Molecular cloning and expression analysis of a new lily-type lectin in the rock bream, Oplegnathus fasciatus.

A new lily-type lectin RbLTL was identified from rock bream (Oplegnathus fasciatus) and its expression analysed. In this study, a new lily-type lectin gene (RbLTL) was cloned from rock bream using expressed sequence tag (EST) analysis. The full-length RbLTL cDNA was encoding a 117-amino acid protein. The deduced amino acid sequence of RbLTL contained all of the conserved features crucial for its fundamental structure, including B-lectin domain and three d-mannose binding sites. RbLTL mRNA was predominately expressed in the gills, with reduced expression noted in intestine tissue. Expression analysis of time series sampled fertilized eggs revealed that expression gradually increased 1, 3, 12, and 24 h: However, expression decreased at 36 h. RbLTL expression was differentially up-regulated in rock bream gills challenged with Streptococcus iniae, Edwardsiella tarda and RSIV. Our results revealed that novel rock bream lily-type lectin may be an important molecule involved in pattern recognition and pathogen elimination in the innate immunity of rock bream.