Onset timing of transient gene expression depends on cell division

By using the time lapse of both phase-contrast and fluorescent images, we examined the morphology of cells and the dynamics of gene expression (EGFP). We applied k-means clustering to the time course data of fluorescent intensity of EGFP and successfully found four subpopulations. Discriminating the appropriate clusters and investigating the details of them, we found that almost all cells express the transfected gene after cell division and also found there is a strong correlation between onset timing and cell division. This result suggested that it is possible to normalize the dynamics of gene by arranging the onset timing of gene expression or by arranging the cell division.