Chromosome Complement of Spontaneous Leukæmia in AKR Mice

Abstract

A NUMBER of tumours of mice, rats, Chinese hamsters and man consist of a cell population with aneuploid chromosome numbers^1–4. These observations are frequently quoted in support of the theory that somatic chromosomal mutations are involved in the process of carcinogenesis. The greater part of the published results concerns tumours in the ascites form, or long-established transplanted tumours, and it is not clear whether these results also apply to primary tumours. The few results obtained so far on primary carcinoma of man show the occurrence of aneuploid cells^5,6, whereas the mammary tumour of C3H mice consists of a cell population with a diploid chromosome number⁷: the question can be raised as to whether the differences in chromosomal behaviour are due to different methods of tumour induction. In regard to this problem virus-induced tumours appeared of particular interest.