Effects of alphafetoprotein on isolated mouse oocytes.

: The supposition of an effect of alphafetoprotein (AFP) on female germinal cells is put forward. The spontaneous in vitro maturation of adult mouse oocytes is significantly inhibited when mouse AFP replaces albumin in culture medium. Furthermore, the very unusual degenerative appearance of the cells subjected to AFP seems to indicate that this meiotic inhibition is linked to a premature degeneration of the oocytes rather than to a blockage of the cells at an earlier stage of maturation. Accordingly AFP, perhaps through its ligands, may play a role in reducing the number of gonocytes during fetal and immediate post-natal life rather than in stopping oocyte meiosis at the diplotene stage.