Khatkar Mehar S, Thomson Peter C, Tammen Imke, Raadsma Herman W
Centre for Advanced Technologies in Animal Genetics and Reproduction (ReproGen), and Co-operative Research Centre for Innovative Dairy Products, Faculty of Veterinary Science, University of Sydney, PMB 3, Camden NSW 2570, Australia.
Genet Sel Evol. 2004 Mar-Apr;36(2):163-90. doi: 10.1186/1297-9686-36-2-163.
From an extensive review of public domain information on dairy cattle quantitative trait loci (QTL), we have prepared a draft online QTL map for dairy production traits. Most publications (45 out of 55 reviewed) reported QTL for the major milk production traits (milk, fat and protein yield, and fat and protein concentration (%)) and somatic cell score. Relatively few QTL studies have been reported for more complex traits such as mastitis, fertility and health. The collated QTL map shows some chromosomal regions with a high density of QTL, as well as a substantial number of QTL at single chromosomal locations. To extract the most information from these published records, a meta-analysis was conducted to obtain consensus on QTL location and allelic substitution effect of these QTL. This required modification and development of statistical methodologies. The meta-analysis indicated a number of consensus regions, the most striking being two distinct regions affecting milk yield on chromosome 6 at 49 cM and 87 cM explaining 4.2 and 3.6 percent of the genetic variance of milk yield, respectively. The first of these regions (near marker BM143) affects five separate milk production traits (protein yield, protein percent, fat yield, fat percent, as well as milk yield).
通过对奶牛数量性状基因座（QTL）公共领域信息的广泛回顾，我们编制了一份奶牛生产性状在线QTL图谱草案。大多数出版物（55篇综述中的45篇）报道了主要产奶性状（产奶量、乳脂产量、乳蛋白产量以及乳脂率和乳蛋白率（%））和体细胞评分的QTL。相对较少有关于乳腺炎、繁殖力和健康等更复杂性状的QTL研究报道。整理后的QTL图谱显示了一些QTL高密度的染色体区域，以及单个染色体位置上大量的QTL。为了从这些已发表的记录中提取最多的信息，我们进行了一项荟萃分析，以就这些QTL的位置和等位基因替代效应达成共识。这需要对统计方法进行修改和开发。荟萃分析表明了一些共识区域，最显著的是在6号染色体上49厘摩和87厘摩处影响产奶量的两个不同区域，分别解释了产奶量遗传变异的4.2%和3.6%。其中第一个区域（靠近标记BM143）影响五个独立的产奶性状（乳蛋白产量、乳蛋白率、乳脂产量、乳脂率以及产奶量）。
