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Fig. 7. Cyclopamine treatment leads to proximodistal defects. A brightfield view of a retina of an embryo incubated in cyclopamine from the two-cell stage (B) shows no closure of the ventral RPE (arrowhead) and ectopic pigment in the central retina (arrow) compared with a control retina (A). In situ hybridisation or immunostaining on retinal sections of stage 39 embryos incubated in cyclopamine solution from the two-cell stage (D,F,H,J,L) or control embryos (C,E,G,I,K). The probes or the antibodies are indicated for each panel. All sections are 12 μm cryostat sections except in E,F,I,J, which are 50 μm vibratome sections. Pax2 expression is strongly reduced in the cyclopamine-treated retina. Only a faint expression remains (arrow in D). Pax6 expression invades the optic stalk region (arrow in F). Ectopic photoreceptors are detected in the optic stalk region (arrowhead in H) and in the central retina along the ectopic pigment (arrow in H). Brn3.0 expression is detected in the optic stalk region (arrow in J). Vax2 expression is also moved towards the optic stalk region (arrowhead in L) but is still present and restricted to the ventral part only, as in the control (K). The dorsoventral borders are indicated with arrows in K and L. |
