Catálogo de publicaciones - revistas

<jats:title>So much more to mucus</jats:title> <jats:p> Mammals accommodate a dense community of metabolically active microorganisms in their gut. This is not a passive relationship, and host and microbe have antagonistic as well as mutualistic responses to each other. Using a whole-colon imaging method in mice, Bergstrom <jats:italic>et al.</jats:italic> looked at the role of colonic mucus in segregating the microbiota from host cells during elimination of feces (see the Perspective by Birchenough and Johansson). Host goblet cells synthesize two forms of mucin that differ in branched chain O-glycosylation and the site of production in the colon. A “thick” mucus in the proximal, ascending colon wraps the microbiota to form fecal pellets. Transit along the distal, descending colon is lubricated by “thin” mucus that transiently links with the thick mucus. Normal mucus encapsulation prevents inflammation and hyperplasia and thus is important for maintenance of a healthy gut. </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="6515" page="467" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.aay7367">467</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6515" page="402" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe7194">402</jats:related-article> </jats:p>

<jats:title>Old chimp friends</jats:title> <jats:p> As humans age, we prioritize established positive friendships over the new, but risky, socializing we do when we are young. It has been hypothesized that this shift may come as our own sense of mortality kicks in. Rosati <jats:italic>et al.</jats:italic> analyzed a rare, long-term dataset on social bonds among male chimpanzees and found a very similar focus on old and positive friendships (see the Perspective by Silk). Though there is evidence of some sense of time among nonhuman animals, it seems unlikely that they have the same impending sense of mortality that we experience; thus, these results suggest that a different, and deeper, mechanism may be at play. </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="6515" page="473" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.aaz9129">473</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6515" page="403" related-article-type="in-this-issue" vol="370" xlink:href="10.1126/science.abe9110">403</jats:related-article> </jats:p>

<jats:title>Microbial selection drives adaptation</jats:title> <jats:p> Many legumes have a host-symbiote relationship with nitrogen-fixing bacteria, or rhizobia, that provides a benefit to both the plant and the microbe. Batstone <jats:italic>et al.</jats:italic> experimentally evolved the association between five legume accessions and different bacterial isolates. Rather than observe selection by the host for bacterial associations (host choice), mutations accumulated within a bacterial plasmid and increased the strength of the mutualism. Thus, local and recent associations between bacterial strains and plant genotypes are due to selection for bacterial adaptation. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6515" page="476" related-article-type="in-this-issue" vol="370">476</jats:related-article> </jats:p>

<jats:p> This issue of <jats:italic>Science</jats:italic> includes the program of the 2021 AAAS Annual Meeting. The 2021 AAAS Annual Meeting will convene entirely online February 8-11. The theme of the AAAS Annual Meeting is <jats:italic>Understanding Dynamic Ecosystems</jats:italic> . </jats:p> <jats:p> A <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/cgi/reprint/370/6515/479.pdf">PDF</jats:ext-link> of the program as it appears in this issue is available here; for more information on the meeting, please visit <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="www.aaas.org/meetings/">www.aaas.org/meetings/</jats:ext-link> . </jats:p>