Researchers at MIT and Alnylam Pharmaceuticals report this week that they have successfully used RNA interference to turn off multiple genes in the livers of mice, an advance that could lead to new treatments for diseases of the liver and other organs.

The early stages of Alzheimer's disease are thought to occur at the synapse, since synapse loss is associated with memory dysfunction. Evidence suggests that amyloid beta (Aβ) plays an important role in early synaptic failure, but little has been understood about Aβ's effect on the plasticity of dendritic spines.

UCLA scientists have identified a molecular switch that prevents Huntington's disease from developing in mice. Published in the Dec. 24 edition of the journal Neuron, the discovery suggests a new approach to treating the genetic disorder, which ultimately leads to death in as little as 10 years.

Cancer progression is commonly thought of as a process involving the growth of a primary tumor followed by metastasis, in which cancer cells leave the primary tumor and spread to distant organs. A new study by researchers at Memorial Sloan-Kettering Cancer Center shows that circulating tumor cells – cancer cells that break away from a primary tumor and disseminate to other areas of the body – can also return to and grow in their tumor of origin, a newly discovered process called "self-seeding."

In order to preserve our DNA, cells have developed an intricate system for monitoring and repairing DNA damage. Yet precisely how the initial damage signal is converted into a repair response remains unclear. Researchers at the Salk Institute for Biological Studies have now solved a crucial piece of the complex puzzle.

Female ducks have evolved an intriguing way to avoid becoming impregnated by undesirable but aggressive males endowed with large corkscrew-shaped penises: vaginas with clockwise spirals that thwart oppositely spiraled males.

Dark spots on flower petals are common across many angiosperm plant families and occur on flowers such as some lilies, orchids, and daisies. Much research has been done on the physiological and behavioral mechanisms for how these spots attract pollinators. But have you ever wondered what these spots are composed of, how they develop, or how they only appear on some but not all of the ray florets?

Brazilian researchers have performed the first-ever autopsy study to examine the precise causes of death in victims of the H1N1 swine flu.

A new study at the University of Wisconsin-Madison suggests that depressed patients are unable to sustain activity in brain areas related to positive emotion.

Researchers at National Jewish Health have discovered that a naturally occurring lipid in the lung can prevent RSV infection and inhibit spread of the virus after an infection is established. RSV is the major cause of hospitalization for children in the first two years of life, and is increasingly recognized as a dangerous pathogen in adults with chronic lung diseases, the elderly, and immunocompromised individuals. Currently, there is no effective vaccine for the virus.

A simple amino acid that is repeated in the center of proteins found in tooth enamel makes teeth stronger and more resilient, according to new research at the University of Illinois at Chicago.

The teeth of some apes are formed primarily to handle the most stressful times when food is scarce, according to new research* performed at the National Institute of Standards and Technology (NIST). The findings imply that if humanity is serious about protecting its close evolutionary cousins, the food apes eat during these tough periods—and where they find it—must be included in conservation efforts.

As the UN Climate Conference in Copenhagen approaches its conclusion, negotiations are focusing on the role of forests in mitigating climate change. The new 'Reducing Emissions from Deforestation and Forest Degradation' policy has gained widespread support as a central element of any new agreement.

A gene associated with a rare form of progressive deafness in males has been identified by an international team of researchers funded by the National Institute on Deafness and Other Communication Disorders. The gene, PRPS1, appears to be crucial in inner ear development and maintenance. The findings are published in the Dec. 17 early online issue of the American Journal of Human Genetics.

In some ways a cell in your body or an organelle in that cell is like an ancient walled town. Life inside either depends critically on the intelligence of the gatekeepers.

Research teams led by the Wellcome Trust Sanger Institute announce the first comprehensive analyses of cancer genomes.

The world's rarest—and most camera shy—great ape has finally been captured on professional video on a forested mountain in Cameroon, according to the Wildlife Conservation Society and Germany's NDR Naturfilm.

In a developing animal, stem cells proliferate and differentiate to form the organs needed for life. A new study shows how a crucial step in this process happens and how a reversal of that step contributes to cancer.

Scientists seeking to understand how to make an AIDS vaccine have found the cause of a major roadblock. It turns out that the immune system can indeed produce cells with the potential to manufacture powerful HIV-blocking antibodies – but at the same time, the immune system works equally hard to make sure these cells are eliminated before they have a chance to mature.

An international team of Canadian and Spanish scientists have found the first potential immunological clue of why some people develop severe pneumonia when infected by the pandemic H1N1 virus.

Free infectious HIV-1 is widely thought to be the major form of the virus in the blood of infected persons. U.S. Military HIV Research Program (MHRP) researchers, however, have demonstrated that essentially all of the infectious virus particles can bind to the surface of red blood cells isolated from each of 30 normal (non-infected) human donors. The results were published today in PLoS ONE, and can be accessed here.

Extinct woolly mammoths and ancient American horses may have been grazing the North American steppe for several thousand years longer than previously thought. After plucking ancient DNA from frozen soil in central Alaska, a team of researchers used cutting-edge techniques to uncover "genetic fossils" of both species locked in permafrost samples dated to between 7,600 and 10,500 calendar years. This new evidence suggests that at least one population of these now-extinct mammals endured longer in the continental interior, challenging the conventional view that these and other large species, or megafauna, disappeared from the Americas about 12,000 years ago.

Bacteria dance the electric slide, officially named electrokinesis by the USC geobiologists who discovered the phenomenon.

New research shows how the migration and settlement patterns associated with the rapid urbanization of Peru may link to Chagas disease transmission. The study, published December 15 in the open-access journal PLoS Neglected Tropical Diseases, suggests that the practice of shantytown residents from Arequipa making frequent seasonal moves to rural valleys where Chagas vectors are present may have contributed to the growing presence of Chagas disease near urban Arequipa, Peru.

If you are spending the holidays with big Uncle Frank or bossy Aunt Minnie and wondering whether you would be better off with another family, spare a thought for the humble cichlid fish.

This is shown by samples of ancient DNA, analysed by an international team of research scientists under the leadership of Professor Eske Willerslev from Copenhagen University. Analyses of ancient DNA thereby once again revoke results of more common methods of dating, such as carbon 14 analysis of bone and tooth remains from extinct animals. These methods which had previously dated the extinction of mammoths and prehistoric horses in Central Asia to within 13-15,000 years ago. But with the DNA-test methods of Eske Willerslev and his colleagues, this boundary has now moved between 2,600 and 5,600 years closer to our time and has thus revised our previous opinion of when the last mammoths and prehistoric horses grazed on the North American Plains.

University of Alberta researchers are part of an international team that has used DNA samples from frozen dirt, not fossilized bones, to revise the history of North America's woolly mammoths and ancient horses.

Scientists have identified a novel antifreeze molecule in a freeze-tolerant Alaska beetle able to survive temperatures below minus 100 degrees Fahrenheit. Unlike all previously described biological antifreezes that contain protein, this new molecule, called xylomannan, has little or no protein. It is composed of a sugar and a fatty acid and may exist in new places within the cells of organisms.

A team led by Yale University researchers has used nanosensors to measure cancer biomarkers in whole blood for the first time. Their findings, which appear December 13 in the advanced online publication of Nature Nanotechnology, could dramatically simplify the way physicians test for biomarkers of cancer and other diseases.

Scientists have discovered five genetic variants that are associated with the health of the human lung. The research by an international consortium of 96 scientists from 63 centres in Europe and Australia sheds new light on the molecular basis of lung diseases.

Name all the venomous animals you can think of and you probably come up with snakes, spiders, bees, wasps and perhaps poisonous frogs. But catfish?

While most school children understand that green plants photosynthesize, absorb carbon dioxide and produce oxygen, few people consider the profound global-scale effects that photosynthesis has had on Earth. One of those actively shedding light on the origins and evolution of photosynthesis is Jeffrey Touchman, assistant professor in Arizona State University's School of Life Sciences.

The sound level of songs blue whales sing across the vast expanses of the ocean to attract potential mates has been steadily creeping downward for the past few decades, and a scientist at Scripps Institution of Oceanography at UC San Diego and his colleagues believe the trend may be good news for the population of the endangered marine mammal.

Ancient DNA retrieved from extinct horse species from around the world has challenged one of the textbook examples of evolution – the fossil record of the horse family Equidae over the past 55 million years.

Almost a century after it was discovered in fruit flies with notches in their wings, the Notch signalling pathway may come to play an important role in the recovery from heart attacks. In a study published today in Circulation Research, scientists at the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, are the first to prove that this signalling pathway targets heart muscle cells and thus reveal its crucial role in heart development and repair.

The eerily beautiful but rarely seen world inside the miniscule cells that compose all living organisms took center stage Tuesday afternoon, Dec. 8, when the winners of "Celldance 2009," the American Society for Cell Biology's annual film and still image contest, were announced at the society's 49th annual meeting.

The 2009 H1N1 influenza virus used a new strategy to cross from birds into humans, a warning that it has more than one trick up its sleeve to jump the species barrier and become virulent.

The fall of 2009 was a truly special season for the Emsland Group: For the first time in the history of the largest German potato starch manufacturer, it processed Tilling potatoes, which exclusively contain amylopectin starch. Not only can nutritional starches for emulsifying soups and desserts be extracted from it – it can also be used for paste and smooth coating for paper and thread production. "This potato is the first product in Germany developed by Tilling that achieves market readiness," explains Prof. Prüfer of the Fraunhofer Institute for Molecular Biology and Applied Ecology IME.

The human sensory experience is far more complex and nuanced than previously thought, according to a groundbreaking new study published in the December 15 issue of the journal Pain (http://www.painjournalonline.com/article/S0304-3959%2809%2900526-0/abstract). In the article, researchers at Albany Medical College, the University of Liverpool and Cambridge University report that the human body has an entirely unique and separate sensory system aside from the nerves that give most of us the ability to touch and feel. Surprisingly, this sensory network is located throughout our blood vessels and sweat glands, and is for most people, largely imperceptible.

Blood vessel blockage, a common condition in old age or diabetes, leads to low blood flow and results in low oxygen, which can kill cells and tissues. Such blockages can require amputation resulting in loss of limbs. Now, using mice as their model, researchers at Johns Hopkins have developed therapies that increase blood flow, improve movement and decrease tissue death and the need for amputation. The findings, published online last week in the early edition of the Proceedings of the National Academy of Sciences, hold promise for developing clinical therapies.