Functional convergence in reduced genomes of bacterial symbionts spanning 200 My of evolution.

ABSTRACT: The main genomic changes in the evolution of host-restricted microbial symbionts are ongoing inactivation and loss of genes combined with rapid sequence evolution and extreme structural stability; these changes reflect high levels of genetic drift due to small population sizes and strict clonality. This genomic erosion includes irreversible loss of genes in many functional categories and can include genes that underlie the nutritional contributions to hosts that are the basis of the symbiotic association. Candidatus Sulcia muelleri is an ancient symbiont of sap-feeding insects and is typically coresident with another bacterial symbiont that varies among host subclades. Previously sequenced Sulcia genomes retain pathways for the same eight essential amino acids, whereas coresident symbionts

SUBMITTER: McCutcheon JP 

PROVIDER: S-EPMC2953269 | biostudies-literature | 2010

REPOSITORIES: biostudies-literature