From glow-in-the-dark kitties to spider goats, researchers have been able to achieve some impressive feats through genetic engineering. With the advancement of technology skyrocketing in recent years, altering other organisms’ DNA has never been easier. Yet, curiously, there is one animal that has evaded the tinkering of scientists: the ant. Until now.
The main issue revolves around their sociality. Ant eggs are incredibly difficult to raise without the aid of worker ants, meaning that in the lab it is tough to get genetically edited eggs to survive. Not only that, but because most species revolve around a single female queen who does all the laying, coupled with their complicated lifecycle and genetics, creating a colony with a large number of ants is long and protracted. While strains of transgenic mice can be developed within months, it can take years to achieve this with ants.
But there is a species of ant that seems ripe for genetic modification. The rather brilliantly named clonal raider ants are peculiar within the ant world in that there is no designated queen within the colony. Each ant is allowed to lay their own unfertilized eggs, which then hatch as perfect clones of their mothers. This means the team could let the ants lay eggs, then inject them with edited DNA.
Using CRISPR, now fairly commonplace among geneticists out there, the researchers targeted a particular gene involved in the olfactory, or smelling, system of the ants. Their results are published in bioRxiv. While other organisms, such as fruit flies, only have around 46 odorant receptors, clonal raider ants have an impressive 350. The team suspected that this might mean that smell is critical to the sociality of the ants, and wanted to see what would happen if they disrupted it.
By knocking out one gene named orco after 2 years and 10,000 attempts, they were able to insert it into ant eggs. Following another few months of trial and error, the researchers were then able to introduce the transgenic ants back into the colony and watch what happened. The GM ants, it seemed, were unable to follow scent paths laid down by other members of the colony, while also being restless and going about on their own. It seemed that the edit had indeed impacted their sociality.
This is now one of a few papers to have come out of The Rockefeller University lab using transgenic ants as models. It is hoped that the information gained by these experiments could help further our understanding of sociality.
[H/T: Science Mag]