tailieunhanh - Báo cáo y học: "Reduced efficacy of selection in regions of the Drosophila genome that lack crossing over"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: Reduced efficacy of selection in regions of the Drosophila genome that lack crossing over. | Open Access Research Reduced efficacy of selection in regions of the Drosophila genome that lack crossing over Penelope R Haddrill Daniel L Halligan Dimitris Tomaras and Brian Charlesworth Addresses institute of Evolutionary Biology School of Biological Sciences University of Edinburgh Edinburgh EH9 3JT UK. 15 Smirnis St 15669 Papagou Athens Greece. Correspondence Penelope R Haddrill. Email Published 6 February 2007 Genome Biology 2007 8 R18 doi gb-2007-8-2-r18 The electronic version of this article is the complete one and can be found online at http 2007 8 2 R18 Received 24 October 2006 Revised 18 December 2006 Accepted 6 February 2007 2007 Haddrill et al. licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background The recombinational environment is predicted to influence patterns of protein sequence evolution through the effects of Hill-Robertson interference among linked sites subject to selection. In freely recombining regions of the genome selection should more effectively incorporate new beneficial mutations and eliminate deleterious ones than in regions with low rates of genetic recombination. Results We examined the effects of recombinational environment on patterns of evolution using a genome-wide comparison of Drosophila melanogaster and D. yakuba. In regions of the genome with no crossing over we find elevated divergence at nonsynonymous sites and in long introns a virtual absence of codon usage bias and an increase in gene length. However we find little evidence for differences in patterns of evolution between regions with high intermediate and low crossover frequencies. In addition genes on the fourth chromosome exhibit more extreme deviations from regions .