Stable association of the human transgenome and host murine chromosomes demonstrated with trispecific microcell hybrids.

Trispecific microcell hybrids were prepared by transferring limited numbers of chromosomes from a human/mouse gene-transfer cell line to a Chinese hamster recipient line. The donor cells employed were murine L-cells that stably expressed the human form of the enzyme hypoxanthine phosphoribosyltransferase. Karyotypic, zymographic, and back-selection tests of the resulting human/mouse/Chinese hamster microcell hybrids provided strong genetic evidence for a stable association of the human transgenome with host murine chromosomes in stable gene-transfer cell lines. This association, which may represent physical integration of the transgenome into the host cell genome, occurred at multiple chromosomal sites.