Disparate consequences of heat stress exposure during meiotic maturation: embryo development after chemical activation vs fertilization of bovine oocytes
Disparate consequences of heat stress exposure during meiotic maturation: embryo development after chemical activation vs fertilization of bovine oocytes
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DOI：
10.1530/rep-11-0032
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发表时间：
2011-12-01
期刊：
影响因子：
3.8
通讯作者：
Edwards, J. L.
中科院分区：
文献类型：
--
作者：
Rispoli, L. A.;Lawrence, J. L.;Edwards, J. L.
在减数分裂成熟的前12小时，热应激暴露的后果取决于牛卵母细胞如何和何时被激活。如果热应激卵母细胞在类似于24小时进行体外受精，囊胚发育少于相应的对照组，并且与非热应激卵母细胞在30小时进行体外受精（即轻度衰老）时获得的囊胚发育相似。相反，如果热应激卵母细胞在24小时被离子霉素/6-二甲氨基嘌呤化学激活，囊胚发育不仅高于各自的对照组，而且与非热应激卵母细胞在30小时被激活后获得的发育相当。化学激活与体外受精胚胎的发育差异与受精失败或细胞骨架成分的明显改变无关。相反，离子霉素诱导的钙释放和MAP激酶活性在热应激卵母细胞中较低。虽然潜在的机制是多因素的，但在孤雌生殖激活后获得同等或更高发育的能力表明，在减数分裂成熟的前12小时经历热应激的卵母细胞具有发育到囊胚期所需的成分，但在受精后就没有了。复制（2011）142 831-843
Consequences of heat stress exposure during the first 12 h of meiotic maturation differed depending on how and when bovine oocytes were activated. If heat-stressed oocytes underwent IVF at similar to 24 h, blastocyst development was less than for respective controls and similar to that obtained for nonheat-stressed oocytes undergoing IVF at 30 h (i.e. slightly aged). In contrast, if heat-stressed oocytes underwent chemical activation with ionomycin/6-dimethylaminopurine at 24 h, blastocyst development was not only higher than respective controls, but also equivalent to development obtained after activation of nonheat-stressed oocytes at 30 h. Developmental differences in chemically activated vs IVF-derived embryos were not related to fertilization failure or gross alterations in cytoskeletal components. Rather, ionomycin-induced calcium release and MAP kinase activity were less in heat-stressed oocytes. While underlying mechanisms are multifactorial, ability to obtain equivalent or higher development after parthenogenetic activation demonstrates that oocytes experiencing heat stress during the first 12 h of meiotic maturation have the necessary components to develop to the blastocyst stage, but fail to do so after fertilization. Reproduction (2011) 142 831-843