Navigation Links
'Wrong'-time eating reduces fertility in fruit flies
Date:6/7/2011

PHILADELPHIA - Dieticians will tell you it isn't healthy to eat late at night: it's a recipe for weight gain. In fruit flies, at least, there's another consequence: reduced fertility.

That's the conclusion of a new study this week in Cell Metabolism by researchers at the Perelman School of Medicine at the University of Pennsylvania, in which they manipulated circadian rhythms in fruit flies and measured the affect on egg-laying capacity.

Lead author Amita Sehgal, PhD, John Herr Musser Professor of Neuroscience, stresses, though, that what is true in flies grown in a lab does not necessarily hold for humans, and any potential link between diet and reproduction would have to be independently tested.

"I wouldn't say eating at the wrong time of the day makes people less fertile, though that is the implication," says Sehgal, who is also a Howard Hughes Medical Institute Investigator. "I would say that eating at the wrong time of the day has deleterious consequences for physiology."

It's All Connected

Many aspects of animal biology cycle over the course of a day. Sleep and wakefulness, activity and rest, body temperature, and more, all fluctuate in a pattern called a circadian rhythm. Disruption of these rhythms has been shown to negatively affect physiology. Shift workers, for instance, often suffer from psychological and metabolic issues that colleagues on normal hours do not. Rodents with disrupted circadian rhythms are more likely to develop obesity.

For a while, Sehgal explains, researchers believed animals had a single master molecular clock, located in the brain, that controlled activity throughout the body. In recent years, however, they have come to understand that some individual organs also have their own, independent clocks, like townspeople who wear a wristwatch and keep it synchronized with the clock in city hall.

The mammalian liver is one organ that has its own independent clock. In 2008, Sehgal's team discovered that the fruit fly equivalent of the liver, called the fat body, has its own clock, which controls eating and food storage. They wanted to know what would happen if the fat body clock became desynchronized from the master clock in the brain.

Decoupling Clocks

First, her team asked which fly genes are controlled specifically by the fat body clock. Using gene chip microarrays, they identified 81 genes related to lipid and carbohydrate metabolism, the immune system, and reproduction that fit those criteria.

Next, the researchers attempted to decouple the fat body and central clocks by keeping the flies in constant darkness (to eliminate effects of light on these clocks) and feeding them at times when they don't normally eat. They found the two clocks could be desynchronized: disrupting the animals' feeding cycles altered the cycling of genes controlled by the fat-body clock, but not those regulated by the central clock itself itself.

Finally, the team addressed the functional consequences of this desynchronization, by counting the number of eggs the flies laid under different conditions. Flies fed at the "right" time of the day deposited about 8 eggs per day, compared to about 5 when they fed at the "wrong" time.

"Circadian desynchrony caused by feeding at the 'wrong' time of day leads to a defect in overall reproductive capacity," the authors wrote.

The next question to pursue, Sehgal says, is finding the molecular mechanism that controls this phenomenon: How does the fat body communicate with the ovaries. And, more importantly, is this effect restricted to fruit flies, or does it also occur in higher organisms, including humans.


'/>"/>

Contact: Karen Kreeger
karen.kreeger@uphs.upenn.edu
215-349-5658
University of Pennsylvania School of Medicine
Source:Eurekalert

Related medicine news :

1. Study carried out into biological risks of eating reptiles
2. Bariatricfurnishings.com Launches Unique Eco-friendly Seating for Health Care, Hospitality, Assisted Living Centers, and Home Use at Competitive Prices
3. Legislating to promote healthy eating and physical activity
4. First Breakthrough in Water Heating Technology!
5. Personalizing cancer: Creating biomarkers from tumor DNA
6. Figure Skating Standards Foster Eating Disorders, Says Kimberly Dennis, M.D.
7. Remuda Ranch Programs for Eating and Anxiety Disorders Sponsors a Special Edition of the Award-Winning Documentary America The Beautiful
8. Taxing unhealthy foods may encourage healthier eating habits
9. Savor: Mindful Eating, Mindful Life -- The Definitive Guide to Changing the Way People Eat and Live
10. Europes top football venues are not prepared for treating spectators who suffer heart attacks
11. Seattle Suttons Healthy Eating Sponsoring The Biggest Loser Chicago Casting Call
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2016)... ... June 24, 2016 , ... The ... in Dallas that it will receive two significant new grants to support its ... PHA marked its 25th anniversary by recognizing patients, medical professionals and scientists for ...
(Date:6/24/2016)... ... ... People across the U.S. are sharpening their pencils and honing their writing ... which patients and their families pay tribute to a genetic counselor by nominating him ... Genetic Counselors (NSGC) Annual Education Conference (AEC) this September. , In April, Genome ...
(Date:6/24/2016)... ... June 24, 2016 , ... National recruitment firm ... sciences executive with extensive sequencing and genomics experience, as Vice President of North American ... Hill will be responsible for leading the sales team in the commercialization of the ...
(Date:6/24/2016)... ... June 24, 2016 , ... To succeed under value-based payments, ... are unsure how to move forward, given the need to sustain current operations. ... tailored to an organization’s specific needs. , PYA Principal Martie Ross states, “Healthcare ...
(Date:6/23/2016)... ... June 23, 2016 , ... Terumo BCT, ... organization responsible for clinical transfusion research programs and for the blood supply in ... Evaluation and Predictive Analytical Rating Score (PREPAReS) study. , Currently in its ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... Calif. , June 24, 2016  American Respiratory Labs (ARL), ... is now able to perform sophisticated lung assessments in patients, homes, ... , Inc. Patients are no longer limited to ... EasyOne PRO ® , ARL patients like Jeanne R. of ... in the comfort of her own home. ...
(Date:6/24/2016)... , June 24, 2016   Pulmatrix, Inc ... company developing innovative inhaled drugs, announced today that it ... Russell Investments reconstituted its comprehensive set of U.S. ... "This is an important milestone for Pulmatrix," said ... increase shareholder awareness of our progress in developing drugs ...
(Date:6/23/2016)... 2016  MedSource announced today that it has ... solution of choice.  This latest decision demonstrates MedSource,s ... their clients by offering a state-of-the-art electronic data ... nowEDC as the EDC platform of choice in ... "nowEDC has long been a preferred EDC platform ...
Breaking Medicine Technology: