When, in 2001, the human genome was sequenced for the first time, we were confronted by several surprises. One was the sheer lack of genes: where we had anticipated perhaps 100,000 there were actually as few as 20,000. A bigger surprise came from analysis of the genetic sequences, which revealed that these genes made up a mere 1.5 per cent of the genome. This is dwarfed by DNA deriving from viruses, which amounts to roughly 9 per cent.On top of that, huge chunks of the genome are made up of mysterious virus-like entities called retrotransposons, pieces of selfish DNA that appear to serve no function other than to make copies of themselves. These account for no less than 34 per cent of our genome. All in all, the virus-like components of the human genome amount to almost half of our DNA. This would once have been dismissed as mere "junk DNA", but we now know that some of it plays a critical role in our biology. As to the origins and function of the rest, we simply do not know...
Tag Archives | DNA
At Yahoo Tech:
The latest airport security trend is the backscatter x-ray machine, touted as a powerful way to virtually frisk a traveler for contraband without the embarassment of a strip search.
Though touted as completely safe because the level of radiation is so low, travelers have been nervous about the devices — and not just because it shows off a nice outline of their privates to the people manning the machines — but because they remain scared of the health problems they might propose.
Looks like a little healthy paranoia might have been a good thing. While the conventional wisdom has held that so-called “terahertz radiation,” upon which backscatter x-ray machines are based, is harmless because it doesn’t carry enough energy to do cellular or genetic damage, new research suggests that may be completely wrong.
Specifically, researchers have found that terahertz radiation may interfere directly with DNA. Although the force generated is small, the waves have been found to “unzip double-stranded DNA, creating bubbles in the double strand that could significantly interfere with processes such as gene expression and DNA replication.”
I’m not a doctor, but that just doesn’t sound good…
[continues at Yahoo Tech]
Reported on AFP via Yahoo News:
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Humans carry in their genome the relics of an animal virus that infected their forerunners at least 40 million years ago, according to research published by the British science journal Nature.The invader is called bornavirus, a brain-infecting pathogen that was first identified in 1970s. Scientists led by Keizo Tomonaga of Japan’s Osaka University compared the DNA of a range of mammals, including humans, apes, elephants, marsupials and rodents, to look for tell-tale signatures of bornavirus code.
In the human genome, the team found several bornavirus fragments but also in the form of two genes that may be functional, although what they do is unclear. Until now, the only viruses known to have been handed on in vertebrates were retroviruses, which work by hijacking cellular machinery in order to reproduce.
Retroviruses are effective in infiltrating the germline — the DNA of reproductive cells, which means their sequence, or part of it, is handed on to ensuing generations.
IRVINE, Calif. -- Jim Fallon recently made a disquieting discovery: A member of his family has some of the biological traits of a psychopathic killer. "These results will cause some problems at the next family party," he said, reviewing the data on his laptop in his backyard. Meanwhile, his wife, Diane, stood in the kitchen, using a knife to slice through a blood-red pepper. Dr. Fallon, 62 years old, is a neuroscientist who studies the biological basis of human behavior at the University of California's campus here. He has analyzed the brains of more than 70 murderers on behalf of psychiatric clinics or criminal defense lawyers. It's a young science. Because jailed killers rarely are permitted to take part in research trials, data linking genes and brain damage to violent crime are tentative and often disputed. "In terms of early factors, we know nothing about who becomes an adult psychopath," says Adrian Raine of the University of Pennsylvania, who applies neuroscience techniques to study the causes and cures of crime. Three years ago, as part of a personal project to assess his family's risk of developing Alzheimer's disease, Dr. Fallon collected brain scans and DNA samples from himself and seven relatives. At a barbecue soon thereafter, Dr. Fallon's mother casually mentioned something he had been unaware of: His late father's lineage was drenched in blood... [continues in the Wall Street Journal]
More than three-quarters of young black men are on system, watchdog says Britain has built the world's biggest DNA database without proper political debate and police routinely arrest people just to get their DNA profiles onto the system, the genetics watchdog said in a report on Tuesday. The Human Genetics Commission, which advises the government on the social, legal and ethical aspects of genetics, called for a review of the database and said new laws must be passed to govern its use. In a damning report, the commission said "function creep" had transformed the system from a DNA store for offenders into a database of suspects.Was on MSNBC via Reuters, also on USA Today
Joseph Shapiro reports for NPR:
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Last month, Matt Williams, an adjunct professor at the University of Akron, opened an e-mail from his bosses about the school’s new rules for hiring and was “absolutely blown away,” he says, “when I saw the reference to collecting DNA samples.”
The university was saying it could ask new workers for a DNA sample — to run background checks. But Williams knew his DNA could also be used to discover the most private of information about his health — like his genetic risk for cancer, heart disease or mental illness.
To Williams, who taught in the School of Communications, it was one more insult in the hard life of an adjunct professor. (He’s an officer in a national organization, New Faculty Majority, that advocates for adjunct professors.) He says adjuncts at the University of Akron sign new contracts from year to year, so he expected to be counted as a new worker the next time his contract came up.
George Orwell couldn’t have dreamed this up; from IT Pro:
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IBM said that experts from nanofabrication, microelectronics, physics and biology are working together to master a technique where a long DNA molecule passes through a three nanometer wide hole (a nanopore).
As the molecule passes through the nanopore one unit of DNA at a time, an electrical sensor can ‘read’ the DNA.
The challenge of the silicon-based ‘DNA Transistor’ would be to slow and control the motion of the DNA through the hole so the reader could decode what is inside it.
IBM claimed that if the project was successful it could make personalised genome analysis as cheap as $100 to $1,000, and compared it to the first ever sequencing done for the Human Genome Project, which cost $3 billion.