Life Sciences and Chemistry

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

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

Chemists make the world’s smallest building blocks.

US researchers have made the world’s smallest building blocks. The nanocubes are just a millionth of a millimetre (a nanometre) across 1 . Stacked like bricks, they could make up a range of materials with useful properties such as light emission or electrical conduction.

Many chemists are currently trying to develop molecular-scale construction kits in which the individual components are single molecules to

When it comes to locating a meal, insect-eating bats generally employ one of two foraging tactics: capturing prey in the air or snatching it from a substrate. Accordingly, the animals use different kinds of echolocation during these activities. Whereas aerial hunters tend toward longer calls with constant frequency, substrate-gleaning species generate short calls that sweep from low to high frequencies (FM echolocation). Less clear, however, is how effective the latter is at distinguishing the prey i

American Society for Cell Biology Meeting, Washington, December 2001

Microscope captures mitochondria bopping to a beat.

An intricate mesh of tubes wiggle, worm-like across the screen. “They’re speeding,” says Tim Richardson proudly, watching mitochondria, the cell’s energy generators, zoom around the cell. His controversial microscopic method is shooting the cell’s innards as they’ve never been seen before.

Live cell imaging has revolutionised cell biology over th