Scientists Emmanuelle Charpentier and Jennifer Doudna have been the winners of the 2020 Nobel Prize in Chemistry for the “development of a method for genome editing” through a tool called CRISPR-Cas9. Thanks to these “genetic scissors”, the DNA in animals, plants and microorganisms can be modified “with extremely high precision”, highlights the official organization The Nobel Prize.
Without a doubt, this technique has a profound impact on medicine and is currently contributing to new cancer therapies and “can make the dream of curing hereditary diseases come true,” they add.
What is it and what is its potential?
It is a biological tool that allows modifying the genome with high precision and in a much simpler and cheaper way than any other previous technique.. Thus, CRISPR-Cas9 is capable of manipulating the genome by means of scissors that cut and paste the DNA sequences.
The CRISPR / Cas9 system is a defense mechanism possessed by prokaryotic cells (bacteria and archaea), that is, unicellular organisms without a defined nucleus and with genetic material dispersed throughout the cell.
In this way, the defense mechanism of these organisms allows them to defend themselves against viruses in a versatile and very effective way. And it is that, to acquire immunity against a virus, humans must vaccinate generation after generation because we are not capable of inheriting that immunity.
Who laid the foundations for this method?
Based on this defense mechanism and the acquisition of immunity against certain pathogens, the Spanish researcher Francis Mojica discovered that bacteria that develop immunity to a virus genetically transfer that immunity to the daughter cells that are derived from them. It is, therefore, an adaptive immune system that is transmitted from generation to generation.
After several years of study, Francis Mojica made this discovery in 2003, but did not publish it until 2005, when the magazine Journal of Molecular Evolution accepted his job. Therefore, these scissors that allow cutting and pasting DNA sequences were initially discovered by MojicaAlthough more than two decades later, researchers Emmanuelle Charpentier and Jennifer Doudna published this invention.
However, Mojica has been left out of this international recognition even being considered the father of the tool. He was in charge of identifying the CRISPR sequence in microorganisms and discovering that it was a natural defense system of the organism. Based on this theory, in 2012, this year’s Nobel Prize winners in Chemistry developed a universal genome editing tool.
How did the Mojica investigation start?
In 1989, the Spanish scientist joined the Microbiology group at the University of Alicante with a contract to measure the water quality of Alicante’s beaches and, in parallel, he began his doctoral thesis focused on the microorganism Haloferax mediterranei. His intention was to find out the molecular mechanisms that allow this prokaryote to live in the salt flats of Santa Pola.
During your investigation, Mojica discovered that in the genome of these microorganisms there were genetic sequences that were repeated at regular intervals. Intrigued by this biological enigma, he had to wait to have his own laboratory, in the mid-nineties, to try to clarify what these curious sequences were for.
In the absence of public funds to finance his work, Mojica had to turn to bioinformatics in order to do his research. Taking advantage of the fact that complete genomes of different microorganisms were finally being published, the researcher consulted databases accessible to the entire scientific community and discovered that sequences repeated at regular intervals are very abundant throughout the microbial world.
Who can use this tool and why is it a revolution?
This genome editing technique has opened the door to a multitude of applications in practically any organism. Since its inception in 2012, CRISPR / Cas9 has been used to search for new treatments against numerous diseases, such as cancer and AIDS, as well as to obtain new plant varieties or in environmental applications.
Thanks to this tool, the time taken so far to alter the genome at will can be cut considerably, and many have referred to it as the democratization of gene editing because it has made this technology available to any molecular biology laboratory.