RESPONSIVENESS OF THE ADULT CRICKET (GRYLLUS-BIMACULATUS AND ACHETA-DOMESTICUS) RETROCEREBRAL COMPLEX TO ALLATOSTATIN-1 FROM A COCKROACH, DIPLOPTERA-PUNCTATA

Brain-retrocerebral complexes of female crickets, Gryllus bimaculatus and Acheta domesticus, treated with antibody to allatostatin-1 from a cockroach, Diploptera punctata, show extensive immunoreactivity. The results suggest that allatostatins or allatostatin-like molecules are produced in neurosecretory cells of the brain and are delivered to the corpora allata through nervous connections and/or via haemolymph. Radiochemical measurements of juvenile hormone III biosynthesis by isolated corpora cardiaca-corpora allata complexes from adult G. bimaculatus have been used to demonstrate an in vitro sensitivity of these glands to allatostatin-1 from D. punctata. Allatostatin-1 is a relatively potent inhibitor of juvenile hormone III biosynthesis in corpora allata of both young adult females and males. In glands taken from 3-day virgin females, 50% inhibition of hormone biosynthesis is reached at ca. 3 nmol.l(-1) allatostatin-1. The inhibitory action of allatostatin-1 is rapid, dose-dependent and reversible. Addition of 200 mu mol.l(-1) farnesol to the incubation medium prevents inhibition of juvenile hormone III biosynthesis by allatostatin-1. Juvenile hormone III biosynthesis by isolated corpora allata of 3-day female house crickets, A. domesticus, is also susceptible to inhibition by 1 mu mol.l(-1) allatostatin-1.