Electrical Properties of Membranes of Cells of the Corpora Allata of the Cockroach Diploptera Punctata: Evidence for the Presence of Voltage-Sensitive Calcium Channels

In adult cockroaches, as in many other insect species, juvenile hormone (JH) is necessary for the vitellogenic growth and maturation of eggs. In adult mated females of the cockroach, Diploptera punctata, rates of JH biosynthesis by the corpora allata (CA) undergo large cyclic changes in rates of JH biosynthesis and release in association with oocyte growth—high rates of JH biosynthesis are observed during vitellogenic growth whereas low rates are observed during previtellogenesis and during chorion formation (Tobe and Stay, 1977). The rate of JH biosynthesis by the CA appears to be regulated by both inhibitory and stimulatory signals reaching the CA by the nervous tracts and by humoral pathways (Tobe and Feyereisen, 1983; Tobe and Stay, 1985). Several second messengers, including cAMP, have been implicated in the transduction of these signals (Meller et al., 1985) and recent evidence suggests that calcium ions also play an important role in the regulation of JH biosynthesis and release (Kikukawa et al., 1986).