Scientists have worked out the genetic ‘recipe’ that lets lizards regrow their tails

Researchers have discovered the genes that prompt tail regeneration in lizards, which takes them a step closer to understanding how to stimulate regeneration in humans

When lizards are caught by predators, they can drop their tails to escape and then grow the appendage back. Scientists have studied this regeneration process for decades, in the hopes of understanding how to regenerate human tissues, such as damaged spinal chords and even lost limbs. 

Now a team of scientists from Arizona State University in the US has performed the first analysis of all RNA molecules, which translate genes into proteins, during the tail regeneration of a green anole lizard  (Anolis carolinensis), and worked out the genetic “recipe” that controls the regrowth process. Their results have been published in PLOS ONE.

"Using next-generation technologies to sequence all the genes expressed during regeneration, we have unlocked the mystery of what genes are needed to regrow the lizard tail,” said lead author Kenro Kusumi in a press release.

“Lizards are the most closely-related animals to humans that can regenerate entire appendages. We discovered that they turn on at least 326 genes in specific regions of the regenerating tail, including genes involved in embryonic development, response to hormonal signals and wound healing."

Interestingly, 302 of those 326 genes have already had homologues (similar genes) identified in mammalian DNA.

The scientists also found that tail regeneration in lizards involves genetic activity along the entire tail, not just at the tip, which is the case for other animals with regenerative abilities, such as salamanders and zebrafish. 

"Regeneration is not an instant process," said Elizabeth Hutchins, a co-author of the paper. "In fact, it takes lizards more than 60 days to regenerate a functional tail. Lizards form a complex regenerating structure with cells growing into tissues at a number of sites along the tail.”

For the first 10 days, the lizard’s tail heals similarly to any other wound—new blood vessels form, and epithelial tissue (the soft, white skin under a scab) closes the gap over raw flesh. Then the tail starts to regrow, beginning with nerve tissue from the spinal cord (days 10-15), soft muscle, and tissue for transporting fluids. By day 20, the muscular tissue is starting to firm up around a cartilaginous tube that will eventually harden, and segment into tail bones.” 

This research is a big step forward for scientists hoping to use the abilities of lizards to improve therapeutic options for humans.

“By following the genetic recipe for regeneration that is found in lizards, and then harnessing those same genes in human cells, it may be possible to regrow new cartilage, muscle or even spinal cord in the future,” said Kusumi.

World's largest laser compresses diamond to pressures of 50 million Earth atmospheres

Physicists in the US have compressed a synthetic diamond to pressures of 50 million Earth atmospheres to recreate conditions in the cores of giant planets.

A team of physicists at the Lawrence Livermore National Laboratory’s National Ignition Facilityin California have used the world's largest and most powerful laser to compress a synthetic diamond to pressures of 50 million times the Earth's atmosphere. This has allowed them to recreate the conditions found deep in the cores of gas giant and super-Earth planets for the first time.

To do this, they created a synthetic diamond, extracted a tiny, millimetre-sized sample of it, and zapped it with 176 high-powered fusion laser beams, half on the top of the sample, and half on the bottom. "Upon firing, the physicists measured the rate of diamond material moving under the tremendous heating and counter-reactions,” says Neomatica. "As the cylindrical piece of diamond is compressed, its middle bulges out at extremely high velocities. The measured peak velocity was 109,000 miles per hour, or about 45 kilometres per second.”

The team measured the peak pressure their diamond sample experienced to be 5 trillion pascals - or 5 terapascals - and at this point the density of the diamond had more than tripled, packing its mass into almost a quarter of the volume it had been in originally. This allowed the team to simulate how dense matter would behave in the incredible pressure within the cores of gas giants such as Jupiter, Saturn, Uranus and Neptune, and super-Earth planets outside the Solar System.

The team plans to use this technique to complete planet evolution models, and in future experiments, they will exert pressures on their diamond samples at 7 terapascals, which is thought to be the pressure in the deep centre of Jupiter. “[The study] paves the way for study of even more extreme environments," Neomatica reports, "for example at the centre of stars."

A mind-blowing swarm of Velella velella - relatives of jellyfish - appeared off the coast of Washington state in the US last week, and researchers aren't entirely sure why...

Children with autism have extra brain synapses

New research has shown that children with autism have a very high number of synapses - connections between neurons in the brain. So researchers have developed a new drug that promotes synaptic pruning, and reverses autistic-like behaviour in mice.

Children with autism have extra synapses in their brain due to a slowdown in the normal brain "pruning" process during development, say US neuroscientists.

They found a drug that restores synaptic pruning also reverses autistic-like behaviours in mice, they report in the journal Neuron.

"We were able to treat mice after the [disorder] had appeared," says study co-author neurobiologist David Sulzer of Columbia University Medical Center.

The findings suggest the condition could one day be treated in teenagers and adults, "though there is a lot of work to be done," he says.

The work is "extremely exciting", says Professor Ralph-Axel Mueller of San Diego State University, who was not involved in the research.

A synapse is where one neurone communicates with another.

With too many synapses, a "brain region that should be talking only to a select number of other regions is receiving irrelevant information from many others," explains Mueller, who has done pioneering work in over-connectivity.

During brain development, a burst of synapse formation occurs in infancy, particularly in the cortex, a region involved in autistic behaviours; pruning eliminates about half of these cortical synapses by late adolescence.

For the new study, the researchers painstakingly counted synapses in a key region of the cortex of 26 children and adolescents aged between 2 and 20 with autism who had died from other causes. They compared that to 22 brains from children without autism that were donated to science.

In the autistic brains, synaptic density was more than 50 per cent higher than that in the brains of children without autism and sometimes two-thirds greater.

"It's the first time that anyone has looked for, and seen, a lack of pruning during development of children with autism," says Sulzer, "although lower numbers of synapses in some brain areas have been detected in brains from older patients and in mice with autistic-like behaviours."

Over-connectivity

It is not clear if too many synapses are the main reason for autism, but many genes linked to autism play a role in synapse pruning. And the discovery that synapse pruning reversed autistic behaviour in the lab mice suggests over-connectivity may be key.

The researchers traced the pruning effect to a protein called mTOR. When mTOR is overactive brain cells lose much of their self-trimming ability.

"Almost all of our human subjects had overactive mTOR and decreased autophagy, and all appear to have a lack of normal synaptic pruning," says Sulzer.

To restore normal synaptic pruning and reverse autistic-like behaviours in mice, the researchers administered rapamycin, an immunosuppressant drug that prevents organ rejection and inhibits mTOR.

However, even if the findings are confirmed -- and Sulzer notes that treatments that work in lab animals often fail in people -- it is unlikely that rapamycin would be used in people with autism because its widescale immune-suppressing effects would likely cause serious side effects.

"But there could be better drugs," says Sulzer "such as a molecule that dials up production of synapse-pruning proteins."

One remaining puzzle is how the mice's brains, or the drug, know which synapses to keep and which to prune.

"But the mice started behaving normally" after receiving the synapse-pruning drug, "which suggests the right ones are being pruned," says Sulzer.

California’s new solar power plant is actually a death ray that’s incinerating birds mid-flight

Solar power is awesome but it turns out the intense beam of light created by the BrightSource solar power plant in California’s Mojave Dessert works like a death ray, killing birds that fly over it:

What spans 1,600 hectares, cost $2.2 billion to build, and potentially fries hundreds of thousands of birds per year? The new BrightSource solar power plant in California’s Mojave Dessert. The plant, which uses some 350,000 garage-door-sized mirrors to focus sunlight on three boiler towers, also acts as a death ray, instantly igniting and killing any wildlife that happen to fly through the intense beam of light. Wildlife officials are concerned that this concentrated solar power plant, and others like it, could turn into “mega-trap” that decimates the ecosystem — first attracting insects, and then attracting birds that eat insects. BrightSource, in the mean time, is forging ahead with an even larger solar power plant that officials say could kill four times as many birds. Won’t somebody stop these not-so-green nature-killing maniacs?

Most of the world’s solar power is generated via photovoltaic cells — wafers of silicon sandwiched between sheets of glass that create electricity directly when struck by sunlight. Another method is concentrated solar power (alternatively called “solar thermal power”), which uses a huge number of mirrors to focus sunlight on a tower in the middle. The tower contains some kind of fluid (super-heated water, molten salt) that in turn creates electricity via a conventional steam turbine. For a while, concentrated solar was seen as the future of solar power, but photovoltaic cells are now back in vogue after large price cuts over the last few years.

In the case of BrightSource’s concentrated solar power site near Ivanpah in the Mojave Desert, there are some 350,000 mirrors that focus light on three boiling towers (each about 40 stories high). The plant cost $2.2 billion to build, with most of the money coming from a US Department of Energy loan, and sizable investments from NRG Energy and Google. The three plants have a total capacity of 392 megawatts and an annual production of around 1,000 gigawatt-hours of reasonably priced electricity. [Read: New solar power plant is the first to go ‘supercritical’, but solar’s long-term cost and efficiency still questioned.]

Unfortunately, though, anything that happens to wander too close to a boiling tower is very rapidly cooked by the focused sunlight. Workers at the Ivanpah solar power plant call these birds “streamers,” as they ignite in midair and plummet to the ground trailing smoke. Federal wildlife investigators said there was, on average, one streamer every two minutes — or hundreds of thousands of incinerated birds per year. Another expert estimated that the number is nearer 28,000 per year. BrightSource’s own estimate is around 1,000 roasted birds per year. BrightSource is reportedly looking to build an even-larger power plant, which wildlife officials say could be “four times as dangerous” to birds. BrightSource has offered $1.8 million in compensation for the expected bird deaths. There are photos online of the cooked birds if you’re interested, but I won’t share them here; they just look like sad, singed birds.

While it might sound like BrightSource has created some kind of bird-blasting death ray, it’s important to keep things in perspective. Back in January, it was estimated that — in the US alone — between 365 million and 988 million birds are killed every year by crashing into windows. We’re mostly talking about domestic, low-rise windows, too — not skyscrapers. Likewise, a study last year showed that domestic cats — yes, your beloved Fluffy — are killing more than a billion birds per year in the US.

Still, while the numbers of dead birds are relatively low at the moment, wildlife experts are worried that these concentrated solar power plants could spiral out of control. They are worried that insects will be attracted to the bright lights of the towers, which in turn will attract large numbers of insect-eating birds. With enough towers, a “mega-trap” that decimates ecosystems might be created. I doubt this will be enough to turn commercial and political interests back towards nuclear power or fusion power, but who knows. Perhaps we’ll even see the inverse, with companies like McDonald’s or KFC becoming investors.

This footage of a velvet worm shooting foot-long strands of slime to immobilise its prey is pretty incredible. After trapping its victim, the velvet worm injects it with enzymes and sucks up the pre-digested flesh.

Life discovered in Antarctic lake 800 metres below the ice

These single-celled organisms live without sunlight in sub-zero temperatures. 

For the first time, scientists have discovered a thriving microbial ecosystem in one of Antarctica’s subglacial lakes, 800 metres beneath the west Antarctic ice sheet.

The team co-led by John Priscu of Montana State University in the US found 4,000 species of metabolically active, single-celled organisms (bacteria and archaea) after drilling into Lake Whillans.

"Our discovery proves that water is habitable space, even if it's at sub-zero temperatures and there is no sunlight," Priscu told New Scientist.

The water containing life was collected on 28 January, 2013 after six years of pain-staking work creating safe sampling procedures, and negotiating the difficult terrain, which presented unique logistic challenges.

The study was published in Nature 20 August 2014. 

The discovery is fantastic news for astrobiologists searching for life in the solar system. If bacteria can thrive deep beneath the surface of Antarctica, then maybe it can exist on the frozen surface of Jupiter's moon Europa or on Mars.

Scientists have been aware of the liquid water beneath the Antarctic ice sheet for more than 40 years, but it was only relatively recently that scientists began investigating for signs of life. 

The drilling was conducted using sterile hot water with filters, heating, ultraviolet light and hydrogen peroxide to ensure that no contaminates made it into the sample. 

A Russian team that drilled down to a lake in 2012 used non-sterile kerosene as the drilling liquid, which raised concerns that their samples were contaminated.

The scientists drilling at Lake Whillans found 130,000 microorganisms in each millilitre of water. This is a density similar to deep oceans or low-nutrient lakes. 

"We were surprised by the cell densities we observed," Priscu's colleague Brent Christner of Louisiana State University in the US told New Scientist.

The organisms survive without sunlight by converting ammonium to nitrite or by feeding off methane. 

Scientists concluded that the organisms must have been surviving without energy from the Sun for between 120,000 and one million years.

The team hopes to find multicellular life such as rotifers, worms or tardigrades in the future. The air bubbles over the lakes mean that oxygen is not a limiting factor but the low rate of carbon fixation by microbes is a concern

Fungus deadly to AIDS patients found to grow on trees

Researchers have finally discovered the source of fungal infections that are responsible for one-third of AIDS-related deaths in Southern California. The fungus, Cryptococcus gattii, grows on trees

Scorpion raising: nurtured under a deadly sting

Unlike most arachnids, scorpions don't lay eggs; they bear live young. The babies are unable to feed or defend themselves so the mother carries them on her back for the first few weeks of their life.

Children’s drawings indicate their future intelligence

New research has shown that the way a child draws at four years old is an indictor of how intelligent they’ll be at age 14.

Researchers from King’s College London in the UK have discovered a link between a child’s drawing and their later intelligence, and they've traced it back to genetics.

The study, which has been published in Psychological Science, looked at 7,752 pairs of identical and non-identical twins. The scientists asked the children at age four to draw a picture of a child, and the researchers then scored each figure between 0 and 12, depending on how anatomically correct they were.

The children also had their intelligence measured both at ages four and 14, and the scientists found that higher scores on the Draw-a-Child test were moderately linked to high intelligence scores at both ages.

"The Draw-a-Child test was devised in the 1920s to assess children's intelligence, so the fact that the test correlated with intelligence at age four was expected. What surprised us was that it correlated with intelligence a decade later,” said Rosalind Arden, the lead author of the paper, in a press release.

However, the correlation was only moderate, and it’s important to note the findings don’t suggest that drawing ability determines intelligence. They simply show there’s a link between the two.

“There are countless factors, both genetic and environmental, which affect intelligence in later life,” explains Arden.

Interesting, the researchers also looked at the differences between the results of the identical twins and the non-identical twins to measure the heritability of drawing ability. Identical twins share all their genes, whereas non-identical twins share about 50 percent. But all the twins tested shared a similar upbringing and family environment.

Overall the results showed that identical twins had more similar drawing skills at age four than non-identical twins, suggesting a genetic link between children’s drawing differences. They also found that there’s a strong genetical link between drawing at age four and intelligence at age 14. 

There is still a lot of research to be done on how genes affect our abilities, but this is interesting early research into the link between drawing and intelligence.

Arden explains: “This does not mean that there is a drawing gene - a child's ability to draw stems from many other abilities, such as observing, holding a pencil etc. We are a long way off understanding how genes influence all these different types of behaviour.”

"Drawing is an ancient behaviour, dating back beyond 15,000 years ago. Through drawing, we are attempting to show someone else what's in our mind. This capacity to reproduce figures is a uniquely human ability and a sign of cognitive ability, in a similar way to writing, which transformed the human species' ability to store information, and build a civilisation," 

Japan's cherry blossom stone is a natural wonder

Meet the cherry blossom stone from Japan - one of the most striking natural rock formations in the world.

So-called because when you crack them open, their internal cross-sections look like tiny golden-pink flowers, cherry blossom stones (sakura ishi in Japanese) get their beautiful patterns frommica, which is a commonly found silicate mineral known for its shiny, light-reflecting surface. 

These flower patterns weren’t always made of mica. They started their existence as a complex matrix of six prism-shaped crystal deposits of a magnesium-iron-aluminium composite calledcordierite, radiating out from a single dumbbell-shaped crystal made from a magnesium-aluminium-silicate composite called indialite in the centre. 

Hosted inside a fine-grained type of rock called a hornfels - formed underground around 100 million years ago by the intense heat of molten lava - cherry blossom stones underwent a second significant metamorphosis in their geological lifespan when they were exposed to a type of hot water called hydrothermal fluids. These fluids altered the chemical composition of minerals inside the cherry blossom stones, causing mica to replace the original cordierite-indialite inclusion.

Because they have to undergo two intense and very specific types of metamorphosis in order to form, cherry blossom stones are incredibly rare, and found - rather serendipitously - only in central Japan.  

Not all cherry blossom stones experienced a complete replacement of their internal minerals during their geological lifetime, but those that did are quite delicate inside, according to a 2006 study published by the journal Rocks & Minerals by John Rakovan from the Department of Geology at Miami University in the US. Rakovan reports:

"They can easily be snapped in half or crushed between one’s fingers. Although they are delicate, complete crystals, showing well-preserved external morphology, are commonly found weathered out of the hornfels. In areas where the cordierite is completely replaced by mica the hornfels is also altered such that it is very friable and poorly consolidated.”

In order to preserve the beauty of their delicate mica patterns, the Japanese locals coat them in a diluted solution of wood glue mixed with water to keep everything in place. Unlike the living cherry blossoms, or sakura, that come and go so quickly each year in Japan, these pretty minerals live on as long as the glue holds.

"Although the sakura are ephemeral in their beauty, lasting only a few weeks each year,” says Rakovan, "their image has been set in stone in the sakura ishi of Kameoka."

Gallery: Meet China's baby-shaped pears and heart-shaped melons

Baby-shaped pears, heart-shaped watermelons and square apples are hitting supermarkets in China and Japan. But are these fruits just frivolous fun?

Since the beginnings of agriculture, humans have been customising their fruits and vegetables to suit their needs. Early on, bigger fruits and higher yields were the most important considerations,and while these factors still outweigh the actual taste factor, other, slightly less pressing desires have come into play over the past decade or so.

Namely, people want to eat fruit that doesn’t look like regular fruit.

Which is how baby-shaped pears have come into existence. Grown by China-based manufacturing company, Fruit Mould Co., these strange little shapes have been selling like crazy in China, along with square-shaped apples, and heart-shaped watermelons and cucumbers. Their Buddha-shaped pears are apparently extremely popular.

The way these fruits are created, says Carl Engelking at Discover Magazine, is by placing very young fruits - still attached to their vines or branches - into a plastic mould. The moulds are then clamped shut with screws and shielded from direct sunlight using a sheet of tough, water-proof paper.

At a certain point in the fruit’s maturity, the mould can be removed and the fruit will continue growing into the desired shape. This last bit can be very tricky, and farmers have spent many years getting the final shapes right. According to Brian Ashcraft at Kotaku, it took farmers in Japan three years to perfect their version of the heart-shaped watermelon.

While this all looks like some frivolous fun, there is the opportunity to apply practical applications to this technology. Packing round fruits for transportation, storage, and display in supermarkets takes up lots of space, which means more money and trucks on the road, and securing their roly-poly shapes in trucks and display spaces takes time. The square watermelon idea originally came to be because Japanese supermarkets don't have a lot of room to display their large, round shapes, so local farmers developed easily-stackable square ones. Of course, they're around three times more expensive than regular watermelons, presumably due to the amount of work that went into their development, but as the technology ages, the prices should eventually come down.

Australian scientists may have found the key to controlling fruit flies without pesticides

Bad news for female fruit flies - scientists have identified the moment the insects determine their sex, which is an important step towards creating sterile, all-male populations.

Each year the Queensland fruit fly costs fruit and vegetable producers millions of dollars in damage, but Australian scientists may now have found the key to controlling them without dangerous chemicals.

Researchers at the Hawkesbury Institute for the Environment at the University of Western Sydney and the University of New South Wales have identified the exact time when a fruit fly becomes either male or female.

Using this knowledge, the scientists are now working on mass producing generations of sterile male fruit flies, which can be released into the wild to help naturally suppress the population.

"Understanding the mechanisms and timing of how insects become either male or female is critical for the development of new bacterial or genetic approaches to pest control," lead author of the study, Dr Jennifer Morrow from the Hawkesbury Institute for the Environment, said in a press release.

The main chemical currently used to control populations is fenthion, which is about to be phased out due to concerns over health risks to humans.

The research, published in Insect Molecular Biology, looked into when genes that trigger sex determining proteins were switched on in fruit fly embryos. Using this information, the scientists found that a fruit fly’s gender is decided shortly after eggs are laid into fruit, in the early hours of embryonic development.

The challenge is now how to mass produce male-only lines.

"Our research significantly adds to understanding the key process of sex determination in this destructive crop pest. This knowledge could enable the industry to develop fruit fly lines that can be used to produce male-only broods in huge quantities. They may be intrinsically sterile or may be sterilised before release, for example by gamma irradiation," Morrow explained.

By combining these male-only lines with the use of damaging bacteria that’s passed down through fruit fly generations, such as Wolbachia, the researchers believe they’ll be able to find new, environmentally friendly ways to control the population.

WATCH: These parasites want to take up residence in your eyes

Meet the parasites that can crawl under your skin and into your eyes to leave you blind.

A parasitic worm called Onchocerca volvulus affects 25 million people around the world in one of the most revolting ways possible. The larvae of this tiny worm, found in sub-Saharan Africa and Latin America, can live for more than 10 years in a person’s skin, and that’s not even the worst part - they often make their way into their eyes.

According to Tommy Leung, a lecturer in parasitology and evolutionary biology at Australia's University of New England, nearly a third of the people affected by Onchocerca larvae will end up with one of these parasites in their eye, at which point they’re at serious risk of blind due to the infection.

And unfortunately, Onchocerca aren’t the only eye-loving parasites out there. As Leung explains at the Conversation, parasitic flatworms called Oculatrema hippopotami live under the eyelids of African hippopotamuses, and parasitic flukes called Philophthalmidae are notorious for feeding on the tears of birds. Flukes are a type of primitive flatworm, found all over the world and ranging from a few millimetres to several centimetres long. There are more than 10,000 known species of flukes, and several of them live inside the guts of birds, laying eggs that are distributed in their host’s droppings. When these eggs hatch, in order to reproduce, these new flukes have to somehow make their way back into a bird’s gut.

Which is where the eyes come into play.

While it might seem like a bad idea for a parasite to damage their hosts - if your host goes blind and dies, you’re going to have to find a new host, and no one likes moving - for flukes, it’s a necessary step towards completing their lifecycle. Flukes attempt to make their way into the body of a bird’s prey, such as a fish or a snail, and partially blind them, handicapping their ability to hide from predators. When the bird eats the prey, it also eats the fluke, and the fluke has fulfilled its mission to get to a bird’s gut and have babies.

But for some animals, strangely enough, having a parasite in the eye doesn’t seem to affect them a whole bunch. "The Greenland shark is infected by the parasite Ommatokoita elongata which plunges a pair of modified limbs straight into the shark’s eyeball and feeds by grazing on its cornea. As unpleasant as it sounds, the shark does not seem too affected by the parasite’s intrusive presence,” says Leung at the Conversation.

Watch the video above to see a freshwater fish from New Zealand called a bully dealing with a large larval fluke in its eyeball.