The goal of this project is to develop a reliable teratogen prescreen test employing embryos of the sea urchin Strongylocentrotus purpuratus. A sea urchin- embryo screen would complement existing tests designed to make potential teratogens at a relatively low cost a priority. The approach involves testing for mortality and structural abnormalities induced by chemical exposure during the embryonic development of the larval organism. Administering the chemical in an identical manner to a later larval stage, the pluteus larva, would permit a direct comparison between the concentration of chemical causing teratogenic effects (in the embryo) associated with unique embryological processes, and the concentration resulting in f rank toxicity to an organism (the pluteus larva) not undergoing tissue differentiation and organogenesis of larval structures and function.Phase I studies are concentrating on protocol development, including the selection of effects criteria, and initial evaluation of the experimental design. A select series of teratogens and nonteratogens, about 20 compounds in all, will then be examined using the method, to evaluate its feasibility. If the Phase I studies are promising, Phase II will refine the protocol, substantially enlarge the documentation data base of chemicals tested, and attempt to incorporate automation into the test. A reliable test will have commercial potential as a teratogen test service, and possibly for the manufacture of a partially automated test system.National Institute Of Environmental Health Sciences
