Pervasive gene conversion in chromosomal inversion heterozygotes.
Journal Article (Journal Article)
Chromosomal inversions shape recombination landscapes, and species differing by inversions may exhibit reduced gene flow in these regions of the genome. Though single crossovers within inversions are not usually recovered from inversion heterozygotes, the recombination barrier imposed by inversions is nuanced by noncrossover gene conversion. Here, we provide a genomewide empirical analysis of gene conversion rates both within species and in species hybrids. We estimate that gene conversion occurs at a rate of 1 × 10-5 to 2.5 × 10-5 converted sites per bp per generation in experimental crosses within Drosophila pseudoobscura and between D. pseudoobscura and its naturally hybridizing sister species D. persimilis. This analysis is the first direct empirical assessment of gene conversion rates within inversions of a species hybrid. Our data show that gene conversion rates in interspecies hybrids are at least as high as within-species estimates of gene conversion rates, and gene conversion occurs regularly within and around inverted regions of species hybrids, even near inversion breakpoints. We also found that several gene conversion events appeared to be mitotic rather than meiotic in origin. Finally, we observed that gene conversion rates are higher in regions of lower local sequence divergence, yet our observed gene conversion rates in more divergent inverted regions were at least as high as in less divergent collinear regions. Given our observed high rates of gene conversion despite the sequence differentiation between species, especially in inverted regions, gene conversion has the potential to reduce the efficacy of inversions as barriers to recombination over evolutionary time.
Full Text
Duke Authors
Cited Authors
- Korunes, KL; Noor, MAF
Published Date
- March 2019
Published In
Volume / Issue
- 28 / 6
Start / End Page
- 1302 - 1315
PubMed ID
- 30387889
Pubmed Central ID
- PMC6475484
Electronic International Standard Serial Number (EISSN)
- 1365-294X
International Standard Serial Number (ISSN)
- 0962-1083
Digital Object Identifier (DOI)
- 10.1111/mec.14921
Language
- eng