| Abstract: | We have demonstrated that X chromosomes are reactivated in hybrids obtained by fusion of mouse PCC4azaI teratocarcinoma cells (XO, 39HPRT-) with splenocytes from mouse females heterozygous in Hprt gene. These hybrids are capable of spontaneous differentiation. We also obtained similar interspecies hybrids of PCC4azaI cells with bone marrow cells of the American mink. The majority of such hybrids remained undifferentiated, however, after long-term cultivation at high cell density they differentiated into epithelial- or fibroblast-like cells similarly to PCC4azaI cells. Two hybrids had the autosomal complement of the mouse and two X chromosomes (mouse and mink); both X chromosomes were active. These X chromosomes were not inactivated during differentiation in vitro. |
