Broken chromosomes. Medical search. Frequent questions

However, says Barbara R. Migeon, M.D., professor of pediatrics at the Johns Hopkins University School of Medicine and a pioneer in X-inactivation research, she and her colleagues reported nearly four decades ago that in some human embryos with triploidy -- a condition in which there are three sets of chromosomes instead of the usual two -- two copies of the X chromosome remained active. (sciencedaily.com)
The 46 comes from the fact that we have two sets of instructions, which means we have two sets of chromosomes. (thetech.org)
Most cells in an organism contain two sets of chromosomes, one inherited from the mother and the other from the father. (nyu.edu)
So they can have anywhere from two to five full sets of chromosomes from up to five different species. (scientificamerican.com)
In this cell division called meiosis, the two complete sets of chromosomes (maternal and paternal ones) in each body cell are reduced to a single one. (scienceblog.com)

But a smaller proportion of the time they actually do add the males genomes, and so then the offspring come out with extra chromosomes. (scientificamerican.com)
Often, DNA-containing cell fragments will fuse with other cells in the embryo, transferring extra chromosomes to those cells. (livescience.com)

These broken fragments result in deletions of genes that lead to genetically unbalanced gametes. (wikipedia.org)
Located on the X chromosome itself, Xist produces a protein that spreads up and down the chromosome during female embryonic development, turning off its genes. (sciencedaily.com)
and the University of California, Santa Cruz, Genome Browser, to look for genes or genomic regions of chromosomes 1 and 19 thought to produce proteins that interact with Xist. (sciencedaily.com)
all genes associated with this syndrome (ie, DKC1 , TERT, TERC, NOP10 ) encode proteins in the telomerase complex responsible for maintaining telomeres at the ends of chromosomes. (medscape.com)
In this process, maternal and paternal versions of each chromosome pair up and swap sections of their DNA through a process known as homologous recombination-a "reshuffling" that gives rise to chromosomes with new combinations of maternal and paternal genes. (nyu.edu)
But SCDC mechanisms work to upregulate, or increase the level, of protein production from genes in the single Z (or X) chromosomes. (newswise.com)
The researchers then compared the activity of genes from sex chromosomes and from autosomes, broken down by male and female turtles. (newswise.com)
Previous research has reported that forming a double-strand break in the DNA reduces the levels of transcription for the genes that surround the break, but it was not clear how this occurred. (elifesciences.org)
In mammalian cells, inhibiting the transcription of genes around a double-strand DNA break depends on a signaling pathway that is activated whenever DNA damage is detected. (elifesciences.org)
One of the next challenges will be to see if the resection process makes any contribution to changes in the transcription of genes that surround a double-strand break in mammals as well. (elifesciences.org)
The gene is a non-coding sequence made of RNA found in the cells of placental mammals that plays a key role in the silencing of genes on X chromosomes. (sciencealert.com)
Another possibility is there are some important genes on the X chromosome that, when silenced, enable the cancer to grow. (sciencealert.com)
Some babies have omphalocele because of a change in their genes or chromosomes . (cdc.gov)

Telomeres When telomeres of chromosomes shorten with continued cell divisions, the chromosome ends may also fuse, forming dicentric chromosomes. (wikipedia.org)
Prior to the first meiotic division, homologous chromosomes pair, synapse, and recombine to ensure their proper disjunction at anaphase I. Additionally, telomeres tethered at the nuclear envelope cluster in the bouquet configuration where they are subjected to dramatic pulling forces acting from outside of the nucleus. (biorxiv.org)
A . Schematic of the bouquet configuration of chromosomes during meiotic prophase I. The spatial arrangement of chromosomes with telomeres clustered and attached at the inner nuclear membrane is shown. (biorxiv.org)
Early work by Muller and McClintock discovered that the physical ends of linear chromosomes, named telomeres, possess an inherent ability to escape unwarranted fusions. (unimib.it)
Due to the inability of conventional DNA replication to fully replicate the chromosome ends and the downregulation of telomerase in most somatic human tissues, telomeres shorten as cells divide and lose this protective capacity. (unimib.it)

Surprisingly, the nup2Δ ndj1Δ double mutant failed to segregate chromosomes, even though the meiotic program continued. (biorxiv.org)
The events of meiotic prophase follow a specialized round of DNA replication when the meiotic chromosome axis is formed. (biorxiv.org)
A process of chromosome organization that is involved in a meiotic cell cycle. (mcw.edu)
In initial experiments, Ms. Penkner observed defects in meiotic chromosome structure, DNA breaks and premature separation of sister chromatides in cells lacking Mnd2. (scienceblog.com)

Recent studies indicate that CRISPR-induced DNA cuts may also result in the exchange of genetic information between homologous chromosome arms. (life-science-alliance.org)
The authors deliberately induced a single DSB in one of the homologous chromosomes in a diploid yeast strain and achieved homologous recombination-based "loss of heterozygosity" events within 20 kb of the target site. (life-science-alliance.org)
During prophase of meiosis I, homologous chromosomes form an inversion loop and crossover occurs. (wikipedia.org)
Both homologous recombination, in which the ends of the broken DNA seek out intact templates with the same sequence, and nonhomologous end-joining pathways are found in Saccharomyces as they are in humans. (brandeis.edu)
Homologous recombination' is one of the main mechanisms used by cells to repair DNA double-strand breaks. (elifesciences.org)

SMC5/6 is required for replication fork stability and faithful chromosome segregation during neurogenesis. (nih.gov)
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)
Chromosome segregation errors during meiosis are the leading cause of birth defects and developmental delays in humans ( H assold and H unt 2001 ). (biorxiv.org)
[5] In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation . (wikipedia.org)

The 23rd pair of chromosomes is a little different depending on your biological sex. (thetech.org)
And this happens within each pair of chromosomes. (thetech.org)
A matched pair of chromosomes results in one sex, while a mismatched pair results in another sex. (newswise.com)

In each cell, most humans have 23 pairs of chromosomes, for a total of 46. (sciencedaily.com)
Humans have 23 pairs of chromosomes, but genetic accidents can alter that number, a condition called aneuploidy. (livescience.com)

This X-shape arrangement of chromosomes is required to ensure that each of the two daughter cells receive an identical copy of the genome. (le.ac.uk)

Only one section of the human genome fit the bill with these criteria -- a stretch of DNA on the short arm of chromosome 19. (sciencedaily.com)
The short arm of chromosome 11 (11p) is also altered in breast and bladder cancer and in the childhood tumor rhabdomyosarcoma and Wilms tumor, he adds. (cancernetwork.com)

After stimulation with phytohemagglutinin and colchicine the cells were examined for chromosome aberrations. (cdc.gov)

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)
Thus, distinct patterns of chromothripsis can be explained by the spatial clustering of pulverized chromosomes from micronuclei. (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)

The research team looked at the LOH11B (LOH = loss of heterozygosity) lung cancer region on chromosome 11. (cancernetwork.com)

We examined the intakes of these B vitamins and their food sources in relation to the frequency of chromosome translocations as a biomarker of cumulative DNA damage, in eighty-two male airline pilots. (cambridge.org)
Heavy pesticide use, however, could be associated with an elevated frequency of chromosome breaks. (cdc.gov)

Most dicentric chromosomes are known to form through chromosomal inversions, which are rotations in regions of a chromosome due to chromosomal breakages or intra-chromosomal recombinations. (wikipedia.org)
The resulting dicentric chromosomes are highly unstable, giving rise to chromosomal translocations, deletions and amplifications, such as the Robertsonian translocation. (wikipedia.org)
To identify the likely location of the repressor protein and the gene that codes for it, the researchers started by looking at cells from human embryos with different forms of chromosomal trisomy, a condition in which cells carry three copies of a particular chromosome instead of two. (sciencedaily.com)
If you already know about chromosomal evolution or do not care, jump directly to information on Drosera chromosome numbers. (carnivorousplants.org)
It is associated with a chromosomal abnormality known as the Philadelphia chromosome. (medicinenet.com)
DNA double-strand breaks (DSBs) are particularly dangerous for cells, since their inefficient or inaccurate repair can result in deletions and chromosomal translocations that can lead to cancer and/or severe developmental abnormalities in humans. (elifesciences.org)

Dicentric chromosomes have important roles in the mitotic stability of chromosomes and the formation of pseudodicentric chromosomes. (wikipedia.org)
Radiation increases the probability that dicentric chromosomes form after every mitotic event, creating physical bridges between them in anaphase and telophase. (wikipedia.org)
Huntingtin (green) "coats" mitotic chromosomes (blue) in PARG inhibitor-treated cells. (openlabnotebooks.org)
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 dicentric chromatid is pulled apart during anaphase of meiosis I with such force that the chromosome breaks at random positions. (wikipedia.org)
Without this restraining mechanism, chromosomes can end up irreversibly broken during meiosis. (nyu.edu)
Through a series of manipulations, in which the researchers inhibited the activity of individual proteins, they found two enzymes that were necessary for meiosis: Mec1, which is similar to ATR, known to suppress tumors in humans, and DDK, which is a vital coordinator of chromosome reshuffling. (nyu.edu)
Chromosome damage in meiosis can have lasting consequences. (scienceblog.com)
Well-known examples are Down Syndrome patients, for whom the proper division of two chromosomes did not occur during the meiosis of one parent. (scienceblog.com)

Recombination can repair broken DNA. (thetech.org)
Recombination is the swapping of DNA between the chromosomes within a pair. (thetech.org)
Since the recombination we have been talking about happens in the egg or sperm, this means the recombined chromosomes end up in someone's children. (thetech.org)
Using synchronized cells undergoing recombination that is initiated at a specific site on a chromosome by an inducible endonuclease, we use physical monitoring techniques (Southern blots, PCR analysis) to follow the sequence of molecular events that occur in real time. (brandeis.edu)
We have shown that this regulation involves the action of a small Recombination Enhancer (RE) sequence that enables a donor on the left chromosome arm to recombine preferentially in MATa cells. (brandeis.edu)

In addition cells have evolved a damage-sensing checkpoint system whereby the cells delay entry into mitosis until the break has been repaired. (brandeis.edu)

This is the process we have studied most intensively, but we are also interested in an alternative process known as break-induced replication (BIR), where only one end of a chromosome break locates a template sequence and assembles a complete replication fork and can copy sequences to the end of a chromosome, producing a nonreciprocal translocation. (brandeis.edu)
To do so, they examined budding yeast--a model organism in cell biology because its chromosome replication and regulation are similar to that of humans. (nyu.edu)
In this way, Mec1 acts like a traffic cop that allows chromosome replication to finish without interruption, before giving DDK the ok to begin the reshuffling. (nyu.edu)

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)
She's seated primly next to a diagram of chromosome migration during cell division, or mitosis. (harvard.edu)
During the division of somatic cells (mitosis) newly duplicated chromosomes (sister chromatids) separate and segregate to opposite daughter cells. (scienceblog.com)

Because so-called X-inactivation is essential for normal female embryo development in humans and other mammals, and two activated X chromosomes create an inherently fatal condition, the research may help explain the worldwide human sex ratio that has slightly favored males over females for as long as science has been able to measure it. (sciencedaily.com)
For example, Down syndrome in humans is marked by a trisomy of chromosome 21. (sciencedaily.com)
Don't humans have 46 chromosomes? (thetech.org)
For instance, in humans and many other species, sex chromosomes are referred to as X and Y. Typically, two X chromosomes result in a female while XY chromosomes result in males. (newswise.com)
The importance of maintaining a proper balance is made evident by diseases caused by abnormal numbers of sex chromosomes, including Klinefelter syndrome and Turner syndrome in humans, and Valenzuela said these processes have evolutionary and health implications in many other organisms as well. (newswise.com)

A number of scientific papers have been published indicating that LSD might cause structural changes in the chromosomes, genetic mutations, disturbances of embryonic development, and malignant degeneration of cells. (druglibrary.net)

For efficient repair of DNA double strand breaks (DSBs) cells rely on a process that involves the Mre11/Rad50/Nbs1 complex, which may help to protect non-repaired DNA ends from separating until they can be rejoined by DNA repair proteins. (nih.gov)

Dicentric chromosomes are studied in model organisms such as yeast (Saccharomyces cerevisiae). (wikipedia.org)
This review focuses on the key experiments that have been performed in the model organism Saccharomyces cerevisiae to uncover the mechanisms that protect the chromosome ends from eliciting a DNA damage response, the conservation of these pathways in mammals, as well as the consequences of their loss in human cancer. (unimib.it)

So we have two copies of chromosome 1, two copies of chromosome 2, and so on up to chromosome 22. (thetech.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)
The Z chromosomes contain instructions for some of the proteins normally functioning cells should produce, and having only a single copy of a chromosome can result in a reduced amount of proteins produced, because protein production is often affected by the number of gene copies. (newswise.com)
Cancers proliferate rapidly, and this can lead to mistakes, like multiple copies of the same chromosome. (sciencealert.com)
A way to fix problems caused by additional copies of chromosomes has been discovered by UK scientists. (thenakedscientists.com)
The fusion of two germ cells, one of which carried two copies of chromosomes 21, gave rise to body cells carrying three chromosomes 21. (scienceblog.com)

Methods: The General situation, clinical manifestations and chromosome breakage test and genetic test results of 107 pediatric FA cases registered in the Chinese Blood and Marrow Transplantation Registry Group (CBMTRG) and the Chinese Children Blood and Marrow Transplantation Registry Group (CCBMTRG) from August 2009 to January 2022 were analyzed retrospectively. (bvsalud.org)
Fifty-five children (51.4%) had chromosome breakage test records, with a positive rate of 81.8% (45/55). (bvsalud.org)

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)
It was not until the early 20 th century that it was demonstrated that chromosomes contain the material of hereditary and it took until the middle 20 th century to determine that DNA in chromosomes was the principle coding molecule of heredity. (carnivorousplants.org)

The genetic controversy about LSD started in 1967 when Cohen, Marinello and Back (22) published a paper suggesting that LSD should be added to the list of substances capable of causing abnormalities in the chromosomes. (druglibrary.net)

A chromosome is a long DNA molecule with part or all of the genetic material of an organism. (wikipedia.org)

This work demonstrates that neither inactivation of the major repair proteins XRCC3 and the DNA-dependent protein kinase (DNA-PK) nor inhibition of DNA-PK by vanillin influences the aggregation of DSB-containing chromosome domains. (nih.gov)
The most likely explanation for this phenomenon, Migeon reasons, was that a protein that represses the X chromosome silencing activity of Xist was working overtime, allowing more than one X chromosome to remain activated. (sciencedaily.com)
and protein localization to chromosome, centromeric region. (nih.gov)
The team studied a key component of a ring-shaped protein complex called cohesin that is known to be important for holding chromosomes together during cell division. (le.ac.uk)
This whole package of DNA (genome) and protein (epigenome) in a chromosome is what controls the development and maintenance of eukaryotic organisms (protists, fungi, animals, and plants). (carnivorousplants.org)
Chromatin is the complex of DNA and protein that packages DNA into chromosomes. (medlineplus.gov)
The protein Mnd2 inhibits premature separation of chromosomes during the formation of gametes. (scienceblog.com)

The 23rd pair is composed of the sex chromosomes, either two X's, in the cases of females, or an X and a Y, in the case of males. (sciencedaily.com)
Sex chromosome researchers have long known that the vast majority of human and other mammalian females have two X chromosomes, while the vast majority of males have a single X and a Y, and only one X chromosome is active in females. (sciencedaily.com)
Randomly turning off an extra X is the body's way of balancing the chromosome dosage of both males and females. (sciencealert.com)
In genetic males, the silencing of the X chromosome is rare but not unknown. (sciencealert.com)

Pseudodicentric chromosomes Dicentric chromosomes may lead to pseudodicentric mutations, in which one of the centromeres on the chromosome becomes inactivated. (wikipedia.org)
The disease comes from mutations in a gene on the X chromosome called HPRT. (emory.edu)

By watching the timing of the cells' development, doctors could determine which cells are genetically healthy, and which have abnormal numbers of chromosomes, finds the study published today (Dec. 4) in the journal Nature Communications. (livescience.com)

It is formed through the fusion of two chromosome segments, each with a centromere, resulting in the loss of acentric fragments (lacking a centromere) and the formation of dicentric fragments. (wikipedia.org)
The formation of dicentric chromosomes and their implications on centromere function are studied in certain clinical cytogenetics laboratories. (wikipedia.org)
FISH involves the use of fluorescent probes to detect and localize specific DNA sequences on chromosomes, and centromere-specific probes can be used to measure dicentric chromosome frequencies. (wikipedia.org)
It specifically stains constitutive heterochromatin, which are regions of the chromosome at or near the centromere. (wikipedia.org)
A spindle "knows" it has found a chromosome when it connects with the chromosome's hubcap-shaped midsection, known as the centromere. (harvard.edu)

The possibility of inducing structural changes in the chromosomes by exogenous agents such as radiation, viruses, and a variety of chemicals, has been a subject of great scientific interest for a long time. (druglibrary.net)

Broken chromosomes that lead to acentric and dicentric fragments can be studied in S. cerevisiae due to its known ability to tolerate aneuploidy, an abnormal number of chromosomes. (wikipedia.org)
However, most fragments derived from pulverized chromosomes are acentric and cannot directly bind to spindle microtubules 14 . (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)
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)
When cells divide, the DNA becomes packed as tightly organised X-shaped chromosomes that are then evenly distributed to the two daughter cells. (le.ac.uk)
Since then, extensive research has shown that this special feature relies on specialized proteins and structural properties that confer identity to the chromosome ends, thus allowing cells to distinguish them from intrachromosomal DNA double-strand breaks. (unimib.it)
Chromosomes got their name by early cell biologists when they observed certain dark-staining objects in dividing cells. (carnivorousplants.org)
In human dividing cells 46 chromosomes can be observed. (carnivorousplants.org)
consequently cells have evolved a variety of mechanisms to repair double-strand breaks (DSBs). (brandeis.edu)
Scientists from the Dana-Farber Cancer Institute have found some male cancer cells, those with X and Y chromosomes, show signs of having their X chromosome silenced. (sciencealert.com)
In normal mammal cells, the X chromosome is only muted when a female cell has a pair of Xs to choose from. (sciencealert.com)
But if there is just one X chromosome, as with most male cells, neither the X nor the Y needs to be inactivated. (sciencealert.com)
In some cancer cells, however, this rule of thumb is broken. (sciencealert.com)
For instance, the authors sometimes found two X chromosomes in male cancer cells. (sciencealert.com)
The professor of molecular and cellular biology is giving a talk in the Science Center about cells and their chromosomes. (harvard.edu)
Instead of the requisite 46 chromosomes per normal cell, cancer cells may have as many as 80. (harvard.edu)
In embryos, however, these cells seem to break apart instead. (livescience.com)
About 75 percent, or 34 of the 45 cells surviving to the zygote stage, had the wrong number of chromosomes. (livescience.com)
Combining data about the abnormal timing with other signs that something has gone wrong (such as fragmented DNA and asymmetrical cell sizes within a developing embryo) could reliably show which cells have the right number of chromosomes and which don't, the researchers report. (livescience.com)
22) * After my arrival in the United States, I participated in a major study concentrating on structural changes of the chromosomes in the white blood cells following LSD administration. (druglibrary.net)
The first group includes papers describing structural changes of the chromosomes produced by LSD in vitro , ** in these experiments various concentrations of LSD are added to cultures of cells from human, animal, or plant tissues in a test-tube. (druglibrary.net)

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)
In spite of our lack of attention to chromosomes and chromosome numbers in formally defining species, it is the chromosomes and the genetic material they contain that define true species and control the evolution of new species. (carnivorousplants.org)
The more similar the chromosomes (the genome and epigenome as well as chromosome number) the more likely hybrids will form and reproduce but also the more likely the net result will only be the introgression of genetic material from one species to the other. (carnivorousplants.org)
Most affected individuals are missing a small amount of genetic material, including the KANSL1 gene, from one copy of chromosome 17 . (medlineplus.gov)

However, in order for normal development to occur, chromosomes must be replicated prior to their reshuffling. (nyu.edu)
It can occur in conditions where the chromosome is duplicated, such as in Klinefelter syndrome (where two or more X chromosomes accompany a Y chromosome). (sciencealert.com)
Most breaks were stated to occur within G-negative bands, but there was little evidence of particular hot spots among these bands. (nih.gov)

The formation of dicentric chromosomes has been attributed to genetic processes, such as Robertsonian translocation and paracentric inversion. (wikipedia.org)

As these chromosomes are pulled apart, the chromosome bridges break, resulting in the formation of "tailed" nuclei, protrusions of the nuclei into the cytoplasm. (wikipedia.org)

After nearly 40 years of searching, researchers report they have identified a part of the human genome that appears to block an RNA responsible for keeping only a single X chromosome active when new female embryos are formed, effectively allowing for the generally lethal activation of more than one X chromosome during development. (sciencedaily.com)
Now, a team of researchers led by Professor Daniel Panne at the University of Leicester and Dr Benjamin Rowland at the Netherlands Cancer Institute have determined at a molecular level how the iconic X-shape of chromosomes is generated during cell division. (le.ac.uk)
Researchers found that a portion of chromosome 11 was missing in 43% of patients who were heavy smokers. (cancernetwork.com)
Analyzing thousands of genomes representing more than 30 different cancers, researchers found the gene responsible for silencing the X chromosome - known as X-inactive specific transcript, or XIST - is highly expressed in a wider variety of cancerous tissues than they'd ever suspected. (sciencealert.com)

Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). (wikipedia.org)
Ever since the invention of the first light microscopes more than 100 years ago, scientists have puzzled over how chromosomes receive their X-shape during cell division. (le.ac.uk)
Professor Panne said: "It is exciting to finally understand at a molecular and atomic level how the iconic X-shape of chromosomes during cell division is generated. (le.ac.uk)
Many organisms determine their sex by a pair of specialized chromosomes that appear in virtually every cell of an organism's body. (newswise.com)
Breaks that form across both strands in a DNA double helix are considered the most dangerous type of DNA damage, and can cause a cell to die or become cancerous if they are not repaired accurately. (elifesciences.org)
Such sex cell cancers were strongly represented among the 4 percent of male cancers identified with a silenced X chromosome. (sciencealert.com)
It sends out fibrous lines, blindly seeking chromosomes within the cell. (harvard.edu)
Prof. Franz Klein and his colleague, Ph.D. student Alexandra Penkner from the Department of Chromosome Biology of the Max Perutz Laboratories at the Campus Vienna Biocenter, have now published results on an important regulation of this process in the journal CELL. (scienceblog.com)
It is Ama1, which activates the APC/C too early in the absence of Mnd2 and thus opens the cohesin rings prematurely, that leads to chromosome damage and finally to the death of the cell. (scienceblog.com)

Strains of S. cerevisiae that tolerate aneuploidy can stabilize products of broken chromosomes during proliferation, which can be recovered and studied in a laboratory setting. (wikipedia.org)
ACMG strongly recommends NIPS over traditional screening methods for all pregnant patients with singleton and twin gestations for fetal trisomies 21, 18, and 13 and strongly recommends NIPS be offered to patients to screen for fetal sex chromosome aneuploidy. (cdc.gov)

CRISPR-Cas9-based genome editing has transformed the life sciences, enabling virtually unlimited genetic manipulation of genomes: The RNA-guided Cas9 endonuclease cuts DNA at a specific target sequence and the resulting double-strand breaks are mended by one of the intrinsic cellular repair pathways. (life-science-alliance.org)
In order to trace the origins and migratory patterns that may have led to the genetic isolation and autosomal clustering in some of these communities we analyzed Y-chromosome STR and SNP sample data from 6327 individuals, in addition to whole genome autosomal sample data from 609 individuals, from Mount Lebanon and other surrounding communities. (nature.com)

Instead, the experiments indicate that it is the resection of the DNA around a double-strand break to form single-stranded tails that inhibits transcription in budding yeast. (elifesciences.org)

The research team reported finding examples of trisomies in every chromosome in embryos that survived at least until later stages, except chromosomes 1 or 19. (sciencedaily.com)
The team reasoned that if the repressor was in a region that was duplicated, it would work overtime and turn off Xist on both X chromosomes, leaving both the X chromosomes active and selectively changing the survival of male vs. female embryos. (sciencedaily.com)
Extra or missing chromosomes are shockingly common, affecting up to 75 percent of all embryos, studies find. (livescience.com)

[1] [2] These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation . (wikipedia.org)
Emerging evidence indicate that the mammalian checkpoint kinase ATM induces transcriptional silencing in cis to DNA double-strand breaks (DSBs) through a poorly understood mechanism. (elifesciences.org)

The resulting DNA double-strand breaks (DSBs) are repaired either by the error-prone nonhomologous end joining (NHEJ) or homology-directed repair ( 11 ). (life-science-alliance.org)

The 23rd pair is usually either two X chromosomes or an X and a Y chromosome. (thetech.org)

Studies done elsewhere identified the mechanism behind the silencing of X chromosomes: a gene called Xist, short for X-inactive specific transcript. (sciencedaily.com)

The break in the chromosome occurred next to the telomere. (cancernetwork.com)

This mechanism requires enzymes to eat away at the end of one of the DNA strands on each side of the double-strand break. (elifesciences.org)
It includes a small number of papers dealing with the detailed mechanism of the action of LSD on the deoxyribonucleic acid (DNA), the most important constituent of the chromosomes. (druglibrary.net)

Most people with Koolen-de Vries syndrome caused by a deletion have had at least one parent with a common variant of the 17q21.31 region of chromosome 17 called the H2 lineage. (medlineplus.gov)
The chromosome deletion indicated more aggressive tumors, with patients living only about half as long as their counterparts who did not have the chromosome loss, says Dr. Gerold Bepler, assistant professor of medicine at Duke and chief of hematology/oncology services at the Veterans Administration Medical Center in Durham, North Carolina. (cancernetwork.com)

The now published discovery of this regulatory function may help to understand the origin of some common congenital chromosome defects. (scienceblog.com)

These iconic X shape chromosomes become visible in the light microscope. (le.ac.uk)
Using biochemical and imaging techniques using a light microscope the team found that when they modified key amino acids, the familiar X-shaped chromosomes could not form any longer. (le.ac.uk)

Dicentric chromosomes were first detected in lymphocytes from blood smears of civil and military personnel who were assigned to deal with the aftermath of the 1986 Chernobyl nuclear disaster (liquidators). (wikipedia.org)

The risk of abnormality for extra nonsatellited marker chromosomes was 14.7% (n = 68), and that for satellited marker chromosomes was 10.9% (n = 55). (nih.gov)

No chromosome loss was found in lung cancer patients who were nonsmokers. (cancernetwork.com)
Specifically, they found that Mec1 senses when chromosomes are being replicated and transmits a molecular "wait" signal to DDK. (nyu.edu)
A certain species of bacteria breaks down compounds, commonly found in black tea, to create a molecule that protects. (thenakedscientists.com)
The gene for phenylalanine hydroxylase is found on chromosome 12 (Longe 2006). (newworldencyclopedia.org)
A connection was found between a genetic region in chromosome 19, linked to the fibroblast growth factor 21 gene, and the intake of sugar. (lu.se)

As you can see, one arm of one chromosome brushes up against the other in the second part of the diagram. (thetech.org)

Walter Sutton (left) and Theodor Boveri (right) independently developed the chromosome theory of inheritance in 1902. (wikipedia.org)
Aided by the rediscovery at the start of the 1900s of Gregor Mendel 's earlier work, Boveri was able to point out the connection between the rules of inheritance and the behaviour of the chromosomes. (wikipedia.org)

This results in broken, deleted gene products of dicentric fragments. (wikipedia.org)

Orthologous to human SMC5 (structural maintenance of chromosomes 5). (nih.gov)

That mismatch means they lack a second copy of the Z chromosome, unlike their male counterparts who have two Z chromosomes. (newswise.com)

Anatomy66

Organisms9

Diseases28

Chemicals and Drugs29

Analytical, Diagnostic and Therapeutic Techniques and Equipment26

Psychiatry and Psychology1

Phenomena and Processes172

Disciplines and Occupations1

Technology, Industry, Agriculture2

Information Science4

Health Care1

Sets of chromosomes5

Extra chromosomes2

Genes13

Telomeres5

Meiotic4

Homologous5

Segregation4

Pair of chromosomes3

Pairs of chromosomes2

Arrangement of chromosomes1

Short arm of chromosome2

Aberrations1

Micronuclei3

Loss of heterozygos1

Frequency of chromosome2

Chromosomal6

Mitotic4

Meiosis5

Recombination5

Entry into mitosis1

Replication3

Mitosis4

Humans5

Embryonic development1

Repair of DNA double strand breaks1

Saccharomyces2

Copies6

Breakage2

Heredity2

Abnormalities1

Organism1

Protein7

Males4

Mutations2

Abnormal numbers1

Centromere5

Radiation1

Acentric2

Cells19

Genetic material4

Occur3

Translocation1

Cytoplasm1

Researchers4

Cell9

Aneuploidy2

Genome2

Yeast1

Embryos3

Transcriptional2

DSBs1

23rd pair1

Specific transcript1

Telomere1

Mechanism2

Deletion2

Congenital1

Light microscope2

Nuclear1

Abnormality1

Found5

Diagram1

Inheritance2

Fragments1

Structural1

Counterparts1