The Specialized Population Research Center proposed in this application targets a synthesis of hypotheses and modern biomedical techniques in a continuum of disciplines in reproductive sciences from molecular biology to physiology. Close integration of principles, resources and expertise is fundamental. The work includes ten projects which fall into the two broad categories of neuroscience and early development; I, a study of TGF-beta, II, an analyses of mammalian spermatogenesis; III, a study of hap26 expression in Drosophila, IV, the study of the GnRH pulse generator in primates, V, a study of the prenatal expression of growth factor genes and receptors; VI, a study of GnRH networks in the rhesus brain by neuroanatomical methods,; VII, analysis of placental CRH in pregnant baboons, VIII, experiments with steroid/growth factors in neurodevelopment; IX, study of sex steroid regulation of brain POMC and LH and X, an analysis of proto-oncogene expression during mammalian gametogenesis. Five biomedical cores are organized to expedite technical usage of a primate colony, molecular cytology/histology techniques, radioimmunoassay of steroids and proteins, cell and hybridization culture, and a molecular biology facility.