Archive for the ‘Ethanol’ Category

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The fruit fly study adds to the evidence “that using toxins in the environment to medicate offspring may be common across the animal kingdom,” says biologist Todd Schlenke.

When fruit flies sense parasitic wasps in their environment, they lay their eggs in an alcohol-soaked environment, essentially forcing their larvae to consume booze as a drug to combat the deadly wasps.

The discovery by biologists at Emory University was published in the journal Science on February 22.

“The adult flies actually anticipate an infection risk to their children, and then they medicate them by depositing them in alcohol,” says Todd Schlenke, the evolutionary geneticist whose lab did the research. “We found that this medicating behavior was shared by diverse fly species, adding to the evidence that using toxins in the environment to medicate offspring may be common across the animal kingdom.”

Adult fruit flies detect the wasps by sight, and appear to have much better vision than previously realized, he adds. “Our data indicate that the flies can visually distinguish the relatively small morphological differences between male and female wasps, and between different species of wasps.”

The experiments were led by Balint Zacsoh, who recently graduated from Emory with a degree in biology and still works in the Schlenke lab. The team also included Emory graduate student Zachary Lynch and postdoc Nathan Mortimer.

The larvae of the common fruit fly, Drosophila melanogaster, eat the rot, or fungi and bacteria, that grows on overripe, fermenting fruit. They have evolved a certain amount of resistance to the toxic effects of the alcohol levels in their natural habitat, which can range up to 15 percent.

Tiny, endoparasitoid wasps are major killers of fruit flies. The wasps inject their eggs inside the fruit fly larvae, along with venom that aims to suppress their hosts’ cellular immune response. If the flies fail to kill the wasp egg, a wasp larva hatches inside the fruit fly larva and begins to eat its host from the inside out.

Last year, the Schlenke lab published a study showing how fruit fly larvae infected with wasps prefer to eat food high in alcohol. This behavior greatly improves the survival rate of the fruit flies because they have evolved high tolerance of the toxic effects of the alcohol, but the wasps have not.

“The fruit fly larvae raise their blood alcohol levels, so that the wasps living in their blood will suffer,” Schlenke says. “When you think of an immune system, you usually think of blood cells and immune proteins, but behavior can also be a big part of an organism’s immune defense.”

For the latest study, the researchers asked whether the fruit fly parents could sense when their children were at risk for infection, and whether they then sought out alcohol to prophylactically medicate them.

Adult female fruit flies were released in one mesh cage with parasitic wasps and another mesh cage with no wasps. Both cages had two petri dishes containing yeast, the nourishment for lab-raised fruit flies and their larvae. The yeast in one of the petri dishes was mixed with 6 percent alcohol, while the yeast in the other dish was alcohol free. After 24 hours, the petri dishes were removed and the researchers counted the eggs that the fruit flies had laid.

The results were dramatic. In the mesh cage with parasitic wasps, 90 percent of the eggs laid were in the dish containing alcohol. In the cage with no wasps, only 40 percent of the eggs were in the alcohol dish.

“The fruit flies clearly change their reproductive behavior when the wasps are present,” Schlenke says. “The alcohol is slightly toxic to the fruit flies as well, but the wasps are a bigger danger than the alcohol.”

The fly strains used in the experiments have been bred in the lab for decades. “The flies that we work with have not seen wasps in their lives before, and neither have their ancestors going back hundreds of generations,” Schlenke says. “And yet, the flies still recognize these wasps as a danger when they are put in a cage with them.”

Further experiments showed that the flies are extremely discerning about differences in the wasps. They preferred to lay their eggs in alcohol when female wasps were present, but not if only male wasps were in the cage.

Theorizing that the flies were reacting to pheromones, the researchers conducted experiments using two groups of mutated fruit flies. One group lacked the ability to smell, and another group lacked sight. The flies unable to smell, however, still preferred to lay their eggs in alcohol when female wasps were present. The blind flies did not make the distinction, choosing the non-alcohol food for their offspring, even in the presence of female wasps.

“This result was a surprise to me,” Schlenke says. “I thought the flies were probably using olfaction to sense the female wasps. The small, compound eyes of flies are believed to be more geared to detecting motion than high-resolution images.”

The only obvious visual differences between the female and male wasps, he adds, is that the males have longer antennae, slightly smaller bodies, and lack an ovipositor.

Further experimentation showed that the fruit flies can distinguish different species of wasps, and will only choose the alcohol food in response to wasp species that infect larvae, not fly pupae. “Fly larvae usually leave the food before they pupate,” Schlenke explains, “so there is likely little benefit to laying eggs at alcoholic sites when pupal parasites are present.”

The researchers also connected the exposure to female parasitic wasps to changes in a fruit fly neuropeptide.

Stress, and the resulting reduced level of neuropeptide F, or NPF, has previously been associated with alcohol-seeking behavior in fruit flies. Similarly, levels of a homologous neuropeptide in humans, NPY, is associated with alcoholism.

We found that when a fruit fly is exposed to female parasitic wasps, this exposure reduces the level of NPF in the fly brain, causing the fly to seek out alcoholic sites for oviposition,” Schlenke says. “Furthermore, the alcohol-seeking behavior appears to remain for the duration of the fly’s life, even when the parasitic wasps are no longer present, an example of long-term memory.”

Finally, Drosophila melanogaster is not unique in using this offspring medication behavior. “We tested a number of fly species,” Schlenke says, “and found that each fly species that uses rotting fruit for food mounts this immune behavior against parasitic wasps. Medication may be far more common in nature than we previously thought.”

http://www.sciencedaily.com/releases/2013/02/130222102958.htm

drinking_drosophila

Rejection stinks. It literally hurts. But worse, it has an immediate and negative impact on our brains, producing withdrawal symptoms as if we’re quitting a serious addiction cold turkey. It’s no wonder, then, that we are tempted to turn to drugs to makeourselves feel better. But we’re not the only species that drowns our sorrows when we’re lonely – as a new study in Science reveals, rejected Drosophila do, too. Scientists have found not only will these sexually frustrated flies choose to consume more alcohol than their happily mated peers, sex and alcohol consumption activate the same neurological pathway in their brains.

Drosophila melanogaster males sure know how to woo a lady. When placed in the same container as a potential mate, a male fly will play her a delicate love song by vibrating one wing, caress her rear end, and gently nuzzle her most private of parts with his proboiscis to convince her that he is one heck of a lover. But even the most romantic fly can’t convince an already mated female Drosophila to give up the goods, so scientists were able to use the girls’ steely resolve to see how rejection affects fly drinking behavior.

“Alcohol is one of the most widely used and abused drugs in the world,” explains lead author Galit Shohat-Ophir. “The fruit fly Drosophila melanogaster is an ideal model organism to study how the social environment modulates behavior.” Previous studies have found that Drosophila melanogaster exhibit complex addiction-like behaviors. So in the controlled setting of Ulrike Heberlein’s lab at the University of California San Francisco, researchers paired male fruit flies with three types of females: 1) unmated females, which were willing and happy to mate; 2) mated females, which actively rejected the men; and 3) decapitated females, which didn’t actively reject the guys but, well, weren’t exactly willing partners either. After the flies were satisfied or frustrated, they were offered regular food and food spiked with ethanol, and the researchers measured which type they preferred to see if there was any connection between sex and drinking.

The flies that were rejected drank significantly more than their satisfied peers, but so did the ones paired with incapacitated girls, suggesting that it wasn’t the social aspect of rejection but sexual deprivation that drives male flies to increase their ethanol consumption (see the video at the end!). This alcoholic behavior was very directly related to the guy fly ever getting laid, for even after days of blue balls, if he was allowed to spend some time with a willing woman, he no longer preferred the spiked food.

What the scientists really wanted to understand, though, was why. What drives a frustrated fly to the flask? So to look at the underlying mechanism of this phenomenon, the scientists examined the flies’ brains. A body of scientific literature has connected one particular neurotransmitter, neuropeptide F (NPF), to ethanol-related behaviors in Drosophila, so it was a logical place to start. A very similar neurotransmitter in our brains, called neuropeptide Y (NPY), is linked to alcoholism.

Increased expression of NPF in mated male brains, as shown through immunochemistry.

The team found that sexual frustration caused an immediate decrease in the expression of NPF, while sex increased expression. Furthermore, when they used genetics to artificially knock down NPF levels in the satisfied flies, they drank as much as their not-so-satisfied friends. Similarly, when the researchers artificially increased NPF levels, flies stayed sober. This is the first time NPF levels have connected sexual activity to drinking. Clearly, NPF levels controlled the flies’ desire to drink, so the team further explored how NPF works in the fly’s brain.

Many animals, including ourselves, possess a neurological reward system which reinforces good behavior. Through this system, we ascribe pleasure or positive feelings to things we do that are necessary for species survival, including sex, eating, and social interaction. Drugs tap into this system, stimulating pleasure which can lead to addiction. Previous studies have shown that flies find intoxication rewarding, so the researchers hypothesized that NPF may play a role in the reward system.

Preference tests showed that artificially increasing NPF levels in the absence of sex or ethanol was rewarding to the flies, confirming the scientists’ hypothesis. This was further supported by the discovery that constantly activating NPF abolished the flies’ tendency to consider ethanol rewarding.

“NPF is a currency of reward” explains Shohat-Ophir. High NPF levels signal good behavior in Drosophila brains, thus reinforcing any activities which led to that state. This is a truly novel discovery, for while NPF and the mammal version, NPY, have been linked to alcohol consumption, no animal model has ever placed NPF/NPY in the reward system.

Understanding the role of NPF in reward-seeking behaviors may lead to better treatments for addicts. “In mammals, including humans, NPY may have a similar role [as NPF],” says Shohat-Ophir. “If so, one could argue that activating the NPY system in the proper brain regions might reverse the detrimental effects of traumatic and stressful experiences, which often lead to drug abuse.” Already, NPY and drugs that affect the function of its receptors are in clinical trials for anxiety, PTSD, mood disorders and obesity. This study suggests that perhaps they should be tested as treatment for alcoholism, too, as well as other reward-based addictions.

Research: Shohat-Ophir, G, KR Kaun & R Azanchi (2012). Sexual Deprivation Increases Ethanol Intake in Drosophila. Science 335: 1351-1355.

Click  http://blogs.scientificamerican.com/science-sushi/2012/03/15/flies-drink-upon-rejection/

to view a sequence of  three videos that show a male fly courting and successfully mating with a female fly, another male fly being rejected by a female, and a male choosing to consume an alcohol-infused solution over a non-alcohol solution. Video © Science/AAAS

 

A drunk man who climbed into a crocodile enclosure in Australia and attempted to ride a 5m (16ft) long crocodile has survived his encounter.

The crocodile, called Fatso, bit the 36-year-old man’s leg, tearing chunks of flesh from him as he straddled the reptile.

He received surgery to serious wounds to his leg and is recovering in hospital, police say.

He had been chucked out of a pub in the town of Broome for being too drunk.

The man, Michael Newman, climbed over a fence and tried to sit on the 800kg (1,800lb) saltwater crocodile.

“Fatso has taken offence to this and has spun around and bit this man on the right leg,” Sgt Roger Haynes of Broome police told journalists.

“The crocodile has let him go and he’s been able to scale the fence again and leave the wildlife park.”

Malcolm Douglas, the park’s owner, said that the crocodile was capable of crushing a man to death with a single bite.

“The man who climbed the fence was fortunate because Fatso was a bit more sluggish than normal, due to the cooler nights we have been experiencing in Broome,” said Mr Douglas.

“If it had been warmer and Fatso was more alert, we would have been dealing with a fatality.”

“No person in their right mind would try to sit on a 5m crocodile, Saltwater crocodiles, once they get hold of you, are not renowned for letting you go.”

The man staggered back to the pub bleeding heavily.

Pub manager Mark Phillips said staff told him that the man reappeared at about 11pm with bits of bark hanging off him and flesh gouged out of his limbs.

“They said he had chunks out of his legs and things like that,” Mr Phillips told The West Australian news website.

An average of two people are killed each year in Australia by aggressive saltwater crocodiles, which can grow up to 7m (23 ft) long and weigh more than a tonne.

http://www.bbc.co.uk/news/10611973

 

 

A woman needing help finding the bathroom is now facing numerous charges.

Her first mistake: calling 911 for her restroom emergency.

The Pasco Sheriff’s Office says 32-year-old Marcia Usher placed the 911 call Wednesday night, saying she was lost in the woods and didn’t know where she should urinate.

Responding deputies found Usher not in the woods, but instead in front of her home, reportedly intoxicated and drinking a beer.

A deputy noticed a nearby open beer cooler and asked Usher if he could check inside for any weapons or drugs. According to the arrest report, Usher complied and told the deputy there was beer and a knife inside.

Instead of a knife, the deputy immediately saw a loaded handgun on top of the beer.

The deputy tried putting Usher in handcuffs, and a brief struggle ensued.  She was reportedly tackled to the ground and taken into custody without further incident.

At the jail, a vial of meth residue was allegedly discovered on Usher during a strip search.

She now faces charges of carrying a concealed weapon without a permit, possession of methamphetamine, introduction/possession of contraband in a detention facility, and resisting arrest without violence.

http://www.wtsp.com/news/article/243316/8/Deputies-Drunk-woman-calls-911-to-say-she-was-lost-in-woods-did-not-know-where-to-urinate

 

Seaweed may well be an ideal plant to turn into biofuel. It grows in much of the two thirds of the planet that is underwater, so it wouldn’t crowd out food crops the way corn for ethanol does. Because it draws its own nutrients and water from the sea, it requires no fertilizer or irrigation. Most importantly for would-be biofuel-makers, it contains no lignin—a strong strand of complex sugars that stiffens plant stalks and poses a big obstacle to turning land-based plants such as switchgrass into biofuel.

Researchers at Bio Architecture Lab, Inc., (BAL) and the University of Washington in Seattle have now taken the first step to exploit the natural advantages of seaweed. They have built a microbe capable of digesting it and converting it into ethanol or other fuels or chemicals. Synthetic biologist Yasuo Yoshikuni, a co-founder of BAL, and his colleagues took Escherichia coli, a gut bacterium most famous as a food contaminant, and made some genetic modifications that give it the ability to turn the sugars in an edible kelp called kombu into fuel. They report their findings in the January 20 issue of the journal Science.

To get his E. coli to digest kombu, Yoshikuni turned to nature—specifically, he looked into the genetics of natural microbes that can break down alginate, the predominant sugar molecule in the brown seaweed. “The form of the sugar inside the seaweed is very exotic,” Yoshikuni told Scientific American. “There is no industrial microbe to break down alginate and convert it into fuels and chemical compounds.”

Once he and his colleagues had isolated the genes that would confer the required traits, they used a fosmid—a carrier for a small chunk of genetic code—to place the DNA into the E. coli cells, where it took its place in the microbe’s own genetic instruction set. To test the new genetically engineered bacterium, the researchers ground up some kombu, mixed it with water and added the altered E. coli. Before two days had gone by the solution contained about 5 percent ethanol and water. It also did this at (relatively) low temperatures between 25 and 30 degrees Celsius, both of which mean that the engineered microbe can turn seaweed to fuel without requiring the use of additional energy for the process.

An analysis from the Pacific Northwest National Laboratory (pdf) suggests that the U.S. could supply 1 percent of its annual gasoline needs by growing such seaweed for harvest in slightly less than 1 percent of the nation’s territorial waters. Humans already grow and harvest some 15 million metric tons of kombu and other seaweeds to eat. And there’s no reason to fear the newly engineered E. coli escaping into the wild and consuming the seaweed already out there, Yoshikuni argues. “E. coli loves the human gut, it doesn’t like the ocean environment,” he says. “I can hardly imagine it would do something. It would just be dead.”

The microbe could turn out to be useful for making molecules other than ethanol, such as isobutanol or even the precursors of plastics, Yoshikuni says. “Consider the microbe as the chassis with engineered functional modules,” or pathways to produce a specific molecule, Yoshikuni says. “If we integrate other pathways instead of the ethanol pathway, this microbe can be a platform for converting sugar into a variety of molecules.”

The fact that such a one-stop industrial microbe can turn seaweed into a variety of molecules has attracted the attention of outfits such as the U.S. Department of Energy’s Advanced Research Projects Agency–Energy, or ARPA–e, which has funded BAL work with DuPont to produce other molecules from such engineered microbes. “Because seaweed grows naturally in the ocean, it uses the two thirds of the planet that we don’t use for agriculture,” ARPA–e program director Jonathan Burbaum wrote in an e-mail. “ARPA–e is directing a small portion of the remaining funding toward an aquafarm experiment to measure area productivity and harvest efficiency.”
http://www.scientificamerican.com/article.cfm?id=genetically-engineered-stomach-microbe-turns-seaweed-into-ethanol&WT.mc_id=MND_20120216