A shrimp C-type lectin inhibits proliferation of the hemolymph microbiota by maintaining the expression of antimicrobial peptides.

Some aquatic invertebrates such as shrimp contain low albeit stable numbers of bacteria in the circulating hemolymph. The proliferation of this hemolymph microbiota in such a nutrient-rich environment is tightly controlled in healthy animals, but the mechanisms responsible had remained elusive. In the present study, we report a C-type lectin (MjHeCL) from the kuruma shrimp (Marsupenaeus japonicus) that participates in restraining the hemolymph microbiota.

A galectin from the kuruma shrimp (Marsupenaeus japonicus) functions as an opsonin and promotes bacterial clearance from hemolymph.

Galectins are a lectin family characterized by a conserved sequence motif in the carbohydrate recognition domain, which preferential binds to galactosyl moieties. However, few studies about the biological roles of galectins in invertebrates have been reported except for the galectin (CvGal1) from the eastern oyster Crassostrea virginica. Furthermore, galectins have been described in only a few crustacean species, and no functional studies have been reported so far.