Appetite, consumption controlled by clockwork genes at cross-purposes in flies

December 6, 2009

One of the pioneers in research on sleep:wake circadian genes, Amita Sehgal, Ph.D., has discovered that fruit flies' appetite and consumption are controlled by two rival sets of clocks, one in neurons and the other in the fly fat body, which is analogous to the liver.

These research results, which extend the repertoire into metabolism, will be reported at the American Society for Cell Biology 49th Annual Meeting, Dec. 5-9, 2009 in San Diego.

In , Drosophila melanogaster, neurons and fat body tissue exert opposing effects on the storage of nutrient reserves, and thereby on food consumption and the response to starvation, explained Sehgal, Howard Hughes Medical Institute investigator at the University of Pennsylvania Medical School.

The fat promotes the storage of nutrients, thereby allowing the animal to survive periods of starvation, while clocks in the nervous system deplete nutrient stores and promote feeding, most likely to replace the nutrients consumed.

Thus, Sehgal concluded that a circadian rhythm of feeding is likely controlled by the interaction of these metabolic and neuronal clocks.

To understand how drive feeding and metabolism, Sehgal charted the expression levels of molecules in the fat body that are known to change over the day:night cycle.

These experiments led to the identification of several molecules that function in , immune response, detoxification and other different pathways.

The feedback is complicated, noted Sehgal. "We have found that metabolic signals, such as feeding, can change the expression of some of these molecules.

Thus, clocks can drive rhythms of metabolic function, and metabolic signals can affect the clock," she commented.

Circadian clocks have been around for billions of years; even organisms at the roots of the tree of life, such as bacteria, have clockwork genes. However, scientists' understanding of 24-hour circadian clocks has dawned only in recent decades when cell biologists began experimenting with the fruit fly and discovered that 24-hour cycling genes controlled its sleeping patterns.

Research has shown that clockwork genes set the pace for many human body organs, such as the liver whose clock drives rhythms in metabolic function.

Source: American Society for Cell Biology

Explore further: Mammals, fruit flies: same biological clock

Related Stories

Scientists find high-fat diet disrupts body clock

November 6, 2007

Our body’s 24-hour internal clock, or circadian clock, regulates the time we go to sleep, wake up and become hungry as well as the daily rhythms of many metabolic functions. The clock -- an ancient molecular machine found ...

Circadian rhythm-metabolism link discovered

July 24, 2008

UC Irvine researchers have found a molecular link between circadian rhythms – our own body clock – and metabolism. The discovery reveals new possibilities for the treatment of diabetes, obesity and other related diseases.

Molecular partnership controls daily rhythms, body metabolism

November 26, 2008

A research team led by Mitchell Lazar, MD, PhD, Director of the Institute for Diabetes, Obesity, and Metabolism at the University of Pennsylvania School of Medicine, has discovered a key molecular partnership that coordinates ...

Recommended for you

Why communication is vital—even among plants and funghi

May 26, 2017

Plant scientists at the University of Cambridge have found a plant protein indispensable for communication early in the formation of symbiosis - the mutually beneficial relationship between plants and fungi. Symbiosis significantly ...

Darwin was right: Females prefer sex with good listeners

May 26, 2017

Almost 150 years after Charles Darwin first proposed a little-known prediction from his theory of sexual selection, researchers have found that male moths with larger antennae are better at detecting female signals.

The high cost of communication among social bees

May 26, 2017

(Phys.org)—Eusocial insects are predominantly dependent on chemosensory communication to coordinate social organization and define group membership. As the social complexity of a species increases, individual members require ...

Knowledge gap on the origin of sex

May 26, 2017

There are significant gaps in our knowledge on the evolution of sex, according to a research review on sex chromosomes from Lund University in Sweden. Even after more than a century of study, researchers do not know enough ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.