Chromosomes in lymphatic leukemia of C58 mice.

A larger size of chromosomes in neoplastic cells than in cells of the corresponding normal tissues has been observed in a number of instances (2, 4, 6, 8, 9, 11, 13). Among the several proposed explanations, that of Biesele, Poyner, and Painter (9) suggested that the chromosomes of malignant cells contained muhiples of the number of chromosome strands present in those of normal cells. In order to test the hypothesis, studies in lymphatic leukemia of C58 mice have been undertaken. The studies reported here, as well as other observations, indicate that chromosomal enlargement in neoplasms results from more subtle changes than those involved in the multiplication of structural entities near the chromatid level of organization.