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Plos Biology : Oxidative Stress Inactivates Cobalamin-independent ...

By: Joan Valentine

Description : In nature, Escherichia coli are exposed to harsh and non-ideal growth environments—nutrients may be limiting, and cells are often challenged by oxidative stress. For E. coli cells confronting these realities, there appears to be a link between oxidative stress, methionine availability, and the enzyme that catalyzes the final step of methionine biosynthesis, cobalamin-independent methionine synthase (MetE). We found that E. coli cells subjected to transient ...

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Plos Biology : Transsynaptic Coordination of Synaptic Growth, Func...

By: Hugo J. Bellen

Description : The precise control of synaptic connectivity is essential for the development and function of neuronal circuits. While there have been significant advances in our understanding how cell adhesion molecules mediate axon guidance and synapse formation, the mechanisms controlling synapse maintenance or plasticity in vivo remain largely uncharacterized. In an unbiased RNAi screen we identified the Drosophila L1-type CAM Neuroglian (Nrg) as a central coordinator ...

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Plos Biology : the Vestibular System Implements a Linear–nonlinear...

By: Kate G. Storey

Description : Although it is well established that the neural code representing the world changes at each stage of a sensory pathway, the transformations that mediate these changes are not well understood. Here we show that self-motion (i.e. vestibular) sensory information encoded by VIIIth nerve afferents is integrated nonlinearly by post-synaptic central vestibular neurons. This response nonlinearity was characterized by a strong (,50%) attenuation in neuronal sensitiv...

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Plos Biology : the N. Gonorrhoeae Type IV Pilus Stimulates Mechano...

By: Matt Waldor

Description : The Neisseria gonorrhoeae type IV pilus is a retractile appendage that can generate forces near 100 pN. We tested the hypothesis that type IV pilus retraction influences epithelial cell gene expression by exerting tension on the host membrane. Wild-type and retraction-defective bacteria altered the expression of an identical set of epithelial cell genes during attachment. Interestingly, pilus retraction, per se, did not regulate novel gene expression but, r...

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Plos Biology : Warming and Resource Availability Shift Food Web St...

By: Michel Loreau

Description : Climate change disrupts ecological systems in many ways. Many documented responses depend on species’ life histories, contributing to the view that climate change effects are important but difficult to characterize generally. However, systematic variation in metabolic effects of temperature across trophic levels suggests that warming may lead to predictable shifts in food web structure and productivity. We experimentally tested the effects of warming on foo...

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Plos Biology : Video-game Play Induces Plasticity in the Visual Sy...

By: Manfred Fahle

Description : Abnormal visual experience during a sensitive period of development disrupts neuronal circuitry in the visual cortex and results in abnormal spatial vision or amblyopia. Here we examined whether playing video games can induce plasticity in the visual system of adults with amblyopia. Specifically 20 adults with amblyopia (age 15–61 y: visual acuity : 20/25–20/480, with no manifest ocular disease or nystagmus) were recruited and allocated into three intervent...

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Plos Biology : Neuroscience Networks, Volume 1

By: Thomas R. Insel
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Plos Biology : Intracellular Proton Access in a Cl2, Volume 10

By: Susan L. Lindquist

Description : Chloride-transporting membrane proteins of the CLC family appear in two distinct mechanistic flavors : H+-gated Cl2 channels and Cl2/H+ antiporters. Transmembrane H+ movement is an essential feature of both types of CLC. X-ray crystal structures of CLC antiporters show the Cl2 ion pathway through these proteins, but the H+ pathway is known only inferentially by two conserved glutamate residues that act as way-stations for H+ in its path through the protein....

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Plos Biology : Pheromonal and Behavioral Cues Trigger Male-to-fema...

By: Scott Waddell

Description : Appropriate displays of aggression rely on the ability to recognize potential competitors. As in most species, Drosophila males fight with other males and do not attack females. In insects, sex recognition is strongly dependent on chemosensory communication, mediated by cuticular hydrocarbons acting as pheromones. While the roles of chemical and other sensory cues in stimulating male to female courtship have been well characterized in Drosophila, the signal...

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Plos Biology : from Parasite to Mutualist ; Rapid Evolution of Wol...

By: Laurent Keller

Description : Wolbachia are maternally inherited bacteria that commonly spread through host populations by causing cytoplasmic incompatibility, often expressed as reduced egg hatch when uninfected females mate with infected males. Infected females are frequently less fecund as a consequence of Wolbachia infection. However, theory predicts that because of maternal transmission, these ‘‘parasites’’ will tend to evolve towards a more mutualistic association with their hosts...

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Plos Biology : the in Vivo Kinetics of Rna Polymerase II Elongatio...

By: Public Library of Science (Plos)

Description : RNA processing events that take place on the transcribed pre-mRNA include capping, splicing, editing, 39 processing, and polyadenylation. Most of these processes occur co-transcriptionally while the RNA polymerase II (Pol II) enzyme is engaged in transcriptional elongation. How Pol II elongation rates are influenced by splicing is not well understood. We generated a family of inducible gene constructs containing increasing numbers of introns and exons, whic...

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Plos Biology : Palmistry, Volume 2

By: Peter Dayan
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Plos Biology : Bacterial Inclusion Bodies Contain Amyloid-like Str...

By: Samir K. Maji

Description : Protein aggregation is a process in which identical proteins self-associate into imperfectly ordered macroscopic entities. Such aggregates are generally classified as amorphous, lacking any long-range order, or highly ordered fibrils. Protein fibrils can be composed of native globular molecules, such as the hemoglobin molecules in sickle-cell fibrils, or can be reorganized b-sheet–rich aggregates, termed amyloid-like fibrils. Amyloid fibrils are associated ...

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Plos Biology : the Telomeric Protein Trf2 Binds the Atm Kinase and...

By: Steve Elledge

Description : The telomeric protein TRF2 is required to prevent mammalian telomeres from activating DNA damage checkpoints. Here we show that overexpression of TRF2 affects the response of the ATM kinase to DNA damage. Overexpression of TRF2 abrogated the cell cycle arrest after ionizing radiation and diminished several other readouts of the DNA damage response, including phosphorylation of Nbs1, induction of p53, and upregulation of p53 targets. TRF2 inhibited autophosp...

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Plos Biology : Transcriptional Dysregulation in Nipbl and Cohesin ...

By: Nicholas Hastie

Description : Cohesin regulates sister chromatid cohesion during the mitotic cell cycle with Nipped-B-Like (NIPBL) facilitating its loading and unloading. In addition to this canonical role, cohesin has also been demonstrated to play a critical role in regulation of gene expression in nondividing cells. Heterozygous mutations in the cohesin regulator NIPBL or cohesin structural components SMC1A and SMC3 result in the multisystem developmental disorder Cornelia de Lange S...

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Plos Biology : Sex Determination in Honeybees ; Two Separate Mecha...

By: Bruce Stewart Baker

Description : Organisms have evolved a bewildering diversity of mechanisms to generate the two sexes. The honeybee (Apis mellifera) employs an interesting system in which sex is determined by heterozygosity at a single locus (the Sex Determination Locus) harbouring the complementary sex determiner (csd) gene. Bees heterozygous at Sex Determination Locus are females, whereas bees homozygous or hemizygous are males. Little is known, however, about the regulation that links...

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Plos Biology : Tuning Into Places, Volume 9

By: Public Library of Science (Plos)
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Plos Biology : Convergent Evolution of Escape from Hepaciviral Ant...

By: Laurence D. Hurst

Description : The ability to mount an interferon response on sensing viral infection is a critical component of mammalian innate immunity. Several viruses directly antagonize viral sensing pathways to block activation of the host immune response. Here, we show that recurrent viral antagonism has shaped the evolution of the host protein MAVS—a crucial component of the viral-sensing pathway in primates. From sequencing and phylogenetic analyses of MAVS from 21 simian prima...

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Plos Biology : Intergenic Locations of Rice Centromeric Chromatin,...

By: Huihuang Yan

Description : Centromeres are sites for assembly of the chromosomal structures that mediate faithful segregation at mitosis and meiosis. Plant and animal centromeres are typically located in megabase-sized arrays of tandem satellite repeats, making their precise mapping difficult. However, some rice centromeres are largely embedded in nonsatellite DNA, providing an excellent model to study centromere structure and evolution. We used chromatin immunoprecipitation and 454 ...

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Plos Biology : Improving Science Education for Sustainable Develop...

By: Michiel Van Eijck
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