Life Sciences and Chemistry

Dr. Mario Capecchi and colleagues at the University of Utah and the Department of Veterans Affairs Medical Center (Salt Lake City, UT) have discovered that a gene called xanthine oxidoreductase, or XOR for short, is required for lactation in female mice. This previously unidentified role for XOR in lactation reveals a possible genetic basis for the lactation difficulties experienced by nearly 5% of women.

XOR was originally identified as encoding an enzyme involved in purine catabolism (the

A key role in synchronizing daily rhythms to the day/night cycle has been traced to a light-sensitive protein in the eye, by knocking out the gene that codes for it. Mice lacking a gene for the photopigment melanopsin show a dramatic deficiency in their ability to regulate their circadian rhythms by light. The discovery, by National Institute of Mental Health (NIMH) grantees, helps unravel the heretofore elusive mechanisms by which day/night cycles regulate such rhythms in mammals. NIMH grantees Igna

Scientists at the University of Pennsylvania School of Veterinary Medicine have found a new wrinkle in the developmental biology dogma that cell differentiation occurs irreversibly as stem cells give rise to increasingly specialized types of offspring cells. The researchers have shown that certain mouse cells retain an ability to oscillate between very distinct blood cell types — B-cells and macrophages — long after what has been commonly regarded as the point of no return.

These latest fi

’Quantum dots’ may allow researchers to track proteins and cells in their natural environments

Imagine if molecular and cell biologists could watch proteins and cells at work in their natural habitat in the same way that wildlife biologists observe animals in the wild. They’d sit back and witness first hand their microscopic subjects’ daily routines, interactions and movements, and the places they prefer to be.

This fantasy is rapidly becoming a reality t

Scientists at UT Southwestern Medical Center at Dallas have identified a new and surprising mechanism by which a class of enzymes responsible for the breakdown of proteins operates.

The process of degrading proteins no longer needed by cells is essential in the normal growth, development and regulation of cells, and the study’s findings have implications for understanding diseases like Parkinson’s and several forms of cancer.

“Many diseases involve the inappropriate accumu

Researchers have discovered the first genetic component of a biochemical pathway in the brain that governs the indelible imprinting of fear-related experiences in memory.

The gene identified by researchers at the Howard Hughes Medical Institute at Columbia University encodes a protein that inhibits the action of the fear-learning circuitry in the brain. Understanding how this protein quells fear may lead to the design of new drugs to treat depression, panic and generalized anxiety di