Major histocompatibility IIβ diversity and peptide-binding groove properties associated with red sea bream iridovirus resistance
Major histocompatibility IIβ diversity and peptide-binding groove properties associated with red sea bream iridovirus resistance
复制标题
与红鲷虹彩病毒抗性相关的主要组织相容性 IIβ 多样性和肽结合沟特性
DOI：
10.1016/j.aquaculture.2022.738038
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发表时间：
2022
期刊：
影响因子：
4.5
通讯作者：
Kitamura Shin-Ichi
中科院分区：
文献类型：
--
作者：
Sawayama Eitaro;Tanizawa Shiho;Nakayama Kei;Ito Risa;Akase Yuri;Kitamura Shin-Ichi
主要组织相容性复合体（MHC）II基因是将来自细胞外病原体的抗原呈递给CD 4 +T细胞的关键因子。已知这些基因与家畜（包括养殖鱼类）的抗病性有关。抗RSIV红鲷的全基因组连锁分析表明，MHC IIβ基因与RSIV抗性性状连锁，可能是控制RSIV抗性性状的候选基因。本研究通过对一个内含子小卫星位点PmaMHC 2b的分析，对野生和养殖红鲷群体的MHC IIβ基因多样性进行了研究。通过克隆鉴定了MHC IIβ βI区的单倍型，并在养殖群体中证实了小卫星多态性与单倍型的连锁。在野生种群中观察到大量等位基因（30），而驯化种群显示出显著较低的值（13）。观察到13种单倍型，大多数单倍型具有唯一的PmaMHC 2球，但有些单倍型存在于一个以上的PmaMHC 2球。每个单倍型具有不同的氨基酸序列，没有同义突变。在16个氨基酸的位置参与肽结合沟，4个是单态和12个多态性。RSIV抗性和RSIV敏感表型中有几个位置不同：5个在亲水/疏水特性中，5个在极性中。这些结果提供了适用于亲鱼管理的见解，并有助于了解RSIV抗性。
Major histocompatibility complex(MHC)IIgenes are key factors in presenting antigens derived from extracellular pathogens to CD4+T cells. These genes are known to be associated with disease resistance in livestock, including cultured fish species. Genome-wide linkage analysis of RSIV-resistant red sea bream has revealed thatMHC IIβis linked to the RSIV-resistant trait and was suggested as a probable candidate gene responsible for the resistant trait. In the present study, diversity of theMHC IIβgene in wild and farmed red sea bream populations was evaluated by analysis of an intronic minisatellite locus,PmaMHC2b. Haplotypes of the βI domain ofMHC IIβwere identified by cloning, and linkage of minisatellite polymorphisms with haplotype was confirmed in farmed populations. Large numbers of alleles were observed in the wild population (30), while the domesticated populations showed significantly lower values (13). Thirteen haplotypes ofMHC IIβwere observed; most haplotypes possessed the uniquePmaMHC2ballele, but some were present in more than onePmaMHC2ballele. Each haplotype possessed a distinct amino acid sequence with no synonymous mutations. Among 16 amino acid positions involved in peptide-binding grooves, four were monomorphic and 12 polymorphic. Several positions differed in the RSIV-resistant and RSIV-susceptible phenotypes: five in hydrophilic/hydrophobic character and five in polarity. These results provide insight applicable to broodstock management and contribute to understanding RSIV resistance.