Preface

The accurate segregation of replicated chromosomes (sister chromatids) during cell division guarantees a correct number of chromosomes in subsequent generations of cells. Importantly, errors made during this process lead to aneuploid progeny with abnormal chromosome numbers, which can either cause genetic diseases, or, in the case of somatic cells, cause diseases such as cancer. For example, virtually all solid tumors known to date are aneuploid, suggesting that chromosome missegregation underlies or contributes to the initiation and/or progression of cancer. Kinetochores are highly conserved multi-protein structures that form on the centromeric regions of sister chromatid pairs. Kinetochores orchestrate sister chromatid segregation and ensure that cellular ploidy is maintained. Following the identification of the first three kinetochore proteins in 1985 by one of us, 80–100 proteins (depending on the species) have now been localized to centromeres. These proteins act either as structural kinetochore or centromere components, or as regulators of centromere establishment, and kinetochor