Oocyte sensitivity to induced meiotic nondisjunction and its relationship to advanced maternal age.

Several potential chromosomal mutagens were employed in an effort to induce mouse oocyte meiotic nondisjunction. Rat follicle-stimulating hormone, clomiphene citrate, and methotrexate each failed to increase the incidence of oocyte metaphase aneuploidy. A "temperature stress" system produced a marked increase in meiotic nondisjunction. Increased maternal age did not cause an increase in susceptibility to this chromosome mutagen model. This suggests that the maternal age relationship to aneuploidy is not likely to be due to an increased sensitivity of oocytes from older females to chromosomal mutagens.