Tg-induced ER stress drives changes in crista orientation in elongated mitochondrial networks. (A) Surface membrane reconstruction colored by inner membrane compartments (IBM, tan; junction, cyan; crista, purple) defining angular measurements between the surface and the nearest OMM or to the growth plane of the cell. (B) Two representative membrane surface reconstructions of lamellar Tg-treated elongated mitochondria, colored by the angle of IMM relative to OMM. (C) Two representative membrane surface reconstructions of a less rigidly oriented Tg-treated elongated mitochondria, colored by an angle of IMM relative to the growth plane of the cell. (D) Combined histogram of the angle of cristae relative to OMM in elongated (top) and fragmented (middle) mitochondria in MEF^mtGFP cells treated with vehicle and Tg. Dashed vertical lines correspond to peak histogram values of pooled data. Graph (bottom) showing distribution of standard deviations within each corresponding treatment and mitochondrial morphology class. Quantifications from vehicle elongated n = 20, Tg elongated n = 18, vehicle fragmented n = 11, and Tg fragmented n = 15 mitochondria are shown. *P < 0.05; **P < 0.01. (E) Combined histogram of the angle of cristae relative to growth plane in elongated (top) and fragmented (middle) mitochondria in MEF^mtGFP cells treated with vehicle and Tg. Dashed vertical lines correspond to peak histogram values of pooled data. Graph (bottom) showing distribution of standard deviations within each corresponding treatment and mitochondrial morphology class. Quantifications from vehicle elongated n = 20, Tg elongated n = 18, vehicle fragmented n = 11, and Tg fragmented n = 15 mitochondria are shown. P values from Mann–Whitney U test are indicated. **P < 0.01.