Figure 3.

Schematic representation of the purported mechanisms underlying the three most commonly applied methods of assisted oocyte activation. (a) Mechanical activation usually involves a disruption of the plasma membrane and/or components within the oolemma, leading to an elevation of Ca²⁺ within the oocyte due to influx of Ca²⁺ and/or disruption of Ca²⁺ store membranes such as the endoplasmic reticulum (ER). (b) The mechanisms underlying chemical activation vary on the type of agent utilized, but usually involve the facilitated transport of extracellular Ca²⁺ into the oocyte either directly or via transport channels. (c) Electrical activation involves generation of pores within the oocyte membrane via application of varying electrical fields, allowing extracellular Ca²⁺ influx into the oolemma.