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The fundamental histone-containing structural subunit of eukaryotic chromosomes. In most eukaryotic organisms, nuclear deoxyribonucleic acid (DNA) is complexed with an approximately equal mass of histone protein. The nucleosome is organized so that the DNA is exterior and the histones interior. The DNA makes two turns around a core of eight histone molecules, thus forming a squat cylinder 11 nanometers in diameter and 5.5 nm in height. A short length of linker or spacer DNA connects one nucleosome to the next, forming a nucleosomal chain that has been likened to a beaded string. This basic structure is found in all forms of chromatin. Nucleosomes have been found in all eukaryotic organisms examined, the only exceptions being some sperm nuclei and the dinoflagellate algae.

A chain of adjacent nucleosomes is approximately sixfold shorter than the DNA it contains. Moreover, chains of nucleosomes have the property of self-assembling into thicker fibers in which the DNA packing ratio approaches 35:1. These observations, and the lack of any obvious catalytic activity, have led to the assumption that the primary function of the nucleosome consists of organizing and packing DNA. See Chromosome, Deoxyribonucleic acid (DNA), Gene


(cell and molecular biology)
A morphologically repeating unit of deoxyribonucleic acid (DNA) containing 190 base pairs of DNA folded together with eight histone molecules. Also known as v-body.
References in periodicals archive ?
The fundamental unit of chromatin is the nucleosome, where 146 bp of DNA are wrapped around a histone octamer core, comprised of two of each core histones, H2A, H2B, H3 and H4, while its structure is completed with the association of H1 linker histone (Wolffe & Guschin, 2000).
Both DNA and protein components of the nucleosome are subject to a variety of modifications that can influence chromatin conformation and accessibility.
Even though nucleosomes are considered to be the main antigens in the pathophysiology of systemic lupus erythematosus (SLE), some investigators have also found these in systemic sclerosis (SSc).
In the opposite direction, nucleosomes can cluster to form large aggregates of "closed" chromatin or heterochromatin, where transcription is prevented.
Made up of histone, a kind of protein, the nucleosomes are repeating units around which the double helix of DNA gets wrapped and vast amounts of genetic information get organized.
There is a strong association between proliferative LGN and serologic findings of high-titer anti-nuclear antibodies and double-stranded anti-DNA antibodies, complexed primarily with nucleosomes and histones.
presence in the blood of nucleosomes associated with particular histone
Distinguishing features of apoptosis and necrosis Feature Apoptosis Necrosis General Genetically programmed, Accidental cell death description orderly process of cell caused by acute injury or death other exogenous effect Membrane Preserved until late in Early loss results in cell integrity cell breakdown process and organelle swelling and rupture Chromosomal Cleavage at nucleosomes Random fragmentation DNA produces ladder pattern on produces smear pattern an agarose gel Inflammatory None; products have Release of intracellular response antiinflammatory effect contents causes acute inflammatory response Table 2.
Nucleosomes, the fundamental unit of eukaryotic chromatin, are composed primarily of DNA and histones.
The PerkinElmer assays cover all the major writer and eraser enzyme families and can be used across a range of substrates, from peptides to histones to full nucleosomes.
The epigenetic mechanisms underlying the transmission of such traits over one or multiple generations are largely unknown but DNA methylation, RNA and nucleosomes have been proposed as mediators of such inheritance.