All Electric Fish Took the Same Bus to the Evolutionary Party

electric-eelThe famed electric ell of South America’s Amazonian waters isn’t really an eel at all—it’s more like a frog.

But it’s definitely electric.

The species is capable of producing an electric field of up to 600 volts—about 100 volts per foot of fish—which is pretty impressive. The electric eel isn’t alone in its abilities, however, as there are hundreds of species in six major lineages spread across the world that can perform the trick.

Now, researchers from the University of Wisconsin have shown that each of these species have developed this trick in much the same way. Despite being separated by millions of years and tens of thousands of miles, each of the six major lineages have used basically the same genetic tool kit to arrive at the same evolutionary destination.

The team of scientists completely sequenced the genome of South America’s electric eel for starters. They then produced protein sequences from the cells of the electric organs and skeletal muscles of three other electric fish lineages. When the dust settled on the time-intensive computational comparisons, they found that electric organs in fish worldwide used the same genetic tools and cellular and developmental pathways to independently create the impressive organ.

“I consider ‘exotic’ organisms such as the electric fish to be one of nature’s wonders and an important ‘gift’ to humanity,” says Michael Sussman, a professor of biochemistry and director of the UW-Madison Biotechnology Center. “Our study demonstrates nature’s creative powers and its parsimony, using the same genetic and developmental tools to invent an adaptive trait time and again in widely disparate environments. By learning how nature does this, we may be able to manipulate the process with muscle in other organisms and, in the near future, perhaps use the tools of synthetic biology to create electrocytes for generating electrical power in bionic devices within the human body or for uses we have not thought of yet.”

The ability to create an electric shock and the need for its use may seem convoluted, but it’s really not at all that surprising. Each muscle cell in your own body—or in any animal’s body—uses tiny electrical potentials to cause muscles to contract. If you remove the contraction part, amplify the potential, and align all of the cells together in series like a string of batteries, you can create a massive flow of positive charge.

It comes as no surprise either that each of these lineages and most of the species within them have evolved in the dark, murky depths of muddy waters. Besides shocking the hell out of prey and enemies, the electric field these fish generate act like echolocation does for bats and also gives them a way to communicate. And once subtle electric fields are evolved to “see” and “talk,” it’s just a matter of ramping it up to hunt.

And as for the electric eel, it ramps it up in 90 percent of its body.

“A six-foot eel is a top predator in the water and is in essence a frog with a built-in five-and-a-half-foot cattle prod,” says Sussman. “Since all of the visceral organs are near the face, the remaining 90 percent of the fish is almost all electric organ.”

The study, “Genomic basis for the convergent evolution of electric organs,” was published by Sussman with the help of 15 other authors from 13 separate institutions.

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All the Ingredients for Another 1918 Flu Pandemic Are Out There Somewhere

Soldiers from Fort Riley, Kansas, ill with Spanish influenza in a hospital ward at Camp Funston. The 1918 pandemic was one of history’s most devastating outbreaks of disease, resulting in an estimated 40 million deaths. Photo: U.S. Army

Soldiers from Fort Riley, Kansas, ill with Spanish influenza in a hospital ward at Camp Funston. The 1918 pandemic was one of history’s most devastating outbreaks of disease, resulting in an estimated 40 million deaths. Photo: U.S. Army

A huge controversy was stirring through the academic ranks a couple of years ago. Two research teams had taken it upon themselves to try to protect the world from another pandemic like the 1918 “Spanish flu” by basically creating the strain again in their laboratories using genetic engineering methods.

Naturally, people freaked out.

There are so many Hollywood portrayals of scientific experiments escaping into the world that people immediately saw the potential dangers. The question that remained was whether or not those potential dangers are worth the risk to figure out how to stop another Spanish flu before it even starts.

After months of debate, researchers around the world concluded that the safety features in place at these two institutions were stringent enough to allow the flu research to continue. One of these laboratories is located at the University of Wisconsin, and they recently published one of their first papers from their research.

In a recent study published in the journal Cell Host & Microbe, an international team of researchers led by Yoshihiro Kawaoka of the University of Wisconsin has shown that all of the ingredients for another flu pandemic are already out there swirling around in nature.

The team took the 1918 Spanish flu virus and reverse engineered it to determine what mutations would be required for modern flu strains to acquire similarly deadly characteristics. The resulting virus differed from its famous ancestor by only three percent of the amino acids that make the virus proteins. What’s more, the researchers identified seven mutations in three viral genes that accounted for this genetic similarity.

Then, by scouring databases of flu found out naturally in the world in birds, they determined that all seven of these mutations are already out in the world. True, the chances of them all accumulating into one super virus is slim—but it’s out there.

But there was a lot of good news, too.

First, the new virus was nowhere near as transmissible as the Spanish flu. It could not transmit between ferrets by means of respiratory droplets—the primary mode of flu transmission—and it wasn’t nearly as deadly. Also, they found that the virus was susceptible to existing vaccines and antiviral medications.

“The point of the study was to assess the risk of avian viruses currently circulating in nature,” explains Kawaoka, who, in addition to his appointment as a professor in the UW-Madison School of Veterinary Medicine, holds a faculty position at the University of Tokyo. “We found genes in avian influenza viruses quite closely related to the 1918 virus and, to evaluate the pandemic potential should such a 1918-like avian virus emerge, identified changes that enabled it to transmit in ferrets.

“With each study, we learn more about the key features that enable an avian influenza virus to adapt to mammals and become transmissible,” says Kawaoka. “Eventually, we hope to be able to reliably identify viruses with significant pandemic potential so we can focus preparedness efforts appropriately.”

It might be dangerous to be creating viruses like this in the laboratory, for fear of it escaping. But the more we know about what makes the flu deadly to humans, the better equipped we’ll be to spot concerning mutations early and quickly create vaccines.

So which is more dangerous, creating viruses in a tightly secured laboratory or ignorance? Personally, I’ll take almost anything over ignorance every time.

The study, “Circulating Avian Influenza Viruses Closely Related to the 1918 Virus Have Pandemic Potential,” was published by Kawaoka and a whole host of collaborators that I’m too lazy to list out. That’s why the link is there.

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Teens Tell Tall Tales, Skew Scientific Surveys

Ever play the creative name game at the host stand in a restaurant? There’s just something compelling about making somebody yell out, “Tupperware Party of three,” “Republican Party of two,” or “Donner Party of five.”

Childish? Sure. Fun? You betcha. Mostly Harmless? Absolutely.

But there are some times when slightly childish antics aren’t quite so harmless. Take, for example, when social scientists give out questionnaires to teenagers as part of an experiment. Being silly or purposefully untruthful can skew statistics and lead researchers to incorrect conclusions.

Joseph Robinson-Cimpian from the University of Illinois, however, believes he has a solution. By asking several questions with possible “low frequency” responses, he can weed out the ones that are just having fun.

For example, if you include questions about gender identification, parenthood and unlikely size – questions that have little if anything to do with one another – you can spot the respondents who aren’t taking things seriously.

How many gay, extremely tall fathers of two could there possibly be in high school?

Robinson-Cimpian gave his method a shot in a recent survey that was collected from 11,800 students at 22 Wisconsin high schools. Based on 10 screener items from the assessment, more than 95 percent of the respondents provided fewer than two low-frequency responses, such as reporting that they were blind or exceptionally tall. Another 2 percent provided three or more of these types of responses.

Looking further into the data, Robinson-Cimpian found that a striking number of LGBQ-identifiers were in the group that claimed three or more low-frequency responses. Of that two percent, a staggering 80 percent claimed to be LGBQ, 76 percent claimed transgendered and 75 percent claimed disabilities. That’s compared to 1 percent LGBQ and 2 percent disabled in those who had less outlandish responses.

The solution? Nip that two percent of off-the-chart respondents in the ass.

Once removed, other percentages of responses started to fall much more in line.

Recent studies have suggested that sexual-minority teens are at higher risk of substance abuse, suicide and other poor outcomes. And data from the full sample of the 2012 Youth Assessment suggested that more than 25 percent of the transgender teens frequently considered suicide, compared to 1.2 percent of their peers.

However, when Robinson-Cimpian screened out respondents who provided three or more low-frequency responses (less than the top 2 percent of participants), the number of transgender teens reporting frequent suicidal thoughts dramatically decreased to less than 1 percent – about the same number as their heterosexual peers.

So there are two possibilities here. One is that about two percent of teens in the survey were answering questions untruthfully just to be asses. The other is that there are 236 LGBQ high school students in 22 Wisconsin schools that are blind fathers of two.

It also means that some studies that have reported a large discrepancy of suicidal thoughts and other concerning indicators among LGBQ teenagers might be way off base.

The paper, “Inaccurate Estimation of Disparities Due to Mischievous Responders: Several Suggestions to Assess Conclusions,” was published in the journal Educational Researcher by Robinson-Cimpian.

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Zinc Doesn’t Just Protect from Kids’ Germs; Also Protects Kids’ Future Before Conception

Magnetic resonance images of two mouse fetuses – the top is a smaller, malformed one from a zinc-deficient mouse; the bottom is a healthy fetus from a mouse in the control group.

Magnetic resonance images of two mouse fetuses – the top is a smaller, malformed one from a zinc-deficient mouse; the bottom is a healthy fetus from a mouse in the control group.

Whenever we know we’re going to be spending a decent amount of time around babies or toddlers, my wife and I start a regimen of zinc and vitamin C several days before the trip. We’ve had plenty of experience subjecting our relatively weak immune systems to the bacterial incubation center that is a human child, and we know the potential consequences of not preparing.

It probably don’t help that such encounters are typically during special occasions and we wind up actively suppressing our immune systems with alcohol, but that’s another story.

Now, researchers at Penn State have shown that zinc is important to stockpile not only before encounters with children, but before trying to make some children of your own.

Doctors have long recommended women start taking folic acid while trying to become pregnant, as the vitamin is important to ensure the quality of the egg even before conception. In a recent study, researchers have shown the same importance for zinc in mice. When deprived of the vitamin in the days leading up to ovulation, there was a much higher incidence of pregnancy loss and the embryos that did make it were 38 percent smaller than those of a control group.  Preconception zinc deficiency also caused approximately half of embryos to exhibit delayed or aberrant development.

While the reasons for this outcome aren’t clear, scientists involved with the study believe it has to do with the genetic programming of the immature egg cell. During egg development, “methyl groups,” or chemical tags, are added at specific locations on the DNA and are essential for that egg to fully support embryo and placenta development later on. And after missing out on zinc, eggs of mice had much less DNA methylation, suggesting that the programming of the egg was deficient.

“The mineral zinc acts as a catalytic, structural and signaling factor in the regulation of a diverse array of cellular pathways involving hundreds of enzymes and proteins,” said Francisco Diaz, assistant professor of reproductive biology at Penn State. “Given these wide-ranging roles, it is not surprising that insufficient zinc during pregnancy causes developmental defects in many species. We have known that for a long time.”

“What these results demonstrate is that a relatively short dietary disruption in nutrients that are available can have an impact on the ovary, the quality of the egg that the ovary produces, and the quality of the embryo and placenta that the egg develops into after fertilization,” Diaz said. “We know that dietary restrictions can have an effect on pregnancy and on fetal and placental development, but we are not as familiar with preconception effects that are relatively acute and then seeing the effect later on in pregnancy. That is the most novel aspect of our work here.”

“It is certainly important during pregnancy, but if the egg development is already compromised, it may not help that aspect of development. I think our work suggests that you need zinc preconception, just like you need folic acid.”

The study, “Preconception Zinc Deficiency Disrupts Postimplantation Fetal and Placental Development in Mice,” was published by Diaz along with co-authors Thomas Neuberger, assistant professor of biomedical engineering in Penn State’s Huck Institutes of Life Sciences, working with Penn State’s High-Field Magnetic Resonance Imaging Facility, and Kate Anthony, research technician in animal science.

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New Atomic Jigsaw Decipherer Proves Ancientness of Aussie Rock

A timeline of the history of our planet places the formation of the Jack Hills zircon and a "cool early Earth" at 4.4 billion years.

A timeline of the history of our planet places the formation of the Jack Hills zircon and a “cool early Earth” at 4.4 billion years.

Imagine you’re digging around your back yard—perhaps making a nice herb garden or digging posts for a deck—and you come across a rock along the way. That’s not too hard to imagine, since either of those activities are bound to turn up a large number of rocks, but perhaps you’re more prone to couch surfing than home improvement.

In any event, you find a rock.

Ever wonder how old that rock might be? Where it might have traveled? Perhaps, for example, it had been stepped on by a dinosaur once upon a time?

These musings become even more interesting if you happen to live in western Australia, particularly in the Jack Hills region. On the outcrops of that sparsely inhabited region of land, you might just come across tiny bits of rock that date back to a few hundred million years after the Earth was first formed. We’re talking rocks that are 4.4 billion years old.

That’s right, billion. With a B.

4,400,000,000.

How do geologists come up with this number? Well, rather than relying on made-up texts, researchers look to the ratios of certain isotopes contained within the sample.

Remember if you will that an isotope is an atom of an element—defined by that atom’s number of protons—that has a varying number of neutrons. For example, the most abundant form of carbon on Earth has eight protons and eight neutrons, but there are also forms of carbon found on earth that have eight protons and seven or six neutrons.

When you get to really disparate numbers–like eight protons and two neutrons, for example–the atom becomes unstable. A proton might spontaneously turn into a neutron to even out the ratio, giving off bits of energy in the process.

That energy is also known as radiation.

This 4.4 billion-year-old zircon crystal is providing new insight into how the Earth cooled from a ball of magma and formed continents much earlier than previously believed.

This 4.4 billion-year-old zircon crystal is providing new insight into how the Earth cooled from a ball of magma and formed continents much earlier than previously believed.

 

Thanks to accelerators around the world that can create these unstable isotopes, scientists know which isotopes eventually turn into what stable atoms. They also know the likely paths they take to get there and how long it takes for this process to occur. So if you know how many original unstable isotopes there are, and you also know how many final stable atoms that have decayed there are, you can figure out how long its been since the sample had only the unstable isotopes—it’s first formation.

Researchers have done this with a few rare zircon rocks from the Jack Hills region, and discovered that the ratio of rare lead ions indicates that the rocks in question are at least 4.4 billion years old. But some people require more proof. What if the ratios got thrown off by atoms being added later in the rock’s life, for example?

John Valley, a geochemist from the University of Wisconsin, has given them this proof. He lead a study that used a new technique called atom-probe tomography that actually maps and weighs the individual atoms in a microscopic sample of zircon. By checking out again the ratio of isotopes and determining their location within the crystalline structure of the zircon, Valley was able to corroborate the earlier findings that the rock comes from 4.4 billion years ago.

But that’s not the end of the story.

Rather than being randomly distributed throughout the sample, the lead isotopes were clustered together like raisins in a pudding. The clusters of lead atoms formed 1 billion years after crystallization of the zircon, by which time the radioactive decay of uranium had formed the lead atoms that then diffused into clusters during reheating.

“The zircon formed 4.4 billion years ago, and at 3.4 billion years, all the lead that existed at that time was concentrated in these hotspots,” Valley says. “This allows us to read a new page of the thermal history recorded by these tiny zircon time capsules.”

The study, according to Valley, strengthens the theory of a “cool early Earth,” where temperatures were low enough for liquid water, oceans and a hydrosphere not long after the planet’s crust congealed from a sea of molten rock.

“The study reinforces our conclusion that Earth had a hydrosphere before 4.3 billion years ago,” and possibly life not long after, says Valley.

“The Earth was assembled from a lot of heterogeneous material from the solar system,” Valley explains, noting that the early Earth experienced intense bombardment by meteors, including a collision with a Mars-sized object about 4.5 billion years ago “that formed our moon, and melted and homogenized the Earth. Our samples formed after the magma oceans cooled and prove that these events were very early.”

The study, “Hadean age for a post-magma-ocean zircon confirmed by atom-probe tomography,” was published by Valley and a whole host of associates from the University of Wisconsin; the University of Puerto Rico; CAMECA in Madison, Wisconsin; Curtin University of Western Australia; and the University of Western Ontario.

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Hocking a Loogie’s Power Potential

spitting-fountainScience has not yet, unfortunately, discovered Mr. Fusion. The coffee-maker-sized cold fusion power generator that runs on garbage would not only be able to power a time-warping DeLorean, it would solve all of the world’s energy needs in a single “Great Scots!”

That doesn’t mean that, however, that scientists aren’t working on some pretty interesting energy harvesting gadgets. Take this one example from Penn State that uses your loogies for power.

Yes, you read that right. Loogies aren’t just for grossing out your siblings anymore.

The idea of microbial fuel cells have been around a long time. You basically introduce a lot of organic material to a bunch of hungry bacteria, which produce energy while they chomp on the meal. Researchers typically turn to wastewater for the organic material fule, but guess what? Your saliva has plenty of it swimming around too.

Of course, a person isn’t going to produce even a gallon of saliva very quickly, so the energy generator we’re talking about here is proportionally small. In a report in a recent issue of Nature Publishing Group’s Asia Materials, environmental engineering professor Bruce Logan and fellow researcher Justine Mink demonstrate a micro-sized microbial fuel cell that can produce minute amounts of energy–enough to run tiny microchips.

While the single microwatt of power they can produce is tiny, the range of potential applications is vast.

The researchers believe that the emergence of ultra-low-power chip-level biomedical electronics, devices able to operate at sub-microwatt power outputs, is becoming a reality. One possible application would be a tiny ovulation predictor based on the conductivity of a woman’s saliva, which changes five days before ovulation. The device would measure the conductivity of the saliva and then use the saliva for power to send the reading to a nearby cell phone.

Or imagine a blood-sugar-level sensor that is powered by a diabetic’s own spit. Or a heart-rate monitor that gets charged by your stinky sweat while you work out.

This stuff is heavy.

The paper, “Energy harvesting from organic liquids in micro-sized microbial fuel cells,” was published by Mink and Logan, along with Ramy Quaisi and Muhammad Hussain from the Integrated Nanotechnology Lab at King Abdullah University of Science and Technology in Thuwal, Saudi Arabia.

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Giant Human Brain Sucks Energy, Stunts Growth for Years

2570892-sbigbrainHave you ever noticed that it’s kind of hard to guess the age of a toddler until they open their mouths and speak? I’ve got a behemoth of a nephew who could have passed for four at age two based on size alone. But at the same time, he was a bit late to the language game, and could potentially have been mistaken for a younger age around his fourth birthday (at least, if he hadn’t been such a behemoth).

There’s a good reason for this, according to a new study from Northwestern University. A human child’s physical growth slows to a snail’s pace between the ages of two and five. That’s why it’s so hard to guess age based on size at that time. So where is all of that energy going to?

Straight to their noggins.

After analyzing a pool of existing PET and MRI brain scan data–which measure glucose uptake and brain volume, respectively–Christopher Kuzawa, professor of anthropology at Northwestern, found that a toddler’s brain sucks up a staggering 66 percent of the energy normally consumed by the entire body at rest. That’s more than 40 percent of a kid’s total energy expenditure during the day.

It’s at this age where a person’s brain soaks in the most information, busily pruning synapses and strengthening connections based on learning and experience. And with the brain soaking up that much energy, there isn’t really any left to fuel physical growth.

It was previously believed that the brain’s resource burden on the body was largest at birth, when the size of the brain relative to the body is greatest. The researchers found instead that the brain maxes out its glucose use at age five.

“At its peak in childhood, the brain burns through two-thirds of the calories the entire body uses at rest, much more than other primate species,” said William Leonard, professor and chair of Northwestern’s Department of Anthropology. “To compensate for these heavy energy demands of our big brains, children grow more slowly and are less physically active during this age range. Our findings strongly suggest that humans evolved to grow slowly during this time in order to free up fuel for our expensive, busy childhood brains.”

The paper, “Metabolic costs and evolutionary implications of human brain development,” was published in the Proceedings of the National Academy of Sciences by Kuzawa and Leonard as well as Harry T. Chugani, Lawrence I. Grossman, Leonard Lipovich, Otto Muzik, Patrick R. Hof, Derek E. Wildman, Chet C. Sherwood and Nicholas Lange.

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