Fig. 4.

Neural crest derivation of the connective-tissue components of cranial muscles in living amphibians (frogs and salamanders). (A) Cross-section through the ceratohyal cartilage (CH) and associated muscle attachments of a larval frog (Bombina orientalis) following embryonic labelling of premigratory cranial neural crest with Dil. The bright red area at lower left is within the tendinous insertion of a cranial muscle. Lateral is left; dorsal is up. Reproduced with permission from Olsson & Hanken (1996). (B) Branchial region of a stage-36 axolotl embryo (Ambystoma mexicanum). Neural crest-derived cells expressing green fluorescent protein (GFP; green) are present in the dermis of branchial arches 1–3 (B1, B2, B3). Other crest-derived cells (arrowheads) surround muscle anlage within each arch (red). Lateral view; anterior is to the left. Additional abbreviation: H, hyoid arch. Reproduced with permission from Ericsson et al. (2004).