Fig. 4.

Rnaseh1 ablation leads to the accumulation of fully incorporated primers at Ori-L. MEF mtDNA from cells culture for 10 (A) or 9 (B) d without (control) or with (ΔRH1) 4HT was restriction digested with XmnI (A) or BstXI and PstI (B), denatured, and fractionated by 1D-AGE (1% agarose Tris-acetate). After transfer the fragments were hybridized with riboprobes (A) L1912-2267 or (B) L8124-8424. RH, samples were treated with (+) or without (−) Eco-RNase HI. (A) All samples were fractionated on the same gel, a longer exposure of the ΔRH1 samples is shown to compensate for unequal loading. (A and B) Below the gel images are interpretations of the RNase H sensitive species (a black line of DNA with a red RNA patch).