a, Relative mtDNA copy number of WT MEFs 24 hours post infection with VSV-GFP, HSV1-GFP, or mock at the indicated MOIs. b, WT MEFs were infected with MHV68-GFP at a MOI 0.5 and after the indicated times, cells were stained and subjected to confocal microscopy or relative mtDNA copy number determined. c, WT MEFs were infected with HSV2, Flu-GFP, or LCMV-GFP, at a MOI 10, and after 6 hours, cells were stained and subjected to confocal microscopy. d, WT MEFs were infected with Vaccinia virus at a MOI 10 or 1, and after the indicated times, cells were stained and subjected to confocal microscopy or relative mtDNA copy number determined. Error bars indicate ± s.e.m. of triplicates and data are representative of two independent experiments. *=p<0.05, **=p<0.01, ***=p<0.001, ns=not significant.