Catálogo de publicaciones - revistas

<jats:title>Bee Adventurous</jats:title> <jats:p> Individuals differ in their behavior, sometimes in consistent ways. For example, some people may seek out new experiences, while others prefer to stick with what they know. This is true in bees as well, where some workers take on the dangerous, novelty-seeking task of scouting more often than others. <jats:bold> Liang <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="1225" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1213962">1225</jats:related-article> ) found that bees that display such scouting behavior not only tend to scout in multiple contexts (both foraging and searching for nests) but also show differences in gene expression in their brains. Experimental manipulation of gene expression predictably changed scouting behavior. The molecular underpinnings of bee scouting behavior appear to be similar to those associated with novelty-seeking in vertebrate species, including humans. </jats:p>

<jats:title>A Toxic Barrel</jats:title> <jats:p> Many studies have suggested that oligomers are an important toxic species in amyloid diseases such as Alzheimer's disease. In an effort to better define these oligomers, <jats:bold> Laganowsky <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="1228" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1213151">1228</jats:related-article> ) identified a segment of the fibril-forming protein αB crystalline (ABC) that forms both amyloid fibrils and a relatively stable oligomer. ABC oligomers were toxic in a cell viability assay and were recognized by an amyloid-oligomer–specific antibody. A crystal structure of the oligomers showed that six peptides formed an antiparallel barrel termed a cylindrin. Amyloid oligomers are likely to be structurally polymorphic, but cylindrin-like assemblies offer a model for these elusive structures. </jats:p>

<jats:title>A Time and a Place</jats:title> <jats:p> The onset of morphogenetic cell shape changes is thought to be triggered by initiation of actomyosin contractions. <jats:bold> Roh-Johnson <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="1232" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1217869">1232</jats:related-article> , published online 9 February; see the Perspective by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6073" page="1181" related-article-type="in-this-publication" vol="335" xlink:href="10.1126/science.1220388"> <jats:bold>Razzell and Martin</jats:bold> </jats:related-article> ) have now discovered in both <jats:italic>Caenorhabditis elegans</jats:italic> and <jats:italic>Drosophila</jats:italic> embryos that the actomyosin contractions driving morphogenesis run constitutively, only being engaged to trigger cell shape changes at a specific time during development. </jats:p>

<jats:title>Nucleosome Maps and Mutation</jats:title> <jats:p> Understanding the processes governing the accumulation of mutations impacts many facets of evolutionary biology. Combining data from a mutation accumulation experiment in a DNA repair-deficient yeast strain with genome-wide substitution, <jats:bold> Chen <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="1235" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1217580">1235</jats:related-article> ) demonstrate that C/G to T/A changes are more likely to affect regions that are nucleosome-free. Furthermore, a similar pattern was seen when comparative analyses were performed among yeast species and in lines of Medaka fish and nematodes. The results are consistent with a model in which DNA bound by nucleosomes is protected against mutations caused by DNA damage. </jats:p>

<jats:title>Neurogenesis and Pattern Integration</jats:title> <jats:p> The adult hippocampus continuously produces new neurons that integrate into the dentate gyrus network and contribute to information processing. What features of adult-born neurons are important for information processing in the dentate gyrus? <jats:bold> Marín-Burgin <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="1238" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1214956">1238</jats:related-article> , published online 26 January; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6073" page="1175" related-article-type="in-this-issue" vol="335" xlink:href="10.1126/science.1219304">Kempermann</jats:related-article> </jats:bold> ) labeled newborn neurons and used sophisticated electrophysiological and imaging techniques to show that immature neurons integrated a broader variety of synaptic inputs from different origins compared with mature neurons, which were highly input specific. Thus, immature neurons may represent a population of integrators that are broadly tuned during a transient period and may encode most features of incoming information. After maturation, new granule cells display a high activation threshold and input specificity to become good pattern separators. </jats:p>

<jats:p>The show includes magnetic anomalies on the Moon, nuclear fuel in a reactor accident, light adaptations in the deep sea, and more.</jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>