Locating protein-coding sequences under selection for additional, overlapping functions in 29 mammalian genomes.

摘要: The degeneracy of the genetic code allows protein-coding DNA and RNA sequences to simultaneously encode additional, overlapping functional elements. A sequence in which both additional functions have evolved under purifying selection should show increased evolutionary conservation compared typical genes--especially at synonymous sites. In this study, we use genome alignments 29 placental mammals systematically locate short regions within human ORFs that conspicuously low estimated rates substitution across these species. 29-species alignment provides statistical power more than 10,000 such with resolution down nine-codon windows, are found a quarter all genes contain ∼2% their We collect numerous lines evidence observed constraint reflects on elements including splicing regulatory elements, dual-coding genes, secondary structures, microRNA target sites, developmental enhancers. Our results common mammalian despite vast genomic landscape.