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 Post subject: Crispr Is Getting Better. Now Its Time to Ask the Hard Ethic
PostPosted: Wed Dec 02, 2015 12:55 pm 
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Crispr Is Getting Better. Now Its Time to Ask the Harsh Ethical Questions

Crispr Is Getting Better. Now It’s Time to Ask the Hard Ethical Questions

When Chinese scientists announced in April they had edited human embryos using a new genetic tool called Crispr, the headlines blared designer babies and the wider world woke up to Crisprs power.

The post Crispr Is Getting Better. Now It’s Time to Ask the Hard Ethical Questions appeared first on WIRED.













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 Post subject: Scientists Capture Crisprs Gene-Cutting in Action
PostPosted: Fri Jan 15, 2016 12:20 pm 
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Scientists Capture Crispr’s Gene-Cutting in Action

For the first time, a study led by Crispr/Cas9 pioneer Jennifer Doudna uses crystallography to capture Cas9 as its primed to cut DNA.

The post Scientists Capture Crispr’s Gene-Cutting in Action appeared first on WIRED.













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 Post subject: Search for Life on Mars --"Organisms on the ISS Survive
PostPosted: Fri Jan 29, 2016 12:25 am 
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Search for Life on Mars --"Organisms on the ISS Survive a Red-Planet Environment"





Space-station-fulllbleed





"The results help to assess the survival ability and long-cycle stability of microorganisms and bioindicators on the surface of Mars, information which becomes basic and relevant for future experiments centred around the search for life on the red planet," says Rosa de la Torre Noetzel from Spains National Institute of Aerospace Technology.



European scientists have gathered tiny fungi that take shelter in Antarctic rocks and sent them to the International Space Station. After 18 months on board in conditions similar to those on Mars, more than 60% of their cells remained intact, with stable DNA. The results provide new information for the search for life on the red planet. Lichens from the Sierra de Gredos (Spain) and the Alps (Austria) also travelled into space for the same experiment.

The McMurdo Dry Valleys, located in the Antarctic Victoria Land, are considered to be the most similar earthly equivalent to Mars. They make up one of the driest and most hostile environments on our planet, where strong winds scour away even snow and ice. Only so-called cryptoendolithic microorganisms, capable of surviving in cracks in rocks, and certain lichens can withstand such harsh climatological conditions.





Valleys_hi





A few years ago a team of European researchers travelled to these remote valleys to collect samples of two species of cryptoendolithic fungi: Cryomyces antarcticus and Cryomyces minteri. The extent was to send them to the International Space Station (ISS) for them to be subjected to Martian conditions and space to notice their responses.



The tiny fungi were placed in cells (1.4 centimetres in diameter) on a platform for experiments known as EXPOSE-E, developed by the European Space Agency to withstand extreme environments. The platform was sent in the Space Shuttle Atlantis to the ISS and placed outside the Columbus module with the help of an astronaut from the team led by Belgian Frank de Winne.



For 18 months half of the Antarctic fungi were exposed to Mars-like conditions. More specifically, this is an atmosphere with 95% CO2, 1.6% argon, 0.15% oxygen, 2.7% nitrogen and 370 parts per million of H2O; and a pressure of 1,000 pascals. Through optical filters, samples were subjected to ultra-violet radiation as if on Mars (higher than 200 nanometres) and others to lower radiation, including separate manage samples.



The image below shows a section of rock coloniszed by cryptoendolithic microorganisms and the Cryomyces fungi in quartz crystals under an electron microscope. (S. Onofri et al.)





107710_web





"The most relevant outcome was that more than 60% of the cells of the endolithic communities studied remained intact after exposure to Mars, or rather, the stability of their cellular DNA was still high," highlights Rosa de la Torre Noetzel from Spains National Institute of Aerospace Technology (INTA), co-researcher on the project.



The scientist explains that this labor, published in the journal Astrobiology, forms part of an experiment known as the Lichens and Fungi Experiment (LIFE), "with which we have studied the fate or destiny of various communities of lithic organisms during a long-cycle voyage into space on the EXPOSE-E platform."



Researchers from the LIFE experiment, coordinated from Italy by Professor Silvano Onofri from the University of Tuscany, have also studied two species of lichens (Rhizocarpon geographicum and Xanthoria elegans) which can withstand extreme high-mountain environments. These have been gathered from the Sierra de Gredos (Avila, Spain) and the Alps (Austria), with half of the specimens also being exposed to Martian conditions.



Another anger of samples (both lichens and fungi) was subjected to an extreme space environment (with temperature fluctuations of between -21.5 and +59.6 C, galactic-cosmic radiation of up to 190 megagrays, and a vacuum of between 10-7 to 10-4 pascals). The effect of the impact of ultra-violet extraterrestrial radiation on half of the samples was also examined.



After the year-and-a-half-long voyage, and the beginning of the experiment on Earth, the two species of lichens exposed to Mars showed double the metabolic activity of those that had been subjected to space conditions, even reaching 80% more in the case of the species Xanthoria elegans.



The results showed subdued photosynthetic activity or viability in the lichens exposed to the harsh conditions of space (2.5% of samples), similar to that presented by the fungal cells (4.11%). In this space environment, 35% of fungal cells were also seen to have kept their membranes intact, a further premonition of the resistance of Antarctic fungi.



The Daily Galaxy via FECYT - Spanish Foundation for Science & Technology



Image credits: NASA and nsf.gov





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 Post subject: Citing Bin Laden raid, US Special Forces testing DNA scanner
PostPosted: Sat Jan 30, 2016 8:56 am 
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Citing Bin Laden raid, US Special Forces testing DNA scanners for juicy missions

Officials at US Special Operations Command said they were testing rapid DNA scanners for use in sensitive overseas missions, citing DNA identification of Osama Bin Laden in the 2011 raid as a model for future targeted operations.
Read Full Article at RT.com

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 Post subject: For little girl born without a jaw, doctors create one
PostPosted: Sat Feb 27, 2016 2:44 am 
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A rare genetic syndrome caused life-threatening problems at birth, but now Lexi Melton is dancing her way through childhood




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 Post subject: "The Virus Planet" --Evolution of "Fossil&quo
PostPosted: Wed Mar 09, 2016 11:49 am 
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"The Virus Planet" --Evolution of "Fossil" Viruses Identified as Far Back as 30 Million Years Ago





Planet-Earth-in-Space






There are 10 billion trillion, trillion viruses inhabiting Planet Earth, which is more than the number of stars in the Universe -- stacked end to end, they would reach out 100,000 light years. Over millions of years, our ancestors have been picking up retroviruses (HIV is a retrovirus) that reproduce by taking their genetic material and inserting it into our own chromosomes. There are probably about 100,000 elements in the human genome that you can trace to a virus ancestor. They make up about 8 percent of our genome, and genes that encode proteins only make up 1.2 percent of our genome making us more virus than human.



Now, researchers from Boston College, have revealed the global broadcast of an ancient group of retroviruses that affected about 28 of 50 modern mammals ancestors some 15 to 30 million years ago. HIV retrovirus and DNA shown below.



849901565-viral-replication-enzyme-integration-retrovirus





"Viruses have been with us for billions of years, and exist everywhere that life is found. They therefore have a important impact on the ecology and evolution of all organisms, from bacteria to humans," says Welkin Johnson, professor of biology at Boston College where his team carried out the research.



"Unfortunately, viruses do not abandon fossils behind, meaning we know very little about how they originate and evolve. Over the course of millions of years, however, viral genetic sequences accumulate in the DNA genomes of living organisms, including humans, and can serve as molecular fossils for exploring the natural history of viruses and their hosts.



Retroviruses are abundant in aspect and include human immunodeficiency viruses (HIV-1 and -2) and human T-cell leukemia viruses. The scientists findings on a obvious group of these viruses called ERV-Fc, to be published in the journal eLife, show that they affected a wide anger of hosts, including species as diverse as carnivores, rodents, and primates.



The distribution of ERV-Fc among these ancient mammals suggests the viruses broadcast to every continent except Antarctica and Australia, and that they jumped from one species to another more than 20 times.



The study also places the origins of ERV-Fc at least as far back as the beginning of the Oligocene epoch, a period of dramatic global change marked partly by climatic cooling that led to the Ice Ages. Vast expanses of grasslands emerged around this time, along with large mammals as the worlds predominate fauna.



Using such "fossil" remnants, the team sought to uncover the natural history of ERV-Fc. They were especially curious to know where and when these pathogens were found in the ancient world, which species they infected, and how they adapted to their mammalian hosts.



To do this, they first performed an exhaustive search of mammalian genome sequence databases for ERV-Fc loci and then compared the recovered sequences. For each genome with sufficient ERV-Fc sequence, they reconstructed the sequences of proteins representing the virus that colonized the ancestors of that fastidious species. These sequences were then used to infer the natural history and evolutionary relationships of ERV-Fc-related viruses.



The studies also allowed the team to pinpoint patterns of evolutionary change in the genes of these viruses, reflecting their adaptation to different kinds of mammalian hosts.



Perhaps most interestingly, the researchers found that these viruses often exchanged genes with each other and with other viruses, suggesting that genetic recombination played a important role in their evolutionary success.



"Mammalian genomes contain hundreds of thousands of ancient viral fossils similar to ERV-Fc," says proceed author William E. Diehl from the University of Massachusetts, who conducted the study while a post-doctoral researcher at Boston College.



"The dare will now be to use ancient viral sequences for looking back in time, which may prove insightful for predicting the long-term consequences of newly emerging viral infections. For example, we could potentially assess the impact of HIV on human health 30 million years from now. The method will allow us to better understand when and why new viruses emerge and how long-term contact with them impacts the evolution of host organisms."



The Daily Galaxy via ELIFE




Image credit: HIV image, with thanks toframepool.com; earth top of page with thanks tohdwallpaperup







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 Post subject: DNA tests reveal twins have two different fathers
PostPosted: Thu Mar 10, 2016 6:57 am 
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Experts explain how the rare event can occur, and say it may be more common than we ponder




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 Post subject: Suspected ISIS bomb-maker reportedly arrested in Brussels
PostPosted: Thu Mar 24, 2016 1:05 am 
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Najim Laachraoui, whose DNA was found on Paris bombs, was reportedly seen with suicide bombers in Brussels




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 Post subject: Paris bombmaker IDd as Brussels airport suicide bomber
PostPosted: Thu Mar 24, 2016 4:18 am 
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DNA links Najim Laachraoui to Brussels bombing and explosives used by suicide bombers in deadly Paris attacks




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 Post subject: Life In the Universe --"Precursor Molecules to DNA Coul
PostPosted: Sat Apr 09, 2016 9:38 pm 
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Life In the Universe --"Precursor Molecules to DNA Could Have Been Delivered Millions of Years Ago"





20150211110221-9





Observations by Researchers working at Frances National Center for Scientific Research (CNRS) support the idea that some of the molecules crucial to the origins of life could have formed in interstellar ices, and were then delivered to Earth by comets or meteors. The findings also hint that the genetic material of any life on other planets could potentially be based around different sugars.



We did not only detect ribose, but many other sugar molecules, says Uwe Meierhenrich, the studys direct author. [This] does not necessarily hint to RNA that preceded DNA and evolved from ribose. Alternative nucleotide precursors might have played their role in chemical evolution as well. The sugar that makes up the backbone of RNA ribose has been produced in experiments that recreate the icy conditions found on comets and asteroids. This discovery suggests that some of lifes precursor molecules could have been delivered to Earth millions of years ago.

"If all these molecules that are basic for life are everywhere out in space, the case gets a lot better that youll find life outside of Earth," said aid Andrew Mattioda, an astrochemist at NASA Ames Research Center, who was not involved with the study.



Ribose, a key component in RNA, only forms under certain conditions, and scientists say those conditions were not present on Earth before life evolved. Many molecular biologists are embracing the intruiging possibility, and strong evidence that the first life on Earth involved chemical multitasking by RNA --that RNA is a more ancient molecule than DNA and that before DNA evolved, an "RNA world" existed on Earth. Molecular subunits of RNA have been found in alien carbonaceous chondrite meteorites, or could have formed through chemical reactions in the early Earths oceans or primordial atmosphere paramount to the exciting new theory that RNA is our earliest molecular ancestor.



Researchers working at Frances National Centre for Scientific Research (CNRS) detected ribose, along with several other related sugars, during experiments that simulate the kinds of ices found in the core of comets. The cosmic ices are created by condensing a mixture of water, methanol and ammonia onto a supercooled surface at temperatures of -195°C and in pressures one billionth that of Earths atmosphere, whilst irradiating the ice with ultraviolet light to simulate bombardment with cosmic rays. Last year the group found that glyceraldehyde the smallest sugar molecule could be formed in similar tests.



Ribose and a diversity of structurally related sugar molecules are formed by a formose-type reaction in evolved pre-cometary ice analogues and detected by multidimensional gas chromatography. Ribose sugars make up the backbone of ribonucleic acid (RNA), which is what scientists ponder coded the genetic instructions for living things before the emergence of DNA. (C. Meinert, CNRS).





57076a1cb794e





We were wondering if even more complex and larger sugars can form in the ices, says Cornelia Meinert, one of the researchers involved. However, we did not expect the large diversity and high quantity.



The team observed a series of related sugars (aldopentoses) forming in the blend, including ribose, a key ingredient of the genetic polymer RNA. They suspect these sugars form via a process related to the formose reaction, in which complex sugars form from formaldehyde. Like in a classical formose reaction we detected sugar alcohols and sugar acids straight-chain and branched ones together with aldose and ketose sugars, says Meinert.



Ribose - a key molecule for the origin of life - detected in an interstellar ice analogue using multidimensional gas chromatography. Ribose sugars make up the backbone of ribonucleic acid (RNA) molecule, which is involved in protein synthesis in living cells. (C. Meinert, CNRS)





57076a4d8799a





Scott Sandford, an astrochemist at Nasas Ames Research Center in the US, agrees that it is possible life elsewhere made different biochemical choices, and adds that the chemical labyrinth the CNRS team oberved may give clues about the origins of life on Earth. Modern life is very efficient it uses RNA and DNA but the original versions of proto-life almost certainly didnt, he says. Some of these other sugars that modern life doesnt use may have actually played key roles back in the beginning.



Next, Meierhenrich says, the team want to explore other questions such as the chirality of ribose. We would like to understand the excuse for which d-ribose is used in DNA instead of l-ribose, he says. We assume that the excuse for this symmetry-breaking event can be found in interstellar space.



Refernces: C Meinert et al, Science, 2016, 352, 6282 (DOI: 10.1126/science.aad8137) and P de Marcellus et al, Proc. Natl. Acad. Sci. USA, 2015, 112, 4 (DOI: 10.1073/pnas.1418602112)



The Daily Galaxy via Science, http://www.rsc.org/chemistryworld/, and Los Angeles Times





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