Mizoshita K, Watanabe T, Hayashi H, Kubota C, Yamakuchi H, Todoroki J, Sugimoto Y
Cattle Breeding Development Institute of Kagoshima Prefecture, Tsukino, Osumi, So, Kagoshima 899-8212, Japan.
J Anim Sci. 2004 Dec;82(12):3415-20. doi: 10.2527/2004.82123415x.
We used a half-sib family of purebred Japanese Black (Wagyu) cattle to locate economically important quantitative trait loci. The family was composed of 348 fattened steers, 236 of which were genotyped for 342 microsatellite markers spanning 2,664 cM of 29 bovine autosomes. The genome scan revealed evidence of 15 significant QTL (<5% chromosome-wise level) affecting growth and carcass traits. Of the 15 QTL, six QTL were significant at the 5% experiment-wise level and were located in bovine chromosomes (BTA) 4, 5, and 14. We analyzed these three chromosomes in more detail in the 348 steers, with an average marker interval of 1.2 cM. The second scan revealed that the same haplotype of the BTA 4 region (52 to 67 cM) positively affected LM area and marbling. We confirmed the QTL for carcass yield estimate on BTA 5 in the region of 45 to 54 cM. Five growth-related QTL located on BTA 14, including slaughter and carcass weights, were positively affected by the same region of the haplotype of BTA 14 (29-51 cM). These data should provide a useful reference for further marker-assisted selection in the family and positional cloning research. The research indicates that progeny design with moderate genotyping efforts is a powerful method for detecting QTL in a purebred half-sib family.
我们利用一个纯种日本黑牛（和牛）的半同胞家系来定位具有经济重要性的数量性状基因座。该家系由348头育肥牛组成，其中236头针对覆盖29条牛常染色体上2664厘摩的342个微卫星标记进行了基因分型。全基因组扫描发现了15个影响生长和胴体性状的显著数量性状基因座（染色体水平上小于5%）。在这15个数量性状基因座中，有6个在5%的实验水平上显著，位于牛染色体（BTA）4、5和14上。我们在这348头育肥牛中对这三条染色体进行了更详细的分析，平均标记间隔为1.2厘摩。第二次扫描显示，BTA 4区域（52至67厘摩）的相同单倍型对腰大肌面积和大理石花纹有正向影响。我们在45至54厘摩区域确认了BTA 5上胴体产量估计的数量性状基因座。位于BTA 14上的5个与生长相关的数量性状基因座，包括屠宰体重和胴体重，受到BTA 14单倍型相同区域（29 - 51厘摩）的正向影响。这些数据应为该家系进一步的标记辅助选择和定位克隆研究提供有用的参考。该研究表明，适度进行基因分型的后代设计是在纯种半同胞家系中检测数量性状基因座的有力方法。
