With the introduction of just four factors, researchers have successfully induced differentiated cells taken from mouse embryos or adult mice to behave like embryonic stem cells. The researchers reported their findings in an immediate early publication of the journal Cell.

Using a sensitive, single-molecule measurement technique, researchers at the University of Illinois at Urbana-Champaign have observed the life cycle of RecA, a protein that plays a major role in repairing damaged DNA.

Songbirds use multiple sources of directional cues to guide their seasonal migrations, including the Sun, star patterns, the earth's magnetic field, and sky polarized light patterns. To avoid navigational errors as cue availability changes with time of day and weather conditions, these "compass" systems must be calibrated to a common reference. Experiments over the last 30 years have failed to resolve the fundamental question of how migratory birds integrate multiple sources of directional information into a coherent navigational system.

A new light microscope so powerful that it allows scientists peering inside cells to discern the precise location of nearly each individual protein they are studying has been developed and successfully demonstrated by scientists at the Howard Hughes Medical Institute's Janelia Farm Research Campus in collaboration with researchers at the National Institutes of Health and Florida State University.

When dangerous infectious diseases or biological weapons are suspected, fast help is required. The first step is a reliable, sensitive, and unambiguous, yet also fast and simple, identification of the pathogen; preferably, this test should be carried out on the spot, not in a laboratory. Portable miniature biodetection systems that can detect multiple pathogens simultaneously would be ideal for this task.

Unlike the Three Musketeers who lived by the motto "All for one, one for all," plant hormones prefer to do their own thing. For years, debate swirled around whether pathways activated by growth-regulating plant hormones converge on a central growth regulatory module. Now, the cooperation model is challenged by researchers at the Salk Institute for Biological Studies. They show that each hormone acts largely independently in the Aug. 11 issue of Cell.

Scientists at the University of New Hampshire (UNH) have found that invasive crab species may precipitate evolutionary change in blue mussels in as little as 15 years. The study, by UNH graduate student Aaren Freeman with associate professor of zoology James Byers and published in the Aug. 11 issue of the journal Science, indicates that such a response can evolve in an evolutionary nanosecond compared to the thousands of years previously assumed. The paper is called "Divergent induced responses to an invasive predator in marine mussel populations."

Scientists have identified genes related to reaching age 90 with preserved cognition, according to a study published in the September issue of the American Journal of Geriatric Psychiatry. The study, which was conducted at the University of Pittsburgh is among the first to identify genetic links to cognitive longevity.

To a tiny tadpole, life boils down to two basic missions: eat, and avoid being eaten. But there's a trade-off. The more a tadpole eats, the faster it grows big enough to transform into a frog; yet finding food requires being active, which ups the odds of becoming someone else's dinner.