Somatic hybrids of normal and tumor Djzungarian hamster cells. I. Preferential elimination of chromosomes of the normal partner

: Normal Djungarian hamster lymphoid cells were fused with SV40 transformed malignant fibroblasts. The resulting 11 hybrid clones were subjected to the chromosome analysis. The karyotype of hybrids proved to be unstable. In some cases the total tetraploid number of chromosomes in hybrids drastically decreased up to the near-diploid level close to that of the malignant parent cells. The G-band chromosome analysis showed that as a rule morphologically unchanged chromosomes were preferentially lost from the hybrid cells, the markers of the malignant partner being retained. On the basis of these data it is assumed than the hybrids between normal and tumour cells of Djungarian hamster preferentially lose the chromosomes of the normal parent cells during cultivation in vitro.