Cold lability of mouse sperm binding to zona pellucida.
Cold lability of mouse sperm binding to zona pellucida.
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小鼠精子与透明带结合的冷不稳定性。
DOI：
10.1002/jez.1402190204
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Storey,BT
中科院分区：
文献类型：
--
作者：
Heffner,LJ;Storey,BT
附睾精子在释放过程中和释放后保持在4℃，以评估膜流动性对精子与小鼠卵子透明带结合能力的影响。要检验的假设是：如果膜流动性是获得结合能力所必需的，那么将精子暴露在4℃下显著降低流动性应该会导致获得与透明带结合的能力的特征延迟时间。没有观察到这一结果；相反，与对照组相比，37℃下测得的结合相对程度在4℃预培养时降低了。15分钟后，结合的相对程度降低到对照组的43%，在4℃预培养60分钟后，结合程度下降到对照的20%。如果将新鲜精子直接从附睾液中分散到冷液中，那么随后在37℃下暴露长达60分钟并不能逆转结合能力的丧失。将精子分散到37°C的培养液中，然后在此温度下预孵育15分钟，在此期间精子获得与透明带结合的能力，从而完全保护精子免受冷诱导的结合能力的丧失。这种损失不能归因于运动效应：如果冷却到4°C，小鼠精子完全不活动，但在升温到37°C，即授精介质的温度时，完全恢复原来的运动能力。在4℃时，精子质膜上与透明带结合的部位似乎不可逆转地失去了结合能力，半衰期约为15分钟。这些结果表明，结合位点亚基的重排参与了与带状蛋白结合能力的获得，而不是质膜蛋白的远程相互作用。
Epididymal spermatozoa were maintained at 4°C during and after release from the epididymis to assess the effect of membrane fluidity on acquisition by the sperm of the ability to bind to zonae pellucidae of mouse eggs. The hypothesis to be tested was: If membrane fluidity is necessary for acquisition of the ability to bind, then exposure of sperm to 4°C to reduce fluidity markedly should lead to a characteristic delay time in acquiring the ability to bind to zonae. This result was not observed; instead, the relative extent of binding measured at 37°C was decreased relative to control by preincubation at 4°C. The relative extent of binding was reduced to 43% of control after 15 min and to 20% of control after a 60‐min preincubation at 4°C. The loss of binding ability was not reversed by subsequent exposure to 37°C in the insemination mixture for up to 60 min if fresh sperm were dispersed directly from epididymides into the cold medium. Dispersal of sperm into medium at 37°C followed by a 15‐min preincubation at this temperature, during which time sperm acquire the ability to bind to zonae, conferred full protection against cold‐induced loss of binding ability. This loss could not be attributed to motility effects: Mouse sperm are completely immotile if cooled to 4°C, but fully regain their original motility upon warming to 37°C, the temperature of the insemination medium. The binding sites on the sperm plasma membrane for the zona pellucida appear to lose irreversibly their binding ability at 4°C with a half‐time of about 15 min. These results suggest the hypothesis that rearrangement of binding site subunits is involved in the acquisition of the ability to bind to zonae, rather than long‐range interaction of plasma membrane proteins.