Scientists Discover Thermal Sensors in Fruit Flies Linked to Taste and Smell

A team of scientists has discovered a molecular temperature sensor in fruit flies that plays a key role in taste and smell. These sensors will help scientists understand how insects spread diseases among humans.

For animals to survive and reproduce, the temperatures has to be right. The sensitive temperature sensors help the animals to stay in their comfort zone in the right temperature. The sensors help animals detect the narrow margin in which they can survive.

In a new finding, a team of scientists from Brandeis University discovered a molecular temperature sensor, unknown till date, in fruit flies. They claim that these sensors are responsible for taste and smell. They are also found in disease spreading insects such as tsetse flies and mosquitoes.

According to Paul Garrity, a professor of biology at Brandeis, biting insects like mosquitoes are easily drawn toward carbon dioxide and heat. In humans, they target a place that has most blood because these areas are the warmest.

"If you can find a mosquito's temperature receptor, you can potentially produce a more effective repellent or trap. The discovery of this new temperature receptor in the fruit fly gives scientists an idea of where to look for similar receptors in the mosquito and in other insects," says Garrity, who is also the co author of the study.

This newly discovered sensor belongs to the family of proteins called gustatory receptors. Several studies have been conducted on the protein but this is the first time that it is being associated to thermosensation.  Previous studies have revealed that gustatory receptors permit insects to smell carbon dioxide and taste sugar and bitter chemicals.

In fruit flies, the receptors mainly sense heat and not smell and taste as in other flies. They can sense external temperature with the help of a receptor called Gr28b. This receptor triggers a response immediately if the temperatures cross the fly's comfort zone.

By revealing that the fruit fly has a distinct external and internal system for detecting heat, this study solves the previous mysteries of how fruit fly senses heat.

"This research reveals a new way in which animals detect temperature," Garrity says. "It's important because heat detection is critical for the behavior of insects that spread disease, kill crops and impact the environment."

The study was published in the journal Nature.