Increased Biosynthetic Gene Dosage in a Genome-Reduced Defensive Bacterial Symbiont.

ABSTRACT: A symbiotic lifestyle frequently results in genome reduction in bacteria; the isolation of small populations promotes genetic drift and the fixation of deletions and deleterious mutations over time. Transitions in lifestyle, including host restriction or adaptation to an intracellular habitat, are thought to precipitate a wave of sequence degradation events and consequent proliferation of pseudogenes. We describe here a verrucomicrobial symbiont of the tunicate Lissoclinum sp. that appears to be undergoing such a transition, with low coding density and many identifiable pseudogenes. However, despite the overall drive toward genome reduction, this symbiont maintains seven copies of a large polyketide synthase (PKS) pathway for the mandelalides (mnd), cytotoxic compounds that l

SUBMITTER: Lopera J 

PROVIDER: S-EPMC5698493 | biostudies-literature | 2017 Nov-Dec

REPOSITORIES: biostudies-literature