Driver A M, Huang W, Gajic S, Monson R L, Rosa G J M, Khatib H
Department of Dairy Science, University of Wisconsin-Madison, Madison, WI 53706, USA.
J Dairy Sci. 2009 Aug;92(8):4082-5. doi: 10.3168/jds.2009-2013.
The progesterone receptor (PGR) gene is a key factor in the initiation and maintenance of pregnancy and in embryo development. Currently, it is unknown what variants of the PGR gene are related to fertility traits in cattle. Identification of such variants would allow the implementation of marker-assisted selection in breeding schemes. The objective of this study was to investigate the association of single nucleotide polymorphisms (SNP) of PGR with fertility traits in Holstein dairy cattle. An in vitro fertilization system was used to maximize the efficiency of the identification of genetic factors affecting fertility. This in vitro fertilization system would allow the assessment of fertilization and embryonic survival rates independently of influences from the uterine environment. A total of 5,566 fertilization attempts were performed, and a total of 3,679 embryos were produced using oocytes from 324 Holstein cows and semen from 10 Holstein bulls. Sequencing of pooled DNA samples from ovaries revealed an SNP (G/C) in intron 3 of PGR. A generalized linear model was used to analyze the association of this SNP with fertilization and embryonic survival rates for each ovary. Oocytes obtained from CC ovaries showed a 61% fertilization rate, compared with 68 and 69% for GC and GG ovaries, respectively. The survival rate of embryos produced from GG ovaries was 5 and 6% higher than that of GC and CC ovaries . These results indicate that the PGR SNP could be used in marker-assisted selection breeding programs in Holstein dairy cattle.
孕酮受体（PGR）基因是妊娠启动与维持以及胚胎发育过程中的关键因素。目前，尚不清楚PGR基因的哪些变体与奶牛的繁殖性状相关。识别这些变体将有助于在育种方案中实施标记辅助选择。本研究的目的是调查PGR单核苷酸多态性（SNP）与荷斯坦奶牛繁殖性状之间的关联。使用体外受精系统来最大化识别影响繁殖力的遗传因素的效率。这种体外受精系统能够独立于子宫环境的影响来评估受精率和胚胎存活率。总共进行了5566次受精尝试，使用来自324头荷斯坦奶牛的卵母细胞和10头荷斯坦公牛的精液共产生了3679个胚胎。对来自卵巢的混合DNA样本进行测序，发现PGR基因内含子3中有一个SNP（G/C）。使用广义线性模型分析该SNP与每个卵巢的受精率和胚胎存活率之间的关联。从CC卵巢获得的卵母细胞受精率为61%，而GC和GG卵巢的受精率分别为68%和69%。GG卵巢产生的胚胎存活率比GC和CC卵巢分别高5%和6%。这些结果表明，PGR SNP可用于荷斯坦奶牛的标记辅助选择育种计划。
