Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Dairy Cattle Genetic, Breeding and Reproduction, Beijing Dairy Cattle Center, Beijing 100192, China.
Genes (Basel). 2019 Jun 13;10(6):449. doi: 10.3390/genes10060449.
We previously used the RNA sequencing technique to detect the hepatic transcriptome of Chinese Holstein cows among the dry period, early lactation, and peak of lactation, and implied that the nucleobindin 2 () gene might be associated with milk production traits due to its expression being significantly increased in early lactation or peak of lactation as compared to dry period ( value < 0.05). Hence, in this study, we detected the single nucleotide polymorphisms (SNPs) of and analyzed their genetic associations with milk yield, fat yield, fat percentage, protein yield, and protein percentage. We re-sequenced the entire coding and 2000 bp of 5' and 3' flanking regions of by pooled sequencing, and identified ten SNPs, including one in 5' flanking region, two in 3' untranslated region (UTR), and seven in 3' flanking region. The single-SNP association analysis results showed that the ten SNPs were significantly associated with milk yield, fat yield, fat percentage, protein yield, or protein percentage in the first or second lactation ( values <= 1 × 10 and 0.05). In addition, we estimated the linkage disequilibrium (LD) of the ten SNPs by Haploview 4.2, and found that the SNPs were highly linked in one haplotype block (D' = 0.98-1.00), and the block was also significantly associated with at least one milk traits in the two lactations ( values: 0.0002-0.047). Further, we predicted the changes of transcription factor binding sites (TFBSs) that are caused by the SNPs in the 5' flanking region of , and considered that g.35735477C>T might affect the expression of by changing the TFBSs for ETS transcription factor 3 (ELF3), caudal type homeobox 2 (CDX2), mammalian C-type LTR TATA box (VTATA), nuclear factor of activated T-cells (NFAT), and v-ets erythroblastosis virus E26 oncogene homolog (ERG) (matrix similarity threshold, MST > 0.85). However, the further study should be performed to verify the regulatory mechanisms of and its polymorphisms on milk traits. Our findings first revealed the genetic effects of on the milk traits in dairy cows, and suggested that the significant SNPs could be used in genomic selection to improve the accuracy of selection for dairy cattle breeding.
我们先前使用 RNA 测序技术检测了中国荷斯坦奶牛干奶期、泌乳早期和泌乳高峰期的肝转录组，并暗示核结合蛋白 2()基因可能与产奶性状有关，因为与干奶期相比，其在泌乳早期或高峰期的表达显著增加（<0.05）。因此，在这项研究中，我们检测了和的单核苷酸多态性（SNPs），并分析了它们与产奶量、乳脂产量、乳脂率、蛋白产量和蛋白率的遗传关联。我们通过混合测序重新测序了的整个编码区和 5'侧翼区 2000bp，鉴定了 10 个 SNPs，包括 1 个 5'侧翼区，2 个 3'非翻译区（UTR）和 7 个 3'侧翼区。单 SNP 关联分析结果表明，这 10 个 SNPs 在第一或第二泌乳期与产奶量、乳脂产量、乳脂率、蛋白产量或蛋白率显著相关（值<=1×10和 0.05）。此外，我们通过 Haploview 4.2 估计了这 10 个 SNPs 的连锁不平衡（LD），发现这些 SNPs 在一个单倍型块中高度连锁（D'=0.98-1.00），并且该块在两个泌乳期与至少一个产奶性状显著相关（值：0.0002-0.047）。进一步，我们预测了 5'侧翼区 SNPs 引起的转录因子结合位点（TFBS）的变化，认为 g.35735477C>T 可能通过改变 ETS 转录因子 3（ELF3）、尾型同源盒 2（CDX2）、哺乳动物 C 型 LTR TATA 盒（VTATA）、核因子活化 T 细胞（NFAT）和 v-ets 红白血病病毒 E26 癌基因同源物（ERG）的 TFBS 而影响的表达（基质相似性阈值，MST>0.85）。然而，应进一步研究以验证和多态性对产奶性状的调节机制。我们的研究结果首次揭示了在奶牛中对产奶性状的遗传效应，并表明显著的 SNP 可用于基因组选择，以提高奶牛育种选择的准确性。
