Catálogo de publicaciones - revistas

<jats:title>Structure of the largest, most complex ribosome</jats:title> <jats:p> Ribosomes are two-subunit ribonucleoprotein assemblies that catalyze the translation of messenger RNA into protein. Ribosomal RNAs (rRNAs) play key structural and functional roles. Ramrath <jats:italic>et al.</jats:italic> report the high-resolution structure of mitochondrial ribosomes from the unicellular parasite <jats:italic>Trypanosoma brucei</jats:italic> that contain the smallest known rRNAs. The trypanosomal mitoribosome is the most complex ribosomal assembly characterized, with two rRNAs and 126 proteins. The increased protein subunits have substituted for rRNA as an architectural scaffold. The structure also reveals the minimal core needed for ribosome function. </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.aau7735">eaau7735</jats:related-article> </jats:p>

<jats:title>How the axolotl makes a new limb</jats:title> <jats:p> Unlike most vertebrate limbs, the axolotl limb regenerates the skeleton after amputation. Dermal and interstitial fibroblasts have been thought to provide sources for skeletal regeneration, but it has been unclear whether preexisting stem cells or dedifferentiation of fibroblasts formed the blastema. Gerber <jats:italic>et al.</jats:italic> developed transgenic reporter animals to compare periskeletal cell and fibroblast contributions to regeneration. Callus-forming periskeletal cells extended existing bone, but fibroblasts built new limb segments. Single-cell transcriptomics and Brainbow-based lineage tracing revealed the lack of a preexisting stem cell. Instead, the heterogeneous population of fibroblasts lost their adult features to form a multipotent skeletal progenitor expressing the embryonic limb program. </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.aaq0681">eaaq0681</jats:related-article> </jats:p>

<jats:title>Faster switching for soft magnets</jats:title> <jats:p> The most familiar magnets are permanent magnets like the ones on a refrigerator door. However, for applications in transformers and motors, soft magnets that can rapidly switch their magnetization in response to a magnetic field are used. In electronics, wide bandgap semiconductors such as silicon carbide will allow power conversion electronics and motor controllers to operate more efficiently, but soft magnets must be developed that can respond at higher frequencies. Silveyra <jats:italic>et al.</jats:italic> review the development of current soft magnetic materials and opportunities for improving their performance in high-frequency operation. Materials being explored include soft ferrites, amorphous and nanocrystalline alloys, and powder cores or soft magnetic composites. </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.aao0195">eaao0195</jats:related-article> </jats:p>

<jats:title>Cancer chromatin accessibility landscape</jats:title> <jats:p> The Cancer Genome Atlas (TCGA) provides a high-quality resource of molecular data on a large variety of human cancers. Corces <jats:italic>et al.</jats:italic> used a recently modified assay to profile chromatin accessibility to determine the accessible chromatin landscape in 410 TCGA samples from 23 cancer types (see the Perspective by Taipale). When the data were integrated with other omics data available for the same tumor samples, inherited risk loci for cancer predisposition were revealed, transcription factors and enhancers driving molecular subtypes of cancer with patient survival differences were identified, and noncoding mutations associated with clinical prognosis were discovered. </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.aav1898">eaav1898</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6413" page="401" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav3494">401</jats:related-article> </jats:p>

<jats:title>Imaging chromatin spatial organization</jats:title> <jats:p> The genome is organized within the nucleus as three-dimensional domains that modulate DNA-templated processes. Bintu <jats:italic>et al.</jats:italic> used high-throughput Oligopaint labeling and imaging to observe chromatin dynamics inside the nuclei of several different mammalian cell lines. After combining the datasets, single-cell matrices revealed chromatin arranged in topologically associating domains (TADs). Removing cohesin resulted in a loss of aggregate TADs among populations of cells, but specific TADs were still detected at the single-cell level. Furthermore, higher-order organization was detected, suggestive of cooperative interactions within the genome. </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.aau1783">eaau1783</jats:related-article> </jats:p>

<jats:p>When I was a young faculty member, my laboratory was deeply engaged in studies of zinc-containing proteins. One evening, after our two sons had been tucked into bed, I was watching The Simpsons and the episode began, uncharacteristically in black and white, with a man trying unsuccessfully to start his car. Another man says, “You said that you wanted to live in a world without zinc…” and explains the essential roles that zinc plays in various machines and expands on the frightening and dysfunctional scenario. I was genuinely concerned that I was hallucinating and wondered whom I could call to confirm what I thought I had seen. We are now living in a world where the reality of facts and the importance of scientific inquiry and responsible journalism are questioned with distressing frequency. This trend needs to be called out and arrested; the consequences of allowing it to continue are potentially quite damaging.</jats:p>

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

<jats:p>Shortage develops as new transgenic models for neurological diseases stoke interest.</jats:p>

<jats:p>Three teams are developing prototypes using Chinese chips.</jats:p>

<jats:p>People who reported having at least one same-sex partner are more likely to share certain genetic variants.</jats:p>