Foraminifera are major primary producers of organic carbon and sinks of nutrients and carbonate in ocean waters. Although all foraminifera contain one of a wide variety of algal symbionts, the diatom-bearing larger foraminifera are a unique form of the symbiotic phenomenon. However, the biological basis for the broad adaptation of foraminifera to symbiosis remains unknown. This project will test several testable hypotheses to understand the molecular basis whereby these marine protists recongnize specific algal species as endosymbionts and others as food. Previous research has already identified the fibrous net outside of the foraminifera shell as the contact site for recognition. The goal of this project is to compare the surface antigens of endosymbiotic and free-living diatoms as possible recognition sites for the initial steps in the pathways leading to the establishment of endosymbiosis or digestion. Immunochemical techniques will be used to screen cross-reactive antigens of diatoms that are involved in the interaction of diatoms with foraminifera.
