Int. J. Dev. Biol. 48: 285 - 291 (2004)
doi: 10.1387/ijdb.031787yi
© UPV/EHU Press

Distinctive expression of Myf5 in relation to differentiation and plasticity of newt muscle cells

Yutaka Imokawa, Phillip B. Gates, Young-Tae Chang1, Hans-Georg Simon2 and Jeremy P. Brockes*

Department of Biochemistry & Molecular Biology, University College London, London, U.K., 1Department of Chemistry, New York University, New York, USA and 2Department of Pediatrics, Northwestern University, The Feinberg School of Medicine, Children's Memorial Institute for Education and Research, Chicago, Illinois, USA

ABSTRACT Regeneration in urodele amphibians such as the newt reflects the local plasticity of differentiated cells. Newt myotubes and myofibres undergo S phase re-entry and cellularisation in the limb blastema, and we have analysed the regulation of Myf5 in relation to these events. Surprisingly, Myf5 was expressed after fusion in cultured newt myotubes and in myofibers of the adult limb, in contrast to its familiar expression in myoblasts in other vertebrates. Its expression was markedly down regulated in cultured newt myotubes after S phase re-entry induced by serum stimulation, as well as by exposure to the trisubstituted purine called myoseverin which induces cellularisation. We have attempted to relate this striking difference from other vertebrates to the requirement for multinucleate urodele muscle cells to contribute to the regeneration blastema.

Keywords:

myofiber, myogenin, myoseverin, regeneration, urodele

*Corresponding author e-mail: j.brockes@ucl.ac.uk