Simultaneous Study of Cholesterol and GM1 Ganglioside by Specific Probes: Lipid Distribution during Maturation, Capacitation and the Acrosome Reaction

SAEZ LANCELOTTI TS; FUNES AK; BOARELLI PV; CABRILLANA ME; FORNÉS MW; MONCLUS MA; SIMÓN L

Journal on Cytology and Histology

Omics

Año: 2016

Lipid distribution has been extensively studied in the plasma membrane of the male gamete due to its relevantrole in sperm physiology. However, there are controversial reports about their distribution. Because of differentreports about this topic, the aim of this work was define cholesterol and GM1 ganglioside location by simultaneousdetection during sperm maturation, capacitation and the acrosome reaction in CF1 mouse sperm. We observed thatthroughout the epididymis, cholesterol detected by filipin III or complex and GM1 ganglioside by cholera toxin, colocalizedin the acrosomal domain of the head and midpiece of the flagellum. During sperm capacitation, a decreaseof cholesterol can be observed like diffuse pattern on the whole head, while GM1 ganglioside was restricted to theapical acrosome. Capacitated sperm incubated with acrosome reaction inducers showed a diffuse location onthe head with both probes after acrosomal exocytosis. Also, both probes did not show different locations on theflagellum. These findings indicate that cholesterol and GM1 ganglioside have a dynamic behaviour during the lifeof the sperm, which could indicate that a continuous assembly or disassembly of the lipid raft could be involved inthe responsiveness of the sperm to different environments. Thus, during sperm capacitation and acrosome reactionthere is a redistribution of the lipids. However, there are not apparent changes during sperm maturation. Cholesterolefflux, a characteristic event of sperm capacitation, could be analyzed through diffuse pattern described by filipin,and GM1 ganglioside patterns observed by the cholera toxin could be interesting when it is needed to evaluatesperm capacitation and the acrosome reaction in fixed sperm.