| Co-Investigator(Kenkyū-buntansha) |
KAWAI Hiroshi Kobe Univ. Research Center for Inland Seas, Prof., 内海域機能教育研究センター, 教授 (30161269)
KATO Atsushi Hokkaido Univ. Grad. School of Sci., Prof., 大学院・理学研究科, 教授 (90177428)
ICHIMURA Terunobu Hokkaido Univ. Field Science Center for Northern Biosphere, Prof., 北方生物圏フィールド科学センター, 教授 (00090481)
MURAKAMI Akio Kobe Univ. Research Center for Inland Seas, Asso. Prof., 内海域機能教育研究センター, 教授 (50304134)
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| Research Abstract |
Swarmers of Heterokonta algae, including brown algae and chrysophyceaen alga Ochromonas have two distinctive flagella, a mastigoneme-bearing long flagellum and a short flagellum. Adding these morphological differences, functions of these flagella are also different. Using synchronized culture of Ochromonas, we found that duplication of the flagellar occurs during G2 - M duding cell cycle, while the formation of daughter basal bodies does during G1 - S. This means that the duplication of flagella of Heterokonta algae is completely dependent to the regulation of the cell cycle. This mechanism is quite similar to the centrosome regulation of animal cells. Various forms of the spindle of Heterokonta algae have been reorted, but we found that basal bodies of flagella are always existed nearby the spindle poles, using antibodies against centrin, gamma-tubulin and microtubules. Also in the case of the brown algae, centrosome functions to the distribution of the cell organella, including chloroplasts, to the daughter cells during mitosis. Recently, it has become clear that centrosome, centriole (=flagellar basal body) and flagellar axomeme affect to the human diseases including cancers. We believe that cell biological studies on the flagellar and centrosomal duplication and the spindle formation using various algae will also attract attentions on the evolution of eukaryotic cells and origin of flagella and centrioles.
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