A genome-wide association study for host resistance to Ostreid Herpesvirus in Pacific oysters ( Crassostrea gigas )
A genome-wide association study for host resistance to Ostreid Herpesvirus in Pacific oysters ( Crassostrea gigas )
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太平洋牡蛎（Crassostrea gigas）宿主对牡蛎疱疹病毒抗性的全基因组关联研究
DOI：
10.1101/223032
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Gutierrez A
中科院分区：
文献类型：
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作者：
Gutierrez A
牡蛎疱疹病毒（Ostreid herpesvirus，OsHV）可引起太平洋牡蛎养殖业的大规模死亡事件。虽然各种因素影响疫情的严重程度，但宿主的遗传抗性显然是死亡率的一个重要决定因素。这提高了选择性育种策略的可能性，以提高养殖牡蛎种群的遗传抗性，从而有助于疾病控制。传统的选择育种可以通过使用遗传标记来增强，无论是通过标记辅助还是基因组选择。本研究的目的是调查太平洋牡蛎对OsHV抗性的遗传结构，确定含有推定抗性基因的基因组区域，并利用基因组学来提高抗性育种的努力。为了实现这一目标，用OsHV的毒性形式对1,000只幼牡蛎进行了实验性挑战，从死亡和存活者中采集样品进行基因分型和qPCR测量病毒载量。使用最近开发的SNP阵列对样本进行基因分型，并使用基因型数据重建系谱。利用这些系谱和基因型数据，构建了太平洋牡蛎的第一个高密度连锁图谱，包含20，353个SNPs定位到10对染色体上。对OsHV抗性的遗传参数进行了估计，表明存活的二元性状和病毒载量测量（h2 0.12 - 0.25）具有显著但较低的遗传力。一个全基因组关联研究突出了一个区域的连锁群6含有一个显着的QTL影响寄主抗性。这些结果是鉴定牡蛎抗OsHV基因的重要一步，也是应用基因组数据加强牡蛎养殖抗病育种的重要一步。
Ostreid herpesvirus (OsHV) can cause mass mortality events in Pacific oyster aquaculture. While various factors impact on the severity of outbreaks, it is clear that genetic resistance of the host is an important determinant of mortality levels. This raises the possibility of selective breeding strategies to improve the genetic resistance of farmed oyster stocks, thereby contributing to disease control. Traditional selective breeding can be augmented by use of genetic markers, either via marker-assisted or genomic selection. The aim of the current study was to investigate the genetic architecture of resistance to OsHV in Pacific oyster, to identify genomic regions containing putative resistance genes, and to inform the use of genomics to enhance efforts to breed for resistance. To achieve this, a population of ∼1,000 juvenile oysters were experimentally challenged with a virulent form of OsHV, with samples taken from mortalities and survivors for genotyping and qPCR measurement of viral load. The samples were genotyped using a recently-developed SNP array, and the genotype data were used to reconstruct the pedigree. Using these pedigree and genotype data, the first high density linkage map was constructed for Pacific oyster, containing 20,353 SNPs mapped to the ten pairs of chromosomes. Genetic parameters for resistance to OsHV were estimated, indicating a significant but low heritability for the binary trait of survival and also for viral load measures (h2 0.12 – 0.25). A genome-wide association study highlighted a region of linkage group 6 containing a significant QTL affecting host resistance. These results are an important step toward identification of genes underlying resistance to OsHV in oyster, and a step toward applying genomic data to enhance selective breeding for disease resistance in oyster aquaculture.