Nobel Laureate Lee Hartwell Explains Cell Cycle Genes and Checkpoint Discovery

Leland Hartwell used genetic screening in yeast to identify a series of cell division cycle genes, the cdc mutations, breaking cell division into steps that can be analyzed. He introduced the checkpoint concept, showing that cells pause the cycle under stresses such as DNA damage, making checkpoints a pillar of cell quality control. Hartwell shared the 2001 Nobel Prize with Tim Hunt and Paul Nurse for these discoveries in cell cycle regulation.