Fig. 6. Expression of the various genes in the P19 clones expressing the exogenous Evi1 gene by Northern blot hybridization. RNA was isolated from those clones under monolayer culture conditions in the absence of RA, separated on formaldehyde-containing agarose gels, and analyzed by Northern blot hybridization. The expressions of Evi1, MAP2, c-jun, c-fos, and ß-actin transcripts were detected by hybridization with each respective labeled cDNA fragment.