Identification and characterization of a novel galectin from the mud crab Scylla paramamosain.

摘要: Abstract Galectins are a family of β-galactoside-binding lectins that play key roles in the invertebrate innate immunity system, but no galectin genes have been identified mud crab (Scylla paramamosain) so far. The present study is first to clone gene (SpGal) from S. paramamosain, by rapid amplification cDNA ends technique based on expressed sequence tags. full-length SpGal was 3142 bp. Its open reading frame encoded polypeptide 280 amino acids containing GLECT/Gal-bind lectin domain and potential N-glycosylation site. deduced acid multi-domain organization were highly similar those galectins, phylogenetic analysis showed closely related isolated Portunus trituberculatus. mRNA transcripts found be constitutively wide range tissues, with its expression level being higher hepatopancreas, gill, hemocytes. increased rapidly after crabs stimulated Vibrio alginolyticus, maximum appeared at 6 h challenge. lipopolysaccharide-binding ability dependent concentration, it also exhibited agglutination activity three Gram-negative (Aeromonas hydrophila, Chryseobacterium indologenes alginolyticus) Gram-positive (Bacillus aquimaris, Staphylococcus aureus Micrococcus lysodeik) bacterial strains. In addition, hemagglutination rabbit erythrocytes observed absence d -galactose. These results indicate paramamosain acts as pattern recognition receptor recognize broad spectrum microbes. findings together plays an important role immune mechanisms against pathogenic infection.