Immortalized cell lines from murine embryos are characterized by progressive destabilization of their karyotype structure

The karyotype structure was studied for three cell lines obtained from cells of transgenic murine embryos at early stages of their establishment. The first line was obtained from a transgenic embryonic explantant containing oncogen v-sis under promotor MMTV, two other lines originated from cells of transgenic embryos containing oncogen k51. The karyotypic analysis of G-banded metaphase chromosomes revealed deviations from the normal mouse karyotype as early as by the third passage of cultivation of independent embryonic cell lines that contained a foreign oncogene in their genome. The repeated analysis that involved 15-22 passages revealed similar abnormalities: variability and progression in chromosome number with the appearance of hyperpolyploid combinations, and a large number of rearranged chromosomes, both marker and unique ones. It is concluded that introduction of a foreign oncogene into murine cell genome leads to its enhanced and progressive non-specific destabilization. Oncogen v-sis produces a more valuable karyotype destabilization than oncogen k51.