Fig. 5. (A-D) Tbx2b is regulated by Fz7. (A) TOP-flash assay shows a reduction of ß-catenin-dependent Tcf activity in fz7 morphants. (B) Expression of fz7 at 5.3 hpf (cross-section). (C) Expression of a dn-fz7-EGFP/BAC (red, see Materials and methods) caused the loss of tbx2b expression (blue) in the eye (arrow). (D) The absence of fz7 MO/fluorescein-injected cells in the eyes and CNS at 24 hpf is rescued by co-injection of tbx2b mRNA. (E) Real-time PCR analysis of Tbx2b and Fz7 morphants showed a decrease in tbx2b and fz7 transcripts in the presence of fz7 MO, but no effect from tbx2b MO at 5 hpf. n=15 for control, n=7 for tbx2b MO and n=4 for fz7 MO. (F-I) Rescue of cell movement defect by transplantation into wild-type host at shield stage. Wild-type donor cells differentiated into morphologically distinct cells in the eye (F) and hindbrain (G) by 24 hpf. By contrast, only a few Tbx2b-deficient cells differentiated into distinct eye (H) and hindbrain (I) cells (arrowheads).