Catálogo de publicaciones - revistas

<jats:title>Genomic havoc from one fateful mistake</jats:title> <jats:p> Many human tumors display scrambled genomes that arise from two distinct mutational processes. The first, the chromosome breakage-fusion-bridge (BFB) cycle, produces gene amplification and genomic instability. The second, chromothripsis, generates massive, clustered genomic rearrangements in one or a few chromosomes. Umbreit <jats:italic>et al.</jats:italic> hypothesized that these two processes are mechanistically related and tested this idea by recreating essential steps of the BFB cycle in cultured cells (see the Perspective by Paiano and Nussenzweig). They found that chromothripsis arises from a cascade of events that begins with aberrant chromosome bridge formation during mitosis, followed by chromosome fragmentation, DNA damage, chromosome missegregation, and the formation of micronuclei. They propose a model that explains how a single cell division error (chromosome bridge formation) can generate many hallmark features of cancer genomes. </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="6488" page="240" related-article-type="in-this-issue" vol="368" xlink:href="10.1126/science.abb4899">240</jats:related-article> ; see also p. <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.aba0712">eaba0712</jats:related-article> </jats:p>

<jats:title>Coupling translation and mRNA decay</jats:title> <jats:p> Gene expression requires messenger RNAs (mRNAs)—DNA-derived blueprints of genes—to be translated by protein-producing ribosomes. The levels of mRNAs are tightly regulated, in part by controlling their half-lives. In eukaryotic cells, mRNA half-life is largely linked to translational efficiency, but the mechanism underlying this link has remained elusive. Buschauer <jats:italic>et al.</jats:italic> used cryo–electron microscopy and RNA sequencing to show how a key regulator of mRNA degradation, the Ccr4-Not complex, monitors the ribosome during mRNA translation. They found that the Not5 subunit directly binds to a ribosomal site exposed specifically during inefficient decoding, thereby triggering mRNA degradation. Analysis of mutants revealed the importance of this sensing mechanism for mRNA homeostasis. </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" related-article-type="in-this-issue" xlink:href="10.1126/science.aay6912">eaay6912</jats:related-article> </jats:p>

<jats:p> Tsai <jats:italic>et al</jats:italic> . (Reports, 6 April 2018, p. 67) report a uniform light-induced lattice expansion of metal halide perovskite films under 1-sun illumination and claim to exclude heat-induced lattice expansion. We show that by controlling the temperature of the perovskite film under both dark and illuminated conditions, the mechanism for lattice expansion is in fact fully consistent with heat-induced thermal expansion during illumination. </jats:p>

<jats:p>The coronavirus disease 2019 (COVID-19) pandemic has illuminated inequities that have put poor people—in both low-income nations and in rich countries—at the greatest risk of suffering. Pope Francis recently pointed to that in an interview: “This is the moment to see the poor.”</jats:p>

<jats:p>The spring of 2020 will be remembered for the coronavirus pandemic. But at this moment, it is worth remembering that 50 years ago, the United States confronted a very different crisis. That April, millions of Americans participated in Earth Day “teach-ins” across the nation. These events galvanized Democrats and Republicans into action: President Nixon and Congress worked together to pass a blitz of science-based policies that aimed to protect public health and the environment—including the Clean Air Act, Clean Water Act, and Endangered Species Act—with large bipartisan majorities.</jats:p>

<jats:p>A roundup of weekly science policy and related news.</jats:p>

<jats:p>Easing the rules while keeping the virus at bay will be a process of trial and error.</jats:p>

<jats:p>2020 is becoming the year of missing data for ecological projects and oceanographic cruises.</jats:p>

<jats:p>Infected lab animals can assess drugs and vaccines.</jats:p>

<jats:p>European Research Council president resigns over spat about agency's role in guiding funding to specific fields.</jats:p>