New gene tech could wipe out entire species

Manipulating naturally-occurring gene drives has potential to vastly reshape ecosystems

HONOLULU • Scientists from around the world are currently gathered in Hawaii for an international conservation congress, where they have spent the past week discussing the most pressing issues facing the environment today.

One topic on the table is a form of genetic editing called "gene drive" technology, which can be used to alter - or even wipe out - entire species.

And while some experts have argued that the practice could be a useful conservation tool, others have warned that its impact on the environment could be devastating should it get out of control.

Members of the International Union for Conservation of Nature (IUCN), which is holding its World Conservation Congress in Honolulu until tomorrow, recently approved a motion that would prohibit the organisation from supporting or endorsing any research or field trials on the use of gene drives until a comprehensive assessment of the technology's effects has been undertaken.

The motion is non-binding and does not dictate the regulations that individual countries may choose to establish for themselves. But it does reflect a growing concern among scientists and environmentalists about the technology's potential power to irrevocably alter species and reshape ecosystems.

A gene drive is a stretch of DNA that gets passed on to offspring more frequently than regular genes. In most sexually reproducing organisms, offspring have a 50 per cent chance of inheriting a given trait from one of their parents. Gene drives increase the odds.

To be clear, gene drives are a naturally occurring phenomenon - they are found in all kinds of species in nature. But it was not until recently, with the advent of new genetic engineering tools, that scientists realised they could be harnessed by humans.

Genetic editing tools such as Crispr allow scientists to make precise cuts and splices in an organism's DNA, allowing them to physically alter genes and change the traits that they code for. Recently, researchers also realised that such tools could also be used to attach gene drives to DNA sequences, greatly increasing the likelihood that these genes would be passed on.

Scientists have already begun to brainstorm ways that this tech- nology could be used for conservation purposes.

Scientists, for example, have suggested that gene drive technology could be used to render mosquitoes on the Hawaiian islands incapable of transmitting malaria, by tricking the mosquitoes' immune systems into attacking the parasite that causes the disease.

Still, the technology could theoretically be used to kill off species in a similar way. Some scientists have suggested, for instance, that gene drives could be used to eradicate invasive populations of rats and mice from islands by engineering the rodents to produce only male offspring.

But while there is clear potential for the technology to do good, many experts have expressed concern about the potential changes it could cause in the natural world.

Gene drives in their most aggressive forms have the potential to spread irreversibly throughout entire species, and it is not clear how this could affect the environment.

However, it is important to note that gene drive technology can take several different forms, and some are safer than others, said Associate Professor Floyd Reed from the University of Hawaii's biology department. Prof Reed's lab is involved in gene drive research on fruit flies, with plans to begin moving forward with mosquitoes next.

Although reversible systems are still not completely understood, a moratorium on research or even field trials for this type of technology may not be necessary, he said, so long as they are subject to rigorous regulation and public consultation.


A version of this article appeared in the print edition of The Straits Times on September 09, 2016, with the headline 'New gene tech could wipe out entire species'. Print Edition | Subscribe