Professor Paul Dunlap received a National Institutes of Health nominated Invitation Fellowship from the Japan Society for the Promotion of Science (JSPS) to carry out research in Okinawa, Japan, at the Okinawa Institute of Science and Technology Graduate University (OIST).
At OIST, Dunlap worked in the laboratory of evolutionary biologist Professor Alexander Mikheyev, in collaboration with OIST graduate student Margaret Brisbin, to begin defining the molecular interactions between the apogonid fish, Siphamia tubifer, and its light-producing symbiotic bacterium, Photobacterium mandapamensis. The fish, which lives on coral reefs in Okinawa, harbors a large population of the bacteria in an abdominal light organ and uses the ventrally emitted bacterial light while foraging at night for zooplankton prey. Using transcriptomic approaches and the extensive sequencing capability at OIST, they are defining the patterns of gene expression of the bacteria within the light organ and of the fish’s light organ tissues.
The goal of the project is to understand at the gene expression level, on the one hand, the physiological and biochemical conditions the host fish sets up in the light organ to provision the symbiotic bacteria and constrain their invasive growth potential while ensuring the bacteria produce a high level of light, and on the other hand, how the bacteria respond functionally and adaptively to those conditions and constraints. The work provides a first example of how a vertebrate animal interacts at the molecular level with a specific bacterium to form an exclusive, mutually beneficial association.
“The work at OIST was very challenging for me, since this was my first experience working at the RNA level; I found it takes exacting care and exceptional patience. Working in the Mikheyev lab, where transcript analysis is routine, was very rewarding,” Dunlap said.
Dunlap’s group has been studying the Siphamia – Photobacterium association over the past several summers in Okinawa, at phylogenetic, developmental and ecological levels. “I am very grateful for the nomination of this project by the NIH and for the generous funding provided by the JSPS, which allowed us to take studies of this fascinating vertebrate – microbe mutualism in a new and exciting direction,” Dunlap said. He was in Okinawa from mid-April through late July 2015.