Catálogo de publicaciones - revistas

<jats:title>Emerging patterns in species distribution</jats:title> <jats:p> Human influences are leading to a shift in the geographical distribution of animal species. Capinha <jats:italic>et al.</jats:italic> compared the distributions of native mollusk species with those introduced to new areas by human activities. The ranges of native species are still broadly constrained by limitations on their capacity for dispersal, whereas those of the introduced aliens are affected more by climate and patterns of human movement. As humans continue to break down barriers to dispersal, more species' distributions will come to be limited by their environmental tolerances. </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="6240" page="1248" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa8913">1248</jats:related-article> </jats:p>

<jats:title>Detecting Gramnegative bacteria</jats:title> <jats:p> Invariant molecules specific to different classes of microbes, but not expressed by eukaryotic cells, alert the immune system to a potential invader. Gaudet <jats:italic>et al.</jats:italic> identified one such molecule expressed by a variety of Gram-negative bacteria: the monosaccharide heptose-1,7-bisphosphate (HBP) (see the Perspective by Brubaker and Monack). HBP is an intermediate in the synthesis of lipopolysaccharide, a major component of bacterial cell walls. Rather than alerting the immune system through traditional pathogen detection pathways, such as Toll-like receptors, HBP signals through the host protein TIFA (TRAF-interacting protein with forkhead-associated domain), which activates both innate and adaptive immune responses to control the 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="6240" page="1251" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4921">1251</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6240" page="1207" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aac5835">1207</jats:related-article> </jats:p>

<jats:title>Receptor in the brain controls breathing</jats:title> <jats:p> Control of breathing in mammals depends primarily not on sensing oxygen, but rather on detecting concentrations of carbon dioxide in the blood. Failure of this system can cause potentially deadly sleep apnias. Taking a hint from insects, which use a heterotrimeric guanine nucleotide–binding protein-coupled receptor (GPCR) to sense carbon dioxide, Kumar <jats:italic>et al.</jats:italic> demonstrate that the GPCR GPR4 is essential to control breathing in mice. GPR4 senses protons generated by the formation of carbonic acid in the blood and works with a pH-sensitive potassium channel called TASK-2 in a set of brain cells that control breathing. </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="6240" page="1255" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa0922">1255</jats:related-article> </jats:p>

<jats:title>How cells sense connected chromosomes</jats:title> <jats:p> Cells have a “checkpoint” that pauses cell division until all chromosomes are properly arranged on the mitotic spindle to allow precise distribution of one copy of each chromosome to each daughter cell. Hiruma <jats:italic>et al.</jats:italic> and Ji <jats:italic>et al.</jats:italic> explain the molecular mechanism by which cells sense that they are ready to divide. The protein kinase MPS1 associates with a protein complex at the kinetochore of the chromosome. Its activity produces signals that pause the cell cycle. When the chromosome becomes properly attached to the mitotic spindle, microtubules of the spindle physically compete for binding to the same site on the kinetochore where MPS1 is bound. Thus, once the kinetochore is properly attached, MPS1 dissociates, the inhibitory signal is lost, and cell division is allowed to proceed. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue pp. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6240" page="1264" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4055">1264</jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6240" page="1260" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4029">1260</jats:related-article> </jats:p>

<jats:title>How cells sense connected chromosomes</jats:title> <jats:p> Cells have a “checkpoint” that pauses cell division until all chromosomes are properly arranged on the mitotic spindle to allow precise distribution of one copy of each chromosome to each daughter cell. Hiruma <jats:italic>et al.</jats:italic> and Ji <jats:italic>et al.</jats:italic> explain the molecular mechanism by which cells sense that they are ready to divide. The protein kinase MPS1 associates with a protein complex at the kinetochore of the chromosome. Its activity produces signals that pause the cell cycle. When the chromosome becomes properly attached to the mitotic spindle, microtubules of the spindle physically compete for binding to the same site on the kinetochore where MPS1 is bound. Thus, once the kinetochore is properly attached, MPS1 dissociates, the inhibitory signal is lost, and cell division is allowed to proceed. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue pp. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6240" page="1264" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4055">1264</jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6240" page="1260" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4029">1260</jats:related-article> </jats:p>

<jats:title>Manipulating M factor alters mosquito sex</jats:title> <jats:p> Female mosquitoes feed on blood and in so doing transmit pathogens to millions annually. Although the molecular mechanism for determining sex in many animals is known, the specific factors in mosquitoes have been elusive. This is because sex determination in insects involves a section of the genome that is highly repetitive. Hall <jats:italic>et al.</jats:italic> now identify a male-determining factor (M factor) in <jats:italic>Aedes aegypti.</jats:italic> Manipulation of the M factor produced sex-change phenotypes. Knocking out the gene <jats:italic>Nix</jats:italic> resulted in feminized males, and ectopic expression gave masculinized females. These findings should help to advance strategies for converting female mosquitoes into nonbiting males. </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="6240" page="1268" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa2850">1268</jats:related-article> </jats:p>

<jats:p> To minimize complexity, researchers often study cellular proteins or nucleic acids in isolation. But sometimes—when testing a drug's efficacy and safety, for instance, or monitoring tumor progression—ex vivo just won't do. The only way to know how a compound or cells will behave in the body is to put them into an animal and watch what happens live. The results are easily recognizable in the pages of your favorite journal: the ghostly outline of a mouse, with a telltale multicolored heat bloom indicating where the action is. <jats:list list-type="bullet"> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/site/products/lst_20150612.xhtml">Read the Feature (Full-Text HTML)</jats:ext-link> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/site/products/lst_20150612.pdf">Read the Feature (PDF)</jats:ext-link> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/site/products/lst_20150612_np.pdf">Read New Products (PDF)</jats:ext-link> </jats:p> </jats:list-item> </jats:list> </jats:p>

<jats:p>On this week's show: Tracking aquatic animals, cochlear implants and emotion recognition, and a roundup of daily news stories.</jats:p>

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