Zielke Lea G, Bortfeldt Ralf H, Tetens Jens, Brockmann Gudrun A
Department of Crop and Animal Sciences, Humboldt University of Berlin Berlin, Germany.
Front Genet. 2011 Apr 5;2:16. doi: 10.3389/fgene.2011.00016. eCollection 2011.
The gene encoding the brain-derived neurotrophic factor (BDNF) has been repeatedly associated with human obesity. As such, it could also contribute to the regulation of energy partitioning and the amount of secreted milk fat during lactation, which plays an important role in milk production in dairy cattle. Therefore, we performed an association study using estimated breeding values (EBVs) of bulls and yield deviations of German Holstein dairy cattle to test the effect of BDNF on milk fat yield (FY). A highly significant effect (corrected p-value = 3.362 × 10(-4)) was identified for an SNP 168 kb up-stream of the BDNF transcription start. The association tests provided evidence for an additive allele effect of 5.13 kg of fat per lactation on the EBV for milk FY in bulls and 6.80 kg of fat of the own production performance in cows explaining 1.72 and 0.60% of the phenotypic variance in the analyzed populations, respectively. The analyses of bulls and cows consistently showed three haplotype groups that differed significantly from each other, suggesting at least two different mutations in the BDNF region affecting the milk FY. The FY increasing alleles also had low but significant positive effects on protein and total milk yield which suggests a general role of the BDNF region in energy partitioning, rather than a specific regulation of fat synthesis. The results obtained in dairy cattle suggest similar effects of BDNF on milk composition in other species, including man.
编码脑源性神经营养因子（BDNF）的基因一直与人类肥胖症相关。因此，它也可能有助于调节能量分配以及哺乳期分泌乳脂肪的量，而这在奶牛产奶中起着重要作用。所以，我们利用公牛的估计育种值（EBV）和德国荷斯坦奶牛的产量偏差进行了一项关联研究，以测试BDNF对乳脂肪产量（FY）的影响。在BDNF转录起始位点上游168 kb处的一个单核苷酸多态性（SNP）被确定具有高度显著的效应（校正p值 = 3.362×10⁻⁴）。关联测试提供了证据，表明在公牛的牛奶FY的EBV上，每个泌乳期5.13千克脂肪的加性等位基因效应，以及在母牛自身生产性能上6.80千克脂肪的加性等位基因效应，分别解释了分析群体中1.72%和0.60%的表型变异。对公牛和母牛的分析一致显示出三个彼此差异显著的单倍型组，这表明BDNF区域至少有两个不同的突变影响牛奶FY。增加FY的等位基因对蛋白质和总产奶量也有低但显著的正向影响，这表明BDNF区域在能量分配中具有普遍作用，而不是对脂肪合成的特定调节。在奶牛中获得的结果表明BDNF对包括人类在内的其他物种的牛奶成分有类似影响。
