There has to be an increase in free Ca2+ in the egg cytosol (Swann 1990). The activation process of oocytes in mammals entails a sequence of joint actions originated by distinctive calcium (Ca2+) oscillations within the cells(Markoulaki, 2004). This commences quickly after gamete union and continues past the conclusion of meiosis. Previous research conducted by a number of scholars shown that a specific isoform present in the semen of mammals is responsible for triggering the process of oocyte activation.In order to validate the evidence that PLC –Z is a primary ingredient in the oocyte activation, the paper will look at the Sperm factor model. The model suggests that during sperm–egg union, a soluble element is transferred from the semen cytosol to the ooplasm, able to trigger the 1,4,5-trisphosphate (IP3) signaling passageway and consequent Ca2+ vacillations in inseminated eggs ( Saunders et al., 2006).This paper will establish the premise that phospholipase C zeta is the primary candidate for oocyte activation.
It is important to know the structure and the functions of the PLC-zeta. All known isozymes are comprised of the catalytic X and Y purviews together with several controlling domains, comprising a pleckstrin homology (PH) purview, EF hand designs, and C2 purview in different conformations, reliant on the isozyme, where every domain executes definite functions (Nomikos et al, 2013). PLC Zeta has a structure which has the X and Y domains that is consistent with all PLC isoforms. That is, a solitary C2 purview which has four EF hand domains in tandem. However, PLC Zeta is different from other PLC isoforms because it does not have the pleckstrin homology and Src homology purviews (Cox et al., 2002). Therefore, the lack of those two homologies makes PLC Zeta to appear very small. They have a mass of 70 kDa in individuals and 74 kDa in rats. The figure below shows the linear structure of PLC Zeta.