[ad_1]
On Sunday evening, a story rocked the scientific community: a Chinese researcher claimed to have successfully created the first genetically modified humans using a technique called CRISPR / Cas9. However, not everyone understands what this technique consists of and how it causes so much agitation. That's why, in N + 1, we will do a little review.
In 1987, scientists from Osaka University, led by molecular biologist Yoshizumi Ishino, described repeated sequences in the bacterial genome E. coli and although they have described them, they have not understood their biological significance. In the early 1990s, the Spanish scientist Francisco J. Mojica observed this same repetition in other unicellular organisms, the archaea. Haloferax and Haloarcula.
Later, these repeats were detected in other bacteria, archaea and mitochondria, and Mojica himself baptized them with the name CRISPR (from English: Short palindromic repeats regularly spaced). Sequences were found to be a form of adaptive immune system; A type of defense system by which bacteria store in their genome small segments of DNA identical to those viruses that attack them. If, in the future, they are attacked again, the bacteria immediately recognize the viruses and isolate them.
Finally, researchers Jennifer Doudna and Emmanuelle Charpentier have discovered that by modifying a protein called Cas9, they could route and use the CRISPR sequence to cut DNA at a given moment. From there, it was possible to develop an inexpensive, relatively simple but incredibly accurate tool for gene editing.
In simple terms, CRISPR / Cas9 is a revolutionary molecular tool used to modify or correct the genome of any cell. A kind of molecular scissors capable of cutting any molecule of DNA in a precise and controlled way, eliminating or inserting a new one to activate or block the functions of the immune system.
CRISPR mechanism possible. / Wikimedia Commons
It can be a blessing …
Although the revolutionary genetic editing technique began to be used timidly in the dairy industry, it quickly spread to other areas. For example, it has been tested to make nine calves born resistant to tuberculosis. This experiment was conducted solely to test the potential side effects of CRISPR / Cas9.
Later, they followed a series of similar experiments suggesting the positive aspects of the technique. In May 2017, a group of US scientists succeeded in eliminating HIV from live mice, and the following month another US team claimed to have succeeded in reversing the signs of Huntington's disease, in which brain cells die. reason for a toxic protein released. for a mutant version of the Huntington gene. And in December of the same year, this technique helped to inhibit the progression of amyotrophic lateral sclerosis (ALS) in mice.
However, CRISPR / Cas9 has not only been used to test hypothetical treatments in animals, but has had more practical applications. Recently, a group of Argentine researchers modified the potatoes to avoid excessive losses and a few months later, another team of US scientists altered a small cherry from South America to make it much more marketable.
Argentinean scientists have managed to ensure that potatoes do not fall apart so quickly using the CRISPR / Cas9 editing technique. / MaxPixel
… or a curse
However, almost immediately after the massive adoption of CRISPR / Cas9, the risks and potential dangers began to become more obvious. Last May, a study published in Nature methods, found that although the technique successfully corrected a gene causing blindness in mice, it also caused more than 1500 mutations and more than 100 insertions and losses of genetic material in two animals.
A similar analysis resulted in an analysis conducted in the United Kingdom, which revealed that the technique appeared to cause significant mutations and genetic damage in human and mouse cells. The riskiest was that these undesirable changes were not detected by existing DNA tests. "We have discovered that DNA modifications have been seriously underestimated," said geneticist Allan Bradley of the Wellcome Sanger Institute in the United Kingdom.
These are some of the reasons why, earlier this month, Luis Montolui, a research scientist at the National Biotechnology Center in Spain, explained that genetic publishing was not yet ready to treat patients. "It is neither prudent nor ethically justifiable to expose patients to risks that we are not yet able to control. Especially for in vivo therapies, in the person, "said the scientist in a detailed article.
Pandora's box
In this scenario, it was prudent to limit genetic modification experiments to bacteria, animals, or plants. Or in the worst case, to human embryos up to 14 days.
That's why news from China has generated a wave of stupor and condemnation. The most important representatives of biotechnology have disagreed with the experiments conducted by researcher He Jiankui (suspended from his university).
Chinese researcher He Jiankui is now in the eye of the cyclone. / Youtube
Julian Savulescu, director of the Practical Ethics Center at Oxford University (UK), described the experience as "monstrous"; and Joyce Harper, specialist in reproductive medicine at University College London, said on the magazine's website Nature What "These babies are used as genetic guinea pigs."
For his part, Francisco Martínez Mojica, discoverer of Crispr-Cas9 techniques, was skeptical of the feat and said in an interview to Onda Cerothis "genetic modification is something that can be done, but should not be done". For the scientist, "something has been done which, according to most scientists, should never be done", besides, "This encourages an open debate, it is good that there is a debate, but it It's not fair that things are done like this man does. "
Less immediate risks
However, beyond the individual risks that, unfortunately, the jewels of the Chinese experience may suffer, there are others much deeper for the rest of society. If CRISPR / Cas9 (or similar products such as CRISPR-GO) is perfected to the point that it can be used safely in humans; and that is not properly regulated, we could be at the doorstep of a society that is coming out of science fiction.
As historian Yuval Harari or Stephen Hawking himself warned in his latest book, nothing could prevent people with better economic resources from choosing the characteristics of their children: better physically, smarter, more quickly, immune to disease or simply aesthetically appealing.
Professor Stephen Hawking, recently deceased, warned of the dangers of genetic engineering in his latest book. / Wikimedia Commons
"There have always been differences between the rich and the poor: economic, political and social," Harari recently said at a conference. "However, with the advent of biotechnology, it is the first time that these differences can become biological." Hawking imagined a similar scenario: "once superhumanthere will be significant political problems with unimproved humans, who will not be able to compete. "
It is true that we are still far from the scenario described by the two thinkers. But given the speed with which all these changes are occurring, the wisest thing to do is to start now intelligently discussing its advantages and disadvantages (for example: do we want to arrive more transparently? eugenics 2.0?) The ultimate intention is that the beneficiaries of progress are all members of society and not just a few … the usual ones.
Victor Roman
This news was originally published in N + 1, the science that adds.
About N + 1: This is the first online science and technology dissemination journal that allows the total or partial reproduction of its content through communication, bloggers and influencers, by mentioning the text and the link to the web: "This news was originally published in the magazine N + 1, the science that adds: www.nmas1.org"
[ad_2]
Source link
