Laboratory Animal Reproduction,Graduate School of Agriculture Science,Tohoku University,Sendai,Japan
The interaction between molecular biology and embryology made an extensive progress in the research on gametogenesis, fertilization and early embryogenesis in mice. In this article, molecules involving in meiotic maturation and apoptosis of oocytes, sperm-oocyte interactions and early cleavage of fertilized embryos in mice are described including our recent following experiments. 1) Phosphatidylinositol 3-kinase and Akt participate in the follicle stimulating hormone-induced meiotic maturation of mouse oocytes. 2) Mos plays a crucial role in normal spindle and chromosome morphology and the reactivation of maturation promoting factor after first meiosis. 3) Follicular atresia is caused by apoptosis and the apoptosis associated with internucleosomal DNA fragmentation is directly regulated by the Fas-Fas ligand system. 4) Integrin α6β1 is involved in sperm-egg binding leading to fusion via direct association of the integrin α 6 with sperm. 5) MAP kinase cascade is activated at the M-phase and some MAP kinases other than ERKs are activated during early cleavage of fertilized eggs.