Shi D-S, Wang J, Yang Y, Lu F-H, Li X-P, Liu Q-Y
State Key Laboratory for Conservation and Utilization of Agricultural Bioresources in the Subtropics, Guangxi University, Nanning, China.
Reprod Domest Anim. 2012 Apr;47(2):328-34. doi: 10.1111/j.1439-0531.2011.01876.x. Epub 2011 Aug 30.
The polymorphism of several genes has been shown to affect the milk composition traits in dairy cattle, including DGAT1-exon8 K232A, GH-intron3 MspI, GH-exon5 AluI, GHR-exon8 F279Y, PRL-exon3 RsaI and PRLR-exon3 S18N. However, the polymorphism and effects of these genes on the milk traits of water buffalo are still unclear. In this study, four DNA pooling samples from Murrah, Nili-ravi, Murrah-Nili-Swamp crossbreed and Chinese swamp buffalo were constructed, respectively, and polymorphism of these sites was investigated using PCR-Single-strand conformation polymorphism and sequencing. Twenty-eight inter-specific single-nucleotide polymorphism (SNPs) were found in these six assayed gene fragments between buffalo and dairy cattle, including nine intra-specific SNPs among buffalo groups. All buffalo fixed a K allele genotype in DGAT1-exon8, MspI(+) restriction site(c nucleotide) and AluI(+) site(c nucleotide) at intron3 and exon5 of GH gene, F allele genotype of F279Y mutation in GHR gene, RsaI(-) restriction site at PRL-exon3/exon4 and N allele genotype of S18N mutation at PRLR-exon3. It provides an indirect evidence that water buffalo have fixed alleles with genotypes reported in dairy cattle, which is thought to be responsible for high milk fat, high protein content and low milk yield. Moreover, three new intra-specific SNPs were found including 275th bp (c/t) in DGAT1 of Murrah buffalo, 109th bp (t/a) in PRL-exon3/exon4 and 43rd bp (c/t) in PRLR-exon3 of Chinese swamp buffalo. Information provided in this study will be useful in further studies to improve buffalo breeding for better lactation performances.
已有研究表明，多个基因的多态性会影响奶牛的乳成分性状，包括二酰甘油酰基转移酶1（DGAT1）基因第8外显子K232A突变、生长激素（GH）基因第3内含子MspI酶切位点、GH基因第5外显子AluI酶切位点、生长激素受体（GHR）基因第8外显子F279Y突变、催乳素（PRL）基因第3外显子RsaI酶切位点以及催乳素受体（PRLR）基因第3外显子S18N突变。然而，这些基因在水牛乳性状上的多态性及其影响仍不清楚。本研究分别构建了摩拉水牛、尼里-拉菲水牛、摩拉-尼里-沼泽杂交水牛和中国沼泽水牛的4个DNA混合样本，并采用聚合酶链反应-单链构象多态性分析和测序技术对这些位点的多态性进行了研究。在水牛和奶牛的这6个被检测基因片段中发现了28个种间单核苷酸多态性（SNP），其中包括水牛群体间的9个种内SNP。所有水牛在DGAT1基因第8外显子、GH基因第3内含子和第5外显子的MspI（+）酶切位点（c核苷酸）和AluI（+）位点（c核苷酸）固定为K等位基因基因型，在GHR基因的F279Y突变处固定为F等位基因基因型，在PRL基因第3外显子/第4外显子处为RsaI（-）酶切位点，在PRLR基因第3外显子的S18N突变处固定为N等位基因基因型。这间接证明了水牛固定了与奶牛报道的基因型相同的等位基因，这些等位基因被认为与高乳脂、高蛋白含量和低产奶量有关。此外，还发现了3个新的种内SNP，包括摩拉水牛DGAT1基因第275位碱基（c/t）、中国沼泽水牛PRL基因第3外显子/第4外显子第109位碱基（t/a）以及PRLR基因第3外显子第43位碱基（c/t）。本研究提供的信息将有助于进一步开展研究，以改良水牛品种，提高泌乳性能。
