FIGURE 1.

A, Nrl upstream promoter/enhancer sequence showing three major conserved regions. Conservation diagram of Nrl promoter sequence displays sequence homology among different vertebrates. B, in vivo dissection of promoter activity of conserved sequence clusters. One or more clusters of the mouse Nrl promoter sequence were used for generating the reporter constructs. Representative sections from neonatal mouse retina, transfected in vivo with three different Nrl promoter lengths −304 to +119 (a′), −938 to +119 (b′), and −2734 to +119 (c′), are shown. C, non-overlapping expression of cone arrestin (CAR) and EGFP expression driven by the Nrl promoter (−938 to +119). Retinas were harvested at P14 for examining the expression of the reporter gene. CAG-mCherry is used to indicate the transfected cells. Scale bars, 20 μm. ONL, outer nuclear layer; GCL, ganglion cell layer; INL, inner nuclear layer.