A natural gene drive may exterminate invading rodents on islands.

Scientists are use the invasive house mouse's own DNA against it in the fight on islands.

The invading mouse population on an island might be eliminated in roughly 25 years with the correct modifications, according to research published in the Proceedings of the National Academy of Sciences on November 15. The idea is to include the modifications into a region of mouse DNA that is inherited far more frequently than it should be.

In the laboratory, researchers have started constructing related extra-heritable genes, often known as gene drives. The pieces are intended to be inherited by most or all of an animal's progeny rather than the customary half, rendering those offspring sterile in the process.

Mammals, though, are a another matter. A gene drive that is inherited by mice roughly 80% of the time has already been created by scientists (SN: 1/23/19). However, the push is insufficient to swiftly halt a population.

Thankfully, nature is in charge of it. A haplotype is a naturally occurring collection of genes that is replicated as a whole. The t haplotype, which is unique to the house mouse (Mus musculus) genome, is passed on to progeny more frequently than 95% of the time, as opposed to the average 50%.

According to Anna Lindholm, a scientist at the University of Zurich who was not involved in the study, this spontaneous gene drive offers advantages.

With the molecular cut-and-paste technology CRISPR/Cas9, molecular researcher Paul Thomas and his colleagues chose to target the t haplotype (SN: 8/24/16). The gene sequence for the CRISPR tool itself was inserted into the t haplotype using CRISPR. The inserted CRISPR tool genes activate when a male mouse with the modified t haplotype mates with a female. The prolactin gene is targeted and rendered inactive using a unique genetic guide, leaving any future female mice sterile.

The best aspect, according to Thomas of the University of Adelaide in Australia, is that the natural t haplotype may also sterilise males. Homozygous men, or those with two copies, are incapable of procreation.

"You could make homozygous guys infertile if you could get a t to propagate across a population," he claims. "And on top of that, we obtain homozygous females that are also sterile because to the CRISPR element."

The researchers utilised a computer simulation of an island with 200,000 mice to see how the t haplotype mice fare on an island where mice are destroying biodiversity. The research team discovered that injecting only 256 mice with the CRISPR-altered t haplotype was sufficient to successfully eradicate the mouse population in about 25 years. Adding mice with the typical t haplotype might wipe out the population in roughly 43 years, even without CRISPR.