Differences in gene organization between type I and type II crustins in the morotoge shrimp, Pandalopsis japonica

Abstract

Crustins are cysteine-rich cationic antimicrobial peptides (AMPs) found in decapod crustaceans. Six novel crustin genes (Paj-CrusIc, Id, Ie, If, IIb and IIc) were identified in the morotoge shrimp, Pandalopsis japonica. Deduced amino acid sequences of isolated Paj-Crus genes ranged from 99 to 178 amino acid residues (10.6e17.8 kDa). Sequence analysis of nine isolated Paj-Crus genes and 100 different crustins from various decapod crustaceans revealed that a splice site and KXXXCP motif within the WAP domain may be the main criteria for classifying type I and II crustins, suggesting that the two types of crustin genes may have been generated by different processes. We also identified three intron-less crustin I genes (Paj-Crus Id, Ie and If) for the first time, which may have been generated by gene duplication. The tissue distribution profiles showed that Paj-CrusI genes were expressed predominantly in the gill and epidermis, whereas Paj-CrusII genes were expressed ubiquitously, suggesting that the two types of crustins may play different roles in various tissues or under different physiological conditions. Differing from previous results, hemocyte-specific crustin was not isolated from Pandalopsis japonica. This study showed that both types of crustin genes (types I and II) exist in decapod crustaceans and their primary structure and expression profiles differ from each other, suggesting that they may pla sequences of isolated Paj-Crus genes ranged from 99 to 178 amino acid residues (10.6e17.8 kDa). Sequence analysis of nine isolated Paj-Crus genes and 100 different crustins from various decapod crustaceans revealed that a splice site and KXXXCP motif within the WAP domain may be the main criteria for classifying type I and II crustins, suggesting that the two types of crustin genes may have been generated by different processes. We also identified three intron-less crustin I genes (Paj-Crus Id, Ie and If) for the first time, which may have been generated by gene duplication. The tissue distribution profiles showed that Paj-CrusI genes were expressed predominantly in the gill and epidermis, whereas Paj-CrusII genes were expressed ubiquitously, suggesting that the two types of crustins may play different roles in various tissues or under different physiological conditions. Differing from previous results, hemocyte-specific crustin was not isolated from Pandalopsis japonica. This study showed that both types of crustin genes (types I and II) exist in decapod crustaceans and their primary structure and expression profiles differ from each other, suggesting that they may pla