Sub-Diploid Chromosome Variation in Man and other Mammals

Abstract

THE existence of sub-diploid chromosome numbers in the somatic tissues of mammals has for long been a matter of controversy. This had centred around several earlier reports of the normal occurrence of many somatic cells with less than the diploid number of chromosomes. The controversy has again been recently revived by reports¹ that the human uterine endometrium normally contains cells with varying numbers, ranging from 4 to 104, of chromosomes. The highest frequency peak of these numbers is supposed to lie in cells with 20–25 chromosomes, with a much lower peak in cells with 45–50 chromosomes. It is also suggested that this type of chromosome variation may be a distinct characteristic of warmblooded animals.