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15 December 2012 | NewScientist | 19 NOBODY’S perfect. Even healthy people have at least 400 faulty genes, including a few that could lead to life-threatening diseases. Chris Tyler-Smith of the Wellcome Trust Sanger Institute in Cambridge, UK, and his colleagues scanned the genomes of 179 healthy men and women from the US, China, Japan and Nigeria. They compared them with a library of 50,000 mutations known to cause disease. The team focused on mutations that are directly linked with a high risk of disease, and also mutations that damage proteins, but with unknown consequences. On average, people had 400 protein-damaging mutations and two or more high-risk mutations. “We can lose a surprising number of genes without any noticeable effects Shed that weight without eating less NEED to lose weight? Don’t bother with a crash diet: just cut down a little on the fat in what you eat. Confirmation that you can lose weight without eating less comes from a review of studies involving almost 74,000 people – none of whom were trying to lose weight. Lee Hooper at the University of East Anglia in Norwich, UK, and her colleagues reviewed 43 studies in which volunteers reduced their fat intake. Some swapped to low- fat versions of foods, while others changed their diet to reduce fat intake by an average of 7 per cent. In all but one study, low-fat groups saw a greater weight loss than people who ate either their usual foods or a healthier diet, such as one with more vegetables and fruit. On average, the groups eating less fat lost 1.6 kilograms (BMJ, doi.org/jxj). Across a population this could lead to a 3 per cent decrease in overall obesity- related mortality, Hooper says. Eye proteins detect a redder red than you’ve ever seen WE ALL see red every now and again, but imagine seeing red beyond red. The structure of a protein normally found in the human eye has been altered so that it absorbs a type of red light that we cannot normally see. This could, in theory, one day give us the ability to see reds that are currently invisible to us. Our colour vision depends on proteins that contain chromophores – chemicals which absorb different wavelengths of light. By engineering mutations within these proteins, Babak Borhan at Michigan State University (MSU) in East Lansing and his colleagues STEPHAN JOUHOFF/PLAINPICTURE IN BRIEF Deep down, we’re all faulty mutants on health,” says Tyler-Smith. And people can stay healthy despite high-risk mutations – such as a variant of the MYBPC3 gene that boosts heart-failure risk – perhaps because they take effect late in life, or are compensated for by other genes. Humans carry about 3 million mutations, says Tyler-Smith: the 400 “damaging” variants reflect a reassuringly tiny proportion of that total (American Journal of Human Genetics, doi.org/jxq). altered their structure. This in turn altered the electrostatic properties within the protein and changed the chromophores’ absorption spectrum. Natural chromophores have a maximum absorption of around 560 nanometres, but one of the team’s 11 modified chromophores was able to absorb red light with a wavelength of around 644 nm – tantalisingly close to infrared, which starts at about 750 nm (Science, doi.org/jxn). If these proteins were put in the eye we would be able to see red light that is invisible to us now, says James Geiger, also at MSU. But since objects reflect a mixture of light, the world would not necessarily look redder. “Something that looked white before would now look green with your new super red vision,” he says. SWADDLED in a cloud of dust and gas, a baby solar system 450 light years away offers one of the best peeks yet at what our sun may have looked like in its infancy. The star is surrounded by enough raw material to build at least seven Jupiter-sized planets. But it was unclear from previous studies whether the disc of debris swirling around developing star L1527 IRS was moving in the necessary way to spawn planets. John Tobin of the National Radio Astronomy Observatory in Charlottesville, Virginia, and colleagues found that the disc’s motion mirrors the way planets orbit stars, hinting that it has all the right moves for planet formation (Nature, doi.org/jxm). Baby star can make its own playmates
