DISSERTATION RESEARCH: The evolutionary ecology of a vertebrate-microbe symbiosis

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

We will study co-evolution between a coral reef fish (Siphamia tubifer) and its symbiotic, light-emitting bacterium (Photobacterium mandapamensis). To test the hypothesis that the host fish?s ecology and behavior shape and maintain the specificity of the fish?s association with the bacterium, this study will determine the extent to which genetic differences exist among populations of both the fish and bacterium, and how these differences correlate over space and time. Work will be carried out on specimens of the fish collected from coral reefs in Okinawa, Japan. We will use a recently developed method in population genetics, restriction site-associated DNA sequencing, to determine the genetic structures of populations of the fish and bacterium with fine-scale resolution. Symbiotic associations between fish and specific types of luminous bacteria are biologically important components of many marine ecosystems, and their persistence depends on their biological specificity. Understanding how specificity arises and is maintained is especially important now, as changes in the marine environment, such as increases in sea surface temperature and acidification, are occurring more rapidly. These changes have the potential to de-couple symbiotic associations by altering the ecology of both organisms. As a vertebrate ? microbe symbiosis, this association is also being developed as an experimental model system for learning how vertebrate animals, including humans, acquire, accommodate, and function cooperatively with beneficial bacteria. This project will contribute to scientific infrastructure by providing research training for undergraduate students and will promote international research exchange with Japanese scientists and students.