Antagonistic Self-Organizing Patterning Systems Control Maintenance and Regeneration of the Anteroposterior Axis in Planarians

Dev Cell. 2017 Feb 6;40(3):248-263.e4. doi: 10.1016/j.devcel.2016.12.024.


Planarian flatworms maintain their body plan in the face of constant internal turnover and can regenerate from arbitrary tissue fragments. Both phenomena require self-maintaining and self-organizing patterning mechanisms, the molecular mechanisms of which remain poorly understood. We show that a morphogenic gradient of canonical Wnt signaling patterns gene expression along the planarian anteroposterior (A/P) axis. Our results demonstrate that gradient formation likely occurs autonomously in the tail and that an autoregulatory module of Wnt-mediated Wnt expression both shapes the gradient at steady state and governs its re-establishment during regeneration. Functional antagonism between the tail Wnt gradient and an unknown head patterning system further determines the spatial proportions of the planarian A/P axis and mediates mutually exclusive molecular fate choices during regeneration. Overall, our results suggest that the planarian A/P axis is patterned by self-organizing patterning systems deployed from either end that are functionally coupled by mutual antagonism.

Keywords: Turing pattern; Wnt signaling; morphogen gradient; patterning; planaria; regeneration; self-organization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Patterning*
  • Gene Expression Regulation, Developmental
  • Homeostasis
  • Models, Biological
  • Planarians / embryology*
  • Planarians / genetics
  • Planarians / physiology*
  • Regeneration / physiology*
  • Wnt Signaling Pathway / genetics
  • beta Catenin / metabolism


  • beta Catenin