| We have used Chinese hamster ovary (CHO)-human hybrid cells containing chromosomes 16, 18, X, or 21 to test the ability of human kinetochores to successfully bind to spindle microtubules and to be distributed to the daughter cells. We have established the intrinsic rate of non-disjunction among these chromosomes and compared these rates with those in cells presented with mitotic challenges. Cells were grown on culture slides, fixed and processed for immunofluorescence and fluorescence in situ hybridization (FISH). Daughter pairs were identified by staining with anti-alpha-tubulin to identify midbodies. Human centromere DNA probes were used for FISH in order to test for the successful passage of human kinetochores to daughter cells. Our data indicate that different human kinetochores vary in their ability to properly engage the spindle and to be successfully distributed. In addition, mitotic challenges have been shown to affect the rate of non-disjunction. |
