Life Sciences and Chemistry

Using a common worm as a model, researchers from Duke University Medical Center have identified specific genes within Salmonella that give the bacteria its ability to infect host cells.

They said their findings could ultimately lead to improved drugs to prevent or treat Salmonella infections.

The researchers found four genes related to the Salmonella’s “molecular syringe” that are required for the bacteria to have maximum potency in infecting the worm, known as Caenorhabditis

For one caterpillar, eating an unusual fruit may be the key to an easy food supply and protection against parasites, according to a team of Penn State researchers.

The Heliothis subflexa caterpillar is a specialist herbivore that eats only the fruit of Physalis plants which include ground cherry, tomatillo and Chinese lantern. H. subflexa’s choice of food turns out to have unusual benefits in the three-way struggle between herbivores, their predatory wasps and the plants.

“We

Manx shearwaters marry for life and share the incubation and feeding of their single chick. Dr Keith Hamer of Leeds University’s School of Biology has discovered that males consistently provide more food than their wives, but it’s not because they’re better parents – they just don’t listen.

By dangling microphones into burrows of nesting shearwaters, Dr Hamer and Cardiff University colleagues Petra Quillfeldt and Juan Masselo found differences in the way shearwaters respond to the begging ca

A University of Arizona graduate student may be the first eyewitness to the birth of a new species. Her new findings, appearing in the June 7, 2004 Proceedings of the National Academy of Science, could help biologists identify and understand the precise genetic changes that lead a species to evolve into two separate species.

Laura K. Reed and her advisor, Regents’ Professor Therese Markow, made the discovery by observing breeding patterns of fruitflies that live among rotting cacti in wester

Dementia in AIDS patients is caused by a large, late invasion of HIV-infected macrophages–large, long-lived cells of the immune system that travel throughout the body and ingest foreign antigens to protect against infection–into the brain, according to researchers at Temple University’s Center for Neurovirology and Cancer Biology (http://www.temple.edu/cnvcb/), debunking a longstanding “Trojan Horse” theory that early infection by macrophages remains latent until the latter stages of AIDS.

Proteins critical for compacting DNA in preparation for cell division actually interact with the double helix to fashion it into a kind of “molecular Velcro,” researchers have discovered.

The proteins, called condensins, are important for a variety of housekeeping processes in chromosomes, but the mechanics behind their function have been largely unknown. When the researchers alternately stretched and compressed a single molecule of DNA with condensins attached, they found that the DNA exten