egg activation

egg activation

Meaning

Process of interaction between sperm and egg at fertilization which stimulates the eggs to begin development

Initiated by

Fertilization

Independent Fertilization

Main topic

Main topic

Stages of egg fertilization

1) Egg membrane wraps microvilli around sperm head

2) Sperm is drawn into egg cytoplasm

3)Formation of fertilization membrane

4)Vitelline layer strengthen and thickens

5) Cortical changes takes place (gray crescent in amphibians)

Once egg activated,egg will resume and complete meiosis ii with release of 2nd polar body

>Initiated by the fusing of egg and sperm
>Causes rise in Ca2+
>Stimulate cortical granules to release their contents outside the egg
>Cause formation of fertilization envelope (to slow block polyspermy)

To restart meiosis, the calcium signal mediates dramatic rearrangement of egg surface including :