Yang, F.-J. et al. (2017) International Worm Meeting "Site-specific single copy insertion of transgenes using phiC31 integrase in C. elegans."

Wang, J., Yang, F.-J., Chang, T.

[International Worm Meeting, 2017]

C. elegans has many tools for genome modification. However, the precise insertion of larger DNA constructs is still relatively laborious and difficult. In hopes of making large integrations at predetermined genomic sites easier, we have adapted the fC31 integrase system for use in C. elegans. We have integrated into the genome a codon-optimized version of fC31 that is expressed in the germline, and we have successfully used this strain to integrate three constructs in proof of principle experiments. In our hands, integration by fC31 appears easier than the selection based MosSCI insertion protocol. The largest construct tested thus far is only ~8 kb, and we are in the process of testing larger ones. Given its relative ease in generating integrants, the fC31 system may offer another useful option for transgene analysis and genome manipulation in C. elegans.

Von Stetina, Stephen E. et al. (2009) International Worm Meeting "Finding Regulators of Cadherin-Independent Epithelialization."

Mango, Susan E., Von Stetina, Stephen E.

[International Worm Meeting, 2009]

How are polarized epithelia established and maintained? This question is of critical importance, as the loss of epithelial polarity is associated with metastasis(1). There are many well-studied protein complexes that lie in specific membrane compartments with roles integral to the epithelial cell. The E-cadherin-containing adherens junction serves to link neighboring epithelial cells together while the more basal tight junction functions to separate the apical and basolateral surfaces. For some cells, E-cadherin is the major initiator of cell polarity and epithelium formation via cell-cell adhesion(2). However, recent studies have discovered E-cadherin independent polarity pathways(3-6). C. elegans offers a powerful system to study this cadherin-independent mechanism, as E-cadherin is dispensible for the initiation of epithelial polarity in nematodes(4). We study cadherin-independent epithelium formation during pharynx development. Nine pharyngeal arcade cells undergo a mesenchymal-to-epithelial transition to link the pharynx to the outer epidermis(7). Ablation of the arcade cells results in a Pharynx unattached (Pun) phenotype, in which the pharynx fails to connect to the epidermis(7). Pun animals die as they are unable to eat. Our lab has undertaken a genetic screen for Pun mutants that fail to form the arcade cell epithelium (Portereiko and Mango, unpublished). This screen revealed that loss of the central-spindlin component ZEN-4/MKLP1 induces a Pun phenotype because the arcade cells fail to polarize(8). We are currently studying where and when ZEN-4 is needed for arcade cell polarization. We have also undertaken a structure/function analysis of this mitotic kinesin in order to elucidate its role in epithelialization. In addition, we are in the process of cloning several mutants that were isolated in the Pun mutagenesis screen. (1). J. M. Lee, S. Dedhar, R. Kalluri, E. W. Thompson, J Cell Biol 172, 973 (Mar 27, 2006). (2). L. N. Nejsum, W. J. Nelson, J Cell Biol 178, 323 (Jul 16, 2007). (3). A. F. Baas et al., Cell 116, 457 (Feb 6, 2004). (4). M. Costa et al., J Cell Biol 141, 297 (Apr 6, 1998). (5). T. J. Harris, M. Peifer, J Cell Biol 167, 135 (Oct 11, 2004). (6). W. B. Raich, C. Agbunag, J. Hardin, Curr Biol 9, 1139 (Oct 21, 1999). (7). M. F. Portereiko, S. E. Mango, Dev Biol 233, 482 (May 15, 2001). (8). M. F. Portereiko, J. Saam, S. E. Mango, Curr Biol 14, 932 (Jun 8, 2004).

Katja Ziegler et al. (2007) International Worm Meeting "A Sodium:Neurotransmitter symporter Family protein required for the induction of antimicrobial peptides in C.elegans."

Jonathan Ewbank, Nathalie Pujol, Katja Ziegler

[International Worm Meeting, 2007]

C. elegans responds to infection with the nematophagous fungus Drechmeria coniospora by up-regulating the expression of antimicrobial peptides including certain NLPs (neuropeptide-like proteins) and CNCs (Caenorhabditis bacteriocins) (1). We have generated a reporter strain containing the promoter of the antimicrobial peptide gene, nlp-29, fused to gfp. This results in a strain in which green fluorescence is highly induced after infection with D. coniospora. Coupled with the Union Biometrica BioSort, this provides us with a valuable tool to study infection-dependent induction in a qualitative and quantitative fashion. Using this strain and a direct visual screen following EMS mutagenesis, we identified 5 Nipi (no induction of peptide after Drechmeria infection) mutants (see abstracts by Pujol et al., Zugasti et al.). This study describes the isolation, characterization and SNP mapping of nipi-2. The mutant was found to carry a mutation in a conserved residue of a member of the sodium-dependent neurotransmitter transporter family in C. elegans. We are currently further characterizing this SNF protein and investigating its role in the induction of nlp-29 that follows infection. Progress will be reported at the meeting. 1.Couillault, C., Pujol, N., Reboul, J., Sabatier, L., Guichou, J. F., Kohara, Y. & Ewbank, J. J. (2004) Nat Immunol 5, 488-494. .

Jun-ichi Aikawa (2001) International C. elegans Meeting "Molecular characterization of heparan sulfate/heparin N-deacetylase/N-sulfotransferase in worms"

Jun-ichi Aikawa

[International C. elegans Meeting, 2001]

Heparan sulfate binds and activates a large variety of growth factors, enzymes and extracellular matrix proteins. These interactions largely depend on the specific arrangement of sulfated moieties and uronic acid epimers within the chains. These oligosaccharide sequences are generated in a step-wise manner, initiated by the formation of a linkage tetrasaccharide which is then extended by copolymerization of alternating a1,4GlcNAc and b1,4GlcA residues. As the chains polymerize, they undergo a series of sulfation and epimerization reactions. The first set of modifications involves the removal of acetyl units from subsets of GlcNAc residues, and the addition of sulfate groups to the resulting free amino groups. These reactions are catalyzed by a family of enzymes designated as GlcNAc N-deacetylase/N-sulfotransferases (NDST), since they simultaneously. Four members of the family have been identified in vertebrates, with single orthologs present in Drosophila and C. elegans. We have revealed tissue-specific expression pattern and unique enzymatic properties of these four isozymes1,2). In fly, loss of NDST (sulfateless) results in unsulfated chains and defective signaling by multiple growth factors and morphogens. I reconstituted cDNA for worm NDST from EST clones and 5' RACE products. Enzymatic activities will be discussed. 1) Aikawa, J. & Esko, J. D J. Biol. Chem. 274, 2690-2695 (1999) 2) Aikawa, J., Grobe, K., Tsujimoto, M. & Esko, J. D J. Biol. Chem. 276, 5876-5882 (2001)

Wei-meng Woo et al. (2004) West Coast Worm Meeting "The extracellular matrix protein F-spondin is essential for muscle attachment and epidermal elongation"

Chris Suh, Yishi Jin, Andrew D Chisholm, Mei Ding, Christie Emigh, Wei-Meng Woo, Jian Cao

[West Coast Worm Meeting, 2004]

In C. elegans epidermal intermediate filaments (IFs) and their associated structures, the trans-epidermal attachments, are essential for embryonic epidermal elongation (Woo et al 2004). The formation of muscle contractile units and trans-epidermal attachments are mutually dependent during epidermal elongation. To understand how the connection between epidermis and muscle is established and how the two tissues communicate during organogenesis, we performed a screen for epidermal elongation-defective mutants. One locus identified in this screen was defined by three lethal alleles and mapped to the cluster of LG II. Subsequent analysis showed that these mutations were allelic to vab-13 and ven-3 . By genetic mapping and allele sequencing we showed that all these mutations affect F10E7.4, which encodes the C. elegans member of the F-spondin family of secreted proteins. F-spondin has been shown to play roles in axon guidance, cell migration, and angiogenesis. Our genetic analysis shows that in C. elegans F-spondin is required for epidermal elongation and muscle attachment, as well as for proper positioning of neuronal processes. Using GFP reporters, we found that F-spondin is expressed in body muscle cells and is a secreted protein. Thus, F-spondin may function in embryogenesis in communication between muscle and epidermis. Immunostaining of F-spondin mutants suggest that F-spondin may indirectly affect the organization of epidermal actin microfilaments and trans-epidermal attachments . We are examining the expression patterns of muscle and basement membrane components in F-spondin mutants. To study the signaling pathways regulated by F-spondin, we are testing mutations in candidate receptor genes for genetic interactions with F-spondin mutations.

Bonnie Kaas et al. (2008) C.elegans Neuronal Development Meeting "Regulation of Levels of UNC-13 at Synapses"

Rebecca Lawson, Rebecca Kohn, Thomas Limouze, Ryan Wennell, Bonnie Kaas

[C.elegans Neuronal Development Meeting, 2008]

Release of neurotransmitters from neurons is highly regulated. Several proteins play roles in this process, including UNC-13, and decreased release of neurotransmitters in unc-13 mutants results in paralysis. We identified an F-box protein that interacts with UNC-13. F-box proteins participate in ubiquitin ligase complexes and in Drosophila, DUNC-13 is degraded via the ubiquitin proteasome pathway. This UNC-13/F-box interaction may therefore indicate that UNC-13 is tagged for proteasomal degradation with ubiquitin by the ligase complex in C. elegans. The C. elegans knockout consortium isolated a strain with a large deletion in the coding region of the gene that codes for the F-box protein. If the F-box protein is indeed involved in the degradation of UNC-13, this strain would be expected to have higher levels of UNC-13, which could result in changes in phenotypes. We characterized the F-box deletion mutant by assaying brood size, developmental rate, and body bends per minute. Aldicarb assays were used to determine whether a deletion in the gene coding for the F-box protein alters the response to inhibitors of acetylcholinesterase. We found that the deletion resulted in some changes in developmental rate and in aldicarb sensitivity. We are continuing to study strains with mutations in both the gene coding for the F-box protein and in unc-13.

Henderson ST et al. (1997) International C. elegans Meeting "REGULATION OF CELL FATE BY LAG-2 AND OTHER DSL PROTEINS"

Crittenden SL, Kimble JE, Henderson ST, Gao DL

[International C. elegans Meeting, 1997]

DSL (for DELTA, SERRATE, LAG-2) ligands act with LNG (for LIN-12, NOTCH, GLP-1) receptors to regulate cell fates in many organisms. To understand how DSL proteins shape metazoan development, we have investigated control by LAG-2 as well as two new DSL proteins. LAG-2, a predicted transmembrane protein, acts in many cell fate decisions (1,2,3). A systematic study of LAG-2 functional domains lead to four new conclusions. First, the non-conserved N-terminal region is critical for LAG-2 activity. Second, EGF-like repeats are not essential. Third, membrane association is required for rescue, but not signaling. Curiously, fusion to GFP can confer rescuing activity upon secreted LAG-2 forms, suggesting that GFP fusion proteins, when secreted, may stick in the membrane or aggregate outside the cell. Fourth, the intracellular domain normally lowers activity: LAG-2 mutants lacking this domain are hyperactive. In addition, a secreted LAG-2 placed under control of the ges-1 intestinal promoter can induce germline tumors, but membrane bound LAG-2 under the same control cannot. Therefore, the secreted form appears to retain activity across two basement membranes. How does LAG-2 control germline mitosis? One idea is that the length of distal tip cell processes may determine the extent of LAG-2 signaling (4). However, we have not been able to confirm this idea. We propose that the LAG-2 DTC signal is not limited to areas of cell-cell contact. Instead, we suggest that the signal is propagated in the germline by downstream factors. The sequencing project has identified two other genes that have the potential to encode DSL proteins, one on cosmid F15B9 and another on F58B3. We have constructed reporter constructs and begun antisense injections of both. Results on expression patterns of these DSL homologs and their antisense phenotypes will be reported. (1) Lambie, E. J., and Kimble, J. (1991). Development 112, 231-240. (2) Henderson, S. T., Gao, D., Lambie, E. J., and Kimble, J. (1994). Development 120, 2913-2924. (3) Tax, F. E., Yeargers, J. J., and Thomas, J. H. (1994). Nature 368, 150-154. (4) Fitzgerald, K., and Greenwald, I. (1995). Development 121, 275-4282.

Schroeder, Frank et al. (2021) International Worm Meeting "Carboxyesterases and intestinal granules in the biosynthesis of novel families of nematode small molecule signals"

Wrobel, Chester, Schroeder, Frank, Sternberg, Paul, Cohen, Sarah

[International Worm Meeting, 2021]

Signaling molecules derived from attachment of diverse primary metabolic building blocks to ascarosides play a central role in the life history of C. elegans and other nematodes; however, the extent to which various inter- and intra-organismal signaling pathways are controlled by small molecules is unclear. Using comparative metabolomics, we show that a pathway mediating formation of intestinal lysosome-related organelles (LROs) is required for biosynthesis of a large library of small molecules, including most modular ascarosides as well as previously undescribed modular glucosides (1). Similar to modular ascarosides, the modular glucosides are derived from highly selective assembly of moieties from nucleoside, amino acid, neurotransmitter, and lipid metabolism. We further show that a family of carboxylesterases (CEST's) that localize to intestinal organelles are required for the assembly of both modular ascarosides and glucosides, suggesting that modular glucosides, like the ascarosides, serve signaling functions. For example, biosynthesis of some modular glucosides is starkly upregulated in long-lived daf-2 mutants, suggesting that insulin signaling is modulated by small molecules produced in a lysosome-dependent manner. Parallel studies in C. briggsae and other nematode species indicate that assembly of modular metabolites via CEST enzymes is widely conserved in nematodes. Further exploration of LRO function and cest homologs in C. elegans and other animals may reveal additional new compound families and signaling paradigms. (1) H. H. Le, C. J. J. Wrobel, S. M. Cohen, J. Yu, H. Park, M. J. Helf, B. J. Curtis, P. R. Rodrigues, P. W. Sternberg, F. C. Schroeder. Modular metabolite assembly in C. elegans depends on carboxylesterases and formation of lysosome-related organelles. eLife, 9, e61886, 2020.

J Grabitzki et al. (2004) European Worm Meeting "THE PCOME OF CAENORHABDITIS ELEGANS IDENTIFICATION OF PHOSPHORYLCHOLINE-SUBSTITUTED PROTEINS AND COMPARISON OF DEVELOPMENTAL CHANGES IN THE EXPRESSION OF THIS EPITOPE"

R Geyer, G Lochnit, J Grabitzki

[European Worm Meeting, 2004]

Caenorhabditis elegans has been found to be good model system for parasitic nematodes, drug screening and developmental studies. Like the respective parasitic worms, C. elegans expresses glycosphingolipids and glycoproteins, carrying, in part, phosphorylcholine (PC) substitutents, which might play important roles in nematode development, fertility and, at least in the case of parasites, the survival within the host (1). With the exception of a major secretory/ excretory product from Achanthocheilonema viteae (ES-62) (2) and the aspartyl-protease ASP-6 (3), no other proteins carrying this epitope has been identified and studied in detail yet. For C. elegans two N-linked PC-epitopes have been reported so far: (I) a pentamannosyl-core structure carrying three PC-residues (4) and (II) a trimannosyl-core species elongated by a N-acetylglucosamine substituted at C-6 with PC (5). Furthermore, in Dauer larvae of C. elegans there was evidence for the presence of glycans with the composition PC1Hex3HexNAc3 to PC2dHex2Hex4HexNAc7 (6). Here we present the 2D-electrophoretic separation of C. elegans proteins, the comparison of the PC-substitution pattern in distinct developmental stages and the mass spectrometric identification of PC-modified proteins. References: 1.Lochnit, G., Dennis, R. D., and Geyer, R. (2000) Biol Chem 381, 839-847 2.Harnett, W., Harnett, M. M., and Byron, O. (2003) Curr Protein Pept Sci 4, 59-71 3.Lochnit, G., Grabitzki, J., Henkel, B., and Geyer, R. (2003) Biochemical Journal submitted 4.Cipollo, J. F., Costello, C. E., and Hirschberg, C. B. (2002) J Biol Chem 277, 49143-49157 5.Haslam, S. M., Gems, D., Morris, H. R., and Dell, A. (2002) Biochem. Soc. Symp. 69, 117-134 6.Cipollo, J. F., Awad, A., Costello, C. E., Robbins, P. W., and Hirschberg, C. B. (2004) Proc Natl Acad Sci U S A 101, 3404-3408

Husson, Steven J. et al. (2011) International Worm Meeting "C. elegans mutants defective in neuropeptide amidation enzymes are abnormal in egg-laying behavior."

Landuyt, Bart, Schoofs, Liliane, Gottschalk, Alexander, Horvitz, H.Robert, Temmerman, Liesbet, Husson, Steven J., Ringstad, Niels, Meelkop, Ellen

[International Worm Meeting, 2011]

Egg laying has mainly been studied at the behavioral, neuronal and neurochemical levels, but little is known about the biochemical control of the relevant neuropeptidergic signaling systems. Biosynthesis of endogenous peptides requires processing enzymes, such as proprotein convertase 2, which is encoded by egl-3 (1, 2), and a carboxypeptidase encoded by egl-21 (3, 4). Mutants defective in these genes have egg-laying defects, consistent with the finding that FMRFamide-like peptides (FLPs) have been linked to egg laying behavior. C. elegans enzymes that carry out the last step in the production of biologically active peptides, the carboxy-terminal amidation reaction, have not been characterized. This multistep reaction involves hydroxylation of the glycine a-carbon by a peptidyl-a-hydroxylating monooxygenase (PHM), followed by a cleavage reaction performed by peptidyl a-hydroxyglycine a-amidating lyase (PAL) to generate a glyoxylate molecule and the a-amidated peptide. In vertebrates, both enzymatic activities responsible for the carboxyterminal amidation reaction are contained in one bifunctional enzyme, peptidylglycine a-amidating monooxygenase (PAM). By contrast, invertebrates generally express two separate enzymes encoded by two different genes. Here we report the identification and characterization of C. elegans amidating enzymes using bioinformatics to identify candidate genes and mass spectrometry to compare the neuropeptides in wild-type and newly generated mutants. Mutants lacking a functional PHM displayed an altered neuropeptide profile, showed impaired egg laying behavior and had a decreased brood size. Interestingly, PHM mutants still displayed fully processed amidated neuropeptides, probably as a result of the presence of a bifunctional PAM, the main amidating enzyme in vertebrates. Our data indicate the existence of a robust complementation system for the amidation reaction of neuropeptides in nematodes and suggest the involvement of amidated neuropeptides in egg laying. (1) S. J. Husson et al., J. Neurochem. 98, 1999 (2006); (2) J. Kass et al., J. Neurosci. 21, 9265 (2001); (3) S. J. Husson et al., J. Neurochem. 102, 246 (2007); (4) T. C. Jacob, J. M. Kaplan, J. Neurosci. 23, 2122 (2003).