Centromere

Centromere: The cinched "waist" of the chromosome essential for the division and the retention of the chromosome in the cell. The centromere is a uniquely specialized region of the chromosome to which spindle fibers attach during cell division.

The human centromere contains a 3-million-base stretch of DNA embedded in what has been called the centromere and that is all it takes to make a functional centromere. The nature of this core DNA indicates that, rather than being highly conserved, the centromere has changed significantly during primate evolution.