Slip into something more functional: selection maintains ancient frameshifts in homopolymeric sequences.

ABSTRACT: Mutational hotspots offer significant sources of genetic variability upon which selection can act. However, with a few notable exceptions, we know little about the dynamics and fitness consequences of mutations in these regions. Here, we explore evolutionary forces shaping homopolymeric tracts that are especially vulnerable to slippage errors during replication and transcription. Such tracts are typically eliminated by selection from most bacterial sequences, yet persist in genomes of endosymbionts with small effective population sizes (N(e)) and biased base compositions. Focusing on Blochmannia, a bacterial endosymbiont of ants, we track the divergence of genes that contain frameshift mutations within long (9-11 bp) polyA or polyT tracts. Earlier experimental work documented that transcri

SUBMITTER: Wernegreen JJ 

PROVIDER: S-EPMC2877537 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature