9724918 Ram This Americas Program award will fund a collaborative research study on the physiology of reproduction in molluscs, between Dr. Jeffrey Ram, Wayne State University, and Dr. Carlos S. Gallardo, Universidad Austral de Chile. The aim of the project is to understand the functional evolution of peptide hormones using snail egg-laying hormone(s) (EHL) as a model system, and to develop techniques for the use of the (ELH) in prosobranch snail aquaculture. The researchers have chosen the CH giganteus species of molluscs for conducting experiments directed at achieving three major objectives: determining the location of ELH-imunoreactive (ELH-IR) neurons and fibers in the nervous system, identifying and purifying egg-laying hormone(s) in their nervous system by bioassay, with the eventual goal of determining its sequence. The proposed project is expected to achieve both scientific and practical results . It will result in an increased understanding of the functional evolution of peptide hormone, and in the development of techniques for using egg-laying hormones in prosobranch snail aquaculture In the long term, results of this study will be used in future studies on mechanisms underlying regulation of electrophysiological activity in neurosecretory cells. The prosobranch gastropod molluscs form the basis of several important fisheries in both US and Chile. An increased knowledge of the mechanisms controlling their reproduction, to be used at desired intervals, under controlled laboratory conditions, will help the development of mariculture. The two researchers are among the leading experts in their respective fields, and both will benefit by this collaboration. Dr. Ram will identify new experimental preparations for basic science investigations of peptide hormone and neurosecretory cell evolution and function, and Dr. Gallardo will benefit by obtaining the expertise and experience of the US PI in hormonal regulation of reproduction of molluscs. B oth countries will benefit by the practical application of molluscan endocrinology to aquaculture and basic science research. ***