Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Sci. Signal., 22 January 2008
Vol. 1, Issue 3, p. ec26
[DOI: 10.1126/stke.13ec26]

EDITORS' CHOICE

Development Heads or Tails

Beverly A. Purnell

Science, AAAS, Washington, DC 20005, USA

Planarians--tubular flatworms--can regenerate all of their body parts and entire organ systems after amputation. However, the mechanism by which the animal "knows" how to generate a head after head removal or a tail after tail removal, a property called regeneration polarity, is unknown. Gurley et al. and Petersen and Reddien now find that a conserved factor within the Wnt signaling pathway is used to distinguish head from tail. Decreased Wnt signaling through β-catenin causes the regeneration of heads, whereas activation of Wnt signaling induces tails. β-catenin also maintains the anteroposterior body axis in uncut animals.

K. A. Gurley, J. C. Rink, A. Sánchez Alvarado, β-catenin defines head versus tail identity during planarian regeneration and homeostasis. Science 319, 323-327 (2008). [Abstract] [Full Text]

C. P. Petersen, P. W. Reddien, Smed-βcatenin-1 is required for anteroposterior blastema polarity in planarian regeneration. Science 319, 327-330 (2008). [Abstract] [Full Text]

Citation: B. A. Purnell, Heads or Tails. Sci. Signal. 1, ec26 (2008).

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882