Biochemical and cytological evidence for triple hybrid cell line formed from fusion of three different cells.

Hybrids between two parental lines of somatic cells have been observed in various genomic multiplicities by ourselves and others. Possible explanations for the higher multiplicities include the fusion of cells in a 1:1 ratio with one genomic set undergoing an asynchronous replication either before or after fusion or the fusion of two or more cells. We now provide evidence for multiple genomic hybrids arising from the fusion of more than two cells in a mixture of three different cell lines. This proof is based on unique chromosomal and biochemical markers characteristic of the three parental cell lines. The distinctive phenotypes of all three lines are expressed in a clonally derived hybrid. Thus, we conclude that long-term, proliferating somatic cell hybrids can arise from the fusion of three or more cells.