chromatin

Definitions

  • WordNet 3.6
    • n chromatin the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins; during mitotic division it condenses into chromosomes
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Webster's Revised Unabridged Dictionary
    • n Chromatin (Biol) The deeply staining substance of the nucleus and chromosomes of eukaryotic cells, composed of DNA and basic proteins (such as histones), the DNA of which comprises the predominant physical basis of inheritance. It was, at the beginning of the 20th century, supposed to be the same substance as was then termed idioplasm or germ plasm. In most eukaryotic cells, there is also DNA in certain plasmids, such as mitochondria, or (in plant cells) chloroplasts; but with the exception of these cytoplasmic genetic factors, the nuclear DNA of the chromatin is believed to contain all the genetic information required to code for the development of an adult organism. In the interphase nucleus the chromosomes are dispersed, but during cell division or meiosis they are condensed into the individually recognizable chromosomes. The set of chromosomes, or a photographic representation of the full set of chromosomes of a cell (often ordered for presentation) is called a karyotype.
    • Chromatin (Biol) Tissue which is capable of being stained by dyes.
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Century Dictionary and Cyclopedia
    • n chromatin In bot, a name proposed for that portion of the substance of the nucleus which is readily colored by staining agents.
    • n chromatin In zoology, that portion of the substance of an ovum which has a special affinity for coloring matter and readily becomes colored; chromophilous protoplasm, which in the process of maturation of the ovum forms various colored figures, as disks and threads: the opposite of achromatin.
    • n chromatin In cytology, that portion of the cell-nucleus in animals and plants which takes on a deep color in certain stains (carmine, hematoxylin, etc.): opposed to achromatin.
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Etymology

Webster's Revised Unabridged Dictionary
Gr. , , color

Usage

In literature:

Half the chromatin material passes into each of the two cells formed.
"Taboo and Genetics" by Melvin Moses Knight, Iva Lowther Peters, and Phyllis Mary Blanchard
Of all parts of the cell this chromatin is the most remarkable.
"The Story of the Living Machine" by H. W. Conn
The nucleus is large and ellipsoidal, with characteristic longitudinal markings of chromatin.
"Marine Protozoa from Woods Hole" by Gary N. Calkins
Chromatin: the minute granules that make up the chromoplasm of a cell nucleus.
"Explanation of Terms Used in Entomology" by John. B. Smith
The chromatin in both pronuclei now forms into a skein.
"Darwin, and After Darwin (Vol. 1 and 3, of 3)" by George John Romanes
It usually contains no chromosomes and often too little chromatin, so that it perishes when conjugation does not occur.
"The Sexual Question" by August Forel
In one giant cell four unusually large combinations of this kind were found, and a corresponding amount of chromatin in the spireme.
"Studies in Spermatogenesis (Part 1 of 2)" by Nettie Maria Stevens
Figure 79 is a very young spermatid showing only diffuse chromatin in the nucleus.
"Studies in Spermatogenesis" by Nettie Maria Stevens
That which is not in the hemoglobin is chiefly found in the chromatin substances of the cells.
"Dietetics for Nurses" by Fairfax T. Proudfit
The fragmented chromatin has lost its affinity for stains, remaining always paler than that of the normal spirochaetes.
"Handbook of Medical Entomology" by William Albert Riley
A long loop of chromatin then appears in each nucleus and divides up into twelve pieces, the chromosomes.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3" by Various
Chromosomes, definite, visible bodies, as which the chromatin of a dividing nucleus appears, xiv, 93.
"The Biological Problem of To-day" by Oscar Hertwig
We must therefore distinguish in the cell between "young" and "adult" chromatin.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8" by Various
When the chromatin is in this shape, a loop is called a chromosome.
"Essays In Pastoral Medicine" by Austin ÓMalley
The germ-plasm resides in the nucleus of cells, and Weismann identifies it with the nuclear material named chromatin.
"Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 3" by Various
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In news:

Epigenetics Tool for the Rapid Determination of Chromatin State for Gene-Expression Studies.
genengnews.com
Sororin Is Required for Stable Binding of Cohesin to Chromatin and for Sister Chromatid Cohesion in Interphase.
cell.com
At least two talks at the Keystone Symposium Conference on Epigenetics and Chromatin Remodeling in Development implicate the power of tandem repeats in RNA-interference induced silencing.
the-scientist.com
While chromatin is well known for the role it plays in controlling genes, it was not previously suspected of being affected by circadian cycles.
rdmag.com
flank of mouse H19 in an unusual chromatin conformation unidirectionally blocks enhancer–promoter communication.
cell.com
Df31 Protein and snoRNAs Maintain Accessible Higher-Order Structures of Chromatin.
cell.com
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In science:

One approach has been to model the chromatin fibre as a random walk in confined geometry .
A Random Loop Model for Long Polymers
Polymer modelling makes use of a coarse-graining approach, i.e. we divide the chromatin fibre into N equal subunits of length b.
A Random Loop Model for Long Polymers
Such a description of a biological polymer is correct when we make N sufficient small so that b is larger than the persistence length of chromatin, i.e., the bending energy vanishes on this length scale.
A Random Loop Model for Long Polymers
In all cases, chromatin loop formation is a dynamic process .
A Random Loop Model for Long Polymers
The model takes into account the looping of the polymer, i.e. the chromatin fibre.
A Random Loop Model for Long Polymers
Our model assumes the chromatin fibre to have a random walk backbone, meaning that κij = κ with |i − j | = 1.
A Random Loop Model for Long Polymers
Furthermore the chromatin forms loops whose size and positions are randomly distributed along the chain.
A Random Loop Model for Long Polymers
In this paper we present a polymer model for the folding of the chromatin fibre in the interphase nucleus, based on recent experimental results .
A Random Loop Model for Long Polymers
This model has been used later (see, for instance, [16, 17]) to describe self–similar hierarchical organization in some biopolymers, like DNA and chromatin.
On scale-free and poly-scale behaviors of random hierarchical network
The heterogeneity of mouse-chromatin nonhistone proteins as evidenced by two-dimensional polyacrylamide-gel electrophoresis and ion-exchange chromatography.
Variations on a theme: Changes to electrophoretic separations that can make a difference
The DNA is usually supercoiled in the form of chromatin or a chromosome, depending the organism or its stage of cell divison (sic).
Biological Concepts Instrument (BCI): A diagnostic tool for revealing student thinking
Ca jal body dynamics and association with chromatin are ATP-dependent.
Anomalous subdiffusion due to obstacles : A critical survey
We also study the dynamics of the boundary between the two locally stable states of chromatin: silenced and unsilenced.
Epigenetic Chromatin Silencing: Bistability and Front Propagation
The model could be of use in guiding the discussion on chromatin silencing in general.
Epigenetic Chromatin Silencing: Bistability and Front Propagation
After submitting this manuscript for publication, we noted a recently published paper on a model for chromatin silencing in S. pombe.
Epigenetic Chromatin Silencing: Bistability and Front Propagation
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