January 14, 2008, 5:21 PM CT

Fruit flies all aglow light the way to cancer prevention

A green glow from a fruit fly is giving researchers the green light when they are on the right path in their quest to develop compounds that help prevent cancer.

The glow, the result of some tinkering in Drosophila, the workhorse of the genetics world, lets researchers know when powerful cancer-prevention signals similar to those spurred by protective chemicals in broccoli, cabbage, and other foods, have been turned on in the organism.

The chemical signaling system is one of the major ways that the body defends itself against toxic assaults and threats like cigarette smoke, diesel exhaust, and dangerous microbes. A gene known as KEAP1 senses danger and then unleashes NRF2, which triggers rampant anti-oxidant activity in a cell.

Now scientists from the University of Rochester Medical Center have discovered that the pathway, long recognized in people and other animals, is active in fruit flies, too, opening the door to faster, less expensive ways to find compounds that spur our natural anti-oxidant activity. The work, funded by the National Cancer Institute, is reported in the Jan. 15 issue of Developmental Cell.

This is one of the main mechanisms the body uses to fight off the things that give you cancer, said Dirk Bohmann, Ph.D., professor in the Department of Biomedical Genetics and a geneticist who studies fruit flies in an effort ultimately aimed at improving human health......... Posted by: Janet      Read more         Source

January 14, 2008, 5:11 PM CT

Starfish outbreak threatens corals

Outbreaks of the notorious crown of thorns starfish now threaten the coral triangle, the richest center of coral reef biodiversity on Earth, as per recent surveys by the Bronx Zoo-based Wildlife Conservation Society and ARC Centre of Excellence for Coral Reef Studies.

The starfish a predator that feeds on corals by spreading its stomach over them and using digestive enzymes to liquefy tissue were discovered in large numbers by the scientists in reefs in Halmahera, Indonesia, at the heart of the Coral Triangle, which lies between Indonesia, Malaysia, the Philippines, Papua New Guinea and the Solomon Islands. It is considered the genetic fountainhead for coral diversity found on Australias Great Barrier Reef, Ningaloo and other reefs in the region.

Researchers fear the outbreak is caused by poor water quality and could be an early warning of widespread reef decline.

Recent surveys of Halmahera by the Wildlife Conservation Society and ARC Centre of Excellence for Coral Reef Studies confirmed that while Halmaheras reefs are still 30-50 percent richer than nearby reefs, some areas were almost completely destroyed.

The main cause of damage to the corals was the Crown of Thorns Starfish, Dr. Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies and James Cook University. We witnessed many active outbreaks of this coral predator. There was little to suggest that the reefs have been much affected by climate change as yet: the threats appear far more localized......... Posted by: Kelly      Read more         Source

January 14, 2008, 5:09 PM CT

Sea otter study reveals striking variability

Ecologists have long found that when food becomes scarce, animal populations exploit a wider range of food sources. So researchers studying southern sea otters at different sites in California's coastal waters were not surprised to find that the dietary diversity of the population is higher where food is limited. But this diversity was not reflected in the diets of individual sea otters, which instead showed dietary specialization in response to limited food.

The new findings by scientists at the University of California, Santa Cruz, will be published online in the Proceedings of the National Academy of Sciences the week of January 14. The study observed that all sea otters in an area with abundant food resources share the same dietary preferences. Where food is limited, however, a diverse array of feeding strategies emerges, with individual sea otters specializing on particular types of prey.

Tim Tinker, a UCSC research biologist and first author of the paper, said the study has both theoretical implications for the science of ecology and practical implications for wildlife management.

"The traditional way of viewing the relationships between predators and prey and how food webs are structured may be oversimplified," Tinker said. "When you look at the population as a whole, you may see a diversification of the diet in response to limited food resources. But when you look at individuals, you see dietary specialization"......... Posted by: Kelly      Read more         Source

January 14, 2008, 4:59 PM CT

Unlocking tree genetics

UBC scientists have discovered some of the genetic secrets that enable pine and spruce trees to fight off pests and disease, uncovering critical new information about forests natural defense systems.

Assoc. Prof. Joerg Bohlmann says this genetic analysis will allow forest stewardship programs to reinforce a forests inherent strength, breeding trees that could in time repel insects such as British Columbias notorious mountain pine beetles.

Bohlmann and his research associate Christopher Keeling explored the genetic makeup of oleoresin within spruce, discovering a sophisticated ability to produce complex blends of chemicals that continuously evolve to protect the tree from changing conditions and challenges.

Conifers are some of the oldest and longest living plants on the planet, says Bohlmann. Weve opened the book to understanding how they can survive in one location for thousands of years despite attacks from generations of insects and diseases.

Their study examines the molecular biochemistry of conifers interacting with genomes of bark beetles and bark beetle-associated fungal pathogens. Bohlmanns study appears in todays edition of the Proceedings of the National Academy of Sciences.

Figuring out how these naturally occurring defenses work has important implications for the long-term sustainability and health of our forests, says Bohlmann, whos working with the B.C. Ministry of Forests and Range, the forestry industry and the Canadian Forest Service......... Posted by: Erica      Read more         Source

January 14, 2008, 4:54 PM CT

From the Journal of Biological Chemistry

COX-2 inhibitors like Celecoxib have come under scrutiny lately due to adverse cardiovascular side-effects stemming from COX-2 reduction. In both fruit fly and rat models, researchers reveal another adverse effect of Celecoxib; this drug can induce arrhythmia. More interestingly, this effect is independent of the COX-2 enzyme.

Satpal Singh and colleagues tested various Celecoxib doses on the heart rate of Drosophila, a good model for human cardiac pharmacology. To their surprise, administering 3 m Celecoxib (not much higher than the plasma levels in humans taking the drug) reduced heart rate and increased beating irregularities, while 30 m was enough to stop the heart within a minute.

The surprise arises from the fact that Drosophila do not have COX-2 enzymes. Rather, Celecoxib could directly inhibit the potassium channels that help generate the electric current that drives heartbeat.

The researchers could achieve similar heart-stopping results in rat cardiac cells, whereas aspirin, another potent COX-2 inhibitor, had no effect, confirming that another mechanism is at work. The drug also inhibited rat and human potassium channels expressed in a human cell line.

Singh and colleagues point out that since these arrhythmia effects bypass COX-2, it is unclear if other COX-2 inhibitors would yield similar results. They also stress it is too early to speculate on human effects, although their results suggest Drosophila are a valuable tool to investigate other COX-2 drugs......... Posted by: Janet      Read more         Source

January 14, 2008, 3:16 PM CT

Critical ingredients for the soup of life

Astronomers from Arecibo Observatory radio telescope in Arecibo, Puerto Rico, have detected for the first time the molecules methanimine and hydrogen cyanide two ingredients that build life-forming amino acids in a galaxy some 250 million light years away.

Just add water! said Robert Minchin, an Arecibo astronomer on the project, who explained that methanimine and hydrogen cyanide are two of the basic ingredients of life, because when combined with water they form glycine, the simplest amino acid, a building block of life on Earth.

The astronomy team, led by Arecibo astronomer Christopher Salter, announced this discovery today (Jan. 11) in a poster presented at the American Astronomical Society meeting in Austin. The Arecibo Observatory is managed by Cornell University for National Science Foundation.

The Arecibo astronomers focused on the distant galaxy Arp 220, an ultra-luminous starburst galaxy, because it forms new stars at a very high rate. They used the 305-meter, or 1,000-foot diameter, Arecibo radio telescope, the worlds largest and most sensitive, to observe the galaxy at different frequencies. In fact, for the first time in April 2007, they used the 800 megahertz wide-band mode of the main spectrometer to make these detections.

These molecules were found by searching for radio emission at specific frequencies. Each chemical substance has its own unique radio frequency and astronomers can in that way identify the different substances, much like people can be identified with their unique fingerprints......... Posted by: Janet      Read more         Source

January 8, 2008, 8:35 PM CT

Newly Patented Purplish 'Lily' Blooms All Summer Long

Mauve Majesty is one cool lily look-alike. This new pinkish-purple ornamental flower, just patented by Cornell, can last for two weeks in a vase, but when left in the garden, it blooms all summer long in the cooler, northern states until the first hard freeze in the fall.

The new hybrid of the Inca lily (Alstroemeria), which was developed by a Cornell professor, is a non-fragrant perennial that is set apart by its lavender-lilac flower color (which is adorned with dark speckling and a creamy yellow throat), its strong, upright flower stems and its winter hardiness. In greenhouses, the new hybrid never goes dormant and grows year-round.

Developed by Mark Bridgen, Cornell professor of horticulture and director of the Department of Horticulture's Long Island Horticultural Research and Extension Center, the hybrid is the first ornamental plant patented by Cornell, as per Richard Cahoon, associate director of Patents and Technology at Cornell's Technology Transfer Office.

It is also one of the first in its color class to be hardy to zone 6 of the U.S. Department of Agriculture Plant Hardiness Zone Map (coasts of Massachusetts, Connecticut, Rhode Island, New York and northern New Jersey and much of the Midwest) and often to a number of parts of the cooler zone 5 (which includes western Massachusetts, mid-state New York, northern Pennsylvania, Ohio, Indiana and Illinois, much of Michigan, southern Iowa and Nebraska, northern Missouri and Kansas, and eastern Colorado)......... Posted by: Erica      Read more         Source

January 8, 2008, 8:30 PM CT

Mechanics Of Gene Transcription

The molecular machinery behind gene transcription -- the intricate transfer of information from a segment of DNA to a corresponding strand of messenger RNA -- isn't stationed in special "transcription factories" within a cell nucleus, as per Cornell researchers. Instead, the enzyme RNA polymerase II (Pol II) and other key molecules can assemble at the site of an activated gene, regardless of the gene's position.

The findings, reported in the Dec. 28, 2007, issue of the journal Molecular Cell, are the result of an ongoing collaboration between the laboratories of John T. Lis, the Barbara McClintock Professor of Molecular Biology and Genetics, and Watt W. Webb, professor of applied physics and the S.B. Eckert Professor in Engineering. Jie Yao, the paper's lead author, recently finished his Ph.D. at Cornell under Webb.

Using multiphoton microscopy, a technique developed by Webb that allows high-precision 3D imaging in living cells, the scientists observed polytene chromosomes -- giant, multistranded chromosomes in the salivary gland tissue of fruit flies that have hundreds of sets of the genome instead of the usual two sets in conventional cells.

They activated heat shock genes, which protect cells from sudden rises in temperature, and watched them in real time as they began to be transcribed. The scientists also tagged Pol II with a fluorescent marker to track its movements within the nucleus......... Posted by: Janet      Read more         Source

January 8, 2008, 8:23 PM CT

An "attractive" man-machine interface

Scientists at Children's Hospital Boston have developed a new "nanobiotechnology" that enables magnetic control of events at the cellular level. They describe the technology, which could lead to finely-tuned but noninvasive therapys for disease, in the recent issue of Nature Nanotechnology (published online January 3).

Don Ingber, MD, PhD, and Robert Mannix, PhD, of Children's program in Vascular Biology, in collaboration with Mara Prentiss, PhD, a physicist at Harvard University, devised a way to get tiny beads--30 nanometers (billionths of a meter) in diameter--to bind to receptor molecules on the cell surface. When exposed to a magnetic field, the beads themselves become magnets, and pull together through magnetic attraction. This pull drags the cell's receptors into large clusters, mimicking what happens when drugs or other molecules bind to them. This clustering, in turn, activates the receptors, triggering a cascade of biochemical signals that influence different cell functions.

The technology could lead to non-invasive ways of controlling drug release or physiologic processes such as heart rhythms and muscle contractions, says Ingber, the study's senior investigator. More importantly, it represents the first time magnetism has been used to harness specific cellular signaling systems normally used by hormones or other natural molecules......... Posted by: Janet      Read more         Source

January 7, 2008, 11:14 PM CT

No convincing evidence for decline in tropical forests

Claims that tropical forests are declining cannot be backed up by hard evidence, as per new research from the University of Leeds.

This major challenge to conventional thinking is the surprising finding of a study published recently in the Proceedings of the US National Academy of Sciences by Dr Alan Grainger, Senior Lecturer in Geography and one of the world's leading experts on tropical deforestation.

"Every few years we get a new estimate of the annual rate of tropical deforestation, said Dr Grainger. They always seem to show that these marvellous forests have only a short time left. Unfortunately, everybody assumes that deforestation is happening and fails to look at the bigger picture what is happening to forest area as a whole.

In the first attempt for a number of years to chart the long-term trend in tropical forest area,.

he spent more than three years going through all available United Nations data with a fine toothcomb and found some serious problems.

The errors and inconsistencies I have discovered in the area data raise too a number of questions to provide convincing support for the accepted picture of tropical forest decline over the last 40 years, he said. Researchers all over the world who have used these data to make predictions of species extinctions and the role of forests in global climate change will find it helpful to revisit their findings in the light of my study......... Posted by: Erica      Read more         Source