Fig. 8.
Identification of ectopic thyroid tissue by whole-mount immunofluorescence staining for T4 and WISH of thyroid marker genes. A, Ventral view of the head region of 120 hpf Tg(fli1a:EGFP) transgenic larvae oriented with anterior to the left. T4 immunofluorescence revealed the presence of an ectopic immunoreactive domain (e) anterior to the ceratohyal cartilage (ch). In situ hybridization of 100-hpf larvae with various thyroid markers, including tg, nkx2.1a, tpo, and hhex, also labels a small cluster of cells in the same region (B–E). Lateral views of the pharyngeal region show that this anterior expression domain is located close to the base of the pharyngeal floor (B and C). Ventral views demonstrate the pharyngeal midline position of this ectopic domain (D and E). All larvae are oriented with anterior to the left.