Sequence conservation and functional constraint on intergenic spacers in reduced genomes of the obligate symbiont Buchnera.

ABSTRACT: Analyses of genome reduction in obligate bacterial symbionts typically focus on the removal and retention of protein-coding regions, which are subject to ongoing inactivation and deletion. However, these same forces operate on intergenic spacers (IGSs) and affect their contents, maintenance, and rates of evolution. IGSs comprise both non-coding, non-functional regions, including decaying pseudogenes at varying stages of recognizability, as well as functional elements, such as genes for sRNAs and regulatory control elements. The genomes of Buchnera and other small genome symbionts display biased nucleotide compositions and high rates of sequence evolution and contain few recognizable regulatory elements. However, IGS lengths are highly correlated across divergent Buchnera genomes, suggestin

SUBMITTER: Degnan PH 

PROVIDER: S-EPMC3164680 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature