Résumé
Living organisms grow and divide to produce genetically identical progeny. To divide continuously, a eukaryotic cell must duplicate all of its constituents including DNA, proteins, ribosomes, organelles, etc., and segregate them more or less equally to daughter cells. To perpetuate its genetic information, a cell must, how-ever, duplicate and segregate its chromosomes with high fidelity 10-6 mutation/bp and 10-5 chromosome loss/ cell division in yeast). An important question in cell biology is therefore how cells manage to replicate and segregate faithfully their chromo-somes? Furthermore, how is cell division regulated by cell growth and external conditions? This formidable task is achieved following the instructions of a programme, the cell cycle, which integrates the many biochemical events needed for chromosome duplication, transmission, and cell separation over time and space. For example, this programme ensures that DNA is replicated before sister chromatids begin to separate, or that sisters move to opposite poles.