Planarian Hedgehog/Patched establishes anterior–posterior polarity by regulating Wnt signaling
スポンサーリンク
概要
- 論文の詳細を見る
100年来の謎に迫る-体の極性を決める仕組みを解明しました. 京都大学プレスリリース. 2009-12-08. http://www.kyoto-u.ac.jp/ja/news_data/h/h1/news6/2009/091208_2.htmDespite long-standing interest, the molecular mechanisms underlying the establishment of anterior–posterior (AP) polarity remain among the unsolved mysteries in metazoans. In the planarians (a family of flatworms), canonical Wnt/β-catenin signaling is required for posterior specification, as it is in many animals. However, the molecular mechanisms regulating the posterior-specific induction of Wnt genes according to the AP polarity have remained unclear. Here, we demonstrate that Hedgehog (Hh) signaling is responsible for the establishment of AP polarity via its regulation of the transcription of Wnt family genes during planarian regeneration. We found that RNAi gene knockdown of Dugesia japonica patched (Djptc) caused ectopic tail formation in the anterior blastema of body fragments, resulting in bipolar-tails regeneration. In contrast, RNAi of hedgehog (Djhh) and gli (Djgli) caused bipolar-heads regeneration. We show that Patched-mediated Hh signaling was crucial for posterior specification, which is established by regulating the transcription of Wnt genes via downstream Gli activity. Moreover, differentiated cells were responsible for the posterior specification of undifferentiated stem cells through Wnt/β-catenin signaling. Surprisingly, Djhh was expressed in neural cells all along the ventral nerve cords (along the AP axis), but not in the posterior blastema of body fragments, where the expression of Wnt genes was induced for posteriorization. We therefore propose that Hh signals direct head or tail regeneration according to the AP polarity, which is established by Hh signaling activity along the body's preexisting nervous system.
- 2009-12-11
論文 | ランダム
- ボイスコイルモータを用いた小型車両用シートの制御 : 自由度モデルに対するスライディングモード制御を用いた実験的考察
- 新構成ボイスコイルモータの特性
- 521 ボイスコイルモータと MR ダンパを用いた自律型セミアクティブ減衰機構
- ボイスコイルモーターによる精密位置決め制御 (特集 メカノオプティクス)
- モータ、トランスなどに要求されているUL1446規格による耐熱性評価方法とULのCAP試験を紹介 コイル、モータにおける絶縁システムの評価技術 (ワイド特集 2002年版 モータドライブ&コントロール最新技術ガイド) -- (最新モータ用デバイス活用&測定技術)