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Gene therapy restores sight in people with eye disease
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Alex Wild
MINIONS, don’t you dare have sex. Queen insects produce a chemical that stops their workers breeding. The pheromone is 145 million years old, and was probably inherited from the insects’ common ancestor. Among insects like honeybees, the queens do all the breeding and the workers are sterile. Because the workers are closely related, they can preserve their genes by working for the good of the nest. Annette Van Oystaeyen of the Catholic University of Leuven (KUL) in Belgium and her colleagues have now found out how the queens maintain the system. They examined common wasps, desert ants and buff-tailed bumblebees, and found that all the queens made large quantities of similar long-chained hydrocarbons. When the team exposed workers to a synthetic version of these scent compounds, the workers’ ovaries didn’t develop, even though no queen was nearby (Science, doi.org/q26). Ants, wasps and bumblebees all belong to the same insect family. That suggests they all inherited the pheromone from their common ancestor, which lived in the early Cretaceous period. However, it is still unclear how or why the pheromone evolved. Van Oystaeyen says it may have been a signal of fertility that attracted male mates, or deterred other females.
Gene tinkering restores vision in people with rare eye disease THE world now looks a lot sharper for Jonathan Wyatt. The 65-yearold has gene therapy to thank for lifting the visual fog caused by a rare inherited eye disease. “I would look at someone and all I could see was blancmange. Now, I can see faces,” says Wyatt. He was one of six people with choroideremia to be treated at least six months ago. The next day, he could see the buttons on a phone. “I hadn’t been able to read digits on a mobile for five years,” he says. The results suggest that the
treatment can halt the descent into blindness and boost failing sight. All six people saw improvements. Wyatt was treated first, two years ago, so the benefits seem to last at least that long (The Lancet, doi.org/q2d). A fault in the CHM gene causes choroideremia, in which cells in the retina stop working and slowly die, leading to blindness. When he was in his twenties, Wyatt was told that he would be blind by 50. Gene therapy uses a virus to insert a functioning copy of a gene into defective cells. In principle,
it could be used to treat many genetic conditions. Robert MacLaren of the University of Oxford and his colleagues injected a virus with a corrective copy of the CHM gene into the retinas of people with choroideremia. Their results could be relevant to the treatment of a more common cause of blindness, age-related macular degeneration, which is caused by a host of faulty genes. MacLaren is also hopeful of stopping choroideremia before significant loss of vision. Stormwlf/Flickr
Smelly queens ban worker sex
Mimic electricity for speedier networks NEED to rapidly transport goods across a country or speed the flow of web traffic? Take this souped-up algorithm for a test drive. Finding the optimal route for moving stuff through a network is called the max flow problem, because you want the highest quantity flowing as quickly as possible. But the paths between nodes can have different capacities, like a wide highway versus a small country road. A max flow algorithm has to consider both the volume of flow and the route it can take. Existing algorithms send flow through one path at a time, trying to find the best via trial and error. This gets trickier as the network gets larger. A team led by Jonathan Kelner at MIT found a way to speed things up by representing paths as electrical resistors and flow as current. This allows the algorithm to use linear equations, which are faster to solve, so it can test multiple routes at once. The latest version works no matter how large the network (arxiv.org/abs/1304.2338). It identifies clusters and bottlenecks first, allowing the algorithm to focus on difficult areas and speed up the solution.
Lucky strike helps probe ball lightning GOODNESS gracious, a great ball of lightning seen in China could help solve the mystery of how these glowing orbs form. Anecdotes about ball lightning abound, but the phenomenon has been hard to study as their appearance is unpredictable – and when they do materialise, they last for mere seconds. Proposed explanations range from electrically charged meteorites to hallucinations. In 2012, Jianyong Cen and his colleagues at Northwestern Normal University in Lanzhou, China, were observing a thunderstorm in Qinghai
with cameras and spectrographs. By chance, they recorded a lightning strike that sent up a 5-metre-wide glowing ball, which vanished after 1.6 seconds. Their analysis showed the key elements in the ball were silicon, iron and calcium. This supports a theory that lightning strikes vaporise silicon oxide in dirt. If there is carbon in the soil, it will steal the silicon’s oxygen, creating silicon vapour. The planet’s oxygen-rich atmosphere rapidly re-oxidises the vapour, making the orb glow briefly. The findings will appear in Physical Review Letters.
25 January 2014 | NewScientist | 17
Alex Wild
MINIONS, don’t you dare have sex. Queen insects produce a chemical that stops their workers breeding. The pheromone is 145 million years old, and was probably inherited from the insects’ common ancestor. Among insects like honeybees, the queens do all the breeding and the workers are sterile. Because the workers are closely related, they can preserve their genes by working for the good of the nest. Annette Van Oystaeyen of the Catholic University of Leuven (KUL) in Belgium and her colleagues have now found out how the queens maintain the system. They examined common wasps, desert ants and buff-tailed bumblebees, and found that all the queens made large quantities of similar long-chained hydrocarbons. When the team exposed workers to a synthetic version of these scent compounds, the workers’ ovaries didn’t develop, even though no queen was nearby (Science, doi.org/q26). Ants, wasps and bumblebees all belong to the same insect family. That suggests they all inherited the pheromone from their common ancestor, which lived in the early Cretaceous period. However, it is still unclear how or why the pheromone evolved. Van Oystaeyen says it may have been a signal of fertility that attracted male mates, or deterred other females.
Gene tinkering restores vision in people with rare eye disease THE world now looks a lot sharper for Jonathan Wyatt. The 65-yearold has gene therapy to thank for lifting the visual fog caused by a rare inherited eye disease. “I would look at someone and all I could see was blancmange. Now, I can see faces,” says Wyatt. He was one of six people with choroideremia to be treated at least six months ago. The next day, he could see the buttons on a phone. “I hadn’t been able to read digits on a mobile for five years,” he says. The results suggest that the
treatment can halt the descent into blindness and boost failing sight. All six people saw improvements. Wyatt was treated first, two years ago, so the benefits seem to last at least that long (The Lancet, doi.org/q2d). A fault in the CHM gene causes choroideremia, in which cells in the retina stop working and slowly die, leading to blindness. When he was in his twenties, Wyatt was told that he would be blind by 50. Gene therapy uses a virus to insert a functioning copy of a gene into defective cells. In principle,
it could be used to treat many genetic conditions. Robert MacLaren of the University of Oxford and his colleagues injected a virus with a corrective copy of the CHM gene into the retinas of people with choroideremia. Their results could be relevant to the treatment of a more common cause of blindness, age-related macular degeneration, which is caused by a host of faulty genes. MacLaren is also hopeful of stopping choroideremia before significant loss of vision. Stormwlf/Flickr
Smelly queens ban worker sex
Mimic electricity for speedier networks NEED to rapidly transport goods across a country or speed the flow of web traffic? Take this souped-up algorithm for a test drive. Finding the optimal route for moving stuff through a network is called the max flow problem, because you want the highest quantity flowing as quickly as possible. But the paths between nodes can have different capacities, like a wide highway versus a small country road. A max flow algorithm has to consider both the volume of flow and the route it can take. Existing algorithms send flow through one path at a time, trying to find the best via trial and error. This gets trickier as the network gets larger. A team led by Jonathan Kelner at MIT found a way to speed things up by representing paths as electrical resistors and flow as current. This allows the algorithm to use linear equations, which are faster to solve, so it can test multiple routes at once. The latest version works no matter how large the network (arxiv.org/abs/1304.2338). It identifies clusters and bottlenecks first, allowing the algorithm to focus on difficult areas and speed up the solution.
Lucky strike helps probe ball lightning GOODNESS gracious, a great ball of lightning seen in China could help solve the mystery of how these glowing orbs form. Anecdotes about ball lightning abound, but the phenomenon has been hard to study as their appearance is unpredictable – and when they do materialise, they last for mere seconds. Proposed explanations range from electrically charged meteorites to hallucinations. In 2012, Jianyong Cen and his colleagues at Northwestern Normal University in Lanzhou, China, were observing a thunderstorm in Qinghai
with cameras and spectrographs. By chance, they recorded a lightning strike that sent up a 5-metre-wide glowing ball, which vanished after 1.6 seconds. Their analysis showed the key elements in the ball were silicon, iron and calcium. This supports a theory that lightning strikes vaporise silicon oxide in dirt. If there is carbon in the soil, it will steal the silicon’s oxygen, creating silicon vapour. The planet’s oxygen-rich atmosphere rapidly re-oxidises the vapour, making the orb glow briefly. The findings will appear in Physical Review Letters.
25 January 2014 | NewScientist | 17