Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Living the high life: high-altitude adaptation. | Scheinfeldt and Tishkoff Genome Biology 2010 11 133 http 2010 11 9 133 w Genome Biology RESEARCH HIGHLIGHT L__ Living the high life high-altitude adaptation Laura B Scheinfeldt1 and Sarah A Tishkoff1-2 Abstract Genome-wide scans demonstrate that genetic variants associated with high-altitude adaptation in Tibetans and Andeans arose independently as a result of convergent adaptation. There is widespread interest in the identification of human genes subject to positive selection in part because they may elucidate the biological basis of human adaptation to novel environments and therefore may lead to the identification of genes and variants that play a role in disease susceptibility. To this end a number of computational approaches have been developed to perform scans for positive selection. Unlike demographic processes such as migration population expansion and bottlenecks which affect whole-genome patterns of variation positive selection shapes variation in a locusspecific manner. Furthermore populations in divergent environments with distinct selective pressures may be subject to local adaptation. Genetic variants that are targets of positive selection in locally adapted populations are expected to show higher levels of population differentiation that is differences between populations and in some cases extended regions of allelic association or linkage disequilibrium. Thus genome-wide scans for selection often identify outliers in the empirical distribution of summary statistics that characterize population differentiation linkage disequilibrium or some combination of the two and these outliers are enriched for loci that have been subject to positive selection reviewed in 1 . Physiological adaptations to high-altitude One of the classic examples of adaptation to a novel environment is adaptation to high-altitude. At high-altitude differences in barometric pressure result in insufficient oxygen in the air thereby causing hypoxia
