The effects of temporally restricted feeding on hepatic gene expression of Cry1, Cry2 double KO mice

Restricted feeding impacts the hepatic circadian clock of WT mice. Cry1, Cry2 double KO mice lack a circadian clock and are thus expected to show rhythmical gene expression in the liver. Imposing a temporally restricted feeding schedule on these mice shows how the hepatic circadian clock and rhythmic food intake regulate rhythmic transcription in parallel Cry1, Cry2 double KO mice were entrained either to ad libitum or temporally restricted feeding (tRF) schedules. Food was made available to mice under the tRF regimen only between ZT(CT)1 and ZT(CT)9. Mice were then released into constant darkness while the respective feeding schedules were still maintained. Liver tissue was collected on the second day of constant darkness at the indicated timepoints. Total RNA was extracted and 5ug of RNA was used in the standard Affymetrix protocol for amplification, labeling and hybridization限食可影响野生型（Wild Type, WT）小鼠的肝脏生物钟。Cry1、Cry2双敲除（Knock Out, KO）小鼠缺失生物钟，其肝脏基因表达理论上应呈现节律性特征。向此类小鼠施加定时限食方案，可揭示肝脏生物钟与节律性进食如何协同调控节律性转录过程。Cry1、Cry2双敲除小鼠分别通过自由采食或定时限食（temporally restricted feeding, tRF）饲养方案完成节律同步。在定时限食方案下，小鼠仅可在ZT(CT)1至ZT(CT)9时段获取食物。随后将小鼠置于持续黑暗环境中，并维持原有饲养方案不变。于持续黑暗环境的次日，在指定时间点采集肝脏组织。提取总RNA后，取5μg RNA按照标准Affymetrix实验流程完成扩增、标记与杂交。