中文摘要：

试验以川西北高原的乳用麦洼牦牛为研究对象,应用实时荧光定量PCR技术对麦洼牦牛乳腺组织中的氨酰-CoA合成酶长链家族成员1（acyl-CoA synthetase long-chain family member 1,ACSL1）、氨酰-CoA合成酶短链家族成员1、2（acyl-CoA synthetase short-chain family member 1、2,ACSS1、ACSS2）和脂肪酸结合蛋白家族成员3（fatty acid binding protein 3,FABP3）等乳脂代谢相关基因全泌乳期转录水平进行了分析。结果表明,4个基因在整个泌乳期均持续表达;分娩后30d（30d）ACSL1、ACSS1、ACSS2和FABP3基因的转录水平均比分娩前15d（-15d）显著增加（P〈0.05）,且达到最大值后逐步下降。产乳量测定结果表明,麦洼牦牛产乳量在120d达到峰值,比乳脂代谢相关基因峰值表达水平晚90d,其后产乳量逐步下降。结果表明,牦牛脂肪合成关键酶基因在全泌乳期的表达规律可能与牦牛对青藏高原生存环境的适应有关。

英文摘要：

The Maiwa yak, which were used as milk producer in the northwest plateau of Sichuan province, were selected as experimental animal. The Real-time quantitive （RT-PCR） was applied to detect the expression level of ACSL1, ACSS1, ACSS2 and FABP3 genes in the mammary gland of yak during the lactation cycle. The results showed that ACSL1, ACSS1, ACSS2 and FABP3 gene were consistently expressed during the whole lactation period. RT-PCR results showed that the expression level of all 4 genes consistently increased from time point -15 d, and the peak appeared at time point 30 d. The expression level of all 4 genes at 30 d significantly increased （P〈0.05） compared with time point -15 d. Meanwhile, the peak of milk yield was at time point 120, 90 d later than the peak of mRNA expression levels, then the milk yield consistently decreased till 240 d. These results implied that the expression pattern of milk fat synthesis gene during the lactation cycle reflected the yak’s genetic adaption to living environment in Tibetan plateau.