Catálogo de publicaciones - revistas

<jats:title>Generating complex movement patterns</jats:title> <jats:p> What exactly does neuronal activity in the brain's motor cortex encode? In monkeys, Griffin <jats:italic>et al.</jats:italic> simultaneously recorded from a large number of muscles and from motor cortex cells that project directly to the motor neurons of the spinal cord. Even though the cortical cells had conventional directional tuning curves, different cortical cells were functionally connected to spinal cells with different muscle actions. </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="6261" page="667" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aaa8035">667</jats:related-article> </jats:p>

<jats:title>Protecting against too much of a good thing</jats:title> <jats:p> The slimy pink rot of potatoes is caused by the bacterium <jats:italic>Clostridium puniceum</jats:italic> , which cannot grow in the presence of oxygen. These bacteria produce a polyphenolic metabolite known as clostrubin that functions as an antibiotic. Shabuer <jats:italic>et al.</jats:italic> now show that the bacteria also use clostrubin to protect themselves from the aerobic environment of the potato tuber. </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="6261" page="670" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac9990">670</jats:related-article> </jats:p>

<jats:title>A visionary approach to transparency</jats:title> <jats:p> Cataracts are the most common cause of vision loss, especially in our ever-increasing elderly population. Cataracts arise when crystallin, a major protein component of the eye lens, begins to aggregate, which causes the lens to become cloudy. Makley <jats:italic>et al.</jats:italic> explored whether small molecules that reverse this aggregation might have therapeutic potential for treating cataracts, which normally require surgery (see the Perspective by Quinlan). They used a screening method that monitors the effect of ligands on temperature-dependent protein unfolding and identified several compounds that bind and stabilize the soluble form of crystallin. In proof-of-concept studies, one of these compounds improved lens transparency in mice. </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="6261" page="674" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac9145">674</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6261" page="636" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad6303">636</jats:related-article> </jats:p>

<jats:title>Proximity best for building protein complexes</jats:title> <jats:p> The synthesis of protein subunits and their assembly into a fully functional complex are generally thought to be two distinct processes. Shieh <jats:italic>et al.</jats:italic> studied the synthesis and assembly of the luciferase complex in <jats:italic>Escherichia coli.</jats:italic> Organization of the luciferase subunits LuxA and LuxB side by side into an operon promotes their colocalized synthesis and assembly into an active enzyme complex. Indeed, the association between the subunits occurs as they are being synthesized on ribosomes, which helps order the sequence of subunit interactions. </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="6261" page="678" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac8171">678</jats:related-article> </jats:p>

<jats:title>Getting rid of carbon dioxide</jats:title> <jats:p> In mammals, red blood cells deliver oxygen to tissues and remove carbon dioxide. Key to this essential process is a membrane protein called anion exchanger 1 (AE1) which transports bicarbonate (formed from carbon dioxide) out of red blood cells in exchange for chloride. This decreases the pH inside the blood cells, so that oxygen is released from hemoglobin and can diffuse into tissues. Arakawa <jats:italic>et al.</jats:italic> report the crystal structure of the transmembrane anion exchanger domain of AE1, which includes 14 transmembrane helices. The structure provides a basis for understanding the effects of mutations that lead to red blood cell diseases and also gives insight into the mechanism of ion transport. </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="6261" page="680" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aaa4335">680</jats:related-article> </jats:p>

<jats:title>Distant relatives can share gene function</jats:title> <jats:p> The plants <jats:italic>Arabidopsis thaliana</jats:italic> and <jats:italic>Papaver rhoeas</jats:italic> (poppy) shared a common ancestor approximately 140 million years ago. Because of this evolutionary distance, although many of their genes share function, the mechanisms that allow these genes to function are expected to have diverged. However, Z. Lin <jats:italic>et al.</jats:italic> found that a pair of genes that prevent self-fertilization in poppy can confer the same trait when expressed in <jats:italic>Arabidopsis.</jats:italic> This incompatibility was much more like that of poppy than that of incompatible close relatives of <jats:italic>Arabidopsis.</jats:italic> Thus, similar long-distance transfer of incompatibility, a trait of interest for plant breeding, may be useful between other distantly related species. </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="6261" page="684" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad2983">684</jats:related-article> </jats:p>

<jats:title>How flowers separate males and females</jats:title> <jats:p> Most flowering plant families have bisexual flowers with both male and female function. However, most members of the <jats:italic>Cucurbiticeae</jats:italic> family, which includes melons, cucumbers, and gourds, have unisexual flowers. To understand this difference in sex expression, Boualem <jats:italic>et al.</jats:italic> identified a cucumber gene expressed in the female flowers. Mutations in this gene were associated with solely male flowers. By integrating this finding into a sex determination model, the authors explain how unisexual flowers can coexist in the same plant. </jats:p> <jats:p> Science, this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6261" page="688" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac8370">688</jats:related-article> </jats:p>

<jats:title>Symbionts are adapted to work with corals</jats:title> <jats:p> Many corals have formed mutualistic associations with dinoflagellate symbionts, which are thought to provide nutrients and other benefits. To examine the underlying genetics of this association, S. Lin <jats:italic>et al.</jats:italic> sequenced the genome of the endosymbiont dinoflagellate <jats:italic>Symbiodinium kawagutii.</jats:italic> The genome includes gene number expansions and encodes microRNAs that show complementarity to genes within the coral genome. Such microRNAs may be involved in regulating coral genes. Furthermore, coral and <jats:italic>S. kawagutii</jats:italic> appear to share homologs of genes encoding specific nutrient transporters. The findings shed light on how symbiosis is established and maintained between dinoflagellates and corals. </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="6261" page="691" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad0408">691</jats:related-article> </jats:p>

<jats:p>Pick a paper, any paper. If it involves the protein, nucleic acid, or metabolite content of bacterial or eukaryotic cells, there's likely a section detailing how those cells were grown in culture. Cell culture is how researchers expand cells to harvest macromolecules or to interrogate their responses to changing conditions or chemical treatment. Inherent in such work is the assumption that all the cells in a dish are identical—by growing them in culture, the researcher is simply amplifying the signal. But that isn't always true. Subtle differences at the molecular level can yield significant variation in cellular behavior, but until recently researchers had no way to probe that variability. Today, they do.</jats:p>

<jats:p>On this week's show: The first data from the MAVEN mission to study the atmosphere of Mars and a roundup of daily news stories.</jats:p>