Cloning and tissue-specific localization of cricket-type allatostatins from Gryllus bimaculatus.

Cricket- or B-type allatostatins [W(X(6))W-amides] inhibit the biosynthesis of juvenile hormones in vitro in crickets. Peptides of this family are present also in other insects where they may bare different functions. Here we report the identification of a partial sequence of the B-type preproallatostatin from Gryllus bimaculatus. By PCR screening of a random primer cDNA library and by RACE, a 535bp 3'cDNA sequence was obtained which encodes a putative translation product of 85 amino acids, containing three copies of Grybi-AST B1 and one copy each of Grybi-AST B2, Grybi-AST B3, and Grybi-AST B6. The last represents a novel member of this peptide family. By means of one-step RT-PCR, RNA dot blot, and RT in situ PCR analyses the mRNA expression of the gene in the central nervous system and the digestive tract of female adult crickets was demonstrated. The results confirm that the B-type allatostatins of G. bimaculatus are brain-gut peptides.