1. Insight Into the Circadian Clock Within Rat Colonic Epithelial Cells
Martin Sládek, Markéta Rybová, Zuzana Jindráková, Zdena Zemanová, Lenka Polidarová, Libor Mrnka, John O’Neill, Jiří Pácha, Alena Sumová 
Gastroenterology 
Volume 133, Issue 4, Pages (October 2007)
DOI: /j.gastro
Copyright © 2007 AGA Institute Terms and Conditions

2. Figure 1
Daily profiles of expression of clock genes Per1 (A–D), Per2 (E–H), Rev-erbα (I–L), Cry1 (M–P), Bmal1 (Q–T), and Clock (U–X) in the rat colon (left panel) and liver (right panel). Control animals (A, E, I, M, Q, U for colon; C, G, K, O, S, W for liver) had free access to food and water, whereas rats under restricted FR (B, F, J, N, R, V for colon; D, H, L, P, T, X for liver) had access to food limited only for 6 hours during the light period. Restricted feeding schedule continued for 14 days. Thereafter, the animals were released into darkness and killed in 4-hour intervals throughout the circadian day, and the mRNA levels were assessed by real-time RT-PCR. Circadian time is used to assess endogenous time in constant darkness; CT0 represents time of the original lights on and CT12 of lights off. Data are expressed as percentage of the maximum value. Each point represents mean of 3 animals ± SEM. Data for control liver samples were taken from Sladek et al.42
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

3. Figure 2
Daily profiles of Per1 (A), Per2 (B), and Bmal1 (C) mRNA in the SCN of rats under ad libitum (●) and restricted (○) feeding schedule (for details see Materials and Methods) were measured by in situ hybridization. The open bar indicates the original light and the solid bar the dark period. Circadian time is used to assess endogenous time in constant darkness; CT0 is assigned to the original time of lights on and CT12 to lights off. Data are expressed as relative OD measured in the SCN. Each point represents mean of 4 animals ± SEM.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

4. Figure 3
Expression of clock genes in the rat colonic epithelium. (A) Representative autoradiographs of colonic sections examined by ISH for Per1, Per2, Cry1 and Bmal1. Alternative sections were counterstained with methylene blue (Histo). Note that the hybridization signal in ISH matches the area of epithelial layer in HISTO. Examples of sections with the highest hybridization signal are shown. (B) Daily profile of Bmal1 mRNA levels in the rat colonic epithelium was assessed by ISH. The open bar indicates the original light period, the solid bar the dark period. Circadian time is used to assess endogenous time in constant darkness; CT0 is assigned to the original time of lights on and CT12 to lights off. Data are expressed as relative OD measured in the epithelial layer. Each point represents mean of 4 animals ± SEM. (C) Immunostaining of PER1 (a,b) and BMAL1 (c,d) proteins in the rat colonic epithelium. Immunopositive cells were localized selectively in the crypt epithelium. The intensity of PER1 and BMAL1 immunoreactivity was higher during the daytime than during the nighttime; ie, it was higher at CT2 (a) than at CT12 (b) for PER1, and at CT2 (c) than at CT14 (d) for BMAL1.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

5. Figure 4
Daily profiles of NHE3 expression in the colon of rats under ad libitum (A) and restricted (B) feeding schedule (for details see “Materials and Methods”) were assessed by real-time RT-PCR. The open bar indicates the original light and the solid bar the dark period. Circadian time used to assess endogenous time in constant darkness; CT0 is assigned to the original time of lights on and CT12 to lights off. Data are expressed as a percentage of the maximum value. Each point represents mean of 3 animals ± SEM.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions