Figure 3.

Mitochondrial morphology and motility are abnormal in arc15-GFP and arp2-1 mutants. The ARP2 parent (A–C), and arp2-1 mutant (D–F) were grown to mid-log phase at 22°C and shifted to 37°C for 1 h. The ARC15 wild-type (G–I) and arc15-GFP mutant cells (J–L) were grown to mid-log phase at 30°C. Mitochondrial morphology (A, D, G, and J) and actin organization (B, E, H, and K) were determined in fixed cells by indirect immunofluorescence by using an antibody raised against mitochondrial outer membrane proteins, and rhodamine phalloidin. Arrowheads point to examples of abnormal mitochondrial morphology. (C, F, I, and L) Tracings of the pattern of mitochondrial movement in living cells stained with the membrane potential sensing dye, DiOC₆ relative to the boundary of dividing yeast. Movements of mitochondria were followed by marking the tip of motile organelles during the time in which they remained in the plane of focus in time lapse images. The points denote the position of organelles at 20-sec intervals. Bar = 1 μm.