tailieunhanh - Báo cáo sinh học: " Detecting selection-induced departures from Hardy-Weinberg proportions"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học quốc tế đề tài: Detecting selection-induced departures from Hardy-Weinberg proportions | Genetics Selection Evolution BioMed Central Research Detecting selection-induced departures from Hardy-Weinberg proportions Joseph Lachance Address Graduate Program in Genetics Department of Ecology and Evolution State University of New York at Stony Brook Stony Brook NY 11794-5222 USA Email Joseph Lachance - Open Access Published 21 January 2009 Received 16 January 2009 Genetics Selection Evolution 2009 41 15 doi l297-9686-4l-l5 Accepted 21 January 2009 This article is available from http content 4l l l5 2009 Lachance 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 Viability selection influences the genotypic contexts of alleles and leads to quantifiable departures from Hardy-Weinberg proportions. One measure of these departures is Wright s inbreeding coefficient F where observed heterozygosity is compared with expected heterozygosity. Here I extend population genetics theory to describe post-selection genotype frequencies in terms of post-selection allele frequencies and fitness dominance. The resulting equations correspond to non-equilibrium populations allowing the following questions to be addressed When selection is present how large a sample size is needed to detect significant departures from Hardy-Weinberg How do selection-induced departures from Hardy-Weinberg vary with allele frequencies and levels of fitness dominance For realistic selection coefficients large sample sizes are required and departures from Hardy-Weinberg proportions are small. Introduction Natural selection modifies the probabilities that alleles are found in either homozygous or heterozygous form. Given .