MHC polymorphism and disease-resistance to Edwardsiella tarda in six turbot (Scophthalmus maximus) families

Abstract

This study examined genetic variation in the major histocompatibility complex (MHC) Class II B gene in turbot (Scophthalmus maximus) by virulent bacterial pathogen challenge. One hundred fry from each of six families were infected with Edwardsiella tarda by intraperitoneal injection. Family mortality ranged from 28.0% to 83.3%. Complete exon 2 and intron 1 sequences of MHC Class II B genes were amplified from five survivor and five non-survivor individuals per family using the clone-sequence method. Thirty-seven sequences from 60 individuals revealed 37 different alleles, 25 of which were unique to this study. The 25 unique alleles belonged to 16 major allele types. Nine alleles were used to examine the association between alleles and resistance/susceptibility to disease. Five alleles were present in an individual, suggesting a minimum of three loci or copies of the turbot MHC Class II B gene. The rate of non-synonymous substitution (d N ) was 2.30 and 1.58 times higher than synonymous substitution (d S ) in the peptide-binding regions (PBR) and non-PBR in whole families, respectively, which suggested balancing selection on exon 2 of the MHC Class II B gene in turbot. One allele, Scma-DBB1*02, was significantly more prevalent in survivor stock than in non-survivor stock (P=0.001). Therefore, this allele might be associated with resistance to bacteria. A second allele, Scma-DBB1*10, was significantly more prevalent in non-survivor stock (P=0.021), and is likely associated with susceptibility to bacteria. turbot (Scophthalmus maximus), Edwardsiella tarda, major histocompatibility complex II B, polymorphism, resistance, susceptibility

Isolation and characterization of polymorphic microsatellite markers in Bagarius yarrelli using RNA-Seq

“…Genomic DNA was isolated from fin tissues of each animal, using the phenol-chloroform method described by Du et al (2012). Following extraction, DNA samples were diluted to 100 µg/µL and stored at -20ºC until further use.…”

Association between MHC II beta chain gene polymorphisms and resistance to infectious haematopoietic necrosis virus in rainbow trout (Oncorhynchus mykiss, Walbaum, 1792)

“…; Du et al . ) respectively. Furthermore, we detected high polymorphism quantity parameters ( K = 16.357, Pi = 0.065).…”

“…In recent years, numerous studies concerning the association between MHC gene polymorphisms and disease resistance have been reported in fish (Zhang, Chen, Liu, Sha & Liu ; Croisetie`re, Tarte, Bernatchez & Belhumeur ; Xu, Chen, Ji & Tian ; Rakus, Wiegertjes, Jurecka, Walker, Pilarczyk & Irnazarow ; Xu, Chen & Zhang ; Li, Liu, Zhao, Ma, Feng & Wang ; Du, Chen, Liu, Niu, Yang & Zhang ). Rainbow trout ( Oncorhynchus mykiss ) are a cold‐water fish that are widely cultured in the global market and have high economic value.…”

Identification of potential molecular markers for disease resistance in giant gourami through major histocompatibility complex (MHC) II gene analysis

“…Molecular markers encoding disease-resistant characters have been studied in a number of aquaculture species. Allele-specific major histocompatibility complex (MHC) II correlates with disease resistance in tilapia (Zhou et al, 2013), goldfish (Hayuningtyas et al, 2013), rainbow trout (Dijkstra et al, 2013), Chinese long snout catfish (Shen et al, 2011), turbot Scophthalmus maximus (Du et al, 2012), Catfish (Alimuddin et al, 2018), and three-spined fish sticklebacks (Gasterosteus aculeatus) (Consuegra & de Leaniz, 2008;Kurtz et al, 2006;Wegner et al, 2006). It is also reported that there is a close relationship between MHC gene variation and resistance traits, such as in Atlantic salmon Salmo salar (Landry & Bernatchez, 2002), sockeye salmon, Oncorhynchus nelka (Miller et al, 2001).…”