Molecular cloning of leucocyte cell-derived chemotaxin-2 gene in croceine croaker (Pseudosciaena crocea)

Leucocyte cell-derived chemotaxin-2 (LECT2) was originally demonstrated to have a chemotactic activity against human neutrophils in vitro. Current evidence suggests that LECT2 may be a multifunctional protein involved in cell growth, differentiation and autoimmune. A full-length cDNA clone of the LECT2 gene, 595 bp in size, was isolated from the fish croceine croaker (Pseudosciaena crocea). Itʹs 3′-UTR was much shorter (112 nts) than that of trout LECT2 gene (210 nts). Its deduced amino acid sequence of 151 residues had 39.7–75.5% identity to that of other animals. Phylogenetic analysis shows that croceine croaker LECT2 (pLECT2) is clustered tightly with other fish LECT2. The relationships of the different LECT2 coincided well with the evolutionary relationships of their organisms. In healthy fish, the expression levels of pLECT2 gene from different tissues were similar, while that in Vibrio alginolyticus-infected fish were significantly increased in liver and spleen comparing to those in healthy fish, and were a little higher in the other tissues.