title: Role for cheR of  Vibrio fischeri  in the Vibrio-squid symbiosis.
abstract: Upon hatching, the Hawaiian squid  Euprymna scolopes  is rapidly colonized by its symbiotic partner, the bioluminescent marine bacterium  Vibrio fischeri . Vibrio fischeri cells present in the seawater enter the light organ of juvenile squid in a process that requires bacterial motility. In this study, we investigated the role chemotaxis may play in establishing this symbiotic colonization. Previously, we reported that V. fischeri migrates toward numerous attractants, including N-acetylneuraminic acid (NANA), a component of squid mucus. However, whether or not migration toward an attractant such as squid-derived NANA helps the bacterium to localize toward the light organ is unknown. When tested for the ability to colonize juvenile squid, a V. fischeri chemotaxis mutant defective for the methyltransferase CheR was outcompeted by the wild-type strain in co-inoculation experiments, even when the mutant was present in fourfold excess. Our results suggest that the ability to perform chemotaxis is an advantage during colonization, but not essential.
authors.affiliation: Department of Biology, University of Southern Indiana, Evansville, IN 47712, USA. crdeloney@usi.edu
authors.forename: Cindy R
authors.initials: CR
authors.lastname: Deloney-Marino
authors.forename: Karen L
authors.initials: KL
authors.lastname: Visick
mesh_terms: D048908:Aliivibrio fischeri / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002633:Chemotaxis / Q000235:genetics / Q000502:physiology*; D049832:Decapodiformes / Q000382:microbiology*; D023061:Gene Order; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D016415:Sequence Alignment; D013559:Symbiosis
chemical_list: D008780:Methyltransferases