Meeting Abstract

P2.149  Wednesday, Jan. 5  Genomic comparison of symbiotic and free-living luminescent bacteria (Vibrio sp.) from different geographical locations: Does environment or host matter? WILLIAMS, B. L.*; TCHOURBANOV, A.; NISHIGUCHI, M. K.; New Mexico State University; New Mexico State University; New Mexico State University toxwilliams@gmail.com

Bobtail squids (Cephalopoda: Sepiolidae) harbor bioluminescent bacterial symbionts (γ-Proteobacteria: Vibrionaceae) in a specialized organ that directs light downwards to mask the squids’ silhouette from benthic predators. The relationship between Euprymna species and Vibrio fischeri has yielded a wealth of information as a model system for mechanisms of host colonization in both mutualistic and pathogenic interactions, interspecies communication, and environmentally transmitted symbioses. Some bacterial strains illustrate host generalism (Mediterranean), while others are more host-specific (Indo-west Pacific). Additionally, environmental variables such as salinity and temperature influence colonization success and subsequent population structure of symbionts. To reveal the potential underlying genetic bases for these different host and environmental adaptations, we sequenced and compared the entire genomes of five Vibrio isolates. Four of these (Vibrio fischeri) were isolated from different squid hosts that occupy varying environments (E. morsei from Tokyo Bay, Japan, E. tasmanica from Jervis Bay, Australia; E. scolopes from Kaneohe Bay, Hawaii, USA; and Sepiola affinis from Banyuls sur Mer, France). A comparison was also made for homologous regions in a free-living, non-symbiotically competent Vibrio sp. isolated from Coogee Bay, Australia. We summarized nonsynonymous mutations within open reading frames throughout the genomes and the potential role of the associated genes in adaptation to the host or environment.