FIG. 7.

Maintenance of mtDNA in abf2 null derivatives of strains a-1/1R/Z1 and aori1rpo41Δ. Colonies isolated from strains a-1/1R/Z1 (RPO41 ABF2), aori1abf2Δ (RPO41 abf2::URA3), aori1rpo41Δ (rpo41::URA3 ABF2), and aori1rpo41Δabf2Δ (rpo41::URA3 abf2::URA3) were grown in liquid medium for about 20 generations. Four independent colonies were cultivated for each strain. Total cellular DNA was prepared from the cultures, restricted with HpaII, and displayed on a 2% agarose gel. The sources of DNA are indicated above the gels. The 416-bp fragment corresponding to the repeat unit of the ori1 genome is indicated by arrows. M, molecular weight markers (1-kb DNA ladder; Gibco BRL).