Abstract

Neoblasts are an abundant, heterogeneous population of adult stem cells (ASCs) that facilitate the maintenance of planarian tissues and organs, providing a powerful system to study ASC self-renewal and differentiation dynamics. It is unknown how the collective output of neoblasts transit through differentiation pathways to produce specific cell types. The planarian epidermis is a simple tissue that undergoes rapid turnover. We found that as epidermal progeny differentiate, they progress through multiple spatiotemporal transition states with distinct gene expression profiles. We also identified a conserved early growth response family transcription factor, egr-5, that is essential for epidermal differentiation. Disruption of epidermal integrity by egr-5 RNAi triggers a global stress response that induces the proliferation of neoblasts and the concomitant expansion of not only epidermal, but also multiple progenitor cell populations. Our results further establish the planarian epidermis as a novel paradigm to uncover the molecular mechanisms regulating ASC specification in vivo.

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Author details

  1. Kimberly C Tu

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    No competing interests declared.
  2. Li-Chun Cheng

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    No competing interests declared.
  3. Hanh TK Vu

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    No competing interests declared.
  4. Jeffrey J Lange

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    No competing interests declared.
  5. Sean A McKinney

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    No competing interests declared.
  6. Chris W Seidel

    Stowers Institute for Medical Research, Kansas City, United States
    Competing interests
    No competing interests declared.
  7. Alejandro Sánchez Alvarado

    Stowers Institute for Medical Research, Kansas City, United States
    For correspondence
    asa@stowers.org
    Competing interests
    Alejandro Sánchez Alvarado, Reviewing editor, eLIFE.

Copyright

© 2015, Tu et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Kimberly C Tu
  2. Li-Chun Cheng
  3. Hanh TK Vu
  4. Jeffrey J Lange
  5. Sean A McKinney
  6. Chris W Seidel
  7. Alejandro Sánchez Alvarado
(2015)
Egr-5 is a post-mitotic regulator of planarian epidermal differentiation
eLife 4:e10501.
https://doi.org/10.7554/eLife.10501

Share this article

https://doi.org/10.7554/eLife.10501

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