The long term objective is to understand the regulation of juvenile hormone (JH) synthesis by the corpora allata (CA). The system studied is the female reproductive cycle of the viviparous cockroach, Diploptera punctata, in which egg development is precisely controlled by cyclic changes in production of JH by the CA. This serves as a model system for understanding the regulation of the CA, an important step in developing methods to limit insect reproduction. The specific aims are to demonstrate how the brain and the ovary act on the CA to alternately stimulate and inhibit the production of JH. The inhibitory and stimulatory factors from these organs will be isolated and their source and mode of action characterized. The cellular and subcellular organization and biochemistry of the CA will be correlated with changes in JH production by the glands during the reproductive cycle. JH synthesis will be measured by a direct short term in vitro radiochemical assay following treatment with extracts of nervous tissue and ovaries. Extracts will be purified with HPLC. The source of the active factors will be demonstrated by cytochemical and immunocytochemical methods. Changes in cellular and subcellular organization will be sought in electron microscopical analyses including autoradiography and stereological measurements.