Science  03 May 2013:
Vol. 340, Issue 6132, pp. 532

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  1. New Liver Hormone to Treat Diabetes?

    Beta test.

    Betatrophin prompts mouse pancreatic β cells (green) to replicate.


    A hormone in mice prompts the rodents to boost their production of pancreatic β cells—the ones that make insulin and are missing or not productive enough in patients with diabetes. The hormone, called betatrophin, is made by people as well; if the effect in the human pancreas is similar, betatrophin could be a new therapy for diabetes, the researchers say.

    Insulin helps cells take up glucose, a key cellular energy source. Many patients with diabetes inject themselves with insulin to make up for what the pancreas can't produce.

    While studying how a healthy pancreas produces β cells, cell biologists Douglas Melton, Peng Yi, and Ji-Sun Park at Harvard University identified a gene activated in the liver and fat tissues of mice. The gene codes for a protein excreted by cells, suggesting that it might be a hormone. They called it betatrophin.

    When the researchers injected copies of the betatrophin gene into the livers of normal mice, the animals' pancreases made as much as 30 times more β cells than usual, the team reported online on 25 April in Cell. After a week, the injected mice had more than twice the number of β cells as animals that didn't get the extra genes.

  2. Gene Swap Helps Bird Flu Spread Between Mammals

    Bird queue.

    A chicken gets a shot of H5N1 vaccine.


    A simple gene swap can make the dangerous bird flu strain H5N1 transmissible between mammals, finds a paper published by Science this week.

    H5N1 can infect humans in contact with infected birds, but does not spread efficiently between people. A team led by Chen Hualan at the Harbin Veterinary Research Institute in China wanted to know if that might change if H5N1 picks up genes from H1N1, a human flu strain, when the two infect the same host. They created 127 hybrids of the two viruses and tested which would spread from one guinea pig to another via respiratory droplets. H5N1 needed to borrow only one gene from H1N1, they found, to efficiently spread between the guinea pigs. A similar study published last month in PLOS ONE by Ron Fouchier's group at Erasmus MC in Rotterdam, the Netherlands, found that these gene swaps alone didn't make the virus airborne between ferrets, another animal model for flu.

    Virologist Simon Wain-Hobson of the Pasteur Institute in Paris says the study is a "super piece of work" scientifically, but also calls it "very dangerous" because the virus could escape from the lab, and the paper could help wannabe bioterrorists.