Dataset Information

Exploring the transcriptional landscape of plant circadian rhythms using genome tiling arrays

ABSTRACT: A casual look at the behavior and function of animals and plants clearly shows that many physiological processes are periodic and tied to cyclical changes in a day. As suggested by the persistence of some rhythms in the absence of external cues, organisms are able to anticipate changes in the daily environment with an internal oscillator know as the circadian clock. Transcription is an important mechanism in maintaining these oscillations. Here we explore, using whole genome tiling arrays, the extent of rhythmic expression patterns genome wide, with an unbiased analysis of coding and noncoding regions of the Arabidopsis genome. As in previous studies, we detected a circadian rhythm for approximately 25% of the protein coding genes in the genome. With an unbiased interrogation of the genome, extensive rhythmic introns were detected predominantly in phase with adjacent rhythmic exons creating a transcript that if translated would be expected to produce a truncated protein. In some cases such as the MYB transcription factor PHOSPATE STARVATION RESPONSE1, an intron was found to exhibit a circadian rhythm while the remainder of the transcript was otherwise arrhythmic. In addition to several known non-coding transcripts including miRNA, trans-acting siRNA, and snoRNA, greater than one thousand intergenic regions were detected as circadian clock regulated, many of which have no predicted function, either coding or non-coding. Nearly 7% of the protein coding genes produced rhythmic antisense transcripts, often for genes whose sense strand was not similarly rhythmic. This study revealed widespread circadian clock regulation of the Arabidopsis genome extending well beyond the protein coding transcripts measured to date. This suggests a greater level of structural and temporal dynamics than previously known.

ORGANISM(S): Arabidopsis thaliana

PROVIDER: GSE13814 | GEO | 2008/12/06

SECONDARY ACCESSION(S): PRJNA110587

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Over the past decade, genome-wide assays have underscored the broad sweep of circadian gene expression. A substantial fraction of the transcriptome undergoes oscillations in many organisms and tissues, which governs the many biochemical, physiological and behavioral functions under circadian control. Based predominantly on the transcription feedback loops important for core circadian timekeeping, it is commonly assumed that this widespread mRNA cycling reflects circadian transcriptional cycling. To address this issue, we directly measured dynamic changes in mouse liver transcription using Nascent-Seq. Many genes are rhythmically transcribed over the 24h day, which include precursors of several non-coding RNAs as well as the expected set of core clock genes. Surprisingly however, nascent RNA rhythms overlap poorly with mRNA abundance rhythms assayed by RNA-seq. This is because most mouse liver genes with rhythmic mRNA expression manifest poor transcriptional rhythms, indicating a prominent role of post-transcriptional regulation in setting mRNA cycling amplitude. To gain further insight into circadian transcriptional regulation, we also characterized the rhythmic transcription of liver genes targeted by the transcription factors CLOCK and BMAL1; they directly target other core clock genes and sit at the top of the molecular circadian clock hierarchy in mammals. CLK:BMAL1 rhythmically bind at the same discrete phase of the circadian cycle to all target genes, which not surprisingly have a much higher percentage of rhythmic transcription than the genome as a whole. However, there is a surprisingly heterogeneous set of cycling transcription phases of direct target genes, which even include core clock genes. This indicates a disconnect between rhythmic DNA binding and the peak of transcription, which is likely due to other transcription factors that collaborate with CLK:BMAL1. In summary, the application of Nascent-Seq to a mammalian tissue provides surprising insights into the rhythmic control of gene expression and should have broad applications beyond the analysis of circadian rhythms. CLK and BMAL1 DNA binding profile in the mouse liver at ZT8, sequenced along an Input sample using GAII (ChIP-Seq) Supplementary file ChIPSeq_Mouse_Liver_Processed_data_Table1.txt represents annotated CLK and BMAL1 peaks.

Dataset Information

Exploring the transcriptional landscape of plant circadian rhythms using genome tiling arrays

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure