The effect of age on the ability of oocytes to synthesize RNA and proteins during in vitro maturation.

The effect of age on the ability of the oocyte to resume meiosis in vitro and to incorporate 3H-uridine and 3H-leucine into RNA and protein, respectively, was examined in the rat. In comparison with the mature control oocyte, the nucleolus of the aged oocyte tends to be retained although the rate of germinal vesicle breakdown is not altered. The incorporation of 3H-uridine is reduced, while 3H-leucine incorporation is not impaired. It is concluded that the inability of the aged oocyte to synthesize RNA may be responsible for its inability to complete meiotic maturation in vitro.