A. Northern blot analysis of Mbnl2 mRNA in selective tissues at night and during day. Rats were housed in a controlled lighting environment (LD 14:10). Total RNA was obtained from day tissues removed at ZT7 and night tissues removed at ZT19 under dim red light. RNA preparation and Northern blot analysis were performed as described in Materials and Methods. The blot was hybridized with a rat Mbnl2 probe. To normalize for RNA loading, blots were stripped and reprobed for 18S rRNA. Abbreviations are HIPPO, hippocampus; HYPO, hypothalamus; CTX cerebral cortex; CB, cerebellum; AD, adrenal gland; PG, pineal gland; PIT, pituitary gland; Muscle, skeletal muscle. Results are presented as the mean ± SE of three replicates. B. Radiochemical in situ hybridization histology of Mbnl2 mRNA in the rat brain. Animals were housed in a controlled lighting environment for two weeks (LD 12:12). The day sample is from an animal killed during daytime (ZT6) and the night one is from an animal killed during nighttime (ZT18). Scale bars, 1 mm. CB, cerebellImmuum; PG, pineal gland; CTX, cortex. For further details see the Materials and Methods section.