TBX5 is required for embryonic cardiac cell cycle progression

Development. 2006 Jul;133(13):2575-84. doi: 10.1242/dev.02420. Epub 2006 May 25.


Despite the critical importance of TBX5 in normal development and disease, relatively little is known about the mechanisms by which TBX5 functions in the embryonic heart. Our present studies demonstrate that TBX5 is necessary to control the length of the embryonic cardiac cell cycle, with depletion of TBX5 leading to cardiac cell cycle arrest in late G(1)- or early S-phase. Blocking cell cycle progression by TBX5 depletion leads to a decrease in cardiac cell number, an alteration in the timing of the cardiac differentiation program, defects in cardiac sarcomere formation, and ultimately, to cardiac programmed cell death. In these studies we have also established that terminally differentiated cardiomyocytes retain the capacity to undergo cell division. We further show that TBX5 is sufficient to determine the length of the embryonic cardiac cell cycle and the timing of the cardiac differentiation program. Thus, these studies establish a role for TBX5 in regulating the progression of the cardiac cell cycle.

Publication types

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

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Cell Cycle / physiology
  • Cell Division
  • DNA Primers
  • In Situ Hybridization
  • Mitosis
  • Myocardium / cytology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • T-Box Domain Proteins / deficiency
  • T-Box Domain Proteins / genetics*
  • Xenopus / genetics*
  • Xenopus Proteins / deficiency
  • Xenopus Proteins / genetics*


  • DNA Primers
  • T-Box Domain Proteins
  • T-box transcription factor 5
  • Xenopus Proteins