RT Journal Article
SR Electronic
T1 Non-paradoxical evolutionary stability of the recombination initiation landscape in Saccharomycetes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 023176
DO 10.1101/023176
A1 Isabel Lam
A1 Scott Keeney
YR 2015
UL http://biorxiv.org/content/early/2015/07/23/023176.abstract
AB The nonrandom distribution of meiotic recombination shapes heredity and genetic diversification. A widely held view is that individual hotspots — favored sites of recombination initiation — are always ephemeral because they evolve rapidly toward extinction. An alternative view, often ignored or dismissed as implausible, predicts conservation of the positions of hotspots if they are chromosomal features under selective constraint, such as gene promoters. Here we empirically test opposite predictions of these theories by comparing genome-wide maps of meiotic recombination initiation from widely divergent species in the Saccharomyces clade. We find that the frequent overlap of hotspots with promoters is true of the species tested and, consequently, hotspot positions are well conserved. Remarkably, however, the relative strength of individual hotspots is also highly conserved, as are larger-scale features of the distribution of recombination initiation. This stability, not predicted by prior models, suggests that the particular shape of the yeast recombination landscape is adaptive, and helps in understanding evolutionary dynamics of recombination in other species.