Fig. 4

Lineage tracing of the hyoid head cavities. a-d″ Transverse sections of CM-DiI-injected embryos aligned with adjacent sections immunostained with myosin heavy chain antibody (b′ and d′), stained with Alcian blue (AB) (b′ and d′), and hybridized in situ with a Scx antisense RNA probe (b″ and d″). By 42 dpi, CM-DiI-labeled cells (magenta) were found in the lateral rectus muscle but not in Scx-positive tendon progenitor cells at the origin of all rectus muscles (asterisks), the insertion site of the lateral rectus muscle (insLR), or the skeleton at the attachment sites of the rectus muscles (pila antotica; outlined by the dotted line). insLR, tendon progenitor cells at the insertion site of the lateral rectus muscle; IR, inferior rectus muscle; LR, lateral rectus muscle. Scale bars = 200 μm