Chromatin found chromosomes take extrachromosomal inheritance. Medical search. Frequent questions

The new findings appeared November 20 in Nature , in an article titled, " Circular ecDNA promotes accessible chromatin and high oncogene expression . (genengnews.com)

The finding surprised cancer biologists who had long focused more on which genes promote cancer rather than where those genes are located. (genengnews.com)
That was the beginning of the epigenetic revolution [1] ( Epigenetic Inheritance - What Genes Remember , SiS 41). (i-sis.org.uk)
We found that ecDNAs contained diverse collections of oncogenes and immunomodulatory genes. (nature.com)
Control of gene expression at transcription and translation level (regulating the expression of phages, viruses, prokaryotic and eukaryotic genes, role of chromatin in gene expression and gene silencing). (aadharinstitute.com)
Whithout mutations we would know very little about inheritance and the existence of genes. (intechopen.com)
These chemical modifications of chromatin influence its three-dimensional structure, which in turn governs its accessibility for DNA transcription and dictates whether genes are expressed or not. (entheohealing.com)
[7] All Y-linked genes are expressed and (apart from duplicated genes) hemizygous (present on only one chromosome) except in the cases of aneuploidy such as XYY syndrome or XXYY syndrome . (iiab.me)
The Y chromosomes of humans and other mammals also contain other genes needed for normal sperm production. (iiab.me)
Over time, genes that were beneficial for males and harmful to (or had no effect on) females either developed on the Y chromosome or were acquired through the process of translocation . (iiab.me)
The functioning of this system seems to involve integration of fragments of foreign genes into archaeal and bacterial chromosomes yielding heritable immunity to the respective agents. (biomedcentral.com)
Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. (alquds.edu)

Although extrachromosomal circular DNA (eccDNA) is found in normal eukaryotic cells, extrachromosomal DNA (ecDNA) is a distinct entity that has been identified in the nuclei of cancer cells and has been shown to carry many copies of driver oncogenes. (wikipedia.org)

Rather than passing DNA to subsequent generations by dividing into genetically identical daughter cells-a process called mitosis, involving paired chromosomes that divide and used by all eukaryotes-cancer cells propagate somewhat like bacterial cells. (genengnews.com)
As each chromosome contains a single centromere, it remains unclear how acentric fragments derived from shattered chromosomes are inherited between daughter cells during mitosis 6 . (nature.com)
Here we tracked micronucleated chromosomes with live-cell imaging and show that acentric fragments cluster in close spatial proximity throughout mitosis for asymmetric inheritance by a single daughter cell. (nature.com)
Here we show that pulverized chromosomes from micronuclei spatially cluster throughout mitosis and identify the CIP2A-TOPBP1 complex as an essential regulator of this process. (nature.com)
All chromosomes normally appear as an amorphous blob under the microscope and only take on a well-defined shape during mitosis. (iiab.me)
It is entirely coincidental that the Y chromosome, during mitosis, has two very short branches which can look merged under the microscope and appear as the descender of a Y-shape. (iiab.me)

Furthermore, ecDNA is shown to have a significantly greater number of ultra-long-range interactions with active chromatin, which provides insight into how the structure of circular ecDNA affects oncogene function, and connects ecDNA biology with modern cancer genomics and epigenetics. (genengnews.com)

Quantitative assessment of the chromatin state reveals that although ecDNA is packaged into chromatin with intact domain structure, it lacks higher-order compaction that is typical of chromosomes and displays significantly enhanced chromatin accessibility," the article's authors wrote. (genengnews.com)
[5] In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation . (wikipedia.org)

[1] [2] These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation . (wikipedia.org)
The mechanisms effecting establishment, maintenance, and modification of that specific physical conformation of CHROMATIN determining the transcriptional accessibility or inaccessibility of the DNA. (lookformedical.com)

Extrachromosomal DNA (abbreviated ecDNA) is any DNA that is found off the chromosomes, either inside or outside the nucleus of a cell. (wikipedia.org)
Some of the DNA in cancer cells may be found in circular structures, rings of extrachromosomal DNA, or ecDNA, that may unloose all manner of mayhem. (genengnews.com)
The authors suggest that ecDNA, because of its increased DNA copy numbers and in association with enhanced chromatin accessibility, promotes massively increased transcription of the oncogenes. (genengnews.com)
More generally, ecDNA contributes to cancer pathogenesis by altering the shape of its chromatin. (genengnews.com)

A chromosome is a long DNA molecule with part or all of the genetic material of an organism. (wikipedia.org)
The X and Y chromosomes are thought to have evolved from a pair of identical chromosomes, [11] [12] termed autosomes, when an ancestral animal developed an allelic variation, a so-called "sex locus" - simply possessing this allele caused the organism to be male. (iiab.me)

In his famous textbook The Cell in Development and Heredity , Wilson linked together the independent work of Boveri and Sutton (both around 1902) by naming the chromosome theory of inheritance the Boveri-Sutton chromosome theory (the names are sometimes reversed). (wikipedia.org)
[14] These observations represent an important prelude to Mendel's theory of particulate inheritance insofar as it features a transition of heredity from its status as myth to that of a scientific discipline, by providing a fundamental theoretical basis for genetics in the twentieth century. (alquds.edu)

Cytosine modifications directly affect the positioning of nucleosomes (the first level of chromatin organization into chromosome involving the DNA chain wound around a core of 8 histone proteins), and recruit chromatin-modifying complexes that modify histones. (i-sis.org.uk)
and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell. (lookformedical.com)
This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS. (lookformedical.com)
Proteins found in the nucleus of a cell. (lookformedical.com)
Silent information regulator 2 (Sir2) proteins, or sirtuins, are protein deacetylases dependent on nicotine adenine dinucleotide (NAD) and are found in organisms ranging from bacteria to humans. (biomedcentral.com)
All living organisms package their DNA with chromatin proteins. (biologists.com)

The maintenance of a single centromere per chromosome is critical for establishing bipolar microtubule attachments to the mitotic spindle and achieving high-fidelity genome segregation 17 . (nature.com)

I've seen many textbook images of alleles on homologous chromosomes with the gene loci identified but how could this be visualised on linear DNA sequences with the bases written out? (stackexchange.com)

H3K9me2 was found at several paternally methylated imprinted regions in sperm, suggesting that this histone mark signals special sites of the paternal genome where methylation is maintained. (i-sis.org.uk)
A retinoblastoma-binding protein that is involved in CHROMATIN REMODELING, histone deacetylation, and repression of GENETIC TRANSCRIPTION. (lookformedical.com)
It is found as a subunit of protein complexes that are in involved in the enzymatic modification of histones including the Mi2 and Sin3 histone deacetylase complexes and the polycomb repressive complex 2. (lookformedical.com)

Although prokaryotic organisms do not possess a membrane-bound nucleus like eukaryotes, they do contain a nucleoid region in which the main chromosome is found. (wikipedia.org)

Bacterial plasmids are typically short sequences, consisting of 1 to a few hundred kilobase (kb) segments, and contain an origin of replication which allows the plasmid to replicate independently of the bacterial chromosome. (wikipedia.org)

In prokaryotes, nonviral extrachromosomal DNA is primarily found in plasmids, whereas, in eukaryotes extrachromosomal DNA is primarily found in organelles. (wikipedia.org)
Mitochondrial DNA is a main source of this extrachromosomal DNA in eukaryotes. (wikipedia.org)

Otto Bütschli was the first scientist to recognize the structures now known as chromosomes. (wikipedia.org)

Human DNA typically forms long, twisting double helices of genetic material: roughly three billion base pairs organized into 23 pairs of chromosomes miraculously squeezed into every cell nucleus, each averaging just six micrometers in diameter. (genengnews.com)
The repeating structural units of chromatin, each consisting of approximately 200 base pairs of DNA wound around a protein core. (lookformedical.com)
The DNA in the human Y chromosome is composed of about 59 million base pairs. (iiab.me)

Most DNA in an individual genome is found in chromosomes contained in the nucleus. (wikipedia.org)
With a 30% difference between humans and chimpanzees, the Y chromosome is one of the fastest-evolving parts of the human genome . (iiab.me)

NcRNAs such as those involved in RNA interference can be independently inherited, and can also direct chromatin modification and DNA methylation see [7, 8] RNA Inheritance of Acquired Characters , and Nucleic Acid Invaders from Food Confirmed , SiS 63). (i-sis.org.uk)
Walter Sutton (left) and Theodor Boveri (right) independently developed the chromosome theory of inheritance in 1902. (wikipedia.org)

Long before the identification of its molecular nature, it was recognized that chromatin exists in two main states: the densely stained heterochromatin contrasting with euchromatin ( Heitz, 1928 ). (biologists.com)

Autosomal dominant is a pattern of inheritance characteristic of some genetic disorders. (genome.gov)
A child of a person affected by an autosomal dominant condition has a 50% chance of being affected by that condition via inheritance of a dominant allele. (genome.gov)
Corollaries of this finding are that, even among closely related prokaryotes, the most commonly encountered phages and plasmids are different and/or that the dominant phages and plasmids turn over rapidly. (biomedcentral.com)
However, it appears that this inheritance is extremely unstable on the evolutionary scale such that the repertoires of unique psiRNAs are completely replaced even in closely related prokaryotes, presumably, in response to rapidly changing repertoires of dominant phages and plasmids. (biomedcentral.com)

Stevens proposed that chromosomes always existed in pairs and that the Y chromosome was the pair of the X chromosome discovered in 1890 by Hermann Henking. (iiab.me)

These studies implicate a potential mechanism suppressing the loss of genetic material after chromosome pulverization, although how distinct patterns of rearrangements arise in cancer and germline disorders remains unclear. (nature.com)

[18] This re-estimation of the age of the therian XY system is based on the finding that sequences that are on the X chromosomes of marsupials and eutherian mammals are present on the autosomes of platypus and birds. (iiab.me)

Aneuploidy is an abnormality in the number of chromosomes in a cell due to loss or duplication. (genome.gov)
In humans, aneuploidy would be any number of chromosomes other than the usual 46. (genome.gov)

Mitotic clustering facilitates the reassembly of acentric fragments into rearranged chromosomes lacking the extensive DNA copy-number losses that are characteristic of canonical chromothripsis. (nature.com)
The stochastic inheritance of chromosome fragments by both newly formed daughter cells could in part contribute to the alternating DNA copy-number states that are characteristic of chromothripsis 2 . (nature.com)
Autosomal recessive is a pattern of inheritance characteristic of some genetic disorders. (genome.gov)
Blending inheritance leads to the averaging out of every characteristic, which as the engineer Fleeming Jenkin pointed out, makes evolution by natural selection impossible. (alquds.edu)

However, most fragments derived from pulverized chromosomes are acentric and cannot directly bind to spindle microtubules 14 . (nature.com)
Mitotic clustering drives the unequal inheritance of acentric fragments by a single daughter cell, providing an explanation for the origins of distinct patterns of chromothripsis found across diverse cancer types and congenital disorders. (nature.com)

An animal model is a non-human species used in biomedical research because it can mimic aspects of a biological process or disease found in humans. (genome.gov)
The Y chromosome is one of two sex chromosomes ( allosomes ) in mammals, including humans , and many other animals. (iiab.me)

Recent Experiments on the Inheritance of Coat Colors in Mice The American Naturalist 43: 494-510. (esp.org)

Multiple forms of extrachromosomal DNA exist, and, while some of these serve important biological functions, they can also play a role in diseases such as cancer. (wikipedia.org)

Thus, distinct patterns of chromothripsis can be explained by the spatial clustering of pulverized chromosomes from micronuclei. (nature.com)
Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. (alquds.edu)

He described several rules of biological inheritance in his works The genetic laws of the Nature (Die genetischen Gesetze der Natur, 1819). (alquds.edu)

Others use the concept in a narrower sense, to refer to the individualized portions of chromatin during cell division, visible under light microscopy due to high condensation. (wikipedia.org)
ecDNAs lack centromeres, and are consequently subject to random inheritance during cell division, driving intratumoral genetic heterogeneity 6 . (nature.com)

All the Samacheer Kalvi Class 12 Bio Zoology Book Solutions Chapter 4 Principles of Inheritance and Variation Questions, answers, Notes, Guide, Pdf along with the explanations are provided by the subject experts. (samacheerkalviguru.com)
Read all the concepts of Tamilnadu Board Solutions for Class 12 Bio Zoology Chapter 4 Principles of Inheritance and Variation. (samacheerkalviguru.com)
Strengthen your weakness by learning the Samacheer Kalvi 12th Bio Zoology Chapter 4 Principles of Inheritance and Variation Questions and Answers on our site. (samacheerkalviguru.com)

In addition to DNA found outside the nucleus in cells, infection by viral genomes also provides an example of extrachromosomal DNA. (wikipedia.org)
Some use the term chromosome in a wider sense, to refer to the individualized portions of chromatin in cells, either visible or not under light microscopy. (wikipedia.org)

Mechanistically, the CIP2A-TOPBP1 complex prematurely associates with DNA lesions within ruptured micronuclei during interphase, which poises pulverized chromosomes for clustering upon mitotic entry. (nature.com)
Eukaryote genomes are packaged into a nucleoprotein complex known as chromatin. (i-sis.org.uk)
Although initially discovered as a retinoblastoma binding protein it has an affinity for core HISTONES and is a subunit of chromatin assembly factor-1 and polycomb repressive complex 2. (lookformedical.com)
Histones help to package and condense the DNA double helix into the cell nucleus in a complex called chromatin, which can be modified by enzymes, acetyl groups, and forms of RNA called small interfering RNAs and microRNAs (1). (entheohealing.com)

Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too. (intechopen.com)

Extrachromosomal DNA exists in prokaryotes outside the nucleoid region as circular or linear plasmids. (wikipedia.org)
Linear plasmids of prokaryotes are found either containing a hairpin loop or a covalently bonded protein attached to the telomeric ends of the DNA molecule. (wikipedia.org)

[4] Before this happens, each chromosome is duplicated ( S phase ), and both copies are joined by a centromere , resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. (wikipedia.org)

In this scanning electron micrograph of inside the nucleus of a cancer cell, chromosomes are indicated by blue arrows and circular extrachromosomal DNA are indicated by orange arrows. (genengnews.com)

[9] The term was coined by the German anatomist Heinrich Wilhelm Waldeyer , [10] referring to the term chromatin , which was introduced by Walther Flemming . (wikipedia.org)

During metaphase the X-shaped structure is called a metaphase chromosome, which is highly condensed and thus easiest to distinguish and study. (wikipedia.org)

Anatomy64

Organisms15

Diseases18

Chemicals and Drugs47

Analytical, Diagnostic and Therapeutic Techniques and Equipment26

Phenomena and Processes163

Information Science4

Accessible chromatin1

Genes11

Eukaryotic1

Mitosis6

Oncogene1

Compaction2

Transcriptional2

EcDNA4

Organism2

Heredity2

Proteins6

Segregation1

Loci1

Histone3

Prokaryotic1

Bacterial1

Eukaryotes2

Structures1

Base pairs3

Genome2

Independently2

Heterochromatin1

Dominant4

Pairs1

Genetic material1

Sequences1

Aneuploidy2

Characteristic4

Fragments2

Humans2

Experiments1

Diseases1

Patterns2

Biological1

Cell division2

Principles3

Cells2

Complex4

Citations1

Prokaryotes2

Copies1

Cancer1

Term1

Highly1