Sentences with phrase «number of chromosomes which»

Not exact matches

Breeders cross varieties with a differing number of chromosomes to produce a sterile fruit, which has small, white, fully edible «seed coats» instead of mature black seeds.

That's because D7 embryos — which develop more slowly — are thought more likely to contain an abnormal number of chromosomes (aneuploidy).

Perhaps because it is normal for human embryos to contain cells with the wrong number of chromosomes, which can cause them to self - destruct.

As women age, their eggs are more likely to have the wrong number of chromosomes, which can lead to miscarriages.

During periods of high stress, he says, men produce less testosterone, which can reduce the number and quality of the «male» sperm, which carry a Y sex chromosome.

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.

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.

Venken first sought a vector that could handle large amounts of DNA efficiently, settling on a bacterial artificial chromosome, which was designed a couple years ago and is known to maintain only a few copies of the DNA (though it can produce a high number of copies if it is induced).

As all school - children learn, cells divide using a process called mitosis, which consists of a number of phases during which duplicate copies of the cell's DNA - containing chromosomes are separated into two distinct cells.

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.

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.

Failure has often struck at the stage of meiosis, a type of cell division during which paired chromosomes swap DNA and the number of chromosomes per cell is halved.

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.

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

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.

Rather gene dosage, which depends on the number of chromosome copies, is responsible for this: «If the chromosome is multiplied, then more copies of the same gene will be transcribed.

Most researchers believed that the Y chromosome of cattle would be similar to the Y chromosome of other mammals, which does not have a large number of genes and is considered mostly transcriptionally inactive, Liu said.

But to complete their maturation into sperm, which have half the number of chromosomes of nongerm cells, these PGC - like cells were transplanted back into mouse testes.

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.

When geographical barriers — such as rising sea levels or retracting ice floes — separate populations, they may develop genetic, physiological, or behavioral differences; changes in chromosome structure or number; differently shaped genitalia; or incompatible mating times and rituals — any of which can prevent successful reproduction.

A. Bar heights indicate the degree to which each chromosome contains an unexpectedly high number of differentially methylated promoters.