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Archive - Mar 10, 2015

Autism Genes May Also Be Linked to Higher Intelligence

Genes linked with a greater risk of developing autism may also be associated with higher intelligence, a study suggests. Researchers have found new evidence linking genetic factors associated with autism to better cognitive ability in people who do not have the condition. The relationship between autism and intelligence is not clear, researchers say. Although up to 70 per cent of individuals with autism have an intellectual disability, some people with the disorder have relatively well-preserved, or even higher than average, non-verbal intelligence, the team says. Autism is a developmental disability that can cause significant language and speech difficulties. Non-verbal intelligence enables people to solve complex problems using visual and hands-on reasoning skills requiring little or no use of language. Researchers at the Universities of Edinburgh and Queensland analyzed almost 10,000 people recruited from the general population of Scotland. Individuals were tested for general cognitive ability and also had their DNA analyzed. The team found that even among people who never develop autism, carrying genetic traits associated with the disorder is, on average, linked to scoring slightly better on cognitive tests. Researchers found further evidence of a link between autism-associated genes and intelligence when they carried out the same tests on 921 adolescents who were part of the Brisbane Adolescent Twin Study. The study is published in the journal Molecular Psychiatry. The research was funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Scottish Funding Council, The Wellcome Trust, The Medical Research Council, and Age UK.

Bats Hibernate in Temperate Temperatures in Israel

Many mammals -- and some birds -- escape the winter by hibernating for three to nine months. This period of dormancy permits species which would otherwise perish from the cold and scarce food to survive to see another spring. The Middle East, with temperate winters, was, until recently, considered an unlikely host for hibernating mammals. New research published online on March 4, 2015 in the Proceedings of the Royal Society of London by Tel Aviv University (TAU) researchers is set to not only correct this fallacy, but also change the very concept of hibernation. Professor Noga Kronfeld-Schor, Chair of the Department of Zoology at TAU's Faculty of Life Sciences, and doctoral student Dr. Eran Levin found two species of mouse-tailed bat (the Rhinopoma microphyllum and the R. Cystops) hibernating at the unusually warm and constant temperature of 68°F in caves in Israel's Great Rift Valley. From October to February, these bats were discovered semi-conscious, breathing only once every 15-30 minutes, with extremely low energy expenditures. "Hibernation in mammals is known to occur at much lower temperatures, allowing the animal to undergo many physiological changes, including decreased heart rate and body temperature," said Professor Kronfeld-Schor. "But we have found these bats maintain a high body temperature while lowering energy expenditure levels drastically. We hypothesize that these caves, which feature a constant high temperature during winter, enable these subtropical species to survive on the northernmost edge of their world distribution." The researchers monitored the activity of the bats during this period and found that they neither fed nor drank, even on warm nights when other bat species were active in the same caves.

Chameleon Has Two Layers of Nanocrystal Lattices Permitting Rapid Color Change and Offering Passive Thermal Protection

Many chameleons have the remarkable ability to exhibit complex and rapid color changes during social interactions. A collaboration of scientists within the Sections of Biology and Physics of the Faculty of Science from the University of Geneva (UNIGE), Switzerland, unveils the mechanisms that regulate this phenomenon. In a study published online on March 10, 2015 in Nature Communications, a team led by Professors Michel Milinkovitch and Dirk van der Marel demonstrates that the changes take place via the active tuning of a lattice of nanocrystals present in a superficial layer of dermal cells called iridophores. The researchers also reveal the existence of a deeper population of iridophores with larger and less ordered crystals that reflect the infrared light. The organization of iridophores into two superimposed layers constitutes an evolutionary novelty and it allows the chameleons to rapidly shift between efficient camouflage and spectacular display, while providing passive thermal protection. Male chameleons are popular for their ability to change colorful adornments depending on their behavior. If the mechanisms responsible for a transformation towards a darker skin are known, those that regulate the transition from a lively color to another vivid hue remained mysterious. Some species, such as the panther chameleon, are able to carry out such a change within one or two minutes to court a female or face a competing male.

Faster, More Accurate, More Flexible Way to Build Artificial DNA; New Approach Amenable to Automation and High-Throughput Processes

A new technique for creating artificial DNA that is faster, more accurate and more flexible than existing methods has been developed by scientists at Imperial College London. The new system – called BASIC – is a major advance for the field of synthetic biology, which designs and builds organisms able to make useful products such as medicines, energy, food, materials, and chemicals. The report was published online on March 8, 2015 in ACS Synthetic Biology. The article is titled “BASIC: A New Biopart Assembly Standard for Idempotent Cloning Provides Accurate, Single-Tier DNA Assembly for Synthetic Biology.” To engineer new organisms, scientists build artificial genes from individual molecules and then put these genes together to create larger genetic constructs which, when Inserted into a cell, will create the required product. Various attempts have been made to standardize the design and assembly process but, until now, none has been completely successful. BASIC, created by researchers from Imperial’s Centre for Synthetic Biology & Innovation, combines the best features of the most popular methods while overcoming their limitations, creating a system that is fast, flexible, and accurate. The new technique should enable greater advances in research and could offer industry a way to automate the design and manufacture of synthetic DNA. Dr. Geoff Baldwin, from Imperial’s Department of Life Sciences, explains: “BASIC uses standardized parts which, like Lego, have the same joining device, so parts will fit together in any order. Unlike some systems that can only join two parts at a time, forcing the gene to be built in several, time-consuming steps, BASIC enables multiple parts to be joined together at once.

Genes May Play Key Role in Increased Number of ACL Injuries in Female Athletes Versus Males

Female athletes endure two to eight times more anterior cruciate ligament, or ACL, injuries than their male counterparts. Genes are likely a major factor, according to Dr. William Landis, G. Stafford Whitby Chair in Polymer Science at The University of Akron, in Ohio, and Dr. Kerwyn Jones, Chair of Pediatric Orthopedics for Akron Children's Hospital. The findings could change the way women athletes receive sports training and treatment for their injuries and could possibly lead to genetic counseling regarding athletic participation. Dr. Jones and Dr. Landis have been probing the significant gap in ACL injury occurrence among young women and men athletes for years, exploring other potential factors such as hormones and the gait or stance of women as compared to men. "We wondered about the influence of genes and how they might affect the structure or integrity of these ligaments," Dr. Landis says, explaining that he and Dr. Jones examined 14 fresh surgical samples of ruptured ligament tissue taken from both female and male athletes who suffered non-contact injuries of the tissues. "After some very detailed and extensive analysis through gene microarray techniques, we discovered 32 genes that were expressed to much different degrees in the female injured ligaments compared with those of males." Of the 32 expressed genes, the researchers closely examined three that gave rise to specific proteins related to ligament structure and integrity. They discovered that all three genes regulated ligament tissue in a much different manner in female compared to male tissue. "The differences clearly may account for weaker anterior cruciate ligaments in the females compared to the males," Dr. Landis says.

Fifteen New Breast-Cancer-Associated SNPs Identified

Scientists have discovered another 15 genetic “hot-spots” that can increase a woman's risk of developing breast cancer, according to research published online on March 9, 2015 in Nature Genetics. The article was titled “Genome-Wide Association Analysis of More Than 120,000 Individuals Identifies 15 New Susceptibility Loci for Breast Cancer.” In the study, funded by Cancer Research UK, scientists compared tiny variations in the genetic make-up of more than 120,000 women of European ancestry, with and without breast cancer, and identified 15 new variations - called single nucleotide polymorphisms (SNPs) - that are linked to a higher risk of the disease. This new discovery means that a total of more than 90 SNPs associated with breast cancer have now been revealed through research. On average, one in every eight women in the UK will develop breast cancer at some stage in their lives. The researchers estimate that about five per cent of women have enough genetic variations to double their risk of developing breast cancer - giving them a risk of approximately one in four. A much smaller group of women, around 0.7 per cent, have genetic variations that make them three times more likely to develop breast cancer, giving them a risk of around one in three. It's hoped that these genetic markers can be used to help identify high-risk women and could lead to improved cancer screening and prevention. Study author Professor Doug Easton, Professor of Genetic Epidemiology at the University of Cambridge, said: "Our study is another step towards untangling the breast cancer puzzle. As well as giving us more information about how and why a higher breast cancer risk can be inherited, the genetic markers we found can help us to target screening and cancer prevention measures at those women who need them the most.”

Progeny of Old Parents Can Have Fewer Offspring

Reproduction at old age involves risks that may impact one's own life and may impose reduced biological fitness on the offspring. Such evidence, previously obtained in humans and other taxa under laboratory conditions, has now been confirmed by researchers from the Max Planck Institute for Ornithology in Seewiesen, Germany, together with colleagues from the UK and New Zealand for the first time in free-living animals. The results were published online on March 9, 2015 in PNAS, The article was titled “Reduced Fitness in Progeny from Old Parents in a Natural Population.” In a long-term study on a population of house sparrows they found that offspring of older parents themselves produced fewer young. Such a trans-generational effect is important for the understanding of the evolution of longevity. Fertility does not decrease in all taxa with increasing age, but may remain constant lifelong as is the case of some invertebrates or may even increase with increasing age as in some reptiles. Generally, both sexes are able to reproduce at old age, with males capable of producing more offspring than females. In some mammals, such as humans, male individuals remain fertile for a longer time compared to females that at some stage enter the menopause. However, reproducing at old age may incur risks such as a higher infant mortality or chromosomal anomalies. Moreover, children of old parents have themselves fewer offspring or have a shorter lifespan, which is commonly known as the "Lansing effect" that was demonstrated, not only in humans, but also in mice and some invertebrates in the laboratory, but never in free-living populations.

The Chemistry of Poison Ivy (Video)

Leaves of three, let them be, right? But what happens when you get covered in poison ivy and can't stop scratching? Jennifer Novotney, winner of the 2014 Chemistry Champions science communications competition, breaks down what it is about that dreaded vine that makes us so itchy. Reactions also offers up a remedy for the poison ivy's itch using the power of chemistry. Check out the video, which is sponsored by the American Chemical Society, here: http://youtu.be/SJEU3PT0O5g.

Why Blood Type O Protects Against Severe Malaria

It has long been known that people with blood type O are protected from dying of severe malaria, although the reason has not been known. In a study published online on March 9, 2015 in Nature Medicine, a team of Scandinavian scientists explains the mechanisms behind the protection that blood type O provides, and suggest that the selective pressure imposed by malaria may contribute to the variable global distribution of ABO blood groups in the human population. The article is titled “RIFINs Are Adhesins Implicated in Severe Plasmodium falciparum Malaria.” Malaria is a serious disease that is estimated by the WHO to infect 200 million people a year, 600,000 of whom, primarily children under five, fatally. Malaria, which is most endemic in sub-Saharan Africa, is caused by different kinds of parasites from the plasmodium family, and effectively all cases of severe or fatal malaria come from the species known as Plasmodium falciparum. In severe cases of the disease, the infected red blood cells adhere excessively in the microvasculature and block the blood flow, causing oxygen deficiency and tissue damage that can lead to coma, brain damage, and, eventually death. Scientists have therefore been keen to learn more about how this species of parasite makes the infected red blood cells so sticky. It has long been known that people with blood type O are protected against severe malaria, while those with other types, such as A, often fall into a coma and die. Unpacking the mechanisms behind this has been one of the main goals of malaria research. A team of scientists led from Karolinska Institutet in Sweden has now identified a new and important piece of the puzzle by describing the key part played by the RIFIN protein.