SOMATIC CELL HYBRIDS BETWEEN MOUSE PERITONEAL MACROPHAGES AND SV40-TRANSFORMED HUMAN CELLS : I. Positive Control of the Transformed Phenotype by the Human Chromosome 7 Carrying the SV40 Genome

Fusion of mouse peritoneal macrophages with SV40-transformed human cells, deficient in hypoxanthine guanine phosphoribosyltransferase, resulted in the formation of transformed somatic cell hybrids which contained, without exception, the human chromosome 7 carrying the SV40 genome. It is postulated that the hybridization of mouse nondividing cells with human cancer cells could permit the identification of the human "oncogenic" chromosome(s) present in human cancer cells, since such chromosome(s) should be retained by the totality of the mouse-human hybrid cells.