A powerful laboratory technique used by fruit fly geneticists for more than a decade is now available to scientists studying genes and diseases in mice.

Writing in the May 6 edition of the journal Cell, researchers from Stanford University describe a streamlined method for creating a "genetic mosaic mouse"--a rodent whose body is genetically engineered to produce small clusters of cells with mutated genes.

The new technique, called Mosaic Analysis with Double Markers (MADM), was developed in the laboratory of Liqun Luo, professor of biological sciences at Stanford who was recently named an investigator with the Howard Hughes Medical Institute.

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While patients hospitalized for a heart attack have long been treated with morphine to relieve chest pain, an analysis by researchers from the Duke Clinical Research Institute has shown that these patients have almost a 50 percent higher risk of dying.

The researchers call for a randomized clinical trial to confirm their analysis. Meanwhile, they advise cardiologists to begin treatment with sufficient doses of nitroglycerin to relieve pain before resorting to morphine.

A brain scan study suggests that a suspect gene may increase susceptibility to anxiety and depression* by weakening a circuit for processing negative emotion. People with the depression-linked gene variant showed less gray matter and weaker connections in the mood-regulating circuit. How well the circuit was connected accounted for nearly 30 percent of their anxious temperament, researchers at the National Institute of Health's (NIH) National Institute of Mental Health (NIMH) found. Dr. Daniel Weinberger and colleagues report on their brain imaging genetics study in the May 8, 2005 online edition of Nature Neuroscience.

A pink, bacterial scum on the floor of an abandoned mine seems an unlikely place to study community development, but a biological breakthrough is allowing University of California, Berkeley, researchers to probe the give and take in this microbial mat.

Last year, the UC Berkeley team joined with the Department of Energy's Joint Genome Institute to pluck out the genomes of the five dominant bacteria in a slime, or biofilm, responsible for acidic drainage from the mine. Now, they have gone further and, with the help of colleagues at the DOE's Oak Ridge National Laboratory, identified the proteins that go with these five organisms, their so-called proteomes.

Compared with a long-used linear model, a correlation-based statistical method is a more reliable way to map complex gene interactions and pinpoint genes that may be potential cancer treatment targets, according to new Brown University research.

The research is important because it describes a promising new tool for tracing human gene connections, a task critical for understanding and treating cancer and other diseases. Results appeared this week in the online edition of the Proceedings of the National Academy of Sciences.