Georges M, Nielsen D, Mackinnon M, Mishra A, Okimoto R, Pasquino A T, Sargeant L S, Sorensen A, Steele M R, Zhao X
Genmark Inc., Salt Lake City, Utah 84108, USA.
Genetics. 1995 Feb;139(2):907-20. doi: 10.1093/genetics/139.2.907.
We have exploited "progeny testing" to map quantitative trait loci (QTL) underlying the genetic variation of milk production in a selected dairy cattle population. A total of 1,518 sires, with progeny tests based on the milking performances of > 150,000 daughters jointly, was genotyped for 159 autosomal microsatellites bracketing 1645 centimorgan or approximately two thirds of the bovine genome. Using a maximum likelihood multilocus linkage analysis accounting for variance heterogeneity of the phenotypes, we identified five chromosomes giving very strong evidence (LOD score > or = 3) for the presence of a QTL controlling milk production: chromosomes 1, 6, 9, 10 and 20. These findings demonstrate that loci with considerable effects on milk production are still segregating in highly selected populations and pave the way toward marker-assisted selection in dairy cattle breeding.
我们利用“后裔测定”对一个经过选育的奶牛群体中影响产奶量遗传变异的数量性状基因座（QTL）进行定位。总共1518头种公牛，基于超过150,000头女儿的挤奶性能进行后裔测定，对覆盖1645厘摩（约占牛基因组的三分之二）的159个常染色体微卫星进行了基因分型。使用考虑表型方差异质性的最大似然多位点连锁分析，我们确定了五条染色体，有非常强的证据（LOD分数≥3）表明存在控制产奶量的QTL：第1、6、9、10和20号染色体。这些发现表明，对产奶量有显著影响的基因座在高度选育的群体中仍在分离，并为奶牛育种中的标记辅助选择铺平了道路。
