IN THIS ISSUE . . .
January 17, 2006

• Cool Image: Worms and Human Infertility
• Marine Chemical Warfare Could Yield New Antibiotics
• Dramatic Structural Changes Reveal How Viruses Infect Cells
• Tool to Detect Potentially Dangerous Flu Strains
• NIGMS-Funded Advances Recognized as 2005’s Most Significant

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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. To read additional news items, visit NIGMS News.

Cool Image: Worms and Human Infertility

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This montage of tiny, transparent C. elegans—or roundworms—may offer insight into understanding human infertility. Researchers used fluorescent dyes to label the worm cells and watch the process of sex-cell division, called meiosis, unfold as nuclei (blue) move through the tube-like gonads. Such visualization helps the scientists identify mechanisms that enable these roundworms to reproduce successfully. Because meiosis is similar in all sexually reproducing organisms, what the scientists learn could apply to humans. Courtesy of Abby Dernburg, a cell biologist at the Lawrence Berkeley National Laboratory.

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Dernburg home page

Marine Chemical Warfare Could Yield New Antibiotics

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Caption: Sea slug squirting a toxic chemical mix. Courtesy of Genevieve Anderson, Santa Barbara City College.

The world's vast oceans are a treasure trove for medical researchers because many marine animals produce powerful poisons in their daily fight for survival. These chemicals could also work against microbes that infect humans. In their study of the toxins produced by sea slugs, biologists Phang C. Tai and Charles Derby at Georgia State University discovered new clues about the chemistry of this process that may lead to the development of new antibiotics. They discovered that these sea creatures produce and store two harmless chemicals in separate sacs inside their bodies. When squirted together, the molecules combine to make a protective fluid that may also guard the slugs against infection. The researchers are now investigating the substance’s potential antimicrobial properties.

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Tai lab
Derby lab
Article abstract (from the January 1, 2006, issue of the Journal of Experimental Biology)

Dramatic Structural Changes Reveal How Viruses Infect Cells

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Caption: Structure of the F protein before (left) and after (right) viral fusion. Courtesy of Theodore Jardetzky.

Like pirates commandeering a ship, viruses hijack cells. Once inside cells, viruses use the inner machinery to reproduce and spread infection. New research shows that certain viruses gain entrance with the help of a large protein, called F, studding their surfaces. Northwestern University biologists Theodore Jardetzky and Robert Lamb detailed the structure of the F protein, which controls the cell-fusing ability of the viruses responsible for measles, mumps, and many human respiratory diseases. When the virus is near a cell it can infect, the F protein undergoes a dramatic structural change that enables it to extend like a harpoon into the cell’s outer membrane. The protein then collapses, pulling in the virus and allowing it to fuse. Knowledge of the protein’s structure before and after fusion could lead to new vaccines and drugs for a number of viral infections.

This work was co-funded by the National Institute of Allergy and Infectious Diseases at NIH.

Full story
Jardetzky home page
Lamb home page
Article abstract (from the January 5, 2006, issue of Nature)

Tool to Detect Potentially Dangerous Flu Strains

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Caption: Superimposed on a glycan array study (green dots) is hemagglutinin (yellow structure, left), a viral protein necessary for infection. The graphs (right) indicate this protein’s binding preferences from four different viral strains.

Many scientists believe that a pandemic flu, possibly arising from genetic changes to a bird flu virus, is inevitable. But now they might have an early warning system. Using a new technology called a glycan array, researchers at the Scripps Research Institute led by glycobiologist James Paulson and structural biologist Ian Wilson, both members of the NIGMS-funded Consortium for Functional Glycomics (CFG), were able to tell how adapted a given flu strain is for infecting human cells. For this study, they compared various strains of bird and human flu viruses, including two from the 1918 flu pandemic. They did not study the H5N1 strain of bird flu. The researchers found that among the studied strains, just two genetic changes could enable a bird flu virus to attack human cells. The glycan array can monitor genetic changes that allow viruses to recognize human cells and can help detect the emergence of flu strains capable of causing human pandemics. The technology, developed by the CFG, is available to the entire scientific community.

News release
Paulson home page
Wilson home page
CFG home page
Article abstract (from the January 3, 2006, issue of the Journal of Molecular Biology)

NIGMS-Funded Advances Recognized as 2005’s Most Significant