BMAL1 ChIP assays were performed with 107 cells using Magna ChIP-seq kit (Millipore, 17-10085) according to manufacturer's instruction. Briefly, cells were fixed with 1% formaldehyde at room temperature for 10 minutes, and subsequently quenched with 0.125M glycine. Then, the cells were washed with cold PBS and suspended with lysis buffer supplemented with Protease Inhibitor Cocktail II. Chromatin was sonicated to obtain DNA fragments with an average length of 200-500 bp for sequencing by Bioruptor Plus sonication device (Diagenode) followed by centrifugation for clearing. Soluble fraction of sheared chromatin was diluted 10-fold with ChIP dilution buffer and incubated with BMAL1 antibody (Cell Signaling Technology) and EZ-Magna ChIP A/G magnetic beads overnight at 4°C with rotation. Chromatin-captured beads were washed once with low salt wash buffer, once with high salt wash buffer, once with LiCl wash buffer and twice with TE buffer for 5 min each by rotation at 4°C. Beads were resuspended in elution buffer and removed by magnet. Proteinase K was added to the eluted DNA followed by incubation at 62°C for 4 hours with shaking. Then the eluted DNA was incubated at 95°C for 10 min to remove RNA. Reverse-crosslinked DNA was purified by using purification columns. Eluted DNA was used to do quantitative PCR (qPCR) or sequencing library preparation. ChIP quantitative RT-PCR was performed by using SYBR Green PCR Master Mix (ABI, 4309155). qPCR primers were listed as Table S1. Then sequencing libraries were prepared by using ThruPLEX® NGS Library Preparation Kits (Rubicon Genomics, R400427) according to manufacturer's instruction. ChIP-seq libraries were sequenced on Illumima HiSeq platform by Genewiz. Then sequencing libraries were prepared by using ThruPLEX® NGS Library Preparation Kits (Rubicon Genomics, R400427) according to manufacturer's instruction. ChIP-seq libraries were sequenced on Illumima HiSeq platform by Genewiz.