We are developing a new focus in our group on coral reproductive biology. Most corals reproduce in spectacular mass spawning events where tens of millions of eggs and sperm from multiple coral species on the reef are released simultaneously, usually timed to the lunar cycle. The remainder of the corals release brooded larvae on various exquisitely timed schedules throughout the year. There is some evidence that the timing of larval release from brooding corals is perturbed by elevated temperature, thereby creating the potential for strong effects of climate change on reproductive phenology. However, the cellular and molecular mechanisms underlying coral reproduction and the timing and synchrony of these events are largely unknown.
We are embarking on a collaborative project that aims to explore the fundamental genetic, cellular and physiological basis of reproduction and reproductive timing in corals. Collaborators include Dr. Patrick Chappell (mammalian reproductive endocrinologist) from Department of Biomedical Sciences at OSU, Dr. Eli Meyer (coral genomicist) from OSU, Dr. Jodi Schwarz (coral genomicist) from Vassar College, Dr. Tony Fan (coral reproductive ecologist) from National Museum of Marine Biology and Aquarium in Taiwan and Dr. Saki Harii (coral biologist) from University of the Ryukyus in Okinawa, Japan. We are developing the anemone Aiptasia pallida (spawner) as a model for the cellular and molecular study of reproduction and examining the coral Pocillopora damicornis (brooder) in Taiwan and in tanks at OSU and the coral Acropora digitifera (spawner) in Japan. Studies include identification and characterization of putative reproductive genes, localization of hormone receptors within the animal, and manipulative hormonal experiments aimed at assigning roles for steroid and peptide hormones in a putative coral reproductive axis.
Hematoxylin and eosin stain carried out by veterinary diagnostic lab showing gonad development. (right) Individual showing multiple stages of development, including undifferentiated mesentery (m), well-developed oocytes (o), and atretic oocytes (a). (left) Individual containing mostly well-developed oocytes with some atresia.