An international team, led by researchers at the Broad Institute of MIT and Harvard, and supported by the National Institutes of Health (NIH), today announced the publication of the first genome of a marsupial, belonging to a South American species of opossum. In a comparison of the marsupial genome to genomes of non-marsupials, including human, published in the May 10 issue of the journal Nature, the team found that most innovations leading to the human genome sequence lie not in protein-coding genes, but in areas that until recently were referred to as "junk" DNA.

Using an innovative statistical approach, a research team from Washington University School of Medicine in St. Louis and the University of California, Los Angeles, has identified two regions of DNA linked to autism. They found the suspicious DNA with a much smaller sample of people than has been used traditionally in searches for autism genes.

Researchers have known for decades that certain neurodegenerative diseases, such as mad cow disease or its human equivalent, Cruetzfeldt-Jakob disease, result from a kind of infectious protein called a prion. Remarkably, in recent years researchers also have discovered non-pathogenic prions that play beneficial roles in biology, and prions even may act as essential elements in learning and memory.

The presence of ecologically distinct males and females greatly increases a species' niche, say researchers.

Some Caribbean lizards' strong sexual dimorphism allows them to colonize much larger niches and habitats than they might otherwise occupy, allowing males and females to avoid competing with each other for resources and setting the stage for the population as a whole to thrive. The finding, reported this week in the journal Nature, suggests sex differences may have fueled the evolutionary flourishing of the Earth's wildly diverse fauna in a way not previously appreciated by scientists.

A plateau on Mars known as Home Plate shows evidence of long-past explosive volcanic activity, say scientists on NASA's Mars Exploration Rover mission. And data collected during the rover Spirit's initial pass across the 90-meter (295 feet) wide plateau also supports earlier findings indicating that water once existed at or beneath the planet's surface.

In suspicious environments, like bars and math study groups, females are at greater risk. Scientists from Seoul National University, in Korea, and the Smithsonian Tropical Research Institute in Panama have recently done a study to determine how females avoid the bad males while assessing the good ones.

The males peacock’s showy plumage, for example, is thought to attract females with the promise of better offspring. Showy male peacocks also escape from predators despite their annoyingly conspicuous ornaments and behavior — proof of their superiority.


Need a place to hide? I have a big claw

Call it sperm competition.

According to a study appearing in Current Directions in Psychological Science, sexual characteristics exhibited by human males indicate that men have evolved to deliver their sperm more effectively to females who have multiple partners to choose from.

Temple University School of Medicine researchers have developed a new biosensor that sniffs out explosives and could one day be used to detect landmines and deadly agents, such as sarin gas.

To create the biosensor, Danny Dhanasekaran and colleagues genetically engineered a yeast strain with mammalian (rat) olfactory signaling machinery and genetically linked it to the expression of green fluorescent protein. Into these yeast cells, they cloned individual rat olfactory receptors. When the olfactory receptor "smells" the odor of DNT, an ingredient in the explosive TNT, the biosensor turns fluorescent green. The research team is the first to identify, clone and sequence this novel olfactory receptor.

In the past, the newborns' umbilical cord was not clamped right after birth, thus allowing the blood flow to stop naturally. This practice, known as "late clamping", was replaced by "early clamping", that is, cutting the cord immediately after the infant is expelled.

However, this new practice lacks studies corroborating its benefits. In fact, recent studies on the importance of when clamping should be done have shown contradictory results.

The long search for Herod the Great's tomb has ended with the exposure of the remains of his grave, sarcophagus and mausoleum on Mount Herodium's northeastern slope, Prof. Ehud Netzer of the Hebrew University of Jerusalem Institute of Archaeology announced today.

Herod was the Roman-appointed king of Judea from 37 to 4 BCE, who was renowned for his many monumental building projects, including the reconstruction of the Temple in Jerusalem, the palace at Masada, as well as the complex at Herodium, 15 kilometers south of Jerusalem.


A general view of the slope of Herodium in which Herod's tomb was found.Credit: Hebrew University of Jerusalem photos