Expression changes (mRNA) of evaluation genes. A-C: Relative mRNA concentrations in the mouse neural retina were measured by qPCR (real time) for the developmental ages P2 and P25. Concentrations were normalized to the beta-Actin mRNA concentration. Bars indicate standard deviation for triplicate assays. Taqman chemistry was used for target specificity with hydrolysis probes that span exon junctions. Rho, Rcvn, Pde6b, and Sag1 are key markers of photoreceptor-specific gene expression. Genes are grouped to account for different scales of relative expression. Most genes had Pol-II peak signal ratios > 1.8, as determined from temporal Pol-II ChIP-on-Chip analysis, except for: Hdac9 (ratio 1.6), Hdac10 (ratio 1.7), and Grik2 (ratio 0.9, Table 1). Genes: Rhodopsin (Rho), Recoverin (Rcvrn), Retinoschisis 1 (Rs1), Phosphodiesterase 6b (Pde6b), S-antigen (Sag), Elongation of very long chain fatty acids-like 4 (Elovl4), D4, zinc and double PHD fingers, family 3 (Dpf3), Spectrin repeat containing, nuclear envelope 1 (Syne1), Solute carrier family 38, Na/H -coupled glutamine transporter, member 3 (Slc38a3), Family with sequence similarity 53, member B (A930008G19Rik, Fam53b), Nuclear receptor subfamily 1, group D, member 1 (Nr1d1), Jumonji domain containing 2C (Jmjd2c), Histone deacetylase 9 (Hdac9), Bardet-Biedl syndrome 9 (E130103I17Rik, Bbs9), Histone deacetylase 10 (Hdac10), Glutamate receptor, ionotropic, kainate 2 (beta 2) (Grik2), Solute carrier family 24, Na/K/Ca exchanger, member 1 (Slc24a1).