Fig. 5. Effect of RA, PITX2 and Ad4BP/SF-1 on cyclin D1 expression.(A-H) Beads soaked in RA (B), RAA (C) and DMSO (D), and chick embryonic fibroblasts expressing Pitx2 (E), Pitx2-en (F), Ad4BP/SF-1 (G) and AP (H) were implanted into embryos of both sexes as described in the legends to Figs 2 and 3. An untreated embryo is shown in A. Embryos were fixed at stage 27, and cyclin D1 expression was examined by whole-mount in situ hybridization. Sections of female (ZW) samples are shown. Arrowheads (B,C,E-G) indicate altered expression of cyclin D1. Scale bars: 100 µm.