Host-selected mutations converging on a global regulator drive an adaptive leap towards symbiosis in bacteria.

ABSTRACT: Host immune and physical barriers protect against pathogens but also impede the establishment of essential symbiotic partnerships. To reveal mechanisms by which beneficial organisms adapt to circumvent host defenses, we experimentally evolved ecologically distinct bioluminescent Vibrio fischeri by colonization and growth within the light organs of the squid Euprymna scolopes. Serial squid passaging of bacteria produced eight distinct mutations in the binK sensor kinase gene, which conferred an exceptional selective advantage that could be demonstrated through both empirical and theoretical analysis. Squid-adaptive binK alleles promoted colonization and immune evasion that were mediated by cell-associated matrices including symbiotic polysaccharide (Syp) and cell

SUBMITTER: Pankey MS 

PROVIDER: S-EPMC5466423 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature