Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
Anim Genet. 2021 Feb;52(1):99-107. doi: 10.1111/age.13016. Epub 2020 Oct 21.
Mature body size is genetically correlated with growth rate, an important economic trait in the sheep industry. Mature body size has been studied extensively in humans as well as cattle and other domestic animal populations but not in sheep. Six-hundred and sixteen ewes, across 22 breeds, were measured for 28 linear measurements representing various skeletal parts. PCA from these measures generated principal components 1 and 2 which represented 66 and 7% of the phenotypic variation respectively. Two-hundred and twenty sheep were genotyped on the Illumina Ovine HD beadchip for a GWAS investigating mature body size and linear body measurements. Forty-six (Bonferroni P < 0.05) SNP associations across 14 chromosomes were identified utilizing principal component 1, representing overall body size, revealing mature body size to have fewer loci of large effect than other domestic species such as dogs and horses. Genome-wide associations for individual linear measures identified major quantitative trait loci for withers height and ear length. Withers height was associated (Bonferroni P < 0.05) with 12 SNPs across six chromosomes whereas ear length was associated with a single locus on chromosome 3, containing MSRB3. This analysis identified several loci known to be associated with mature body size in other species such as NCAPG, LCORL, and HMGA2. Mature body size is more polygenic in sheep than other domesticated species, making the development of genomic selection for the trait the most efficient option for maintaining or reducing mature body size in sheep.
成熟体尺与生长速度密切相关，这是绵羊产业的一个重要经济性状。成熟体尺在人类以及牛和其他家畜群体中已经得到了广泛的研究，但在绵羊中尚未进行研究。对 22 个绵羊品种的 616 只母羊进行了 28 个线性测量，这些测量代表了各种骨骼部位。对这些测量值进行 PCA 生成了主成分 1 和 2，分别代表了 66%和 7%的表型变异。对 220 只绵羊进行了 Illumina Ovine HD 珠芯芯片的基因分型，以进行一项关于成熟体尺和线性体尺的全基因组关联研究。利用主成分 1 鉴定了 14 条染色体上的 46 个 SNP 关联（Bonferroni P<0.05），这些 SNP 代表了整体体尺，表明成熟体尺的大效应基因座数量比狗和马等其他家畜物种要少。对个体线性测量的全基因组关联研究确定了肩高和耳长的主要数量性状基因座。肩高与 6 条染色体上的 12 个 SNP 相关（Bonferroni P<0.05），而耳长与 3 号染色体上的单个基因座相关，该基因座包含 MSRB3。这项分析确定了几个与其他物种成熟体尺相关的基因座，如 NCAPG、LCORL 和 HMGA2。成熟体尺在绵羊中的多基因性比其他驯化物种更高，因此开发针对该性状的基因组选择是维持或减少绵羊成熟体尺的最有效选择。
