L-Rhamnose-binding lectins (RBLs) in channel catfish, Ictalurus punctatus: Characterization and expression profiling in mucosal tissues.
Rhamnose-binding lectins (RBLs) have recently emerged as important molecules in the context of innate immunity in teleost fishes. Previously, using RNA-seq technology, we observed marked up-regulation of a RBL in channel catfish (Ictalurus punctatus) gill following a challenge with the bacterial pathogen Flavobacterium columnare. Furthermore, the magnitude of RBL up-regulation positively correlated with disease susceptibility. Moving forward from these findings, we wished to more broadly understand RBL function, diversity, and expression kinetics in channel catfish. Therefore, in the present study we characterized the RBL gene family present in select channel catfish tissues and profiled family member expression after challenge with two different Gram-negative bacterial pathogens. Here, six RBLs were identified from channel catfish and were designated IpRBL1a, IpRBL1b, IpRBL1c, IpRBL3a, IpRBL3b, and IpRBL5a. These RBLs contained carbohydrate recognition domains (CRD) ranging from one to three domains and each CRD contained the conserved motifs of -YGR- and -DPC-. Despite a level of structural conservation, the catfish RBLs showed low full-length identity with RBLs from outside the order Siluriformes. IpRBL expression after bacterial infection varied depending on both pathogen and tissue type, suggesting that IpRBLs may exert disparate functions or exhibit distinct tissue-selective roles in the host immune response to bacterial pathogens.
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
Wilawan
W
Thongda
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
Chao
C
Li
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
Yupeng
Y
Luo
United States Department of Agriculture, Agricultural Research Service, Stuttgart National Aquaculture Research Center, Stuttgart, AR 72160, USA.
Benjamin H
BH
Beck
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA. Electronic address: peatmer@auburn.edu.
Eric
E
Peatman
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D002397:Catfishes / Q000276:immunology; D020610:Edwardsiella ictaluri / Q000276:immunology*; D004756:Enterobacteriaceae Infections / Q000276:immunology*; D045826:Flavobacteriaceae Infections / Q000276:immunology*; D005417:Flavobacterium / Q000276:immunology*; D007059:Ictaluridae / Q000276:immunology*; D018928:Immunity, Mucosal; D037102:Lectins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009092:Mucous Membrane / Q000378:metabolism*; D009928:Organ Specificity; D017434:Protein Structure, Tertiary / Q000235:genetics; D012210:Rhamnose / Q000378:metabolism; D016415:Sequence Alignment; D040681:Structural Homology, Protein; D059467:Transcriptome; D015854:Up-Regulation
D037102:Lectins; D012210:Rhamnose
Catfish; Infection; Mucosal immunity; Rhamnose-binding lectin