Catálogo de publicaciones - revistas

<jats:title>Clostridial metabolite production</jats:title> <jats:p> The clostridia are Firmicute bacterial commensals commonly found in the mammalian gut. Clostridia produce a range of metabolites that diffuse into the host's circulation and have been difficult to manipulate genetically, but Guo <jats:italic>et al.</jats:italic> successfully developed a CRISPR-Cas9 deletion system in <jats:italic>Clostridium sporogenes</jats:italic> (see the Perspective by Henke and Clardy). The authors used deletion mutants and mass spectrometry to elucidate clostridial synthesis of several different branched short-chain fatty acids (SCFAs), including isobutyrate, 2-methylbutyrate, and isovalerate. Germ-free mice colonized with mutants incapable of synthesizing SCFAs showed altered immunoglobulin A production. This finding potentially links bacterial SCFA production and host responses to the presence of the clostridia. </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.aav1282">eaav1282</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6471" page="1309" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz4164">1309</jats:related-article> </jats:p>

<jats:title>The time is now</jats:title> <jats:p> For decades, scientists have been raising calls for societal changes that will reduce our impacts on nature. Though much conservation has occurred, our natural environment continues to decline under the weight of our consumption. Humanity depends directly on the output of nature; thus, this decline will affect us, just as it does the other species with which we share this world. Díaz <jats:italic>et al.</jats:italic> review the findings of the largest assessment of the state of nature conducted as of yet. They report that the state of nature, and the state of the equitable distribution of nature's support, is in serious decline. Only immediate transformation of global business-as-usual economies and operations will sustain nature as we know it, and us, into the future. </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.aax3100">eaax3100</jats:related-article> </jats:p>

<jats:title>Mobile farming advice</jats:title> <jats:p> Mobile phones are almost universally available, and the costs of information transmission are low. They are used by smallholder farmers in low-income countries, largely successfully, to optimize markets for their produce. Fabregas <jats:italic>et al.</jats:italic> review the potential for boosting mobile phone use with smartphones to deliver not only market information but also more sophisticated agricultural extension advice. GPS-linked smartphones could provide locally relevant weather and pest information and video-based farming advice. But how to support the financial requirements of such extension services is less obvious, given the unwieldiness of government agencies and the vested interests of commercial suppliers. </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.aay3038">eaay3038</jats:related-article> </jats:p>

<jats:title>Measuring mitigation and adaptation</jats:title> <jats:p> As more and more carbon dioxide is emitted into the atmosphere, humans and the natural world are beset by the damaging consequences of a rapidly changing climate. Natural and seminatural ecosystems are likely to be the best starting place for immediate adaptation and mitigation solutions. First, though, many natural environments need restoration to maximize their own resilience to climate change. In reviewing our options, Morecroft <jats:italic>et al.</jats:italic> point out that we can directly observe the success of mitigation strategies by quantifying atmospheric carbon dioxide. Successful adaptation is more challenging because it involves a range of social and biodiversity measures. However, we could make matters worse if we do not constantly monitor the effects of the interventions we devise and react flexibly as changing conditions unfold. </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.aaw9256">eaaw9256</jats:related-article> </jats:p>

<jats:title>Prospecting for drugs in the microbiome</jats:title> <jats:p> The microbiome is an important source of natural products that can profoundly influence health and disease in the host. Sugimoto <jats:italic>et al.</jats:italic> constructed a modular, probabilistic strategy called <jats:italic>MetaBGC</jats:italic> to uncover biosynthetic gene clusters (BGCs) in human microbiome samples (see the Perspective by Henke and Clardy). The authors found geographic and strain-specific distributions of BGCs. By zeroing in on two type II aromatic polyketides, the native organisms were identified, the BGCs were reconstructed in <jats:italic>Streptomyces</jats:italic> , and the products were characterized. When expressed in <jats:italic>Bacillus subtilis</jats:italic> , the products resembled currently used anticancer drugs and antibiotics. These polyketides were not cytotoxic but had inhibitory activity against oral Gram-positive bacteria, which may reflect the niche and ecology of the originating organisms. </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.aax9176">eaax9176</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6471" page="1309" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz4164">1309</jats:related-article> </jats:p>

<jats:title>Revised view of anticancer drug mechanism</jats:title> <jats:p> A crystal structure of the active form of cyclin-dependent kinase 4 (CDK4) provides insight into regulation of the cell cycle and the mechanism of action of a drug used for breast cancer therapy. The protein p27 has been thought to act as a CDK inhibitor. Guiley <jats:italic>et al.</jats:italic> performed a structural analysis of active complexes of CDK4 with cyclin D1 (CycD1) and p27 (see the Perspective by Sherr). The results showed that p27 actually remodels the active site of CDK4 to allow full activation when p27 is phosphorylated on tyrosine (phosp27). Furthermore, they found that the breast cancer drug palbociclib, a CDK4 inhibitor, doesn't actually interact with active phosp27-CDK4-CycD1 trimers. Instead, it appears that the drug, which shows promise in the clinic, binds to inactive CDK4 monomers and prevents interaction with p27. </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.aaw2106">eaaw2106</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6471" page="1315" related-article-type="in-this-issue" vol="366" xlink:href="10.1126/science.aaz4043">1315</jats:related-article> </jats:p>

<jats:p>Organized intellectual espionage is a concept that may not seem relevant to most American scientists because such instances are extremely rare, like most cases of scientific misconduct. But this type of theft from research institutions in the United States, although infrequent and isolated, is very real and very serious. It compromises the scientific values that uphold the openness of academic institutions in the United States as well as the nation's security. Over the past decade, U.S. academic, security, and intelligence communities have identified an increasing number of instances of such misconduct by foreign nations, primarily China but also Russia and Iran. As policies to aggressively deter these occurrences are under vigorous discussion, the scientific community needs to step up and participate in designing the legal path forward, no matter how unpalatable that might seem. Otherwise, scientists will simply be left accepting the cards dealt to them regarding openness and collaboration, which could be even more distasteful.</jats:p>

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

<jats:p>Surging demand for hides, used in Chinese medicine, sends populations crashing.</jats:p>