Muscle development and differentiation in the urodele Ambystoma mexicanum

Dev Growth Differ. 2012 May;54(4):489-502. doi: 10.1111/j.1440-169X.2012.01338.x. Epub 2012 Apr 23.

Abstract

Muscle differentiation has been widely described in zebrafish and Xenopus, but nothing is known about this process in amphibian urodeles. Both anatomical features and locomotor activity in urodeles are known to show intermediate features between fish and anurans. Therefore, a better understanding of myogenesis in urodeles could be useful to clarify the evolutionary changes that led to the formation of skeletal muscle in the trunk of land vertebrates. We report here a detailed morphological and molecular investigation on several embryonic stages of Ambystoma mexicanum and show that the first differentiating muscle fibers are the slow ones, originating from a myoblast population initially localized close to the notochord that forms a superficial layer on the somitic surface afterwards. Subsequently, fast fibers differentiation ensues. We also identified and cloned A. mexicanum Myf5 as a muscle-specific transcriptional factor likely involved in urodele muscle differentiation.

MeSH terms

  • Ambystoma mexicanum / anatomy & histology
  • Ambystoma mexicanum / embryology*
  • Ambystoma mexicanum / genetics
  • Animals
  • Body Patterning
  • Cell Differentiation*
  • Cloning, Molecular
  • Embryo, Nonmammalian / embryology
  • Embryo, Nonmammalian / ultrastructure
  • Embryonic Development
  • Enzyme Assays
  • Gene Expression Regulation, Developmental*
  • Immunohistochemistry
  • Muscle Development*
  • Muscle Fibers, Fast-Twitch / metabolism
  • Muscle Fibers, Fast-Twitch / ultrastructure
  • Muscle Fibers, Slow-Twitch / metabolism
  • Muscle Fibers, Slow-Twitch / ultrastructure
  • Muscle, Skeletal / embryology
  • Muscle, Skeletal / ultrastructure
  • Myoblasts, Skeletal / metabolism
  • Myogenic Regulatory Factor 5 / genetics
  • Myogenic Regulatory Factor 5 / metabolism
  • Myosins / genetics
  • Myosins / metabolism
  • Notochord / embryology
  • Notochord / ultrastructure
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism

Substances

  • Myogenic Regulatory Factor 5
  • Protein Isoforms
  • RNA, Messenger
  • Myosins