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Archive - 2014

January 17th

Male Honey Bees More Susceptible Than Females to Widespread Intestinal Parasite

Gender differences in nature are common, including in humans. A research team from Bern, Switzerland has found that male European honey bees, or drones, are much more susceptible than female European honey bees, known as workers, to a fungal intestinal parasite called Nosema ceranae. Originally from Asia, Nosema ceranae has rapidly spread throughout the world in recent years, and may contribute to the high number of colony deaths now observed in many regions of the northern hemisphere. These findings demonstrate the delicate nature of male honey bees, which are important to honey bee colony reproduction, and its susceptibility to a well-distributed parasite. Honey bees are complex social organisms that demonstrate haploid-diploidy. The two female castes, workers and queens, are diploid, like humans. They contain two copies of each chromosome. Male honey bees, known as drones, on the other hand, are haploid and contain only one chromosome set. The haploid susceptibility hypothesis predicts that haploid males are more prone to disease compared to their diploid female counterparts because dominant genes on one chromosome copy have the opportunity to mask mutated genes on the other copy in diploid organisms. A research team from the Vetsuisse Faculty of the University of Bern in Switerland demonstrated in a January 17, 2014 online article in the open-access journal PLOS ONE that male honey bees are significantly more susceptible (they die sooner and have poor body condition) to an exotic fungal intestinal parasite called Nosema ceranae compared to female worker honey bees. The parasite, originally from Asia, has recently spread to have a near-global distribution during a period of high honey bee colony losses in many global regions.

January 17th

Scientists ID Evolutionary Switch in Regulation of Low Oxygen Response in Fungi; Possible Huge Clinical Impact

All but a few eukaryotes die without oxygen, and they respond dynamically to changes in the level of oxygen available to them. University College Dublin (UCD) scientists used genetic analysis to pinpoint an evolutionary switch in regulating response to low oxygen levels in fungi. One example of an ancient oxygen-requiring biochemical pathway in eukaryotes is the biosynthesis of sterols, producing cholesterol in animals and ergosterol in fungi. The mechanism regulating the sterol pathway is widely conserved between animals and fungi and centers on a protein family of transcription activators named the sterol regulatory element binding proteins (SREBPs), which form part of a sterol-sensing complex. However, in one group of fungi; the Saccharomycotina, which includes the model yeast Saccharomyces cerevisiae and the major pathogen Candida albicans, control of the sterol pathway has been taken over by an unrelated regulatory protein, Upc2. New research published in PLOS Genetics by UCD researchers, in collaboration with colleagues from AgroParisTech, France, and the University of Kansas, USA, used comparative genomic analysis to investigate the timing of the evolutionary switch from one regulatory mechanism to another; from SREBPs to Upc2. Led by Professor Geraldine Butler, UCD Conway Institute and UCD School of Biomolecular & Biomedical Science, the group found that one yeast species, Yarrowia lipolytica (image), is unique in that it contains both SREBP and Upc2 genes. Y. lipolytica is used in the biotechnology industry to produce lipids and lies at the base of the Saccharomycotina group. Using a mixture of genetic and biochemical analysis, the group showed that Upc2 is the main regulator of the hypoxic response in Y.

How Male Black Widow Avoids Appearing As Prey When Approaching Potential Mate

A team of Simon Fraser University (Canada) (SFU) biologists has found that male black widow spiders shake their abdomens to produce carefully pitched vibrations that let females know they have “come a-courting” and are not potential prey. The team’s research has just been published online on January 17, 2014 in the open-access journal Frontiers in Zoology. SFU graduate students Samantha Vibert and Catherine Scott, working with SFU biology professor Dr. Gerhard Gries, recorded the vibrations made by male black widow spiders (Latrodectus hesperus), hobo spiders (Tegenaria agrestis), and prey insects. Ms. Scott explains: “The web functions as an extension of the spider's exquisitely tuned sensory system, allowing her to very quickly detect and respond to prey coming into contact with her silk. This presents prospective mates with a real challenge when they first arrive at a female's web: they need to signal their presence and desirability, without triggering the female's predatory response.” The researchers found that the courtship vibrations of both species differed from those of prey, but that the very low-amplitude vibratory signals produced when male black widows shake their abdomens were particularly distinctive. “These 'whispers' may help to avoid potential attacks from the females they are wooing," explains Ms. Scott. [Press release] [Frontiers in Zoology article]

Scientists Find Possible Cure for Deadly Flesh-Eating Streptococcus Infection

Collaboration between the National University of Singapore (NUS) and The Hebrew University of Jerusalem (HUJ) on inflammation research may lead to a potential treatment for deadly bacterial infections. Scientists from the NUS-HUJ-CREATE Inflammation Research Programme based in Singapore have found that asparaginase (ASNASE) – the enzyme that degrades the amino acid asparagine and serves as a common chemotherapeutic agent – arrests Group A Streptococcus (GAS) growth in human blood and blocks bacteria’s proliferation, thus initiating a new potential treatment against deadly Streptococcal infections. These findings were published in the January 16, 2014 issue of the prestigious journal Cell. The research program is funded by the National Research Foundation, Prime Minister’s Office, Singapore, under its Campus for Research Excellence and Technological Enterprise (CREATE) program. The NUS-HUJ-CREATE Inflammation Research Program was established in 2011, and is focused on advancing an understanding of cellular and molecular mechanisms of inflammation of diseases prevalent in Asia, a field that is currently under-studied. GAS is a strict human pathogen that causes a wide range of infections, from mild to deadly. It can colonize the host without causing any symptoms, or cause mild infections of skin and trough such as pharyngitis. On the invasive end of the spectrum, GAS can cause life-threatening infections such as bacteremia, necrotizing fasciitis (commonly known as flesh-eating disease), and streptococcal toxic shock syndrome. Annually, disseminated GAS infections cause approximately 160,000 deaths globally and severe injuries to those infected.

Vitamin D Relaxes Blood Vessels, Affects Blood Pressure

It’s not just your mood that the dark months of winter can influence. Low levels of sunlight also mean lower levels of vitamin D in the body. Vitamin D deficiency can trigger a range of diseases, but until recently little was known about the exact biological mechanisms behind this. A research team at the University of Veterinary Medicine, Vienna, Austria, has now decrypted one of these unknown molecular mechanisms. Vitamin D regulates the elasticity of blood vessels and thus also affects blood pressure amplitude. The results were published in the January 2014 issue of Molecular Endocrinology. UV-B radiation in sunlight is the most important factor for the production of vitamin D, and that is why many people suffer from low levels of vitamin D during the winter months. Although certain foods do contain vitamin D, it is not usually possible to get an adequate supply of the vitamin from food. Many clinical studies have indicated that low vitamin D levels are related to cardiovascular disease such as high blood pressure, but also other diseases such as diabetes mellitus, autoimmune diseases, and even cancer. However, the underlying molecular mechanisms were unclear. The two primary authors of the Molecular Endocrinology article, molecular biologist Dr. Olena Andrukhova and medical doctor Svetlana Slavic, of the Institute of Physiology, Pathophysiology, and Biophysics at the Vetmeduni Vienna, found that prolonged vitamin D deficiency can stiffen blood vessels. Examining the aorta, an elastic blood vessel that expands with each pulse of blood and then constricts again, the researchers showed that vitamin D deficiency makes the vessel less flexible. Dr. Andrukhova explains in detail: "Vitamin D enhances the production of the enzyme eNOS (endothelial nitric oxide synthase) in the inner layer of blood vessels, the endothelium.

January 16th

Silencing p57 Triples Replication Rate of Transplanted Human Beta-Cells in Diabetic Mice

Klaus Kaestner, Ph.D., professor of Genetics and postdoctoral fellow Dana Avrahami, Ph.D., from the Perelman School of Medicine, University of Pennsylvania, published a study online in the Journal of Clinical Investigation, with colleague Benjamin Glaser, M.D., from the Hadassah-Hebrew University Medical Center, Jerusalem, and colleagues. In this study, they were able to replicate human pancreatic beta cells – the cells in our body that produce the critical hormone insulin – in a mouse model in which donor cells were transplanted. The newly replicated cells retained features of mature beta cells and showed a physiological response to glucose. The results of this proof-of-principle experiment have implications for helping both type 1 and type 2 diabetic patients. In type 1 diabetes, beta cells are destroyed by the patient's own immune system and thus restoration of their numbers must be coupled with a method of preventing immune-mediated destruction. Similarly, a decrease in the number of functional insulin-producing beta cells contributes to the development of type 2 diabetes, so in principle, restoration of beta-cell mass can reverse or ameliorate both forms of diabetes. The idea for this study came from newborns with a well-characterized, but rare, condition called hyperinsulinism of infancy, in which beta cells produce too much insulin – the exact opposite of diabetes. The blood sugar levels in these babies are too low. In about one-third of these newborns, most of their pancreatic beta cells are normal, but a small portion of cells lack a specific protein called p57, due to a mutation that occurs in a single or a few beta cells during fetal development.

Soil Microbes Alter DNA in Response to Warming

As scientists forecast the impacts of climate change, one missing piece of the puzzle is what will happen to the carbon in the soil and the microbes that control the fate of this carbon as the planet warms. Scientists studying grasslands in Oklahoma have discovered that an increase of 2 degrees Celsius in the air temperature above the soil creates significant changes to the microbial ecosystem underground. Compared to a control group with no warming, plants in the warmer plots grew faster and higher, which put more carbon into the soil as the plants senesce. The microbial ecosystem responded by altering its DNA to enhance the ability to handle the excess carbon. “What we conclude from this study is the warming has an effect on the soil ecosystem,” said Dr. Kostas Konstantinidis, an assistant professor who holds the Carlton S. Wilder Chair in Environmental Engineering at the Georgia Institute of Technology. “It does appear that the microbes change genetically to take advantage of the opportunity given to them.” The study was published online on December 27, 2013, in the journal Applied and Environmental Microbiology. The research was sponsored by the Department of Energy, and involved collaboration with several universities, including the University of Oklahoma. The findings are the culmination of a 10-year study that seeks to understand how the most intricate ecosystem in nature — soil — will respond to climate change. A single gram of soil is home to a billion bacterial cells, representing at least 4,000 different species. In comparison, the human gut is home to at least 10 times fewer different species of bacteria. Scientists have little idea what microbes in the soil do, how they do it, or how they respond to changes in their environment, Dr. Konstantinidis said.

Gene Therapy Shows Promise in Clinical Trial for Specific Type of Inherited Blindness

The first clinical trial of a gene therapy for an inherited cause of progressive blindness called choroideremia has shown very promising initial results which have surpassed expectations of the Oxford University researchers leading the study. The aim of the study was to get the gene therapy into the cells in the retina of the eye without causing damage. After six months, however, the patients actually showed improvements in their vision in dim light and two of the six were able to read more lines on the eye chart. A total of nine patients have now had one eye treated with the gene therapy in operations at the Oxford Eye Hospital, part of the Oxford University Hospitals NHS Trust. The therapy is given in one eye to allow comparison with progression of the disease in the other eye. The first patient to be treated, Jonathan Wyatt, 65, says: “My left eye, which had always been the weaker one, was that which was treated as part of this trial...Now when I watch a football match on the TV, if I look at the screen with my left eye alone, it is as if someone has switched on the floodlights. The green of the pitch is brighter, and the numbers on the shirts are much clearer.” Professor Robert MacLaren of the Nuffield Laboratory of Ophthalmology at the University of Oxford led the development of the retinal gene therapy and this first clinical trial. He says: “It is still too early to know if the gene therapy treatment will last indefinitely, but we can say that the vision improvements have been maintained for as long as we have been following up the patients, which is two years in one case.” The clinical trial is funded by the Health Innovation Challenge Fund, a partnership between the Wellcome Trust and the Department of Health.

Ice-Loving Sea Anemones Discovered Living in Antarctica

Using a camera-equipped robot to explore beneath the Ross Ice Shelf off Antarctica, scientists and engineers with the Antarctic Geological Drilling (ANDRILL) Program made an astonishing discovery. Thousands upon thousands of small sea anemones were burrowed into the underside of the ice shelf, their tentacles protruding into frigid water like flowers on a ceiling. "The pictures blew my mind," said Dr. Marymegan Daly of Ohio State University, who studied the specimens retrieved by ANDRILL team members in Antarctica. The new species, discovered in late December 2010, was publicly identified for the first time in an open-access online article published on December 11, 2013 in PLoS ONE. Though other sea anemones have been found in Antarctica, the newly discovered species is the first known to live in ice. They also live upside down, hanging from the ice, compared to other sea anemones that live on or in the sea floor. The white anemones have been named Edwardsiella andrillae, in honor of the ANDRILL program. The discovery was "total serendipity," said Dr. Frank Rack, executive director of the ANDRILL Science Management Office at the University of Nebraska-Lincoln (UNL) and associate professor of Earth and Atmospheric Sciences at UNL. "When we looked up at the bottom of the ice shelf, there they were," he said. Scientists had lowered the robot, a 4 and 1/2-foot cylinder equipped with two cameras, a side-mounted lateral camera and a forward-looking camera with a fish-eye lens, into a hole bored through the 270-meter-thick shelf of ice that extends more than 600 miles northward into the Ross Sea from the grounding zone of the West Antarctic Ice Sheet. Their mission, financed by the National Science Foundation in the U.S.

Discovery of Quantum Vibrations in “Microtubules” inside Brain Neurons Corroborates Controversial 20-Year-Old Theory of Consciousness

A review and update of a controversial 20-year-old theory of consciousness published online on August 20,2013 in an open-access article in Physics of Life Reviews claims that consciousness derives from deeper-level, finer-scale activities inside brain neurons. The recent discovery of quantum vibrations in “microtubules” inside brain neurons corroborates this theory, according to review authors Dr. Stuart Hameroff and Sir Dr. Roger Penrose. They suggest that EEG rhythms (brain waves) also derive from deeper-level microtubule vibrations, and that from a practical standpoint, treating brain microtubule vibrations could benefit a host of mental, neurological, and cognitive conditions. The theory, called “orchestrated objective reduction” ('Orch OR'), was first put forward in the mid-1990s by eminent mathematical physicist Dr. Penrose, FRS, Mathematical Institute and Wadham College, University of Oxford, and prominent anesthesiologist Stuart Hameroff, M.D., Anesthesiology, Psychology and Center for Consciousness Studies, The University of Arizona, Tucson, Arizona. They suggested that quantum vibrational computations in microtubules were “orchestrated” (“Orch”) by synaptic inputs and memory stored in microtubules, and termed by Dr. Penrose “objective reduction” ('OR'), hence “Orch OR.” Microtubules are major components of the cell structural skeleton. Orch OR was harshly criticized from its inception, as the brain was considered too “warm, wet, and noisy” for seemingly delicate quantum processes. However, evidence has now shown warm quantum coherence in plant photosynthesis, bird brain navigation, our sense of smell, and brain microtubules.