Natural variation in theirldgene family affects starvation resistance inC. elegans

Abstract

Starvation resistance is a fundamental, disease-relevant trait, but the genetic basis of its natural variation is unknown. We developed a synthetic population-sequencing approach to measure starvation resistance for many wild C. elegans strains simultaneously. We identified three quantitative trait loci with variants in 16 insulin/EGF receptor-like domain (irld) family members. We show that four irld genes affect starvation resistance by regulating insulin/IGF signaling. We propose that IRLD proteins bind insulin-like peptides to modify signaling in the sensory nervous system thereby affecting organismal physiology. This work demonstrates efficacy of using population sequencing to dissect a complex trait, identifies irld genes that regulate insulin/IGF signaling, and shows that an expanded gene family modifies a deeply conserved signaling pathway to affect a fitness-proximal trait.

High-throughput phenotyping of infection by diverse microsporidia species reveals a wildC. elegansstrain with opposing resistance and susceptibility traits

“…Although studying phenotypic variation in wild isolates is a powerful approach, measuring each strain individually is time-consuming and laborious. To circumvent this issue, strategies have been developed to perform multiplex competitive fitness assays under selective conditions such as starvation stress or different bacterial diets [38][39][40]. Several approaches, termed either PhenoMIP or MIP-seq, determine the identity of these individual strains by using molecular inversion probes (MIPs) to enrich for their unique genomic signatures [39,40].…”