G_M1 dynamics as a marker for membrane changes associated with the process of capacitation in murine and bovine spermatozoa

Authors

Vimal Selvaraj
Danielle E. Buttke
Atsushi Asano
John L. McElwee
Collin A. Wolff
Jacquelyn L. Nelson
Angela V. Klaus
Gary R. Hunnicutt, Population Council
Alexander J. Travis

Document Type

Article (peer-reviewed)

Publication Date

2007

Abstract

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 G_M1 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.

Recommended Citation

Selvaraj, Vimal, Danielle E. Buttke, Atsushi Asano, John L. McElwee, Collin A. Wolff, Jacquelyn L. Nelson, Angela V. Klaus, Gary R. Hunnicutt, and Alexander J. Travis. 2007. "G_M1 dynamics as a marker for membrane changes associated with the process of capacitation in murine and bovine spermatozoa," Journal of Andrology 28(4): 588–599.

DOI

10.2164/jandrol.106.002279

Language

English

https://doi.org/10.2164/jandrol.106.002279