Fig. 4.

Lack of mPer1 light-inducibility in the retina of clock/clock mutant mice. (A) Retinal expression patterns of mPer1 at CT18 before and after a 30-min light pulse in WT and clock/clock (c/c) mice. Retinal sections (10 μm) were examined for mPer1 RNA by in situ hybridization using an antisense probe. ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer. (Scale bar, 100 μm.) (B) Light regulation of mPer1 expression in the eye of WT and clock/clock mice. RPA analysis of mPer1 and β-actin before and after a 30-min light pulse given at CT18.