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Chinese gender edited children's Chinese teacher, health concerns



(Independent conversation and a nonprofit source, academic experts, analysis and comments).

George Seidel, from Colorado State University

On November 28, He Jiankui organized a conference room in Hong Kong's Human Genome Editors' Second Summit, two twin girls born in China, Lulu and Nana.

Scientists from the Southern University of Science and Technology in Guangdong, China condemned the investigation that "academic ethics and codes of conduct have been completely violated," and philosophers and bioethics joined the human genome editing wizard. So I do not cover this territory. We want to know what I mean: how did these babies?

I am a retired professor of biomedical science department at Colorado State University. For more than 50 years, I have investigated various aspects of reproductive technology, including the cloning of embryonic mammals and genetic modifications. That's why I'm interested in most of the "designer babies" about the health problems we face.

First?

In Congress he gave an overview of science. Such studies will usually approach the scientific community, when they are published in a periodic journalized magazine, we can get a sensible sense of how they created children changed. This was done in other species successfully and last year it was something that happened in human embryos, but the latter did not enter the woman. He spent three years examining mice and monkeys in the procedure before working on human embryos.

Certainly human experiments, eggs, embryos and even cells can be genetically accurate adults. These changes have been performed in nausea in mice, pigs and other mammals. So, scientists like myself are obvious that these genetic changes can be made in humans. The easiest way to make genetic changes begins with embryos.

Toolbox

Today's most intense DNA modification strategy is a tool for editing CRISPR / Cas-9 genes to make specific genetic mutations in living cells. Although useful for other years, the CRISPR / Cas-9 approach is simpler, easier, more accurate and costly.

In this way the simple concept works. The Cas-9 component molecular glands is a DNA fragment defined by small DNA, called "CRISPR template". After cutting DNA, a gene may be modified at that location. Then, it will be solved by the enzymes that are in the cells of the cuts.

In this case, he directed a gene that generated protein in the cell called CCR5. The HIV virus uses this protein to add and infect cells. CCR5 was a genetically modified idea because HIV does not infect cells, so girls become resistant to the virus.

At this point it has not specified how CCR5 and how genetic change has been deactivated. But this type of "decommissioning" is commonly used in research.

How did

From the schematic it presented, it seems CRISPR / Cas-9 injects an egg at the same time, injecting a fertilizer. After that, split the egg and make dozens of balls of cells – the embryo. At this time, we removed some cells from each embryo to determine the genetic modification we wanted. According to my experience, embryos probably froze at this point. When the study was completed, Modified Embrios thawed and the best mother's uterus was researched in the short term. The embryo with modifications or modifications would not be discarded or used for research.

For many applications, it is ideal to make gene chapters in one cell. Then, when the embryo is divided into DNA and when it is divided into two embryo cells, the genetic change is doubled. This continues, therefore, that each cell has a genetic change as a result of the child.

However, in this case, the genetic modification did not occur at a stage or later in two cells, as the baby cells changed, unlike others. This situation is called mosaicism, because it is a normal mosaic of the child's cell and edited mosaic.

The embryo editing risks?

What happened in a gene-edition embryo? With many

The first scam has not changed, what is often the case. It is a change, that changes occur in embryonic cells, but not in cells, as in any of these babies.

The most common concern is called non-target effects, where there is a genetic change, but the genome is mixed with other unusual events. In a wrong change location, you can create all types of development problems, such as abnormal development of organs, abortion and even cancer.

From his slide, he sequenced the genome to determine the genetic plane of each child in various stages of pregnancy to determine if the changes were bad. But independent scientists study two children's baby DNA, they do not know the results. There are no clear results. Until now, this genetic modification has been transmitted to the next generation.

Another common problem with regard to other things related to mosaics seems to have occurred in one of these twins. If some cells are edited and others do not, the liver's liver cells may be like those with normal genes and heart cells. They can cause serious problems or not.

Another problem is: manipulating in vitro embryos – abnormal development abnormalities, excessive fetuses, metabolic problems, etc., of normal nutrition, oxygen levels, hormones, and growth factors outside of normal reproductive environment. so Sometimes it occurs with common procedures, such as in vitro fertilization, when it is not an attempt to make genetic changes.

Fortunately, it is very good to abolish the abnormal embryos through embryonic death and spontaneous abortion. Healthy human populations are commonly reproduced, even if almost half the embryo is dead, even though the woman is pregnant.

Already designed babies – and there are benefits

When I explained what is wrong, I think that science evolves that genetically modified babies will be healthier than untargeted. These improvements will be passed on to future generations. Genetic abnormalities, such as Tay-Sachs syndrome, can be removed from a family that is very unpleasant to change genetically.


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