Mammalian sperm must undergo the process of capacitation - series of physiological and biochemical modifications prior fertilization. In last stage of capacitation sperm undergoes acrosome reaction (AR). During AR the cell membrane of the sperm fuses with the outer acrosomal membrane and the contents of acrosomal vesicle are released into extracellular space. Sperm which did not undergo AR or sperm missing acrosome at all are unable to fertilize. AR results into dramatical changes in the sperm head. Most of the proteins present in plasmatic and outer acrosomal membrane are reorganized or lost. There are also significant changes in cytoskeletal and intraacrosomal proteins are released to extracellular space uncovering new surface domains. Some sperms undergo AR even without presence of inductor of AR during capacitation in vitro. This event is called spontaneous (accelerated) AR. The latest research indicates that spontaneous AR is natural part of the process of fertilization. Field mice (Apodemus) show high level of promiscuity leading to significant risk of sperm competition. Unique reproduction strategy where the sperms form so-called sperm trains was evolved in field mice. Spontaneous AR is probably enabling the dissociation of sperms from the sperm train. The spontaneous AR rate is dependent on...
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:266301 |
| Date | January 2015 |
| Creators | Frolíková, Michaela |
| Contributors | Stopka, Pavel, Jonáková, Věra, Petr, Jaroslav |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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