The spindle checkpoint is an evolutionarily conserved regulatory mechanism that ensures correct segregation of chromosomes at mitosis and meiosis. The kinetochore plays an integral role in spindle checkpoint signaling by integrating chromosome attachment to the spindle with cell cycle progression. A single kinetochore can inhibit cell cycle progression in the absence of proper spindle attachment or tension from bipolar orientation. Recent advances have shed light on how the kinetochore measures these situations, transduces a signal, and inhibits the entry into anaphase.
