Centromere

Chromosomal components:

(1)Chromatid
(2)Centromere
(3) Short arm
(4) Long arm

Thecentromereis a special region of achromosome,usually near the middle. It is where the two identical sisterchromatidsstay in contact as the chromosome attaches to thespindleinmitosis.The region contains specific types ofDNA,which are tandem repetitive sequences (satellite DNA). These sequences bind specificproteins called "cen" -proteins.

During mitosis the centromeres can be seen during themetaphasestage as a constriction at the chromosome. At this centromeric constriction the two halves of the chromosome, the sister chromatids, are held together until latemetaphase.