Sexual reproduction requires the fusion of sperm cell and oocyte during fertilization to produce the diploid zygote. In mammals complex changes in the plasma membrane of the sperm cell are involved in this process.
Sperm-egg fusion is a cell-cell membrane fusion event essential for the propagation of sexually reproducing organisms. In gamete fusion, as in other fusion events, such as virus-cell and intracellular vesicle fusion, membrane fusion is a two-step process.
[Updated detection of the function of sperm plasma membrane]. - PubMed - NCBI
Dynamics of the mammalian sperm plasma membrane in the process of fertilization - ScienceDirect
Sumpars Khunsook, Barry S. N-glycanase studies indicated the subunit contains N -glycans, and lectin blot analysis detected the presence of mannose, but no terminal galactose or sialic acid residues.
Dynamics of the mammalian sperm plasma membrane in the process of fertilization. - PubMed - NCBI
Fertilization typically involves membrane fusion between sperm and eggs.