Geneticists create mice that find the smell of landmines irresistible

Scientists at Hunter College in NYC have genetically engineered mice to be 500 times more sensitive than normal to the smell of TNT. And because they're attracted to the smell, the researchers hope these "hero mice" will be used to detect landmines. Should the idea work, they anticipate the creation of other GMO mice that might some day be able to locate chemical and biological weapons as well.

Detecting landmines is not easy — it's time consuming, expensive, and very dangerous. Normally, metal detectors, radar, magnetometers, and sniffer dogs are used to find them, but so too are specially trained sniffer mice (who are not genetically modified). These mice don't trigger the bombs — they merely allow the minesweeping crew to figure out where the bombs are. But preparing these mice for this special tasks is an incredibly tedious and expensive process — about $7,842 per mouse.

But as Susan Young reports in Technology Review, the new genetically engineered mice could solve these problems, while at the same time providing an incredibly efficient method for bomb detection:

The genetically engineered mice...are so sensitive to TNT that encountering the molecule is likely to change their behavior involuntarily, so they would need little to no training. Charlotte D'Hulst, a molecular neurobiologist at Hunter College who presented her work at a meeting of the Society for Neuroscience, used genetic modification to ensure that the mice have 10,000 to 1,000,000 odor-sensing neurons with a TNT-detecting receptor compared with only 4,000 in a normal animal, "possibly amplifying the detection limit for this odor 500-fold," she says. Each odor-sensing neuron in a mouse's nose is spotted with one kind of odor receptor. Usually, each specific receptor is found in one out of every thousand odor-sensing neurons, but about half the scent-detecting neurons in D'Hulst's mice have the TNT-detecting receptor.

Essentially, the researchers have created a mouse with an "overwhelming dedication" to one particular odor. And isolating this receptor wasn't terribly difficult as TNT smells like bread (at least to the mice).

But not only that, it's also known that a sudden and intense stimulation of the olfactory system can make mice go into seizures — which is not a bad thing. Assuming that a sniffer mouse could be equipped with a location chip, it would go into one of these seizures when it finds the bomb, making it and the landmine easier to find (man, the things they do to mice).

Looking further ahead to the future, the researchers anticipate that other mice might be engineered to sniff out more dangerous compounds like chemical and biological weapons.

The study can be found at PubMed.

Top image: AP Photo | Robert F. Bukaty.