NATUREVol 460|27|Vol August 460|27 2009 August 2009 RESEARCH HIGHLIGHTS Paul Rothemund of the California PHYSICS — molecules that prevent translation of Institute of Technology in Pasadena, messenger RNAs into proteins — can Gregory Wallraff of the IBM Almaden Trip the light magnetic stimulate flowering independently of Research Center in San Jose, California, and Science 325, 973–976 (2009) daylight cues. their colleagues now show that DNA, folded Researchers have coaxed the tiny particles They find that levels of microRNA-156 origami-style into triangles measuring 127 known as quantum dots to change their decline as the plant ages, parallelling a rise nanometres on each side, can slot neatly into magnetic properties simply by shining light in expression of the genes it seems to silence. matching depressions carved onto a silica on them. The finding is another development The products of these genes, called SPLs, set surface. in the quest to produce ‘spintronic’ devices off floral development. In principle, each chunk of DNA origami that rely on particles’ spin states, rather than can be attached to an individual molecule such their charge, to convey information. GEOSCIENCE as a conducting nanowire or a fluorescent By adding manganese to a chemical protein. As a result, these structures offer a suspension, or colloid, of cadmium Ground down way to control the positioning and orientation selenide quantum dots, Daniel Gamelin Nature Geosci. doi:10.1038/ngeo616 (2009) of single molecules using straightforward at the University of Washington in Glaciers are often said to be better than rivers lithographic techniques. Seattle and his co-workers were able to at eroding the land, in part because of the manipulate the particles’ magnetism in dramatic landscapes they leave behind. But BIOLOGY new ways. Earlier work had had to be done Michele Koppes of the University of British at ultracold temperatures; the colloidal Columbia in Vancouver, Canada, and David Following in the wake suspension permitted the particles to Montgomery at the University of Washington Phys. Rev. Lett. 103, 078102 (2009) power up strong magnetic fields, retaining in Seattle challenge this belief. Fish can sense subtle differences in water magnetic signatures even at room pressure and velocity using the lateral line, temperature. a collection of sense organs that run the The researchers say that future length of their bodies. So far, most research steps might include incorporating into this capability has been limited to the colloids into nanoparticle sensing of simple oscillating objects. Jan- manufacturing technologies to see Moritz Franosch of the Technical University what other effects occur. of Munich in Germany and his colleagues now show how fish detect more complex PLANT BIOLOGY disturbances — the orientation of ring- shaped vortices left in the wake of other The other garden path fishes. Cell 138, 738–749 (2009) The authors modelled the stimulus There is more than one way to expected from a vortex ring passing a fish’s flower. In the thale cress, Arabidopsis By compiling global data on erosion rates lateral line and compared this with recorded thaliana, the well characterized FT gene from glacial and non-glacial environments, neuronal responses from a fish fixed in encodes a pro-flowering protein that travels they show that both ice and water flows can place and subjected to passing vortices. from leaf to shoot in response to changes in erode rock at up to 10 millimetres per year in The recordings fit the model’s predictions. day length. areas of rapid tectonic uplift. Information on the orientation of vortices Now, Detlef Weigel and his colleagues at It seems that tectonics controls erosion should allow fish to track the movement of the Max Planck Institute for Developmental rates from both rivers and glaciers, they PHOTOS E. WELTY/AURORA other animals — and perhaps a meal — the Biology in Tübingen, Germany, show that say, and claims that glaciers erode faster are authors argue. another pathway regulated by microRNAs largely explained by incomplete data. JOURNAL CLUB cardiovascular disease is still on way (K. Bersell et al. Cell 138, have not only plenty of neuregulin, the up worldwide and, not unlike 257–270; 2009). but also more heart muscle Paul Riley swine flu, is a true pandemic that They simply asked whether cells with one nucleus instead University College London respects no borders. As a result, or not existing heart muscle can of two, because only the former A molecular cardiologist looks and for some time now, I and be instructed to divide and make responded to the growth factor. into getting to the heart of his others have been asking how we more of the same. Apparently it Unfortunately, this presents inner fish. might become more newt-like or can, with the help of the epidermal something of a conundrum fish-like and repair our own hearts growth factor neuregulin (famed where mammals are concerned. Newts do it, fish do it, but sadly after a heart attack. for its role in the nervous system), Mammalian heart-muscle cells humans and other mammals We have favoured looking at and its Erb4 receptor. While generally become binuclear cannot repair or regenerate small resident progenitor cells under the influence of neuregulin, shortly after birth. Thus, for a damaged heart tissue as adults. which, when stimulated, might some mature heart cells in mice complete fix, we are left heading Despite the modern-day make new heart muscle and blood disassemble their scaffold, back in the direction of the drawing promotion of healthier lifestyles vessels. But a study by Bernhard re-enter the cell cycle, divide and board. (such as bans on smoking in public Kühn and his colleagues at the regenerate injured muscle. places and pro-fitness campaigns Children’s Hospital Boston in Of course, the devil is in the Discuss this paper at http://blogs. in the run-up to London 2012), Massachusetts shows us another detail: the trick, it seems, is to nature.com/nature/journalclub 1061 © 2009 Macmillan Publishers Limited. All rights reserved.