Contrasting patterns of nonneutral evolution in proteins encoded in nuclear and mitochondrial genomes.

摘要: We report that patterns of nonneutral DNA sequence evolution among published nuclear and mitochondrially encoded protein-coding loci differ significantly in animals. Whereas an apparent excess amino acid polymorphism is seen most (25/31) mitochondrial genes, this pattern fewer than half (15/36) the data sets. This differentiation even greater sets with significant departures from neutrality (14/15 vs. 1/6). Using forward simulations, we examined using parameters chosen to mimic differences between genetics (we varied recombination rate, population size, mutation selective dominance, intensity germ line bottleneck). Patterns were correlated only effective size strength selection, no single genetic factor explains empirical contrast patterns. further Arabidopsis thaliana, a highly self-fertilizing plant effectively low recombination, five six also exhibit polymorphism. suggest nonneutrality animals stems rates conjunction distribution effects. If majority mutations segregating populations are deleterious, high linkage may hinder spread occasional beneficial mutation.