; Liu et al., 2020; Wang et al., 2017). Our previous work has shown that TSP-12 is localized to multiple cellular compartments, including the cell surface, the Golgi, and early, late and recycling endosomes (Liu et al., 2020; Liu et al., 2026; Wang et al., 2017). When analyzing the protein sequence of TSP-12, we found two putative COPII (ER to Golgi) sorting motifs in the C-terminal tail of TSP-12, IL and WYY (ILxxxxxWYY, Figure 1B). To test the importance of these motifs for the localization and function of TSP-12, we first used CRISPR/Cas9 to change the IL and the WYY residues to alanines in an endogenous GFP::TSP-12 background, generating the \"5A mutant\" (abbreviated 5A mut; Figure 1C). The “5A mutant” animals do not have any detectable phenotypes. To our surprise, in both early embryos and proximal oocytes, GFP::TSP-12(5A mut) does not appear to accumulate in either the ER or the cis-Golgi compared to wild-type (WT) GFP::TSP-12. Instead, there is increased localization of GFP::TSP-12(5A mut) at or near the cell surface (Figure1E-L). These observations suggest that the ILxxxxxWYY motif is unlikely to be a sorting motif for the ER-to-Golgi trafficking of TSP-12.
We have previously shown that on western blots, WT GFP::TSP-12 can be detected as two major bands at around 60kDa, representing both glycosylated and un-glycosylated forms of GFP::TSP-12, as well as a band near 55kDa (Liu et al., 2026). As shown in Figure 1D, we observed a decrease in the amount of the ~55kDa band and an increase in the amount and a downward mobility shift of the 60kDa bands in the GFP::TSP-12(5A mut) lane compared to the WT GFP::TSP-12 lane. The downward mobility shift may indicate differential glycosylation in the 5A mut, or may be simply due to the amino acid changes altering migration of the mutant protein in the gel. Because the ~55kDa band is absent in sup-17(ts) mutants at the restrictive temperature when GFP::TSP-12 protein is accumulated in the ER, we speculated previously that the ~55kDa band may represent a cleaved form of GFP::TSP-12 produced after the protein has trafficked past the Golgi, possibly due to endocytic processing (Liu et al., 2026). The reduced amount of this ~55kDa band, along with increased level and near cell surface localization of GFP::TSP-12(5A mut) is consistent with this hypothesis, suggesting that the increased GFP::TSP-12(5A mut) protein near the cell surface might be a consequence of the GFP::TSP-12(5A mut) mutant protein unable to be internalized or unable to be sorted to various endosomal compartments.
TSP-12 and SUP-17/ADAM10 are known to exhibit cell type-specific interdependence in their trafficking through the Golgi (Liu et al., 2026). To determine whether increased localization of TSP-12(5A mut) near the cell surface affects SUP-17 localization, we next generated TSP-12(5A mut) mutation in the untagged TSP-12 background and examined SUP-17::GFP localization. As shown in Figure 1(M-T), the TSP-12(5A mut) mutation did not significantly alter the cell surface or intracellular localization of SUP-17::GFP in either embryos or proximal oocytes.
In summary, we have identified a putative internalization or endocytic compartment-targeting signal in the C-terminal tail of the tetraspanin protein TSP-12. The ILxxxxxWYY motif has similarities to, but is not identical to, previously identified internalization or endolysosomal targeting motifs (NPxY, YxxØ, [DE]xxxL[LI], and DxxLL). Future work will be needed to identify the specific coat protein complexes that mediate TSP-12 internalization or targeting to the endocytic compartment.
","references":[{"reference":"Barlowe C. 2003. Signals for COPII-dependent export from the ER: what's the ticket out?. Trends in Cell Biology. 13: 295-300. 6.","pubmedId":"","doi":"https://doi.org/10.1016/S0962-8924(03)00082-5"},{"reference":"Bonifacino JS, Traub LM. 2003. Signals for sorting of transmembrane proteins to endosomes and lysosomes. Annu Rev Biochem. 72: 395-447. 11.","pubmedId":"12651740","doi":"10.1146/annurev.biochem.72.121801.161800"},{"reference":"Dancourt J, Barlowe C. 2010. Protein Sorting Receptors in the Early Secretory Pathway. Annual Review of Biochemistry. 79: 777-802. 3.","pubmedId":"","doi":"https://doi.org/10.1146/annurev-biochem-061608-091319"},{"reference":"Dell, Apos, Angelica EC, Bonifacino JS. 2019. Coatopathies: Genetic Disorders of Protein Coats. Annual Review of Cell and Developmental Biology. 35: 131-168. 5.","pubmedId":"","doi":"https://doi.org/10.1146/annurev-cellbio-100818-125234"},{"reference":"Downes KW, Zanetti G. 2025. Mechanisms of COPII coat assembly and cargo recognition in the secretory pathway. Nature Reviews Molecular Cell Biology. 26: 910-925. 4.","pubmedId":"","doi":"10.1038/s41580-025-00839-y"},{"reference":"Dunn CD, Sulis ML, Ferrando AA, Greenwald I. 2010. A conserved tetraspanin subfamily promotes Notch signaling in Caenorhabditis elegans and in human cells. Proceedings of the National Academy of Sciences. 107: 5907-5912. 13.","pubmedId":"","doi":"doi:10.1073/pnas.1001647107"},{"reference":"Farhan H, Raote I, Campelo F, Ge L, Hirschberg K, Forrester A, et al., Malhotra V. 2025. Towards a unified framework for the function of endoplasmic reticulum exit sites. Nature Reviews Molecular Cell Biology. 26: 957-969. 1.","pubmedId":"","doi":"10.1038/s41580-025-00899-0"},{"reference":"Gomez Navarro N, Miller E. 2016. Protein sorting at the ER–Golgi interface. Journal of Cell Biology. 215: 769-778. 9.","pubmedId":"","doi":"10.1083/jcb.201610031"},{"reference":"Hsu VW, Bai M, Li J. 2012. Getting active: protein sorting in endocytic recycling. Nature Reviews Molecular Cell Biology. 13: 323-328. 10.","pubmedId":"","doi":"10.1038/nrm3332"},{"reference":"Ichikawa K, Shoura MJ, Artiles KL, Jeong DE, Owa C, Kobayashi H, et al., Morishita S. 2025. CGC1, a new reference genome for Caenorhabditis elegans. Genome Res. 35: 1902-1918. 17.","pubmedId":"40664475","doi":"10.1101/gr.280274.124"},{"reference":"Kelly BT, Owen DJ. 2011. Endocytic sorting of transmembrane protein cargo. Current Opinion in Cell Biology. 23: 404-412. 12.","pubmedId":"","doi":"https://doi.org/10.1016/j.ceb.2011.03.004"},{"reference":"Liu Z, Shi H, Nzessi AK, Norris A, Grant BD, Liu J. 2020. Tetraspanins TSP-12 and TSP-14 function redundantly to regulate the trafficking of the type II BMP receptor in Caenorhabditis elegans. Proceedings of the National Academy of Sciences. 117: 2968-2977. 14.","pubmedId":"","doi":"doi:10.1073/pnas.1918807117"},{"reference":"Liu Z, Williams B, Wang L, Clark FK, Vignogna RC, Fromme JC, Liu J. 2026. Tetraspanin TSP-12 and SUP-17/ADAM10 exhibit cell type-specific codependence for trafficking through the Golgi. Proc Natl Acad Sci U S A. 123: e2524916123. 16.","pubmedId":"41481460","doi":"10.1073/pnas.2524916123"},{"reference":"Malhotra V. 2024. Tailored assemblies of COPII proteins in secretion. Journal of Cell Biology. 223 7.","pubmedId":"","doi":"10.1083/jcb.202404013"},{"reference":"Sakaguchi A, Sato M, Sato K, Gengyo Ando K, Yorimitsu T, Nakai J, et al., Sato K. 2015. REI-1 Is a Guanine Nucleotide Exchange Factor Regulating RAB-11 Localization and Function in C. elegans Embryos. Developmental Cell. 35: 211-221. 18.","pubmedId":"","doi":"https://doi.org/10.1016/j.devcel.2015.09.013"},{"reference":"Tu L, Tai WCS, Chen L, Banfield DK. 2008. Signal-Mediated Dynamic Retention of Glycosyltransferases in the Golgi. Science. 321: 404-407. 8.","pubmedId":"","doi":"doi:10.1126/science.1159411"},{"reference":"Wang L, Liu Z, Shi H, Liu J. 2017. Two Paralogous Tetraspanins TSP-12 and TSP-14 Function with the ADAM10 Metalloprotease SUP-17 to Promote BMP Signaling in Caenorhabditis elegans. PLoS Genet. 13: e1006568. 15.","pubmedId":"28068334","doi":"10.1371/journal.pgen.1006568"},{"reference":"Watson ET, Wegeng WR, Aravani S, Ernst AM, Von Blume J. 2025. Mechanistic insights into cargo sorting and export from the Golgi apparatus. Nature Reviews Molecular Cell Biology. 26: 940-956. 2.","pubmedId":"","doi":"10.1038/s41580-025-00907-3"}],"title":"Identification of a potential internalization or endocytic compartment-targeting signal in the C-terminal tail of the tetraspanin protein TSP-12
","reviews":[],"curatorReviews":[{"curator":{"displayName":"KJ Yook"},"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":"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":"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":"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":"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":"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":"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":"c1718787-4a18-436b-b874-d15762e8d032","citedBy":[],"parsedCsv":{"csvHeader":[],"csvData":[]}}}, "staticQueryHashes": ["2114697108"]}