Immortalization of bipotential glial progenitors and generation of permanent "blue" cell lines

The transfer of the adenovirus 5 E1A gene into brain cells from rat embryos led to the establishment of phenotypically untransformed clonal glial cell lines. Some lines displayed properties of oligodendrocyte-astrocyte progenitors. Their differentiation involved several steps that were dependent on culture conditions and cell interactions. Subsequently, a few lines were cotransfected with a vector carrying a modified dihydrofolate reductase gene and with the Escherichia coli lacZ gene. After selection for resistance to methotrexate, cell lines were derived that stably expressed the lacZ gene. These cells were individually detectable by histochemical staining for beta-galactosidase activity, even in the presence of other cells. These results suggest that this type of cell line could be of interest for further in vitro, and possibly transplant, studies of the differentiation and interactions of glial cells.