Identification and evolution characteristics of galectins and their roles in largemouth bass (Micropterus salmoides) following external stress

Abstract

Galectins (Gals) are evolutionally conserved endogenous beta-galactoside-binding lectins that can recognize specific carbohydrates on the surface of microorganisms. Thus far, they have not been systematically studied in largemouth bass (Micropterus salmoides). In this study, 13 Gals were identified in largemouth bass. Phylogenetic analysis together with gene structural analysis of coding/noncoding regions, motif information and gene location were performed, and the results showed that Gals were relatively well conserved. According to the expression profiles linked to environmental stresses, 12 Gal gene members were involved in the response to pathogen infection, and gal-2 and gal-3 showed significant changes after acute temperature stress. The Gal-2 gene was selected for investigating the roles of Gals in response to pathogen infection. The rMsGal-2 protein exhibited intense agglutination and binding abilities against pathogenic bacteria. Finally, a protein interaction network indicated that Gals participate in antibacterial defense by interacting with multiple pathways, such as the FN1a, Kras, and TLR pathways. This study lays a scientific basis for further functional studies of Gals in fish and provides theoretical support for maintaining the health of aquaculture organisms.