Dr. McFall-Ngai proposes to investigate the initiation, development and maintenance of the symbiosis that exists between a sepiolid squid, Euprymna scolopes, and the marine luminous bacterium, Vibrio fischeri, which E. scolopes harbors within the tissues of a complex light-emitting organ. The work outlined in the present proposal will focus specifically upon: 1) assessing the influence of the bacterial partner on stage-specific host tissue morphogenesis, 2) identifying temporal windows during which developmental interactions must be initiated, 3) determining the bacterial specificity of the association, and 4) isolating and identifying classes of symbiosis incompetent mutants of Vibrio fischeri that will define crucial symbiotic genes. %%% The Euprymna/Vibrio symbiosis presents a rare opportunity to discover the significance of interspecies interactions in the control of gene expression, organ morphogenesis, immunological recognition and the consequences of other developmentally controlled signal processes.
