| |
Fig. 3. ckie and ckid are expressed constitutively in the photoreceptors of the
Xenopus retina. (A) Total RNA was isolated from retinas collected at 4-h
intervals throughout a circadian cycle (Zeitgeber time [ZT] 0, 4, 8, 12, 16,
20). Three micrograms of pooled RNA (R) or RNA isolated at ZT 4, 8, 16,
and 20 were subjected to Northern blot analysis. Blots were probed with ckid
or ckie. Following the cki probes, the filters were stripped and reprobed with
a h-actin probe. Exposure time was 24 h for the cki panels. (B) X. laevis eyes
were dissected and fixed at ZT 16, and 12 Am sections were prepared. In situ
hybridization analysis was done with digoxygenin-labeled antisense or sense
ckid riboprobes. The white arrow indicates the labeling in the inner segments
of the photoreceptor cells. Retinal layers are labeled on the left: RPE, retinal
pigment epithelium; OS, photoreceptor outer segments; ONL, outer nuclear
layer (photoreceptor cell nuclei); INL, inner nuclear layer; and GCL,
ganglion cell layer. |
