GM1 dynamics as a marker for membrane changes associated with the process of capacitation in murine and bovine spermatozoa
GM1 dynamics as a marker for membrane changes associated with the process of capacitation in murine and bovine spermatozoa
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DOI：
10.2164/jandrol.106.002279
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发表时间：
2007-07-01
影响因子：
--
通讯作者：
Travis, Alexander J.
中科院分区：
文献类型：
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作者：
Selvaraj, Vimal;Buttke, Danielle E.;Travis, Alexander J.
我们之前表明，在活的小鼠和牛精子头中，神经节苷脂 G(M1) 定位于顶体 (APM) 上富含甾醇的质膜。使用五聚霍乱毒素 B 亚基 (CTB) 标记 G(M1) 会在精子死亡时诱导信号从 APM 显着重新分配到缺乏甾醇的顶体后质膜 (PAPM)。我们现在在鞭毛中显示了类似的现象，其中 CTB 诱导 G(M1) 重新分布到环和鞭毛拉链的甾醇贫乏的膜子域。由于获能需要甾醇从质膜流出，因此我们检查了 G(M1) 定位是否可用于检测与获能和/或顶体胞吐作用相关的膜变化。首先，将小鼠和牛精子与其各自的获能刺激一起孵育并不会改变活细胞中的 G(M1) 分布。然而，在特定刺激下孵育两种物种的精子以获得获能，然后使用特定的固定条件，诱导了可重复的、刺激特异性的 G(M1) 分布模式。通过评估 Gm 的变化，分布响应黄体酮诱导的 AE，我们表明这些模式反映了小鼠精子群体对获能刺激的反应。这些数据表明 G(M1) 定位可用作评估精子对获能和/或 AE 刺激的反应的诊断工具。在决定辅助生殖技术或筛查男性生育能力时，这些信息可能很有用。此外，G(M1) 分布的刺激特异性变化表明精子可以独立地对 NaHCO3 或甾醇流出介质做出反应，从而完善现有的获能模型。
We previously showed that in live murine and bovine sperm heads, the ganglioside G(M1) localizes to the sterol-rich plasma membrane overlying the acrosome (APM). Labeling G(M1) using the pentameric cholera toxin subunit B (CTB) induced a dramatic redistribution of signal from the APM to the sterol-poor postacrosomal plasma membrane (PAPM) upon sperm death. We now show a similar phenomenon in the flagellum where CTB induces G(M1) redistribution to sterol-poor membrane subdomains of the annulus and flagellar zipper. Because sterol efflux from the plasma membrane is required for capacitation, we examined whether G(M1) localization might be useful to detect membrane changes associated with capacitation and/or acrosomal exocytosis. First, incubation of murine and bovine sperm with their respective stimuli for capacitation did not change G(M1) distribution in live cells. However, incubation of sperm of both species with specific stimuli for capacitation, followed by the use of specific fixation conditions, induced reproducible, stimulus-specific patterns of G(M1) distribution. By assessing changes in Gm, distribution in response to progesterone-induced AE, we show that these patterns reflect the response of murine sperm populations to capacitating stimuli. These data suggest that G(M1) localization can be used as a diagnostic tool for evaluating sperm response to stimuli for capacitation and/or AE. Such information could be useful when deciding between technologies of assisted reproduction or when screening for male fertility. Furthermore, stimulus-specific changes in G(M1) distribution showed that sperm could respond to NaHCO3 or mediators of sterol efflux independently, thereby refining existing models of capacitation.