The molecules involved in the interaction of gametic membranes during fertilization: Contribution of the mouse model

Abstract

Gamete membrane adhesion and fusion is a crucial step of
fertilization involving molecular mechanisms very complex
and partially unknown. On the egg side, the role in fusion for
GPI-anchored proteins has been shown, and in mice lacking
both tetraspanins CD9 and CD81, fertilization is block by a
fusion failure. On the other side, sperm lacking the protein
Izumo are unable to fuse. The egg a6b1 integrin, initially
identified as the sperm ADAM2 receptor, were found to be not
essential in gamete fusion as a6 or b1 integrin deleted eggs
normally fertilized.