Department of Animal Science, University of Minnesota, Saint Paul, MN 55108, USA.
Int J Mol Sci. 2023 Apr 12;24(8):7109. doi: 10.3390/ijms24087109.
A genome-wide association study (GWAS) of age at first calving (AFC) using 813,114 first lactation Holstein cows and 75,524 SNPs identified 2063 additive effects and 29 dominance effects with -values < 10. Three chromosomes had highly significant additive effects in the regions of 7.86-8.12 Mb of Chr15, 27.07-27.48 Mb and 31.25-32.11 Mb of Chr19, and 26.92-32.60 Mb of Chr23. Two of the genes in those regions were reproductive hormone genes with known biological functions that should be relevant to AFC, the sex hormone binding globulin () gene, and the progesterone receptor () gene. The most significant dominance effects were near or in and of Chr05 and and of Chr06. All dominance effects were positive overdominance effects where the heterozygous genotype had an advantage, and the homozygous recessive genotype of each SNP had a very negative dominance value. Results from this study provided new evidence and understanding about the genetic variants and genome regions affecting AFC in U.S. Holstein cows.
一项针对首次产犊年龄（AFC）的全基因组关联研究（GWAS），使用了 813,114 头首次泌乳荷斯坦奶牛和 75,524 个 SNP，鉴定出 2063 个加性效应和 29 个显性效应，其 - 值 < 10。三个染色体在 Chr15 的 7.86-8.12 Mb、Chr19 的 27.07-27.48 Mb 和 31.25-32.11 Mb 以及 Chr23 的 26.92-32.60 Mb 区域具有高度显著的加性效应。这些区域的两个基因是具有已知生物学功能的生殖激素基因，应该与 AFC 相关，即性激素结合球蛋白（）基因和孕激素受体（）基因。最显著的显性效应位于 Chr05 的附近或和 Chr06 的附近。所有显性效应均为正超显性效应，杂合基因型具有优势，每个 SNP 的纯合隐性基因型具有非常负的显性值。这项研究的结果为美国荷斯坦奶牛 AFC 影响的遗传变异和基因组区域提供了新的证据和理解。
