The long-term goal of this ROW Career Advancement Award is to determine how the Kinetochore region of a eucaryotic chromosome associates with a spindle fiber to ensure proper chromosome segregation. Eventually, the investigator will investigate the role the kinetochore plays in organizing the chromosomes in the nucleus during interphase. This specific project will make use of both genetic and biochemical approaches. Antibodies will be prepared and used to determine the cellular location of proteins for various mutant cells and will facilitate the isolation of components with which the proteins interact. These powerful approaches will permit direct investigation of the requirements for kinetochore assembly and function in yeast. This approach, combined with classical genetic approaches, make yeast an excellent model eucaryotic system for determining the molecular mechanisms underlying successful cell division.