Long & Medium-Term Research: Chloroplast Enslavement in Marine Oligotrich Ciliates This award is under the Program for Long-& Medium Term Research at Foreign Centers of Excellence, which enables U.S. scientists and engineers to conduct three to twelve months of research abroad at research centers of proven excellence. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twelve-month postdoctoral research visit by Dr. John Dolan with Fereidoun Rassoulzadegan, Director of Research at the Station Zoologique, Villefranche- sur-Mer, France. The researchers will focus on the oligotrich ciliates which often dominate marine microzo plankton communities, about which recent work has shown a large fraction (. 1/3) are mixotrophic; that is, in addition to herbivory they use photosynthate produced by chloroplasts sequestered from ingested algae. The researchers propose to use field work and laboratory work to ask what large-scale environmental properties influence the abundance of these forms and what cellular mechanisms may be involved in chloroplast enslavement. Field work will examine the variability of mixotrophic oligotrichs in relation to changes in the abundance of autotrophic nanoplankton, light, and heterotrophic competitors. Laboratory work will investigate cellular mechanisms. The postulate that a chemical cue, derived from the algae source of chloroplasts, modifies the normal course of food vacuole processing is justified. A set of experiments designed to locate the chemical cue and examine the effect of the state of the source algae as well as the state of the oligotrich is outlined. The study will add significantly to knowledge of how some plankters survive in nutritionally dilute environ- ments and also will further understanding of the cellular mechanisms involved with symbiosis. The award recommendation provides funds to cover international travel and a dependents' allowance.
