Catálogo de publicaciones - revistas

<jats:title>A diffuse cosmic glow is not primordial</jats:title> <jats:p> A cumulative map of all photons ever emitted by any star or galaxy is a highly desirable historical record of the universe's evolution. For this reason, cosmologists have sought to measure this diffuse distribution of light: the extragalactic background light. Zemcov <jats:italic>et al.</jats:italic> sent up a rocket to measure the fluctuations in this faint background and found largescale fluctuations greater than known galaxies alone should produce (see the Perspective by Moseley). Stars tidally stripped from their host galaxies are the most likely culprit, rather than unknown primordial galaxies. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="732" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258168">732</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="696" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.aaa1077">696</jats:related-article> </jats:p>

<jats:title>Dissecting ancient microbial sulfur cycling</jats:title> <jats:p> Before the rise of oxygen, life on Earth depended on the marine sulfur cycle. The fractionation of different sulfur isotopes provides clues to which biogeochemical cycles were active long ago (see the Perspective by Ueno). Zhelezinskaia <jats:italic>et al.</jats:italic> found negative isotope anomalies in Archean rocks from Brazil and posit that metabolic fluxes from sulfate-reducing microorganisms influenced the global sulfur cycle, including sulfur in the atmosphere. In contrast, Paris <jats:italic>et al.</jats:italic> found positive isotope anomalies in Archean sediments from South Africa, implying that the marine sulfate pool was more disconnected from atmospheric sulfur. As an analog for the Archean ocean, Crowe <jats:italic>et al.</jats:italic> measured sulfur isotope signatures in modern Lake Matano, Indonesia, and suggest that low seawater sulfate concentrations restricted early microbial activity. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="703" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1261676">703</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="742" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1256211">742</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="739" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258211">739</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="735" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258966">735</jats:related-article> </jats:p>

<jats:title>Dissecting ancient microbial sulfur cycling</jats:title> <jats:p> Before the rise of oxygen, life on Earth depended on the marine sulfur cycle. The fractionation of different sulfur isotopes provides clues to which biogeochemical cycles were active long ago (see the Perspective by Ueno). Zhelezinskaia <jats:italic>et al.</jats:italic> found negative isotope anomalies in Archean rocks from Brazil and posit that metabolic fluxes from sulfate-reducing microorganisms influenced the global sulfur cycle, including sulfur in the atmosphere. In contrast, Paris <jats:italic>et al.</jats:italic> found positive isotope anomalies in Archean sediments from South Africa, implying that the marine sulfate pool was more disconnected from atmospheric sulfur. As an analog for the Archean ocean, Crowe <jats:italic>et al.</jats:italic> measured sulfur isotope signatures in modern Lake Matano, Indonesia, and suggest that low seawater sulfate concentrations restricted early microbial activity. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="703" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1261676">703</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="742" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1256211">742</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="739" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258211">739</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="735" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258966">735</jats:related-article> </jats:p>

<jats:title>Dissecting ancient microbial sulfur cycling</jats:title> <jats:p> Before the rise of oxygen, life on Earth depended on the marine sulfur cycle. The fractionation of different sulfur isotopes provides clues to which biogeochemical cycles were active long ago (see the Perspective by Ueno). Zhelezinskaia <jats:italic>et al.</jats:italic> found negative isotope anomalies in Archean rocks from Brazil and posit that metabolic fluxes from sulfate-reducing microorganisms influenced the global sulfur cycle, including sulfur in the atmosphere. In contrast, Paris <jats:italic>et al.</jats:italic> found positive isotope anomalies in Archean sediments from South Africa, implying that the marine sulfate pool was more disconnected from atmospheric sulfur. As an analog for the Archean ocean, Crowe <jats:italic>et al.</jats:italic> measured sulfur isotope signatures in modern Lake Matano, Indonesia, and suggest that low seawater sulfate concentrations restricted early microbial activity. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="703" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1261676">703</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="742" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1256211">742</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="739" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258211">739</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="735" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1258966">735</jats:related-article> </jats:p>

<jats:title>Competing bats jam one another's signal</jats:title> <jats:p>Animals that live in large social colonies may benefit from many aspects of group living, but also have to contend with many of the downsides of living and foraging, with countless neighbors. Corcoran and Conner show that Mexican free-tailed bats, which live in colonies that can number in the hundreds of thousands, deal with this high level of competition for food by actively jamming competitors' echolocation. The interfering bats produce an ultrasonic signal just as the foraging bat produces its feeding call, effectively jamming the echolocation signal and causing the forager to miss its target.</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="745" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1259512">745</jats:related-article> </jats:p>

<jats:title>The wheres and whys of protein translation</jats:title> <jats:p> Localized protein synthesis is important for a broad range of biological activities, from specifying the animal body plan to coordinating entry into the secretory pathway. Few tools are available that can investigate translation at specific subcellular sites. Jan <jats:italic>et al.</jats:italic> present a flexible ribosome profiling–based methodology to enable precise characterization of localized protein synthesis (see the Perspective by Shao and Hegde). Proximity-specific ribosome profiling provides a high-precision tool for looking at the mechanism of localized protein targeting and synthesis in living cells. The approach yielded a high-resolution systems-level view of cotranslational translocation at the endoplasmic reticulum. Williams <jats:italic>et al.</jats:italic> applied the technique to look at localized mRNA translation at the mitochondrial outer membrane. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.1257521">10.1126/science.1257521</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="701" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1261602">701</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="748" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1257522">748</jats:related-article> </jats:p>

<jats:title>Trashing misfolded membrane proteins</jats:title> <jats:p> Proteins move to and from the inner nuclear membrane (INM) from the rest of the endoplasmic reticulum through the nuclear pores. This movement is tightly controlled. Consequently, the INM accumulates a specific set of proteins required for a variety of functions, including chromosome organization and transcriptional control. But when INM proteins misfold, how are they eliminated? Foresti <jats:italic>et al.</jats:italic> addressed this question in yeast and found that a previously elusive branch of the endo–plasmic reticulum–associated degradation system was key (see the Perspective by Shao and Hegde). </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="751" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1255638">751</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="701" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1261602">701</jats:related-article> </jats:p>

<jats:title>Bacteria help norovius infect B cells</jats:title> <jats:p> Stomach ache, nausea, diarrhea—many people know the sort of gastrointestinal havoc norovirus can wreak. Despite this, norovirus biology remains unclear, because human norovirus cannot be grown in culture. Jones <jats:italic>et al.</jats:italic> now report that with the help of bacteria, human norovirus can infect cultured B cells (see the Perspective by Robinson and Pfeiffer). To infect B cells, human norovirus required the presence of gut bacteria that expressed proteins involved in determining blood type. Mouse norovirus also infected B cells, and the treatment of mice with antibiotics protected them from norovirus infection. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="755" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1257147">755</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="700" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.aaa0607">700</jats:related-article> </jats:p>

<jats:title>HIV's shape-shifting envelope protein</jats:title> <jats:p> HIV's envelope protein (Env) coats virus particles and allows HIV to enter host cells. HIV entry is highly dynamic. Env proteins work in groups of three (called trimers), which bind to the viral receptor and co-receptor, both expressed by host cells. Viral receptor binding causes a structural rearrangement in the trimer that allows for co-receptor binding and finally, viral entry. To visualize dynamic changes in Env conformation during viral entry, Munro <jats:italic>et al.</jats:italic> added differently colored fluorescent tags to two different regions of individual HIV trimers. Single-molecule fluorescence resonance entry transfer revealed three distinct Env conformations before cell entry. Occupation of particular conformations depended on host receptor binding. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="759" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1254426">759</jats:related-article> </jats:p>

<jats:title>Toward an insect evolution resolution</jats:title> <jats:p> Insects are the most diverse group of animals, with the largest number of species. However, many of the evolutionary relationships between insect species have been controversial and difficult to resolve. Misof <jats:italic>et al.</jats:italic> performed a phylogenomic analysis of protein-coding genes from all major insect orders and close relatives, resolving the placement of taxa. The authors used this resolved phylogenetic tree together with fossil analysis to date the origin of insects to ~479 million years ago and to resolve long-controversial subjects in insect phylogeny. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6210" page="763" related-article-type="in-this-issue" vol="346" xlink:href="10.1126/science.1257570">763</jats:related-article> </jats:p>