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, C. 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.
| Original language | English (US) |
|---|---|
| Article number | e62587 |
| Pages (from-to) | 1-64 |
| Number of pages | 64 |
| Journal | eLife |
| Volume | 10 |
| DOIs | |
| State | Published - 2021 |
Funding
1272 We thank Arielle Martel, Jia Shen, and Patrick Ammerman for assistance in the lab, and the Félix, 1273 Teotónio, and Rockman labs for discussion. We are grateful to Marie-Anne Félix for the use of the JU 1274 strains, for stimulating discussions with her and Henrique Teotónio, and for helpful comments on the 1275 preprint from Asher Cutter. This work was supported by R01GM121828 (MVR), R01GM089972 (MVR), 1276 R01ES029930 (ECA and MVR), Dean’s Undergraduate Research Fund grants (JY), the Centre 1277 National de la Recherche Scientifique (CNRS; CB), and the European Commission Marie Skłodowska-1278 Curie Fellowship H2020-MSCA-IF-2017-798083 (LMN). C. tropicalis strain QG843 was collected under 1279 permit SEX/A-25-12 from the Republic of Panama. Sequencing data were generated by the Duke 1280 University Center for Genomic and Computational Biology and the New York University Center for 1281 Genomics and Systems Biology Core Facility, and this work was supported in part through the NYU IT 1282 High Performance Computing resources, services, and staff expertise. 1283 We thank Arielle Martel, Jia Shen, and Patrick Ammerman for assistance in the lab, and the F?lix, Teot?nio, and Rockman labs for discussion. We are grateful to Marie-Anne F?lix for the use of the JU strains, for stimulating discussions with her and Henrique Teot?nio, and for helpful comments on the preprint from Asher Cutter. This work was supported by R01GM121828 (MVR), R01GM089972 (MVR), R01ES029930 (ECA and MVR), Dean?s Undergraduate Research Fund grants (JY), the Centre National de la Recherche Scientifique (CNRS; CB), and the European Commission Marie Sk?odowska- Curie Fellowship H2020-MSCA-IF-2017-798083 (LMN). C. tropicalis strain QG843 was collected under permit SEX/A-25-12 from the Republic of Panama. Sequencing data were generated by the Duke University Center for Genomic and Computational Biology and the New York University Center for Genomics and Systems Biology Core Facility, and this work was supported in part through the NYU IT High Performance Computing resources, services, and staff expertise.
ASJC Scopus subject areas
- General Immunology and Microbiology
- General Biochemistry, Genetics and Molecular Biology
- General Neuroscience