MOLECULAR-CLONING OF THE GENE FOR THE ALLATOSTATIN FAMILY OF NEUROPEPTIDES FROM THE COCKROACH DIPLOPTERA-PUNCTATA

Allatostatins (ASTs) are insect neuropeptides that inhibit juvenile ho rmone biosynthesis by the corpora allata. We have isolated a cDNA from the cockroach Diploptera punctata that encodes a 41.5-kDa precursor p olypeptide containing the AST family of peptides. Translation of the c DNA revealed a 370-amino acid pre-pro-peptide consisting of 13 AST-typ e peptides and appropriate processing sites for endoproteolytic cleava ge and amidation. The 13 potential AST sequences are characterized by the C-terminal AST core-structure Phe-Gly-Leu-NH2, with only one excep tion. Separating the clustered ASTs in the precursor, three acidic spa cer regions are found. Contained within the largest of these are two p otentially related peptides that may also be processed. Southern blot analysis revealed the presence of a single copy of the AST gene per ha ploid genome, as well as the probability that the gene may be present in at least two allelic forms. In situ hybridization indicated the AST -encoding gene is expressed in neurosecretory cells of D. punctata bra in.