ARS | Publication request: Characterization of mannose binding lectin from channel catfish Ictalurus punctatus

Submitted to: Research in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 23, 2011
Publication Date: June 1, 2012
Citation: Zhang, H., Peatman, E., Liu, H., Niu, D., Feng, T., Kucuktas, H., Waldbieser, G.C., Chen, L., Liu, Z. 2012. Characterization of mannose binding lectin from channel catfish Ictalurus punctatus. Research in Veterinary Science. 92:408-413.

Interpretive Summary: Losses to disease are a significant cost to commercial catfish producers, so it is important to understand disease mechanisms in order to approach methods of improving catfish immunity. In this research, the mannose binding lectin (MBL) gene was identified in catfish genomic DNA sequence based on similarity to the zebrafish MBL gene. The catfish MBL demonstrated gene activity in the liver as would be expected for MBL, but gene expression rose significantly in spleen after fish were exposed to a bacterial pathogen. MBL is an important component of innate immunity in other vertebrates and further research will determine whether it can be used as a biomarker for catfish with improved immunity.

Technical Abstract: Mannose-binding lectin (MBL) is an important component of innate immunity capable of activating the lectin pathway of the complement system. A MBL gene was isolated from channel catfish (Ictalurus punctatus). The deduced protein contains a canonical collagen-like domain, a carbohydrate recognition domain (CRD), and a neck region similar to mammalian mannose-binding lectin. The catfish mannose-binding lectin CRD contains the EPN motif shown previously to mediate mannose specificity. The catfish mannose-binding lectin showed 30–43% identity with MBL protein sequences of rainbow trout, zebrafish, common carp, and goldfish, and 33–35% identity with sequences of mammalian species. In this study, while liver was the predominant source of mannose-binding lectin gene expression in healthy tissues, mannose-binding lectin expression in spleen rose sharply following challenge with a Gram-negative bacterium.