The mystery of how some animals can sniff out sickness may have been solved. at the University of Geneva, Switzerland, and his colleagues have identified a type of smell receptor in mice that seems to respond to disease-related molecules produced by bacteria, viruses, or as the result of inflammation.
Several species of mammal, including mice, rats and dogs, are able to sniff out disease in humans and other animals. Researchers had previously identified four classes of receptor that mice and other mammals use to smell, but none of these provided an explanation for this phenomenon.
To see if any other receptors existed, Rodriguez鈥檚 team took tissue from the vomeronasal organ 鈥� a pheromone-detecting sense organ found in the nasal cavity of mice, and some other mammals 鈥� and searched for genes expressing other possible smell receptors.
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They identified five receptors closely related to a class of receptor already known to help immune cells hone in on pathogens and inflammation.
Further experiments showed that these vomeronasal receptors could be activated by molecules related to disease, which are excreted in urine when animals are sick.
Nose for illness
The next step is to destroy these receptors and see if the mice can still sniff out disease.
Rodriguez believes the receptors could ultimately be incorporated into an artificial nose that would detect illness.
鈥淭he receptors are very versatile, so you won鈥檛 be able to say 鈥榯his is the disease鈥�, but you might be able to say 鈥榯his [person] is sick鈥�,鈥� he says.
Journal reference: (in press)
