Kim K S, Larsen N, Short T, Plastow G, Rothschild M F
Department of Animal Science, Iowa State University, Ames 50011, USA.
Mamm Genome. 2000 Feb;11(2):131-5. doi: 10.1007/s003350010025.
Our knowledge of the genetic factors affecting obesity is increasing, but information about the individual gene effects remains limited in humans as well as in animal models. The melanocortin-4 receptor gene (MC4R) has been implicated in the regulation of feeding behavior and body weight in humans and mice. We have studied MC4R as a candidate gene for the control of economically important growth and performance traits in the pig. A missense mutation was identified in a region highly conserved among melanocortin receptor (MCR) genes. To determine whether there was an association of this MC4R polymorphism with phenotypic variation, we tested the mutation in a large number of individual animals from several different pig lines. Analyses of growth and performance test records showed significant associations of MC4R genotypes with backfat and growth rate in a number of lines as well as feed intake overall. It is probable that the variant amino acid residue of the MC4R mutation (or a closely linked mutation) causes a significant change of the MC4R function. These results support the functional significance of a pig MC4R missense mutation and suggest that comparative genomics based on model species may be equally important for application to farm animals as they are for human medicine.
我们对影响肥胖的遗传因素的了解正在增加，但关于单个基因效应的信息在人类和动物模型中仍然有限。黑皮质素-4受体基因（MC4R）已被证明与人类和小鼠的摄食行为及体重调节有关。我们将MC4R作为控制猪经济上重要的生长和生产性能性状的候选基因进行了研究。在黑皮质素受体（MCR）基因中高度保守的区域发现了一个错义突变。为了确定这种MC4R多态性与表型变异是否存在关联，我们在来自几个不同猪系的大量个体动物中检测了该突变。生长和生产性能测试记录分析表明，MC4R基因型与多个猪系的背膘厚度、生长速度以及总体采食量存在显著关联。MC4R突变的变异氨基酸残基（或紧密连锁的突变）很可能导致了MC4R功能的显著变化。这些结果支持了猪MC4R错义突变的功能重要性，并表明基于模式物种的比较基因组学对于应用于家畜可能与应用于人类医学同样重要。
