Abstract: Scygonadins are a group of antimicrobial peptides (AMPs)ubiquitously found in crustaceans. In this study, a full-lenth cDNA of type Scygonadin had been cloned from the male gonad of Portunus trituberculatus by the RACE technology.The length of the Scygonadin is 549 bp and contains an ORF of 1372 bp encoding 123 amino acid, including a signal peptide with 29 amino acids,a 5′untranslatedregion of 56 bp and a 3′untranslated region of 121 bp.According to the search results of GenBank databases, the cDNA nucleotides and the deduced amino acid sequence of ORF share 77.4% and 68.3% identity with that of Scylla serrata. This will set the base for study of immune defense mechanism and gene function of Portunus trituberculatus Scygonadin.

Key words: Portunus trituberculatus, Scygonadin, cloning, sequence analysis