Recent identification of an ERK signal gradient governing planarian regeneration.
Planarians have strong regenerative abilities derived from their adult pluripotent stem cell (neoblast) system. However, the molecular mechanisms involved in planarian regeneration have long remained a mystery. In particular, no anterior-specifying factor(s) could be found, although Wnt family proteins had been successfully identified as posterior-specifying factors during planarian regeneration (Gurley et al., 2008; Petersen and Reddien, 2008). A recent textbook of developmental biology therefore proposes a Wnt antagonist as a putative anterior factor (Gilbert, 2013). That is, planarian regeneration was supposed to be explained by a single decreasing gradient of the β-catenin signal from tail to head. However, recently we succeeded in demonstrating that in fact the extracellular-signal regulated kinases (ERK) form a decreasing gradient from head to tail to direct the reorganization of planarian body regionality after amputation (Umesono et al., 2013).
Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan. Electronic address: agata@mdb.biophys.kyoto-u.ac.jp.
Kiyokazu
K
Agata
Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Junichi
J
Tasaki
Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Elizabeth
E
Nakajima
Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Yoshihiko
Y
Umesono
D000818:Animals; D049109:Cell Proliferation; D020935:MAP Kinase Signaling System / Q000502:physiology*; D010932:Planarians / Q000166:cytology / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*; D015398:Signal Transduction; D051176:beta Catenin / Q000378:metabolism
D051176:beta Catenin
Blastema formation; ERK signaling; MAP kinase; Planarian regeneration; Stem cell system