Birds: Feather Color Is More Than Skin Deep
April 15, 2009
Where do birds get their red feathers from? According to Esther del Val, from the National History Museum in Barcelona, Spain, and her team, the red carotenoids that give the common crossbill (Loxia curvirostra) its red coloration are produced in the liver, not the skin, as previously thought.
Their findings, published online in Springer’s journal Naturwissenschaften, have implications for understanding the evolution of color signaling in bird species.
Carotenoids have important physiological functions, including antioxidant, immunomodulating, and photoprotectant properties. Carotenoid pigments are also used by many bird species as colorants, and are responsible for most of their red, orange and yellow coloration. In particular, carotenoid-red coloration in birds has been shown to act as an ornament, signaling the nutritional and health status of the individual and its ability to locate high quality resources. Recent studies have suggested that the transformation of carotenoid pigments takes place directly in the follicles during feather growth.
Genes That Make Bacteria Make Up Their Minds
April 6, 2009
Bacteria are single cell organisms with no nervous system or brain. So how do individual bacterial cells living as part of a complex community called a biofilm “decide” between different physiological processes (such as movement or producing the “glue” that forms the biofilm)?
Is The Hippopotamus The Closest Living Relative To The Whale?
March 19, 2009
Hippos spend lots of time in the water and now it turns out (or researchers argue), they are the closest living relative to whales. It also turns out, the two are swimming in a bit of controversy.
Jessica Theodor, an associate professor in the Department of Biological Sciences at the University of Calgary, and her colleague Jonathan Geisler, associate professor at Georgia Southern University are disputing a recent study that creates a different family tree for the hippo.
That research was published inNature in December 2007 by J. G. M. Thewissen, a professor at Northeastern Ohio Universities College of Medicine, and his colleagues. Thewissen says that whales are more closely linked to an extinct pig-like animal, often known as India’s pig or Indohyus, while hippos are closely related to living pigs.
Bacteria-killing Enzyme Cures Mice With Fatal Pneumonia
March 11, 2009
Before the advent of antibiotics, pneumonia claimed so many lives — and was so feared — that it was called the “captain of the ship of death.” Now, at a time when the new antibiotics have proved futile against resistant strains of bacteria, researchers at Rockefeller University are using a different tactic to keep this ship at bay.
From Stem Cells To New Organs: Scientists Cross Threshold In Regenerative Medicine
March 3, 2009
Stem cells can thrive in segments of well-vascularized tissue temporarily removed from laboratory animals, say researchers at the Stanford University School of Medicine. Once the cells have nestled into the tissue’s nooks and crannies, the so-called “bioscaffold” can then be seamlessly reconnected to the animal’s circulatory system.
New Lab Evidence Suggests Preventive Effect Of Herbal Supplement In Prostate Cancer
February 24, 2009
DHEA is a natural circulating hormone and the body’s production of it decreases with age. Men take DHEA as an over-the-counter supplement because it has been suggested that DHEA can reverse aging or have anabolic effects since it can be metabolized in the body to androgens. Increased consumption of dietary isoflavones is associated with a decreased risk of prostate cancer.
Red clover (Trifolium pretense) is one source of isoflavones. Both supplements may have hormonal effects in the prostate and little is known about the safety of these supplements.
In a recent report in Cancer Prevention Research, a journal of the American Association for Cancer Research, researchers report that DHEA levels can be manipulated in cells in the laboratory to understand its effects.
Julia Arnold, Ph.D., a staff scientist at the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health, said more research is necessary in an environment where men and women concerned about health problems tend to self-prescribe based on information they find on the Internet.
Fruit Flies Soar As Lab Model, Drug Screen For The Deadliest Of Human Brain Cancers
February 23, 2009
Fruit flies and humans share most of their genes, including 70 percent of all known human disease genes. Taking advantage of this remarkable evolutionary conservation, researchers at the Salk Institute for Biological Studies transformed the fruit fly into a laboratory model for an innovative study of gliomas, the most common malignant brain tumors.
“Gliomas are a devastating disease but we still know very little about the underlying disease process,” explains John B. Thomas, Ph.D., a professor in the Molecular Neurobiology Laboratory and senior author of the study, which is published in the current edition of the Public Library of Science Genetics. “We can now use the power of Drosophila genetics to uncover genes that drive these tumors and identify novel therapeutic targets, which will speed up the development of effective drugs.”
Protective Shield Used By Hundreds Of Viruses Deciphered
February 17, 2009
If a picture is worth a thousand words, then Rice University’s precise new image of a virus’ protective coat is seriously undervalued. More than three years in the making, the image contains some 5 million atoms — each in precisely the right place — and it could help scientists find better ways to both fight viral infections and design new gene therapies.
The stunning image, which appears online this week in the Proceedings of the National Academy of Sciences, reveals the structure of a type of protein coat shared by hundreds of known viruses containing double-stranded RNA genomes. The image was painstakingly created from hundreds of high-energy X-ray diffraction images and paints the clearest picture yet of the viruses’ genome-encasing shell called a “capsid.”
Rot’s Unique Wood Degrading Machinery To Be Harnessed For Better Biofuels Production
February 9, 2009
An international team led by scientists from the U.S. Department of Energy (DOE) Joint Genome Institute (JGI) and the U.S. Department of Agriculture Forest Service, Forest Products Laboratory (FPL) have translated the genetic code that explains the complex biochemical machinery making brown-rot fungi uniquely destructive to wood. The same processes that provide easier access to the energy-rich sugar molecules bound up in the plant’s tenacious architecture are leading to innovations for the biofuels industry.
The research, conducted by more than 50 authors, is reported in the February 4 online edition of the Proceedings of the National Academy of Sciences (PNAS).
Single Gene Lets Bacteria Jump From Host To Host
February 2, 2009
All life — plants, animals, people — depends on peaceful coexistence with a swarm of microbial life that performs vital services from helping to convert food to energy to protection from disease.
Now, with the help of a squid that uses a luminescent bacterium to create a predator-fooling light organ and a fish that uses a different strain of the same species of bacteria like a flashlight to illuminate the dark nooks of the reefs where it lives, scientists have found that gaining a single gene is enough for the microbe to switch host animals.
The finding, reported this week (Feb. 1) in the journal Nature by a team of scientists from the University of Wisconsin-Madison, is important not only because it peels back some of the mystery of how bacteria evolved to colonize different animals, but also because it reveals a genetic pressure point that could be manipulated to thwart the germs that make us sick.
