Since the advent of the revolutionary CRISPR genome editing technology, scientists have conducted many daring experiments. Perhaps the loudest was the editing of the human embryo genome. Despite calls to ban such experiments, in 2015, Chinese scientists for the first time edited the DNA of human embryos incapable of living.
While ethical controversy flared up in the scientific community, the genes of human embryos continued to be modified, albeit with a low level of efficiency.
In March 2017, the CRISPR method was first tested on viable human embryos, that is, those that could potentially become a fetus in a woman's womb and be born into the world. Then the researchers from the Middle Kingdom decided on a controversial experiment again, and now their colleagues from the United States have “caught up” with them.
Actually, the first experiment on editing the human genome in America started a year ago. Now, a team led by Shoukhrat Mitalipov of Oregon Health and Science University has announced the successful editing of the human embryo's genome.
This work surpassed all previous ones both in the number of embryos that underwent modification, and in efficiency. The team has demonstrated that it is 100% safe and effective to repair defective genes responsible for hereditary diseases.
Although none of the embryos was allowed to develop for more than a few days (and even more so it was not planned to carry out artificial insemination with their help), the experiment clearly showed the possibility of creating genetically modified people.
Let us clarify that by changing the DNA code of human embryos, the goal of scientists is to show that they can “fix” the genes that lead to diseases such as beta thalassemia, a dangerous blood disorder.
The very process of such modification is called by experts the engineering of germ line cells. Because if we allow the birth of a child with "corrected" DNA, then he will pass on the changes to subsequent generations through his own cells - an egg or sperm.
Promotional video:
This is why such experiments are ethically controversial: in theory, researchers can create "designer" children, that is, genetically enhanced. A number of religious organizations, some public figures and biotechnology companies are now strongly opposed to such a prospect, and CRISPR technology is already being called a potential weapon of mass destruction.
Moreover, previous studies of the Chinese have identified some errors that appear during the editing process, and have shown that DNA changes can affect not all cells, but only a few. This phenomenon is called genetic mosaicism. The American managed to avoid all this: they proved that it is possible to circumvent both mosaicism and the "off-target" action (or simply errors) of the CRISPR system.
Shukhrat Mitalipov himself declined to comment, but his colleagues confirmed the success of the experiments.
The team is known to have used several dozen embryos in their study, created using sperm provided by volunteers carrying inherited mutations. True, it still remains unknown which genes were edited.
The video below shows how chemicals that modify the desired gene are injected into the egg at the time of fertilization.
Despite this success, the controversy over editing the genome of human embryos continues. Many researchers have already come out in support of the idea that, in principle, there is nothing wrong with modification when it comes to serious hereditary diseases that threaten the life of a future person.
At the same time, experts are unanimous in their opinion regarding any genetic improvements, for example, to create children with potentially higher intelligence.
“Editing the genome to improve some trait or ability, not health, raises concerns about whether the benefits may outweigh the risks, and whether it is fair that such experiments will only be available to a few people,” concludes Alta Charo., co-chair of the research committee of the US National Academy of Sciences and professor of law and bioethics at the University of Wisconsin at Madison.
Today in the United States, any attempt to give life to an embryo with edited DNA is prohibited by law. In addition, there is a bill to stop any funding for such clinical trials. However, despite such barriers, the creation of a "genetically modified" person can be carried out in any country where there are no legal restrictions on this process.