Fig. 3.
Circadian behaviors were altered in the miR-183/96/182 cluster–deficient mice. (A–C) Representative wheel-running locomotor activity profiles of homozygous wild-type, heterozygous, and homozygous gene-trap mice (miR-183C+/+, n = 14; miR-183CGT/+, n = 22; miR-183CGT/GT, n = 10). Animals were maintained on LD12:12 entrained conditions for the first week, indicated by the yellow filled and open area in the records, and then were released to constant darkness (DD) for 3 wk to measure free-running periods. (D) Diurnal wheel-running activity profiles under the entrained condition. Wheel-running activities were normalized to the highest activity level of each animal and then averaged across 7 d prior to DD. (E) Free-running periods under constant darkness. The free-running period of heterozygous mice was significantly shorter than that of wild-type mice (t test: *P = 0.004). The miR-183CGT/GT mice became arrhythmic (AR) after release into DD. (F) Beam-break total activities of homozygous wild-type and gene-trap mice (miR-183C+/+, n = 4; miR-183CGT/GT, n = 4). Animals were maintained on LD12:12 for the first 7 d, indicated by the gray and white shading, and then released to DD for 14 d. The red and black curves denote the mean activities of mutant mice and wild-type mice, respectively. The light red and light gray vertical lines denote the SD of the mean activities of mutant mice and wild-type mice, respectively. (G) Circadian periodicity of the beam-break total activity DD condition was detected by Lomb–Scargle periodogram. Activity of miR-183CGT/GT in the second week of DD did not pass the threshold for period detection. PN on y-axis stands for normalized power. (H) Diurnal beam-break total activity profiles under the entrained condition. Activities were normalized to the highest activity level of each animal and then averaged across 7 d prior to DD. Data represent the mean ± SD.