Sentences with phrase «number of cell divisions»

It promotes tumor cell proliferation and resistance to apoptosis (programmed cell death after a certain number of cell divisions, a good thing when it comes to cancer cells).

He observed that normal human cells had a finite lifespan in vitro and could execute only a limited number of cell divisions.

By examining the results of genome - wide association studies (GWAS) in conjunction with experiments on mouse and human red blood cells (RBCs), researchers in the lab of Whitehead Institute Founding Member Harvey Lodish have identified the protein cyclin D3 as regulating the number of cell divisions RBC progenitors undergo, which ultimately affects the resulting size and quantity of RBCs.

They speculate that because the process of reprogramming increases the number of cell divisions that take place (as compared to what happens in adult skin cells), there are more opportunities for the cell cycle checkpoints to correct for the chromosomal breakage.

The researchers hypothesize that in older people, many of the cell lineages in the blood have reached their maximum number of cell divisions and died off, leaving the ones that have divided more slowly and, therefore, have accumulated fewer mutations.

In their 2015 study, Tomasetti and Vogelstein compared cancer incidence in the United States to the total number of cell divisions to different kinds of tissues in the body.

After an extended number of cell divisions, random segregation of mitochondria may lead to cells containing a majority of mitochondria from the donor egg.

However, stem cells and some cancer cells make enough telomerase to keep their telomeres from shortening, effectively stopping the aging clock and allowing a seemingly unlimited number of cell divisions.

PE: To progress toward cancer, you need a few specific genes to be mutated, within a limited number of cell divisions, to cause the cells to divide uncontrollably.

It is also a way of counting the number of cell divisions the bacilli have been through since they parted company with the most closely related strain.

The initial single cell of the egg undergoes a number of cell divisions to produce a mass of similar cells.

Not exact matches

For a scale using more than one load cell, vmin must be less than or equal to the scale division divided by the square root of the number of cells.

One of the team's new biosensors is made from a nanoplasmonic material that is able to accommodate a large number of cells on a single substrate and to monitor cell proliferation, a fundamental process involving cell growth and division, in real time.

Indeed, although stem cells can divide indefinitely, once they are differentiated, they are locked into a limited life - span, counted down by the number of divisions they undergo.

(A correlation of 1 means that by knowing the variable on the x-axis — in this case, the lifetime number of stem cell divisions — one can predict the y - axis value 100 % of the time.)

Thus, Tomasetti and Vogelstein reasoned, the tissues that host the greatest number of stem cell divisions are those most vulnerable to cancer.

In humans, basal progenitors can undergo multiple rounds of cell division, thereby substantially increasing neuron number and ultimately the size of the neocortex.

As the number of stem cell divisions in a tissue rises, so does the chance of cancer striking that site.

By plotting the lifetime incidence of various cancers against the estimated number of normal stem cell divisions in the corresponding tissues over a lifetime, they found a strong correlation extending over five orders of magnitude.

Tomasetti and Vogelstein conclude that these differences can be explained by the number of stem cell divisions.

Plotting the total number of stem cell divisions over a lifetime against the lifetime risk of cancer in 31 different organs revealed a correlation.

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.

As a result, the telomere limits the cell to a fixed number of divisions and a limited life span.

Plant growth occurs by increasing the number of cells by cell division followed by enlargement of the cells.

The assay uses time - lapse microscopy to monitor individual yeast cells undergoing a small number of divisions to form microcolonies.

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.

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.

Telomere shortening limits the number of divisions that cells can undergo.

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.

«Is there a limit to the number of stem cell divisions, and does that imply that there's a limit to human life?»

Vastly different outcomes, but relatively few genes regulate the number of rounds of cell division in the nervous system before calling a halt.

Analysis linking number of stem cell divisions to different cancer risks suggests most cancer cases can't be prevented

Although unequal division occurs among stem cells — allowing one daughter cell to remain a stem cell while the other matures into another cell type, such as a skin or muscle cell — the goal of a normal symmetric cell division is to generate identical daughter cells and increase cell number.

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 division.

«P53 was already known to monitor many things, like DNA damage and having the wrong number of chromosomes, that make division dangerous for cells,» says Andrew Holland, Ph.D., an assistant professor of molecular biology and genetics at the Johns Hopkins University School of Medicine.

[11] Since ABL activates a number of cell cycle - controlling proteins and enzymes, the result of the BCR - Abl fusion is to speed up cell division.

They examined 17 cancer types in 69 countries and found a strong correlation between the number of stem - cell divisions and the incidence of the disease, regardless of the countries» environment or state of economic development.

Importantly, this results in an abnormal increase in centrosome number, a 10-fold reduction in the numbers of satellite stem cells undergoing asymmetric divisions, and a marked decrease in the generation of myogenin - expressing progenitors.

u Christian Tomasetti and Bert Vogelstein, «Variation in Cancer Risk among Tissues Can Be Explained by the Number of Stem Cell Divisions,» Science, Vol.

The outcome of a given division is unpredictable, but in homeostasis the probabilities of producing two progenitor and two differentiating daughters are the same, so that on average, equal numbers of progenitors and differentiating cells are produced across whole population of progenitors.

Among them, there are genetic instability (mainly aneuploidy, a defect in chromosome number), defects in the symmetry of cell division (important for cell fate specification and tissue architecture) and impaired ciliogenesis.

Instead, most stem cell divisions produce offspring fated to develop into neurons, reducing the number of stem cells remaining.

Publishing in Science a group of researchers studied the relationship between the number of normal stem cell divisions and the risk of 17 cancer types in 69 countries.

Both types of BA were found be mutagens, meaning capable of altering genetic material, and both were also found to be aneugenic, meaning they affect cell division and lead to aneuploidy, an incorrect number of chromosomes.

It appears to offer a number of ways to help our health including blocking the division of some cancer cells.

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