Data from: Temporal transcriptomics suggest that twin-peaking genes reset the clock

The mammalian suprachiasmatic nucleus (SCN) drives daily rhythmic behavior and physiology, yet a detailed understanding of its coordinated transcriptional programmes is lacking. To reveal the finer details of circadian variation in the mammalian SCN transcriptome we combined laser-capture microdissection and RNA-seq over a 24-hour light/dark cycle. We show that 7-times more genes exhibited a classic sinusoidal expression signature than previously observed in the SCN. Another group of 766 genes unexpectedly peaked twice, near both the start and end of the dark phase; this twin-peaking group is significantly enriched for synaptic transmission genes that are crucial for light-induced phase shifting of the circadian clock. 341 intergenic non-coding RNAs, together with novel exons of annotated protein-coding genes, including Cry1, also show specific circadian expression variation. Overall, our data provide an important chronobiological resource (www.wgpembroke.com/shiny/SCNseq/) and allow us to propose that transcriptional timing in the SCN is gating clock resetting mechanisms.

哺乳动物视交叉上核（suprachiasmatic nucleus, SCN）调控每日节律性行为与生理活动，但目前学界对其协同转录程序的精细调控机制仍缺乏全面认知。为揭示哺乳动物视交叉上核转录组中昼夜节律变化的精细细节，本研究结合激光捕获显微切割（laser-capture microdissection）技术与RNA测序（RNA-seq），在24小时光暗周期内开展了多时间点采样分析。研究发现，呈现经典正弦表达模式的基因数量较此前在视交叉上核中的报道高出7倍。另有766个基因呈现出意想不到的双峰表达模式，其表达峰值分别出现在暗期的起始与临近结束阶段；该双峰基因集显著富集于突触传递相关基因，而这类基因对于生物钟的光诱导相位偏移至关重要。此外，341个基因间非编码RNA（intergenic non-coding RNAs）以及部分已注释蛋白编码基因的全新外显子（如隐花色素1（Cry1）），也呈现出特异性的昼夜节律表达变化。综上，本研究的数据提供了一个重要的时间生物学（chronobiology）研究资源库（www.wgpembroke.com/shiny/SCNseq/），并支持我们提出假说：视交叉上核内的转录时序对生物钟重置机制具有门控调控作用。