The sci-fi technology tackling malarial mosquitos

Liz O'Neill, an environmental crusader, is outspoken about gene drives, the next generation of genetic modification (GM) technology.

"It is extremely worrying," said the director of GM Freeze, a UK anti-GM lobbying organization. "To release something that has been specifically created in a laboratory in order to outfight nature, and spread without exception within wild populations, is extraordinary arrogant.
"And once the genie is out of the bottle, you cannot put it back in."

Gene drives function in a way that sounds like something out of a science fiction novel, yet they're already being tested in labs. It's difficult, but here's a straightforward explanation.
Gene drive technology goes one step farther than traditional GM in that it delivers a new, lab-tweaked gene into an organism. It adds a gene drive, which is a lab-created gene that can also reproduce itself and targets and eliminates a native gene.
This is how it works: when an animal (parent A) with a gene drive mates with one that doesn't (parent B), parent A's gene drive kicks in when the growing embryo begins to merge their genetic material.

It recognizes the natural gene form of itself on the chromosome opposing parent B and cuts it out of the DNA chain to destroy it. The chromosome of parent B then repairs itself, but it does so by replicating parent A's gene drive.

So, rather than a 50% chance with ordinary GM, the embryo and its children are very certain to carry the gene drive.

Genetic scissors

Gene drives are made by combining a gene with Crispr, a programmable DNA sequence. This instructs it to look for the natural version of itself in the other parent's DNA in the new embryo. Additionally, the gene drive contains an enzyme that performs the actual cutting.

Gene drives are able to cut another gene out of a strip of DNA

So, what exactly is the aim of such sophisticated technology? Gene drives might be used to drastically reduce the number of malarial mosquitos, as well as other pests and invasive species.

This method is more successful than traditional DNA since the implanted gene characteristic spreads more quicker and further because every offspring has it.
Target Malaria, for example, has created gene drives that prevent mosquitos from developing female progeny. Only female mosquitos bite, and without females, mosquito populations will drop.

The main goal is to drastically reduce malaria deaths, which the World Health Organization estimates will total 627,000 by 2020.

It may also reduce the disease's economic effect. Malaria is expected to cost the region $12 billion (£9.7 billion) in lost economic production per year by 2020, with 241 million cases predominantly in Africa.

Invasive species' financial impact is considerably greater, ranging from cane toads to lionfish, brown snakes, fruit flies, zebra mussels, and Japanese knotweed. According to the US Department of Agriculture's National Invasive Species Information Center, they cost the US and Canada $26 billion (£21 billion) every year. It estimates a global effect of $1.29 trillion over the last 50 years.

However, activists like as Liz O'Neill argue that the hazards of unintended consequences, such as the gene drive causing damaging and unexpected mutations and knock-on effects, are too great.

"Gene drives are GM on steroids supercharged," she explains. "Every concern one would have about the use of any genetic modification is exponentially more worrying when talking about gene drives because of how far and wide they are designed to spread."

Despite the fact that the technology has yet to be approved for use in the wild, there are no restrictions on further laboratory study. The United Nations Convention on Biodiversity determined in 2018 that this may continue after extensive discussion.

Dr. Jonathan Kayondo works at Target Malaria in Uganda as a primary investigator. He reminds out that natural gene drives already exist, such as dominant or "selfish genes" that take precedence over weaker genes. He also emphasizes that safety is still a top priority in the development of modified gene drives.

"Malaria is one of the oldest diseases on the planet, and despite decades of efforts, a child still dies of malaria every minute," he adds. "Innovative approaches are urgently needed as both the malaria mosquito and the malaria parasite are becoming increasingly resistant to current methods. Gene drive approaches could be part of an integrated approach to combat malaria, complementing existing interventions."

Target Malaria is continuing to test gene drives on mosquitos at Imperial College in London and Polo GGB, an Italian research organization, according to Dr. Kayondo.

"The project is proceeding step-by-step, and at each phase the safety of the technology is being evaluated," he says.
"External scientific advice and independent external risk assessment are being sought for each stage and phase of the research, and the project will not proceed further if evidence of a concern about human, animal health or environmental safety makes the technology unacceptable to participating communities and national governments."

Kevin Esvelt, an associate professor at Massachusetts Institute of Technology, is one of the world's pioneering gene drive innovators. He initially proposed the concept in 2013.

Prof. Esvelt claims that the key worry is safety, which is included into the most recent gene drive technology.

"Given the potential for gene drives to alter entire wild populations and therefore ecosystems, the development of this technology must include robust safeguards and methods of control," he writes.

Prof. Esvelt says that "daisy chain" technology is used to supply this technology. A gene drive is designed to become inactive after a few generations in this way. Alternatively, halving its spread every generation until it ceases.
He claims that with this method, he can regulate and isolate the distribution of gene drives.

"A town could release GM organisms with its boundaries to alter the local population [of a particular organism] while minimally affecting the town next door," he explains.

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