Flies Don't Buzz About Aimlessly:
Have you ever stopped to wonder how a fruit fly is able to locate and blissfully drown in your wine glass on a warm summer evening, especially since its flight path seems to be so erratic? Mark Frye at the University of California and Andy Reynolds at Rothamsted Research in the United Kingdom have been pondering this very question. Fruit flies explore their environment using a series of straight flight paths punctuated by rapid 90° body-saccades. Some of these manoeuvres avoid obstacles in their path. But many others seem to appear spontaneously. Are the spontaneous flight paths really random, do they serve any real purpose?
Stronger than steel and more elastic than rubber: spider silk is unsurpassed in its expandability, resistance to tearing, and toughness. Spider silk would be an ideal material for a large variety of medical and technical applications, and researchers are thus interested in learning the spiders' secrets and imitating their technique.
Right Angles Are All Wrong For Tree Frog Adhesion:
Tree frogs have the unique ability to stick to smooth surfaces even when they are tilted well beyond the vertical - some small tree frogs can even adhere when completely upside down. Conversely when walking or jumping they can detach their toe pads easily. Researchers from the University of Glasgow presented insights into how this fascinating ability is controlled at the Society for Experimental Biology's Annual Meeting in Glasgow, UK. "The toe pads of tree frogs are coated with a thin mucus which adhere to surfaces by wet adhesion, like wet tissue paper sticking to glass. The process by which they detach their toe pads is called peeling and is akin to us removing a sticking plaster from ourselves," explains Dr Jon Barnes, head of the research group, "We were keen to understand why a tree frog on an overhanging surface didn't simply peel off rather than adhere."
Bacteria Communication: Counting Heads or Measuring Space?:
Bacteria can "talk" to each other: by using signal substances they inform their neighbours as to whether or not it is worth switching certain genes on or off. This communication between bacterial cells is essential for the adaptation to changing environments and for the survival. What exactly do bacteria learn from the signal substances? There have been two theories: the release of signal substances is understood to be either a cooperative strategy to determine the cell density (quorum sensing) or - alternatively - a non-cooperative strategy in which the signal substance is only used to determine the dimensions of the space surrounding the cell (diffusion sensing). However, both theories have not been shown to work under natural conditions, which usually are much more complex than those in laboratory.
Mutualism: Fungus Found That Needs Bacteria In Cytoplasm To Reproduce:
Endosymbiotic relationships--in which one organism lives within another--are striking examples of mutualism, and can often significantly shape the biology of the participant species. In new findings that highlight the extent to which a host organism can become dependent on its internal symbiont, researchers have identified a case in which the reproduction of a fungus has become dependent on bacteria that live within its cytoplasm. The findings, which appear online in the journal Current Biology on April 5th, are reported by Laila Partida and Christian Hertweck from the Leibniz Institute for Natural Product Research and Infection Biology in Jena, Germany.
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