不同氧气浓度对绵羊体外受精胚胎凋亡相关基因表达的影响

目的]研究绵羊胚胎体外发育过程中细胞凋亡的机制,以进一步提高胚胎体外发育能力。方法]利用Real-time PCR技术,分别检测凋亡相关基因Mcl-1、Bad、Bak、Bik和Caspase-3在低氧环境(5%O2)和高氧环境(20%O2)培养的绵羊体外受精(IVF)胚胎中的表达水平。结果]不论是高氧环境还是低氧环境,从2-细胞阶段到囊胚期均可检测到Mcl-1、Bad、Bak、Bik和Caspase-3的表达,Caspase-3基因表达水平随着胚胎的发育有逐渐增高的趋势,且高氧和低氧间差异不显著(P0.05);从8-16细胞期开始,Mcl-1、Bad、Bak和Bik表达水平都显著增加,且低氧环境中的表达水平均明显低于高氧环境中的表达水平(P0.05)。结论]氧气浓度在一定程度上影响了绵羊胚胎中凋亡相关基因的表达,绵羊胚胎细胞凋亡可能是凋亡相关基因Mcl-1、Bad、Bak、Bik和Caspase-3相互协同的结果。

Effect of Different Oxygen Tension on the Expression of Apoptosis Related Genes in Sheep in vitro Fertilization(IVF) Embryos

Objective] In order to investigate the mechanism of sheep IVF （in vitro fertihzation） embryo apoptosis and improve the develop- ment of embryo. Method] The expression profiles of Mcl-1, Bad, Bak, Bik and Caspase-3 genes were detected by real-time PCR in the sheep IVF embryos which cultured in 5% 02 and 20% 02 environment. Result] The expression of Mcl-1, Bad, Bak, Bik and Caspase-3 genes can be detected from the 2-cell stage to the blastocyst in the sheep IVF embryos, regardless of cultured in 5% 02 or20% 02 environment. The expression level of Caspase-3 gene was increasing gradually with the development of the embryo, but there were no significant differences in 5% vs 20% O2 groups （P 〉 O. 05 ）. The expression levels of Mcl-1, Bad, Bak and Bik were significantly increased from 8-16 cell stage, and the expression level of Mcl-1, Bad, Bak and Bik in 5% 02 group were significantly lower than those of 20% O5 group （P 〈 O. 05）. Conclu- sion] The oxygen tension of culture environment can influence the expression of apoptosis related genes Mcl-1, Bad, Bak, Bik and Caspase-3 in sheep IVF embryos. These genes might affect synergistically the apoptosis process of sheep IVF embryos.