Horizontal Gene Acquisitions Contributed to Genome Expansion in Insect-Symbiotic Spiroplasma clarkii.

ABSTRACT: Genome reduction is a recurring theme of symbiont evolution. The genus Spiroplasma contains species that are mostly facultative insect symbionts. The typical genome sizes of those species within the Apis clade were estimated to be ∼1.0-1.4 Mb. Intriguingly, Spiroplasma clarkii was found to have a genome size that is >30% larger than the median of other species within the same clade. To investigate the molecular evolution events that led to the genome expansion of this bacterium, we determined its complete genome sequence and inferred the evolutionary origin of each protein-coding gene based on the phylogenetic distribution of homologs. Among the 1,346 annotated protein-coding genes, 641 were originated from within the Apis clade while 233 were putatively acquired from outside of the clade

SUBMITTER: Tsai YM 

PROVIDER: S-EPMC6007557 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature