Electron tomography of wild-type and ESCRT mutant MVEs from Arabidopsis. (A) Tomographic reconstructions of dual-axis tomograms of wild-type, chmp1, and lip5 mutant MVEs. Red spheres were placed inside ILV and ILV buds to facilitate their identification. Note the reduced number of ILVs and the limited ILV concatenation in mutant MVEs. (B–D) Tomographic slices of WT, lip5, and chmp1 MVEs. The red arrowhead in D indicates a long neck connecting two concatenated ILV buds with the limiting membrane. Bars: (A) 50 nm; (B–D) 20 nm. (E–H) Quantitative analyses of MVE structural features. Error bars indicate SEM. Letters above bars represent statistical significance (one-way ANOVA followed by Tukey’s test: P < 0.05); bars sharing a letter are not significantly different from one another. n = 11 (wild type), 7 (chmp1), and 11 (lip5) MVEs; n = 183 (wild type), 27 (chmp1), and 162 (lip5) ILVs.