Dinoflagellates are distinctive among eucaryotes in several ways, one being that their chromosomes are thought to be permanently condensed except during DNA synthesis or fertilization. This investigation will employ molecular techniques (chromosome isolation, restriction enzyme digestion of the chromosomes and cloning of the released DNA fragments, Southern blot hybridization, in situ hybridization, autoradiography) to demonstrate that genetically active DNA is found in extrachromosomal filaments, not in the bulk or structural DNA. Once the techniques are developed, dinoflagellates from different from different extremes of a proposed evolutionary lineage will be examined and compared, as will the resting cysts of these species. The similarities between vegetative cells and cysts (which must retain low level metabolic activity while protecting their DNA from degradation during prolonged dormancy) should provide valuable insights into adaptive mechanisms that might relate to the unique chromosome structure of modern dinoflagellates. This fellowship award will allow Dr. Anderson to accomplish the research and training at the Laboratory Arago of the University of Paris in France. The motivation for an extended stay at this lab is to learn cell and molecular biological techniques from colleagues who have strong ongoing programs focused on the dinoflagellates - an ecologically and evolutionarily important class of marine algae that has been the focus of Dr. Anderson's excellent research. The vehicle for this training and transfer of technology will be a project examining the unique manner in which dinoflagellates package and transcribe genetic information, both as vegetative cells and as resting cysts. This project is of fundamental scientific importance on its own but also to allow Dr. Anderson to learn new concepts and tools that can be incorporated into his ongoing research program, which focuses on the physiological ecology of toxic phytoplankton.