Division of Symbiosis and Cell Evolution • Miyagishima Group

Evolutionary integration of two independent organisms by endosymbioses


Research Summary

Mitochondria and chloroplasts, energy-converting organelles in eukaryotic cells, are relicts of ancient bacterial endosymbionts. In addition to these particular organelles, there are many other endosymbiotic events which have integrated new functions into eukaryotic host cells. In order to maintain a permanent endosymbiotic relationship, a host cell and an endosymbiotic cell coordinate their proliferation. The major goal of our study is to understand how organelle (or other endosymbiotic cell) division is controlled by host cells and how host cells proliferate depending on chemical energy that are supplied by organelles (or other endosymbiotic cells).

Reminiscent of their cyanobacterial (A) ancestor, chloroplasts replicate by binary division (B, unicellular alga; C, land plant cells). Chloroplast division is performed by the division ring (D) which involves cyanobacterial FtsZ and eukaryotic dynamin (E).


Sumiya, N., Fujiwara, T., Era, A., and Miyagishima, S. (2016). Chloroplast division checkpoint in eukaryotic algae. Proc Natl Acad Sci USA 113, 7629-7638.

Nakabachi, A., Ishida, K., Hongoh, Y., Ohkuma, M., and Miyagishima, S. (2014). Aphid gene of bacterial origin encodes a protein transported to an obligate endosymbiont. Curr Biol 24, 640-641.

Miyagishima, S., Fujiwara, T., Sumiya, N., Hirooka, S., Nakano, A., Kabeya, Y., and, Nakamura, M. (2014). Translation-independent circadian control of the cell cycle in a unicellular photosynthetic eukaryote. Nat Commun 5, 3807.

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