Catálogo de publicaciones - revistas

<jats:p>Coevolution of a virus and a bacterium leads to the emergence of a key adaptive innovation.</jats:p>

<jats:p>Transmission of prions between species through both lymphoid and neural tissues has implications for public health and risk management.</jats:p>

<jats:p>Graphene oxide membranes can show unusually high water permeability, and diamond-like carbon membranes exhibited ultrafast permeation of organic solvents.</jats:p>

<jats:p>Could conscious perception reflect a memory process?</jats:p>

<jats:p>Structures of two–pore domain potassium channels reveal key differences from the more widely found tetrameric channels.</jats:p>

<jats:p>Light, Sight, and Rainbows, the IBI prize-winning module, provides questions for exploring simple atmospheric phenomena.</jats:p>

<jats:p> A monthly roundup of recent news and projects of <jats:italic>Science</jats:italic> 's publisher, the American Association for the Advancement of Science. </jats:p>

<jats:title>Centrosome Center Stage?</jats:title> <jats:p> The centrosome is a major organizer of the cytoskeleton in animal cells. The precise duplication of this organelle at each cell cycle ensures proper organization of the mitotic apparatus and chromosome segregation. However, centrosomes are dispensable for cell division during some stages of development in mouse and <jats:italic>Drosophila</jats:italic> . <jats:bold>Bornens</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="422" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1209037">422</jats:related-article> ) reviews the role of the centrosome in a variety of organisms and discusses how and why they can be dispensed with on occasion. In this vein, <jats:bold> Azimzadeh <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="461" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1214457">461</jats:related-article> , published online 5 January) now demonstrate that centrosomes in Planarian flatworms, best known for their remarkable regeneration abilities, are completely dispensable for both cell division and development. </jats:p>

<jats:p>A plasmonic antenna array is used to control the propagation of a light beam across an interface.</jats:p>

<jats:title>Natural Selection Caught in the Act</jats:title> <jats:p> Understanding how new functions evolve has been of long-standing interest. However, the number of mutations needed to evolve a key innovation is rarely known, or whether other sets of mutations would also suffice, whether the intermediate steps are driven by natural selection, or how contingent the outcome is on steps along the way. <jats:bold> Meyer <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="428" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1214449">428</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6067" page="410" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1217807">Thompson</jats:related-article> </jats:bold> ) answer these questions for a case in which phage lambda evolved the ability to infect its host <jats:italic>Escherichia coli</jats:italic> through a novel receptor. This shift required four mutations, which accumulated under natural selection in concert with coevolution of the host. However, when <jats:bold> Tenaillon <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="457" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1212986">457</jats:related-article> ) exposed 115 lines of <jats:italic>E. coli</jats:italic> to high temperature and sequenced them, adaptation occurred through many different genetic paths, showing parallelism at the level of genes and interacting protein complexes, but only rarely at the nucleotide level. Thus, epistasis—nonadditive genetic interaction—is likely to play an important part in the process of adaptation to this environment. </jats:p>