Two chemists received the Nobel Prize in chemistry for their gene editing work, NPR reported Wednesday. Emmanuelle Charpentier and Jennifer Doudna took the prize for their groundbreaking work with CRISPR, a precise gene editing technology. CRISPR is key to modern human genome work.
According to NPR, the two women who won the 2020 Nobel Prize in chemistry have been instrumental in the use of CRISPR, a gene editing tool that has skyrocketed to fame in the last eight years and that NPR referred to as “genetic scissors that can cut DNA at a precise location, allowing scientists to make specific changes to specific genes.”
“Already, doctors have used the technology to experimentally treat sickle cell disease, with promising results,” the article said. “While some research advances take decades for people to fully appreciate how transformative they are, that wasn’t the case for this new tool, known as CRISPR-Cas9.”
The article also mentioned that with CRISPR’s potential, scientists must carefully consider how to use it ethically and responsibly.
The Best Offense
CRISPR technology resulted from the study of naturally occurring activities of bacteria in cutting DNA precisely, developing into the process of scientific bacterial genome editing, but how does this all work?
“The CRISPR defense system involves two steps: recognizing viruses and killing them,” said Professor Sam Kean, bestselling author. “Whenever bacteria survive a virus attack, they take some viral DNA and store it as a spacer. It’s basically a genetic mugshot to help them recognize the virus next time.”
To kill the virus, Professor Kean said, bacteria use a special enzyme like Cas9 to cut the DNA. The spacer DNA build something called an RNA guide, which is complementary to the viral DNA. The RNA guide locks onto the complementary DNA so Cas9 knows where to cut.
“Overall, then, the ‘mugshot-guide system’ is a safety measure,” he said. “It ensures that only the virus DNA gets snipped, and only at a specific point.”
Microbiologists at Danisco, a food company that sold yogurt, figured this out in order to stop viruses from killing off harmless bacteria that are used to help give yogurt its sour flavor. Danisco was eventually bought by Dupont, who used the research for yogurt and cheese, making CRISPR a household name in the dairy industry.
The Road to Nobel
“In 2011, Emmanuelle Charpentier attended a scientific conference in San Juan, Puerto Rico,” Professor Kean said. “Charpentier studied flesh-eating bacteria and had come across the CRISPR defense system in one of those bacteria. The idea that bacteria were capable of actually cutting DNA so precisely fascinated her; she realized that what the bacteria were doing could be an amazing gene-editing tool, and not just in bacteria.”
Charpentier tracked down Jennifer Doudna, whose lab at the University of California at Berkeley had been studying CRISPR, and they decided to work together. According to Professor Kean, bacteria DNA share the same base as all other organisms, so why wouldn’t CRISPR work on plants and animals as well?
“Instead of relying on the virus mugshots to tell the scissors where to cut, Doudna and Charpentier realized that they could swap in their own RNA guide,” he said. “That way, the scissors could cut the DNA at any point they chose.”
The two have worked together ever since, quickly realizing CRISPR’s potential and leading to their Nobel Prize in chemistry.
Professor Sam Kean contributed to this article. Professor Kean received BA degrees with honors in Physics and English Literature from the University of Minnesota Twin Cities as well as a master’s degree in Library Science from the Catholic University of America in Washington, DC.