While p73 is essential, p63 is completely dispensable for the development of the central nervous system

Cell Cycle. 2011 Feb 15;10(4):680-9. doi: 10.4161/cc.10.4.14859. Epub 2011 Feb 15.

Abstract

The ancient p53 paralogs p63 and p73 regulate specific tissue formation, cell survival and cell death via their TA and ΔN isoforms. Targeted disruption of the p73 locus leads to severe defects in the development of the central nervous system (CNS), and p73 has recently been shown to be an essential regulator of neural stem cell maintenance and differentiation in both embryonal and adult neurogenesis. In contrast, global p63-/- mice lack skin and limbs. Moreover, p63 is detectable in embryonic cortex. It has previously been proposed to also play critical pro-death and pro-survival roles in neural precursors of the developing sympathetic and central nervous system, respectively, based on experimental overexpression and siRNA-mediated knockdown of p63. Here we perform an extensive analysis of the developing central nervous system in global p63-/- mice and their wildtype littermates. Brain and spinal cord of embryos and newborn mice were assessed in vivo for neuroanatomy, histology, apoptosis, proliferation, stemness and differentiation, and in vitro for self-renewal and maturation in neurosphere assays. None of these analyses revealed a detectable phenotype in p63-/- mice. Hence, despite the profound impact of p63 on the development of stratified epithelia and limbs, p63 is completely dispensable for proper development of the central nervous system. Thus, despite their strong homology, the non-overlapping tissue specificity of p63 and p73 functions appears more pronounced than previously anticipated.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Brain / embryology*
  • Brain / metabolism
  • Cell Death
  • Cell Differentiation
  • Cell Survival
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Gene Knockdown Techniques
  • Humans
  • Mice
  • Mice, Transgenic
  • Neural Stem Cells / cytology
  • Neural Stem Cells / physiology*
  • Neurogenesis / genetics
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Organogenesis
  • Polymerase Chain Reaction
  • RNA, Small Interfering
  • Spinal Cord / embryology*
  • Spinal Cord / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Tumor Protein p73
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism

Substances

  • DNA-Binding Proteins
  • Nuclear Proteins
  • RNA, Small Interfering
  • TP63 protein, human
  • TP73 protein, human
  • Transcription Factors
  • Trp73 protein, mouse
  • Tumor Protein p73
  • Tumor Suppressor Proteins