Inheritance of Chromatin Structures

Although all somatic cells contain the same genetic information, the cells of the liver divide to form only liver cells, and skin cells divide into new skin cells.

Each tissue type has specific chromatin packaging and histone modifications which result in distinct gene expression patterns. 

These structural features of chromatin - such as the centromere, the heterochromatin, and  euchromatin regions - are epigenetically inherited, meaning their characteristics are passed from mother to daughter cell in addition to the genetic material. 

This means that the tissue specific phenotypes of liver or skin or other specialized cells are passed on during each round of cell division without the necessity for changes to the genetic material. 

De novo centromere formation on newly synthesized DNA begins with the binding of histone H3 variant CENP-A to the AT-rich satellite DNA to form centromere specific nucleosomes. Once initiated, the structure selectively recruits more CENP-A histones to its vicinity, in a cooperative manner. 

During DNA replication, the histone octamer ahead of the replication fork is broken down into two H2A-H2B dimers and H3-H4 tetramer. 

The two H2A-H2B dimers are comp