Cell cycle-regulated gene expression in tobacco cells

Tobacco BY-2 cells can be highly synchronized by treatment with an inhibitor of DNA synthesis, aphidicolin. For comprehensive understanding of cell cycle-regulated gene expression in tobacco, microarray analysis was conducted in synchronized cultures of BY-2 cells. Cells were treated with aphidicolin for 24 hours to block the entry into and progression through the S phase. After release from the aphidicolin block, cells were sampled every 2 h from 0–16 h. cDNA probes prepared from these samples were hybridised to a custom-made16K microarray. We performed this procedure twice independently to identify transcripts that reproducibly showed similar cell cycle-regulated expression. A total of 883 putative cell cycle-regulated transcripts were identified from 16,896 duplicated spots on the microarrays. These transcripts could be categorised into 10 classes on the basis of transcript expression patterns in the cell cycle. Keywords: time course Synchronization experiments were repeated twice (experiments A and B). In each experiment, cells were sampled every 2 h during the culture periods (0-16 h), and used for microarray analysis.