Figure 1.

Generation and phenotypic comparison of iso-nuclear F1 diploids. (A) The MIP1^DN- and centromere-containing plasmid pLND46 (Dimitrov et al. 2009) (pMIP1-DN) was introduced into haploid ρ+ strains. MIP1^DN induction led to the complete loss of the mitochondrial genome, generating ρ0 petites that were then screened for plasmid loss. Nucleus, N-containing blue circle; ovals, parental ρ+ (shaded) and ρ0 (open) mitochondria. (B) Pairwise crosses between haploid ρ+ strains and ρ0 strains of opposite mating types differing in nuclear (N1 vs. N2) and mitochondrial (ρ1 vs. ρ2) DNA backgrounds generated pairs of iso-nuclear F1 diploids (N1/N2) that carried the parental mitochondrial genomes (ρ1 or ρ2), thus allowing for systematic phenotypic comparison of distinct mitochondrial genomes. Mitochondria: solid blue ovals, ρ1; solid red ovals, ρ2; open ovals, ρ0.