Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China.
Qingdao Agricultural University, Qingdao, China.
Mar Biotechnol (NY). 2018 Oct;20(5):666-675. doi: 10.1007/s10126-018-9837-1. Epub 2018 Jun 22.
Golden shell color and mineral content are important economic traits of Pacific oyster (Crassostrea gigas). In this study, we mapped a series of quantitative trait loci (QTLs) that control zinc (Zn) and magnesium (Mg) content, shell color and growth performance to two sex-averaged linkage maps from the FAM-A and FAM-B families. In total, ten QTLs were identified in seven linkage groups (LGs) in the FAM-B family, and seven QTLs were identified in four linkage groups in the FAM-A family. Two QTLs affecting the trait of golden shell color were identified in LG8 of the FAM-A and LG10 of the FAM-B families, which could explain 20.2 and 10.5% of the phenotypic variations, respectively. Two QTLs for Zn content were identified that could contribute to 17.9 and 34.44% of the phenotypic variations in FAM-A. Six QTLs for Zn and Mg contents were identified in four LGs (LG1, LG2, LG5, and LG9) in FAM-B, which explained 13.5-26.7% of the phenotypic variations. In addition, seven QTLs related to oyster growth were recognized in both FAM-A and FAM-B families accounting for 14.6-36.7% of the phenotypic variations. All of the DNA markers in QTL regions were blasted and 14 genes associated with above traits were identified. The mRNA expression of these genes was determined by quantitative RT-PCR. These QTLs and candidate genes could be used as potential targets for marker-assisted selection in C. gigas breeding.
金黄色贝壳颜色和矿物质含量是太平洋牡蛎（Crassostrea gigas）的重要经济性状。本研究以雌雄同体的 FAM-A 和 FAM-B 家系为材料，构建了 2 个连锁图谱，共检测到与锌（Zn）和镁（Mg）含量、贝壳颜色和生长性能相关的 10 个和 7 个数量性状位点（QTLs），分布在 7 个和 4 个连锁群（LGs）上。在家系 FAM-A 的 LG8 和 FAM-B 的 LG10 上定位到影响金黄色贝壳颜色的 2 个 QTL，分别解释表型变异的 20.2%和 10.5%。在家系 FAM-A 上定位到 2 个与 Zn 含量相关的 QTL，可解释表型变异的 17.9%和 34.44%。在家系 FAM-B 的 LG1、LG2、LG5 和 LG9 上定位到 6 个与 Zn 和 Mg 含量相关的 QTL，解释表型变异的 13.5%-26.7%。此外，在家系 FAM-A 和 FAM-B 上共检测到与生长相关的 7 个 QTL，解释表型变异的 14.6%-36.7%。对 QTL 区域的所有 DNA 标记进行 Blast 分析，鉴定出与上述性状相关的 14 个候选基因。通过定量 RT-PCR 检测这些基因的 mRNA 表达。这些 QTL 和候选基因可作为 C. gigas 遗传育种中标记辅助选择的潜在目标。
