— Archaeologists find new evidence of animals being introduced to prehistoric Caribbean — An archaeological research team from North Carolina State University, the University of Washington and University of Florida has found one of the most diverse collections of prehistoric…
— Microscopic worms could hold the key to living life on Mars — The astrophysicist Stephen Hawking believes that if humanity is to survive we will have up sticks and colonise space. But is the human body up to the challenge?…
— Chemical warfare of stealthy silverfish — A co-evolutionary arms race exists between social insects and their parasites. Army ants (Leptogenys distinguenda) share their nests with several parasites such as beetles, snails and…
— Stinky frogs are a treasure trove of antibiotic substances — Some of the nastiest smelling creatures on Earth have skin that produces the greatest known variety of anti-bacterial substances that hold promise for becoming new weapons in the battle…
— Genetic code of first arachnid cracked — An international team of scientists - including Ghent VIB scientists - has succeeded in deciphering the genome of the spider mite. This is also the first known genome of an arachnid.…
— How bats 'hear' objects in their path — By placing real and virtual objects in the flight paths of bats, scientists at the Universities of Bristol and Munich have shed new light on how echolocation works. Their research is…
— Counting cats: The endangered snow leopards of the Himalayas — The elusive snow leopard (Panthera uncia) lives high in the mountains across Central Asia. Despite potentially living across 12 countries the actual numbers of this beautiful large…
— Surprise role of nuclear structure protein in development — Scientists have long held theories about the importance of proteins called B-type lamins in the process of embryonic stem cells replicating and differentiating into different varieties…
— Pregnancy is a drag for bottlenose dolphins — Lumbering around during the final weeks before delivery is tough for any pregnant mum. Most females adjust their movements to compensate for the extreme physical changes that accompany…
How do organisms make dietary choices?
When given a choice, organisms will choose a diet that maintains a nutritional balance in tune with their needs. That choice, studied in fruit flies for the first time, is regulated by activity in a molecular pathway involved in ageing, cancer and diabetes. The research undertaken in fruit flies at the Buck Institute for Age Research has implications for humans, who share the same molecular pathway. The study, the first to be done in a genetically tractable lab animal, provides a way to begin the development of treatments that could 'reboot' metabolic pathways in individuals who are obese or suffer from diabetes. The study appears in the May 13, 2010 online edition of the journal Current Biology.
'How an organism balances its intake of nutrients has a great impact on its health and survival,' said Buck faculty member Pankaj Kapahi, PhD, the lead author on the study, who said that an imbalance of protein and carbohydrates has been implicated as a cause for both diabetes and obesity and influences the ageing process, 'In this study we've established a model using the fruit fly to address the question of how an organism chooses between protein and carbohydrate.'
The study revealed that fruit flies deprived of either carbohydrates or protein (yeast) in their diet show a strong preference for the nutrient they were previously deficient in. In addition, the researchers discovered that the gender and the mating status of the species alters its dietary choices. They found that S6 Kinase, a key protein in the TOR (target of rapamycin) pathway which is involved in nutrient sensing in all species ranging from plants to humans, also influences dietary choices. TOR is well established as playing an important role in cancer, diabetes and ageing. The study also found that changes in levels of serotonin influence the choice between protein and carbohydrate. Serotonin is a key neurotransmitter found in the gut and in the brain and is involved in the regulation of mood, appetite, sleep and cognitive functions.
Kapahi emphasised that this study opens the doors to study the phenomenon of dietary choices in a genetically tractable animal, something new in a laboratory environment where animals are generally put on fixed diets. 'This study allows us to begin to ask the question of whether changes in metabolism and ageing are influenced by dietary choices,' said Kapahi. 'These studies will have great relevance for humans who share these nutritional signalling pathways with flies.' Kapahi said the issue of choice becomes vital as treatments are developed for obesity and diabetes. 'This adds a crucial dimension to the research, one that takes into account the reality of human experience which involves food choice,' he said.
'Dietary choices in humans play a critical role in the development of obesity and diabetes,' said Kapahi. 'This research can help us develop treatments that correct nutritional imbalances.' As examples, Kapahi mentioned possible treatments for those genetically predisposed to diabetes or obesity. He also said it may be possible to develop treatments that would 'reboot' the metabolism of people who have become accustomed to eating excess sugar and carbohydrates.
Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.
Rare behind-the-scenes peek at national treasures
Study offers new evidence of how snake fangs evolved from regular teeth
Scientists describe new species of water mite using confocal microscopy
Stem cell chicken and egg debate moves to unlikely arena - the testes