Fig. 4. Downregulation of BMP expression by transgenic Noggin. In wild-type eyes, Bmp4 was highly expressed in E18 (A), P1 (C) and P7 (E) ciliary epithelia (CE). No apparent change in Bmp4 expression was detected in the CE of E18 transgenic eyes (B) but its transcripts were significantly downregulated in P1 (D) and P7 (F) eyes. Similarly, transgenic Noggin had no apparent effect on Bmp7 expression in the CE of E18 embryos (data not shown) but drastically downregulated its expression in the postnatal presumptive CE (compare H with G). Abbreviations: IE, iris epithelium; L, lens; NR, neural retina. Scale bars: 100 µm.