The allatostatin gene of the cricket Gryllus bimaculatus (Ensifera, Gryllidae)

The gene encoding allatostatins (AST) of the FGLamide family from the crick et Gryllus bimaculatus is expressed in the brain. The mRNA, which contains four polyadenylation signals, encodes a hormone precursor that is split int o at least 14 putative hormones. Five of them have been previously found in the cricket, six to seven others, or their close homologues. are known fro m other insects. Hormone AST 2 contains an internal cleavage site and may e xist in a shorter version 2b. The hormones AST 3 and 4 are identical. The c DNA sequence revealed that a single point mutation and a single deletion el iminated an additional hormone between AST 12 and 13. The deduced hormone p recursor is very similar to that in cockroaches. but is different from a sh orter precursor in locusts. indicating that the gene evolved very fast in t he latter. Regions conserved between cockroaches and crickets include parts of the acidic spacers that separate clusters of hormones. suggesting that these spacers may have additional functions. (C) 2001 Elsevier Science Irel and Ltd. All rights reserved.