McCarthy S D, Butler S T, Patton J, Daly M, Morris D G, Kenny D A, Waters S M
Teagasc, Animal Production Research Centre, Athenry, Co Galway, Ireland.
J Dairy Sci. 2009 Oct;92(10):5229-38. doi: 10.3168/jds.2008-1856.
Differences in genetic selection criteria for dairy cows internationally have led to divergence in the Holstein-Friesian breed. The objective of this study was to compare hepatic expression of genes of the somatotropic axis in the North American Holstein-Friesian and the New Zealand Holstein-Friesian strains of dairy cow at early and mid lactation. Mature cows of both the North American Holstein-Friesian (n = 10) and New Zealand Holstein-Friesian (n = 10) strains were selected. Liver tissue was collected by percutaneous punch biopsy from all cows at 35 and 140 d postpartum, representing early and mid lactation, respectively. Total RNA was extracted and the hepatic expression of genes involved in the control of the somatotropic axis was examined. Abundance of insulin-like growth factor (IGF)-1 mRNA was greater in the New Zealand strain, concomitant with a tendency for increased expression of acid-labile subunit mRNA. Across strains, mRNA abundance of IGF-binding protein-1, IGF-binding protein-2, and growth hormone receptor 1A decreased from d 35 to 140 postpartum, whereas expression of IGF-1 and acid-labile subunit tended to increase. Abundance of suppressor of cytokine signaling-3 mRNA was increased at d 140 postpartum. Both the strain of Holstein-Friesian cow and the stage of lactation influenced expression of genes controlling the somatotropic axis in hepatic tissue.
国际上奶牛遗传选择标准的差异导致了荷斯坦-弗里生品种的分化。本研究的目的是比较北美荷斯坦-弗里生和新西兰荷斯坦-弗里生奶牛品系在泌乳早期和中期肝脏中生长激素轴相关基因的表达。选择了北美荷斯坦-弗里生（n = 10）和新西兰荷斯坦-弗里生（n = 10）品系的成年母牛。在产后35天和140天分别从所有母牛身上通过经皮穿刺活检采集肝脏组织，分别代表泌乳早期和中期。提取总RNA并检测参与生长激素轴调控的基因在肝脏中的表达。新西兰品系中胰岛素样生长因子（IGF）-1 mRNA的丰度更高，同时酸性不稳定亚基mRNA的表达有增加趋势。在所有品系中，产后35天至140天，IGF结合蛋白-1、IGF结合蛋白-2和生长激素受体1A的mRNA丰度下降，而IGF-1和酸性不稳定亚基的表达有增加趋势。产后140天时细胞因子信号转导抑制因子-3 mRNA的丰度增加。荷斯坦-弗里生奶牛的品系和泌乳阶段均影响肝脏组织中生长激素轴调控基因的表达。
