Transcriptional regulation and function during the human cell cycle

We report here the transcriptional profiling of the cell cycle on a genome- wide scale in human fibroblasts. We identified approximately 700 genes that display transcriptional fluctuation with a periodicity consistent with tha t of the cell cycle. Systematic analysis of these genes revealed functional organization within groups of coregulated transcripts. A diverse set of cy toskeletal reorganization genes exhibit cell-cycle-dependent regulation, in dicating that biological pathways are redirected for the execution of cell division. Many genes involved in cell motility and remodeling of the extrac ellular matrix are expressed predominantly in M phase, indicating a mechani sm for balancing proliferative and invasive cellular behavior. Transcripts upregulated during S phase displayed extensive overlap with genes induced b y DNA damage; cell-cycle-regulated transcripts may therefore constitute coh erent programs used in response to external stimuli. Our data also provide clues to biological function for hundreds of previously uncharacterized hum an genes.