Host-selected mutations converging on a global regulator drive an adaptive leap towards symbiosis in bacteria.
Elife
; 62017 04 27.
Article
en En
| MEDLINE
| ID: mdl-28447935
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 cellulose. binK variation also altered quorum sensing, raising the threshold for luminescence induction. Preexisting coordinated regulation of symbiosis traits by BinK presented an efficient solution where altered BinK function was the key to unlock multiple colonization barriers. These results identify a genetic basis for microbial adaptability and underscore the importance of hosts as selective agents that shape emergent symbiont populations.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Quinasas
/
Selección Genética
/
Decapodiformes
/
Simbiosis
/
Aliivibrio fischeri
/
Mutación
Límite:
Animals
Idioma:
En
Revista:
Elife
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos