Sentences with phrase «number of chromosomes in»

Surveillance that is not stringent enough, on the other hand, would allow eggs with a lot of jumping gene - related errors to survive, and lead to a high level of birth defects, such as those caused by an incorrect number of chromosomes in the offspring.

Those steps, known as reproductive cell division or meiosis, split the original number of chromosomes in half so that offspring will inherit half their genetic material from one parent and half from the other.

It may be due to problems with the number of chromosomes in a fetus, the structure of the chromosome, or even the genetic material that they carry.

How could both of them have suddenly been able to halve the number of chromosomes in their reproductive cells in the manner needed to produce a healthy offspring with some characteristics of both parents?

Not exact matches

In order to supply the proper number of chromosomes to the offspring, each parent's reproductive cells undergo a remarkable process called meiosis, whereby cells from each parent are left with half the usual number of chromosomes.

A large number of current and former female employees at the Premier League are wondering if they ever appeared in any of these emails, if their boss thinks their chromosomes make them irrational, if they might once have been nicknamed Edna.

Essentially, what we look at, are the number of chromosomes that are in that embryo.

Using the correct numbers for the risk of miscarrying after an amniocentesis, the natural conclusion would seem to be that moms whose risk of having a baby with a chromosome disorder is less than 1 in 400 should not have an amniocentesis (since the odds of the test causing a miscarriage would be higher).

But it also might be chromosome number two, and so if you have an abnormal amount of chromosome number two, and then the sperm comes in and meets it you either have only one or you might have three.

Karyotype is the number and appearance of chromosomes in the nucleus of your eukaryotic cells.

They made these clones by a process called automatic parthenogenesis: The egg is formed normally (with half the species» usual number of chromosomes), then fertilized by the «polar body,» a cell that is created during oogenesis and contains the same gene copies as the egg, resulting in the shark having half the genetic variation of its mother.

«One of the main causes of female infertility is a defect in the eggs that causes them to have an abnormal number of chromosomes.

But in a separate study, geneticist David Page of the Whitehead Institute at MIT and his colleagues found that the chimp Y, the male sex chromosome, contains debilitating mutations in a number of genes.

During the formation of eggs and sperm, the cell's chromosomes must pair up and part in an elaborate sequence that results in sex cells with exactly half the number of chromosomes as the parent cell.

When the dancers don't pair or part appropriately it can result in eggs and sperm with the wrong number of chromosomes, a major cause of miscarriage and birth defects.

«Studying congenital heart defects in the «at risk» Down syndrome population can make it possible to reveal genes that impact the risk of heart defects in all children, including those with typical number of chromosomes.»

27 percent reduction in conotruncal defects, or severe heart outflow tract abnormalities; 23 percent reduction in coarctation of the aorta — a narrowing of the major artery (the aorta) that carries blood to the body; 15 percent reduction in atrial and ventricular septal defects — holes in the wall separating heart chambers; however, no changes were seen with regard to chromosomally associated defects — abnormality in the number of an infant's chromosomes.

Any deviation in these processes could lead to cells that do not have the proper number of chromosomes, which could accelerate tumor initiation and progression.

Among its oddities: 52 chromosomes, including 10 sex chromosomes, as well as the highest number of repeated segments in the genome of any mammal sequenced so far.

Another reason that determining the genetic sequence of the Y chromosome is so difficult is that it is composed of an unusually high number of repeated sequences — regions where the sequence of As, Ts, Cs, and Gs are identical, or nearly identical, for thousands or millions of bases in a row.

However, the chimpanzee Y chromosome appears to have undergone more changes in the number of genes and contains a different amount of repetitive elements compared to the human or gorilla.

The researchers then confirmed that the number of singly paired chromosomes — also called univalents — was higher in older mouse and even human egg cells, indicating that age - related segregation errors could be tracked back to increased numbers of prematurely separated chromosome pairs.

The researchers discovered that female and male cells behave differently after the reprogramming process and that this is due to their different number of X chromosomes — two in female cells and one in male cells.

They found that the number of copies of lncRNA genes on a chromosome consistently change in 12 different cancer types and lncRNA genes are widely expressed in cancer cells.

Results from the analysis confirmed previous findings of some copy number variants already associated with autism, but they also found a host of other genes (SHANK2, SYNGAP1, DLGAP2 and the X chromosome — linked DDX53 - PTCHD1 locus) in which mutations seem to be linked to autism.

That is because something about the aging process upsets the process of meiosis, the nuclear division of the ovum or sperm in which chromosomes are reduced to half their original number.

For women in their mid-forties, there is a dramatic increase in the risk that their eggs will have the wrong number of chromosomes after ovulation.

During the key step in sperm formation — a division that results in two cells, each with half the original number of chromosomes — the X and Y chromosomes peeled off from the chain one by one and headed into separate cells, all segregating faithfully with their own kind.

Dr Siddharth Banka, Clinical Senior Lecturer at the Manchester Centre for Genomic Medicine, who led the study, explained: «Our team has identified that this new syndrome is caused by a small deletion on chromosome 6 that affects the function of hypothalamus, a region of the brain that plays a number of important roles in the body.»

As with most cancers, triple - negative breast cancer (TNBC) cells have abnormal amounts of chromosomes or DNA copy number aberrations (CNAs) in their genomes.

But Greg Fitzharris at the University of Montreal in Canada and his team have now identified another way in which cells can be left with the wrong number of chromosomes.

They found that women with the lowest number of eggs also had the shortest telomeres — the chromosome caps that wear away as cells age — in their white blood cells.

Aneuploidy is a condition in which cells contain an abnormal number of chromosomes, and is known to be the cause of many types of cancer and genetic disorders, including Down Syndrome.

Both are present in nearly all other organisms because they fulfil a function in a checkpoint that ensures that both daughter cells get the same number of chromosomes after cell division.

In the illustration, each tissue type is followed by the number of genes whose level of activity is controlled by nearby genes on the same chromosome (cis); those whose activity is associated with genes on other chromosomes (trans); and the number of tissue samples studied.

In other words, alterations in the number of chromosomes, which can lead to a tumour process,» explains MontoyIn other words, alterations in the number of chromosomes, which can lead to a tumour process,» explains Montoyin the number of chromosomes, which can lead to a tumour process,» explains Montoya.

UroSEEK uses urine samples to seek out mutations in 11 genes or the presence of abnormal numbers of chromosomes that would indicate the presence of DNA associated with bladder cancer or upper tract urothelial cancer (UTUC).

Chromosomal instability refers to changes in the number and appearance of chromosomes in a species.

The other marker is an aberrant pattern in the chromosomes; the DNA shows a greater number of abnormalities than normal, including DNA that is missing or moved.

Their work, which is published in Nature Ecology and Evolution, shows for the first time the existence in Leishmania of a relation between changes in chromosome copy number and the selection of new alleles important for parasite survival.

Work in other organisms shows that having an extra set of chromosomes can boost the number of young and may help the clones adjust to new environments.

If the cells reduce the copy number of this specific chromosome again — say upon another change in environmental conditions — then they turn back into a smooth colony.

They discovered that the number of tumor suppressor genes or oncogenes in a chromosome correlated with how often the whole chromosome or part of the chromosome was deleted or duplicated in cancers.

This phenomenon almost never happened in sets of control cells that were pre-malignant but still had a normal chromosome number.

For example, part of a description of a method for karyotyping — examining the number and structure of chromosomes in a cell — was not only copied from a paper published by a separate group, but was also not consistent with the procedure actually followed by Obokata's team.

In 1902 he reasoned that having the wrong number of chromosomes could cause cells to grow uncontrollably and become the seeds of cancerous tumors.

Having an irregular number of chromosomes, almost by definition, leads to imbalances in the numbers of proteins expressed in aneuploid cells.

Scientists first reported a link between a surplus of genetic material on chromosome 15 and autism in 1994, a finding that has since been replicated and confirmed to be a copy number variation.

In contrast to the cells in the rest of the body, sex cells hold half the number of chromosomes (they are haploid) as a result of this special kind of cell divisioIn contrast to the cells in the rest of the body, sex cells hold half the number of chromosomes (they are haploid) as a result of this special kind of cell divisioin the rest of the body, sex cells hold half the number of chromosomes (they are haploid) as a result of this special kind of cell division.

Both of the new studies found that copy number events involving either duplication or deletion of the 25 to 30 chromosome - 16 genes — several of which are known to play a role in the developing brain — appear to cause autism.