Adult stem cell plasticity: neoblast repopulation in non-lethally irradiated planarians

Dev Biol. 2009 Apr 15;328(2):305-14. doi: 10.1016/j.ydbio.2009.01.029. Epub 2009 Jan 30.

Abstract

Planarians are a model system for studying adult stem cells, as they possess the neoblasts, a population of pluripotent adult stem cells able to give rise to both somatic and germ cells. Although over the last years several efforts have been made to shed light on neoblast biology, only recent evidence indicate that this population of cells is heterogeneous. In this study we irradiated planarians with different non-lethal X-ray doses (1-5 Gy) and we identified subpopulations of neoblasts with diverse levels of tolerance to X-rays. We demonstrated that a dramatic reduction of neoblasts occurred soon after non-lethal irradiations and that de-novo proliferation of some radioresistant cells re-established the primary neoblast number. In particular, a strong proliferation activity occurred at the ventral side of irradiated animals close to the nervous system. The produced cells migrated towards the dorsal parenchyma and, together with some dorsal radioresistant cells, reconstituted the entire neoblast population demonstrating the extreme plasticity of this adult stem cell system.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult Stem Cells / cytology*
  • Adult Stem Cells / physiology
  • Animals
  • Cell Differentiation / physiology
  • Cell Differentiation / radiation effects
  • Cell Movement / physiology
  • Cell Movement / radiation effects
  • Cell Proliferation / radiation effects*
  • Planarians / cytology*
  • Planarians / radiation effects