Figure 3. Deletion or mutation of OXPHOS genes inhibits mitochondrial fusion.

Cells expressing matrix-targeted mtGFP or mtRFP were conjugated and the proportion of zygotes with Total (T), Partial (P) or No fusion (N) was determined by fluorescence microscopy after the indicated times (A–C) or after 4 hours (D). A: Fusion in strains devoid of mitochondrial COX2 (Δcox2) or mitochondrial DNA (ρ⁰). B: Fusion in strains with defects in ATP-synthase genes (Δatp6, atp6-L183R, atp6-L247R, Δatp12). C, D: Comparison of total fusion as a function of time (C) or of Total, Partial and No fusion after 4 hours (D) in wild-type, Δmgm1 and OXPHOS-deficient cells. Dashed line: proportion of fusion in wild-type cells.