Ca(2+) dynamics in oocytes from naturally-aged mice.
Ca(2+) dynamics in oocytes from naturally-aged mice.
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DOI：
10.1038/srep19357
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发表时间：
2016-01-20
影响因子：
4.6
通讯作者：
FitzHarris G
中科院分区：
文献类型：
--
作者：
Haverfield J;Nakagawa S;Love D;Tsichlaki E;Nomikos M;Lai FA;Swann K;FitzHarris G
人类中期-II被捕卵子激活受精后的能力随着母亲年龄的增长而下降。卵子激活是由精卵融合导致的卵质中细胞内Ca 2+浓度（[Ca 2 +]i）的反复增加触发的。因此，我们假设，来自老年女性的卵子在受精时安装适当的Ca 2+反应的能力降低。为了验证这一假设，我们首次检查了年轻和自然衰老小鼠卵子中的Ca 2+动态。值得注意的是，我们发现钙库和静息[Ca 2 +]i随年龄的增长而不变。尽管来自老龄小鼠的卵子在耗尽后补充细胞内Ca 2+储存的能力降低，但这种差异对胞浆内精子注射或磷脂酶C ζ表达后Ca 2+振荡的持续时间、数量或幅度没有影响。相比之下，我们描述了一个显着减少的频率和振荡的持续时间在老化的鸡蛋后，与SrCl 2孤雌激活。我们的结论是，在受精时安装和响应适当的Ca 2+信号的能力在很大程度上是不变的，通过提高产妇年龄，但在Ca 2+处理发生微妙的变化，可能有更大的影响后，常用的手段孤雌激活。
The ability of human metaphase-II arrested eggs to activate following fertilisation declines with advancing maternal age. Egg activation is triggered by repetitive increases in intracellular Ca2+ concentration ([Ca2+]i) in the ooplasm as a result of sperm-egg fusion. We therefore hypothesised that eggs from older females feature a reduced ability to mount appropriate Ca2+ responses at fertilisation. To test this hypothesis we performed the first examination of Ca2+ dynamics in eggs from young and naturally-aged mice. Strikingly, we find that Ca2+ stores and resting [Ca2+]i are unchanged with age. Although eggs from aged mice feature a reduced ability to replenish intracellular Ca2+ stores following depletion, this difference had no effect on the duration, number, or amplitude of Ca2+ oscillations following intracytoplasmic sperm injection or expression of phospholipase C zeta. In contrast, we describe a substantial reduction in the frequency and duration of oscillations in aged eggs upon parthenogenetic activation with SrCl2. We conclude that the ability to mount and respond to an appropriate Ca2+ signal at fertilisation is largely unchanged by advancing maternal age, but subtle changes in Ca2+ handling occur that may have more substantial impacts upon commonly used means of parthenogenetic activation.