Rap-treated yeast produce mitochondrial-derived multilamellar structures. (A) Super-resolution confocal fluorescence microscopy images of DMSO or Rap-treated haploid yeast cells expressing Tom70-yEGFP and Tim50-mCherry. MDCs are indicated by white arrows. Scale bar = 1 µm. Yellow line marks the position of the line-scan fluorescence intensity profile shown on the right. The left and right y axes correspond to Tom70-GFP and Tim50-mCherry fluorescence intensity, respectively. The bracket denotes MDC. (B) Quantification of MDC formation in DMSO or Rap-treated yeast. Error bars show mean ± SE of three replicates, n ≥ 100 cells per replicate. (C) Scatter plot showing the diameter of Rap-induced MDCs. The black line indicates the mean (0.41 µm) of n = 104 MDCs. (D–I) Thin-section TEM analysis of 80-nm cell sections from the same yeast strain analyzed above. Yeast were treated with either DMSO (D and E) or 200 nM Rap (F–I). White dotted-line squares in D, F, and H indicate the region magnified and shown in E, G, and I, respectively. Yellow arrows: mitochondria, white arrows: multilamellar structures, N: Nucleus. Scale bars = (D) 500 nm (E–I) 200 nm. (H and I) Immunogold labeling with monoclonal antibodies targeting GFP and secondary antibodies conjugated to 10-nm gold particles. White arrowheads in I point to gold particles. (J) Quantification of the total anti-GFP immunogold particles that labeled the indicated cell structures from an analysis of >100 cell sections.