Mostrando recursos 1 - 20 de 28.419

  1. Relevance of secretor status genotype and microbiota composition in susceptibility to rotavirus and norovirus infections in humans

    Rodríguez Díaz, Jesús; García Mantrana, Izaskun; Vila Vicent, Susana; Gozalbo Rovira, Roberto; Buesa, Javier; Monedero, Vicente; Collado, Maria Carmen
    Host genetic factors, such as histo-blood group antigens (HBGAs), are associated with susceptibility to norovirus (NoV) and rotavirus (RV) infections. Recent advances point to the gut microbiome as a key player necessary for a viral pathogen to cause infection. In vitro NoV attachment to host cells and resulting infections have been linked to interactions with certain bacterial types in the gut microbiota. We investigated the relationship between host genotype, gut microbiota, and viral infections. Saliva and fecal samples from 35 adult volunteers were analysed for secretor status genotype, the gut microbiota composition by 16S rRNA gene sequencing, and salivary IgA...

  2. Rho GTPases and their regulators in addiction: A focus on the association of a ß2-chimaerin polymorphism with smoking

    Caloca, María J.; Barrio, Laura del; González-Sarmiento, Rogelio
    Tobacco addiction is a complex disorder that involves multiple molecular mechanisms and is influenced by genetic factors. Repeated exposure to nicotine induces the remodeling of synaptic connections, a process that contributes to the long-lasting nature of tobacco addiction. Rho GTPases are key regulators of synaptic structure and function and, therefore, these proteins have a potential role in nicotine addiction. In this chapter we will briefly describe some studies that identify genes encoding Rho GTPases and their regulators as candidate genes for smoking-related behaviors, with special focus on the CHN2 gene. The CHN2 gene encodes the β2-chimaerin, a member of the...

  3. Role of transcriptional regulation in the evolution of plant phenotype: A dynamic systems approach

    Rodríguez-Mega, Emiliano; Piñeiro-Nelson, Alma; Gutiérrez Armenta, Crisanto; García-Ponce, Berenice; Sánchez, María de La Paz; Zluhan-Martínez, Estephania; Álvarez-Buylla, Elena R.; Garay-Arroyo, Adriana
    © 2015 Wiley Periodicals, Inc. A growing body of evidence suggests that alterations in transcriptional regulation of genes involved in modulating development are an important part of phenotypic evolution, and this can be documented among species and within populations. While the effects of differential transcriptional regulation in organismal development have been preferentially studied in animal systems, this phenomenon has also been addressed in plants. In this review, we summarize evidence for cis-regulatory mutations, trans-regulatory changes and epigenetic modifications as molecular events underlying important phenotypic alterations, and thus shaping the evolution of plant development. We postulate that a mechanistic understanding of...

  4. Genome architecture: from linear organisation of chromatin to the 3D assembly in the nucleus

    Sequeira-Mendes, Joana; Gutiérrez Armenta, Crisanto
    The genetic information is stored in the eukaryotic nucleus in the form of chromatin. This is a macromolecular entity that includes genomic DNA and histone proteins that form nucleosomes, plus a large variety of chromatin-associated non-histone proteins. Chromatin is structurally and functionally organised at various levels. One reveals the linear topography of DNA, histones and their post-translational modifications and non-histone proteins along each chromosome. This level provides regulatory information about the association of genomic elements with particular signatures that have been used to define chromatin states. Importantly, these chromatin states correlate with structural and functional genomic features. Another regulatory layer...

  5. Decreased glycogen synthase kinase-3 levels and activity contribute to Huntington's disease

    Fernández-Nogales, Marta; Hernández Pérez, Félix; Miguez, Andrés; Alberch, Jordi; Ginés, Silvia; Pérez-Navarro, Esther; Lucas, José Javier
    © The Author 2015. Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by brain atrophy particularly in striatum leading to personality changes, chorea and dementia. Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase in the crossroad of many signaling pathways that is highly pleiotropic as it phosphorylates more than hundred substrates including structural, metabolic, and signaling proteins. Increased GSK-3 activity is believed to contribute to the pathogenesis of neurodegenerative diseases like Alzheimer's disease and GSK-3 inhibitors have been postulated as therapeutic agents for neurodegeneration. Regarding HD, GSK-3 inhibitors have shown beneficial effects in cell and invertebrate animal models but...

  6. Secreted frizzled-related proteins are required for Wnt/beta-catenin signalling activation in the vertebrate optic cup.

    Esteve, Pilar; Sandonis Consuegra, África; Ibáñez, Carmen; Shimono, Akihiko; Guerrero Vega, Isabel; Bovolenta, Paola
    Secreted frizzled-related proteins (Sfrps) are considered Wnt signalling antagonists but recent studies have shown that specific family members enhance Wnt diffusion and thus positively modulate Wnt signalling. Whether this is a general and physiological property of all Sfrps remains unexplored. It is equally unclear whether disruption of Sfrp expression interferes with developmental events mediated by Wnt signalling activation. Here, we have addressed these questions by investigating the functional consequences of Sfrp disruption in the canonical Wnt signalling-dependent specification of the mouse optic cup periphery. We show that compound genetic inactivation of Sfrp1 and Sfrp2 prevents Wnt/-catenin signalling activation in this structure,...

  7. Different susceptibility to neurodegeneration of dorsal and ventral hippocampal dentate gyrus: A study with transgenic mice overexpressing GSK3β

    Fuster-Matanzo, Almudena; Llorens-Martín, M.; Gómez de Barreda, Elena; Ávila, Jesús; Hernández Pérez, Félix
    Dorsal hippocampal regions are involved in memory and learning processes, while ventral areas are related to emotional and anxiety processes. Hippocampal dependent memory and behaviour alterations do not always come out in neurodegenerative diseases at the same time. In this study we have tested the hypothesis that dorsal and ventral dentate gyrus (DG) regions respond in a different manner to increased glycogen synthase kinase-3β (GSK3β) levels in GSK3β transgenic mice, a genetic model of neurodegeneration. Reactive astrocytosis indicate tissue stress in dorsal DG, while ventral area does not show that marker. These changes occurred with a significant reduction of total...

  8. GSK-3β, a pivotal kinase in Alzheimer disease

    Llorens-Martín, M.; Jurado, Jerónimo; Hernández Pérez, Félix; Ávila, Jesús
    Alzheimer disease (AD) is the most common form of age-related dementia. The etiology of AD is considered to be multifactorial as only a negligible percentage of cases have a familial or genetic origin. Glycogen synthase kinase-3 (GSK-3) is regarded as a critical molecular link between the two histopathological hallmarks of the disease, namely senile plaques and neurofibrillary tangles. In this review, we summarize current data regarding the involvement of this kinase in several aspects of AD development and progression, as well as key observations highlighting GSK-3 as one of the most relevant targets for AD treatment. © 2014 Llorens-Martín, Jurado,...

  9. Selective inhibition of clade A PP2Cs by PYR/PYLs

    Antoni, Regina; González-Guzmán, Miguel; Rodríguez, Lesia; Rodrigues, Americo do Patrocinio; Pizzio, Gastón A.; Rodríguez, Pedro L.
    Clade A protein phosphatases type 2C (PP2Cs) are negative regulators of abscisic acid (ABA) signalling that are inhibited in an ABA-dependent manner by PYRABACTIN RESISTANCE1 (PYR1)/PYR1-LIKE (PYL)/ REGULATORY COMPONENTS OF ABA RECEPTORS (RCAR) intracellular receptors. We provide genetic evidence that a previously uncharacterized member of this PP2C family in Arabidopsis thaliana, At5g59220, is a negative regulator of osmotic stress and ABA signalling and this function was only apparent when double loss-of-function mutants with pp2ca-1/ahg3 were generated. At5g59220-GFP and its close relative PP2CA-GFP showed a predominant nuclear localization, however, hemagglutinin (HA)-tagged versions were also localized to cytosol and microsomal pellets. At5g59220...

  10. Mixed infections of Pepino mosaic virus strains modulate the evolutionary dynamics of this emergent virus

    Gómez, Pedro; Sempere, R. N.; Elena, Santiago F.; Aranda, Miguel A.
    Pepino mosaic virus (PepMV) is an emerging pathogen that causes severe economic losses in tomato crops (Solanum lycopersicum L.) in the Northern hemisphere, despite persistent attempts of control. In fact, it is considered one of the most significant viral diseases for tomato production worldwide, and it may constitute a good model for the analysis of virus emergence in crops. We have combined a population genetics approach with an analysis of in planta properties of virus strains to explain an observed epidemiological pattern. Hybridization analysis showed that PepMV populations are composed of isolates of two types (PepMV-CH2 and PepMV-EU) that cocirculate....

  11. Tricomonosis bovina: caracterización de cepas prevalentes en la provincia de La Pampa e inmunoprofilaxis de la enfermedad mediante el empleo de vacunas experimentales en vaquillonas

    Fuchs, Lumila Ivana
    La tricomonosis bovina es una enfermedad de transmisión sexual causada por el protozoo flagelado Tritrichomonas foetus. En la hembra, la enfermedad se manifiesta or ciclos estrales irregulares, pérdidas embrionarias y fetales tempranas y piómetras. En el macho, la infección es asintomática y no afecta la calidad seminal ni la libido. Este trabajo tuvo dos objetivos fundamentales. Primero, se evaluó el efecto protector de vacunas a base de célula entera de T. foetus en vaquillonas, para mejorar el conocimiento de la respuesta inmunitaria y favorecer el control de la enfermedad. Segundo, se caracterizaron las cepas de T. foetus obtenidas de casos naturales...

  12. Variabilidade genetica em hordeum euclaston l. (gramineae)

    Ferreira, Carlos Alexandre Sanchez
    Resumo não disponível

  13. Genetic diversity of multidrug resistant Mycobacterium tuberculosis Central Asian Strain isolates in Nepal [an abstract of dissertation and a summary of dissertation review]

    SHAH, YOGENDRA

  14. Genetic characterization of Mycobacterium orygis isolates from animals of South Asia [an abstract of dissertation and a summary of dissertation review]

    THAPA, JEEWAN

  15. Genetic characterization of Mycobacterium orygis isolates from animals of South Asia

    THAPA, JEEWAN

  16. Occurrence and Origin of Andalusite in Peraluminous Felsic Igneous Rocks.

    Barrie Clarke, D.; Dorais, Michael; Barbarin, Bernard; Barker, Dan; Cesare, Bernardo; Clarke, Geoffrey; El Baghdadi, Mohamed; Erdmann, Saskia; FÖrster, Hans-JÜrgen; Gaeta, Mario; Gottesmann, BÄrbel; Jamieson, Rebecca,; Kontak, Daniel,; Koller, Friedrich; Leal Gomes, Carlos; London, David; Morgan, George,; Neves, Luis,; Pattison, David,; Pereira, Alcides,; Pichavant, Michel; Rapela, Carlos,; Renno, Axel,; Richards, Simon; Roberts, Malcolm; Rottura, Alessandro; Saavedra, Julio; Nobrega Sial, Alcides; Toselli, Alejandro,; Ugidos, Jose,; Uher, Pavel; Villaseca, Carlos; Visonà, Dario; Whitney, Donna,; Williamson, Ben; Woodard, Henry,
    Andalusite occurs as an accessory mineral in many types of peraluminous felsic igneous rocks, including rhyolites, aplites, granites, pegmatites, and anatectic migmatites. Some published stability curves for And = Sil and the water-saturated granite solidus permit a small stability field for andalusite in equilibrium with felsic melts. We examine 108 samples of andalusite-bearing felsic rocks from more than 40 localities world-wide. Our purpose is to determine the origin of andalusite, including the T–P–X controls on andalusite formation, using eight textural and chemical criteria: size—compatibility with grain sizes of igneous minerals in the same rock; shape—ranging from euhedral to anhedral, with...

  17. Basalt-inherited microlites in silicic magmas: evidence from Mt. Pelée (Martinique, F.W.I.).

    Martel, Caroline; Radadi Ali, Ahmed; Poussineau, Stéphane; Gourgaud, Alain; Pichavant, Michel
    During magma ascent in the volcanic conduit, the decompression of a silicic melt may result in the crystallization of morphologically and compositionally specific crystals, designated as microlites. Hence, microlites have been considered as probes of mechanisms and timescales of magma ascent. Some microlites, however, appear to be in strong thermodynamic disequilibrium with their surrounding melt. We present here an experimental data set revealing that these microlites actually grew prior to ascent during mafic recharge of the magma chamber. These microlites have therefore no genetic relation with decompression-induced crystallization processes. Their presence may affect the rheological properties of the melt, as...

  18. "The Fragility of Beginnings : The First Genetic Stratum of Le Square by Marguerite Duras (1956)"

    Mervant-Roux, Marie-Madeleine
    Titre du numéro : Genetics of Performance

  19. Detection of genetic hypopituitarism in an adult population of idiopathic pituitary insufficiency patients with growth hormone deficiency.

    Nyström, Helena Filipsson; Saveanu, Alexandru; Barbosa, Edna J L; Barlier, Anne; Enjalbert, Alain; Glad, Camilla; Palming, Jenny; Johannsson, Gudmundur; Brue, Thierry
    International audience

  20. Genetic causes of combined pituitary hormone deficiencies in humans.

    Castinetti, Frédéric; Reynaud, Rachel; Saveanu, Alexandru; Barlier, Anne; Brue, Thierry
    International audience

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