Catálogo de publicaciones - revistas

<jats:p> Strecker <jats:italic>et al</jats:italic> . (Research Articles, 5 July 2019, p. 48) described a system for exploiting a Tn7-type transposon-encoded CRISPR-Cas system to make RNA-guided, programmable insertions. Although this system has great promise, we note that the well-established biochemistry of Tn7 suggests that the particular system used may insert not only the transposon but also the entire donor plasmid. </jats:p>

<jats:p> Rice <jats:italic>et al</jats:italic> . suggest that the CRISPR-associated transposase ShCAST system could lead to additional insertion products beyond simple integration of the donor. We clarify the outcomes of ShCAST-mediated insertions in <jats:italic>Escherichia coli</jats:italic> , which consist of both simple insertions and integration of the donor plasmid. This latter outcome can be avoided by use of a 5′ nicked DNA donor. </jats:p>

<jats:title>From bottom to top</jats:title> <jats:p> The doubling of the number of transistors on a chip every 2 years, a seemly inevitable trend that has been called Moore's law, has contributed immensely to improvements in computer performance. However, silicon-based transistors cannot get much smaller than they are today, and other approaches should be explored to keep performance growing. Leiserson <jats:italic>et al.</jats:italic> review recent examples and argue that the most promising place to look is at the top of the computing stack, where improvements in software, algorithms, and hardware architecture can bring the much-needed boost. </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.aam9744">eaam9744</jats:related-article> </jats:p>

<jats:title>Agrobacteria virulence writ large</jats:title> <jats:p> Plasmids are widespread among bacteria and are important because they spread virulence and antibiotic resistance traits, among others. They are horizontally transferred between strains and species, so it is difficult to work out their evolution and epidemiology. Agrobacteria, a diverse grouping of species that infect plants, inject oncogenic Ti and Ri plasmids, which cause crown galls and hairy root diseases, respectively. The upside is that these plasmids have become valuable biotechnological tools. Weisberg <jats:italic>et al.</jats:italic> combed through an 80-year-old collection of <jats:italic>Agrobacterium</jats:italic> strains but found a surprisingly low diversity of plasmids. It is puzzling how limited the number of plasmid lineages is despite reported high levels of plasmid recombination, but what is clear is how plant production systems have influenced plasmid spread into various genomic backbones. </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.aba5256">eaba5256</jats:related-article> </jats:p>

<jats:p>As coronavirus disease 2019 (COVID-19) has quickly killed hundreds of thousands across an unprepared world, destroyed the livelihoods of millions, and cost trillions of dollars, nations must now expand their mindsets and focus not only on overcoming the next phases but also on long-range strategies—for this and for future pandemics. The world needs a permanent preparedness enterprise to engage in a sustained effort to avert pandemics, and provide for the affordable and widespread administration of vaccines and therapies when they are discovered.</jats:p>

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