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Ion channels are extraordinarily efficient machines that move ions in diversely controlled manners, allowing cells to rapidly exchange information with the outside world and with other cells. Communication is the currency of fertilization, as it is of most fundamental cell signaling events. Ion channels are deeply involved in the dialogue between sperm, its(More)
Research on fertilization in mammalian species has revealed that Ca(2+) is an important player in biochemical and physiological events enabling the sperm to penetrate the oocyte. Ca(2+) is a signal transducer that particularly mediates capacitation and acrosome reaction (AR). Before becoming fertilization competent, sperm must experience several molecular,(More)
In a process called capacitation, mammalian sperm gain the ability to fertilize after residing in the female tract. During capacitation the mouse sperm plasma membrane potential (E(m)) hyperpolarizes. However, the mechanisms that regulate sperm E(m) are not well understood. Here we show that sperm hyperpolarize when external Na(+) is replaced by(More)
The acrosome reaction (AR) is a regulated exocytotic process. In several cell types, an actin network situated under the plasma membrane (PM) acts as a physical barrier to prevent this exocytosis. In seeking a function for a cortical skeleton in guinea pig spermatozoa, the PM and the outer acrosomal membrane (OAM) were investigated for the presence of(More)
In this study, the presence and cellular distribution of dystrophin family products (i.e. Dp71d, Dp71f-like protein and dystrobrevin) was examined by indirect immunofluorescence and Western blotting in guinea pig spermatozoa. Two dystrophin-associated proteins, beta-dystroglycan and alpha-syntrophin, and nNOS a protein frequently associated with(More)
BACKGROUND The transient receptor potential channel (TRP) family includes more than 30 proteins; they participate in various Ca(2+) dependent processes. TRPs are functionally diverse involving thermal, chemical and mechanical transducers which modulate the concentration of intracellular Ca(2+) ([Ca(2+)]i). Ca(2+) triggers and/or regulates principal sperm(More)
In the mammalian sperm, the acrosome reaction (AR) is considered to be a regulated secretion that is an essential requirement for physiological fertilization. The AR is the all-or-nothing secretion system that allows for multiple membrane fusion events. It is a Ca(2)(+)-regulated exocytosis reaction that has also been shown to be regulated by several(More)
Mammalian spermatozoa acquire the capacity to fertilize the ovum and display motility during their passage through the epididymis. At the same time, they undergo changes in metabolic patterns, enzymatic activities, ability to bind to zona pellucida surface, and electrophoretic properties and, furthermore, stabilization of some sperm structures by the(More)
The acrosome reaction (AR) is an exocytotic process of spermatozoa, and an absolute requirement for fertilization. During AR, actin polymerization is necessary in the equatorial and postacrosomal regions of guinea pig sperm for spermatozoa incorporation deep into the egg cytoplasm, but not for plasma membrane (PM) fusion nor the early steps of egg(More)
In muscle, the absence of dystrophin alters the dystrophin-associated protein complex (DAPC), which is involved in the clustering and anchoring of signaling proteins and ion and water channels. Here we show that mice spermatozoa express only dystrophin Dp71 and utrophin Up71. The purpose of this study was to explore the effect of the absence of Dp71 on the(More)