title: Differentially expressed genes reveal adaptations between free-living and symbiotic niches of Vibrio fischeri in a fully established mutualism.
abstract: A major force driving in the innovation of mutualistic symbioses is the number of adaptations that both organisms must acquire to provide overall increased fitness for a successful partnership. Many of these symbioses are relatively dependent on the ability of the symbiont to locate a host (specificity), as well as provide some novel capability upon colonization. The mutualism between sepiolid squids and members of the Vibrionaceae is a unique system in which development of the symbiotic partnership has been studied in detail, but much remains unknown about the genetics of symbiont colonization and persistence within the host. Using a method that captures exclusively expressed transcripts in either free-living or host-associated strains of Vibrio fischeri, we identified and verified expression of genes differentially expressed in both states from two symbiotic strains of V. fischeri. These genes provide a glimpse into the microhabitat V. fischeri encounters in both free-living seawater and symbiotic host light organ-associated habitats, providing insight into the elements necessary for local adaptation and the evolution of host specificity in this unique mutualism.
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces 88003-8001, USA.
authors.forename: B W
authors.initials: BW
authors.lastname: Jones
authors.forename: M K
authors.initials: MK
authors.lastname: Nishiguchi
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology; D048908:Aliivibrio fischeri / Q000235:genetics* / Q000254:growth & development; D000818:Animals; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D049832:Decapodiformes / Q000382:microbiology*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013559:Symbiosis / Q000235:genetics*
chemical_list: D018076:DNA, Complementary