PRJNA471398
Natural genetic variation in a multigenerational phenotype in C. elegans
In this study, we report the surprising finding that several C. elegans wild isolates display a heat-sensitive mortal germline phenotype in laboratory conditions: upon chronic exposure to higher temperatures such as 25°C, lines reproducibly become sterile after several generations. This phenomenon is reversible as it can be suppressed by temperature alternations at each generation, suggesting a non-genetic basis for the sterility. We tested whether natural variation in the temperature-induced Mrt phenotype was of genetic nature by building recombinant inbred lines between the isolates MY10 (Mrt) and JU1395 (non-Mrt). Using bulk segregant analysis, we detected two quantitative trait loci. After further recombinant mapping and genome editing, we identified the major causal locus as a polymorphism in the set-24 gene, encoding a SET- and SPK-domain protein. We conclude that C. elegans natural populations harbor natural genetic variation in epigenetic inheritance phenomena.Details on submitted data:(A) 120 Rils were obtained by crossing two wild isolates of contrasted Mrt phenotype, MY10 and JU1395. The Mrt phenotype was assessed for the 120 RILs in triplicate . The two extremes of the Mrt-value distribution were incorporated in the bulk segregant analysis : non-Mrt pool (21 lines ) and a Mrt pool (22 lines). We whole genome sequenced the two parents and the two bulks.(B) We characterized the small RNA populations along the progressive onset of sterility at 23°C in MY10 (Mrt) and compared them to the JU1395 (non-Mrt) small RNA populations.