Figure 5

Epaxial SEM grafted to the hypaxial domain cannot generate chondrocytes. A) Schematic illustration of the grafting procedure. Quail epaxial SEM (blue) at the level of somite 20/21 was transplanted to the hypaxial domain of chick embryo (red). m, myotome; n, neural tube; sc, sclerotome; sem, sub-ectodermal mesenchyme. B and C) Skeletal staining after five days of re-incubation. B) Control side shows normal scapula (s) and humerus (h). C) Operated side reveals a missing segment of the scapula (s) as indicated by the white arrow. D) Immunohistochemistry on transverse sections through the operated region. Quail cells (black asterisk) are found in dermis and inter-muscular connective tissue. n, neural tube; s, scapula; vb, vertebral body.