Microbiology

Researchers at Texas A&M University are shedding light on a rare form of early blindness, identifying the cells involved and paving the way for possible therapies to treat or even prevent what is currently an incurable disease.

The findings, funded by Fight for Sight and the National Institutes of Health, are published in the March 5-9 online Early Edition (EE) of the Proceedings of the National Academy of Sciences.

Since his post-doctoral days at Harvard University, Texas A&M biologist Dr. Brian Perkins has been studying protein transport within photoreceptors—the rod and cone cells that allow organisms to detect their visual worlds—in zebrafish, a vertebrate whose eye physiology is essentially identical to that of a human.

Scientists have identified a molecular switch that causes the differentiation of neurons in the cerebellum, a part of the brain that helps to regulate motor functions.

A study published this week in the scientific journal PNAS provides new information on the origin of different cells in the cerebellum, an important component of the central nervous system found in all vertebrates, including humans, and the part of the brain that controls movement. The study was completed by researchers from the Institute for Research in Biomedicine (IRB Barcelona), the Department of Cell Biology of the University of Barcelona (UB), the IMIM-Hospital del Mar, Pompeu Fabra University (UPF) and Vanderbilt University (Nashville, Tennessee, USA). The main authors of the study are Dr.

Antifreeze or “ice structuring” proteins – found in some fish, insects, plants, fungi and bacteria – attach to the surface of ice crystals to inhibit their growth and keep the host organism from freezing to death. Scientists have been puzzled, however, about why some ice structuring proteins, such as those found in the spruce budworm, are more active than others.

Fluorescence microscopy now has shown how those aggressive proteins protect the cells of the insect, which is native to U.S. and Canadian forests.


Ice crystals decorated by fluorescent antifreeze proteins. Credit: Ido Braslavsky/Ohio University

For a lucky subset of vertebrates, losing an appendage is no big deal. As many an inquisitive child knows, salamanders can regenerate lost limbs or tails; and as lab investigators know, zebrafish can regrow lost fins. Of course, humans and other "higher" vertebrates must make do with repairing rather than regenerating damaged tissues. Though whole body generation (WBR) does occur, it’s typically restricted to a subset of morphologically less complex invertebrates, such as sponges, flatworms, and jellyfish.

In a new study, Yuval Rinkevich et al. discovered an unusual mode of WBR in our closest invertebrate relative, the sea squirt Botrylloides leachi.

Researchers at Yale have identified multiple pathogenic "alien islands" in the genome of the A. baumannii, bacteria that has been responsible for new and highly drug-resistant infections in combat troops in the Middle East, according to a report in the March 1 issue of Genes and Development.

"Drug resistant bacterial infections are a rapidly growing problem in hospital settings, and now in difficult conditions of combat. We targeted A. baumannii as a growing threat for our troops in Iraq," said s principal investigator Michael Snyder, the Lewis B Cullman Professor of Molecular Cellular & Developmental Biology.

Among the central mysteries of neurobiology is what properties of the young brain enable it to so adeptly wire itself to adapt to experience—a quality known as plasticity. The extraordinary plasticity of the young brain occurs only during a narrow window of time known as the critical period.

Using a state-of-the-art technique to map neurons in the spinal cord of a larval zebrafish, Cornell University scientists have found a surprising pattern of activity that regulates the speed of the fish’s movement. The research may have long-term implications for treating injured human spinal cords and Parkinson’s disease, where movements slow down and become erratic.

The study, "A Topographic Map of Recruitment in Spinal Cord," published in the March 1 issue of the journal Nature, maps how neurons in the bottom of the fish’s spinal cord become active during slow movements, while cells further up the spinal cord activate as movements speed up.

To function, each living cell needs both to build new and to degrade old or damaged proteins. To accomplish that, a number of intracellular systems work in concert to keep the cell healthy and from clogging up with damaged proteins. When proteins or peptides mutate, they can present major problems to the clearing up of the intracellular environment. In Huntington's disease (HD) the disease provoking mutation in the huntingtin gene eventually causes the cell to build up intranuclear and cellular inclusions of protein-aggregates, made up primarily of huntingtin.

An artificial nose could be a real benefit at times: this kind of biosensor could sniff out poisons, explosives or drugs, for instance. Researchers at the Max Planck Institute for Polymer Research and the Max Planck Institute of Biochemistry recently revealed a technique for integrating membrane proteins into artificial structures.

Membrane proteins have several important functions in the cell, one of which is to act as receptors, passing on signals from molecules in the air, for example, to the cell interior. They are thus ideal biosensors, but until now were difficult to access in the lab.

Human nerve stem cells transplanted into rats' damaged spinal cords have survived, grown and in some cases connected with the rats' own spinal cord cells in a Johns Hopkins laboratory, overturning the long-held notion that spinal cords won't allow nerve repair.

A report on the experiments will be published online this week at PLoS Medicine and "establishes a new doctrine for regenerative neuroscience," says Vassilis Koliatsos, M.D., associate professor of neuropathology at Johns Hopkins.