Calcium and sperm components in the establishment of the membrane block to polyspermy: studies of ICSI and activation with sperm factor.
Calcium and sperm components in the establishment of the membrane block to polyspermy: studies of ICSI and activation with sperm factor.
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DOI：
10.1093/molehr/gam042
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发表时间：
2007-08
影响因子：
4
通讯作者：
Genevieve B Wortzman-Show;M. Kurokawa;R. Fissore;J. Evans
中科院分区：
文献类型：
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作者：
Genevieve B Wortzman-Show;M. Kurokawa;R. Fissore;J. Evans
卵子激活的一个重要结果是建立阻止多精受精的屏障；这些块建立在透明带和卵质膜上。本研究考察了精子给卵子带来了什么来诱导膜阻滞的建立，建立在过去的证据基础上，即膜阻滞的建立不会发生在孤雌生殖刺激的反应中，这种刺激会诱导胞浆内Ca2+的单一短暂增加或胞浆内单精子注射（ICSI）。我们测试了以下假设：(i)精子相关的Ca2+释放活动触发膜阻断的建立；（ii）通过ICSI方案的变化引入精子内容物（导致比传统ICSI方案改善的Ca2+瞬态、卵子激活和胚胎发育）触发膜阻断的建立；（iii）精子粘附[细胞外精子配体与卵子受体的结合]结合精子相关的Ca2+释放活性触发膜阻断的建立。有趣的是，这些刺激都没有诱导小鼠卵子中多精子的膜阻滞的建立。然而，精子相关的卵子皮质细胞骨架重塑在常规受精和icsi受精卵之间是不同的；考虑到我们之前的数据暗示肌动蛋白微丝在膜阻滞的建立中，这提出了皮层重组可能是一个促成因素的可能性。总之，受精样Ca2+瞬间，无论是单独的还是与精卵结合的，都不足以建立膜阻断，但与配子相互作用相关的事件在这种膜功能变化中起作用。
One important result of egg activation is the establishment of blocks to prevent polyspermic fertilization; these blocks are established on the zona pellucida and the egg plasma membrane. This study examines what the sperm brings to the egg to induce the establishment of the membrane block to polyspermy, building on past evidence that membrane block establishment does not occur in response to parthenogenetic stimuli that induce a single transient increase in cytosolic Ca2+ or intracytoplasmic sperm injection (ICSI). We test the hypotheses that (i) sperm-associated Ca2+ release activity triggers membrane block establishment; (ii) introduction of sperm contents via variations on ICSI protocols (resulting in improved Ca2+ transients, egg activation and embryo development over traditional ICSI protocols) triggers membrane block establishment and (iii) sperm adhesion [binding of an extracellular sperm ligand(s) to an egg receptor(s)] combined with sperm-associated Ca2+ release activity triggers membrane block establishment. Interestingly, none of these stimuli induced establishment of the membrane block to polyspermy in mouse eggs. However, the sperm-associated remodeling of the egg cortical cytoskeleton differs between conventionally fertilized and ICSI-fertilized eggs; taken with our previous data implicating actin microfilaments in membrane block establishment, this raises the possibility that cortical reorganization may be a contributing factor. In sum, fertilization-like Ca2+ transients, either alone or combined with sperm-egg binding, are not sufficient for membrane block establishment, but that an event(s) associated with gamete interaction plays a role in this membrane function change.