Research Seminar: Stephanie Smith

A research seminar from UNC Marine Sciences graduate student, Stephanie Smith. Presented by the UNC at Chapel Hill Department of Marine Sciences. The location of this event will be in seminar room G201 on the ground floor of Murray Hall on UNC-CH campus in Chapel Hill, NC. This event will be held on Wednesday, September 18th at 12:30pm. This seminar will also be broadcast live to UNC’s Institute of Marine Sciences room 222.

Seminar Title: Using the vibrio-squid symbiosis as a model system to study the evolution of symbiotic partnerships

Abstract: Animals evolved surrounded by bacteria, resulting in widespread symbioses in which host and symbiont often form specialized partnerships essential for host development, reproduction, or survival. Specific genes are often required for bacteria to colonize a given host, and it is predicted that these genetic factors can be rapidly transferred between bacteria through the exchange of genetic material (gene transfer). However, little is known about how gene transfer drives the evolution of symbiotic partnerships or the implications this could have on host fitness. To help fill this knowledge gap, we optimized culture conditions to permit gene transfer between different isolates of the bioluminescent light organ symbiont, Vibrio fischeri. Using these optimized conditions, we evolved a fish symbiont by growing it in the presence of a squid isolate, which served as the DNA donor. Our work revealed that after just a ten hour of growing together in culture, we isolated evolved fish-symbiont strains that had gained the ability to colonize a new host, the Hawaiian bobtail squid. We predict that this ability to colonize a new host is the result of genetic factors transferred from the squid symbiont into the fish symbiont. Future work will investigate the extent of gene transfer among evolved isolates and will identify the newly-acquired genes that allow colonization of a new host. Taken together, these findings suggest that V. fischeri is able to rapidly evolve to colonize new hosts, and provides the framework for using the vibrio-squid symbiosis as a model for studying the evolution of bacterial genomes and symbiotic partnerships.