- 著者
- Miyazaki Takamichi Isobe Takehisa Nakatsuji Norio Suemori Hirofumi
- 出版者
- Springer Nature
- 雑誌
- Scientific Reports
- 巻号頁・発行日
- vol.7, 2017-01-30
- 被引用文献数
- 50
ヒト多能性幹細胞の拡大培養法の簡便かつ低コスト化に成功 : 培養基質のコーティングを必要としない培養法を開発. 京都大学プレスリリース. 2017-01-31.
- 著者
- 末盛 博文 Suemori Hirofumi Hirai Yuko Hamasaki Kanya Kodama Yoshiaki Mitani Hiroshi Landes Reid D. Nakamura Nori
- 出版者
- Public Library of Science
- 雑誌
- PLOS ONE (ISSN:19326203)
- 巻号頁・発行日
- vol.10, no.8, 2015-08-21
It is becoming clear that apparently normal somatic cells accumulate mutations. Such accumulations or propagations of mutant cells are thought to be related to certain diseases such as cancer. To better understand the nature of somatic mutations, we developed a mouse model that enables in vivo detection of rare genetically altered cells via GFP positive cells. The mouse model carries a partial duplication of 3' portion of X-chromosomal HPRT gene and a GFP gene at the end of the last exon. In addition, although HPRT gene expression was thought ubiquitous, the expression level was found insufficient in vivo to make the revertant cells detectable by GFP positivity. To overcome the problem, we replaced the natural HPRT-gene promoter with a CAG promoter. In such animals, termed HPRT-dup-GFP mouse, losing one duplicated segment by crossover between the two sister chromatids or within a single molecule of DNA reactivates gene function, producing hybrid HPRT-GFP proteins which, in turn, cause the revertant cells to be detected as GFP-positive cells in various tissues. Frequencies of green mutant cells were measured using fixed and frozen sections (liver and pancreas), fixed whole mount (small intestine), or by means of flow cytometry (unfixed splenocytes). The results showed that the frequencies varied extensively among individuals as well as among tissues. X-ray exposure (3 Gy) increased the frequency moderately (~2 times) in the liver and small intestine. Further, in two animals out of 278 examined, some solid tissues showed too many GFP-positive cells to score (termed extreme jackpot mutation). Present results illustrated a complex nature of somatic mutations occurring in vivo. While the HPRT-dup-GFP mouse may have a potential for detecting tissue-specific environmental mutagens, large inter-individual variations of mutant cell frequency cause the results unstable and hence have to be reduced. This future challenge will likely involve lowering the background mutation frequency, thus reducing inter-individual variation.
- 著者
- Miyazaki Takamichi Futaki Sugiko Suemori Hirofumi Taniguchi Yukimasa Yamada Masashi Kawasaki Miwa Hayashi Maria Kumagai Hideaki Nakatsuji Norio Sekiguchi Kiyotoshi Kawase Eihachiro
- 出版者
- Nature Publishing Group
- 雑誌
- Nature communications (ISSN:20411723)
- 巻号頁・発行日
- vol.3, 2012-12-04
- 被引用文献数
- 287
細胞接着タンパクを用い、 安全・高効率なヒトES / iPS細胞の培養法を開発 : 幹細胞実用化に必要な品質保証・大量生産に向けて前進. 京都大学プレスリリース. 2012-12-05.