Circadian clocks were recently discovered in the rat and mouse colon as well as mouse stomach and jejunum. The aim of this study was to determine whether clocks in the upper part of the gut are synchronized with those in the lower part, or whether there is a difference in their circadian phases. Moreover, the profiles of core clock-gene expression were compared with the profiles of the clock-driven Wee1 gene expression in the upper and lower parts of the gut. Adult rats were transferred to constant darkness on the day of sampling. 24 h expression profiles of the clock genes Per1, Per2, Rev-erbalpha, and Bmal1 and the cell-cycle regulator Wee1 were examined by a reverse transcriptase-polymerase chain reaction within the epithelium of the rat duodenum, ileum, jejunum, and colon. In contrast to the duodenum, the rhythms in expression of all genes but Rev-erbalpha and Bmal1 in the colon exhibited non-sinusoidal profiles. Therefore, a detailed analysis of the gene expression every 1 h within the 12 h interval corresponding to the previous lights-on was performed. The data demonstrate that rhythmic profiles of the clock gene Per1, Per2, Bmal1, Rev-erbalpha, and clock-driven Wee1 expression within the epithelium from different parts of the rat gut exhibited a difference in phasing, such that the upper part of the gut, as represented by the duodenum, was phase-advanced to the lower part, as represented by the distal colon. Our data demonstrate that the circadian clocks within each part of the gut are mutually synchronized with a phase delay in the cranio-caudal axis. Moreover, they support the view that the individual circadian clocks may control the timing of cell cycle within different regions of the gut.

• MeSH
• cirkadiánní rytmus genetika   fyziologie   MeSH
• DNA primery MeSH
• duodenum fyziologie   MeSH
• gastrointestinální motilita MeSH
• gastrointestinální trakt fyziologie   MeSH
• ileum fyziologie   MeSH
• jaderné proteiny genetika   MeSH
• jejunum fyziologie   MeSH
• kolon fyziologie   MeSH
• krysa rodu Rattus MeSH
• messenger RNA genetika   izolace a purifikace   MeSH
• myši MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• potkani Wistar MeSH
• proteiny buněčného cyklu genetika   MeSH
• střevní sliznice fyziologie   MeSH
• světlo MeSH
• tma MeSH
• tyrosinkinasy genetika   MeSH
• žaludeční sliznice fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA primery MeSH
• jaderné proteiny MeSH
• messenger RNA MeSH
• proteiny buněčného cyklu MeSH
• tyrosinkinasy MeSH
• Wee1 protein, mouse MeSH Prohlížeč