TMS division and segregation occur within mitochondrial tubules in the absence of mtDNA. Mgm101GFP in cells lacking mtDNA is visualized in the context of the dsRED-labeled mitochondrion over a time period of 5 min. Each frame was taken at 10-s intervals, and the image represents a 0.2-µm section. A single Mgm101GFP spot is visualized and becomes two in the context of an intact mitochondrial tubule, representing a TMS replication/segregation event (see Materials and methods for analysis). Note that the rate of mitochondrial movement in cells lacking mtDNA is greater than in cells containing mtDNA. The significance of this observation with respect to TMS is presently unknown.
