Skip Over Navigation Links
Biomedical Beat logo

The National Institute of General Medical Sciences (NIGMS), one of the National Institutes of Health, supports all research featured in this digest. Although only the lead scientists are named, coworkers and other collaborators also contributed to the findings.

In This Issue... April 18, 2013

Quick Links

Browse All Issues

View Cool Image Gallery

Link to Us


Search Issues




Microscopic view of the process of mitosis. Credit: Jane Stout, Indiana University.

Cool Image: OMX, Mitosis!

Claire Walczak • Indiana University

Mitosis is the process that divides a single cell into two new cells. In this scene from mitosis, chromosomes (blue) are pulled apart by hook-like kinetochores (green) and spindle fibers (red). A light microscope called the OMX (the researchers later nicknamed it the OMG because of its stunning results) captured this image using high-resolution super-speed cameras. The incredible resolution will let scientists see where specific proteins act on spindle fibers to coordinate chromosome segregation. Such details could lead to a better understanding of what happens when cell division goes awry, as it does in cancer cells. The snapshot, which took first place in a cell imaging competition, will be displayed this weekend on an electronic billboard in New York City’s Times Square. Read more. Link to external Web site

X-ray of lungs infected with C. neoformans. Credit: CDC.

How a Fungus Outmaneuvers a Copper Attack

Dennis J. Thiele • Duke University Medical Center

Inhaled fungal spores can lead to fatal infections in people with compromised immune systems, and few antifungal drugs are effective. Researchers have discovered two mechanisms used by lethal strains of the fungus, Cryptococcus neoformans, to disarm the immune response in the lungs of mice. When defense cells known as macrophages encounter C. neoformans, they engulf the pathogen and pump it full of copper. In response, the fungus creates a protein shield, protecting it from the toxic copper environment. C. neoformans then shuts down the host's ability to concentrate copper in macrophages. Scientists are now studying how antifungals could thwart these detoxification systems. Read more... Link to external Web site

This work also was supported by NIH's National Institute of Allergy and Infectious Diseases.

Caption: X-ray of lungs infected with C. neoformans. Credit: CDC. High res. image (JPG, 69KB)
Mouse taste bud cells. Credit: Akiyuki Taruno, Perelman School of Medicine at the University of Pennsylvania.

Ion Channel Releases ATP for Taste Perception

Kevin Foskett • Perelman School of Medicine at the University of Pennsylvania

The sense of taste consists of five primary types: sweet, sour, salt, bitter and umami (savory). Researchers have figured out how cells transmit information regarding three of these taste types. The involvement of ATP, the body's main fuel source, was already known, but how it participated remained a mystery. A study conducted in mice found that CALHM1, which is expressed in sweet, bitter and savory tastes bud cells and forms an opening in the pore of the cell membrane, releases ATP molecules. These molecules alert neurons to signal the taste centers of the brain. CALHM1 and its different forms could also play a part in physiologically important ATP release elsewhere. Read more... Link to external Web site

This work also was supported by NIH's National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Institute on Deafness and Other Communication Disorders and National Eye Institute.

Caption: Mouse taste bud cells. Credit: Akiyuki Taruno, Perelman School of Medicine at the University of Pennsylvania. High res. image (JPG, 64KB)
CRISPR gene. Credit: NIH's National Human Genome Research Institute.

CRISPR Gene Silencing Tool

Wendell Lim • University of California, San Francisco

One way to find out what a gene does is to shut it off and observe how the cell responds. However, current techniques often turn off untargeted genes as well, making it harder to understand the effects. Now scientists have found a "crisper" way to deactivate a specific gene. The new technique, which is based on the CRISPR interference mechanism that bacteria use to fight off viruses, silences a target gene while having little effect on other genes. The method is a valuable new tool for exploring gene functions and offers a new therapeutic strategy for quieting overly active genes in diseases like cancer.
Read more... Link to external Web site

Caption: CRISPR interference is a new tool for deactivating specific genes. Credit: NIH's National Human Genome Research Institute. High res. image (JPG, 57KB)
Vial of blood.

Molecule Linked to Rare Blood Type

Judith Van Houten • University of Vermont

In addition to the familiar ABO blood group system, there are more than 30 others. Scientists now better understand the molecular underpinnings of a rare blood type called Vel-negative. An international research team has shown that a previously unknown protein, SMIM1, is missing from the red blood cells of individuals who are Vel-negative. About 1 in 2,500 people have this blood type, and they are at great risk for potentially fatal complications from successive transfusions. Based on these findings, the researchers have developed two DNA-based tests to assist health professionals in detecting and treating Vel-negative patients. Read more... Link to external Web site

Caption: Researchers describe the molecular underpinnings of a rare blood type called Vel-negative.

To read additional news items, visit NIGMS News, Twitter or Facebook or check out our free publications. You may subscribe to receive Biomedical Beat issues by e-mail or by RSS by selecting this XML link and following your news reader's instructions for adding a feed.

For more information about Biomedical Beat, please contact the editor, Emily Carlson, in the NIGMS Office of Communications and Public Liaison at 301-496-7301. The text in this newsletter is not copyrighted, and we encourage its use or reprinting.

This page last reviewed on April 18, 2013