Theresa Moser et al. (2005) International Worm Meeting "Analysis of different forms of UNC-13 proteins in the Caenorhabditis elegans nervous system"

Bethany Stitt, Lydia Sanchez, Chanelle Houston, Cristina Polinsky, Erika Darrah, Graciela Gallo, Monique Spencer, Nancy Fernandez, Dana Francis, Theresa Moser

[International Worm Meeting, 2005]

We are studying the expression and function of unc-13 protein products in the Caenorhabditis elegans nervous system. The predominant protein expressed from unc-13 interacts with syntaxin and affects SNARE complex formation. This form of UNC-13 localizes to presynaptic plasma membranes and is important in priming synaptic vesicles (Richmond, 2001). Expression and function of other UNC-13 protein products are not completely characterized. We are analyzing regions of unc-13 for internal promoters regulating expression of shorter UNC-13 protein products. We fused regions of unc-13 including possible promoters to GFP and injected constructs into C. elegans. Progeny were analyzed for GFP expression. A construct incorporating 2.5kb of a 7.5kb intron did not express GFP. A construct including a larger region of this intron and a construct including a different intron are being tested for promoter activity. To identify additional proteins that interact with UNC-13, we used a yeast two-hybrid screen and analyzed a suppressor mutant. The yeast two-hybrid screen identified three candidates for proteins interacting with the predominant form of UNC-13. Five candidates for proteins interacting with a short form of UNC-13 were found. Eight candidates for proteins that may interact with all forms of UNC-13 were identified. A mutation that partially suppresses paralysis in an unc-13 missense mutant was analyzed. Genetic crosses showed that the suppressor is recessive and unlinked to unc-13. The mutation also suppresses an unc-13 allele that does not express the predominant unc-13 protein product. We are mapping the suppressor gene using snip-SNP mapping.

Taylor, Remington et al. (2021) International Worm Meeting "Snip-SNP mapping of a trembler C. elegans mutant strain with undergraduate students"

Pham, Kelvin, Henderson, Jacklyn, Soebianto, Sarita, Mathai, Kristina, Taylor, Remington, Nguyen, Gina, LaForce, Michael, Simmons, Dr. Alexandra

[International Worm Meeting, 2021]

Caenorhabditis elegans is a valued model organism that is easy to maintain in the lab. We obtained a mutant strain of C. elegans that exhibits constant involuntary muscle spasms, a phenotype that has not been described before in the literature (MCW230, curtesy of Dr Wang, BCM, Houston, TX). The 'trembler' mutant strain has a nre-1(hd20) lin-15b(hd126) genetic background. We use snip-SNP mapping to seek the causal mutant gene responsible for the trembling phenotype in the MCW230 strain. MCW230 worms were backcrossed with wild-type N2 worms to eliminate the double mutant background (nre-1, lin-15b). For snip-SNP gross mapping, we crossed our mutant with CB4856 worms. DNA was extracted from 43 F2 individuals resulting from the MCW230 x CB4856 cross. The F2 samples were studied to identify the presence of specific single nucleotide polymorphisms at 18 genomic locations (3 per chromosome) and assess how the alleles segregate relative to the trembler phenotype. We completed genotyping at all genomic locations and our data supports the idea that the trembler phenotype seems to be linked to one of the markers on chromosome III. Our work is an example of how research using C. elegans can be done in the undergraduate environment with basic laboratory equipment.

G Lochnit et al. (2004) European Worm Meeting "FIRST IDENTIFICATION OF A PHOSPHORYLCHOLINE-SUBSTITUTED PROTEIN FROM CAENORHABDITIS ELEGANS ISOLATION AND CHARACTERIZATION OF THE ASPARTYL PROTEASE ASP-6."

R Geyer, G Lochnit, B Henkel, J Grabitzki

[European Worm Meeting, 2004]

Caenorhabditis elegans has been found to be a good model system for parasitic nematodes, drug screening and developmental studies. Structural analyses have revealed nematode specific glycosphingolipid structures of the arthro-series, carrying, in part, phosphorylcholine (PC) substituents. PC is a widespread antigenic epitope of pathogens like parasitic nematodes and has also been detected on N-glycans of this model organism (1, 2). The PC modification seems to play an important role in nematodes development, fertility and survival within the host. With the exception of ES-62 from Achanthocheilonema viteae no protein carrying this epitope has been yet identified and further characterized (3). In the axenic medium of C. elegans culture we detected a single protein with an apparent molecular mass of 40 kDa which reacted with the PC-specific antibody TEPC-15. The protein was purified by anion-exchange chromatography and 2D-gel electrophoresis. After in-gel digestion with trypsin, the protein was identified by MALDI-TOF-MS peptide finger print and nanoLC-ESI-MS/MS microsequencing as the aspartyl protease ASP-6. RNAi experiments confirmed is assignment. Lectin analysis of the purified ASP-6 protein revealed the presence of the GlcNAc-residues by binding of WGA, whereas Con A showed no binding, indicating the absence of terminal mannosyl residues. Treatment of the protein with PNGase A and PNGase F abolished the binding of WGA, but not that of TEPC-15. This might be an indication for a PC-epitope distinct from those described so far. References: 1. Lochnit, G. et al. (2000) Biol. Chem. 381: 839-47 2. Houston, K., et al. (2002) Mol. Biochem. Parasitol. 123: 55-66 3. Harnett, W., et al. (2003) Curr.Protein Pept. Sci. 4: 59-71