Inhibition of Mitosis in Human Triploid Cells

TRIPLOIDY—the possession of three instead of two sets of chromosomes per cell-is a substantial cause of death in man. At least 1% of conceptions produce triploid zygotes, most of which are aborted by the end of the third month of pregnancy¹. Only a few triploid infants are reported to have survived birth but the reason is not known. Death in utero also seems to be the fate of triploid rats, mice and rabbits², but in amphibia³, Drosophila⁴ and many plants^5,6, triploid individuals are not only viable but do not differ markedly from normal diploids.