Fig. 1: TGFβ signalling inhibits C2C12 fusion, and is expressed in the chicken embryo.
From: TGFβ signalling acts as a molecular brake of myoblast fusion
a EsiRNAs corresponding to 8627 distinct mouse genes were transfected into a (GFP-positive) C2C12 mouse muscle cell line to identify novel molecules regulating myoblast fusion. b After differentiation, the area of myofibres (GFP staining), the nuclei count (Hoechst) and myogenin expression were evaluated with an image analysis program. c Quantification of the number of nuclei per myofibre identified a number of genes that are either necessary or inhibit myoblast fusion in vitro, compared to controls. d Gene ontology (Panther) and protein interaction (String) analyses showed that the TGFβ pathway is over-represented within the inhibitors of fusion. e Loss of function of ligands, receptors or effectors of the TGFβ pathway led to a strong increase of C2C12 fusion, compared to controls. f–h Lateral view of whole-mount (WM) in situ hybridization of chicken embryos at E5.5. The secreted ligands TGFB2 and TGFB3, as well as TGFBR1 are expressed in the myotome of the chicken embryo (yellow arrowheads, f–h). i In contrast, TGFBR2 is expressed in epithelial cells located at the anterior and posterior borders of the dermomyotome (shown in WM and longitudinal section of chicken embryos at E5.5, red arrowheads). Dm: dermomyotome, My: myotome, NT: neural tube. Scale bars f–i: 0.5 mm.
