The Population Genetics of dN/dS Export

@article{citeulike:3782992, abstract = {Evolutionary pressures on proteins are often quantified by the ratio of substitution rates at non-synonymous and synonymous sites. The dN/dS ratio was originally developed for application to distantly diverged sequences, the differences among which represent substitutions that have fixed along independent lineages. Nevertheless, the dN/dS measure is often applied to sequences sampled from a single population, the differences among which represent segregating polymorphisms. Here, we study the expected dN/dS ratio for samples drawn from a single population under selection, and we find that in this context, dN/dS is relatively insensitive to the selection coefficient. Moreover, the hallmark signature of positive selection over divergent lineages, dN/dS>1, is violated within a population. For population samples, the relationship between selection and dN/dS does not follow a monotonic function, and so it may be impossible to infer selection pressures from dN/dS. These results have significant implications for the interpretation of dN/dS measurements among population-genetic samples.}, author = {Kryazhimskiy, Sergey and Plotkin, Joshua B.}, citeulike-article-id = {3782992}, citeulike-linkout-0 = {http://dx.doi.org/10.1371/journal.pgen.1000304}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19081788}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19081788}, day = {12}, doi = {10.1371/journal.pgen.1000304}, journal = {PLoS Genet}, keywords = {e-slr}, month = {December}, number = {12}, pages = {e1000304+}, posted-at = {2009-11-06 14:13:41}, priority = {2}, publisher = {Public Library of Science}, title = {The Population Genetics of dN/dS}, url = {http://dx.doi.org/10.1371/journal.pgen.1000304}, volume = {4}, year = {2008} }

TY - JOUR ID - citeulike:3782992 L3 - citeulike-article-id:3782992 N2 - Evolutionary pressures on proteins are often quantified by the ratio of substitution rates at non-synonymous and synonymous sites. The dN/dS ratio was originally developed for application to distantly diverged sequences, the differences among which represent substitutions that have fixed along independent lineages. Nevertheless, the dN/dS measure is often applied to sequences sampled from a single population, the differences among which represent segregating polymorphisms. Here, we study the expected dN/dS ratio for samples drawn from a single population under selection, and we find that in this context, dN/dS is relatively insensitive to the selection coefficient. Moreover, the hallmark signature of positive selection over divergent lineages, dN/dS>1, is violated within a population. For population samples, the relationship between selection and dN/dS does not follow a monotonic function, and so it may be impossible to infer selection pressures from dN/dS. These results have significant implications for the interpretation of dN/dS measurements among population-genetic samples. IS - 12 JF - PLoS Genet TI - The Population Genetics of dN/dS PB - Public Library of Science VL - 4 SP - e1000304 KW - e-slr AU - Kryazhimskiy, Sergey AU - Plotkin, Joshua PY - 2008/12/12/ UR - http://dx.doi.org/10.1371/journal.pgen.1000304 ER -