Gene that enables fruit flies to smell identified

Washington, Jan 20 (ANI): Researchers have discovered a gene that is critical to sense of smell in fruit flies, which don't have noses.

A huge part of Fruit flies' brains is dedicated to processing smells.

Flies probably rely on the sense of smell more than any other sense for essential activities such as finding mates and avoiding danger.

UW-Madison researchers have discovered that a gene called distal-less is critical to the fly's ability to receive, process and respond to smells.

The mushroom body is the major centre in the fruit fly brain that processes olfactory information.

The large structure is seen in green, while a subset of axons in the brain are red and dividing cells are blue.

The scientists also found evidence that distal-less is important for generating and maintaining self-renewing stem cells in the large brain structure that is responsible for processing odours and carrying out other important duties.

The corresponding gene in mammals and humans, called Dlx, is known to be important in the sense of smell.

The Dlx gene has also been implicated in autism and epilepsy.

By studying how distal-less works in fruit fly neurons, the scientists also hope to expand understanding of Dlx.

"We're really interested in knowing at a very fundamental level what distal-less is doing in the fly olfactory system and how it's doing it," senior author Dr. Grace Boekhoff-Falk, associate professor of cell and regenerative biology at the University of Wisconsin School of Medicine and Public Health said.

"We're also hoping that what we learn in flies can give us a better understanding of how Dlx works in vertebrates, including humans," Boekhoff-Falk said.

She said that studying distal-less is much easier than studying Dlx, partly because mice and humans have six Dlx genes while flies have only one distal-less.

Odours enter fruit flies through nerve cells designed to receive smells - olfactory receptor neurons.

From receptor neurons, projection neurons relay olfactory information to the large brain structure called the mushroom body (MB), which then triggers the animals to move in the right direction - toward the fragrance of food, for example, or away from the odour of a predator.

The study was published in the Proceedings of the National Academy of Sciences. (ANI)