Connective tissue development / mesenchymal cell differentiation

Connective tissue is an irreplaceable component of the musculoskeletal system; however it has attracted far less attention than other tissue types. Odd-skipped is a drosophila pair-rule gene involved in embryonic segmentation. In mammals, two odd-skipped paralogs exist, Osr1 and Osr2. Odd-skipped genes encode zinc-finger transcription factors expressed in several organs of the developing embryo. For Osr1, functions in heart and kidney development have been described, while Osr2 has been linked to secondary palate formation and tooth development. We have analysed the expression of Osr1 and Osr2 in the chick limb and found both genes to be highly specific for irregular connective tissue.

Figure 1
Figure 1: Expression of Osr1 and Osr2: left panel: in-situ hybridisation for Osr1 and Osr2 showing widespread expression of both genes in the chicken limb at Hamburger-Hamilton stage 32. The right panel shows a two-colour ISH for Osr1 or Osr2 together with the myogenic factor MyoD. This shows expression of both Osr genes in muscle connective tissue. Modified from Stricker et al. 2011.

We have recently shown that Osr1 and Osr2 are both involved in the differentiation of irregular connective tissue fibroblasts and are potent inhibitors of mesenchymal differentiation along other cell lineages(Stricker et al. 2012). We aim at further analysing the role of Osr genes in development of the connective tissue and the communication of connective tissue cells with other cell types during limb development. 

This project is a part of the international graduate school for Myology, “MyoGrad”

Collaboration partners: 

  • Delphine Duprez, UMR7622, CNRS, Université Pierre et Marie Curie, Laboratoire de Biologie du Développement, Campus de Jussieu, Paris, France 
  • David Sassoon, Giovanna Marazzi; Stem Cells and Regenerative Medicine,ICAN Institute of Cardiometabolism and Nutrition, UMRS 1166, INSERM/Sorbonne University (Université Pierre et Marie Curie Paris VI), Paris, France