EGFR activation induces circadian time (CT) dependent and CT independent transcriptional programs in the SCN. Results for genes with expression changes detected at a False Discovery Rate (FDR) <2% (see Materials and methods). (a) Genes with expression levels modulated by CT but not EGF treatment. (b) Genes with expression responses to EGFR activation that were not CT-dependent. (c) Genes with expression levels modulated by EGFR activation at nighttime only. (d) Genes with expression levels modulated by EGFR activation during daytime only. (e) Genes up-regulated by EGFR activation during the circadian day and repressed at night. (f) Genes down-regulated by EGFR activation during the circadian day and induced at night. Blue and red shades represent negative and positive scaled log2-expression levels or expression differences, respectively. C.1 and C.2 represent daytime control rats whereas C.N1 and C.N2 represent nighttime control rats. E.1 and E.2 represent EGF-treated (20 nM, 1 hour) daytime rats while E.N1 and E.N2 represent EGF-treated nighttime rats. Log2-expression levels in these cases were scaled for each gene by first subtracting random components for each rat, and then subtracting the mean log2-expression level over all conditions. To facilitate comparisons between genes, these mean-zeroed expression levels were divided by their maximum absolute value. dE.1 and dE.2 represent scaled EGF-induced log-expression differences in daytime rats while dE.N1 and dE.N2 represent scaled EGF-induced log-expression differences in nighttime rats. To facilitate comparisons between genes, these expression differences were divided by their maximum absolute value. Genes are represented by gene symbols, except in cases where annotation was not available and clone IDs are given instead. Images were created using the free Treeview program . 1 displays the relativeanimal-animal variability in the expression responses for a selected subset of genes.
Zak et al. Genome Biology 2006 7:R48 doi:10.1186/gb-2006-7-6-r48