Catálogo de publicaciones - revistas

<jats:title>How cells haul down their “eat me” flags</jats:title> <jats:p> Dead and dying cells expose a membrane lipid called phosphatidylserine (PS) on their cell surface as a sort of “eat me” signal. Segawa <jats:italic>et al.</jats:italic> identified the membrane enzyme responsible for flipping any PS that inadvertently makes it way from the inner to the outer leaflet of the plasma membrane lipid bilayer. Without the enzyme, macrophages gobbled up healthy cells. </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="6188" page="1164" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1252809">1164</jats:related-article> </jats:p>

<jats:title>A genome for ewe and ewe</jats:title> <jats:p>Sheep-specific genetic changes underlie differences in lipid metabolism between sheep and other mammals, and may have contributed to the production of wool. Jiang et al. sequenced the genome of two Texel sheep, a breed that produces high-value meat, milk, and wool. The genome information will provide an important resource for livestock production and aid in the understanding of mammalian evolution.</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="6188" page="1168" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1252806">1168</jats:related-article> </jats:p>

<jats:title>To sleep, perchance to remember</jats:title> <jats:p> Many researchers believe sleep helps us consolidate our memories, but no one knows quite how. Yang <jats:italic>et al.</jats:italic> investigated the precise role of sleep in changing mouse brain structures (see the Perspective by Euston and Steenland). When mice learned motor tasks, small protuberances—or “spines”—formed on some of the dendritic branches of specific brain neurons. These spines represent the physical correlate of a memory. But the neurons grew and retained these spines better when the mice slept after learning the task. Neurons that fired during learning fired again during subsequent slow-wave sleep, allowing the mice to conserve the newly formed spines—and memories. </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="6188" page="1173" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1249098">1173</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6188" page="1087" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1255649">1087</jats:related-article> </jats:p>

<jats:title>Genes, synapses, and hallucinations</jats:title> <jats:p> In a schizophrenia mouse model, Chun <jats:italic>et al.</jats:italic> found that an abnormal increase of dopamine D2 receptors in the brain's thalamic nuclei caused thalamocortical synapse deficits owing to reduced glutamate release. Antipsychotic agents or a dopamine receptor antagonist reversed this down-regulation. The defect was associated with the loss of a component of the microRNA processing machinery encoded by the <jats:italic>dgcr8</jats:italic> gene. </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="6188" page="1178" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1253895">1178</jats:related-article> </jats:p>

<jats:title>Wiring the developing insect brain</jats:title> <jats:p> Developmental brain wiring requires a complex set of cellular interactions often orchestrated by a large number of surface receptors. Thousands of Dscam1 receptor isoforms function as “surface tags” endowing neurons with unique molecular identities. These isoforms are important for neuronal self-recognition and dendrite self-avoidance. He <jats:italic>et al.</jats:italic> report that the diversity of Dscam1 isoforms is also essential for complex axonal branching of sensory neurons in developing fruit flies. </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="6188" page="1182" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251852">1182</jats:related-article> </jats:p>

<jats:p>On this week's show: The science of sustainable supply chains and a roundup of stories from our daily news site.</jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>

<jats:p>Recent research has revealed the importance of copy number analysis in the study of solid tumors. New evidence argues that tumors can be classified in those driven by either mutations (M class) or copy number aberrations (C class). C class tumors include breast, ovarian, and squamous cell lung cancers as well as, some believe, prostate cancer. Other publications have noted that predictive copy number changes are more frequent than predictive somatic mutation changes in solid tumor samples. These results seem to indicate that there is some risk to limiting tumor profiling to somatic mutations, and emphasize the importance of whole genome copy number analysis in identifying clinically relevant prognostic and predictive markers. This process is technically challenging, especially when using formalin-fixed, paraffin-embedded (FFPE) tissue or heterogeneous samples where only a small fraction of cells may be aberrant. Next generation sequencing technologies have limited ability to detect clinically relevant lower level amplifications, copy neutral loss of heterozygosity, and homozygous deletions, even at significant depth of coverage. This webinar will explore the importance of copy number analysis and highlight new technologies that are making this process more accessible, especially in solid tumor samples.</jats:p>

<jats:title>The versatility of epithelial stem cells</jats:title> <jats:p>Stem cells are very important in the maintenance of our bodies' tissues and organs. Blanpain and Fuchs review how different populations of naturally lineage-restricted epithelial stem cells and committed progenitors can also display remarkable plasticity. These cells can reacquire long-term self-renewing capacities and multilineage differentiation potential during physiological and regenerative conditions. These abilities depend on whether the stem cell remains within its resident niche or has been mobilized to repair a wound. Such cellular plasticity has implications for regenerative medicine and for cancer.</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.1242281">10.1126/science.1242281</jats:related-article> </jats:p>