Gene drive could be used to wipe out invasive mice on islands

The person is Michael Le Page.

For the first time, researchers have created a type of genetic parasites that can be used to eradicate pests such as mice.

The technology could provide a humane alternative to the poison baits currently used to tackle mice on islands, which have severe impacts on native birds.

It is the first example of a technology that has had proof of concept in a laboratory.

The offspring of animals get one copy from each parent. Half of an individual's offspring will inherit a piece of their parent's genetic material if it is added to one of their chromosomes.

Gene drives are bits of DNA that are used to cheat the system and make sure they are passed on to more than half of offspring. Even if they are harmful, they can spread.

Natural genes have been discovered. The first synthetic gene drive was created by Kevin Esvelt at Massachusetts Institute of Technology. Several teams hope to use CRISPR-based gene drives to prevent the spread of malaria by wiping out mosquitoes or by making them less likely to transmit the disease.

Is there a species that really exists? Is genes fate? Is there only one way to survive? Is it possible toshape or stop evolution? A new picture of life is being provided by new insights into nature.

The reasons why gene drives don't work in mammals aren't understood. Thomas modified a natural gene drive in mice to make them infertile.

The t haplotype slows the swimming speed of sperm if they have a counter mechanism in the genes. 95 percent of children inherit the t haplotype. The researchers added a component that modifies agene essential for female fertility

80% of the fertility genes were disabled when the system was tested in mice.

As the drive spread in a population, more and more mice would inherit two copies and they would be infertile. Thomas thinks that the population will crash at that time.

The mice would be wiped out in 20 to 25 years if 250 were released on an island with 200,000 mice. The model shows that 80 per cent works better than 100 per cent when it comes to slowing the spread of the drive.

Safety first

The risk of gene drives is that they can spread to areas where animals are native. The drive couldn't spread if the mice somehow escaped because the components were split and put on different chromosomes.

It was only tested over a single generation. A high-level containment lab was used for the tests. Thomas says that they are conscious of the safety aspects of the project.

The next step is to create a fully assembled gene drive that will only work in mice with one of the genetic variations identified. The team hopes to get regulatory approval to release it on the one island where it can spread.

"Baits are expensive and do not always work." The cause of death is not horrible.

The goal is not to eradicate mice on mainland Australia, but to eradicate mice from islands.

The University of California, San Diego's team is trying to get a drive that works in mice.

She says that the individual components do work well in a single generation. The system will need to be tested for many generations.

There is a journal reference in the Pnas.