5,073 research outputs found

    Bartonella spp. in Bats, Guatemala

    Get PDF
    To better understand the role of bats as reservoirs of Bartonella spp., we estimated Bartonella spp. prevalence and genetic diversity in bats in Guatemala during 2009. We found prevalence of 33% and identified 21 genetic variants of 13 phylogroups. Vampire bat–associated Bartonella spp. may cause undiagnosed illnesses in humans

    Effect of flecainide derivatives on sarcoplasmic reticulum calcium release suggests a lack of direct action on the cardiac ryanodine receptor

    Get PDF
    Background and Purpose Flecainide is a use-dependent blocker of cardiac Na+ channels. Mechanistic analysis of this block showed that the cationic form of flecainide enters the cytosolic vestibule of the open Na+ channel. Flecainide is also effective in the treatment of catecholaminergic polymorphic ventricular tachycardia but, in this condition, its mechanism of action is contentious. We investigated how flecainide derivatives influence Ca2+-release from the sarcoplasmic reticulum through the ryanodine receptor channel (RyR2) and whether this correlates with their effectiveness as blockers of Na+ and/or RyR2 channels. Experimental Approach We compared the ability of fully charged (QX-FL) and neutral (NU-FL) derivatives of flecainide to block individual recombinant human RyR2 channels incorporated into planar phospholipid bilayers, and their effects on the properties of Ca2+ sparks in intact adult rat cardiac myocytes. Key Results Both QX-FL and NU-FL were partial blockers of the non-physiological cytosolic to luminal flux of cations through RyR2 channels but were significantly less effective than flecainide. None of the compounds influenced the physiologically relevant luminal to cytosol cation flux through RyR2 channels. Intracellular flecainide or QX-FL, but not NU-FL, reduced Ca2+ spark frequency. Conclusions and Implications Given its inability to block physiologically relevant cation flux through RyR2 channels, and its lack of efficacy in blocking the cytosolic-to-luminal current, the effect of QX-FL on Ca2+ sparks is likely, by analogy with flecainide, to result from Na+ channel block. Our data reveal important differences in the interaction of flecainide with sites in the cytosolic vestibules of Na+ and RyR2 channels

    Chance and necessity in the genome evolution of endosymbiotic bacteria of insects

    Full text link
    [EN] An open question in evolutionary biology is how does the selection¿drift balance determine the fates of biological interactions. We searched for signatures of selection and drift in genomes of five endosymbiotic bacterial groups known to evolve under strong genetic drift. Although most genes in endosymbiotic bacteria showed evidence of relaxed purifying selection, many genes in these bacteria exhibited stronger selective constraints than their orthologs in free-living bacterial relatives. Remarkably, most of these highly constrained genes had no role in the host¿symbiont interactions but were involved in either buffering the deleterious consequences of drift or other host-unrelated functions, suggesting that they have either acquired new roles or their role became more central in endosymbiotic bacteria. Experimental evolution of Escherichia coli under strong genetic drift revealed remarkable similarities in the mutational spectrum, genome reduction patterns and gene losses to endosymbiotic bacteria of insects. Interestingly, the transcriptome of the experimentally evolved lines showed a generalized deregulation of the genome that affected genes encoding proteins involved in mutational buffering, regulation and amino acid biosynthesis, patterns identical to those found in endosymbiotic bacteria. Our results indicate that drift has shaped endosymbiotic associations through a change in the functional landscape of bacterial genes and that the host had only a small role in such a shiftThis work was supported by Science Foundation Ireland (12/IP/1637) and grants from the Spanish Ministerio de Economia y Competitividad (MINECO-FEDER; BFU2012-36346 and BFU2015-66073-P) to MAF. DAP and CT were supported by Juan de la Cierva fellowships from MINECO (references: JCI-2011-11089 and JCA-2012-14056, respectively). DAP is supported by funds from the University of Nevada, Reno, NV, USA.Sabater-Muñoz, B.; Toft, C.; Alvarez-Ponce, D.; Fares Riaño, MA. (2017). Chance and necessity in the genome evolution of endosymbiotic bacteria of insects. The ISME Journal. 11(6):1291-1304. https://doi.org/10.1038/ismej.2017.18S12911304116Aguilar-Rodriguez J, Sabater-Munoz B, Montagud-Martinez R, Berlanga V, Alvarez-Ponce D, Wagner A et al. (2016). The molecular chaperone DnaK is a source of mutational robustness. Genome Biol Evol 8: 2979–2991.Alvarez-Ponce D, Sabater-Munoz B, Toft C, Ruiz-Gonzalez MX, Fares MA . (2016). Essentiality is a strong determinant of protein rates of evolution during mutation accumulation experiments in Escherichia coli. Genome Biol Evol 8: 2914–2927.Anders S, Huber W . (2010). Differential expression analysis for sequence count data. Genome Biol 11: R106.Archibald J . (2014) One Plus One Equals One: Symbiosis and the Evolution of Complex Life. Oxford University Press: Oxford, UK.Aussel L, Loiseau L, Hajj Chehade M, Pocachard B, Fontecave M, Pierrel F et al. (2014). ubiJ, a new gene required for aerobic growth and proliferation in macrophage, is involved in coenzyme Q biosynthesis in Escherichia coli and Salmonella enterica serovar Typhimurium. J Bacteriol 196: 70–79.Baumann P, Baumann L, Clark MA . (1996). Levels of Buchnera aphidicola chaperonin groEL during growth of the aphid Schizaphis graminum. Curr Microbiol 32: 7.Benjamini Y, Yekutieli Y . (2005). False discovery rate controlling confidence intervals for selected parameters. J Am Stat Assoc 100: 10.Bennett GM, Moran NA . (2015). Heritable symbiosis: the advantages and perils of an evolutionary rabbit hole. Proc Natl Acad Sci USA 112: 10169–10176.Bermingham J, Rabatel A, Calevro F, Vinuelas J, Febvay G, Charles H et al. (2009). Impact of host developmental age on the transcriptome of the symbiotic bacterium Buchnera aphidicola in the pea aphid (Acyrthosiphon pisum. Appl Environ Microbiol 75: 7294–7297.Bogumil D, Dagan T . (2010). Chaperonin-dependent accelerated substitution rates in prokaryotes. Genome Biol Evol 2: 602–608.Carbon S, Ireland A, Mungall CJ, Shu S, Marshall B, Lewis S et al. (2009). AmiGO: online access to ontology and annotation data. Bioinformatics 25: 288–289.Chen Z, Wang Y, Li Y, Li Y, Fu N, Ye J et al. (2012). Esre: a novel essential non-coding RNA in Escherichia coli. FEBS Lett 586: 1195–1200.Clark JW, Hossain S, Burnside CA, Kambhampati S . (2001). Coevolution between a cockroach and its bacterial endosymbiont: a biogeographical perspective. Proc Biol Sci 268: 393–398.Dale C, Wang B, Moran N, Ochman H . (2003). Loss of DNA recombinational repair enzymes in the initial stages of genome degeneration. Mol Biol Evol 20: 1188–1194.Deatherage DE, Barrick JE . (2014). Identification of mutations in laboratory-evolved microbes from next-generation sequencing data using breseq. Methods Mol Biol 1151: 165–188.Douglas AE . (2003). The nutritional physiology of aphids. Adv Insect Physiol 31: 68.Fares MA, Barrio E, Sabater-Munoz B, Moya A . (2002a). The evolution of the heat-shock protein GroEL from Buchnera, the primary endosymbiont of aphids, is governed by positive selection. Mol Biol Evol 19: 1162–1170.Fares MA, Ruiz-Gonzalez MX, Moya A, Elena SF, Barrio E . (2002b). Endosymbiotic bacteria: groEL buffers against deleterious mutations. Nature 417: 398.Gancedo C, Flores CL, Gancedo JM . (2016). The expanding landscape of moonlighting proteins in yeasts. Microbiol Mol Biol Rev 80: 765–777.Gerardo NM, Altincicek B, Anselme C, Atamian H, Barribeau SM, de Vos M et al. (2010). Immunity and other defenses in pea aphids, Acyrthosiphon pisum. Genome Biol 11: R21.Gomez-Valero L, Latorre A, Silva FJ . (2004). The evolutionary fate of nonfunctional DNA in the bacterial endosymbiont Buchnera aphidicola. Mol Biol Evol 21: 2172–2181.Gomez-Valero L, Silva FJ, Christophe Simon J, Latorre A . (2007). Genome reduction of the aphid endosymbiont Buchnera aphidicola in a recent evolutionary time scale. Gene 389: 87–95.Gonzalez-Domenech CM, Belda E, Patino-Navarrete R, Moya A, Pereto J, Latorre A . (2012). Metabolic stasis in an ancient symbiosis: genome-scale metabolic networks from two Blattabacterium cuenoti strains, primary endosymbionts of cockroaches. BMC Microbiol 12 (Suppl 1): S5.Hansen AK, Moran NA . (2011). Aphid genome expression reveals host-symbiont cooperation in the production of amino acids. Proc Natl Acad Sci USA 108: 2849–2854.Hansen AK, Moran NA . (2014). The impact of microbial symbionts on host plant utilization by herbivorous insects. Mol Ecol 23: 1473–1496.Henderson B, Fares MA, Lund PA . (2013). Chaperonin 60: a paradoxical, evolutionarily conserved protein family with multiple moonlighting functions. Biol Rev Camb Philos Soc 88: 955–987.Humphreys NJ, Douglas AE . (1997). Partitioning of symbiotic bacteria between generations of an insect: a quantitative study of a Buchnera sp. in the pea aphid (Acyrthosiphon pisum reared at different temperatures. Appl Environ Microbiol 63: 3294–3296.International Aphid Genomics Consortium. (2010). Genome sequence of the pea aphid Acyrthosiphon pisum. PLoS Biol 8: e1000313.Kadibalban AS, Bogumil D, Landan G, Dagan T . (2016). DnaK-dependent accelerated evolutionary rate in prokaryotes. Genome Biol Evol 8: 1590–1599.Katoh K, Standley DM . (2013). MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Mol Biol Evol 30: 772–780.Kelkar YD, Ochman H . (2013). Genome reduction promotes increase in protein functional complexity in bacteria. Genetics 193: 303–307.Koga R, Meng XY, Tsuchida T, Fukatsu T . (2012). Cellular mechanism for selective vertical transmission of an obligate insect symbiont at the bacteriocyte-embryo interface. Proc Natl Acad Sci USA 109: E1230–E1237.Kuo CH, Moran NA, Ochman H . (2009). The consequences of genetic drift for bacterial genome complexity. Genome Res 19: 1450–1454.Kuo CH, Ochman H . (2009). Deletional bias across the three domains of life. Genome Biol Evol 1: 145–152.Law R, Lewis DH . (1983). Biotic environments and the maintenance of sex-some evidence from mutualistic symbioses. Biol J Linnean Soc 20: 28.Liu XD, Xie L, Wei Y, Zhou X, Jia B, Liu J et al. (2014). Abiotic stress resistance, a novel moonlighting function of ribosomal protein RPL44 in the halophilic fungus Aspergillus glaucus. Appl Environ Microbiol 80: 4294–4300.Lohse M, Bolger AM, Nagel A, Fernie AR, Lunn JE, Stitt M et al. (2012). RobiNA: a user-friendly, integrated software solution for RNA-Seq-based transcriptomics. Nucleic Acids Res 40: W622–W627.Macdonald SJ, Lin GG, Russell CW, Thomas GH, Douglas AE . (2012). The central role of the host cell in symbiotic nitrogen metabolism. Proc Biol Sci 279: 2965–2973.McClure R, Balasubramanian D, Sun Y, Bobrovskyy M, Sumby P, Genco CA et al. (2013). Computational analysis of bacterial RNA-Seq data. Nucleic Acids Res 41: e140.McCutcheon JP, Moran NA . (2012). Extreme genome reduction in symbiotic bacteria. Nat Rev Microbiol 10: 13–26.McFall-Ngai M, Hadfield MG, Bosch TC, Carey HV, Domazet-Loso T, Douglas AE et al. (2013). Animals in a bacterial world, a new imperative for the life sciences. Proc Natl Acad Sci USA 110: 3229–3236.Mira A, Ochman H, Moran NA . (2001). Deletional bias and the evolution of bacterial genomes. Trends Genet 17: 589–596.Moran NA . (1996). Accelerated evolution and Muller's rachet in endosymbiotic bacteria. Proc Natl Acad Sci USA 93: 2873–2878.Moran NA, Dunbar HE, Wilcox JL . (2005). Regulation of transcription in a reduced bacterial genome: nutrient-provisioning genes of the obligate symbiont Buchnera aphidicola. J Bacteriol 187: 4229–4237.Moran NA, McCutcheon JP, Nakabachi A . (2008). Genomics and evolution of heritable bacterial symbionts. Annu Rev Genet 42: 165–190.Moran NA, McLaughlin HJ, Sorek R . (2009). The dynamics and time scale of ongoing genomic erosion in symbiotic bacteria. Science 323: 379–382.Nakabachi A, Ishida K, Hongoh Y, Ohkuma M, Miyagishima SY . (2014). Aphid gene of bacterial origin encodes a protein transported to an obligate endosymbiont. Curr Biol 24: R640–R641.Nilsson AI, Koskiniemi S, Eriksson S, Kugelberg E, Hinton JC, Andersson DI . (2005). Bacterial genome size reduction by experimental evolution. Proc Natl Acad Sci USA 102: 12112–12116.Patino-Navarrete R, Moya A, Latorre A, Pereto J . (2013). Comparative genomics of Blattabacterium cuenoti: the frozen legacy of an ancient endosymbiont genome. Genome Biol Evol 5: 351–361.Pettersson ME, Berg OG . (2007). Muller's ratchet in symbiont populations. Genetica 130: 199–211.Price DR, Feng H, Baker JD, Bavan S, Luetje CW, Wilson AC . (2014). Aphid amino acid transporter regulates glutamine supply to intracellular bacterial symbionts. Proc Natl Acad Sci USA 111: 320–325.Reyes-Prieto M, Vargas-Chavez C, Latorre A, Moya A . (2015). SymbioGenomesDB: a database for the integration and access to knowledge on host-symbiont relationships. Database 2015: bav109 (1–8).Robinson MD, McCarthy DJ, Smyth GK . (2010). edgeR: a Bioconductor package for differential expression analysis of digital gene expression data. Bioinformatics 26: 139–140.Sabater-Muñoz B, Prats-Escriche M, Montagud-Martinez R, Lopez-Cerdan A, Toft C, Aguilar-Rodriguez J et al. (2015). Fitness trade-offs determine the role of the molecular chaperonin groel in buffering mutations. Mol Biol Evol 32: 2681–2693.Schlicker A, Domingues FS, Rahnenfuhrer J, Lengauer T . (2006). A new measure for functional similarity of gene products based on Gene Ontology. BMC Bioinformatics 7: 302.Shigenobu S, Watanabe H, Hattori M, Sakaki Y, Ishikawa H . (2000). Genome sequence of the endocellular bacterial symbiont of aphids Buchnera sp. APS. Nature 407: 81–86.Supek F, Bosnjak M, Skunca N, Smuc T . (2011). REVIGO summarizes and visualizes long lists of gene ontology terms. PLoS ONE 6: e21800.Tamas I, Klasson L, Canback B, Naslund AK, Eriksson AS, Wernegreen JJ et al. (2002). 50 million years of genomic stasis in endosymbiotic bacteria. Science 296: 2376–2379.Toft C, Fares MA . (2008). The evolution of the flagellar assembly pathway in endosymbiotic bacterial genomes. Mol Biol Evol 25: 2069–2076.van Ham RC, Kamerbeek J, Palacios C, Rausell C, Abascal F, Bastolla U et al. (2003). Reductive genome evolution in Buchnera aphidicola. Proc Natl Acad Sci USA 100: 581–586.Wernegreen JJ . (2002). Genome evolution in bacterial endosymbionts of insects. Nat Rev Genet 3: 850–861.Wernegreen JJ . (2011). Reduced selective constraint in endosymbionts: elevation in radical amino acid replacements occurs genome-wide. PLoS One 6: e28905.Williams TA, Fares MA . (2010). The effect of chaperonin buffering on protein evolution. Genome Biol Evol 2: 609–619.Yang Z . (2007). PAML 4: phylogenetic analysis by maximum likelihood. Mol Biol Evol 24: 1586–1591

    oPOSSUM: integrated tools for analysis of regulatory motif over-representation

    Get PDF
    The identification of over-represented transcription factor binding sites from sets of co-expressed genes provides insights into the mechanisms of regulation for diverse biological contexts. oPOSSUM, an internet-based system for such studies of regulation, has been improved and expanded in this new release. New features include a worm-specific version for investigating binding sites conserved between Caenorhabditis elegans and C. briggsae, as well as a yeast-specific version for the analysis of co-expressed sets of Saccharomyces cerevisiae genes. The human and mouse applications feature improvements in ortholog mapping, sequence alignments and the delineation of multiple alternative promoters. oPOSSUM2, introduced for the analysis of over-represented combinations of motifs in human and mouse genes, has been integrated with the original oPOSSUM system. Analysis using user-defined background gene sets is now supported. The transcription factor binding site models have been updated to include new profiles from the JASPAR database. oPOSSUM is available at http://www.cisreg.ca/oPOSSUM

    Polycystic ovary syndrome: a complex condition with psychological, reproductive and metabolic manifestations that impacts on health across the lifespan

    Get PDF
    Polycystic ovary syndrome (PCOS) is of clinical and public health importance as it is very common, affecting up to one in five women of reproductive age. It has significant and diverse clinical implications including reproductive (infertility, hyperandrogenism, hirsutism), metabolic (insulin resistance, impaired glucose tolerance, type 2 diabetes mellitus, adverse cardiovascular risk profiles) and psychological features (increased anxiety, depression and worsened quality of life). Polycystic ovary syndrome is a heterogeneous condition and, as such, clinical and research agendas are broad and involve many disciplines. The phenotype varies widely depending on life stage, genotype, ethnicity and environmental factors including lifestyle and bodyweight. Importantly, PCOS has unique interactions with the ever increasing obesity prevalence worldwide as obesity-induced insulin resistance significantly exacerbates all the features of PCOS. Furthermore, it has clinical implications across the lifespan and is relevant to related family members with an increased risk for metabolic conditions reported in first-degree relatives. Therapy should focus on both the short and long-term reproductive, metabolic and psychological features. Given the aetiological role of insulin resistance and the impact of obesity on both hyperinsulinaemia and hyperandrogenism, multidisciplinary lifestyle improvement aimed at normalising insulin resistance, improving androgen status and aiding weight management is recognised as a crucial initial treatment strategy. Modest weight loss of 5% to 10% of initial body weight has been demonstrated to improve many of the features of PCOS. Management should focus on support, education, addressing psychological factors and strongly emphasising healthy lifestyle with targeted medical therapy as required. Monitoring and management of long-term metabolic complications is also an important part of routine clinical care. Comprehensive evidence-based guidelines are needed to aid early diagnosis, appropriate investigation, regular screening and treatment of this common condition. Whilst reproductive features of PCOS are well recognised and are covered here, this review focuses primarily on the less appreciated cardiometabolic and psychological features of PCOS

    Observation of associated production of a ZZ boson with a DD meson in the~forward region

    Get PDF
    A search for associated production of a ZZ boson with an open charm meson is presented using a data sample, corresponding to an integrated luminosity of 1.0fb1.0\,\mathrm{fb}^{-`} of proton--proton collisions at a centre-of-mass energy of 7\,TeV, collected by the LHCb experiment. %% Seven candidate events for associated production of a ZZ boson with a D0D^0 meson and four candidate events for a ZZ boson with a D+D^+ meson are observed with a combined significance of 5.1standard deviations. The production cross-sections in the forward region are measured to be σZμ+μ ⁣,D0=2.50±1.12±0.22pb\sigma_{Z\rightarrow\mu^+\mu^-\!,D^0} = 2.50\pm1.12\pm0.22pb σZμ+μ ⁣,D+=0.44±0.23±0.03pb,\sigma_{Z\rightarrow\mu^+\mu^-\!,D^+} = 0.44\pm0.23\pm0.03pb, where the first uncertainty is statistical and the second systematic.Comment: 18 pages, 2 figure

    Search for CP violation in D+KK+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

    Get PDF
    A model-independent search for direct CP violation in the Cabibbo suppressed decay D+KK+π+D^+ \to K^- K^+\pi^+ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb1^{-1}. The normalized Dalitz plot distributions for D+D^+ and DD^- are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

    Measurements of the B+B^+, B0B^0, Bs0B_s^0 meson and Λb0\Lambda_b^0 baryon lifetimes

    Get PDF
    Measurements of bb-hadron lifetimes are reported using pppp collision data, corresponding to an integrated luminosity of 1.0fb1^{-1}, collected by the LHCb detector at a centre-of-mass energy of 77Tev. Using the exclusive decays B+J/ψK+B^+\to J/\psi K^+, B0J/ψK(892)0B^0\to J/\psi K^*(892)^0, B0J/ψKS0B^0\to J/\psi K^0_{\rm S}, Λb0J/ψΛ\Lambda_b^0\to J/\psi \Lambda and Bs0J/ψϕB^0_s\to J/\psi \phi the average decay times in these modes are measured to be τB+J/ψK+\tau_{B^+\to J/\psi K^+} = 1.637±1.637 \pm 0.004 ±\pm 0.003 ps, τB0J/ψK(892)0\tau_{B^0\to J/\psi K^*(892)^0} = 1.524±1.524 \pm 0.006 ±\pm 0.004 ps, τB0J/ψKS0\tau_{B^0\to J/\psi K^0_{\rm S}} = 1.499±1.499 \pm 0.013 ±\pm 0.005 ps, τΛb0J/ψΛ\tau_{\Lambda_b^0\to J/\psi \Lambda} = 1.415±1.415 \pm 0.027 ±\pm 0.006 ps and τBs0J/ψϕ\tau_{B^0_s\to J/\psi \phi} = 1.480±1.480 \pm 0.011 ±\pm 0.005 ps, where the first uncertainty is statistical and the second is systematic. These represent the most precise lifetime measurements in these decay modes. In addition, ratios of these lifetimes, and the ratio of the decay-width difference, ΔΓd\Delta\Gamma_d, to the average width, Γd\Gamma_d, in the B0B^0 system, ΔΓd/Γd=0.044±0.025±0.011\Delta \Gamma_d/\Gamma_d = -0.044 \pm 0.025 \pm 0.011, are reported. All quantities are found to be consistent with Standard Model expectations.Comment: 28 pages, 4 figures. Updated reference
    corecore