Experts have discovered the first mutation in the development of human evolution.

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For the first time, scientists have caught a glimpse of the earliest genetic mutations in human development.

Using whole genome sequencing, they wound back time on cell samples from adults and revealed what took place in the genome when they were still microscopic embryos. It turns out, our first two cells contribute to our development in very different ways.

Biology Reference

Mutations come in two forms: the hereditary ones we get from our parents, which can be found in virtually every cell of the body; and the acquired (or somatic) mutations that can occur at any stage of a person's life, including those very first days when the embryo is just starting to split into multiple cells.

Somatic mutations don't necessarily cause problems, but they can sometimes lead to cancer and other diseases. They also don't necessarily live in every cell (that's called mosaicism). 

We have a fairly murky understanding of the somatic mutations that happen during the earliest life stages, because we can't just watch that stuff happening in real time.

But now researchers have discovered a way to trace these mutations back to their first appearance.

Medical Xpress

"This is the first time that anyone has seen where mutations arise in the very early human development. It is like finding a needle in a haystack," says geneticist Young Seok Ju from the Wellcome Trust Sanger Institute in the UK and the Korea Advanced Institute of Science and Technology.


"There are just a handful of these mutations, compared with millions of inherited genetic variations, and finding them allowed us to track what happened during embryogenesis."

To find these mutations, the team analysed blood and tissue samples from 279 people with breast cancer. Using samples from cancer patients allowed them to test whether mutations were present in both normal blood and tissue, and in surgically removed tumour samples.

Since breast cancer tumours develop from a single cell, a somatic mutation would either be present in every tumour cell, or not at all, which gives a clue to its possible origins.

By tracking and comparing the spread of different mutations in these various tissue samples, the scientists verified a whopping 163 mutations that must have happened within the first few cell divisions of the persons' embryonic development.

University of South Florida

This gave them a unique insight into how early embryonic cells interact.

And that's not all - a statistical analysis revealed that when a fertilised egg divides for the first time, those two cells actually contribute building material for the rest of the body at different proportions.

It appears that one of the first two cells that make us up gives rise to 70 percent of the body tissue, while the other one chips in for the rest.

"We determined the relative contribution of the first embryonic cells to the adult blood cell pool and found one dominant cell - that led to 70 percent of the blood cells - and one minor cell," says molecular biologist Inigo Martincorena from the Sanger Institute.

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"This opens an unprecedented window into the earliest stages of human development."

That's exciting, because having that window will let us discover even more about how humans develop and acquire various mutations from the get-go.

Even though the vast majority of mutations are random and harmless, occasionally they can affect an important gene, causing a developmental disorder or a disease.

"Essentially, the mutations are archaeological traces of embryonic development left in our adult tissues, so if we can find and interpret them, we can understand human embryology better," says lead researcher Mike Stratton, director of the Wellcome Trust Sanger Institute.

The researchers hope their discovery is just the first of many steps that will help us gain a better understanding of what happens to humans in the earliest days, when we're all nothing more than just a clump of cells.

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DOCTORS SUCCESSFULLY TREAT TWO BABIES WITH LEUKEMIA USING GENE-EDITED IMMUNE CELLS

Scientists are using gene-editing techniques to fight cancer.

IT’S A PROMISING APPROACH, BUT STILL NEEDS A LOT MORE RESEARCH

In a study out this week in the journal Science Translational Medicine, a group of British doctors reported that they had successfully “cured” two infants of the blood cancer leukemia using a treatment that involves genetically modified immune cells from a donor.

The study was incredibly small—just two babies—and the infants have only been free of leukemia for 16 and 18 months. Technically, that’s not long enough to say they are cured. Declaring someone who previously had cancer as “cured” usually doesn’t happen until that person has been free of the disease for a few years, at least. But what’s significant about this study is that it combines a promising, novel approach—CAR T cell therapy—with a relatively new gene-editing technique called TALENS, which enables the direct manipulation of genes within a person’s DNA.

In the cancer community, CAR T cell therapy is already touted as a promising immunotherapy treatment (which involves harnessing a person’s immune system to fight cancer on its own), but in preliminary trials, it’s had its limitations. Before it can become a universal cancer treatment, these kinks and logistics need to be worked out. And researchers in the field think that many of them can be solved using gene-editing techniques such as TALENS, the one used in this study, as well as CRISPR, supposedly the easiest such technique to date.


First, what is CAR T-cell treatment?

CAR T, which stands for chimeric antigen receptor T cell, is a new type of cancer treatment which is not yet publicly available, but is in active clinical trials in the United States as well as many other countries such as the United Kingdom and China. The therapy involves removing some T cells (specialized immune cells) from a patient's blood. Then those cells are genetically altered in a lab, giving them special receptors on their surface called CARs. Once the cells are ready, they are infused back into the patient’s blood, where the new (CAR) receptors seek out tumor cells, attach to them, and kill them.
CAR T-cell trials are currently in phase II clinical trials in the United States. A few drug companies, including Novartis, have plans to make the therapy available as early as this year.


How does gene-editing help?

This new treatment has worked really well for blood cancers like leukemia, especially in young children. The problem, as the researchers point out in their study, is that each set of T cells have to be custom made for each patient. That takes a lot of time, and a lot of money. Further, it’s not always feasible, or even possible, to harvest T cells from leukemia patients who simply don’t have enough healthy ones to begin with.
And that’s where gene-editing comes in. The researchers took T cells from donor recipients and made a total of four genetic changes. The two they made with TALENS enabled the T cells to become universal—allowing them to be used in any person without the risk of rejection (a phenomenon called graft-versus-host disease, where the recipient’s immune system creates such an overwhelming response to the foreign cells that the patient can die as a result). The other genetic alterations added that signature receptor to seek out and attack cancer.


What are the limitations of this study?

The two infants in the study—aged 11 and 18 months—both had an aggressive form of leukemia, and had already been subjected to other treatments like chemotherapy and stem cell transplants. And the fact that they have remained cancer free is extremely promising. But again, the study was small. Further, according to a report in MIT Technology Review, many CAR T experts argue that because the children also received other treatments simultaneously (one had a stem cell transplant soon after receiving the CAR T cells) it’s impossible to know for sure whether the CAR T cells were the sole reason the cancer cells stayed away. “There is a hint of efficacy but no proof,” Stephan Grupp, director of cancer immunotherapy at the Children’s Hospital of Philadelphia, told MIT Tech Review. “It would be great if it works, but that just hasn’t been shown yet.


What’s next?

The combination of CAR T cell immunotherapy with gene-editing remains an incredibly promising area of research. Not only to create a “universal donor” CAR T cell, but also to make the treatment more effective. Researchers at the University of Pennsylvania are currently researching using the the gene-editing technique CRISPR to edit out two genes—called checkpoint inhibitors—that prevent CAR T from working as well as it should. The trial, which could take place this year, would be the first case of a CRISPR-altered cell being used in a human patient in the United States. In November, a Chinese group tested their first CRISPR gene-edited T cells in a patient with lung cancer.
However, it’s important to remember that CAR T cell therapy is in its early stages, and CRISPR/TALEN gene edited CAR T is even newer. There’s still a lot more work to be done, including many, many more studies like this one, with a lot more patients, before it’s available for everyone.

Other articles on the same theme:

• DNA from the human embryo has been modified by a Swedish researcher

• The genes of extinct species, unidentified, were found in Melanesian DNA, ( NATURAL BLACK BLONDES ) the population is located in the South Pacific

• This woman from USA could be the first person in the world that will not grow old. '' We made history '

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The above post is reprinted from materials provided by Popsci . Note: Materials may be edited for content and length.

How life emerged on Earth? The old theory is removed

The argument is the fact that, until now, knew too little information on how life on Earth is driven.

For several decades, the main hypothesis on the origins of life was linked to the formation ,, primordial soup ", an event which would have occurred during the first bodies as a result of a chemical reaction triggered within an area with warm water. Recent research however, indicate that life on Earth would have appeared in the depths of the oceans, in the so-called hydrothermal vents ,, ".

A study published in the journal Nature Microbiology suggests that the oldest common ancestor of all living beings is fed with hydrogen as a gas in a high temperature environment, such as hydrothermal vents. On the other hand, the primordial soup hypothesis ,, "says that life would appear when an energy source came into contact with water from the Earth's surface, creating simple molecules first. They were subsequently grouped into structures DNA, which in time led to the formation of the first living organisms.

Recent studies made on genes that most likely were present and there were first living cells on Earth have shown that organisms first appeared on our planet in the deep-sea hydrothermal vents. From within these structures, the alkaline fluids penetrate into the ocean water, producing the natural gaps proton concentrations in a manner similar to the activating all living cells.

The research conducted recently suggests that in the early stages of development of living organisms, chemical reactions in the cells of these variations were driven proton. Then, the cells were able to reproduce these individual differences out of the area of ​​activity of hydrothermal vents, colonizing the oceans and, eventually, the entire planet.

Hydrothermal vents are the only known natural structures that could constitute places of occurrence of the first organic molecules. Aeastă hypothesis was accepted on ,, detriment of primordial soup "because until now knew very little about the principles that govern how life is driven.



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