SNARE protein mediated secretory events in porcine fertilization

Abstract

Fertilization is an event that involves highly dynamic intra- and intercellular processes which enable the merge of two gametes with the aim to ultimately form a new organism. Preparative changes are required in both gametes prior to fertilization since freshly ejaculated sperm cells and germinal vesicle (GV) stage arrested oocytes are not capable to form a zygote. Only functionally matured sperm can fertilize the oocyte and specific modifications have to be accomplished at the surface of the sperm head. Like sperm, the oocyte has to be prepared for gamete fusion and to this end resumes meiosis prior to ovulation. Immediately after sperm binding to the oocyte plasma membrane (oolemma), the oocyte initiates a restrictive process - the cortical reaction (CR) - to prevent polyspermic fertilization which is incompatible with subsequent normal development of the zygote. Aberration of any of these processes will lead to the failure of fertilization; therefore, the aim of this thesis is to contribute to the knowledge of specific intracellular processes (namely the acrosome reaction in the sperm cell and the CR in the oocyte) that are crucial in gametes for successful fertilization