Thalamic coordination of cortical communication

Higher-order thalamic nuclei, like the pulvinar, have extensive connections with cortex, suggesting a role in?the coordination of cortical communication. A recent study in Science by Saalmann et?al. (2012) implicates the pulvinar in promoting cortical alpha-band synchronization that subserves communication of attended information.     

Micromechanical modeling of elastic properties of cortical bone accounting for anisotropy of dense tissue

The paper analyzes the connection between microstructure of the osteonal cortical bone and its overall elastic properties. The existing models either neglect anisotropy of the dense tissue or simplify cortical bone microstructure (accounting for Haversian canals only). These simplifications (related mostly to insufficient mathematical apparatus) complicate quantitative analysis of the effect of microstructural changes – produced by age, microgravity, or some diseases – on the overall mechanical performance of cortical bone. The present analysis fills this gap; it accounts for anisotropy of the dense tissue and uses realistic model of the porous microstructure. The approach is based on recent results of Sevostianov et al. (2005) and Saadat et al. (2012) on inhomogeneities in a transversely-isotropic material. Bone?s microstructure is modeled according to books of Martin and Burr (1989), Currey (2002), and Fung (1993) and includes four main families of pores. The calculated elastic constants for porous cortical bone are in agreement with available experimental data. The influence of each of the pore types on the overall moduli is examined.     

Superimposed hemifields in primary visual cortex of achiasmic individuals

In the rare condition of achiasma, the visual cortex in each hemisphere receives information from both halves of the visual field. How is this "doubling" of information accommodated in V1? In this issue of Neuron, Hoffmann et?al. (2012) investigate the cortical consequences of this anomaly.     

Cbx proteins help ESCs walk the line between self-renewal and differentiation

The Polycomb repressive complexes (PRC) regulate self-renewal and differentiation in embryonic stem cells (ESCs). In this issue of Cell Stem Cell, Morey et al. (2012) and O'Loghlen et al. (2012) report that dynamic interchange of PRC subunits modulates the balance between self-renewal and lineage commitment in ESCs.     

Finally, Polyubiquitinated PCNA Gets Recognized

Studies from Ciccia et?al. (2012) and Yuan et?al. (2012) in this issue of Molecular Cell, together with Weston et?al. (2012), reveal that the translocase ZRANB3/AH2 can recognize K63-linked polyubiquitinated PCNA and plays an important role in restarting stalled replication forks.     

How to remake a fibroblast into a neural stem cell

In this issue of Cell Stem Cell and in a recent issue of PNAS, Thier et?al. (2012), Han et?al. (2012), and Lujan et?al. (2012) report the derivation of multipotent neural stem/progenitor cells from cultured mouse fibroblasts using distinct reprograming approaches.     

Epigenetic Variations in Plant Hybrids and Their Potential Roles in Heterosis

Heterosis,one of the most important biological phenomena,refers to the phenotypic superiority of a hybrid over its genetically diverse parents with respect to many traits such as biomass,growth rate and yield.Despite its successful application in breeding and agronomic production of many crop and animal varieties,the molecular basis of heterosis remains elusive.The classic genetic explanations for heterosis centered on three hypotheses:dominance (Davenport,1908;Bruce,1910;Keeble and Pellew,1910;Jones,1917),overdominance (East,1908;Shull,1908) and epistasis (Powers,1944;Yu et al.,1997).However,these hypotheses are largely conceptual and not connected to molecular principles,and are therefore insufficient to explain the molecular basis of heterosis (Birchler et al.,2003).Recently,many studies have explored the molecular mechanism of heterosis in plants at a genome-wide level.These studies suggest that global differential gene expression between hybrids and parental lines potentially contributes to heterosis in plants (e.g.,Swanson-Wagner et al.,2006;Zhang et al.,2008;Wei et al.,2009;Song et al.,2010).Research suggests that genetic components,including cis-acting elements and trans-acting factors,are critical regulators of differential gene expression in hybrids (Hochholdinger and Hoecker,2007;Springer and Stupar,2007;Zhang et al.,2008).However,other research indicates that epigenetic components,the regulators of chromatin states and genome activity,also have the potential to impact heterosis (e.g.,Ha et al.,2009;He et al.,2010;Groszmann et al.,2011;Barber et al.,2012;Chodavarapu et al.,2012;Greaves et al.,2012a;Shen et al.,2012).     

Immune plexins and semaphorins: old proteins,new immune functions

Plexins and semaphorins are a large family of proteins that are involved in cell movement and response. The importance of plexins and semaphorins has been emphasized by their discovery in many organ systems including the nervous (Nkyimbeng-Takwi and Chapoval, 2011; McCormick and Leipzig, 2012; Yaron and Sprinzak, 2012), epithelial (Miao et al., 1999; Fujii et al., 2002), and immune systems (Takamatsu and Kumanogoh, 2012) as well as diverse cell processes including angiogenesis (Serini et al., 2009; Sakurai et al., 2012), embryogenesis (Perala et al., 2012), and cancer (Potiron et al., 2009; Micucci et al., 2010). Plexins and semaphorins are transmembrane proteins that share a conserved extracellular semaphorin domain (Hota and Buck, 2012). The plexins and semaphorins are divided into four and eight subfamilies respectively based on their structural homology. Semaphorins are relatively small proteins containing the extracellular semaphorin domain and short intracellular tails. Plexins contain the semaphorin domain and long intracellular tails (Hota and Buck, 2012). The majority of plexin and semaphorin research has focused on the nervous system, particularly the developing nervous system, where these proteins are found to mediate many common neuronal cell processes including cell movement, cytoskeletal rearrangement, and signal transduction (Choi et al., 2008; Takamatsu et al., 2010). Their roles in the immune system are the focus of this review.     

TXNIP Switches Tracks toward a Terminal UPR

During the progression of diabetes, crosstalk between ER stress and inflammation controls islet cell fate. In this issue, Lerner et?al. (2012) and Oslowski et?al. (2012) discover that thioredoxin-interacting protein (TXNIP) is a regulatory switch connecting the terminal unfolded protein response (UPR) and NLRP3 inflammasome to mediate β cell death.     

Lymphocyte choriomeningitis virus plays hide-and-seek with type 1 interferon

In this issue, Macal et?al. (2012); Walsh et?al. (2012), and Wang et?al. (2012) examine how adaptive immune responses to acute and chronic lymphocyte choriomeningitis virus infection are regulated by type 1 interferon produced early during infection by different cell types upon activation by intracellular nucleic acid sensors.     

Some progress in the study of plant–soil interactions in China

Plants and soil are the base for sustainably surviving human beings on the globe as the role of materials, energy, resources and environment (Shao & Chu 2008; Shao et al. 2008, 2009, 2010, 2012a,b; Liu & Shao, 2010; Ruan et al. 2010; Xu et al. 2010, 2012; Shao 2012; Huang et al. 2013). This topic has been extensively investigated for 100 years with more achievements in many sectors and practical significance in conducting high-efficient agriculture and eco-environmental construction. The plant–soil interaction is the core issue of this topic, which has been given much attention for the past 30 years (Wu et al. 2007, 2010; Zhang et al. 2011, 2013; Xu et al. 2012, 2013).     

Sporoptosis: sowing the seeds of nuclear destruction

Previous models of neuronal dendrite arborization suggested that contact-dependent self-avoidance between dendrite branches prevents self-crossings within the arbor. Two papers in Neuron show how integrin-mediated adhesion to the extracellular matrix restricts dendrites to a two-dimensional space to optimize this mechanism (Han et al., 2012; Kim et al., 2012).     

Cortex shatters the glass ceiling

Recreating developmental structures in vitro has been a primary challenge for stem cell biologists. Recent studies in Cell Stem Cell (Eiraku et al., 2008) and Nature (Gaspard et al., 2008) demonstrate that embryonic stem cells can recapitulate early cortical development, enabling them to generate specific cortical subtypes.     

Editorial

The Per Brinck Foundation at the editorial office of the journal Oikos and Wiley/Blackwell Publishing annually awards the Per Brinck Oikos Award in honor of the Swedish ecologist Professor Per Brinck, who has played an instrumental role for the development and recognition of the science of ecology in the Nordic countries, especially as serving as the Editor‐in‐Chief for Oikos for many years. The Per Brinck Oikos Award recognizes extraordinary and important contributions to the science of ecology. Particular emphasis is given to scientific work aimed at synthesis that has led to novel and original research in unexplored or neglected fields or to bridging gaps between ecological disciplines. Such achievements typically require theoretical innovation and development as well as imaginative observational or experimental work, all of which will be valid grounds for recognition. The 2012 laureate is Prof. Tim Coulson from Imperial College London for his timely and synthesizing work on linking ecological and evolutionary theory. Instead of treating individual variation in life history as noise, he is embracing individual variation and the mechanisms leading to it. By integrating this variation into models he developed novel theoretical approaches to predict ecological and evolutionary consequences of environmental change on life history, population dynamics and the distribution of quantitative characters and genotypes. In this issue, we publish Tim Coulson’s Per Brinck lecture in which he demonstrates the advantages of integral projection models for the understanding of eco‐evolutionary dynamics in systems that cannot be easily replicated in the field ( Coulson 2012 ). By this hands‐ on paper, Tim advocates the benefits of IPM’s to field biologists who may not have tried to construct models before but might be interested in doing so. Oikos is publishing novel work that aims at synthesis and generalization; for instance recent empirical ( Auld and Charmantier 2011 ) and theoretical work of ( Bårdsen et al. 2011 ) on the linkage of life history and population dynamics to climate change. As evidenced by the per Brinck paper in this issue, real synthesis can be created by the integration of empirical and theoretical approaches in both marine ( Dias and Marshall 2010 ) and terrestrial environments ( Jacquemin et al. 2012 , Rodríguez‐Pérez and Traveset 2012 ). Oikos is aiming to stimulate synthesis in specific fields by bringing together papers from different disciplines and systems into more thematic issues that are centred on key contributions ( Bonte et al. 2012 ). In order to improve our understanding of the wealth of mechanisms determining life history variation, we have compiled such an issue consisting of 17 articles documenting novel insights in life history theory and its relevance for predicting phenomena at higher level of biological organization. We especially would like to highlight the contributions on density dependency in larger herbivores ( Mobæk et al. 2012 ) and novel approaches for testing them in nature ( Simard et al. 2012 ). Equally important is the synthesis created by the compilation of contributions demonstrating the interplay between genetics and environment on floral display and subsequent reproduction ( von Euler et al. 2012 ), its further importance for pollinator fitness ( Cahenzli and Erhardt 2012 ). By means of an elegant experiment, Brody and Irwin (2012) show that variability in plant response to herbivory can be attributed by plant interactions with mutualists and enemies. In a final package of papers, we compile work demonstrating amongst others the importance of stage‐ or age specific life history responses on predation ( Sand et al. 2012 ), phenology ( Briscoe et al. 2012 ) and the importance of overall life history variation on immunology and reservoir competence of infectious diseases ( Previtali et al. 2012 ).     

Is oral microbiome of children able to maintain resistance and functional stability in response to short-term interference of ingesta?

Dear Editor, A series of studies had focused on the ecological stability of human microbiome (Lozupone et al.,2012;Faith et al.,2013;Moya and Ferrer,2016).Despite the continuous perturbation and the highly personalized composition within the human microbiome (Human Microbiome Project,2012),healthy adults stably maintain their microbial communities in terms of space and time (Faith et al.,2013;Moya and Ferrer,2016;Oh et al.,2016).This stability is proved to be critical for the well-being of human body (Lozupone et al.,2012).On the contrary,major shifts in microbial community composition are often related to diseases (Lynch and Pedersen,2016).     

Axon trapping: constructing the visual system one layer at a time

Zhang et?al. (2012) and Rozas et?al. (2012) in this issue of Neuron find that cysteine string protein α, a protein involved in neurodegeneration, regulates vesicle endocytosis via interaction with dynamin 1, which may participate in regulating synaptic transmission and possibly in maintaining synapses.     

Synapses let loose for a change: inhibitory synapse pruning throughout experience-dependent cortical plasticity

In this issue of Neuron, Chen et?al. (2012) and van Versendaal et?al. (2012) used fluorescently tagged gephyrin to track inhibitory synapses in the mouse visual cortex in?vivo. Their studies show that visual experience-dependent plasticity is associated with clustered and location-specific pruning of inhibitory synapses.     

The mitochondrial pyruvate carrier: has it been unearthed at last?

The mitochondrial pyruvate carrier (MPC) is essential for several major pathways of carbohydrate, fat, and amino acid metabolism, yet its molecular identity has remained elusive. Two recent papers in Science (Herzig et?al., 2012; Bricker et?al., 2012) implicate three newly identified inner mitochondrial membrane proteins as MPC components.