Selfing is the safest sex for Caenorhabditis tropicalis.

Journal Article (Journal Article)

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.

Full Text

Duke Authors

Cited Authors

  • Noble, LM; Yuen, J; Stevens, L; Moya, N; Persaud, R; Moscatelli, M; Jackson, JL; Zhang, G; Chitrakar, R; Baugh, LR; Braendle, C; Andersen, EC; Seidel, HS; Rockman, MV

Published Date

  • January 2021

Published In

Volume / Issue

  • 10 /

Start / End Page

  • e62587 -

PubMed ID

  • 33427200

Pubmed Central ID

  • PMC7853720

Electronic International Standard Serial Number (EISSN)

  • 2050-084X

International Standard Serial Number (ISSN)

  • 2050-084X

Digital Object Identifier (DOI)

  • 10.7554/elife.62587


  • eng