Fig. 4

Fig. 4

TCFsiam expression domains resemble characteristic regions of Wnt/β-catenin signaling activity. (A–H) are reconstructed confocal projections images. (I–L) are images taken with conventional fluorescent microscope. In A–G a comparison between Tg(7xTCF-Xla.Siam:GFP)^ia4 and Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5 (small inset) show an identical pattern of expression. (A-H) 48-hpf larva. (A) Tg(7xTCF-Xla.Siam:GFP)^ia4 is highly expressed in the brain, particularly in the MHB. More caudally, strong Tg(7xTCF-Xla.Siam:GFP)^ia4 expression is seen in the spinal cord (B), in the cristae of the otic vesicle (C), in the somitic mesoderm (D), in fin buds (E) and eye(F). (G–H) Posterior lateral line neusromasts actively express the Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5 transgene. Confirmation of the neuromasts identity of the cell cluster seen in H (arrowheads) was obtained by Tg(-8.0cldnb:lynEGFP)^zf106 transgene coexpression in Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5 expressing cells of the neuromasts primordium at 36 hpf of Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5/Tg(-8.0cldnb:lynEGFP)^zf106 double transgenics. (I) Longitudinal paraffin section of a representative 30 dpf Tg(7xTCF-Xla.Siam:GFP)^ia4 larva showing GFP-expressing cells in the retinal pigmented epithelium (rpe). Counterstaining was performed with the nuclear dye DAPI. (J) Representative image of the branchial arch of a one year old Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5 fish demonstrating transgene expression in the tip of gill rackers (gr) and in gill filaments. In the small inset, a magnification of a single gill raker with its fluorescently labeled tip is depicted. (K) Ventral view of a representative forebrain from a one year old Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5 fish, showing strong fluorescence in the hypothalamic region and optic commissure together with labeled endothelial cells of the vascular newtork. (L) Magnification of a representative olphactory bulb labeled in a representative one year old Tg(7xTCF-Xla.Siam:nlsmCherry)^ia5 fish. MHB: midbrain-hindbrain boundary; e: eye; fb: fin bud; e:eye; gf: gill filaments; gr:gill rackers; lln:lateral line neuromasts; ob: olphactory bulb; och: optic commissure; ov: otic vesicle. poc: post-optic commissure; rpe: retinal pigmented epithelium.