Science  28 Sep 2012:
Vol. 337, Issue 6102, pp. 1590

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  1. Bacterial Cell Death Leads to New Art Form


    Ridges in biofilms grown on petri dishes have sparked a fundamental discovery in how cells self-assemble into three-dimensional structures. Gürol Süel, a systems biologist at the University of California, San Diego, wanted to learn more about the coupling of physical and biological factors determining an organism's shape, so he turned to one of the simplest living systems he could think of: the biofilms of the soil bacterium Bacillus subtilis, which develop wrinkles on their surfaces. Before the wrinkles form, discrete patches of cells in the biofilm die, laying down the wrinkling pattern, Süel and his colleagues reported online this week in the Proceedings of the National Academy of Sciences. Harnessing their new insight that overcrowding seems to lead to cell death, the researchers plated out cells in different densities to form customized biofilms. More than fanciful, the technique may one day prove useful in tissue engineering and in making biofilms that produce useful chemicals.

  2. Mouse Saves Its Skin By Shedding It


    Known for their stiff hairs, African spiny mice now have a new claim to fame: They can survive losing 60% of the skin off their backs. Their weak skin rips off in the clutches of attackers, enabling the mice to scoot free. Rather than scarring over, the skin quickly grows back, regenerating hair follicles and glands, something most mammals can't do. Developmental biologist Ashley Seifert of the University of Florida in Gainesville and colleagues compared lab mice skin to spiny mice skin and found the African rodent's skin tears much more readily, possibly because it has larger hair follicles. Their wounds also heal much quicker, with much less scarring, the researchers reported on 26 September in Nature. Only lizards are known to employ a similar response, but in their case, just the top layer sloughs off. The mice lose their entire skin, baring muscles underneath, so replacing it is a much bigger task. “It's a nice example that shows the maximum capacity of what the mammalian skin can do in terms of healing,” says Elly Tanaka, a developmental biologist at the Technical University of Dresden in Germany.