Department of Animal Genetics and Breeding, College of Animal Science and Technology, National Engineering Laboratory for Animal Breeding, China Agricultural University, Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Beijing 100193, China.
Beijing Dairy Cattle Center, Beijing 100192, China.
Genes (Basel). 2022 Aug 12;13(8):1437. doi: 10.3390/genes13081437.
Our preliminary work had suggested two genes, aldehyde dehydrogenase 18 family member A1 (ALDH18A1) and methionine adenosyltransferase 2A (MAT2A), related to amino acid synthesis and metabolism as candidates affecting milk traits by analyzing the liver transcriptome and proteome of dairy cows at different lactation stages. In this study, the single nucleotide polymorphisms (SNPs) of ALDH18A1 and MAT2A genes were identified and their genetic effects and underlying causative mechanisms on milk production traits in dairy cattle were analyzed, with the aim of providing effective genetic information for the molecular breeding of dairy cows. By resequencing the entire coding and partial flanking regions of ALDH18A1 and MAT2A, we found eight SNPs located in ALDH18A1 and two in MAT2A. Single-SNP association analysis showed that most of the 10 SNPs of these two genes were significantly associated with the milk yield traits, 305-day milk yield, fat yield, and protein yield in the first and second lactations (corrected p ≤ 0.0488). Using Haploview 4.2, we found that the seven SNPs of ALDH18A1 formed two haplotype blocks; subsequently, the haplotype-based association analysis showed that both haplotypes were significantly associated with 305-day milk yield, fat yield, and protein yield (corrected p ≤ 0.014). Furthermore, by Jaspar and Genomatix software, we found that 26:g.17130318 C>A and 11:g.49472723G>C, respectively, in the 5′ flanking region of ALDH18A1 and MAT2A genes changed the transcription factor binding sites (TFBSs), which might regulate the expression of corresponding genes to affect the phenotypes of milk production traits. Therefore, these two SNPs were considered as potential functional mutations, but they also require further verification. In summary, ALDH18A1 and MAT2A were proved to probably have genetic effects on milk production traits, and their valuable SNPs might be used as candidate genetic markers for dairy cattle’s genomic selection (GS).
我们的初步工作表明，醛脱氢酶 18 家族成员 A1（ALDH18A1）和蛋氨酸腺苷转移酶 2A（MAT2A）这两个与氨基酸合成和代谢有关的基因可能通过分析不同泌乳阶段奶牛的肝脏转录组和蛋白质组来影响牛奶性状，是候选基因。在这项研究中，我们鉴定了 ALDH18A1 和 MAT2A 基因的单核苷酸多态性（SNP），并分析了它们对奶牛产奶性状的遗传效应及其潜在的因果机制，旨在为奶牛的分子育种提供有效的遗传信息。通过对 ALDH18A1 和 MAT2A 基因的整个编码区和部分侧翼区进行重测序，我们发现了 8 个位于 ALDH18A1 中的 SNP 和 2 个位于 MAT2A 中的 SNP。单 SNP 关联分析表明，这两个基因的 10 个 SNP 中的大多数与第一和第二泌乳期的产奶量、乳脂产量和乳蛋白产量显著相关（校正后 p ≤ 0.0488）。使用 Haploview 4.2，我们发现 ALDH18A1 的 7 个 SNP 形成了两个单倍型块；随后，基于单倍型的关联分析表明，这两个单倍型均与 305 天产奶量、乳脂产量和乳蛋白产量显著相关（校正后 p ≤ 0.014）。此外，通过 Jaspar 和 Genomatix 软件，我们发现 ALDH18A1 和 MAT2A 基因的 5′侧翼区的 26:g.17130318 C>A 和 11:g.49472723G>C 分别改变了转录因子结合位点（TFBS），这可能调节相应基因的表达，从而影响产奶性状的表型。因此，这两个 SNP 被认为是潜在的功能突变，但还需要进一步验证。综上所述，ALDH18A1 和 MAT2A 可能对产奶性状有遗传效应，其有价值的 SNP 可能作为奶牛基因组选择（GS）的候选遗传标记。
