Detección de la capacitación espermática basada en la visualización de los componentes lipídicos de microdominios de membrana

BOARELLI P.V.; CATTANEO C.B.; MONCLUS M.A.; FORNES M.W.

Revista Médica Universitaria

Secretaria de Ciencia y Técnica

Año: 2007 vol. 3 p. 1 - 5

1669-8991

Sperm plasma membranes support lipids changes during sperm capacitation directly related with sperm functions. Specifically, membranes micro-domains also described in others cells are modified during sperm capacitation. These micro-domains are enriched in cholesterol, sphingolipids (GM1) and specific proteins constituted a unit inside the membrane. In this work, mice sperm from adult animals were used under culture media that support (experimental) or not (control) the sperm capacitation. To follow the lipids behaviour, it was used Filipin III (FIII, a fluorescent cholesterol cell marker) and fraction ß from cholera toxin (a GM1 cell maker) conjugated with AlexaFluor 594®, both higly detectable with fluorescent microscopy. Control sperm marked with FIII, show a clear fluorescent signal over the acrosomal area. Instead, capacitated sperm support a fluorescent decrease at the same area. Furthermore, under the same conditions, sperm support a redistribution of the cholera toxin from the acrosomal area to the postacrosomal one. Simultaneously, in aliquots of the same experimental conditions, the tyrosin phosphorilation was detected in capacitated sperm indicating that the capacitation takes place. The lipid changes stated here, cholesterol lost and redistribution of GM1 are good markers to detect sperm capacitation.