A time lapse experiment of Saccharomyces cerevisiae expressing GFP tagged Cln2. Cln2 is a G1 cyclin involved in regulation of the cell cycle; activates Cdc28p kinase to promote the G1 to S phase transition; late G1 specific expression depends on transcription factor complexes, MBF (Swi6p-Mbp1p) and SBF (Swi6p-Swi4p). These phase, gfp images are part of an image group that ranges from CIL:35620-35639. Note that there are additional groups showing time series of other cell cycle regulation proteins by the same authors in the Library.