Catálogo de publicaciones - revistas

<jats:p>Optical metamaterials that have a refractive index of zero can boost the efficiency of nonlinear optical processes.</jats:p>

<jats:p>Epidermal stem cells produce the signals that control tissue homeostasis.</jats:p>

<jats:p>Interdisciplinary research on zoonotic pathogens illuminates ecology and evolution, while guiding disease prevention and control.</jats:p>

<jats:p>Differential expression of cell-surface molecules instruct the precise assembly of a neural circuit.</jats:p>

<jats:p>Comparative evolutionary analysis of transcriptional regulator binding across several vertebrate species reveals intricate regulatory genome evolution.</jats:p>

<jats:p>Mouse genetics and intravital microscopy are combined to investigate how antibody evolution correlates with, and depends on, B lymphocytes.</jats:p>

<jats:p>In individual cells, transcription is a random process obeying single-molecule kinetics. Often, it occurs in a bursty, intermittent manner. The frequency and size of these bursts affect the magnitude of temporal fluctuations in messenger RNA and protein content within a cell, creating variation or “noise” in gene expression. It is still unclear to what degree transcriptional kinetics are specific to each gene and determined by its promoter sequence. Alternative scenarios have been proposed, in which the kinetics of transcription are governed by cellular constraints and follow universal rules across the genome. Evidence from genome-wide noise studies and from systematic perturbations of promoter sequences suggest that both scenarios—namely gene-specific versus genome-wide regulation of transcription kinetics—may be present to different degrees in bacteria, yeast, and animal cells.</jats:p>

<jats:p>A fundamental problem in biology is to understand how genetic circuits implement core cellular functions. Time-lapse microscopy techniques are beginning to provide a direct view of circuit dynamics in individual living cells. Unexpectedly, we are discovering that key transcription and regulatory factors pulse on and off repeatedly, and often stochastically, even when cells are maintained in constant conditions. This type of spontaneous dynamic behavior is pervasive, appearing in diverse cell types from microbes to mammalian cells. Here, we review recent work showing how pulsing is generated and controlled by underlying regulatory circuits and how it provides critical capabilities to cells in stress response, signaling, and development. A major theme is the ability of pulsing to enable time-based regulation analogous to strategies used in engineered systems. Thus, pulsatile dynamics is emerging as a central, and still largely unexplored, layer of temporal organization in the cell.</jats:p>

<jats:title>Oscillation Stabilizes the Progenitor State</jats:title> <jats:p> Transcription factors regulate fate choice between different neural lineages, but the same transcription factors are also expressed in neural progenitor cells. <jats:bold> Imayoshi <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6163" page="1203" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242366">1203</jats:related-article> , published online 31 October) analyzed the details of expression of several transcription factors in mouse neural cells. In neural progenitor cells, several different transcription factors were expressed in an oscillatory manner, whereas differentiated neurons stably expressed a single lineage-specific factor. </jats:p>