Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
PLoS One. 2012;7(10):e46926. doi: 10.1371/journal.pone.0046926. Epub 2012 Oct 16.
Bay scallop (Argopecten irradians) is one of the most economically important aquaculture species in China. In this study, we constructed a consensus microsatellite-based genetic linkage map with a mapping panel containing two hybrid backcross-like families involving two subspecies of bay scallop, A. i. irradians and A. i. concentricus. One hundred sixty-one microsatellite and one phenotypic (shell color) markers were mapped to 16 linkage groups (LGs), which corresponds to the haploid chromosome number of bay scallop. The sex-specific map was 779.2 cM and 781.6 cM long in female and male, respectively, whereas the sex-averaged map spanned 849.3 cM. The average resolution of integrated map was 5.9 cM/locus and the estimated coverage was 81.3%. The proportion of distorted markers occurred more in the hybrid parents, suggesting that the segregation distortion was possibly resulted from heterospecific interaction between genomes of two subspecies of bay scallop. The overall female-to-male recombination rate was 1.13:1 across all linked markers in common to both parents, and considerable differences in recombination also existed among different parents in both families. Four size-related traits, including shell length (SL), shell height (SH), shell width (SW) and total weight (TW) were measured for quantitative trait loci (QTL) analysis. Three significant and six suggestive QTL were detected on five LGs. Among the three significant QTL, two (qSW-10 and qTW-10, controlling SW and TW, respectively) were mapped on the same region near marker AiAD121 on LG10 and explained 20.5% and 27.7% of the phenotypic variance, while the third (qSH-7, controlling SH) was located on LG7 and accounted for 15.8% of the phenotypic variance. Six suggestive QTL were detected on four different LGs. The linkage map and size-related QTL obtained in this study may facilitate marker-assisted selection (MAS) in bay scallop.
海湾扇贝（Argopecten irradians）是中国最重要的水产养殖经济物种之一。本研究构建了一张基于微卫星的共识遗传连锁图谱，图谱的作图群体包含了两个杂交回交类群，分别涉及到海湾扇贝的两个亚种，即辐射亚种种质和同心亚种种质。161 个微卫星标记和 1 个表型（壳色）标记被定位到 16 个连锁群（LGs）上，与海湾扇贝的单倍体染色体数相对应。雌性和雄性的性别特异图谱分别长 779.2 和 781.6cM，而性别平均图谱跨度为 849.3cM。整合图谱的平均分辨率为 5.9cM/标记，估计的覆盖率为 81.3%。标记的偏分离主要发生在杂交亲本中，表明偏分离可能是由两个亚种基因组之间的异源相互作用引起的。在两个家系中，所有连锁标记在双亲中共同的雌性到雄性的重组率为 1.13:1，不同亲本之间的重组率也存在显著差异。对壳长（SL）、壳高（SH）、壳宽（SW）和总重（TW）四个大小相关性状进行了数量性状位点（QTL）分析。在五个 LGs 上检测到 3 个显著和 6 个暗示性 QTL。在三个显著 QTL 中，两个（qSW-10 和 qTW-10，分别控制 SW 和 TW）被定位在 LG10 上标记 AiAD121 附近的同一区域，解释了 20.5%和 27.7%的表型方差，而第三个（qSH-7，控制 SH）位于 LG7 上，解释了 15.8%的表型方差。在四个不同的 LGs 上检测到 6 个暗示性 QTL。本研究获得的连锁图谱和大小相关 QTL 可能有助于海湾扇贝的标记辅助选择（MAS）。
