Isolation and Characterization of Three CDNAs Encoding CHH-family Peptides from the Crab Oziotelphusa senex senex

Crustacean hyperglycemic hormone family (CHH-family) peptides play a very important role in the regulation of different physiological activities in crustaceans. In the present study three cDNAs encoding partial CHH-family peptides were isolated and characterized from crab eyestalk neural tissue using RT-PCR with degenerated oligo primers that were designed based on the conserved amino acid sequence. The deduced amino acid sequences of three cloned genes exhibited 55.8 to 80.8% homology with each other. The amino acid sequences of three cloned genes were also compared with the existing CHH-family peptide sequences of different crab species (obtained from GenBank at NCBI) and exhibited a close relationship with crustacean hyperglycemic hormones of Pachygrapsus marmoratus (54.0%), Scylla serrata (47.0%) and far from molt-inhibiting hormones (MIHs) of Carcinus maenas, Cancer pagurus, Scylla serrata and Cancer magister (>35.0%) and mandibular organ-inhibiting hormone (MOIH) of Cancer pagurus (27.0%). Using the amino acid sequences alignment the GROWTREE phylogram was constructed and the percentage of divergence from each other was analyzed.