Researchers have discovered a key protein that controls how stem cells “choose” to become either skeletal muscle cells that move limbs, or smooth muscle cells that support blood vessels, according to a study published today in the Proceedings of the National Academy of Sciences (PNAS). The results not only provide insight into the development of muscle types in the human fetus, but also suggest new ways to treat atherosclerosis and cancer, diseases that involve the creation of new blood vessels from stem cell reserves that would otherwise replace worn out skeletal muscle. The newly discovered mechanism also suggests that some current cancer treatments may weaken muscle, and that physician researchers should start watching to see if a previously undetected side effect exists.

The ability to tactually recognize fine spatial details, such as the raised dots used in braille, is especially important to those who are blind. With that in mind, a team of researchers has identified the neural circuitry that facilitates spatial discrimination through touch. Understanding this circuitry may lead to the creation of sensory-substitution devices, such as tactile maps for the visually impaired.

In a molecular tour de force, researchers at the University of Wisconsin-Madison have provided an exquisitely detailed picture of natural selection as it occurs at the genetic level.

Embryologists at UCL (University College London) have helped solve an evolutionary riddle that has been puzzling scientists for over a century. They have identified a key mechanism in the initial stages of an embryo’s development that helps differentiate more highly evolved species, including humans, from less evolved species, such as fish. The findings of the research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), were published online today by the journal Nature.

Based in part on protein structures determined at the National Synchrotron Light Source (NSLS) at the U.S. Department of Energy's Brookhaven National Laboratory, scientists at the University of Utah have developed new peptides that appear to be significantly more effective at blocking HIV's entry into cells than other drugs in their class. In a paper being published online by the Proceedings of the National Academy of Sciences the week of October 8, 2007, the researchers say these peptides are sufficiently potent to begin pre-clinical studies as a new class of agents for the prevention and treatment of HIV/AIDS.

The protein Oct4 plays a major role in embryonic stem cells, acting as a master regulator of the genes that keep the cells in an undifferentiated state. Unsurprisingly, researchers studying adult stem cells have long suspected that Oct4 also is critical in allowing these cells to remain undifferentiated. Indeed, more than 50 studies have reported finding Oct4 activity in adult stem cells.

Often called the most devastating epidemic in the recorded history of the world, the 1918 influenza virus pandemic was responsible for more than 40 million deaths across the globe. The incredible lethality of the 1918 flu strain is not well understood, despite having been under intense scrutiny for many years. Now, a new study published by Cell Press in the October issue of the journal Cell Host & Microbe unravels some of the mystery surrounding the devastating 1918 pandemic and provides key information that will help prepare for future pandemics.

Chemicals on ants’ feet tranquilise and subdue colonies of aphids, keeping them close-by as a ready source of food, says new research published today (10 October). The study throws new light on the complex relationship between ants and the colonies of aphids whose sugary secretions the ants eat.

According to paleontologic and molecular studies, the chimpanzee (Pan troglodytes) is the closer relative to the humans (Homo sapiens) and that both lineages had a common ancestor at 5 to 7 million years ago. Moreover, the human-chimp lineage split from that of the rhesus monkey (Macaca mulatta) around 25 million years ago. However, by studying the population dynamics of complete copies of primate endogenous retrovirus family K (ERV-K) in the genomes of humans, chimpanzee and rhesus monkey, a surprising pattern was observed. The study by Romano and colleagues being published this week on PLoS ONE revealed that human ERV-K had a similar demographic signature to that of the rhesus monkey, both differing greatly from that of the chimpanzee. The data suggested that the humans and rhesus have been purging ERV-K copies from their genomes while the chimpanzee ERV-K population kept the signature of increasing numbers of ERV-K amplification in the genome of ancestral primates during the last 20 million years.

Marijuana and its main psychoactive component, THC, exert a plethora of behavioral and autonomic effects on humans and animals. Some of these effects are the cause of the widespread illicit use of marijuana, while others might be involved in the potential therapeutic use of this drug for the treatment of several neuronal disorders. The great majority of these effects of THC are mediated by cannabinoid receptor type 1 (CB1), which is abundantly expressed in the central nervous system. The exact anatomical and neuronal substrates of each action, however, were previously unknown. Using an advanced genetic approach, Krisztina Monory and colleagues at the Johannes Gutenberg University Mainz discovered that specific neuronal subpopulations mediate the distinct effects of THC. Their work is published online this week in the open-access journal PLoS Biology.

Researchers have found evidence of an increase in low birth weights among babies born in and around New York City in the weeks and months after the terrorist attacks on the World Trade Center. Writing in the journal Human Reproduction [1], they suggest that stress may have contributed to the effect.