Casandra Newkirk of the Martindale Lab defends her PhD!

On October 28^th, Casandra Newkirk, a graduate student co-advised by Tom Frazer, Professor and Director of UF’s School of Natural Resources and Environment, (and the State of Florida’s first Chief Science Officer), and Mark Q. Martindale, Professor and Director of the Whitney Laboratory for Marine Bioscience, gave her exit seminar entitled “Experimental system for the ecological and cellular study of cnidarian-dinoflagellate symbiosis” and successfully earned her Ph.D. 

Her dissertation included a fundamental characterization of a new “model system” for understanding the cellular and molecular basis for cnidarian symbiosis.  One of the most important and well-known examples of this kind of symbiosis is coral-dinoflagellate algal symbioses.  A breakdown in these interactions due to environmental stress is seen on coral reefs across the globe and causes “coral bleaching” events. This results in the death of corals and death of other animals that depend on the reef.  Studying corals is problematic for a number of reasons, so Casandra has helped develop the “upside down” jellyfish, Cassiopea xamachana, as a new laboratory system for understanding the initiation, maintenance, and breakdown of the interaction between the jellyfish and its symbiont. Among other things, Casandra showed that Cassiopea harbors the exact same kinds of symbionts that corals do, and that many assumptions related to “adaptive bleaching’ theories are likely to be wrong. She also developed a system amenable to high throughput, forward genetic screening of mutant symbionts in Cassiopea. 

These are tremendous contributions to the development of a better understanding of cnidarian-dinoflagellate interactions and a real contribution to the future of this field!  Congratulations Casandra!