Repositioning forelimb superficialis muscles: Tendon attachment and muscle activity enable active relocation of functional myofibers

Alice H. Huang, Timothy J. Riordan, Lingyan Wang, Shai Eyal, Elazar Zelzer, John V. Brigande, Ronen Schweitzer

Research output: Contribution to journalArticle

24 Scopus citations


The muscles that govern hand motion are composed of extrinsic muscles that reside within the forearm and intrinsic muscles that reside within the hand. We find that the extrinsic muscles of the flexor digitorum superficialis (FDS) first differentiate as intrinsic muscles within the hand and then relocate as myofibers to their final position in the arm. This remarkable translocation of differentiated myofibers across a joint is dependent on muscle contraction and muscle-tendon attachment. Interestingly, the intrinsic flexor digitorum brevis (FDB) muscles of the foot are identical to the FDS in tendon pattern and delayed developmental timing but undergo limited muscle translocation, providing strong support for evolutionary homology between the FDS and FDB muscles. We propose that the intrinsic FDB pattern represents the original tetrapod limb and that translocation of the muscles to form the FDS is a mammalian evolutionary addition.

Original languageEnglish (US)
Pages (from-to)544-551
Number of pages8
JournalDevelopmental Cell
Issue number5
StatePublished - Sep 16 2013


ASJC Scopus subject areas

  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Developmental Biology
  • Cell Biology

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