Data used in this article are available at http://makarich.fbb.msu.ru/indel_polymorphism.
SHORT INDELS ARE SUBJECT TO INSERTION-BIASED GENE CONVERSION
Article first published online: 11 MAY 2013
© 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.
Volume 67, Issue 9, pages 2604–2613, September 2013
How to Cite
Leushkin, E. V. and Bazykin, G. A. (2013), SHORT INDELS ARE SUBJECT TO INSERTION-BIASED GENE CONVERSION. Evolution, 67: 2604–2613. doi: 10.1111/evo.12129
- Issue published online: 3 SEP 2013
- Article first published online: 11 MAY 2013
- Accepted manuscript online: 22 APR 2013 04:55PM EST
- Manuscript Accepted: 5 APR 2013
- Manuscript Received: 31 JAN 2013
- Ministry of Education and Science of the Russian Federation. Grant Numbers: 11.G34.31.0008, 14.512.11.0042, 8814
- Russian Foundation for Basic Research. Grant Number: 12-04-33202
- Gene conversion;
- indel polymorphisms;
- insertions and deletions;
Recombination between homologous loci is accompanied by formation of heteroduplexes. Repairing mismatches in heteroduplexes often leads to single nucleotide substitutions in a process known as gene conversion. Gene conversion was shown to be GC-biased in different organisms; that is, a W(A or T)→S(G or C) substitution is more likely in this process than a S→W substitution. Here, we show that the insertion/deletion ratio for short noncoding indels that reach fixation between species is positively correlated with the recombination rate in Drosophila melanogaster, Homo sapiens, and Saccharomyces cerevisiae. This correlation is both due to an increase of the fixation rate of insertions and decrease of the fixation rate of deletions in regions of high recombination. Whole-genome data on indel polymorphism and divergence in D. melanogaster rule out mutation biases and selection as the cause of this trend, pointing to insertion-biased gene conversion as the most likely explanation. The bias toward insertions is the strongest for single-nucleotide indels, and decreases with indel length. In regions of high recombination rate this bias leads to an up to ∼5-fold excess of fixed short insertions over deletions, and substantially affects the evolution of DNA segments.