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Archive - Dec 19, 2014


New Hermit Cockroach Species Identified in China

Scientists from the Southwest University, Chongqing, China have found a new species and a new subspecies of cockroach. What makes these cockroaches distinct from the cockroaches most of us know is that they don't infest human houses. On the contrary, they prefer to live a hermit life drilling logs, hidden away from human eyes. The study was published online on December 19, 2014 in the open-access journal ZooKeys. Out of around 4,600 cockroach species worldwide, only 30 are the cockroaches associated with human habitats that gives a bad name to these creatures. The representatives of the genus Panesthia, to which the new species and subspecies belong, for example are distinctive for drilling logs and xylophagy (feeding on wood), rather than living in houses and eating rubbish. The new species, P. guizhouensis, was firstly collected from a rotten wood near a large pool where it was living undisturbed, and far away from cities in Guizhou Province. A colony of more than 60 nymphs and 52 adults, emerged from the log when the wood was split, quickly fleeing away. Up to now, 55 species and 9 subspecies have been reported in this genus, but because of their secluded lifestyle, these cockroaches are still mysterious to scientists, and their study had been nearly stagnant since 1999. "With this new discovery, we hope to reignite the scientific interest towards this peculiar and rather intriguing cockroach genus," comments Dr. Yanli Che, Southwest University, China. The image shows a cockroach belonging to the genus Panesthia. (Credit: Yanli Che).

[Press release] [Zoo Keys article]

Orphan Receptor Proteins Deliver Double Knock-Out Punch to Glioblastoma Cells in Vitro

Two related proteins exert a lethal double-whammy effect against glioblastoma cells when activated with a small molecule, say researchers at Georgetown Lombardi Comprehensive Cancer Center. The scientists report that, when activated, one protein, called the short form, stops glioblastoma cells from replicating their DNA, and the other, called the long form, prevents cell division if the DNA has already been replicated, explains Rebecca Riggins, Ph.D., Assistant Professor of Oncology at Georgetown Lombardi. The study was posted online on December 12, 2014 in an open-access article in the journal Cell Cycle. Both proteins are produced by the estrogen-related receptor beta (ERRβ) gene. They are known as "orphan receptors" because they are not known to bind to any substances naturally produced by the body. ERRβ proteins are similar in shape to the receptor that binds the hormone estrogen -- hence their name -- but they do not bind estrogen and are not otherwise related. Both men and women have ERRβ genes. In this study, Dr. Riggins and her co-author, postdoctoral fellow Mary Heckler, Ph.D., examined glioblastoma cells in the laboratory for the presence of ERRβ and found both long and short forms. To understand what these proteins were doing, they used a laboratory chemical, DY131, which had been designed to bind and activate these proteins. To their surprise, the researchers discovered that DY131 exerted a strong, but distinct, effect on both the short and long forms of ERRβ. The short form had been known to act as a tumor suppressor in prostate cancer, and a similar anti-cancer action was found by the researchers in glioblastoma. The study, however, is the first to find a function for the long form in cancer.

Scientists Discover Protein Protecting Against Chlorine

Chlorine is a common disinfectant that is used to kill bacteria, for example, in swimming pools and drinking water supplies. Our immune system also produces chlorine, which causes proteins in bacteria to lose their natural folding. These unfolded proteins then begin to clump and lose their function. Ruhr-Universitaet-Bochum (RUB) researchers in Germany, headed by Professor Dr. Lars Leichert, have discovered a protein (RidA) in the intestinal bacterium E. coli that protects bacteria from chlorine. In the presence of chlorine, this newly discovered protein tightly bonds with other proteins, thus preventing them from coagulating. Once the danger has passed, this protein releases the bound proteins and they can continue to work as usual. The researchers reported their findings online on December 17, 2014 in an open-access article in Nature Communications. The scientists look into oxidative stress, which affects cells when they encounter so-called “reactive oxygen species” (ROS), chemically reactive molecules containing oxygen. Oxidative stress plays a role during cell aging and in immune defense. By producing reactive oxygen species, immune cells subject bacteria to oxidative stress. But what happens inside those bacteria, and more specifically, what happens to their proteins? The researchers sought to answer this question by looking for proteins that change due to oxidative stress. This is how they discovered the protein RidA.

Adaptive Evolution of Human Color Vision

The evolution of trichromatic color vision in humans occurred by first switching from the ability to detect UV light to blue light (between 80-30 million years ago-MYA) and then by adding green-sensitivity (between 45-30 MYA) to the preexisting red-sensitivity in the vertebrate ancestor. The detailed molecular and functional changes of the human color vision have been revealed by lead author Dr. Shozo Yokoyama of Emory University and colleagues from Emory and other institutions. The article was published online on December 18, 2014 in the open-accessd journal PLOS Genetics. The molecular basis of functional differentiation is a fundamental question in biology. To fully appreciate how these changes are generated, it is necessary to evaluate the relationship between genes and functions. This is a difficult task because new mutations can produce different functional changes when they occur with different preexisting mutations, causing complex non-additive interactions. The blue-sensitive visual pigment in human evolved from the UV-sensitive pigment in the ancient Boreoeutherian ancestor by seven mutations. There are 5,040 possible evolutionary paths connecting them. The team examined experimentally the genetic composition and color perception of the visual pigment at every evolutionary step of all 5,040 trajectories. They found that 4,008 trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Eight most likely trajectories reveal that the blue-sensitivity evolved gradually almost exclusively by non-additive interactions among the seven mutations.

Wild Blueberries May Reduce Adverse Effects of High-Fat Diet

Eating wild blueberries (bilberries) diminishes the adverse effects of a high-fat diet, according to a recent study at the University of Eastern Finland. For the first time, bilberries were shown to have beneficial effects on both blood pressure and nutrition-derived inflammatory responses. Low-grade inflammation and elevated blood pressure are often associated with obesity-related diseases. The current study focused on the health effects of bilberries on mice that were fed a high-fat diet for a period of three months. Some of the mice were fed either 5% or 10% of freeze-dried bilberries in the diet. The researchers assessed the effects of the diets by looking at inflammatory cell and cytokine levels, systolic blood pressure, glucose tolerance, insulin sensitivity, and weight gain. Mice on the high-fat diet experienced significant weight gain and detrimental changes in glucose and lipid metabolism, inflammation factors, and blood pressure. Bilberries diminished the pro-inflammatory effects of the high-fat diet, indicated by an altered cytokine profile and a reduced relative prevalence of inflammation supporting T-cells. Bilberries also prevented elevated blood pressure caused by the high-fat diet. Bilberries constitute an integral part of the Nordic diet and they could be better utilized also elsewhere in the world. Bilberries are associated with several beneficial health effects and their use involves plenty of traditional wisdom. The beneficial health effects of bilberries are thought to be explained by polyphenols, especially anthocyanins, the levels of which are significantly higher in bilberries than in commercially cultivated blueberries. The original article was published online on December 12, 2014 in the open-access journal PLOS ONE.