Comprehensive Transcriptional Analysis Reveals Gene-Specific Transcriptional Variations In A Seed Plant, Arabidopsis Thaliana

The multicellular biological organism comprises a number of cells connected, while each cell independently works. It seems to have a system to orchestrate a number of cells, like a parallel multi-agent intelligent system. In such a biological system, gene expression of even identical genes within homogeneous cell populations is varied due to a stochastic fluctuation of the transcriptional process. This gene expression variation (GEV) is observed in development, cell differentiation, and environmental responses. Although the GEV has been generally reported, a gene-specific GEV remains unclear. Using publicly available genome-wide gene expression data from a model plant, Arabidopsis thaliana, we successfully identified two groups of genes whose GEVs demonstrated consistently high and low. Analysis of 632 experimental conditions derived from more than 1,300 microarrays revealed that 65 and 296 genes had high and low GEVs, respectively. We named genes with the high GEV DOTABATA (DTBT), which means "romping about" in Japanese, and genes with the low GEV PISHIPASHI (PSPS), which means "over-discipline" in Japanese. Gene function enrichment analysis resulted that DTBT genes significantly enriched stress response genes. Our results suggest a gene-specific GEV, and the regulation of GEV would be involved in biological processes.