IMMUNOCHEMICAL IDENTIFICATION AND EXPRESSION OF ALLATOSTATINS IN THE GUT OF DIPLOPTERA-PUNCTATA

Dip-allatostatins are a family of related neuropeptides in the cockroa ch Diploptera punctata that were identified originally on the basis of their ability to inhibit juvenile hormone biosynthesis by corpora all ata. These peptides were subsequently also found to inhibit myogenic a nd proctolin-induced contractions of the cockroach hindgut. Dip-allato statin immunoreactive material is distributed in several sites within the brain, subesophageal and ventral ganglia and in nerves to the ante nnal pulsatile organ and hindgut muscles, We have demonstrated here th at Dip-allatostatin immunoreactivity is also found in the proctodeal i nnervation and endocrine cells of the midgut, The endocrine cells whic h are distributed unequally in different regions of the midgut are als o sites of Dip-allatostatin mRNA synthesis. The quantity of Dip-allato statin immunoreactive material within and released from the gut was as sessed by ELISA and RIA, The changes in Dip-allatostatin content in mi dgut and hindgut extracts during the first 8 days of the reproductive cycle, paralleled, to some degree, the changes noted previously in bra in. Our data suggest that the midgut may be another source from which Dip-allatostatins are released into the hemolymph and this release may be regulated, in part, by nutritional status.