PAX6 and MITF/TFEC together suppress <i>Fgf15 and Dkk3</i> in the developing RPE.

<p>(A,B) Quantitative RT-PCR of <i>Fgf15</i> and <i>Dkk3</i> RNA of E11.5 RPE fractions of wild type and indicated mutants. Mean, S.D. and statistical significance based on 3 biological replicates. (C–N) In situ hybridization for <i>Fgf15</i> (C–H) and <i>Dkk3</i> (I–N) on eye sections of E11.5 embryos of the indicated genotypes. Arrows in E–G,K–M point to the RPE (note ectopic <i>Fgf15</i> expression in the RPE of <i>Pax6^Sey-Neu/Mitf^mi-vga9</i> double mutant in F and ectopic <i>Dkk3</i> expression in the RPE of <i>Pax6^Sey-Neu/Mitf^mi-vga9</i> double mutant in L). Scale bar (C–N):115 µm. (O) Schematic representation of <i>Fgf15</i> and <i>Dkk3</i> enhancer/promoter regions showing amplicons containing conserved potential binding sites for MITF (▪) and PAX6 (consensus , non-consensus ), with positions indicated relative to translation start sites. (P) ChIP assays performed with indicated antibodies on RPE fractions dissected from E11.5 wild-type embryonic eyes. Amplicons as indicated in (O). (Q) ChIP assays performed with the indicated antibodies on optic vesicle tissue dissected from E10.5 embryonic eyes of the indicated genotypes. Anti-acetyl H3 signal represents active chromatin domains and anti-dimethyl H3K9 signal inactive chromatin domains. For details see text.