Expression patterns of the Dlx genes in the late-pharyngula embryo at the inner ear level. (A) Transverse view of a haematoxylin- and eosin-stained section. (B–D) Expression patterns of the Dlx genes. The sections for in situ hybridization were counterstained with ISH Red (B–D). (B) Expression of EbDlx1/4/6A was detected in the mesenchymal cells at t. vag (arrowhead). (C) EbDlx2/3/5B showed a broad expression pattern in three skeletal elements (t. cl, t. vag, and c. bas) (arrowheads). (C′) Higher magnification of the dotted box shown in C; restricted expression pattern of EbDlx2/3/5B was detected in one cartilaginous complex consisting of d. l. b, ex. pq, and trab, (arrowheads). (D) EbDlx2/3/5C was expressed in the c. bas and mesenchymal cells on the ventral aspect of ph. The level of the section is indicated by an arrowhead in Figure 1B. Abbreviations: c. bas, basal cartilage; d. l. b, dorsal longitudinal bar; ex. pq, extrapalato-quadrate; ph, pharynx; t. cl, tendon of the clavatus muscle; t. vag, tendon of the vagina of the clavatus; trab, trabecula; VII, facialis nerve; VIII, saccularis nerve. Scale bars, 100 μm (A); 10 μm (C′).
Fujimoto et al. BMC Evolutionary Biology 2013 13:15 doi:10.1186/1471-2148-13-15