absence of the tap2 human recombination hotspot in chimpanzees缺席tap2人类重组热点的黑猩猩.pdfVIP

PLoS BIOLOGY Absence of the TAP2 Human Recombination Hotspot in Chimpanzees 1[ 1¤1[ 2 1¤2 ¨ ¨ 1 1¤3* Susan E. Ptak , Amy D. Roeder , Matthew Stephens , Yoav Gilad , Svante Paabo , Molly Przeworski 1 Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, 2 Department of Statistics, University of Washington, Seattle, Washington, United States of America Recent experiments using sperm typing have demonstrated that, in several regions of the human genome, recombination does not occur uniformly but instead is concentrated in ‘‘hotspots’’ of 1–2 kb. Moreover, the crossover asymmetry observed in a subset of these has led to the suggestion that hotspots may be short-lived on an evolutionary time scale. To test this possibility, we focused on a region known to contain a recombination hotspot in humans, TAP2, and asked whether chimpanzees, the closest living evolutionary relatives of humans, harbor a hotspot in a similar location. Specifically, we used a new statistical approach to estimate recombination rate variation from patterns of linkage disequilibrium in a sample of 24 western chimpanzees (Pan troglodytes verus). This method has been shown to produce reliable results on simulated data and on human data from the TAP2 region. Strikingly, however, it finds very little support for recombination rate variation at TAP2 in the western chimpanzee data. Moreover, simulations suggest that there should be stronger support if there were a hotspot similar to the one characterized in humans. Thus, it appears that the human TAP2 recombination hotspot is not shared by western chimpanzees. These findings demonstrate that fine-scale recombination rates