Fruit fly's 'sweet tooth' short-lived, research finds

October 16, 2012
Fruit fly (Drosophila melanogaster) feeding on a strawberry. Credit: Michael Gordon, the University of British Columbia.

While flies initially prefer food with a sweet flavor, they quickly learn to opt for less sweet food sources that offer more calories and nutritional value, according to new research by University of British Columbia zoologists. The findings, published this week in the Journal of Neuroscience, are the first to measure the shift in food preference over time, and the first to find that flies opt for nutritious food more quickly when they're hungry.

The humble fruit fly may have something to teach us about forgoing for more nutritional ones – especially when we're hungry.

While the flies initially prefer food with a sweet flavour, they quickly learn to opt for less sweet food sources that offer more calories and nutritional value, according to new research by University of British Columbia zoologists.

The findings, published this week in the Journal of Neuroscience, are the first to measure the shift in food preference over time, and the first to find that flies opt for more quickly when they're hungry.

"The is important for quick – often life and death – decisions about what to eat," says Michael Gordon, a UBC and senior author on the paper. "Typically the initial taste of sugar indicates a good source of carbohydrates, but longer-term feeding preferences integrate past experiences and learning. It appears that is an important part of that."

"From a behavioural standpoint, it seems that mammals and flies can show similar responses to calorie sensing," adds Gordon, an assistant professor with the Department of Zoology. "But mechanistically we're still only beginning to understand how either senses the caloric value of food independently of taste after eating it."

The researchers allowed (Drosophila melanogaster) to choose between sources of liquid sugar that varied in their ratios of sweetness to caloric value. In some instances it took the populations of flies as little as four hours to shift their preference towards more nutritious food sources – typically based on sugars like sucrose, maltose and D-glucose.

Researchers also isolated several molecular pathways in a strain of flies that appear to affect taste and feeding preference and found that blocking insulin signaling increased preference for nutritious sugars.

Explore further: Brain's 'sixth sense' for calories discovered

More information:

Research Method

In addition to observing food preferences, the UBC research team also used mutant strains of fruit flies to isolate several molecular pathways that appear to affect taste and feeding preference. They found that developing a preference for caloric sugars depends on the cAMP pathway, which plays a wide array of roles in the nervous system but is best known for affecting learning and memory.

The researchers also found that blocking insulin signaling in a strain of flies increased their preference for nutritious sugars. Insulin plays important metabolic roles in both flies and mammals and is known to be regulated by feeding. The regulating of feeding behaviour by insulin signaling has also been demonstrated in mammals.

Related Stories

Brain's 'sixth sense' for calories discovered

March 26, 2008

The brain can sense the calories in food, independent of the taste mechanism, researchers have found in studies with mice. Their finding that the brain’s reward system is switched on by this “sixth sense” machinery ...

Liking sweets makes sense for kids

March 18, 2009

As any parent knows, children love sweet-tasting foods. Now, new research from the University of Washington and the Monell Center indicates that this heightened liking for sweetness has a biological basis and is related ...

Happy flies look for a place like home

October 19, 2009

(PhysOrg.com) -- A happy youth can influence where a fruit fly chooses to live as an adult, according to new research in The American Naturalist. The study, led by Judy Stamps from the University of California at Davis, provides ...

How the brain decides what to eat

May 13, 2010

Having a balanced diet is a vital concern to all living organisms, not only humans. Animals choose between different food sources according to their nutritional needs. In a study just published in the journal Current Biology, ...

The buzz around beer

November 17, 2011

Ever wondered why flies are attracted to beer? Entomologists at the University of California, Riverside have, and offer an explanation. They report that flies sense glycerol, a sweet-tasting compound that yeasts make during ...

Recommended for you

Secrets of a heat-loving microbe unlocked

September 4, 2015

Scientists studying how a heat-loving microbe transfers its DNA from one generation to the next say it could further our understanding of an extraordinary superbug.

Plants also suffer from stress

September 4, 2015

High salt in soil dramatically stresses plant biology and reduces the growth and yield of crops. Now researchers have found specific proteins that allow plants to grow better under salt stress, and may help breed future generations ...

Ancient walnut forests linked to languages, trade routes

September 4, 2015

If Persian walnut trees could talk, they might tell of the numerous traders who moved along the Silk Roads' thousands of miles over thousands of years, carrying among their valuable merchandise the seeds that would turn into ...

Huddling rats behave as a 'super-organism'

September 3, 2015

Rodents huddle together when it is cold, they separate when it is warm, and at moderate temperatures they cycle between the warm center and the cold edges of the group. In a new study published in PLOS Computational Biology, ...

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.