Make Peace, Not War: The Establishment of the Squid-Vibrio Symbiosis
Margaret McFall-Ngai, Dept. of Medical Microbiology, University of Wisconsin, Madison
Colloquium Speaker18 Feb 2005
The symbiosis between the Hawaiian bobtail squid Euprymna scolopes and the marine luminous bacterium Vibrio fischeri offers an experimental system for the study of the onset, development and maintenance of an animal-bacterial interaction. The symbiosis is horizontally transmitted, beginning within hours of the host’s hatching. During embryogenesis, the host develops mechanisms by which to harvest the bacterial symbionts efficiently from the surrounding seawater, where they are naturally occurring members of the bacterioplankton. Once the bacteria colonize host light-organ tissues, they induce a series of developmental changes, which result in the transformation of the light organ from a morphology that promotes colonization to one that ensures a stable, functional symbiosis. Underlying these events that surround the inception and maturation of the association is a complex molecular dialogue. To understand this dialogue, molecular tools are being or have been developed, including the full sequence of the V. fischeri genome and large-scale sequencing of stage-specific, symbiotic/aposymbiotic EST libraries of the E. scolopes light organ. Data enabled by these tools are revealing the involvement of a wide array of developmental, immunological and stress-related pathways in the orchestration of this partnership.