Crossing-over in a hypervariable species preferentially occurs in regions of high local similarity.
Bottom Line: Furthermore, CO events preferentially occurred in regions under stronger negative selection, in particular within exons that showed reduced levels of nucleotide diversity.Apparently, in hypervariable species CO must avoid regions of higher divergence between the recombining genomes due to limitations imposed by the mismatch repair system, with regions under strong negative selection providing the opportunity for recombination.These patterns are opposite to those observed in a number of less variable species indicating that population genomics of hypervariable species may reveal novel biological phenomena.
Affiliation: School of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia Institute of Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia firstname.lastname@example.org.Show MeSH
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Mentions: In both the US and the Russian populations, LD between pairs of SNPs at opposite sides of a CO is markedly reduced (fig. 7). Indeed, LD for close SNPs not separated by CO is high, and disappears only when the distance between such SNPs exceeds ≈1,000 nt. By contrast, LD is low even for very close SNPs separated by a CO. This effect indicates that recombination is frequent between most SNPs associated with COs and, thus, that COs mostly occurred at recombination hotspots. Higher LD in the Russian population, together with its lower nucleotide diversity, indicates that this population has a lower population effective size than the US population, consistent with earlier estimates of global population structure and diversity (James et al. 2001).Fig. 7.
Affiliation: School of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia Institute of Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia email@example.com.