Molecular cloning of the precursors of pigment dispersing hormone in crustaceans

The cDNAs encoding the precursors of a chromactive crustacean hormone, Pigment Dispersing Hormone (PDH) of the shrimp Penaeus vannamei, were studied by PCR and molecular cloning. Three different cDNAs were isolated and sequenced. The PDH precursor consists of a putative 22- or 23-amino acid signal peptide, a 34-amino acid PDH-Precursor Related Peptide (PPRP) of unknown function, and the 18-amino acid mature PDH. The deduced mature PDH amino acid sequences are identical except the change of a Leucine by an Isoleucine in one variant and are very similar to those of other species. The signal peptides appear highly variable. The variability between the PPRP sequences is low between the different species, suggesting that this peptide may have a physiological role. (C) 1996 Academic Press, Inc.