Title: Selfing is the safest sex for Caenorhabditis tropicalis.

Authors: Noble, Luke M; Yuen, John; Stevens, Lewis; Moya, Nicolas; Persaud, Riaad; Moscatelli, Marc; Jackson, Jacqueline L; Zhang, Gaotian; Chitrakar, Rojin; Baugh, L Ryan; Braendle, Christian; Andersen, Erik C; Seidel, Hannah S; Rockman, Matthew V

Published In Elife, (2021 Jan 11)

Abstract: Mating systems have profound effects on genetic diversity and compatibility. The convergent evolution of self-fertilization in three Caenorhabditis species provides a powerful lens to examine causes and consequences of mating system transitions. Among the selfers, Caenorhabditis tropicalis is the least genetically diverse and most afflicted by outbreeding depression. We generated a chromosomal-scale genome for C. tropicalis and surveyed global diversity. Population structure is very strong, and islands of extreme divergence punctuate a genomic background that is highly homogeneous around the globe. Outbreeding depression in the laboratory is caused largely by multiple Medea-like elements, genetically consistent with maternal toxin/zygotic antidote systems. Loci with Medea activity harbor novel and duplicated genes, and their activity is modified by mito-nuclear background. Segregating Medea elements dramatically reduce fitness, and simulations show that selfing limits their spread. Frequent selfing in C. tropicalis may therefore be a strategy to avoid Medea-mediated outbreeding depression.

PubMed ID: 33427200

MeSH Terms: No MeSH terms associated with this publication