In a screen for C. elegans strains with enhanced susceptibility to pathogen (Esp) we have isolated an Esp mutant,
aj17, which responds differently to infection by various pathogens. When exposed to the Gram negative bacterium Pseudomonas aeruginosa,
aj17 dies more rapidly than wild type worms. In contrast
aj17 dies with the same kinetics as wild type when infected with the Gram positive bacterium Enterococcus faecalis. When exposed to P. aeuruginosa,
aj17 worms are more rapidly colonized than their wild type counterparts. This increased rate of colonization may explain their faster death kinetics on the pathogen. In addition to its sensitivity to P. aeruginosa,
aj17 exhibits several other phenotypes including a smaller body length, reduced brood size, and a semi-penetrant roller phenotype when grown at 25C. Using these visual phenotypes, we SNP mapped
aj17 to the gene
dpy-8.
aj17 failed to complement
dpy-8 (
e130) for body size and sequencing of
dpy-8 in
aj17 revealed a single nucleotide transition resulting in the introduction of a stop codon approximately a third of the way thru the protein. Thus
aj17 is likely to be a null allele of
dpy-8. Sequence homology, the pre-molt spikes in expression and the general morphology of
dpy-8 mutants all indicate that DPY-8 is a cuticle collagen.[1] We have generated an antibody to DPY-8 and will determine if the protein is limited to the cuticle or if it also localizes to other places. We will address how DPY-8 as a cuticle collagen can differently affect the worms response to pathogen. 1.McMahon, L., et al., Two sets of interacting collagens form functionally distinct substructures within a Caenorhabditis elegans extracellular matrix. Mol Biol Cell, 2003. 14(4): p. 1366-78.