Catálogo de publicaciones - revistas

<jats:title>Biofilm Today, Gone Tomorrow</jats:title> <jats:p> Most bacteria can form complex, matrix-containing multicellular communities known as biofilms, which protect residents from environmental stresses such as antibiotic exposure. However, as biofilms age, nutrients become limiting and waste products accumulate, and biofim disassembly is triggered. Now <jats:bold> Kolodkin-Gal <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="627" related-article-type="in-this-issue" vol="328" xlink:href="10.1126/science.1188628">627</jats:related-article> ) have found that <jats:sc>d</jats:sc> -amino acids found in conditioned medium from mature biofilms of <jats:italic>Bacillus subtilis</jats:italic> prevent biofilm formation and trigger existing biofilm disassembly. </jats:p>

<jats:title>Light Structures</jats:title> <jats:p> Absorption of light by photosynthetic reaction centers causes structural changes and triggers a series of electron transfer reactions, resulting in a transmembrane potential difference that can be used to drive the subsequent chemistry. The initial electron transfer generates a charge-separated state that must be stabilized to prevent dissipation of energy through recombination. <jats:bold> Wöhri <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="630" related-article-type="in-this-issue" vol="328" xlink:href="10.1126/science.1186159">630</jats:related-article> ) have used time-resolved Laue diffraction crystallography to observe light-induced conformational changes that occur within milliseconds of photooxidation of the dimer of bacteriochlorophyll molecules, known as the “special pair,” in the photosynthetic reaction center of <jats:italic>Blastochloris viridis</jats:italic> . Stabilization appears to occur because of the deprotonation of a conserved tyrosine residue that moves closer to the special pair. </jats:p>

<jats:title>Frog Genome</jats:title> <jats:p> The African clawed frog <jats:italic>Xenopus tropicalis</jats:italic> is the first amphibian to have its genome sequenced. <jats:bold> Hellsten <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="633" related-article-type="in-this-issue" vol="328" xlink:href="10.1126/science.1183670">633</jats:related-article> , see the cover) present an analysis of a draft assembly of the genome. The genome of the frog, which is an important model system for developmental biology, encodes over 20,000 protein-coding genes, of which more than 1700 genes have identified human disease associations. Detailed comparison of the content of protein-coding genes with other tetrapods—human and chicken—reveals extensive shared synteny, occasionally spanning entire chromosomes. </jats:p>

<jats:title>Runs in the Family</jats:title> <jats:p> The power to detect mutations involved in disease by genome sequencing is enhanced when combined with the ability to discover specific mutations that may have arisen between offspring and parents. <jats:bold> Roach <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="636" related-article-type="in-this-issue" vol="328" xlink:href="10.1126/science.1186802">636</jats:related-article> , published online 10 March) present the sequence of a family with two offspring affected with two genetic disorders: Miller syndrome and primary ciliary dyskinesia. Sequence analysis of the children and their parents not only showed that the intergenerational mutation rate was lower than anticipated but also revealed recombination sites and the occurrence of rare polymorphisms. </jats:p>

<jats:p>The show includes lab experiments of a dynamic social-ecological system, the return of Japan's Hayabusa asteroid mission, and more.</jats:p>

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