FACT

FACT, or "Fertilization-Activated Calcium Transients," refers to a crucial biological process that occurs during the early stages of fertilization in animals and some other organisms. When a sperm cell successfully penetrates an egg cell, it triggers a series of rapid calcium ion fluctuations, known as calcium transients, within the egg. These transients play a vital role in activating various cellular events necessary for the fusion of the sperm and egg nuclei, initiating embryonic development, and preventing polyspermy (the entry of multiple sperm cells). FACT is a fundamental mechanism that underlies the initial stages of animal reproduction.