New hope for powdery mildew resistant barley

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New research at the University of Adelaide has opened the way for the development of new lines of barley with resistance to powdery mildew.In Australia, annual barley production is second only to wheat with 7-8 million tonnes a year. Powdery mildew is one of the most important diseases of barley.Senior Research Scientist Dr Alan Little and team have discovered the composition of special growths on the cell walls of barley plants that block the penetration of the fungus into the leaf.The research, by the ARC Centre of Excellence in Plant Cell Walls in the University’s School of Agriculture, Food and Wine in collaboration with the Leibniz Institute of Plant Genetics and Crop Plant Research in Germany, will be presented at the upcoming 5th International Conference on Plant Cell Wall Biology and published in the journal New Phytologist.”Powdery mildew is a significant problem wherever barley is grown around the world,” says Dr Little. “Growers with infected crops can expect up to 25% reductions in yield and the barley may also be downgraded from high quality malting barley to that of feed quality, with an associated loss in market value.”In recent times we’ve seen resistance in powdery mildew to the class of fungicide most commonly used to control the disease in Australia. Developing barley with improved resistance to the disease is therefore even more important.”The discovery means researchers have new targets for breeding powdery mildew resistant barley lines.”Powdery mildew feeds on the living plant,” says Dr Little. “The fungus spore lands on the leaf and sends out a tube-like structure which punches its way through cell walls, penetrating the cells and taking the nutrients from the plant. The plant tries to stop this penetration by building a plug of cell wall material — a papillae — around the infection site. Effective papillae can block the penetration by the fungus.”It has long been thought that callose is the main polysaccharide component of papilla. But using new techniques, we’ve been able to show that in the papillae that block fungal penetration, two other polysaccharides are present in significant concentrations and play a key role.”It appears that callose acts like an initial plug in the wall but arabinoxylan and cellulose fill the gaps in the wall and make it much stronger.”In his PhD project, Jamil Chowdhury showed that effective papillae contained up to four times the concentration of callose, arabinoxylan and cellulose as cell wall plugs which didn’t block penetration.”We can now use this knowledge find ways of increasing these polysaccharides in barley plants to produce more resistant lines available for growers,” says Dr Little.Story Source:The above story is based on materials provided by University of Adelaide. Note: Materials may be edited for content and length.


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#Agriculture, #Biology, #Conference, #Disease, #Genetics, #International, #King, #Plant, #Research, #School, #Scientist

Zebrafish neurons may lead to understanding of birth defects like spina bifida

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The zebrafish, a tropical freshwater fish similar to a minnow and native to the southeastern Himalayan region, is well established as a key tool for researchers studying human diseases, including brain disorders. Using zebrafish, scientists can determine how individual neurons develop, mature and support basic functions like breathing, swallowing and jaw movement. Researchers at the University of Missouri say that learning about neuronal development and maturation in zebrafish could lead to a better understanding of birth defects such as spina bifida in humans.”We are studying how neurons move to their final destinations,” said Anand Chandrasekhar, professor of biological sciences and a researcher in the Bond Life Sciences Center at MU. “It’s especially critical in the nervous system because these neurons are generating circuits similar to what you might see in computers. If those circuits don’t form properly, and if different types of neurons don’t end up in the right locations, the behavior and survival of the animal will be compromised.”The scientists studied zebrafish embryos, which are nearly transparent, making internal processes easy to observe. Using modified zebrafish expressing green fluorescent jellyfish protein, Chandrasekhar and his team were able to track neuronal migration.”This approach is used extensively to visualize a group of cells,” Chandrasekhar said. “In our study, clusters of green cells glowed and indicated where motor neurons were located in the brain. Some groupings are shaped like sausages while others are round, but each cluster of 50 to150 cells sends out signals to different groups of jaw muscles.”These motor neurons that Chandrasekhar studied are located in the hindbrain, which corresponds to the human brainstem and controls gill and jaw movement in these tiny fish. Genes controlling the development and organization of these neurons in zebrafish are functionally similar to genes in higher vertebrates including mammals.Chandrasekhar’s work contributes to a better understanding of how neuronal networks are organized and “wired” during development. These studies also may provide insight into birth defects like spina bifida, which affects 1 in every 2,000 births, according to the National Institutes of Health.”One of the hallmarks of spina bifida is an open neural tube in the spinal cord,” Chandrasekhar said. …


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#Biology, #Birth, #Chandrasekhar, #Development, #Health, #Human, #National, #Process, #Researchers

Beauty and bacteria: Slim, attractive men have less nasal bacteria than heavy men

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Do attractive traits tell us anything about a person’s reproductive health? New research in the American Journal of Human Biology reveals a link between Body Mass Index (BMI) and the amount of bacteria colonizing noses. The results show that heavier men harbor more potentially pathogenic species of bacteria in their nose, compared with slimmer, more traditionally attractive men.”According to an evolutionary point of view, traits related to attractiveness are supposed to be honest signals of biological quality,” said Dr. Boguslaw Pawlowski. “We analyzed whether nasal and throat colonization with potentially pathogenic bacteria is related to body height and BMI in both sexes.”103 healthy females and 90 healthy males participated in the study. Heights and weights were self-reported, while waist and hip circumferences were measured. Six potentially pathogenic bacteria were isolated and identified from nasal and throat swabs. The results showed that ‘colonized’ men were found to have a higher BMI than non-colonized males, although no differences were found in females.”To our knowledge, this is the first attempt to study body morphology traits related to physical attractiveness in relation to bacterial colonization in young people,” said Pawlowski. “The results confirmed our hypothesis, but only for BMI in males.”Story Source:The above story is based on materials provided by Wiley. Note: Materials may be edited for content and length.


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#Agriculture, #American, #Biology, #Bmi, #Health, #Heights, #Humanbiology, #Materials, #Source, #Story, #Storysource

Better batters from brain-training research: Baseball player study significantly improves vision, reduces strikeouts

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Four words no baseball player wants to hear: Strike three. You’re out.The University of California, Riverside’s baseball team heard those words less frequently in the 2013 season after participating in novel brain-training research that significantly improved the vision of individual players and may have added up to four or five games to the win column.The results of that study appear in a paper, “Improved vision and on-field performance in baseball through perceptual learning,” published in the Feb. 17 issue of the peer-reviewed Current Biology.Most studies of visual abilities focus on mechanisms that might be used to improve sight, such as exercising the ocular muscles. Improvements in vision resulting from those experiments typically do not transfer to real-world tasks, however.A team of UCR psychologists — professors Aaron Seitz and Daniel Ozer and recent Ph.D. graduate Jenni Deveau — combined multiple perceptual-learning approaches to determine if improvements gained from an integrated, perceptual learning-based training program would transfer to real-world tasks.They did.Before the start of the 2013 NCAA Division 1 baseball season the UCR researchers assigned 19 baseball players to complete 30 25-minute sessions of a vision-training video game Seitz developed. Another 18 team members received no training. Players who participated in the training saw a 31 percent improvement in visual acuity — some gaining as much as two lines on the Snellen eye chart — and greater sensitivity to contrasts in light.”The vision tests demonstrate that training-based benefits transfer outside the context of the computerized training program to standard eye charts,” Seitz said. “Players reported seeing the ball better, greater peripheral vision and an ability to distinguish lower-contrast objects.”The researchers found that the trained players had 4.4 percent fewer strikeouts — a decrease not experienced in the rest of the Big West Conference. The UCR team also scored 41 more runs than projected after controlling for skills improvements players would be expected to gain over the course of a season. Ozer arrived at this number by using the runs-created formula developed by baseball historian and statistician Bill James.The longtime baseball fan then used the Pythagorean Winning Percentage formula, a statistical tool used by sabermetricians to compute a team’s wins and losses based upon their runs scored and runs allowed, to estimate that the training resulted in as many as four or five more wins.(The team had a season record of 22-32, but later was forced to vacate eight wins due to an ineligible player.)UCR’s year-over-year improvements were at least three times greater than the rest of the league in batting average, slugging percentage, on-base percentage, walks and strikeouts, the researchers determined.”Elite baseball batters use various kinds of sensory information to be successful batters, but most weight is given to visual feedback,” Seitz said. …


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#Baseball, #Biology, #Division, #League, #Research, #Season, #Snellen, #Team

Researchers rejuvenate stem cell population from elderly mice, enabling muscle recovery

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Researchers at the Stanford University School of Medicine have pinpointed why normal aging is accompanied by a diminished ability to regain strength and mobility after muscle injury: Over time, stem cells within muscle tissues dedicated to repairing damage become less able to generate new muscle fibers and struggle to self-renew.”In the past, it’s been thought that muscle stem cells themselves don’t change with age, and that any loss of function is primarily due to external factors in the cells’ environment,” said Helen Blau, PhD, the Donald and Delia B. Baxter Foundation Professor. “However, when we isolated stem cells from older mice, we found that they exhibit profound changes with age. In fact, two-thirds of the cells are dysfunctional when compared to those from younger mice, and the defect persists even when transplanted into young muscles.”Blau and her colleagues also identified for the first time a process by which the older muscle stem cell populations can be rejuvenated to function like younger cells. “Our findings identify a defect inherent to old muscle stem cells,” she said. “Most exciting is that we also discovered a way to overcome the defect. As a result, we have a new therapeutic target that could one day be used to help elderly human patients repair muscle damage.”Blau, a professor of microbiology and immunology and director of Stanford’s Baxter Laboratory for Stem Cell Biology, is the senior author of a paper describing the research, which will be published online Feb. 16 in Nature Medicine. Postdoctoral scholar Benjamin Cosgrove, PhD, and former postdoctoral scholar Penney Gilbert, PhD, now an assistant professor at the University of Toronto, are the lead authors.The researchers found that many muscle stem cells isolated from mice that were 2 years old, equivalent to about 80 years of human life, exhibited elevated levels of activity in a biological cascade called the p38 MAP kinase pathway. This pathway impedes the proliferation of the stem cells and encourages them to instead become non-stem, muscle progenitor cells. …


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#Baxter, #Biology, #Map, #Nature, #Pregnancy, #Professor, #Science, #Standard

Fertilization destabilizes global grassland ecosystems

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A new study led by University of Minnesota researchers demonstrates that fertilization of natural grasslands — either intentionally or unintentionally as a side effect of global farming and industry — is having a destabilizing effect on global grassland ecosystems. Using a network of natural grassland research sites around the world called the Nutrient Network, the study represents the first time such a large experiment has been conducted using naturally occurring sites.Led by Yann Hautier, a Marie Curie Fellow associated with both the Department of Ecology, Evolution, and Behavior at the University of Minnesota and the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich, the research team included U of M associate professors Eric Seabloom and Elizabeth Borer, and research scientist Eric Lind, along with scientists from institutions around the world including Andy Hector at Oxford University’s Department of Plant Sciences. The findings were published on February 16 in the journal Nature.The researchers found that plant diversity in natural ecosystems creates more stable ecosystems over time because of less synchronized growth of plants. “This is sometimes called the portfolio effect,” says Seabloom. “If you have money in two investments and they’re both stocks, they’re going to track each other, but if one is a stock and one is a bond, they’re going to respond differently to the overall economy and are more likely to balance each other.”The researchers collected plants from each of the sites, then sorted, dried, and weighed them to monitor the number of species of plants and total amount of plants, or “biomass,” grown over time. They used this information to quantify species diversity and ecosystem stability. Says Hautier: “It was really striking to see the relationship between diversity and stability” and the similarities to data collected from artificial grasslands as part of a research effort called BioDepth, indicating that the results from natural grasslands of the Nutrient Network could be predicted from the results of artificial grasslands.”The results of our study emphasize that we need to consider not just how productive ecosystems are but also how stable they are in the long-term, and how biodiversity is related to both aspects of ecosystem functioning,” says Andy Hector.The researchers also found that grassland diversity and stability are reduced when fertilizer is added. Fertilizers are intentionally used in grassland to increase livestock fodder. Fertilizer addition is also occurring unintentionally in many places around the world because nitrogen, a common fertilizer, is released into the atmosphere from farming, industry, and burning fossil fuels. Rainfall brings nitrogen out of the atmosphere and on to grasslands, changing the growth and types of plant species. …


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#Alzheimer, #Biology, #Department, #Environmental, #Hautier, #Health, #King, #Network

New RNA interference technique finds seven genes for head and neck cancer

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In the hunt for genetic mutations that cause cancer, there is a lot of white noise. So although genetic sequencing has identified hundreds of genetic alterations linked to tumors, it’s still an enormous challenge to figure out which ones are actually responsible for the growth and metastasis of cancer. Scientists in Rockefeller’s Laboratory of Mammalian Cell Biology and Development have created a new technique that can weed out that noise — eliminating the random bystander genes and identifying the ones that are critical for cancer. Applying their technique to head and neck cancers, they’ve discovered seven new tumor-suppressor genes whose role in cancer was previously unknown.The new technique, which the lab recently applied to a screen for skin tumor genes, is particularly useful because it takes a fraction of the resources and much less time than the traditional method for determining gene function — breeding genetically modified animals to study the impact of missing genes.”Using knockout mice, which are model organisms bred to have a particular gene missing, is not feasible when there are 800 potential head and neck cancer genes to sort through,” says Daniel Schramek, a postdoctoral fellow in the lab, which is headed by Rebecca C. Lancefield Professor Elaine Fuchs. “It can take about two years per gene. Our method can assess about 300 genes in a single mouse, in as little as five weeks.”The researchers made use of RNA interference, a natural process whereby RNA molecules inhibit gene expression. They took short pieces of RNA which are able to turn off the function of specific genes, attached them to highly concentrated viruses, and then, using ultrasound to guide the needle without damaging surrounding tissue, they injected the viruses into the sacs of mouse embryos.”The virus is absorbed and integrated into the chromosomes of the single layer of surface cells that cover the tiny embryo,” explains Fuchs. “As the embryo develops, this layer of cells becomes the skin, mammary glands and oral tissue, enabling us to efficiently, selectively and quickly eliminate the expression of any desired gene in these tissues. The non-invasive method avoids triggering a wound or inflammatory response that is typically associated with conventional methods to knockdown a gene in cultured cells and then engraft the cells onto a mouse.”When the mice grew, the researchers determined which genes, when turned off, were promoting tumor growth, and what they found was surprising.”Among the seven novel tumor suppressor genes we found, our strongest hit was Myh9, which codes for the protein myosin IIa, a motor protein with well-known function in cell structure and cell migration,” says Schramek. …


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#Biology, #Health, #Mammalian, #Mutations, #Neck, #Noise, #Protein, #Rockefeller, #Schramek, #Single, #Tumors, #Virus

Geographic variation of human gut microbes tied to obesity

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People living in cold, northern latitudes have bacteria in their guts that may predispose them to obesity, according to a new study by researchers at the University of California, Berkeley, and the University of Arizona, Tucson.The researchers’ analysis of the gut microbes of more than a thousand people from around the world showed that those living in northern latitudes had more gut bacteria that have been linked to obesity than did people living farther south.The meta-analysis of six earlier studies was published this month in the online journal Biology Letters by UC Berkeley graduate student Taichi Suzuki and evolutionary biology professor Michael Worobey of the University of Arizona.”People think obesity is a bad thing, but maybe in the past getting more fat and more energy from the diet might have been important to survival in cold places. Our gut microbes today might be influenced by our ancestors,” said Suzuki, noting that one theory is that obesity-linked bacteria are better at extracting energy from food. “This suggests that what we call ‘healthy microbiota’ may differ in different geographic regions.”"This observation is pretty cool, but it is not clear why we are seeing the relationship we do with latitude,” Worobey said. “There is something amazing and weird going on with microbiomes.”To Worobey, the results are fascinating from an evolutionary biology perspective. “Maybe changes to your gut community of bacteria are important for allowing populations to adapt to different environmental conditions in lots of animals, including humans,” he said.Body size increases with latitudeSuzuki proposed the study while rotating through Worobey’s lab during his first year as a graduate student at the University of Arizona. Studies of gut microbes have become a hot research area among scientists because the proportion of different types of bacteria and Archaea in the gut seems to be correlated with diseases ranging from diabetes and obesity to cancer. In particular, the group of bacteria called Firmicutes seems to dominate in the intestines of obese people — and obese mice — while a group called Bacteroidetes dominates in slimmer people and mice.Suzuki reasoned that, since animals and humans in the north tend to be larger in size — an observation called Bergmann’s rule — then perhaps their gut microbiota would contain a greater proportion of Firmicutes than Bacteriodetes. While at the University of Arizona, and since moving to UC Berkeley, Suzuki has been studying how rodents adapt to living at different latitudes.”It was almost as a lark,” Woroby said. “Taichi thought that if Firmicutes and Bacteroidetes are linked to obesity, why not look at large scale trends in humans. When he came back with results that really showed there was something to it, it was quite a surprise.”Suzuki used data published in six previous studies, totaling 1,020 people from 23 populations in Africa, Europe, North and South America and Asia. …


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#Africa, #Agriculture, #Alzheimer, #Arizona, #Biology, #California, #Europe, #Health, #People, #University

Embryology: Scientists crack open "black box" of development and see a "rosette"

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We know much about how embryos develop, but one key stage — implantation — has remained a mystery. Now, scientists from Cambridge have discovered a way to study and film this ‘black box’ of development. Their results — which will lead to the rewriting of biology text books worldwide — are published in the journal Cell.Embryo development in mammals occurs in two phases. During the first phase, pre-implantation, the embryo is a small, free-floating ball of cells called a blastocyst. In the second, post-implantation, phase the blastocyst embeds itself in the mother’s uterus.While blastocysts can be grown and studied outside the body, the same has not been true from implantation. And because embryos are so closely connected to their mothers, implantation has also been difficult to study in the womb.According to study author Professor Magdalena Zernicka-Goetz of the University of Cambridge: “We know a lot about pre-implantation, but what happens after implantation — and particularly the moment of implantation — is an enigma.”Scientists are interested in studying implantation because the embryo undergoes huge changes in such a short space of time.”During these two days, it goes from a relatively simple ball to a much larger, more complex cup-like structure, but exactly how that happens was a mystery — a black box of development. That is why we needed to develop a method that would allow us to culture and study embryos during implantation,” she explained.Working with mouse cells, Professor Zernicka-Goetz and her colleague Dr Ivan Bedzhov succeeded in creating the right conditions outside the womb to study the implantation process.To be able to support development, they created a system comprising a gel and medium that, as well as having the right chemical and biological properties, was of similar elasticity to uterine tissue. Crucially, this gel was transparent to optical light, allowing then to film the embryo during implantation.This new method revealed that on its way from ball to cup, the blastocyst becomes a ‘rosette’ of wedge-shaped cells, a structure never before seen by scientists.”It’s a beautiful structure. This rosette is what a mouse looks like on the 4th day of its life, and most likely what we look like on the 7th day of ours, and it’s fascinating how beautiful we are then, and how these small cells organise so perfectly to allow us to develop.”As well as answering a fundamental question in developmental biology, the new method will allow scientists to study embryo growth and development at implantation for the first time, which could help improve the success of IVF, and extend our knowledge of stem cells, which could advance their use in regenerative medicine.The findings also mean developmental biology text books will need rewriting. “The text books make an educated guess of what happened during this part of development, but we now know that what I learned and what I teach my students about this was totally wrong,” said Professor Zernicka-Goetz.Story Source:The above story is based on materials provided by University of Cambridge. …


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#Biology, #Body, #Cambridge, #Development, #Ecology, #Goetz, #Journal, #King, #Pregnancy, #Science, #Scientists, #Zernicka

Investigating the fiber of our being: How our gut bacteria metabolizes complex carbohydrates from fruits, vegetables

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We are all aware of the health benefits of dietary fiber. But what is dietary fiber and how do we metabolize it?Research at the University of Michigan Medical School, the University of York’s Structural Biology Laboratory, and institutions in Canada and Sweden, has begun to uncover how our gut bacteria metabolize the complex dietary carbohydrates found in fruits and vegetables.Trillions of bacteria live in human intestines — there are about ten times more bacterial cells in the average person’s body than human ones. Known as “microbiota,” these bacteria have a vital role to play in human health: they are central to our metabolism and well-being.The research team has uncovered how one group of gut bacteria, known as Bacteroidetes, digest complex sugars known as xyloglucans. These make up to 25 per cent of the dry weight of dietary fruit and vegetables including lettuce, onion, eggplant and tomatoes.In a recent issue of Nature, the researchers reported on a particular gene sequence that allows Bacteroidetes to carry out this function. They show that about 92 per cent of the population harbors bacteria with a variant of the gene sequence, according to a survey of public genome data from 250 adult humans.Understanding how these bacteria digest complex carbohydrates informs studies on a wide range of nutritional issues. These include probiotics (the consumption of ‘beneficial’ micro-organisms as a food supplement) and prebiotics (the consumption of foods or supplements intended to stimulate the production of healthy bacteria in the gut).”Its been appreciated for a long time that our symbiotic gut bacteria provide us with greatly expanded abilities to digest dietary fiber. However, the precise details of how this happens remain largely unexplored,” says co-corresponding author Eric Martens, Ph.D., an assistant professor in the Department of Microbiology & Immunology at the U-M Medical School. Martens is participating in the Host Microbiome Initiative, part of the U-M Medical School’s Strategic Research Initiative.Large-scale genome sequencing efforts, like the Human Microbiome Project, have focused on the community of microorganisms that live in the human gut. But these approaches can only uncover functions that have already been experimentally described, and much of what is sequenced is still unknown.”In this study, we took an empirical approach to decipher how one model gut bacterium digests one type of fiber that is abundant in the foods we eat. We were subsequently able to fit our findings into a much larger picture because of the existing data that the Human Microbiome Project has already gathered. …


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#Alzheimer, #Bacteroidetes, #Biology, #Cancer, #Gene, #Initiative, #Michigan, #Professor, #Project, #Research, #Science