How Pathogenic Bacteria Hide Inside Host Cells

A new study into Staphylococcus aureus, the bacterium which is responsible for severe chronic infections worldwide, reveals how the bacteria have developed a strategy of hiding within host cells to escape the immune system as well as many antibacterial treatments. The research, published by EMBO Molecular Medicine, demonstrates how ‘phenotype switching’ enables bacteria to adapt to their environmental conditions, lie dormant inside host cells and become a reservoir for relapsing infections.

Neuroscientists Learn How Channels Fine-Tune Neuronal Excitability

 Scientists in the Hotchkiss Brain Institute at the Faculty of Medicine, University of Calgary, have discovered a new mechanism that nerve cells (neurons) use to fine-tune their electrical output. The discovery, published in the journal Nature Neuroscience, provides new insights about how the activity of the nervous system is regulated at the cellular level.

Scientists ID Gene Behind Cancer’s Spread

Scientists in England say they have identified the gene that is responsible for cancer’s spread through the body – raising the possibility of a “one-size-fits-all” cure for the disease by developing a drug that switches off the gene.

Most deaths from cancer result from its gradual metastasis, or spreading, from the original cancer site to other tissues and organs. Halting that spread wouldn’t eliminate a patient’s primary cancer, but it would allow it to be treated with conventional therapies and surgery, “with no risk of the disease taking hold elsewhere,” according to researchers.

The research was conducted at the University of East Anglia and published Tuesday in the journal Oncogene.

“The culprit gene – known as WWP2 – is an enzymic bonding agent found inside cancer cells. It attacks and breaks down a natural inhibitor in the body which normally prevents cancer cells spreading,” the university said in a release detailing the findings. “The UEA team found that by blocking WWP2, levels of the natural inhibitor are boosted and the cancer cells remain dormant.”

“The challenge now is to identify a potent drug that will get inside cancer cells and destroy the activity of the rogue gene,” said lead author Andrew Chantry. “This is a difficult but not impossible task, made easier by the deeper understanding of the biological processes revealed in this study.”

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Recommended Readings: Neil Shubin, Ph.D.

Friday Lecture Series

Fairfield Osborn Memorial Lecture

Fossils, Genes and the Origin of Organs

Neil Shubin, Ph. D., professor and chair of organismal biology and anatomy,

University of Chicago

January 28, 2011

3:45 p.m.-5:00 p.m. (Refreshments, 3:15 p.m., Abby Lounge)

Caspary Auditorium

Davis, M. C., R. D. Dahn, and N. H. Shubin. 2007. An autopodial-like pattern of hox expression in the fins of a basal actinopterygian fish. Nature 447, (7143): 473-476

Davis, M. C., N. H. Shubin, and A. Force. 2004. Pectoral fin and girdle development in the basal actinopterygians polyodon spathula and acipenser transmontanus. Journal of Morphology 262, (2): 608-628

Gao, K. -Q, and N. H. Shubin. 2001. Late jurassic salamanders from northern china. Nature 410, (6828): 574-577

Shubin, N., C. Tabin, and S. Carroll. 2009. Deep homology and the origins of evolutionary novelty. Nature 457, (7231): 818-823

Shubin, N. H., E. B. Daeschler, and M. I. Coates. 2004. The early evolution of the tetrapod humerus. Science 304, (5667): 90-93

Shubin, N. H., and C. R. Marshall. 2000. Fossils, genes, and the origin of novelty. Paleobiology 26, (4 SUPPL.): 324-340

Recommended Readings: Lisa Stowers, Ph. D.

Friday Lecture Series

Specialized Odors That Generate Stereotyped Behavior

Lisa Stowers, Ph. D., associate professor, department of cell biology,

The Scripps Research Institute

January 21, 2011

3:45 p.m.-5:00 p.m. (Refreshments, 3:15 p.m., Abby Lounge)

Caspary Auditorium

Chamero, P., T. F. Marton, D. W. Logan, K. Flanagan, J. R. Cruz, A. Saghatelian, B. F. Cravatt, and L. Stowers. 2007. Identification of protein pheromones that promote aggressive behaviour. Nature 450, (7171): 899-902

Chant, J., and L. Stowers. 1995. GTPase cascades choreographing cellular behavior: Movement, morphogenesis, and more. Cell 81, (1): 1-4

Loconto, J., F. Papes, E. Chang, L. Stowers, E. P. Jones, T. Takada, A. Kumánovics, K. F. Lindahl, and C. Dulac. 2003. Functional expression of murine V2R pheromone receptors involves selective association with the M10 and M1 families of MHC class ib molecules. Cell 112, (5): 607-618

Stowers, L., T. E. Holy, M. Meister, C. Dulac, and G. Koentges. 2002. Loss of sex discrimination and male-male aggression in mice deficient for TRP2. Science 295, (5559): 1493-1500

Stowers, L., and D. W. Logan. 2010. Olfactory mechanisms of stereotyped behavior: On the scent of specialized circuits. Current opinion in neurobiology 20, (3): 274-280

Polymer Membranes With Molecular-Sized Channels That Assemble Themselves

ScienceDaily (Jan. 11, 2011) — Many futurists envision a world in which polymer membranes with molecular-sized channels are used to capture carbon, produce solar-based fuels, or desalinate sea water, among many other functions. This will require methods by which such membranes can be readily fabricated in bulk quantities. A technique representing a significant first step down that road has now been successfully demonstrated.

Researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have developed a solution-based method for inducing the self-assembly of flexible polymer membranes with highly aligned subnanometer channels. Fully compatible with commercial membrane-fabrication processes, this new technique is believed to be the first example of organic nanotubes fabricated into a functional membrane over macroscopic distances.    This research was published in the journal ACS Nano 2011  10.1021/nn103083t.   Request a copy from Markus Library.

Species Loss Tied to Ecosystem Collapse and Recovery

ScienceDaily (Jan. 12, 2011) — Geologists at Brown University and the University of Washington have a cautionary tale: Lose enough species in the oceans, and the entire ecosystem could collapse. Looking at two of the greatest mass extinctions in Earth’s history, the scientists attribute the ecosystems’ collapse to a loss in the variety of species sharing the same space. It took up to 10 million years after the mass extinctions for the ecosystem to stabilize.

The world’s oceans are under siege. Conservation biologists regularly note the precipitous decline of key species, such as cod, bluefin tuna, swordfish and sharks. Lose enough of these top-line predators (among other species), and the fear is that the oceanic web of life may collapse.

In a new paper in Geology, researchers at Brown University and the University of Washington used a group of marine creatures similar to today’s nautilus to examine the collapse of marine ecosystems that coincided with two of the greatest mass extinctions in the Earth’s history. They attribute the ecosystems’ collapse to a loss of enough species occupying the same space in the oceans, called “ecological redundancy.”

The research appears in Geology 2011   39(2):99.  Request a copy from Markus Library.