Sequence polymorphism of two major histocompatibility (MH) class II B genes and their association with Vibrio anguillarum infection in half-smooth tongue sole (Cynoglossus semilaevis)
Sequence polymorphism of two major histocompatibility (MH) class II B genes and their association with Vibrio anguillarum infection in half-smooth tongue sole (Cynoglossus semilaevis)
复制标题
半滑舌鳎（Cynoglossus semilaevis）两个主要组织相容性（MH）II B类基因的序列多态性及其与鳗弧菌感染的关联
DOI：
10.1007/s00343-011-0278-1
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发表时间：
2011-11-01
影响因子：
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通讯作者：
Wang Xubo
中科院分区：
文献类型：
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作者：
Li Chunmei;Zhang Quanqi;Wang Xubo
主要组织相容性复合体（MHC）Ⅱ B类分子在鱼类适应性免疫应答中起重要作用。已有研究报道半滑舌鳎（Cynoglossus semilaevis）中存在两个高度多态的Ⅱ B类基因Cyse-DAB和Cyse-DBB。在这项研究中，在细菌挑战后的II B类基因外显子2内的多态性进行了评估。两百度。用鳗弧菌（Vibrioanguillarum）腹腔内注射半条尼罗鱼。从最初的20名死者和20名幸存者身上收集肌肉组织进行基因分型。从40个个体中分离到60个等位基因，其中32个属于Cyse-DAB，28个属于Cyse-DBB。在两个IIB类基因的PBRs（肽结合残基）中，dN（非同义取代）的发生率高于dS（同义取代）。相反，在非PBRs和外显子2全序列中，dS的比率高于和N。因此，结果表明，在PBRs中发生了正选择，而在非PBRs和外显子2中发生了纯化选择。使用13个IIB类等位基因来研究等位基因与感染抵抗力之间的关联。Cyse-DAB *0601、Cyse-DAB*0706和Cyse-DBB *0101、Cyse-DBB*1301等位基因仅在存活个体中发现，但不显著，可能代表对V具有抗性的等位基因。鳗感染等位基因Cyse-DAB *0701和Cyse-DAB *1301在死亡个体中比在存活个体中显著更普遍，并且可能代表与增加对V的易感性相关的等位基因。鳗感染
Major histocompatibility complex (MHC) class IIBmolecules play an important role in the adaptive immune response in fish. Previous study has reported that two highly polymorphic class IIBgenes,Cyse-DABandCyse-DBBexist in half-smooth tongue sole (Cynoglossus semilaevis). In this study, the polymorphism within exon 2 of the class IIBgenes following bacterial challenge was evaluated. Two hundredC. semilaevisindividuals were injected intraperitoneally withVibrio anguillarum. Muscle tissue from the first 20 dead and 20 of the survivors was collected for genotyping. Sixty alleles from the 40 individuals were isolated, of which 32 belonged toCyse-DABand 28 belonged toCyse-DBB. The rate ofdN(non-synonymous substitution) was higher than that ofdS(synonymous substitution) in the PBRs (peptide binding residues) of both class IIBgenes. Conversely, the rate ofdSwas higher thandNin the non-PBRs and the complete exon 2 sequence. Thus, the results suggest that positive selection has occurred in the PBRs and purifying selection in the non-PBRs and exon 2. Thirteen class IIBalleles were used to study the association between alleles and resistance to infection. Though not significant, allelesCyse-DAB*0601,Cyse-DAB*0706, andCyse-DBB*0101,Cyse-DBB*1301 were only found in surviving individuals and may represent alleles that have resistance againstV. anguillaruminfection. AllelesCyse-DAB*0701 andCyse-DAB*1301 were significantly more prevalent in dead individuals than in surviving ones and may represent alleles that are associated with increased susceptibility toV. anguillaruminfection.