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Archive - Mar 16, 2015

Gecko Discovery Could Eliminate Need to Wash Clothes

In a world first, a research team including James Cook University (JCU) scientists in Queensland, Australia, has discovered how geckos manage to stay clean, even in dusty deserts. The process, described in an article published online on March 11, 2015 in the journal Interface, may also turn out to have important human applications. JCU's Professor Lin Schwarzkopf said the research group found that tiny droplets of water on geckos, for instance from condensing dew, come into contact with hundreds of thousands of extremely small hair-like spines that cover the animals' bodies. "If you have seen how drops of water roll off a car after it is waxed, or off a couch that's had protective spray used on it, you've seen the process happening," she said. "The wax and spray make the surface very bumpy at micro and nano levels, and the water droplets remain as little balls, which roll easily and come off with gravity or even a slight wind." The geckos' hair-like spines trap pockets of air and work on the same principle, but have an even more dramatic effect. Through a scanning electron microscope, tiny water droplets can be seen rolling into each other and jumping like popcorn off the skin of the animal as they merge and release energy. Scientists were aware that hydrophobic surfaces repelled water, and that the rolling droplets helped clean the surfaces of leaves and insects, but this is the first time it has been documented in a vertebrate animal. Box-patterned geckos live in semi-arid habitats, with little rain, but may have dew forming on them when the temperature drops overnight. Professor Schwarzkopf said the process may help geckos keep clean, as the water can carry small particles of dust and dirt away from their body. "They tend to live in dry environments where they can't depend on it raining, and this process keeps them clean," she said.

Study Compares Proteins in Human Breast Milk with Those in Macaque Breast Milk; Results Consistent with Belief That Human Infants Are Born at a Slightly Earlier Stage of Development Than Other Primate Infants

Human babies appear to need more of a nutritional boost from breast-milk proteins than do infants of one of their closest primate relatives, suggests a study comparing human milk with the milk of rhesus macaque monkeys. The research team, led by scientists from the University of California, Davis, came to this conclusion after developing a new technique for comparing the proteome -- all detectable proteins -- of human milk with the proteome of the rhesus macaque monkey. The researchers expect the findings will provide a better understanding of human breast-milk composition and identify fundamental nutrients that should be included in infant formula. The study, which revealed the first comprehensive macaque milk proteome and newly identified 524 human milk proteins, was published online on March 11, 2015 in the Journal of Proteome Research. The article was titled “Comparative Proteomics of Human and Macaque Milk Reveals Species-Specific Nutrition During Post-Natal Development.” "Human milk provides a recipe for human nutrition during the neonatal period," said principal investigator Dr. Danielle Lemay, a Nutritional Biologist at the UC Davis Genome Center. "But because so much remains to be understood about milk's molecular composition, we developed a new technique for analyzing milk proteomics that overcomes earlier barriers," she said. Using this new method, Dr. Lemay and colleagues identified 1,606 proteins in human milk and 518 proteins in rhesus macaque milk. These included 88 milk proteins that were common to both species, but at different levels. Ninety-three percent of those shared proteins were more abundant in human milk than in macaque milk.

CRISPR-Cas9 Technology Rapidly Speeds Up Mosquito Genetic Studies; Scientists Silence a Mosquito DNA Repair Mechanism to Further Enhance Effectiveness of CRISPR-Cas9

Life science researchers at Virginia Tech have accelerated a game-changing technology that's being used to study one of the planet's most lethal disease-carrying animals. Writing in an article published online on March 16, 2015 in PNAS, researchers revealed an improved way to study genes in mosquitoes using a genome-editing method known as CRISPR-Cas9, which exploded onto the life science scene in 2012. Editing the genome of an organism allows scientists to study it by deleting certain genes to observe how the organism is affected, or even to add new genes. The new CRISPR-Cas9 technique makes the editing process more efficient and may accelerate efforts to develop novel mosquito-control or disease-prevention strategies. "We've cut the human capital it takes to evaluate genes in disease-carrying mosquitoes by a factor of 10," said Dr. Zach N. Adelman, an Associate Professor of Entomology in the College of Agriculture and Life Sciences at Virginia Tech and a member of the Fralin Life Science Institute. "Not a lot of research groups have the resources to spend four months working with up to 5,000 mosquito embryos to investigate a gene that may ultimately have no bearing on their work. Now they can potentially do the same investigation in a week." Mosquitoes transmit pathogens that cause malaria, dengue fever, and other high-impact diseases. In 2013, malaria killed an estimated 584,000 people, most of them young children, according to the World Health Organization. Bill Gates, the co-founder of Microsoft and a philanthropist who supports social and health causes, has called the mosquito the world's deadliest animal. "The mosquito is incredibly important as far as transmission of disease," said Dr. Kevin M.

Bacteria Produce Their Own "Molecular Ruler" to Determine Proper Length of Injection Needle to Initiate Infection

When a salmonella bacterium attacks a cell, it uses a nanoscopic needle to inject the cell with proteins to aid the infection. If the needle is too short, the cell won't be infected. If the needle is too long, it breaks. Now, University of Utah biologists report how a disposable molecular ruler or tape measure determines the length of the bacterial needle so it is just right. The findings have potential long-term applications for developing new antibiotics against salmonella and certain other disease-causing bacteria, for designing bacteria that could inject cancer cells with chemotherapy drugs, and for helping people determine how to design machines at the nanoscopic or molecular scale. The study by University of Utah Biology Professor Kelly Hughes and doctoral student Daniel Wee was published online on March 16, 2015 in PNAS. "If you look at important pathogens - the bubonic plague bacterium, salmonella, shigella, and plant pathogens like fire blight - they all use hypodermic-like needles to inject proteins that facilitate disease processes," Dr. Hughes says. "Our work says that there is one mechanism - the molecular ruler - to explain how the lengths are controlled for needles in gram-negative bacteria and for hooks on flagella [the U-joints in propellers bacteria use to move] in all bacteria," he adds. In their study, Wee and Dr. Hughes found that as a bacterial needle or "injectisome" grows, a molecular ruler - really, more like a gooey tape measure - is secreted from within the needle's base. It oozes up through the tube-like needle, and when the bottom end of the ruler reaches the bottom end of the needle, the needle stops growing and begins to inject proteins into the target cell to help the infection process.