Without the help of fossils or any other record from the distant past, scientists have identified what they believe represents a common ancestor of all animals on Earth, a microscopic organism with key genetic traits that, until now, have been found only in true animals.
Writing in Tuesday’s Proceedings of the National Academy of Sciences, a team of scientists from the Howard Hughes Medical Institute at the University of Wisconsin-Madison reports the discovery of a key cell communication ge

A fast, sensitive laboratory test that measures the molecular components involved during the critical moment when HIV infects a normal cell has been developed.
The advance was made by researchers in the University of California, San Diego (UCSD) School of Medicine and VA San Diego Healthcare System.

Described in the December 2001 issue of the Journal of Biological Chemistry (JBC), the test makes it possible to study and design new compounds to block the action of these molecular componen

A vaccine against one of the world’s leading killers could one day be manufactured by livestock, researchers report. According to a study released today by the Proceedings of the National Academy of Sciences, scientists have developed mice that secrete malaria vaccine proteins into their milk. The purified experimental vaccine protected 80 percent of monkeys subsequently exposed to a lethal dose of the malarial parasite.

Anthony Stowers and Louis Miller of the National Institute of All

The tell-tale signature of most lasers used in everyday applications—from bar-code scanners to pen-size pointers—is a bright red glow. The color is determined by the light’s wavelength, and most lasers emit at only one wavelength. Now a new report published in the current issue of the journal Nature describes a light source measuring only tens of millimeters across that changes color according to temperature.

To make the new laser, Diederik Wiersma and Stefano Cavalieri of the European

Sloshing proteins help bacteria find their waists.

Chemical waves may help a bacterium to divide by pinpointing its middle, according to a new model of protein interactions 1 .

Bacteria such as Escherichia coli multiply by dividing. Bacterial division (called binary fission) is simpler than human cell division (mitosis). Human cells erect scaffolding to transport components to the two nascent daughter cells at either end; bacteria just pinch in two.

Using tiny rust-containing spheres to tag cells, scientists from Johns Hopkins and elsewhere have successfully used magnetic resonance imaging to track stem cells implanted into a living animal, believed to be a first.

In the December issue of the journal Nature Biotechnology, the research team report that the neuronal stem cells take up and hold onto the spheres, which contain a compound of iron and oxygen. The iron-laden cells create a magnetic black hole easily spotted by magnetic resonan