Dauer is an important survival strategy for nematodes across free-living and parasitic nematodes. In C. elegans, L1 and L2d larvae are able to integrate surrounding environmental condition and choose to develop into dauer stage in harsh condition, surviving up to several months until they encounter favorable environment. While studies on dauer formation in C. elegans have provided insights in the decision processes prior to dauer commitment, the downstream factors that directly participate directly in dauer development have remained elusive. This is in part due to difficulty in generating dauer stage-specific lethal mutants by random mutagenesis. We have discovered a novel mutant strain that exhibits developmental defect specifically during dauer development and identified its causative nonsense mutation in the
daf-42 gene.
daf-42 mutants develop normally into reproducing adult animals under normal laboratory conditions, but become trapped in their own cuticle and fail to molt into dauer larvae in harsh conditions.
daf-2;
daf-42 double mutant animals started to develop into dead dauer corpses when dauers started to form in
daf-2 mutants, and had the same dauer-commitment timepoint as that of
daf-2 mutant. Analysis of RNA-seq data of larvae in dauer development (Lee et al, 2017) showed that
daf-42 expresses briefly during dauer entry, and we will show its temporal and spatial expression. As
daf-42 is already known to have homologs in other Caenorhabditis species, we seek to elucidate both molecular mechanism of
daf-42 in dauer development and its evolutionary conservation among nematode species. Reference: Lee, J. S., Shih, P. Y., Schaedel, O. N., Quintero-Cadena, P., Rogers, A. K., & Sternberg, P. W. (2017). PNAS, 114(50), E10726-E10735.