‘Free choice’ in primates altered through brain stimulation

When electrical pulses are applied to the ventral tegmental area of their brain, macaques presented with two images change their preference from one image to the other. The study by researchers Wim Vanduffel and John Arsenault (KU Leuven and Massachusetts General Hospital) is the first to confirm a causal link between activity in the ventral tegmental area and choice behaviour in primates.

The ventral tegmental area is located in the midbrain and helps regulate learning and reinforcement in the brain’s reward system. It produces dopamine, a neurotransmitter that plays an important role in positive feelings, such as receiving a reward. “In this way, this small area of the brain provides learning signals,” explains Professor Vanduffel. “If a reward is larger or smaller than expected, behavior is reinforced or discouraged accordingly.”

Causal link

This effect can be artificially induced: “In one experiment, we allowed macaques to choose multiple times between two images — a star or a ball, for example. This told us which of the two visual stimuli they tended to naturally prefer. In a second experiment, we stimulated the ventral tegmental area with mild electrical currents whenever they chose the initially nonpreferred image. This quickly changed their preference. We were also able to manipulate their altered preference back to the original favorite.”

The study, which will be published online in the journal Current Biology on 16 June, is the first to confirm a causal link between activity in the ventral tegmental area and choice behaviour in primates. “In scans we found that electrically stimulating this tiny brain area activated the brain’s entire reward system, just as it does spontaneously when a reward is received. This has important implications for research into disorders relating to the brain’s reward network, such as addiction or learning disabilities.”

Could this method be used in the future to manipulate our choices? “Theoretically, yes. But the ventral tegmental area is very deep in the brain. At this point, stimulating it can only be done invasively, by surgically placing electrodes — just as is currently done for deep brain stimulation to treat Parkinson’s or depression. Once non-invasive methods — light or ultrasound, for example — can be applied with a sufficiently high level of precision, they could potentially be used for correcting defects in the reward system, such as addiction and learning disabilities.”

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Clues to stillbirths may be found in marmoset monkeys

The marmoset monkey may offer clues to reducing stillbirths in human mothers, according to new research at the University of Illinois at Chicago College of Nursing.

The prenatal environment that a female marmoset fetus develops in seems to affect her later reproductive success as an adult, says Julienne Rutherford, assistant professor of women, children and family health science at UIC and lead author of a study in PLOS ONE.

The marmoset, a squirrel-sized monkey indigenous to South America, reaches sexual maturity by 15 months of age. They have multiple births, usually twins and triplets. Adult females who were born into triplet litters get pregnant just as often as twin females, but they lose three times as many fetuses. Nearly half of the losses occur during labor and delivery, Rutherford said.

The new research looked at more than a decade of data on 1,395 animals of both sexes and all birth conditions at the Southwest National Primate Research Center in San Antonio. It has important implications for human stillbirth, which remains poorly understood, Rutherford said.

Current research on pregnancy loss focuses primarily on circumstances near the time of the loss, Rutherford said. “Things like the woman’s current health and nutritional status, her race and income, and her lifestyle.”

“Taken together, these factors explain a large portion of pregnancy loss, but not all,” she said. “Our study suggests we need to consider a woman’s entire life history, including her experience as a fetus herself, to solve the mystery of childbirth.”

In marmosets, females who had a brother in the litter also lost more fetuses than those who shared the womb with sisters only, Rutherford said.

This unexplained “brother effect” on female fertility could be due to exposure to male hormones during fetal development, Rutherford said. What is clear, she said, is that adult reproductive function, specifically stillbirth, is shaped by events that occurred long before adulthood.

The study may suggest new ways to screen, diagnose and treat human reproductive dysfunction based on developmental milestones. There may also be “profound policy implications for the kinds of environments we as a society provide for babies, girls and women,” Rutherford said.

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The above story is based on materials provided by University of Illinois at Chicago . The original article was written by Sam Hostettler. Note: Materials may be edited for content and length.

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Intertwined evolution of human brain and brawn

The cognitive differences between humans and our closest living cousins, the chimpanzees, are staggeringly obvious. Although we share strong superficial physical similarities, we have been able to use our incredible mental abilities to construct civilisations and manipulate our environment to our will, allowing us to take over our planet and walk on the moon while the chimps grub around in a few remaining African forests.

But a new study suggests that human muscle may be just as unique. Scientists from Shanghai’s CAS-MPG Partner Institute for Computational Biology, together with teams from German Max Planck Institutes, investigated the evolution of metabolites — small molecules like sugars, vitamins, amino acids and neurotransmitters that represent key elements of our physiological functions. Their study found that metabolite concentrations evolved rapidly over the course of human evolution in two tissues: in the brain and, more surprisingly, in muscle. An article describing their findings will be published on May 27th in the open-access journal PLOS Biology.

Genomes, including the human genome, accumulate changes steadily over time. Among the genetic changes that have happened over the course of human evolution, only a few might be responsible for the rise of distinct human features. To determine what other molecules played a role in human evolution, scientists began to look beyond the genome. The international team of scientists, led by Dr Philipp Khaitovich from Shanghai, examined for the first time the evolution of the human metabolome — the compendium of metabolites present in human tissues. “Metabolites are more dynamic than the genome and they can give us more information about what makes us human,” says Khaitovich. “It is also commonly known that the human brain consumes way more energy than the brains of other species; we were curious to see which metabolic processes this involves.”

Indeed, it turned out that unlike the uniformly-paced evolution of the genome, the metabolome of the human brain has evolved four times faster than that of the chimpanzee. What was more surprising, however, is that human muscle accumulated an even higher amount of metabolic change — ten times that of the chimpanzee!

To rule out the possibility that this change simply reflects our couch potato lifestyle, the scientists performed additional measurements in specially treated macaque monkeys. These macaques were moved from a spacious countryside facility to small indoor enclosures and served fatty and sugary food for several weeks, to imitate the environment of many contemporary humans. These lifestyle changes had only a small effect on the macaque muscle metabolome. “For a long time we were confused by metabolic changes in human muscle,” says Dr Kasia Bozek, the lead author of the study, “until we realized that what other primates have in common, in contrast to humans, is their enormous muscle strength.” Dr Josep Call, from the Wolfgang Kohler Primate Research Center in Leipzig, Germany, concurs: “This is common knowledge to all the zoo keepers, but it was never tested systematically.” To prove their point, researchers involved several chimpanzees, macaques, university students, and even professional athletes in a pulling strength competition. Despite their sweat and determination, all of the human participants of the experiment were outcompeted by their primate opponents by more than two-fold.

A tantalizing hypothesis suggested by the scientists is that the metabolic roles of human brain and brawn are intertwined. “Our results suggest a special energy management in humans, that allows us to spare energy for our extraordinary cognitive powers at a cost of weak muscle,” summarizes Dr Kasia Bozek. “The world of human metabolomics is just starting to open up its secrets to us,” adds Dr Patrick Giavalisco, who led the metabolome measurement effort at the Max Planck Institute for Molecular Plant Physiology in Golm. “Such human-specific metabolic features we find could be related not only to physical or cognitive performance but also to common human metabolic diseases.”

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Ebola Vaccine For Chimps Could Help Save Wild Populations

Researchers at the University of Louisiana at Lafayette’s New Iberia Research Center have conducted a vaccine trial on chimpanzees that could help protect endangered wild apes from deadly infectious diseases, such as the Ebola virus.

It’s believed to be the first time that a vaccine intended for apes – rather than humans – has been tested on captive chimpanzees. Results of the trial are published in the latest issue of Proceedings of the National Academy of Sciences.

Vaccines haven’t been used to fight outbreaks of diseases in chimpanzees and gorillas because of concerns about their safety, according to the journal article.

But Joe Simmons, NIRC director, said high mortality rates have made many conservationists more receptive to the potential protection of vaccines.

“Preserving endangered chimpanzee and gorilla species is a common cause for conservationists and medical researchers,” he said.

NIRC researchers tested a virus-like particle vaccine, which contains a small amount of viral proteins but is incapable of replicating. “The vaccine doesn’t cause infection, but it does cause an immune response to those proteins that can protect against infection,” Simmons explained.

Full story here .

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Six Quarantined Monkeys Die At Oregon Zoo

Six monkeys died of unknown causes while in quarantine at the Oregon Zoo.

The cotton-top tamarins, a species of small New World monkey, were part of a group of nine that arrived at the zoo on May 22.

“It’s sad,” said zoo visitor Maria Maarigal. “The Oregon Zoo should have taken care of them properly, how can this happen?”

The remaining three monkeys, including a 5-week-old baby, appear to be in good health, according to zoo workers. They are still being closely monitored.

The deaths were discovered by a veterinary staff member early Sunday morning. Initial necropsy results were inconclusive, according to a zoo statement.

“We are shocked and heartbroken,” said zoo veterinarian Dr. Tim Storms. “We are really trying to get to the bottom of it. Certainly, I have seen animals die in unfortunate situations before, but never six animals all at once like that.”

Tissue samples were submitted to a pathologist for further analysis. Zoo officials hope to receive those results within a few weeks.

“At this point it could be anything, from exposure to something to disease or even acclimation problems, we really don’t know,” said Storms.

Full story here .

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Stronger Brains, Weaker Bodies

Testing paleo diet hypothesis in test tubes: Surprising relationships between diet and hormones that suppress eating

By comparing how gut microbes from human vegetarians and grass-grazing baboons digest different diets, researchers have shown that ancestral human diets, so called “paleo” diets, did not necessarily result in better appetite suppression. The study, published in mBio® the online open-access journal of the American Society for Microbiology, reveals surprising relationships between diet and the release of hormones that suppress eating.

While Western diets have changed dramatically in the last century to become high energy, low fiber, and high fat (think: cheeseburger), our digestive systems, including our gut bacterial colonies, adapted over millennia to process a low-energy, nutrient-poor, and presumably high fiber diet. One idea about the current obesity epidemic is that appetite suppression systems that evolved to work with a paleo diet are off-kilter today.

The appetite-suppressing gut hormones peptide YY (PYY) and glucagon-like-peptide-1 (GLP-1) can be triggered by the presence of short-chain fatty acids (SCFAs) in the colon. Fermentation of plant fiber in the colon by bacteria can produce these SCFAs, so it stands to reason that digestion of a diet high in plant fiber might lead to better appetite suppression.

Gary Frost and his colleagues at Imperial College London in the United Kingdom wanted to test that hypothesis in the laboratory using fecal bacterial samples from three human vegetarian volunteers and from three gelada baboons, the only modern primate to eat mainly grasses.

“Getting to the bottom of how our gut bacteria and diets interact to control appetites is vitally important for tackling the problem of obesity,” said Glenn Gibson, co-author on the study based at University of Reading. Frost added, “Understanding how a paleo-like diet impacts the colon’s microbiota and the signals those bacteria produce to release hormones that reduce appetite may give us new insight that we can adapt in the modern world.”

The team established gut bacteria cultures in flasks and then ‘fed’ them two different diets — either a predigested potato, high-starch diet or a predigested grass, high-fiber diet. Then they tracked changes in the numbers and types of bacteria and measured the metabolites produced by digestion.

Surprisingly, the human cultures on a potato diet produced the highest levels of SCFAs. Even the baboon cultures fed potato produced more SCFAs than the baboon cultures fed grass. When the researchers applied some of these cultures to mouse colon cells in the lab dish, the cells were stimulated to release PYY hormone. Those exposed to human cultures digesting a potato diet released the most PYY, followed by those exposed to baboon cultures on a potato diet.

This evidence argues that the previous view of paleo diets and appetite suppression is flawed and that high-fiber, plant-based diets likely do not lead to increased SCFAs and increased appetite suppression. Rather, the researchers propose, little to no appetite suppression might help baboons maintain grazing all day to consume enough nutrients.

A closer cataloguing of all the metabolites produced by the bacterial cultures digesting potato or grass diets showed that as the levels of the amino acids isoleucine and valine rose, so too did the amount of PYY released. This relationship was even stronger than that with SCFAs.

“This hints that protein might play a greater role in appetite suppression than the breakdown of starch or fiber,” said Timothy Barraclough, another co-author of the study. “More work will be needed to explore the effects of alternative breakdown products of various foods.”

The researchers note that this study of digestion in the test tube is limited by not including the roles of gut cells, which absorb and secrete metabolites as well.

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Having and raising offspring is costly phase of life for baboon moms

Observations made over the past 29 years in Kenya as part of one of the world’s longest-running studies of a wild primate show how having offspring influences the health of female baboons. These observations highlight that females are mostly injured on days when they are likely to conceive. In addition, injuries heal the slowest when they are suckling their young. The study, published in Springer’s journal Behavioral Ecology and Sociobiology, is led by Elizabeth Archie of the University of Notre Dame in the US and the National Museums of Kenya.

Reproduction can be dangerous and energetically costly, exposing individuals to physical harm, infectious disease and reduced immunity. To investigate how long-lived, slow-reproducing species such as primates adjust to this, Archie and her colleagues turned to data collected as part of the Amboseli Baboon Research Project near Kilimanjaro. Here, trained observers have made almost daily notes since 1971 on groups of yellow baboons. Among others, 707 injuries to 160 female baboons between 1982 and 2011 were noted.

The analysis of the data makes it possible to predict the risk of injury to specific females by taking their ovarian cycle, dominance rank and age into account, as well as whether their social group is separating into two or more distinct groups. Ovulating females are, for instance, twice as likely to be wounded as those who are in the less fertile days of their cycle. Such injuries occur in the context of reproductive competition through interactions with both adult males and females.

The injuries of lactating baboons were about 21 percent less likely to heal in a given time period than those of non-lactating females. This may be because lactating females are in poorer physical condition or have less energy in general. This influences how well a wound can heal, tissue is repaired and infections are curbed.

The researchers do not find it at all surprising that low-ranking females experience higher injury risk than high-ranking females. Prior research has shown that these baboons are subject to more aggression and are less likely to be supported in conflicts than high-ranking females.

Older females might incur more injuries because they take greater risks to make the best of their declining reproductive years, or because their health and resilience is generally failing. Old age has another drawback for female baboons: older ones tend to heal more slowly than younger females, because immunity and subsequent wound healing commonly decline with age.

“As yet it’s unclear if these costs of reproduction influence female survival, but in many species injuries and slow healing have important functional consequences, including reduced mobility and greater risk of infection or predation,” says Archie. “Our results contribute to a growing understanding of the costs of reproduction in long-lived species.”

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First test of pluripotent stem cell therapy in monkeys is successful

Researchers have shown for the first time in an animal that is more closely related to humans that it is possible to make new bone from stem-cell-like induced pluripotent stem cells (iPSCs) made from an individual animal’s own skin cells. The study in monkeys reported in the Cell Press journal Cell Reports on May 15th also shows that there is some risk that those iPSCs could seed tumors, but that unfortunate outcome appears to be less likely than studies in immune-compromised mice would suggest.

“We have been able to design an animal model for testing of pluripotent stem cell therapies using the rhesus macaque, a small monkey that is readily available and has been validated as being closely related physiologically to humans,” said Cynthia Dunbar of the National Heart, Lung, and Blood Institute. “We have used this model to demonstrate that tumor formation of a type called a ‘teratoma’ from undifferentiated autologous iPSCs does occur; however, tumor formation is very slow and requires large numbers of iPSCs given under very hospitable conditions. We have also shown that new bone can be produced from autologous iPSCs, as a model for their possible clinical application.”

Autologous refers to the fact that the iPSCs capable of producing any tissue type—in this case bone—were derived from the very individual that later received them. That means that use of these cells in tissue repair would not require long-term or possibly toxic immune suppression drugs to prevent rejection.

The researchers first used a standard recipe to reprogram skin cells taken from rhesus macaques. They then coaxed those cells to form first pluripotent stem cells and then cells that have the potential to act more specifically as bone progenitors. Those progenitor cells were then seeded onto ceramic scaffolds that are already in use by reconstructive surgeons attempting to fill in or rebuild bone. And, it worked; the monkeys grew new bone.

Importantly, the researchers report that no teratoma structures developed in monkeys that had received the bone “stem cells.” In other experiments, undifferentiated iPSCs did form teratomas in a dose-dependent manner.

The researchers say that therapies based on this approach could be particularly beneficial for people with large congenital bone defects or other traumatic injuries. Although bone replacement is an unlikely “first in human” use for stem cell therapies given that the condition it treats is not life threatening, the findings in a primate are an essential step on the path toward regenerative clinical medicine.

“A large animal preclinical model for the development of pluripotent or other high-risk/high-reward generative cell therapies is absolutely required to address issues of tissue integration or homing, risk of tumor formation, and immunogenicity,” Dunbar said. “The testing of human-derived cells in vitro or in profoundly immunodeficient mice simply cannot model these crucial preclinical safety and efficiency issues.”

The NIH team is now working with collaborators on differentiation of the macaque iPSCs into liver, heart, and white blood cells for eventual clinical trials in hepatitis C, heart failure, and chronic granulomatous disease, respectively.

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Tenn. Zoo Gorilla Recovering from Surgery After Femur Fracture

A gorilla at the Knoxville Zoo is up and about, just one day after he had surgery to repair a broken leg.

Wanto, a 37 year old silverback gorilla, broke his right femur in what zoo officials called a “freak accident” on Monday, while climbing bars in the indoor courtyard of his exhibit. His keepers think he may have been trying to avoid the three female gorillas in his group who like to tease him.

The surgery was a little risky, since he’s considered an “old man” in gorilla years and has an existing heart condition, but zoo officials wanted to give him the best chance to get better.

Full story here .

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Stem Cells Made From Skin Safely Grow New Bone in Monkeys for the First Time

Researchers have shown for the first time that it is possible to grow new bone from stem cells made from an animal’s own skin cells. While this is not the first successful stem cell therapy tested on animals closely related to humans, it offers another potential source of stem cells for transplantation—the individual’s own adult cells.

In the new study, published online today in Cell Reports, researchers chose a type of monkey called the rhesus macaque as a model for how the technique might work in people. These primates are physiologically similar to humans, especially when it comes to their immune system and how it reacts to foreign bodies.

Researchers harvested skin cells from the monkeys and then genetically reprogrammed them into the equivalent of embryonic stem cells. Unlike adult cells, which are committed to being a specific type of cell (such as skin, bone, or heart-tissue cells), these so-called induced pluripotent stem cells (iPSCs) have the ability to mature into any other type of cell.

Full story here .

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Getting to the root of enamel evolution: Connecting genes to hominin teeth shows evidence of natural selection

Along with our big brains and upright posture, thick tooth enamel is one of the features that distinguishes our genus, Homo, from our primate relatives and forebears. A new study, published May 5 in the Journal of Human Evolution, offers insight into how evolution shaped our teeth, one gene at a time.

By comparing the human genome with those of five other primate species, a team of geneticists and evolutionary anthropologists at Duke University has identified two segments of DNA where natural selection may have acted to give modern humans their thick enamel.

Teeth have been an invaluable resource for scientists who study evolution, the authors said.

“The fossil record is always the most complete for teeth,” said coauthor Christine Wall, associate research professor of evolutionary anthropology at Duke. “And enamel thickness has long been a key trait used to diagnose fossil hominins and reconstruct their diets and life histories.”

Clear differences in enamel thickness among primates have been linked to diet. Of the six species included in this study, fruit- and leaf-loving gorillas and chimpanzees have the thinnest enamel; omnivorous orangutans, gibbons and rhesus macaques have an intermediate thickness; and humans possess the thickest enamel, well suited to crushing tough foods.

“Teeth also preserve their growth bands,” Wall said, referring to the way enamel is deposited in layers, like concentric tree rings. “So in terms of understanding fossils, teeth can tell you how old a juvenile was when it died, or how long it takes for teeth to develop — so you can compare between living and extinct species.”

All of this makes tooth enamel one of the few traits that’s both found in the fossil record and amenable to genomic analyses, Wall said.

The team set out to identify some of the genetic changes that contributed to humans acquiring thicker enamel. The work is part of a large-scale investigation of the links between genes, physical characteristics and diet during human evolution.

“We decided to look just at genes that have a known role in tooth development,” said Greg Wray, professor of biology at Duke. The team chose four genes, each of which codes for a protein involved in tooth formation (enamelysin, amelogenin, ameloblastin and enamelin), making the genes good candidates for seeing evidence of positive selection, but not necessarily the only ones involved in tooth evolution, Wray said.

Publicly available data provided the sequences for the four genes across six species — except in the case of the gorilla and orangutan, whose DNA the team isolated themselves.

The researchers then fed the sequences to a software program that pinpointed which base pairs had changed between the species, and where changes had accumulated at an accelerated rate. “That’s when we know a gene is under positive selection,” said first author Julie Horvath, director of the genomics and microbiology lab at the Nature Research Center in Raleigh, NC and research associate professor of biology at North Carolina Central University.

They used the concept of genetic drift to reach this conclusion. Drift is a phenomenon in which changes to the DNA sequence accumulate at an expected rate, Horvath said. When changes add up faster than expected, it suggests to scientists that the affected genes are under positive selection — that they give organisms some kind of advantage.

Previous research had shown positive selection on one of the genes, called MMP20, also known as enamelysin. The present analysis confirmed that MMP20 shows the distinct signature of natural selection acting on tooth enamel thickness in humans. They also found another gene, called ENAM or enamelin, which is under positive selection.

Selection pressure did not affect ENAM and MMP20 in the protein-coding region, where even slight changes can dramatically alter or destroy a gene’s functionality. Instead, ENAM and MMP20 showed positive selection changes in their regulatory regions, a sequence slightly upstream or downstream in the DNA that controls how a gene is transcribed.

“This study provides the important bridges between morphology, developmental processes, and their underlying genetic regulating mechanisms,” said Timothy Bromage, professor of biomaterials and biomimetics at New York University, who was not involved with the study. “Already the results of the reported work are whittling away the many layers of regulation and evolution of enamel structure.”

By connecting genes and fossils across species — and in the future, across different age groups — the team hopes to build a roadmap for untangling how the many pieces of natural selection are linked.

How and where to find cheap monkeys for sale

Getting to the root of enamel evolution

Along with our big brains and upright posture, thick tooth enamel is one of the features that distinguishes our genus, Homo, from our primate relatives and forebears. A new study, published May 5 in the Journal of Human Evolution, offers insight into how evolution shaped our teeth, one gene at a time.

By comparing the human genome with those of five other primate species, a team of geneticists and evolutionary anthropologists at Duke University has identified two segments of DNA where natural selection may have acted to give modern humans their thick enamel.

Teeth have been an invaluable resource for scientists who study evolution, the authors said.

“The fossil record is always the most complete for teeth,” said coauthor Christine Wall, associate research professor of evolutionary anthropology at Duke. “And enamel thickness has long been a key trait used to diagnose fossil hominins and reconstruct their diets and life histories.”

Clear differences in enamel thickness among primates have been linked to diet. Of the six species included in this study, fruit- and leaf-loving gorillas and chimpanzees have the thinnest enamel; omnivorous orangutans, gibbons and rhesus macaques have an intermediate thickness; and humans possess the thickest enamel, well suited to crushing tough foods.

“Teeth also preserve their growth bands,” Wall said, referring to the way enamel is deposited in layers, like concentric tree rings. “So in terms of understanding fossils, teeth can tell you how old a juvenile was when it died, or how long it takes for teeth to develop — so you can compare between living and extinct species.”

All of this makes tooth enamel one of the few traits that’s both found in the fossil record and amenable to genomic analyses, Wall said.

The team set out to identify some of the genetic changes that contributed to humans acquiring thicker enamel. The work is part of a large-scale investigation of the links between genes, physical characteristics and diet during human evolution.

“We decided to look just at genes that have a known role in tooth development,” said Greg Wray, professor of biology at Duke. The team chose four genes, each of which codes for a protein involved in tooth formation (enamelysin, amelogenin, ameloblastin and enamelin), making the genes good candidates for seeing evidence of positive selection, but not necessarily the only ones involved in tooth evolution, Wray said.

Publicly available data provided the sequences for the four genes across six species — except in the case of the gorilla and orangutan, whose DNA the team isolated themselves.

The researchers then fed the sequences to a software program that pinpointed which base pairs had changed between the species, and where changes had accumulated at an accelerated rate. “That’s when we know a gene is under positive selection,” said first author Julie Horvath, director of the genomics and microbiology lab at the Nature Research Center in Raleigh, NC and research associate professor of biology at North Carolina Central University.

They used the concept of genetic drift to reach this conclusion. Drift is a phenomenon in which changes to the DNA sequence accumulate at an expected rate, Horvath said. When changes add up faster than expected, it suggests to scientists that the affected genes are under positive selection — that they give organisms some kind of advantage.

Previous research had shown positive selection on one of the genes, called MMP20, also known as enamelysin. The present analysis confirmed that MMP20 shows the distinct signature of natural selection acting on tooth enamel thickness in humans. They also found another gene, called ENAM or enamelin, which is under positive selection.

Selection pressure did not affect ENAM and MMP20 in the protein-coding region, where even slight changes can dramatically alter or destroy a gene’s functionality. Instead, ENAM and MMP20 showed positive selection changes in their regulatory regions, a sequence slightly upstream or downstream in the DNA that controls how a gene is transcribed.

“This study provides the important bridges between morphology, developmental processes, and their underlying genetic regulating mechanisms,” said Timothy Bromage, professor of biomaterials and biomimetics at New York University, who was not involved with the study. “Already the results of the reported work are whittling away the many layers of regulation and evolution of enamel structure.”

By connecting genes and fossils across species — and in the future, across different age groups — the team hopes to build a roadmap for untangling how the many pieces of natural selection are linked.

How and where to find cheap monkeys for sale

Stolen Blackpool Monkeys: Four Found But Baby Missing

Four monkeys stolen from a zoo in a “planned and pre-meditated” break-in have been found.

Blackpool Zoo in Lancashire said two female cotton-top tamarins and two male emperor tamarins had been recovered in Yorkshire. However a baby tamarin which was also taken had not been found.

Raiders cut a hole in the perimeter fence of the zoo and removed the locks from two separate monkey enclosures on Tuesday.

They took two female and one baby cotton-top tamarin, which are a critically endangered species, and two male emperor tamarins.

But the zoo said the four recovered monkeys were now safely back at the zoo.

Full story here .

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How and where to find cheap monkeys for sale

Crocodile tears please thirsty butterflies and bees

The butterfly (Dryas iulia) and the bee (Centris sp.) were most likely seeking scarce minerals and an extra boost of protein. On a beautiful December day in 2013, they found the precious nutrients in the tears of a spectacled caiman (Caiman crocodilus), relaxing on the banks of the Río Puerto Viejo in northeastern Costa Rica.

A boat carrying students, photographers, and aquatic ecologist Carlos de la Rosa was passing slowing and quietly by, and caught the moment on film. They watched [and photographed] in barely suppressed excitement for a quarter of an hour while the caiman basked placidly and the insects fluttered about the corners of its eyes.

De la Rosa reported the encounter in a peer-reviewed letter in the May 2014 issue of the Ecological Society of America’s journal Frontiers in Ecology and the Environment.

“It was one of those natural history moments that you long to see up close,” said de la Rosa, the director of the La Selva Biological Station for the Organization for Tropical Field Studies in San Pedro, Costa Rica. “But then the question becomes, what’s going on in here? Why are these insects tapping into this resource?”

Though bountiful in the ocean, salt is often a rare and valuable resource on land, especially for vegetarians. It is not uncommon to see butterflies sipping mineral-laden water from mud puddles. When minerals are rare in the soil, animals sometimes gather salt and other rare minerals and proteins from sweat, tears, urine, and even blood.

De la Rosa had seen butterflies and moths in the Amazon feeding on the tears of turtles and a few caimans. Tear-drinking “lachryphagous” behavior in bees had only recently been observed by biologists. He remembered a 2012 report of a solitary bee sipping the tears of a yellow-spotted river turtle in Ecuador’s Yasuní National Park. But how common is this behavior?

Back at the field station, he did a little research. He was surprised to find more evidence of tear-drinking than he expected in the collective online record of wilderness enthusiasts, casual tourists, professional photographers, and scientists. He now thinks the phenomenon may not be as rare as biologists had assumed — just hard to witness.

“I did a Google search for images and I found out that it is quite common! A lot of people have recorded butterflies, and some bees, doing this,” said de la Rosa.

A search of the scientific literature produced a detailed study of bees drinking human tears in Thailand, as well as the remembered October 2012 “Trails and Tribulations” story about the Ecuadorian bee and the river turtle by Olivier Dangles and Jérôme Casas in ESA’s Frontiers. This experience reminds us that the world still has many surprises for ecologists, de la Rosa said. There so much still to be studied. De la Rosa is a specialist in the biology of non-biting midges, and a natural historian, with his eyes always open to new discoveries. Scientists at La Selva have discovered hundreds of species of aquatic insects that are still unnamed and undescribed.

“I have over 450 undescribed species from Costa Rica in my laboratory. If I did nothing for the rest of my life but collaborate with taxonomists and try to describe those, I would never get done,” he said.

De la Rosa’s job as director of La Selva Biological Station brings him an unusual number of serendipitous encounters with wildlife. He lives on site in the lowland rainforest, and he never needs an alarm clock. Howler monkeys wake him every morning.

“I learned I have to carry a camera with me 24/7, because you never know what you’re going to find when you’re walking to the office or the dining hall,” he said. One day, he spied a new species of dragonfly on his way to breakfast. It had emerged from its larval form in the small pool of water caught in the cupped leaves of a bromeliad plant. He did a double-take. Dragonflies don’t live on bromeliads. Or do they?

“Those are the kinds of things that, you know, you don’t plan for them, you can’t plan for them,” de la Rosa said. There was only one known species of dragonfly in the world that lives in bromeliads. Now there will be two. “You just keep your eyes open and have curiosity, and when you see something that doesn’t seem to fit, dig.”

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The above story is based on materials provided by Ecological Society of America . Note: Materials may be edited for content and length.

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Stem cell therapy regenerates heart muscle damaged from heart attacks in primates

Heart cells created from human embryonic stem cells successfully restored damaged heart muscles in monkeys.

The results of the experiment appear in the April 30 advanced online edition of the journal Nature in a paper titled, “Human embryonic-stem cell derived cardiomyocytes regenerate non-human primate hearts.”

The findings suggest that the approach should be feasible in humans, the researchers said.

“Before this study, it was not known if it is possible to produce sufficient numbers of these cells and successfully use them to remuscularize damaged hearts in a large animal whose heart size and physiology is similar to that of the human heart,” said Dr. Charles Murry, UW professor of pathology and bioengineering, who led the research team that conducted the experiment.

A physician/scientist, Murry directs the UW Center for Cardiovascular Biology and is a UW Medicine pathologist.

Murry said he expected the approach could be ready for clinical trials in humans within four years.

In the study, Murry, along with Dr. Michael Laflamme and other colleagues at the UW Institute for Stem Cell & Regenerative Medicine, experimentally induced controlled myocardial infarctions, a form of heart attack, in anesthetized pigtail macaques.

The infarcts were created by blocking the coronary artery of macaque for 90 minutes, an established model for the study of myocardial infarction in primates.

In humans, myocardial infarctions are typically caused by coronary artery disease. The resulting lack of adequate blood flow can damage heart muscle and other tissues by depriving them of oxygen. Because the infarcted heart muscle does not grow back, myocardial infarction leaves the heart less able to pump blood and often leads to heart failure, a leading cause of cardiovascular death.

The goal of stem cell therapy is to replace the damaged tissue with new heart cells and restore the failing heart to normal function.

Two weeks after the experimental myocardial infarctions, the Seattle researchers injected 1 billion heart muscle cells derived from human embryonic stem cells, called human embryonic stem cell-derived cardiomyocytes, into the infarcted muscle. This was ten times more of these types of cells than researchers have ever been able to generate before.

All the monkeys had been put on immunosuppressive therapy to prevent rejection of the transplanted human cells.

The researchers found that over subsequent weeks, the stem-cell derived heart muscle cells infiltrated into the damaged heart tissue, then matured, assembled into muscle fibers and began to beat in synchrony with the macaque heart cells. After three months, the cells appear to have fully integrated into the macaque heart muscle.

On average the transplanted stem cells regenerated 40 percent of the damaged heart tissue, said Dr. Michael Laflamme, UW assistant professor of pathology, whose team was principally responsible for generating the replacement heart muscle cells.

“The results show we can now produce the number of cells needed for human therapy and get formation of new heart muscle on a scale that is relevant to improving the function of the human heart,” Laflamme said.

Ultrasound studies of the macaques’ hearts showed that the ejection fraction, an indication of the hearts ability to pump blood, improved in some of the treated animals but not all. The researchers also found that arteries and veins from the macaques’ hearts grew into the new heart tissue, the first time it has been shown that blood vessels from a host animal will grow into and nurture a large stem-cell derived graft of this type.

The most concerning complications were episodes of irregular heartbeats, or arrhythmias, that occurred in the weeks after the macaques received the stem cell injections, Murry said. None of the macaques, however, appeared to have symptoms during these episodes, which disappeared after two to three weeks as the stem cells matured and became more electrically stable.

Going forward the UW researchers will work to reduce the risk of arrhythmias, perhaps by using more electrically mature stem cells. They also will try to demonstrate definitively that the stem cells are actually strengthening the heart’s pumping power.

These cells have improved the mechanical function in every other species in which they have been tested, so we are optimistic they will do so in this model as well,” Murry said.

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Monkey model of hantavirus disease established

National Institutes of Health (NIH) researchers have developed an animal model of human hantavirus pulmonary syndrome (HPS) in rhesus macaques, an advance that may lead to treatments, vaccines and improved methods of diagnosing the disease. The study, conducted by researchers at NIH’s National Institute of Allergy and Infectious Diseases (NIAID), is published in the Proceedings of the National Academy of Sciences.

People become infected with hantaviruses by inhaling virus from the urine, droppings or saliva of infected rodents. This infection can progress to HPS, a severe respiratory disease that was first identified in 1993 in the southwestern United States. HPS attained global attention in the summer of 2012 when physicians diagnosed 10 cases — three of them fatal — in Yosemite National Park in California. The primary HPS agents are Sin Nombre virus in North America and Andes virus in South America. Since 1993, the Centers for Disease Control and Prevention has reported approximately 600 HPS cases, including 200 deaths, in the United States; case numbers for South America are not available.

In their study, NIAID scientists infected healthy deer mice with Sin Nombre virus obtained from descendants of wild deer mice. The researchers then exposed 10 rhesus macaques to the virus derived from the newly infected deer mice. Nine monkeys became infected and seven developed severe disease. In the diseased macaques, researchers observed how and where the virus established infection, evaded the immune system and caused pneumonia. Of note, they report that, similar to hantavirus infection in people, the virus in the monkey model triggers a life-threatening immune response nearly two weeks after infection. NIAID researchers aim to identify biological markers during that initial timeframe that may be useful for early diagnosis.

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The above story is based on materials provided by NIH/National Institute of Allergy and Infectious Diseases . Note: Materials may be edited for content and length.

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Five Rare Monkeys Stolen In Blackpool Zoo Night Raid

A group of rare monkeys stolen from Blackpool zoo have prompted police to issue an air and sea ports warning amid fears they will be smuggled out of Britain and sold.

Five monkeys have been taken in what police said appeared to be a “planned and premeditated” break-in.

The thieves cut a hole in the perimeter fence of the zoo and removed the locks from two separate monkey enclosures.

Two female and one baby cotton-top tamarin, which are a critically endangered species, and two male emperor tamarins were stolen overnight on Tuesday.

Police believe they were targeted specifically and their details have been circulated to all ports and airports in case the thieves try to take them abroad.

Full story here .

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How and where to find cheap monkeys for sale

Stem Cell Treatment Repairs Damaged Hearts In Monkeys

Scientists have successfully repaired damaged monkey hearts by injecting new heart cells made from human stem cells, paving the way for a trial in humans before the end of the decade.

Researchers now hope that the treatment could give patients a new lease of life after massive heart attacks that cause scarring and ultimately heart failure.

“When human embryonic stem cells were first discovered, this is just the sort of therapy people hoped they would lead to. We are optimistic, but we are also cautious,” said Charles Murry, who led the team at the University of Washington in Seattle.

The heart is one of the poorest organs in the body at repairing itself when it sustains damage. After a heart attack, muscle tissue in the heart dies off, and is replaced a month or so later with scar tissue. This does not contract like normal heart tissue, so the heart is weakened and struggles to pump blood around the body.

Full story here .

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