抄録
Mitochondrial and plastid division can be clearly separated into two main events : division of the organelle nuclei (nucleoids), and subsequent division of the rest of the organelles, the process of organellokinesis. Organellokinesis makes use of organelle dividing apparatuses such as plastid-dividing ring (PD ring) and mitochondrion-dividing ring (MD ring). FtsZ protein is located on the bacterial contractile ring at the equator of dividing bacteria, and controls bacterial division. Since chloroplasts and mitochondria evolved from bacteria, there is debate whether the inner or outer PD rings evolved from FtsZ ring during eukaryogenesis. Immuno-electron microscopy using the antibody of Bacillus subtilis FtsZ showed that the FtsZ protein was not located on the outer PD and MD rings but on entire chloroplasts and cell nuclei in Cyanidioschyzon merolae and Cyanidium caldarium Forma A. This suggests that the function of FtsZ protein changed from contraction at the equator of bacteria into another during eukaryogenesis.
