Photo Credit: Omar Akbari

Although gene-drive technology stands as one of the most widely debated inventions of modern biology, it is what California cherry growers are relying on to eradicate the fly species destroying their agriculture. 

According to MIT Technology Review, ever since the spotted wing drosophilia landed in Northern California back in 2008, it has continued to cost US agriculture up to approximately $700 million a year.

Rather than lay their eggs in rotting berries like domestic flies, instead they punch holes in fruit that’s still ripening. In order to eradicate the problem, the cherry growers are relying on a gene drive that is able to spread DNA alterations among wild flies, with the end goal of potentially killing them off. 

Despite controversy, for the first time, thanks to the efforts of the growers, commercial uses are now on the table. With funding from the California Cherry Board, scientists at the University of California, have installed a gene drive in the invasive pest, making it the first time the technology has been established in a commercially important species. 

Futhermore, the work doesn’t stop there. In addition to the efforts, which remain confined to the laboratory, two spinout companies from the University of California, San Diego, are also pursuing commercial use of gene drives. This includes one with, Agragene, which intends to alter plants and insects. Its sister company, Synbal, wants to harness the technology as a speedy way of engineering lab mice and possibly pet dogs. 

The gene drive works via a selfish gene which is able to replicate itself and get inherited by most of an animal’s offspring rather than just half, which is the usual. This process is known as “super-Mendelian” inheritance.

David Webb, acting CEO of both UCSD spin out companies, neither of which has raised capital, said, “It’s about having genes under precise control in whatever organism you are modifying.”

Such work cannot be discussed however, without divulging in some of the potential danger zones. Some scientists are concerned that if laboratory animals escape, then the gene drives could cause changes in the wild. It is worth mentioning, that The Broad Institute of MIT and Harvard has even added gene drives to a list of gene-editing technology it doesn’t think companies should pursue. 

As well as this, technology as powerful as it is will need to be highly regulated. It is for this reason that explains why most gene-drive funding has come from either philanthropies or the military. 

The plan from the growers was put into motion in 2013, when the organisation began funding development of the technology, spending around $100,000 a year, or about a third of its research budget, to have Riverside professor Omar Akbari install a gene drive in that fly’s genome. 

By July, he has already experienced success. The technology, named Medea, spread to 100 percent of flies in experiments in laboratory cages. 

Looking ahead, he explained that the next step will be to determine what genetic cargo to attach to the selfish gene. Female flies survive the winter because their bodies make crypoprotectants. Adding a gene to block those chemicals could cause the flies to freeze. Another possibility is geentically altering the bugs’ ovipositor so that they change their behaviour.