FIG. 4.

c-Jun deficiency results in increased levels of spontaneous DNA damage. (a) c-Jun^−/− MEF, c-Jun^−/− MEF reconstituted with ectopic c-Jun, and WT MEF were cultured at either 3 or 21% oxygen for 4 days prior to analysis. For control purposes the WT and c-Jun^−/− MEF were infected with the same empty retroviral vector (pBabe) used to express ectopic c-Jun in the reconstituted cells. A denaturing comet assay was performed, and DNA was stained and examined by fluorescence microscopy. (b) Western blotting analysis of c-Jun expression levels in the cell cultures used for panel a.