Activated satellite cells respond to BMP signals. Satellite cells attached to myofibers were analyzed after 0 (A-D), 24 (E-L), 48 (M-T) and 72 hours (U-X) in culture by co-immunostaining for Pax7 (A,E,I,M), myogenin (Q,U), MyoD (J,R) sein and p-Smad 1/5/8 (B,F,N,V) as indicated. (A-D) p-Smads are absent in quiescent satellite cells. (E-L) Satellite cells co-express Pax7, MyoD and p-Smads after 24 hours. (M-T) after 48 hours Pax7 and MyoD are co-expressed with p-Smad, while Myogenin is absent. (U-X) Myogenin colocalizes with p-Smad after 72 hours. Nuclei were counterstained with DAPI. Magnification is 200×.
Friedrichs et al. BMC Cell Biology 2011 12:26 doi:10.1186/1471-2121-12-26