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August 20th, 2017

Portable DNA Sequencer (MinION) Used in Field to Rapidly Identify Closely-Related Plants

In a paper published online on August 21, 2017 in Scientific Reports (Nature Publishing Group), researchers at the Royal Botanic Gardens, Kew, detail for the first time the opportunities for plant sciences that are now available with portable, real-time DNA sequencing. The open-access article is titled “"Field-Based Species Identification of Closely-Related Plants Using Real-Time Nanopore Sequencing.” Kew scientist and co-author of the paper Joe Parker says, "This research proves that we can now rapidly read the DNA sequence of an organism to identify it with minimum equipment. Rapidly reading DNA anywhere, at will, should become a routine step in many research fields. Despite hundreds of years of taxonomic research, it is still not always easy to work out which species a plant belongs to just by looking at it. Few people could correctly identify all the species in their own gardens." Over the last forty years, DNA sequencing has revolutionized the scientific world, but has remained laboratory-bound. Using current methods, a complete experiment to identify a species, from fieldwork to result, could easily take a scientist months to complete. Species identification is, by nature, largely a field-based area of pursuit, thereby limiting the pace of discovery and decision-making that can depend upon it. Using new technology to identify species quickly and on-site is critical for scientific research, the conservation of biodiversity, and in the fight against species crime. In this new study, Kew scientists used a portable DNA sequencer, the MinION from Oxford Nanopore Technologies, to analyze plant species in Snowdonia National Park. This was the first time genomic sequencing of plants has been performed in the field.

August 20th

Exosome Diagnostics Launches MedOncAlyzer™ Pan-Cancer Panel That Simultaneously Interrogates Exosomal RNA and ctDNA in Single Assay of Liquid Biopsy

On August 9, 2017, Exosome Diagnostics, a leader in the liquid biopsy market, announced the launch of the MedOncAlyzer 170, the first liquid biopsy pan-cancer panel that simultaneously interrogates exosomal RNA (exoRNA) and circulating tumor DNA (ctDNA) in a single assay. The MedOncAlyzer 170 is a targeted panel for tumor profiling that identifies clinically actionable and functionally important mutations across multiple cancer types starting from a small volume (≥ 0.5ml) of patient blood or plasma. “The MedOncAlyzer is the only cancer panel on the market that interrogates information on both RNA and DNA, giving it a higher sensitivity compared to ctDNA assays when profiling early-stage and late-stage cancers in plasma,” said Johan Skog, PhD, Chief Science Officer of Exosome Diagnostics. “ctDNA-only solutions are seeing their most accurate measurements in late-stage cancers. The primary drivers of ctDNA release into the bloodstream are apoptosis and necrosis of tumor cells. Existing solutions that rely on ctDNA alone are building a profile of the tumor that is biased towards consequences of cell death. Exosomes, in contrast, are actively released by living cells including viable tumor cells.

No Guts, No Glory—Scientists Probe Microbiomes of Elite Athletes

Elite athletes work hard to excel in sports, but they may also get a natural edge from the bacteria that inhabit their digestive tracts. Scientists have now tapped into the microbiomes of exceptional runners and rowers, and have identified particular bacteria that may aid athletic performance. The goal is to develop probiotic supplements that may help athletes -- and even amateur fitness enthusiasts -- recover from a tough workout or more efficiently convert nutrients to energy. The researchers presented their work on Sunday August 20, 2017 at the 254th National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world's largest scientific society, is holding the meeting in Washington, DC, through Thursday. It features nearly 9,400 presentations on a wide range of science topics. The microbiome presentation was titled “FitBiomics: Understanding Elite Microbiomes for Performance and Recovery Applications.” "When we first started thinking about this, I was asked whether we could use genomics to predict the next Michael Jordan," Jonathan Scheiman, Ph.D., says. "But my response was that a better question is: Can you extract Jordan's biology and give it to others to help make the next Michael Jordan?" To answer that question, microbes seemed like a good place to start. "We are more bacteria than we are human," says Dr. Scheiman, who is a postdoctoral fellow in the laboratory of George Church, PhD, at Harvard Medical School. "The bugs in our gut affect our energy metabolism, making it easier to break down carbohydrates, protein, and fiber. They are also involved in inflammation and neurological function.

August 19th

New Findings Challenge Dogma of How Dopamine-Releasing Neurons Communicate

Researchers at the University of Pittsburgh (Pitt) have uncovered the mechanism by which neurons keep up with the demands of repeatedly sending signals to other neurons. The new findings, made in fruit flies and mice, challenge the existing dogma about how neurons that release the chemical signal dopamine communicate, and may have important implications for many dopamine-related diseases, including schizophrenia, Parkinson's disease, and addiction. The research conducted at Pitt and Columbia University was published online on August 17, 2017 in Neuron. The article is titled “Neuronal Depolarization Drives Increased Dopamine Synaptic Vesicle Loading via VGLUT.” Neurons communicate with one another by releasing chemicals called neurotransmitters, such as dopamine and glutamate, into the small space between two neurons that is known as a synapse. Inside neurons, neurotransmitters awaiting release are housed in small sacs called synaptic vesicles. "Our findings demonstrate, for the first time, that neurons can change how much dopamine they release as a function of their overall activity. When this mechanism doesn't work properly, it could lead to profound effects on health," explained the study's senior author Zachary Freyberg, MD, PhD, who recently joined Pitt as an Assistant Professor of Psychiatry and Cell Biology. Dr. Freyberg initiated the research while at Columbia University. When the researchers triggered the dopamine neurons to fire, the neurons' vesicles began to release dopamine as expected. But then the team noticed something surprising: additional content was loaded into the vesicles before they had the opportunity to empty. Subsequent experiments showed that this activity-induced vesicle loading was due to an increase in acidity levels inside the vesicles.

New Bio-Optical Imaging Technique Is Fast and Economical

A new approach to optical imaging makes it possible to quickly and economically monitor multiple molecular interactions in a large area of living tissue -- such as an organ or a small animal; technology that could have applications in medical diagnosis, guided surgery, or pre-clinical drug testing. The method, which was published online on June 5, 2017 in Nature Photonics, is capable of simultaneously tracking 16 colors of spatially linked information over an area spanning several centimeters, and can capture interactions that occur in mere billionths of a second. The article is titled “Compressive Hyperspectral Time-Resolved Wide-Field Fluorescence Lifetime Imaging.” "We have developed a smart way to acquire a massive amount of information in a short period of time," said Dr. Xavier Intes, a Professor of Biomedical Engineering at Rensselaer Polytechnic Institute. "Our approach is faster and less expensive than existing technology without any compromise in the precision of the data we acquire." As its name implies, optical imaging uses light to investigate a target. In biomedical applications, optical imaging has many advantages over techniques such as MRI and PET, which use magnetism and positron emissions to acquire images inside of living tissue. The method the Intes lab developed makes use of advanced optical imaging techniques -- fluorescence lifetime imaging, paired with foster resonance energy transfer -- to reveal the molecular state of tissues. In fluorescence lifetime imaging (FLIM), molecules of interest are tagged with fluorescent "reporter" molecules which, when excited by a beam of light, emit a light signal with a certain color over time that is indicative of their immediate environment. Reporter molecules can be tuned to offer information on environmental factors such as viscosity, pH, or the presence of oxygen.

Invitation to ASEMV 2017 Annual Meeting (Exosomes & Microvesicles) in Asilomar, California (October 8-12)

The American Society for Exosomes and Microvesicles (ASEMV) is inviting interested scientists to the ASEMV 2017 meeting, to be held October 8-12, 2017 at the Asilomar Conference Center in California. This center is located on the Monterrey peninsula, just south of San Francisco (www.visitasilomar.com). The meeting will cover the full breadth of the exosome field, from basic cell biology to clinical applications, and follow the ASEMV tradition of inclusion and diversity as participants learn about the latest advances in the field. ASEMV 2017 is a forum for learning the latest discoveries in the field of exosomes, microvesicles, and extracellular RNAs. Over the course of four days at the Asilomar Conference Center, ASEMV 2017 will offer presentations from leading scientists and young researchers. Topics will span the breadth of the extracellular vesicle/RNA field, including the basic sciences, disease research, translation efforts, and clinical applications. Talks will be presented in multiple sessions, beginning at 7 pm on Sunday, October 8, 2017, and concluding at 4 pm on Thursday, October 12, 2017. Poster sessions will run throughout the meeting, with ample time to get to know your colleagues in the field and explore the many opportunities in this rapidly expanding field. Please see the links below.

Scientists Identify & Characterize Over 20 Odorant/Pherome Receptors in Ants

Queen ants spend most of their time having babies. To reign supreme in a colony, the queens exude a special scent, or pheromone, on the waxy surface of their body that suppresses ovary development in their sisters, rendering the latter reproductively inactive workers that find food, nurse the young, and protect the colony. Now, researchers at the University of California, Riverside (UCR) have begun to unravel the molecular mechanisms underlying how ants sense these pheromones and how they control reproduction regulation and other social activities in ant communities. The research, published on August 17, 2017 in Nature Communications, highlights how ants use olfactory receptors to distinguish between colony members so they can work together in a complex, hierarchical society. The open-access article is titled “Specialized Odorant Receptors in Social Insects That Detect Cuticular Hydrocarbon Cues and Candidate Pheromones.” The findings could help in the development of new pest management strategies. The research team, led by Dr. Anandasankar Ray, an Associate Professor in the Department of Molecular Cell Systems Biology at UCR, has identified and characterized more than 20 receptors found on the antennae of worker ants that play a role in the division of labor within colonies. Among these receptors is one that responds specifically to a pheromone produced by queen ants, an interaction that ultimately results in a physiological change to workers' ovaries. Ants are eusocial insects, meaning they live in cooperative groups where one female and several males are involved in reproduction, and non-breeding individuals play specialized roles, such as caring for the young, finding food, and warding off enemies.

H. pylori Bacteria Send Stomach Stem Cells into Overdrive; May Be Mechanism Underlying H. pylori-Caused Gastric Carcinoma

Gastric carcinoma is one of the most common causes of cancer-related deaths, primarily because most patients present at an advanced stage of the disease. The main cause of this cancer is the bacterium Helicobacter pylori, which chronically infects about half of all humans. However, unlike tumor viruses, bacteria do not deposit transforming genes in their host cells and how bacteria are able to cause cancer has so far remained a mystery. An interdisciplinary research team at the Max Planck Institute in Berlin, in collaboration with researchers at the Standord University School of Medicine, has now discovered that the bacterium sends stem cell renewal in the stomach into overdrive - and stem cell turnover has been suspected by many scientists to play a role in the development of cancer. By showing that the stomach contains two different stem cell types, which respond differently to the same driver signal, the scientists have uncovered a new mechanism of tissue plasticity. It allows tuning tissue renewal in response to bacterial infection. While it has long been recognized that certain viruses can cause cancer by inserting oncogenes into the host cell DNA, the fact that some bacteria can also cause cancer has been slower to emerge and much harder to prove. While it is now clear that most cases of stomach cancer are linked to chronic infections with H. pylori, the mechanism remains unknown. Dr. Thomas F. Meyer and his colleagues at the Max Planck Institute for Infection Biology in Berlin have spent many years investigating this bacterium and the changes it induces in the cells of the stomach epithelium. In particular, they were puzzled as to how malignancy could be induced in an environment in which cells are rapidly replaced.

August 18th

Mysteries in Development of Smallpox Vaccine—A Historical Investigation

Smallpox is an infectious disease caused by variola virus that has killed millions of people over the centuries. The disease is characterized by the growth of innumerable bumps that cover the entire body of the patient. The disease is fatal in 30% of cases, but this rate is much higher for hemorrhagic smallpox and flat-type smallpox. Vaccination against smallpox throughout the 19th and 20th centuries was successful and contributed to the eradication of the disease in 1977, after a successful worldwide campaign (1967-1977) coordinated by the World Health Organization. The vaccine was developed by British physician Edward Jenner in 1796 and the virus circulating in the vaccine was named as vaccinia virus. Cowpox virus, a cousin of variola virus, causes a mild smallpox-like disease in cows. The story goes that Jenner was told that milkers who acquired the "cow-version" of smallpox were immune to the human version of the disease. Thus, one day Jenner decided to perform a risky experiment. The researcher took pustular material from the lesion of a milker and used it to inoculate a young boy, the eight-year-old son of his gardener. If the hypothesis that previous cowpox infection protected humans from smallpox proved right, then the boy would not develop smallpox when later challenged with smallpox pustular material. Sure enough, the young boy remained immune to smallpox and the experiment was a milestone in the history of the smallpox vaccine (see additional information at Wikipedia link below). Following this success, vaccination (from the Latin vacca meaning cow) was adopted worldwide as the main strategy to prevent smallpox.

Ocean Channel in Bahamas Marks Genetic Divide in Brazilian Free-Tailed Bats

Brazilian free-tailed bats are expert flyers, capable of migrating hundreds of miles and regularly traveling more than 30 miles a night. But they pull up short at a narrow ocean channel that cuts across the Bahamas, dividing bat populations that last shared an ancestor hundreds of thousands of years ago. A new study, published online on August 17, 2017, in Ecology and Evolution, uncovers a dramatic and unexpected genetic rift between populations of Tadarida brasiliensis on either side of the Northwest and Northeast Providence Channels, about 35 miles across at their most narrow point. Genetic analysis of the populations suggests that bats from Florida colonized the northern Bahamian islands while bats from other parts of the Caribbean likely colonized the southern Bahamas. The open-access article is titled “Population Structure of a Widespread Bat (Tadarida Brasiliensis) in an Island System.” Why the bats balk at crossing a channel so narrow they can likely see land on the other side while in flight remains a mystery, said Kelly Speer, the study's lead author who completed the research while a master's student at the Florida Museum of Natural History. "Based on their mainland population behavior, we know they're able to disperse much farther than the distances between islands in the Caribbean," said Speer, now a doctoral student at the American Museum of Natural History. "It doesn't seem like distance is the factor, and there's no association with wind direction. We don't have any idea why they don't cross this channel." Because they can fly, bats are good models for studying mammal movement in fragmented habitats, Speer said.