Chromosome counts of 90Sr-induced osteosarcomas in mice. I. Transplanted tumour series.

From 90Sr-induced primary tumours, three transfer series were established by serial in vivo transplantation. Chromosome counts were obtained from 2 of the primary tumours and 284 transplanted tumours. The recording of abnormalities was limited to numerical chromosome deviations and the occurrence of metacentric configurations. By means of the serial tumour transplantation the numerical chromosome progression was also analysed. Though appearing at different stages of the tumour evolution, similarities in chromosome pattern were observed.