Figure 2.

Mitochondrial fusion is defective in mgm1Δ and mgm1Δ dnm1Δ cells. MATa cells were transformed with plasmid pHS70, which expresses IM-targeted cyan fluorescent protein (YTA10-CFP) under the control of the GAL1 promoter. MATα cells were transformed with plasmid pHS71, which expresses IM-targeted yellow fluorescent protein (YTA10-YFP) from the GAL1 promoter. Cells were grown to log phase in SGalSuc medium overnight to induce the expression of the fusion proteins. MATa and α cells were mated for 3–3.5 h on YEPD medium, which inhibits further fusion protein expression. The distribution of YTA10-CFP and YTA10-YFP in representative zygotes containing a medial bud is shown. Zygotes formed by mating between wild-type cells (FY833 and FY834), mgm1Δ mutants (YRJ1383 and YRJ1384), dnm1Δ mutants (YRJ1289 and YRJ1290), mgm1Δ dnm1Δ mutants (YRJ1398 and YRJ1493), and mgm1Δ dnm1Δ mutants in W303 strain (YRJ1554 and YRJ1555) were examined by DIC and fluorescence (FL) microscopy. Partial overlaps between YFP and CFP are seen in mgm1Δ dnm1Δ zygotes because one tubule lies on the top of another in the same focal plane. Bar, 3 μm.