How gene editing is changing the world

Scientists have made a breakthrough that has the potential to revolutionise the fight against malaria, a disease that still affects more than 200 million people a year and claims over 400,000 lives.

Using the gene editing tool, known as CRISPR-Cas9, researchers genetically modified mosquitoes to make them resistant to malaria. This means that it may now be possible to eradicate the malaria parasite from the mosquito population and stop it spreading to humans.

The discovery is a major milestone in the development of a controversial technology called a “gene drive” that works by making a modified gene spread rapidly through a population.

Gene drives are the latest example of the power of CRISPR editing, which can alter the DNA of living things. CRISPR could have enormous benefits for human development but has also sparked a debate over the possibility that it could be used to create “designer babies”. The gene editing technology is also being used in other areas of biomedical research such as diseases that devastate crops and may become an important tool in future medicine and agriculture.

What is CRISPR-Cas9?

CRISPR (clustered regularly interspaced short palindromic repeats) is a DNA sequence which is part of the bacterial defence system. Cas9 is the name of the protein that transfers resistance. In 2012, researchers showed CRISPR could be used to edit genomes.

What can it do?

The technique allows scientists to tweak the DNA of almost any living being, from bacteria to people. Unlike other gene-editing methods, CRISPR is cheap, quick and easy to use and is now being used in labs around the world. Scientists say CRISPR editing has the potential to treat genetic defects, eradicate diseases, increase food crop yields and even end the organ transplant shortage.

The global spread of CRISPR research publications

How do gene drives work?

Gene drives, which force a gene to spread rapidly through a population, can transform the genetic makeup of natural species because the modified DNA is inherited by future generations.

Previously scientists have managed to genetically engineer mosquitoes that kill off the malaria parasite, but needed a way to ensure the resistance genes would keep spreading through a wild population; and this is where the gene drive comes in.

Using the CRISPR-Cas9 technique to build the gene drive, researchers succeeded in getting the offspring of modified and wild mosquitoes to pass on their anti-malarial genes, spreading resistance through the whole population in the lab.

Why are gene drives controversial?

As well as making mosquitoes resistant to malaria, gene drives have the potential to be used to eradicate pests such as cane toads in Australia, or block the gene that makes locusts swarm.

But scientists have warned that the accidental release of modified organisms could have serious ecological consequences, such as the extinction of important species. And, if they fell into the wrong hands, they could even be used as biological weapons.

Earlier this year, scientists in the UK, US, Australia and Japan called on researchers working in the field to ensure that experimental organisms cannot escape from their labs, be released on purpose, or find their way out in the event of a natural disaster.

Anthony James, a molecular biologist at the University of California, Irvine, and an author of the work on the anti-malaria gene drive, predicts that it will take his team less than a year to prepare mosquitoes that would be suitable for field tests. However, he is quoted as saying he in no rush to release them.

“It’s not going to go anywhere until the social science advances to the point where we can handle it,” he said. “We’re not about to do anything foolish.”

Publication does not imply endorsement of views by the World Economic Forum.

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Author: Rosamond Hutt is a Senior Producer at Formative Content.

Image: A biologist puts her hand in a box with mosquitoes. REUTERS/Paulo Whitaker.