Lindersson M, Andersson-Eklund L, de Koning D J, Lundén A, Mäki-Tanila A, Andersson L
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
J Dairy Sci. 1998 May;81(5):1454-61. doi: 10.3168/jds.S0022-0302(98)75709-1.
The present study was undertaken to confirm and refine the mapping of a quantitative trait locus in cattle for milk fat percentage that had earlier been reported to be linked to the serum amylase-1 locus, AM1. Five half-sib families from the previous study and 7 new ones were genotyped for nine microsatellite markers spanning chromosome 4. AM1 was mapped between the microsatellite markers BMS648 and BR6303. In a granddaughter design, interval mapping based on multiple-marker regression was utilized for an analysis of five milk production traits: milk yield, fat percentage and yield, and protein percentage and yield. In the families reported on previously, significant effects for fat and protein percentages were detected. In the new families, an effect on milk and fat yields was found. The most likely positions of the quantitative trait locus in both groups of families were in the same area of chromosome 4 in the vicinity of the obese locus. Direct effects of the obese locus were tested for using polymorphism in two closely linked microsatellites located 2.5 and 3.6 top downstream of the coding sequence. No firm evidence was found for an association between the obese locus and the tested traits.
本研究旨在确认并完善牛的乳脂率数量性状位点的定位，该位点此前报道与血清淀粉酶-1位点（AM1）相关。对先前研究中的五个半同胞家系和七个新的家系进行了基因分型，检测了跨越4号染色体的九个微卫星标记。AM1被定位在微卫星标记BMS648和BR6303之间。在一个孙女设计中，基于多标记回归的区间定位被用于分析五个产奶性状：产奶量、乳脂率和乳脂产量，以及蛋白质率和蛋白质产量。在先前报道的家系中，检测到了对乳脂率和蛋白质率的显著影响。在新的家系中，发现了对产奶量和乳脂产量的影响。两组家系中数量性状位点最可能的位置都在4号染色体上靠近肥胖位点的同一区域。利用位于编码序列上游2.5和3.6厘摩处的两个紧密连锁微卫星中的多态性，对肥胖位点的直接效应进行了检测。未发现肥胖位点与所检测性状之间存在关联的确凿证据。
