Goddard M E
School of Agriculture and Food Systems, University of Melbourne, Melbourne Australia and Department of Primary Industries, Victoria, Australia.
Dev Biol (Basel). 2008;132:383-389. doi: 10.1159/000317189.
The sequencing of genomes, such as that of the cow, has led to the discovery of thousands of single nucleotide polymorphisms (SNPs). By combining this knowledge with new methods that can genotype thousands of SNPs efficiently, it has become possible to carry out genome-wide association studies in domestic animals to map genes for complex traits, including disease resistance, using the linkage disequilibrium between the SNPs and the unknown genes affecting the trait of interest. Although experiments using 10,000 SNPs and 384 animals have found many significant associations, power calculations suggest that we need >50,000 SNPs and >1000 animals to map genes explaining most of the genetic variance for complex traits. Such experiments are now underway and the results will have two applications. Firstly, they will lead to panels of SNPs that can be used to accurately select animals with high breeding value for desired traits leading to a great increase in the rate of genetic improvement. Secondly, they will form the first step in identifying the genes and mutations that cause variation in complex traits. A collaborative approach to achieving this second goal is proposed.
对基因组（如牛的基因组）进行测序已发现了数千个单核苷酸多态性（SNP）。通过将这一知识与能够高效对数千个SNP进行基因分型的新方法相结合，利用SNP与影响目标性状的未知基因之间的连锁不平衡，在家畜中开展全基因组关联研究以定位复杂性状（包括抗病性）的基因已成为可能。尽管使用10000个SNP和384只动物进行的实验已发现了许多显著关联，但功效计算表明，我们需要超过50000个SNP和超过1000只动物才能定位出解释复杂性状大部分遗传变异的基因。此类实验正在进行中，其结果将有两个应用方向。首先，它们将产生SNP面板，可用于准确选择具有所需性状高育种价值的动物，从而大幅提高遗传改良速度。其次，它们将成为识别导致复杂性状变异的基因和突变的第一步。为此第二个目标提出了一种协作方法。
