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オカモト カズコ
Kazuko Okamoto
岡本 和子 所属 川崎医科大学 医学部 一般教養 自然科学 職種 助教 |
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| 論文種別 | 研究論文（学術雑誌） |
| 言語種別 | 英語 |
| 査読の有無 | 査読あり |
| 表題 | The active stem cell specific expression of sponge Musashi homolog EflMsiA suggests its involvement in maintaining the stem cell state. |
| 掲載誌名 | 正式名：Mechanisms of development 略 称：Mech Dev ISSNコード：18726356/09254773 |
| 掲載区分 | 国外 |
| 巻・号・頁 | 129(1-4),pp.24-37 |
| 著者・共著者 | Kazuko Okamoto, Mikiko Nakatsukasa, Alexandre Alié, Yoshiki Masuda, Kiyokazu Agata, Noriko Funayama |
| 担当区分 | 筆頭著者 |
| 発行年月 | 2012 |
| 概要 | A hallmark of stem cells is the ability to sustainably generate stem cells themselves (self-renew) as well as differentiated cells. Although a full understanding of this ability will require clarifying underlying the primordial molecular and cellular mechanisms, how stem cells maintain their stem state and their population in the evolutionarily oldest extant multicellular organisms, sponges, is poorly understood. Here, we report the identification of the first stem cell-specific gene in demosponges, a homolog of Musashi (an evolutionarily conserved RNA binding protein that regulates the stem cell state in various organisms). EflMsiA, a Musashi paralog, is specifically expressed in stem cells (archeocytes) in the freshwater sponge Ephydatia fluviatilis. EflMsiA protein is localized predominantly in the nucleus, with a small fraction in the cytoplasm, in archeocytes. When archeocytes enter M-phase, EflMsiA protein diffuses into the cytoplasm, probably because of the breakdown of the nuclear membrane. In the present study, the existence of two types of M-phase archeocytes [(M)-archeocytes] was revealed by a precise analysis of the expression levels of EflMsiA mRNA and protein. In Type I (M)-archeocytes, presumably archeocytes undergoing self-renewal, the expression levels of EflMsiA mRNA and protein were high. In Type II (M)-archeocytes, presumably archeocytes committed to differentiate (committed archeocytes), the expression levels of EflMsiA mRNA and protein were about 60% and 30% lower than those in Type I (M)-archeocytes. From these results, archeocytes can be molecularly defined for the first time as EflMsiA-mRNA-expressing cells. Furthermore, these findings shed light on the mode of cell division of archeocytes and suggest that archeocytes divide symmetrically for both self-renewal and differentiation. |
| DOI | 10.1016/j.mod.2012.03.001 |
| PMID | 22464976 |