Updated: October 8, 2020 7:25:53 am
First, the researchers artificially create a guide RNA, which helps guide the genetic scissors to the place in the genome where the cut will be made. To edit a gene, they specially design a small DNA template. When the cell repairs the cut, it will use this DNA template. This changes the code of the genome. (Johan Jarnestad / The Royal Swedish Academy of Sciences)
Its simplicity has often been compared to the ‘Cut-Copy-Paste’ mechanism in any word processor (or probably, the equally common ‘Find-Replace’ mechanism), while its uses can potentially transform humans and all the other forms of life. It can potentially eliminate genetic and other diseases, multiply agricultural production, correct deformities, and even open up the most controversial possibilities of producing “designer babies” and bringing cosmetic perfection. In fact, everything that is related to the functioning of the genes can be corrected or “edited”.
CRISPR (short for regularly interspaced grouped short palindromic repeats) technology for gene editing has been causing tremendous excitement since it was developed in 2012, both for the promise it holds for improving quality of life, and the dangers of its misuse. Since then, hundreds of scientists and laboratories have started working on the technology for a variety of uses. In the last eight years, the technology has brought a number of awards and honors for its developers. On Wednesday, it culminated in the Nobel Prize in Chemistry for the two women who started it all, Emmanuelle Charpentier of France, 52, and Jennifer Doudna, 56, the American.
It is possibly the only time in the history of the Nobel Prize that two women have been declared the only winners.
The technology
Editing or modifying gene sequences is nothing new. It has been going on for several decades, particularly in the field of agriculture, where various crops have been genetically modified to provide particular traits.
“But what CRISPR has done is make gene editing very easy and simple, and at the same time extremely efficient. And the possibilities are almost endless, ”said Debojyoti Chakraborty, who works with this technology at the New Delhi-based CSIR-Institute of Genomics and Integrative Biology.
In essence, the technology works in a simple way: it locates the specific area in the genetic sequence that has been diagnosed as causing the problem, cuts it out, and replaces it with a new, correct sequence that no longer causes the problem. trouble.
The technology replicates a natural defense mechanism in some bacteria that uses a similar method to protect itself from virus attacks.
An RNA molecule is programmed to locate the particular problematic sequence in the DNA strand, and a special protein called Cas9, now often described in popular literature as “genetic scissors,” is used to break and remove the problematic sequence . A strand of DNA, when broken, has a natural tendency to repair itself. But the automatic repair mechanism can lead to the growth of a troublesome sequence. Scientists intervene during this self-repair process by providing the desired sequence of genetic codes, which replaces the original sequence. It’s like cutting a part of a long zipper somewhere in between and replacing that part with a new segment.
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Because the entire process is programmable, it is remarkably efficient and has already produced near-miraculous results. There are many diseases and disorders, including some forms of cancer, that are caused by an unwanted genetic mutation. All of these can be solved with this technology. There are wide applications elsewhere as well. The genetic sequences of disease-causing organisms can be altered to render them ineffective. Plant genes can be edited to resist pests or improve their tolerance to drought or temperature.
“In terms of its implications, this is possibly the most significant discovery in the life sciences after the discovery of the double helix structure of the DNA molecule in the 1950s,” said Siddharth Tiwari of the National Institute for Agri-Food Biotechnology. based in Mohali, who has been using CRISPR technology on genes from banana plants.
Emmanuelle Charpentier and Jennifer Doudna, for discovering the CRISPR / Cas9 genetic scissors, which can be used to change the DNA of living things.
Winners
Charpentier and Doudna were working independently when they came across different pieces of information that later came together to develop this technology. Charpentier, a biologist then working in a laboratory in Sweden, needed the expertise of a biochemist to process the new information she had gained about the genetic sequences of a particular bacterium she had been working on called Streptococcus pyogenes.
He had heard of Doudna’s work at the University of California, Berkeley, and the two met at a scientific conference in Puerto Rico in 2011, according to an account posted on the Nobel Prize website. Chapentier proposed a collaboration, to which Doudna agreed. Then their research groups collaborated long-distance over the next year. Within a year, they had been able to introduce revolutionary gene editing technology.
Several other scientists and research groups also made vital contributions in the development of this technology. Someone like Virginijus Siksnys, a biochemist working at Vilnius University in Lithuania, is widely recognized as a co-inventor of this technology. In fact, Siksnys shared the 2018 Kavli Award in Nanoscience with Doudna and Chapentier for this technology. But the fundamental contribution of the two women is indisputable. His achievement has been recognized through several prestigious awards in recent years, including the Breakthrough Award in Life Sciences in 2015 and the Wolf Award in Medicine earlier this year.
There have been some murmurs in the scientific community that the Nobel Prize in Chemistry was awarded to biologists. But apparently this is not a new phenomenon. The central role of chemistry in the life sciences – at the molecular level, biology is essentially chemistry – has ensured that a growing number of Nobel Prizes have recently been awarded for work in the field of biochemistry. In fact, a research article published earlier this year has pointed out this gradual change in the nature of the Chemistry award. According to Chemistry World, a news magazine published by the Royal Society of Chemistry, of the 189 scientists awarded the Nobel Prize in Chemistry so far, 59 had worked in the field of biochemistry. This was more than any other branch of chemistry.
Read also | The Nobel Laureates in Physics and Medicine
Ethical concerns
In November 2018, a Chinese researcher in Shenzen caused an international sensation with his claim that he had altered the genes of a human embryo that ultimately resulted in the birth of twin girls. This was the first documented case of ‘designer babies’ to be produced using new gene editing tools like CRISPR, and it raised exactly the kinds of ethical concerns that scientists like Doudna have been talking about.
In the case of the Chinese twins, the genes were edited to ensure that they do not become infected with HIV, the virus that causes AIDS. This special trait would also be inherited by later generations. The concerns were not so much about why the technology was used as about the ethics of producing babies with particular genetic traits. The scientists pointed out that the problem in this case, the potential infection by the HIV virus, already had other solutions and alternative treatments. What made matters worse was that the gene editing was likely done without any permission or regulatory oversight. Others also pointed out that while the CRISPR technology was incredibly accurate, it was not 100% accurate and it is possible that some other genes were mistakenly altered as well.
Doudna herself has been campaigning for the development of international rules and guidelines for the use of CRISPR technology, and has advocated for a widespread hiatus from such applications up to that point.
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