建鲤生长性状QTL区间及其与镜鲤同源性比对

QTL for growth traits in Jian carp and inferred homologies in mirror carp

以建鲤（Cyprinus carpio var．jian）F．群体的94尾个体为材料，利用254个微卫星标记构建了建鲤的遗传图谱，并对体长、体高和体厚性状进行了QTL定位，共检测到17个生长相关性状QTL，分布在10个连锁群上，解释表型变异为10．8％～35．2％。以相同的分子标记，构建建鲤与镜鲤（Cyprinus carpio L．）的比较图谱，分析了建鲤和镜鲤群体生长性状QTL的同源性关系。结果表明，建鲤与镜鲤图谱具有广泛的共线性或同线性关系，建鲤每个连锁群在镜鲤图谱中均找到了对应的同源连锁群，其中建鲤10个生长性状QTL与镜鲤13个相同性状QTL具有同源性，同源比例高达58．8％。同时发现，建鲤QTL置信区间相对较大，与之同源的镜鲤QTL置信区间较小，通常位于建鲤QTL子区间内，定位结果更精细。此外，建鲤与镜鲤连锁群上都存在QTL的富集区域，而这些富集区域常常存在于同源连锁群的共线性区域，可作为标记辅助选择的重点区域。鲤通用QTL的发掘，为分子标记辅助育种和更进一步的精细定位打下基础。

We used an F1 population consisting of 94 individuals to construct a linkage map for Jian carp （Cyprinus carpio var. jian） using 254 microsatellite markers. We identified 17 quantitative trait loci for body length, body height, and body thickness on 10 linkage groups （LG）, which explained 10.8%-35.2% of the phenotypic variance. Comparative mapping between Jian carp and mirror carp （Cyprinus carpio L.） was used to assess the homology of quantitative trait loci for growth traits based on the same markers. A comparative analysis revealed extensive synteny or collinearity between the two varieties and each Jian carp LG showed homology towards a single mirror carp LG, sharing two or more loci with mirror carp LG in most cases. Ten QTLs for growth traits in Jian carp were conserved compared with 13 QTL for the same traits in mirror carp, accounting for 58.8% of the total. The QTL confidence interval in mirror carp was more precise than the homologous interval in Jian carp, which was generally contained within the QTL interval in Jian carp. Of note, we observed QTL rich regions on the LG in Jian carp and mirror carp, where QTL affecting different traits were generally clustered. The orthologous rich regions between the two varieties may represent ＂hot spots＂ for marker assisted selection. The detection of consensus QTL provides a basis for marker assisted breeding and fine mapping in carp.