\u3ci\u3eSUB1A\u3c/i\u3e-mediated submergence tolerance response in rice involves differential regulation of the brassinosteroid pathway

Submergence 1A (SUB1A), is an ethylene response factor (ERF) that confers submergence tolerance in rice (Oryza sativa) via limiting shoot elongation during the inundation period. SUB1A has been proposed to restrict shoot growth by modulating gibberellic acid (GA) signaling. Our transcriptome analysis indicated that SUB1A differentially regulates genes associated with brassinosteroid (BR) synthesis during submergence. Consistent with the gene expression data, the SUB1A genotype had higher brassinosteroid levels after submergence compared to the intolerant genotype. Tolerance to submergence can be activated in the intolerant genotype by pretreatment with exogenous brassinolide, which results in restricted shoot elongation during submergence. BR induced a GA catabolic gene, resulting in lower GA levels in SUB1A plants. BR treatment also induced the DELLA protein SLR1, a known repressor of GA responses such as shoot elongation. We propose that BR limits GA levels during submergence in the SUB1A rice through a GA catabolic enzyme as part of an early response and may repress GA responses by inducing SLR1 after several days of submergence. Our results suggest that BR biosynthesis is regulated in a SUB1A-dependent manner during submergence and is involved in modulating the GA signaling and homeostasis

A role for the RabA4b effector protein PI-4Kβ1 in polarized expansion of root hair cells in Arabidopsis thaliana

The RabA4b GTPase labels a novel, trans-Golgi network compartment displaying a developmentally regulated polar distribution in growing Arabidopsis thaliana root hair cells. GTP bound RabA4b selectively recruits the plant phosphatidylinositol 4-OH kinase, PI-4Kβ1, but not members of other PI-4K families. PI-4Kβ1 colocalizes with RabA4b on tip-localized membranes in growing root hairs, and mutant plants in which both the PI-4Kβ1 and -4Kβ2 genes are disrupted display aberrant root hair morphologies. PI-4Kβ1 interacts with RabA4b through a novel homology domain, specific to eukaryotic type IIIβ PI-4Ks, and PI-4Kβ1 also interacts with a Ca2+ sensor, AtCBL1, through its NH2 terminus. We propose that RabA4b recruitment of PI-4Kβ1 results in Ca2+-dependent generation of PI-4P on this compartment, providing a link between Ca2+ and PI-4,5P2–dependent signals during the polarized secretion of cell wall components in tip-growing root hair cells

Human NK cells confer protection against HIV-1 infection in humanized mice

The role of NK cells against HIV-1 infections remains to be elucidated in vivo. While humanized mouse models potentially could be used to directly evaluate human NK cell responses during HIV-1 infection, improved functional development of human NK cells in these hosts is needed. Here, we report the humanized MISTRG-6-15 mouse model, in which NK cells were quick to expand and exhibit degranulation, cytotoxicity, and proinflammatory cytokine production in nonlymphoid organs upon HIV-1 infection but had reduced functionality in lymphoid organs. Although HIV-1 infection induced functional impairment of NK cells, antiretroviral therapy reinvigorated NK cells in response to HIV-1 rebound after analytic treatment interruption. Moreover, a broadly neutralizing antibody, PGT121, enhanced NK cell function in vivo, consistent with antibody-dependent cellular cytotoxicity. Monoclonal antibody depletion of NK cells resulted in higher viral loads in multiple nonlymphoid organs. Overall, our results in humanized MISTRG-6-15 mice demonstrated that NK cells provided direct anti-HIV-1 responses in vivo but were limited in their responses in lymphoid organs

Polyclonal epitope mapping reveals temporal dynamics and diversity of human antibody responses to H5N1 vaccination

Novel influenza A virus (IAV) strains elicit recall immune responses to conserved epitopes, making them favorable antigenic choices for universal influenza virus vaccines. Evaluating these immunogens requires a thorough understanding of the antigenic sites targeted by the polyclonal antibody (pAb) response, which single-particle electron microscopy (EM) can sensitively detect. In this study, we employ EM polyclonal epitope mapping (EMPEM) to extensively characterize the pAb response to hemagglutinin (HA) after H5N1 immunization in humans. Cross-reactive pAbs originating from memory B cells immediately bound the stem of HA and persisted for more than a year after vaccination. In contrast, de novo pAb responses to multiple sites on the head of HA, targeting previously determined key neutralizing sites on H5 HA, expanded after the second immunization and waned quickly. Thus, EMPEM provides a robust tool for comprehensively tracking the specificity and durability of immune responses elicited by novel universal influenza vaccine candidates

Arbetsplatser i Kortedala och Gårdsten : branschstruktur och lokaliseringsmönster i två bostadsområden i Göteborg /

<p><b>Shoot (A-C) and root (D-F) ion content for <i>HKT1;1</i> native overexpression lines.</b> Statistical significance was determined using Tukey’s HSD test between each line within treatments. Bars with the same letters indicate no significant difference (<i>p</i> < 0.05). Error bars represent standard error of the mean where n = 12–18 plants.</p

Genetic Determinants of Circulating Sphingolipid Concentrations in European Populations

Sphingolipids have essential roles as structural components of cell membranes and in cell signalling, and disruption of their metabolism causes several diseases, with diverse neurological, psychiatric, and metabolic consequences. Increasingly, variants within a few of the genes that encode enzymes involved in sphingolipid metabolism are being associated with complex disease phenotypes. Direct experimental evidence supports a role of specific sphingolipid species in several common complex chronic disease processes including atherosclerotic plaque formation, myocardial infarction (MI), cardiomyopathy, pancreatic beta-cell failure, insulin resistance, and type 2 diabetes mellitus. Therefore, sphingolipids represent novel and important intermediate phenotypes for genetic analysis, yet little is known about the major genetic variants that influence their circulating levels in the general population. We performed a genome-wide association study (GWAS) between 318,237 single-nucleotide polymorphisms (SNPs) and levels of circulating sphingomyelin (SM), dihydrosphingomyelin (Dih-SM), ceramide (Cer), and glucosylceramide (GluCer) single lipid species (33 traits); and 43 matched metabolite ratios measured in 4,400 subjects from five diverse European populations. Associated variants (32) in five genomic regions were identified with genome-wide significant corrected p-values ranging down to 9.08 x 10(-66). The strongest associations were observed in or near 7 genes functionally involved in ceramide biosynthesis and trafficking: SPTLC3, LASS4, SGPP1, ATP10D, and FADS1-3. Variants in 3 loci (ATP10D, FADS3, and SPTLC3) associate with MI in a series of three German MI studies. An additional 70 variants across 23 candidate genes involved in sphingolipid-metabolizing pathways also demonstrate association (p = 10(-4) or less). Circulating concentrations of several key components in sphingolipid metabolism are thus under strong genetic control, and variants in these loci can be tested for a role in the development of common cardiovascular, metabolic, neurological, and psychiatric diseases

Towards a cohesive, holistic view of top predation: a definition, synthesis and perspective

Research on the ecology of top predators – upper trophic level consumers that are relatively free from predation once they reach adult size – has provided regular contributions to general ecology and is a rapidly expanding and increasingly experimental, multidisciplinary and technological endeavour. Yet, an exponentially expanding literature coupled with rapid disintegration into specialized, disconnected subfields for study (e.g. vertebrate predators versus invertebrate predators, community ecology versus biological control etc.) increasingly means that we are losing a coherent, integrated understating of the role and importance of these species in ecosystems. This process of canalization is likely to hinder sharing of scientific discovery and continued progress, especially as there is a growing need to understand the generality of the top–down forcing, as demonstrated for some members of this group. Here, we propose ways to facilitate synthesis by promoting changes in mentality and awareness among specialists through increased debate and collaboration, conceptual reviews and a series of exemplary case studies. The strategy will rely on the collective contribution by all scientists in the field and will strive to consolidate and formalise top-order predation as a holistic, cohesive, cross-taxonomical field of research studying the ecology, evolution and behaviour of apex predators and their capability to exert top–down forcing on lower trophic levels.SYNTHESIS: The ongoing global loss of top predators and their recolonization of various regions are causing a rapid upsurge of studies on these species and a consequent fragmentation of this field into disconnected, specialized subcompartments: this will weaken efforts to produce synthetic generalisations of broader ecological interest. Here, we show that top predation provides regular contributions to general ecology, is well grounded in theoretical ecology and is a rapidly expanding and increasingly experimental, multidisciplinary and technological field of research. The novelty of this forum lies in providing a concise synthesis of this area of ecology, in attempting to formalise “top predation” as a specific, inter-connected area of investigation, and in proposing a marked change of mentality by stressing the need for cross-taxonomic approaches enabling broader views of the role of predators in ecosystems

Biophysical and Functional Characterization of Rhesus Macaque IgG Subclasses

Antibodies raised in Indian rhesus macaques [Macaca mulatta (MM)] in many preclinical vaccine studies are often evaluated in vitro for titer, antigen-recognition breadth, neu- tralization potency, and/or effector function, and in vivo for potential associations with protection. However, despite reliance on this key animal model in translation of promising candidate vaccines for evaluation in first in man studies, little is known about the proper- ties of MM immunoglobulin G (IgG) subclasses and how they may compare to human IgG subclasses. Here, we evaluate the binding of MM IgG1, IgG2, IgG3, and IgG4 to human Fc gamma receptors (FcγR) and their ability to elicit the effector functions of human FcγR-bearing cells, and unlike in humans, find a notable absence of subclasses with dramatically silent Fc regions. Biophysical, in vitro, and in vivo characterization revealed MM IgG1 exhibited the greatest effector function activity followed by IgG2 and then IgG3/4. These findings in rhesus are in contrast with the canonical understanding that IgG1 and IgG3 dominate effector function in humans, indicating that subclass-switching profiles observed in rhesus studies may not strictly recapitulate those observed in human vaccine studies

Localized Populations of CD8low/− MHC Class I Tetramer+ SIV-Specific T Cells in Lymphoid Follicles and Genital Epithelium

CD8 T cells play an important role in controlling viral infections. We investigated the in situ localization of simian immunodeficiency virus (SIV)-specific T cells in lymph and genital tissues from SIV-infected macaques using MHC-class I tetramers. The majority of tetramer-binding cells localized in T cell zones and were CD8+. Curiously, small subpopulations of tetramer-binding cells that had little to no surface CD8 were detected in situ both early and late post-infection, and in both vaginally and rectally inoculated macaques. These tetramer+CD8low/− cells were more often localized in apparent B cell follicles relative to T cell zones and more often found near or within the genital epithelium than the submucosa. Cells analyzed by flow cytometry showed similar populations of cells. Further immunohistological characterization revealed small populations of tetramer+CD20− cells inside B cell follicles and that tetramer+ cells did not stain with γδ-TCR nor CD4 antibodies. Negative control tetramer staining indicated that tetramer+CD8low/− cells were not likely NK cells non-specifically binding to MHC tetramers. These findings have important implications for SIV-specific and other antigen-specific T cell function in these specific tissue locations, and suggest a model in which antigen-specific CD8+ T cells down modulate CD8 upon entering B cell follicles or the epithelial layer of tissues, or alternatively a model in which only antigen-specific CD8 T cells that down-modulate CD8 can enter B cell follicles or the epithelium

The Promoter of the Cereal VERNALIZATION1 Gene Is Sufficient for Transcriptional Induction by Prolonged Cold

The VERNALIZATION1 (VRN1) gene of temperate cereals is transcriptionally activated by prolonged cold during winter (vernalization) to promote flowering. To investigate the mechanisms controlling induction of VRN1 by prolonged cold, different regions of the VRN1 gene were fused to the GREEN FLUORESCENT PROTEIN (GFP) reporter and expression of the resulting gene constructs was assayed in transgenic barley (Hordeum vulgare). A 2 kb segment of the promoter of VRN1 was sufficient for GFP expression in the leaves and shoot apex of transgenic barley plants. Fluorescence increased at the shoot apex prior to inflorescence initiation and was subsequently maintained in the developing inflorescence. The promoter was also sufficient for low-temperature induction of GFP expression. A naturally occurring insertion in the proximal promoter, which is associated with elevated VRN1 expression and early flowering in some spring wheats, did not abolish induction of VRN1 transcription by prolonged cold, however. A translational fusion of the promoter and transcribed regions of VRN1 to GFP, VRN1::GFP, was localised to nuclei of cells at the shoot apex of transgenic barley plants. The distribution of VRN1::GFP at the shoot apex was similar to the expression pattern of the VRN1 promoter-GFP reporter gene. Fluorescence from the VRN1::GFP fusion protein increased in the developing leaves after prolonged cold treatment. These observations suggest that the promoter of VRN1 is targeted by mechanisms that trigger vernalization-induced flowering in economically important temperate cereal crops