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Male Didelphids Opossum Uses Sperm-Pairing To Increase Sperm Survival

Male Didelphids Opossum Uses Sperm-Pairing To Increase Sperm Survival | Amazing Science | Scoop.it

Sperm pairing is an unusual phenomenon that occurs in New World, but not Australian or New Guinean, marsupial mammals. Newly formed spermatozoa join up precisely along the sides of their heads, leaving their tails to move freely, thus apparently improving their ability to navigate the fluids contained in the female reproductive tract. The mechanism that causes the sperm to pair in the male reproductive tract and, later in the female tract, to separate, is not fully understood.

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Emergence of individuality in genetically identical mice raised identically

Emergence of individuality in genetically identical mice raised identically | Amazing Science | Scoop.it

How do people and other organisms evolve into individuals that are distinguished from others by their own personal brain structure and behavior? Why do identical twins not resemble each other perfectly even when they grew up together?


To shed light on these questions, the scientists observed 40 genetically identical mice that were kept in an enclosure that offered a rich shared environment with a large variety of activity and exploration options.

They showed that individual experiences influence the development of new neurons in mice, leading to measurable changes in the brain.

 

“The animals were not only genetically identical, they were also living in the same environment,” explained principal investigator Gerd Kempermann, Professor for Genomics of Regeneration, CRTD, and Site Speaker of the DZNE in Dresden. “However, this environment was so rich that each mouse gathered its own individual experiences in it. Over time, the animals therefore increasingly differed in their realm of experience and behavior.”

 

Each of the mice was equipped with a special microchip emitting electromagnetic signals. This allowed the scientists to construct the mice movement profiles and quantify their exploratory behavior.

 

The result: despite a common environment and identical genes, the mice showed highly individualized behavioral patterns. In the course of the three-month experiment, these differences increased in size.

 

“These differences were associated with differences in the generation of new neurons in the hippocampus, a region of the brain that supports learning and memory,” said Kempermann “Animals that explored the environment to a greater degree also grew more new neurons than animals that were more passive.”

 

Adult neurogenesis [generation of new neurons] in the hippocampus allows the brain to react to new information flexibly. With this study, the authors show for the first time that personal experiences and ensuing behavior contribute to the “individualization of the brain.” The individualization they observed cannot be reduced to differences in environment or genetic makeup.

 

“Adult neurogenesis also occurs in the hippocampus of humans,” said Kempermann. “Hence we assume that we have tracked down a neurobiological foundation for individuality that also applies to humans.”

 

“The finding that behavior and experience contribute to differences between individuals has implications for debates in psychology, education, biology, and medicine,” said Ulman Lindenberger, Director of the Center for Lifespan Psychology at the Max Planck Institute for Human Development (MPIB) in Berlin.

 

“Our findings show that development itself contributes to differences in adult behavior. This is what many have assumed, but now there is direct neurobiological evidence in support of this claim. Our results suggest that experience influences the aging of the human mind.”

 

In the study, a control group of animals housed in a relatively unattractive enclosure was also examined; on average, neurogenesis in these animals was lower than in the experimental mice. “When viewed from educational and psychological perspectives, the results of our experiment suggest that an enriched environment fosters the development of individuality,” said Lindenberger.

 
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Brain DNA changes throughout life

Brain DNA changes throughout life | Amazing Science | Scoop.it

Researchers from The Roslin Institute at the University of Edinburgh have found brain cells alter their genetic make-up during a person's lifetime. They have identified genes - known as retrotransposons - responsible for thousands of tiny changes in the DNA of brain tissue.

 

Researchers, whose work is published in the journal Nature, found that the genes were particularly active in areas of the brain linked to cell renewal. By mapping the locations of these genes in the human genome, scientists could identify mutations that impact on brain function and that may cause diseases to develop.

 

The study shows for the first time that brain cells are genetically different to other cells in the body and are also genetically distinct from each other.

Scientists are now researching whether brain tumour formation and neurodegenerative diseases such as Alzheimer's are associated with a change in retrotransposon activity.

 

Dr Geoff Faulkner said: "This research completely overturns the belief that the genetic make-up of brain cells remains static throughout life and provides us with new information about how the brain works.

 

"If we can understand better how these subtle genetic changes occur we could shed light on how brain cells regenerate, how processes like memory formation may have a genetic basis and possibly link the activity of these genes to brain diseases."

 

The research was carried out in collaboration with scientists from the Netherlands, Italy, Australia, Japan and the United States, and was funded by the Wellcome Trust, the Biotechnology and Biological Sciences Research Council and the Australian National Health and Medical Research Council.

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Plants communicate with each other through fungus network of roots

Plants communicate with each other through fungus network of roots | Amazing Science | Scoop.it
Researchers show that plants can communicate the need to protect themselves from attack by aphids by making use of an underground network of fungi.

 

Instances of plant communication through the air have been documented, in which chemicals emitted by a damaged plant can be picked up by a neighbour. But below ground, most land plants are connected by fungi called mycorrhizae.

 

Researchers from the University of Aberdeen, the James Hutton Institute and Rothamsted Research, all in the UK, devised a clever experiment to isolate the effects of these thread-like networks of mycorrhizae. The team concerned themselves with aphids, tiny insects that feed on and damage plants.

 

Many plants have a chemical armoury that they deploy when aphids attack, with chemicals that both repel the aphids and attract parasitic wasps that are aphids' natural predators.

 

The team grew sets of five broad bean plants, allowing three in each group to develop mycorrhizal networks, and preventing the networks' growth in the other two. To prevent any through-the-air chemical communication, the plants were covered with bags.

 

As the researchers allowed single plants in the sets to be infested with aphids, they found that if the infested plant was connected to another by the mycorrhizae, the un-infested plant began to mount its chemical defence.

 Those unconnected by the networks appeared not to receive the signal of attack, and showed no chemical response. 

"Mycorrhizal fungi need to get [products of photosynthesis] from the plant, and they have to do something for the plant," explained John Pickett of Rothamsted Research.

 

"In the past, we thought of them making nutrients available from the [roots and soil], but now we see another evolutionary role for them in which they pay the plant back by transmitting the signal efficiently," he told BBC News. Prof Pickett expressed his "abject surprise that it was just so powerful - just such a fantastic signalling system".

 

The finding could be put to use in many crops that suffer aphid damage, by arranging for a particular, "sacrificial" plant to be more susceptible to aphid infestation, so that when aphids threaten, the network can provide advance notice for the rest of the crop.

 

"Now we've got a chance in a really robust manner of switching on the defence when it is needed - not straining the plant to do it all the time - and to reduce the development of resistance (of the aphids to the plants' defences)," Prof Pickett said.

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The Greater Wax Moth Has 15 Times Greater Sensitivity To Sounds Than Humans: Highest In The Whole Animal Kingdom

The Greater Wax Moth Has 15 Times Greater Sensitivity To Sounds Than Humans: Highest In The Whole Animal Kingdom | Amazing Science | Scoop.it

Researchers have found that the greater wax moths have the capability to sense sound frequencies up to 300 kHz, the highest recorded of any species' hearing capability, according to the University's news release.

 

 The greater wax moth otherwise known as honeycomb moth or Galleria Mellonella belongs to the Pyralidae family. The greater wax moths measuring about 1 1/2 inches long, lay their eggs in beehives where the larvae feed on the wax and the debris of the honeycombs, hence the name. But the extra-ordinary factor about these moths is their sensory characteristic.

 

The research team led by Dr. James Windmill, said that the discovery will help in better understanding the "air-coupled ultrasound."

 

"The use of ultrasound in air is extremely difficult as such high frequency signals are quickly weakened in air," Dr. Windmill said. "Other animals such as bats are known to use ultrasound to communicate and now it is clear that moths are capable of even more advanced use of sound."

 

In comparison to sound-sensitive dolphins, which sense sounds up to 160 kHz, greater wax moth still stands apart with its highest hearing capability. Humans can only hear sounds up to 20 kHz. Scientists say that the moth's super-sensitivity to sound may have been evolved as a result of evasion from their natural predators, bats.


Bats are known for their echolocation with which they can sense a presence of an object even in complete darkness. Echolocation helps bats in flight navigation and even hunting. Bats can accurately identify the location, size and direction or even a nature of an object by emitting ultrasonic chirps. Even with such accuracy, bats can only hear up to 212 kHz.

 

For the study, researchers used an advanced laser Doppler vibrometer to record the hearing of 20 moths. With the help of the findings, Dr. Windmill and his team hope to understand the gist of ultrasound transmission. With the highest capability of hearing sounds, studying moth's ear will represent the beginning of developing new technologies, which may be useful in miniature microphones or mobile devices.


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Ancient DNA Found Hidden Below Sea Floor

Ancient DNA Found Hidden Below Sea Floor | Amazing Science | Scoop.it

In the middle of the South Atlantic, there's a patch of sea almost devoid of life. There are no birds, few fish, not even much plankton. But researchers report that they've found buried treasure under the empty waters: ancient DNA hidden in the muck of the sea floor, which lies 5000 meters below the waves.

 

The DNA, from tiny, one-celled sea creatures that lived up to 32,500 years ago, is the first to be recovered from the abyssal plains, the deep-sea bottoms that cover huge stretches of Earth. In a separate finding published this week, another research team reports teasing out plankton DNA that's up to 11,400 years old from the floor of the much shallower Black Sea. The researchers say that the ability to retrieve such old DNA from such large stretches of the planet's surface could help reveal everything from ancient climate to the evolutionary ecology of the seas.

 

"We have been able to show that the deep sea is the largest long-time archive of DNA, and a major window to study past biodiversity," says Pedro Martinez Arbizu, a deep-sea biologist of the German Centre for Marine Biodiversity Research in Wilhelmshaven.

 

The new studies are "very exciting," says micropaleontologist Bridget Wade of the University of Leeds in the United Kingdom, who was not connected to the research. Until now, it wasn't clear "how far back in time you could take these DNA studies. … These records are telling you new information that wasn't found in the fossil record."

 

The South Atlantic team went looking for DNA in plugs of silt and clay coaxed out of the ocean floor hundreds of kilometers off the Brazilian coast. The researchers were after genetic material from two related groups of marine organisms, the foraminifera and the radiolarians. Both are single-celled, and both include many species with beautiful pearly shells that fossilize nicely, making them a favorite target of researchers studying the prehistoric oceans.

 

The researchers used special pieces of DNA specific to radiolarians and foraminifera to fish out DNA from those groups. Then they sequenced the DNA and compared the results to known foraminifera and radiolarian DNA sequences. Their analysis showed they'd found 169 foraminifera species and 21 radiolarian species, many of which were unknown. What's more, many of the foraminifera species belonged to groups that don't form fossils

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First live observations of a rare deep-sea anglerfish

First live observations of a rare deep-sea anglerfish | Amazing Science | Scoop.it

C. coloratus was first described from a single specimen collected off the coast of Panama during an expedition in 1891 aboard the U.S. Fish Commission steamer Albatross. However, for over 100 years, marine researchers collected deep-sea fish using trawl nets and dredges, so this anglerfish was never seen alive. That changed in 2002, when researchers from MBARI, Moss Landing Marine Laboratories, and the Monterey Bay National Marine Sanctuary used the remotely operated vehicle (ROV) Tiburon to explore Davidson Seamount—an extinct volcano off the coast of Central California.

 

Video: http://www.youtube.com/watch?feature=player_embedded&v=Cl_MbvSUvTk

 

When the researchers first spotted this fish on video from the ROV, they weren’t exactly sure what kind of fish it was. Although C. coloratus had been dredged from deep-sea environments in other ocean basins, it had never been seen in the north Pacific. After the cruise, the researchers recruited ichthyologists from California Academy of Sciences and elsewhere to help them identify the fish.

 

Then, in 2010, MBARI researchers observed six more of these unique fish during ROV dives at Taney Seamounts, another set of extinct volcanoes off the California coast. This time, the research team noticed that not all of the fish were red or rose-colored, as they had previously been described in the scientific literature. Instead, some of the fish were blue.

After comparing the sizes of the fish in ROV videos, the scientists noted that the red fish were larger and more mature, while the blue fish were younger and smaller. From these observations, they inferred that this fish likely begins its life in a transparent larval form, turns blue as a juvenile, and turns red at adulthood.

 

One of the remarkable traits of all anglerfish is their ability to attract prey using parts of their bodies that function as lures. During one ROV dive, the researchers observed C. coloratusdeploying a shaggy, mop-like lure, called an esca, which it dangled from the end of a modified fin near the top of its head. After an unsuccessful attempt at attracting prey, the anglerfish then stowed its fishing gear away in a special cavity located between its eyes.

 

In addition to witnessing the anglerfish using its ”fishing lure” Lundsten and his colleagues also watched C. coloratus move across the seafloor in a manner akin to walking. This behavior is common among C. coloratus’ shallow-water relatives, the frogfish, but had not been observed in C. coloratus. Scientists speculate that 'walking' is more energy efficient than swimming short distances, and that it also disturbs the surrounding seawater less, reducing the chances of startling nearby prey.

 

As a result of MBARI's ROV observations, researchers also learned that C. coloratus can live as deep as 3,300 meters (11,000 feet) below the ocean’s surface. Previous trawl-net collections suggested that the fish lived only at depths of 1,250 to 1,789 meters (4,100 to 5,900 feet).

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Intelligence in the ocean: Whales give each other tips about new fishing techniques

Intelligence in the ocean: Whales give each other tips about new fishing techniques | Amazing Science | Scoop.it

Whales are one the most fascinating and intelligent creatures we know and we certainly want to protect these biggest fishes, or actually mamals, in the sea. But luckily whales are not helpless against the latest ecological changes. A new study found they work together in adapting to their environments, just like us.

 

For a period of 27 years a team of researchers monitored the fishing habits of a community of American humpback whales. The dimishing of their usual prey in the 1980′s led some of the whales to invent a new hunting technique: first hitting their tail on the water before diving down.

But it weren’t just these few smart ones that benefited from their own innovation. The whales were intelligent enough to also pass it on to the others. In 2007 around 40 percent of the population was using the new fishing skill.

 

Didn’t all these whales just discover the tail-on-the-water-thing themselves? No, say the researchers. Their analysis revealed that the new behavior spreaded roughly along the lines of social networks. Yes, whales have them too, apparently.

 

So culture is not something uniquely human. These marine animals, very distinct from our own primate lineage, also are able to transmit knowledge and keep traditions. It’s actually not so surprising if you know that whales also teach each other their mysterious songs. Maybe many years from now we find out that all this time they have been singing about fishing techniques.

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Scientists have crossed two strains of avian flu virus to create one that can be transmitted through the air

Scientists have crossed two strains of avian flu virus to create one that can be transmitted through the air | Amazing Science | Scoop.it

As the world is transfixed by a new H7N9 bird flu virus spreading through China, a study reminds us that a different avian influenza — H5N1 — still poses a pandemic threat.

 

A team of scientists in China has created hybrid viruses by mixing genes from H5N1 and the H1N1 strain behind the 2009 swine flu pandemic, and showed that some of the hybrids can spread through the air between guinea pigs.

 

Flu hybrids can arise naturally when two viral strains infect the same cell and exchange genes. This process, known as reassortment, produced the strains responsible for at least three past flu pandemics, including the one in 2009.

 

There is no evidence that H5N1 and H1N1 have reassorted naturally yet, but they have many opportunities to do so. The viruses overlap both in their geographical range and in the species they infect, and although H5N1 tends mostly to swap genes in its own lineage, the pandemic H1N1 strain seems to be particularly prone to reassortment.

 

“If these mammalian-transmissible H5N1 viruses are generated in nature, a pandemic will be highly likely,” says Hualan Chen, a virologist at the Harbin Veterinary Research Institute of the Chinese Academy of Sciences, who led the study.

 

“It's remarkable work and clearly shows how the continued circulation of H5N1 strains in Asia and Egypt continues to pose a very real threat for human and animal health,” says Jeremy Farrar, director of the Oxford University Clinical Research Unit in Ho Chi Minh City, Vietnam.

 

Chen's results are likely to reignite the controversy that plagued the flu community last year, when two groups found that H5N1 could go airborne if it carried certain mutations in a gene that produced a protein called haemagglutinin (HA). Following heated debate over biosecurity issues raised by the work, the flu community instigated a voluntary year-long moratorium on research that would produce further transmissible strains. Chen’s experiments were all finished before the hiatus came into effect, but more work of this nature can be expected now that the moratorium has been lifted.

 

“I do believe such research is critical to our understanding of influenza,” says Farrar. “But such work, anywhere in the world, needs to be tightly regulated and conducted in the most secure facilities, which are registered and certified to a common international standard.”

 

Virologists have created H5N1 reassortants before. One study found that H5N1 did not produce transmissible hybrids when it reassorts with a flu strain called H3N2. But in 2011, Stacey Schultz-Cherry, a virologist at St. Jude Children's Research Hospital in Memphis, Tennessee, showed that pandemic H1N1 becomes more virulent if it carries the HA gene from H5N1.

 

Chen’s team mixed and matched seven gene segments from H5N1 and H1N1 in every possible combination, to create 127 reassortant viruses, all with H5N1’s HA gene. Some of these hybrids could spread through the air between guinea pigs in adjacent cages, as long as they carried either or both of two genes from H1N1 called PA and NS. Two further genes from H1N1, NA and M, promoted airborne transmission to a lesser extent, and another, the NP gene, did so in combination with PA.

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Super-hydrophobic self-cleaning surfaces as seen on cicada wings

Super-hydrophobic self-cleaning surfaces as seen on cicada wings | Amazing Science | Scoop.it

Scientists had known that cicada wings are super-water-repellent, or super-hydrophobic. This is different from a great many substances that are simply water-repellent, or hydrophobic — for instance, oil and water famously do not mix. But a number of surfaces such as lotus leaves can make themselves even more water-repellent by covering themselves with microscopic bumps, so water drops can float on top much as mystics can lie on beds of nails. For example, cicada wings are covered in rows of waxy cones about 200 nanometers or billionths of a meter high. In comparison, the average human hair is roughly 100 microns or millionths of a meter wide.

 

Mechanical engineer Chuan-Hua Chen at Duke University in Durham, N.C., and his colleagues were investigating a number of natural and artificial super-hydrophobic surfaces when they noticed drops of water at times rapidly disappeared. They were mystified by this behavior for years until they made observations from a different angle — they used a high-speed video camera to watch the droplets from the side of these materials instead of from above.  "That's when we saw them jumping upward," Chen recalled. The scientists found that when these surfaces are exposed to water vapor, dew can condense on them. When growing droplets fused together, the merged drop then leapt off the super-water-repellant surfaces. These drops, each up to a few microns to a few hundred microns wide, can jump up to a few millimeters in the air.  "We've since found this happens on almost all normal super-hydrophobic surfaces," Chen said. "If you take a lotus leaf or any of the many other super-water-repellant surfaces out there and you let it cool in your freezer and then take it out, as humidity in the air condenses on it, you can see with your bare eyes that water drops will jump in the air."

 

When small water droplets combine on super-water-repellent surfaces, a single bigger drop results that has less surface area than its original parts. As such, energy that is no longer needed to flatten that water across the surface the smaller droplets once occupied gets released, popping the drop upward, Chen explained. "These findings show that super-hydrophobic surfaces don't need water driven by gravity to take contaminants away — jumping droplets can do so," Chen said. "This is a great piece of work that highlights a mechanism that has not been conventionally considered for self-cleaning," said mechanical engineer Evelyn Wang at the Massachusetts Institute of Technology, who did not take part in this research.

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Little Fish Is a Super Sucker on Any Type of Surface

Little Fish Is a Super Sucker on Any Type of Surface | Amazing Science | Scoop.it

The slimy and mud-colored northern clingfish, Gobiesox maeandricus, probably won't win any beauty contests. But scientists have declared that the creature, which uses the giant suction cup on its belly to grip rocks along the coast of the western United States, is a champion of stickiness.

 

When the researchers pitted euthanized clingfish against eight manufactured suction cups, the fish held fast to eight materials ranging from glass to the grittiest sandpaper. The suction cups managed to adhere to only the three smoothest surfaces. The fish have a secret weapon, according to a new study: Sticky mucus keeps seawater from leaking under its "adhesive disk" and disrupting the seal. So the researchers tested how well the artificial cups held when immersed in vats of viscous liquid, which is slower to leak under the edges of the cups and so mimics the benefit of mucus. Still, the fish won out. Scanning electron microscope images showed that the clingfish's suction cup is bordered with filaments similar in size to those on the sticky feet of geckos, according to a paper online today in Biology Letters. The researchers argue that the hairs (inset image) increase friction, giving the cup's edges a grip even on very rough objects. That's how the fish serenely sticks to rocks through pounding waves and buffeting currents and when reaching out to snatch its favorite food, the limpet. The researchers hope that the clingfish's superior suction cup may show the way to artificial devices that can better adhere to rough, wet surfaces. Applications could include surgical materials and tags for marine mammals, the researchers say.

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Osedax Zombie Worms Lack Any Type of Mouse Parts and Drill Whale Bones with Acid

Osedax Zombie Worms Lack Any Type of Mouse Parts and Drill Whale Bones with Acid | Amazing Science | Scoop.it

So-called zombie worms — and yes, they actually exist — like to munch on whale bones for dinner. The creatures also use the bones for shelter. Spread throughout the world's oceans, zombie worms are quite adept at making the bones of whales and other large marine animals look like Swiss cheese.

 

But these worms don't have any mouthparts with which to gnaw the holes. So how do they do it? A study published in the May 1 online edition of the journal Proceedings of the Royal Society B found that rather than being "bone-drilling" worms, they're actually "bone-dissolving" worms: The worms’ skin produces acid in large quantities to break down bones.

The acid is produced by proton pumps, protein-containing structures abundant in the front end of the worm's body, said Martin Tresguerres, a marine physiologist at the Scripps Institution of Oceanography in La Jolla, California.

 

The cellular mechanism used to produce the acid is nearly identical to that used in osteoclasts, the human cells that break down bone so that it can be rebuilt. Insight into how the worm dissolves bone could possibly be applied to osteoclasts, Tresguerres said. Human kidneys also contain similar proton pumps involved in processing bodily waste, he added.

Even stranger, Tresguerres said, is that the worms lack digestive systems. The study suggests the acid the worms produce frees collagen and other proteins from the whale bones, but how they are broken down and absorbed by the worms is unclear. Tresguerres, along with co-authors Sigrid Katz and Greg Rouse, think that symbiotic bacteria help the animals digest the food.  

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Discovery of Wound-Healing Genes in Flies Could Mitigate Human Skin Ailments

Discovery of Wound-Healing Genes in Flies Could Mitigate Human Skin Ailments | Amazing Science | Scoop.it
Biologists at UC San Diego have identified eight genes never before suspected to play a role in wound healing that are called into action near the areas where wounds occur.

 

After injury to the animal epidermis, a variety of genes are transcriptionally activated in nearby cells to regenerate the missing cells and facilitate barrier repair. The range and types of diffusible wound signals that are produced by damaged epidermis and function to activate repair genes during epidermal regeneration remains a subject of very active study in many animals. In Drosophila embryos, serine proteases are locally activated around wound sites, and are also required for localized activation of epidermal repair genes. The serine protease trypsin is sufficient to induce a striking global epidermal wound response without inflicting cell death or compromising the integrity of the epithelial barrier. The fly researchers developed a trypsin wounding treatment as an amplification tool to more fully understand the changes in the Drosophila transcriptome that occur after epidermal injury.


By comparing these array results with similar results on mammalian skin wounding they were able to see which evolutionarily conserved pathways are activated after epidermal wounding in very diverse animals. This innovative serine protease-mediated wounding protocol allowed the researchers to identify 8 additional genes that are activated in epidermal cells in the immediate vicinity of puncture wounds, and the functions of many of these genes suggest novel genetic pathways that may control epidermal wound repair. Additionally, these data augments the evidence that clean puncture wounding can mount a powerful innate immune transcriptional response, with different innate immune genes being activated in an interesting variety of ways. These include puncture-induced activation only in epidermal cells in the immediate vicinity of wounds, or in all epidermal cells, or specifically in the fat body, or in multiple tissues.

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Sydney's curator insight, April 26, 2013 12:36 PM

Cool!

Connor Keesee's curator insight, December 5, 2013 9:36 AM

Would healing & barrier repairing genes found in flies. The genes regenerate missing cells and also repair them. This gene is activated by injury to the epidermis. This discovery was found by biologists at UC San Diego in April. 

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Secret of efficient photosynthesis in purple bacteria is decoded

Secret of efficient photosynthesis in purple bacteria is decoded | Amazing Science | Scoop.it
MIT researchers find that the key to purple bacteria’s light-harvesting prowess lies in highly symmetrical molecules.

 

Purple bacteria are among Earth’s oldest organisms, and among its most efficient in turning sunlight into usable chemical energy. Now, a key to their light-harvesting prowess has been explained through a detailed structural analysis by scientists at MIT.

A ring-shaped molecule with an unusual ninefold symmetry is critical, the researchers found. The circular symmetry accounts for its efficiency in converting sunlight, and for its mechanical durability and strength. The new analysis, carried out by professors of chemistry Jianshu Cao and the late Robert Silbey, postdoc Liam Cleary, and graduate students Hang Chen and Chern Chuang, has been published in Proceedings of the National Academy of Sciences.

“The symmetry makes the energy transfer much more robust,” Cao says. “Most biological systems are quite soft and disordered. You would not expect a regular structure, almost a perfect structure,” as is found in this primitive microbe, he says.

In these regular round complexes, Cao says, “nature only used certain symmetry numbers: mostly ninefold, some eightfold, very few tenfold. It’s very selective.” His group’s mathematical analysis shows there are good reasons for that, he says.

These ring-shaped molecules, in turn, are arranged in a hexagonal pattern on the spherical photosynthetic membrane of purple bacteria, Cao says. 

“With these symmetry numbers, the interactions between all pairs of the symmetric rings are optimized at the same time. … We believe that nature found the most robust structures in terms of energy transfer,” Cao says. Both eightfold and tenfold symmetries also work, though not as well: Only a lattice made up of ninefold symmetric complexes can tolerate an error in either direction. “You want consecutive numbers so it can tolerate such mistakes,” Cao says.

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Carnivorous Utricularia gibba plant cleans its genomic DNA from non-coding DNA

Carnivorous Utricularia gibba plant cleans its genomic DNA from non-coding DNA | Amazing Science | Scoop.it

Scientists have discovered that a carnivorous plant deletes so much of its own junk DNA that it has hardly any left. The finding, published online in Nature, hints that such noncoding DNA may not be as important as some scientists believe.

 

Junk DNA is probably well named as junk. There doesn’t seem to be any glorious reason or function behind it," said Victor Albert, a University at Buffalo molecular evolutionary biologist and one of the lead authors on the study.

 

Only 2% of the human genome is actually made up of functional elements such as  genes, according to Albert. The rest of it is non-coding DNA that doesn’t appear to carry active, relevant information for that living creature’s proper functioning (i.e. for building proteins).

 

But the carnivorous bladderwort plant, Utricularia gibba, has only about 3% junk, according to an international team of researchers -- which is unusual even by plant standards. About 97% of its code actually consists of genes -- making it a lean, mean genetic machine.


U. gibba is a feathery carnivorous plant that forms mats over water and traps single-celled organisms and tiny crustaceans in submerged, millimeter-wide bladders. It draws nutrients from those tiny carcasses in environments where the soil is often very nutrient-poor.


U. gibba's genome is already short -- it’s made of 82 million base pairs, while humans have over 3 billion base pairs, Albert said. Even the basic "lab rat" of plant science,Arabidopsis, has a genetic code that’s about 1.5 times as long as U. gibba's.

 

And yet the plant packs efficiently, stuffing all its useful genetic code into a fraction of the sprawling DNA real estate afforded other plants and animals.

 

Repeated segments buried in the plant's DNA show them that the entire genome has been duplicated three times since its lineage split off from its common ancestor with the tomato and the grape -- and yet this regular doubling of the code hasn’t increased its length. Clearly the plant must be cutting unnecessary DNA faster than it’s adding it, the researchers concluded.

 

The scientists aren’t sure why this particular bladderwort has such a tiny, efficient genetic code. It may be pure chance, Albert said, particularly since other carnivorous plants' codes can stretch much longer.

 

But it does show that perhaps all that junk DNA — which some scientists have argued serves some undiscovered purpose — may be getting more credit than is due, in humans as well as plants.

 

The bladderwort certainly shows that at least one plant makes a perfectly good plant without it," Albert said. "By extension, I would say it's suggestive that maybe junk DNA in general isn't of much importance."

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Extrapolation of genetic complexity of organisms to earlier times suggests that life began before the Earth was formed

Extrapolation of genetic complexity of organisms to earlier times suggests that life began before the Earth was formed | Amazing Science | Scoop.it

Applying a maxim from computer science to biology raises the intriguing possibility that life existed before Earth did. An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide. The genetic complexity, roughly measured by the number of non-redundant functional nucleotides, is expected to have grown exponentially due to several positive feedback factors: gene cooperation, duplication of genes with their subsequent specialization, and emergence of novel functional niches associated with existing genes. Linear regression of genetic complexity on a log scale extrapolated back to just one base pair suggests the time of the origin of life 9.7 billion years ago. This cosmic time scale for the evolution of life has important consequences: (i) Life took ca. 5 billion years to reach the complexity of bacteria; (ii) the environments in which life originated and evolved to the prokaryote stage may have been quite different from those envisaged on Earth; (iii) there was no intelligent life in our universe prior to the origin of Earth, thus Earth could not have been deliberately seeded with life by intelligent aliens; (iv) Earth was seeded by panspermia; (v) experimental replication of the origin of life from scratch may have to emulate many cumulative rare events; and (vi) the Drake equation for guesstimating the number of civilizations in the universe is likely wrong, as intelligent life has just begun appearing in our universe.

 

Evolution of advanced organisms has accelerated via development of additional information-processing systems: epigenetic memory, primitive mind, multicellular brain, language, books, computers, and Internet. As a result the doubling time of complexity has reached ca. 20 years. Finally, the research team discusses the issue of the predicted technological singularity and give a biosemiotics perspective on the increase of complexity.

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Leonard Susskind: Is the Universe Fine-Tuned for Life?

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Engineered spider protein used for anti-venom vaccine against ‘brown recluse’

Engineered spider protein used for anti-venom vaccine against ‘brown recluse’ | Amazing Science | Scoop.it
New approach to act as model for the development of non-toxic vaccines against Loxosceles spider venoms, say researchers in the journal Vaccine.

 

Researchers have engineered a spider protein that could be the start of a new generation of anti-venom vaccines with the potential to save thousands of lives worldwide. “In Brazil we see thousands of cases of people being bitten by spiders, and the bites can have very serious side-effects,” said Dr. Carlos Chávez-Olórtegui of Federal University Minas Gerais in Brazil, the corresponding author of the study.

 

“Existing anti-venoms are made of the pure toxins and can be harmful to people who take them,” he said. “We wanted to develop a new way of protecting people from the effects of Reaper spider bites, without them having to suffer from side effects.”

 

Loxosceles spiders, commonly known as reaper or recluse spiders, are found all over the world and produce harmful venoms. The toxic bite of these spiders causes skin around the bite to die and can lead to more serious effects like kidney failure and hemorrhaging. These Loxosceles spiders are most prevalent in Brazil, where they cause almost 7,000 cases of spider bites every year.

 

According to a World Health Organization report, a review of current antivenom production methods indicates that the majority of antivenoms are still produced by traditional technology using animals. The production method involves injecting the venom into animals and removing the resulting antibodies to use in the anti-venom serum for humans. These antibodies enable the human immune system to prepare to neutralize venom from bites. Although this method is somewhat effective, it is problematic as the animals required to produce the antibodies do suffer from the effects of the venom.In an attempt to improve these conditions Dr. Chávez-Olortegui and his team of researchers identified a protein that can be engineered in the lab, omitting the need to use real spider venom. It is made up of three proteins rather than the whole venom toxin, so it is not harmful to the immunized animal that produces the antibodies for use in the human serum. It is also more effective than existing approaches and easier to produce than preparing crude venom from spiders.

 

The researchers tested the lab-engineered protein on rabbits and showed an immune response similar to the way they respond to the whole toxin, previously experienced in the old method. The protein was effective for venom of two sub-species of Loxosceles spiders, which have similar toxins. The rabbits were protected from skin damage at the site of the venom injection and from hemorrhaging.

 

The authors concluded that this engineered protein may be a promising candidate for vaccination against Loxosceles spider bites in the future.

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Tongue bristles help bats lap up nectar

Tongue bristles help bats lap up nectar | Amazing Science | Scoop.it

A rush of blood to the tongue helps some bats slurp up their food. Erect bristles that spring from the tongue tip of a nectar-feeding bat, Glossophaga soricina, help the bats snag sweetness from flowers, a new study finds.

 

As a bat reaches its tongue deep into a flower (or a manmade feeder), muscles stretch out, forcing blood from the middle of the tongue down into hairlike nubs that sprout from the tip, biomechanist Cally Harper and her colleagues at Brown University in Providence, R.I., report. The nubs are like water balloons that fill up when the bat feeds.

 

Those blood-inflated bristles grab lots of nectar quickly, making it easier for the mammals to snatch food on the fly.

 

Scientists had assumed the hairy bristles lining nectar-feeding bats’ tongue tips were like floppy mop strands, limply soaking up liquid. But the new study shows that the tongue bristles are actually much more active.

“It’s like if you walked into your kitchen, picked up the mop out of the corner, and the mop reached down to the floor and spread out all of its tendrils,” says biologist Margaret Rubega of the University of Connecticut in Storrs, who studies hummingbird tongues.

 

To see the bristles in action, Harper and colleagues stuck a high-speed video camera on a clear acrylic feeder, and rigged up fiber optics to shine bright lights on the bats’ tongues. Then the team filled the feeder with sugar water and watched as bats swooped in for the treat.

 

When the animals lapped up the sweet water, the sides of their glistening pink tongues turned bright red and blood-engorged bristles swelled into spikes. Like a multipronged soup ladle, the swollen spikes each pull in some nectar, Harper says.

 

Unlike with other mammals’ tongues, the nubs of nectar-feeding bats have adapted to the flowers the animals drink from, says biologist Alejandro Rico-Guevara, a colleague of Rubega’s at the University of Connecticut. Other nectar-feeding animals such as bees, butterflies and hummingbirds, use different strategies to suck up food, but all have evolved long tongues with special tubes, tweezers or bristles to help them drink.

 

The findings suggest that the honey possum, a mammal with a brush-shaped tongue tip, might also use the inflate-a-bristle technique to gather its treats, Harper says. And perhaps the bats’ tongue action could one day inspire floppy surgical tools that become firm when pumped full of air or liquid, she says.

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Muscles in old mice made young again

Muscles in old mice made young again | Amazing Science | Scoop.it

Researchers have identified for the first time a key factor responsible for declining muscle repair during aging, and discovered that a common drug halts the process in mice.

 

A dormant reservoir of stem cells is present inside every muscle, ready to be activated by exercise and injury to repair any damage. When needed, these cells divide into hundreds of new muscle fibers that repair the muscle. At the end of the repairing process some of the cells also replenish the pool of dormant stem cells so that the muscle retains the ability to repair itself again and again.

 

The researchers carried out a study on old mice and found the number of dormant stem cells present in the pool reduces with age, which could explain the decline in the muscle’s ability to repair and regenerate as it gets older.

When these old muscles were screened the team found high levels of FGF2, a protein that has the ability to stimulate cells to divide. While encouraging stem cells to divide and repair muscle is a normal and crucial process, they found that FGF2 could also awaken the dormant pool of stem cells even when they were not needed. The continued activation of dormant stem cells meant the pool was depleted over time, so when the muscle really needed stem cells to repair itself the muscle was unable to respond properly.

 

Researchers then attempted to inhibit FGF2 in old muscles to prevent the stem cell pool from being kick-started into action unnecessarily. By administering a common FGF2 inhibitor drug they were able to inhibit the decline in the number of muscle stem cells in the mice.

 

“Preventing or reversing muscle wasting in old age in humans is still a way off, but this study has for the first time revealed a process which could be responsible for age-related muscle wasting, which is extremely exciting,” says Albert Basson, Senior Lecturer from the department of craniofacial development and stem cell biology at the King’s College London Dental Institute.

 

“The finding opens up the possibility that one day we could develop treatments to make old muscles young again. If we could do this, we may be able to enable people to live more mobile, independent lives as they age.”

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Leaf Growth & Tree Height Limited By Physics

Leaf Growth & Tree Height Limited By Physics | Amazing Science | Scoop.it

New research indicates that leaf growth may not be as complicated as it seems. When compared species to species, shorter trees exhibit a greater variety of leaf sizes than taller ones, with the tallest trees all having leaves that measure 10 to 20 centimeters in length.

 

The scientists published their findings in the journal Physical Review Letters⊃1;. The narrow size range may be simply explained in the inner workings of trees. If this is correct, this could also explain why the tallest trees can only attain about 100 meters.

 

The team only considered angiosperms like maples and oaks, not gymnosperms, like pines and redwoods. They reviewed data for 1925 species and found that among angiosperms shorter than 30 meters, leaf length varies enormously, from 3 cm all the way up to 60 cm. The range narrows as the trees become taller.

 

The flow of sap and energy throughout the tree is what explains this. A leaf of an angiosperm produces a sugary sap that flows into a network of cells called the phloem, which transports the sap down to the tree’s trunk and through the roots. While it’s in transit, the tree metabolizes the sugar. The flow is driven by the difference in concentration in the sugars, which generates osmotic pressure.

 

The scientists modeled a tree as a pair of cylindrical tubes. A short, permeable tube, which represented the phloem in the leaf, was attached to a long, impermeable tube, the phloem in the trunk. Sap diffuses into the leave phloem and travels down into the trunk phloem. The longer the permeable leaf tube is, the more the surface area it has, so the more easily sap can enter. In the trunk phloem, the longer the tube is, the more resistance it offers to flow.

 

The scientists then considered how the total flow of sap and energy varies with leaf length. If the leaves are big, the resistance from the trunk limits the flow and making the leaves bigger than a certain maximum length yields no additional flow or benefit. On the other hand, if the leaves are very small, their resistance limits the flow. And if the leaf is shorter than a certain minimum length, the sap would flow through the phloem more slowly than it could diffuse through the entire tree.

 

Trees taller than 100 meters simply could not produce leaves that obey both length limits, setting a limit for tree height. Other scientists think that the uniformity of leaf size amongst the tallest trees could come from the comparable environments and conditions that produce them.

 

One way to test how the flow speed varies with the height of a tree and the length of its leaves would be to directly measure it in different species of tall trees, but that might require taking an MRI machine into a rain forest canopy.

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mdashf's curator insight, May 8, 2013 12:11 AM

why some trees are so tall while others are short? well their leaves size will be affected as well deoending on their heights. Its like very tall men will have proportionate to their height smaller fingers. But shorter men and women will grow fingers in many differet ratio to their height. You lose certain privilege if you are tall. 

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Epilepsy Cured in Mice Using A One-Time Transplantation Of MGE Brain Cells

Epilepsy Cured in Mice Using A One-Time Transplantation Of MGE Brain Cells | Amazing Science | Scoop.it

UCSF scientists controlled seizures in epileptic mice with a one-time transplantation of medial ganglionic eminence (MGE) cells, which inhibit signaling in overactive nerve circuits, into the hippocampus, a brain region associated with seizures, as well as with learning and memory. Other researchers had previously used different cell types in rodent cell transplantation experiments and failed to stop seizures.

 

Cell therapy has become an active focus of epilepsy research, in part because current medications, even when effective, only control symptoms and not underlying causes of the disease, according to Scott C. Baraban, PhD, who holds the William K. Bowes Jr. Endowed Chair in Neuroscience Research at UCSF and led the new study. In many types of epilepsy, he said, current drugs have no therapeutic value at all.

 

"Our results are an encouraging step toward using inhibitory neurons for cell transplantation in adults with severe forms of epilepsy," Baraban said. "This procedure offers the possibility of controlling seizures and rescuing cognitive deficits in these patients."


In the UCSF study, the transplanted inhibitory cells quenched this synchronous, nerve-signaling firestorm, eliminating seizures in half of the treated mice and dramatically reducing the number of spontaneous seizures in the rest. Robert Hunt, PhD, a postdoctoral fellow in the Baraban lab, guided many of the key experiments.


he mouse model of disease that Baraban's lab team worked with is meant to resemble a severe and typically drug-resistant form of human epilepsy called mesial temporal lobe epilepsy, in which seizures are thought to arise in the hippocampus. In contrast to transplants into the hippocampus, transplants into the amygdala, a brain region involved in memory and emotion, failed to halt seizure activity in this same mouse model, the researcher found.

 

Temporal lobe epilepsy often develops in adolescence, in some cases long after a seizure episode triggered during early childhood by a high fever. A similar condition in mice can be induced with a chemical exposure, and in addition to seizures, this mouse model shares other pathological features with the human condition, such as loss of cells in the hippocampus, behavioral alterations and impaired problem solving.


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Biosciencia's curator insight, May 6, 2013 3:38 AM

Cell therapy has become an active focus of epilepsy research, in part because current medications, even when effective, only control symptoms and not underlying causes of the disease.

Brenda Elliott's curator insight, May 8, 2013 4:00 AM

curative_ that's amazing...

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Shark Embryos Eat Each Other in the Womb: Sibling Rivalry at its Finest

Shark Embryos Eat Each Other in the Womb: Sibling Rivalry at its Finest | Amazing Science | Scoop.it

Shark embryos actually cannibalize their littermates while still in the womb; the largest one eats all but one of its siblings. Now, new research reveals why sharks are such bad brothers.

 

In order to find out why this phenomenon occurs, researchers analyzed shark embryos found in sand tiger sharks which, despite their name and their in utero behavior, are a non-aggressive species. They are only known to attack humans when bothered first. In order to better understand these embryos, the scientists examined them at various stages of gestation. They discovered that the later the pregnancy is, the more likely the remaining shark embryos had just one father.

 

So what does that mean exactly? Before now, researchers weren't sure whether females mated with just one partner or with multiple partners. After a bit of DNA testing, researchers discovered that litters that possessed five to seven embryos had at least two fathers. It's possible that females mated with even more males, though; at the start of gestation, there can be as many as 12 littermates. It could be that the other littermates with different fathers had already been eaten.

 

The cannibalization itself is actually a useful strategy for the sharks. It allows the two remaining babies to grow large enough to be relatively unbothered by predators once they're actually born. What is more surprising, though, is the fact that the two sharks are usually full siblings as opposed to half siblings. This suggests that the largest embryo actually targets other embryos that are from other fathers.

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Jesse Bradley's curator insight, May 5, 2013 4:37 AM

Why do you think that sharks cannibalize in the womb?

 

 

How do you think that sharks culling the weaker embryo's has effected their evolution?

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Researchers Uncover Molecular Pathway to Grow New Arteries

Researchers Uncover Molecular Pathway to Grow New Arteries | Amazing Science | Scoop.it

Scientists from Yale and UCL have identified a new mechanism that regulates VEGFR2 transport in vascular cells, opening new therapeutic opportunities for developing drugs to stimulate or inhibit blood vessel formation.


Arteries form in utero and during development, but can also form in adults when organs become deprived of oxygen — for example, after a heart attack. The organs release a molecular signal called VEGF. Working with mice, the Yale-UCL team discovered that in order for VEGF-driven artery formation to occur, VEGF must bind with two molecules known as VEGFR2 and NRP1, and all three must work as a team.

 

The researchers examined mice that were lacking a particular part of the NRP1 molecule that transports VEGF and VEGFR2 to a signaling center inside blood vessel walls. They observed that the internal organs of these mice contained poorly constructed arterial branches. Further, the mice where unable to efficiently repair blood vessel blockage through the formation of new arteries.

 

“We have identified an important new mechanism that regulates VEGFR2 transport in vascular cells,” said corresponding author Michael Simons, professor of medicine and cell biology, and director of the cardiovascular research center at Yale School of Medicine. “This opens new therapeutic opportunities for developing drugs that would either stimulate or inhibit blood vessel formation — important goals in cardiovascular and anti-cancer therapies, respectively.”

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Biosciencia's curator insight, May 2, 2013 2:16 AM

Michael Simons, professor of medicine and cell biology, and director of the cardiovascular research center at Yale School of Medicine said "We have identified an important new mechanism that regulates VEGFR2 transport in vascular cells”

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Researchers find high-fructose corn syrup may be tied to worldwide collapse of bee colonies

Researchers find high-fructose corn syrup may be tied to worldwide collapse of bee colonies | Amazing Science | Scoop.it

A team of entomologists from the University of Illinois has found a possible link between the practice of feeding commercial honeybees high-fructose corn syrup and the collapse of honeybee colonies around the world.

 

Since approximately 2006, groups that manage commercial honeybee colonies have been reporting what has become known as colony collapse disorder—whole colonies of bees simply died, of no apparent cause. As time has passed, the disorder has been reported at sites all across the world, even as scientists have been racing to find the cause, and a possible cure. To date, most evidence has implicated pesticides used to kill other insects such as mites. In this new effort, the researchers have found evidence to suggest the real culprit might be high-fructose corn syrup, which beekeepers have been feeding bees as their natural staple, honey, has been taken away from them.

Commercial honeybee enterprises began feeding bees high-fructose corn syrup back in the 70's after research was conducted that indicated that doing so was safe. Since that time, new pesticides have been developed and put into use and over time it appears the bees' immunity response to such compounds may have become compromised.

 

The researchers aren't suggesting that high-fructose corn syrup is itself toxic to bees, instead, they say their findings indicate that by eating the replacement food instead of honey, the bees are not being exposed to other chemicals that help the bees fight off toxins, such as those found in pesticides.

 

Specifically, they found that when bees are exposed to the enzyme p-coumaric, their immune system appears stronger—it turns on detoxification genes. P-coumaric is found in pollen walls, not nectar, and makes its way into honey inadvertently via sticking to the legs of bees as they visit flowers. Similarly, the team discovered other compounds found in poplar sap that appear to do much the same thing. It all together adds up to a diet that helps bees fight off toxins, the researchers report. Taking away the honey to sell it, and feeding the bees high-fructose corn syrup instead, they claim, compromises their immune systems, making them more vulnerable to the toxins that are meant to kill other bugs.

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