The rockefeller university

Background: Magnolia champaca, commonly known as champak is a well-known tree due to its highly fragrant flowers. Champak floral scent is attributed to a complex mix of volatile organic compounds (VOCs). These aromatic flowers are widely used in flavors and fragrances industry. Despite its commercial importance, the VOC biosynthesis pathways in these flowers are largely unknown. Here, we combine metabolite and RNA sequencing (RNA-seq) analyses of fully opened champak flowers to discover the active VOC biosynthesis pathways as well as floral scent-related genes. Results: Volatile collection by headspace method and analysis by gas chromatography-mass spectrometry (GC-MS) identified a total of 43 VOCs from fully opened champak flowers, of which 46.9% were terpenoids, 38.9% were volatile esters and 5.2% belonged to phenylpropanoids/benzenoids. Sequencing and de novo assembly of champak flower transcriptome yielded 47,688 non-redundant unigenes. Transcriptome assembly was validated using standard polymerase chain reaction (PCR) based approach for randomly selected unigenes. The detailed profiles of VOCs led to the discovery of pathways and genes involved in floral scent biosynthesis from RNA-seq data. Analysis of expression levels of many floral-scent biosynthesis-related unigenes in flowers and leaves showed that most of them were expressed higher in flowers than in leaf tissues. Moreover, our metabolite-guided transcriptomics, in vitro and in vivo enzyme assays and transgenic studies identified (R)-linalool synthase that is essential for the production of major VOCs of champak flowers, (R)-linalool and linalool oxides. Conclusion: As our study is the first report on transcriptome analysis of Magnolia champaca, this transcriptome dataset that serves as an important public information for functional genomics will not only facilitate better understanding of ecological functions of champak floral VOCs, but also provide biotechnological targets for sustainable production of champak floral scent.

Mendelian susceptibility to mycobacterial disease is a rare syndrome characterized by severe clinical infections usually caused by weakly virulent mycobacterial species such as Bacillus Calmette-Guerin vaccines and environmental nontuberculous mycobacteria or more virulent mycobacteria as mycobacterium tuberculosis. Since 1996, 9 genes including 7 autosomal (STAT1, IFNGR1, IFNGR2, IL12B, IL12RB1, ISG15, and IRF8) and 2 X-linked genes ( NEMO and CYBB) have been identified. Allelic heterogeneity leaded to recognize about 18 genetic diseases with variable clinical phenotypes, but sharing a same physiological mechanism represented by a defect in human IL-12-dependant-INF-gamma-mediated immunity. We report here a case of multifocal Bacillus Calmette-Guerin osteomyelitis in a context Mendelian susceptibility to mycobacterial disease mimicking a metastatic neuroblastoma in a child presenting with delayed growth. The investigation of her twin sister showed the same disease. A heterozygous mutation in exon 22 of STAT1 gene was found in both sisters, another sister and the father being healthy and heterozygous for the same mutation.

Systemic lupus erythematosus (SLE) is an incurable autoimmune disease characterized by autoantibody deposition in tissues such as kidney, skin and lungs. Notably, up to 75% of patients with SLE experience neuropsychiatric symptoms that range from anxiety, depression and cognitive impairment to seizures and, in rare cases, psychosis-collectively this is referred to as central nervous system (CNS) lupus(1-4). In some cases, certain autoantibodies, such as anti-NMDAR or anti-phospholipid antibodies(5,6), promote CNS lupus. However, in most patients, the mechanisms that underlie these symptoms are unknown. CNS lupus typically presents at lupus diagnosis or within the first year, suggesting that early factors contributing to peripheral autoimmunity may promote CNS lupus symptoms. Here we report behavioural phenotypes and synapse loss in lupus-prone mice that are prevented by blocking type I interferon (IFN) signalling. Furthermore, we show that type I IFN stimulates microglia to become reactive and engulf neuronal and synaptic material in lupus-prone mice. These findings and our observation of increased type I IFN signalling in post-mortem hippocampal brain sections from patients with SLE may instruct the evaluation of ongoing clinical trials of anifrolumab(7), a type I IFN-receptor antagonist. Moreover, identification of IFN-driven microglia-dependent synapse loss, along with microglia transcriptome data, connects CNS lupus with other CNS diseases and provides an explanation for the neurological symptoms observed in some patients with SLE.

Background: Fusion of the human IgG1 Fc domain to the C-terminal C2 domain of B-domaindeleted (BDD) factor VIII (FVIII) results in the recombinant FVIII Fc (rFVIIIFc) fusion protein, which has a 1.5-fold longer half-life in humans. Objective: To assess the structural properties of rFVIIIFc by comparing its constituent FVIII and Fc elements with their respective isolated components, and evaluating their structural independence within rFVIIIFc. Methods: rFVIIIFc and its isolated FVIII and Fc components were compared by the use of hydrogen-deuterium exchange mass spectrometry (HDX-MS). The structure of rFVIIIFc was also evaluated by the use of X-ray crystallography, small-angle Xray scattering (SAXS), and electron microscopy (EM). The degree of steric interference by the appended Fc domain was assessed by EM and surface plasmon resonance (SPR). Results: HDX-MS analysis of rFVIIIFc revealed that fusion caused no structural perturbations in FVIII or Fc. The rFVIIIFc crystal structure showed that the FVIII component is indistinguishable from published BDD FVIII structures. The Fc domain was not observed, indicating high mobility. SAXS analysis was consistent with an ensemble of rigid-body models in which the Fc domain exists in a largely extended orientation relative to FVIII. Binding of Fab fragments of anti-C2 domain antibodies to BDD FVIII was visualized by EM, and the affinities of the corresponding intact antibodies for BDD FVIII and rFVIIIFc were comparable by SPR analysis. Conclusions: The FVIII and Fc components of rFVIIIFc are structurally indistinguishable from their isolated constituents, and show a high degree of structural independence, consistent with the functional comparability of rFVIIIFc and unmodified FVIII.

Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresismass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-D-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, alpha-cyano-4-hydroxycinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.

SAMHDI is a triphosphohydrolase that restricts HIV-1 by limiting the intracellular dNTP pool required for reverse transcription. Although SAMHDI is expressed and active/unphosphorylated in most cell lines, its restriction activity is thought to be relevant only in non-cycling cells. However, an in depth evaluation of SAMHD1 function and relevance in cycling cells is required. Here, we show that SAMHDI-induced degradation by HIV-2 Vpx affects the dNTP pool and HIV-1 replication capacity in the presence of the 3'-azido-3'-deoxythymidine (AZT) in cycling cells. Similarly, in SAMHD1 knockout cells, HIV-1 showed increased replicative capacity in the presence of nucleoside inhibitors, especially AZT, that was reverted by re-expression of wild type SAMHDI. Sensitivity to non-nucleoside inhibitors (nevirapine and efavirenz) or the integrase inhibitor raltegravir was not affected by SAMHDI. Combination of three mutations (S18A, T21A, T25A) significantly prevented SAMHDI phosphorylation but did not significantly affect HIV-1 replication in the presence of AZT. Our results demonstrate that SAMHDI is active in HIV-1 permissive cells, does not modify susceptibility to HIV-1 infection but strongly affects sensitivity to nucleoside inhibitors. (C) 2017 Elsevier B.V. All rights reserved.

Many animals keep track of their angular heading over time while navigating through their environment. However, a neural-circuit architecture for computing heading has not been experimentally defined in any species. Here we describe a set of clockwise-and anticlockwise-shifting neurons in the Drosophila central complex whose wiring and physiology provide a means to rotate an angular heading estimate based on the fly's angular velocity. We show that each class of shifting neurons exists in two subtypes, with spatiotemporal activity profiles that suggest different roles for each subtype at the start and end of tethered-walking turns. Shifting neurons are required for the heading system to properly track the fly's heading in the dark, and stimulation of these neurons induces predictable shifts in the heading signal. The central features of this biological circuit are analogous to those of computational models proposed for head-direction cells in rodents and may shed light on how neural systems, in general, perform integration.

Type III CRISPR-Cas systems have a unique targeting mechanism that requires the transcription of the DNA target and results in the degradation of not only the genome of the invader but also its transcripts. Here we discuss the most recent studies describing dual DNA and RNA targeting by these systems, as well as the implications of this complex molecular mechanism for immunity in vivo.

We compare several major white-matter tracts in human and macaque occipital lobe using diffusion magnetic resonance imaging. The comparison suggests similarities but also significant differences in the tracts. There are several apparently homologous tracts in the 2 species, including the vertical occipital fasciculus (VOF), optic radiation, forceps major, and inferior longitudinal fasciculus (ILF). There is one large human tract, the inferior fronto-occipital fasciculus, with no corresponding fasciculus in macaque. We could identify the macaque VOF (mVOF), which has been little studied. Its position is consistent with classical invasive anatomical studies by Wernicke. VOF homology is supported by similarity of the endpoints in V3A and ventral V4 across species. The mVOF fibers intertwine with the dorsal segment of the ILF, but the human VOF appears to be lateral to the ILF. These similarities and differences between the occipital lobe tracts will be useful in establishing which circuitry in the macaque can serve as an accurate model for human visual cortex.