Molekulární podstata penetrace spermií a jejich membránové fúze s oocytem v rámci oplození u savců

Fertilization is a process involving multiple steps, which are in continuity and complement each other. Spermatozoa become competent to fertilize after capacitation, hyperactivation and acrosome reaction. Oocytes are surrounded by a layer of cumulus cells and give a signals for spermatozoa to activation and orientation. This study focuses on the latest knowledges about a roles of cumulus cells, production of chemoattractants and the possibility that cumulus cells induce the acrosome reaction after binding a novel sperm protein NYD-SP8 to the cumulus. It seems that progesterone induce the acrosome reaction and also is the best chemoattractant secreted by cumulus cells. Next I am focus on gamete fusion including the role of surface proteins such as Juno and IZUMO1. Key words: membrane fusion, cumulus cells, acrosome reaction, chemotaxis sperm, oocyte, fertilization