Heat stress during in vitro fertilization decreases fertilization success by disrupting anti-polyspermy systems of the oocytes
Heat stress during in vitro fertilization decreases fertilization success by disrupting anti-polyspermy systems of the oocytes
复制标题
体外受精过程中的热应激会破坏卵母细胞的抗多精系统，从而降低受精成功率
DOI：
10.1002/mrd.22441
复制
发表时间：
2015
影响因子：
2.5
通讯作者：
Takahashi M
中科院分区：
文献类型：
--
作者：
Sakatani M;Yamanaka K;Balboula AZ;Takenouchi N;Takahashi M
夏季的低怀孕率部分是由于受精减少。鉴于温度升高与这个季节有关，我们使用体外模型研究了受精过程中热应激的影响。进行了三个实验来确定暴露在高温下破坏受精的机制。卵母细胞在38.5°C或41.0°C或40.0°C条件下与未预孵育的精子受精6小时，或与在38.5°C或41.0°C条件下预孵育4小时的精子在38.5°C条件下受精6小时。在每个实验中，受精卵在38.5°C、5% co2和5% O2条件下培养。当受精发生在较高温度时，卵裂率和囊胚形成率降低。在40.0°C的预孵育和受精中，使用双醋酸荧光素标记分类为活精子的百分比降低。虽然在精子穿透率上没有观察到差异，但受精过程中的热应激倾向于增加多精现象。在40.0℃受精6 h后形成的受精卵透明带对酶的消化更敏感。此外，通过2,7‐二氢二氯荧光素双乙酸染色，这些受精卵表现出更高的过氧化氢水平，并显示出hspa1a（一种参与热休克反应的基因）的转录丰度增加，但uchl1（一种参与防止多精子的基因）的转录丰度降低。结果表明，受精过程中的热应激对精子是致命的，并引起氧化应激、转录物丰度改变和合子多精体的缺陷阻滞。因此，多精现象的增加很可能是在高温下受精卵发育到囊胚阶段的能力降低的原因之一。天线转换开关。开发，82:36-47,2015。©2014 Wiley期刊公司
Low pregnancy rates during the summer are due, in part, to reduced fertilization. Given that elevated temperature is associated with this season, we investigated the effect of heat stress during fertilization using an in vitro model. Three experiments were performed to determine the mechanism by which exposure to elevated temperature disrupts fertilization. Oocytes were fertilized for 6 hr at 38.5°C or 41.0°C or 40.0°C with non‐pre‐incubated sperm, or for 6 hr at 38.5°C with sperm that had been pre‐incubated at 38.5°C or 41.0°C for 4 hr. In each experiment, zygotes were cultured at 38.5°C in 5% CO2and 5% O2. Rates of cleavage and blasocyst formation were reduced when fertilization occurs at elevated temperatures. The percent of sperm classified as alive, using fluorescein diacetate labeling, was decreased by pre‐incubation and fertilization at 40.0°C. Although no difference was observed in sperm penetration rate, polyspermy tended to be increased by heat stress during fertilization. The zona pellucidae of zygotes formed following fertilization at 40.0°C for 6 hr were more sensitive to digestion with pronase. Furthermore, these zygotes exhibited higher hydrogen peroxide levels, measured by 2,7‐dihydrodichlorofluorescein diacetate staining, and showed increased transcript abundance forHSPA1A, a gene involved in the heat‐shock response, but decreased transcript abundance forUCHL1, a gene involved in preventing polyspermy. Results indicate that heat stress during fertilization is lethal to sperm, and causes oxidative stress, altered transcript abundance, and a defective block to polyspermy in the zygote. Thus, an increase in polyspermy is likely one cause of the reduced competency of zygotes fertilized under elevated temperatures to develop to the blastocyst stage.Mol. Reprod. Dev. 82: 36–47, 2015. © 2014 Wiley Periodicals, Inc.