The association between Euprymna scolopes, the Hawaiian bobtail squid, and Vibrio fischeri, a bioluminescent bacterium, has served as a model for beneficial symbioses for over 25 years. The experimental tractability of this association has helped researchers characterize many of the colonization events necessary for symbiosis. Recent technological advances, such as the sequenced genome of V. fi...

Symbiotic associations have been studied extensively in recent years, focusing mainly on the potential benefits to host. However, understanding role played by microorganisms physiology and fitness of host, an aspect subject that had neglected for a long time, has now become important goal symbiotic studies. Among interesting philosophical questions are following: how should we study impact symb...

Female members of many cephalopod species house a bacterial consortium in the accessory nidamental gland (ANG), part of the reproductive system. These bacteria are deposited into eggs that are then laid in the environment where they must develop unprotected from predation, pathogens, and fouling. In this study, we characterized the genome and secondary metabolite production of Leisingera sp. JC...

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. Pre...

Vibrio fischeri is a bioluminescent bacterium that enters into a symbiosis with the bobtail squid Euprymna scolopes. The bacterium colonizes a specialized light organ, in which it generates light that might help the squid to hide its silhouette from animals beneath it. Previous studies have shown that the host nitric oxide (NO) synthase is active during colonization, suggesting that V. fischeri...

Here we show that bioluminescent organs of the squid Euprymna scolopes possess the molecular, biochemical, and physiological capability for light detection. Transcriptome analyses revealed expression of genes encoding key visual transduction proteins in light-organ tissues, including the same isoform of opsin that occurs in the retina. Electroretinograms demonstrated that the organ responds phy...

Vibrio fischeri, a luminescent marine bacterium, specifically colonizes the light organ of its symbiotic partner, the Hawaiian squid Euprymna scolopes. In a screen for V. fischeri colonization mutants, we identified a strain that exhibited on average a 10-fold decrease in colonization levels relative to that achieved by wild-type V. fischeri. Further characterization revealed that this defect d...