9505416 Pierce This proposal describes several experiments designed to understand the mechanism(s) that are used by the cells of the marine slug, Elysia chlorotica, to capture chloroplasts from the marine alga, Vaucheria litorea, and keep the plastids photosynthetically active within the animal cell for periods as long as 8 months after capture. The photosynthesis requires that certain chloroplast proteins be continually replaced. The genetic information for the synthesis of some of those proteins is contained within the chloroplast, but for other of the proteins is normally supplied by the plant nucleus. The experiments, which will use radiolabelling and gel electrophoresis techniques, will indicate which of the chloroplast proteins are synthesized while the plastid is within the animal cell. Using pharmacological agents, the site (chloroplast or animal nucleus) of the genetic information for the synthesized proteins will be determined. Antibody labelling will be used to identify the synthesized proteins. The results will begin to provide information leading to understanding how the animal cell maintains within it a completely foreign structure (chloroplast) in a functional condition. ***
