By Melody Schreiber February 23 at 2:57 PM Four years ago, Candra Alston and her 3-year-old daughter, Malaysia Boykin, were murdered inside their South Carolina apartment. Police in Columbia collected DNA at the scene, but the investigation stalled. Prime-time crime shows would have you believe DNA samples can convict the guilty and clear the innocent, but real life is more complicated. In order to find an assailant, the DNA has to match either a previous offender in the FBIs CODIS database or a sample from one of the victims acquaintances. When it doesnt, the investigation hits a wall. In the South Carolina case, police gathered 150 DNA samples and conducted 200 interviews with likely suspects and still nothing. Now the Columbia police are experimenting with a new technology that uses tiny amounts of DNA to create a computer-generated illustration of their suspect. Snapshot, a program developed by a Reston, Va., company called Parabon NanoLabs, goes beyond simply listing physical attributes eye color, hair color, ethnicity and facial features and creates a 3-D image of what the killer might look like. The police in South Carolina hope that publicly releasing the suspects image and description will bring up fresh leads in … Continue reading →

Gerald Herbert/AP Photo Robyn Thompson, an associate scientist with InnoGenomics Technologies, works with DNA samples in their laboratory at the New Orleans BioInnovation Center in New Orleans, Thursday, Sept. 29, 2011. Four years ago, Candra Alston and her 3-year-old daughter, Malaysia Boykin, were murdered inside their South Carolina apartment. Police in Columbia collected DNA at the scene, but the investigation stalled. Prime-time crime shows would have you believe DNA samples can convict the guilty and clear the innocent, but real life is more complicated. In order to find an assailant, the DNA has to match either a previous offender in the FBIs CODIS database or a sample from one of the victims acquaintances. When it doesnt, the investigation hits a wall. In the South Carolina case, police gathered 150 DNA samples and conducted 200 interviews with likely suspects and still nothing. Now the Columbia police are experimenting with a new technology that uses tiny amounts of DNA to create a computer-generated illustration of their suspect. Snapshot, a program developed by a Reston, Va., company called Parabon NanoLabs, goes beyond simply listing physical attributes eye color, hair color, ethnicity and facial features and creates a 3-D image of what the killer … Continue reading →

The New York Times; Images and renderings by Mark D. Shriver/Penn State University Individuals' faces compared with Dr. Shriver's computer-generated DNA predictions. See more comparisons. There were no known eyewitnesses to the murder of a young woman and her 3-year-old daughter four years ago. No security cameras caught a figure coming or going. Nonetheless, the police in Columbia, S.C., last month released a sketch of a possible suspect. Rather than an artists rendering based on witness descriptions, the face was generated by a computer relying solely on DNA found at the scene of the crime. It may be the first time a suspects face has been put before the public in this way, but it will not be the last. Investigators are increasingly able to determine the physical characteristics of crime suspects from the DNA they leave behind, providing what could become a powerful new tool for law enforcement. Already genetic sleuths can determine a suspects eye and hair color fairly accurately. It is also possible, or might soon be, to predict skin color, freckling, baldness, hair curliness, tooth shape and age. Computers may eventually be able to match faces generated from DNA to those in a database of mug … Continue reading →

A study that examined 17 million mutations in the genomes of 650 cancer patients concludes that large differences in mutation rates across the human genome are caused by the DNA repair machinery. 'DNA spellchecker' is preferentially directed towards more important parts of chromosomes that contain key genes. The study illustrates how data from medical sequencing projects can answer basic questions about how cells work. The work, performed by two scientists from the EMBL-CRG Systems Biology Unit in Barcelona, will be published online in Nature on 23rd February. Copying the large book that it is our genome without mistakes every time a cell divides is a difficult job. Luckily, our cells are well-equipped to proof-read and repair DNA mistakes. Now, two scientists at the Centre for Genomic Regulation in Barcelona have published a study showing that mistakes in different parts of our genome are not equally well corrected. This means that some of our genes are more likely to mutate and so contribute to disease than others. The scientists analysed 17 million 'single nucleotide variants' -- mutations in just one nucleotide (letter) of the DNA sequence -- by examining 650 human tumours from different tissues. These were 'somatic' mutations, meaning they … Continue reading →

Injecting mouse embryos with a human DNA sequence leads to a marked increase in brain size -- and may provide insights into Alzheimer's. Mouse embryo injected with HARE5. Gene actvity is stained blue. Duke University/Silver Lab The human genetic code is very similar to the genetic code of our closest living relative -- the chimpanzee -- sharing around 95 percent. Of all the differences, however, one is particularly interesting: the human brain is a lot bigger than the brain of a chimp. The brain of a chimp weighs, on average, 384 grams, whereas a human brain is more than triple that, at 1,352 grams. Although it's not brain size alone that accounts for human intelligence, it certainly plays a pretty important role -- and now, researchers at Duke University have identified the DNA sequence that may be responsible for that particular evolutionary deviation. How? By using mouse embryos. The DNA sequence, called HARE5, is a gene activity regulator shown to markedly increase the size of a mouse embryo's brain when injected into the embryo. Compared to a mouse embryo injected with chimpanzee HARE5, the mouse embryo's brain grew 12 percent larger. "I think we've just scratched the surface, in terms … Continue reading →

Contact Information Available for logged-in reporters only Newswise Researchers at McGill University have developed a new, low-cost method to build DNA nanotubes block by block a breakthrough that could help pave the way for scaffolds made from DNA strands to be used in applications such as optical and electronic devices or smart drug-delivery systems. Many researchers, including the McGill team, have previously constructed nanotubes using a method that relies on spontaneous assembly of DNA in solution. The new technique, reported today in Nature Chemistry, promises to yield fewer structural flaws than the spontaneous-assembly method. The building-block approach also makes it possible to better control the size and patterns of the DNA structures, the scientists report. Just like a Tetris game, where we manipulate the game pieces with the aim of creating a horizontal line of several blocks, we can now build long nanotubes block by block, said Amani Hariri, a PhD student in McGills Department of Chemistry and lead author of the study. By using a fluorescence microscope we can further visualize the formation of the tubes at each stage of assembly, as each block is tagged with a fluorescent compound that serves as a beacon. We can then count … Continue reading →