Abstract
Muscle differentiation involves the fusion of mononucleate myoblasts to form multinucleate syncytial myotubes. In order to assess reversibility of the mononucleate-to-multinucleate transition in urodele limb regeneration, myotube formation was induced in cultured newt limb blastemal cells. Myotubes were purified, replated at low density and injected with a cytoplasmic lineage tracer. In some cases nuclei of myotubes were labelled by incorporation of tritiated thymidine. Labelled myotubes were stable in culture for 6-8 weeks and no transfer to mononucleate cells was observed. The myotubes were implanted under the wound epidermis of a hindlimb blastema. Labelled mononucleate cells were observed 1 week after implantation and such cells could derive both the cytoplasmic lineage tracer and the nuclear marker. The number of such cells increased by 2-3 weeks after implantation. These results provide strong support for the reversibility of muscle differentiation during urodele limb regeneration, and raise questions about the mechanism of such a reversal.
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Blau HM, Baltimore D . Differentiation requires continuous regulation. J Cell Biol 1991; 112: 781–3.
Blau HM . Differentiation requires continuous active control. Annu Rev Biochem 1991; 61: 1213–30.
Okada TS . Transdifferentiation. Oxford: Oxford University Press, 1991.
Weintraub H, Davis R, Tapscott S, et al. The myoD gene family: nodal point during specification of the muscle cell lineage. Science 1991; 251: 761–6.
Buckingham M . Making muscle in mammals. Trends Genet 1992; 8: 144–9.
Hay ED . Electron microscope observations of muscle dedifferentiation in regenerating Amblystoma limbs. Dev Biol 1959; 1: 555–85.
Kintner CR, Brockes JP . Monoclonal antibodies identify blastemal cells derived from de-differentiating muscle in newt limb regeneration. Nature 1984; 308: 67–9.
Casimir CM, Gates PB, Patient RK, Brockes JP . Evidence for dedifferentiation and metaplasia in amphibian limb regeneration from inheritance of DNA methylation. Development 1988; 104: 657–68.
Cameron JA, Hilgers AR, Hinterberger TJ . Evidence that reserve cells are a source of regenerated adult newt muscle in vitro. Nature 1986; 321: 607–10.
Griffin KJP, Fekete DM, Carlson BM . A monoclonal antibody stains myogenic cells in regenerating newt muscle. Development 1987; 101: 267–77.
Lo DC, Allen F, Brockes JP . Reversal of muscle differentiation during urodele limb regeneration. Proc Natl Acad Sci USA 1993; 90: 7230–4.
Iujvidin S, Fuchs O, Nudel U, Yaffe D . SV40 immortalizes myogenic cells: DNA synthesis and mitosis in differentiating myotubes. Differentiation 1990; 43: 192–203.
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Brockes, J., Lo, D. Reversibility of the mononucleate-to-multinucleate myogenic transition during amphibian limb regeneration. Eye 8, 151–154 (1994). https://doi.org/10.1038/eye.1994.38
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DOI: https://doi.org/10.1038/eye.1994.38