The ciliated protista, Paramecium species, are extremely valuable cells that enable the reestablishment experiments of the endosymbiosis, which frequently bear prokaryotic, eukaryotic, or both endosymbionts in the cell. Although most endosymbiotic bacteria of Paramecium species cannot grow outside the host cell as a result of their reduced genome size, endonuclear symbiotic bacteria Holospora species, even when isolated from the host cells, can maintain their infectivity to new host cell for few days at room temperature. Although the host can acquire various stress resistances by endosymbiosis with Holospora, the symbionts are not indispensable for the host’s survival. Consequently, reestablishment of endosymbiosis between the symbiotic bacteria-free Paramecium and Holospora cells isolated from the host cells can be induced easily through the host phagocytosis by mixing them.
On the other hand, among Paramecium species, only P. bursaria and P. chlorelligerum have the capacity to harbor endosymbiotic green algae in the cytoplasm. Irrespective of mutual relationship between P. bursaria and the symbiotic algae, both cells still retain the ability to grow without the partner, and can easily reestablish endosymbiosis by mixing them. Thus, interactions between Paramecium species and Holospora species, and between P. bursaria or P. chlorelligerum and symbiotic green algae provide excellent opportunities to elucidate not only for control mechanisms for establishment of primary symbiosis, but also for secondary symbiosis leading to eukaryotic cell evolution.
Our research is focused on
1. How does the symbiont invade the host cytoplasm?
2. How can the symbiont avoid digestion by the host's lysosomal enzymes?
3. How can the symbiont grow synchronously with the host cell?
4. How and when is the horizontal gene transfer from symbiont to the host genome induced?
5. What benefit does the host cell receive by endosymbiosis to stabilize endosymbiosis and to adapt to new environments for expanding the range that the hosts can live in?
Proceedings of the National Academy of Sciences of the United States of America. Nov 2018 [Refereed]
Symbiotic digestion of lignocellulose in wood-feeding higher termites (family Termitidae) is a two-step process that involves endogenous host cellulases secreted in the midgut and a dense bacterial community in the hindgut compartment. The genomes...
We present draft genome sequences of three Holospora species, hosted by the ciliate Paramecium caudatum; that is, the macronucleus-specific H. obtusa and&0a;the micronucleus-specific H. undulata and H. elegans. We investigate functions of ortholog...
To expedite the process of gene discovery related to the endosymbiosis, we have undertaken Illumina deep sequencing of mRNAs prepared from symbiont-bearing and symbiont-free P. bursaria cells. We assembled the reads de novo to build the transcript...
Infectivity of Chlorella species for the ciliate Paramecium bursaria is not based on sugar residues of their cell wall components, but based on their ability to localize beneath the host cell membrane after escaping from the host digestive vacuole...
On the origin of mitochondria and Rickettsia-related eukaryotic endosymbionts. Review article.
B. Franz Lang, Henner Brinkman, Liisa Koski, Masahiro Fujishima Hans-Dieter Gortz and Gertraud Burger
Japanese Journal of Protozoology 38(2) 171-183 2005
Biocommunication in ciliates (Eds, Guenther Witzany, Mariusz Nowacki)
Yuuki Kodama, Masahiro Fujishima (Part:Joint Work, Chapter 16. Paramecium as a model organism for studies on primary and secondary endosymbioses.)
Springer International Publishing Switzerland, 2016 ISBN:doi: 10.1007/978-3-319-32211-7_16
Cilia/flagella and ciliates/flagellates, (Eds) Hausmann K., Radek R., Schweizerbart
Fujishima M., Kodama Y. (Part:Joint Work, Insights into the Paramecium-Holospora and Paramecium-Chlorella symbioses.)
Science Publishers, Stuttgart Jan 2014 ISBN:978-3-510-65287-7
The Prokaryotes, 4th Edition, (Eds) Rosenberg E., DeLong E. F., Thompson F., Lory S., Stackebrand E., Quinones D.
Schweikert M., Fujishima M., Görtz H.-D. (Part:Joint Work, Symbiotic associations between ciliates and prokaryotes.)
Springer-Verlag Berlin Heidelberg 2013 ISBN:DOI 10.1007/978-3-642-30194-0_18
International Review of Cell and Molecular Biology", (Ed) Jeon K. W.
Kodama Y. and Fujishima M. (Part:Joint Work, Chapter 2. Secondary symbiosis between Paramecium and Chlorella cells.)
2010 ISBN:978-0-12-381011-3
Kodama Y. and Fujishima M. Chapter 2. Secondary symbiosis between Paramecium and Chlorella cells. In, International Review of Cell and Molecular Biology, K.W. Jeon (Ed.)
Academic Press 2010
Endosymbionts in Paramecium
FUJISHIMA Masahiro (Part:Editor)
Springer 2009
Kodama Y. and Fujishima M. Chapter 2. Infection of Paramecium bursaria with symbiotic Chlorella species. In, Endosymbionts in Paramecium. Microbiology Monographs Vol. 12, Fujishima M. (Ed.)
Springer 2009 ISBN:978-3-540-92676-4
Fujishima, M. Chapter 8. Infection and Maintenance of Holospora Species in Paramecium caudatum. In, Endosymbionts in Paramecium. Microbiology Monographs Vol. 12, Fujishima M. (Ed.).
Springer 2008 ISBN:978-3-540-92676-4
Fujishima M. and Kodama Y. Environmental adaptation of Paramecium by endosymbionts and application to remediation of ecosystem. In, Proceedings of Infrastructure and Environmental Management Symposium in Yamaguchi 2008, Miyamoto A. and Fujishima M. (・・・
Research Center for Environmental Safety (RCES), Yamaguchi University 2008 ISBN:9901161-9-4 C3060
Fujishima M. and Kodama Y. Environmental adaptation of Paramecium by endosymbionts and application to remediation of ecosystem. In, Proceedings of Infrastructure and Environmental Management Symposium in Yamaguchi 2008, Miyamoto A. and Fujishima...
Endosymbiotic bacteria and its genetics
Gentics of ┣DBParamecium(/)-┫DB. (Tohoku University Press) 1999
17th International Symposium on Microbial Ecology 12 Aug 2018
Prospects of Paramecium collection that has been used as a model organism for eukaryotic cells[Invited]
FUJISHIMA Masahiro
Workshop 7 “Introduction of the 4th NBRP collections as attractive research materials and the forefront of ABS information”, The 91th Annual Meeting of Japanese Society for Bacteriology 28 Mar 2018
Legionella pneumonia TolC inhibits cellular trafficking in Paramecium tetraurelia
Nishida T, Hara N, Watanabe K, Shimizu T, Fujishima M, Watarai M.
27 Mar 2018
Kodama, Y. and Fujishima, M. Infection process of symbiotic algae to the algae-free Paramecium bursaria.
XIII International Congress of Protistology 2009
Masahiro Fujishima. Infection of Holospora and acquisition of stress resistance of the host Paramecium.
XIII International Congress of Protistology, Symposium “Symbiosis and Evolution”. 2009
Kodama, Y. and Fujishima, M. Infection process of symbiotic algae to the algae-free Paramecium bursaria.
XIII International Congress of Protistology 2009
Masahiro Fujishima. Infection of Holospora and acquisition of stress resistance of the host Paramecium.
XIII International Congress of Protistology, Symposium “Symbiosis and Evolution”. 2009
Masahiro Fujishima. Infection and maintenance of Holospora in Paramecium.
International Symposium on Protistology. Evolution and Diversity 2008
Masahiro Fujishima. Infection and maintenance of Holospora in Paramecium.
International Symposium on Protistology. Evolution and Diversity 2008
