Abstract: Oocytes activation is the first step of embryonic development, which is triggered by a series of cytoplasmic calcium (Ca2+) oscillations in mammals. Sperm-egg fusion initiates these Ca2+ oscillations by introducing a sperm-specific protein factor into oocytes cytoplasm. This protein factor has been indiated to be sperm-specific phospholipase C (PLC), termed PLC-zeta (PLCζ). Moreover, increasing clinical evidence revealed that some types of male infertility could be related with the aberrant expression of PLCζ and its localization, structure and function in human sperm. PLCζ can be used as a potential diagnostic and prognostic indicator of male infertility. Microinjection of recombinant human PLCζ protein could thus provide an efficient biological solution for inducing artificial activation of oocytes. This review is about the PLCζ and oocytes activation, the PLCζ expression and localization pattern, and male infertility, and advance of PLCζ in the clinical applications of male infertility.

Key words: Oocytes, Ca2+ oscillations, Calcium, Signal transduction, Infertility, male, Phospholipase C zeta