chromatin

chromatin /chro·ma·tin/ (kro´mah-tin) the substance of chromosomes, the portion of the cell nucleus that stains with basic dyes. See euchromatin and heterochromatin.

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sex chromatin  Barr body; the persistent mass of the inactivated X chromosome in cells of normal females.

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chro·ma·tin (krm-tn)

n.

A complex of nucleic acids and proteins in the cell nucleus that stains readily with basic dyes and condenses to form chromosomes during cell division.

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chromatin

[krō′mətin]

Etymology: Gk, chroma, color

the material within a cell nucleus from which the chromosomes are formed. It consists of fine, threadlike strands of DNA attached to proteins called histones and is readily stained with basic dyes. Chromatin occurs in two forms, euchromatin and heterochromatin, which are distinguishable during the phases of the cell cycle by their different degrees of staining, which in turn depends how tightly they are coiled. During cell division, portions of the chromatin condense and coil to form the chromosomes. Also called chromoplasm, karyotin. See also chromatid, euchromatin, heterochromatin, sex chromatin. chromatinic, adj.

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chromatin (krō´mtin),

n the genetic material present in the nucleus, consisting of DNA and associated proteins, seen as irregular clumps in quiescent cells.

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chromatin

the substance of the chromosomes, composed of nucleic acids and basic proteins (histones), the material in the nucleus that stains with basic dyes.

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sex chromatin

Barr body; the persistent mass of the material of the inactivated X chromosome in cells of normal females. See also drumstick.

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chromatin

Genetics The stainable material of interphase nuclei corresponding to chromosomes; chromatin consists of nucleic acids–DNA and associated histone protein, which are packed into nucleosomes; euchromatin is loosely packed and accessible to RNA polymerases. See Salt & pepper chromatin. Cf Heterochromatin.