Transcriptome in 129sv and Crx-/- pineal gland at ZT (Zeitgeber time) 6 and ZT20

The cone-rod homeobox gene (Crx) encodes Crx, a transcription factor selectively expressed in two cell types, retinal photoreceptors and the melatonin secreting pinealocytes of the pineal gland. In this report the role of Crx in regulating gene expression in the mammalian pineal gland was extended using Affymetrix GeneChip technology. Deletion of Crx results in broad modulation of the mouse pineal transcriptome, including a >2-fold downregulation of 543 genes and a >2-fold upregulation of 745 genes. In addition to Crx, there was a >10-fold downregulation of 13 other genes. Of special interest was the discovery of a link between Crx and the homeobox gene Hoxc4, which was upregulated ~20-fold in the Crx-/- pineal gland. Analysis of night and day expression of genes indicated that a set of 51 genes exhibited differential expression in control animals.

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