This movie is a time-lapse series of phase contrast and fluorescence images (frame was taken every three minutes) of yeast growing on agarose pads under a fluorescence microscope. For a sense of scale, the yeast are typically several microns in diameter and divide approximately every 90 minutes. The yellow fluorescence is generated by yellow fluorescent protein (YFP), which is produced and controlled by a synthetic gene circuit built in the Buchler lab.