Abstract
In eukaryotes, chromatin is essential for heredity. Chromatin architecture is sometimes "epistatic" over the DNA and imparts a different heritable state to the same DNA sequence or the same functional state to unrelated DNA sequences. This has been documented recently in a wide variety of studies focused on regulation of the yeast mating type, the function of Polycomb and trithorax group proteins, the specification of eukaryotic centromeres and neocentromeres, and genomic imprinting.
