FIG. 4.

Increased levels of maxicircle transcripts in kap2/3^−/− mutant cells. (A) Northern blot analysis of mitochondrial and nuclear transcripts. Total RNA was isolated from wild-type cells in logarithmic (log.) or stationary (stat.) phase and kap2/3^−/− mutant cells in logarithmic (log.), middle logarithmic (mid.log.), and stationary (stat.) phase. Total RNA (10 μg) was fractionated on a 1.2% agarose-formaldehyde gel, stained with ethidium bromide, and transferred to a nylon membrane. The membrane was hybridized to the ND 7 DNA probe and was stripped and rehybridized sequentially to mitochondrial Cox3, Cyb, ATPase 6, Cox2, and nuclear ISP, Cyt-c₁ DNA probes. rRNA stained with ethidium bromide was used as a loading control (EtBr rRNA). (B) PhosphorImager quantitation of expression levels of several mitochondrial and two nuclear transcripts.