Although chromosomes human. Medical search. Frequent questions

Other species have different numbers of chromosomes in their nuclei. (encyclopedia.com)
Re: How do species evolve different numbers of chromosomes? (madsci.org)
two daughter cells with either broken chromosomes or different numbers of chromosomes result and severe diseases including cancer can arise. (embl.org)

That is, instead of 46 chromosomes, the cell could have 47 with the 47th being very small, roughly 6-10 megabases (Mb) in size instead of 50-250 Mb for natural chromosomes, and able to carry new genes introduced by human researchers. (wikipedia.org)
The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor. (nature.com)
Additionally, recent work demonstrates that genes on the Y chromosome contribute to other aspects of human biology, such as cancer risk and severity. (nih.gov)
One such section of the Y chromosome is called the azoospermia factor region, a stretch of DNA containing several genes known to be involved in sperm production. (nih.gov)
Most genes in the human genome have two copies, one inherited from each parent. (nih.gov)
X chromosome inactivation (XCI) is a key developmental process taking place in female mammals to compensate for the imbalance in the dosage of X-chromosomal genes between sexes. (nih.gov)
The researchers estimated that the Y chromosome has lost more than 900 active genes in the 166 million years, the time period that humans and Australian platypuses evolved separately. (wireservice.ca)
At this rate, genes associated with the Y chromosomes will become extinct in 11 million years. (wireservice.ca)
While the eventual disappearance of the Y chromosomes could theoretically lead to Human extinction Evolution can also lead to the development of new sex-determining genes that take precedence over weakening of the Y chromosomes. (wireservice.ca)
Approximately 60 % of the expressed genes of the human genome is known to be associated with CpG islands, most of which are able to be detected with BssHII, EagI and SacII.To help isolate and identify genes, we have sought CpG-islands in the cosmid/PAC contigs with these diagnostic enzymes, assuming close clustering (within l kb) of two or more cutting sites as potential CpG islands. (nii.ac.jp)
Chromosomes are tiny "packages" in your cells that contain your genes. (nih.gov)
Genes are expressed when the chromosome uncoils with the help of enzymes called helicases and specific DNA binding proteins. (encyclopedia.com)
Out of the 3 billion base pairs that exist in human DNA, the sequence obtained from the Human Genome Project has revealed that there are only about 30, 000 genes. (encyclopedia.com)
Identifying genes on each chromosome is an active area of genetic research. (nih.gov)
Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. (nih.gov)
Chromosome 18 likely contains 200 to 300 genes that provide instructions for making proteins. (nih.gov)
The signs and symptoms of distal 18q deletion syndrome are thought to be related to the loss of multiple genes from this part of the long arm of chromosome 18. (nih.gov)
Most people have 46 chromosomes in each cell, divided into 23 pairs: people with Down syndrome (DS) have an extra copy of chromosome 21, which carries over 200 genes. (scitechdaily.com)
Chromosome 21 and its genes are also found in mice, although the genes have dispersed onto three smaller regions on three different mouse chromosomes. (scitechdaily.com)
The researchers looked at the effect of the genes in each of these three different mouse regions (chromosomes) on learning and memory. (scitechdaily.com)
The functionality of human genes and networks are examined in these processes, with special emphasis on the prominent p53 tumor suppressor and stress responses. (nih.gov)
Chromosome 19 likely contains about 1,500 genes that provide instructions for making proteins. (medlineplus.gov)
Among the changes in chromosome 19 that have been reported are microdeletions, which remove a relatively small number of genes. (medlineplus.gov)
These gaps most often contain repetitive DNA segments that are exceptionally difficult to sequence, and yet these repetitive segments include genes and other functional elements that may be relevant to human health and disease. (nih.gov)
The draft, which includes survey sequences for all 21 wheat chromosomes and involved allocating roughly half of the known wheat genes, is a stepping stone en route to a wheat reference genome, explained Kellye Eversole, director of the IWGSC. (genomeweb.com)
The distribution of genes assigned to chromosomes so far indicate that protein-coding sequences are spread fairly uniformly along the chromosome and even into centromeric sequences, Eversole noted, rather than residing in discrete gene-rich regions. (genomeweb.com)
The team saw somewhat more genes falling in wheat's B genome than in its other two sub-genomes, though there were examples of A or C sub-genome chromosomes with higher gene counts than their B genome counterparts. (genomeweb.com)

Simon C. Body, MBChB, MPH, from the Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, in Boston, Massachusetts, presented the study here at the American Society of Human Genetics 58th Annual Meeting. (medscape.com)
American Society of Human Genetics (ASHG) 58th Annual Meeting: Abstract 72. (medscape.com)
Human Genetics (1975) 30 (2): 143. (karger.com)
Genetics Even after losing their Y chromosomes, two species of rodents. (wireservice.ca)
The molecular genetics of human chromosome 6. (bmj.com)
MedlinePlus Genetics provides information about each human chromosome written in lay language. (medlineplus.gov)
NIEHS research uses state-of-the-art science and technology to investigate the interplay between environmental exposures, human biology, genetics, and common diseases to help prevent disease and improve human health. (nih.gov)

As a result, each cell has four copies of the short arm of chromosome 18. (nih.gov)
People with this condition are missing anywhere from about 300,000 DNA building blocks (300 kilobases or 300 Kb) to more than 3 million DNA building blocks (3 megabases or 3 Mb) on the short arm of chromosome 19. (medlineplus.gov)

When researchers completed the first human genome sequence 20 years ago, gaps were left in the sequences of all 24 chromosomes. (nih.gov)
While all human chromosomes contain repeats, about 30 million letters of the Y chromosome are repetitive sequences. (nih.gov)
To tackle the most repetitive pieces of the human genome, the T2T Consortium applied new DNA sequencing technologies and sequence assembly methods, as well as knowledge gained from generating the first gapless sequences for the other 23 human chromosomes. (nih.gov)
It could have been very chaotic, but instead, nearly half of the chromosome is made of alternating blocks of two specific repeating sequences known as satellite DNA. (nih.gov)
To further define the type and arrangement of sequences at the ends of human chromosomes, we developed a direct cloning strategy for telomere-associated DNA. (nih.gov)
Nineteen (TTAGGG)n-bearing plasmids were isolated, two of which contain additional human sequences proximal to the telomeric repeats. (nih.gov)
These telomere-flanking sequences detect BAL 31-sensitive loci and thus are located close to chromosome ends. (nih.gov)
Two recent studies published in the journal Science obtained the Y chromosome sequences of many more males, and these new data brought the formerly discordant results into general agreement at 120,000-200,000 years ago. (icr.org)
The ability to generate truly complete sequences of chromosomes and genomes is a technical feat that will help us gain a comprehensive understanding of genome function and inform the use of genomic information in medical care. (nih.gov)
HaploSync leverages the relationship between haplotypes to improve the quality and accuracy of assemblies, separates haplotypes while reconstructing chromosome-scale pseudomolecule sequences, and recovers a location for genomic regions that cannot be placed during other assembly steps. (biorxiv.org)
As the result of opportunities to do some shotgun sequencing of individual chromosome and chromosome arms, we launched an interim or short-term milestone to achieve survey sequences for all 21 chromosomes," Eversole told GenomeWeb Daily News . (genomeweb.com)
Using wheat lines developed from the Chinese Spring cultivar of bread wheat, the researchers generated and assembled sequences for each of the plant's chromosomes using Illumina paired-end sequencing and the ABySS assembler. (genomeweb.com)

A gain or loss of chromosomes from the standard 46 ( called aneuploidy ) occurs either during the formation of reproductive cells (sperm and egg), in early fetal development or in any other cell of the body after birth. (howstuffworks.com)
An abnormal number of chromosomes is known as aneuploidy , and occurs when an individual is either missing a chromosome from a pair (resulting in monosomy ) or has more than two chromosomes of a pair ( trisomy , tetrasomy , etc.). [3] [4] Aneuploidy can be full, involving a whole chromosome missing or added, or partial, where only part of a chromosome is missing or added. (wikipedia.org)
[3] Aneuploidy can occur with sex chromosomes or autosomes . (wikipedia.org)
Detection of segmental aneuploidy and mosaicism in the human preimplantation embryo: technical considerations and limitations. (jefferson.edu)
Aneuploidy across individual chromosomes at the embryonic level in trophectoderm biopsies: changes with patient age and chromosome structure. (jefferson.edu)

A portion of one chromosome has been deleted from its normal place and inserted into another chromosome. (wikipedia.org)
A portion of one chromosome has been transferred to another chromosome. (wikipedia.org)
Partial trisomy 18 occurs when part of the q arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. (nih.gov)
Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. (nih.gov)
Translocations of genetic material between chromosome 19 and another chromosome can also lead to extra or missing material from chromosome 19. (medlineplus.gov)

In 2011, researchers formed a human artificial chromosome by truncating chromosome 14. (wikipedia.org)
Extending noninvasive prenatal screening to all 24 human chromosomes can detect genetic disorders that may explain miscarriage and abnormalities during pregnancy, according to a study by researchers at the National Institutes of Health and other institutions. (nih.gov)
For each, researchers calculated a normalized chromosome denominator quality (NCDQ), which measures the likelihood that a sample has the standard two copies of each chromosome. (nih.gov)
The study, led by the Telomere-to-Telomere (T2T) Consortium, a team of researchers funded by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, was published today in Nature . (nih.gov)
With a complete Y chromosome sequence, researchers can now more precisely analyze these deletions and their effects on sperm production. (nih.gov)
It's unclear how mole chars evolved beyond the Y chromosomes, though the researchers will use the findings in spiny mice to continue research. (wireservice.ca)
Researchers at the National Institutes of Health have found a duplication of a short stretch of the X chromosome in some people with a rare disorder that causes excessive childhood growth. (nih.gov)
Researchers discovered specific regions on chromosome 21 that cause memory and decision-making problems in mice with Down syndrome, shedding light on the condition in humans. (scitechdaily.com)
Researchers at the National Human Genome Research Institute have produced the first end-to-end DNA sequence of a human chromosome. (nih.gov)
The results, published July 14 in Nature , show that generating a precise, base-by-base sequence of a human chromosome is now possible, and will enable researchers to produce a complete sequence of the human genome. (nih.gov)
Now researchers from the European Molecular Biology Laboratory (EMBL) for the first time tracked chromosome condensation in mammalian cells over the entire course of cell division. (embl.org)
Using powerful microscopes, researchers led by Jan Ellenberg at EMBL looked at living mammalian cells to find out how and when chromosomes shorten during cell division. (embl.org)
In particular, researchers suspect T. aestivum resulted from an ancient hybridization between T. urartu -related species to form T. turgidum , which eventually hybridized with the Aegilops tauschii grass species to produce an allohexaploid plant with three chromosome sets or sub-genomes comprised of seven chromosomes apiece. (genomeweb.com)
For example, the researchers tracked down more than 124,000 apparent gene loci, including more than 75,000 that could be mapped to a particular chromosome site. (genomeweb.com)

Almost every human cell has 23 pairs of chromosomes for a total of 46. (howstuffworks.com)
Every human cell has 23 pairs of chromosomes for a total of 46 (aside from sperm and egg cells , which each contain only 23 chromosomes). (howstuffworks.com)
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. (medlineplus.gov)
Practically, this means that Adam may have had different versions of chromosomes 1-22 (i.e., 22*2 = 44, plus the X and Y for a total of 46 chromosomes). (icr.org)

Females are born with two X chromosomes, while males are born with one X and one Y. This future may be in jeopardy as The Y chromosomes continue to disappear gradually in many mammalian species, according to a new study. (wireservice.ca)
The 23rd pair, the sex chromosomes, differ between males and females. (medlineplus.gov)
Females have two copies of the X chromosome , while males have one X and one Y chromosome . (medlineplus.gov)
In a diploid cell, males have both an X and a Y chromosome , while females have two X chromosomes. (encyclopedia.com)
At creation, the Y chromosome would have been present in a single copy in Adam since males have an XY chromosome pairing and females an XX pairing. (icr.org)
This DNA sequence of about 16,500 DNA letters exists in addition to the 46 chromosomes, and is found in both males and females in cellular energy factories known as mitochondria. (icr.org)
Simply count the number of Y-chromosome differences among males and the number of mitochondrial differences among all females. (icr.org)

Why Do Most Humans Have 23 Pairs of Chromosomes? (howstuffworks.com)
Because that's the total number of chromosomes found in almost every human cell - 23 pairs to be exact - and those little thread-like structures pack all the information about who you are and what makes you unique. (howstuffworks.com)
First, though, humans also happen to be a 'diploid' species, which means that most of our chromosomes come in matched sets called homologous pairs (the two members of each pair are called homologues). (howstuffworks.com)
But why do humans have 23 pairs? (howstuffworks.com)
Humans have 23 pairs of chromosomes, while all other great apes (chimpanzees, bonobos, gorillas and orangutans) have 24 pairs of chromosomes,' Belen Hurle, Ph.D., says via email. (howstuffworks.com)
Now you know the textbook example of a healthy human has 23 pairs of chromosomes in almost every cell of their body, but life isn't always a textbook. (howstuffworks.com)
However, the Australian platypus has pairs of XY chromosomes that would normally indicate that the mammal was male, indicating that XY pairing was typical of mammalian species not so long ago. (wireservice.ca)
This picture of the human chromosomes lined up in pairs is called a karyotype. (medlineplus.gov)
The human genome (which represents the total amount of DNA in a typical human cell) has approximately 3 × 10 9 base pairs. (encyclopedia.com)
There are 23 pairs of chromosomes, for a total number of 46 chromosomes in a diploid cell, or a cell having all the genetic material. (encyclopedia.com)
This suggests that sometime in our the ancestry of our human race, two pairs of chromosomes fused together. (madsci.org)
Humans normally have 46 chromosomes in each cell, divided into 23 pairs. (nih.gov)
Two copies of chromosome 18, one copy inherited from each parent, form one of the pairs. (nih.gov)
Chromosome 18 spans about 78 million DNA building blocks (base pairs) and represents approximately 2.5 percent of the total DNA in cells. (nih.gov)
Sex chromosomes are inherited (see heredity ) in the same way as the other 22 human chromosome pairs, normal persons being either XX (female) or YY (male). (daviddarling.info)
Chromosome 19 spans about 59 million base pairs (the building blocks of DNA) and represents almost 2 percent of the total DNA in cells. (medlineplus.gov)
The GRCh37 build of the Y chromosome has a length of 59,373,566 base-pairs, but only 25,653,566 base-pairs are actually positioned. (isogg.org)
A typical human centromere extends over many millions of base pairs containing mainly alphoid satellite DNA organized into higher order repeats (HORs). (nih.gov)

Now let's go back to that sperm and egg issue - these cells only have one homologous chromosome from each pair and are considered 'haploid. (howstuffworks.com)

The study, published in the interdisciplinary scientific journal PNAS ( Proceedings of the National Academy of Sciences ), they analyzed the platypus, a mammal that has different sex chromosomes, while most mammals have an X- and Y-chromosome-based system similar to that of humans. (wireservice.ca)
Mammals have a very stable XY chromosome system, with almost complete Y degradation. (wireservice.ca)

The feasibility of using fluorescent ISH for sexing biopsied embryos in couples at risk of X-linked disease and for the preimplantation diagnosis of chromosome abnormalities is discussed. (eurekamag.com)
[1] These can occur in the form of numerical abnormalities, where there is an atypical number of chromosomes, or as structural abnormalities, where one or more individual chromosomes are altered. (wikipedia.org)
Chromosome abnormalities may be detected or confirmed by comparing an individual's karyotype , or full set of chromosomes, to a typical karyotype for the species via genetic testing . (wikipedia.org)
Most chromosome abnormalities occur as an accident in the egg cell or sperm, and therefore the anomaly is present in every cell of the body. (wikipedia.org)
Previous studies in hybrids detected multiple abnormalities of spermatogenesis and a high frequency of dissociation between the X and Y chromosomes at the meiotic prophase. (mdpi.com)
These chromosome abnormalities are somatic, which means they are acquired during a person's lifetime and are present only in the cells that give rise to cancer. (medlineplus.gov)

Mosquitoes, for example have a diploid chromosome number of six, frogs have 26 and shrimp have a whopping 508 chromosomes! (howstuffworks.com)
Here's why: When a sperm and egg fuse, they combine their genetic material to form one complete, diploid set of chromosomes. (howstuffworks.com)
We developed HaploSync, a suite of tools that produces fully phased, chromosome-scale diploid genome assemblies, and performs extensive quality control to limit assembly artifacts. (biorxiv.org)
Here, we present HaploSync, an open-source package that scaffolds, refines, and fully phases diploid and chromosome-anchored genomes. (biorxiv.org)

A human artificial chromosome (HAC) is a microchromosome that can act as a new chromosome in a population of human cells. (wikipedia.org)
HACs were first constructed de novo in 1997 by adding alpha-satellite DNA to telomeric and genomic DNA in human HT1080 cells. (wikipedia.org)
21HAC was also able to be transferred into cells from a variety of species (mice, chickens, humans). (wikipedia.org)
It means each parent contributes one homologue to a homologous pair of chromosomes in their child's cells. (howstuffworks.com)
Both tumorigenic segregant HeLa X human fibroblast hybrids and tumorigenic HeLa (D98/AH-2) cells can be converted to a non-tumorigenic state following introduction of a single copy of a fibroblast t(X;11) chromosome. (nih.gov)
Suppression of tumorigenicity is relieved by selecting cells which have lost the t(X;11) chromosome by growth in medium containing 6-thioguanine (6-TG). (nih.gov)
Further, reintroduction of the t(X;11) chromosome into tumorigenic 6TGR cells again suppresses tumorigenicity. (nih.gov)
Thus, the introduction of a single copy of a human chromosome 11 is sufficient to completely suppress the tumorigenic phenotype of HeLa cells and is suggestive of the presence of tumor-suppressor gene(s) on this chromosome. (nih.gov)
However, successful transformation of human cells has not been established using Tax. (nih.gov)
Here, we will summarize the current knowledge of human XCI, mainly based on the analyses of embryos derived from in vitro fertilization and of pluripotent stem cells, and highlight any unanswered questions. (nih.gov)
Here we summarize our recent work on gene transfer into human cells using the HACs for complementation studies as well as the use of HACs for screening of new drugs affecting chromosome instability. (nih.gov)
A chromosome is a threadlike structure found in the nucleus of most cells that carries the genetic material in the form of a linear sequence of deoxyribonucleic acid (DNA). (encyclopedia.com)
In prokaryotes, or cells without a nucleus, the chromosome represents circular DNA containing the entire genome. (encyclopedia.com)
In eukaryotes, or cells with a distinct nucleus, chromosomes are much more complex in structure. (encyclopedia.com)
If the one of the sex cells has the full complement of chromosomes (diploidy), then the zygote would have an extra set of chromosomes. (encyclopedia.com)
During meiosis, two rounds of cell division ensure that the sex cells receive the haploid number of chromosomes. (encyclopedia.com)
Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. (jefferson.edu)
Soni A, Siemann M, Pantelias GE, Iliakis G. Marked contribution of alternative end-joining to chromosome-translocation-formation by stochastically induced DNA double-strand-breaks in G2-phase human cells. (jefferson.edu)
Cells normally have two copies of each chromosome, one inherited from each parent. (nih.gov)
In people with tetrasomy 18p, cells have the usual two copies of chromosome 18 plus an isochromosome 18p. (nih.gov)
In some cases, the extra copy of chromosome 18 is present in only some of the body's cells. (nih.gov)
A normal human female has two X-chromosomes in her body cells, so that each of her ova (eggs) is haploid , having only one X-chromosome. (daviddarling.info)
Her male offspring will have one X- and one Y-chromosome in his body cells. (daviddarling.info)
A nomal human male has one X- and one Y-chromosome in his body cells, and his sperm cells are haploid, containing either an X- or a Y-chromosome. (daviddarling.info)
HACs are partial or "micro" chromosomes, functioning and behaving as new, normal chromosomes in human cells. (nih.gov)
Sometimes chromosomes get stuck and cannot be fully separated by the spindle that normally distributes them into the daughter cells," says Felipe Mora-Bermúdez, who carried out the experiments in Ellenberg's lab, "we think that the 'super condensation' at later stages helps to disentangle such chromosomes and acts as a back-up mechanism to rescue separation defects. (embl.org)
The possible effects of environmental and genetic factors on spontaneous frequencies of sister chromatid exchanges (SCEs) and cells with chromosome aberrations (CAs) in human lymphocytes were investigated by analysing 177 completed families (mother, father and at least one child). (unipi.it)

Conceptual image of a cell karyotype exhibiting trisomy, three copies of one chromosome. (nih.gov)
Because of the way data have been analyzed, typical genomic tests performed during pregnancy have targeted extra copies of chromosomes 21, 18 and 13, but rarely evaluated all 24 chromosomes. (nih.gov)
Copies of TSPY are organized in the second largest gene array in the human genome. (nih.gov)
A karyotype of an individual with trisomy 21 , showing three copies of chromosome 21. (wikipedia.org)
The following chromosomal conditions are associated with changes in the structure or number of copies of chromosome 18. (nih.gov)
Trisomy 18 occurs when each cell in the body has three copies of chromosome 18 instead of the usual two copies, causing severe intellectual disability and multiple birth defects that are usually fatal by early childhood. (nih.gov)
The following chromosomal conditions are associated with changes in the structure or number of copies of chromosome 19. (medlineplus.gov)
This deletion affects one of the two copies of chromosome 19 in each cell. (medlineplus.gov)
Each person inherits two copies of the approximately 3 billion chemical letters ('A', 'T', 'G' and 'C') of the human genome-one copy from each parent. (icr.org)

However, it is important to realize that each individual chromosome is very important to an organism's survival, and a new species probably could do without almost all of it's "parent" species chromosomes. (madsci.org)
With the exception of chromosome 3B, which was sequenced in its entirety, the sequence data represented individual chromosome arms that had been isolated and shotgun sequenced. (genomeweb.com)

Sometimes sex is determined by the presence or absence of one particular chromosome, as in grasshoppers. (daviddarling.info)

Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. (nature.com)
The human Y chromosome is the final human chromosome to be fully sequenced. (nih.gov)
An international research team has generated the first truly complete sequence of a human Y chromosome , the final human chromosome to be fully sequenced. (nih.gov)

Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. (blogspot.com)
While we show that purifying selection removing deleterious mutations can explain the low diversity on the Y chromosome, we cannot exclude the possibility that positive selection acting on beneficial mutations could have also reduced diversity in linked neutral regions, and may have contributed to lowering human Y chromosome diversity. (blogspot.com)
The three major single-chromosome mutations: deletion (1), duplication (2) and inversion (3). (wikipedia.org)
The two major two-chromosome mutations: insertion (1) and translocation (2). (wikipedia.org)
When mutations (errors in the copying process) arise in the Y chromosome in the form of single-nucleotide polymorphisms ) or short tandem repeats , they are passed down directly from father to son in a direct male line of descent. (isogg.org)
Hence, differences among modern males would represent mutations to Adam's created Y chromosome sequence. (icr.org)

The 3D reconstruction of microscope images of a living mammalian cell shows the chromosomes just after separation when late shortening begins. (embl.org)

We also offer a very wide range of chromosome painting probes from Cytotest™ which whole chromosomes, chromosome arms and terminal bands, sub-telomeric probes, chromosome counting probes, locus probes and oncology probes. (cambio.co.uk)
This is the first example of a transcriptional activator that accumulates transiently and reversibly on a chromosome-specific heterochromatic locus. (rupress.org)

Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model. (blogspot.com)
To produce the type of reference sequence required for more detailed regulatory and genome-wide studies, she explained, the team first needs to complete physical maps for 20 of the 21 wheat chromosomes. (genomeweb.com)

Neither migration nor admixture are mentioned in the text, and, in my opinion, these processes have shaped modern human Y chromosomal variation. (blogspot.com)
Chromosome mutation was formerly used in a strict sense to mean a change in a chromosomal segment, involving more than one gene . (wikipedia.org)
Chromosome instability syndromes are a group of disorders characterized by chromosomal instability and breakage. (wikipedia.org)
So the other requirement for this new species to emerge from the chromosomal rearrangement is that heterozygote brothers and sisters from the parent with the unusual chromosome must mate (inbreeding). (madsci.org)
Through inbreeding, the rare chromosomal rearrangement may come to exist in both affected chromosomes of one of the next offspring ( homozygote ). (madsci.org)
Like distal 18q deletion syndrome (described above), proximal 18q deletion syndrome is a chromosomal condition that occurs when a piece of the q arm of chromosome 18 is missing. (nih.gov)
Background: The bacterial artificial chromosome (BAC) is a vector system of choice for the construction of the large-insert chromosomal DNA libraries that are needed in genomic studies. (nih.gov)
The Chromosomal Stability Group integrates mechanisms and genetic controls of genome stability with environmental factors and stress-signaling to better understand their complex contributions to human health. (nih.gov)

Alternative methods of creating transgenes, such as utilizing yeast artificial chromosomes and bacterial artificial chromosomes, lead to unpredictable problems. (wikipedia.org)
Yeast artificial chromosomes and bacterial artificial chromosomes were created before human artificial chromosomes, which were first developed in 1997. (wikipedia.org)
There are currently two accepted models for the creation of human artificial chromosome vectors. (wikipedia.org)
In 2010, a refined human artificial chromosome called 21HAC was reported. (wikipedia.org)
Truncation of chromosome 21 resulted in a human artificial chromosome that was mitotically stable. (wikipedia.org)
Human artificial chromosomes (HACs) based vectors have several advantages over viruses as gene delivery vectors and the ability to carry large gene inserts. (nih.gov)
Construction of a human chromosome 4 YAC pool and analysis of artificial chromosome stability. (nih.gov)
Our results also suggest that increasing the length of an artificial chromosome improves its mitotic stability. (nih.gov)
Human artificial chromosomes (HACs) provide a unique opportunity to develop a new generation of nonviral vectors for therapeutic use as gene expression and delivery systems. (nih.gov)

This is accomplished by truncating the natural chromosome, followed by the introduction of unique genetic material via the Cre-Lox system of recombination. (wikipedia.org)
We suggest that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, 'genetic hitchhiking' effects in the absence of meiotic crossing over, frequent ectopic recombination within the MSY, and species differences in mating behaviour. (nature.com)
One YAC that showed a very high frequency of rearrangement by mitotic recombination proved to be a mouse/human chimera. (nih.gov)

Tax can also immortalize human primary T lymphocytes. (nih.gov)

We have developed rapid screening and chromosome walking with which almost all gaps were able to be sealed with use of a half million PAC clones, representing approx. (nii.ac.jp)
The GRC tracks issues relating to the Y chromosome such as gaps and errors in the sequence. (isogg.org)
In a series of plant, fungal, and animal kingdom case studies, we demonstrate that HaploSync efficiently increases the assembly contiguity of phased chromosomes, improves completeness by filling gaps, corrects scaffolding, and correctly phases highly heterozygous, complex regions. (biorxiv.org)

November 17, 2008 (Philadelphia, Pennsylvania) - A new genetic study has identified 7 single-nucleotide polymorphisms (SNPs) within a single haplotype on human chromosome 4, which are associated with atrial fibrillation (AF) after cardiac surgery. (medscape.com)

By single-cell DNA replication sequencing, here we show that the entire Xi is reorganized to replicate rapidly and uniformly in late S-phase during X-chromosome inactivation (XCI), reflecting its relatively uniform structure revealed by 4C-seq. (nature.com)

HACs differ in this regard, as they are entirely separate chromosomes. (wikipedia.org)
HACs are useful in expression studies as gene transfer vectors, as a tool for elucidating human chromosome function, and as a method for actively annotating the human genome. (wikipedia.org)
HACs have been used to create transgenic animals for use as animal models of human disease and for production of therapeutic products. (wikipedia.org)
HACs avoid the limited cloning capacity, lack of copy number control, and insertional mutagenesis caused by integration into host chromosomes that plague viral vectors. (nih.gov)
The generation of a functional centromere (a complex structure needed for segregation at cell division) is key in the production of synthetic chromosomes such as HACs. (nih.gov)

However, recent advances in the experimental capacity to access human embryonic-derived material and in the laws governing ethical considerations of human embryonic research have allowed us to enlighten this black box. (nih.gov)

Gene therapy is a promising strategy to treat a wide range of human diseases, and several gene therapy vectors have been developed to deliver these novel treatments. (nih.gov)

[2] Chromosome anomalies usually occur when there is an error in cell division following meiosis or mitosis . (wikipedia.org)
An entire chromosome has attached to another at the centromere - in humans, these only occur with chromosomes 13, 14, 15, 21, and 22. (wikipedia.org)
The deletion that causes distal 18q deletion syndrome can occur anywhere between a region called 18q21 and the end of the chromosome. (nih.gov)
X-chromosomes occur in other organisms as well, such as fruitflies. (daviddarling.info)
Ring chromosomes occur when a chromosome breaks in two places and the ends of the chromosome arms fuse together to form a circular structure. (medlineplus.gov)

We have found that the majority of YACs examined are one to two orders of magnitude less stable than authentic yeast chromosomes. (nih.gov)
Interestingly, the largest YAC analyzed displayed a loss rate typical for natural yeast chromosomes. (nih.gov)
Using budding yeast and human cell models, the group has focused on genome maintenance and natural or environmental challenges to chromosome stability. (nih.gov)
Because of similarities in genome organization, enzymatic processes and genetic controls, findings with yeast are often applicable to human disease. (nih.gov)

With its name rooted in the Greek words for color (chroma) and body (soma), the chromosome is a cell structure (or body) that scientists can spot under a microscope by staining it with colored dyes (get it? (howstuffworks.com)
Every chromosome contains exactly one molecule of DNA, to be exact, and that long string of genetic info is tightly wrapped around the protein (called a histone), which acts like a spool, efficiently bundling the lengthy, info-rich molecule into the perfect size and shape to fit inside the nucleus of a cell. (howstuffworks.com)
Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. (nih.gov)
Human T-cell Leukemia Virus type 1 (HTLV-1) is a delta-retrovirus that infects approximately 20 million individuals worldwide. (nih.gov)
In order to construct a human chromosome 4-specific YAC library, we have utilized pYAC4 and a mouse/human hybrid cell line HA(4)A in which the only human chromosome present is chromosome 4. (nih.gov)
From this cell line, approximately 8Mb of chromosome 4 have been cloned. (nih.gov)
If DNA were not coiled within chromosomes, the total DNA in a typical eukaryotic cell would extend thousands of times the length of the cell nucleus. (encyclopedia.com)
Chromosomes can be visualized using a microscope just prior to cell division, when the DNA within the nucleus uncoils as it replicates. (encyclopedia.com)
Tetrasomy 18p results from the presence of an abnormal extra chromosome, called an isochromosome 18p, in each cell. (nih.gov)
The studies of DNA damage, repair and cell surveillance of its genome are directly relevant to human exposures, both endogenous and environmental, repair capabilities and therapies. (nih.gov)
19p13.13 deletion syndrome results from the deletion of a small piece of the short (p) arm of chromosome 19 in each cell. (medlineplus.gov)
Other possible changes include the presence of an extra piece of the chromosome in each cell (partial trisomy 19) or the absence of a larger segment of the chromosome in each cell (partial monosomy 19). (medlineplus.gov)
A human cell contains an enormous 1.8 metres of DNA partitioned into 46 chromosomes. (embl.org)
Condensation, the shortening of chromosomes, allows the cell to handle such huge amounts of genetic material during cell division and helps preventing fatal defects in chromosome separation. (embl.org)
In this week's advanced online publication of Nature Cell Biology they report crucial new insights into timing, function and molecular basis of chromosome condensation. (embl.org)
Condensation begins early, when the cell starts preparing for division, and the chromosomes become shorter and shorter until they are about to separate and migrate towards the poles of the cell. (embl.org)
The extreme condensation of chromosomes towards the end of cell division can also serve as a safety net if something goes wrong with chromosome separation in earlier phases of division. (embl.org)
This could further advance our understanding of cell division and the risk factors that lead to defects in chromosome separation and their dramatic consequences. (embl.org)

It is true that different species have different number of chromosomes. (madsci.org)

A portion of the chromosome has been duplicated, resulting in extra genetic material. (wikipedia.org)
A portion of the chromosome has broken off, turned upside down, and reattached, therefore the genetic material is inverted. (wikipedia.org)
Rearrangements of genetic material between chromosome 19 and one of several other chromosomes have been found in some forms of blood cancer (leukemia). (medlineplus.gov)

Marin D, Wang Y, Tao X, Scott RT, Treff NR. Comprehensive chromosome screening and gene expression analysis from the same biopsy in human preimplantation embryos. (jefferson.edu)

Structure and variability of human chromosome ends. (nih.gov)

Formed by the mirror image copy of a chromosome segment including the centromere. (wikipedia.org)

These include 19p13.13 deletions (described above) and small deletions in other regions of the chromosome. (medlineplus.gov)

The Y chromosome carries little genetic information and it is largely the properties of the X chromosome that determine "sex-linked" characteristics in males. (daviddarling.info)

these studies will also determine if there are intrinsic differences in the properties of chromosomes containing higher eukaryotic DNAs. (nih.gov)

This is because in the human evolutionary lineage, two ancestral ape chromosomes fused at their telomeres [tips], producing human chromosome 2. (howstuffworks.com)
Lahn, B. T. & Page, D. C. Four evolutionary strata on the human X chromosome. (nature.com)
Throughout evolutionary history, organisms have changed the numbers and organization of their chromosomes in a variety of ways. (madsci.org)
One could imagine that events like this in other evolutionary scenarios might involve chromosomes duplicating or breaking into two. (madsci.org)

Support also came from NIH's National Institute of Neurological Disorders and Stroke and the National Human Genome Research Institute. (nih.gov)
Known human disorders include Charcot-Marie-Tooth disease type 1A , which may be caused by duplication of the gene encoding peripheral myelin protein 22 (PMP22) on chromosome 17. (wikipedia.org)

These results strengthen the suitability of the use of SCEs and CAs analysis in human cytogenetic surveillance for the detection of effective environmental factors. (unipi.it)

Migration may result in the expansion of a successful set of Y chromosome lineages, while admixture between divergent populations may inflate estimates of diversity in a population. (blogspot.com)

Our results are consistent with the idea that the default 3D architecture of the X chromosome forms the basis for regional differences in Xi heterochromatin stability. (nature.com)

Anatomy66

Organisms12

Diseases29

Chemicals and Drugs28

Analytical, Diagnostic and Therapeutic Techniques and Equipment26

Psychiatry and Psychology1

Phenomena and Processes170

Disciplines and Occupations1

Technology, Industry, Agriculture2

Information Science4

Health Care1

Different numbers of chromosomes3

Genes27

Genetics7

Short arm of chromosome2

Sequences12

Aneuploidy5

Another chromosome5

Researchers14

Total of 464

Females7

Pairs18

Homologous chromosome1

Mammals2

Abnormalities6

Diploid4

Cells27

Copies9

Individual chromosome2

Particular chromosome1

Fully sequenced3

Mutations6

Mammalian1

Locus2

Genome-wide2

Chromosomal8

Artificial9

Recombination3

LYMPHOCYTES1

Gaps3

Single-nucleotide po1

Inactivation1

HACs5

Embryonic1

Vectors1

Occur5

Yeast4

Cell18

Species have different1

Genetic material3

Preimplantation embryos1

Variability1

Centromere1

Deletions1

Males1

Eukaryotic1

Evolutionary4

Disorders2

Cytogenetic1

Divergent1

Heterochromatin1