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Archive - Mar 14, 2014

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Five New Species of Armored Spiders Identified in Chinese Caves

Armored spiders are medium to small species that derive their name from the complex pattern of the plates covering their abdomen strongly resembling body armor. Lurking in the darkness of caves in Southeast China, scientists have discovered and described five new species of this exciting group of spiders. The study was published online on March 13, 2014 in the open-access journal ZooKeys. The common name “armored spiders” is given to the engaging family Tetrablemmidae. Distinguished by their peculiar armor-like abdominal pattern, these tropical and subtropical spiders are mainly collected from litter and soil, but like the newly described species some live in caves. Some cave species, but also some soil inhabitants, show typical adaptations of cave spiders, such as loss of eyes. The genus Tetrablemma, for example, to which two of the new species belong, is distinguished by having only four eyes. All these new spiders were collected from the South China Karst, a UNESCO World Heritage Site. The South China Karst spans the provinces of Guangxi, Guizhou, and Yunnan. It is noted for its karst features and landscapes, as well as rich biodiversity. UNESCO describes the South China Karst as "unrivalled in terms of the diversity of its karst features and landscapes." Colleagues from the Chinese Academy of Sciences under the leadership of Professor Shuqiang LI have investigated more than 2,000 caves in the South China Karst. Several hundred new species of cave spiders are reported by Dr. Li and colleagues. As a result, the total known spider species of China increased from 2,300 species to 4,300 species in the last ten years.

USP9X Gene Critical to Brain Development

Research from the University of Adelaide in Australia has confirmed that a gene linked to intellectual disability is critical to the earliest stages of the development of human brains. Known as USP9X, the gene has been investigated by Adelaide researchers for more than a decade, but in recent years scientists have begun to understand its particular importance to brain development. In a new paper published online on March 6, 2014 in the American Journal of Human Genetics, an international research team led by the University of Adelaide's Robinson Research Institute explains how mutations in USP9X are associated with intellectual disability. These mutations, which can be inherited from one generation to the next, have been shown to cause disruptions to normal brain cell functioning. Speaking during Brain Awareness Week, senior co-author Dr. Lachlan Jolly from the University of Adelaide's Neurogenetics Research Program says the USP9X gene has shed new light on the mysteries of brain development and disability. Dr. Jolly says the base framework for the brain's complex network of cells begins to form at the embryo stage. "Not surprisingly, disorders that cause changes to this network of cells, such as intellectual disabilities, epilepsy, and autism, are hard to understand, and treat," Dr. Jolly says. "By looking at patients with severe learning and memory problems, we discovered a gene - called USP9X - that is involved in creating this base network of nerve cells. USP9X controls both the initial generation of the nerve cells from stem cells, and also their ability to connect with one another and form the proper networks," he says. "This work is critical to understanding how the brain develops, and how it is altered in individuals with brain disorders.

Harvard Scientists Create DNA Polyhedra That Could Deliver Drugs, Perform Other Functions

Move over, nanotechnologists, and make room for the biggest of the small. Scientists at Harvard's Wyss Institute have built a set of self-assembling DNA cages one-tenth as wide as a bacterium. The structures are some of the largest and most complex structures ever constructed solely from DNA, the scientists reported online on March 13, 2014 in Science. Moreover, the scientists visualized the structures using a DNA-based super-resolution microscopy method -- and obtained the first sharp 3D optical images of intact synthetic DNA nanostructures in solution. In the future, scientists could potentially coat the DNA cages to enclose their contents, packaging drugs for delivery to tissues. And, like a roomy closet, the cage could be modified with chemical hooks that could be used to hang other components such as proteins or gold nanoparticles. This could help scientists build a variety of technologies, including tiny power plants, miniscule factories that produce specialty chemicals, or high-sensitivity photonic sensors that diagnose disease by detecting molecules produced by abnormal tissue. "I see exciting possibilities for this technology," said Peng Yin, Ph.D., a Core Faculty member at the Wyss Institute and Assistant Professor of Systems Biology at Harvard Medical School, and senior author of the paper. DNA is best known as a keeper of genetic information. But scientists in the emerging field of DNA nanotechnology are exploring ways to use it to build tiny structures for a variety of applications. These structures are programmable, in that scientists can specify the sequence of letters, or bases, in the DNA, and those sequences then determine the structure it creates.