Figure 5. Expression of cone markers and Crx by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. The expression value of each bar was compared to its respective age-matched lean rat which is taken as 1 (or 100%) for calculating the fold change. A: Expression of cone-specific genes (Opnl MW and Gnat2) and rod–cone transcriptional marker Crx in 3-,6-, 12- and 15-month-old WNIN/GR-Ob rats. Data represent fold change (mean ± standard deviation [SD]) over respective age-matched lean rats (n = 3; “*” p<0.05). “*” significantly different from the respective age-matched lean rats at p≤0.05. B: Immunohistochemical evaluation of expression of cone marker M-opsin in 12-month-old WNIN/GR-Ob and respective lean rats. Nuclei are labeled with 4,6-diamidino-2-phenylindole (DAPI). Arrows indicate staining of M-opsin. Scale bar, 50 µm.