热应激对牛卵子及其胚胎表观遗传修饰与发育能力的影响  

Effects of Heat Stress on Epigenetic Modifications and Developmental Competence of Bovine Oocytes and Their Embryos

作　　者：冯肖艺 张培培 张航 郝海生[2] 杜卫华[2] 朱化彬[2] 崔凯[1] 赵学明[2] FENG Xiaoyi;ZHANG Peipei;ZHANG Hang;HAO Haisheng;DU Weihua;ZHU Huabin;CUI Kai;ZHAO Xueming(College of Animal Science and Technology,Qingdao Agricultural University,Qingdao 266109,China;Institute of Animal Science,Chinese Academy of Agricultural Sciences,Beijing 100193,China)

机构地区：[1]青岛农业大学动物科技学院,青岛266109 [2]中国农业科学院北京畜牧兽医研究所,北京100193

出　　处：《畜牧兽医学报》2024年第6期2460-2473,共14页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金国际合作项目(32161143032);国家重点研发计划政府间重点专项(2022YFE0100200);农业农村部和财政部资助:现代农业产业技术体系资助(CARS-36);中国农业科学院科技创新工程(ASTIP-IAS06)。

摘　　要：旨在探究热应激对牛卵子及其胚胎表观遗传修饰与发育能力的影响。本研究将卵子置于体外热应激条件下培养(41℃12 h+38.5℃12 h),进行体外成熟(in vitro maturtion, IVM)和体外受精(in vitro fertilization, IVF),检测对照组(38.5℃24 h)和热应激组牛卵子和胚胎的发育能力及表观遗传修饰组蛋白H1、组蛋白H2、组蛋白H4和DNA甲基化的修饰水平。本研究还检测了卵子活性氧(reactive oxygen species, ROS)水平、线粒体膜电位(mitochondrial membrane potential,ΔΨm)水平及与表观遗传修饰和发育能力相关基因的表达水平。结果表明,热应激处理组卵子成熟率((59.21±4.29)%)、卵裂率((57.78±4.58)%)和囊胚率((22.31±1.67)%)均显著低于对照组((85.10±6.75)%、(78.64±2.46)%、(42.64±1.38)%,P<0.05);热应激组牛卵子及各阶段胚胎表观遗传修饰组蛋白H1、组蛋白H2、组蛋白H4、DNA甲基化水平显著低于对照组(P<0.05);热应激组牛卵子ΔΨm水平显著低于对照组(P<0.05);热应激组牛卵子ROS水平显著高于对照组(P<0.05);热应激组牛卵子表观遗传修饰相关基因DNMT1、DNMT3A、DNMT3B、Histone H2A、SMYD3、IGF-2R的mRNA表达水平显著低于对照组(P<0.05);热应激组牛卵子发育能力相关基因C-MOS、GDF-9和POU5F1的mRNA表达水平显著低于对照组(P<0.05)。本研究表明,热应激显著降低了牛卵子和胚胎表观遗传修饰组蛋白H1、组蛋白H2、组蛋白H4、DNA甲基化水平,显著降低了牛卵子ΔΨm水平及与表观遗传修饰和发育能力相关基因的mRNA表达水平,显著提高了ROS水平,降低了卵子质量。The aim of this study was to investigate the effects of heat stress on epigenetic modifications and developmental capacity of bovine oocytes and their embryos.In this study,oocytes were cultured under in vitro heat stress conditions(41℃for 12 h+38.5℃for 12 h)for in vitro maturation(IVM)and in vitro fertilization(IVF).The developmental ability of oocytes and subsequent embryos and the modification levels of epigenetic modifications histone H1,histone H2,histone H4,and DNA methylation during oocyte development were examined in control(38.5℃for 24 h)and heat-stressed cattle.In this study,we also examined oocyte reactive oxygen species(ROS)levels,mitochondrial membrane potential(ΔΨm)levels,and expression levels of genes associated with epigenetic modifications and developmental competence.The results showed that the maturation rate((59.21±4.29)%),oocyte cleavage rate((57.78±4.58)%)and blastocyst rate((22.31±1.67)%)of the heat stress treatment group were significantly lower than those of the control group((85.10±6.75)%,(78.64±2.46)%,and(42.64±1.38)%,P<0.05);The levels of epigenetic modifications histone H1,histone H2,histone H4,and DNA methylation of bovine oocytes and embryos at all stages in the heat stress group were significantly lower than those of the control group(P<0.05);the level ofΔΨm of bovine oocytes in the heat stress group was significantly lower than that of the control group(P<0.05);the level of ROS in bovine oocytes of heat stress group was significantly higher than that of the control group(P<0.05);the mRNA expression levels of genes related to epigenetic modification of bovine oocytes DNMT1,DNMT 3A,DNMT 3B,Histone H 2A,SMYD 3,and IGF-2R were significantly lower in the heat stress group than in the control group(P<0.05);the mRNA expression levels of the genes C-MOS,GDF-9 and POU 5F1 related to oocyte developmental competence were significantly lower in the heat stress group than in the control group(P<0.05).In this study,we The results showed that heat stress significantly reduced the

关 键 词：热应激 牛 卵子 表观遗传修饰 发育能力 

分 类 号：S823.3[农业科学—畜牧学]