Kinetochores

Not to be confused with1⁄4 centrosomes. But it’s OK to confuse them with centromeres. The centromere is the chromosomal domain where the kinetochore is assembled. Genetically speaking, the centromere is the locus necessary to segregate chromosomes. In many species, the centromere is also defined cytologically as the primary constriction visible on condensed chromosomes (the intersection point of the classical X-shaped chromosome) — this is also the point where one observes connection to spindle microtubules. Probably the most commonsensical definition describes the kinetochore as the protein machine that assembles on centromeric DNA during mitosis/meiosis.