2015年2月22日日曜日

【報道されない小保方さん問題】 武田教授、渾身の解説 / 武田 邦彦 #小保方晴子

【報道されない小保方さん問題】 武田教授、渾身の解説 / 武田 邦彦 #小保方晴子



2014/04/01 に公開
中部大学教授・武田邦彦さんのブログ音声をご紹介します
( ご本人のご厚意により、引用が認められています )

武田邦彦さんのサイト [ http://takedanet.com ]

・ 学生の錯覚・・・普段の社会の仁義と科学の世界
2014/04/01 [ http://youtu.be/PeVkajqbE4g ]

・ 公道、公園、公海、公知・・・それこそ私の学問のプライド
2014/04/01 [ http://youtu.be/mUJicBKcuXU ]

▼ 関連した番組

● 「小保方さんは悪くない!」 武田邦彦がSTAP細胞問題を徹底解説!

2014年4月1日、シアター・テレビジョン [ http://www.theatertv.co.jp ] にて、約1時間半インターネット生放送された番組の4分割された各映像です。

・ 1 / 4 → [ http://youtu.be/YNsNNatMn6U ]
・ 2 / 4 → [ http://youtu.be/WAWLSNBy2do ]
・ 3 / 4 → [ http://youtu.be/1JVOpkox7Ig ]
・ 4 / 4 → [ http://youtu.be/ynXSLUU5_yk ]

そして2014年4月18日、番組の第二弾が放送されました。­­

・ 1 / 4 → [ http://youtu.be/kNP3lUYfAF0 ]
・ 2 / 4 → [ http://youtu.be/OIaK1F6hzaw ]
・ 3 / 4 → [ http://youtu.be/tsUyPiyyiRE ]
・ 4 / 4 → [ http://youtu.be/Ey4LzULNbto ]

▼ 関連した音声動画

・ 「小保方さん問題を武田教授が解説」(武田邦彦ブログ音声より)

[ 01 ] 日本とアメリカの論文の違い
2014/03/13 [ http://youtu.be/oSHm3eVRE_g ]

[ 02 ] ジェファーソンの言葉
2014/03/14 [ http://youtu.be/6YO_EFCDvak ]

[ 03 ] 学生の責任か ?
2014/03/16 [ http://youtu.be/QI2Xrb7WgvM ]

[ 04 ] 学問と社会
2014/03/17 [ http://youtu.be/qbqG3CpExG0 ]

[ 05 ] コピペは悪いことか ? (1)
2014/03/18 [ http://youtu.be/luE0gUc00O0 ]

[ 06 ] コピペは悪いことか ? (2)
2014/03/19 [ http://youtu.be/YZ7MUijCp08 ]

[ 07 ] クーベルタン男爵
2014/03/20 [ http://youtu.be/IecYrbB7ycg ]

[ 08 ] コピペは悪いことか ? (3)
2014/03/21 [ http://youtu.be/HjOElcPOdOs ]

[ 09 ] リンチは犯罪である
2014/03/22 [ http://youtu.be/fY2K8oNeKCw ]

[ 10 ] 保安官ワイアット・アープ
2014/03/23 [ http://youtu.be/aFZeIej-RWQ ]

[ 11 ] 30歳の研究者
2014/03/27 [ http://youtu.be/cnZJtiZAlRw ]

[ 12 ] 論文と特許
2014/03/29 [ http://youtu.be/aJO7wKPjXgQ ]

[ 13 ] 教育者の責務
2014/03/30 [ http://youtu.be/1gHsCPIcTWs ]

[ 14 ] 引用という罪
2014/04/01 [ http://youtu.be/1cGFXdyYb_4 ]

[ 15 ] 学問の公性
2014/04/01 [ http://youtu.be/VSkEwJdxHFA ]

[ 16 ] 小保方さん問題の結論
2014/04/02 [ http://youtu.be/BG-QaWmPXMc ]

[ 17 ] 科学と拝金主義
2014/04/04 [ http://youtu.be/skFMPJ7T3mY ]

[ 18 ] 2冊の実験ノート
2014/04/04 [ http://youtu.be/MTweTiWdcy8 ]

[ 19 ] STAP事件簿 (1) 2013年正月
2014/04/07 [ http://youtu.be/9u9t077IiqM ]

[ 20 ] STAP事件簿 (2) 2013年暮れ
2014/04/08 [ http://youtu.be/Ks0lQTCUobM ]

[ 21 ] STAP事件簿 (3) Xデー / 2014年1月28日
2014/04/09 [ http://youtu.be/3e7uDzrIEQc ]

[ 22 ] STAP事件簿 (4) ネットの人
2014/04/09 [ http://youtu.be/-wPE7CQWM-I ]

[ 23 ] STAP事件簿 (5) 小保方晴子記者会見 / 2014年4月9日
2014/04/09 [ http://youtu.be/bQFo2x2l1PI ]

[ 24 ] STAP事件簿 (6) 暗闇研究
2014/04/10 [ http://youtu.be/jOQdwHu6d2g ]

[ 25 ] STAP事件簿 (7) STAP論文
2014/04/10 [ http://youtu.be/t9HZtPaugE4 ]

[ 26 ] STAP事件簿 (8) 素人の参戦 (1) コピペ
2014/04/11 [ http://youtu.be/VLSst61TI8U ]

[ 27 ] STAP事件簿 (9) 素人の参戦 (2) STAP論文の良心性
2014/04/11 [ http://youtu.be/56v2E2TLEtQ ]

[ 28 ] STAP事件簿 (10) 素人の参戦 (3) 悪意
2014/04/11 [ http://youtu.be/jNaAkLIuIi8 ]

[ 29 ] STAP事件簿 (11) 素人の参戦 (4) 学生の論文
2014/04/11 [ http://youtu.be/FsNtB1_HOQw ]

[ 30 ] STAP事件簿 (12) 深層 (1) 未熟と迷惑
2014/04/12 [ http://youtu.be/y3P3gFSu0P4 ]

[ 31 ] STAP事件簿 (13) 批判の矛盾
2014/04/13 [ http://youtu.be/tP-hXHbR9Bc ]

[ 32 ] STAP事件簿 (14) 深層 (2) 集団催眠現象
2014/04/13 [ http://youtu.be/cRzk83kL_cQ ]

※ 2014年4月13日 [ 32 ] 以降の回は、 [ http://www.youtube.com/starslife2011 ] でアップしています。

[ 小保方 晴子 , STAP細胞 , STAP論文 , 理化学研究所 , 理研 , iPS細胞 , 山中伸弥教授 , 山中教授 , 博士論文 , 新型万能細胞 , スタップ細胞 , リケジョ , 理系女子 , 京都大学iPS細胞研究所 , スタップ論文 , 幹細胞 , バカンティ教授 , 山梨大学 , 若山教授 , 若山 照彦 , 笹井 芳樹 , 大和 雅之 , 野依 良治 , 早稲田大学 ]

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【続・小保方さんは悪くない!】武田邦彦がSTAP細胞問題を徹底解説!その1(4月18日収録)  


2014/04/21 に公開
再生リスト(その1〜その4 全80分)
https://www.youtube.com/playlist?list...

シアター・テレビジョンpresents
2014/4/18にニコニコ生放送しました、
好評の<真実を語り合うシリーズ>の第8弾!

今回は、前回に引き続き「小保方さんとSTAP細胞を巡る問題」を
お送りします!
"科学者" 武田邦彦が、発信しなければならない理由がここにあります。

視聴者からの「こういう意見は貴重。もっと多くに人に、ぜひ無料で配信してくれないか­」といった声を受け、Youtubeにも録画を配信することにしました。

こちらの番組をご覧頂きまして、皆様が思った事など、
ぜひコメント頂けますと幸いです。
また良いと思った方は、SNSなどでご友人の皆様へお知らせ頂けますと幸いです。

今後とも武田邦彦×シアター・テレビジョンの熱き試み「現代のコペルニクス」を、ご支­援のほど、どうぞよろしくお願いいたします。

シアター・テレビジョン(スカパー!プレミアムサービス547ch)
http://www.theatertv.co.jp/

シアターネットTV(ニコニコチャンネル /ネット生放送)
http://ch.nicovideo.jp/ch2620

→武田邦彦教授の過去の番組も多数配信中です!

出演:武田邦彦
<プロフィール>
工学博士・中部大学教授。1943年生まれ。
シアター・テレビジョンのレギュラー番組「現代のコペルニクス」を監修・出演中。

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【続・小保方さんは悪くない!】武田邦彦がSTAP細胞問題を徹底解説!その2(4月18日収録)



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【続・小保方さんは悪くない!】武田邦彦がSTAP細胞問題を徹底解説!その3(4月18日収録)



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【続・小保方さんは悪くない!】武田邦彦がSTAP細胞問題を徹底解説!その4(4月18日収録)



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【動画】STAP細胞論文の共著者・笹井芳樹氏が会見


 
2014/04/16 に公開
http://thepage.jp/detail/20140415-000...
STAP細胞論文の共著者で、理化学研究所の発生・再生科学総合研究センター(CDB­)副センター長、笹井芳樹氏が16日午後3時から都内で会見した。
 
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【一体誰が笹井芳樹氏を死なせたか】 無念 - 笹井芳樹 氏の死去を悼む - / 武田 邦彦 [ 2014.08.05 ] #笹井芳樹 #大隅典子 #小保方晴子 #NHK #毎日新聞 #日本分子生物学会  



2014/08/05 に公開
※ 公開の翌日、武田先生がブログの記事と音声を取り下げられましたので、この動画音声も­即日非公開としていましたが、亡くなられた笹井さんの無念、そしてこの動画音声が、み­なさんの間で既に広く共有がされていることから、このブログ音声を敢えて再公開させて­頂きます。 [ 2014.08.09 ]

笹井芳樹さんの死を悼み、慎しみお悔み申し上げます。以下、本日緊急にて出された中部­大学・武田邦彦教授のブログ音声をご紹介します。 [ 2014.08.06 ]

武田邦彦ブログ [ http://takedanet.com ]

・ また起こったメディア殺人・・・笹井さんの自殺と浅田農園の老夫婦の自殺
2014/08/05 [ http://youtu.be/PunYbCI9Nbg ]

▼ 笹井氏悲劇の裏に「裏切りリーク」「小保方氏とのメール暴露」
http://goo.gl/j3mLyy

【お知らせ(重要)】 現在、Channel K にチャンネル移転中ですが、移転先URLが [ http://www.youtube.com/channelk2014 ] に変更となりました。STARS LIFE ☆ YouTube のサブチャンネルとして、独自の動画を発信します。両方のチャンネル登録をお願いしま­す。 [ 2014年04月25日 / 清瀬 航輝 ]

▼ 関連番組

・ 「小保方さんは悪くない!」 武田邦彦がSTAP細胞問題を徹底解説!

・ 1 / 4 → [ http://youtu.be/YNsNNatMn6U ]
・ 2 / 4 → [ http://youtu.be/WAWLSNBy2do ]
・ 3 / 4 → [ http://youtu.be/1JVOpkox7Ig ]
・ 4 / 4 → [ http://youtu.be/ynXSLUU5_yk ]

・ 続編番組

・ 1 / 4 → [ http://youtu.be/kNP3lUYfAF0 ]
・ 2 / 4 → [ http://youtu.be/OIaK1F6hzaw ]
・ 3 / 4 → [ http://youtu.be/tsUyPiyyiRE ]
・ 4 / 4 → [ http://youtu.be/Ey4LzULNbto ]

▼ 関連した音声動画

・ 「小保方さん問題を武田教授が解説」(武田邦彦ブログ音声より)

[ 01 ] 日本とアメリカの論文の違い
2014/03/13 [ http://youtu.be/oSHm3eVRE_g ]

[ 02 ] ジェファーソンの言葉
2014/03/14 [ http://youtu.be/6YO_EFCDvak ]

[ 03 ] 学生の責任か ?
2014/03/16 [ http://youtu.be/QI2Xrb7WgvM ]

[ 04 ] 学問と社会
2014/03/17 [ http://youtu.be/qbqG3CpExG0 ]

[ 05 ] コピペは悪いことか ? (1)
2014/03/18 [ http://youtu.be/luE0gUc00O0 ]

[ 06 ] コピペは悪いことか ? (2)
2014/03/19 [ http://youtu.be/YZ7MUijCp08 ]

[ 07 ] クーベルタン男爵
2014/03/20 [ http://youtu.be/IecYrbB7ycg ]

[ 08 ] コピペは悪いことか ? (3)
2014/03/21 [ http://youtu.be/HjOElcPOdOs ]

[ 09 ] リンチは犯罪である
2014/03/22 [ http://youtu.be/fY2K8oNeKCw ]

[ 10 ] 保安官ワイアット・アープ
2014/03/23 [ http://youtu.be/aFZeIej-RWQ ]

[ 11 ] 30歳の研究者
2014/03/27 [ http://youtu.be/cnZJtiZAlRw ]

[ 12 ] 論文と特許
2014/03/29 [ http://youtu.be/aJO7wKPjXgQ ]

[ 13 ] 教育者の責務
2014/03/30 [ http://youtu.be/1gHsCPIcTWs ]

[ 14 ] 引用という罪
2014/04/01 [ http://youtu.be/1cGFXdyYb_4 ]

[ 15 ] 学問の公性
2014/04/01 [ http://youtu.be/VSkEwJdxHFA ]

[ 16 ] 小保方さん問題の結論
2014/04/02 [ http://youtu.be/BG-QaWmPXMc ]

[ 17 ] 科学と拝金主義
2014/04/04 [ http://youtu.be/skFMPJ7T3mY ]

[ 18 ] 2冊の実験ノート
2014/04/04 [ http://youtu.be/MTweTiWdcy8 ]

[ 19 ] STAP事件簿 (1) 2013年正月
2014/04/07 [ http://youtu.be/9u9t077IiqM ]

[ 20 ] STAP事件簿 (2) 2013年暮れ
2014/04/08 [ http://youtu.be/Ks0lQTCUobM ]

[ 21 ] STAP事件簿 (3) Xデー / 2014年1月28日
2014/04/09 [ http://youtu.be/3e7uDzrIEQc ]

[ 22 ] STAP事件簿 (4) ネットの人
2014/04/09 [ http://youtu.be/-wPE7CQWM-I ]

[ 23 ] STAP事件簿 (5) 小保方晴子記者会見 / 2014年4月9日
2014/04/09 [ http://youtu.be/bQFo2x2l1PI ]

[ 24 ] STAP事件簿 (6) 暗闇研究
2014/04/10 [ http://youtu.be/jOQdwHu6d2g ]

[ 25 ] STAP事件簿 (7) STAP論文
2014/04/10 [ http://youtu.be/t9HZtPaugE4 ]

[ 26 ] STAP事件簿 (8) 素人の参戦 (1) コピペ
2014/04/11 [ http://youtu.be/VLSst61TI8U ]

[ 27 ] STAP事件簿 (9) 素人の参戦 (2) STAP論文の良心性
2014/04/11 [ http://youtu.be/56v2E2TLEtQ ]

[ 28 ] STAP事件簿 (10) 素人の参戦 (3) 悪意
2014/04/11 [ http://youtu.be/jNaAkLIuIi8 ]

[ 29 ] STAP事件簿 (11) 素人の参戦 (4) 学生の論文
2014/04/11 [ http://youtu.be/FsNtB1_HOQw ]

[ 30 ] STAP事件簿 (12) 深層 (1) 未熟と迷惑
2014/04/12 [ http://youtu.be/3o_a7j2Lzgw ]

[ 31 ] STAP事件簿 (13) 批判の矛盾
2014/04/13 [ http://youtu.be/0azR7ttAcf0 ]

[ 32 ] STAP事件簿 (14) 深層 (2) 集団催眠現象
2014/04/13 [ http://youtu.be/QHiR5SQ9-qU ]

※ 2014年4月13日 [ 32 ] 以降の回は、 [ http://www.youtube.com/starslife2011 ] でアップします。

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【STAP細胞】10解析結果報告 若山照彦氏による記者会見【2014/6/16】  



2014/06/16 に公開
「STAP細胞」をもとに作ったとされる細胞の遺伝子を第三者機関が解析したところ、­別の万能細胞である「ES細胞」の特徴が確認されたことがわかりました。
解析を依頼した「STAP論文」共著者の若山照彦山梨大教授がこの結果を受けて開く記­者会見の模様となります。
 
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Nature

figures

http://www.nature.com/nature/journal/v505/n7485/full/nature12968.html#figures

Videos

http://www.nature.com/nature/journal/v505/n7485/full/nature12968.html#videos


Nature | Article
 
Stimulus-triggered fate conversion of somatic cells into pluripotency

 
 
Nature 
Volume:
505,

Pages:
641–647
            
Date published:


DOI:doi:10.1038/nature12968
    Received

Accept
Published online

Abstract

Abstract

Introduction

Low pH triggers fate conversion in somatic cells

Low-pH-induced Oct4+ cells have pluripotency

STAP cells compared to ES cells

STAP cells from other tissue sources

Chimaera formation and germline transmission in mice

Expandable pluripotent cell lines from STAP cells

Discussion

Methods

References

Acknowledgements

Author information

Extended data figures and tables

Supplementary information

Comments

Here we report a unique cellular reprogramming phenomenon, called stimulus-triggered acquisition of pluripotency (STAP), which requires neither nuclear transfer nor the introduction of transcription factors. In STAP, strong external stimuli such as a transient low-pH stressor reprogrammed mammalian somatic cells, resulting in the generation of pluripotent cells. Through real-time imaging of STAP cells derived from purified lymphocytes, as well as gene rearrangement analysis, we found that committed somatic cells give rise to STAP cells by reprogramming rather than selection. STAP cells showed a substantial decrease in DNA methylation in the regulatory regions of pluripotency marker genes. Blastocyst injection showed that STAP cells efficiently contribute to chimaeric embryos and to offspring via germline transmission. We also demonstrate the derivation of robustly expandable pluripotent cell lines from STAP cells. Thus, our findings indicate that epigenetic fate determination of mammalian cells can be markedly converted in a context-dependent manner by strong environmental cues.

Figures
  1. Stimulus-triggered conversion of lymphocytes into Oct4-GFP+ cells.
  2. Figure 1: Stimulus-triggered conversion of lymphocytes into Oct4-GFP+ cells.
  3. a, Schematic of low-pH treatment. b, Oct4-GFP+ cell clusters appeared in culture of low-pH-treated CD45+ cells (middle; high magnification, right) on day 7 (d7) but not in culture of control CD45+ cells (left). Top: bright-field view; bottom, GFP signals. Scale bar, 100μm. c, FACS analysis. The x axis shows CD45 epifluorescence level; y axis shows Oct4-GFP level. Non-treated, cultured in the same medium but not treated with low pH. d, GFP+ (green) and GFP (yellow) cell populations (average cell numbers per visual field; ×10 objective lens). n = 25; error bars show average±s.d. e, Snapshots of live imaging of culture of low-pH-treated CD45+ cells (Oct4-gfp). Arrows indicate cells that started expressing Oct4-GFP. Scale bar, 50μm. f, Cell size reduction in low-pH-treated CD45+ cells on day1 before turning on Oct4-GFP without cell division on day 2. In this live imaging, cells were plated at a half density for easier viewing of individual cells. Scale bar, 10μm. g, Electron microscope analysis. Scale bar, 1μm. h, Forward scattering analysis of Oct4-GFPCD45+ cells (red) and Oct4-GFP+CD45 cells (green) on day 7. Blue line, ES cells. i, Genomic PCR analysis of (D)J recombination at the Tcrb gene. GL is the size of the non-rearranged germline type, whereas the smaller ladders correspond to the alternative rearrangements of J exons. Negative controls, lanes 1, 2; positive controls, lane 3; FACS-sorted Oct4-GFP+ cells (two independent preparations on day 7), lanes 4, 5.
  4. Low-pH-induced Oct4-GFP+ cells represent pluripotent cells.
    Figure 2: Low-pH-induced Oct4-GFP+ cells represent pluripotent cells.
    a, Immunostaining for pluripotent cell markers (red) in day 7 Oct4-GFP+ (green) clusters. DAPI, white. Scale bar, 50μm. b, qPCR analysis of pluripotency marker genes. From left to right, mouse ES cells; parental CD45+ cells; low-pH-induced Oct4-GFP+ cells on day 3; low-pH-induced Oct4-GFP+ cells on day 7. n = 3; error bars show average±s.d. c, DNA methylation study by bisulphite sequencing. Filled and open circles indicate methylated and non-methlylated CpG, respectively. d, Immunostaining analysis of in vitro differentiation capacity of day 7 Oct4-GFP+ cells. Ectoderm: the neural markers Sox1/Tuj1 (100%, n = 8) and N-cadherin (100%, n = 5). Mesoderm: smooth muscle actin (50%, n = 6) and brachyury (40%, n = 5). Endoderm: Sox17/E-cadherin (67%, n = 6) and Foxa2/Pdgfrα (67%, n = 6). Scale bar, 50μm. e, Teratoma formation assay of day 7 clusters of Oct4-GFP+ cells. Haematoxylin and eosin staining showed keratinized epidermis (ectoderm), skeletal muscle (mesoderm) and intestinal villi (endoderm), whereas immunostaining showed expression of Tuj1 (neurons), smooth muscle actin and α-fetoprotein. Scale bar, 100μm. fi, Dissociation culture of ES cells and STAP cells (additional 7 days from day 7; f, g) on gelatin-coated dishes. Top, bright-field; bottom, alkaline phosphatase (AP) staining. Partially dissociated STAP cells slowly generated small colonies (i), whereas dissociated STAP cells did not, even in the presence of the ROCK inhibitor (g, h), which allows dissociation culture of EpiSCs29.

    STAP cell conversion from a variety of cells by low-pH treatment.
    Figure 3: STAP cell conversion from a variety of cells by low-pH treatment.

Introduction
Abstract Introduction Low pH triggers fate conversion in somatic cells Low-pH-induced Oct4+ cells have pluripotency STAP cells compared to ES cells STAP cells from other tissue sources Chimaera formation and germline transmission in mice Expandable pluripotent cell lines from STAP cells Discussion Methods References Acknowledgements Author information Extended data figures and tables Supplementary information Comments

In the canalization view of Waddington’s epigenetic landscape, fates of somatic cells are progressively determined as cellular differentiation proceeds, like going downhill. It is generally believed that reversal of differentiated status requires artificial physical or genetic manipulation of nuclear function such as nuclear transfer1, 2 or the introduction of multiple transcription factors3. Here we investigated the question of whether somatic cells can undergo nuclear reprogramming simply in response to external triggers without direct nuclear manipulation. This type of situation is known to occur in plants—drastic environmental changes can convert mature somatic cells (for example, dissociated carrot cells) into immature blastema cells, from which a whole plant structure, including stalks and roots, develops in the presence of auxins4. A challenging question is whether animal somatic cells have a similar potential that emerges under special conditions. Over the past decade, the presence of pluripotent cells (or closely relevant cell types) in adult tissues has been a matter of debate, for which conflicting conclusions have been reported by various groups5, 6, 7, 8, 9, 10, 11. However, no study so far has proven that such pluripotent cells can arise from differentiated somatic cells.
Haematopoietic cells positive for CD45 (leukocyte common antigen) are typical lineage-committed somatic cells that never express pluripotency-related markers such as Oct4 unless they are reprogrammed12, 13. We therefore addressed the question of whether splenic CD45+ cells could acquire pluripotency by drastic changes in their external environment such as those caused by simple chemical perturbations.

Low pH triggers fate conversion in somatic cells

Abstract

Introduction

Low pH triggers fate conversion in somatic cells

Low-pH-induced Oct4+ cells have pluripotency

STAP cells compared to ES cells

STAP cells from other tissue sources

Chimaera formation and germline transmission in mice

Expandable pluripotent cell lines from STAP cells

Discussion

Methods

References

Acknowledgements

Author information

Extended data figures and tables

Supplementary information

Comments

CD45+ cells were sorted by fluorescence-activated cell sorting (FACS) from the lymphocyte fraction of postnatal spleens (1-week old) of C57BL/6 mice carrying an Oct4-gfp transgene14, and were exposed to various types of strong, transient, physical and chemical stimuli (described below). We examined these cells for activation of the Oct4 promoter after culture for several days in suspension using DMEM/F12 medium supplemented with leukaemia inhibitory factor (LIF) and B27 (hereafter called LIF+B27 medium). Among the various perturbations, we were particularly interested in low-pH perturbations for two reasons. First, as shown below, low-pH treatment turned out to be most effective for the induction of Oct4. Second, classical experimental embryology has shown that a transient low-pH treatment under ‘sublethal’ conditions can alter the differentiation status of tissues. Spontaneous neural conversion from salamander animal caps by soaking the tissues in citrate-based acidic medium below pH6.0 has been demonstrated previously15, 16, 17.
Without exposure to the stimuli, none of the cells sorted with CD45 expressed Oct4-GFP regardless of the culture period in LIF+B27 medium. In contrast, a 30-min treatment with low-pH medium (25-min incubation followed by 5-min centrifugation; Fig. 1a; the most effective range was pH5.4–5.8; Extended Data Fig. 1a) caused the emergence of substantial numbers of spherical clusters that expressed Oct4-GFP in day-7 culture (Fig. 1b). Substantial numbers of GFP+ cells appeared in all cases performed with neonatal splenic cells (n = 30 experiments). The emergence of Oct4-GFP+ cells at the expense of CD45+ cells was also observed by flow cytometry (Fig. 1c, top, and Extended Data Fig. 1b, c). We next fractionated CD45+ cells into populations positive and negative for CD90 (T cells), CD19 (B cells) and CD34 (haematopoietic progenitors18), and subjected them to low-pH treatment. Cells of these fractions, including T and B cells, generated Oct4-GFP+ cells at an efficacy comparable to unfractionated CD45+ cells (25–50% of surviving cells on day 7), except for CD34+ haematopoietic progenitors19, which rarely produced Oct4-GFP+ cells (<2%; Extended Data Fig. 1d).

Stimulus-triggered conversion of lymphocytes into Oct4-GFP+ cells.
a, Schematic of low-pH treatment. b, Oct4-GFP+ cell clusters appeared in culture of low-pH-treated CD45+ cells (middle; high magnification, right) on day 7 (d7) but not in culture of control CD45+ cells (left). Top: bright-field view; bottom, GFP signals. Scale bar, 100μm. c, FACS analysis. The x axis shows CD45 epifluorescence level; y axis shows Oct4-GFP level. Non-treated, cultured in the same medium but not treated with low pH. d, GFP+ (green) and GFP (yellow) cell populations (average cell numbers per visual field; ×10 objective lens). n = 25; error bars show average±s.d. e, Snapshots of live imaging of culture of low-pH-treated CD45+ cells (Oct4-gfp). Arrows indicate cells that started expressing Oct4-GFP. Scale bar, 50μm. f, Cell size reduction in low-pH-treated CD45+ cells on day1 before turning on Oct4-GFP without cell division on day 2. In this live imaging, cells were plated at a half density for easier viewing of individual cells. Scale bar, 10μm. g, Electron microscope analysis. Scale bar, 1μm. h, Forward scattering analysis of Oct4-GFPCD45+ cells (red) and Oct4-GFP+CD45 cells (green) on day 7. Blue line, ES cells. i, Genomic PCR analysis of (D)J recombination at the Tcrb gene. GL is the size of the non-rearranged germline type, whereas the smaller ladders correspond to the alternative rearrangements of J exons. Negative controls, lanes 1, 2; positive controls, lane 3; FACS-sorted Oct4-GFP+ cells (two independent preparations on day 7), lanes 4, 5.
Among maintenance media for pluripotent cells20, the appearance of Oct4-GFP+ cells was most efficient in LIF+B27 medium, and did not occur in mouse epiblast-derived stem-cell (EpiSC) medium21, 22 (Extended Data Fig. 1e). The presence or absence of LIF during days 0–2 did not substantially affect the frequency of Oct4-GFP+ cell generation on day 7 (Extended Data Fig. 1f), whereas the addition of LIF during days 4–7 was not sufficient, indicating that LIF dependency started during days 2–4.
Most of the surviving cells on day 1 were still CD45+ and Oct4-GFP. On day3, the total cell numbers were reduced to between one-third to one-half of the day 0 population (Fig. 1d; see Extended Data Fig. 1g, h for apoptosis analysis), and a substantial number of total surviving cells became Oct4-GFP+ (Fig. 1d), albeit with relatively weak signal intensity. On day 7, a significant number of Oct4-GFP+CD45 cells (one-half to two-thirds of total surviving cells) constituted a distinct population from the Oct4-GFPCD45 cells (Fig. 1c, top, day 7, and Fig. 1d). No obvious generation of Oct4-GFP+CD45 populations was seen in non-treated CD45+ cells cultured similarly but without low-pH treatment (Fig. 1c, bottom).
Low-pH-treated CD45+ cells, but not untreated cells, gradually turned on GFP signals over the first few days (Fig. 1e, Supplementary Videos 1 and 2 and Extended Data Fig. 2a), whereas CD45 immunoreactivity became gradually reduced in the cells that demonstrated Oct4-GFP expression (Fig. 1f and Extended Data Fig. 2b). By day 5, the Oct4-GFP+ cells attached together and formed clusters by accretion. These GFP+ clusters (but not GFP cells) were quite mobile and often showed cell processes on moving (Supplementary Video 1).
The Oct4-GFP+ cells demonstrated a characteristic small cell size with little cytoplasm and also showed a distinct fine structure of the nucleus compared with that of parental CD45+ lymphocytes (Fig. 1g). The Oct4-GFP+ cells on day 7 were smaller than non-treated CD45+ cells (Fig. 1g, h and Extended Data Fig. 2c) and embryonic stem (ES) cells (Fig. 1h), both of which are generally considered to be small in size. The diameter of low-pH-treated CD45+ cells became reduced during the first 2days, even before they started Oct4-GFP expression (Fig. 1f), whereas the onset of GFP expression was not accompanied by cell divisions. Consistent with this, no substantial 5-ethynyl-2′-deoxyuridine (EdU) uptake was observed in the Oct4-GFP+ cells after the stressor (Extended Data Fig. 2d).
The lack of substantial proliferation argues against the possibility that CD45 cells, contaminating as a very minor population in the FACS-sorted CD45+ cells, quickly grew and formed a substantial Oct4-GFP+ population over the first few days after the low-pH treatment. In addition, genomic rearrangements of Tcrb (T-cell receptor gene) were observed in Oct4-GFP+ cells derived from FACS-purified CD45+ cells and CD90+CD45+ T cells (Fig. 1i, lanes 4, 5, and Extended Data Fig. 2e–g), indicating at least some contribution from lineage-committed T cells. Thus, Oct4-GFP+ cells were generated de novo from low-pH-treated CD45+ haematopoietic cells by reprogramming, rather than by simple selection of stress-enduring cells23.

Low-pH-induced Oct4+ cells have pluripotency

On day 7, the Oct4-GFP+ spheres expressed pluripotency-related marker proteins22 (Oct4, SSEA1, Nanog and E-cadherin; Fig. 2a) and marker genes (Oct4, Nanog, Sox2, Ecat1 (also called Khdc3), Esg1 (Dppa5a), Dax1 (Nrob1) and Rex1 (Zfp42); Fig. 2b and Extended Data Fig. 3a) in a manner comparable to those seen in ES cells24. Moderate levels of expression of these pluripotency marker genes were observed on day 3 (Fig. 2b and Extended Data Fig. 3b). Notably, the Oct4-GFP+ cells on day 3, but not on day 7, expressed early haematopoietic marker genes such as Flk1 (also called Kdr) and Tal1 (Extended Data Fig. 3c), indicating that Oct4-GFP+ cells on day 3, as judged by their expression pattern at the population level, were still in a dynamic process of conversion.
Figure 2: Low-pH-induced Oct4-GFP+ cells represent pluripotent cells.
Low-pH-induced Oct4-GFP+ cells represent pluripotent cells.
a, Immunostaining for pluripotent cell markers (red) in day 7 Oct4-GFP+ (green) clusters. DAPI, white. Scale bar, 50μm. b, qPCR analysis of pluripotency marker genes. From left to right, mouse ES cells; parental CD45+ cells; low-pH-induced Oct4-GFP+ cells on day 3; low-pH-induced Oct4-GFP+ cells on day 7. n = 3; error bars show average±s.d. c, DNA methylation study by bisulphite sequencing. Filled and open circles indicate methylated and non-methlylated CpG, respectively. d, Immunostaining analysis of in vitro differentiation capacity of day 7 Oct4-GFP+ cells. Ectoderm: the neural markers Sox1/Tuj1 (100%, n = 8) and N-cadherin (100%, n = 5). Mesoderm: smooth muscle actin (50%, n = 6) and brachyury (40%, n = 5). Endoderm: Sox17/E-cadherin (67%, n = 6) and Foxa2/Pdgfrα (67%, n = 6). Scale bar, 50μm. e, Teratoma formation assay of day 7 clusters of Oct4-GFP+ cells. Haematoxylin and eosin staining showed keratinized epidermis (ectoderm), skeletal muscle (mesoderm) and intestinal villi (endoderm), whereas immunostaining showed expression of Tuj1 (neurons), smooth muscle actin and α-fetoprotein. Scale bar, 100μm. fi, Dissociation culture of ES cells and STAP cells (additional 7 days from day 7; f, g) on gelatin-coated dishes. Top, bright-field; bottom, alkaline phosphatase (AP) staining. Partially dissociated STAP cells slowly generated small colonies (i), whereas dissociated STAP cells did not, even in the presence of the ROCK inhibitor (g, h), which allows dissociation culture of EpiSCs29.

On day 7, unlike CD45+ cells and like ES cells, low-pH-induced Oct4-GFP+ cells displayed extensive demethylation at the Oct4 and Nanog promoter areas (Fig. 2c), indicating that these cells underwent a substantial reprogramming of epigenetic status in these key genes for pluripotency.
In vitro differentiation assays25, 26, 27 demonstrated that low-pH-induced Oct4-GFP+ cells gave rise to three-germ-layer derivatives (Fig. 2d) as well as visceral endoderm-like epithelium (Extended Data Fig. 3d). When grafted into mice, low-pH-induced Oct4-GFP+ cell clusters formed teratomas (40%, n = 20) (Fig. 2e and Extended Data Fig. 4a–c) but no teratocarcinomas that persistently contained Oct4-GFP+ cells (n = 50). Because some cellular variation was observed in the signal levels of Oct4-GFP within the clusters, we sorted GFP-strong cells (a major population) and GFP-dim cells (a minor population) by FACS on day 7 and separately injected them into mice. In this case, only GFP-strong cells formed teratomas (Extended Data Fig. 4d). In quantitative polymerase chain reaction (qPCR) analysis, the GFP-strong population expressed pluripotency marker genes but not early lineage-specific marker genes, whereas the GFP-dim cells showed substantial expression of some early lineage-specific marker genes (Flk1, Gata2, Gata4, Pax6 and Sox17; Extended Data Fig. 4e) but not Nanog and Rex1. These observations indicate that three-germ-layer derivatives were generated from the GFP-strong cells expressing pluripotency marker genes, rather than from GFP-dim cells that seem to contain partially reprogrammed cells.
Collectively, these findings show that the differentiation state of a committed somatic cell lineage can be converted into a state of pluripotency by strong stimuli given externally. Hereafter, we refer to the fate conversion from somatic cells into pluripotent cells by strong external stimuli such as low pH as ‘stimulus-triggered acquisition of pluripotency’ (STAP) and the resultant cells as STAP cells. Under their establishment conditions, these STAP cells were rarely proliferative (Extended Data Figs 2d and 5a, b). Comparative genomic hybridization array analysis of STAP cells indicated no major global changes in chromosome number (Extended Data Fig. 5c).
 

STAP cells compared to ES cells

STAP cells, unlike mouse ES cells, showed a limited capacity for self-renewal in the LIF-containing medium and did not efficiently form colonies in dissociation culture (Fig. 2f, g), even in the presence of the ROCK inhibitor Y-27632, which suppresses dissociation-induced apoptosis28, 29 (Fig. 2h). Also, even under high-density culture conditions after partial dissociation (Fig. 2i), STAP cell numbers started to decline substantially after two passages. Furthermore, expression of the ES cell marker protein Esrrβ was low in STAP cells (Extended Data Fig. 5d, e). In general, female ES cells do not show X-chromosomal inactivation30 and contain no H3K27me3-dense foci (indicative of inactivated X chromosomes), unlike female CD45+ cells and EpiSCs. In contrast, H3K27me3-dense foci were found in ~40% of female STAP cells strongly positive for Oct4-GFP (Extended Data Fig. 5f, g).
STAP cells were also dissimilar to mouse EpiSCs, another category of pluripotent stem cell21, 22, 29, 31, and were positive for Klf4 and negative for the epithelial tight junction markers claudin 7 and ZO-1 (Extended Data Fig. 5d, e).
 

STAP cells from other tissue sources

We next performed similar conversion experiments with somatic cells collected from brain, skin, muscle, fat, bone marrow, lung and liver tissues of 1-week-old Oct4-gfp mice. Although conversion efficacy varied, the low-pH-triggered generation of Oct4-GFP+ cells was observed in day 7 culture of all tissues examined (Fig. 3a and Extended Data Fig. 6a–c), including mesenchymal cells of adipose tissues (Fig. 3a–c) and neonatal cardiac cells that were negatively sorted for CD45 by FACS (Fig. 3d–g; see Extended Data Fig. 6d for suppression of cardiac genes such as Nkx2-5 and cardiac actin).
Figure 3: STAP cell conversion from a variety of cells by low-pH treatment.
STAP cell conversion from a variety of cells by low-pH treatment.
a, Percentage of Oct4-GFP+ cells in day 7 culture of low-pH-treated cells from different origins (1×105 cells per ml×3ml). The number of surviving cells on day 7 compared to the plating cell number was 20–30%, except for lung, muscle and adipose cells, for which surviving cells were ~10% (n = 3, average±s.d.). b, Oct4-GFP+ cell clusters were induced by low-pH treatment from adipose-tissue-derived mesenchymal cells on day 7. Scale bar, 100μm. c, Expression of pluripotent cell markers in day 7 clusters of low-pH-treated adipose-tissue-derived mesenchymal cells. Scale bar, 50μm. d, Expression of pluripotency marker genes in STAP cells derived from various tissues. Gene expressions were normalized by Gapdh (n = 3, average±s.d.). Asterisk indicates adipose tissue-derived mesenchymal cells. e, Quantification of Oct4-GFP+ cells in culture of low-pH-treated neonatal cardiac muscle cells. ***P<0.001; Tukey’s test (n = 3). f, Generation of Oct4-GFP+ cell clusters (d7) from CD45 cardiac muscle cells. g, qPCR analysis of pluripotency marker genes in STAP cells from CD45 cardiac muscle cells.

Chimaera formation and germline transmission in mice

We next performed a blastocyst injection assay with STAP cells that were generated from CD45+ cells of neonatal mice constitutively expressing GFP (this C57BL/6 line with cag-gfp transgenes is referred to hereafter as B6GFP). We injected STAP cell clusters en bloc that were manually cut into small pieces using a microknife (Fig. 4a). A high-to-moderate contribution of GFP-expressing cells was seen in the chimaeric embryos (Fig. 4b and Extended Data Fig. 7a). These chimaeric mice were born at a substantial rate and all developed normally (Fig. 4c and Extended Data Fig. 7b).
Figure 4: Chimaeric mouse generation from STAP cells.
Chimaeric mouse generation from STAP cells.
a, Schematic of chimaeric mouse generation. b, E13.5 chimaera fetuses from 2N blastocytes injected with STAP cells (derived from B6GFP CD45+ cells carrying cag-gfp). c, Adult chimaeric mice generated by STAP-cell (B6GFP × 129/Sv; agouti) injection into blastocysts (ICR strain; albino). Asterisk indicates a highly contributed chimaeric mouse. d, Chimaera contribution analysis. Tissues from nine pups were analysed by FACS. e, Offspring of chimaeric mice derived from STAP cells. Asterisk indicates the same chimaeric mouse shown in c. f, E10.5 embryo generated in the tetraploid complementation assay with STAP cells (B6GFP×129/Sv).

CD45+ cell-derived STAP cells contributed to all tissues examined (Fig. 4d). Furthermore, offspring derived from STAP cells were born to the chimaeric mice (Fig. 4e and Extended Data Fig. 7c), demonstrating their germline transmission, which is a strict criterion for pluripotency as well as genetic and epigenetic normality32, 33. Furthermore, in a tetraploid (4N) complementation assay, which is considered to be the most rigorous test for developmental potency34, 35 (Fig. 4a, bottom), CD45+ cell-derived STAP cells (from F1 mice of B6GFP × 129/Sv or DBA/2) generated all-GFP+ embryos on embryonic day (E)10.5 (Fig. 4f, Extended Data Fig. 7d and Supplementary Video 3), demonstrating that STAP cells alone are sufficient to construct an entire embryonic structure. Thus, STAP cells have the developmental capacity to differentiate into all somatic-cell lineages as well as germ-cell lineages in vivo.
 

Expandable pluripotent cell lines from STAP cells

STAP cells have a limited self-renewal capacity under the conditions used for establishment (Fig. 2g and Extended Data Figs 2e and 5a). However, in the context of the embryonic environment, a small fragment of a STAP cell cluster could grow even into a whole embryo (Fig. 4f). With this in mind, we next examined whether STAP cells have the potential to generate expandable pluripotent cell lines in vitro under certain conditions.
STAP cells could not be efficiently maintained for additional passages in conventional LIF+FBS-containing medium or 2i medium20 (most STAP cells died in 2i medium within 7days; Extended Data Fig. 8a). Notably, an adrenocorticotropic hormone (ACTH)+LIF-containing medium (hereafter called ACTH medium) known to facilitate clonal expansion of ES cells36 supported outgrowth of STAP cell colonies. When cultured in this medium on a MEF feeder or gelatin, a portion of STAP cell clusters started to grow (Fig. 5a, bottom; such outgrowth was typically found in 10–20% of wells in single cluster culture using 96-well plates and in >75% when 12 clusters were plated per well). These growing colonies looked similar to those of mouse ES cells and expressed a high level of Oct4-GFP.
Figure 5: ES-cell-like stem cells can be derived from STAP cells.
ES-cell-like stem cells can be derived from STAP cells.
a, Growth of STAP stem cells carrying Oct4-gfp. Scale bar, 50μm. b, Dissociation culture of STAP stem cells to form colonies. Scale bar, 100μm. c, Robust growth of STAP stem cells in maintenance culture. Similar results were obtained with eight independent lines. In contrast, parental STAP cells decreased in number quickly. d, Immunostaining of STAP stem cells for pluripotency markers (red). Scale bar, 50μm. e, qPCR analysis of pluripotency marker gene expression. fh, In vitro differentiation assays into three-germ-layer derivatives. f, Ectoderm: Rx+/Pax6+ (retinal epithelium; 83%, n = 6). g, Mesoderm: troponin-T+ (cardiac muscle; 50%, n = 6). h, Endoderm: Sox17+/E-cadherin+ (endodermal progenitors; 67%, n = 6). Scale bar, 50μm. i, Teratoma formation assays. Formation of keratinized epidermis (ectoderm; left), cartilage (mesoderm; middle) and bronchial-like epithelium (endoderm; right) is shown. Scale bar, 100μm. j, Blastocyst injection assays. These pictures of live animals were taken serially (asterisk indicates the same chimaeric pup). k, l, Tetraploid complementation assay. ‘All-GFP+’ pups were born (k) and germline transmission was observed (l).

After culturing in ACTH medium for 7days, this growing population of cells, unlike parental STAP cells, could be passaged as single cells (Fig. 5a, bottom, and Fig. 5b), grow in 2i medium (Extended Data Fig. 8a) and expand exponentially, up to at least 120days of culture (Fig. 5c; no substantial chromosomal abnormality was seen; Extended Data Fig. 8b, c). Hereafter, we refer to the proliferative cells derived from STAP cells as STAP stem cells.
STAP stem cells expressed protein and RNA markers for pluripotent cells (Fig. 5d, e), showed low DNA methylation levels at the Oct4 and Nanog loci (Extended Data Fig. 8d), and had a nuclear fine structure similar to that of ES cells (Extended Data Fig. 8e; few electron-dense areas corresponding to heterochromatin). In differentiation culture25, 26, 27, STAP stem cells generated ectodermal, mesodermal and endodermal derivatives in vitro (Fig. 5f–h and Extended Data Fig. 8f, g), including beating cardiac muscles (Supplementary Video 4), and formed teratomas in vivo (Fig.5i and Extended Data Fig. 8h; no teratocarcinomas, n = 40). After blastocyst injection, STAP stem cells efficiently contributed to chimaeric mice (Fig. 5j), in which germline transmission was seen (Extended Data Fig. 8i). Even in tetraploid complementation assays, injected STAP stem cells could generate mice capable of growing to adults and producing offspring (Fig. 5k, l; in all eight independent lines, Extended Data Fig. 8j).
In addition to their expandability, we noticed at least two other differences between STAP stem cells and parental STAP cells. First, the expression of the ES cell marker protein Esrrβ, which was undetectable in STAP cells (Extended Data Fig. 5d, e), was clearly seen in STAP stem cells (Fig. 5e). Second, the presence of H3K27me3 foci, which was found in a substantial proportion of female STAP cells, was no longer observed in STAP stem cells (Extended Data Figs 5f and 8k). Thus, STAP cells have the potential to give rise to expandable cell lines that exhibit features similar to those of ES cells.
 

Discussion

This study has revealed that somatic cells latently possess a surprising plasticity. This dynamic plasticity—the ability to become pluripotent cells—emerges when cells are transiently exposed to strong stimuli that they would not normally experience in their living environments.
Low-pH treatment was also used in the ‘autoneuralization’ experiment15, 16, 17 by Holtfreter in 1947, in which exposure to acidic medium caused tissue-autonomous neural conversion of salamander animal caps in vitro in the absence of Spemann’s organizer signals. Although the mechanism has remained elusive, Holtfreter hypothesized that the strong stimulus releases the animal cap cells from some intrinsic inhibitory mechanisms that suppress fate conversion or, in his words, they pass through ‘sublethal cytolysis’ (meaning stimulus-evoked lysis of the cell’s inhibitory state)15, 37. Although Holtfreter’s study and ours differ in the direction of fate conversion—orthograde differentiation and nuclear reprogramming, respectively—these phenomena may share some common aspects, particularly with regard to sublethal stimulus-evoked release from a static (conversion-resisting) state in the cell.
A remaining question is whether cellular reprogramming is initiated specifically by the low-pH treatment or also by some other types of sublethal stress such as physical damage, plasma membrane perforation, osmotic pressure shock, growth-factor deprivation, heat shock or high Ca2+ exposure. At least some of these stressors, particularly physical damage by rigorous trituration and membrane perforation by streptolysin O, induced the generation of Oct4-GFP+ cells from CD45+ cells (Extended Data Fig. 9a; see Methods). These findings raise the possibility that certain common regulatory modules, lying downstream of these distantly related sublethal stresses, act as a key for releasing somatic cells from the tightly locked epigenetic state of differentiation, leading to a global change in epigenetic regulation. In other words, unknown cellular functions, activated by sublethal stimuli, may set somatic cells free from their current commitment to recover the naive cell state.
Our present finding of an unexpectedly large capacity for radical reprogramming in committed somatic cells raises various important questions. For instance, why, and for what purpose, do somatic cells latently possess this self-driven ability for nuclear reprogramming, which emerges only after sublethal stimulation, and how, then, is this reprogramming mechanism normally suppressed? Furthermore, why isn’t teratoma (or pluripotent cell mass) formation normally seen in in vivo tissues that may receive strong environmental stress? In our preliminary study, experimental reflux oesophagitis locally induced moderate expression of Oct4-GFP but not endogenous Nanog in the mouse oesophageal mucosa (Extended Data Fig. 9b). Therefore, an intriguing hypothesis for future research is that the progression from initial Oct4 activation to further reprogramming is suppressed by certain inhibitory mechanisms in vivo.
The question of why and how this self-driven reprogramming is directed towards the pluripotent state is fundamentally important, given that STAP reprogramming takes a remarkably short period, only a few days for substantial expression of pluripotency marker genes, unlike transgene- or chemical-induced iPS cell conversion38. Thus, our results cast new light on the biological meaning of diverse cellular states in multicellular organisms.
 

Methods


Animal studies

Research involving animals complied with protocols approved by the Harvard Medical School/Brigham and Women’s Hospital Committee on Animal Care, and the Institutional Committee of Laboratory Animal Experimentation of the RIKEN Center for Developmental Biology.

Tissue collection and low-pH treatment

To isolate CD45+ haematopoietic cells, spleens were excised from 1-week-old Oct4-gfp mice (unless specified otherwise), minced by scissors and mechanically dissociated with pasture pipettes. Dissociated spleen cells were suspended with PBS and strained through a cell strainer (BD Biosciences). After centrifuge at 1,000r.p.m. for 5min, collected cells were re-suspended in DMEM medium and added to the same volume of lympholyte (Cedarlane), then centrifuged at 1,000g for 20min. The lymphocyte layer was taken out and stained with CD45 antibody (ab25603, Abcam). CD45-positive cells were sorted by FACS Aria (BD Biosciences). After cell sorting, 1× 106 CD45-positive cells were treated with 500μl of low-pH HBSS solution (titrated to pH5.7 by HCl) for 25min at 37°C, and then centrifuged at 1,000r.p.m. at room temperature for 5min. After the supernatant (low-pH solution) was removed, precipitated cells were re-suspended and plated onto non-adhesive culture plates (typically, 1×105 cellsml−1) in DMEM/F12 medium supplemented with 1,000U LIF (Sigma) and 2% B27 (Invitrogen). Cell cluster formation was more sensitive to the plating cell density than the percentage of Oct4-GFP+ cells. The number of surviving cells was sensitive to the age of donor mice and was low under the treatment conditions above when adult spleens were used. The addition of LIF during days 2–7 was essential for generating Oct4-GFP+ STAP cell clusters on day 7, as shown in Extended Data Fig. 1f. Even in the absence of LIF, Oct4-GFP+ cells (most of them were dim in signal) appeared transiently during days 2–5 in culture of low-pH-treated CD45+ cells, but subsequently disappeared, indicating that there is a LIF-independent early phase, whereas the subsequent phase is LIF-dependent.

Chimaeric mouse generation and analyses

For production of diploid and tetraploid chimaeras with STAP cells, diploid embryos were obtained from ICR strain females. Tetraploid embryos were produced by electrofusion of 2-cell embryos. Because trypsin treatment of donor samples turned out to cause low chimaerism, STAP spherical colonies were cut into small pieces using a microknife under the microscope, and small clusters of STAP cells were then injected into day-4.5 blastocysts by a large pipette. The next day, the chimaeric blastocysts were transferred into day-2.5 pseudopregnant females. For experiments using STAP cells from CD45+ cells without the Oct4-gfp reporter, STAP cell clusters were identified by their characteristic cluster morphology (they are made of very small cells with no strong compaction in the aggregate). When the STAP conversion conditions (low pH) were applied to CD45+ lymphocytes, most day-7 clusters that were large and contained more than a few dozen small cells were positive for Oct4 (although the expression level varied). Therefore, we used only well-formed characteristic clusters (large ones) for this type of study and cut them by microknife to prepare donor cell clusters in a proper size for glass needle injection. For an estimate of the contribution of these injected cells, we used STAP cells that were generated from CD45+ cells of mice constitutively expressing GFP (C57BL/6 line with cag-gfp transgenes; F1 of C57BL/6 and 129/Sv or DBA/2 was used from the viewpoint of heterosis).
Because the number of CD45+ cells from a neonatal spleen was small, we mixed spleen cells from male and female mice for STAP cell conversion. To make germline transmission more efficient, we intercrossed chimaeras in some experiments.
For the production of diploid and tetraploid chimaeras with STAP stem cells, diploid embryos were obtained from ICR strain females. Tetraploid embryos were produced by electrofusion of 2-cell embryos. STAP stem cells were dissociated into single cells and injected into day-4.5 blastocysts. In the chimaera studies with both STAP cells and STAP stem cells, we did not find tumorigenetic tendencies in their chimaeras or their offspring (up to 18months).

In vivo differentiation assay

1×107 STAP cells were seeded onto a sheet composed of a non-woven mesh of polyglycolic acid fibres (3× 3×1mm; 200μm in pore diameter), cultured for 24h in DMEM + 10% FBS, and implanted subcutaneously into the dorsal flanks of 4-week-old mice. In this experiment, to better support tumour formation from slow growing STAP cells by keeping cells in a locally dense manner, we implanted STAP cells with artificial scaffold made of polyglycolic acid fibres. Given the artificial nature of the material, we used NOD/SCID mice as hosts, to avoid possible enhancement of post-graft inflammation caused by this scaffold even in syngenic mice. STAP stem cells were dissociated into single cells and cell suspension containing 1×107 cells was injected into the testis. Six weeks later, the implants were analysed using histochemical techniques. The implants were fixed with 10% formaldehyde, embedded in paraffin, and routinely processed into 4-µm-thick sections. Sections were stained with haematoxylin and eosin. Endoderm tissues were identified with expression of anti-α-fetoprotein (mouse monoclonal antibody; MAB1368, R&D Systems). Ectodermal tissues were identified with expression of anti-βIII tubulin (mouse monoclonal antibody; G7121, Promega). Mesodermal tissues were identified with expression of anti-α-smooth muscle actin (rabbit polyclonal; DAKO). In negative controls, the primary antibody was replaced with IgG-negative controls of the same isotype to ensure specificity.

STAP by exposure to other external stimuli

To give a mechanical stress to mature cells, a pasture pipette was heated and then stretched to create thin capillaries with the lumens approximately 50μm in diameter, and then broken into appropriate lengths. Mature somatic cells were then repeatedly triturated through these pipettes for 20min, and then cultured for 7days. To provide a heat shock, cells were heated at 42°C for 20min and cultured for 7days. A nutrition-deprivation stress was provided to mature cells, by culturing the cells in basal culture medium for 3weeks. High Ca2+ concentration stress was provided to mature cells by culturing cells in medium containing 2mM CaCl2 for 7days. To give a strong stress by creating pores in cell membranes, cells were treated with 230ngml−1 streptolysine O (SLO) (S5265, Sigma) for 2h, then cultured for 7days. After each treatment, the ratio of Oct4-GFP-positive cells was analysed by FACS.

Bisulphite sequencing

GFP-positive cells in STAP clusters were collected by FACS Aria. Genomic DNA was extracted from STAP cells and analysed. Bisulphite treatment of DNA was performed using the CpGenome DNA modification kit (Chemicon, http://www.chemicon.com), following the manufacturer’s instructions. The resulting modified DNA was amplified by nested PCR using two forward (F) primers and one reverse (R) primer: Oct4 (F1, 5′-GTTGTTTTGTTTTGGTTTTGGATAT-3′; F2, 5′-ATGGGTTGAAATATTGGGTTTATTTA-3′; R, 5′-CCACCCTCTAACCTTAACCTCTAAC-3′). And Nanog (F1, 5′-GAGGATGTTTTTTAAGTTTTTTTT-3′; F2, 5′-AATGTTTATGGTGGATTTTGTAGGT-3′; R, 5′-CCCACACTCATATCAATATAATAAC-3′). PCR was done using TaKaKa Ex Taq Hot Start Version (RR030A). DNA sequencing was performed using a M13 primer at the Genome Resource and Analysis Unit, RIKEN CDB.

Immunohistochemistry

Cultured cells were fixed with 4% paraformaldehyde and permeabilized with 0.1% Triton X-100/PBS before blocking with 1% BSA solution. Cells were incubated with the following primary antibodies: anti-Oct4 (Santa Cruz Biotechnology; C-10), anti-Nanog (eBioscience; MLC-51), anti-SSEA-1 (Millipore; MC480), anti-E-cadherin (Abcam), anti-ZO-1 (Santa Cruz Biotechnology; c1607), anti-claudin7 (Abcam), anti-Klf4 (R&D Systems), anti-Esrrβ (R&D Systems), anti-H3K27me3 (Millipore), anti-BrdU (BD Bioscience) and anti-Ki67 (BD Pharmingen). After overnight incubation, cells were incubated with secondary antibodies: goat anti-mouse or -rabbit coupled to Alexa-488 or -594 (Invitrogen). Cell nuclei were visualized with DAPI (Sigma). Slides were mounted with a SlowFade Gold antifade reagent (Invitrogen).

Fluorescence-activated cell sorting and flow cytometry

Cells were prepared according to standard protocols and suspended in 0.1% BSA/PBS on ice before FACS. Propidium iodide (BD Biosciences) was used to exclude dead cells. In negative controls, the primary antibody was replaced with IgG-negative controls of the same isotype to ensure specificity. Cells were sorted on a BD FACSAria SORP and analysed on a BD LSRII with BD FACS Diva Software (BD Biosciences). For haematopoietic fraction sorting, antibodies against T-cell marker (anti-CD90; eBioscience), B-cell marker (anti-CD19; Abcam) and haematopoietic progenitor marker (anti-CD34; Abcam) were used.

RNA preparation and RT–PCR analysis

RNA was isolated with the RNeasy Micro kit (Qiagen). Reverse transcription was performed with the SuperScript III first strand synthesis kit (Invitrogen). Power SYBR Green Mix (Roche Diagnostics) was used for amplification, and samples were run on a Lightcycler-II Instrument (Roche Diagnostics). The primer sets for each gene are listed in Supplementary Table 1.

In vitro differentiation assays

For mesodermal differentiation assay, STAP cells were collected at 7days, and Oct4-GFP-positive cells were collected by cell sorter and subjected to culture in DMEM supplemented with 20% FBS. Medium was exchanged every 3days. After 7–14days, muscle cells were stained with an anti-α-smooth muscle actin antibody (DAKO).
For neural lineage differentiation assay, STAP cells were collected at 7days and subjected to SDIA or SFEBq culture. For SDIA culture, collected STAP cell clusters were plated on PA6 cell feeder as described previously26. For SFEBq culture, STAP cell clusters (one per well; non-cell-adhesive 96-well plate, PrimeSurface V-bottom, Sumitomo Bakelite) were plated and cultured in suspension as described previously36.
For endodermal differentiation, STAP cells were collected at 7days and subjected to suspension culture with inducers in 96-well plates27.

TCR-β chain gene rearrangement analysis

Genomic DNA was extracted from STAP cells and tail tips from chimaeric mice generated with STAP cells derived from CD45+ cells. PCR was performed with 50ng DNA using the following primers (Dβ2: 5′-GCACCTGTGGGGAAGAAACT-3′ and Jβ2.6: 5′-TGAGAGCTGTCTCCTACTATCGATT-3′) that amplify the regions of the (D)J recombination. The PCR products were subjected to gel electrophoresis in Tris-acetate-EDTA buffer with 1.6% agarose and visualized by staining with ethidium bromide. PCR bands from STAP cells were subjected to sequencing analysis and identified as rearranged genomic fragments of the (D)J recombination.

EdU uptake assay and apoptosis analysis

At various phases in STAP cell culture (days 0–2, 2–7, 7–14), EdU was added to the culture medium (final concentration: 10μM) and EdU uptake was analysed by FACS. This assay was performed according to the manufacturer’s protocol with the Click-iT EdU Flow cytometry assay kit (Invitrogen).
Apoptosis analysis was performed with flow cytometry using Annexin-V (Biovision) and propidium iodide. Annexin-V analysis by FACS on day 14 showed that most Oct4-GFP+ cells were positive for this apoptotic marker; indeed, the number of surviving cells declined thereafter.

Soft agar assay

Sorted STAP cells (Oct4-GFP-strong or -dim) and control mouse ES cells (1,000 cells per well of 96-well plate) were plated into soft ager medium (0.4% agarose) in LIF-B27 medium. After 7days of culture, cells were dissociated and their anchorage-independent growth was quantified by fluorescent measurement with the cytoselect 96-well cell transformation assay kit (Cell Biolabs) according to the manufacturer’s protocol.

Comparative genomic hybridization (CGH) array analysis

Genomic DNA was extracted from STAP (male) and CD45-positive cells (male) by the Gene JET Genomic DNA purification kit (Thermo Scientific). Using CGH array (Agilent), the normality of chromosomes derived from STAP was compared with that of CD45-positive cells whose chromosomal normality was confirmed by a separate experiment. CGH array and data analysis were performed at TAKARA Bio.

Electron microscopy

For electron microscopic analysis, dissociated cells were fixed in 2.5% glutaraldehyde and 2% formaldehyde in 0.1M cacodylate buffer (pH7.2) and then processed for thin sectioning and transmission electron microscopy.

Live cell imaging

All live-cell imaging was performed with LCV110-CSUW1 (Olympus). For live-cell imaging of ‘in culture CD45 antibody staining’, CD45+ cells treated with low pH were plated in culture medium containing 20ngml−1 of fluorescent-labelled CD45 antibody (eBioscience)40.

RNA-sequencing and ChIP sequencing analyses

For RNA sequencing of cell lines, total RNA was extracted from cells by the RNasy mini kit (Qiagen). RNA-seq libraries were prepared from 1μg total RNAs following the protocol of the TruSeq RNA Sample Prep kit (Illumina) and subjected to the deep sequencing analysis with Illumina Hi-Seq1500. Cluster tree diagram of various cell types was obtained from hierarchical clustering of global expression profiles (log2 FPKM of all transcripts; FPKM, fragments per kilobase of transcript per million mapped reads). Complete linkage method applied to 1r (r = Pearson’s correlation between profiles) was used for generating the tree and 1,000 cycles of bootstrap resampling were carried out to obtain statistical confidence score in per cent units (also called AU P values).
ChIP-seq libraries were prepared from 20ng input DNAs, 1ng H3K4me3 ChIP DNAs, or 5ng H3K27me3 ChIP DNAs using the KAPA Library Preparation kit (KAPA Biosystems). TruSeq adaptors were prepared in-house by annealing a TruSeq universal oligonucleotide and each of index oligonucleotides (5′-AATGATACGGCGACCACCGAGATCTACACTCTTTCCCTACACGACGCTCTTCCGATCT-3′, and 5′-GATCGGAAGAGCACACGTCTGAACTCCAGTCACXXXXXXATCTCGTATGCCGTCTTCTGCTTG-3′; where X represents index sequences).
Chromatin immunoprecipitation was performed as follows. Cells were fixed in PBS(-) containing 1% formaldehyde for 10min at room temperature. Glycine was added to a final concentration of 0.25M to stop the fixation. After washing the cells twice in ice-cold PBS(-), cells were further washed in LB1 (50mM HEPES-KOH pH7.5, 140mM NaCl, 1mM EDTA, 10% glycerol, 0.5% NP-40, 0.25% Triton X-100) and LB2 (10mM Tris-HCl pH8.0, 200mM NaCl, 1mM EDTA, 0.5mM EGTA). Cells were then re-suspended in lysis buffer (50mM Tris-HCl pH8.0, 10mM EDTA, 1% SDS). Lysates were prepared by sonication using Covaris S220 in a mini tube at duty cycle = 5%, PIP = 70, cycles per burst = 200, and the treatment time of 20min. Lysates from 2×106 cells were diluted in ChIP dilution buffer (16.7mM Tris-HCl pH8.0, 167mM NaCl, 1.2mM EDTA, 1.1% Triton X-100, 0.01% SDS). ChIP was performed using sheep anti-mouse IgG beads (Invitrogen) or protein A beads (Invitrogen) coupled with anti-histone H3K4me3 antibody (Wako, catalogue no. 307-34813) or anti-histone H3K27me3 antibody (CST, catalogue no. 9733), respectively. After 4–6h of incubation in a rotator at 4°C, beads were washed five times in low-salt wash buffer (20mM Tris HCl pH8.0, 150mM NaCl, 2mM EDTA, 1% Triton X-100, 0.1% SDS), and three times in high-salt wash buffer (20mM Tris-HCl pH8.0, 500mM NaCl, 2mM EDTA, 1% Triton X-100, 0.1% SDS). Target chromatin was eluted off the beads in elution buffer (10mM Tris-HCl pH8.0, 300mM NaCl, 5mM EDTA, 1% SDS) at room temperature for 20min. Crosslink was reversed at 65°C, and then samples were treated with RNaseA and proteinase K. The prepared DNA samples were purified by phenol-chloroform extraction followed by ethanol precipitation and dissolved in TE buffer.

STAP stem-cell conversion culture

For establishment of STAP stem-cell lines, STAP cell clusters were transferred to ACTH-containing medium36 on MEF feeder cells (several clusters, up to a dozen clusters, per well of 96-well plates). Four to seven days later, the cells were subjected to the first passage using a conventional trypsin method, and suspended cells were plated in ES maintain medium containing 20% FBS. Subsequent passaging was performed at a split ratio of 1:10 every second day before they reached subconfluency. We tested the following three different genetic backgrounds of mice for STAP stem-cell establishment from STAP cell clusters, and observed reproducible data of establishment: C57BL/6 carrying Oct4-gfp (29 of 29), 129/Sv carrying Rosa26-gfp (2 of 2) and 129/Sv×C57BL/6 carrying cag-gfp (12 of 16). STAP stem cells with all these genetic backgrounds showed chimaera-forming activity.
For clonal analysis of STAP stem cells, single STAP stem cells were manually picked by a thin-glass pipette, and plated into 96-well plates at one cell per well. The clonal colonies were cultured in ES medium containing 20% FBS, and expanded for subsequent experiments.

Karyotype analysis

Karyotype analysis was performed by Multicolor FISH analysis (M-FISH). Subconfluent STAP stem cells were arrested in metaphase by colcemid (final concentration 0.270µgml−1) to the culture medium for 2.5h at 37°C in 5% CO2. Cells were washed with PBS, treated with trypsin and EDTA (EDTA), re-suspended into cell medium and centrifuged for 5min at 1,200r.p.m. To the cell pellet in 3ml of PBS, 7ml of a pre-warmed hypotonic 0.0375M KC1 solution was added. Cells were incubated for 20min at 37°C. Cells were centrifuged for 5min at 1,200r.p.m. and the pellet was re-suspended in 3–5ml of 0.0375M KC1 solution. The cells were fixed with methanol/acetic acid (3:1; vol/vol) by gently pipetting. Fixation was performed four times before spreading the cells on glass slides. For the FISH procedure, mouse chromosome-specific painting probes were combinatorially labelled using seven different fluorochromes and hybridized as previously described41. For each cell line, 9–15 metaphase spreads were acquired by using a Leica DM RXA RF8 epifluorescence microscope (Leica Mikrosysteme GmbH) equipped with a Sensys CCD camera (Photometrics). Camera and microscope were controlled by the Leica Q-FISH software (Leica Microsystems). Metaphase spreads were processed on the basis of the Leica MCK software and presented as multicolour karyograms.
Q-band analysis was performed at Chromocentre (Japan). After quinacrin staining, 20 cells from each sample were randomly selected and the normality of chromosomes was analysed. Five different independent lines of STAP stem cells showed no chromosomal abnormalities in Q-band analysis after >10 passages.
 

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Acknowledgements


We thank S. Nishikawa for discussion and J. D. Ross, N. Takata, M. Eiraku, M. Ohgushi, S. Itoh, S. Yonemura, S. Ohtsuka and K. Kakiguchi for help with experiments and analyses. We thank A. Penvose and K. Westerman for comments on the manuscript. H.O. is grateful to T. Okano, S. Tsuneda and K. Kuroda for support and encouragement. Financial support for this research was provided by Intramural RIKEN Research Budget (H.O., T.W. and Y.S.), a Scientific Research in Priority Areas (20062015) to T.W., the Network Project for Realization of Regenerative Medicine to Y.S., and Department of Anesthesiology, Perioperative and Pain Medicine at Brigham and Women’s Hospital to C.A.V.
 

Author information


Affiliations

  1. Laboratory for Tissue Engineering and Regenerative Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA

    • Haruko Obokata,
    • Koji Kojima,
    • Martin P. Vacanti &
    • Charles A. Vacanti
  2. Laboratory for Cellular Reprogramming, RIKEN Center for Developmental biology, Kobe 650-0047, Japan

    • Haruko Obokata
  3. Laboratory for Genomic Reprogramming, RIKEN Center for Developmental biology, Kobe 650-0047, Japan

    • Haruko Obokata &
    • Teruhiko Wakayama
  4. Laboratory for Organogenesis and Neurogenesis, RIKEN Center for Developmental biology, Kobe 650-0047, Japan

    • Yoshiki Sasai
  5. Department of Pathology, Irwin Army Community Hospital, Fort Riley, Kansas 66442, USA

    • Martin P. Vacanti
  6. Laboratory for Pluripotent Stem Cell Studies, RIKEN Center for Developmental biology, Kobe 650-0047, Japan

    • Hitoshi Niwa
  7. Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, Tokyo 162-8666, Japan

    • Masayuki Yamato
  8. Present address: Faculty of Life and Environmental Sciences, University of Yamanashi, Yamanashi 400-8510, Japan.

    • Teruhiko Wakayama

Contributions

H.O. and Y.S. wrote the manuscript. H.O., T.W. and Y.S. performed experiments, and K.K. assisted with H.O.’s transplantation experiments. H.O., T.W., Y.S., H.N. and C.A.V. designed the project. M.P.V. and M.Y. helped with the design and evaluation of the project.
 

Competing financial interests

The authors declare no competing financial interests.
 

Corresponding authors

Correspondence to:

Author details

Extended data figures and tables



Extended Data Figures

1.Extended Data Figure 1: Conversion of haematopoietic cells into Oct4-GFP+ cells by a low-pH exposure. (292 KB)
a, Optimization of pH conditions for Oct4-GFP induction. Five days after CD45-positive cells were exposed to acidic solution treatment at different pH, Oct4-GFP expression was analysed by FACS (n = 3, average±s.d.). b, Gating strategy for Oct4-GFP+ cell sorting. Top: representative results 7days after the stress treatment. Bottom: non-treated control. P3 populations were sorted and counted as Oct4-GFP+ cells for all experiments. c, Controls for FACS analysis. In Oct4-GFP+ cell analysis, the grey and white histograms indicate the negative control (non-stress-treated Oct4-gfp haematopoietic cells) and the positive control (Oct4-gfp ES cells), respectively. Also, the green histograms indicate non-treated cells (left) and stress-treated cells at day7 (right). In CD45+ cell analysis, the grey and white histograms indicate the negative (isotype) and positive controls, respectively. The red histograms indicate non-stress-treated cells (left) and stress-treated cells at day7 (right). d, Oct4-GFP+ cell generation from various subpopulations of CD45+ cells. Seven days after the stress treatment, Oct4-GFP expression was analysed by FACS (n = 3, average±s.d.). Among total CD45+ fraction and its subfractions of CD19+, CD90+, CD34+ and CD34 cells, the efficacy of CD34+ cells was significantly lower than the others. P<0.05 by the Newman–Keuls test and P<0.01 by one-way ANOVA. e, Comparison of culture conditions for low-pH-induced conversion. Stress-treated cells were cultured in various media. The number of Oct4-GFP-expressing clusters was counted at day 14 (n = 3, average±s.d.). ***P<0.001 (B27+LIF versus all other groups); Tukey’s test. In the case of 3i medium, although the clusters appeared at a moderate efficiency, they appeared late and grew slowly. ACTH, ACTH-containing ES medium; ES+LIF+FBS, 20% FBS+LIF-containing ES culture medium; B27, DMEM/F12 medium containing 2% B27; B27+LIF, DMEM/F12 medium containing 2% B27+LIF; EpiSC, EpiSC culture medium containing Fgf2+activin. f, Signalling factor dependency of STAP cell generation. Growth factors that are conventionally used for pluripotent cell culture such as LIF, activin, Bmp4 and Fgf2 were added to basal culture medium (B27-supplemented DMEM/F12) in different culture phases (days 0–7, 2–7 and 4–7), and Oct4-GFP expression was analysed by FACS at day 7 (n = 3, average±s.d.). g, h, Time course of apoptosis after the low-pH exposure. Stress-treated cells and non-stress-treated control cells were stained with CD45, annexin-V and propidium iodide at day 0 (immediately after stress treatment), day 3 and day 7. g, Blue bars, GFP+CD45; orange bars, GFPCD45+. Percentages in total cells included propidium-iodide-positive cells. h, Annexin-V-positive cells in these cell populations were analysed by FACS.

2.Extended Data Figure 2: Phenotypic change during STAP cell conversion. (231 KB)
a, Oct4 protein expression in STAP cells was detected by immunostaining at day 2 (left) and day 7 (right). b, Live cell imaging of STAP conversion (grey, CD45 antibody; green, Oct4-GFP). See Methods for experimental details to monitor live CD45 immunostaining. c, Immunostaining of a parental CD45+ cell (left) and an Oct4-GFP+ cell (right). Scale bar, 10μm. d, EdU uptake assay (n = 3, average±s.d.). e, Schematic of Tcrb gene rearrangement. f, T-cell-derived STAP cells. Scale bar, 100μm. g, Genomic PCR analysis of (D)J recombination at the Tcrb gene of T-cell-derived STAP cells. G.L. is the size of the non-rearranged germline type, whereas the smaller ladders correspond to the alternative rearrangements of J exons (confirmed by sequencing). Negative controls (ES cells), positive controls (lymphocytes) and T-cell-derived STAP (two independent preparations on d7) are indicated.

3.Extended Data Figure 3: Gene expression analyses during STAP conversion and endoderm differentiation assay. (213 KB)
a, Expression of pluripotency marker genes in STAP cells derived from T cells (n = 3, average±s.d.). b, Expression of pluripotency marker genes in STAP cells. In this experiment, Oct4-GFP+ cells seen in live cell imaging (Extended Data Fig. 2b) were analysed to confirm their conversion into STAP cells (n = 3, average±s.d.). c, Haematopoietic marker expression during STAP conversion from CD45+ cells (n = 3, average±s.d.). d, Formation of visceral endoderm-like surface epithelium in differentiating STAP cluster on day 2 (left) and day 8 (right). Scale bars, 50μm.

4.Extended Data Figure 4: Teratoma formation assay and characterization of Oct4-GFP-dim cells. (265 KB)
ac, Teratomas formed from STAP cell clusters included neuroepithelium (a), striated muscle (b) and pancreas (c; right, high-magnification view showing a typical acinar morphology and ductal structures). Scale bars, 100μm. d, Teratoma-forming ability of Oct4-GFP+ and Oct4-GFP-dim cells (isolated by FACS, top). Oct4-GFP+ cells, but not Oct4-GFP-dim cells, efficiently formed teratomas (table at the bottom). However, because STAP cells were dissociation-intolerant, the teratoma-forming efficiency of dissociated Oct4-GFP+ cells was lower than that of non-dissociated STAP cell clusters. e, Gene expression of Oct4-GFP+ and Oct4-GFP-dim cells (n = 3, the average±s.d.). Haematopoietic marker gene expression (left) and early lineage marker gene expression (right) are shown.

5.Extended Data Figure 5: In vitro characterization of STAP cells. (430 KB)
a, Immunostaining for Ki67 and BrdU. STAP cell clusters (top) and ES cell colonies (bottom) are shown. For BrdU uptake, BrdU was added into each culture medium (10μM) for 12h until fixation. Scale bar, 100μm. b, Transformation assay by soft agar culture. Neither Oct4-GFP+ nor Oct4-GFP-dim cells showed colony formation in soft agar, whereas ES cells and STAP stem cells showed anchorage-independent growth in the same LIF-B27 medium. Scale bar, 100µm. Proliferated cells were lysed and the amount of DNA in each well was estimated by chemical luminescence (graph). n = 3 , average±s.d. c, No substantial change in chromosome number was seen with STAP cells in the CGH array. Genomic DNA derived from CD45+ cells (male) was used as reference DNA. The spikes (for example, those seen in the X chromosome) were nonspecific and also found in the data of these parental CD45+ cells when the manufacturer’s control DNA was used as a reference. d, qPCR analysis for pluripotency markers that highly express in ES cells, but not in EpiSCs. Average±s.d. e, Immunostaining of markers for mouse EpiSC and ES cells. Scale bar, 100 μm. f, g, H3K27me3+ foci in female cells, which are indicative of X-chromosomal inactivation. These foci were not observed in male cells. Scale bar, 10μm. In the case of female STAP cells, ~40% of cells retained H3K27me3+ foci (g). **P<0.001; Tukey’s test. n = 3, average±s.d. Although nuclear staining looked to be higher in STAP cells with H3K27me3+ foci (f), this appeared to be caused by some optical artefacts scattering from the strong focal signal. h, qPCR analysis for the tight junction markers Zo-1 and claudin 7, which were highly expressed in EpiSCs, but not in ES cells or STAP cells. **P<0.01; ns, not significant; Tukey's test; n = 3, average±s.d.

6.Extended Data Figure 6: Conversion of somatic tissue cells into STAP cells. (371 KB)
a, Alkaline phosphatase expression of STAP cells derived from adipose-derived mesenchymal cells. Scale bar, 100μm. b, E-cadherin expression of STAP cells derived from adipose-derived mesenchymal cells. Scale bar, 50μm. c, FACS sorting of dissociated neonatal cardiac muscle cells by removing CD45+ cells. d, Cardiomyocyte marker gene expression during STAP conversion from cardiomyocytes (n = 3, average±s.d.).

7.Extended Data Figure 7: Generation chimaeras with STAP cells. (170 KB)
a, 2N chimaeras generated with STAP cells derived from Oct4-gfp C57BL/6 mice (left) and 129/Sv×C57BL/6 F1 mice (right). b, Generation of chimaeric mice from STAP cells by cluster injection. STAP cells used in the experiments above were generated from CD45+ lymphocytes of multiple neonatal spleens (male and female tissues were mixed). *All fetuses were collected at 13.5d.p.c. to 15.5d.p.c. and the contribution rate of STAP cells into each organ was examined by FACS. **The contribution of STAP cells into each chimaera was scored as high (>50% of the coat colour of GFP expression). ***B6GFP: C57BL/6 mouse carrying cag-gfp. c, Production of offspring from STAP cells via germline transmission. Chimaeras generated with 129/Sv×B6GFP STAP cells (obtained from the experiments shown in b) were used for germline transmission study. d, 4N embryos at E9.5 generated with STAP cells derived from F1 GFP mice (B6GFP and DBA/2 or 129/Sv). B6GFP, C57BL/6 mouse carrying cag-gfp.

8.Extended Data Figure 8: Molecular and cellular characterization of STAP stem cells. (347 KB)
a, Compatibility of 2i conditions with STAP stem-cell derivation from STAP cells and STAP stem-cell maintenance. STAP stem cells could not be established directly from STAP cells in 2i + LIF medium (top). However, once established in ACTH medium, STAP stem cells were able to survive and expand in 2i + LIF medium. Scale bar, 100μm. b, Q-band analysis (n = 4; all cell lines showed the normal karyotype). c, Multicolour FISH analysis (n = 8; all cell lines showed the normal karyotype) of STAP stem cells. d, Methylation status of the Oct4 and Nanog promoters. e, Electron microscope analysis of STAP stem cells. Scale bar, 1μm. f, g, Beating cardiac muscle (mesoderm; 38%, n = 8). Red line indicates an analysed region for kymograph (g). h, Clonability of STAP stem cells. Clonal expansion from single STAP stem cells was performed. Pluripotency of clonal cell lines was confirmed by teratoma formation assay, showing the formation of neuroectoderm (left), muscle tissue (middle) and bronchial-like epithelium (right). Scale bar, 100μm. i, Production of chimaeric mice from STAP stem-cell lines using diploid embryos. *These STAP stem-cell lines were generated from independent STAP cell clusters. j, Production of mouse chimaeras from STAP stem-cell lines by the tetraploid complementation method. *These STAP stem-cell lines were generated from independent STAP cell clusters. k, No H3K27me3-dense foci are seen in female STAP stem cells (n = 50; the CD45+ cell is a positive control). Scale bar, 10μm.

9.Extended Data Figure 9: Effects of various stressors on STAP conversion. (123 KB)
a, Percentages of Oct4-GFP-expressing cells 7days after stress treatment. Somatic cells were isolated from various tissues and exposed to different stressors. Oct4-GFP expression was analysed by FACS. b, Oct4 and Oct4-GFP expression induced in the reflux oesophagitis mouse model as an in vivo acid exposure model (top, experimental procedure). Oct4, but not Nanog, expression was observed in the oesophageal epithelium exposed to gastric acid (75% of 12 operated mice).

Video
Video 1: Live imaging of low-pH-treated CD45+cells (22.67 MB, Download)
DIC images during day 0 – day 7, overlaid with oct3/4::GFP (green). A strong contrast of DIC (as compared to video 2) was applied to imaging so that lamellipodia-like processes (frequently seen on and after day 4) could be viewed easily.
Video 2: Live imaging of low-pH-treated CD45+cells (another view) (11.62 MB, Download)              DIC images during day 0 – day 6, overlaid with oct3/4::GFP (green). The interval of imaging was half (15 min) of that of video 1 (the overall speed of the video is three-times slower than video 1). In this view field where the cell density was relatively low, behaviours of individual cells were more easily seen. In this case, forming clusters were slightly smaller in size.

Video 3: STAP cell-derived embryo (E10.5) from 4N blastocyst injection (1.61 MB, Download)             
STAP cells with constitutive GFP expression were injected into 4N blastocysts and produced normal embryos with heart beating.

Video 4: Beating cardiac muscle generated from STAP-SCs in vitro Bright-field image. (2.42 MB, Download)
 
 
PDF files
Supplementary Information (102 KB)
This file contains Supplementary Table 1.
 

Additional data


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刺激惹起性多能性獲得細胞

刺激惹起性多能性獲得細胞[1][2](しげきじゃっきせいたのうせいかくとくさいぼう、: Stimulus-Triggered Acquisition of Pluripotency cells[1][3])とは、動物の分化した細胞に弱酸性溶液に浸すなどの外的刺激(ストレス)を与えて再び分化する能力[注 1]を獲得させたとされる細胞。その英語名から一般にはSTAP細胞(スタップさいぼう、STAP cells)と呼ばれる[注 2]。この細胞をもたらす現象をSTAP現象、STAP細胞に増殖能を持たせたものをSTAP幹細胞、胎盤形成へ寄与できるものをFI幹細胞と呼ぶ[7][8]

2014年1月に小保方晴子理化学研究所)らが、チャールズ・バカンティハーバード・メディカルスクール)や若山照彦山梨大学)と共同で発見したとして、論文2本をネイチャー1月30日付)に発表した[9][10]。発表直後には、生物学の常識をくつがえす大発見とされ[3][11]、小保方が若い女性研究者であることに注目した大々的な報道もあって世間から大いに注目された。
しかし、論文発表直後から様々な疑義が指摘され、同年7月2日に著者らはネイチャーの2本の論文を撤回した[12][13]。その後も検証実験を続けていた理化学研究所は、同年12月19日に「STAP現象の確認に至らなかった」と報告し、実験打ち切りを発表[14][15]。同25日に「研究論文に関する調査委員会」によって提出された調査報告書は、STAP細胞・STAP幹細胞・FI幹細胞とされるサンプルはすべてES細胞の混入によって説明できるとし、STAP論文はほぼ全て否定されたと結論した[16]
なお、8番染色体のトリソミーは、すでに研究で広く使われているマウスのES細胞を長期間培養するとしばしば起きる異常としても知られている[7]

多能性を示す指標遺伝子
STAP細胞のmRNAの発現量をTruSeqを使用して解析したデータにおいて、多能性を示す指標遺伝子がまったく転写されていなかった。従前よりSTAP細胞作成の根拠の一つとされる蛍光が、指標遺伝子の発現によるものではなく、死にかけた細胞がよく発する自家蛍光ではないかと指摘されていたが、それを補強する結果であった。また、SMARTerで解析した結果と一致せず、STAP細胞とされるものが2種類存在したことになる[7]

ドナーマウスとSTAP幹細胞の間の重大な矛盾
論文撤回理由として以下の説明のつかない重大な矛盾があることが報告された。ドナーマウスとSTAP幹細胞では違う染色体にGFP遺伝子が挿入されていた。また、そのGFP遺伝子はドナーマウスはホモ接合であるのに、STAP幹細胞はヘテロ接合であった[66]

研究不正の認定と研究の実態
理化学研究所調査委員会最終報告
2014年4月1日、理化学研究所は研究論文の疑義に関する調査最終報告を公表し、2項目について不正と認定した[67][68][69][70][注 14]
  1. アーティクル論文 の Figure 1i[39](TCR再構成を示すDNAゲル電気泳動の画像)に認められた切り貼り(改竄[70]
  2. アーティクル論文 の Figure 2d, 2e[42](STAP細胞が3胚葉組織への分化能をもつことを示すものとして掲載された組織の蛍光顕微鏡画像)と小保方の博士論文に使用された画像との間に認められた一致(捏造[70]
論文の撤回とその理由
画像や解析結果の誤りなどにより、7月2日にネイチャーに投稿された論文は撤回に追い込まれ[71][66][72][73][74]、「STAP現象全体の整合性を疑念なく語ることは現在困難」[75]などの著者らのコメントも発表された[76][77] [78][79]
撤回理由は調査委員会が調査した疑義や不正認定した2枚の画像に加え、1) レター論文のキメラ胚の写真において、ES細胞由来とSTAP細胞由来の写真がともにSTAP細胞由来のものであったこと、2) アーティクル論文の2倍体キメラ胚の写真に、4倍体キメラ胚の別の写真が使用されていたこと、3) デジタル画像処理によるものを「長時間露光」と誤って記載していたこと、4) レター論文のSTAP細胞とES細胞の図において、ラベルが逆になってしまっていたこと、5) 『ドナーマウスと報告された STAP幹細胞では遺伝背景と遺伝子挿入部位に説明のつかない齟齬がある。』、の5点があげられている[80][81]

理化学研究所 研究論文に関する調査報告書
2014年12月25日、理化学研究所は研究論文に関する調査報告書を公表し、以下のように結論した。
  1. STAP幹細胞およびFI幹細胞は、ES細胞由来である[82]
  2. STAP細胞やSTAP幹細胞由来のキメラは ES細胞由来である可能性が高い[83]
  3. STAP細胞から作製されたテラトーマは、ES細胞に由来する可能性が高い[84]
  4. アーティクル論文Fig.5c(細胞増殖曲線)[34]およびFig.2c(DNAメチル化解析)[42]のデータの捏造を認定[85]
実験手技と追試結果
公表されていた実験手技解説
理化学研究所によるプロトコル
実験手技要旨[34]に加え、理化学研究所2014年3月5日に、より詳細な実験手技解説[35]を公開した[49]。なお、アーティクル論文とレター論文の取り下げに伴い、この実験手技解説も7月2日付けで取り下げられている。
このプロトコル・エクスチェンジには、「単純に見えるが、細胞の処理と培養条件、さらに細胞個体群の選択に、とりわけ慎重さを要する」という「注意書」があり、カリフォルニア大学デービス校准教授のポール・ノフラーは、これは「STAP細胞は作るのがきわめて難しい」と同義だと指摘した[86]。また、ウォール・ストリート・ジャーナル紙も、プロトコル・エクスチェンジが、元の論文と矛盾するとした[87]

チャールズ・バカンティらによるプロトコル
更に同年3月20日には、細いガラス管に通した後で弱酸性液に浸す改善版実験手技[88]を、チャールズ・バカンティらが公表した[89]。これについて、ノフラーは「作製効率や検証方法が書かれておらず、筆者が誰かの明示がない。実際に作製できるかは疑問」と指摘した[90]。同年4月9日には、米国の幹細胞学者でマサチューセッツ工科大学教授であるルドルフ・イエーニッシュが、STAP細胞の作製法を今すぐ公開すべきだとし、既報の作製法が既に4種類も存在するのは異常だと指摘した[91]
なお、この実験手技についてチャールズ・バカンティ小島宏司は、同年9月3日に連名でさらなる修正版[92]を発表した[93]。簡単に作成できるという発言を撤回し、ATPを加えることに言及している[94][95][96]

酸刺激による実験主技の追試
論文が公開されるまでに、論文共著者の若山照彦は再現実験を山梨大学で数十回実施したが一度も成功しなかった[97][57]理化学研究所発生・再生科学総合研究センター内で、小保方以外の人物が独立に成功したことはなかったという[57]
また、ポール・ノフラーはウェブサイトにて世界の研究者たちに呼びかけてSTAP細胞作製の追試のデータを集め、2014年2月14日から2月19日に間に様々な細胞で試行された10件の報告が寄せられた[98]。その中には追試に成功したという報告は無い[98]。マウス胎児線維芽細胞で追試を試み、多くの自家蛍光が見られたと報告した関西学院大学の関由行は[98]、「いくら詳細な手順が示されているといっても、論文のデータの信頼性が失われた中では再現に取り組みようがない」と述べた[99]
近畿大ではリンパ球ではなく線維芽細胞を対象として約30回、細胞を酸に浸す実験に取り組んだ。細胞塊が出現し、万能細胞特有の遺伝子が微弱に反応して発光も見られたものの、発光には緑色だけでなく赤色の光も含まれていた。発光は死細胞の自家蛍光で、遺伝子の反応は極めて微弱で不十分なものであり、STAP細胞の再現には至っていない。また、9月に発表されたバカンティ・プロトコルで言及されたATPを酸に追加することも試したが、失敗している[96]

酸と機械的刺激を組み合わせた実験手技の追試
2014年4月1日香港中文大学教授の李嘉豪は、チャールズ・バカンティ発表の実験手技に基づく追試において、対照実験として研和のみを与えた細胞で予期しなかった多能性マーカー(Oct4Nanog)の発現を確認したが、多くの細胞が死んだことや、多能性マーカーの発現量が多能性細胞に比べて10分の1以下だったことから、細胞死に伴う無秩序な遺伝子発現による副産物であろうと論じ、STAP細胞の一部の過程の再現との解釈に否定的な見解を示した[100][101]。李は「研和のみの操作は難しくないので他の研究室でも試せないだろうか」「個人的にはSTAP細胞は実在しないと考える。労力財力の無駄なので、これ以上の追試はしない」と述べ[101]、同グループは追試の結果を論文にまとめてオンライン誌で発表した[102]

理化学研究所における検証実験
2014年4月以降、理化学研究所はSTAP現象の検証チームを立ち上げた。チームは相沢慎一・丹羽仁史を中心として小保方は除外した形で構成され、翌年3月を期限として論文に報じられていたプロトコルでのSTAP現象の再現を試みた。また、7月からはこれとは別に小保方にも11月末を期限とした単独での検証実験を実施させた[103][104]。同年8月27日の中間発表の段階では、論文に記載されているプロトコルでのSTAP細胞の出現を確認することはできなかった[105][96]。同年12月19日、理化学研究所は、検証チーム・小保方のいずれもSTAP現象を再現できなかったとし、以下の検証結果を発表し、実験打ち切りを発表した[14][15]

検証実験に用いたマウスの遺伝子系統、リンパ球を採取する部位、弱酸性溶液の種類
検証実験では、生後5~10日目の、Oct-GFPを導入した2種類の遺伝系統のマウス:C57BL/6〔以下、B6〕とF1(C57BL/6×129)〔以下、F1〕の、脾臓肝臓心臓の3部位から採取したリンパ球を用い(小保方実験では脾臓)、HClATPの2種類の弱酸性溶液で処理する、の組み合わせでSTAP現象の再現を試みた[14]。また、対照実験として弱酸性処理なしの試料でも実験した[14]

STAP細胞様細胞塊の出現数の検証
HCl処理、ATP処理いずれも多くの細胞塊でGFP遺伝子発現による緑色蛍光が確認されたが(以下、STAP細胞様細胞塊)、個々の細胞レベルでは10/106播種細胞ほどしか光っておらず(小保方実験)、撤回論文報告の数百/106とは異なっていた[14]
また、STAP細胞様細胞塊の出現率がマウス系統の違いにより異なるかを検証したが、出現率は、B6で78%(8/28)、F1で44%(4/9)と、有意な差ではなかった(小保方実験)[14]
別途、フローサイトメーターでも解析したが、19回の酸処理のうち17回はCD45-GFP+の有意な遺伝子発現が認められなかった(小保方実験)[14]

多能性細胞特異的分子マーカーによる検証
緑色蛍光および赤色蛍光の分離検出、DAPI、E-カドヘリン、Oct3/Oct4多能性細胞特異的分子マーカー遺伝子発現の確認を行った[14]。しかし、小保方実験、検証チーム実験とも成果は乏しく、理化学研究所として「細胞塊が有する緑色蛍光を自家蛍光と区別することも困難で、その由来を判定することは出来なかった。」と帰結する結果だった[14]

キメラ形成能の検証
キメラ形成能の確認(マウス実験)については、小保方実験、検証チーム実験共に、検証チームの同じ研究員が実験を担当した[14]。小保方実験では、48回の独立の実験で得られた1,615の移植細胞塊のうち、845の着床を得たが、リプログラミングを有意に示す(GFP陽性細胞を含む)キメラを形成した胚は0だった[14]
検証チーム実験では、8回の独立の実験で得られた244の移植細胞塊のうち、117の着床後胚を得たが、リプログラミングを有意に示すキメラを形成した胚は0だった[14]

幹細胞株の樹立
検証チーム実験では、14回の独立の実験で得られた492のSTAP細胞様細胞塊のLIF/ACTH含有培地での培養を試み、3が増殖したが、継代培養に成功したものは0だった[14]。FI幹細胞を再現できるかについては、検証チームのみが8回試みたが、得られた細胞株は0だった[14]

学術界の反応
 
理化学研究所が設置した外部有識者による「研究不正再発防止のための改革委員会」は、2014年6月12日、理研CDBの構造的問題を指摘し、早急に解体すべきとしつつ、再現実験と研究不正の追及の双方を提言した[106][107]

日本分子生物学会は、2014年7月4日、声明の中で、再現実験を優先して「論文不正に対して適切な対応をしないこと」は「国民に対する背信行為」であると非難し、「今回の研究不正問題が科学者コミュニティーを超えて広く国民の関心を惹くことに至ったのは、論文発表当初に不適切な記者発表や過剰な報道誘致が為されたことに原因があり、それらは生命科学研究の商業化や産業化とも関係していると考えられ」ると言明した[108]

日本学術会議は、2014年7月25日、声明の中で「研究全体が虚構であったのではないかという疑念を禁じ得ない段階に達してい」ると述べ、小保方晴子を加えた再現実験が開始と、懲戒の先送りに対し「この再現実験の帰趨にかかわらず、理研は保存されている関係試料を速やかに調査し、取り下げられた2つの論文にどれだけの不正が含まれていたかを明らかにするべき」、「そこで認定された研究不正に応じて、関係者に対する処分を下すことは、この事案における関係者の責任を曖昧にしないという意味で重要」とし、「関係試料の速やかな調査による不正の解明と、関係者の責任を明確にすることを要望」した[109]

山中伸弥は、2014年12月22日、「この騒動から学んだことは、生データの保存の大切さだ」と述べ、「個人に任せるのではなく、組織として未然に防ぐ体制を敷いていくしかない。理想論では無理だ」と話した[110]

アメリカの科学雑誌The Scientist英語版の「2014年の論文撤回トップ10」においてSTAP論文が挙げられており、2014年の論文撤回を語る上で外せないものとしている[111]

公表文献・公開情報
 
Obokata, H.; Wakayama, T.; Sasai, Y.; Kojima, K.; Vacanti, M. P.; Niwa, H.; Yamato, M.; Vacanti, C. A. (2014-07-02). "Retraction:Stimulus-triggered fate conversion of somatic cells into pluripotency". Nature 505: 641–647. 

Obokata, H.; Sasai, Y.; Niwa, H.; Kadota, M.; Andrabi, M.; Takata, N.; Tokoro, M.; Terashita, Y.; Yonemura, S.; Vacanti, C. A.; Wakayama, T. (2014-07-02). "Retraction:Bidirectional developmental potential in reprogrammed cells with acquired pluripotency". Nature 505: 676–680. 

Obokata, H.; Sasai, Y. ; Niwa, H. (2014-03-05). "Essential technical tips for STAP cell conversion culture from somatic cells". Protocol Exchange.

特許出願文献
Vacanti, C. A. et al. (2013年10月31日). “Generating pluripotent cells de novo WO 2013163296 A1”. 2014年2月5日閲覧。(英語)(国際特許公開、優先日:2012年4月24日、出願日:2013年4月24日、公開日:2013年10月31日)

(PDF) US 61/637,631, http://patentscope.wipo.int/search/docservicepdf_pct/id00000022851022.pdf (英語) - 米国仮特許出願(出願日:2012年4月24日)

(PDF) US 61/779,533, http://patentscope.wipo.int/search/docservicepdf_pct/id00000022881386.pdf (英語) - 米国仮特許出願(出願日:2013年3月13日)

(PDF) PCT/US2013/037996, http://patentscope.wipo.int/search/docservicepdf_pct/id00000022883817.pdf (英語) - 国際特許出願(出願日:2014年4月24日、優先日:2012年4月24日)

検証論文
Mei Kuen Tang, Lok Man Lo, Wen Ting Shi, Yao Yao, Henry Siu Sum Lee, Kenneth Ka Ho Lee (2014-05-08). Transient acid treatment cannot induce neonatal somatic cells to become pluripotent stem cells. F1000Research. (李嘉豪らの追試結果)

Takaho A. Endo (2014-09-21). "Quality control method for RNA-seq using single nucleotide polymorphism allele frequency". Genes to Cells. (遠藤高帆の遺伝子解析結果)

公開情報
Refined protocol for generating STAP cells from mature somatic cells. (PDF)” (2014年3月20日). 2014年10月23日閲覧。(機械的刺激を伴うハーバードのプロトコル)

Charles A. Vacant, Koji Kojima (2014-09-03) (PDF), REVISED STAP CELL PROTOCOL. 09.03.14., https://research.bwhanesthesia.org/site_assets/51520d191eea6679ce000001/cterm/Revised_STAP_protocol-28bcd7e61d02a23624eb590717e241fe.pdf 2014年10月23日閲覧。 (訂正されたハーバードのプロトコル)

NGS 解析データの SHA1 チェックサム一覧”. 2014年10月14日閲覧。(著者らが公開していた遺伝子解析データの一覧)

報告書
研究論文の疑義に関する調査委員会 (2014年3月31日). “研究論文の疑義に関する調査報告書 (PDF)”. 理化学研究所. 2014年4月1日閲覧。

CDB 自己点検検証委員会 (2014-06-10) (PDF). CDB 自己点検の検証について (Report). 理化学研究所. http://www3.riken.jp/stap/j/c13document14.pdf 2014年6月12日閲覧。. 

“STAP現象の検証結果について” (PDF) (プレスリリース), 理化学研究所, (2014年12月19日), http://www.riken.jp/pr/topics/2014/20141219_1/ 2014年12月19日閲覧。 

研究論文に関する調査委員会 (2014-12-25) (PDF). 研究論文に関する調査報告書 (Report). 理化学研究所. http://www3.riken.jp/stap/j/c13document5.pdf. 

研究論文に関する調査委員会 (2014-12-26) (PDF). 調査結果報告 (Report). 理化学研究所. http://www3.riken.jp/stap/j/h9document6.pdf.

参考文献
※2014年7月2日付けで本論文は取り下げられました。体細胞の分化状態の記憶を消去し初期化する原理を発見 (PDF)”. 理化学研究所 (2014年1月29日). 2014年1月30日閲覧。

60秒でわかるプレスリリース 体細胞の分化状態の記憶を消去し初期化する原理を発見”. 理化学研究所 (2014年1月29日). 2014年1月30日閲覧。[リンク切れ]

(記事取り下げ)細胞外からの強いストレスが多能性幹細胞を生み出す”. 独立行政法人 理化学研究所 神戸研究所 発生・再生科学総合研究センター (2014年1月30日). 2014年2月6日時点のオリジナルよりアーカイブ。2014年2月4日閲覧。

Helen Thomson (2014年1月29日). “Stem cell power unleashed after 30 minute dip in acid”. Health

NewScientist. 2015年1月2日閲覧。(英語)

Cyranoski, D. (2014-01-29). "Acid bath offers easy path to stem cells". Nature 505: 596. (英語)(2014年9月17日更新)

Smith, A. (2014-01-30). "Cell biology: Potency unchained Retraction (July, 2014)". Nature 505: 622–623. (英語)

赤谷拓和「STAP細胞とは何か?-生物学や再生医療の分野に衝撃! 新たな"万能細胞"は,どのようにして生みだされたのか?」、『Newton』第34巻第4号、2014年4月、 10-17頁。



詫摩雅子、古田彩「研究倫理 緑のマウスはどこから-STAP細胞は存在したのか」、『日経サイエンス』第44巻第6号、2014a、 54-61頁。

詫摩雅子、古田彩「NEWS SCAN - 研究倫理 - 終わらないSTAP問題」、『日経サイエンス』第44巻第7号、2014b、 14-18頁。

古田彩、詫摩雅子「(2014年6月11日付号外)STAP細胞 元細胞の由来論文と矛盾 (PDF) 」 、『日経サイエンス』2014年6月11日2014年6月11日閲覧。

粥川準二「STAP細胞事件が忘却させたこと」、『現代思想』第42巻第12号、2014年8月、 84-99頁。

古田彩、詫摩雅子「NEWS SCAN - 研究倫理 - STAP細胞の正体」、『日経サイエンス』第44巻第8号、2014d、 54-61頁。

古田彩、詫摩雅子「国内 News Scan STAP幹細胞はどこから?」、『日経サイエンス』第44巻第9号、2014e、 13-15頁。

古田彩、詫摩雅子「NEWS SCAN 国内ウォッチ 研究倫理 STAP細胞論文,全容調査へ-疑義の指摘から7カ月,ようやく科学的な調査が始まった」、『日経サイエンス』第44巻第11号、2014f、 16-19頁。

古田彩、詫摩雅子「NEWS SCAN 国内ウォッチ 研究倫理 STAP細胞 見えてきた実態-遺伝子解析が示した 名が体を表さないSTAP実験の杜撰さ」、『日経サイエンス』第44巻第12号、2014g、 34-37頁。

須田桃子 『捏造の科学者 STAP細胞事件文藝春秋2015年1月7日ISBN 978-4163901916

科学的な報道・解説
The rise and fall of STAP”. Specials and supplements archive. Nature. 2014年1月2日閲覧。(英語)

関由行、武田俊之. “STAP現象を理解するための多能性幹細胞入門”. CANVAS学習支援システム. 2014年7月15日閲覧。

Toshiyuki Takeda (2014年7月3日). “サイエンス・カフェ「STAP細胞はあったのか?-STAP細胞論文を科学的に検証する-」”. 2015年1月12日閲覧。(2014年6月28日開催)

古田彩、詫摩雅子 (2014年12月25日). “「STAP幹細胞」として用いられたES細胞を特定 東大,東北大など”. きょうの日経サイエンス. 日経サイエンス. 2015年1月2日閲覧。

片瀬久美子 (2014年12月30日). “理研外部調査委員会報告の内容整理1-STAP細胞の正体はES細胞”. warblerの日記. 2015年1月2日閲覧。

科学的な疑義の指摘・検証
PubPeer > Nature > "Bidirectional developmental potential in reprogrammed cells with acquired pluripotency"”. 2014年5月21日閲覧。(英語)

Paul S. Knoepfler. “Knoepfler Lab Stem Cell Blog - Building stem cell bridges”. 2014年6月8日閲覧。(英語)

STAP NEW DATA”. 2014年6月9日閲覧。(英語)ポール・ノフラーによるSTAP再現実験の情報サイト)

関由行 (2014年5月13日). “STAP細胞騒動を振り返る”. 2014年6月10日閲覧。

STAP細胞由来幹細胞の正体は既存幹細胞なのか?”. 2014年6月18日閲覧。

11jigen. “小保方晴子のSTAP細胞論文の疑惑”. 2014年5月21日閲覧。

Haruko Obokata, STAP stem cells”. 2014年6月10日閲覧。(英語)

世界変動展望. “小保方晴子が筆頭著者の論文の不適切さについて”. 2014年6月9日閲覧。

kaho. “kahoの日記”. 2014年6月4日閲覧。(公開遺伝子データを解析し、疑義を指摘)- STAP細胞の非実在について同#2同#3同#4同#5オオカミ少年

片瀬久美子. 6/16の若山教授の会見で判明した事など-STAP細胞がES細胞である可能性について” (2014年6月18日). 2014年6月18日閲覧。

Nature誌のSTAP細胞論文取り下げ告知文に関する経緯について” (2014年7月10日). 2014年7月10日閲覧。

若山さんの記者会見(2014/6/16)の配布資料にあるPCR解析データ” (2014年7月12日). 2014年7月15日閲覧。

STAP現象の検証実験に関する会見記録 2014年8月27日” (2014年9月2日). 2014年10月16日閲覧。

大隅典子 (2014年4月16日). “STAP細胞を前提にしないと説明できない?”. 大隅典子の仙台通信. 2014年6月27日閲覧。

STAP細胞の遺伝子解析からわかったこと” (2014年6月26日). 2014年7月4日閲覧。


最終更新 2015年2月4日

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https://ja.wikipedia.org/wiki/%E3%82%AD%E3%83%A1%E3%83%A9

キメラ

生物学における キメラ (chimera) とは、同一個体内に異なった遺伝情報を持つ細胞が混じっていること。またそのような状態の個体のこと。
この用語はギリシア神話に登場する伝説の生物「キマイラ」に由来する。 近年は「キメラ分子」「キメラ型タンパク質」のように「由来が異なる複数の部分から構成されている」意味で使われることもある。

植物
植物では、異なる遺伝情報を持つ細胞が縞状に分布するものを区分キメラ、組織層を形成して重なるものを周縁キメラと呼ぶ。それらは成長点細胞の突然変異や接ぎ木で生じることがある。

動物
脊椎動物には移植免疫があるため、生体でキメラを作ることはできない。医学獣医学では、2個以上の胚に由来する細胞集団(キメラ胚)から発生した個体を指す。例としては、ニワトリウズラのキメラがある。また、キメラ胚由来ではないが、1個体が異なった個体由来の血液細胞を同時に持っている状態を血液キメラという。1つ胚に由来しているが異なる遺伝情報を持つ細胞が部分的に入り交じるものをモザイクと呼び、キメラと区別する。モザイクはキメラよりはるかに頻度が高い。

ヒトキメラ
多くは血液キメラである。双生児の胚はしばしば胎盤における血液供給を共有しているため、血液幹細胞がもう一方の胚へ移動可能で、移動した血液幹細胞が骨髄に定着した場合、持続的に血液細胞を供給するようになり血液キメラが作られる。二卵性双生児のペアの8%ほどは血液キメラである。双生児でない場合の血液キメラも知られているが、これは妊娠初期に双生児の一方が死亡し、生存している方に吸収されて血液キメラが生じたと考えられている。
2つの受精卵が子宮内で融合して1つの胚となった場合に作られる真のヒトキメラは1994年のイギリスで生まれた少年の例[1]など僅かしか知られていない。なお、この少年は体外受精で生まれている。
 
 


生殖系列キメラ
生殖系列(精巣卵巣)が置き換えられたキメラ。胚盤葉細胞キメラまたは始原生殖細胞キメラから作られる。

骨髄移植
白血病治療のため、骨髄移植を受けた患者も医学用語でキメラと呼ばれている。骨髄移植は同一の血液型でなくても可能である。血液型が異なるドナーから骨髄移植を受けた場合、元々の造血幹細胞で造られる血液と移植された造血幹細胞で造られる血液型は異なることからそのように呼ばれる。

最終更新 2014年10月10日

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【STAP細胞】18 「STAP細胞ほぼ確実にない ES細胞が混入」調査委員会記者会見【2014/12/26】



2014/12/25 に公開
桂勲委員長は「STAP細胞はなかったというのは、科学的検証からほぼ確実だ」と答え­ました51:18
また、研究室に残っていた「STAP幹細胞」などを調べた結果、「STAP細胞の証拠­となる細胞は、すべてES細胞の混入で説明できることが科学的証拠で明らかになった」­と判断しました
しかし、どのようにES細胞が混入したかは謎が残ったとし、小保方氏は調査委の聴取に­対し、「私はES細胞を混入させたことは絶対ありません」と答えたとのことです01:­05:06
【調査委員会 出席者】
桂勲 調査委員長(情報・システム研究機構 理事、国立遺伝学研究所 所長)
五十嵐和彦 委員(東北大学大学院 教授)
伊藤武彦 委員(東京工業大学大学院 教授)
大森一志 委員(大森法律事務所 弁護士)
久保田健夫 委員(山梨大学大学院 教授)
五木田彬 委員(五木田・三浦法律事務所 弁護士)
米川博通 委員(東京都医学総合研究所 シニア研究員)

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【STAP細胞】19「結論は出た、調査は終了」理研記者会見【2014/12/26】  



2014/12/25 に公開
川合理事は「3月末に(不正があったとの)結論を出した時点で、出せる結論は出した。­(今回を加え)2段階の調査を合わせて全容が解明されたと理解してほしい」と話しまし­た。

ES細胞混入の経緯が不明なままの調査結果について有信理事は「調査委員会ができる限­りの調査をし、理研としても協力できることはした。これ以上の調査をするつもりはない­」と答えました。

理事長の進退については、有信理事は「すでに給与返上などの処分が行われた」と、新た­に処分の対象としないことを明らかにしました。

【理化学研究所 出席者】
川合眞紀 理事
有信睦弘 理事
加賀屋悟 広報室長

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https://ja.wikipedia.org/wiki/%E5%B0%8F%E4%BF%9D%E6%96%B9%E6%99%B4%E5%AD%90



小保方 晴子(おぼかた はるこ、1983年9月25日[2][3][4][5] - )は、独立行政法人理化学研究所の元研究員[6]学位早稲田大学博士(工学)[7][8]であるが、猶予期間を設けたうえでの取り消しが決定している[9][10]
ハーバード大学医学大学院客員研究員、理化学研究所発生・再生科学総合センター客員研究員、同・細胞リプログラミング研究ユニットリーダー[11][12]として、胞子様細胞刺激惹起性多能性獲得細胞の研究に従事。2014年1月に自身が筆頭著者であるネイチャー誌への論文掲載に伴い、「リケジョの星」[13]として注目を集めるが、自身の博士論文も含めて論文不正や研究実態の疑義が問題となった。

概要
2014年1月末にSTAP研究を発表して一躍「時の人」となったが、その後、様々な研究不正を行っていたと疑われるようになり、本人同意の上で論文は撤回に至り[14][15][16][17]、一連の現象と細胞は科学的根拠を失った[18]。画像2点の不正が認定されていたが、新たな科学的疑義についての調査や小保方自身による検証実験(再現実験)により理化学研究所の処分検討が一旦停止し[19]、大きな議論となった。
小保方の博士論文に発覚した疑惑[20]に対し、早稲田大学の調査委員会は多数の問題を指摘し[21]その一部を不正認定したうえで[22]、「博士学位を授与されるべき人物に値しない」[23]と断じたものの、学位取り消しは不問と報告した[24][25][26][27]。2014年10月7日、早稲田大学は小保方の博士号を取り消すと決定した[9][10]。しかし、研究指導および学位審査過程に重大な欠陥があったことから、1年程度の猶予期間が設けられ、その間に小保方が再指導・再教育を受けたうえで論文を訂正・再提出し、これが博士論文としてふさわしいものと認められた場合には学位を維持するとしている[9][10]
なお、小保方の人物像や記者会見、実験ノートに関する報道、多くの批判意見や擁護意見も世間を騒がせた[28]。現在も世界的な研究不正事件[29][30][31][32][33][34]の中心人物として、研究者としての行く末や自身による検証実験の行方が大きな注目を集めた[35][36][37][38]2014年12月19日、理化学研究所は小保方による検証実験でSTAP現象は確認できなかったと発表し[39]、現在は理研を依願退職している[6]

来歴・人物
1983年昭和58年)9月25日生まれ[注 2]千葉県松戸市出身[41]松戸市立第六中学校東邦大学付属東邦高等学校[42]卒業。幼い頃から研究者を志し、生命や再生医療に興味を持っていた[41][43][44]
2002年4月、AO入試の一種である「創成入試」(現・特別選抜入試)で早稲田大学理工学部応用化学科に入学[45]。学部時代はラクロス部で活動し[42][46]、卒業研究では常田聡の元で微生物に関する研究に取り組んだ[47][48][49]2006年3月に、早稲田大学理工学部応用化学科を卒業。

TWInsでの細胞シートの研究
早稲田大学大学院に進学すると専門分野を転向し、東京女子医科大学先端生命医科学研究所の研修生となり、東京女子医科大学教授大和雅之の指導の下、医工融合研究教育拠点である先端生命医科学センター (TWIns) にて[50]再生医療の研究を開始する[51]。ベンチャー企業セルシードでも活躍している岡野光夫や大和雅之の指導の元、細胞シートについての研究に取り組む。
研究は細胞をシート状にして組織工学へ応用する内容で、温度応答性培養皿で作製した口腔粘膜上皮細胞シートを皮下移植する技術について研究し、国内の学術講演会[52][53]や国際会議(シカゴ[54]、大阪[55]、東京[56])における学会発表も経験した。指導教授の一人である岡野光夫は当時を振り返り、日曜日の夜遅くまで残る熱心さであったこと、プレゼンテーション資料に非の打ちどころがなかったこと、自分の意見をはっきり述べる力があったこと等を述懐し、小保方を評価している[46]
2008年3月に早稲田大学大学院理工学研究科応用化学専攻修士課程を修了する。同年に小保方が筆頭著者の論文が掲載され[57]、同年4月には早稲田大学大学院先進理工学研究科生命医科学専攻博士課程に進学した際には、日本学術振興会特別研究員 (DC1) に採択された[58][注 3]
博士論文は後述の胞子様細胞が中心になるが、博士課程においても再現性が高い皮下移植法の開発や、野生型マウスとヌードマウスにおける皮下移植後の組織や免疫応答の比較を行っている[58]。学会発表[60][61][62][63]や論文執筆も活発に行い、2011年には開発した皮下移植法がネイチャー・プロトコルに掲載された[64]。また、別の論文においても第三著者として貢献している[65]

BWHでの胞子様細胞の研究
小島宏司と大和雅之の縁で、2008年にはグローバルCOEプログラムの一環でハーバード大学医学大学院教授のチャールズ・バカンティの研究室に短期留学する[66]。チャールズ・バカンティの元で胞子様細胞 (spore-like cells) の研究に取り組み、セミナーを受講したり留学生仲間と小旅行に出かける等、留学生活を謳歌する[66][67]。留学期間終了後も客員研究員[68]として2009年冬まで滞在する[66]胞子様細胞(spore-like cells)研究を発展させる実験に取り組み、2009年4月には幹細胞研究の論文を徹夜で200本読み込み、プレゼンテーションを行った[67]。同年8月には論文を書いて投稿するが、2010年春に論文はにリジェクトされてしまう[69][67]。同じくバカンティ教授の下で研究し、論文の共著者の1人でもある小島宏司は「その後の2-3年は彼女は本当につらかっただろう」と語っている[69]
小保方は博士論文研究としてこの細胞の多能性を検証することに取り組む。「分化した動物細胞が刺激だけで多能性分化能を再獲得することはあり得ない」というのが常識であったため、ハーバード大学では多能性の判定の仕事を手伝ってくれる人が見つからなかった[70]。そこで理化学研究所のチームリーダーだった若山照彦(後に山梨大学教授)の協力を仰いだ。若山は「最初は『できるはずがない』と思ったが、あり得ないことを試すのは自分も好きだったので手伝った」という[70]
最終的にティッシュ・エンジニアリング誌へ論文を投稿し、2011年に掲載。2011年2月には博士論文「三胚葉由来組織に共通した万能性体性幹細胞の探索」をまとめあげ、同年3月15日に早稲田大学で博士(工学)の学位を取得した[8][7]

CDBにおけるSTAP研究
2011年4月から2013年2月まで理化学研究所発生・再生科学総合研究センター(CDB)ゲノムリプログラミング研究チーム(チームリーダー:若山照彦)客員研究員としてSTAP細胞の研究に取り組む[注 4]。なお、この間ハーバード・メディカルスクールのポスドク研究員の籍も持つ。
2010年チャールズ・バカンティ大和雅之は独立に刺激で細胞が初期化されるアイデアを思い付き[74][75]、小保方は幹細胞を取り出す実験を繰り返すうちに、取り出しているのではなく刺激でできていることを発見したとされる[76]。この外からの刺激で体細胞初期化する現象を「刺激惹起性多能性獲得」(英語名のstimulus-triggered acquisition of pluripotencyから「STAP」)」[77]、それで得られる全ての生体組織と胎盤組織に分化できる多能性を持った細胞を「STAP細胞」(スタップさいぼう、STAP cells[78][79][80][注 5]、STAP細胞に増殖能を持たせたものを「STAP幹細胞」 (STAP-SC)、胎盤へ寄与できるものを「FI幹細胞」 (FI-SC)[注 6] と名付けた[86]
2011年11月には若山照彦の指導のもと、キメラマウスの作成に成功[87]2012年4月にはネイチャーへの論文投稿と米国仮特許出願[88]を行う。しかし論文はリジェクトされ、セルサイエンスへも投稿し直すが、全てリジェクトされてしまう。その後2012年12月に笹井芳樹2013年1月に丹羽仁史が参加し、論文を再執筆[89]。なお、この間の11月15日に小保方へ対して研究ユニットリーダー(RUL)応募の打診があり、12月21日に採用面接を受けている[90]
2013年3月1日には研究ユニットリーダーに就任し、理化学研究所 発生・再生科学総合研究センター 細胞リプログラミング研究ユニットを主宰する[11]笹井芳樹らがメンターの元、3月中に米国仮特許出願[91]とネイチャー再投稿、4月に国際特許出願[92]を行う[93]2013年10月には国際特許が公開され[94]、12月には念願のネイチャー論文2報(万能細胞の作製法が中心の撤回済みアーティクル論文[95]と、多能性の検証が中心の撤回済みレター論文[96])がアクセプトされる。
2014年1月末にはSTAP研究を発表し、「リケジョの星」[97]「ノーベル賞級の発見」[98]として一躍時の人となるが、STAP論文や博士論文において様々な研究不正の疑義が発覚。2月17日には理化学研究所やネイチャーが本格的に調査を開始。3月28日には早稲田大学も博士論文について調査委員会を立ち上げ、3ヶ月程で報告を行うと発表した[99]

博士論文の不正調査と処分

早稲田大学博士論文不正問題」および「胞子様細胞」も参照

博士論文の疑義については7月17日早稲田大学の調査委員会が総長へ報告し[100] [101]、合わせて記者会見を実施。早稲田大学の調査委員会は「著作権侵害行為、創作者誤認惹起行為、意味不明な記載、論旨が不明瞭な記載、Tissue誌論文との記載内容と整合性がない記載、及び論文の形式上の不備と多くの問題個所が認められた」[23]と認定したうえで、小保方について「博士学位を授与されるべき人物に値しない」[23]と断定したが、学位の取り消し規定には該当しないとの調査結果をまとめた[24][26][25][26][102]。同日会見した鎌田薫総長は、論文取り下げや審査やり直しも含めて学内で再議論するとした[103]。同調査委員会は、7月に公表した報告書で、小保方氏の博士論文には米国立衛生研究所(NIH)のWEBサイトからの英文のコピーや画像の流用など、少なくとも26カ所の問題点があり、そのうち6カ所は「故意による不正」だと認定したのである[10]
2014年10月7日、早稲田大学は調査委員会の結論を受け入れず小保方の博士号を取り消すと決定した[9]。ただし、論文の指導および審査過程にも重大な欠陥があったとし、1年程度の猶予期間が設けられ、その間に小保方が再指導・再教育を受けたうえで論文を訂正・再提出し、これが博士論文としてふさわしいものと認められた場合には学位を維持する、とした[9][10]

STAP騒動と理研からの離職

刺激惹起性多能性獲得細胞」および「調査報告 STAP細胞 不正の深層」も参照

4月1日には理化学研究所の調査委員会が最終報告を行ったが、小保方は4月7日から入院し、調査不服申し立てのために三木秀夫ら4名の弁護士からなる弁護団を雇う[104]4月8日には記者会見を行ったものの、通常は弁護団経由でコメントを発信しており、会見やコメントも様々な批判を受けた。また、入院していながら5月下旬から検証実験への助言のため、CDBに出勤していたことが報道されている[105]
5月8日に認定された画像2点の不正によって、懲戒委員会が発足して処分が検討されていた。再現ができないこと、論文に盗用や改ざん等の不正が見つかったこと、サンプルや公開遺伝子データの遺伝子解析が論文と矛盾したこと等から、6月には論文撤回に追い込まれた。また、ユニットリーダー採用試験において、研究計画書の疑義[106][107][108]や英語セミナーを省略する等の特別扱いが発覚[109][110]。更には小保方逮捕の可能性も報道される状況であったが[111][112][113][114]、科学的な疑義に対する新たな予備調査の開始したり検証実験への小保方自身が参加することになり、6月30日に懲戒委員会は一時停止となった[115]。なお、予備調査を経て9月3日には本調査の委員会が設置されている[116]
なお、7月2日のネイチャーによるSTAP論文の撤回は海外でも多く報道され[117][118]、小保方も不正事件の中心人物として大きく取り上げられた[119][120][121][122]。STAP研究の検証実験や事件の真相についても注目を集める中、7月23日には過剰な取材による騒動や負傷が発生[123][124][125][126]7月27日にはSTAP研究不正事件の特集がNHKにより放送された[127]。更に同年8月5日には笹井芳樹が自殺し 小保方のメンタル面も心配された(詳細は笹井芳樹#自殺とその波紋を参照)[128][129]
12月15日には理化学研究所に退職願いを提出、19日に承認され、21日付で退職した[130]。同年12月19日には検証実験の結果が発表され、小保方も丹羽仁史らもSTAP細胞を再現できなかったことが明らかにされ[39]12月26日には科学的な調査結果が公表され、STAP細胞・STAP幹細胞・FI幹細胞らはことごとくES細胞などの混入であったと結論付けられた。どのようにES細胞が混入するに至ったかの実態は解明されなかったが、理化学研究所は調査終了を発表した[131][132]
なお、ハーバードは調査を継続中と報道されており[133]2015年1月26日には理研ライフサイエンス技術基盤研究センター・元上級研究員の石川智久により、若山研究室におけるES細胞の窃盗容疑で兵庫県警察刑事告発されている[134]

最終更新 2015年1月29日

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理研によるSTAP細胞問題に関する緊急会見(場所:文部科学省)



2015/02/10 にライブ配信
10日午後3時より、文部科学省において、理研によるSTAP細胞問題に関する緊急会­見が行われます。THE PAGEでは、こちらの会見を生中継します。

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【STAP細胞】20小保方氏「懲戒解雇相当」 懲戒処分等についての記者会見【2015/2/10】  



2015/02/10 に公開
理化学研究所(理研)は小保方晴子・元研究員について「懲戒解雇」に相当するという見­解を発表しました。小保方氏は既に理研を依願退職しているため懲戒処分の対象者ではな­いが、仮に任期制職員として在籍しているとした場合の処分のあり方について検討を行い­ました。

STAP細胞の問題を受け、理研は関係者の処分を検討していました。論文の共著者の若­山照彦氏については出勤停止相当、丹羽仁史氏は文書による厳重注意としました。また、­論文発表時に小保方氏が所属していた発生・再生科学総合研究センター(現多細胞システ­ム形成研究センター)の竹市雅俊・元センター長は譴責(けんせき)とし、これを受けて­給与の10分の1(3カ月)の自主返納を行うこととしました。竹市雅俊・元センター長­「当時のセンター長として、研究の不正を事前に発見し、不適切な論文の発表を防ぐこと­ができなかった責任を重く受け止めております」

出席者
堤 精史(理化学研究所 人事部長)
加賀屋 悟(理化学研究所 広報室長)

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小保方晴子 「捏造」不服申し立て4/9



2014/04/08 に公開
【記者質問 前半64min→】https://www.youtube.com/watch?v=lKUDx...
【記者質問 後半104min→】https://www.youtube.com/watch?v=1xkr-...
小保方晴子4/9 理研調査委員会の最終報告書に対する不服申し立て記者会見
 
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