heterochromatin The chromosome material that accepts stains in the interphase nucleus (unlike euchromatin). Such regions, particularly those containing the centromeric and nucleolus organizers, may adhere to form a chromocentre. Some chromosomes are composed primarily of heterochromatin: these are termed heterochromosomes. In many species, the Y chromosome is a heterochromosome.

heterochromatin Chromosome material that accepts stains in the interphase nucleus (unlike euchromatin). Such regions, particularly those containing the centromeric and nucleolus organizers, may adhere to form a chromocentre. Some chromosomes are composed primarily of heterochromatin: these are termed heterochromosomes. In many species, the Y-chromosome is a heterochromosome.

heterochromatin See chromatin.