The Genetic Basis of Specificity in Dinoflagellate-Invertebrate Symbiosis
Annual rept. 1 Jul 1988-30 Jun 1989
CALIFORNIA UNIV SANTA BARBARA MARINE SCIENCE INST
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The aim of the study is to understand how marine invertebrates can distinguish between certain dinoflagellates with which they form symbioses, and others with recognition involving algal cell wall-associated proteins protetoglycans that inter-act with receptors on the animal cel symbiosome membrane. We have successfully isolated cell walls from three symbiotic dinoflagellate species that have been grown in axenic culture. These three species of algae represent examples of a a species compatible with a test host, b a species that is initially accepted, but ultimately rejected, and c a species that is not accepted. SDS-PAGE analyses of the solubilised cell wall fractions illustrated that i the cell walls of all three species of dinoflagellates contained a complex of proteinsproteoglycans ranging in apparent molecular size from about 13.5 to about 200 kD and ii that some of these polypeptide species were common to all three algal species, while others were unique to one species only. These are the first data showing protein proteoglycans associated with dinoflagellate cell walls. In addition, we have also found that one species of symbiotic dinoflagellate releases a range of polypeptidesproteoglycans when cultured in vitro, raising the novel possibility that released proteinsproteoglycans could be the signals passing between symbiont and host.
- Biological Oceanography