レターの説明は以下ね。
>>
However, as Fgf4-induced stem cells lay between STAP stem cells and trophoblast stem cells in the dendrogram, the possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population cannot be ruled out. Previous studies have indicated that inner cell mass (ICM)-type pluripotent cells can be removed from culture by treating the culture with a JAK inhibitor <16>(Extended Data Fig. 5a, b). In contrast, the JAK inhibitor treatment had no substantial effect on Oct4-GFP expression in Fgf4-induced stem-cell culture (Extended Data Fig. 5c, d; see Extended Data Fig. 5e, f for control). Expression of neither pluripotency markers (Fig. 2j) nor trophoblast markers (Fig. 2k) was substantially affected, indicating that pluripotency marker expression is unlikely to reflect contaminating STAP stem cells (ICM-type). Consistent with this idea, Fgf4-induced stem cells that were strongly positive for the trophoblast marker Itga7 (a surface marker for trophoblasts but not ES cells) also expressed high levels of Oct4-GFP (Extended Data Fig. 5g).
紛らわしい書き方になってるけど、(Extended Data Fig. 5a, b)は先行研究論文の中にある写真の引用ではなくて小保方さんが実際にやってみて確認した写真だね。
>>
Previous studies have indicated that inner cell mass (ICM)-type pluripotent cells can be removed from culture by treating the culture with a JAK inhibitor <16>(Extended Data Fig. 5a, b).
先行する研究では、内部細胞塊（ICM)タイプの多能性細胞は、JAK阻害剤で培養を処理することにより培養物から除去することができることを示した（拡張データ図5a,b）。
笹井さんの文章でthe possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population cannot be ruled out.と書かれているSTAP幹細胞コンタミというのはあくまでも、STAP細胞をACTH+Lifで幹細胞誘導したものだからね。性質はES細胞そっくりだけどES細胞のようにインナーセルマスを取り出して培養されたものではないよな。リンパ球を酸浴させてできたとされるSTAP細胞をACTH+Lifで幹細胞誘導したとされているんだから、インナーセルマス由来細胞ではない。ところが笹井さんはあたかもESのコンタミであったらいけないからというような理由でJAKiを入れた。変でしょ。
Yang, J.の論文のハイライト解説があるわね。
>>
Highlights
LIF promotes induction of pluripotency independent of its role in self-renewal
Increased Jak/Stat3 activation is sufficient to convert EpiSCs to naive pluripotency
Jak/Stat3 activation is a limiting factor in somatic cell reprogramming
Jak/Stat3 facilitates progression of intermediate states to pluripotency
いいわよ。時間はたっぷりあって急ぐことは何もない。何度でも貼り付けるわよ。
>>
However, as Fgf4-induced stem cells lay between STAP stem cells and trophoblast stem cells in the dendrogram, the possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population cannot be ruled out. Previous studies have indicated that inner cell mass (ICM)-type pluripotent cells can be removed from culture by treating the culture with a JAK inhibitor <16>(Extended Data Fig. 5a, b). In contrast, the JAK inhibitor treatment had no substantial effect on Oct4-GFP expression in Fgf4-induced stem-cell culture (Extended Data Fig. 5c, d; see Extended Data Fig. 5e, f for control). Expression of neither pluripotency markers (Fig. 2j) nor trophoblast markers (Fig. 2k) was substantially affected, indicating that pluripotency marker expression is unlikely to reflect contaminating STAP stem cells (ICM-type). Consistent with this idea, Fgf4-induced stem cells that were strongly positive for the trophoblast marker Itga7 (a surface marker for trophoblasts but not ES cells) also expressed high levels of Oct4-GFP (Extended Data Fig. 5g).
the possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population って
FI幹細胞の培養中にSTAP幹細胞が入った可能性を言ってるんでしょ。FI幹細胞の元はSTAP細胞だよね。STAP細胞を
FGF4培地に入れているところにSTAP幹細胞が入ったからといって、何がどうだというのかな。
