Plos Genetics : the Population Genetics of Dn, Volume 4

By Gojobori, Takashi

Book Id: WPLBN0003926143
Format Type: PDF eBook :
File Size:
Reproduction Date: 2015

Title:	Plos Genetics : the Population Genetics of Dn, Volume 4
Author:	Gojobori, Takashi
Volume:	Volume 4
Language:	English
Subject:	Journals, Science, Genetics
Collections:	Periodicals: Journal and Magazine Collection (Contemporary), PLoS Genetics
Historic Publication Date:
Publisher:	Plos


Citation APA MLA Chicago Gojobori, T. (n.d.). Plos Genetics : the Population Genetics of Dn, Volume 4. Retrieved from http://gutenberg.cc/

Description
Description : 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.