Flies Get Drunk to Kill Off Parasites

Fruit flies can apparently out-drink Frank the Tank and not get sick from alcohol poisoning. Now researchers have found this fraternity-party ability may save flies from a gory death.

The results showed that drunk fruit-fly larvae turned the tables by killing wasp parasites in their bloodstream, essentially causing the parasite's organs to drain from its anus, the researchers found.

Fruit fly larvae feed on the yeast and other fungi from rotting, or fermenting, fruit; during their snacking, the flies are bound to ingest the boozy byproducts of the fungi's fermentation — they are even able to use it as a food source and thrive on food with up to 4 percent alcohol.

Higher alcohol levels can be toxic to the fruit flies, study researcher Todd Schlenke, an assistant professor at Emory University, told LiveScience. "If the alcohol level gets too high, they can't break it down fast enough." The flies in the study only reached about 0.02 percent blood alcohol levels, they would have to drink four times that to reach the blood alcohol level considered illegal for driving.

Read on:  http://www.livescience.com/18513-fruit-flies-alcohol-parasites.html

Fruit Flies Watch the Sky to Stay On Course

ScienceDaily (Jan. 17, 2012) — Insects, equipped with complex compound eyes, can maintain a constant heading in their travels, some of them for thousands of miles. New research demonstrates that fruit flies keep their bearings by using the polarization pattern of natural skylight, bolstering the belief that many, if not all, insects have that capability.

"If you go out in a field, lie on your back and look up at the sky, that's pretty much what an insect sees," said Michael Dickinson, a University of Washington biology professor. "Insects have been looking up at this view forever."Dickinson is the senior author of a paper providing details on the findings, published Jan. 10 in the journal Current Biology. The lead author is Peter Weir, a doctoral student at the California Institute of Technology.The researchers noted that insects such as monarch butterflies and locusts maintain a constant heading while migrating thousands of miles across continents, while bees and ants hunting for food successfully find their way hundreds of feet back to the nest without a problem. That has led scientists to believe that the animals must possess a compass of sorts.

Continued: http://www.sciencedaily.com/releases/2012/01/120117161432.htm

Fruit Fly Intestine May Hold Secret to Fountain of Youth: Long-Lived Fruit Flies Offer Clues to Slowing Human Aging and Fighting Disease

ScienceDaily (Nov. 2, 2011) — One of the few reliable ways to extend an organism's lifespan, be it a fruit fly or a mouse, is to restrict calorie intake. Now, a new study in fruit flies is helping to explain why such minimal diets are linked to longevity and offering clues to the effects of aging on stem cell behavior.

Scientists at the Salk Institute for Biological Studies and their collaborators found that tweaking a gene known as PGC-1, which is also found in human DNA, in the intestinal stem cells of fruit flies delayed the aging of their intestine and extended their lifespan by as much as 50 percent.

"Fruit flies and humans have a lot more in common than most people think," says Leanne Jones, an associate professor in Salk's Laboratory of Genetics and a lead scientist on the project. "There is a tremendous amount of similarity between a human small intestine and the fruit fly intestine."

The findings of the study, which was a collaboration between researchers at the Salk Institute for Biological Studies and the University of California, Los Angeles, were published online in Cell Metabolism.

Scientists have long known that calorie restriction, the practice of limiting daily food intake, can extend the healthy lifespan of a range of animals. In some studies, animals on restricted diets lived more than twice as long on average as those on non-restricted diets.

While little is known about the biological mechanisms underlying this phenomenon, studies have shown that the cells of calorie-restricted animals have greater numbers of energy-generating structures known as mitochondria. In mammals and flies, the PCG-1 gene regulates the number of these cellular power plants, which convert sugars and fats from food into the energy for cellular functions.

This chain of connections between the mitochondria and longevity inspired Jones and her colleague to investigate what happens when the PCG-1 gene is forced into overdrive. To do this, they used genetic engineering techniques to boost the activity of the fruit fly equivalent of the PCG-1 gene. The flies (known as Drosophila melanogaster) have a short lifespan, allowing the scientists to study aging and longevity in ways that aren't as feasible in longer-lived organisms such as mice or human.

Read on ...

Female flies' sex energy

01 October 2009 16:30 PM

Sex makes female housewives do more chores.

Scientists have discovered a chemical reaction takes place in the female bugs body after mating, which causes them to indulge in intense domestic work for up to ten days.

While the female insects rush about, the exhausted male fruit flies sleep.

Fly sperm is coated with a "sex peptide", which reacts with the females and gives them more energy.

Professor Elwyn Isaac, from Britain's University of Leeds, explained: "Mating made the male flies very lazy and they took a long siesta period afterwards. But the females became much more active and busy.

"They also developed a much more adventurous lifestyle than virgin females, flying around to forage, find nesting sites and perform domestic-type duties."

http://entertainment.stv.tv/showbiz/127275-female-flies-sex-energy/

Female flies' sex energy

01 October 2009 16:30 PM

Sex makes female housewives do more chores.

Scientists have discovered a chemical reaction takes place in the female bugs body after mating, which causes them to indulge in intense domestic work for up to ten days.

While the female insects rush about, the exhausted male fruit flies sleep.

Fly sperm is coated with a "sex peptide", which reacts with the females and gives them more energy.

Professor Elwyn Isaac, from Britain's University of Leeds, explained: "Mating made the male flies very lazy and they took a long siesta period afterwards. But the females became much more active and busy.

"They also developed a much more adventurous lifestyle than virgin females, flying around to forage, find nesting sites and perform domestic-type duties."

http://entertainment.stv.tv/showbiz/127275-female-flies-sex-energy/

Fruit flies sick from mating

Photo: Ted Morrow
Mating can be exhausting. When fruit flies mate, the females' genes are activated to roughly the same extent as when an immune reaction starts. This is shown in a study at Uppsala University that is now appearing in the scientific publication, Journal of Evolutionary Biology.*

Using a combination of behavioral studies and genomic technology, so-called microarrays, researchers at Uppsala University can show how fruit fly females are affected by mating.

"We monitor how genetic expression is impacted by mating and show that the most common process that is affected is the immune defense system," says Ted Morrow at the Department of Ecology and Evolution, Uppsala University.

What's more, the cost of mating turns out to be rather high.

"Previous research findings show that if this cost were not a factor, females would produce 20 percent more offspring," says Ted Morrow.

It is costly for females to mate because competition among males has led to behaviours and adaptations in males that are injurious to females, such as harassment during mating rituals and toxic proteins in their sperm fluid.

"Our results are the strongest evidence that the cost to females is probably tied to the cost of starting an immune reaction. In other words, the males are like a 'sickness' to females," says Ted Morrow.

We can thus conclude the following from the study: the immune defence has developed to combat not only pathogens but also substances produced by males. This lends new meaning to the term 'lovesick.'

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Read the full article online at: http://www3.interscience.wiley.com/journal/119880717/issue

Article: "Immunogenic males: a genome-wide analysis of reproduction and the cost of mating in Drosophila melanogaster females" P. INNOCENTI & E. H. MORROW Department of Animal Ecology, Evolutionary Biology Center, Uppsala University, Uppsala, Sweden DOI: 10.1111/j.1420-9101.2009.01708.x