Genetic loot transformed little viruses into giants

by Giorgia Guglielmi Giant viruses are the sperm whales of the microscopic world, dozens of times larger than typical viruses. They’re also richer in genes and much more complex—so much so, in fact, that scientists have speculated whether they evolved from ancient single-celled organisms. But the discovery of a novel group of giant viruses, reported today in Science, indicates that was likely not the case. These mammoth viruses, named Klosneuviruses, started out similar in size to their tiny, simpler brethren, and increased in complexity by gradually pilfering genes from the cells they infected. Compared to other known viruses, the newfound giants contain a more complete set of molecules able to translate genetic instructions into proteins. The researchers found that the genes that produce these protein-making molecules do not derive from an individual organism but rather from several single-celled algae—Klosneuviruses’ favorite hosts. This suggests that, over the course of evolution, Klosneuviruses—and probably other giant viruses—repeatedly gained new genes from the cells they took over. Over billions of years, this genetic larceny turned them into something unique: a cell-like virus that straddles the line between living and non-living.   Publication: Frederik Schulz, Natalya Yutin, Natalia N. Ivanova, Davi R. Ortega, Tae Kwon Lee, Julia Vierheilig, Holger Daims, Matthias Horn, Michael Wagner, Grant J. Jensen, Nikos C. Kyrpides, Eugene V. Koonin, Tanja Woyke. Giant viruses with an expanded complement of translation system components. Science, 2017; 356 (6333): 82 http://science.sciencemag.org/content/356/6333/82     Giorgia Guglielmi is a graduate student in the MIT Program in Science Writing and a freelance science journalist based in Cambridge, MA. She received a PhD in Biology from the European Molecular...

Zika hijacks host cells’ skeleton, persists in a wide range of tissues for weeks

By Giorgia Guglielmi       Scientists moved one step closer to understanding how Zika virus takes hold of host cells, and where and for how long it lurks inside the body. A new study, published in Cell Reports, showed that Zika reshapes the cell’s skeleton to fortify hollow structures where it makes daughter viruses. When scientists used a drug that makes the cell’s structural fibers immovable, the virus was unable to make copies of itself. These drugs might provide a therapeutic option against Zika. To develop new Zika therapies, it’s crucial to know where and when the virus is present within the organism. To address this issue, researchers studied Zika’s spread in infected macaques. The results are detailed in PLOS Pathogens. Zika infected a wide range of tissues, including peripheral nervous system, joints, and muscles, and it persisted in those tissues up to five weeks. What’s more, Zika was found in the reproductive tract of infected animals. The virus’ persistence in reproductive organs might be key to its sexual transmission. It could also explain why Zika infection during pregnancy is associated with crippling birth defects such as abnormally small heads, a condition known as microcephaly.   Giorgia Guglielmi is a graduate student in the MIT Program in Science Writing and a freelance science journalist based in Cambridge, MA. She received a PhD in Biology from the European Molecular Biology Laboratory in Heidelberg, Germany, where she studied how embryos get their final shape.   Please follow and like...
NASA announces 7 new planets in the universe, 3 of which in habitable zones

NASA announces 7 new planets in the universe, 3 of which in habitable zones

By Chiara Bertipaglia, Postdoctoral Research Scientist at Columbia University and KnowScience editor On Wednesday 22nd February NASA announced the discovery of 7 rocky planets just 39 light years (235 trillion miles) away from the Earth. The study, published in the scientific journal Nature, is fruit of collaboration between astronomers at the University of Liege in Belgium and NASA’s laboratories at Caltech in California. These 7 exoplanets (planets beyond our solar system) appear to be rocky and are part of the TRAPPIST-1 system, meaning they all orbit around the same star called TRAPPIST-1. The TRAPPIST-1 system was discovered just a year ago by the Transiting Planets and Planetesimal Small Telescope (TRAPPIST) in Chile reporting, at the time, only 2 planets around the star. TRAPPIST-1 is an ultracool dwarf, a type of star emitting infrared light, impossible to see by naked eye. It is 10 times smaller than the sun and much dimmer and colder since it produces nearly a thousand times less radiation.  It was therefore an ideal candidate to be studied by the infrared space telescope Spitzer, which was launched in space in the Summer of 2003 to explore the corners of the universe that are inaccessible to normal optical telescopes. To properly record the light emitted by TRAPPIST-1, Spitzer had to be modified directly “in space” by astronauts, said Sean Carey, manager of NASA’s Spitzer Science Center at Caltech/IPAC, during the press conference of last Wednesday. It was worth it, since the new modifications allowed to record the presence of 5 more planets. The 7 planets appear to orbit relatively close to the star, 20-200 times closer than the...
Undermining science damages society: Scientists unite against the latest political changes

Undermining science damages society: Scientists unite against the latest political changes

Know Science is a non-profit organization that was born with the mission to share science and the latest scientific discoveries with the taxpayers that finance the research: YOU. A week after the Trump administration took office, the scientific community has already begun fearing for its operational independence, its freedom in communicating scientific findings to the public and, ultimately, in the ability for the US to continue being a leader in science and biotech. The EPA (Environmental Protection Agency), the USDA (United States Department of Agriculture), the HHS (Department of Health and Human Services), the Department of Transportation and the National Park Service were told to stop any form of communication to the media and the general public regarding their research results. Publication in scientific journals would still be allowed, but photographs, press releases, blogs or social media posts are forbidden, at least until the content has been vetted by the political appointees (aka, the Trump administration’s transition team). Which raises the question, should politics control the press in such a radical way? And, when it comes to science and facts-based evidence, withholding information from the public sounds even more radical. If this is not enough to alarm you, it also seems that EPA contracts approvals have been frozen and new funds for research withheld. It’s not only access to information that is being oppressed – it’s access to resources too. EPA is the agency that writes and enforces rules aimed at protecting the environment: it regulates and controls matters like emissions from vehicles, the chemical composition of drinking water, or the safe disposal of hazardous wastes. Significant cuts in...
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