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Sample records for automated eukaryotic gene

  1. Automated Eukaryotic Gene Structure Annotation Using EVidenceModeler and the Program to Assemble Spliced Alignments

    Energy Technology Data Exchange (ETDEWEB)

    Haas, B J; Salzberg, S L; Zhu, W; Pertea, M; Allen, J E; Orvis, J; White, O; Buell, C R; Wortman, J R

    2007-12-10

    EVidenceModeler (EVM) is presented as an automated eukaryotic gene structure annotation tool that reports eukaryotic gene structures as a weighted consensus of all available evidence. EVM, when combined with the Program to Assemble Spliced Alignments (PASA), yields a comprehensive, configurable annotation system that predicts protein-coding genes and alternatively spliced isoforms. Our experiments on both rice and human genome sequences demonstrate that EVM produces automated gene structure annotation approaching the quality of manual curation.

  2. Endosymbiotic origin and differential loss of eukaryotic genes.

    Science.gov (United States)

    Ku, Chuan; Nelson-Sathi, Shijulal; Roettger, Mayo; Sousa, Filipa L; Lockhart, Peter J; Bryant, David; Hazkani-Covo, Einat; McInerney, James O; Landan, Giddy; Martin, William F

    2015-08-27

    Chloroplasts arose from cyanobacteria, mitochondria arose from proteobacteria. Both organelles have conserved their prokaryotic biochemistry, but their genomes are reduced, and most organelle proteins are encoded in the nucleus. Endosymbiotic theory posits that bacterial genes in eukaryotic genomes entered the eukaryotic lineage via organelle ancestors. It predicts episodic influx of prokaryotic genes into the eukaryotic lineage, with acquisition corresponding to endosymbiotic events. Eukaryotic genome sequences, however, increasingly implicate lateral gene transfer, both from prokaryotes to eukaryotes and among eukaryotes, as a source of gene content variation in eukaryotic genomes, which predicts continuous, lineage-specific acquisition of prokaryotic genes in divergent eukaryotic groups. Here we discriminate between these two alternatives by clustering and phylogenetic analysis of eukaryotic gene families having prokaryotic homologues. Our results indicate (1) that gene transfer from bacteria to eukaryotes is episodic, as revealed by gene distributions, and coincides with major evolutionary transitions at the origin of chloroplasts and mitochondria; (2) that gene inheritance in eukaryotes is vertical, as revealed by extensive topological comparison, sparse gene distributions stemming from differential loss; and (3) that continuous, lineage-specific lateral gene transfer, although it sometimes occurs, does not contribute to long-term gene content evolution in eukaryotic genomes. PMID:26287458

  3. Endosymbiotic gene transfer from prokaryotic pangenomes: Inherited chimerism in eukaryotes

    OpenAIRE

    Ku, Chuan; Nelson-Sathi, Shijulal; Roettger, Mayo; Garg, Sriram; Hazkani-Covo, Einat; Martin, William F.

    2015-01-01

    Endosymbiotic theory in eukaryotic-cell evolution rests upon a foundation of three cornerstone partners—the plastid (a cyanobacterium), the mitochondrion (a proteobacterium), and its host (an archaeon)—and carries a corollary that, over time, the majority of genes once present in the organelle genomes were relinquished to the chromosomes of the host (endosymbiotic gene transfer). However, notwithstanding eukaryote-specific gene inventions, single-gene phylogenies have never traced eukaryotic ...

  4. Evolutionary advantage conferred by an eukaryote-to-eukaryote gene transfer event in wine yeasts

    OpenAIRE

    Marsit, Souhir; Mena, Adriana; Bigey, Frederic; Sauvage, Francois Xavier; Couloux, Arnaud; Guy, Julie; Legras, Jean Luc; Barrio, Eladio; Dequin, Sylvie

    2015-01-01

    Although an increasing number of horizontal gene transfers have been reported in eukaryotes, experimental evidence for their adaptive value is lacking. Here, we report the recent transfer of a 158-kb genomic region between Torulaspora microellipsoides and Saccharomyces cerevisiae wine yeasts or closely related strains. This genomic region has undergone several rearrangements in S. cerevisiae strains, including gene loss and gene conversion between two tandemly duplicated FOT genes encoding ol...

  5. Nitrile hydratase genes are present in multiple eukaryotic supergroups.

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    Alan O Marron

    Full Text Available BACKGROUND: Nitrile hydratases are enzymes involved in the conversion of nitrile-containing compounds into ammonia and organic acids. Although they are widespread in prokaryotes, nitrile hydratases have only been reported in two eukaryotes: the choanoflagellate Monosiga brevicollis and the stramenopile Aureococcus anophagefferens. The nitrile hydratase gene in M. brevicollis was believed to have arisen by lateral gene transfer from a prokaryote, and is a fusion of beta and alpha nitrile hydratase subunits. Only the alpha subunit has been reported in A. anophagefferens. METHODOLOGY/PRINCIPAL FINDINGS: Here we report the detection of nitrile hydratase genes in five eukaryotic supergroups: opisthokonts, amoebozoa, archaeplastids, CCTH and SAR. Beta-alpha subunit fusion genes are found in the choanoflagellates, ichthyosporeans, apusozoans, haptophytes, rhizarians and stramenopiles, and potentially also in the amoebozoans. An individual alpha subunit is found in a dinoflagellate and an individual beta subunit is found in a haptophyte. Phylogenetic analyses recover a clade of eukaryotic-type nitrile hydratases in the Opisthokonta, Amoebozoa, SAR and CCTH; this is supported by analyses of introns and gene architecture. Two nitrile hydratase sequences from an animal and a plant resolve in the prokaryotic nitrile hydratase clade. CONCLUSIONS/SIGNIFICANCE: The evidence presented here demonstrates that nitrile hydratase genes are present in multiple eukaryotic supergroups, suggesting that a subunit fusion gene was present in the last common ancestor of all eukaryotes. The absence of nitrile hydratase from several sequenced species indicates that subunits were lost in multiple eukaryotic taxa. The presence of nitrile hydratases in many other eukaryotic groups is unresolved due to insufficient data and taxon sampling. The retention and expression of the gene in distantly related eukaryotic species suggests that it plays an important metabolic role. The novel

  6. Patterns of prokaryotic lateral gene transfers affecting parasitic microbial eukaryotes

    DEFF Research Database (Denmark)

    Alsmark, Cecilia; Foster, Peter G; Sicheritz-Pontén, Thomas;

    2013-01-01

    approach to systematically investigate lateral gene transfer affecting the proteomes of thirteen, mainly parasitic, microbial eukaryotes, representing four of the six eukaryotic super-groups. All of the genomes investigated have been significantly affected by prokaryote-to-eukaryote lateral gene transfers......, dramatically affecting the enzymes of core pathways, particularly amino acid and sugar metabolism, but also providing new genes of potential adaptive significance in the life of parasites. A broad range of prokaryotic donors is involved in such transfers, but there is clear and significant enrichment for...... bacterial groups that share the same habitats, including the human microbiota, as the parasites investigated. CONCLUSIONS: Our data show that ecology and lifestyle strongly influence gene origins and opportunities for gene transfer and reveal that, although the outlines of the core eukaryotic metabolism are...

  7. Endosymbiotic gene transfer from prokaryotic pangenomes: Inherited chimerism in eukaryotes.

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    Ku, Chuan; Nelson-Sathi, Shijulal; Roettger, Mayo; Garg, Sriram; Hazkani-Covo, Einat; Martin, William F

    2015-08-18

    Endosymbiotic theory in eukaryotic-cell evolution rests upon a foundation of three cornerstone partners--the plastid (a cyanobacterium), the mitochondrion (a proteobacterium), and its host (an archaeon)--and carries a corollary that, over time, the majority of genes once present in the organelle genomes were relinquished to the chromosomes of the host (endosymbiotic gene transfer). However, notwithstanding eukaryote-specific gene inventions, single-gene phylogenies have never traced eukaryotic genes to three single prokaryotic sources, an issue that hinges crucially upon factors influencing phylogenetic inference. In the age of genomes, single-gene trees, once used to test the predictions of endosymbiotic theory, now spawn new theories that stand to eventually replace endosymbiotic theory with descriptive, gene tree-based variants featuring supernumerary symbionts: prokaryotic partners distinct from the cornerstone trio and whose existence is inferred solely from single-gene trees. We reason that the endosymbiotic ancestors of mitochondria and chloroplasts brought into the eukaryotic--and plant and algal--lineage a genome-sized sample of genes from the proteobacterial and cyanobacterial pangenomes of their respective day and that, even if molecular phylogeny were artifact-free, sampling prokaryotic pangenomes through endosymbiotic gene transfer would lead to inherited chimerism. Recombination in prokaryotes (transduction, conjugation, transformation) differs from recombination in eukaryotes (sex). Prokaryotic recombination leads to pangenomes, and eukaryotic recombination leads to vertical inheritance. Viewed from the perspective of endosymbiotic theory, the critical transition at the eukaryote origin that allowed escape from Muller's ratchet--the origin of eukaryotic recombination, or sex--might have required surprisingly little evolutionary innovation. PMID:25733873

  8. Massive expansion of the calpain gene family in unicellular eukaryotes

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    Zhao Sen

    2012-09-01

    Full Text Available Abstract Background Calpains are Ca2+-dependent cysteine proteases that participate in a range of crucial cellular processes. Dysfunction of these enzymes may cause, for instance, life-threatening diseases in humans, the loss of sex determination in nematodes and embryo lethality in plants. Although the calpain family is well characterized in animal and plant model organisms, there is a great lack of knowledge about these genes in unicellular eukaryote species (i.e. protists. Here, we study the distribution and evolution of calpain genes in a wide range of eukaryote genomes from major branches in the tree of life. Results Our investigations reveal 24 types of protein domains that are combined with the calpain-specific catalytic domain CysPc. In total we identify 41 different calpain domain architectures, 28 of these domain combinations have not been previously described. Based on our phylogenetic inferences, we propose that at least four calpain variants were established in the early evolution of eukaryotes, most likely before the radiation of all the major supergroups of eukaryotes. Many domains associated with eukaryotic calpain genes can be found among eubacteria or archaebacteria but never in combination with the CysPc domain. Conclusions The analyses presented here show that ancient modules present in prokaryotes, and a few de novo eukaryote domains, have been assembled into many novel domain combinations along the evolutionary history of eukaryotes. Some of the new calpain genes show a narrow distribution in a few branches in the tree of life, likely representing lineage-specific innovations. Hence, the functionally important classical calpain genes found among humans and vertebrates make up only a tiny fraction of the calpain family. In fact, a massive expansion of the calpain family occurred by domain shuffling among unicellular eukaryotes and contributed to a wealth of functionally different genes.

  9. Horizontal gene transfer in the evolution of photosynthetic eukaryotes

    Institute of Scientific and Technical Information of China (English)

    Jinling HUANG; Jipei YUE

    2013-01-01

    Horizontal gene transfer (HGT) may not only create genome mosaicism,but also introduce evolutionary novelties to recipient organisms.HGT in plastid genomes,though relatively rare,still exists.HGT-derived genes are particularly common in unicellular photosynthetic eukaryotes and they also occur in multicellular plants.In particular,ancient HGT events occurring during the early evolution of primary photosynthetic eukaryotes were probably frequent.There is clear evidence that anciently acquired genes played an important role in the establishment of primary plastids and in the transition of plants from aquatic to terrestrial environments.Although algal genes have often been used to infer historical plastids in plastid-lacking eukaryotes,reliable approaches are needed to distinguish endosymbionts-derived genes from those independently acquired from preferential feeding or other activities.

  10. Combined eukaryotic and bacterial community fingerprinting of natural freshwater biofilms using automated ribosomal intergenic spacer analysis

    OpenAIRE

    2010-01-01

    Biofilms are complex communities playing an important role in aquatic ecosystems. Automated ribosomal intergenic spacer analysis (ARISA) has been used successfully to explore biofilm bacterial diversity. However, a gap remains to be filled as regards its application to biofilm eukaryotic populations. The aim of this study is to use ARISA to detect eukaryotic population shifts in biofilm. We designed a new set of primers to focus specifically on the ITS1-5.8S-ITS2 region of diatoms and tested ...

  11. Noise minimization in eukaryotic gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, Hunter B.; Hirsh, Aaron E.; Giaever, Guri; Kumm, Jochen; Eisen, Michael B.

    2004-01-15

    All organisms have elaborate mechanisms to control rates of protein production. However, protein production is also subject to stochastic fluctuations, or noise. Several recent studies in Saccharomyces cerevisiae and Escherichia coli have investigated the relationship between transcription and translation rates and stochastic fluctuations in protein levels, or more generally, how such randomness is a function of intrinsic and extrinsic factors. However, the fundamental question of whether stochasticity in protein expression is generally biologically relevant has not been addressed, and it remains unknown whether random noise in the protein production rate of most genes significantly affects the fitness of any organism. We propose that organisms should be particularly sensitive to variation in the protein levels of two classes of genes: genes whose deletion is lethal to the organism and genes that encode subunits of multiprotein complexes. Using an experimentally verified model of stochastic gene expression in S. cerevisiae, we estimate the noise in protein production for nearly every yeast gene, and confirm our prediction that the production of essential and complex-forming proteins involves lower levels of noise than does the production of most other genes. Our results support the hypothesis that noise in gene expression is a biologically important variable, is generally detrimental to organismal fitness, and is subject to natural selection.

  12. Soil metatranscriptomics for mining eukaryotic heavy metal resistance genes.

    Science.gov (United States)

    Lehembre, Frédéric; Doillon, Didier; David, Elise; Perrotto, Sandrine; Baude, Jessica; Foulon, Julie; Harfouche, Lamia; Vallon, Laurent; Poulain, Julie; Da Silva, Corinne; Wincker, Patrick; Oger-Desfeux, Christine; Richaud, Pierre; Colpaert, Jan V; Chalot, Michel; Fraissinet-Tachet, Laurence; Blaudez, Damien; Marmeisse, Roland

    2013-10-01

    Heavy metals are pollutants which affect all organisms. Since a small number of eukaryotes have been investigated with respect to metal resistance, we hypothesize that many genes that control this phenomenon remain to be identified. This was tested by screening soil eukaryotic metatranscriptomes which encompass RNA from organisms belonging to the main eukaryotic phyla. Soil-extracted polyadenylated mRNAs were converted into cDNAs and 35 of them were selected for their ability to rescue the metal (Cd or Zn) sensitive phenotype of yeast mutants. Few of the genes belonged to families known to confer metal resistance when overexpressed in yeast. Several of them were homologous to genes that had not been studied in the context of metal resistance. For instance, the BOLA ones, which conferred cross metal (Zn, Co, Cd, Mn) resistance may act by interfering with Fe homeostasis. Other genes, such as those encoding 110- to 130-amino-acid-long, cysteine-rich polypeptides, had no homologues in databases. This study confirms that functional metatranscriptomics represents a powerful approach to address basic biological processes in eukaryotes. The selected genes can be used to probe new pathways involved in metal homeostasis and to manipulate the resistance level of selected organisms. PMID:23663419

  13. Eukaryote-to-eukaryote gene transfer gives rise to genome mosaicism in euglenids

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    Weber Andreas PM

    2011-04-01

    Full Text Available Abstract Background Euglenophytes are a group of photosynthetic flagellates possessing a plastid derived from a green algal endosymbiont, which was incorporated into an ancestral host cell via secondary endosymbiosis. However, the impact of endosymbiosis on the euglenophyte nuclear genome is not fully understood due to its complex nature as a 'hybrid' of a non-photosynthetic host cell and a secondary endosymbiont. Results We analyzed an EST dataset of the model euglenophyte Euglena gracilis using a gene mining program designed to detect laterally transferred genes. We found E. gracilis genes showing affinity not only with green algae, from which the secondary plastid in euglenophytes evolved, but also red algae and/or secondary algae containing red algal-derived plastids. Phylogenetic analyses of these 'red lineage' genes suggest that E. gracilis acquired at least 14 genes via eukaryote-to-eukaryote lateral gene transfer from algal sources other than the green algal endosymbiont that gave rise to its current plastid. We constructed an EST library of the aplastidic euglenid Peranema trichophorum, which is a eukaryovorous relative of euglenophytes, and also identified 'red lineage' genes in its genome. Conclusions Our data show genome mosaicism in E. gracilis and P. trichophorum. One possible explanation for the presence of these genes in these organisms is that some or all of them were independently acquired by lateral gene transfer and contributed to the successful integration and functioning of the green algal endosymbiont as a secondary plastid. Alternative hypotheses include the presence of a phagocytosed alga as the single source of those genes, or a cryptic tertiary endosymbiont harboring secondary plastid of red algal origin, which the eukaryovorous ancestor of euglenophytes had acquired prior to the secondary endosymbiosis of a green alga.

  14. Patterns of intron gain and conservation in eukaryotic genes

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    Wolf Yuri I

    2007-10-01

    Full Text Available Abstract Background: The presence of introns in protein-coding genes is a universal feature of eukaryotic genome organization, and the genes of multicellular eukaryotes, typically, contain multiple introns, a substantial fraction of which share position in distant taxa, such as plants and animals. Depending on the methods and data sets used, researchers have reached opposite conclusions on the causes of the high fraction of shared introns in orthologous genes from distant eukaryotes. Some studies conclude that shared intron positions reflect, almost entirely, a remarkable evolutionary conservation, whereas others attribute it to parallel gain of introns. To resolve these contradictions, it is crucial to analyze the evolution of introns by using a model that minimally relies on arbitrary assumptions. Results: We developed a probabilistic model of evolution that allows for variability of intron gain and loss rates over branches of the phylogenetic tree, individual genes, and individual sites. Applying this model to an extended set of conserved eukaryotic genes, we find that parallel gain, on average, accounts for only ~8% of the shared intron positions. However, the distribution of parallel gains over the phylogenetic tree of eukaryotes is highly non-uniform. There are, practically, no parallel gains in closely related lineages, whereas for distant lineages, such as animals and plants, parallel gains appear to contribute up to 20% of the shared intron positions. In accord with these findings, we estimated that ancestral introns have a high probability to be retained in extant genomes, and conversely, that a substantial fraction of extant introns have retained their positions since the early stages of eukaryotic evolution. In addition, the density of sites that are available for intron insertion is estimated to be, approximately, one in seven basepairs. Conclusion: We obtained robust estimates of the contribution of parallel gain to the observed

  15. Eukaryotic gene prediction using GeneMark.hmm-E and GeneMark-ES.

    Science.gov (United States)

    Borodovsky, Mark; Lomsadze, Alex

    2011-09-01

    This unit describes how to use the gene-finding programs GeneMark.hmm-E and GeneMark-ES for finding protein-coding genes in the genomic DNA of eukaryotic organisms. These bioinformatics tools have been demonstrated to have state-of-the-art accuracy for many fungal, plant, and animal genomes, and have frequently been used for gene annotation in novel genomic sequences. An additional advantage of GeneMark-ES is that the problem of algorithm parameterization is solved automatically, with parameters estimated by iterative self-training (unsupervised training). PMID:21901742

  16. Dynamic chromatin: the regulatory domain organization of eukaryotic gene loci.

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    Bonifer, C; Hecht, A; Saueressig, H; Winter, D M; Sippel, A E

    1991-10-01

    It is hypothesized that nuclear DNA is organized in topologically constrained loop domains defining basic units of higher order chromatin structure. Our studies are performed in order to investigate the functional relevance of this structural subdivision of eukaryotic chromatin for the control of gene expression. We used the chicken lysozyme gene locus as a model to examine the relation between chromatin structure and gene function. Several structural features of the lysozyme locus are known: the extension of the region of general DNAasel sensitivity of the active gene, the location of DNA-sequences with high affinity for the nuclear matrix in vitro, and the position of DNAasel hypersensitive chromatin sites (DHSs). The pattern of DHSs changes depending on the transcriptional status of the gene. Functional studies demonstrated that DHSs mark the position of cis-acting regulatory elements. Additionally, we discovered a novel cis-activity of the border regions of the DNAasel sensitive domain (A-elements). By eliminating the position effect on gene expression usually observed when genes are randomly integrated into the genome after transfection, A-elements possibly serve as punctuation marks for a regulatory chromatin domain. Experiments using transgenic mice confirmed that the complete structurally defined lysozyme gene domain behaves as an independent regulatory unit, expressing the gene in a tissue specific and position independent manner. These expression features were lost in transgenic mice carrying a construct, in which the A-elements as well as an upstream enhancer region were deleted, indicating the lack of a locus activation function on this construct. Experiments are designed in order to uncover possible hierarchical relationships between the different cis-acting regulatory elements for stepwise gene activation during cell differentiation. We are aiming at the definition of the basic structural and functional requirements for position independent and high

  17. Analysis of gene order conservation in eukaryotes identifies transcriptionally and functionally linked genes.

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    Marcela Dávila López

    Full Text Available The order of genes in eukaryotes is not entirely random. Studies of gene order conservation are important to understand genome evolution and to reveal mechanisms why certain neighboring genes are more difficult to separate during evolution. Here, genome-wide gene order information was compiled for 64 species, representing a wide variety of eukaryotic phyla. This information is presented in a browser where gene order may be displayed and compared between species. Factors related to non-random gene order in eukaryotes were examined by considering pairs of neighboring genes. The evolutionary conservation of gene pairs was studied with respect to relative transcriptional direction, intergenic distance and functional relationship as inferred by gene ontology. The results show that among gene pairs that are conserved the divergently and co-directionally transcribed genes are much more common than those that are convergently transcribed. Furthermore, highly conserved pairs, in particular those of fungi, are characterized by a short intergenic distance. Finally, gene pairs of metazoa and fungi that are evolutionary conserved and that are divergently transcribed are much more likely to be related by function as compared to poorly conserved gene pairs. One example is the ribosomal protein gene pair L13/S16, which is unusual as it occurs both in fungi and alveolates. A specific functional relationship between these two proteins is also suggested by the fact that they are part of the same operon in both eubacteria and archaea. In conclusion, factors associated with non-random gene order in eukaryotes include relative gene orientation, intergenic distance and functional relationships. It seems likely that certain pairs of genes are conserved because the genes involved have a transcriptional and/or functional relationship. The results also indicate that studies of gene order conservation aid in identifying genes that are related in terms of transcriptional

  18. Group II intron-based gene targeting reactions in eukaryotes.

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    Marta Mastroianni

    Full Text Available Mobile group II introns insert site-specifically into DNA target sites by a mechanism termed retrohoming in which the excised intron RNA reverse splices into a DNA strand and is reverse transcribed by the intron-encoded protein. Retrohoming is mediated by a ribonucleoprotein particle that contains the intron-encoded protein and excised intron RNA, with target specificity determined largely by base pairing of the intron RNA to the DNA target sequence. This feature enabled the development of mobile group II introns into bacterial gene targeting vectors ("targetrons" with programmable target specificity. Thus far, however, efficient group II intron-based gene targeting reactions have not been demonstrated in eukaryotes.By using a plasmid-based Xenopus laevis oocyte microinjection assay, we show that group II intron RNPs can integrate efficiently into target DNAs in a eukaryotic nucleus, but the reaction is limited by low Mg(2+ concentrations. By supplying additional Mg(2+, site-specific integration occurs in up to 38% of plasmid target sites. The integration products isolated from X. laevis nuclei are sensitive to restriction enzymes specific for double-stranded DNA, indicating second-strand synthesis via host enzymes. We also show that group II intron RNPs containing either lariat or linear intron RNA can introduce a double-strand break into a plasmid target site, thereby stimulating homologous recombination with a co-transformed DNA fragment at frequencies up to 4.8% of target sites. Chromatinization of the target DNA inhibits both types of targeting reactions, presumably by impeding RNP access. However, by using similar RNP microinjection methods, we show efficient Mg(2+-dependent group II intron integration into plasmid target sites in zebrafish (Danio rerio embryos and into plasmid and chromosomal target sites in Drosophila melanogster embryos, indicating that DNA replication can mitigate effects of chromatinization.Our results provide an

  19. Evolution of the multifaceted eukaryotic akirin gene family

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    Johnston Ian A

    2009-02-01

    Full Text Available Abstract Background Akirins are nuclear proteins that form part of an innate immune response pathway conserved in Drosophila and mice. This studies aim was to characterise the evolution of akirin gene structure and protein function in the eukaryotes. Results akirin genes are present throughout the metazoa and arose before the separation of animal, plant and fungi lineages. Using comprehensive phylogenetic analysis, coupled with comparisons of conserved synteny and genomic organisation, we show that the intron-exon structure of metazoan akirin genes was established prior to the bilateria and that a single proto-orthologue duplicated in the vertebrates, before the gnathostome-agnathan separation, producing akirin1 and akirin2. Phylogenetic analyses of seven vertebrate gene families with members in chromosomal proximity to both akirin1 and akirin2 were compatible with a common duplication event affecting the genomic neighbourhood of the akirin proto-orthologue. A further duplication of akirins occurred in the teleost lineage and was followed by lineage-specific patterns of paralogue loss. Remarkably, akirins have been independently characterised by five research groups under different aliases and a comparison of the available literature revealed diverse functions, generally in regulating gene expression. For example, akirin was characterised in arthropods as subolesin, an important growth factor and in Drosophila as bhringi, which has an essential myogenic role. In vertebrates, akirin1 was named mighty in mice and was shown to regulate myogenesis, whereas akirin2 was characterised as FBI1 in rats and promoted carcinogenesis, acting as a transcriptional repressor when bound to a 14-3-3 protein. Both vertebrate Akirins have evolved under comparably strict constraints of purifying selection, although a likelihood ratio test predicted that functional divergence has occurred between paralogues. Bayesian and maximum likelihood tests identified amino

  20. Gene shuttling: moving of cloned DNA into and out of eukaryotic cells.

    OpenAIRE

    Lindenmaier, W; Hauser, H.; de Wilke, I G; Schütz, G

    1982-01-01

    Successful shuttling of cloned DNA in eukaryotic cells should allow isolation of expressed genes. We tested the utility of cosmids for moving DNA into and out of eukaryotic cells. The unique cleavage of DNA at the cos site by the terminase function of lambda was exploited to maintain the linkage between the vector and inserted gene sequences, a prerequisite for successful rescue of the transforming DNA from high molecular weight DNA of the eukaryotic transformant. A cosmid recombinant contain...

  1. Gene Ontology annotation quality analysis in model eukaryotes

    Science.gov (United States)

    Buza, Teresia J.; McCarthy, Fiona M.; Wang, Nan; Bridges, Susan M.; Burgess, Shane C.

    2008-01-01

    Functional analysis using the Gene Ontology (GO) is crucial for array analysis, but it is often difficult for researchers to assess the amount and quality of GO annotations associated with different sets of gene products. In many cases the source of the GO annotations and the date the GO annotations were last updated is not apparent, further complicating a researchers’ ability to assess the quality of the GO data provided. Moreover, GO biocurators need to ensure that the GO quality is maintained and optimal for the functional processes that are most relevant for their research community. We report the GO Annotation Quality (GAQ) score, a quantitative measure of GO quality that includes breadth of GO annotation, the level of detail of annotation and the type of evidence used to make the annotation. As a case study, we apply the GAQ scoring method to a set of diverse eukaryotes and demonstrate how the GAQ score can be used to track changes in GO annotations over time and to assess the quality of GO annotations available for specific biological processes. The GAQ score also allows researchers to quantitatively assess the functional data available for their experimental systems (arrays or databases). PMID:18187504

  2. A eukaryotic gene encoding an endonuclease that specifically repairs DNA damaged by ultraviolet light.

    OpenAIRE

    Yajima, H; Takao, M; Yasuhira, S; Zhao, J. H.; Ishii, C.; Inoue, H; Yasui, A

    1995-01-01

    Many eukaryotic organisms, including humans, remove ultraviolet (UV) damage from their genomes by the nucleotide excision repair pathway, which requires more than 10 separate protein factors. However, no nucleotide excision repair pathway has been found in the filamentous fungus Neurospora crassa. We have isolated a new eukaryotic DNA repair gene from N.crassa by its ability to complement UV-sensitive Escherichia coli cells. The gene is altered in a N.crassa mus-18 mutant and responsible for ...

  3. Microsporidia: Eukaryotic Intracellular Parasites Shaped by Gene Loss and Horizontal Gene Transfers.

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    Corradi, Nicolas

    2015-01-01

    Microsporidia are eukaryotic parasites of many animals that appear to have adapted to an obligate intracellular lifestyle by modifying the morphology and content of their cells. Living inside other cells, they have lost many, or all, metabolic functions, resulting in genomes that are always gene poor and often very small. The minute content of microsporidian genomes led many to assume that these parasites are biochemically static and uninteresting. However, recent studies have demonstrated that these organisms can be surprisingly complex and dynamic. In this review I detail the most significant recent advances in microsporidian genomics and discuss how these have affected our understanding of many biological aspects of these peculiar eukaryotic intracellular pathogens. PMID:26195306

  4. Modular, rule-based modeling for the design of eukaryotic synthetic gene circuits

    OpenAIRE

    Marchisio, Mario Andrea; Colaiacovo, Moreno; Whitehead, Ellis; Stelling, Jörg

    2013-01-01

    Background The modular design of synthetic gene circuits via composable parts (DNA segments) and pools of signal carriers (molecules such as RNA polymerases and ribosomes) has been successfully applied to bacterial systems. However, eukaryotic cells are becoming a preferential host for new synthetic biology applications. Therefore, an accurate description of the intricate network of reactions that take place inside eukaryotic parts and pools is necessary. Rule-based modeling approaches are in...

  5. Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus.

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    Monier, Adam; Pagarete, António; de Vargas, Colomban; Allen, Michael J; Read, Betsy; Claverie, Jean-Michel; Ogata, Hiroyuki

    2009-08-01

    Interactions between viruses and phytoplankton, the main primary producers in the oceans, affect global biogeochemical cycles and climate. Recent studies are increasingly revealing possible cases of gene transfers between cyanobacteria and phages, which might have played significant roles in the evolution of cyanobacteria/phage systems. However, little has been documented about the occurrence of horizontal gene transfer in eukaryotic phytoplankton/virus systems. Here we report phylogenetic evidence for the transfer of seven genes involved in the sphingolipid biosynthesis pathway between the cosmopolitan eukaryotic microalga Emiliania huxleyi and its large DNA virus EhV. PCR assays indicate that these genes are prevalent in E. huxleyi and EhV strains isolated from different geographic locations. Patterns of protein and gene sequence conservation support that these genes are functional in both E. huxleyi and EhV. This is the first clear case of horizontal gene transfer of multiple functionally linked enzymes in a eukaryotic phytoplankton-virus system. We examine arguments for the possible direction of the gene transfer. The virus-to-host direction suggests the existence of ancient viruses that controlled the complex metabolic pathway in order to infect primitive eukaryotic cells. In contrast, the host-to-virus direction suggests that the serial acquisition of genes involved in the same metabolic pathway might have been a strategy for the ancestor of EhVs to stay ahead of their closest relatives in the great evolutionary race for survival. PMID:19451591

  6. Use of eukaryotic expression technology in the functional analysis of cloned genes

    International Nuclear Information System (INIS)

    The purpose of this chapter is to describe ways in which eukaryotic expression technology can be used to identify and to analyze the function of cloned eukaryotic genes. The assumption is made that the clone of interest has been sequenced and an open reading frame has been identified. Although expression of genomic sequences will be briefly discussed, in general it is assumed that the sequence of interest is a cDNA. This chapter is divided into three sections. The first section describes several possible strategies for maximizing heterologous gene expression in the cells of higher eukaryotes. The second section deals with potential assays for gene expression based on function, and the third section describes some immunological approaches. Overall, the focus is on the use of techniques which yield information not obtainable from heterologous gene expression in bacteria or yeast

  7. Construction and transfection of sense/antisense eukaryotic expression vectors for human cathepsin L gene

    Institute of Scientific and Technical Information of China (English)

    Maolin He; Anmin Chen

    2005-01-01

    Objective: To obtain sense/antisense eukaryotic expression vectors for human cathepsin L gene, and study the biological effects on human osteosarcoma cell line MG-63 after transfection. Methods: Cathepsin L gene sense/antisense eukaryotic expression vectors were constructed with recombinant technology and transfected into the human osteosarcoma cell line MG-63. The expression of cathepsin L gene mRNA was examined with RT-PCR and the expression of cathepsin L was examined with Western blot. Results: The sense/antisense recombinant eukaryotic expression vectors for cathepsin L were successfully constructed and transfected into MG-63 cell.Conclusion: Antisense cathepsin L gene can significantly inhibit the expression of cathepsin L mRNA and protein.

  8. Prokaryotic genes in eukaryotic genome sequences: when to infer horizontal gene transfer and when to suspect an actual microbe.

    Science.gov (United States)

    Artamonova, Irena I; Lappi, Tanya; Zudina, Liudmila; Mushegian, Arcady R

    2015-07-01

    Assessment of phylogenetic positions of predicted gene and protein sequences is a routine step in any genome project, useful for validating the species' taxonomic position and for evaluating hypotheses about genome evolution and function. Several recent eukaryotic genome projects have reported multiple gene sequences that were much more similar to homologues in bacteria than to any eukaryotic sequence. In the spirit of the times, horizontal gene transfer from bacteria to eukaryotes has been invoked in some of these cases. Here, we show, using comparative sequence analysis, that some of those bacteria-like genes indeed appear likely to have been horizontally transferred from bacteria to eukaryotes. In other cases, however, the evidence strongly indicates that the eukaryotic DNA sequenced in the genome project contains a sample of non-integrated DNA from the actual bacteria, possibly providing a window into the host microbiome. Recent literature suggests also that common reagents, kits and laboratory equipment may be systematically contaminated with bacterial DNA, which appears to be sampled by metagenome projects non-specifically. We review several bioinformatic criteria that help to distinguish putative horizontal gene transfers from the admixture of genes from autonomously replicating bacteria in their hosts' genome databases or from the reagent contamination. PMID:25919787

  9. Algal endosymbionts as vectors of horizontal gene transfer in photosynthetic eukaryotes

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    Huan eQiu

    2013-09-01

    Full Text Available Photosynthesis in eukaryotes occurs in the plastid, an organelle that is derived from a single cyanobacterial primary endosymbiosis in the common ancestor of the supergroup Plantae (or Archaeplastida that includes green, red, and glaucophyte algae and plants. However a variety of other phytoplankton such as the chlorophyll c-containing diatoms, dinoflagellates, and haptophytes contain a red alga-derived plastid that traces its origin to secondary or tertiary (eukaryote engulfs eukaryote endosymbiosis. The hypothesis of Plantae monophyly has only recently been substantiated, however the extent and role of endosymbiotic and horizontal gene transfer (EGT and HGT in algal genome evolution still remain to be fully understood. What is becoming clear from analysis of complete genome data is that algal gene complements can no longer be considered essentially eukaryotic in provenance; i.e., with the expected addition of several hundred cyanobacterial genes derived from EGT and a similar number derived from the mitochondrial ancestor. For example, we now know that foreign cells such as Chlamydiae and other prokaryotes have made significant contributions to plastid functions in Plantae. Perhaps more surprising is the recent finding of extensive bacterium-derived HGT in the nuclear genome of the unicellular red alga Porphyridium purpureum that does not relate to plastid functions. These non-endosymbiont gene transfers not only shaped the evolutionary history of Plantae but also were propagated via secondary endosymbiosis to a multitude of other phytoplankton. Here we discuss the idea that Plantae (in particular red algae are one of the major players in eukaryote genome evolution by virtue of their ability to act as sinks and sources of foreign genes through HGT and endosymbiosis, respectively. This hypothesis recognizes the often under-appreciated Rhodophyta as major sources of genetic novelty among photosynthetic eukaryotes.

  10. Biosurfactant gene clusters in eukaryotes: regulation and biotechnological potential.

    Science.gov (United States)

    Roelants, Sophie L K W; De Maeseneire, Sofie L; Ciesielska, Katarzyna; Van Bogaert, Inge N A; Soetaert, Wim

    2014-04-01

    Biosurfactants (BSs) are a class of secondary metabolites representing a wide variety of structures that can be produced from renewable feedstock by a wide variety of micro-organisms. They have (potential) applications in the medical world, personal care sector, mining processes, food industry, cosmetics, crop protection, pharmaceuticals, bio-remediation, household detergents, paper and pulp industry, textiles, paint industries, etc. Especially glycolipid BSs like sophorolipids (SLs), rhamnolipids (RLs), mannosylerythritol lipids (MELs) and cellobioselipids (CBLs) have been described to provide significant opportunities to (partially) replace chemical surfactants. The major two factors currently limiting the penetration of BSs into the market are firstly the limited structural variety and secondly the rather high production price linked with the productivity. One of the keys to resolve the above mentioned bottlenecks can be found in the genetic engineering of natural producers. This could not only result in more efficient (economical) recombinant producers, but also in a diversification of the spectrum of available BSs as such resolving both limiting factors at once. Unraveling the genetics behind the biosynthesis of these interesting biological compounds is indispensable for the tinkering, fine tuning and rearrangement of these biological pathways with the aim of obtaining higher yields and a more extensive structural variety. Therefore, this review focuses on recent developments in the investigation of the biosynthesis, genetics and regulation of some important members of the family of the eukaryotic glycolipid BSs (MELs, CBLs and SLs). Moreover, recent biotechnological achievements and the industrial potential of engineered strains are discussed. PMID:24531239

  11. Gene Ontology annotation quality analysis in model eukaryotes

    OpenAIRE

    Buza, Teresia J; McCarthy, Fiona M; Wang, Nan; Bridges, Susan M.; Burgess, Shane C.

    2008-01-01

    Functional analysis using the Gene Ontology (GO) is crucial for array analysis, but it is often difficult for researchers to assess the amount and quality of GO annotations associated with different sets of gene products. In many cases the source of the GO annotations and the date the GO annotations were last updated is not apparent, further complicating a researchers’ ability to assess the quality of the GO data provided. Moreover, GO biocurators need to ensure that the GO quality is maintai...

  12. Correlating overrepresented upstream motifs to gene expression a computational approach to regulatory element discovery in eukaryotes

    CERN Document Server

    Caselle, M; Provero, P

    2002-01-01

    Gene regulation in eukaryotes is mainly effected through transcription factors binding to rather short recognition motifs generally located upstream of the coding region. We present a novel computational method to identify regulatory elements in the upstream region of eukaryotic genes. The genes are grouped in sets sharing an overrepresented short motif in their upstream sequence. For each set, the average expression level from a microarray experiment is determined: If this level is significantly higher or lower than the average taken over the whole genome, then the overerpresented motif shared by the genes in the set is likely to play a role in their regulation. The method was tested by applying it to the genome of Saccharomyces cerevisiae, using the publicly available results of a DNA microarray experiment, in which expression levels for virtually all the genes were measured during the diauxic shift from fermentation to respiration. Several known motifs were correctly identified, and a new candidate regulat...

  13. Gene flow and biological conflict systems in the origin and evolution of eukaryotes.

    Science.gov (United States)

    Aravind, L; Anantharaman, Vivek; Zhang, Dapeng; de Souza, Robson F; Iyer, Lakshminarayan M

    2012-01-01

    The endosymbiotic origin of eukaryotes brought together two disparate genomes in the cell. Additionally, eukaryotic natural history has included other endosymbiotic events, phagotrophic consumption of organisms, and intimate interactions with viruses and endoparasites. These phenomena facilitated large-scale lateral gene transfer and biological conflicts. We synthesize information from nearly two decades of genomics to illustrate how the interplay between lateral gene transfer and biological conflicts has impacted the emergence of new adaptations in eukaryotes. Using apicomplexans as example, we illustrate how lateral transfer from animals has contributed to unique parasite-host interfaces comprised of adhesion- and O-linked glycosylation-related domains. Adaptations, emerging due to intense selection for diversity in the molecular participants in organismal and genomic conflicts, being dispersed by lateral transfer, were subsequently exapted for eukaryote-specific innovations. We illustrate this using examples relating to eukaryotic chromatin, RNAi and RNA-processing systems, signaling pathways, apoptosis and immunity. We highlight the major contributions from catalytic domains of bacterial toxin systems to the origin of signaling enzymes (e.g., ADP-ribosylation and small molecule messenger synthesis), mutagenic enzymes for immune receptor diversification and RNA-processing. Similarly, we discuss contributions of bacterial antibiotic/siderophore synthesis systems and intra-genomic and intra-cellular selfish elements (e.g., restriction-modification, mobile elements and lysogenic phages) in the emergence of chromatin remodeling/modifying enzymes and RNA-based regulation. We develop the concept that biological conflict systems served as evolutionary "nurseries" for innovations in the protein world, which were delivered to eukaryotes via lateral gene flow to spur key evolutionary innovations all the way from nucleogenesis to lineage-specific adaptations. PMID:22919680

  14. Gene Cloning of Murine α-Fetoprotein Gene and Construction of Its Eukaryotic Expression Vector and Expression in CHO Cells

    Institute of Scientific and Technical Information of China (English)

    易继林; 田耕

    2003-01-01

    To clone the murine α-fetoprotein (AFP) gene, construct the eukaryotic expression vector of AFP and express in CHO cells, total RNA were extracted from Hepa 1-6 cells, and then the murine α-fetoprotein gene was amplified by RT-PCR and cloned into the eukaryotic expression vector pcDNA3.1. The recombinant of vector was identified by restriction enzyme analysis and sequencing. A fter transient transfection of CHO cells with the vector, Western blotting was used to detect the expression of AFP. It is concluded that the 1.8kb murine α-fetoprotein gene was successfully cloned and its eukaryotic expression vector was successfully constructed.

  15. Construction and Expression of Eukaryotic Expression Vector of Mature Polypeptide of Duck Interferon Alpha Gene

    Institute of Scientific and Technical Information of China (English)

    PEI Fucheng; LI Jingpeng; LI Lu; ZHANG Jianguang; REN Guiping

    2006-01-01

    To study biological activities of Duck Interferon Alpha (DuIFN-α) and prepare antivirus medicine, the eukaryotic expression vector of mature polypeptide of Duck Interferon Alpha (mDuIFN-α) gene was constructed and expressed in insect cell. By means of PCR technique, the mDuIFN-α gene was cloned from pMD-18-duIFN-αrecombinant. The gene was then inserted to pGEM-T vector and identified by restriction endonuclease analysis and sequencing. The mDuIFN-α gene was ligated with the eukaryotic expression vector pMelBacA, then transfected into Sf9cell line. Recombinant polypeptide was effectively expressed in insect cell and its molecular weight was 34 ku.

  16. Multiple Origins of Eukaryotic cox15 Suggest Horizontal Gene Transfer from Bacteria to Jakobid Mitochondrial DNA.

    Science.gov (United States)

    He, Ding; Fu, Cheng-Jie; Baldauf, Sandra L

    2016-01-01

    The most gene-rich and bacterial-like mitochondrial genomes known are those of Jakobida (Excavata). Of these, the most extreme example to date is the Andalucia godoyi mitochondrial DNA (mtDNA), including a cox15 gene encoding the respiratory enzyme heme A synthase (HAS), which is nuclear-encoded in nearly all other mitochondriate eukaryotes. Thus cox15 in eukaryotes appears to be a classic example of mitochondrion-to-nucleus (endosymbiotic) gene transfer, with A. godoyi uniquely retaining the ancestral state. However, our analyses reveal two highly distinct HAS types (encoded by cox15-1 and cox15-2 genes) and identify A. godoyi mitochondrial cox15-encoded HAS as type-1 and all other eukaryotic cox15-encoded HAS as type-2. Molecular phylogeny places the two HAS types in widely separated clades with eukaryotic type-2 HAS clustering with the bulk of α-proteobacteria (>670 sequences), whereas A. godoyi type-1 HAS clusters with an eclectic set of bacteria and archaea including two α-proteobacteria missing from the type-2 clade. This wide phylogenetic separation of the two HAS types is reinforced by unique features of their predicted protein structures. Meanwhile, RNA-sequencing and genomic analyses fail to detect either cox15 type in the nuclear genome of any jakobid including A. godoyi. This suggests that not only is cox15-1 a relatively recent acquisition unique to the Andalucia lineage but also the jakobid last common ancestor probably lacked both cox15 types. These results indicate that uptake of foreign genes by mtDNA is more taxonomically widespread than previously thought. They also caution against the assumption that all α-proteobacterial-like features of eukaryotes are ancient remnants of endosymbiosis. PMID:26412445

  17. Integration of mapped RNA-Seq reads into automatic training of eukaryotic gene finding algorithm.

    Science.gov (United States)

    Lomsadze, Alexandre; Burns, Paul D; Borodovsky, Mark

    2014-09-01

    We present a new approach to automatic training of a eukaryotic ab initio gene finding algorithm. With the advent of Next-Generation Sequencing, automatic training has become paramount, allowing genome annotation pipelines to keep pace with the speed of genome sequencing. Earlier we developed GeneMark-ES, currently the only gene finding algorithm for eukaryotic genomes that performs automatic training in unsupervised ab initio mode. The new algorithm, GeneMark-ET augments GeneMark-ES with a novel method that integrates RNA-Seq read alignments into the self-training procedure. Use of 'assembled' RNA-Seq transcripts is far from trivial; significant error rate of assembly was revealed in recent assessments. We demonstrated in computational experiments that the proposed method of incorporation of 'unassembled' RNA-Seq reads improves the accuracy of gene prediction; particularly, for the 1.3 GB genome of Aedes aegypti the mean value of prediction Sensitivity and Specificity at the gene level increased over GeneMark-ES by 24.5%. In the current surge of genomic data when the need for accurate sequence annotation is higher than ever, GeneMark-ET will be a valuable addition to the narrow arsenal of automatic gene prediction tools. PMID:24990371

  18. Evolutionary history of the poly(ADP-ribose polymerase gene family in eukaryotes

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    Teotia Sachin

    2010-10-01

    Full Text Available Abstract Background The Poly(ADP-ribosepolymerase (PARP superfamily was originally identified as enzymes that catalyze the attachment of ADP-ribose subunits to target proteins using NAD+ as a substrate. The family is characterized by the catalytic site, termed the PARP signature. While these proteins can be found in a range of eukaryotes, they have been best studied in mammals. In these organisms, PARPs have key functions in DNA repair, genome integrity and epigenetic regulation. More recently it has been found that proteins within the PARP superfamily have altered catalytic sites, and have mono(ADP-ribose transferase (mART activity or are enzymatically inactive. These findings suggest that the PARP signature has a broader range of functions that initially predicted. In this study, we investigate the evolutionary history of PARP genes across the eukaryotes. Results We identified in silico 236 PARP proteins from 77 species across five of the six eukaryotic supergroups. We performed extensive phylogenetic analyses of the identified PARPs. They are found in all eukaryotic supergroups for which sequence is available, but some individual lineages within supergroups have independently lost these genes. The PARP superfamily can be subdivided into six clades. Two of these clades were likely found in the last common eukaryotic ancestor. In addition, we have identified PARPs in organisms in which they have not previously been described. Conclusions Three main conclusions can be drawn from our study. First, the broad distribution and pattern of representation of PARP genes indicates that the ancestor of all extant eukaryotes encoded proteins of this type. Second, the ancestral PARP proteins had different functions and activities. One of these proteins was similar to human PARP1 and likely functioned in DNA damage response. The second of the ancestral PARPs had already evolved differences in its catalytic domain that suggest that these proteins may not have

  19. Eukaryote to gut bacteria transfer of a glycoside hydrolase gene essential for starch breakdown in plants

    OpenAIRE

    Arias, Maria Cecilia; Danchin, Étienne G.J.; Coutinho, Pedro; Henrissat, Bernard; Ball, Steven

    2012-01-01

    Lateral gene transfer (LGT) between bacteria constitutes a strong force in prokaryote evolution, transforming the hierarchical tree of life into a network of relationships between species. In contrast, only a few cases of LGT from eukaryotes to prokaryotes have been reported so far. The distal animal intestine is predominantly a bacterial ecosystem, supplying the host with energy from dietary polysaccharides through carbohydrate-active enzymes absent from its genome. It has been suggested tha...

  20. Multiple, non-allelic, intein-coding sequences in eukaryotic RNA polymerase genes

    Directory of Open Access Journals (Sweden)

    Butler Margaret I

    2006-10-01

    Full Text Available Abstract Background Inteins are self-splicing protein elements. They are translated as inserts within host proteins that excise themselves and ligate the flanking portions of the host protein (exteins with a peptide bond. They are encoded as in-frame insertions within the genes for the host proteins. Inteins are found in all three domains of life and in viruses, but have a very sporadic distribution. Only a small number of intein coding sequences have been identified in eukaryotic nuclear genes, and all of these are from ascomycete or basidiomycete fungi. Results We identified seven intein coding sequences within nuclear genes coding for the second largest subunits of RNA polymerase. These sequences were found in diverse eukaryotes: one is in the second largest subunit of RNA polymerase I (RPA2 from the ascomycete fungus Phaeosphaeria nodorum, one is in the RNA polymerase III (RPC2 of the slime mould Dictyostelium discoideum and four intein coding sequences are in RNA polymerase II genes (RPB2, one each from the green alga Chlamydomonas reinhardtii, the zygomycete fungus Spiromyces aspiralis and the chytrid fungi Batrachochytrium dendrobatidis and Coelomomyces stegomyiae. The remaining intein coding sequence is in a viral relic embedded within the genome of the oomycete Phytophthora ramorum. The Chlamydomonas and Dictyostelium inteins are the first nuclear-encoded inteins found outside of the fungi. These new inteins represent a unique dataset: they are found in homologous proteins that form a paralogous group. Although these paralogues diverged early in eukaryotic evolution, their sequences can be aligned over most of their length. The inteins are inserted at multiple distinct sites, each of which corresponds to a highly conserved region of RNA polymerase. This dataset supports earlier work suggesting that inteins preferentially occur in highly conserved regions of their host proteins. Conclusion The identification of these new inteins

  1. Construction and Identification of Human Tissue Kallikrein Gene Eukaryotic Expressing Vector

    Institute of Scientific and Technical Information of China (English)

    DAI Yong; PENG Wujian; LI Tiyuan; DU Hong; SUN Wenxue; CHEN Deheng; XU Zhuojia

    2007-01-01

    To clone and sequence the human tissue kallikrein gene of Chinese, and to construct eukaryotic expression recombinant of KK, total RNA was extracted from human pancreas and human tissue kallikrein gene cDNA was amplified by PCR after reverse-transcription by using Oligo(dT)primer. The original kallikrein cDNA was recovered and filled with Klenow enzyme and inserted into KS plasmid. After restriction endonuclease digestion, KK cDNA was sequenced by ABI 377 analyzer.Then the KKgene was amplified from pBluescript KSKK and inserted into pcDNA3. A sequence comparison showed that the cloned kallikrein gene was only one nucleotide different from that reported in the Genbank. The coding amino acid was Asp in the Genbank gene, while the coding amino acid of Chinese kallikrein gene was Asn. The KK cDNA fragment was inserted into the eukaryotic expression vector pcDNA3. The cloned kallikrein gene and the pcDNA3KK can be used for further study in gene therapy...

  2. Snapshot of the eukaryotic gene expression in muskoxen rumen--a metatranscriptomic approach.

    Directory of Open Access Journals (Sweden)

    Meng Qi

    Full Text Available BACKGROUND: Herbivores rely on digestive tract lignocellulolytic microorganisms, including bacteria, fungi and protozoa, to derive energy and carbon from plant cell wall polysaccharides. Culture independent metagenomic studies have been used to reveal the genetic content of the bacterial species within gut microbiomes. However, the nature of the genes encoded by eukaryotic protozoa and fungi within these environments has not been explored using metagenomic or metatranscriptomic approaches. METHODOLOGY/PRINCIPAL FINDINGS: In this study, a metatranscriptomic approach was used to investigate the functional diversity of the eukaryotic microorganisms within the rumen of muskoxen (Ovibos moschatus, with a focus on plant cell wall degrading enzymes. Polyadenylated RNA (mRNA was sequenced on the Illumina Genome Analyzer II system and 2.8 gigabases of sequences were obtained and 59129 contigs assembled. Plant cell wall degrading enzyme modules including glycoside hydrolases, carbohydrate esterases and polysaccharide lyases were identified from over 2500 contigs. These included a number of glycoside hydrolase family 6 (GH6, GH48 and swollenin modules, which have rarely been described in previous gut metagenomic studies. CONCLUSIONS/SIGNIFICANCE: The muskoxen rumen metatranscriptome demonstrates a much higher percentage of cellulase enzyme discovery and an 8.7x higher rate of total carbohydrate active enzyme discovery per gigabase of sequence than previous rumen metagenomes. This study provides a snapshot of eukaryotic gene expression in the muskoxen rumen, and identifies a number of candidate genes coding for potentially valuable lignocellulolytic enzymes.

  3. The adjacent positioning of co-regulated gene pairs is widely conserved across eukaryotes

    Directory of Open Access Journals (Sweden)

    Arnone James T

    2012-10-01

    Full Text Available Abstract Background Coordinated cell growth and development requires that cells regulate the expression of large sets of genes in an appropriate manner, and one of the most complex and metabolically demanding pathways that cells must manage is that of ribosome biogenesis. Ribosome biosynthesis depends upon the activity of hundreds of gene products, and it is subject to extensive regulation in response to changing cellular conditions. We previously described an unusual property of the genes that are involved in ribosome biogenesis in yeast; a significant fraction of the genes exist on the chromosomes as immediately adjacent gene pairs. The incidence of gene pairing can be as high as 24% in some species, and the gene pairs are found in all of the possible tandem, divergent, and convergent orientations. Results We investigated co-regulated gene sets in S. cerevisiae beyond those related to ribosome biogenesis, and found that a number of these regulons, including those involved in DNA metabolism, heat shock, and the response to cellular stressors were also significantly enriched for adjacent gene pairs. We found that as a whole, adjacent gene pairs were more tightly co-regulated than unpaired genes, and that the specific gene pairing relationships that were most widely conserved across divergent fungal lineages were correlated with those genes that exhibited the highest levels of transcription. Finally, we investigated the gene positions of ribosome related genes across a widely divergent set of eukaryotes, and found a significant level of adjacent gene pairing well beyond yeast species. Conclusion While it has long been understood that there are connections between genomic organization and transcriptional regulation, this study reveals that the strategy of organizing genes from related, co-regulated pathways into pairs of immediately adjacent genes is widespread, evolutionarily conserved, and functionally significant.

  4. Gene invasion in distant eukaryotic lineages: discovery of mutually exclusive genetic elements reveals marine biodiversity.

    Science.gov (United States)

    Monier, Adam; Sudek, Sebastian; Fast, Naomi M; Worden, Alexandra Z

    2013-09-01

    Inteins are rare, translated genetic parasites mainly found in bacteria and archaea, while spliceosomal introns are distinctly eukaryotic features abundant in most nuclear genomes. Using targeted metagenomics, we discovered an intein in an Atlantic population of the photosynthetic eukaryote, Bathycoccus, harbored by the essential spliceosomal protein PRP8 (processing factor 8 protein). Although previously thought exclusive to fungi, we also identified PRP8 inteins in parasitic (Capsaspora) and predatory (Salpingoeca) protists. Most new PRP8 inteins were at novel insertion sites that, surprisingly, were not in the most conserved regions of the gene. Evolutionarily, Dikarya fungal inteins at PRP8 insertion site a appeared more related to the Bathycoccus intein at a unique insertion site, than to other fungal and opisthokont inteins. Strikingly, independent analyses of Pacific and Atlantic samples revealed an intron at the same codon as the Bathycoccus PRP8 intein. The two elements are mutually exclusive and neither was found in cultured Bathycoccus or other picoprasinophyte genomes. Thus, wild Bathycoccus contain one of few non-fungal eukaryotic inteins known and a rare polymorphic intron. Our data indicate at least two Bathycoccus ecotypes exist, associated respectively with oceanic or mesotrophic environments. We hypothesize that intein propagation is facilitated by marine viruses; and, while intron gain is still poorly understood, presence of a spliceosomal intron where a locus lacks an intein raises the possibility of new, intein-primed mechanisms for intron gain. The discovery of nucleus-encoded inteins and associated sequence polymorphisms in uncultivated marine eukaryotes highlights their diversity and reveals potential sexual boundaries between populations indistinguishable by common marker genes. PMID:23635865

  5. Patterns of Transcript Abundance of Eukaryotic Biogeochemically-Relevant Genes in the Amazon River Plume.

    Science.gov (United States)

    Zielinski, Brian L; Allen, Andrew E; Carpenter, Edward J; Coles, Victoria J; Crump, Byron C; Doherty, Mary; Foster, Rachel A; Goes, Joaquim I; Gomes, Helga R; Hood, Raleigh R; McCrow, John P; Montoya, Joseph P; Moustafa, Ahmed; Satinsky, Brandon M; Sharma, Shalabh; Smith, Christa B; Yager, Patricia L; Paul, John H

    2016-01-01

    The Amazon River has the largest discharge of all rivers on Earth, and its complex plume system fuels a wide array of biogeochemical processes, across a large area of the western tropical North Atlantic. The plume thus stimulates microbial processes affecting carbon sequestration and nutrient cycles at a global scale. Chromosomal gene expression patterns of the 2.0 to 156 μm size-fraction eukaryotic microbial community were investigated in the Amazon River Plume, generating a robust dataset (more than 100 million mRNA sequences) that depicts the metabolic capabilities and interactions among the eukaryotic microbes. Combining classical oceanographic field measurements with metatranscriptomics yielded characterization of the hydrographic conditions simultaneous with a quantification of transcriptional activity and identity of the community. We highlight the patterns of eukaryotic gene expression for 31 biogeochemically significant gene targets hypothesized to be valuable within forecasting models. An advantage to this targeted approach is that the database of reference sequences used to identify the target genes was selectively constructed and highly curated optimizing taxonomic coverage, throughput, and the accuracy of annotations. A coastal diatom bloom highly expressed nitrate transporters and carbonic anhydrase presumably to support high growth rates and enhance uptake of low levels of dissolved nitrate and CO2. Diatom-diazotroph association (DDA: diatoms with nitrogen fixing symbionts) blooms were common when surface salinity was mesohaline and dissolved nitrate concentrations were below detection, and hence did not show evidence of nitrate utilization, suggesting they relied on ammonium transporters to aquire recently fixed nitrogen. These DDA blooms in the outer plume had rapid turnover of the photosystem D1 protein presumably caused by photodegradation under increased light penetration in clearer waters, and increased expression of silicon transporters as

  6. An ensemble classifier for eukaryotic protein subcellular location prediction using gene ontology categories and amino acid hydrophobicity.

    Directory of Open Access Journals (Sweden)

    Liqi Li

    Full Text Available With the rapid increase of protein sequences in the post-genomic age, it is challenging to develop accurate and automated methods for reliably and quickly predicting their subcellular localizations. Till now, many efforts have been tried, but most of which used only a single algorithm. In this paper, we proposed an ensemble classifier of KNN (k-nearest neighbor and SVM (support vector machine algorithms to predict the subcellular localization of eukaryotic proteins based on a voting system. The overall prediction accuracies by the one-versus-one strategy are 78.17%, 89.94% and 75.55% for three benchmark datasets of eukaryotic proteins. The improved prediction accuracies reveal that GO annotations and hydrophobicity of amino acids help to predict subcellular locations of eukaryotic proteins.

  7. Use of recombinant DNA technology to program eukaryotic cells to synthesize rat proinsulin: a rapid expression assay for cloned genes.

    OpenAIRE

    Lomedico, P T

    1982-01-01

    To use recombinant DNA technology to functionally analyze mutations introduced into cloned eukaryotic genes, a rapid procedure is necessary to assay the steps along the gene expression pathway. Since cloned rat insulin genes are not transcribed efficiently after transfection into various cell lines, I have asked whether one could drive expression by placing the insulin gene inside a transcriptional unit that functions in all mammalian cells. By using a small simian virus 40 (SV40) fragment th...

  8. Longer first introns are a general property of eukaryotic gene structure.

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    Keith R Bradnam

    Full Text Available While many properties of eukaryotic gene structure are well characterized, differences in the form and function of introns that occur at different positions within a transcript are less well understood. In particular, the dynamics of intron length variation with respect to intron position has received relatively little attention. This study analyzes all available data on intron lengths in GenBank and finds a significant trend of increased length in first introns throughout a wide range of species. This trend was found to be even stronger when using high-confidence gene annotation data for three model organisms (Arabidopsis thaliana, Caenorhabditis elegans, and Drosophila melanogaster which show that the first intron in the 5' UTR is--on average--significantly longer than all downstream introns within a gene. A partial explanation for increased first intron length in A. thaliana is suggested by the increased frequency of certain motifs that are present in first introns. The phenomenon of longer first introns can potentially be used to improve gene prediction software and also to detect errors in existing gene annotations.

  9. Metatranscriptomics reveals the diversity of genes expressed by eukaryotes in forest soils.

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    Coralie Damon

    Full Text Available Eukaryotic organisms play essential roles in the biology and fertility of soils. For example the micro and mesofauna contribute to the fragmentation and homogenization of plant organic matter, while its hydrolysis is primarily performed by the fungi. To get a global picture of the activities carried out by soil eukaryotes we sequenced 2×10,000 cDNAs synthesized from polyadenylated mRNA directly extracted from soils sampled in beech (Fagus sylvatica and spruce (Picea abies forests. Taxonomic affiliation of both cDNAs and 18S rRNA sequences showed a dominance of sequences from fungi (up to 60% and metazoans while protists represented less than 12% of the 18S rRNA sequences. Sixty percent of cDNA sequences from beech forest soil and 52% from spruce forest soil had no homologs in the GenBank/EMBL/DDJB protein database. A Gene Ontology term was attributed to 39% and 31.5% of the spruce and beech soil sequences respectively. Altogether 2076 sequences were putative homologs to different enzyme classes participating to 129 KEGG pathways among which several were implicated in the utilisation of soil nutrients such as nitrogen (ammonium, amino acids, oligopeptides, sugars, phosphates and sulfate. Specific annotation of plant cell wall degrading enzymes identified enzymes active on major polymers (cellulose, hemicelluloses, pectin, lignin and glycoside hydrolases represented 0.5% (beech soil-0.8% (spruce soil of the cDNAs. Other sequences coding enzymes active on organic matter (extracellular proteases, lipases, a phytase, P450 monooxygenases were identified, thus underlining the biotechnological potential of eukaryotic metatranscriptomes. The phylogenetic affiliation of 12 full-length carbohydrate active enzymes showed that most of them were distantly related to sequences from known fungi. For example, a putative GH45 endocellulase was closely associated to molluscan sequences, while a GH7 cellobiohydrolase was closest to crustacean sequences, thus

  10. Functional and evolutionary analysis of alternatively spliced genes is consistent with an early eukaryotic origin of alternative splicing

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    Penny David

    2007-10-01

    Full Text Available Abstract Background Alternative splicing has been reported in various eukaryotic groups including plants, apicomplexans, diatoms, amoebae, animals and fungi. However, whether widespread alternative splicing has evolved independently in the different eukaryotic groups or was inherited from their last common ancestor, and may therefore predate multicellularity, is still unknown. To better understand the origin and evolution of alternative splicing and its usage in diverse organisms, we studied alternative splicing in 12 eukaryotic species, comparing rates of alternative splicing across genes of different functional classes, cellular locations, intron/exon structures and evolutionary origins. Results For each species, we find that genes from most functional categories are alternatively spliced. Ancient genes (shared between animals, fungi and plants show high levels of alternative splicing. Genes with products expressed in the nucleus or plasma membrane are generally more alternatively spliced while those expressed in extracellular location show less alternative splicing. We find a clear correspondence between incidence of alternative splicing and intron number per gene both within and between genomes. In general, we find several similarities in patterns of alternative splicing across these diverse eukaryotes. Conclusion Along with previous studies indicating intron-rich genes with weak intron boundary consensus and complex spliceosomes in ancestral organisms, our results suggest that at least a simple form of alternative splicing may already have been present in the unicellular ancestor of plants, fungi and animals. A role for alternative splicing in the evolution of multicellularity then would largely have arisen by co-opting the preexisting process.

  11. The R-Operon: A Model of Repetitive DNA-Organized Transcriptional Compartmentation of Eukaryotic Chromosomes for Coordinated Gene Expression

    Science.gov (United States)

    Tang, Shao-Jun

    2016-01-01

    In eukaryotic genomes, it is essential to coordinate the activity of genes that function together to fulfill the same biological processes. Genomic organization likely plays a key role in coordinating transcription of different genes. However, little is known about how co-regulated genes are organized in the cell nucleus and how the chromosomal organization facilitates the co-regulation of different genes. I propose that eukaryotic genomes are organized into repeat assembly (RA)-based structural domains (“R-operons”) in the nuclear space. R-operons result from the interaction of homologous DNA repeats. In an R-operon, genes in different loci of the linear genome are brought into spatial vicinity and co-regulated by the same pool of transcription factors. This type of large-scale chromosomal organization may provide a mechanism for functional compartmentation of chromosomes to facilitate the transcriptional coordination of gene expression. PMID:27110825

  12. The Ccr4-Not complex is a key regulator of eukaryotic gene expression.

    Science.gov (United States)

    Collart, Martine A

    2016-07-01

    The Ccr4-Not complex is a multisubunit complex present in all eukaryotes that contributes to regulate gene expression at all steps, from production of messenger RNAs (mRNAs) in the nucleus to their degradation in the cytoplasm. In the nucleus it influences the post-translational modifications of the chromatin template that has to be remodeled for transcription, it is present at sites of transcription and associates with transcription factors as well as with the elongating polymerase, it interacts with the factors that prepare the new transcript for export to the cytoplasm and finally is important for nuclear quality control and influences mRNA export. In the cytoplasm it is present in polysomes where mRNAs are translated and in RNA granules where mRNAs will be redirected upon inhibition of translation. It influences mRNA translatability, and is needed during translation, on one hand for co-translational protein interactions and on the other hand to preserve translation that stalls. It is one of the relevant players during co-translational quality control. It also interacts with factors that will repress translation or induce mRNA decapping when recruited to the translating template. Finally, Ccr4-Not carries deadenylating enzymes and is a key player in mRNA decay, generic mRNA decay that follows normal translation termination, co-translational mRNA decay of transcripts on which the ribosomes stall durably or which carry a non-sense mutation and finally mRNA decay that is induced by external signaling for a change in genetic programming. Ccr4-Not is a master regulator of eukaryotic gene expression. WIREs RNA 2016, 7:438-454. doi: 10.1002/wrna.1332 For further resources related to this article, please visit the WIREs website. PMID:26821858

  13. The Prediction and Validation of Small CDSs Expand the Gene Repertoire of the Smallest Known Eukaryotic Genomes

    OpenAIRE

    Belkorchia, Abdel; Gasc , Cyrielle; Polonais, Valerie; Parisot, Nicolas; GALLOIS, Nicolas; Ribiere, Celine; LERAT, Emmanuelle; Gaspin, Christine; Pombert, Jean-Francois; Peyret, Pierre; Peyretaillade, Eric

    2015-01-01

    The proper prediction of the gene catalogue of an organism is essential to obtain a representative snapshot of its overall lifestyle, especially when it is not amenable to culturing. Microsporidia are obligate intracellular, sometimes hard to culture, eukaryotic parasites known to infect members of every animal phylum. To date, sequencing and annotation of microsporidian genomes have revealed a poor gene complement with highly reduced gene sizes. In the present paper, we investigated whether ...

  14. Evidence that the intra-amoebal Legionella drancourtii acquired a sterol reductase gene from eukaryotes

    Directory of Open Access Journals (Sweden)

    Fournier Pierre-Edouard

    2009-03-01

    Full Text Available Abstract Background Free-living amoebae serve as a natural reservoir for some bacteria that have evolved into «amoeba-resistant» bacteria. Among these, some are strictly intra-amoebal, such as Candidatus "Protochlamydia amoebophila" (Candidatus "P. amoebophila", whose genomic sequence is available. We sequenced the genome of Legionella drancourtii (L. drancourtii, another recently described intra-amoebal bacterium. By comparing these two genomes with those of their closely related species, we were able to study the genetic characteristics specific to their amoebal lifestyle. Findings We identified a sterol delta-7 reductase-encoding gene common to these two bacteria and absent in their relatives. This gene encodes an enzyme which catalyses the last step of cholesterol biosynthesis in eukaryotes, and is probably functional within L. drancourtii since it is transcribed. The phylogenetic analysis of this protein suggests that it was acquired horizontally by a few bacteria from viridiplantae. This gene was also found in the Acanthamoeba polyphaga Mimivirus genome, a virus that grows in amoebae and possesses the largest viral genome known to date. Conclusion L. drancourtii acquired a sterol delta-7 reductase-encoding gene of viridiplantae origin. The most parsimonious hypothesis is that this gene was initially acquired by a Chlamydiales ancestor parasite of plants. Subsequently, its descendents transmitted this gene in amoebae to other intra-amoebal microorganisms, including L. drancourtii and Coxiella burnetii. The role of the sterol delta-7 reductase in prokaryotes is as yet unknown but we speculate that it is involved in host cholesterol parasitism.

  15. FrameD: a flexible program for quality check and gene prediction in prokaryotic genomes and noisy matured eukaryotic sequences

    Science.gov (United States)

    Schiex, Thomas; Gouzy, Jérôme; Moisan, Annick; de Oliveira, Yannick

    2003-01-01

    We describe FrameD, a program that predicts coding regions in prokaryotic and matured eukaryotic sequences. Initially targeted at gene prediction in bacterial GC rich genomes, the gene model used in FrameD also allows to predict genes in the presence of frameshifts and partially undetermined sequences which makes it also very suitable for gene prediction and frameshift correction in unfinished sequences such as EST and EST cluster sequences. Like recent eukaryotic gene prediction programs, FrameD also includes the ability to take into account protein similarity information both in its prediction and its graphical output. Its performances are evaluated on different bacterial genomes. The web site (http://genopole.toulouse.inra.fr/bioinfo/FrameD/FD) allows direct prediction, sequence correction and translation and the ability to learn new models for new organisms. PMID:12824407

  16. UPRT, a suicide-gene therapy candidate in higher eukaryotes, is required for Drosophila larval growth and normal adult lifespan.

    Science.gov (United States)

    Ghosh, Arpan C; Shimell, MaryJane; Leof, Emma R; Haley, Macy J; O'Connor, Michael B

    2015-01-01

    Uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage pathway enzyme that catalyzes the conversion of uracil to uridine monophosphate (UMP). The enzyme is highly conserved from prokaryotes to humans and yet phylogenetic evidence suggests that UPRT homologues from higher-eukaryotes, including Drosophila, are incapable of binding uracil. Purified human UPRT also do not show any enzymatic activity in vitro, making microbial UPRT an attractive candidate for anti-microbial drug development, suicide-gene therapy, and cell-specific mRNA labeling techniques. Nevertheless, the enzymatic site of UPRT remains conserved across the animal kingdom indicating an in vivo role for the enzyme. We find that the Drosophila UPRT homologue, krishah (kri), codes for an enzyme that is required for larval growth, pre-pupal/pupal viability and long-term adult lifespan. Our findings suggest that UPRT from all higher eukaryotes is likely enzymatically active in vivo and challenges the previous notion that the enzyme is non-essential in higher eukaryotes and cautions against targeting the enzyme for therapeutic purposes. Our findings also suggest that expression of the endogenous UPRT gene will likely cause background incorporation when using microbial UPRT as a cell-specific mRNA labeling reagent in higher eukaryotes. PMID:26271729

  17. Characterization of Greenbeard Genes Involved in Long-Distance Kind Discrimination in a Microbial Eukaryote.

    Science.gov (United States)

    Heller, Jens; Zhao, Jiuhai; Rosenfield, Gabriel; Kowbel, David J; Gladieux, Pierre; Glass, N Louise

    2016-04-01

    Microorganisms are capable of communication and cooperation to perform social activities. Cooperation can be enforced using kind discrimination mechanisms in which individuals preferentially help or punish others, depending on genetic relatedness only at certain loci. In the filamentous fungus Neurospora crassa, genetically identical asexual spores (germlings) communicate and fuse in a highly regulated process, which is associated with fitness benefits during colony establishment. Recognition and chemotropic interactions between isogenic germlings requires oscillation of the mitogen-activated protein kinase (MAPK) signal transduction protein complex (NRC-1, MEK-2, MAK-2, and the scaffold protein HAM-5) to specialized cell fusion structures termed conidial anastomosis tubes. Using a population of 110 wild N. crassa isolates, we investigated germling fusion between genetically unrelated individuals and discovered that chemotropic interactions are regulated by kind discrimination. Distinct communication groups were identified, in which germlings within one communication group interacted at high frequency, while germlings from different communication groups avoided each other. Bulk segregant analysis followed by whole genome resequencing identified three linked genes (doc-1, doc-2, and doc-3), which were associated with communication group phenotype. Alleles at doc-1, doc-2, and doc-3 fell into five haplotypes that showed transspecies polymorphism. Swapping doc-1 and doc-2 alleles from different communication group strains was necessary and sufficient to confer communication group affiliation. During chemotropic interactions, DOC-1 oscillated with MAK-2 to the tips of conidial anastomosis tubes, while DOC-2 was statically localized to the plasma membrane. Our data indicate that doc-1, doc-2, and doc-3 function as "greenbeard" genes, involved in mediating long-distance kind recognition that involves actively searching for one's own type, resulting in cooperation between

  18. Cloning of HBsAg-encoded genes in different vectors and their expression in eukaryotic cells

    Institute of Scientific and Technical Information of China (English)

    Shan Qin; Hong Tang; Lian-San Zhao; Fang He; Yong Lin; Li Liu; Xiao-Mei He

    2003-01-01

    AIM: To compare the efficiency of different plasmids as DNA vectors by cloning three HBsAg-encoded genes into two eukaryotic expression vectors, pRc/CMV and pSG5UTPL/Flag, and to express HBsAg S, MS, and LS proteins in SP2/0 cells, and to establish monoclone SP2/0 cell strains that are capable of expressing S or S2S proteins stably.METHODS: Segments of S, preS2-S, preS1-preS2-S genes of Hepatitis B virus were amplified by routine PCR and preS1S fragment was amplified by Over-Lap Extension PCR. The amplified segments were cleaved with restricted endonuclease Hind Ⅲ/Not Ⅰ followed by ligation with pRc/CMV, or BamHI/EcoR Ⅰ followed by ligation with pSG5UTPL/Flag. After the plasmid vectors were cleaved with the correspond enzymes, the amplified segments were inserted into pRc/CMV or pSGSUTPL/Flag plasmid vectors with T4DNA ligase. KOZAK sequence was added before the initial ATG code of each fragment using specific primer. The inserted segments in the recombinant plasmids were sequenced after subcloning. BALB/c mice myeloma cells (SP2/0 cell line) were transfected with the recombinant plasmids. The expressions of the different recombinants were compared by Western-blot, using a monoclonal anti-HBs antibody as the primary antibody and peroxidase-labeled multi-linker as the secondary. Stable SP2/0-pRc/CMV-S or SP2/0- pRc/CMV-MS clones were established through clone screening with G418.RESULTS: Fragments with anticipated size were harvested after PCR. After recombination and screening, the sequences of the inserted segments in the recombinants were confirmed to be S, preS2S, preSl-preS2S and preSlS encoding genes,determined by sequencing. The results of Western-blot hybridization were positive for the anticipated proteins.Among them, pRc/CMV-S or pRc/CMV-MS demonstrated the highest expressing their respective antigen.CONCLUSION: Eight recombinant plasmids expressing S,M, L or preSlS proteins are obtained. For hepatitis surface antigen expression in eukaryotic cells

  19. Metatranscriptomics reveals the diversity of genes expressed by eukaryotes in forest soils

    OpenAIRE

    Damon, Coralie; Lehembre, Frederic; OGER, Christine; Luis, Patricia; Ranger, Jacques; Fraissinet-Tachet, Laurence; Marmeisse, Roland

    2012-01-01

    Eukaryotic organisms play essential roles in the biology and fertility of soils. For example the micro and mesofauna contribute to the fragmentation and homogenization of plant organic matter, while its hydrolysis is primarily performed by the fungi. To get a global picture of the activities carried out by soil eukaryotes we sequenced 2×10,000 cDNAs synthesized from polyadenylated mRNA directly extracted from soils sampled in beech (Fagus sylvatica) and spruce (Picea abies) forests. Taxonomic...

  20. Functional and evolutionary analysis of alternatively spliced genes is consistent with an early eukaryotic origin of alternative splicing

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob Lewin; Penny, David;

    2007-01-01

    , and may therefore predate multicellularity, is still unknown. To better understand the origin and evolution of alternative splicing and its usage in diverse organisms, we studied alternative splicing in 12 eukaryotic species, comparing rates of alternative splicing across genes of different functional...... classes, cellular locations, intron/exon structures and evolutionary origins. RESULTS: For each species, we find that genes from most functional categories are alternatively spliced. Ancient genes (shared between animals, fungi and plants) show high levels of alternative splicing. Genes with products...... expressed in the nucleus or plasma membrane are generally more alternatively spliced while those expressed in extracellular location show less alternative splicing. We find a clear correspondence between incidence of alternative splicing and intron number per gene both within and between genomes. In general...

  1. Construction of eukaryotic expression vector carrying canine β-defensin-1 gene and its expression in HEK293T cells

    Directory of Open Access Journals (Sweden)

    JIN Hui-Jun

    2008-10-01

    Full Text Available Mammalian β-defensins are small cationic peptides that possess broad antimicrobial and physiological activities. To obtain the gene construct of canine β-defensin-1 (cBD-1, we cloned cBD-1gene and established a method to express cBD-1 in HEK293T cells. The cDNA encoding cBD-1 was amplified from canine testicular tissues by RT-PCR, and the cBD-1 gene was inserted into eukaryotic expression vector pcDNA3.1A. Then, the recombinant pcDNA3.1A-cBD-1 plasmids were transfected into HEK293T cells using calcium phosphate. The results showed that the sequence of cBD-1 gene amplified in this research was almost identical to the published sequence (GenBank accession number: NM_001024641 since the homology between them was 99.7%. The expressed cBD-1 protein isolated from cell culture medium was detected by Western-blot suggesting that cBD-1 gene could be secretively expressed in eukaryotic cells. These results also provide a basis for further investigation of canine β-defensin function [Acta Zoologica Sinica 54(5: 897- 902, 2008].

  2. Eukaryotic aldehyde dehydrogenase (ALDH) genes: human polymorphisms, and recommended nomenclature based on divergent evolution and chromosomal mapping.

    Science.gov (United States)

    Vasiliou, V; Bairoch, A; Tipton, K F; Nebert, D W

    1999-08-01

    As currently being performed with an increasing number of superfamilies, a standardized gene nomenclature system is proposed here, based on divergent evolution, using multiple alignment analysis of all 86 eukaryotic aldehyde dehydrogenase (ALDH) amino-acid sequences known at this time. The ALDHs represent a superfamily of NAD(P)(+)-dependent enzymes having similar primary structures that oxidize a wide spectrum of endogenous and exogenous aliphatic and aromatic aldehydes. To date, a total of 54 animal, 15 plant, 14 yeast, and three fungal ALDH genes or cDNAs have been sequenced. These ALDHs can be divided into a total of 18 families (comprising 37 subfamilies), and all nonhuman ALDH genes are named here after the established human ALDH genes, when possible. An ALDH protein from one gene family is defined as having approximately or = 60% amino-acid identity and are expected to be located at the same subchromosomal site. For naming each gene, it is proposed that the root symbol 'ALDH' denoting 'aldehyde dehydrogenase' be followed by an Arabic number representing the family and, when needed, a letter designating the subfamily and an Arabic number denoting the individual gene within the subfamily; all letters are capitalized in all mammals except mouse and fruit fly, e.g. 'human ALDH3A1 (mouse, Drosophila Aldh3a1).' It is suggested that the Human Gene Nomenclature Guidelines (http://++www.gene.ucl.ac.uk/nomenclature/guidelines.h tml) be used for all species other than mouse and Drosophila. Following these guidelines, the gene is italicized, whereas the corresponding cDNA, mRNA, protein or enzyme activity is written with upper-case letters and without italics, e.g. 'human, mouse or Drosophila ALDH3A1 cDNA, mRNA, or activity'. If an orthologous gene between species cannot be identified with certainty, sequential naming of these genes will be carried out in chronological order as they are reported to us. In addition, 20 human ALDH variant alleles that have been reported

  3. Construction of eukaryotic expression vector carrying canine β-defensin-1 gene and its expression in HEK293T cells

    OpenAIRE

    JIN Hui-Jun; Zhong, Fei; Wu, Ling-Juan; Xie, Min; Wang, Wei; Han, Dong-Mei

    2008-01-01

    Mammalian β-defensins are small cationic peptides that possess broad antimicrobial and physiological activities. To obtain the gene construct of canine β-defensin-1 (cBD-1), we cloned cBD-1gene and established a method to express cBD-1 in HEK293T cells. The cDNA encoding cBD-1 was amplified from canine testicular tissues by RT-PCR, and the cBD-1 gene was inserted into eukaryotic expression vector pcDNA3.1A. Then, the recombinant pcDNA3.1A-cBD-1 plasmids were transfected into HEK293T cells usi...

  4. The Prediction and Validation of Small CDSs Expand the Gene Repertoire of the Smallest Known Eukaryotic Genomes.

    Directory of Open Access Journals (Sweden)

    Abdel Belkorchia

    Full Text Available The proper prediction of the gene catalogue of an organism is essential to obtain a representative snapshot of its overall lifestyle, especially when it is not amenable to culturing. Microsporidia are obligate intracellular, sometimes hard to culture, eukaryotic parasites known to infect members of every animal phylum. To date, sequencing and annotation of microsporidian genomes have revealed a poor gene complement with highly reduced gene sizes. In the present paper, we investigated whether such gene sizes may have induced biases for the methodologies used for genome annotation, with an emphasis on small coding sequence (CDS gene prediction. Using better delineated intergenic regions from four Encephalitozoon genomes, we predicted de novo new small CDSs with sizes ranging from 78 to 255 bp (median 168 and corroborated these predictions by RACE-PCR experiments in Encephalitozoon cuniculi. Most of the newly found genes are present in other distantly related microsporidian species, suggesting their biological relevance. The present study provides a better framework for annotating microsporidian genomes and to train and evaluate new computational methods dedicated at detecting ultra-small genes in various organisms.

  5. The Prediction and Validation of Small CDSs Expand the Gene Repertoire of the Smallest Known Eukaryotic Genomes.

    Science.gov (United States)

    Belkorchia, Abdel; Gasc, Cyrielle; Polonais, Valérie; Parisot, Nicolas; Gallois, Nicolas; Ribière, Céline; Lerat, Emmanuelle; Gaspin, Christine; Pombert, Jean-François; Peyret, Pierre; Peyretaillade, Eric

    2015-01-01

    The proper prediction of the gene catalogue of an organism is essential to obtain a representative snapshot of its overall lifestyle, especially when it is not amenable to culturing. Microsporidia are obligate intracellular, sometimes hard to culture, eukaryotic parasites known to infect members of every animal phylum. To date, sequencing and annotation of microsporidian genomes have revealed a poor gene complement with highly reduced gene sizes. In the present paper, we investigated whether such gene sizes may have induced biases for the methodologies used for genome annotation, with an emphasis on small coding sequence (CDS) gene prediction. Using better delineated intergenic regions from four Encephalitozoon genomes, we predicted de novo new small CDSs with sizes ranging from 78 to 255 bp (median 168) and corroborated these predictions by RACE-PCR experiments in Encephalitozoon cuniculi. Most of the newly found genes are present in other distantly related microsporidian species, suggesting their biological relevance. The present study provides a better framework for annotating microsporidian genomes and to train and evaluate new computational methods dedicated at detecting ultra-small genes in various organisms. PMID:26421846

  6. Ionizing and ultraviolet radiation enhances the efficiency of both eukaryotic-DNA and prokaryotic-DNA mediated gene transfer

    International Nuclear Information System (INIS)

    The enhancement effects of ionizing and UV radiation on the efficiency of DNA mediated gene transfer are being studied. Rat-2 cells are (1) flat, (2) nonpermissive for SV40 viral infection, and (3) deficient in thymidine kinase activity (tk/sup -/), hence they will die in HAT selective media. Confluent Rat-2 cells were either X-irradiated or UV-irradiated immediately after transfection with a recombinant DNA plasmid, pTK2, that contains the herpes simplex virus thymidine kinase gene (tk). In both cases, these cells showed a higher frequency of HAT/sup +/ colonies per survivor than unirradiated transfected cells. The enhancement of tk gene activity appeared to be a nonlinear function of X-ray dose. Rat-2 cells transfected with purified SV40 viral DNA (harvested from infected CV1 cells, X irradiated, and assayed in a monolayer for piling-up foci) appeared to show the same enhancement for SV40 transformation as for tk transformation. UV also enhances SV40 viral DNA mediated gene transfer. These results show that both X rays and UV radiation enhance the efficiency of gene transfer of either eukaryotic or prokaryotic DNA into mammalian cells

  7. Successful expression of heterologous egfp gene in the mitochondria of a photosynthetic eukaryote Chlamydomonas reinhardtii.

    Science.gov (United States)

    Hu, Zhangli; Zhao, Zhonglin; Wu, Zhihua; Fan, Zhun; Chen, Jun; Wu, Jinxia; Li, Jiancheng

    2011-09-01

    The efficient expression of exogenous gene in mitochondria of photosynthetic organism has been an insurmountable problem. In this study, the pBsLPNCG was constructed by inserting the egfp gene into a site between TERMINVREP-Left repeats and the cob gene in a fragment of mitochondrial DNA of Chlamydomonas reinhardtii CC-124 and introduced into the mitochondria of respiratory deficient dum-1 mutation of C. reinhardtii CC-2654. Sequencing and DNA Southern analyses revealed that egfp gene had been integrated into the mitochondrial genome of transgenic algae as expected and no other copy of egfp existed in their nucleic genome. Both the fluorescence detection and Western blot analysis confirmed the presence of eGFP protein in the transgenic algae; it indicated that the egfp gene was successfully expressed in the mitochondria of C. reinhardtii. PMID:21664493

  8. Finding regulatory sites from statistical analysis of nucleotide frequencies in the upstream region of eukaryotic genes

    CERN Document Server

    Caselle, M; Pellegrino, M; Provero, P

    2002-01-01

    We discuss two new approaches to extract relevant biological information on the Transcription Factors (and in particular to identify their binding sequences) from the statistical distribution of oligonucleotides in the upstream region of the genes. Both the methods are based on the notion of a ``regulatory network'' responsible for the various expression patterns of the genes. In particular we concentrate on families of coregulated genes and look for the simultaneous presence in the upstream regions of these genes of the same set of transcription factor binding sites. We discuss two instances which well exemplify the features of the two methods: the coregulation of glycolysis in Drosophila melanogaster and the diauxic shift in Saccharomyces cerevisiae.

  9. Growth inhibiting effects of antisense eukaryotic expression vector of proliferating cell nuclear antigen gene on human bladder cancer cells

    Institute of Scientific and Technical Information of China (English)

    童强松; 曾甫清; 林晨; 赵军; 鲁功成

    2003-01-01

    Objective To explore the growth inhibiting effects on human bladder cancer by antisense RNA targeting the proliferating cell nuclear antigen (PCNA) gene. Methods The eukaryotic expression vector for antisense PCNA cDNA was constructed and transferred into a bladder cancer EJ cell line. The PCNA expression in the cancer cells was detected by RT-PCR and Western blotting assays. The in vitro proliferation activities of the transferred cells were observed by growth curve, tetrazolium bromide (MTT) colorimetry, tritiated thymidine (3H-TdR)incorporation, flow cytometry and clone formation testing, while its in vivo anti-tumor effects were detected on nude mice allograft models.Results After the antisense vector, pLAPSN, was transferred, cellular PCNA expression was inhibited at both protein and mRNA levels. The growth rates of EJ cells were reduced from 27.91% to 62.07% (P<0.01), with an inhibition of DNA synthesis rate by 52.31% (P<0.01). Transferred cells were blocked at G0/G1 phases in cell-cycle assay, with the clone formation ability decreased by 50.81% (P<0.01). The in vivo carcinogenic abilities of the transferred cancer cells were decreased by 54.23% (P<0.05). Conclusions Antisense PCNA gene transfer could inhibit the growth of bladder cancer cells in vitro and in vivo, which provided an ideal strategy for gene therapy of human cancers.

  10. Eukaryotic gene invasion by a bacterial mobile insertion sequence element IS2 during cloning into a plasmid vector.

    Science.gov (United States)

    Senejani, Alireza G; Sweasy, Joann B

    2010-01-01

    Escherichia coli (E. coli) are commonly used as hosts for DNA cloning and sequencing. Upon transformation of E. coli with recombined vector carrying a gene of interest, the bacteria multiply the gene of interest while maintaining the integrity of its content. During the subcloning of a mouse genomic fragment into a plasmid vector, we noticed that the size of the insert increased significantly upon replication in E. coli. The sequence of the insert was determined and found to contain a novel DNA sequence within the mouse genomic insert. A BLAST search of GenBank revealed the novel sequence to be that of the Insertion Sequence 2 (IS2) element from E. coli that was likely inserted during replication in that organism. Importantly, a detailed search of GenBank shows that the IS2 is present within many eukaryotic nucleotide sequences, and in many cases, has been annotated as being part of the protein. The results of this study suggest that one must perform additional careful analysis of the sequence results using BLAST comparisons, and further verification of gene annotation before submission into the GenBank. PMID:20678256

  11. Eukaryotic gene invasion by a bacterial mobile insertion sequence element IS2 during cloning into a plasmid vector

    Directory of Open Access Journals (Sweden)

    Senejani Alireza G

    2010-05-01

    Full Text Available Abstract Escherichia coli (E. coli are commonly used as hosts for DNA cloning and sequencing. Upon transformation of E. coli with recombined vector carrying a gene of interest, the bacteria multiply the gene of interest while maintaining the integrity of its content. During the subcloning of a mouse genomic fragment into a plasmid vector, we noticed that the size of the insert increased significantly upon replication in E. coli. The sequence of the insert was determined and found to contain a novel DNA sequence within the mouse genomic insert. A BLAST search of GenBank revealed the novel sequence to be that of the Insertion Sequence 2 (IS2 element from E. coli that was likely inserted during replication in that organism. Importantly, a detailed search of GenBank shows that the IS2 is present within many eukaryotic nucleotide sequences, and in many cases, has been annotated as being part of the protein. The results of this study suggest that one must perform additional careful analysis of the sequence results using BLAST comparisons, and further verification of gene annotation before submission into the GenBank.

  12. Automated, Miniaturized Instrument for Measuring Gene Expression in Space

    Science.gov (United States)

    Pohorille, A.; Peyvan, K.; Danley, D.; Ricco, A. J.

    2010-01-01

    To facilitate astrobiological studies on the survival and adaptation of microorganisms and mixed microbial cultures to space environment, we have been developing a fully automated, miniaturized system for measuring their gene expression on small spacecraft. This low-cost, multi-purpose instrument represents a major scientific and technological advancement in our ability to study the impact of the space environment on biological systems by providing data on cellular metabolism and regulation orders of magnitude richer than what is currently available. The system supports growth of the organism, lyse it to release the expressed RNA, label the RNA, read the expression levels of a large number of genes by microarray analysis of labeled RNA and transmit the measurements to Earth. To measure gene expression we use microarray technology developed by CombiMatrix, which is based on electrochemical reactions on arrays of electrodes on a semiconductor substrate. Since the electrical integrity of the microarray remains intact after probe synthesis, the circuitry can be employed to sense nucleic acid binding at each electrode. CombiMatrix arrays can be sectored to allow multiple samples per chip. In addition, a single array can be used for several assays. The array has been integrated into an automated microfluidic cartridge that uses flexible reagent blisters and pinch pumping to move liquid reagents between chambers. The proposed instrument will help to understand adaptation of terrestrial life to conditions beyond the planet of origin, identify deleterious effects of the space environment, develop effective countermeasures against these effects, and test our ability to sustain and grow in space organisms that can be used for life support and in situ resource utilization during long-duration space exploration. The instrument is suitable for small satellite platforms, which provide frequent, low cost access to space. It can be also used on any other platform in space

  13. Structural and dynamic characterization of eukaryotic gene regulatory protein domains in solution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A L [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1996-05-01

    Solution NMR was primarily used to characterize structure and dynamics in two different eukaryotic protein systems: the {delta}-Al-{var_epsilon} activation domain from c-jun and the Drosophila RNA-binding protein Sex-lethal. The second system is the Drosophila Sex-lethal (Sxl) protein, an RNA-binding protein which is the ``master switch`` in sex determination. Sxl contains two adjacent RNA-binding domains (RBDs) of the RNP consensus-type. The NMR spectrum of the second RBD (Sxl-RBD2) was assigned using multidimensional heteronuclear NMR, and an intermediate-resolution family of structures was calculated from primarily NOE distance restraints. The overall fold was determined to be similar to other RBDs: a {beta}{alpha}{beta}-{beta}{alpha}{beta} pattern of secondary structure, with the two helices packed against a 4-stranded anti-parallel {beta}-sheet. In addition {sup 15}N T{sub 1}, T{sub 2}, and {sup 15}N/{sup 1}H NOE relaxation measurements were carried out to characterize the backbone dynamics of Sxl-RBD2 in solution. RNA corresponding to the polypyrimidine tract of transformer pre-mRNA was generated and titrated into 3 different Sxl-RBD protein constructs. Combining Sxl-RBD1+2 (bht RBDs) with this RNA formed a specific, high affinity protein/RNA complex that is amenable to further NMR characterization. The backbone {sup 1}H, {sup 13}C, and {sup 15}N resonances of Sxl-RBD1+2 were assigned using a triple-resonance approach, and {sup 15}N relaxation experiments were carried out to characterize the backbone dynamics of this complex. The changes in chemical shift in Sxl-RBD1+2 upon binding RNA are observed using Sxl-RBD2 as a substitute for unbound Sxl-RBD1+2. This allowed the binding interface to be qualitatively mapped for the second domain.

  14. Plastid 16S rRNA gene diversity among eukaryotic picophytoplankton sorted by flow cytometry from the South Pacific Ocean.

    Directory of Open Access Journals (Sweden)

    Xiao Li Shi

    Full Text Available The genetic diversity of photosynthetic picoeukaryotes was investigated in the South East Pacific Ocean. Genetic libraries of the plastid 16S rRNA gene were constructed on picoeukaryote populations sorted by flow cytometry, using two different primer sets, OXY107F/OXY1313R commonly used to amplify oxygenic organisms, and PLA491F/OXY1313R, biased towards plastids of marine algae. Surprisingly, the two sets revealed quite different photosynthetic picoeukaryote diversity patterns, which were moreover different from what we previously reported using the 18S rRNA nuclear gene as a marker. The first 16S primer set revealed many sequences related to Pelagophyceae and Dictyochophyceae, the second 16S primer set was heavily biased toward Prymnesiophyceae, while 18S sequences were dominated by Prasinophyceae, Chrysophyceae and Haptophyta. Primer mismatches with major algal lineages is probably one reason behind this discrepancy. However, other reasons, such as DNA accessibility or gene copy numbers, may be also critical. Based on plastid 16S rRNA gene sequences, the structure of photosynthetic picoeukaryotes varied along the BIOSOPE transect vertically and horizontally. In oligotrophic regions, Pelagophyceae, Chrysophyceae, and Prymnesiophyceae dominated. Pelagophyceae were prevalent at the DCM depth and Chrysophyceae at the surface. In mesotrophic regions Pelagophyceae were still important but Chlorophyta contribution increased. Phylogenetic analysis revealed a new clade of Prasinophyceae (clade 16S-IX, which seems to be restricted to hyper-oligotrophic stations. Our data suggest that a single gene marker, even as widely used as 18S rRNA, provides a biased view of eukaryotic communities and that the use of several markers is necessary to obtain a complete image.

  15. A simple model to explain evolutionary trends of eukaryotic gene architecture and expression

    Science.gov (United States)

    Catania, Francesco; Lynch, Michael

    2016-01-01

    Enormous phylogenetic variation exists in the number and sizes of introns in protein-coding genes. Although some consideration has been given to the underlying role of the population-genetic environment in defining such patterns, the influence of the intracellular environment remains virtually unexplored. Drawing from observations on interactions between co-transcriptional processes involved in splicing and mRNA 3′-end formation, a mechanistic model is proposed for splice-site recognition that challenges the commonly accepted intron- and exon-definition models. Under the suggested model, splicing factors that outcompete 3′-end processing factors for access to intronic binding sites concurrently favor the recruitment of 3′-end processing factors at the pre-mRNA tail. This hypothesis sheds new light on observations such as the intron-mediated enhancement of gene expression and the negative correlation between intron length and levels of gene expression. PMID:23568225

  16. rRNA genes from the lower chordate Herdmania momus: structural similarity with higher eukaryotes.

    OpenAIRE

    Degnan, B M; Yan, J.; Hawkins, C J; Lavin, M F

    1990-01-01

    Ascidians, primitive chordates that have retained features of the likely progenitors to all vertebrates, are a useful model to study the evolutionary relationship of chordates to other animals. We have selected the well characterized ribosomal RNA (rRNA) genes to investigate this relationship, and we describe here the cloning and characterization of an entire ribosomal DNA (rDNA) tandem repeat unit from a lower chordate, the ascidian Herdmania momus. rDNA copy number and considerable sequence...

  17. Construction of A Eukaryotic Expression Vector Carrying the iNOS Gene and Its Effect on A549 Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sujuan YE

    2012-05-01

    Full Text Available Background and objective The iNOS gene is associated with NO-mediated antitumor effects. The aims of this study are to construct a eukaryotic expression plasmid that carries the iNOS gene and to detect the expression levels and antitumor effects of the iNOS gene on A549 lung cancer cells. Methods A DNA fragment of the human iNOS coding sequence was amplified using reverse transcription polymerase chain reaction (RT-PCR. The DNA fragment was subsequently cloned into the multiple cloning sites of the eukaryotic expression vector pVAX. The recombinant plasmid was confirmed using restriction enzyme treatment, PCR, and sequencing and was then transfected into A549 lung cancer cells. The expression of the iNOS gene in the A549 lung cancer cells after transfection was verified by RT-PCR and Western blot analysis. The effects of iNOS on cell apoptosis, proliferation, and migration were identified by staining with Hoechst 3235, an MTT assay, and a scratch assay, respectively. Results The results of the restriction enzyme digestion, PCR, and sequencing verified the successful construction of the eukaryotic expression plasmid pVAX-iNOS. The iNOS gene expression level was increased in the transfected A549 cells. Further experiments also showed increased cell apoptosis among the A549 lung cancer cells transfected with pVAX-iNOS. Meanwhile, the proliferation and migration of A549 cells were significantly inhibited by the enhanced iNOS gene expression. Conclusion The recombinant eukaryotic expression vector pVAX-iNOS was successfully constructed and transfected into A549 cells. The enhanced iNOS gene expression significantly promoted cell apoptosis, whereas the proliferation and migration of A549 cells were inhibited. These findings contribute to the development of novel and effective gene therapies for lung cancer.

  18. In vitro transcription of eukaryotic genes is affected differently by the degree of DNA supercoiling.

    OpenAIRE

    Hirose, S; Suzuki, Y

    1988-01-01

    In a posterior silk gland extract, covalently closed circular (ccc) DNA is in a superhelical state that supports more transcription of fibroin gene than does linear DNA. A HeLa cell extract showed neither the supercoiling activity nor the preference for the transcription of ccc DNA over linear DNA. These activities could be added to the HeLa cell extract. Phosphocellulose fractionation of the posterior silk gland extract yielded a flow-through fraction and a 0.6 M KCl eluate fraction that wer...

  19. Expression of flounder Paralichthys olivaceus calmodulin gene in prokaryotic and eukaryotic cells

    OpenAIRE

    LÜ Ai-Jun; HU Xiu-Cai

    2008-01-01

    The primer was designed based on the sequence which was obtained from subtractive cDNA library, and then cloned the flounder Paralichthys olivaceus calmodulin gene(PoCaM) using SMART cDNA as the model. Computer-assisted analysis revealed the potential open reading frame encoded a protein of 149 amino acids with a predicted size of 17 kDa, the predicted theoretical isoelectric points (PI) is 3.93. Sequence alignment of PoCaM with other well known calmodulin proteins showed a significant homolo...

  20. GOPET: A tool for automated predictions of Gene Ontology terms

    Directory of Open Access Journals (Sweden)

    Glatting Karl-Heinz

    2006-03-01

    Full Text Available Abstract Background Vast progress in sequencing projects has called for annotation on a large scale. A Number of methods have been developed to address this challenging task. These methods, however, either apply to specific subsets, or their predictions are not formalised, or they do not provide precise confidence values for their predictions. Description We recently established a learning system for automated annotation, trained with a broad variety of different organisms to predict the standardised annotation terms from Gene Ontology (GO. Now, this method has been made available to the public via our web-service GOPET (Gene Ontology term Prediction and Evaluation Tool. It supplies annotation for sequences of any organism. For each predicted term an appropriate confidence value is provided. The basic method had been developed for predicting molecular function GO-terms. It is now expanded to predict biological process terms. This web service is available via http://genius.embnet.dkfz-heidelberg.de/menu/biounit/open-husar Conclusion Our web service gives experimental researchers as well as the bioinformatics community a valuable sequence annotation device. Additionally, GOPET also provides less significant annotation data which may serve as an extended discovery platform for the user.

  1. Evolution of hedgehog and hedgehog-related genes, their origin from Hog proteins in ancestral eukaryotes and discovery of a novel Hint motif

    Directory of Open Access Journals (Sweden)

    Bürglin Thomas R

    2008-03-01

    Full Text Available Abstract Background The Hedgehog (Hh signaling pathway plays important roles in human and animal development as well as in carcinogenesis. Hh molecules have been found in both protostomes and deuterostomes, but curiously the nematode Caenorhabditis elegans lacks a bona-fide Hh. Instead a series of Hh-related proteins are found, which share the Hint/Hog domain with Hh, but have distinct N-termini. Results We performed extensive genome searches of the cnidarian Nematostella vectensis and several nematodes to gain further insights into Hh evolution. We found six genes in N. vectensis with a relationship to Hh: two Hh genes, one gene with a Hh N-terminal domain fused to a Willebrand factor type A domain (VWA, and three genes containing Hint/Hog domains with distinct novel N-termini. In the nematode Brugia malayi we find the same types of hh-related genes as in C. elegans. In the more distantly related Enoplea nematodes Xiphinema and Trichinella spiralis we find a bona-fide Hh. In addition, T. spiralis also has a quahog gene like C. elegans, and there are several additional hh-related genes, some of which have secreted N-terminal domains of only 15 to 25 residues. Examination of other Hh pathway components revealed that T. spiralis - like C. elegans - lacks some of these components. Extending our search to all eukaryotes, we recovered genes containing a Hog domain similar to Hh from many different groups of protists. In addition, we identified a novel Hint gene family present in many eukaryote groups that encodes a VWA domain fused to a distinct Hint domain we call Vint. Further members of a poorly characterized Hint family were also retrieved from bacteria. Conclusion In Cnidaria and nematodes the evolution of hh genes occurred in parallel to the evolution of other genes that contain a Hog domain but have different N-termini. The fact that Hog genes comprising a secreted N-terminus and a Hog domain are also found in many protists suggests that this

  2. Complete Sequence Construction of the Highly Repetitive Ribosomal RNA Gene Repeats in Eukaryotes Using Whole Genome Sequence Data.

    Science.gov (United States)

    Agrawal, Saumya; Ganley, Austen R D

    2016-01-01

    The ribosomal RNA genes (rDNA) encode the major rRNA species of the ribosome, and thus are essential across life. These genes are highly repetitive in most eukaryotes, forming blocks of tandem repeats that form the core of nucleoli. The primary role of the rDNA in encoding rRNA has been long understood, but more recently the rDNA has been implicated in a number of other important biological phenomena, including genome stability, cell cycle, and epigenetic silencing. Noncoding elements, primarily located in the intergenic spacer region, appear to mediate many of these phenomena. Although sequence information is available for the genomes of many organisms, in almost all cases rDNA repeat sequences are lacking, primarily due to problems in assembling these intriguing regions during whole genome assemblies. Here, we present a method to obtain complete rDNA repeat unit sequences from whole genome assemblies. Limitations of next generation sequencing (NGS) data make them unsuitable for assembling complete rDNA unit sequences; therefore, the method we present relies on the use of Sanger whole genome sequence data. Our method makes use of the Arachne assembler, which can assemble highly repetitive regions such as the rDNA in a memory-efficient way. We provide a detailed step-by-step protocol for generating rDNA sequences from whole genome Sanger sequence data using Arachne, for refining complete rDNA unit sequences, and for validating the sequences obtained. In principle, our method will work for any species where the rDNA is organized into tandem repeats. This will help researchers working on species without a complete rDNA sequence, those working on evolutionary aspects of the rDNA, and those interested in conducting phylogenetic footprinting studies with the rDNA. PMID:27576718

  3. An evolutionary conserved pattern of 18S rRNA sequence complementarity to mRNA 5 ' UTRs and its implications for eukaryotic gene translation regulation

    OpenAIRE

    Pánek, J. (Josef); Kolář, M. (Michal); Vohradský, J; Valášek, L. (Leoš)

    2013-01-01

    There are several key mechanisms regulating eukaryotic gene expression at the level of protein synthesis. Interestingly, the least explored mechanisms of translational control are those that involve the translating ribosome per se, mediated for example via predicted interactions between the ribosomal RNAs (rRNAs) and mRNAs. Here, we took advantage of robustly growing large-scale data sets of mRNA sequences for numerous organisms, solved ribosomal structures and computational power to computat...

  4. Comparative genomic analysis reveals a diverse repertoire of genes involved in prokaryote-eukaryote interactions within the Pseudovibrio genus.

    Directory of Open Access Journals (Sweden)

    Stefano eRomano

    2016-03-01

    Full Text Available Strains of the Pseudovibrio genus have been detected worldwide, mainly as part of bacterial communities associated with marine invertebrates, particularly sponges. This recurrent association has been considered as an indication of a symbiotic relationship between these microbes and their host. Until recently, the availability of only two genomes, belonging to closely related strains, has limited the knowledge on the genomic and physiological features of the genus to a single phylogenetic lineage.Here we present 10 newly sequenced genomes of Pseudovibrio strains isolated from marine sponges from the west coast of Ireland, and including the other two publicly available genomes we performed an extensive comparative genomic analysis. Homogeneity was apparent in terms of both the orthologous genes and the metabolic features shared amongst the 12 strains. At the genomic level, a key physiological difference observed amongst the isolates was the presence only in strain P. axinellae AD2 of genes encoding proteins involved in assimilatory nitrate reduction, which was then proved experimentally. We then focused on studying those systems known to be involved in the interactions with eukaryotic and prokaryotic cells. This analysis revealed that the genus harbors a large diversity of toxin-like proteins, secretion systems and their potential effectors. Their distribution in the genus was not always consistent with the phylogenetic relationship of the strains. Finally, our analyses identified new genomic islands encoding potential toxin-immunity systems, previously unknown in the genus.Our analyses shed new light on the Pseudovibrio genus, indicating a large diversity of both metabolic features and systems for interacting with the host. The diversity in both distribution and abundance of these systems amongst the strains underlines how metabolically and phylogenetically similar bacteria may use different strategies to interact with the host and find a niche

  5. Comparative Genomic Analysis Reveals a Diverse Repertoire of Genes Involved in Prokaryote-Eukaryote Interactions within the Pseudovibrio Genus

    Science.gov (United States)

    Romano, Stefano; Fernàndez-Guerra, Antonio; Reen, F. Jerry; Glöckner, Frank O.; Crowley, Susan P.; O'Sullivan, Orla; Cotter, Paul D.; Adams, Claire; Dobson, Alan D. W.; O'Gara, Fergal

    2016-01-01

    Strains of the Pseudovibrio genus have been detected worldwide, mainly as part of bacterial communities associated with marine invertebrates, particularly sponges. This recurrent association has been considered as an indication of a symbiotic relationship between these microbes and their host. Until recently, the availability of only two genomes, belonging to closely related strains, has limited the knowledge on the genomic and physiological features of the genus to a single phylogenetic lineage. Here we present 10 newly sequenced genomes of Pseudovibrio strains isolated from marine sponges from the west coast of Ireland, and including the other two publicly available genomes we performed an extensive comparative genomic analysis. Homogeneity was apparent in terms of both the orthologous genes and the metabolic features shared amongst the 12 strains. At the genomic level, a key physiological difference observed amongst the isolates was the presence only in strain P. axinellae AD2 of genes encoding proteins involved in assimilatory nitrate reduction, which was then proved experimentally. We then focused on studying those systems known to be involved in the interactions with eukaryotic and prokaryotic cells. This analysis revealed that the genus harbors a large diversity of toxin-like proteins, secretion systems and their potential effectors. Their distribution in the genus was not always consistent with the phylogenetic relationship of the strains. Finally, our analyses identified new genomic islands encoding potential toxin-immunity systems, previously unknown in the genus. Our analyses shed new light on the Pseudovibrio genus, indicating a large diversity of both metabolic features and systems for interacting with the host. The diversity in both distribution and abundance of these systems amongst the strains underlines how metabolically and phylogenetically similar bacteria may use different strategies to interact with the host and find a niche within its

  6. PhytoREF: a reference database of the plastidial 16S rRNA gene of photosynthetic eukaryotes with curated taxonomy.

    Science.gov (United States)

    Decelle, Johan; Romac, Sarah; Stern, Rowena F; Bendif, El Mahdi; Zingone, Adriana; Audic, Stéphane; Guiry, Michael D; Guillou, Laure; Tessier, Désiré; Le Gall, Florence; Gourvil, Priscillia; Dos Santos, Adriana L; Probert, Ian; Vaulot, Daniel; de Vargas, Colomban; Christen, Richard

    2015-11-01

    Photosynthetic eukaryotes have a critical role as the main producers in most ecosystems of the biosphere. The ongoing environmental metabarcoding revolution opens the perspective for holistic ecosystems biological studies of these organisms, in particular the unicellular microalgae that often lack distinctive morphological characters and have complex life cycles. To interpret environmental sequences, metabarcoding necessarily relies on taxonomically curated databases containing reference sequences of the targeted gene (or barcode) from identified organisms. To date, no such reference framework exists for photosynthetic eukaryotes. In this study, we built the PhytoREF database that contains 6490 plastidial 16S rDNA reference sequences that originate from a large diversity of eukaryotes representing all known major photosynthetic lineages. We compiled 3333 amplicon sequences available from public databases and 879 sequences extracted from plastidial genomes, and generated 411 novel sequences from cultured marine microalgal strains belonging to different eukaryotic lineages. A total of 1867 environmental Sanger 16S rDNA sequences were also included in the database. Stringent quality filtering and a phylogeny-based taxonomic classification were applied for each 16S rDNA sequence. The database mainly focuses on marine microalgae, but sequences from land plants (representing half of the PhytoREF sequences) and freshwater taxa were also included to broaden the applicability of PhytoREF to different aquatic and terrestrial habitats. PhytoREF, accessible via a web interface (http://phytoref.fr), is a new resource in molecular ecology to foster the discovery, assessment and monitoring of the diversity of photosynthetic eukaryotes using high-throughput sequencing. PMID:25740460

  7. Rapid gene-based SNP and haplotype marker development in non-model eukaryotes using 3'UTR sequencing

    Directory of Open Access Journals (Sweden)

    Koepke Tyson

    2012-01-01

    yielded 34,620 contigs containing 2243 putative SNPs in 887 contigs after stringent filtering. Contigs with multiple SNPs were visually parsed to identify 685 putative haplotypes at 335 loci in 301 contigs. Conclusions This approach, which leverages the advantages of RNA-seq approaches, enabled rapid generation of gene-linked SNP and haplotype markers. The general approach presented in this study can be easily applied to other non-model eukaryotes irrespective of the ploidy level to identify gene-linked polymorphisms that are expected to facilitate efficient Gene Assisted Breeding (GAB, genotyping and population genetics studies. The identified SNP haplotypes reveal some of the allelic differences in the two sweet cherry cultivars analyzed. The identification of these SNP and haplotype markers is expected to significantly improve the genomic resources for sweet cherry and facilitate efficient GAB in this non-model crop.

  8. Expression of TIMP-3 Gene by Construction of a Eukaryotic Cell Expression Vector and Its Role in Reduction of Metastasis in a Human Breast Cancer Cell Line

    Institute of Scientific and Technical Information of China (English)

    Xichun Han; Hong Zhang; Mingku Jia; Gang Han; Weidong Jiang

    2004-01-01

    The present study is aimed at studying the gene for TIMP-3, a mammalian tissue inhibitor, by constructing a recombinant eukaryotic cell vector for gene therapy in human breast cancer. We obtained the TIMP-3 gene from the human placent by RT-PCR. TIMP-3 gene was subcloned into pcDNA3.1 vetor from pMD18T vector by means of gene cloning to construct pcDNA3.1 recombinant vector. Human breast cancer cell line MDA-MB-453 was transfected with pcDNA3.1-TIMP3 recombinant vector using lipofectamine reagent. Then the expression of TIMP-3 and the effect on the metastasis of MDA-MB-453 were examined. The correct construction of pcDNA-TIMP3 was identified by means of restriction enzyme analysis, PCR amplication and nucleotide sequencing. Western blotting showed that the transfected cells were able to express TIMP-3,indicating that our construction of the pcDNA-TIMP3 eukaryotic expression vector was constructed successfully. Our experiments further indicated that the potential of metastasis was significantly reduced for the transfected cell line MDA-MB-453.

  9. A genomic survey of the fish parasite Spironucleus salmonicida indicates genomic plasticity among diplomonads and significant lateral gene transfer in eukaryote genome evolution

    Directory of Open Access Journals (Sweden)

    Logsdon John M

    2007-02-01

    Full Text Available Abstract Background Comparative genomic studies of the mitochondrion-lacking protist group Diplomonadida (diplomonads has been lacking, although Giardia lamblia has been intensively studied. We have performed a sequence survey project resulting in 2341 expressed sequence tags (EST corresponding to 853 unique clones, 5275 genome survey sequences (GSS, and eleven finished contigs from the diplomonad fish parasite Spironucleus salmonicida (previously described as S. barkhanus. Results The analyses revealed a compact genome with few, if any, introns and very short 3' untranslated regions. Strikingly different patterns of codon usage were observed in genes corresponding to frequently sampled ESTs versus genes poorly sampled, indicating that translational selection is influencing the codon usage of highly expressed genes. Rigorous phylogenomic analyses identified 84 genes – mostly encoding metabolic proteins – that have been acquired by diplomonads or their relatively close ancestors via lateral gene transfer (LGT. Although most acquisitions were from prokaryotes, more than a dozen represent likely transfers of genes between eukaryotic lineages. Many genes that provide novel insights into the genetic basis of the biology and pathogenicity of this parasitic protist were identified including 149 that putatively encode variant-surface cysteine-rich proteins which are candidate virulence factors. A number of genomic properties that distinguish S. salmonicida from its human parasitic relative G. lamblia were identified such as nineteen putative lineage-specific gene acquisitions, distinct mutational biases and codon usage and distinct polyadenylation signals. Conclusion Our results highlight the power of comparative genomic studies to yield insights into the biology of parasitic protists and the evolution of their genomes, and suggest that genetic exchange between distantly-related protist lineages may be occurring at an appreciable rate in eukaryote

  10. Changing ideas about eukaryotic origins

    OpenAIRE

    Williams, Tom A.; Embley, T. Martin

    2015-01-01

    The origin of eukaryotic cells is one of the most fascinating challenges in biology, and has inspired decades of controversy and debate. Recent work has led to major upheavals in our understanding of eukaryotic origins and has catalysed new debates about the roles of endosymbiosis and gene flow across the tree of life. Improved methods of phylogenetic analysis support scenarios in which the host cell for the mitochondrial endosymbiont was a member of the Archaea, and new technologies for samp...

  11. An extended phylogenetic analysis reveals ancient origin of "non-green" phosphoribulokinase genes from two lineages of "green" secondary photosynthetic eukaryotes: Euglenophyta and Chlorarachniophyta

    Directory of Open Access Journals (Sweden)

    Sekimoto Hiroyuki

    2011-09-01

    Full Text Available Abstract Background Euglenophyta and Chlorarachniophyta are groups of photosynthetic eukaryotes harboring secondary plastids of distinct green algal origins. Although previous phylogenetic analyses of genes encoding Calvin cycle enzymes demonstrated the presence of genes apparently not derived from green algal endosymbionts in the nuclear genomes of Euglena gracilis (Euglenophyta and Bigelowiella natans (Chlorarachniophyta, the origins of these "non-green" genes in "green" secondary phototrophs were unclear due to the limited taxon sampling. Results Here, we sequenced five new phosphoribulokinase (PRK genes (from one euglenophyte, two chlorarachniophytes, and two glaucophytes and performed an extended phylogenetic analysis of the genes based on a phylum-wide taxon sampling from various photosynthetic eukaryotes. Our phylogenetic analyses demonstrated that the PRK sequences form two genera of Euglenophyta formed a robust monophyletic group within a large clade including stramenopiles, haptophytes and a cryptophyte, and three genera of Chlorarachniophyta were placed within the red algal clade. These "non-green" affiliations were supported by the taxon-specific insertion/deletion sequences in the PRK alignment, especially between euglenophytes and stramenopiles. In addition, phylogenetic analysis of another Calvin cycle enzyme, plastid-targeted sedoheptulose-bisphosphatase (SBP, showed that the SBP sequences from two genera of Chlorarachniophyta were positioned within a red algal clade. Conclusions Our results suggest that PRK genes may have been transferred from a "stramenopile" ancestor to Euglenophyta and from a "red algal" ancestor to Chlorarachniophyta before radiation of extant taxa of these two "green" secondary phototrophs. The presence of two of key Calvin cycle enzymes, PRK and SBP, of red algal origins in Chlorarachniophyta indicate that the contribution of "non-green" algae to the plastid proteome in the "green" secondary phototrophs is

  12. UPRT, a suicide-gene therapy candidate in higher eukaryotes, is required for Drosophila larval growth and normal adult lifespan

    OpenAIRE

    Arpan C. Ghosh; MaryJane Shimell; Leof, Emma R.; Macy J. Haley; O’Connor, Michael B.

    2015-01-01

    Uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage pathway enzyme that catalyzes the conversion of uracil to uridine monophosphate (UMP). The enzyme is highly conserved from prokaryotes to humans and yet phylogenetic evidence suggests that UPRT homologues from higher-eukaryotes, including Drosophila, are incapable of binding uracil. Purified human UPRT also do not show any enzymatic activity in vitro, making microbial UPRT an attractive candidate for anti-microbial drug developme...

  13. Production and characterization of novel recombinant adeno-associated virus replicative-form genomes: a eukaryotic source of DNA for gene transfer.

    Directory of Open Access Journals (Sweden)

    Lina Li

    Full Text Available Conventional non-viral gene transfer uses bacterial plasmid DNA containing antibiotic resistance genes, cis-acting bacterial sequence elements, and prokaryotic methylation patterns that may adversely affect transgene expression and vector stability in vivo. Here, we describe novel replicative forms of a eukaryotic vector DNA that consist solely of an expression cassette flanked by adeno-associated virus (AAV inverted terminal repeats. Extensive structural analyses revealed that this AAV-derived vector DNA consists of linear, duplex molecules with covalently closed ends (termed closed-ended, linear duplex, or "CELiD", DNA. CELiD vectors, produced in Sf9 insect cells, require AAV rep gene expression for amplification. Amounts of CELiD DNA produced from insect cell lines stably transfected with an ITR-flanked transgene exceeded 60 mg per 5 × 10(9 Sf9 cells, and 1-15 mg from a comparable number of parental Sf9 cells in which the transgene was introduced via recombinant baculovirus infection. In mice, systemically delivered CELiD DNA resulted in long-term, stable transgene expression in the liver. CELiD vectors represent a novel eukaryotic alternative to bacterial plasmid DNA.

  14. Construction of eukaryotic expression vector encoding ATP synthase lipid-binding protein-like protein gene of Sj and its expression in HeLa cells

    Institute of Scientific and Technical Information of China (English)

    Ouyang Danming; Hu Yongxuan; Li Mulan; Zeng Xiaojun; He Zhixiong; Yuan Caijia

    2008-01-01

    Objective: To clone and construct the recombinant plasmid containing ATP synthase lipid-binding protein-like protein gene of Schistosoma japonicum,(SjAslp) and transfer it into mammalian cells to express the objective protein. Methods: By polymerase chain reaction (PCR) technique, SjAslp was amplified from the constructed recombinant plasmid pBCSK+/SjAslp, and inserted into cloning vector pUCm-T. Then, SjAslp was subcloned into an eukaryotic expression vector pcDNA3.1(+). After identifying it by PCR, restrictive enzymes digestion and DNA sequencing, the recombinant plasmid was transfected into HeLa cells using electroporation, and the expression of the recombinant protein was analyzed by immunocytochemical assay. Resnlts: The specific gene fragment of 558 bp was successfully amplified. The DNA vaccine of SjAslp was successfully constructed. Immunocytochemical assay showed that SjAslp was expressed in the cytoplasm of HeLa cells. Conclusion: SjAslp gene can be expressed in eukaryotic system, which lays the foundation for development of the SjAslp DNA vaccine against schitosomiasis.

  15. Automated discovery of functional generality of human gene expression programs.

    Directory of Open Access Journals (Sweden)

    Georg K Gerber

    2007-08-01

    Full Text Available An important research problem in computational biology is the identification of expression programs, sets of co-expressed genes orchestrating normal or pathological processes, and the characterization of the functional breadth of these programs. The use of human expression data compendia for discovery of such programs presents several challenges including cellular inhomogeneity within samples, genetic and environmental variation across samples, uncertainty in the numbers of programs and sample populations, and temporal behavior. We developed GeneProgram, a new unsupervised computational framework based on Hierarchical Dirichlet Processes that addresses each of the above challenges. GeneProgram uses expression data to simultaneously organize tissues into groups and genes into overlapping programs with consistent temporal behavior, to produce maps of expression programs, which are sorted by generality scores that exploit the automatically learned groupings. Using synthetic and real gene expression data, we showed that GeneProgram outperformed several popular expression analysis methods. We applied GeneProgram to a compendium of 62 short time-series gene expression datasets exploring the responses of human cells to infectious agents and immune-modulating molecules. GeneProgram produced a map of 104 expression programs, a substantial number of which were significantly enriched for genes involved in key signaling pathways and/or bound by NF-kappaB transcription factors in genome-wide experiments. Further, GeneProgram discovered expression programs that appear to implicate surprising signaling pathways or receptor types in the response to infection, including Wnt signaling and neurotransmitter receptors. We believe the discovered map of expression programs involved in the response to infection will be useful for guiding future biological experiments; genes from programs with low generality scores might serve as new drug targets that exhibit minimal

  16. Overexpression of a eukaryotic glutathione reductase gene from Brassica campestris improved resistance to oxidative stress in Escherichia coli

    International Nuclear Information System (INIS)

    Glutathione reductase (GR) plays an essential role in a cell's defense against reactive oxygen metabolites by sustaining the reduced status of an important antioxidant glutathione. We constructed a recombinant plasmid based on the expression vector pET-18a that overexpresses a eukaryotic GR from Brassica campestris (BcGR) in Escherichia coli. For comparative analyses, E. coli GR (EcGR) was also subcloned in the same manner. The transformed E. coli with the recombinant constructs accumulated a high level of GR transcripts upon IPTG induction. Also, Western blot analysis showed overproduction of the BcGR protein in a soluble fraction of the transformed E. coli extract. When treated with oxidative stress generating reagents such as paraquat, salicylic acid, and cadmium, the BcGR overproducing E. coli exhibited a higher level of growth and survival rate than the control E. coli strain, but it was not as high as the E. coli strain transformed with the inducible EcGR. The translated amino acid sequences of BcGR and EcGR share 37.3% identity but all the functionally known important residues are conserved. It appears that eukaryotic BcGR functions in a prokaryotic system by providing protection against oxidative damages in E. coli

  17. Selección automática de imágenes. Photo- Storytelling

    OpenAIRE

    Alcoceba Hornos, Iván

    2012-01-01

    En este proyecto se estudia como generar un resumen de una colección de fotografías seleccionándolas automáticamente.Se construye un sistema capaz de permitir a un usuario subir una colección de imágenes a una plataforma web, que estás sean procesadas y posteriormente darle la opción de generar un resumen automático de su colección personal.Realizar la selección automática de imágenes es una tarea muy compleja debido a todos los factores a tener en cuenta a la hora de escogerlas. Eventos temp...

  18. Gene Expression Measurement Module (GEMM) - a fully automated, miniaturized instrument for measuring gene expression in space

    Science.gov (United States)

    Karouia, Fathi; Ricco, Antonio; Pohorille, Andrew; Peyvan, Kianoosh

    2012-07-01

    The capability to measure gene expression on board spacecrafts opens the doors to a large number of experiments on the influence of space environment on biological systems that will profoundly impact our ability to conduct safe and effective space travel, and might also shed light on terrestrial physiology or biological function and human disease and aging processes. Measurements of gene expression will help us to understand adaptation of terrestrial life to conditions beyond the planet of origin, identify deleterious effects of the space environment on a wide range of organisms from microbes to humans, develop effective countermeasures against these effects, determine metabolic basis of microbial pathogenicity and drug resistance, test our ability to sustain and grow in space organisms that can be used for life support and in situ resource utilization during long-duration space exploration, and monitor both the spacecraft environment and crew health. These and other applications hold significant potential for discoveries in space biology, biotechnology and medicine. Accordingly, supported by funding from the NASA Astrobiology Science and Technology Instrument Development Program, we are developing a fully automated, miniaturized, integrated fluidic system for small spacecraft capable of in-situ measuring microbial expression of thousands of genes from multiple samples. The instrument will be capable of (1) lysing bacterial cell walls, (2) extracting and purifying RNA released from cells, (3) hybridizing it on a microarray and (4) providing electrochemical readout, all in a microfluidics cartridge. The prototype under development is suitable for deployment on nanosatellite platforms developed by the NASA Small Spacecraft Office. The first target application is to cultivate and measure gene expression of the photosynthetic bacterium Synechococcus elongatus, i.e. a cyanobacterium known to exhibit remarkable metabolic diversity and resilience to adverse conditions

  19. An automated annotation tool for genomic DNA sequences using GeneScan and BLAST

    Indian Academy of Sciences (India)

    Andrew M. Lynn; Chakresh Kumar Jain; K. Kosalai; Pranjan Barman; Nupur Thakur; Harish Batra; Alok Bhattacharya

    2001-04-01

    Genomic sequence data are often available well before the annotated sequence is published. We present a method for analysis of genomic DNA to identify coding sequences using the GeneScan algorithm and characterize these resultant sequences by BLAST. The routines are used to develop a system for automated annotation of genome DNA sequences.

  20. GenePublisher: automated analysis of DNA microarray data

    DEFF Research Database (Denmark)

    Knudsen, Steen; Workman, Christopher; Sicheritz-Ponten, T.;

    2003-01-01

    GenePublisher, a system for automatic analysis of data from DNA microarray experiments, has been implemented with a web interface at http://www.cbs.dtu.dk/services/GenePublisher. Raw data are uploaded to the server together with aspecification of the data. The server performs normalization......, statistical analysis and visualization of the data. The results are run against databases of signal transduction pathways, metabolic pathways and promoter sequences in order to extract more information. The results of the entire analysis are summarized in report form and returned to the user....

  1. Gene Expression Measurement Module (GEMM) - A Fully Automated, Miniaturized Instrument for Measuring Gene Expression in Space

    Science.gov (United States)

    Pohorille, Andrew; Peyvan, Kia; Karouia, Fathi; Ricco, Antonio

    2012-01-01

    The capability to measure gene expression on board spacecraft opens the door to a large number of high-value experiments on the influence of the space environment on biological systems. For example, measurements of gene expression will help us to understand adaptation of terrestrial life to conditions beyond the planet of origin, identify deleterious effects of the space environment on a wide range of organisms from microbes to humans, develop effective countermeasures against these effects, and determine the metabolic bases of microbial pathogenicity and drug resistance. These and other applications hold significant potential for discoveries in space biology, biotechnology, and medicine. Supported by funding from the NASA Astrobiology Science and Technology Instrument Development Program, we are developing a fully automated, miniaturized, integrated fluidic system for small spacecraft capable of in-situ measurement of expression of several hundreds of microbial genes from multiple samples. The instrument will be capable of (1) lysing cell walls of bacteria sampled from cultures grown in space, (2) extracting and purifying RNA released from cells, (3) hybridizing the RNA on a microarray and (4) providing readout of the microarray signal, all in a single microfluidics cartridge. The device is suitable for deployment on nanosatellite platforms developed by NASA Ames' Small Spacecraft Division. To meet space and other technical constraints imposed by these platforms, a number of technical innovations are being implemented. The integration and end-to-end technological and biological validation of the instrument are carried out using as a model the photosynthetic bacterium Synechococcus elongatus, known for its remarkable metabolic diversity and resilience to adverse conditions. Each step in the measurement process-lysis, nucleic acid extraction, purification, and hybridization to an array-is assessed through comparison of the results obtained using the instrument with

  2. Eukaryotic diversity in historical soil samples

    NARCIS (Netherlands)

    Moon-van der Staay, S.Y.; Tzeneva, V.A.; Staay, van der G.W.M.; Vos, de W.M.; Smidt, H.; Hackstein, J.H.P.

    2006-01-01

    The eukaryotic biodiversity in historical air-dried samples of Dutch agricultural soil has been assessed by random sequencing of an 18S rRNA gene library and by denaturing gradient gel electrophoresis. Representatives of nearly all taxa of eukaryotic soil microbes could be identified, demonstrating

  3. Automated type specific ELISA probe detection of amplified NS3 gene products of dengue viruses.

    OpenAIRE

    Chow, V T; Yong, R Y; Ngoh, B L; Chan, Y. C.

    1997-01-01

    AIM: To apply an automated system of nucleic acid hybridisation coupled with the enzyme linked immunosorbent assay (ELISA) for the type specific detection of amplification products of dengue viruses. METHODS: Non-structural 3 (NS3) gene targets of reference strains of all four dengue and other flaviviruses, as well as dengue patient viraemic sera, were subjected to reverse transcription and polymerase chain reaction using consensus and dengue type specific primers and digoxigenin-11-dUTP labe...

  4. PLMItRNA, a database for mitochondrial tRNA genes and tRNAs in photosynthetic eukaryotes

    Science.gov (United States)

    Damiano, Fabrizio; Gallerani, Raffaele; Liuni, Sabino; Licciulli, Flavio; Ceci, Luigi R.

    2001-01-01

    The PLMItRNA database for mitochondrial tRNA molecules and genes in Viridiplantae (green plants) [Volpetti,V., Gallerani,R., DeBenedetto,C., Liuni,S., Licciulli,F. and Ceci,L.R. (2000) Nucleic Acids Res., 28, 159–162] has been enlarged to include algae. The database now contains 436 genes and 16 tRNA entries relative to 25 higher plants, eight green algae, four red algae (Rhodophytae) and two Stramenopiles. The PLMItRNA database is accessible via the WWW at http://bio-www.ba.cnr.it:8000/PLMItRNA. PMID:11125079

  5. Structure and organization of Escherichia coli genes involved in biosynthesis of the deazaguanine derivative queuine, a nutrient factor for eukaryotes.

    OpenAIRE

    Reuter, K.; Slany, R; Ullrich, F.; Kersten, H.

    1991-01-01

    The plasmid pPR20 contains the gene tgt, which encodes tRNA guanine transglycosylase (Tgt), on a 33-kbp DNA insert from a region around 9 min on the Escherichia coli linkage map. The plasmid was subcloned to determine the sequence and organization of the tgt gene. Tgt is a unique enzyme that exchanges the guanine residue with 7-aminomethyl-7-deazaguanine in tRNAs with GU(N) anticodons. After this exchange, a cyclopentendiol moiety is attached to the 7-aminomethyl group of 7-deazaguanine, resu...

  6. Automated DNA mutation detection using universal conditions direct sequencing: application to ten muscular dystrophy genes

    Directory of Open Access Journals (Sweden)

    Wu Bai-Lin

    2009-10-01

    Full Text Available Abstract Background One of the most common and efficient methods for detecting mutations in genes is PCR amplification followed by direct sequencing. Until recently, the process of designing PCR assays has been to focus on individual assay parameters rather than concentrating on matching conditions for a set of assays. Primers for each individual assay were selected based on location and sequence concerns. The two primer sequences were then iteratively adjusted to make the individual assays work properly. This generally resulted in groups of assays with different annealing temperatures that required the use of multiple thermal cyclers or multiple passes in a single thermal cycler making diagnostic testing time-consuming, laborious and expensive. These factors have severely hampered diagnostic testing services, leaving many families without an answer for the exact cause of a familial genetic disease. A search of GeneTests for sequencing analysis of the entire coding sequence for genes that are known to cause muscular dystrophies returns only a small list of laboratories that perform comprehensive gene panels. The hypothesis for the study was that a complete set of universal assays can be designed to amplify and sequence any gene or family of genes using computer aided design tools. If true, this would allow automation and optimization of the mutation detection process resulting in reduced cost and increased throughput. Results An automated process has been developed for the detection of deletions, duplications/insertions and point mutations in any gene or family of genes and has been applied to ten genes known to bear mutations that cause muscular dystrophy: DMD; CAV3; CAPN3; FKRP; TRIM32; LMNA; SGCA; SGCB; SGCG; SGCD. Using this process, mutations have been found in five DMD patients and four LGMD patients (one in the FKRP gene, one in the CAV3 gene, and two likely causative heterozygous pairs of variations in the CAPN3 gene of two other

  7. Automating gene library synthesis by structure-based combinatorial protein engineering: examples from plant sesquiterpene synthases.

    Science.gov (United States)

    Dokarry, Melissa; Laurendon, Caroline; O'Maille, Paul E

    2012-01-01

    Structure-based combinatorial protein engineering (SCOPE) is a homology-independent recombination method to create multiple crossover gene libraries by assembling defined combinations of structural elements ranging from single mutations to domains of protein structure. SCOPE was originally inspired by DNA shuffling, which mimics recombination during meiosis, where mutations from parental genes are "shuffled" to create novel combinations in the resulting progeny. DNA shuffling utilizes sequence identity between parental genes to mediate template-switching events (the annealing and extension of one parental gene fragment on another) in PCR reassembly reactions to generate crossovers and hence recombination between parental genes. In light of the conservation of protein structure and degeneracy of sequence, SCOPE was developed to enable the "shuffling" of distantly related genes with no requirement for sequence identity. The central principle involves the use of oligonucleotides to encode for crossover regions to choreograph template-switching events during PCR assembly of gene fragments to create chimeric genes. This approach was initially developed to create libraries of hybrid DNA polymerases from distantly related parents, and later developed to create a combinatorial mutant library of sesquiterpene synthases to explore the catalytic landscapes underlying the functional divergence of related enzymes. This chapter presents a simplified protocol of SCOPE that can be integrated with different mutagenesis techniques and is suitable for automation by liquid-handling robots. Two examples are presented to illustrate the application of SCOPE to create gene libraries using plant sesquiterpene synthases as the model system. In the first example, we outline how to create an active-site library as a series of complex mixtures of diverse mutants. In the second example, we outline how to create a focused library as an array of individual clones to distil minimal combinations of

  8. CpLEA5, the Late Embryogenesis Abundant Protein Gene from Chimonanthus praecox, Possesses Low Temperature and Osmotic Resistances in Prokaryote and Eukaryotes

    Directory of Open Access Journals (Sweden)

    Yiling Liu

    2015-11-01

    Full Text Available Plants synthesize and accumulate a series of stress-resistance proteins to protect normal physiological activities under adverse conditions. Chimonanthus praecox which blooms in freezing weather accumulates late embryogenesis abundant proteins (LEAs in flowers, but C. praecox LEAs are little reported. Here, we report a group of five LEA genes of C. praecox (CpLEA5, KT727031. Prokaryotic-expressed CpLEA5 was employed in Escherichia coli to investigate bioactivities and membrane permeability at low-temperature. In comparison with the vacant strains, CpLEA5-containing strains survived in a 20% higher rate; and the degree of cell membrane damage in CpLEA5-containing strains was 55% of that of the vacant strains according to a conductivity test, revealing the low-temperature resistance of CpLEA5 in bacteria. CpLEA5 was also expressed in Pichia pastoris. Interestingly, besides low-temperature resistance, CpLEA5 conferred high resistance to salt and alkali in CpLEA5 overexpressing yeast. The CpLEA5 gene was transferred into Arabidopsis thaliana to also demonstrate CpLEA5 actions in plants. As expected, the transgenic lines were more resistant against low-temperature and drought while compared with the wild type. Taken together, CpLEA5-conferred resistances to several conditions in prokaryote and eukaryotes could have great value as a genetic technology to enhance osmotic stress and low-temperature tolerance.

  9. CpLEA5, the Late Embryogenesis Abundant Protein Gene from Chimonanthus praecox, Possesses Low Temperature and Osmotic Resistances in Prokaryote and Eukaryotes.

    Science.gov (United States)

    Liu, Yiling; Xie, Lixia; Liang, Xilong; Zhang, Shihong

    2015-01-01

    Plants synthesize and accumulate a series of stress-resistance proteins to protect normal physiological activities under adverse conditions. Chimonanthus praecox which blooms in freezing weather accumulates late embryogenesis abundant proteins (LEAs) in flowers, but C. praecox LEAs are little reported. Here, we report a group of five LEA genes of C. praecox (CpLEA5, KT727031). Prokaryotic-expressed CpLEA5 was employed in Escherichia coli to investigate bioactivities and membrane permeability at low-temperature. In comparison with the vacant strains, CpLEA5-containing strains survived in a 20% higher rate; and the degree of cell membrane damage in CpLEA5-containing strains was 55% of that of the vacant strains according to a conductivity test, revealing the low-temperature resistance of CpLEA5 in bacteria. CpLEA5 was also expressed in Pichia pastoris. Interestingly, besides low-temperature resistance, CpLEA5 conferred high resistance to salt and alkali in CpLEA5 overexpressing yeast. The CpLEA5 gene was transferred into Arabidopsis thaliana to also demonstrate CpLEA5 actions in plants. As expected, the transgenic lines were more resistant against low-temperature and drought while compared with the wild type. Taken together, CpLEA5-conferred resistances to several conditions in prokaryote and eukaryotes could have great value as a genetic technology to enhance osmotic stress and low-temperature tolerance. PMID:26569231

  10. Construction of the Eukaryotic Expression Vector with EGFP and hVE GF121 Gene and its Expression in Rat Mesenchymal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    Su Li; Chen Yunzhen; Zhang Xiaogang; She Qiang

    2005-01-01

    Objectives To construct a recombinant plasmid carrying enhanced green fluorescent protein (EGFP) and human vascular endothelial growth factor (VEGF) 121 gene and detect its expression in rat mesenchymal stem cells (MSCs). Methods Human VEGF121 cDNA was amplified with polymerase chain reaction (PCR) from pCD/hVEGF121 and was inserted into the eukaryotic expression vector pEGFPC1. After being identified with PCR, double enzyme digestion and DNA sequencing. The recombinant plasmid pEGFP/hVEGF121 was transferred into rat MSCs with lipofectamine. The expression of EGFP/VEGF121 fusion protein were detected with fluorescence microscope and immunocytochemical staining respectively. Results The recombinant plasmid was confirmed with PCR, double enzyme digestion and DNA sequencing. The fluorescence microscope and immunocytochemical staining results showed that the EGFP and VEGF121 protein were expressed in MSCs 48 h after transfection.Conclusions The recombinant plasmid carrying EGFP and human VEGF was successfully constructed and expressed positively in rat MSCs. It offers a promise tool for further research on differentiation of MSCs and VEGF gene therapy for ischemial cardiovascular disease.

  11. In vitro Expression in Eukaryotic Cells of a Prion Protein Gene Cloned from Scrapie-Infected Mouse Brain

    Science.gov (United States)

    Caughey, Byron; Race, Richard E.; Vogel, Mari; Buchmeier, Michael J.; Chesebro, Bruce

    1988-07-01

    It has been proposed that the causative agent of scrapie represents a class of infectious particle that is devoid of nucleic acid and that an altered form of the endogenous prion protein (PrP) is the agent. However, it has been difficult to exclude the possibility that PrP purified from scrapie tissues might be contaminated with a more conventional viral agent. To obtain PrP uncontaminated by scrapie-infected tissues, PrP cDNA cloned from a scrapie-infected mouse brain was expressed in mouse C127 cells in vitro. mRNA and protein encoded by the cloned PrP gene were identified. The expressed PrP polypeptides appeared to be glycosylated and were released from the cell surface into the medium. Homogenates of the cells expressing the cloned PrP gene were inoculated into susceptible mice but failed to induce clinical signs of scrapie. Thus, either PrP is not the transmissible agent of scrapie or the expressed PrP requires additional modification to be infectious.

  12. Genetic control of chromosome instability in Aspergillus nidulans as a means for gene amplification in eukaryotic microorganisms

    International Nuclear Information System (INIS)

    A haploid strain of Aspergillus nidulans carrying I-II duplication homozygous for the leaky mutation adE20 shows improved growth on minimal medium. The duplication, though more stable than disomics, still shows instability. Several methods were used for detecting genetic control of improved stability. a) visual selection, using a duplicated strain which is very unstable due to UV sensitivity, (adE20, biAl/dp yA2; uvsB). One stable strain showed a deletion (or a lethal mutation) distal to biA on the segment at the original position (on chromosome I). This deletion reduces crossing-over frequency detween the two homologous segments. As the deletion of the non-translated segment (yellow sectors) must be preceded by crossing-over, the above reduces the frequency of yellow sectors. A deletion of the translocated segment (green sectors) results in non-viability due to the deletion, and such sectors do not appear. The net result is a stable duplication involving only 12 C.O. units carrying the gene in concern. b) Suppressors of UV sensitivity (su-uvsB) were attempted using the above uvs duplicated strain. Phenotypic revertants were easily obtained, but all were back mutations at the uvsB locus. c) Mutations for UV resistance higher than that of the wild type were not obtained, in spite of the strong selective pressure inserted. d) Recombination deficient mutations (rec), six altogether, all uvs+, did not have any effect on stability. (orig.)

  13. A rapid method for sequencing of rRNA gene(s) amplified by polymerase chain reaction using an automated DNA sequencer

    OpenAIRE

    Dwivedi, P.P.; Patel, B.K.C.; Rees, G.N.; Ollivier, Bernard

    1996-01-01

    A method for DNA sequencing of ribosomal RNA (rRNA) genes, amplified by polymerase chain reaction (PCR), using internal primers, designed on the basis of conserved regions of rRNA genes for determining a near complete sequence (99%) of the gene using an automated DNA sequencer (Applied Biosystem Incorporation, USA) is described. The procedure is extremely rapid as cloning of the gene is not required for sequence determination. In addition time consuming steps such as ethanol precipitation and...

  14. GeneLook: a novel ab initio gene identification system suitable for automated annotation of prokaryotic sequences.

    Science.gov (United States)

    Nishi, Tatsunari; Ikemura, Toshimichi; Kanaya, Shigehiko

    2005-02-14

    With the rapid increases in the amounts of sequence data for prokaryotic genomes, it has become important to develop systems for automated and accurate genome annotation. We present herein a novel ab initio gene identification system, GeneLook, that predicts protein-coding open reading frames (ORFs) with high sensitivity and specificity with no prior knowledge of the sequence composition. The system predicts protein-coding ORFs in two stages, seed ORF selection and main prediction. In the selection of reliable seed ORFs containing at least 200 codons, GeneLook predicts translation start sites and operon structures through searches for ribosome-binding sites and a novel operon prediction algorithm. The codon and nucleotide frequencies of seed ORFs are then used to determine values for two new coding-potential parameters for identification of protein-coding ORFs of at least 34 codons and for another parameter that improves the prediction accuracy for GC-rich genomes. In the main prediction, GeneLook uses these parameters to identify the most likely genes of a given minimal length. We assessed the performance of GeneLook with two indices, sensitivity and specificity that are defined as true positives (TP)/(TP+false negatives) and TP/(TP+false positives), respectively. This system predicted protein-coding ORFs for Escherichia coli and Bacillus subtilis with sensitivities of 96.5% and 96.2%, respectively, and specificities of 96.9% and 96.1%, respectively. The system also identified 94.1% of annotated genes of the Pseudomonas aeruginosa genome, which is GC-rich, with high specificity (97.2%). Furthermore, GeneLook identified protein-coding ORFs with high accuracy from a wide variety of prokaryotic genomes. PMID:15716020

  15. GSMA: Gene Set Matrix Analysis, An Automated Method for Rapid Hypothesis Testing of Gene Expression Data

    Directory of Open Access Journals (Sweden)

    Chris Cheadle

    2007-01-01

    Full Text Available Background: Microarray technology has become highly valuable for identifying complex global changes in gene expression patterns. The assignment of functional information to these complex patterns remains a challenging task in effectively interpreting data and correlating results from across experiments, projects and laboratories. Methods which allow the rapid and robust evaluation of multiple functional hypotheses increase the power of individual researchers to data mine gene expression data more efficiently.Results: We have developed (gene set matrix analysis GSMA as a useful method for the rapid testing of group-wise up- or downregulation of gene expression simultaneously for multiple lists of genes (gene sets against entire distributions of gene expression changes (datasets for single or multiple experiments. The utility of GSMA lies in its flexibility to rapidly poll gene sets related by known biological function or as designated solely by the end-user against large numbers of datasets simultaneously.Conclusions: GSMA provides a simple and straightforward method for hypothesis testing in which genes are tested by groups across multiple datasets for patterns of expression enrichment.

  16. The Genome of Naegleria gruberi Illuminates Early Eukaryotic Versatility

    Energy Technology Data Exchange (ETDEWEB)

    Fritz-Laylin, Lillian K.; Prochnik, Simon E.; Ginger, Michael L.; Dacks, Joel; Carpenter, Meredith L.; Field, Mark C.; Kuo, Alan; Paredez, Alex; Chapman, Jarrod; Pham, Jonathan; Shu, Shengqiang; Neupane, Rochak; Cipriano, Michael; Mancuso, Joel; Tu, Hank; Salamov, Asaf; Lindquist, Erika; Shapiro, Harris; Lucas, Susan; Grigoriev, Igor V.; Cande, W. Zacheus; Fulton, Chandler; Rokhsar, Daniel S.; Dawson, Scott C.

    2010-03-01

    Genome sequences of diverse free-living protists are essential for understanding eukaryotic evolution and molecular and cell biology. The free-living amoeboflagellate Naegleria gruberi belongs to a varied and ubiquitous protist clade (Heterolobosea) that diverged from other eukaryotic lineages over a billion years ago. Analysis of the 15,727 protein-coding genes encoded by Naegleria's 41 Mb nuclear genome indicates a capacity for both aerobic respiration and anaerobic metabolism with concomitant hydrogen production, with fundamental implications for the evolution of organelle metabolism. The Naegleria genome facilitates substantially broader phylogenomic comparisons of free-living eukaryotes than previously possible, allowing us to identify thousands of genes likely present in the pan-eukaryotic ancestor, with 40% likely eukaryotic inventions. Moreover, we construct a comprehensive catalog of amoeboid-motility genes. The Naegleria genome, analyzed in the context of other protists, reveals a remarkably complex ancestral eukaryote with a rich repertoire of cytoskeletal, sexual, signaling, and metabolic modules.

  17. Reconstructing the mosaic glycolytic pathway of the anaerobic eukaryote Monocercomonoides.

    Science.gov (United States)

    Liapounova, Natalia A; Hampl, Vladimir; Gordon, Paul M K; Sensen, Christoph W; Gedamu, Lashitew; Dacks, Joel B

    2006-12-01

    All eukaryotes carry out glycolysis, interestingly, not all using the same enzymes. Anaerobic eukaryotes face the challenge of fewer molecules of ATP extracted per molecule of glucose due to their lack of a complete tricarboxylic acid cycle. This may have pressured anaerobic eukaryotes to acquire the more ATP-efficient alternative glycolytic enzymes, such as pyrophosphate-fructose 6-phosphate phosphotransferase and pyruvate orthophosphate dikinase, through lateral gene transfers from bacteria and other eukaryotes. Most studies of these enzymes in eukaryotes involve pathogenic anaerobes; Monocercomonoides, an oxymonad belonging to the eukaryotic supergroup Excavata, is a nonpathogenic anaerobe representing an evolutionarily and ecologically distinct sampling of an anaerobic glycolytic pathway. We sequenced cDNA encoding glycolytic enzymes from a previously established cDNA library of Monocercomonoides and analyzed the relationships of these enzymes to those from other organisms spanning the major groups of Eukaryota, Bacteria, and Archaea. We established that, firstly, Monocercomonoides possesses alternative versions of glycolytic enzymes: fructose-6-phosphate phosphotransferase, both pyruvate kinase and pyruvate orthophosphate dikinase, cofactor-independent phosphoglycerate mutase, and fructose-bisphosphate aldolase (class II, type B). Secondly, we found evidence for the monophyly of oxymonads, kinetoplastids, diplomonads, and parabasalids, the major representatives of the Excavata. We also found several prokaryote-to-eukaryote as well as eukaryote-to-eukaryote lateral gene transfers involving glycolytic enzymes from anaerobic eukaryotes, further suggesting that lateral gene transfer was an important factor in the evolution of this pathway for denizens of this environment. PMID:17071828

  18. Comparative genomics and evolution of eukaryotic phospholipidbiosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lykidis, Athanasios

    2006-12-01

    Phospholipid biosynthetic enzymes produce diverse molecular structures and are often present in multiple forms encoded by different genes. This work utilizes comparative genomics and phylogenetics for exploring the distribution, structure and evolution of phospholipid biosynthetic genes and pathways in 26 eukaryotic genomes. Although the basic structure of the pathways was formed early in eukaryotic evolution, the emerging picture indicates that individual enzyme families followed unique evolutionary courses. For example, choline and ethanolamine kinases and cytidylyltransferases emerged in ancestral eukaryotes, whereas, multiple forms of the corresponding phosphatidyltransferases evolved mainly in a lineage specific manner. Furthermore, several unicellular eukaryotes maintain bacterial-type enzymes and reactions for the synthesis of phosphatidylglycerol and cardiolipin. Also, base-exchange phosphatidylserine synthases are widespread and ancestral enzymes. The multiplicity of phospholipid biosynthetic enzymes has been largely generated by gene expansion in a lineage specific manner. Thus, these observations suggest that phospholipid biosynthesis has been an actively evolving system. Finally, comparative genomic analysis indicates the existence of novel phosphatidyltransferases and provides a candidate for the uncharacterized eukaryotic phosphatidylglycerol phosphate phosphatase.

  19. Automated analysis of protein expression and gene amplification within the same cells of paraffin-embedded tumour tissue

    OpenAIRE

    Timo Gaiser; Lissa Berroa-Garcia; Ralf Kemmerling; Aparajita Dutta; Thomas Ried; Kerstin Heselmeyer-Haddad

    2010-01-01

    Background: The simultaneous detection of protein expression and gene copy number changes in patient samples, like paraffin-embedded tissue sections, is challenging since the procedures of immunohistochemistry (IHC) and Fluorescence in situ Hybridization (FISH) negatively influence each other which often results in suboptimal staining. Therefore, we developed a novel automated algorithm based on relocation which allows subsequent detection of protein content and gene copy number changes withi...

  20. Automated Extraction Of Associations Between Methylated Genes and Diseases From Biomedical Literature

    KAUST Repository

    Bin Res, Arwa A.

    2012-12-01

    Associations between methylated genes and diseases have been investigated in several studies, and it is critical to have such information available for better understanding of diseases and clinical decisions. However, such information is scattered in a large number of electronic publications and it is difficult to manually search for it. Therefore, the goal of the project is to develop a machine learning model that can efficiently extract such information. Twelve machine learning algorithms were applied and compared in application to this problem based on three approaches that involve: document-term frequency matrices, position weight matrices, and a hybrid approach that uses the combination of the previous two. The best results we obtained by the hybrid approach with a random forest model that, in a 10-fold cross-validation, achieved F-score and accuracy of nearly 85% and 84%, respectively. On a completely separate testing set, F-score and accuracy of 89% and 88%, respectively, were obtained. Based on this model, we developed a tool that automates extraction of associations between methylated genes and diseases from electronic text. Our study contributed an efficient method for extracting specific types of associations from free text and the methodology developed here can be extended to other similar association extraction problems.

  1. Hidden ribozymes in eukaryotic genome sequence

    OpenAIRE

    Sean P Ryder

    2010-01-01

    The small self-cleaving ribozymes fold into complex tertiary structures to promote autocatalytic cleavage or ligation at a precise position within their sequence. Until recently, relatively few examples had been identified. Two papers now reveal that self-cleaving ribozymes are prevalent in eukaryotic genomes and, in some cases, might play a role in regulating gene expression.

  2. A case study for effects of operational taxonomic units from intracellular endoparasites and ciliates on the eukaryotic phylogeny: phylogenetic position of the haptophyta in analyses of multiple slowly evolving genes.

    Directory of Open Access Journals (Sweden)

    Hisayoshi Nozaki

    Full Text Available Recent multigene phylogenetic analyses have contributed much to our understanding of eukaryotic phylogeny. However, the phylogenetic positions of various lineages within the eukaryotes have remained unresolved or in conflict between different phylogenetic studies. These phylogenetic ambiguities might have resulted from mixtures or integration from various factors including limited taxon sampling, missing data in the alignment, saturations of rapidly evolving genes, mixed analyses of short- and long-branched operational taxonomic units (OTUs, intracellular endoparasite and ciliate OTUs with unusual substitution etc. In order to evaluate the effects from intracellular endoparasite and ciliate OTUs co-analyzed on the eukaryotic phylogeny and simplify the results, we here used two different sets of data matrices of multiple slowly evolving genes with small amounts of missing data and examined the phylogenetic position of the secondary photosynthetic chromalveolates Haptophyta, one of the most abundant groups of oceanic phytoplankton and significant primary producers. In both sets, a robust sister relationship between Haptophyta and SAR (stramenopiles, alveolates, rhizarians, or SA [stramenopiles and alveolates] was resolved when intracellular endoparasite/ciliate OTUs were excluded, but not in their presence. Based on comparisons of character optimizations on a fixed tree (with a clade composed of haptophytes and SAR or SA, disruption of the monophyly between haptophytes and SAR (or SA in the presence of intracellular endoparasite/ciliate OTUs can be considered to be a result of multiple evolutionary reversals of character positions that supported the synapomorphy of the haptophyte and SAR (or SA clade in the absence of intracellular endoparasite/ciliate OTUs.

  3. Mapping of Brain Activity by Automated Volume Analysis of Immediate Early Genes.

    Science.gov (United States)

    Renier, Nicolas; Adams, Eliza L; Kirst, Christoph; Wu, Zhuhao; Azevedo, Ricardo; Kohl, Johannes; Autry, Anita E; Kadiri, Lolahon; Umadevi Venkataraju, Kannan; Zhou, Yu; Wang, Victoria X; Tang, Cheuk Y; Olsen, Olav; Dulac, Catherine; Osten, Pavel; Tessier-Lavigne, Marc

    2016-06-16

    Understanding how neural information is processed in physiological and pathological states would benefit from precise detection, localization, and quantification of the activity of all neurons across the entire brain, which has not, to date, been achieved in the mammalian brain. We introduce a pipeline for high-speed acquisition of brain activity at cellular resolution through profiling immediate early gene expression using immunostaining and light-sheet fluorescence imaging, followed by automated mapping and analysis of activity by an open-source software program we term ClearMap. We validate the pipeline first by analysis of brain regions activated in response to haloperidol. Next, we report new cortical regions downstream of whisker-evoked sensory processing during active exploration. Last, we combine activity mapping with axon tracing to uncover new brain regions differentially activated during parenting behavior. This pipeline is widely applicable to different experimental paradigms, including animal species for which transgenic activity reporters are not readily available. PMID:27238021

  4. Atypical mitochondrial inheritance patterns in eukaryotes.

    Science.gov (United States)

    Breton, Sophie; Stewart, Donald T

    2015-10-01

    Mitochondrial DNA (mtDNA) is predominantly maternally inherited in eukaryotes. Diverse molecular mechanisms underlying the phenomenon of strict maternal inheritance (SMI) of mtDNA have been described, but the evolutionary forces responsible for its predominance in eukaryotes remain to be elucidated. Exceptions to SMI have been reported in diverse eukaryotic taxa, leading to the prediction that several distinct molecular mechanisms controlling mtDNA transmission are present among the eukaryotes. We propose that these mechanisms will be better understood by studying the deviations from the predominating pattern of SMI. This minireview summarizes studies on eukaryote species with unusual or rare mitochondrial inheritance patterns, i.e., other than the predominant SMI pattern, such as maternal inheritance of stable heteroplasmy, paternal leakage of mtDNA, biparental and strictly paternal inheritance, and doubly uniparental inheritance of mtDNA. The potential genes and mechanisms involved in controlling mitochondrial inheritance in these organisms are discussed. The linkage between mitochondrial inheritance and sex determination is also discussed, given that the atypical systems of mtDNA inheritance examined in this minireview are frequently found in organisms with uncommon sexual systems such as gynodioecy, monoecy, or andromonoecy. The potential of deviations from SMI for facilitating a better understanding of a number of fundamental questions in biology, such as the evolution of mtDNA inheritance, the coevolution of nuclear and mitochondrial genomes, and, perhaps, the role of mitochondria in sex determination, is considerable. PMID:26501689

  5. The COG database: an updated version includes eukaryotes

    Directory of Open Access Journals (Sweden)

    Sverdlov Alexander V

    2003-09-01

    Full Text Available Abstract Background The availability of multiple, essentially complete genome sequences of prokaryotes and eukaryotes spurred both the demand and the opportunity for the construction of an evolutionary classification of genes from these genomes. Such a classification system based on orthologous relationships between genes appears to be a natural framework for comparative genomics and should facilitate both functional annotation of genomes and large-scale evolutionary studies. Results We describe here a major update of the previously developed system for delineation of Clusters of Orthologous Groups of proteins (COGs from the sequenced genomes of prokaryotes and unicellular eukaryotes and the construction of clusters of predicted orthologs for 7 eukaryotic genomes, which we named KOGs after eukaryotic orthologous groups. The COG collection currently consists of 138,458 proteins, which form 4873 COGs and comprise 75% of the 185,505 (predicted proteins encoded in 66 genomes of unicellular organisms. The eukaryotic orthologous groups (KOGs include proteins from 7 eukaryotic genomes: three animals (the nematode Caenorhabditis elegans, the fruit fly Drosophila melanogaster and Homo sapiens, one plant, Arabidopsis thaliana, two fungi (Saccharomyces cerevisiae and Schizosaccharomyces pombe, and the intracellular microsporidian parasite Encephalitozoon cuniculi. The current KOG set consists of 4852 clusters of orthologs, which include 59,838 proteins, or ~54% of the analyzed eukaryotic 110,655 gene products. Compared to the coverage of the prokaryotic genomes with COGs, a considerably smaller fraction of eukaryotic genes could be included into the KOGs; addition of new eukaryotic genomes is expected to result in substantial increase in the coverage of eukaryotic genomes with KOGs. Examination of the phyletic patterns of KOGs reveals a conserved core represented in all analyzed species and consisting of ~20% of the KOG set. This conserved portion of the

  6. Horizontal DNA transfer from bacteria to eukaryotes and a lesson from experimental transfers.

    Science.gov (United States)

    Suzuki, Katsunori; Moriguchi, Kazuki; Yamamoto, Shinji

    2015-12-01

    Horizontal gene transfer (HGT) is widespread among bacteria and plays a key role in genome dynamics. HGT is much less common in eukaryotes, but is being reported with increasing frequency in eukaryotes. The mechanism as to how eukaryotes acquired genes from distantly related organisms remains obscure yet. This paper cites examples of bacteria-derived genes found in eukaryotic organisms, and then describes experimental DNA transports to eukaryotes by bacterial type 4 secretion systems in optimized conditions. The mechanisms of the latter are efficient, quite reproducible in vitro and predictable, and thereby would provide insight into natural HGT and to the development of new research tools. PMID:26291765

  7. Statistical characteristics of eukaryotic intron database

    Institute of Scientific and Technical Information of China (English)

    HE Miao; LI Jidong; ZHANG Shanghong

    2006-01-01

    A database called eukaryotic intron database (EID) was developed based on the data from GenBank.Studies on the statistical characteristics of EID show that there were 103,848 genes,478,484 introns,and 582,332 exons,with an average of 4.61 introns and 5.61 exons per gene.Introns of 40-120 nt in length were abundant in the database.Results of the statistical analysis on the data from nine model species showed that in eukaryotes,higher species do not necessarily have more introns or exons in a gene than lower species.Furthermore,characteristics of EID,such as intron phase,distribution of different splice sites,and the relationship between genome size and intron proportion or intron density,have been studied.

  8. Origins and evolution of viruses of eukaryotes: The ultimate modularity

    Energy Technology Data Exchange (ETDEWEB)

    Koonin, Eugene V., E-mail: koonin@ncbi.nlm.nih.gov [National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894 (United States); Dolja, Valerian V., E-mail: doljav@science.oregonstate.edu [Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331 (United States); Krupovic, Mart, E-mail: krupovic@pasteur.fr [Institut Pasteur, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Department of Microbiology, Paris 75015 (France)

    2015-05-15

    Viruses and other selfish genetic elements are dominant entities in the biosphere, with respect to both physical abundance and genetic diversity. Various selfish elements parasitize on all cellular life forms. The relative abundances of different classes of viruses are dramatically different between prokaryotes and eukaryotes. In prokaryotes, the great majority of viruses possess double-stranded (ds) DNA genomes, with a substantial minority of single-stranded (ss) DNA viruses and only limited presence of RNA viruses. In contrast, in eukaryotes, RNA viruses account for the majority of the virome diversity although ssDNA and dsDNA viruses are common as well. Phylogenomic analysis yields tangible clues for the origins of major classes of eukaryotic viruses and in particular their likely roots in prokaryotes. Specifically, the ancestral genome of positive-strand RNA viruses of eukaryotes might have been assembled de novo from genes derived from prokaryotic retroelements and bacteria although a primordial origin of this class of viruses cannot be ruled out. Different groups of double-stranded RNA viruses derive either from dsRNA bacteriophages or from positive-strand RNA viruses. The eukaryotic ssDNA viruses apparently evolved via a fusion of genes from prokaryotic rolling circle-replicating plasmids and positive-strand RNA viruses. Different families of eukaryotic dsDNA viruses appear to have originated from specific groups of bacteriophages on at least two independent occasions. Polintons, the largest known eukaryotic transposons, predicted to also form virus particles, most likely, were the evolutionary intermediates between bacterial tectiviruses and several groups of eukaryotic dsDNA viruses including the proposed order “Megavirales” that unites diverse families of large and giant viruses. Strikingly, evolution of all classes of eukaryotic viruses appears to have involved fusion between structural and replicative gene modules derived from different sources

  9. Origins and evolution of viruses of eukaryotes: The ultimate modularity

    International Nuclear Information System (INIS)

    Viruses and other selfish genetic elements are dominant entities in the biosphere, with respect to both physical abundance and genetic diversity. Various selfish elements parasitize on all cellular life forms. The relative abundances of different classes of viruses are dramatically different between prokaryotes and eukaryotes. In prokaryotes, the great majority of viruses possess double-stranded (ds) DNA genomes, with a substantial minority of single-stranded (ss) DNA viruses and only limited presence of RNA viruses. In contrast, in eukaryotes, RNA viruses account for the majority of the virome diversity although ssDNA and dsDNA viruses are common as well. Phylogenomic analysis yields tangible clues for the origins of major classes of eukaryotic viruses and in particular their likely roots in prokaryotes. Specifically, the ancestral genome of positive-strand RNA viruses of eukaryotes might have been assembled de novo from genes derived from prokaryotic retroelements and bacteria although a primordial origin of this class of viruses cannot be ruled out. Different groups of double-stranded RNA viruses derive either from dsRNA bacteriophages or from positive-strand RNA viruses. The eukaryotic ssDNA viruses apparently evolved via a fusion of genes from prokaryotic rolling circle-replicating plasmids and positive-strand RNA viruses. Different families of eukaryotic dsDNA viruses appear to have originated from specific groups of bacteriophages on at least two independent occasions. Polintons, the largest known eukaryotic transposons, predicted to also form virus particles, most likely, were the evolutionary intermediates between bacterial tectiviruses and several groups of eukaryotic dsDNA viruses including the proposed order “Megavirales” that unites diverse families of large and giant viruses. Strikingly, evolution of all classes of eukaryotic viruses appears to have involved fusion between structural and replicative gene modules derived from different sources

  10. Procedimiento automático para seccionar imágenes remotas y caracterizar indicadores agronómicos y ambientales en las mismas

    OpenAIRE

    García Torres, Luis; López Granados, Francisca; Jurado-Expósito, Montserrat; Peña Barragán, José Manuel; Caballero Novella, Juan José

    2008-01-01

    Procedimiento automático para seccionar imágenes remotas y caracterizar indicadores agronómicos y ambientales en las mismas. El objeto de la presente invención es un procedimiento que permite seccionar/dividir automáticamente imágenes remotas en otras rectangulares de tamaño reducido (microimágenes/ microparcelas), y obtener indicadores agronómicos y ambientales en cada una de ellas y en el conjunto de la parcela. Se basa en el procesado de imágenes remotas de alta ...

  11. ASYMMETRIC-LEAVES2 and an ortholog of eukaryotic NudC domain proteins repress expression of AUXIN-RESPONSE-FACTOR and class 1 KNOX homeobox genes for development of flat symmetric leaves in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Nanako Ishibashi

    2012-01-01

    Leaf primordia form around the shoot apical meristem, which consists of indeterminate stem cells. Upon initiation of leaf development, adaxial-abaxial patterning is crucial for appropriate lateral expansion, via cellular proliferation, and the formation of flat symmetric leaves. Many genes that specify such patterning have been identified, but regulation by upstream factors of the expression of relevant effector genes remains poorly understood. In Arabidopsis thaliana, ASYMMETRIC LEAVES2 (AS2 and AS1 play important roles in repressing transcription of class 1 KNOTTED1-like homeobox (KNOX genes and leaf abaxial-determinant effector genes. We report here a mutation, designated enhancer of asymmetric leaves2 and asymmetric leaves1 (eal, that is associated with efficient generation of abaxialized filamentous leaves on the as2 or as1 background. Levels of transcripts of many abaxial-determinant genes, including ETTIN (ETT/AUXIN RESPONSE FACTOR3 (ARF3, and all four class 1 KNOX genes were markedly elevated in as2 eal shoot apices. Rudimentary patterning in as2 eal leaves was suppressed by the ett mutation. EAL encodes BOBBER1 (BOB1, an Arabidopsis ortholog of eukaryotic NudC domain proteins. BOB1 was expressed in plant tissues with division potential and bob1 mutations resulted in lowered levels of transcripts of some cell-cycle genes and decreased rates of cell division in shoot and root apices. Coordinated cellular proliferation, supported by BOB1, and repression of all class 1 KNOX genes, ETT/ARF3 by AS2 (AS1 and BOB1 might be critical for repression of the indeterminate state and of aberrant abaxialization in the presumptive adaxial domain of leaf primordia, which might ensure the formation of flat symmetric leaves.

  12. Endosymbiotic theories for eukaryote origin.

    Science.gov (United States)

    Martin, William F; Garg, Sriram; Zimorski, Verena

    2015-09-26

    For over 100 years, endosymbiotic theories have figured in thoughts about the differences between prokaryotic and eukaryotic cells. More than 20 different versions of endosymbiotic theory have been presented in the literature to explain the origin of eukaryotes and their mitochondria. Very few of those models account for eukaryotic anaerobes. The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come to bear on endosymbiotic theory. Only cells that possessed mitochondria had the bioenergetic means to attain eukaryotic cell complexity, which is why there are no true intermediates in the prokaryote-to-eukaryote transition. Current versions of endosymbiotic theory have it that the host was an archaeon (an archaebacterium), not a eukaryote. Hence the evolutionary history and biology of archaea increasingly comes to bear on eukaryotic origins, more than ever before. Here, we have compiled a survey of endosymbiotic theories for the origin of eukaryotes and mitochondria, and for the origin of the eukaryotic nucleus, summarizing the essentials of each and contrasting some of their predictions to the observations. A new aspect of endosymbiosis in eukaryote evolution comes into focus from these considerations: the host for the origin of plastids was a facultative anaerobe. PMID:26323761

  13. Molecular Data are Transforming Hypotheses on the Origin and Diversification of Eukaryotes

    OpenAIRE

    Tekle, Yonas I.; Parfrey, Laura Wegener; Katz, Laura A

    2009-01-01

    The explosion of molecular data has transformed hypotheses on both the origin of eukaryotes and the structure of the eukaryotic tree of life. Early ideas about the evolution of eukaryotes arose through analyses of morphology by light microscopy and later electron microscopy. Though such studies have proven powerful at resolving more recent events, theories on origins and diversification of eukaryotic life have been substantially revised in light of analyses of molecular data including gene an...

  14. Pathogenic Eukaryotes in Gut Microbiota of Western Lowland Gorillas as Revealed by Molecular Survey

    OpenAIRE

    Ibrahim Hamad; Mamadou B. Keita; Martine Peeters; Eric Delaporte; Didier Raoult; Fadi Bittar

    2014-01-01

    Although gorillas regarded as the largest extant species of primates and have a close phylogenetic relationship with humans, eukaryotic communities have not been previously studied in these populations. Herein, 35 eukaryotic primer sets targeting the 18S rRNA gene, internal transcribed spacer gene and other specific genes were used firstly to explore the eukaryotes in a fecal sample from a wild western lowland gorilla (Gorilla gorilla gorilla). Then specific real-time PCRs were achieved in ad...

  15. Endosymbiotic theories for eukaryote origin

    OpenAIRE

    Martin, William F.; Garg, Sriram; Zimorski, Verena

    2015-01-01

    For over 100 years, endosymbiotic theories have figured in thoughts about the differences between prokaryotic and eukaryotic cells. More than 20 different versions of endosymbiotic theory have been presented in the literature to explain the origin of eukaryotes and their mitochondria. Very few of those models account for eukaryotic anaerobes. The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come ...

  16. Construction of Eukaryotic Expression Vector of Human CC10 Gene and Expression of CC10 Protein in Lung Adenocarcinoma A549 Cell Line

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A mammalian expression plasmid pcDNA3.1-hCC10 was constructed and identified, then CC10 protein expression in A549 lung cancer cell line was detected. A 273 bp cDNA fragment was amplified from the total RNA of normal lung tissue by using RT-PCR and cloned into expression plasmid cDNA3.1, and the recombinant plasmid was identified by employing double digestion restriction enzymes HindⅢ and BamH Ⅰ and the cDNA sequence was assayed by the Sanger dideoxymediated chain termination method. The segment was then transfected into the A549 lung cancer cell line. The protein expression of CC10 was detected by immunofluorescence and Western blot.Our results showed that the cDNA fragment included the entire coding region (273 bp). The recombinant eukaryotic cell expression vector of pcDNA3.1-hCC10 was successfully constructed, and the sequence of the insert was identical to the published sequence. A549 cells line transfected with the pcDNA3.1-hCC10 expressed high level of CC10 protein. The recombinant plasmid cDNA3. 1hCC10 may serve as an effective tool for the study of tumorogenesis and tumor treatment.

  17. Energetics and genetics across the prokaryote-eukaryote divide

    Directory of Open Access Journals (Sweden)

    Lane Nick

    2011-06-01

    Full Text Available Abstract Background All complex life on Earth is eukaryotic. All eukaryotic cells share a common ancestor that arose just once in four billion years of evolution. Prokaryotes show no tendency to evolve greater morphological complexity, despite their metabolic virtuosity. Here I argue that the eukaryotic cell originated in a unique prokaryotic endosymbiosis, a singular event that transformed the selection pressures acting on both host and endosymbiont. Results The reductive evolution and specialisation of endosymbionts to mitochondria resulted in an extreme genomic asymmetry, in which the residual mitochondrial genomes enabled the expansion of bioenergetic membranes over several orders of magnitude, overcoming the energetic constraints on prokaryotic genome size, and permitting the host cell genome to expand (in principle over 200,000-fold. This energetic transformation was permissive, not prescriptive; I suggest that the actual increase in early eukaryotic genome size was driven by a heavy early bombardment of genes and introns from the endosymbiont to the host cell, producing a high mutation rate. Unlike prokaryotes, with lower mutation rates and heavy selection pressure to lose genes, early eukaryotes without genome-size limitations could mask mutations by cell fusion and genome duplication, as in allopolyploidy, giving rise to a proto-sexual cell cycle. The side effect was that a large number of shared eukaryotic basal traits accumulated in the same population, a sexual eukaryotic common ancestor, radically different to any known prokaryote. Conclusions The combination of massive bioenergetic expansion, release from genome-size constraints, and high mutation rate favoured a protosexual cell cycle and the accumulation of eukaryotic traits. These factors explain the unique origin of eukaryotes, the absence of true evolutionary intermediates, and the evolution of sex in eukaryotes but not prokaryotes. Reviewers This article was reviewed by

  18. Procedimiento para la normalización automática de imágenes remotas multitemporales en base a usos de suelo pseudo-invariantes vegetales

    OpenAIRE

    García Torres, Luis; Caballero Novella, Juan José; Gómez-Candón, David; Peña Barragán, José Manuel; López Granados, Francisca

    2012-01-01

    Procedimiento para la normalización automática de imágenes remotas multitemporales en base a usos de suelo pseudo-invariantes vegetales. Procedimiento automático para la normalización radiométrica de series de imágenes remotas multitemporales de una misma área o escena geográfica, en base a usos de suelo vegetales pseudo-invariantes que comprende: a) toma de imágenes remotas multiespectrales correspondientes a bandas que se seleccionan del espectro visible o hipe...

  19. Correlation of the UV-induced mutational spectra and the DNA damage distribution of the human HPRT gene: Automating the analysis

    International Nuclear Information System (INIS)

    Automated DNA sequencers can be readily adapted for various types of sequence-based nucleic acid analysis: more recently it was determined the distribution of UV photoproducts in the E. coli laci gene using techniques developed for automated fluorescence-based analysis. We have been working to improve the automated approach of damage distribution. Our current method is more rigorous. We have new software that integrates the area under the individual peaks, rather than measuring the height of the curve. In addition, we now employ an internal standard. The analysis can also be partially automated. Detection limits for both major types of UV-photoproducts (cyclobutane dimers and pyrimidine (6-4) pyrimidone photoproducts) are reported. The UV-induced damage distribution in the hprt gene is compared to the mutational spectra in human and rodents cells

  20. MicroRNAs Form Triplexes with Double Stranded DNA at Sequence-Specific Binding Sites; a Eukaryotic Mechanism via which microRNAs Could Directly Alter Gene Expression.

    Directory of Open Access Journals (Sweden)

    Steven W Paugh

    2016-02-01

    Full Text Available MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA and typically down-regulating their stability or translation. Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence (i.e., NMR, FRET, SPR that purine or pyrimidine-rich microRNAs of appropriate length and sequence form triple-helical structures with purine-rich sequences of duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident to search genome-wide for potential triplex-forming sites and show that several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 × 10(-16 for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. This work has thus revealed a new mechanism by which microRNAs could interact with gene promoter regions to modify gene transcription.

  1. Expanding the eukaryotic genetic code

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Jason W; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G

    2015-02-03

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  2. Origins of Eukaryotic Sexual Reproduction

    OpenAIRE

    Goodenough, Ursula; Heitman, Joseph

    2014-01-01

    Sexual reproduction is a nearly universal feature of eukaryotic organisms. Given its ubiquity and shared core features, sex is thought to have arisen once in the last common ancestor to all eukaryotes. Using the perspectives of molecular genetics and cell biology, we consider documented and hypothetical scenarios for the instantiation and evolution of meiosis, fertilization, sex determination, uniparental inheritance of organelle genomes, and speciation.

  3. Expanding the eukaryotic genetic code

    Science.gov (United States)

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2013-01-22

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  4. Endosymbiosis and Eukaryotic Cell Evolution.

    Science.gov (United States)

    Archibald, John M

    2015-10-01

    Understanding the evolution of eukaryotic cellular complexity is one of the grand challenges of modern biology. It has now been firmly established that mitochondria and plastids, the classical membrane-bound organelles of eukaryotic cells, evolved from bacteria by endosymbiosis. In the case of mitochondria, evidence points very clearly to an endosymbiont of α-proteobacterial ancestry. The precise nature of the host cell that partnered with this endosymbiont is, however, very much an open question. And while the host for the cyanobacterial progenitor of the plastid was undoubtedly a fully-fledged eukaryote, how - and how often - plastids moved from one eukaryote to another during algal diversification is vigorously debated. In this article I frame modern views on endosymbiotic theory in a historical context, highlighting the transformative role DNA sequencing played in solving early problems in eukaryotic cell evolution, and posing key unanswered questions emerging from the age of comparative genomics. PMID:26439354

  5. MicroRNAs Form Triplexes with Double Stranded DNA at Sequence-Specific Binding Sites; a Eukaryotic Mechanism via which microRNAs Could Directly Alter Gene Expression.

    Science.gov (United States)

    Paugh, Steven W; Coss, David R; Bao, Ju; Laudermilk, Lucas T; Grace, Christy R; Ferreira, Antonio M; Waddell, M Brett; Ridout, Granger; Naeve, Deanna; Leuze, Michael; LoCascio, Philip F; Panetta, John C; Wilkinson, Mark R; Pui, Ching-Hon; Naeve, Clayton W; Uberbacher, Edward C; Bonten, Erik J; Evans, William E

    2016-02-01

    MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA) and typically down-regulating their stability or translation. Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence (i.e., NMR, FRET, SPR) that purine or pyrimidine-rich microRNAs of appropriate length and sequence form triple-helical structures with purine-rich sequences of duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show that several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, ptriplex binding sequences. This work has thus revealed a new mechanism by which microRNAs could interact with gene promoter regions to modify gene transcription. PMID:26844769

  6. Analysis of the role of the LH92_11085 gene of a biofilm hyper-producing Acinetobacter baumannii strain on biofilm formation and attachment to eukaryotic cells.

    Science.gov (United States)

    Álvarez-Fraga, Laura; Pérez, Astrid; Rumbo-Feal, Soraya; Merino, María; Vallejo, Juan Andrés; Ohneck, Emily J; Edelmann, Richard E; Beceiro, Alejandro; Vázquez-Ucha, Juan C; Valle, Jaione; Actis, Luis A; Bou, Germán; Poza, Margarita

    2016-05-18

    Acinetobacter baumannii is a nosocomial pathogen that has a considerable ability to survive in the hospital environment partly due to its capacity to form biofilms. The first step in the process of establishing an infection is adherence of the bacteria to target cells. Chaperone-usher pili assembly systems are involved in pilus biogenesis pathways that play an important role in adhesion to host cells and tissues as well as medically relevant surfaces. After screening a collection of strains, a biofilm hyper-producing A. baumannii strain (MAR002) was selected to describe potential targets involved in pathogenicity. MAR002 showed a remarkable ability to form biofilm and attach to A549 human alveolar epithelial cells. Analysis of MAR002 using transmission electron microscopy (TEM) showed a significant presence of pili on the bacterial surface. Putative protein-coding genes involved in pili formation were identified based on the newly sequenced genome of MAR002 strain (JRHB01000001/2 or NZ_JRHB01000001/2). As assessed by qRT-PCR, the gene LH92_11085, belonging to the operon LH92_11070-11085, is overexpressed (ca. 25-fold more) in biofilm-associated cells compared to exponential planktonic cells. In the present work we investigate the role of this gene on the MAR002 biofilm phenotype. Scanning electron microscopy (SEM) and biofilm assays showed that inactivation of LH92_11085 gene significantly reduced bacterial attachment to A549 cells and biofilm formation on plastic, respectively. TEM analysis of the LH92_11085 mutant showed the absence of long pili formations normally present in the wild-type. These observations indicate the potential role this LH92_11085 gene could play in the pathobiology of A baumannii. PMID:26854744

  7. Synchronization of Eukaryotic Flagella

    Science.gov (United States)

    Goldstein, Raymond E.

    2012-11-01

    From unicellular organisms as small as a few microns to the largest vertebrates on earth we find groups of beating flagella or cilia that exhibit striking spatio-temporal organization. This may take the form of precise frequency and phase locking as frequently found in the swimming of green algae, or beating with long-wavelength phase modulations known as metachronal waves, seen in ciliates and in our respiratory systems. The remarkable similarity in the underlying molecular structure of flagella across the whole eukaryotic world leads naturally to the hypothesis that a similarly universal mechanism might be responsible for synchronization. Although this mechanism is poorly understood, one appealing hypothesis is that it results from hydrodynamic interactions between flagella. In this talk I will describe a synthesis of recent experimental and theoretical studies of this issue that have provided the strongest evidence to date for the hydrodynamic origin of flagellar synchronization. At the unicellular level this includes studies of the beating of the two flagella of the wild type unicellular alga Chlamydomonas reinhardtii in their native state and under conditions of regrowth following autotomy, and of the flagellar dominance mutant ptx1, which displays unusual anti-phase synchronization. Analysis of the related multicellular organism Volvox carteri shows it to be an ideal model organism for the study of metachronal waves. Supported by BBSRC, EPSRC, ERC, and The Wellcome Trust.

  8. Symbiosis and the origin of eukaryotic motility

    Science.gov (United States)

    Margulis, L.; Hinkle, G.

    1991-01-01

    Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the serial endosymbiotic theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.

  9. Ancient diversification of eukaryotic MCM DNA replication proteins

    Directory of Open Access Journals (Sweden)

    Aves Stephen J

    2009-03-01

    Full Text Available Abstract Background Yeast and animal cells require six mini-chromosome maintenance proteins (Mcm2-7 for pre-replication complex formation, DNA replication initiation and DNA synthesis. These six individual MCM proteins form distinct heterogeneous subunits within a hexamer which is believed to form the replicative helicase and which associates with the essential but non-homologous Mcm10 protein during DNA replication. In contrast Archaea generally only possess one MCM homologue which forms a homohexameric MCM helicase. In some eukaryotes Mcm8 and Mcm9 paralogues also appear to be involved in DNA replication although their exact roles are unclear. Results We used comparative genomics and phylogenetics to reconstruct the diversification of the eukaryotic Mcm2-9 gene family, demonstrating that Mcm2-9 were formed by seven gene duplication events before the last common ancestor of the eukaryotes. Mcm2-7 protein paralogues were present in all eukaryote genomes studied suggesting that no gene loss or functional replacements have been tolerated during the evolutionary diversification of eukaryotes. Mcm8 and 9 are widely distributed in eukaryotes and group together on the MCM phylogenetic tree to the exclusion of all other MCM paralogues suggesting co-ancestry. Mcm8 and Mcm9 are absent in some taxa, including Trichomonas and Giardia, and appear to have been secondarily lost in some fungi and some animals. The presence and absence of Mcm8 and 9 is concordant in all taxa sampled with the exception of Drosophila species. Mcm10 is present in most eukaryotes sampled but shows no concordant pattern of presence or absence with Mcm8 or 9. Conclusion A multifaceted and heterogeneous Mcm2-7 hexamer evolved during the early evolution of the eukaryote cell in parallel with numerous other acquisitions in cell complexity and prior to the diversification of extant eukaryotes. The conservation of all six paralogues throughout the eukaryotes suggests that each Mcm2

  10. Eukaryotic-Type Serine/Threonine Protein Kinase StkP Is a Global Regulator of Gene Expression in Streptococcus pneumoniae

    Czech Academy of Sciences Publication Activity Database

    Přenosilová, Lenka; Nováková, Linda; Basler, Marek; Branny, Pavel

    2007-01-01

    Roč. 189, č. 11 (2007), s. 4168-4179. ISSN 0021-9193 R&D Projects: GA ČR GP204/07/P082; GA ČR GA204/02/1423; GA MZe 1G46068 Institutional research plan: CEZ:AV0Z50200510 Keywords : protein kinase * streptococus pneumoniae * gene expression Subject RIV: EE - Microbiology, Virology Impact factor: 4.013, year: 2007

  11. A eukaryotic-acquired gene by a biotrophic phytopathogen allows prolonged survival on the host by counteracting the shut-down of plant photosynthesis

    KAUST Repository

    Garavaglia, Betiana S.

    2010-01-28

    Xanthomonas citri pv. citri, the bacteria responsible for citrus canker posses a biological active plant natriuretic peptide (PNP)-like protein, not present in any other bacteria. PNPs are a class of extracellular, systemically mobile peptides that elicit a number of plant responses important in homeostasis and growth. Previously, we showed that a Xanthomonas citri pv. citri mutant lacking the PNP-like protein XacPNP produced more necrotic lesions in citrus leaves than wild type infections and suggested a role for XacPNP in the regulation of host homeostasis. Here we have analyzed the proteome modifications observed in citrus leaves infected with the wild type and XacPNP deletion mutant bacteria. While both of them cause downregulation of enzymes related to photosynthesis as well as chloroplastic ribosomal proteins, proteins related to defense responses are up-regulated. However, leaves infiltrated with the XacPNP deletion mutant show a more pronounced decrease in photosynthetic proteins while no reduction in defense related proteins as compared to the wild-type pathogen. This suggests that XacPNP serves the pathogen to maintain host photosynthetic efficiency during pathogenesis. The results from the proteomics analyses are consistent with our chlorophyll fluorescence data and transcript analyses of defense genes that show a more marked reduction in photosynthesis in the mutant but no difference in the induction of genes diagnostic for biotic-stress responses. We therefore conclude that XacPNP counteracts the shut-down of host photosynthesis during infection and in that way maintains the tissue in better conditions, suggesting that the pathogen has adapted a host gene to modify its natural host and render it a better reservoir for prolonged bacterial survival and thus for further colonization. 2010 Garavaglia et al.

  12. Production of Candida antaractica Lipase B Gene Open Reading Frame using Automated PCR Gene Assembly Protocol on Robotic Workcell & Expression in Ethanologenic Yeast for use as Resin-Bound Biocatalyst in Biodiesel Production

    Science.gov (United States)

    A synthetic Candida antarctica lipase B (CALB) gene open reading frame (ORF) for expression in yeast was produced using an automated PCR assembly and DNA purification protocol on an integrated robotic workcell. The lycotoxin-1 (Lyt-1) C3 variant gene ORF was added in-frame with the CALB ORF to pote...

  13. Cryopreservation of eukaryotic soil algae

    Czech Academy of Sciences Publication Activity Database

    Lukešová, Alena; Worland, M. R.; Hrouzek, Pavel

    Coimbra: Society for Cryobiology, 2003. s. 32. [Cryobiomol 2003 - Low Temperature Biology. 14.09.2003-18.09.2003, Coimbra] Institutional research plan: CEZ:AV0Z6066911 Keywords : cryopreservation * eukaryotic soil algae Subject RIV: EH - Ecology, Behaviour

  14. An Automated Method for Rapid Identification of Putative Gene Family Members in Plants

    OpenAIRE

    2006-01-01

    Background Gene duplication events have played a significant role in genome evolution, particularly in plants. Exhaustive searches for all members of a known gene family as well as the identification of new gene families has become increasingly important. Subfunctionalization via changes in regulatory sequences following duplication (adaptive selection) appears to be a common mechanism of evolution in plants and can be accompanied by purifying selection on the coding region. Such negative sel...

  15. The Revised Classification of Eukaryotes

    OpenAIRE

    Adl, Sina M; Simpson, Alastair G.B.; Lane, Christopher E.; Lukeš, Julius; Bass, David; Bowser, Samuel S.; Brown, Matthew W.; Burki, Fabien; Dunthorn, Micah; Hampl, Vladimir; Heiss, Aaron; Hoppenrath, Mona; Lara, Enrique; Le Gall, Line; Lynn, Denis H.

    2013-01-01

    This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothes...

  16. Construction of a eukaryotic expression plasmid of Humanin

    Institute of Scientific and Technical Information of China (English)

    LUO Ben-yan; CHEN Xiang-ming; TANG Min; CHEN Feng; CHEN Zhi

    2005-01-01

    Objective: To construct a eukaryotic expression plasmid pcDNA3.1 (-)-Humanin. Methods: The recombinant plasm pGEMEX- 1-Humanin was digested with restriction endonucleases BamH I and Hind Ⅲ and the Humanin gene fragments, abo 100 bp length, were obtained. Then the Humanin gene fragments were inserted into eukaryotic expression vector pcDNA3.1 (-) and the recombinant plasmids pcDNA3. l(-)-Humanin were identified by sequencing. Results: Recombinant plasmid DNA succesfully produced a band which had the same size as that of the Humanin positive control. The sequence of recombinant plasmids accorded with the Humnain gene sequence. Conclusions: A eukaryotic expression plasmid of Humanin was successfully constructed.

  17. New Insights into Polycistronic Transcripts in Eukaryotes

    Directory of Open Access Journals (Sweden)

    Haiwei Pi

    2009-10-01

    Full Text Available In bacteria and archaea, many functionally related genes are organized into operons inorder to be transcribed and translated simultaneously. Operons are rarely seen in eukaryotesexcept for the Trypanosome and nematode, in which they are first transcribed into polycistronictranscripts but then processed into individual mature mRNAs. Recently, severalresearchers described the findings of polycistronic transcripts also in insects, which revisedthe previous thoughts that polycistronic genes were absent or few in eukaryotes. Similar toprokaryotic operons, the encoded peptides or proteins are translated simultaneously from asingle polycistronic mRNA, providing new insights into the evolution of polycistronicgenes. More interestingly, one type of the newly identified polycistronic genes encodes biologicallyimportant peptides composed of as few as 11 amino acids. These new findings willspur scientists to identify more small peptides in genome-solved organisms, and change thedefinition of coding sequences in genomic annotation.

  18. Construction of a eukaryotic expression plasmid of Humanin*

    OpenAIRE

    Luo, Ben-yan; Chen, Xiang-ming; Tang, Min; Chen, Feng; Chen, Zhi

    2004-01-01

    Objective: To construct a eukaryotic expression plasmid pcDNA3.1(-)-Humanin. Methods: The recombinant plasmid pGEMEX-1-Humanin was digested with restriction endonucleases BamH I and Hind III and the Humanin gene fragments, about 100 bp length, were obtained. Then the Humanin gene fragments were inserted into eukaryotic expression vector pcDNA3.1(-) and the recombinant plasmids pcDNA3.1(-)-Humanin were identified by sequencing. Results: Recombinant plasmid DNA successfully produced a band whic...

  19. Repetitive DNA in eukaryotic genomes.

    Science.gov (United States)

    Biscotti, Maria Assunta; Olmo, Ettore; Heslop-Harrison, J S Pat

    2015-09-01

    Repetitive DNA--sequence motifs repeated hundreds or thousands of times in the genome--makes up the major proportion of all the nuclear DNA in most eukaryotic genomes. However, the significance of repetitive DNA in the genome is not completely understood, and it has been considered to have both structural and functional roles, or perhaps even no essential role. High-throughput DNA sequencing reveals huge numbers of repetitive sequences. Most bioinformatic studies focus on low-copy DNA including genes, and hence, the analyses collapse repeats in assemblies presenting only one or a few copies, often masking out and ignoring them in both DNA and RNA read data. Chromosomal studies are proving vital to examine the distribution and evolution of sequences because of the challenges of analysis of sequence data. Many questions are open about the origin, evolutionary mode and functions that repetitive sequences might have in the genome. Some, the satellite DNAs, are present in long arrays of similar motifs at a small number of sites, while others, particularly the transposable elements (DNA transposons and retrotranposons), are dispersed over regions of the genome; in both cases, sequence motifs may be located at relatively specific chromosome domains such as centromeres or subtelomeric regions. Here, we overview a range of works involving detailed characterization of the nature of all types of repetitive sequences, in particular their organization, abundance, chromosome localization, variation in sequence within and between chromosomes, and, importantly, the investigation of their transcription or expression activity. Comparison of the nature and locations of sequences between more, and less, related species is providing extensive information about their evolution and amplification. Some repetitive sequences are extremely well conserved between species, while others are among the most variable, defining differences between even closely relative species. These data suggest

  20. DNA2 Encodes a DNA Helicase Essential for Replication of Eukaryotic Chromosomes

    OpenAIRE

    Budd, Martin E.; Choe, Won-chae; Campbell, Judith L.

    1995-01-01

    Although a number of eukaryotic DNA helicases have been identified biochemically and still more have been inferred from the amino acid sequences of the products of cloned genes, none of the cellular helicases or putative helicases has to date been implicated in eukaryotic chromosomal DNA replication. By the same token, numerous eukaryotic replication proteins have been identified, but none of these is a helicase. We have recently identified and characterized a temperature-sensitive yeast muta...

  1. Automation of ALK gene rearrangement testing with fluorescence in situ hybridization (FISH): A feasibility study

    OpenAIRE

    Zwaenepoel, Karen; Merkle, Dennis; Cabillic, Florian; Berg, Erica; Belaud-Rotureau, Marc-Antoine; Grazioli, Vittorio; Herelle, Olga; Hummel, Michael; Le Calve, Michele; Lenze, Dido; Mende, Stefanie; Pauwels, Patrick; Quilichini, Benoit; Repetti, Elena

    2015-01-01

    In the past several years we have observed a significant increase in our understanding of molecular mechanisms that drive lung cancer. Specifically in the non-small cell lung cancer sub-types, ALK gene rearrangements represent a sub-group of tumors that are targetable by the tyrosine kinase inhibitor Crizotinib, resulting in significant reductions in tumor burden. Phase II and III clinical trials were performed using an ALK break-apart FISH probe kit, making FISH the gold standard for identif...

  2. Characterization of prokaryotic and eukaryotic promoters using hidden Markov models

    DEFF Research Database (Denmark)

    Pedersen, Anders Gorm; Baldi, P.; Chauvin, Y.; Brunak, Søren

    that bind to them. We find that HMMs trained on such subclasses of Escherichia coli promoters (specifically, the so-called sigma 70 and sigma 54 classes) give an excellent classification of unknown promoters with respect to sigma-class. HMMs trained on eukaryotic sequences from human genes also model...

  3. Phylogenomic analysis of the cystatin superfamily in eukaryotes and prokaryotes

    Directory of Open Access Journals (Sweden)

    Turk Vito

    2009-11-01

    Full Text Available Abstract Background The cystatin superfamily comprises cysteine protease inhibitors that play key regulatory roles in protein degradation processes. Although they have been the subject of many studies, little is known about their genesis, evolution and functional diversification. Our aim has been to obtain a comprehensive insight into their origin, distribution, diversity, evolution and classification in Eukaryota, Bacteria and Archaea. Results We have identified in silico the full complement of the cystatin superfamily in more than 2100 prokaryotic and eukaryotic genomes. The analysis of numerous eukaryotic genomes has provided strong evidence for the emergence of this superfamily in the ancestor of eukaryotes. The progenitor of this superfamily was most probably intracellular and lacked a signal peptide and disulfide bridges, much like the extant Giardia cystatin. A primordial gene duplication produced two ancestral eukaryotic lineages, cystatins and stefins. While stefins remain encoded by a single or a small number of genes throughout the eukaryotes, the cystatins have undergone a more complex and dynamic evolution through numerous gene and domain duplications. In the cystatin superfamily we discovered twenty vertebrate-specific and three angiosperm-specific orthologous families, indicating that functional diversification has occurred only in multicellular eukaryotes. In vertebrate orthologous families, the prevailing trends were loss of the ancestral inhibitory activity and acquisition of novel functions in innate immunity. Bacterial cystatins and stefins may be emergency inhibitors that enable survival of bacteria in the host, defending them from the host's proteolytic activity. Conclusion This study challenges the current view on the classification, origin and evolution of the cystatin superfamily and provides valuable insights into their functional diversification. The findings of this comprehensive study provide guides for future

  4. Eukaryotic expression and DNA immunization of hemolysin HlyX gene from Leptospira serovar Lai%赖型钩端螺旋体溶血素基因HlyX的真核表达及基因免疫

    Institute of Scientific and Technical Information of China (English)

    黄毕; 鲍朗; 钟琪; 商正玲; 张会东; 张英

    2008-01-01

    目的 在哺乳动物细胞中表达含有赖型钩端螺旋体溶血素基因HlyX的重组质粒,并检测其作为DNA疫苗诱导小鼠体液免疫应答的效果.方法 以赖型钩端螺旋体全基因组为模板,PCR扩增出目的基因HlyX,以质粒pcDNA3.1为载体,双酶切构建重组质粒,转化大肠杆菌DH5α,双酶切、PCR及测序鉴定重组质粒.将构建成功的重组质粒转染COS-7细胞,通过RT-PCR、Western blot鉴定目的基因的表达.将重组质粒免疫BALB/c小鼠,每两周1次,共3次,ELISA法检测小鼠的体液免疫应答水平.结果 扩增出全长约1100 bp的HlyX基因,重组质粒经双酶切、PCR及测序鉴定表明重组质粒构建成功.RT-PCR检测显示重组质粒转染组能扩增出约1100 bp的目的基因片段,Western blot分析可见在相对分子质量(Mr)40×103左右出现特异性的目的条带.DNA免疫后诱导小鼠产生了较高的抗体水平(1∶6561~1∶19 683).结论 赖型钩端螺旋体溶血素基因HlyX真核表达质粒能够诱导小鼠产生高滴度的特异性抗体,为其作为钩体DNA疫苗的研究和开发奠定了基础.%Objective To study on the expression of the eukaryotic recombinant vector carrying HlyX gene of Leptospira serovar Lai in mammalian cell and explore the humoral immune response in BALB/c mice immunized with the recombinant plasmid. Methods The HlyX gene was amplified from Leptospira serovar Lai genomic DNA by PCR and inserted into pcDNA3.1 vector. After transformed into E. coli DH5α,the recombinant plasmid was assayed for identification by PCR analysis,restriction nuclease enzyme digestion and sequencing. The recombinant plasmid was transfected into COS-7 cells,then RT-PCR and Western blot were performed to test the expression of the target gene. The recombinant plasmid was injected intramuscularly into BALB/c mice for three times at intervals of two weeks,and the antibody titer was measured by ELISA. Results PCR showed the full length HlyX gene was

  5. A second pathway to degrade pyrimidine nucleic acid precursors in eukaryotes

    DEFF Research Database (Denmark)

    Andersen, Gorm; Bjornberg, Olof; Polakova, Silvia;

    2008-01-01

    Pyrimidine bases are the central precursors for RNA and DNA, and their intracellular pools are determined by de novo, salvage and catabolic pathways. In eukaryotes, degradation of uracil has been believed to proceed only via the reduction to dihydrouracil. Using a yeast model, Saccharomyces kluyv...... of the eukaryotic or prokaryotic genes involved in pyrimidine degradation described to date....

  6. Developing genetic tools to exploit Chaetomium thermophilum for biochemical analyses of eukaryotic macromolecular assemblies

    OpenAIRE

    Nikola Kellner; Johannes Schwarz; Miriam Sturm; Javier Fernandez-Martinez; Sabine Griesel; Wenzhu Zhang; Chait, Brian T.; Rout, Michael P.; Ulrich Kück; Ed Hurt

    2016-01-01

    We describe a method to genetically manipulate Chaetomium thermophilum, a eukaryotic thermophile, along with various biochemical applications. The transformation method depends on a thermostable endogenous selection marker operating at high temperatures combined with chromosomal integration of target genes. Our technique allows exploiting eukaryotic thermophiles as source for purifying thermostable native macromolecular complexes with an emphasis on the nuclear pore complex, holding great pot...

  7. pcDNA3.1(+)-CYP19-GFP真核表达质粒构建%Construction of eukaryotic expression plasmids containing green fluorescent protein gene and CYP19 WT or its variants

    Institute of Scientific and Technical Information of China (English)

    邵喜英; 陈占红; 曹江; 方永明; 王晓稼

    2011-01-01

    Objective: To construct eukaryotic expression plasmids containing green fluorescent protein gene and CYP19 wild-type or its vatiants (W39R, R264C, W39R-R264C) and to observe its expression in MCF-7 and Bcap-37 cells. Methods: The aromatase WT cDNA sequence was obtained by RT-PCR amplification and cloned into the eukaryotic expression vector pcDNA3. 1 ( + ). pcDNA3. 1 ( + )-CYP19-GFP plasmid was then used as the template for site-directed mutation to create variant constructs (W39R, R264C, W39R-R264C). pcDNA3. 1 ( + )-CYP19-GFP was transfected and expressed in MCF-7 and Bcap-37 cells. Results: The construction of pcDNA3. 1 ( + )-CYP19-GFP plasmid was confirmed by enzyme digestion and DNA sequencing. pcDNA3. 1 ( + )-CYP19W39R-GFP,pcDNA3.1 ( + )-CYP19R264C-GFP, pcDNA3.1 ( + )- CYP19W39R-R264C-GFP plasmids were confirmed by DNA sequencing. The MCF-7 and Bcap-37 cells transfected with the pcDNA3. 1 ( + )-CYP19-GFP plasmid expressed reporter gene of GFP. Conclusion: The eukaryotic expression plasmids have been constructed and expressed in MCF-7 and Bcap-37 cells successfully, which lays the foundation for the research of biological activities of CYP19 variant allozymes.%目的:构建pcDNA3.1(+)-CYP19-GFP、pcDNA3.1(+)-CYP19W39R-GFP、pcDNA3.1(+)-CYP19R264C-GFP与pcDNA3.1(+)-CYP19W39R-R264C-GFP真核表达质粒,并观察pcDNA3.1(+)-CYP19-GFP质粒在MCF-7和Bcap-37细胞中的表达.方法:①采用RT-PCR技术扩增CYP19 cDNA,插入pcDNA3.1(+)载体中,构建pcDNA3.1(+)-CYPl9表达质粒;酶切pcDNA3.1(+)-CYP19(304bp BamH I)-GFP和pcDNA3.1(+)-CYP19质粒,构建pcDNA3.1(+)-CYP19-GFP表达质粒;②以pcDNA3.1(+)-CYP19-GFP质粒为模板,采用定点突变技术,构建pcDNA3.1(+).CYPl9W39R-GFP和pcDNA3.1(+).CYP19R264C-GFP及pcDNA3.1(+).CYP19W39R-R264C-GFP表达质粒;③pcDNA3.1(+)-CYP19-GFP质粒通过脂质体介导转染MCF-7和Bcap-37细胞,荧光显微镜观察其在细胞中的表达.结果:①酶切鉴定及测序验证pcDNA3.1(+)-CYP19-GFP构

  8. Automated cleaning and pre-processing of immunoglobulin gene sequences from high-throughput sequencing

    Directory of Open Access Journals (Sweden)

    Miri eMichaeli

    2012-12-01

    Full Text Available High throughput sequencing (HTS yields tens of thousands to millions of sequences that require a large amount of pre-processing work to clean various artifacts. Such cleaning cannot be performed manually. Existing programs are not suitable for immunoglobulin (Ig genes, which are variable and often highly mutated. This paper describes Ig-HTS-Cleaner (Ig High Throughput Sequencing Cleaner, a program containing a simple cleaning procedure that successfully deals with pre-processing of Ig sequences derived from HTS, and Ig-Indel-Identifier (Ig Insertion – Deletion Identifier, a program for identifying legitimate and artifact insertions and/or deletions (indels. Our programs were designed for analyzing Ig gene sequences obtained by 454 sequencing, but they are applicable to all types of sequences and sequencing platforms. Ig-HTS-Cleaner and Ig-Indel-Identifier have been implemented in Java and saved as executable JAR files, supported on Linux and MS Windows. No special requirements are needed in order to run the programs, except for correctly constructing the input files as explained in the text. The programs' performance has been tested and validated on real and simulated data sets.

  9. Automated conserved noncoding sequence (CNS discovery reveals differences in gene content and promoter evolution among grasses

    Directory of Open Access Journals (Sweden)

    Gina eTurco

    2013-07-01

    Full Text Available Conserved noncoding sequences (CNS are islands of noncoding sequence that, like protein coding exons, show less divergence in sequence between related species than functionless DNA. Several of CNSs have been demonstrated experimentally to function as cis-regulatory regions. However, the specific functions of most CNSs remain unknown. Previous searchers for CNS in plants have either anchored on exons and only identified nearby sequences or required years of painstaking manual annotation. Here we present an open source tool that can accurately identify CNSs between any two related species with sequenced genomes, including both those immediately adjacent to exons and distal sequences separated by >12 KB of noncoding sequence. We have used this tool to characterize new motifs, associate CNSs with additional functions and identify previously undetected genes encoding RNA and protein in the genomes of five grass species. We provide a list of 15,363 orthologous CNSs conserved across all grasses tested. We were also able to identify regulatory sequences present in the common ancestor of grasses that have been lost in one or more extant grass lineages. Lists of orthologous gene pairs and associated CNSs are provided for reference inbred lines of arabidopsis, Japonica rice, foxtail millet, sorghum, brachypodium and maize.

  10. Accurate binning of metagenomic contigs via automated clustering sequences using information of genomic signatures and marker genes.

    Science.gov (United States)

    Lin, Hsin-Hung; Liao, Yu-Chieh

    2016-01-01

    Metagenomics, the application of shotgun sequencing, facilitates the reconstruction of the genomes of individual species from natural environments. A major challenge in the genome recovery domain is to agglomerate or 'bin' sequences assembled from metagenomic reads into individual groups. Metagenomic binning without consideration of reference sequences enables the comprehensive discovery of new microbial organisms and aids in the microbial genome reconstruction process. Here we present MyCC, an automated binning tool that combines genomic signatures, marker genes and optional contig coverages within one or multiple samples, in order to visualize the metagenomes and to identify the reconstructed genomic fragments. We demonstrate the superior performance of MyCC compared to other binning tools including CONCOCT, GroopM, MaxBin and MetaBAT on both synthetic and real human gut communities with a small sample size (one to 11 samples), as well as on a large metagenome dataset (over 250 samples). Moreover, we demonstrate the visualization of metagenomes in MyCC to aid in the reconstruction of genomes from distinct bins. MyCC is freely available at http://sourceforge.net/projects/sb2nhri/files/MyCC/. PMID:27067514

  11. What Entamoeba histolytica and Giardia lamblia tell us about the evolution of eukaryotic diversity

    Indian Academy of Sciences (India)

    J Samuelson

    2002-11-01

    Entamoeba histolytica and Giardia lamblia are microaerophilic protists, which have long been considered models of ancient pre-mitochondriate eukaryotes. As transitional eukaryotes, amoebae and giardia appeared to lack organelles of higher eukaryotes and to depend upon energy metabolism appropriate for anaerobic conditions, early in the history of the planet. However, our studies have shown that amoebae and giardia contain splicoeosomal introns, ras-family signal-transduction proteins, ATP-binding casettes (ABC)-family drug transporters, Golgi, and a mitochondrion-derived organelle (amoebae only). These results suggest that most of the organelles of higher eukaryotes were present in the common ancestor of all eukaryotes, and so dispute the notion of transitional eukaryotic forms. In addition, phylogenetic studies suggest many of the genes encoding the fermentation enzymes of amoebae and giardia derive from prokaryotes by lateral gene transfer (LGT). While LGT has recently been shown to be an important determinant of prokaryotic evolution, this is the first time that LGT has been shown to be an important determinant of eukaryotic evolution. Further, amoebae contain cyst wall-associated lectins, which resemble, but are distinct from lectins in the walls of insects (convergent evolution). Giardia have a novel microtubule-associated structure which tethers together pairs of nuclei during cell division. It appears then that amoebae and giardia tell us less about the origins of eukaryotes and more about the origins of eukaryotic diversity.

  12. Automated design of hammerhead ribozymes and validation by targeting the PABPN1 gene transcript.

    Science.gov (United States)

    Kharma, Nawwaf; Varin, Luc; Abu-Baker, Aida; Ouellet, Jonathan; Najeh, Sabrine; Ehdaeivand, Mohammad-Reza; Belmonte, Gabriel; Ambri, Anas; Rouleau, Guy; Perreault, Jonathan

    2016-02-29

    We present a new publicly accessible web-service, RiboSoft, which implements a comprehensive hammerhead ribozyme design procedure. It accepts as input a target sequence (and some design parameters) then generates a set of ranked hammerhead ribozymes, which target the input sequence. This paper describes the implemented procedure, which takes into consideration multiple objectives leading to a multi-objective ranking of the computer-generated ribozymes. Many ribozymes were assayed and validated, including four ribozymes targeting the transcript of a disease-causing gene (a mutant version of PABPN1). These four ribozymes were successfully tested in vitro and in vivo, for their ability to cleave the targeted transcript. The wet-lab positive results of the test are presented here demonstrating the real-world potential of both hammerhead ribozymes and RiboSoft. RiboSoft is freely available at the website http://ribosoft.fungalgenomics.ca/ribosoft/. PMID:26527730

  13. Construction of Eukaryotic Expression Vector with Rana Antimicrobial Peptides Gene Temporin-lCEa%中国林蛙抗菌肽Temporin-1CEa基因的真核表达载体构建。

    Institute of Scientific and Technical Information of China (English)

    张志崇; 王春生; 张秋婷; 朴善花; 苗向阳; 安铁洙

    2012-01-01

    In order to establish a method to get a large number of antimicrobial peptides from Rana chensinensis,a series of experiments were conducted as follows.According to Chinese frog skin antimicrobial peptides Temporin-1CEa gene mRNA sequence(EU624139) in GenBank,a pair of specific primers were designed and cDNA was obtained from Chinese forest frog skin RNA by reverse transcription.Temporin-1CEa gene coding sequence was amplified using the cDNA,and linked with pEASY-T3 cloning vector.The GFP gene was inserted into the recombinant plasmid Tem-T3 by molecular methods.The Tem-GFP fragment was linked with eukaryotic expression vector pcDNA3.1,and Tem-GFP-pcDNA3.1 recombinant plasmid was achieved finally.Using of lipid infection method,the plasmids were transfected into sheep fibroblast cells,the green fluorescence was observed under a fluorescence microscope after 48 h.qPCR data showed that Tem-GFP fusion protein expression level of transfected Tem-GFP-pcDNA3.1 sheep fibroblasts increased about 300 folds than that of the control group.This study supplied the technical basis for developing mammary gland bioreactor of expressing Temporin-1CEa gene.%为了建立大量获取中国林蛙抗菌肽的方法,根据GenBank中的中国林蛙皮肤抗菌肽Temporin-1CEa基因的mRNA序列(EU624139)设计一对特异性引物,以提取的中国林蛙皮肤总RNA反转录出的cDNA为模板,将扩增的编码序列与pEASY-T3克隆载体连接获得Tem-T3;利用酶切、连接等分子生物学手段,将GFP基因连入Tem-T3克隆载体,再经酶切获得Tem-GFP片段,并插入真核表达载体pcDNA3.1,最终得到Tem-GFP-pcD-NA3.1重组质粒;利用脂质体转染法将该质粒转入绵羊成纤维细胞,48 h后可在荧光倒置显微镜下观察到GFP的绿色荧光表达;qPCR数据分析显示,与对照组相比,转染Tem-GFP-pcDNA3.1的绵羊成纤维细胞中融合蛋白Tem-GFP的表达量可提高约300倍。本研究为构建Temporin-1CEa基因山羊乳腺特异表达载体提供依据。

  14. Censusing marine eukaryotic diversity in the twenty-first century.

    Science.gov (United States)

    Leray, Matthieu; Knowlton, Nancy

    2016-09-01

    The ocean constitutes one of the vastest and richest biomes on our planet. Most recent estimations, all based on indirect approaches, suggest that there are millions of marine eukaryotic species. Moreover, a large majority of these are small (less than 1 mm), cryptic and still unknown to science. However, this knowledge gap, caused by the lack of diagnostic morphological features in small organisms and the limited sampling of the global ocean, is currently being filled, thanks to new DNA-based approaches. The molecular technique of PCR amplification of homologous gene regions combined with high-throughput sequencing, routinely used to census unculturable prokaryotes, is now also being used to characterize whole communities of marine eukaryotes. Here, we review how this methodological advancement has helped to better quantify the magnitude and patterns of marine eukaryotic diversity, with an emphasis on taxonomic groups previously largely overlooked. We then discuss obstacles remaining to achieve a global understanding of marine eukaryotic diversity. In particular, we argue that 18S variable regions do not provide sufficient taxonomic resolution to census marine life, and suggest combining broad eukaryotic surveys targeting the 18S rRNA region with more taxon-focused analyses of hypervariable regions to improve our understanding of the diversity of species, the functional units of marine ecosystems.This article is part of the themed issue 'From DNA barcodes to biomes'. PMID:27481783

  15. Automated optogenetic feedback control for precise and robust regulation of gene expression and cell growth.

    Science.gov (United States)

    Milias-Argeitis, Andreas; Rullan, Marc; Aoki, Stephanie K; Buchmann, Peter; Khammash, Mustafa

    2016-01-01

    Dynamic control of gene expression can have far-reaching implications for biotechnological applications and biological discovery. Thanks to the advantages of light, optogenetics has emerged as an ideal technology for this task. Current state-of-the-art methods for optical expression control fail to combine precision with repeatability and cannot withstand changing operating culture conditions. Here, we present a novel fully automatic experimental platform for the robust and precise long-term optogenetic regulation of protein production in liquid Escherichia coli cultures. Using a computer-controlled light-responsive two-component system, we accurately track prescribed dynamic green fluorescent protein expression profiles through the application of feedback control, and show that the system adapts to global perturbations such as nutrient and temperature changes. We demonstrate the efficacy and potential utility of our approach by placing a key metabolic enzyme under optogenetic control, thus enabling dynamic regulation of the culture growth rate with potential applications in bacterial physiology studies and biotechnology. PMID:27562138

  16. Defensins: antifungal lessons from eukaryotes

    Directory of Open Access Journals (Sweden)

    Patrícia M. Silva

    2014-03-01

    Full Text Available Over the last years, antimicrobial peptides (AMPs have been the focus of intense research towards the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several of these cysteine-stabilized peptides present a relevant effect against fungi. Defensins are the AMPs with the broader distribution across all eukaryotic kingdoms, namely, Fungi, Plantæ and Animalia, and were recently shown to have an ancestor in a bacterial organism. As a part of the host defense, defensins act as an important vehicle of information between innate and adaptive immune system and have a role in immunomodulation. This multidimensionality represents a powerful host shield, hard for microorganisms to overcome using single approach resistance strategies. Pathogenic fungi resistance to conventional antimycotic drugs is becoming a major problem. Defensins, as other AMPs, have shown to be an effective alternative to the current antimycotic therapies, demonstrating potential as novel therapeutic agents or drug leads. In this review, we summarize the current knowledge on some eukaryotic defensins with antifungal action. An overview of the main targets in the fungal cell and the mechanism of action of these AMPs (namely, the selectivity for some fungal membrane components are presented. Additionally, recent works on antifungal defensins structure, activity and citotoxicity are also reviewed.

  17. Construction and expression of eukaryotic vector of elastase gene in human%人源弹性蛋白酶基因真核载体构建及表达

    Institute of Scientific and Technical Information of China (English)

    王海峰; 许文涛; 苏春元; 邱芳萍; 罗云波; 谷新晰; 田洪涛; 黄昆仑

    2011-01-01

    从人体肾脏组织中提取的总RNA中通过反转录PCR(RT—PCR)扩增得到了ELA2B基因,并将其克隆到pGEM—Teasy载体中。然后用限制性内切酶EcoRI和NotI对重组质粒pGEM—Teasy/ELA2B和毕赤酵母质粒pHC9K进行双酶切,并且通过PCR技术去除ELA2B的信号肽,成功构建了真核表达载体pPIC9K/ELA2B,并将其转入毕赤酵母表达宿主GS115中。得到150株转化子,经含不同浓度G418的YPD平板筛选获得20株高拷贝转化子。甲醇诱导表达后.发酵液上清经SDS—PAGE检测,获得了大小约为28ku的目的条带。通过酪蛋白平板检测发酵液上清,出现透明圈.初步证明获得了有生物活性的弹性蛋白酶。%The human ELA2B gene was cloned from total RNA which was extracted from kidney of human by reverse transcription polymerase chain reaction (RT-PCR),then a recombinant plasmid pGEM-T easy/ELA2B was obtained. After the recombinant plasmid pGEM-T easy/ELA2B and pichia expression plasmid pPIC9K digesting with EcoR I and Not I,and removing the signal peptide of ELA2B by PCR,the recombinant eukaryotic expression plasmid pPIC9K/ELA2B were successfully constructed and transformed into pichia host GS115. 101 transformants were selected on the MD agar plates,and 16 highly expression transformants were screened by YPD plates containing G418. After expression of recombinant elastase in shaking flask by methanol induction,it was found the size of recombinant elastase was approximately 28ku by SDS-PAGE analysis. The casein protein could be hydrolyzed by fermentation supernatant which initially indicated that the expression product had biological activity.

  18. Redox characteristics of the eukaryotic cytosol

    DEFF Research Database (Denmark)

    López-Mirabal, H Reynaldo; Winther, Jakob R

    2007-01-01

    The eukaryotic cytoplasm has long been regarded as a cellular compartment in which the reduced state of protein cysteines is largely favored. Under normal conditions, the cytosolic low-molecular weight redox buffer, comprising primarily of glutathione, is highly reducing and reactive oxygen species...... (ROS) and glutathionylated proteins are maintained at very low levels. In the present review, recent progress in the understanding of the cytosolic thiol-disulfide redox metabolism and novel analytical approaches to studying cytosolic redox properties are discussed. We will focus on the yeast model...... restricting the cytosolic glutathione redox potential to a relatively narrow interval. Several mutations in genes involved in cellular redox regulation cause ROS accumulation but only moderate decreases in the cytosolic glutathione reducing power. The redox regulation in the cytosol depends not only on...

  19. Functions and structures of eukaryotic recombination proteins

    International Nuclear Information System (INIS)

    We have found that Rad51 and RecA Proteins form strikingly similar structures together with dsDNA and ATP. Their right handed helical nucleoprotein filaments extend the B-form DNA double helixes to 1.5 times in length and wind the helix. The similarity and uniqueness of their structures must reflect functional homologies between these proteins. Therefore, it is highly probable that similar recombination proteins are present in various organisms of different evolutional states. We have succeeded to clone RAD51 genes from human, mouse, chicken and fission yeast genes, and found that the homologues are widely distributed in eukaryotes. The HsRad51 and MmRad51 or ChRad51 proteins consist of 339 amino acids differing only by 4 or 12 amino acids, respectively, and highly homologous to both yeast proteins, but less so to Dmcl. All of these proteins are homologous to the region from residues 33 to 240 of RecA which was named ''homologous core. The homologous core is likely to be responsible for functions common for all of them, such as the formation of helical nucleoprotein filament that is considered to be involved in homologous pairing in the recombination reaction. The mouse gene is transcribed at a high level in thymus, spleen, testis, and ovary, at lower level in brain and at a further lower level in some other tissues. It is transcribed efficiently in recombination active tissues. A clear functional difference of Rad51 homologues from RecA was suggested by the failure of heterologous genes to complement the deficiency of Scrad51 mutants. This failure seems to reflect the absence of a compatible partner, such as ScRad52 protein in the case of ScRad51 protein, between different species. Thus, these discoveries play a role of the starting point to understand the fundamental gene targeting in mammalian cells and in gene therapy. (J.P.N.)

  20. Eukaryotic TPP riboswitch regulation of alternative splicing involving long-distance base pairing

    OpenAIRE

    Li, Sanshu; Breaker, Ronald R.

    2013-01-01

    Thiamin pyrophosphate (TPP) riboswitches are found in organisms from all three domains of life. Examples in bacteria commonly repress gene expression by terminating transcription or by blocking ribosome binding, whereas most eukaryotic TPP riboswitches are predicted to regulate gene expression by modulating RNA splicing. Given the widespread distribution of eukaryotic TPP riboswitches and the diversity of their locations in precursor messenger RNAs (pre-mRNAs), we sought to examine the mechan...

  1. EuCAP, a Eukaryotic Community Annotation Package, and its application to the rice genome

    Directory of Open Access Journals (Sweden)

    Hamilton John P

    2007-10-01

    Full Text Available Abstract Background Despite the improvements of tools for automated annotation of genome sequences, manual curation at the structural and functional level can provide an increased level of refinement to genome annotation. The Institute for Genomic Research Rice Genome Annotation (hereafter named the Osa1 Genome Annotation is the product of an automated pipeline and, for this reason, will benefit from the input of biologists with expertise in rice and/or particular gene families. Leveraging knowledge from a dispersed community of scientists is a demonstrated way of improving a genome annotation. This requires tools that facilitate 1 the submission of gene annotation to an annotation project, 2 the review of the submitted models by project annotators, and 3 the incorporation of the submitted models in the ongoing annotation effort. Results We have developed the Eukaryotic Community Annotation Package (EuCAP, an annotation tool, and have applied it to the rice genome. The primary level of curation by community annotators (CA has been the annotation of gene families. Annotation can be submitted by email or through the EuCAP Web Tool. The CA models are aligned to the rice pseudomolecules and the coordinates of these alignments, along with functional annotation, are stored in the MySQL EuCAP Gene Model database. Web pages displaying the alignments of the CA models to the Osa1 Genome models are automatically generated from the EuCAP Gene Model database. The alignments are reviewed by the project annotators (PAs in the context of experimental evidence. Upon approval by the PAs, the CA models, along with the corresponding functional annotations, are integrated into the Osa1 Genome Annotation. The CA annotations, grouped by family, are displayed on the Community Annotation pages of the project website http://rice.tigr.org, as well as in the Community Annotation track of the Genome Browser. Conclusion We have applied EuCAP to rice. As of July 2007, the

  2. CGMIM: Automated text-mining of Online Mendelian Inheritance in Man (OMIM to identify genetically-associated cancers and candidate genes

    Directory of Open Access Journals (Sweden)

    Jones Steven

    2005-03-01

    Full Text Available Abstract Background Online Mendelian Inheritance in Man (OMIM is a computerized database of information about genes and heritable traits in human populations, based on information reported in the scientific literature. Our objective was to establish an automated text-mining system for OMIM that will identify genetically-related cancers and cancer-related genes. We developed the computer program CGMIM to search for entries in OMIM that are related to one or more cancer types. We performed manual searches of OMIM to verify the program results. Results In the OMIM database on September 30, 2004, CGMIM identified 1943 genes related to cancer. BRCA2 (OMIM *164757, BRAF (OMIM *164757 and CDKN2A (OMIM *600160 were each related to 14 types of cancer. There were 45 genes related to cancer of the esophagus, 121 genes related to cancer of the stomach, and 21 genes related to both. Analysis of CGMIM results indicate that fewer than three gene entries in OMIM should mention both, and the more than seven-fold discrepancy suggests cancers of the esophagus and stomach are more genetically related than current literature suggests. Conclusion CGMIM identifies genetically-related cancers and cancer-related genes. In several ways, cancers with shared genetic etiology are anticipated to lead to further etiologic hypotheses and advances regarding environmental agents. CGMIM results are posted monthly and the source code can be obtained free of charge from the BC Cancer Research Centre website http://www.bccrc.ca/ccr/CGMIM.

  3. Birth of the eukaryotes by a set of reactive innovations: New insights force us to relinquish gradual models.

    Science.gov (United States)

    Speijer, Dave

    2015-12-01

    Of two contending models for eukaryotic evolution the "archezoan" has an amitochondriate eukaryote take up an endosymbiont, while "symbiogenesis" states that an Archaeon became a eukaryote as the result of this uptake. If so, organelle formation resulting from new engulfments is simplified by the primordial symbiogenesis, and less informative regarding the bacterium-to-mitochondrion conversion. Gradualist archezoan visions still permeate evolutionary thinking, but are much less likely than symbiogenesis. Genuine amitochondriate eukaryotes have never been found and rapid, explosive adaptive periods characteristic of symbiogenetic models explain this. Mitochondrial proteomes, encoded by genes of "eukaryotic origin" not easily linked to host or endosymbiont, can be understood in light of rapid adjustments to new evolutionary pressures. Symbiogenesis allows "expensive" eukaryotic inventions via efficient ATP generation by nascent mitochondria. However, efficient ATP production equals enhanced toxic internal ROS formation. The synergistic combination of these two driving forces gave rise to the rapid evolution of eukaryotes. Also watch the Video Abstract. PMID:26577075

  4. 含CpG和CTB的HIV多表位基因真核表达载体的构建及表达%Construction and expression of eukaryotic expression vector of HIV multi-epitope gene containing CpG sequence and CTB gene

    Institute of Scientific and Technical Information of China (English)

    杜寿文; 任大勇; 王宇航; 王婧; 孙丹丹; 任静强; 李昌; 金宁一

    2011-01-01

    Objective To construct a eukaryotic expression vector of HIV multi-epitope gene containing unmethylated CpG ODN sequence and cholera toxin B subunit( CTB ) and expression in vitro. Methods The primers of CTB gene containing CpG ODN and linker sequence were designed and synthesized. CpG-CTB gene sequence(CC) was obtained by PCR,and connected to pVL. HIV multi-epitope gene was inserted into the downstream of CC gene to construct pVL-CC-MEGNp24. The recombination plasmid was confirmed by enzyme digestion. 293T Cells were transfected with the purified recombination plasmid pVL-CC-MEGNp24. The transcription of CTB and p24 gene in the transfected 293T cells was detected by RT-PCR, and the expression of CTB and p24 protein was confirmed by cellular immunostaining. The plasmid pVL and blank controls were established simultaneously. Results The results showed that the recombination plasmid of pVL-CC-MEGNp24 was constructed, and CTB and multi-epitope gene were stably expressed in the 293T ceils transfected with the plasmid pVL-CC-MEGNp24. Conclusion The eukaryotic expression vector of HIV multi-epitope gene containing immunological adjuvants is successfully constructed, facilitating studies of HIV vaccine.%目的 构建含非甲基化的CpG ODN序列及霍乱毒素B亚单位(CTB)的HIV复合多表位基因的真核表达载体,并在体外进行表达.方法 设计并合成含CpG ODN序列和linker序列的CTB基因引物,用PCR方法扩增CpG-CTB基因(CC),定向连接到真核表达载体pVL上,然后在CC基因下游插入HIV复合多表位基因MEGNp24,构建重组质粒pVL-CC-MEGNp24,酶切鉴定.纯化重组质粒,转染293T细胞,RT-PCR和细胞免疫染色方法分别检测CTB和p24基因的转录及表达,同时设质粒pVL及空白对照.结果 构建了重组质粒pVL-CC-MEGNp24,该质粒转染293T细胞后,CTB和复合多表位基因在293T细胞中得到稳定表达.结论 成功构建了含免疫佐剂的HIV复合多表位真核表达载体,为后期疫苗的研究奠定了基础.

  5. Expression of bacterial luciferase in eukaryotic cells

    International Nuclear Information System (INIS)

    Expression of Bacterial luciferase enzyme (lux) in mammalian cells would be a powerful bioreporter protein system for in vivo imaging because eukaryotic luciferases need expensive substrates. However, only a few efforts have been made to express bacterial luciferase enzyme in mammalian cells. As the result of this, we attempted to construct bicistronic vector including two bacterial luciferase genes (LuxA and LuxB) for assessing the potential to be visualized in vitro or in vivo by optical imaging system after transfection to mammalian cells. We designed and synthesized luxA and luxB genes from Photorhabdus Luminescens. To co-express both luxA and luxB genes from a single promoter, we cloned as a bicistronic transcript fused with an internal ribosomal entry site (IRES). This bicistronic transcript was transfected by Superfect to HEK 293T cell line. We also transfected lux A and lux B vector to HEK 293T cells separately. To evaluate gene expression, n-decanal and FMNH2 were supplemented to transfected HEK 293T cell lines which were measured by In Vivo Imaging System. The luxA gene was cloned into the MCS(A) of pIRESGFP via the 5' SalI and 3' EcoRI restriction sites to generate pIRESluxA. The luxB gene was cleaved via a 5' NcoI and 3' NotI site from luxB and cloned into the MCS(B) of pIRESluxA to generate pIRESluxAB. LuxA and B genes was cleaved by 5' EcoRI and 3' SpeI and cloned into the pcDNA3.1 mammalian expression vector to create pcDNALuxA and pcDNALuxB. We constructed bicistronic vector system which is composed of bacterial luciferase genes (lux A and B) on the single reading frame. These results hold a promise of an available development of an autonomous light generating lux reporter system in mammalian cells

  6. Evolutionary distinctiveness of fatty acid and polyketide synthesis in eukaryotes.

    Science.gov (United States)

    Kohli, Gurjeet S; John, Uwe; Van Dolah, Frances M; Murray, Shauna A

    2016-08-01

    Fatty acids, which are essential cell membrane constituents and fuel storage molecules, are thought to share a common evolutionary origin with polyketide toxins in eukaryotes. While fatty acids are primary metabolic products, polyketide toxins are secondary metabolites that are involved in ecologically relevant processes, such as chemical defence, and produce the adverse effects of harmful algal blooms. Selection pressures on such compounds may be different, resulting in differing evolutionary histories. Surprisingly, some studies of dinoflagellates have suggested that the same enzymes may catalyse these processes. Here we show the presence and evolutionary distinctiveness of genes encoding six key enzymes essential for fatty acid production in 13 eukaryotic lineages for which no previous sequence data were available (alveolates: dinoflagellates, Vitrella, Chromera; stramenopiles: bolidophytes, chrysophytes, pelagophytes, raphidophytes, dictyochophytes, pinguiophytes, xanthophytes; Rhizaria: chlorarachniophytes, haplosporida; euglenids) and 8 other lineages (apicomplexans, bacillariophytes, synurophytes, cryptophytes, haptophytes, chlorophyceans, prasinophytes, trebouxiophytes). The phylogeny of fatty acid synthase genes reflects the evolutionary history of the organism, indicating selection to maintain conserved functionality. In contrast, polyketide synthase gene families are highly expanded in dinoflagellates and haptophytes, suggesting relaxed constraints in their evolutionary history, while completely absent from some protist lineages. This demonstrates a vast potential for the production of bioactive polyketide compounds in some lineages of microbial eukaryotes, indicating that the evolution of these compounds may have played an important role in their ecological success. PMID:26784357

  7. DNA polymerase zeta (polζ) in higher eukaryotes

    Institute of Scientific and Technical Information of China (English)

    Gregory N Gan; John P Wittschieben; Birgitte φ Wittschieben; Richard D Wood

    2008-01-01

    Most current knowledge about DNA polymerase zeta (pol ζ) comes from studies of the enzyme in the budding yeast Saccharomyces cerevisiae, where polζ consists of a complex of the catalytic subunit Rev3 with Rev7, which associates with Rev1. Most spontaneous and induced mutagenesis in yeast is dependent on these gene products, and yeast pol can mediate translesion DNA synthesis past some adducts in DNA templates. Study of the homologous gene products in higher eukaryotes is in a relatively early stage, but additional functions for the eukaryotic proteins are already appar-ent. Suppression of vertebrate REV3L function not only reduces induced point mutagenesis but also causes larger-scale genuine instability by raising the frequency of spontaneous chromosome translocations. Disruption of Rev3L function is tolerated in Drosophila, Arabidopsis, and in vertebrate cell lines under some conditions, but is incompatible with mouse embryonic development. Functions for REV3L and REV7(MAD2B) in higher eukaryotes have been suggested not only in translesion DNA synthesis but also in some forms of homologous recombination, repair ofinterstrand DNA erosslinks, somatic hypermutation of immunoglobulin genes and cell-cycle control. This review discusses recent devel-opments in these areas.

  8. Automation of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus Assay for High-Throughput Screening of Nasal Swab Specimens▿

    OpenAIRE

    Wang, Xue-Ping; Ginocchio, Christine C.

    2009-01-01

    This study demonstrated that an automated version of the BD-GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) assay (BD-MRSA), using achromopeptidase sample lysis and PCR setup performed on the Hamilton MICROLAB STARlet (Auto-MRSA), gave results comparable to those obtained with BD-MRSA. The positive- and negative-result concordance rates and overall concordance of BD-MRSA and Auto-MRSA were 98.2, 97.7, and 97.6%, respectively. Auto-MRSA required 60% less technical time than BD-MRSA,...

  9. GEGEINTOOL: A Computer-Based Tool for Automated Analysis of Gene-Gene Interactions in Large Epidemiological Studies in Cardiovascular Genomics

    OpenAIRE

    Oscar Coltell; José M. Ordovás; Carmen Saiz; Manuel Forner; Francisco Gabriel; Dolores Corella

    2013-01-01

    Current methods of data analysis of gene-gene interactions in complex diseases, after taking into account environmental factors using traditional approaches, are inefficient. High-throughput methods of analysis in large scale studies including thousands of subjects and hundreds of SNPs should be implemented. We developed an integrative computer tool, GEGEINTOOL (GEne- GEne INTeraction tOOL), for large-scale analysis of gene-gene interactions, in human studies of complex diseases including a l...

  10. A versatile selection system for folding competent proteins using genetic complementation in a eukaryotic host

    DEFF Research Database (Denmark)

    Lyngsø, C.; Kjaerulff, S.; Muller, S.;

    2010-01-01

    Recombinant expression of native or modified eukaryotic proteins is pivotal for structural and functional studies and for industrial and pharmaceutical production of proteins. However, it is often impeded by the lack of proper folding. Here, we present a stringent and broadly applicable eukaryotic...... in vivo selection system for folded proteins. It is based on genetic complementation of the Schizosaccharomyces pombe growth marker gene invertase fused C-terminally to a protein library. The fusion proteins are directed to the secretion system, utilizing the ability of the eukaryotic protein quality...... demonstrated using a complex insertion mutant library of TNF-alpha, from which different folding competent mutant proteins were uncovered....

  11. Bacterial inosine 5'-monophosphate dehydrogenase ("IMPDH") DNA as a dominant selectable marker in mammals and other eukaryotes

    Science.gov (United States)

    Huberman, Eliezer; Baccam, Mekhine J.

    2007-02-27

    The present invention relates to a nucleic acid sequence and its corresponding protein sequence useful as a dominant selectable marker in eukaryotes. More specifically the invention relates to a nucleic acid encoding a bacterial IMPDH gene that has been engineered into a eukaryotic expression vectors, thereby permitting bacterial IMPDH expression in mammalian cells. Bacterial IMPDH expression confers resistance to MPA which can be used as dominant selectable marker in eukaryotes including mammals. The invention also relates to expression vectors and cells that express the bacterial IMPDH gene as well as gene therapies and protein synthesis.

  12. Genetic Diversity of Small Eukaryotes in Lakes Differing by Their Trophic Status

    OpenAIRE

    Lefranc, Marie; Thénot, Aurélie; Lepère, Cécile; Debroas, Didier

    2005-01-01

    Small eukaryotes, cells with a diameter of less than 5 μm, are fundamental components of lacustrine planktonic systems. In this study, small-eukaryote diversity was determined by sequencing cloned 18S rRNA genes in three libraries from lakes of differing trophic status in the Massif Central, France: the oligotrophic Lake Godivelle, the oligomesotrophic Lake Pavin, and the eutrophic Lake Aydat. This analysis shows that the least diversified library was in the eutrophic lake (12 operational tax...

  13. BEACON: automated tool for Bacterial GEnome Annotation ComparisON

    KAUST Repository

    Kalkatawi, Manal Matoq Saeed

    2015-08-18

    Background Genome annotation is one way of summarizing the existing knowledge about genomic characteristics of an organism. There has been an increased interest during the last several decades in computer-based structural and functional genome annotation. Many methods for this purpose have been developed for eukaryotes and prokaryotes. Our study focuses on comparison of functional annotations of prokaryotic genomes. To the best of our knowledge there is no fully automated system for detailed comparison of functional genome annotations generated by different annotation methods (AMs). Results The presence of many AMs and development of new ones introduce needs to: a/ compare different annotations for a single genome, and b/ generate annotation by combining individual ones. To address these issues we developed an Automated Tool for Bacterial GEnome Annotation ComparisON (BEACON) that benefits both AM developers and annotation analysers. BEACON provides detailed comparison of gene function annotations of prokaryotic genomes obtained by different AMs and generates extended annotations through combination of individual ones. For the illustration of BEACON’s utility, we provide a comparison analysis of multiple different annotations generated for four genomes and show on these examples that the extended annotation can increase the number of genes annotated by putative functions up to 27 %, while the number of genes without any function assignment is reduced. Conclusions We developed BEACON, a fast tool for an automated and a systematic comparison of different annotations of single genomes. The extended annotation assigns putative functions to many genes with unknown functions. BEACON is available under GNU General Public License version 3.0 and is accessible at: http://www.cbrc.kaust.edu.sa/BEACON/

  14. Pathogenic eukaryotes in gut microbiota of western lowland gorillas as revealed by molecular survey.

    Science.gov (United States)

    Hamad, Ibrahim; Keita, Mamadou B; Peeters, Martine; Delaporte, Eric; Raoult, Didier; Bittar, Fadi

    2014-01-01

    Although gorillas regarded as the largest extant species of primates and have a close phylogenetic relationship with humans, eukaryotic communities have not been previously studied in these populations. Herein, 35 eukaryotic primer sets targeting the 18S rRNA gene, internal transcribed spacer gene and other specific genes were used firstly to explore the eukaryotes in a fecal sample from a wild western lowland gorilla (Gorilla gorilla gorilla). Then specific real-time PCRs were achieved in additional 48 fecal samples from 21 individual gorillas to investigate the presence of human eukaryotic pathogens. In total, 1,572 clones were obtained and sequenced from the 15 cloning libraries, resulting in the retrieval of 87 eukaryotic species, including 52 fungi, 10 protozoa, 4 nematodes and 21 plant species, of which 52, 5, 2 and 21 species, respectively, have never before been described in gorillas. We also reported the occurrence of pathogenic fungi and parasites (i.e. Oesophagostomum bifurcum (86%), Necator americanus (43%), Candida tropicalis (81%) and other pathogenic fungi were identified). In conclusion, molecular techniques using multiple primer sets may offer an effective tool to study complex eukaryotic communities and to identify potential pathogens in the gastrointestinal tracts of primates. PMID:25231746

  15. Home Automation

    OpenAIRE

    Ahmed, Zeeshan

    2010-01-01

    In this paper I briefly discuss the importance of home automation system. Going in to the details I briefly present a real time designed and implemented software and hardware oriented house automation research project, capable of automating house's electricity and providing a security system to detect the presence of unexpected behavior.

  16. Sulfate assimilation in eukaryotes: fusions, relocations and lateral transfers

    Directory of Open Access Journals (Sweden)

    Durnford Dion G

    2008-02-01

    Full Text Available Abstract Background The sulfate assimilation pathway is present in photosynthetic organisms, fungi, and many bacteria, providing reduced sulfur for the synthesis of cysteine and methionine and a range of other metabolites. In photosynthetic eukaryotes sulfate is reduced in the plastids whereas in aplastidic eukaryotes the pathway is cytosolic. The only known exception is Euglena gracilis, where the pathway is localized in mitochondria. To obtain an insight into the evolution of the sulfate assimilation pathway in eukaryotes and relationships of the differently compartmentalized isoforms we determined the locations of the pathway in lineages for which this was unknown and performed detailed phylogenetic analyses of three enzymes involved in sulfate reduction: ATP sulfurylase (ATPS, adenosine 5'-phosphosulfate reductase (APR and sulfite reductase (SiR. Results The inheritance of ATPS, APR and the related 3'-phosphoadenosine 5'-phosphosulfate reductase (PAPR are remarkable, with multiple origins in the lineages that comprise the opisthokonts, different isoforms in chlorophytes and streptophytes, gene fusions with other enzymes of the pathway, evidence a eukaryote to prokaryote lateral gene transfer, changes in substrate specificity and two reversals of cellular location of host- and endosymbiont-originating enzymes. We also found that the ATPS and APR active in the mitochondria of Euglena were inherited from its secondary, green algal plastid. Conclusion Our results reveal a complex history for the enzymes of the sulfate assimilation pathway. Whilst they shed light on the origin of some characterised novelties, such as a recently described novel isoform of APR from Bryophytes and the origin of the pathway active in the mitochondria of Euglenids, the many distinct and novel isoforms identified here represent an excellent resource for detailed biochemical studies of the enzyme structure/function relationships.

  17. Detección automática de NEOs en imágenes CCD utilizando la transformada de Hough

    Science.gov (United States)

    Ruétalo, M.; Tancredi, G.

    El interés y la dedicación por los objetos que se acercan a la órbita de la Tierra (NEOs) ha aumentado considerablemente en los últimos años, tanto que se han iniciado varias campañas de búsqueda sistemática para aumentar la población identificada de éstos. El uso de placas fotográficas e identificación visual está siendo sustituído, progresivamente, por el uso de cámaras CCD y paquetes de detección automática de los objetos en las imágenes digitales. Una parte muy importante para la implementación exitosa de un programa automatizado de detección de este tipo es el desarrollo de algoritmos capaces de identificar objetos de baja relación señal-ruido y con requerimientos computacionales no elevados. En el presente trabajo proponemos la utilización de la transformada de Hough (utilizada en algunas áreas de visión artificial) para detectar automáticamente trazas, aproximadamente rectilíneas y de baja relación señal-ruido, en imágenes CCD. Desarrollamos una primera implementación de un algoritmo basado en ésta y lo probamos con una serie de imágenes reales conteniendo trazas con picos de señales de entre ~1 σ y ~3 σ por encima del nivel del ruido de fondo. El algoritmo detecta, sin inconvenientes, la mayoría de los casos y en tiempos razonablemente adecuados.

  18. Eukaryotic beta-alanine synthases are functionally related but have a high degree of structural diversity

    DEFF Research Database (Denmark)

    Gojkovic, Zoran; Sandrini, Michael; Piskur, Jure

    2001-01-01

    activity was used to clone analogous genes from different eukaryotes. Putative PYD3 sequences from the yeast S. kluyveri, the slime mold Dictyostelium discoideum, and the fruit fly Drosophila melanogaster complemented the pyd3 defect. When the S. kluyveri PYD3 gene was expressed in S. cerevisiae, which has...

  19. P Transposable Elements in Drosophila and other Eukaryotic Organisms.

    Science.gov (United States)

    Majumdar, Sharmistha; Rio, Donald C

    2015-04-01

    P transposable elements were discovered in Drosophila as the causative agents of a syndrome of genetic traits called hybrid dysgenesis. Hybrid dysgenesis exhibits a unique pattern of maternal inheritance linked to the germline-specific small RNA piwi-interacting (piRNA) pathway. The use of P transposable elements as vectors for gene transfer and as genetic tools revolutionized the field of Drosophila molecular genetics. P element transposons have served as a useful model to investigate mechanisms of cut-and-paste transposition in eukaryotes. Biochemical studies have revealed new and unexpected insights into how eukaryotic DNA-based transposons are mobilized. For example, the P element transposase makes unusual 17nt-3' extended double-strand DNA breaks at the transposon termini and uses guanosine triphosphate (GTP) as a cofactor to promote synapsis of the two transposon ends early in the transposition pathway. The N-terminal DNA binding domain of the P element transposase, called a THAP domain, contains a C2CH zinc-coordinating motif and is the founding member of a large family of animal-specific site-specific DNA binding proteins. Over the past decade genome sequencing efforts have revealed the presence of P element-like transposable elements or P element transposase-like genes (called THAP9) in many eukaryotic genomes, including vertebrates, such as primates including humans, zebrafish and Xenopus, as well as the human parasite Trichomonas vaginalis, the sea squirt Ciona, sea urchin and hydra. Surprisingly, the human and zebrafish P element transposase-related THAP9 genes promote transposition of the Drosophila P element transposon DNA in human and Drosophila cells, indicating that the THAP9 genes encode active P element "transposase" proteins. PMID:26104714

  20. Molecular typing of fecal eukaryotic microbiota of human infants and their respective mothers

    Indian Academy of Sciences (India)

    Prashant K Pandey; Jay Siddharth; Pankaj Verma; Ashish Bavdekar; Milind S Patole; Yogesh S Shouche

    2012-06-01

    The micro-eukaryotic diversity from the human gut was investigated using universal primers directed towards 18S rRNA gene, fecal samples being the source of DNA. The subjects in this study included two breast-fed and two formula-milk-fed infants and their mothers. The study revealed that the infants did not seem to harbour any micro-eukaryotes in their gut. In contrast, there were distinct eukaryotic microbiota present in the mothers. The investigation is the first of its kind in the comparative study of the human feces to reveal the presence of micro-eukaryotic diversity variance in infants and adults from the Indian subcontinent. The micro-eukaryotes encountered during the investigation include known gut colonizers like Blastocystis and some fungi species. Some of these micro-eukaryotes have been speculated to be involved in clinical manifestations of various diseases. The study is an attempt to highlight the importance of micro-eukaryotes in the human gut.

  1. miRSel: Automated extraction of associations between microRNAs and genes from the biomedical literature

    Directory of Open Access Journals (Sweden)

    Zimmer Ralf

    2010-03-01

    Full Text Available Abstract Background MicroRNAs have been discovered as important regulators of gene expression. To identify the target genes of microRNAs, several databases and prediction algorithms have been developed. Only few experimentally confirmed microRNA targets are available in databases. Many of the microRNA targets stored in databases were derived from large-scale experiments that are considered not very reliable. We propose to use text mining of publication abstracts for extracting microRNA-gene associations including microRNA-target relations to complement current repositories. Results The microRNA-gene association database miRSel combines text-mining results with existing databases and computational predictions. Text mining enables the reliable extraction of microRNA, gene and protein occurrences as well as their relationships from texts. Thereby, we increased the number of human, mouse and rat miRNA-gene associations by at least three-fold as compared to e.g. TarBase, a resource for miRNA-gene associations. Conclusions Our database miRSel offers the currently largest collection of literature derived miRNA-gene associations. Comprehensive collections of miRNA-gene associations are important for the development of miRNA target prediction tools and the analysis of regulatory networks. miRSel is updated daily and can be queried using a web-based interface via microRNA identifiers, gene and protein names, PubMed queries as well as gene ontology (GO terms. miRSel is freely available online at http://services.bio.ifi.lmu.de/mirsel.

  2. The Center for Eukaryotic Structural Genomics

    OpenAIRE

    Markley, John L.; Aceti, David J.; Bingman, Craig A.; Fox, Brian G.; Frederick, Ronnie O.; Makino, Shin-ichi; Nichols, Karl W.; Phillips, George N.; Primm, John G.; Sahu, Sarata C.; Vojtik, Frank C.; Volkman, Brian F.; Wrobel, Russell L.; Zolnai, Zsolt

    2009-01-01

    The Center for Eukaryotic Structural Genomics (CESG) is a “specialized” or “technology development” center supported by the Protein Structure Initiative (PSI). CESG’s mission is to develop improved methods for the high-throughput solution of structures from eukaryotic proteins, with a very strong weighting toward human proteins of biomedical relevance. During the first three years of PSI-2, CESG selected targets representing 601 proteins from Homo sapiens, 33 from mouse, 10 from rat, 139 from...

  3. Eukaryotic DNA Ligases: Structural and Functional Insights

    OpenAIRE

    Ellenberger, Tom; Tomkinson, Alan E.

    2008-01-01

    DNA ligases are required for DNA replication, repair, and recombination. In eukaryotes, there are three families of ATP-dependent DNA ligases. Members of the DNA ligase I and IV families are found in all eukaryotes, whereas DNA ligase III family members are restricted to vertebrates. These enzymes share a common catalytic region comprising a DNA-binding domain, a nucleotidyltransferase (NTase) domain, and an oligonucleotide/oligosaccharide binding (OB)-fold domain. The catalytic region encirc...

  4. Reproduction, symbiosis, and the eukaryotic cell

    OpenAIRE

    Godfrey-Smith, Peter

    2015-01-01

    This paper develops a conceptual framework for addressing questions about reproduction, individuality, and the units of selection in symbiotic associations, with special attention to the origin of the eukaryotic cell. Three kinds of reproduction are distinguished, and a possible evolutionary sequence giving rise to a mitochondrion-containing eukaryotic cell from an endosymbiotic partnership is analyzed as a series of transitions between each of the three forms of reproduction. The sequence of...

  5. Multiplex SSR-PCR approaches for semi-automated genotyping and characterization of loci linked to blast disease resistance genes in rice.

    Science.gov (United States)

    Ashkani, Sadegh; Rafii, Mohd Yusop; Shabanimofrad, Mahmoodreza; Foroughi, Majid; Azizia, Parisa; Akhtar, Mohd Sayeed; Sahebi, Mahbod; Harun, Abd Rahim; Nasehi, Abbas

    2015-11-01

    In the present study, 63 polymorphic microsatellite markers related to rice blast resistance genes were fluorescently labelled at the 5'-end with either 6-FAM or HEX using the G5 dye set and incorporated into a multiplex SSR-PCR for the detection of fragments using an automated system. For rice F3 families obtained from crosses between Pongsu Seribu 2 (Malaysian blast resistant cultivar) and Mahsuri (a susceptible rice cultivar), the genotypes for 13 designated multiplex SSR panels were determined. The genotyping assays were performed using a capillary-based ABIPRISM 3100 genetic analyser. The sizes of the SSRs alleles observed in the range from 79 to 324 bp. The observed marker segregation data were analysed using the Chi(2) test. A genetic linkage map covering ten chromosomes and comprising 63 polymorphic SSR markers was constructed, and the distorted loci were localised to linkage groups. The results indicated that distorted loci are presented on eight chromosomes. PMID:26318048

  6. Fusión automática de imágenes a través de la obtención de sinogramas

    Directory of Open Access Journals (Sweden)

    Manuel Guillermo Forero

    2011-01-01

    Full Text Available El desarrollo de técnicas de fusión tiene un alto costo computacional y demandan, por el uso que de ellas se da, excelentes resultados. Este trabajo compara la aplicación de dos técnicas de retroproyección (proyección de máxima intensidad y promedio para la obtención de sinogramas, los cuales serán utilizados como herramienta analítica dentro del procedimiento, junto con un par de métodos de correlación que permiten fusionar dos imágenes del mismo tipo; estos resultados constituyen el material principal de la fusión automática de imágenes propuesta. Este procedimiento no requiere el uso de marcadores externos, ni de marcadores corporales. Los principios esenciales aplicados en este artículo han sido previamente utilizados en la fusión de imágenes.

  7. Challenges in Whole-Genome Annotation of Pyrosequenced Eukaryotic Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2009-04-17

    Pyrosequencing technologies such as 454/Roche and Solexa/Illumina vastly lower the cost of nucleotide sequencing compared to the traditional Sanger method, and thus promise to greatly expand the number of sequenced eukaryotic genomes. However, the new technologies also bring new challenges such as shorter reads and new kinds and higher rates of sequencing errors, which complicate genome assembly and gene prediction. At JGI we are deploying 454 technology for the sequencing and assembly of ever-larger eukaryotic genomes. Here we describe our first whole-genome annotation of a purely 454-sequenced fungal genome that is larger than a yeast (>30 Mbp). The pezizomycotine (filamentous ascomycote) Aspergillus carbonarius belongs to the Aspergillus section Nigri species complex, members of which are significant as platforms for bioenergy and bioindustrial technology, as members of soil microbial communities and players in the global carbon cycle, and as agricultural toxigens. Application of a modified version of the standard JGI Annotation Pipeline has so far predicted ~;;10k genes. ~;;12percent of these preliminary annotations suffer a potential frameshift error, which is somewhat higher than the ~;;9percent rate in the Sanger-sequenced and conventionally assembled and annotated genome of fellow Aspergillus section Nigri member A. niger. Also,>90percent of A. niger genes have potential homologs in the A. carbonarius preliminary annotation. Weconclude, and with further annotation and comparative analysis expect to confirm, that 454 sequencing strategies provide a promising substrate for annotation of modestly sized eukaryotic genomes. We will also present results of annotation of a number of other pyrosequenced fungal genomes of bioenergy interest.

  8. Automated brightfield break-apart in situ hybridization (ba-ISH) application: ALK and MALT1 genes as models.

    Science.gov (United States)

    Nitta, Hiroaki; Zhang, Wenjun; Kelly, Brian D; Miller, Melanie; Pestic-Dragovich, Lidija; Bieniarz, Christopher; Vasicek, Thomas J; Marafioti, Teresa; Rimsza, Lisa; Grogan, Thomas M

    2010-12-01

    Cancer diagnosis can be a complex process, which takes consideration of histopathological, clinical, immunophenotypic, and genetic features. Since non-random chromosomal translocations are specifically involved in the development of various cancers, the detection of these gene aberrations becomes increasingly important. In recent years, break-apart (or split-signal) fluorescence in situ hybridization (FISH) has emerged as an advantageous technique to detect gene translocations on tissue sections. However, FISH assays are technically challenging and require specialized fluorescence microscopes. Furthermore, the FISH signal is not stable for long term archiving due to photo bleaching. Our objective was to demonstrate the feasibility of brightfield break-apart in situ hybridization (ba-ISH) for anaplastic lymphoma kinase (ALK) and mucosa-associated lymphoid tissue translocation protein 1 (MALT1) genes as models. ALK or MALT1 break-apart probes were labeled with digoxigenin (DIG) or 2,4-dinitrophenyl (DNP) on both sides of a known gene breakpoint region and the hybridization sites were visualized with the combination of alkaline phosphatase (AP)-based blue and red detection. Therefore, normal genes are detected as purple dots by mixing blue and red colors while translocated genes are detected as isolated blue or red dots. Formalin-fixed, paraffin-embedded tonsil was used as control for the co-localized 5' and 3' probes. Gene translocations of ALK or MALT1 were detected as separate blue and red dots on ALCL and MALT lymphoma cases. Thus, ISH analyses of gene translocations can be conducted with a regular light microscope and the long term archiving of break-apart ISH slides can be achieved. PMID:20621192

  9. The WRKY transcription factor superfamily: its origin in eukaryotes and expansion in plants

    Directory of Open Access Journals (Sweden)

    Wang Liangjiang

    2005-01-01

    Full Text Available Abstract Background WRKY proteins are newly identified transcription factors involved in many plant processes including plant responses to biotic and abiotic stresses. To date, genes encoding WRKY proteins have been identified only from plants. Comprehensive search for WRKY genes in non-plant organisms and phylogenetic analysis would provide invaluable information about the origin and expansion of the WRKY family. Results We searched all publicly available sequence data for WRKY genes. A single copy of the WRKY gene encoding two WRKY domains was identified from Giardia lamblia, a primitive eukaryote, Dictyostelium discoideum, a slime mold closely related to the lineage of animals and fungi, and the green alga Chlamydomonas reinhardtii, an early branching of plants. This ancestral WRKY gene seems to have duplicated many times during the evolution of plants, resulting in a large family in evolutionarily advanced flowering plants. In rice, the WRKY gene family consists of over 100 members. Analyses suggest that the C-terminal domain of the two-WRKY-domain encoding gene appears to be the ancestor of the single-WRKY-domain encoding genes, and that the WRKY domains may be phylogenetically classified into five groups. We propose a model to explain the WRKY family's origin in eukaryotes and expansion in plants. Conclusions WRKY genes seem to have originated in early eukaryotes and greatly expanded in plants. The elucidation of the evolution and duplicative expansion of the WRKY genes should provide valuable information on their functions.

  10. Transcription factor IID in the Archaea: sequences in the Thermococcus celer genome would encode a product closely related to the TATA-binding protein of eukaryotes

    Science.gov (United States)

    Marsh, T. L.; Reich, C. I.; Whitelock, R. B.; Olsen, G. J.; Woese, C. R. (Principal Investigator)

    1994-01-01

    The first step in transcription initiation in eukaryotes is mediated by the TATA-binding protein, a subunit of the transcription factor IID complex. We have cloned and sequenced the gene for a presumptive homolog of this eukaryotic protein from Thermococcus celer, a member of the Archaea (formerly archaebacteria). The protein encoded by the archaeal gene is a tandem repeat of a conserved domain, corresponding to the repeated domain in its eukaryotic counterparts. Molecular phylogenetic analyses of the two halves of the repeat are consistent with the duplication occurring before the divergence of the archael and eukaryotic domains. In conjunction with previous observations of similarity in RNA polymerase subunit composition and sequences and the finding of a transcription factor IIB-like sequence in Pyrococcus woesei (a relative of T. celer) it appears that major features of the eukaryotic transcription apparatus were well-established before the origin of eukaryotic cellular organization. The divergence between the two halves of the archael protein is less than that between the halves of the individual eukaryotic sequences, indicating that the average rate of sequence change in the archael protein has been less than in its eukaryotic counterparts. To the extent that this lower rate applies to the genome as a whole, a clearer picture of the early genes (and gene families) that gave rise to present-day genomes is more apt to emerge from the study of sequences from the Archaea than from the corresponding sequences from eukaryotes.

  11. Comparative genome analysis across a kingdom of eukaryotic organisms: Specialization and diversification in the Fungi

    OpenAIRE

    Cornell, Michael J.; Alam, Intikhab; Soanes, Darren M.; Wong, Han Min; Hedeler, Cornelia; Paton, Norman W; Rattray, Magnus; Hubbard, Simon J; Talbot, Nicholas J.; Oliver, Stephen G

    2007-01-01

    The recent proliferation of genome sequencing in diverse fungal species has provided the first opportunity for comparative genome analysis across a eukaryotic kingdom. Here, we report a comparative study of 34 complete fungal genome sequences, representing a broad diversity of Ascomycete, Basidiomycete, and Zygomycete species. We have clustered all predicted protein-encoding gene sequences from these species to provide a means of investigating gene innovations, gene family expansions, protein...

  12. Library Automation

    OpenAIRE

    Dhakne, B. N.; Giri, V. V; Waghmode, S. S.

    2010-01-01

    New technologies library provides several new materials, media and mode of storing and communicating the information. Library Automation reduces the drudgery of repeated manual efforts in library routine. By use of library automation collection, Storage, Administration, Processing, Preservation and communication etc.

  13. Extracción automática de modelos UML contenidos en imágenes

    OpenAIRE

    Moreno Pelayo, Valentín

    2015-01-01

    Aunque parezca extraño, pese a no poder encontrar sitios web especializados en ofertar diseños de software representados mediante diagramas UML, existe una ingente cantidad de documentación a disposición de cualquiera, y que contiene dichos modelos: como imágenes en documentos textuales. Este universo de información no se encuentra fácilmente accesible para los desarrolladores porque no es posible, con la tecnología actual, buscar de forma precisa información semántica dentro de imágenes. Lo ...

  14. Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Lamellomorpha sp. indicated by metagenomics

    Science.gov (United States)

    Li, Zhi-Yong; Wang, Yue-Zhu; He, Li-Ming; Zheng, Hua-Jun

    2014-01-01

    The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Lamellomorpha sp. at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Lamellomorpha sp.. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO2 fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Lamellomorpha sp..

  15. Force generation in a regrowing eukaryotic flagellum

    Science.gov (United States)

    Polin, Marco; Bruneau, Bastien; Johnson, Thomas; Goldstein, Raymond

    2012-02-01

    Flagella are whip-like organelles with a complex internal structure, the axoneme, highly conserved across eukaryotic species. The highly regulated activity of motor proteins arranged along the axoneme moves the flagellum in the surrounding fluid, generating forces that can be used for swimming or fluid propulsion. Although our understanding of the general mechanism behind flagellar motion is well established, the details of its implementation in a real axoneme is still poorly understood. Here we explore the inner working of the eukaryotic flagellum using a uniflagellated mutant of the unicellular green alga Chlamydomonas reinhardtii to investigate in detail the force and power generated by a moving flagellum during axonemal regrowth after deflagellation. These experiments will contribute to our understanding of the inner working of the eukaryotic flagellum.

  16. cMonkey2: Automated, systematic, integrated detection of co-regulated gene modules for any organism.

    Science.gov (United States)

    Reiss, David J; Plaisier, Christopher L; Wu, Wei-Ju; Baliga, Nitin S

    2015-07-27

    The cMonkey integrated biclustering algorithm identifies conditionally co-regulated modules of genes (biclusters). cMonkey integrates various orthogonal pieces of information which support evidence of gene co-regulation, and optimizes biclusters to be supported simultaneously by one or more of these prior constraints. The algorithm served as the cornerstone for constructing the first global, predictive Environmental Gene Regulatory Influence Network (EGRIN) model for a free-living cell, and has now been applied to many more organisms. However, due to its computational inefficiencies, long run-time and complexity of various input data types, cMonkey was not readily usable by the wider community. To address these primary concerns, we have significantly updated the cMonkey algorithm and refactored its implementation, improving its usability and extendibility. These improvements provide a fully functioning and user-friendly platform for building co-regulated gene modules and the tools necessary for their exploration and interpretation. We show, via three separate analyses of data for E. coli, M. tuberculosis and H. sapiens, that the updated algorithm and inclusion of novel scoring functions for new data types (e.g. ChIP-seq and transcription factor over-expression [TFOE]) improve discovery of biologically informative co-regulated modules. The complete cMonkey2 software package, including source code, is available at https://github.com/baliga-lab/cmonkey2. PMID:25873626

  17. Reproduction, symbiosis, and the eukaryotic cell.

    Science.gov (United States)

    Godfrey-Smith, Peter

    2015-08-18

    This paper develops a conceptual framework for addressing questions about reproduction, individuality, and the units of selection in symbiotic associations, with special attention to the origin of the eukaryotic cell. Three kinds of reproduction are distinguished, and a possible evolutionary sequence giving rise to a mitochondrion-containing eukaryotic cell from an endosymbiotic partnership is analyzed as a series of transitions between each of the three forms of reproduction. The sequence of changes seen in this "egalitarian" evolutionary transition is compared with those that apply in "fraternal" transitions, such as the evolution of multicellularity in animals. PMID:26286983

  18. Process automation

    International Nuclear Information System (INIS)

    Process automation technology has been pursued in the chemical processing industries and to a very limited extent in nuclear fuel reprocessing. Its effective use has been restricted in the past by the lack of diverse and reliable process instrumentation and the unavailability of sophisticated software designed for process control. The Integrated Equipment Test (IET) facility was developed by the Consolidated Fuel Reprocessing Program (CFRP) in part to demonstrate new concepts for control of advanced nuclear fuel reprocessing plants. A demonstration of fuel reprocessing equipment automation using advanced instrumentation and a modern, microprocessor-based control system is nearing completion in the facility. This facility provides for the synergistic testing of all chemical process features of a prototypical fuel reprocessing plant that can be attained with unirradiated uranium-bearing feed materials. The unique equipment and mission of the IET facility make it an ideal test bed for automation studies. This effort will provide for the demonstration of the plant automation concept and for the development of techniques for similar applications in a full-scale plant. A set of preliminary recommendations for implementing process automation has been compiled. Some of these concepts are not generally recognized or accepted. The automation work now under way in the IET facility should be useful to others in helping avoid costly mistakes because of the underutilization or misapplication of process automation. 6 figs

  19. A Droplet Microfluidic Platform for Automating Genetic Engineering.

    Science.gov (United States)

    Gach, Philip C; Shih, Steve C C; Sustarich, Jess; Keasling, Jay D; Hillson, Nathan J; Adams, Paul D; Singh, Anup K

    2016-05-20

    We present a water-in-oil droplet microfluidic platform for transformation, culture and expression of recombinant proteins in multiple host organisms including bacteria, yeast and fungi. The platform consists of a hybrid digital microfluidic/channel-based droplet chip with integrated temperature control to allow complete automation and integration of plasmid addition, heat-shock transformation, addition of selection medium, culture, and protein expression. The microfluidic format permitted significant reduction in consumption (100-fold) of expensive reagents such as DNA and enzymes compared to the benchtop method. The chip contains a channel to continuously replenish oil to the culture chamber to provide a fresh supply of oxygen to the cells for long-term (∼5 days) cell culture. The flow channel also replenished oil lost to evaporation and increased the number of droplets that could be processed and cultured. The platform was validated by transforming several plasmids into Escherichia coli including plasmids containing genes for fluorescent proteins GFP, BFP and RFP; plasmids with selectable markers for ampicillin or kanamycin resistance; and a Golden Gate DNA assembly reaction. We also demonstrate the applicability of this platform for transformation in widely used eukaryotic organisms such as Saccharomyces cerevisiae and Aspergillus niger. Duration and temperatures of the microfluidic heat-shock procedures were optimized to yield transformation efficiencies comparable to those obtained by benchtop methods with a throughput up to 6 droplets/min. The proposed platform offers potential for automation of molecular biology experiments significantly reducing cost, time and variability while improving throughput. PMID:26830031

  20. Evaluation of an automated rapid diagnostic assay for detection of Gram-negative bacteria and their drug-resistance genes in positive blood cultures.

    Directory of Open Access Journals (Sweden)

    Masayoshi Tojo

    Full Text Available We evaluated the performance of the Verigene Gram-Negative Blood Culture Nucleic Acid Test (BC-GN; Nanosphere, Northbrook, IL, USA, an automated multiplex assay for rapid identification of positive blood cultures caused by 9 Gram-negative bacteria (GNB and for detection of 9 genes associated with β-lactam resistance. The BC-GN assay can be performed directly from positive blood cultures with 5 minutes of hands-on and 2 hours of run time per sample. A total of 397 GNB positive blood cultures were analyzed using the BC-GN assay. Of the 397 samples, 295 were simulated samples prepared by inoculating GNB into blood culture bottles, and the remaining were clinical samples from 102 patients with positive blood cultures. Aliquots of the positive blood cultures were tested by the BC-GN assay. The results of bacterial identification between the BC-GN assay and standard laboratory methods were as follows: Acinetobacter spp. (39 isolates for the BC-GN assay/39 for the standard methods, Citrobacter spp. (7/7, Escherichia coli (87/87, Klebsiella oxytoca (13/13, and Proteus spp. (11/11; Enterobacter spp. (29/30; Klebsiella pneumoniae (62/72; Pseudomonas aeruginosa (124/125; and Serratia marcescens (18/21; respectively. From the 102 clinical samples, 104 bacterial species were identified with the BC-GN assay, whereas 110 were identified with the standard methods. The BC-GN assay also detected all β-lactam resistance genes tested (233 genes, including 54 bla(CTX-M, 119 bla(IMP, 8 bla(KPC, 16 bla(NDM, 24 bla(OXA-23, 1 bla(OXA-24/40, 1 bla(OXA-48, 4 bla(OXA-58, and 6 blaVIM. The data shows that the BC-GN assay provides rapid detection of GNB and β-lactam resistance genes in positive blood cultures and has the potential to contributing to optimal patient management by earlier detection of major antimicrobial resistance genes.

  1. RING FISSION OF ANTHRACENE BY A EUKARYOTE

    Science.gov (United States)

    Ligninolytic fungi are unique among eukaryotes in their ability to degrade polycyclic aromatic hydrocarbons (PAHs), but the mechanism for this process is unknown. lthough certain PAHs are oxidized in vitro by the fungal lignin peroxidases (LiPs) that catalyze ligninolysis, it has...

  2. Assessing performance of orthology detection strategies applied to eukaryotic genomes.

    Directory of Open Access Journals (Sweden)

    Feng Chen

    Full Text Available Orthology detection is critically important for accurate functional annotation, and has been widely used to facilitate studies on comparative and evolutionary genomics. Although various methods are now available, there has been no comprehensive analysis of performance, due to the lack of a genomic-scale 'gold standard' orthology dataset. Even in the absence of such datasets, the comparison of results from alternative methodologies contains useful information, as agreement enhances confidence and disagreement indicates possible errors. Latent Class Analysis (LCA is a statistical technique that can exploit this information to reasonably infer sensitivities and specificities, and is applied here to evaluate the performance of various orthology detection methods on a eukaryotic dataset. Overall, we observe a trade-off between sensitivity and specificity in orthology detection, with BLAST-based methods characterized by high sensitivity, and tree-based methods by high specificity. Two algorithms exhibit the best overall balance, with both sensitivity and specificity>80%: INPARANOID identifies orthologs across two species while OrthoMCL clusters orthologs from multiple species. Among methods that permit clustering of ortholog groups spanning multiple genomes, the (automated OrthoMCL algorithm exhibits better within-group consistency with respect to protein function and domain architecture than the (manually curated KOG database, and the homolog clustering algorithm TribeMCL as well. By way of using LCA, we are also able to comprehensively assess similarities and statistical dependence between various strategies, and evaluate the effects of parameter settings on performance. In summary, we present a comprehensive evaluation of orthology detection on a divergent set of eukaryotic genomes, thus providing insights and guides for method selection, tuning and development for different applications. Many biological questions have been addressed by multiple

  3. 线虫Fat-1基因密码子的优化及其真核表达载体构建%Codon Optimization and Eukaryotic Expression Vector Construction of Fat-1 Gene Coming From Caenorhabditis elegans

    Institute of Scientific and Technical Information of China (English)

    张立春; 刘晓辉; 曹阳; 于永生; 朴庆林; 金海国; 王晓阳

    2012-01-01

    Objective: In order to make Fat-1 gene from Caenorhabditis elegans be highly expressed in cattle, the Fat-1 gene was optimized and obtained by nucleotide synthesis, the transgenic vector was constructed in the end. Methods: The codons of Fat-1 gene from C.elegans were optimized by bio-information software according cattle as the expressional host. The optimized Fat-1 gene was named as bFat-1. The bFat-1 was obtained by nucleotide synthesis, and the transgenic vector pcDNA3.1-bFat-l was consturcted in the end. Results: The results showed that some indexes which control the expression level in cattle were significantly improved, including codon adaptation index (CAI), frequency of optimal codons (FOP) and GC content. The results of nucleotide synthesis, gene clone and sequencing aproved the bFat-1 gene was obtained successfully; the results of vector construction and identification showed that the construction of pcDNA3.1-bFat-l was successful. Conclusion: The transgenic vector pcDNA3.1-bFat-l, which expresses optimized Fat-1 gene from C.elegans was successfully established and would be used to construct the Fal-1 transgenic cell lines in follows study.%目的:为使线虫Fat-Ⅰ基因能够在牛中高效表达,通过密码子优化及全基因合成方法制备Fat-1基因,并构建其转基因表达载体.方法:通过生物信息学手段,将来源于线虫的Fat-1基因以牛为表达宿主进行密码子优化,将优化后的Fat-1基因命名为bFat-1;通过全基因合成方法获得bFat-1基因,构建pcDNA3,1-bFat-Ⅰ真核表达载体.结果:通过密码子优化,影响Fat-Ⅰ基因在牛中表达的密码子适应指数、优势密码子频率及GC含量等各项指标均有显著改善;全基因合成、克隆及测序结果显示已获得bFat-1基因;构建并鉴定了pcDNA3.1-bFat-1载体.结论:获得了适合牛体表达的Fat-1基因并构建了其转基因载体,为获得高效表达Fat-1基因的转基因牛细胞系奠定了基础.

  4. Construction of the eukaryotic expression vector encoding IT15 gene fragment and its expression in SH-SY5Y cells%亨廷顿舞蹈病的IT15基因片段真核表达载体构建及其在SH-SY5Y细胞中的表达定位

    Institute of Scientific and Technical Information of China (English)

    田均; 李盈枝; 殷鑫浈; 张宝荣

    2008-01-01

    Objective To construct the eukaryotic expression vector encoding IT15 gene and detect its expression in SH-SY5Y cells.Methods The exon1 of IT15 gene was amplified from genomic DNA isolated from a healthy adult and a Huntington disease patient lymphoblastoid cell lines by PCR.PCR products were subcloned into eukaryotic expression vector pEGFP-C1.The SH-SY5Y cells were transiently transfected with the recombinant plasmids and observed under fluorescence microscope.Western blot was used to detect the expression of the fusion protein.Results PCR products had approximately 170 and 310 bp specific segments.The recombinant eukaryotie expression plasmids were confirmed by restriction endonuclease analysis and sequencing.The N-terminal fragment of normal huntingtin primarily localized in the cytoplasim of SH-SY5Y cells,while the N-terminal fragment of mutant huntingtin aggregated both perinuclearly and intranuelearly.Conclusions The recombinant eukaryotic expression vectors encoding wild type and mutant IT15 gene fragments are useful for studying pathogenesis of Huntington disease.The Nterminal fragment of mutant huntingtin aggregats both perinuclearly and intranuclearly,which could be important for Huntington disease pathophysiology.%目的 构建亨廷顿舞蹈病的致病基因IT15基因片段的真核表达载体,观察其在SH-SY5Y细胞内的表达分布情况.方法 以PCR方法扩增出健康人和亨廷顿舞蹈病患者的IT15基因1号外显子片段,应用基因重组技术与绿色荧光蛋白(GFP)基因融合构建以GFP为报告基因的重组真核表达质粒GFP-Htt-19Q与GFP-mHtt-70Q,并经酶切分析和测序证实.利用脂质体瞬时转染人神经母细胞瘤细胞SH-SY5Y细胞;Western blot证实亨廷顿蛋白氨基末端片段在SH-SY5Y细胞内表达;荧光显微镜观察正常与变异亨廷顿蛋白氨基末端片段在细胞内的表达定位情况.结果 健康人和亨廷顿舞蹈病患者的IT15基因1号外显子的PCR产物分别为170

  5. 羊布氏菌P39基因重组真核表达质粒的构建及其免疫效果%Construction and Immune Effect of Recombinant Eukaryotic Expression Vector for P39 Gene of Brucella melitensis

    Institute of Scientific and Technical Information of China (English)

    石艳春; 韩堃; 郑源强; 毕力夫

    2011-01-01

    Objective To construct a recombinant eukaryotic expression vector for P39 gene of Brucella melitensis and determine its immune effect. Methods Previously cloned P39 gene fragment was inserted to the multiple cloning site (MCS) of eukaryotic expression vector pcDNA3. 1 (+). The constructed recombinant plasmid pcDNA3. 1-P39 was transformed to E. coli DH5α, and positive clones were screened, from which recombinant plasmid was extracted and identified by restriction analysis. BALB/c mice were immunized with the constructed recombinant plasmid, then determined for serum specific antibody level by agglutination test, for cytokine content in sera by ELISA, and for splenic lymphocyte proliferation effect by MTT assay. Results Restriction analysis proved that recombinant plasmid pcDNA3. 1-P39 was constructed correctly. The recombinant plasmid stimulated the production of specific antibody in mice (the peak value of antibody titer was 1: 320), increased the Th1 cytokines significantly, and enhanced the splenic lymphocyte proliferation response. Conclusion Recombinant eukaryotic expression vector pcDNA3. 1-P39 for P39 gene of B. melitensis was successfully constructed, which induced specific immune response in BALB/c mice.%目的 构建羊布氏菌P39基因重组真核表达质粒,并检测其免疫效果.方法 将前期克隆的P39基因片段连接到真核表达载体pcDNA3.1(+)的多克隆位点中,构建重组真核表达质粒pcDNA3.1-P39,转化E.coli DH5α,筛选阳性克隆,提取重组质粒,进行双酶切鉴定.以鉴定正确的重组质粒免疫BALB/c小鼠,凝集试验检测小鼠血清特异性抗体水平,ELISA法检测小鼠血清中细胞因子含量,MIT掺人法检测小鼠脾脏淋巴细胞的增殖效应.结果 重组真核表达质粒pcDNA3.1-P39经双酶切鉴定构建正确;该重组质粒能够刺激小鼠产生特异性抗体(抗体峰值滴度为1:320),显著增加Thl型细胞因子的产生,并能够增强小鼠脾脏淋巴

  6. 牛朊蛋白基因真核表达载体的构建及其在牛骨髓间充质干细胞中的稳定表达%Construction and Stably Expression of Eukaryotic Expression Vector of Bovine PRNP Gene in Bovine BMSC

    Institute of Scientific and Technical Information of China (English)

    宋少康; 董雅娟; 柏学进; 王文明; 刘玮; 牛召珊; 赵仕全; 杨莉

    2012-01-01

    试验构建牛朊蛋白(prion protein,PRNP)基因的真核表达载体,为进一步研究牛朊蛋白的生理功能和从细胞水平研究抗疯牛病转基因克隆牛奠定基础.采用重叠延伸PCR(splicing overlap extension PCR,SOE-PCR)法扩增获得牛PRNP基因序列,并克隆到带有DsRED2报告基因的真核表达载体pDsRED2-N1中,将双酶切、PCR、测序鉴定的阳性质粒经脂质体转染牛骨髓间充质干细胞(BMSC);通过荧光显微镜观察转染细胞,并用800 μg/mL G418对转染的细胞进行药物筛选.琼脂糖凝胶电泳显示基因合成的片段大小和构建的载体大小与预期相符;重组表达载体转染BMSC后有红色荧光出现;通过药物筛选出了稳定转染的细胞单克隆.通过SOE-PCR成功扩增了牛PRNP基因序列,并构建成真核表达载体,得到稳定表达目的蛋白的BMSC细胞.%In order to further study the physiological function of bovine prion protein and anti-mad cow disease cloned transgenic cattle basis form cellular level, we constructed a bovine prion protein gene (PRNP) eukaryotic expression vector. The PRNP gene was cloned by splicing overlap extension PCR (SQE-PCR) method, and inserted into the report with DsRED2 eukaryotic vector pDsRED2-Nl. This recombinant plasmid pDsRED2-Nl was identified by digestion of endonuclease, PCR and sequencing. Then, it was transfected into bovine BMSC cell line mediated by Lipofectamine?2000. The transfected cells was detected by fluorescence microscopy and drug screening by 800 ptg/mL G418. Electrophoresis analysis showed that the sequences were amplified and the sizes of products were accord with expectation. The recombinant plasmid was expressed in BMSC. The positive single stable transfection cell clones were also got by drug screening. The PRNP gene had been cloned by splicing overlap extension PCR method, and the recombinant eukaryotic vector stable expressed in BMSC successfully.

  7. Construction of eukaryotic expression vector and expression of stage-specific gene T314 from newborn larvae of Trichinella spiralis%旋毛虫新生幼虫期特异性T314基因真核表达质粒的构建及表达

    Institute of Scientific and Technical Information of China (English)

    于建立; 白雪; 吴秀萍; 刘明远

    2012-01-01

    目的 构建旋毛虫(Trichinella spirais)新生幼虫期特异性T314基因真核表达质粒,并在BHK细胞中进行表达.方法 从旋毛虫新生幼虫RNA中通过RT-PCR技术扩增无信号肽T314全长基因,定向克隆至真核表达载体pEGFP-N1中,构建重组真核表达质粒T314-pEGFP-N1,脂质体法转染BHK细胞,荧光显微镜观察EGFP的表达,Western blot检测T314融合蛋白的表达.结果 重组真核表达质粒T314-pEGFP-N1经双酶切及测序证实构建正确;转染的BHK细胞48 h转染效率最高;表达的T314融合蛋白可与旋毛虫感染的猪血清发生特异性反应.结论 已成功构建了T314基因重组真核表达质粒T314-pEGFP-N1,并在BHK细胞中融合表达,为进一步研究旋毛虫包囊形成机制奠定了基础.%Objective To construct a eukaryotic expression vector for stage-specific gene T314 from newborn larvae of Trichinella spiralis and express in BHK cells. Methods Signal peptide-free full-length T314 gene was amplified from RNA of newborn larvae of T. Spiralis by RT-PCR and cloned into eukaryotic expression vector Pegfp-Nl. BHK cells were transfected with the constructed recombinant plasmid T314-Pegfp-Nl in mediation of Hposome, then observed for expression of EGFP by fluorescent microscopy, and for that of T314 fusion protein by Western blot. Results Restriction analysis and sequencing proved that recombinant plasmid T314-Pegfp-Nl was constructed correctly. The transfection efficacy of BHK cells reached the maximum 48 h after transfection. The expressed T314 fusion protein showed specific reaction with porcine serum infected with T. Spiralis. Conclusion The recombinant eukaryotic expression vector T314-Pegfp-Nl for T314 gene was successfully constructed, and fusion protein was expressed in BHK cells, which laid a foundation of further study on mechanism of nurse cell formation of T. Spiralis.

  8. From the Cover: Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features

    Science.gov (United States)

    Derelle, Evelyne; Ferraz, Conchita; Rombauts, Stephane; Rouzé, Pierre; Worden, Alexandra Z.; Robbens, Steven; Partensky, Frédéric; Degroeve, Sven; Echeynié, Sophie; Cooke, Richard; Saeys, Yvan; Wuyts, Jan; Jabbari, Kamel; Bowler, Chris; Panaud, Olivier; Piégu, Benoît; Ball, Steven G.; Ral, Jean-Philippe; Bouget, François-Yves; Piganeau, Gwenael; de Baets, Bernard; Picard, André; Delseny, Michel; Demaille, Jacques; van de Peer, Yves; Moreau, Hervé

    2006-08-01

    The green lineage is reportedly 1,500 million years old, evolving shortly after the endosymbiosis event that gave rise to early photosynthetic eukaryotes. In this study, we unveil the complete genome sequence of an ancient member of this lineage, the unicellular green alga Ostreococcus tauri (Prasinophyceae). This cosmopolitan marine primary producer is the world's smallest free-living eukaryote known to date. Features likely reflecting optimization of environmentally relevant pathways, including resource acquisition, unusual photosynthesis apparatus, and genes potentially involved in C4 photosynthesis, were observed, as was downsizing of many gene families. Overall, the 12.56-Mb nuclear genome has an extremely high gene density, in part because of extensive reduction of intergenic regions and other forms of compaction such as gene fusion. However, the genome is structurally complex. It exhibits previously unobserved levels of heterogeneity for a eukaryote. Two chromosomes differ structurally from the other eighteen. Both have a significantly biased G+C content, and, remarkably, they contain the majority of transposable elements. Many chromosome 2 genes also have unique codon usage and splicing, but phylogenetic analysis and composition do not support alien gene origin. In contrast, most chromosome 19 genes show no similarity to green lineage genes and a large number of them are specialized in cell surface processes. Taken together, the complete genome sequence, unusual features, and downsized gene families, make O. tauri an ideal model system for research on eukaryotic genome evolution, including chromosome specialization and green lineage ancestry. genome heterogeneity | genome sequence | green alga | Prasinophyceae | gene prediction

  9. Automated discovery of tissue-targeting enhancers and transcription factors from binding motif and gene function data.

    Directory of Open Access Journals (Sweden)

    Geetu Tuteja

    2014-01-01

    Full Text Available Identifying enhancers regulating gene expression remains an important and challenging task. While recent sequencing-based methods provide epigenomic characteristics that correlate well with enhancer activity, it remains onerous to comprehensively identify all enhancers across development. Here we introduce a computational framework to identify tissue-specific enhancers evolving under purifying selection. First, we incorporate high-confidence binding site predictions with target gene functional enrichment analysis to identify transcription factors (TFs likely functioning in a particular context. We then search the genome for clusters of binding sites for these TFs, overcoming previous constraints associated with biased manual curation of TFs or enhancers. Applying our method to the placenta, we find 33 known and implicate 17 novel TFs in placental function, and discover 2,216 putative placenta enhancers. Using luciferase reporter assays, 31/36 (86% tested candidates drive activity in placental cells. Our predictions agree well with recent epigenomic data in human and mouse, yet over half our loci, including 7/8 (87% tested regions, are novel. Finally, we establish that our method is generalizable by applying it to 5 additional tissues: heart, pancreas, blood vessel, bone marrow, and liver.

  10. Positive selection for unpreferred codon usage in eukaryotic genomes

    Directory of Open Access Journals (Sweden)

    Galagan James E

    2007-07-01

    Full Text Available Abstract Background Natural selection has traditionally been understood as a force responsible for pushing genes to states of higher translational efficiency, whereas lower translational efficiency has been explained by neutral mutation and genetic drift. We looked for evidence of directional selection resulting in increased unpreferred codon usage (and presumably reduced translational efficiency in three divergent clusters of eukaryotic genomes using a simple optimal-codon-based metric (Kp/Ku. Results Here we show that for some genes natural selection is indeed responsible for causing accelerated unpreferred codon substitution, and document the scope of this selection. In Cryptococcus and to a lesser extent Drosophila, we find many genes showing a statistically significant signal of selection for unpreferred codon usage in one or more lineages. We did not find evidence for this type of selection in Saccharomyces. The signal of positive selection observed from unpreferred synonymous codon substitutions is coincident in Cryptococcus and Drosophila with the distribution of upstream open reading frames (uORFs, another genic feature known to reduce translational efficiency. Functional enrichment analysis of genes exhibiting low Kp/Ku ratios reveals that genes in regulatory roles are particularly subject to this type of selection. Conclusion Through genome-wide scans, we find recent selection for unpreferred codon usage at approximately 1% of genetic loci in a Cryptococcus and several genes in Drosophila. Unpreferred codons can impede translation efficiency, and we find that genes with translation-impeding uORFs are enriched for this selection signal. We find that regulatory genes are particularly likely to be subject to selection for unpreferred codon usage. Given that expression noise can propagate through regulatory cascades, and that low translational efficiency can reduce expression noise, this finding supports the hypothesis that translational

  11. Phylogenetic analysis of P5 P-type ATPases, a eukaryotic lineage of secretory pathway pumps

    DEFF Research Database (Denmark)

    Møller, Annette; Asp, Torben; Holm, Preben Bach;

    2008-01-01

    Eukaryotes encompass a remarkable variety of organisms and unresolved lineages. Different phylogenetic analyses have lead to conflicting conclusions as to the origin and associations between lineages and species. In this work, we investigated evolutionary relationship of a family of cation pumps...... far, while P5B ATPases appear to be lost in three eukaryotic lineages; excavates, entamoebas and land plants. A lineage-specific gene expansion of up to four different P5B ATPases is seen in animals....

  12. Translation Regulation by Eukaryotic Initiation Factor-2 Kinases in the Development of Latent Cysts in Toxoplasma gondii*S⃞

    OpenAIRE

    Narasimhan, Jana; Joyce, Bradley R; Naguleswaran, Arunasalam; Smith, Aaron T.; Livingston, Meredith R.; Dixon, Stacy E.; Coppens, Isabelle; Wek, Ronald C.; Sullivan, William J.

    2008-01-01

    A key problem in the treatment of numerous pathogenic eukaryotes centers on their development into latent forms during stress. For example, the opportunistic protist Toxoplasma gondii converts to latent cysts (bradyzoites) responsible for recrudescence of disease. We report that Toxoplasma eukaryotic initiation factor-2α (TgIF2α) is phosphorylated during stress and establish that protozoan parasites utilize translation control to modulate gene expression during development. ...

  13. Large-scale comparative analysis of splicing signals and their corresponding splicing factors in eukaryotes

    OpenAIRE

    Schwartz, Schraga; Silva, João(CFTP, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049, Lisboa, Portugal); Burstein, David; Pupko, Tal; Eyras, Eduardo; Ast, Gil

    2008-01-01

    Introns are among the hallmarks of eukaryotic genes. Splicing of introns is directed by three main splicing signals: the 5′ splice site (5′ss), the branch site (BS), and the polypyrimdine tract/3′splice site (PPT-3′ss). To study the evolution of these splicing signals, we have conducted a systematic comparative analysis of these signals in over 1.2 million introns from 22 eukaryotes. Our analyses suggest that all these signals have dramatically evolved: The PPT is weak among most fungi, inter...

  14. Construction of Trichomonas vaginalis Adhesion Protein 33 Gene Eukaryotic Expression Plasmid%阴道毛滴虫黏附蛋白33基因真核表达载体的构建与鉴定

    Institute of Scientific and Technical Information of China (English)

    杨树国; 王雅静; 帖超男; 谢辉; 毕世樑; 刘佩娜; 廖琳

    2006-01-01

    目的 构建并鉴定阴道毛滴虫黏附蛋白33基因(adhesion protein 33 gene,ap33 gene)真核表达载体.方法 提取阴道毛滴虫分离株基因组DNA,PCR扩增黏附蛋白33基因,克隆入pMD-18T线性质粒,重组子经双酶切、PCR鉴定及测序分析.鉴定出的重组质粒pMD-18T-ap33和pcDNA3.1(+)空质粒经BamH Ⅰ和Xba Ⅰ限制性内切酶双酶切,凝胶电泳后回收ap33目的基因和pcDNA3.1(+)空质粒酶切片段,将ap33基因亚克隆入pcDNA3.1(+)载体并进行筛选和鉴定.结果 PCR扩增出阴道毛滴虫黏附蛋白33基因,重组质粒pMD-18T-ap33经双酶切,PCR及序列分析,ap33基因的长度为930 bp,与GenBank上公布的ap33基因序列同源性达99%.经凝胶电泳、PCR鉴定和限制性酶切鉴定,构建出pcDNA3.1(+)-ap33重组质粒.结论 成功构建了阴道毛滴虫pMD-18T-ap33克隆质粒及pcDNA3.1(+)-ap33重组质粒.

  15. Towards New Antifolates Targeting Eukaryotic Opportunistic Infections

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.; Bolstad, D; Bolstad, E; Wright, D; Anderson, A

    2009-01-01

    Trimethoprim, an antifolate commonly prescribed in combination with sulfamethoxazole, potently inhibits several prokaryotic species of dihydrofolate reductase (DHFR). However, several eukaryotic pathogenic organisms are resistant to trimethoprim, preventing its effective use as a therapeutic for those infections. We have been building a program to reengineer trimethoprim to more potently and selectively inhibit eukaryotic species of DHFR as a viable strategy for new drug discovery targeting several opportunistic pathogens. We have developed a series of compounds that exhibit potent and selective inhibition of DHFR from the parasitic protozoa Cryptosporidium and Toxoplasma as well as the fungus Candida glabrata. A comparison of the structures of DHFR from the fungal species Candida glabrata and Pneumocystis suggests that the compounds may also potently inhibit Pneumocystis DHFR.

  16. Prokaryotes Versus Eukaryotes: Who is Hosting Whom?

    OpenAIRE

    Tellez, Guillermo

    2014-01-01

    Microorganisms represent the largest component of biodiversity in our world. For millions of years, prokaryotic microorganisms have functioned as a major selective force shaping eukaryotic evolution. Microbes that live inside and on animals outnumber the animals’ actual somatic and germ cells by an estimated 10-fold. Collectively, the intestinal microbiome represents a “forgotten organ,” functioning as an organ inside another that can execute many physiological responsibilities. The nature of...

  17. Evolution of the tetrapyrrole synthesis in eukaryotes

    OpenAIRE

    Kořený, Luděk

    2011-01-01

    This thesis focuses on the nature of heme metabolism in various eukaryotes. One of the aims was the elucidation of the origin of the unique heme biosynthesis pathway in apicomplexan parasites through a comparative study of their photosynthetic relative Chromera velia combining molecular biology, biochemistry and bioinformatics approach. Using similar strategy, I have also investigated the origin and spatial organization of tetrapyrrole biosynthesis in Euglena gracilis. Based on the phylogenet...

  18. Strong Eukaryotic IRESs Have Weak Secondary Structure

    OpenAIRE

    Xuhua Xia; Martin Holcik

    2009-01-01

    BACKGROUND: The objective of this work was to investigate the hypothesis that eukaryotic Internal Ribosome Entry Sites (IRES) lack secondary structure and to examine the generality of the hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: IRESs of the yeast and the fruit fly are located in the 5'UTR immediately upstream of the initiation codon. The minimum folding energy (MFE) of 60 nt RNA segments immediately upstream of the initiation codons was calculated as a proxy of secondary structure stabili...

  19. Construction and identification of eukaryotic eukaryotic expression plasmid pcdna3.1-bace and its transient expression in cells

    Institute of Scientific and Technical Information of China (English)

    Huilin Gong; Guanjun Zhang; Weijiang Dong

    2006-01-01

    Objective: To generate eukaryotic expression vector of pcDNA3.1-BACE and obtain its transient expression in COS-7 cells and high expression in the neuroblastoma SK-N-SH cells. Methods: A 1503 bp cDNA fragment was amplified from the total RNA of human neuroblastoma by RT-PCR method and cloned into plasmid pcDNA3.1. The vector was identified by digestion with restriction enzymes BamHI and XhoI and sequenced by Sanger-dideoxy-mediated chain termination. The expression of BACE gene was detected by immunocytochemistry method. Results: The results showed that the cDNAfragment included 1503 bp total coding region. The recombinant eukaryotic cell expression vector of pcDNA3.1-BACE was constructed successfully,and the sequence of insert was identical to the published sequence. The COS-7 cells and the neuroblastoma SK-N-SH cells transfected with the pcDNA3.1-BACE plasmid expressed high level of BACE protein in cytoplasm. Conclusion: The recombinant plasmid pcDNA3.1-BACE can provide very useful tool for researching the reason of Alzheimer's disease and lays the important foundation for preventing the AD laterly.

  20. Growth control of the eukaryote cell: a systems biology study in yeast

    Directory of Open Access Journals (Sweden)

    Castrillo Juan I

    2007-04-01

    Full Text Available Abstract Background Cell growth underlies many key cellular and developmental processes, yet a limited number of studies have been carried out on cell-growth regulation. Comprehensive studies at the transcriptional, proteomic and metabolic levels under defined controlled conditions are currently lacking. Results Metabolic control analysis is being exploited in a systems biology study of the eukaryotic cell. Using chemostat culture, we have measured the impact of changes in flux (growth rate on the transcriptome, proteome, endometabolome and exometabolome of the yeast Saccharomyces cerevisiae. Each functional genomic level shows clear growth-rate-associated trends and discriminates between carbon-sufficient and carbon-limited conditions. Genes consistently and significantly upregulated with increasing growth rate are frequently essential and encode evolutionarily conserved proteins of known function that participate in many protein-protein interactions. In contrast, more unknown, and fewer essential, genes are downregulated with increasing growth rate; their protein products rarely interact with one another. A large proportion of yeast genes under positive growth-rate control share orthologs with other eukaryotes, including humans. Significantly, transcription of genes encoding components of the TOR complex (a major controller of eukaryotic cell growth is not subject to growth-rate regulation. Moreover, integrative studies reveal the extent and importance of post-transcriptional control, patterns of control of metabolic fluxes at the level of enzyme synthesis, and the relevance of specific enzymatic reactions in the control of metabolic fluxes during cell growth. Conclusion This work constitutes a first comprehensive systems biology study on growth-rate control in the eukaryotic cell. The results have direct implications for advanced studies on cell growth, in vivo regulation of metabolic fluxes for comprehensive metabolic engineering, and for

  1. 人骨形态发生蛋白-2基因的真核表达载体构建%Construction of the Eukaryotic Expression Vector for hBMP-gene

    Institute of Scientific and Technical Information of China (English)

    沈伟; 郭善一; 鲍秋野; 梁东春; 张镜宇

    2001-01-01

    Objective:To construct the recombinant bacmid DNA of human bone morpbogenetic protein-2 (hBMP-2) gene and ex press hBMP-2 by transfecting the insect cell line (Sf 9). Methods:The full-length coding region (1188 bp) for hBMP-2 in cluding signal peptide,inter pro-peptide and mature peptide was inserted to the multi-cloning sites of baculovirus vector pFastBacl which was controlled by the promoter pPolh, the recombinant plasmid (pFBBMP) was constructed, and pF- BBMP was transformed into E. coli DH 10 Bac. After transposition, the positive colonies were selected and the bacmid DNA was extracted. Confirmed by PCR,Sf 9 was transfected with recombinant bacmid DNA by liposome-mediated gene transfer method. Results: The recombinant bacmid DNA which can directly transfect Sf 9 was produced,and the expression produc tion (hBMP-2) was of 35.6% of total insect cell protein. Conclusion: The recombinant bacmid DNA is successfully con structed by baculovirus vector,and hBMP-2 highly expresses in insect cells.%目的:利用杆状病毒载体,构建可直接转染昆虫细胞Sf 9 的含人骨形态发生蛋白-2(hBMP-2)基因的重 组穿梭载体(bacmid DNA),最终获得重组蛋白。方法:将编码包含hBMP-2 N-端信号肽,中间前肽以及C-端成熟肽 共1188bp的cDNA片断,插入真核表达载体pFastBacl的多克隆位点,受控于pPolh启动子,构建成pFastBacl/ hBMP-2重组转移载体。重组子转化大肠杆菌DH10Bac。转座后,挑选阳性菌落,提取bacmid DNA,经PCR鉴定 后,以重组bacmid DNA转染Sf9细胞。收集重组病毒,扩大转染Sf9,表达产物行SDS-PAGE初步鉴定。结果:获 得了含hBMP-2全长cDNA片段的重组bacmid DNA和重组病毒,经SDS-PAGE证实在昆虫细胞中表达了分泌型 hBMP-2蛋白,经激光密度扫描仪扫描显示分泌性蛋白表达量占细胞蛋白总量的35.6%。结论:利用杆状病毒载 体成功构建了可用于直接转染昆虫细胞而

  2. 碱基切除修复基因HOGG1特异性锤头状核酶表达载体的构建及其功能的初步研究%Constructing the Eukaryotic Expression Vector to Study Preliminarily the Functions of Hammerhead Ribozyme Targeting Base Excision Repair Gene HOGG1

    Institute of Scientific and Technical Information of China (English)

    张遵真; 张勤; 吴媚

    2006-01-01

    Objective Adriamycin is widely used as an effective anti-tumor drug clinically treating a number of human cancers, but the effect of adriamycin is limited by drug resistance. The various kinds of investigations indicated that the anti-tumor activity of adriamycin resulted from drug-induced free radical formation. The free radicals could lead to oxidative DNA damage, and the lesion would be repaired by base excision repair (BER) pathway. Human 8-oxoguanine DNA glycosylase 1 (HOGG1) is a key enzyme on BER pathway. To study the influence and biological mechanism of the HOGG1 to adriamycin drug-sensitivity, the eukaryotic expression vector with gene of hammerhead ribozyme targeting HOGG1 mRNA would be constructed and identified, and then the change of drug-sensitivity in lung cancer A549 cells would be investigated. Methods According to computer design, two specific restriction site BamHⅠ and EcoRⅠ were added to both ends of the ribozyme gene, then the modified ribozyme gene was synthesized and cloned into the eukaryotic expression vector pcDNA3.1(+). The positive recombinants were screened by ampicillin resistance, and plasmids were extracted from the positive recombinants and digested by BamH Ⅰ and EcoR Ⅰ, and then were analyzed by agarose gel electrophoresis and DNA sequencing. The recombinants were transiently transfected into A549 cells. The positive recombinants were identified by reverse transcription-polymerase chain reaction (RT-PCR) targeting to NEO gene, which was a neomycin resistance gene for selection of stable cell lines and only existed in vectors. The changes of HOGG1 mRNA in A549 cells were detected by RT-PCR. Then the cellular sensitivity to adriamycin was tested by comparison between untransfected cells and transfected cells by MTT assay. The adriamycin-induced DNA damage was investigated by comet assay or single cell gel electrophoresis (SCGE) between untransfected and transfected cells. Results The recombinants containing the ribozyme gene

  3. Chimeric viruses blur the borders between the major groups of eukaryotic single-stranded DNA viruses.

    Science.gov (United States)

    Roux, Simon; Enault, François; Bronner, Gisèle; Vaulot, Daniel; Forterre, Patrick; Krupovic, Mart

    2013-01-01

    Metagenomic studies have uncovered an astonishing diversity of ssDNA viruses encoding replication proteins (Reps) related to those of eukaryotic Circoviridae, Geminiviridae or Nanoviridae; however, exact evolutionary relationships among these viruses remain obscure. Recently, a unique chimeric virus (CHIV) genome, which has apparently emerged via recombination between ssRNA and ssDNA viruses, has been discovered. Here we report on the assembly of 13 new CHIV genomes recovered from various environments. Our results indicate a single event of capsid protein (CP) gene capture from an RNA virus in the history of this virus group. The domestication of the CP gene was followed by an unprecedented recurrent replacement of the Rep genes in CHIVs with distant counterparts from diverse ssDNA viruses. We suggest that parasitic and symbiotic interactions between unicellular eukaryotes were central for the emergence of CHIVs and that such turbulent evolution was primarily dictated by incongruence between the CP and Rep proteins. PMID:24193254

  4. The evolutionary history of histone H3 suggests a deep eukaryotic root of chromatin modifying mechanisms

    Directory of Open Access Journals (Sweden)

    Postberg Jan

    2010-08-01

    Full Text Available Abstract Background The phenotype of an organism is an outcome of both its genotype, encoding the primary sequence of proteins, and the developmental orchestration of gene expression. The substrate of gene expression in eukaryotes is the chromatin, whose fundamental units are nucleosomes composed of DNA wrapped around each two of the core histone types H2A, H2B, H3 and H4. Key regulatory steps involved in the determination of chromatin conformations are posttranslational modifications (PTM at histone tails as well as the assembly of histone variants into nucleosomal arrays. Although the mechanistic background is fragmentary understood, it appears that the chromatin signature of metazoan cell types is inheritable over generations. Even less understood is the conservation of epigenetic mechanisms among eukaryotes and their origins. Results In the light of recent progress in understanding the tree of eukaryotic life we discovered the origin of histone H3 by phylogenetic analyses of variants from all supergroups, which allowed the reconstruction of ancestral states. We found that H3 variants evolved frequently but independently within related species of almost all eukaryotic supergroups. Interestingly, we found all core histone types encoded in the genome of a basal dinoflagellate and H3 variants in two other species, although is was reported that dinoflagellate chromatin is not organized into nucleosomes. Most probably one or more animal/nuclearid H3.3-like variants gave rise to H3 variants of all opisthokonts (animals, choanozoa, fungi, nuclearids, Amoebozoa. H3.2 and H3.1 as well as H3.1t are derivatives of H3.3, whereas H3.2 evolved already in early branching animals, such as Trichoplax. H3.1 and H3.1t are probably restricted to mammals. We deduced a model for protoH3 of the last eukaryotic common ancestor (LECA confirming a remarkable degree of sequence conservation in comparison to canonical human H3.1. We found evidence that multiple PTMs are

  5. Searching for the role of protein phosphatases in eukaryotic microorganisms

    Directory of Open Access Journals (Sweden)

    da-Silva A.M.

    1999-01-01

    Full Text Available Preference for specific protein substrates together with differential sensitivity to activators and inhibitors has allowed classification of serine/threonine protein phosphatases (PPs into four major types designated types 1, 2A, 2B and 2C (PP1, PP2A, PP2B and PP2C, respectively. Comparison of sequences within their catalytic domains has indicated that PP1, PP2A and PP2B are members of the same gene family named PPP. On the other hand, the type 2C enzyme does not share sequence homology with the PPP members and thus represents another gene family, known as PPM. In this report we briefly summarize some of our studies about the role of serine/threonine phosphatases in growth and differentiation of three different eukaryotic models: Blastocladiella emersonii, Neurospora crassa and Dictyostelium discoideum. Our observations suggest that PP2C is the major phosphatase responsible for dephosphorylation of amidotransferase, an enzyme that controls cell wall synthesis during Blastocladiella emersonii zoospore germination. We also report the existence of a novel acid- and thermo-stable protein purified from Neurospora crassa mycelia, which specifically inhibits the PP1 activity of this fungus and mammals. Finally, we comment on our recent results demonstrating that Dictyostelium discoideum expresses a gene that codes for PP1, although this activity has never been demonstrated biochemically in this organism.

  6. Earth's earliest non-marine eukaryotes.

    Science.gov (United States)

    Strother, Paul K; Battison, Leila; Brasier, Martin D; Wellman, Charles H

    2011-05-26

    The existence of a terrestrial Precambrian (more than 542 Myr ago) biota has been largely inferred from indirect chemical and geological evidence associated with palaeosols, the weathering of clay minerals and microbially induced sedimentary structures in siliciclastic sediments. Direct evidence of fossils within rocks of non-marine origin in the Precambrian is exceedingly rare. The most widely cited example comprises a single report of morphologically simple mineralized tubes and spheres interpreted as cyanobacteria, obtained from 1,200-Myr-old palaeokarst in Arizona. Organic-walled microfossils were first described from the non-marine Torridonian (1.2-1.0 Gyr ago) sequence of northwest Scotland in 1907. Subsequent studies found few distinctive taxa-a century later, the Torridonian microflora is still being characterized as primarily nondescript "leiospheres". We have comprehensively sampled grey shales and phosphatic nodules throughout the Torridonian sequence. Here we report the recovery of large populations of diverse organic-walled microfossils extracted by acid maceration, complemented by studies using thin sections of phosphatic nodules that yield exceptionally detailed three-dimensional preservation. These assemblages contain multicellular structures, complex-walled cysts, asymmetric organic structures, and dorsiventral, compressed organic thalli, some approaching one millimetre in diameter. They offer direct evidence of eukaryotes living in freshwater aquatic and subaerially exposed habitats during the Proterozoic era. The apparent dominance of eukaryotes in non-marine settings by 1 Gyr ago indicates that eukaryotic evolution on land may have commenced far earlier than previously thought. PMID:21490597

  7. Prokaryotes versus Eukaryotes: Who is hosting whom?

    Directory of Open Access Journals (Sweden)

    Guillermo eTellez

    2014-10-01

    Full Text Available Microorganisms represent the largest component of biodiversity in our world. For millions of years, prokaryotic microorganisms have functioned as a major selective force shaping eukaryotic evolution. Microbes that live inside and on animals outnumber the animals’ actual somatic and germ cells by an estimated 10-fold. Collectively, the intestinal microbiome represents a ‘forgotten organ’, functioning as an organ inside another that can execute many physiological responsibilities. The nature of primitive eukaryotes was drastically changed due to the association with symbiotic prokaryotes facilitating mutual coevolution of host and microbe. Phytophagous insects have long been used to test theories of evolutionary diversification; moreover, the diversification of a number of phytophagous insect lineages has been linked to mutualisms with microbes. From termites and honey bees to ruminants and mammals, depending on novel biochemistries provided by the prokaryotic microbiome, the association helps to metabolize several nutrients that the host cannot digest and converting these into useful end products (such as short chain fatty acids, a process which has huge impact on the biology and homeostasis of metazoans. More importantly, in a direct and/or indirect way, the intestinal microbiota influences the assembly of gut-associated lymphoid tissue, helps to educate immune system, affects the integrity of the intestinal mucosal barrier, modulates proliferation and differentiation of its epithelial lineages, regulates angiogenesis, and modifies the activity of enteric as well as the central nervous system,. Despite these important effects, the mechanisms by which the gut microbial community influences the host’s biology remains almost entirely unknown. Our aim here is to encourage empirical inquiry into the relationship between mutualism and evolutionary diversification between prokaryotes and eukaryotes which encourage us to postulate: Who is

  8. Automation Security

    OpenAIRE

    Mirzoev, Dr. Timur

    2014-01-01

    Web-based Automated Process Control systems are a new type of applications that use the Internet to control industrial processes with the access to the real-time data. Supervisory control and data acquisition (SCADA) networks contain computers and applications that perform key functions in providing essential services and commodities (e.g., electricity, natural gas, gasoline, water, waste treatment, transportation) to all Americans. As such, they are part of the nation s critical infrastructu...

  9. Structural Studies of RNA Helicases Involved in Eukaryotic Pre-mRNA Splicing, Ribosome Biogenesis, and Translation Initiation

    DEFF Research Database (Denmark)

    He, Yangzi

    Ribonucleic acids (RNAs) take centre stage in gene expression. In eukaryotes, most RNAs are transcribed as precursors, and these precursors are co- or post-transcriptionally processed and assemble with particular proteins to form ribonucleoproteins (RNPs). Mature RNPs participate in various gene...... expression events, are then subject to recycling, disassembly or degradation. RNA helicases are highly conserved enzymes that use ATP to bind or remodel RNA or RNPs. They function in nearly every aspect of eukaryotic RNA metabolism. The spliceosome catalyzes pre-mRNAs splicing, which removes introns and...

  10. Initiation of translation in bacteria by a structured eukaryotic IRES RNA.

    Science.gov (United States)

    Colussi, Timothy M; Costantino, David A; Zhu, Jianyu; Donohue, John Paul; Korostelev, Andrei A; Jaafar, Zane A; Plank, Terra-Dawn M; Noller, Harry F; Kieft, Jeffrey S

    2015-03-01

    The central dogma of gene expression (DNA to RNA to protein) is universal, but in different domains of life there are fundamental mechanistic differences within this pathway. For example, the canonical molecular signals used to initiate protein synthesis in bacteria and eukaryotes are mutually exclusive. However, the core structures and conformational dynamics of ribosomes that are responsible for the translation steps that take place after initiation are ancient and conserved across the domains of life. We wanted to explore whether an undiscovered RNA-based signal might be able to use these conserved features, bypassing mechanisms specific to each domain of life, and initiate protein synthesis in both bacteria and eukaryotes. Although structured internal ribosome entry site (IRES) RNAs can manipulate ribosomes to initiate translation in eukaryotic cells, an analogous RNA structure-based mechanism has not been observed in bacteria. Here we report our discovery that a eukaryotic viral IRES can initiate translation in live bacteria. We solved the crystal structure of this IRES bound to a bacterial ribosome to 3.8 Å resolution, revealing that despite differences between bacterial and eukaryotic ribosomes this IRES binds directly to both and occupies the space normally used by transfer RNAs. Initiation in both bacteria and eukaryotes depends on the structure of the IRES RNA, but in bacteria this RNA uses a different mechanism that includes a form of ribosome repositioning after initial recruitment. This IRES RNA bridges billions of years of evolutionary divergence and provides an example of an RNA structure-based translation initiation signal capable of operating in two domains of life. PMID:25652826

  11. Convergent use of RhoGAP toxins by eukaryotic parasites and bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    Dominique Colinet

    2007-12-01

    Full Text Available Inactivation of host Rho GTPases is a widespread strategy employed by bacterial pathogens to manipulate mammalian cellular functions and avoid immune defenses. Some bacterial toxins mimic eukaryotic Rho GTPase-activating proteins (GAPs to inactivate mammalian GTPases, probably as a result of evolutionary convergence. An intriguing question remains whether eukaryotic pathogens or parasites may use endogenous GAPs as immune-suppressive toxins to target the same key genes as bacterial pathogens. Interestingly, a RhoGAP domain-containing protein, LbGAP, was recently characterized from the parasitoid wasp Leptopilina boulardi, and shown to protect parasitoid eggs from the immune response of Drosophila host larvae. We demonstrate here that LbGAP has structural characteristics of eukaryotic RhoGAPs but that it acts similarly to bacterial RhoGAP toxins in mammals. First, we show by immunocytochemistry that LbGAP enters Drosophila immune cells, plasmatocytes and lamellocytes, and that morphological changes in lamellocytes are correlated with the quantity of LbGAP they contain. Demonstration that LbGAP displays a GAP activity and specifically interacts with the active, GTP-bound form of the two Drosophila Rho GTPases Rac1 and Rac2, both required for successful encapsulation of Leptopilina eggs, was then achieved using biochemical tests, yeast two-hybrid analysis, and GST pull-down assays. In addition, we show that the overall structure of LbGAP is similar to that of eukaryotic RhoGAP domains, and we identify distinct residues involved in its interaction with Rac GTPases. Altogether, these results show that eukaryotic parasites can use endogenous RhoGAPs as virulence factors and that despite their differences in sequence and structure, eukaryotic and bacterial RhoGAP toxins are similarly used to target the same immune pathways in insects and mammals.

  12. CONSTRUCTION OF EUKARYOTIC EXPRESSION VECTOR FOR HUMAN CCL21 AND CHARACTERIZATION OF ITS CHEMOTACTIC ACTIVITY

    Institute of Scientific and Technical Information of China (English)

    HOU Li; LIU Qi; JIAO Yu-lian; ZHANG Jie; WANG Lai-cheng; MA Chun-yan; CUI Bin; ZHANG Xue; ZHAO Yue-ran

    2006-01-01

    Objective: To obtain recombinant human CCL21 with biological activity from eukaryotic expression system for further use in cancer gene therapy. Methods: A fragment of human CCL21 gene was obtained from pSK-hCCL21 plasmid digested by Xho I and BamH I, inserted into the responding sites of eukaryotic expression vector pVAX1, and then transfected into COS-7 cells by electroporation method. The expression of hCCL21 protein was detected by western blotting analysis. The in vitro chemotaxis assay was used to test the chemotactic function of the expression product to lymphocytes. Results: Human CCL21 protein was expressed by transfected COS-7 cells with recombinant plasmid containing hCCL21 gene, and was verified by western blotting. The in vitro chemotaxis assay demonstrated that human CCL21 protein had a potent chemotactic function to lymphocytes. Conclusion: Human CCL21 was successfully and transiently expressed in eukaryotic cells, which lays some foundation for the study of CCL21 gene therapy in murine tumor models.

  13. Phosphorylation Stoichiometries of Human Eukaryotic Initiation Factors

    Directory of Open Access Journals (Sweden)

    Armann Andaya

    2014-06-01

    Full Text Available Eukaryotic translation initiation factors are the principal molecular effectors regulating the process converting nucleic acid to functional protein. Commonly referred to as eIFs (eukaryotic initiation factors, this suite of proteins is comprised of at least 25 individual subunits that function in a coordinated, regulated, manner during mRNA translation. Multiple facets of eIF regulation have yet to be elucidated; however, many of the necessary protein factors are phosphorylated. Herein, we have isolated, identified and quantified phosphosites from eIF2, eIF3, and eIF4G generated from log phase grown HeLa cell lysates. Our investigation is the first study to globally quantify eIF phosphosites and illustrates differences in abundance of phosphorylation between the residues of each factor. Thus, identification of those phosphosites that exhibit either high or low levels of phosphorylation under log phase growing conditions may aid researchers to concentrate their investigative efforts to specific phosphosites that potentially harbor important regulatory mechanisms germane to mRNA translation.

  14. Consistent mutational paths predict eukaryotic thermostability

    Directory of Open Access Journals (Sweden)

    van Noort Vera

    2013-01-01

    Full Text Available Abstract Background Proteomes of thermophilic prokaryotes have been instrumental in structural biology and successfully exploited in biotechnology, however many proteins required for eukaryotic cell function are absent from bacteria or archaea. With Chaetomium thermophilum, Thielavia terrestris and Thielavia heterothallica three genome sequences of thermophilic eukaryotes have been published. Results Studying the genomes and proteomes of these thermophilic fungi, we found common strategies of thermal adaptation across the different kingdoms of Life, including amino acid biases and a reduced genome size. A phylogenetics-guided comparison of thermophilic proteomes with those of other, mesophilic Sordariomycetes revealed consistent amino acid substitutions associated to thermophily that were also present in an independent lineage of thermophilic fungi. The most consistent pattern is the substitution of lysine by arginine, which we could find in almost all lineages but has not been extensively used in protein stability engineering. By exploiting mutational paths towards the thermophiles, we could predict particular amino acid residues in individual proteins that contribute to thermostability and validated some of them experimentally. By determining the three-dimensional structure of an exemplar protein from C. thermophilum (Arx1, we could also characterise the molecular consequences of some of these mutations. Conclusions The comparative analysis of these three genomes not only enhances our understanding of the evolution of thermophily, but also provides new ways to engineer protein stability.

  15. Extremophilic Eukaryote Life in Hawaiian Fumaroles

    Science.gov (United States)

    Ackerman, C.; Anderson, S.; Anderson, C.

    2008-12-01

    Extremophilic microorganisms exist in all three domains of life (Eukarya, Archaea, Bacteria), but are less known in eukaryotes. Fumaroles provide heat and moisture characteristic of an environment suitable for these organisms. On the Island of Hawaii, fumaroles are scattered across the southeastern portion of the island as a result of the volcanic activity from Kilauea Crater and Pu'u' O'o vent with all forming within geochemically similar basalt substrates. We used metagenomics to detect 18S rDNA from eukaryotic extremophilic microorganisms indicating their presence in Hawaiian fumaroles. To determine the effects of environmental gradients (temperature and pH) on microbial diversity within and among fumaroles, 11 samples from 3 fumaroles were collected over a three-day period in February of 2007. Temperatures of the different fumaroles range from 31.0oC to 62.7oC, with pH values that vary from 2.55 to 6.93 allowing for 8 different microenvironments. Fifty sequences per sample were analyzed with eighteen different organisms identified, the majority belonging to the family Cercozoa. The most diverse fumarole consisted of 8 different genera residing in a temperature of 34.1oC and a pH of 3.0. Unclassified mosses were identified in the fumarole with the highest temperature and Phaeoceros (hornworts) were identified at the most acidic fumarole. Both of these groups have been previously identified in geothermal areas.

  16. Strong eukaryotic IRESs have weak secondary structure.

    Directory of Open Access Journals (Sweden)

    Xuhua Xia

    Full Text Available BACKGROUND: The objective of this work was to investigate the hypothesis that eukaryotic Internal Ribosome Entry Sites (IRES lack secondary structure and to examine the generality of the hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: IRESs of the yeast and the fruit fly are located in the 5'UTR immediately upstream of the initiation codon. The minimum folding energy (MFE of 60 nt RNA segments immediately upstream of the initiation codons was calculated as a proxy of secondary structure stability. MFE of the reverse complements of these 60 nt segments was also calculated. The relationship between MFE and empirically determined IRES activity was investigated to test the hypothesis that strong IRES activity is associated with weak secondary structure. We show that IRES activity in the yeast and the fruit fly correlates strongly with the structural stability, with highest IRES activity found in RNA segments that exhibit the weakest secondary structure. CONCLUSIONS: We found that a subset of eukaryotic IRESs exhibits very low secondary structure in the 5'-UTR sequences immediately upstream of the initiation codon. The consistency in results between the yeast and the fruit fly suggests a possible shared mechanism of cap-independent translation initiation that relies on an unstructured RNA segment.

  17. Protein Acetylation in Archaea, Bacteria, and Eukaryotes

    Directory of Open Access Journals (Sweden)

    Jörg Soppa

    2010-01-01

    Full Text Available Proteins can be acetylated at the alpha-amino group of the N-terminal amino acid (methionine or the penultimate amino acid after methionine removal or at the epsilon-amino group of internal lysines. In eukaryotes the majority of proteins are N-terminally acetylated, while this is extremely rare in bacteria. A variety of studies about N-terminal acetylation in archaea have been reported recently, and it was revealed that a considerable fraction of proteins is N-terminally acetylated in haloarchaea and Sulfolobus, while this does not seem to apply for methanogenic archaea. Many eukaryotic proteins are modified by differential internal acetylation, which is important for a variety of processes. Until very recently, only two bacterial proteins were known to be acetylation targets, but now 125 acetylation sites are known for E. coli. Knowledge about internal acetylation in archaea is extremely limited; only two target proteins are known, only one of which—Alba—was used to study differential acetylation. However, indications accumulate that the degree of internal acetylation of archaeal proteins might be underestimated, and differential acetylation has been shown to be essential for the viability of haloarchaea. Focused proteomic approaches are needed to get an overview of the extent of internal protein acetylation in archaea.

  18. The scanning mechanism of eukaryotic translation initiation.

    Science.gov (United States)

    Hinnebusch, Alan G

    2014-01-01

    In eukaryotes, the translation initiation codon is generally identified by the scanning mechanism, wherein every triplet in the messenger RNA leader is inspected for complementarity to the anticodon of methionyl initiator transfer RNA (Met-tRNAi). Binding of Met-tRNAi to the small (40S) ribosomal subunit, in a ternary complex (TC) with eIF2-GTP, is stimulated by eukaryotic initiation factor 1 (eIF1), eIF1A, eIF3, and eIF5, and the resulting preinitiation complex (PIC) joins the 5' end of mRNA preactivated by eIF4F and poly(A)-binding protein. RNA helicases remove secondary structures that impede ribosome attachment and subsequent scanning. Hydrolysis of eIF2-bound GTP is stimulated by eIF5 in the scanning PIC, but completion of the reaction is impeded at non-AUG triplets. Although eIF1 and eIF1A promote scanning, eIF1 and possibly the C-terminal tail of eIF1A must be displaced from the P decoding site to permit base-pairing between Met-tRNAi and the AUG codon, as well as to allow subsequent phosphate release from eIF2-GDP. A second GTPase, eIF5B, catalyzes the joining of the 60S subunit to produce an 80S initiation complex that is competent for elongation. PMID:24499181

  19. Identification of selenocyst- eine insertion sequence (SECIS) element in eukaryotic selenoproteins by RNA Draw program

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The computer program RNA Draw was used to identify the secondary structures in the 3′ untranslated re- gions (3′UTRs) of the mRNAs from 46 eukaryotic seleno- proteins among 7 species. The program found one or two possible SECIS elements in these selenoproteins. The SECIS element consists of a stem-loop or hairpin structure with three conserved sequences of AUGA-(A)AA-GA. SECIS element was not found by the RNA Draw program in randomly selected non-selenoproteins. The results showed that SECIS element is the unique character of the genes of eukaryotic selenoproteins. Thus it is possible to use RNA Draw to search the SECIS elements in gene bank for poten- tial new selenoproteins.

  20. EuCAP, a Eukaryotic Community Annotation Package, and its application to the rice genome

    OpenAIRE

    Hamilton John P; Campbell Matthew; Thibaud-Nissen Françoise; Zhu Wei; Buell C

    2007-01-01

    Abstract Background Despite the improvements of tools for automated annotation of genome sequences, manual curation at the structural and functional level can provide an increased level of refinement to genome annotation. The Institute for Genomic Research Rice Genome Annotation (hereafter named the Osa1 Genome Annotation) is the product of an automated pipeline and, for this reason, will benefit from the input of biologists with expertise in rice and/or particular gene families. Leveraging k...

  1. An Ariadne's thread to the identification and annotation of noncoding RNAs in eukaryotes

    OpenAIRE

    Solda, Giulia; Makunin, Igor V; Sezerman, Uğur; Sezerman, Ugur; Corradin, Alberto; Corti, Giorgio; Guffanti, Alessandro

    2009-01-01

    Non-protein coding RNAs (ncRNAs) have emerged as a vast and heterogeneous portion of eukaryotic transcriptomes. Several ncRNA families, either short (200 nt), have been described and implicated in a variety of biological processes, from translation to gene expression regulation and nuclear trafficking. Most probably, other families are still to be discovered. Computational methods for ncRNA research require different approaches from the ones normally used in the prediction of protein-coding g...

  2. High Genetic Diversity and Novelty in Eukaryotic Plankton Assemblages Inhabiting Saline Lakes in the Qaidam Basin

    OpenAIRE

    WANG, Jiali; Wang, Fang; Chu, Limin; Wang, Hao; Zhong, Zhiping; Liu, Zhipei; Gao, Jianyong; Duan, Hairong

    2014-01-01

    Saline lakes are intriguing ecosystems harboring extremely productive microbial communities in spite of their extreme environmental conditions. We performed a comprehensive analysis of the genetic diversity (18S rRNA gene) of the planktonic microbial eukaryotes (nano- and picoeukaryotes) in six different inland saline lakes located in the Qaidam Basin. The novelty level are high, with about 11.23% of the whole dataset showing

  3. A Physical Model for the Condensation and Decondensation of Eukaryotic Chromosomes

    OpenAIRE

    Mozziconacci, Julien; Lavelle, Christophe; Barbi, Maria; Lesne, Annick; Victor, Jean-Marc

    2005-01-01

    During the eukaryotic cell cycle, chromatin undergoes several conformational changes, which are believed to play key roles in gene expression regulation during interphase, and in genome replication and division during mitosis. In this paper, we propose a scenario for chromatin structural reorganization during mitosis, which bridges all the different scales involved in chromatin architecture, from nucleosomes to chromatin loops. We build a model for chromatin, based on available data, taking i...

  4. Unraveling adaptation in eukaryotic pathways: lessons from protocells.

    OpenAIRE

    Giovanna De Palo; Robert G Endres

    2013-01-01

    Eukaryotic adaptation pathways operate within wide-ranging environmental conditions without stimulus saturation. Despite numerous differences in the adaptation mechanisms employed by bacteria and eukaryotes, all require energy consumption. Here, we present two minimal models showing that expenditure of energy by the cell is not essential for adaptation. Both models share important features with large eukaryotic cells: they employ small diffusible molecules and involve receptor subunits resemb...

  5. Widespread 3′-end uridylation in eukaryotic RNA viruses

    OpenAIRE

    Huo, Yayun; Shen, Jianguo; Wu, Huanian; Zhang, Chao; Guo, Lihua; Yang, Jinguang; Weimin LI

    2016-01-01

    RNA 3′ uridylation occurs pervasively in eukaryotes, but is poorly characterized in viruses. In this study, we demonstrate that a broad array of RNA viruses, including mycoviruses, plant viruses and animal viruses, possess a novel population of RNA species bearing nontemplated oligo(U) or (U)-rich tails, suggesting widespread 3′ uridylation in eukaryotic viruses. Given the biological relevance of 3′ uridylation to eukaryotic RNA degradation, we propose a conserved but as-yet-unknown mechanism...

  6. High-resolution statistical mapping reveals gene territories in live yeast.

    Science.gov (United States)

    Berger, Axel B; Cabal, Ghislain G; Fabre, Emmanuelle; Duong, Tarn; Buc, Henri; Nehrbass, Ulf; Olivo-Marin, Jean-Christophe; Gadal, Olivier; Zimmer, Christophe

    2008-12-01

    The nonrandom positioning of genes inside eukaryotic cell nuclei is implicated in central nuclear functions. However, the spatial organization of the genome remains largely uncharted, owing to limited resolution of optical microscopy, paucity of nuclear landmarks and moderate cell sampling. We developed a computational imaging approach that creates high-resolution probabilistic maps of subnuclear domains occupied by individual loci in budding yeast through automated analysis of thousands of living cells. After validation, we applied the technique to genes involved in galactose metabolism and ribosome biogenesis. We found that genomic loci are confined to 'gene territories' much smaller than the nucleus, which can be remodeled during transcriptional activation, and that the nucleolus is an important landmark for gene positioning. The technique can be used to visualize and quantify territory positions relative to each other and to nuclear landmarks, and should advance studies of nuclear architecture and function. PMID:18978785

  7. EuMicroSatdb: A database for microsatellites in the sequenced genomes of eukaryotes

    Directory of Open Access Journals (Sweden)

    Grover Atul

    2007-07-01

    Full Text Available Abstract Background Microsatellites have immense utility as molecular markers in different fields like genome characterization and mapping, phylogeny and evolutionary biology. Existing microsatellite databases are of limited utility for experimental and computational biologists with regard to their content and information output. EuMicroSatdb (Eukaryotic MicroSatellite database http://ipu.ac.in/usbt/EuMicroSatdb.htm is a web based relational database for easy and efficient positional mining of microsatellites from sequenced eukaryotic genomes. Description A user friendly web interface has been developed for microsatellite data retrieval using Active Server Pages (ASP. The backend database codes for data extraction and assembly have been written using Perl based scripts and C++. Precise need based microsatellites data retrieval is possible using different input parameters like microsatellite type (simple perfect or compound perfect, repeat unit length (mono- to hexa-nucleotide, repeat number, microsatellite length and chromosomal location in the genome. Furthermore, information about clustering of different microsatellites in the genome can also be retrieved. Finally, to facilitate primer designing for PCR amplification of any desired microsatellite locus, 200 bp upstream and downstream sequences are provided. Conclusion The database allows easy systematic retrieval of comprehensive information about simple and compound microsatellites, microsatellite clusters and their locus coordinates in 31 sequenced eukaryotic genomes. The information content of the database is useful in different areas of research like gene tagging, genome mapping, population genetics, germplasm characterization and in understanding microsatellite dynamics in eukaryotic genomes.

  8. Are maternal mitochondria the selfish entities that are masters of the cells of eukaryotic multicellular organisms?

    Science.gov (United States)

    Agnati, Luigi F; Barlow, Peter W; Baldelli, E; Baluska, Frantisek

    2009-01-01

    The Energide concept, as well as the endosymbiotic theory of eukaryotic cell organization and evolution, proposes that present-day cells of eukaryotic organisms are mosaics of specialized and cooperating units, or organelles. Some of these units were originally free-living prokaryotes, which were engulfed during evolutionary time. Mitochondria represent one of these types of previously independent organisms, the Energide, is another type. This new perspective on the organization of the cell has been further expanded to reveal the concept of a public milieu, the cytosol, in which Energides and mitochondria live, each with their own private internal milieu. The present paper discusses how the endosymbiotic theory implicates a new hypothesis about the hierarchical and communicational organization of the integrated prokaryotic components of the eukaryotic cell and provides a new angle from which to consider the theory of evolution and its bearing upon cellular complexity. Thus, it is proposed that the "selfish gene" hypothesis of Dawkins1 is not the only possible perspective for comprehending genomic and cellular evolution. Our proposal is that maternal mitochondria are the selfish "master" entities of the eukaryotic cell with respect not only to their propagation from cell-to-cell and from generation-to-generation but also to their regulation of all other cellular functions. However, it should be recognized that the concept of "master" and "servant" cell components is a metaphor; in present-day living organisms their organellar components are considered to be interdependent and inseparable. PMID:19513277

  9. Avian leukosis virus is a versatile eukaryotic platform for polypeptide display

    International Nuclear Information System (INIS)

    Display technology refers to methods of generating libraries of modularly coded biomolecules and screening them for particular properties. Retroviruses are good candidates to be a eukaryotic viral platform for the display of polypeptides synthesized in eukaryotic cells. Here we demonstrate that avian leukosis virus (ALV) provides an ideal platform for display of nonviral polyaeptides expressed in a eukaryotic cell substrate. Different sizes of polypeptides were genetically fused to the extreme N-terminus of the ALV envelope glycoprotein in an ALV infectious clone containing an alkaline phosphatase reporter gene. The chimeric envelope glycoproteins were efficiently incorporated into virions and were stably displayed on the surface of the virions through multiple virus replication cycles. The foreign polypeptides did not interfere with the attachment and entry functions of the underlying ALV envelope glycoproteins. The displayed polypeptides were fully functional and could efficiently mediate attachment of the recombinant viruses to their respective cognate receptors. This study demonstrates that ALV is an ideal display platform for the generation and selection of libraries of polypeptides where there is a need for expression, folding, and posttranslational modification in the endoplasmic reticulum of eukaryotic cells

  10. Eukaryotic Ribosome Assembly and Nuclear Export.

    Science.gov (United States)

    Nerurkar, Purnima; Altvater, Martin; Gerhardy, Stefan; Schütz, Sabina; Fischer, Ute; Weirich, Christine; Panse, Vikram Govind

    2015-01-01

    Accurate translation of the genetic code into functional polypeptides is key to cellular growth and proliferation. This essential process is carried out by the ribosome, a ribonucleoprotein complex of remarkable size and intricacy. Although the structure of the mature ribosome has provided insight into the mechanism of translation, our knowledge regarding the assembly, quality control, and intracellular targeting of this molecular machine is still emerging. Assembly of the eukaryotic ribosome begins in the nucleolus and requires more than 350 conserved assembly factors, which transiently associate with the preribosome at specific maturation stages. After accomplishing their tasks, early-acting assembly factors are released, preparing preribosomes for nuclear export. Export competent preribosomal subunits are transported through nuclear pore complexes into the cytoplasm, where they undergo final maturation steps, which are closely connected to quality control, before engaging in translation. In this chapter, we focus on the final events that commit correctly assembled ribosomal subunits for translation. PMID:26404467

  11. Bacterial proteins pinpoint a single eukaryotic root

    Czech Academy of Sciences Publication Activity Database

    Derelle, R.; Torruella, G.; Klimeš, V.; Brinkmann, H.; Kim, E.; Vlček, Čestmír; Lang, B.F.; Eliáš, M.

    2015-01-01

    Roč. 112, č. 7 (2015), E693-E699. ISSN 0027-8424 R&D Projects: GA ČR GA13-24983S Grant ostatní: GA MŠk(CZ) ED2.1.00/03.0100; Howard Hughes Medical Institute International Early Career Scientist Program(US) 55007424; Spanish Ministry of Economy and Competitiveness, European Molecular Biology Organization Young Investigator Program(ES) BFU2012-31329; Spanish Ministry of Economy and Competitiveness, "Centro de Excelencia Severo Ochoa" - European Regional Development Fund(ES) Sev-2012-0208, BES-2013-064004 Institutional support: RVO:68378050 Keywords : eukaryote phylogeny * phylogenomics * Opimoda * Diphoda * LECA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.674, year: 2014

  12. Protein splicing and its evolution in eukaryotes

    Directory of Open Access Journals (Sweden)

    Starokadomskyy P. L.

    2010-02-01

    Full Text Available Inteins, or protein introns, are parts of protein sequences that are post-translationally excised, their flanking regions (exteins being spliced together. This process was called protein splicing. Originally inteins were found in prokaryotic or unicellular eukaryotic organisms. But the general principles of post-translation protein rearrangement are evolving yielding different post-translation modification of proteins in multicellular organisms. For clarity, these non-intein mediated events call either protein rearrangements or protein editing. The most intriguing example of protein editing is proteasome-mediated splicing of antigens in vertebrates that may play important role in antigen presentation. Other examples of protein rearrangements are maturation of Hg-proteins (critical receptors in embryogenesis as well as maturation of several metabolic enzymes. Despite a lack of experimental data we try to analyze some intriguing examples of protein splicing evolution.

  13. Eukaryotic protein production in designed storage organelles

    Directory of Open Access Journals (Sweden)

    Saloheimo Markku

    2009-01-01

    Full Text Available Abstract Background Protein bodies (PBs are natural endoplasmic reticulum (ER or vacuole plant-derived organelles that stably accumulate large amounts of storage proteins in seeds. The proline-rich N-terminal domain derived from the maize storage protein γ zein (Zera is sufficient to induce PBs in non-seed tissues of Arabidopsis and tobacco. This Zera property opens up new routes for high-level accumulation of recombinant proteins by fusion of Zera with proteins of interest. In this work we extend the advantageous properties of plant seed PBs to recombinant protein production in useful non-plant eukaryotic hosts including cultured fungal, mammalian and insect cells. Results Various Zera fusions with fluorescent and therapeutic proteins accumulate in induced PB-like organelles in all eukaryotic systems tested: tobacco leaves, Trichoderma reesei, several mammalian cultured cells and Sf9 insect cells. This accumulation in membranous organelles insulates both recombinant protein and host from undesirable activities of either. Recombinant protein encapsulation in these PBs facilitates stable accumulation of proteins in a protected sub-cellular compartment which results in an enhancement of protein production without affecting the viability and development of stably transformed hosts. The induced PBs also retain the high-density properties of native seed PBs which facilitate the recovery and purification of the recombinant proteins they contain. Conclusion The Zera sequence provides an efficient and universal means to produce recombinant proteins by accumulation in ER-derived organelles. The remarkable cross-kingdom conservation of PB formation and their biophysical properties should have broad application in the manufacture of non-secreted recombinant proteins and suggests the existence of universal ER pathways for protein insulation.

  14. Structure and diversity of bacterial, eukaryotic and archaeal communities in glacial cryoconite holes from the Arctic and the Antarctic.

    Science.gov (United States)

    Cameron, Karen A; Hodson, Andrew J; Osborn, A Mark

    2012-11-01

    The cryosphere presents some of the most challenging conditions for life on earth. Nevertheless, (micro)biota survive in a range of niches in glacial systems, including water-filled depressions on glacial surfaces termed cryoconite holes (centimetre to metre in diameter and up to 0.5 m deep) that contain dark granular material (cryoconite). In this study, the structure of bacterial and eukaryotic cryoconite communities from ten different locations in the Arctic and Antarctica was compared using T-RFLP analysis of rRNA genes. Community structure varied with geography, with greatest differences seen between communities from the Arctic and the Antarctic. DNA sequencing of rRNA genes revealed considerable diversity, with individual cryoconite hole communities containing between six and eight bacterial phyla and five and eight eukaryotic 'first-rank' taxa and including both bacterial and eukaryotic photoautotrophs. Bacterial Firmicutes and Deltaproteobacteria and Epsilonproteobacteria, eukaryotic Rhizaria, Haptophyta, Choanomonada and Centroheliozoa, and archaea were identified for the first time in cryoconite ecosystems. Archaea were only found within Antarctic locations, with the majority of sequences (77%) related to members of the Thaumarchaeota. In conclusion, this research has revealed that Antarctic and Arctic cryoconite holes harbour geographically distinct highly diverse communities and has identified hitherto unknown bacterial, eukaryotic and archaeal taxa, therein. PMID:22168226

  15. Horizontal gene transfer in fungi

    OpenAIRE

    Fitzpatrick, David A.

    2011-01-01

    Horizontal gene transfer (HGT) is frequently observed in prokaryotes and until recently was assumed to be of limited importance to eukaryotes. However, there is an increasing body of evidence to suggest that HGT is an important mechanism in eukaryotic genome evolution, particularly in unicellular organisms. The transfer of individual genes, gene clusters or entire chromosomes can have significant impacts on niche specification, disease emergence or shift in metabolic capabil...

  16. Automated Budget System

    Data.gov (United States)

    Department of Transportation — The Automated Budget System (ABS) automates management and planning of the Mike Monroney Aeronautical Center (MMAC) budget by providing enhanced capability to plan,...

  17. MetWAMer: eukaryotic translation initiation site prediction

    Directory of Open Access Journals (Sweden)

    Brendel Volker

    2008-09-01

    Full Text Available Abstract Background Translation initiation site (TIS identification is an important aspect of the gene annotation process, requisite for the accurate delineation of protein sequences from transcript data. We have developed the MetWAMer package for TIS prediction in eukaryotic open reading frames of non-viral origin. MetWAMer can be used as a stand-alone, third-party tool for post-processing gene structure annotations generated by external computational programs and/or pipelines, or directly integrated into gene structure prediction software implementations. Results MetWAMer currently implements five distinct methods for TIS prediction, the most accurate of which is a routine that combines weighted, signal-based translation initiation site scores and the contrast in coding potential of sequences flanking TISs using a perceptron. Also, our program implements clustering capabilities through use of the k-medoids algorithm, thereby enabling cluster-specific TIS parameter utilization. In practice, our static weight array matrix-based indexing method for parameter set lookup can be used with good results in data sets exhibiting moderate levels of 5'-complete coverage. Conclusion We demonstrate that improvements in statistically-based models for TIS prediction can be achieved by taking the class of each potential start-methionine into account pending certain testing conditions, and that our perceptron-based model is suitable for the TIS identification task. MetWAMer represents a well-documented, extensible, and freely available software system that can be readily re-trained for differing target applications and/or extended with existing and novel TIS prediction methods, to support further research efforts in this area.

  18. Biomolecular engineering of intracellular switches in eukaryotes

    OpenAIRE

    Pastuszka, M.K.; Mackay, J.A.

    2010-01-01

    Tools to selectively and reversibly control gene expression are useful to study and model cellular functions. When optimized, these cellular switches can turn a protein's function “on” and “off” based on cues designated by the researcher. These cues include small molecules, drugs, hormones, and even temperature variations. Here we review three distinct areas in gene expression that are commonly targeted when designing cellular switches. Transcriptional switches target gene expression at the l...

  19. Diversity and distribution of microbial eukaryotes in the deep tropical and subtropical North Atlantic Ocean

    Science.gov (United States)

    Morgan-Smith, Danielle; Clouse, Melissa A.; Herndl, Gerhard J.; Bochdansky, Alexander B.

    2013-08-01

    Employing a combination of 4',6-diamidino-2-phenylindole and fluorescein isothiocyanate (DAPI-FITC) staining and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH), we distinguished a variety of taxonomic and morphological types of eukaryotic microbes in the central and deep water masses of the tropical and subtropical North Atlantic Ocean. Samples were taken along a transect across the tropical Atlantic, along the equatorial upwelling and into the West-African upwelling region. Samples were collected as deep as 7000 m in the Romanche Fracture Zone within the Mid-Atlantic Ridge. Approximately 50-70% of FISH-identified eukaryotes in deep water masses belong to one of seven groups: kinetoplastids, labyrinthulomycetes, fungi, diplonemids, group II alveolates, MAST 4 (stramenopiles), and an unidentified organism with a peculiar nuclear morphology. A smaller percentage of total eukaryotes was identified in the Central Water, especially in the oxygen minimum zone, than in deep water masses. CARD-FISH probes designed to identify broad taxonomic groups revealed kinetoplastids and fungi were more abundant than noted in previous studies employing 18S rRNA gene clone libraries. Group II alveolates, in contrast, were much less prevalent than previously reported. On a second survey, eukaryotic microbes were enumerated in the deep-sea basins below the North Atlantic subtropical gyre including the Vema Fracture Zone, which is another prominent trench in the Mid-Atlantic Ridge. The abundance of eukaryotes and chlorophyll concentrations were significantly different between the two cruises, which covered very different hydrographic regimes with associated high and low levels of primary production, respectively.

  20. Microbial eukaryote plankton communities of high-mountain lakes from three continents exhibit strong biogeographic patterns.

    Science.gov (United States)

    Filker, Sabine; Sommaruga, Ruben; Vila, Irma; Stoeck, Thorsten

    2016-05-01

    Microbial eukaryotes hold a key role in aquatic ecosystem functioning. Yet, their diversity in freshwater lakes, particularly in high-mountain lakes, is relatively unknown compared with the marine environment. Low nutrient availability, low water temperature and high ultraviolet radiation make most high-mountain lakes extremely challenging habitats for life and require specific molecular and physiological adaptations. We therefore expected that these ecosystems support a plankton diversity that differs notably from other freshwater lakes. In addition, we hypothesized that the communities under study exhibit geographic structuring. Our rationale was that geographic dispersal of small-sized eukaryotes in high-mountain lakes over continental distances seems difficult. We analysed hypervariable V4 fragments of the SSU rRNA gene to compare the genetic microbial eukaryote diversity in high-mountain lakes located in the European Alps, the Chilean Altiplano and the Ethiopian Bale Mountains. Microbial eukaryotes were not globally distributed corroborating patterns found for bacteria, multicellular animals and plants. Instead, the plankton community composition emerged as a highly specific fingerprint of a geographic region even on higher taxonomic levels. The intraregional heterogeneity of the investigated lakes was mirrored in shifts in microbial eukaryote community structure, which, however, was much less pronounced compared with interregional beta-diversity. Statistical analyses revealed that on a regional scale, environmental factors are strong predictors for plankton community structures in high-mountain lakes. While on long-distance scales (>10 000 km), isolation by distance is the most plausible scenario, on intermediate scales (up to 6000 km), both contemporary environmental factors and historical contingencies interact to shift plankton community structures. PMID:27029537

  1. 猪TPST1基因的克隆、序列分析及真核表达载体的构建%Cloning, sequence characterization and construction of eukaryotic cell expression vector of TPST1 gene in pig

    Institute of Scientific and Technical Information of China (English)

    别墅; 孙洪涛; 张冬杰; 汪亮; 刘娣

    2011-01-01

    Ctyrosine O-sulfation is a common posttranslational modification of proteins which is mediated tyrosylprotein sulfotransferase. In this study, Porcine TPST1 cDNA was obtained by reverse transcription polymerase chain reaction (RT-PCR), using in silico cloning strategy based on porcine ESTs database, the nucleotide and amino acid sequences were characterized with bioinformatics methods. The length of the cloned porcine TPST1 cDNA was 1 543 bp including a 1 113 bp entire open reading frame (ORF), which encoded a 370 amino acids protein. Multiple sequences alignment and phylogeny analysis indicated that porcine TPST1 protein shared high similarity with that of other species, such as Bos taurus (97.6%), Musmusculus (96.8%), Rattus norvegicus (97%) and Homo sapiens. Protein sequence analysis showed that the deduced porcine TPST1 protein sequence (pl=9.0, MW= 42.13 ku). This study had completed the clone TPST1 of min pig and construction of eukaryotic cell expression vector of pcDNA3.1(+)-TPST1, and providing the theoretical basis for the expression and function research of TPST1 gene in cell.%酪氨酸硫化转移酶(Tyrosylrotein sulfotransferase,TPST)在酪氨酸硫化修饰过程中起调节作用.试验参照人、鼠、牛等动物的TPST1 mRNA全长序列设计引物,通过电子克隆结合RT-RCR的方法首次克隆获得包括完整CDS区的猪TPST1基因cDNA序列(HQ439987),分析其核苷酸序列及其编码蛋白质分子结构特征.结果表明,猪TPST1序列全长1543 bp,包含1113bp的完整开放阅读框,编码370个氨基酸.多序列比对和系统进化分析表明,该基因编码蛋白质与牛(97.6%)、小鼠(96.8%)、大鼠(97%)、人(97.03%)等物种TPST1蛋白质具有较高的一致性.蛋白质序列预测分析发现,猪TPST1氨基酸序列理论等电点(pI)为9.0,相对分子质量(MW)为42.13 ku.

  2. Eukaryotic checkpoints are absent in the cell division cycle of Entamoeba histolytica

    Indian Academy of Sciences (India)

    Sulagna Banerjee; Suchismita Das; Anuradha Lohia

    2002-11-01

    Fidelity in transmission of genetic characters is ensured by the faithful duplication of the genome, followed by equal segregation of the genetic material in the progeny. Thus, alternation of DNA duplication (S-phase) and chromosome segregation during the M-phase are hallmarks of most well studied eukaryotes. Several rounds of genome reduplication before chromosome segregation upsets this cycle and leads to polyploidy. Polyploidy is often witnessed in cells prior to differentiation, in embryonic cells or in diseases such as cancer. Studies on the protozoan parasite, Entamoeba histolytica suggest that in its proliferative phase, this organism may accumulate polyploid cells. It has also been shown that although this organism contains sequence homologs of genes which are known to control the cell cycle of most eukaryotes, these genes may be structurally altered and their equivalent function yet to be demonstrated in amoeba. The available information suggests that surveillance mechanisms or ‘checkpoints’ which are known to regulate the eukaryotic cell cycle may be absent or altered in E. histolytica.

  3. Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications.

    Science.gov (United States)

    Yeo, Chew Chieng; Abu Bakar, Fauziah; Chan, Wai Ting; Espinosa, Manuel; Harikrishna, Jennifer Ann

    2016-02-01

    Toxin-antitoxin (TA) systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies. PMID:26907343

  4. Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications

    Directory of Open Access Journals (Sweden)

    Chew Chieng Yeo

    2016-02-01

    Full Text Available Toxin-antitoxin (TA systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies.

  5. THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS: THE NUCLEAR BODIES (I

    Directory of Open Access Journals (Sweden)

    Cristian Campeanu

    2012-10-01

    Full Text Available Identified short time after the discovery of cells, over 300 years ago, the cell nucleus of eukaryotes continuously focused the interest of scientists, which used increasingly sophisticated research tools to clarify its complex structure and functions. The results of all these studies, especially those carried out in the second half of the past century, proved and confirmed that the eukaryotic cell nucleus is the control center of all cellular activities and also ensures the continuity of genetic information along successive generations of cells. These vital functions are the result of selective expression of genes contained in the nuclear chromatin, which is a high ordered and dynamic structure, in permanent and bilateral relations with other nuclear components. Based on these considerations, the present review aims to synthetize the latest researches and concepts about the cell nuclear territory in three distinctive parts, according to the complexity of the topic

  6. CLONING, EUKARYOTIC EXPRESSION AND EXPRESSION PATTERN OF SPHINGOMYELIN SYNTHASE-RELATED GENE (CsSMSr)FROM Chilo Suppressalis (WALKER)%二化螟鞘磷脂合酶相关基因CsSMSr的克隆、真核表达及表达谱分析

    Institute of Scientific and Technical Information of China (English)

    张艳茹; 郑作林; 周瀛; 杨琼; 巩中军; 程家安; 祝增荣

    2013-01-01

    Sphingomyelin synthase (SMS) plays an important role in regulating the metabolism of sphingolipids, and activation of SMS promotes cell survival and suppresses apoptosis either by decreasing the pro-apoptotic ceramide or by increasing the levels of mitogenic factor DAG. The full-length cDNA encoding SMSr gene (CsSMSr, genebank ID; JQ664739) was obtained by using RT-PCR and rapid amplification of cDNA ends (RACE) strategies. The full length of SMSr gene contains a 1587bp open reading frame (ORF) encoding a 528 amino acid residues. Amino acid sequence analysis revealed that CsSMSr contains a N-terminal sterile alpha motif (SAM) domain and six transmembranes, it also shares four highly conserved sequences motifs, designated Dl ~ D4. Among them, Motifs D3 and D4 include the His302, His345, Asp349 which form a catalytic triad. CsSMSr gene was successfully eukaryotically expressed in Tn cell, the recombinant protein molecular weight was 60kDa. RT-PCR was carried out to analyze the temporal and spatial gene expression patterns, the results showed that the expression level of CsSMSr was much higher in the adult stage than in the pre-adult stages, and highly expressed in the reproductive organs of male larvae and female adults, furthermore the expression level of CsSMSr was much higher in testis, but not significant different from midgut and Malpighian tubules in male adults, suggesting that CsSMSr gene may play a key role in organ maturity and reproductive function. All these results laid a basis for further research on the physiological and population ecological functions of CsSMSr gene.%鞘磷脂合酶(SMS)基因家族在鞘脂质代谢中起着关键作用,可以通过调节神经酰胺和甘油二酯的平衡调控细胞的生存和凋亡.本研究利用RT-PCR和RACE技术克隆得到1个二化螟鞘磷脂合酶相关基因的全长eDNA,命名为CsSMSr(Genbank登录号:JQ664739).CsSMSr开放阅读框1587bp,可编码528个氨基酸;序列分析表明,CsSMSr基因编

  7. Eukaryotic plankton diversity in the sunlit ocean

    Czech Academy of Sciences Publication Activity Database

    de Vargas, C.; Audic, S.; Henry, N.; Decelle, J.; Mahé, F.; Logares, R.; Lara, E.; Berney, C.; Le Bescot, N.; Probert, I.; Carmichael, M.; Poulain, J.; Romac, S.; Colin, S.; Aury, J.-M.; Bittner, L.; Chaffron, S.; Dunthorn, M.; Engelen, S.; Flegontova, Olga; Guidi, L.; Horák, Aleš; Jaillon, O.; Lima-Mendez, G.; Lukeš, Julius

    2015-01-01

    Roč. 348, č. 6237 (2015), UNSP 1261605. ISSN 0036-8075 Institutional support: RVO:60077344 Keywords : ribosomal RNA gene * protistan diversity * extreme diversity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 33.611, year: 2014

  8. Manufacturing and automation

    OpenAIRE

    Ernesto Córdoba Nieto

    2010-01-01

    The article presents concepts and definitions from different sources concerning automation. The work approaches automation by virtue of the author’s experience in manufacturing production; why and how automation prolects are embarked upon is considered. Technological reflection regarding the progressive advances or stages of automation in the production area is stressed. Coriat and Freyssenet’s thoughts about and approaches to the problem of automation and its current state are taken and e...

  9. Diversity and dynamics of active microbial eukaryotes in the anoxic zone of a freshwater meromictic lake (Pavin, France

    Directory of Open Access Journals (Sweden)

    CECILE eLEPERE

    2016-02-01

    Full Text Available Microbial eukaryotes play a crucial role in ecosystem functioning and oxygen is considered to be one of the strongest barriers against their local dispersal. However, diversity of microbial eukaryotes in freshwater habitats with oxygen gradients has previously received very little attention. We applied high-throughput sequencing (V4 region of the 18S rRNA gene in conjunction with quantitative PCR (DNA and RNA and fluorescent in situ hybridization analyses, to provide an unique spatio-temporal analysis of microbial eukaryotes diversity and potential activity in a meromictic freshwater lake (lake Pavin. This study revealed a high genetic diversity of unicellular eukaryotes in the permanent anoxic zone of lake Pavin and allowed the discrimination of active vs. inactive components. 42 % of the OTUs (Operational taxonomic Units are exclusively present in the monimolimnion, where Alveolata (Ciliophora and Dinophyceae and Fungi (Dikarya and Chytrids are the most active phyla and are probably represented by species capable of anaerobic metabolism. Pigmented eukaryotes (Haptophyceae and Chlorophyceae are also present and active in this zone, which opens up questions regarding their metabolism.

  10. Diversity and Dynamics of Active Small Microbial Eukaryotes in the Anoxic Zone of a Freshwater Meromictic Lake (Pavin, France)

    Science.gov (United States)

    Lepère, Cécile; Domaizon, Isabelle; Hugoni, Mylène; Vellet, Agnès; Debroas, Didier

    2016-01-01

    Microbial eukaryotes play a crucial role in ecosystem functioning and oxygen is considered to be one of the strongest barriers against their local dispersal. However, diversity of microbial eukaryotes in freshwater habitats with oxygen gradients has previously received very little attention. We applied high-throughput sequencing (V4 region of the 18S rRNA gene) in conjunction with quantitative PCR (DNA and RNA) and fluorescent in situ hybridization (FISH) analyses, to provide an unique spatio-temporal analysis of microbial eukaryotes diversity and potential activity in a meromictic freshwater lake (lake Pavin). This study revealed a high genetic diversity of unicellular eukaryotes in the permanent anoxic zone of lake Pavin and allowed the discrimination of active vs. inactive components. Forty-two percent of the OTUs (Operational Taxonomic Units) are exclusively present in the monimolimnion, where Alveolata (Ciliophora and Dinophyceae) and Fungi (Dikarya and Chytrids) are the most active phyla and are probably represented by species capable of anaerobic metabolism. Pigmented eukaryotes (Haptophyceae and Chlorophyceae) are also present and active in this zone, which opens up questions regarding their metabolism. PMID:26904006

  11. HIV-1 Replication and the Cellular Eukaryotic Translation Apparatus

    Directory of Open Access Journals (Sweden)

    Santiago Guerrero

    2015-01-01

    Full Text Available Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1 uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by targeting key translation factors and overcomes different cellular obstacles that affect protein translation. In this review, we describe how HIV-1 proteins target several components of the eukaryotic translation machinery, which consequently improves viral translation and replication.

  12. HIV-1 replication and the cellular eukaryotic translation apparatus.

    Science.gov (United States)

    Guerrero, Santiago; Batisse, Julien; Libre, Camille; Bernacchi, Serena; Marquet, Roland; Paillart, Jean-Christophe

    2015-01-01

    Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1) uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by targeting key translation factors and overcomes different cellular obstacles that affect protein translation. In this review, we describe how HIV-1 proteins target several components of the eukaryotic translation machinery, which consequently improves viral translation and replication. PMID:25606970

  13. Widespread 3'-end uridylation in eukaryotic RNA viruses.

    Science.gov (United States)

    Huo, Yayun; Shen, Jianguo; Wu, Huanian; Zhang, Chao; Guo, Lihua; Yang, Jinguang; Li, Weimin

    2016-01-01

    RNA 3' uridylation occurs pervasively in eukaryotes, but is poorly characterized in viruses. In this study, we demonstrate that a broad array of RNA viruses, including mycoviruses, plant viruses and animal viruses, possess a novel population of RNA species bearing nontemplated oligo(U) or (U)-rich tails, suggesting widespread 3' uridylation in eukaryotic viruses. Given the biological relevance of 3' uridylation to eukaryotic RNA degradation, we propose a conserved but as-yet-unknown mechanism in virus-host interaction. PMID:27151171

  14. Automated pangenomic analysis in target selection for PCR detection and identification of bacteria by use of ssGeneFinder Webserver and its application to Salmonella enterica serovar Typhi.

    Science.gov (United States)

    Ho, Chi-Chun; Wu, Alan K L; Tse, Cindy W S; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2012-06-01

    With the advent of high-throughput DNA sequencing, more than 4,000 bacterial genomes have been sequenced and are publicly available. We report a user-friendly web platform, ssGeneFinder Webserver (http://147.8.74.24/ssGeneFinder/), which is updated weekly for the automated pangenomic selection of specific targets for direct PCR detection and the identification of clinically important bacteria without the need of gene sequencing. To apply the ssGeneFinder Webserver for identifying specific targets for Salmonella enterica serovar Typhi, we analyzed 11 S. Typhi genomes, generated two specific targets, and validated them using 40 S. Typhi, 110 non-Typhi Salmonella serovars (serovar Paratyphi A, n = 4; Paratyphi B, n = 1; Typhimurium, n = 5; Enteritidis, n = 12; non-Paratyphi group A, n = 6; non-Paratyphi group B, n = 29; non-Paratyphi group C, n = 12; non-Typhi group D, n = 35; group E and others, n = 6), 115 Enterobacteriaceae isolates (Escherichia, n = 78; Shigella, n = 2; Klebsiella, n = 13; Enterobacter, n = 9; others, n = 13), and 66 human stool samples that were culture negative for S. Typhi. Both targets successfully detected all typical and atypical S. Typhi isolates, including an H1-j flagellin gene mutant, an aflagellated mutant which reacted with 2O Salmonella antiserum, and the Vi-negative attenuated vaccine strain Ty21a. No false positive was detected from any of the bacterial isolates and stool samples. DNA sequencing confirmed the identity of all positive amplicons. The PCR assays have detection limits as low as 100 CFU per reaction and were tested using spiked stool samples. Using a pangenomic approach, ssGeneFinder Webserver generated targets specific to S. Typhi. These and other validated targets should be applicable to the identification and direct PCR detection of bacterial pathogens from uncultured, mixed, and environmental samples. PMID:22442318

  15. Automated identification of medically important bacteria by 16S rRNA gene sequencing using a novel comprehensive database, 16SpathDB

    OpenAIRE

    Woo, Patrick C. Y.; Teng, Jade L. L.; Yeung, Juilian M. Y.; Tse, Herman; Lau, Susanna K. P.; Yuen, Kwok-Yung

    2011-01-01

    Despite the increasing use of 16S rRNA gene sequencing, interpretation of 16S rRNA gene sequence results is one of the most difficult problems faced by clinical microbiologists and technicians. To overcome the problems we encountered in the existing databases during 16S rRNA gene sequence interpretation, we built a comprehensive database, 16SpathDB (http://147.8.74.24/16SpathDB) based on the 16S rRNA gene sequences of all medically important bacteria listed in the Manual of Clinical Microbiol...

  16. AXIOME: automated exploration of microbial diversity

    OpenAIRE

    Lynch, Michael DJ; Andre P Masella; Hall, Michael W; Bartram, Andrea K.; Neufeld, Josh D.

    2013-01-01

    Background Although high-throughput sequencing of small subunit rRNA genes has revolutionized our understanding of microbial ecosystems, these technologies generate data at depths that benefit from automated analysis. Here we present AXIOME (Automation, eXtension, and Integration Of Microbial Ecology), a highly flexible and extensible management tool for popular microbial ecology analysis packages that promotes reproducibility and customization in microbial research. Findings AXIOME streamlin...

  17. Mitochondrial genome evolution and the origin of eukaryotes.

    Science.gov (United States)

    Lang, B F; Gray, M W; Burger, G

    1999-01-01

    Recent results from ancestral (minimally derived) protists testify to the tremendous diversity of the mitochondrial genome in various eukaryotic lineages, but also reinforce the view that mitochondria, descendants of an endosymbiotic alpha-Proteobacterium, arose only once in evolution. The serial endosymbiosis theory, currently the most popular hypothesis to explain the origin of mitochondria, postulates the capture of an alpha-proteobacterial endosymbiont by a nucleus-containing eukaryotic host resembling extant amitochondriate protists. New sequence data have challenged this scenario, instead raising the possibility that the origin of the mitochondrion was coincident with, and contributed substantially to, the origin of the nuclear genome of the eukaryotic cell. Defining more precisely the alpha-proteobacterial ancestry of the mitochondrial genome, and the contribution of the endosymbiotic event to the nuclear genome, will be essential for a full understanding of the origin and evolution of the eukaryotic cell as a whole. PMID:10690412

  18. Evolution of prokaryote and eukaryote lines inferred from sequence evidence

    Science.gov (United States)

    Hunt, L. T.; George, D. G.; Yeh, L.-S.; Dayhoff, M. O.

    1984-01-01

    This paper describes the evolution of prokaryotes and early eukaryotes, including their symbiotic relationships, as inferred from phylogenetic trees of bacterial ferredoxin, 5S ribosomal RNA, ribulose-1,5-biphosphate carboxylase large chain, and mitochondrial cytochrome oxidase polypeptide II.

  19. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

    NARCIS (Netherlands)

    R.H. Wijffels; O. Kruse; K.J. Hellingwerf

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms fo

  20. Evaluation of 3 automated real-time PCR (Xpert C. difficile assay, BD MAX Cdiff, and IMDx C. difficile for Abbott m2000 assay) for detecting Clostridium difficile toxin gene compared to toxigenic culture in stool specimens.

    Science.gov (United States)

    Yoo, Jaeeun; Lee, Hyeyoung; Park, Kang Gyun; Lee, Gun Dong; Park, Yong Gyu; Park, Yeon-Joon

    2015-09-01

    We evaluated the performance of the 3 automated systems (Cepheid Xpert, BD MAX, and IMDx C. difficile for Abbott m2000) detecting Clostridium difficile toxin gene compared to toxigenic culture. Of the 254 stool specimens tested, 87 (48 slight, 35 moderate, and 4 heavy growth) were toxigenic culture positive. The overall sensitivities and specificities were 82.8% and 98.8% for Xpert, 81.6% and 95.8% for BD MAX, and 62.1% and 99.4% for IMDx, respectively. The specificity was significantly higher in IMDx than BD MAX (P= 0.03). All stool samples underwent toxin A/B enzyme immunoassay testing, and of the 254 samples, only 29 samples were positive and 2 of them were toxigenic culture negative. Considering the rapidity and high specificity of the real-time PCR assays compared to the toxigenic culture, they can be used as the first test method for C. difficile infection/colonization. PMID:26081240

  1. A statistical anomaly indicates symbiotic origins of eukaryotic membranes

    OpenAIRE

    Bansal, Suneyna; Mittal, Aditya

    2015-01-01

    Compositional analyses of nucleic acids and proteins have shed light on possible origins of living cells. In this work, rigorous compositional analyses of ∼5000 plasma membrane lipid constituents of 273 species in the three life domains (archaea, eubacteria, and eukaryotes) revealed a remarkable statistical paradox, indicating symbiotic origins of eukaryotic cells involving eubacteria. For lipids common to plasma membranes of the three domains, the number of carbon atoms in eubacteria was fou...

  2. Repbase Update, a database of repetitive elements in eukaryotic genomes

    OpenAIRE

    Bao, Weidong; Kojima, Kenji K.; Kohany, Oleksiy

    2015-01-01

    Repbase Update (RU) is a database of representative repeat sequences in eukaryotic genomes. Since its first development as a database of human repetitive sequences in 1992, RU has been serving as a well-curated reference database fundamental for almost all eukaryotic genome sequence analyses. Here, we introduce recent updates of RU, focusing on technical issues concerning the submission and updating of Repbase entries and will give short examples of using RU data. RU sincerely invites a broad...

  3. HIV-1 Replication and the Cellular Eukaryotic Translation Apparatus

    OpenAIRE

    Santiago Guerrero; Julien Batisse; Camille Libre; Serena Bernacchi; Roland Marquet; Jean-Christophe Paillart

    2015-01-01

    Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1) uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by ta...

  4. Death of a dogma: eukaryotic mRNAs can code for more than one protein.

    Science.gov (United States)

    Mouilleron, Hélène; Delcourt, Vivian; Roucou, Xavier

    2016-01-01

    mRNAs carry the genetic information that is translated by ribosomes. The traditional view of a mature eukaryotic mRNA is a molecule with three main regions, the 5' UTR, the protein coding open reading frame (ORF) or coding sequence (CDS), and the 3' UTR. This concept assumes that ribosomes translate one ORF only, generally the longest one, and produce one protein. As a result, in the early days of genomics and bioinformatics, one CDS was associated with each protein-coding gene. This fundamental concept of a single CDS is being challenged by increasing experimental evidence indicating that annotated proteins are not the only proteins translated from mRNAs. In particular, mass spectrometry (MS)-based proteomics and ribosome profiling have detected productive translation of alternative open reading frames. In several cases, the alternative and annotated proteins interact. Thus, the expression of two or more proteins translated from the same mRNA may offer a mechanism to ensure the co-expression of proteins which have functional interactions. Translational mechanisms already described in eukaryotic cells indicate that the cellular machinery is able to translate different CDSs from a single viral or cellular mRNA. In addition to summarizing data showing that the protein coding potential of eukaryotic mRNAs has been underestimated, this review aims to challenge the single translated CDS dogma. PMID:26578573

  5. Dramatic shifts in benthic microbial eukaryote communities following the Deepwater Horizon oil spill.

    Directory of Open Access Journals (Sweden)

    Holly M Bik

    Full Text Available Benthic habitats harbour a significant (yet unexplored diversity of microscopic eukaryote taxa, including metazoan phyla, protists, algae and fungi. These groups are thought to underpin ecosystem functioning across diverse marine environments. Coastal marine habitats in the Gulf of Mexico experienced visible, heavy impacts following the Deepwater Horizon oil spill in 2010, yet our scant knowledge of prior eukaryotic biodiversity has precluded a thorough assessment of this disturbance. Using a marker gene and morphological approach, we present an intensive evaluation of microbial eukaryote communities prior to and following oiling around heavily impacted shorelines. Our results show significant changes in community structure, with pre-spill assemblages of diverse Metazoa giving way to dominant fungal communities in post-spill sediments. Post-spill fungal taxa exhibit low richness and are characterized by an abundance of known hydrocarbon-degrading genera, compared to prior communities that contained smaller and more diverse fungal assemblages. Comparative taxonomic data from nematodes further suggests drastic impacts; while pre-spill samples exhibit high richness and evenness of genera, post-spill communities contain mainly predatory and scavenger taxa alongside an abundance of juveniles. Based on this community analysis, our data suggest considerable (hidden initial impacts across Gulf beaches may be ongoing, despite the disappearance of visible surface oil in the region.

  6. Manufacturing and automation

    Directory of Open Access Journals (Sweden)

    Ernesto Córdoba Nieto

    2010-04-01

    Full Text Available The article presents concepts and definitions from different sources concerning automation. The work approaches automation by virtue of the author’s experience in manufacturing production; why and how automation prolects are embarked upon is considered. Technological reflection regarding the progressive advances or stages of automation in the production area is stressed. Coriat and Freyssenet’s thoughts about and approaches to the problem of automation and its current state are taken and examined, especially that referring to the problem’s relationship with reconciling the level of automation with the flexibility and productivity demanded by competitive, worldwide manufacturing.

  7. Identification of genes in anonymous DNA sequences. Annual performance report, February 1, 1991--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Fields, C.A.

    1996-06-01

    The objective of this project is the development of practical software to automate the identification of genes in anonymous DNA sequences from the human, and other higher eukaryotic genomes. A software system for automated sequence analysis, gm (gene modeler) has been designed, implemented, tested, and distributed to several dozen laboratories worldwide. A significantly faster, more robust, and more flexible version of this software, gm 2.0 has now been completed, and is being tested by operational use to analyze human cosmid sequence data. A range of efforts to further understand the features of eukaryoyic gene sequences are also underway. This progress report also contains papers coming out of the project including the following: gm: a Tool for Exploratory Analysis of DNA Sequence Data; The Human THE-LTR(O) and MstII Interspersed Repeats are subfamilies of a single widely distruted highly variable repeat family; Information contents and dinucleotide compostions of plant intron sequences vary with evolutionary origin; Splicing signals in Drosophila: intron size, information content, and consensus sequences; Integration of automated sequence analysis into mapping and sequencing projects; Software for the C. elegans genome project.

  8. An Evolutionary Framework for Understanding the Origin of Eukaryotes.

    Science.gov (United States)

    Blackstone, Neil W

    2016-01-01

    Two major obstacles hinder the application of evolutionary theory to the origin of eukaryotes. The first is more apparent than real-the endosymbiosis that led to the mitochondrion is often described as "non-Darwinian" because it deviates from the incremental evolution championed by the modern synthesis. Nevertheless, endosymbiosis can be accommodated by a multi-level generalization of evolutionary theory, which Darwin himself pioneered. The second obstacle is more serious-all of the major features of eukaryotes were likely present in the last eukaryotic common ancestor thus rendering comparative methods ineffective. In addition to a multi-level theory, the development of rigorous, sequence-based phylogenetic and comparative methods represents the greatest achievement of modern evolutionary theory. Nevertheless, the rapid evolution of major features in the eukaryotic stem group requires the consideration of an alternative framework. Such a framework, based on the contingent nature of these evolutionary events, is developed and illustrated with three examples: the putative intron proliferation leading to the nucleus and the cell cycle; conflict and cooperation in the origin of eukaryotic bioenergetics; and the inter-relationship between aerobic metabolism, sterol synthesis, membranes, and sex. The modern synthesis thus provides sufficient scope to develop an evolutionary framework to understand the origin of eukaryotes. PMID:27128953

  9. Single Cell Genomics and Transcriptomics for Unicellular Eukaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Ciobanu, Doina; Clum, Alicia; Singh, Vasanth; Salamov, Asaf; Han, James; Copeland, Alex; Grigoriev, Igor; James, Timothy; Singer, Steven; Woyke, Tanja; Malmstrom, Rex; Cheng, Jan-Fang

    2014-03-14

    Despite their small size, unicellular eukaryotes have complex genomes with a high degree of plasticity that allow them to adapt quickly to environmental changes. Unicellular eukaryotes live with prokaryotes and higher eukaryotes, frequently in symbiotic or parasitic niches. To this day their contribution to the dynamics of the environmental communities remains to be understood. Unfortunately, the vast majority of eukaryotic microorganisms are either uncultured or unculturable, making genome sequencing impossible using traditional approaches. We have developed an approach to isolate unicellular eukaryotes of interest from environmental samples, and to sequence and analyze their genomes and transcriptomes. We have tested our methods with six species: an uncharacterized protist from cellulose-enriched compost identified as Platyophrya, a close relative of P. vorax; the fungus Metschnikowia bicuspidate, a parasite of water flea Daphnia; the mycoparasitic fungi Piptocephalis cylindrospora, a parasite of Cokeromyces and Mucor; Caulochytrium protosteloides, a parasite of Sordaria; Rozella allomycis, a parasite of the water mold Allomyces; and the microalgae Chlamydomonas reinhardtii. Here, we present the four components of our approach: pre-sequencing methods, sequence analysis for single cell genome assembly, sequence analysis of single cell transcriptomes, and genome annotation. This technology has the potential to uncover the complexity of single cell eukaryotes and their role in the environmental samples.

  10. Characterization of eukaryotic microbial diversity in hypersaline Lake Tyrrell, Australia

    Directory of Open Access Journals (Sweden)

    Karla B Heidelberg

    2013-05-01

    Full Text Available This study describes the community structure of the microbial eukaryotic community from hypersaline Lake Tyrrell, Australia, using near full length 18S rRNA sequences. Water samples were taken in both summer and winter over a four year period. The extent of eukaryotic diversity detected was low, with only 35 unique phylotypes using a 97% sequence similarity threshold. The water samples were dominated (91% by a novel cluster of the Alveolate, Apicomplexa Colpodella spp., most closely related to C. edax. The Chlorophyte, Dunaliella spp. accounted for less than 35% of water column samples. However, the eukaryotic community entrained in a salt crust sample was vastly different and was dominated (83% by the Dunaliella spp. The patterns described here represent the first observation of microbial eukaryotic dynamics in this system and provide a multiyear comparison of community composition by season. The lack of expected seasonal distribution in eukaryotic communities paired with abundant nanoflagellates suggests that grazing may significantly structure microbial eukaryotic communities in this system.

  11. On the Diversification of the Translation Apparatus across Eukaryotes

    Directory of Open Access Journals (Sweden)

    Greco Hernández

    2012-01-01

    Full Text Available Diversity is one of the most remarkable features of living organisms. Current assessments of eukaryote biodiversity reaches 1.5 million species, but the true figure could be several times that number. Diversity is ingrained in all stages and echelons of life, namely, the occupancy of ecological niches, behavioral patterns, body plans and organismal complexity, as well as metabolic needs and genetics. In this review, we will discuss that diversity also exists in a key biochemical process, translation, across eukaryotes. Translation is a fundamental process for all forms of life, and the basic components and mechanisms of translation in eukaryotes have been largely established upon the study of traditional, so-called model organisms. By using modern genome-wide, high-throughput technologies, recent studies of many nonmodel eukaryotes have unveiled a surprising diversity in the configuration of the translation apparatus across eukaryotes, showing that this apparatus is far from being evolutionarily static. For some of the components of this machinery, functional differences between different species have also been found. The recent research reviewed in this article highlights the molecular and functional diversification the translational machinery has undergone during eukaryotic evolution. A better understanding of all aspects of organismal diversity is key to a more profound knowledge of life.

  12. An Evolutionary Framework for Understanding the Origin of Eukaryotes

    Directory of Open Access Journals (Sweden)

    Neil W. Blackstone

    2016-04-01

    Full Text Available Two major obstacles hinder the application of evolutionary theory to the origin of eukaryotes. The first is more apparent than real—the endosymbiosis that led to the mitochondrion is often described as “non-Darwinian” because it deviates from the incremental evolution championed by the modern synthesis. Nevertheless, endosymbiosis can be accommodated by a multi-level generalization of evolutionary theory, which Darwin himself pioneered. The second obstacle is more serious—all of the major features of eukaryotes were likely present in the last eukaryotic common ancestor thus rendering comparative methods ineffective. In addition to a multi-level theory, the development of rigorous, sequence-based phylogenetic and comparative methods represents the greatest achievement of modern evolutionary theory. Nevertheless, the rapid evolution of major features in the eukaryotic stem group requires the consideration of an alternative framework. Such a framework, based on the contingent nature of these evolutionary events, is developed and illustrated with three examples: the putative intron proliferation leading to the nucleus and the cell cycle; conflict and cooperation in the origin of eukaryotic bioenergetics; and the inter-relationship between aerobic metabolism, sterol synthesis, membranes, and sex. The modern synthesis thus provides sufficient scope to develop an evolutionary framework to understand the origin of eukaryotes.

  13. Métodos para la Clasificación Automática de Imágenes de Resonancia Magnética del Cerebro

    OpenAIRE

    Peláez Brioso, Gerardo Arturo

    2014-01-01

    Las imágenes digitales adquiridas como resultado de la Resonancia Magnética son ampliamente utilizadas para diagnosticar, estudiar y pronosticar la evolución y respuesta al tratamiento de una gran variedad de patologías. La interpretación adecuada de estas imágenes requiere un extenso y complejo análisis asociado que involucra numerosas técnicas informáticas. En la práctica, las principales dificultades para clasificar las Imágenes de Resonancia Magnética (IRM) utilizando métodos de Aprend...

  14. Construction of Eukaryotic Expression Vector of cfb Gene from Bovine Streptococcus agalactiaee%牛源性无乳链球菌分离鉴定及 cfb 基因的克隆和真核表达载体的构建

    Institute of Scientific and Technical Information of China (English)

    阚威; 王华; 马友记; 赵兴绪; 张勇

    2014-01-01

    In order to develop genetic engineering subunit vaccine ,milk samples of cows with subclinic mastitis were collected .THB ( Todd-Hewitt Broth ) solid selective medium and pigment test were adopted , combined with species specific gene cfb to isolate and identify Streptococcus agalactiae.ORF and B cell epitope analysis were car-ried out according to the cfb gene sequences published in GenBank .Primers designed with Primer 5 in cfb′s B cell epitope enriched sequence and eukaryotic expression elements and restriction enzyme sites were added .Genome DNA of the isolates were extracted and served as PCR templates for cfb amplification,prior to link with the T-A clo-ning vector for sequencing.Correctly cloned cfb sequence were then linked to the pcDNATM 3.1 V5-His A(pcDNA-cfb) and transformed to DH5αcompetent cell for plasmid proliferation and sequencing .Results showed 8 strains of Streptococcus agalactiaee were characterized from 89 milk samples,and the pcDNA-cfb was successfully constructed . Primary selection by THB selective medium and pigment test could be used for quick isolation of Streptococcus aga-lactiae.Analysis of the cfb sequence by Bcepred and Lasergene-Protean software showed the cloned cfb sequence contained multiple dominant B cell epitope ,thus had the potential to serve as target gene sequence for genetic engi-neering subunit vaccine of Streptococcus agalactiae.This work could served as the basis for further developing genet-ic engineering subunit vaccine for Streptococcus agalactiae.%为研制奶牛乳房炎无乳链球菌的基因工程疫苗,采集隐性奶牛乳房炎奶样,利用THB ( Todd-Hewitt Broth )固体选择培养基和色素试验,并结合无乳链球菌种属特异性基因cfb,采用PCR技术从隐性乳房炎奶样中分离和鉴定无乳链球菌。根据GenBank已报道的链球菌cfb基因序列,经ORF分析和B细胞表位预测,利用Primer 5.0软件设计cfb因子富含B细胞表位区域引物,添加酶

  15. Update and evaluation of 16SpathDB, an automated comprehensive database for identification of medically important bacteria by 16S rRNA gene sequencing

    OpenAIRE

    Yeung, Shiu-yan; 楊兆恩

    2013-01-01

    Identification of pathogens is one of the important duties of clinical microbiology laboratory. Traditionally, phenotypic tests are used to identify the bacteria. However, due to some limitations of the phenotypic tests, the bacteria may not be identified sometimes and cannot be identified promptly. 16S rRNA gene sequencing is a rapid and accurate method to achieve this target. It is especially useful for identify rare or slow growing bacteria. However, the interpretation of the 16S rRNA gene...

  16. An automated swimming respirometer

    DEFF Research Database (Denmark)

    STEFFENSEN, JF; JOHANSEN, K; BUSHNELL, PG

    1984-01-01

    An automated respirometer is described that can be used for computerized respirometry of trout and sharks.......An automated respirometer is described that can be used for computerized respirometry of trout and sharks....

  17. Configuration Management Automation (CMA)

    Data.gov (United States)

    Department of Transportation — Configuration Management Automation (CMA) will provide an automated, integrated enterprise solution to support CM of FAA NAS and Non-NAS assets and investments. CMA...

  18. Characterization and Evolution of the Cell Cycle-Associated Mob Domain-Containing Proteins in Eukaryotes

    Directory of Open Access Journals (Sweden)

    Nicola Vitulo

    2007-01-01

    Full Text Available The MOB family includes a group of cell cycle-associated proteins highly conserved throughout eukaryotes, whose founding members are implicated in mitotic exit and co-ordination of cell cycle progression with cell polarity and morphogenesis. Here we report the characterization and evolution of the MOB domain-containing proteins as inferred from the 43 eukaryotic genomes so far sequenced. We show that genes for Mob-like proteins are present in at least 41 of these genomes, confi rming the universal distribution of this protein family and suggesting its prominent biological function. The phylogenetic analysis reveals fi ve distinct MOB domain classes, showing a progressive expansion of this family from unicellular to multicellular organisms, reaching the highest number in mammals. Plant Mob genes appear to have evolved from a single ancestor, most likely after the loss of one or more genes during the early stage of Viridiplantae evolutionary history. Three of the Mob classes are widespread among most of the analyzed organisms. The possible biological and molecular function of Mob proteins and their role in conserved signaling pathways related to cell proliferation, cell death and cell polarity are also presented and critically discussed.

  19. Basal transcription machinery: role in regulation of stress response in eukaryotes

    Indian Academy of Sciences (India)

    Parag Sadhale; Jiyoti Verma; Aruna Naorem

    2007-04-01

    The holoenzyme of prokaryotic RNA polymerase consists of the core enzyme, made of two , , ’ and subunits, which lacks promoter selectivity and a sigma () subunit which enables the core enzyme to initiate transcription in a promoter dependent fashion. A stress sigma factor s, in prokaryotes seems to regulate several stress response genes in conjunction with other stress specific regulators. Since the basic principles of transcription are conserved from simple bacteria to multicellular complex organisms, an obvious question is: what is the identity of a counterpart of s, that is closest to the core polymerase and that dictates transcription of stress regulated genes in general? In this review, we discuss the logic behind the suggestion that like in prokaryotes, eukaryotes also have a common functional unit in the transcription machinery through which the stress specific transcription factors regulate rapid and highly controlled induction of gene expression associated with generalized stress response and point to some candidates that would fit the bill of the eukaryotic s.

  20. Evolution of the 2'-5'-Oligoadenylate Synthetase family in eukaryotes and bacteria

    DEFF Research Database (Denmark)

    Kjær, Karina Hansen; Poulsen, Jesper Buchhave; Reitamm, Tonu;

    2009-01-01

    The 2′-5′-oligoadenylate synthetase (OAS) belongs to a nucleotidyl transferase family that includes poly(A) polymerases and CCA-adding enzymes. In mammals and birds, the OAS functions in the interferon system but it is also present in an active form in sponges, which are devoid of the interferon...... system. In view of these observations, we have pursued the idea that OAS genes could be present in other metazoans and in unicellular organisms as well. We have identified a number of OAS1 genes in annelids, mollusks, a cnidarian, chordates, and unicellular eukaryotes and also found a family of proteins...... the OASL may have evolved from an ancestor of cartilaginous fishes, and that the OAS2 and the OAS3 genes evolved from a mammalian ancestor. OAS proteins function in the interferon system in mammals. This system is only found in jawed vertebrates. We therefore suggest that the original function of OAS...

  1. A comparative study of protein synthesis in in vitro systems: from the prokaryotic reconstituted to the eukaryotic extract-based

    Directory of Open Access Journals (Sweden)

    Hillebrecht Jason R

    2008-07-01

    Full Text Available Abstract Background Cell-free protein synthesis is not only a rapid and high throughput technology to obtain proteins from their genes, but also provides an in vitro platform to study protein translation and folding. A detailed comparison of in vitro protein synthesis in different cell-free systems may provide insights to their biological differences and guidelines for their applications. Results Protein synthesis was investigated in vitro in a reconstituted prokaryotic system, a S30 extract-based system and a eukaryotic system. Compared to the S30 system, protein synthesis in the reconstituted system resulted in a reduced yield, and was more cold-sensitive. Supplementing the reconstituted system with fractions from a size-exclusion separation of the S30 extract significantly increased the yield and activity, to a level close to that of the S30 system. Though protein synthesis in both prokaryotic and eukaryotic systems showed no significant differences for eukaryotic reporter proteins, drastic differences were observed when an artificial fusion protein was synthesized in vitro. The prokaryotic systems failed to synthesize and correctly fold a significant amount of the full-length fusion protein, even when supplemented with the eukaryotic lysate. The active full-length fusion protein was synthesized only in the eukaryotic system. Conclusion The reconstituted bacterial system is sufficient but not efficient in protein synthesis. The S30 system by comparison contains additional cellular factors capable of enhancing protein translation and folding. The eukaryotic translation machinery may have evolved from its prokaryotic counterpart in order to translate more complex (difficult-to-translate templates into active proteins.

  2. Workflow automation architecture standard

    Energy Technology Data Exchange (ETDEWEB)

    Moshofsky, R.P.; Rohen, W.T. [Boeing Computer Services Co., Richland, WA (United States)

    1994-11-14

    This document presents an architectural standard for application of workflow automation technology. The standard includes a functional architecture, process for developing an automated workflow system for a work group, functional and collateral specifications for workflow automation, and results of a proof of concept prototype.

  3. Automated direct sequencing of the iduronate-2 sulfatase gene reveals a vast spectrum of mutations causing Hunter syndrome (mucopolysaccharidosis type II) and a {open_quotes}hot spot{close_quotes} at R468

    Energy Technology Data Exchange (ETDEWEB)

    Whitley, C.B; Jonsson, J.J.; Aronovich, E.L. [Univ. of Minnesota Medical School, Minneapolis, MN (United States)

    1994-09-01

    Hunter syndrome is an X-linked recessive, lethal disease resulting from deficiency of iduronate-2-sulfatase (IDS) catalytic activity. Because of low reproductive fitness, most affected individuals are expected to have new mutations. Most of such defects are anticipated to be single base pair (bp) changes; however, several previous studies utilizing Southern analysis of RT-PCR have identified numerous large gene deletions in patients having the {open_quotes}severe form{close_quotes} with neurologic disease. To investigate the spectrum of IDS mutations, we have developed a method of automated direct sequencing of RT-PCR products representing the entire IDS coding region. Of 19 patients studied by this approach, only 1 had an IDS coding region which did not contain a mutation; 1 had a single bp insertion; 1 had a 2 bp deletion; and 13 had single-base substitutions. Of the 13 having single base substitutions, 2 resulted in aberrant splicing. Only 1 patient had a complete gene deletion; in view of previous reports, there was a surprising lack of major gene deletions. Notably, a CpG dinucleotide at R468 was identified as a {open_quotes}hot spot{close_quotes} for mutation. Five unrelated individuals had substitutions at this site which thus accounted for 28% of all mutations in this series: R468W (3 patients) and R468Q (2 patients). MspI digestion provided a method of rapid diagnosis and determination of heterozygote status for such R468 mutations. Genotype-phenotype correlations in this R468 group are not yet possible because of confounding information, i.e., there are both {open_quotes}mild{close_quotes} and {open_quotes}severe{close_quotes} patients in this group and some have co-existing neurologic diseases. This approach of gene sequencing appears to be necessary, and sufficient, to characterize the vast spectrum of mutations in Hunter syndrome.

  4. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  5. Comparative analysis of serine/arginine-rich proteins across 27 eukaryotes: insights into sub-family classification and extent of alternative splicing.

    Directory of Open Access Journals (Sweden)

    Dale N Richardson

    Full Text Available Alternative splicing (AS of pre-mRNA is a fundamental molecular process that generates diversity in the transcriptome and proteome of eukaryotic organisms. SR proteins, a family of splicing regulators with one or two RNA recognition motifs (RRMs at the N-terminus and an arg/ser-rich domain at the C-terminus, function in both constitutive and alternative splicing. We identified SR proteins in 27 eukaryotic species, which include plants, animals, fungi and "basal" eukaryotes that lie outside of these lineages. Using RNA recognition motifs (RRMs as a phylogenetic marker, we classified 272 SR genes into robust sub-families. The SR gene family can be split into five major groupings, which can be further separated into 11 distinct sub-families. Most flowering plants have double or nearly double the number of SR genes found in vertebrates. The majority of plant SR genes are under purifying selection. Moreover, in all paralogous SR genes in Arabidopsis, rice, soybean and maize, one of the two paralogs is preferentially expressed throughout plant development. We also assessed the extent of AS in SR genes based on a splice graph approach (http://combi.cs.colostate.edu/as/gmap_SRgenes. AS of SR genes is a widespread phenomenon throughout multiple lineages, with alternative 3' or 5' splicing events being the most prominent type of event. However, plant-enriched sub-families have 57%-88% of their SR genes experiencing some type of AS compared to the 40%-54% seen in other sub-families. The SR gene family is pervasive throughout multiple eukaryotic lineages, conserved in sequence and domain organization, but differs in gene number across lineages with an abundance of SR genes in flowering plants. The higher number of alternatively spliced SR genes in plants emphasizes the importance of AS in generating splice variants in these organisms.

  6. Shoe-String Automation

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, M.L.

    2001-07-30

    Faced with a downsizing organization, serious budget reductions and retirement of key metrology personnel, maintaining capabilities to provide necessary services to our customers was becoming increasingly difficult. It appeared that the only solution was to automate some of our more personnel-intensive processes; however, it was crucial that the most personnel-intensive candidate process be automated, at the lowest price possible and with the lowest risk of failure. This discussion relates factors in the selection of the Standard Leak Calibration System for automation, the methods of automation used to provide the lowest-cost solution and the benefits realized as a result of the automation.

  7. Genome-wide analysis of eukaryote thaumatin-like proteins (TLPs with an emphasis on poplar

    Directory of Open Access Journals (Sweden)

    Duplessis Sébastien

    2011-02-01

    Full Text Available Abstract Background Plant inducible immunity includes the accumulation of a set of defense proteins during infection called pathogenesis-related (PR proteins, which are grouped into families termed PR-1 to PR-17. The PR-5 family is composed of thaumatin-like proteins (TLPs, which are responsive to biotic and abiotic stress and are widely studied in plants. TLPs were also recently discovered in fungi and animals. In the poplar genome, TLPs are over-represented compared with annual species and their transcripts strongly accumulate during stress conditions. Results Our analysis of the poplar TLP family suggests that the expansion of this gene family was followed by diversification, as differences in expression patterns and predicted properties correlate with phylogeny. In particular, we identified a clade of poplar TLPs that cluster to a single 350 kb locus of chromosome I and that are up-regulated by poplar leaf rust infection. A wider phylogenetic analysis of eukaryote TLPs - including plant, animal and fungi sequences - shows that TLP gene content and diversity increased markedly during land plant evolution. Mapping the reported functions of characterized TLPs to the eukaryote phylogenetic tree showed that antifungal or glycan-lytic properties are widespread across eukaryote phylogeny, suggesting that these properties are shared by most TLPs and are likely associated with the presence of a conserved acidic cleft in their 3D structure. Also, we established an exhaustive catalog of TLPs with atypical architectures such as small-TLPs, TLP-kinases and small-TLP-kinases, which have potentially developed alternative functions (such as putative receptor kinases for pathogen sensing and signaling. Conclusion Our study, based on the most recent plant genome sequences, provides evidence for TLP gene family diversification during land plant evolution. We have shown that the diverse functions described for TLPs are not restricted to specific clades but seem

  8. Eukaryotic cell encystation and cancer cell dormancy: is a greater devil veiled in the details of a lesser evil?

    OpenAIRE

    Baig, Abdul Mannan; Khan, Naveed Ahmed; Abbas, Farhat

    2015-01-01

    Cancer cell dormancy is the main cause of cancer recurrence and failure of therapy as dormant cells evade not only the anticancer drugs but also the host immune system. These dormant cells veil themselves from detection by imaging and/or using biomarkers, which imposes an additional problem in targeting such cells. A similar form of hibernation process known as encystation is studied in detail for pathogenic unicellular eukaryotic microorganisms. By examination using microarray gene expressio...

  9. Intermittency as a universal characteristic of the complete chromosome DNA sequences of eukaryotes: From protozoa to human genomes

    Science.gov (United States)

    Rybalko, S.; Larionov, S.; Poptsova, M.; Loskutov, A.

    2011-10-01

    Large-scale dynamical properties of complete chromosome DNA sequences of eukaryotes are considered. Using the proposed deterministic models with intermittency and symbolic dynamics we describe a wide spectrum of large-scale patterns inherent in these sequences, such as segmental duplications, tandem repeats, and other complex sequence structures. It is shown that the recently discovered gene number balance on the strands is not of a random nature, and certain subsystems of a complete chromosome DNA sequence exhibit the properties of deterministic chaos.

  10. Unraveling adaptation in eukaryotic pathways: lessons from protocells.

    Science.gov (United States)

    De Palo, Giovanna; Endres, Robert G

    2013-10-01

    Eukaryotic adaptation pathways operate within wide-ranging environmental conditions without stimulus saturation. Despite numerous differences in the adaptation mechanisms employed by bacteria and eukaryotes, all require energy consumption. Here, we present two minimal models showing that expenditure of energy by the cell is not essential for adaptation. Both models share important features with large eukaryotic cells: they employ small diffusible molecules and involve receptor subunits resembling highly conserved G-protein cascades. Analyzing the drawbacks of these models helps us understand the benefits of energy consumption, in terms of adjustability of response and adaptation times as well as separation of cell-external sensing and cell-internal signaling. Our work thus sheds new light on the evolution of adaptation mechanisms in complex systems. PMID:24204235

  11. Interaction of tRNA with Eukaryotic Ribosome

    Directory of Open Access Journals (Sweden)

    Dmitri Graifer

    2015-03-01

    Full Text Available This paper is a review of currently available data concerning interactions of tRNAs with the eukaryotic ribosome at various stages of translation. These data include the results obtained by means of cryo-electron microscopy and X-ray crystallography applied to various model ribosomal complexes, site-directed cross-linking with the use of tRNA derivatives bearing chemically or photochemically reactive groups in the CCA-terminal fragment and chemical probing of 28S rRNA in the region of the peptidyl transferase center. Similarities and differences in the interactions of tRNAs with prokaryotic and eukaryotic ribosomes are discussed with concomitant consideration of the extent of resemblance between molecular mechanisms of translation in eukaryotes and bacteria.

  12. Unraveling adaptation in eukaryotic pathways: lessons from protocells.

    Directory of Open Access Journals (Sweden)

    Giovanna De Palo

    2013-10-01

    Full Text Available Eukaryotic adaptation pathways operate within wide-ranging environmental conditions without stimulus saturation. Despite numerous differences in the adaptation mechanisms employed by bacteria and eukaryotes, all require energy consumption. Here, we present two minimal models showing that expenditure of energy by the cell is not essential for adaptation. Both models share important features with large eukaryotic cells: they employ small diffusible molecules and involve receptor subunits resembling highly conserved G-protein cascades. Analyzing the drawbacks of these models helps us understand the benefits of energy consumption, in terms of adjustability of response and adaptation times as well as separation of cell-external sensing and cell-internal signaling. Our work thus sheds new light on the evolution of adaptation mechanisms in complex systems.

  13. Introns in higher plant genes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The intron is an important component of eukaryotic gene. Extensive studies have been conducted to get a better understanding of its structure and function. This paper presents a brief review of the structure and function of introns in higher plant genes. It is shown that higher plant introns possess structural properties shared by all eukaryotic introns, however, they also exhibit a striking degree of diversity. The process of intron splicing in higher plant genes involves interaction between multiple cis-acting elements and trans-acting factors, such as 5′ splicing site, 3′ splicing site and many protein factors. The process of intron splicing is an important level at which gene expression is regulated. Especially alternative splicing of intron can regulate time and space of gene expression. In addition, some introns in higher plant genes also regulate gene expression by affecting the pattern of gene expression, enhancing the level of gene expression and driving the gene expression.

  14. [Genetic diversity of eukaryotic picoplankton of eight lakes in Nanjing].

    Science.gov (United States)

    Zhao, Bi-ying; Chen, Mei-jun; Sun, Ying; Chen, Fei-zhou; Yang, Jia-xin

    2010-05-01

    The method of terminal restriction fragment length polymorphism (T-RFLP) was used to study the genetic diversity of eukaryotic picoplankton (0.2-5.0 microm) in the pelagic and littoral zones in 8 lakes with different trophic status in Nanjing. The objectives of this study were to confirm the difference of the genetic diversity of eukaryotic picoplankton among lakes and the main factors affecting this difference. T-RFLP indicated that there were various fingerprints among lakes and zones. The average terminal restriction fragments (T-RFs) in the littoral and pelagic zones were 16.4 and 15.9, respectively. The littoral zone in Lake Nan and the pelagic zone in Lake Mochou had 30 T-RFs and 27 T-RFs, respectively. The T-RFs were the least abundant (10) in the pelagic zone in Lake Baijia with relatively low trophic status. The genetic diversity of eukaryotic picoplankton was higher in the littoral zone than that in the pelagic zone except Lake Pipa and Mochou. The cluster analysis indicated that the similarities of the littoral zones and the pelagic zones were very high except Lake Baijia, Qian and Nan. The canonical correspondence analysis between the genetic diversity of eukaryotic picoplankton and environmental factors revealed the concentration of chlorophyll a had the most important impact on the eukaryotic picoplankton communities (p = 0.004). The results indicated that the genetic diversity of eukaryotic picoplankton is affected by the trophic status and has the difference in the pelagic and littoral zones. PMID:20623867

  15. Protein N-myristoylation in Escherichia coli: Reconstitution of a eukaryotic protein modification in bacteria

    International Nuclear Information System (INIS)

    Protein N-myristoylation refers to the covalent attachment of a myristoyl group (C14:0), via amide linkage, to the NH2-terminal glycine residue of certain cellular and viral proteins. Myristoyl-CoA:protein N-myristoyltransferase (NMT) catalyzes this cotranslational modification. The authors have developed a system for studying the substrate requirements and biological effects of protein N-myristoylation as well as NMT structure-activity relationships. Expression of the yeast NMT1 gene in Escherichia coli, a bacterium that has no endogenous NMT activity, results in production of the intact 53-kDa NMT polypeptide as well as a truncated polypeptide derived from proteolytic removal of its NH2-terminal 39 amino acids. By using a dual plasmid system, N-myristoylation of a mammalian protein was reconstituted in E. coli by simultaneous expression of the yeast NMT1 gene and a murine cDNA encoding the catalytic (C) subunit of cAMP-dependent protein kinase (PK-A). A major advantage of the bacterial system over eukaryotic systems is the absence of endogenous NMT and substrates, providing a more straightforward way of preparing myristoylated, analog-substituted, and nonmyristoylated forms of a given protein for comparison of their structural and functional properties. The experimental system may prove useful for recapitulating other eukaryotic protein modifications in E. coli so that structure-activity relationships of modifying enzymes and their substrates can be more readily assessed

  16. Structure of the prolyl-tRNA synthetase from the eukaryotic pathogen Giardia lamblia

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Eric T.; Kim, Jessica E.; Napuli, Alberto J.; Verlinde, Christophe L. M. J.; Fan, Erkang; Zucker, Frank H.; Van Voorhis, Wesley C.; Buckner, Frederick S.; Hol, Wim G. J.; Merritt, Ethan A., E-mail: merritt@u.washington.edu [Medical Structural Genomics of Pathogenic Protozoa, (United States); University of Washington, Seattle, WA 98195 (United States)

    2012-09-01

    The structure of Giardia prolyl-tRNA synthetase cocrystallized with proline and ATP shows evidence for half-of-the-sites activity, leading to a corresponding mixture of reaction substrates and product (prolyl-AMP) in the two active sites of the dimer. The genome of the human intestinal parasite Giardia lamblia contains only a single aminoacyl-tRNA synthetase gene for each amino acid. The Giardia prolyl-tRNA synthetase gene product was originally misidentified as a dual-specificity Pro/Cys enzyme, in part owing to its unexpectedly high off-target activation of cysteine, but is now believed to be a normal representative of the class of archaeal/eukaryotic prolyl-tRNA synthetases. The 2.2 Å resolution crystal structure of the G. lamblia enzyme presented here is thus the first structure determination of a prolyl-tRNA synthetase from a eukaryote. The relative occupancies of substrate (proline) and product (prolyl-AMP) in the active site are consistent with half-of-the-sites reactivity, as is the observed biphasic thermal denaturation curve for the protein in the presence of proline and MgATP. However, no corresponding induced asymmetry is evident in the structure of the protein. No thermal stabilization is observed in the presence of cysteine and ATP. The implied low affinity for the off-target activation product cysteinyl-AMP suggests that translational fidelity in Giardia is aided by the rapid release of misactivated cysteine.

  17. Structure of the prolyl-tRNA synthetase from the eukaryotic pathogen Giardia lamblia

    International Nuclear Information System (INIS)

    The structure of Giardia prolyl-tRNA synthetase cocrystallized with proline and ATP shows evidence for half-of-the-sites activity, leading to a corresponding mixture of reaction substrates and product (prolyl-AMP) in the two active sites of the dimer. The genome of the human intestinal parasite Giardia lamblia contains only a single aminoacyl-tRNA synthetase gene for each amino acid. The Giardia prolyl-tRNA synthetase gene product was originally misidentified as a dual-specificity Pro/Cys enzyme, in part owing to its unexpectedly high off-target activation of cysteine, but is now believed to be a normal representative of the class of archaeal/eukaryotic prolyl-tRNA synthetases. The 2.2 Å resolution crystal structure of the G. lamblia enzyme presented here is thus the first structure determination of a prolyl-tRNA synthetase from a eukaryote. The relative occupancies of substrate (proline) and product (prolyl-AMP) in the active site are consistent with half-of-the-sites reactivity, as is the observed biphasic thermal denaturation curve for the protein in the presence of proline and MgATP. However, no corresponding induced asymmetry is evident in the structure of the protein. No thermal stabilization is observed in the presence of cysteine and ATP. The implied low affinity for the off-target activation product cysteinyl-AMP suggests that translational fidelity in Giardia is aided by the rapid release of misactivated cysteine

  18. Human T24 Ha-ras cassette suitable for expression in eukaryotic cells

    Energy Technology Data Exchange (ETDEWEB)

    Bailleul, B.; Lang, J.; Wilkie, N.; Balmain, A.

    1988-01-11

    The T24 Ha-ras-1 oncogene is known to transform a wide range of eukaryotic cell types both in vivo and in vitro. Interpretation of the role played by ras genes in transformed cells would clearly by aided by employing a biological system capable of regulating ras p21 production. This can be achieved by substitution of the transcriptional control signals of Ha-ras with heterologous eukaryotic promoters. In this way, ras p21 may be expressed at high or low levels or inducibly expressed, depending on the promoter used. To facilitate construction of ras fusion genes, the authors have produced a T24 Ha-ras a cassette containing multiple cloning sites 5' to the Ha-ras coding exons. The polyadenylic site and the VTR region have been retained while the splice acceptor site upstream the ATG initiator codon has been deleted. The pR8-T24 construct should be useful for a variety of research applications, allowing insertion of any desired promoter into the 5' polylinker. In addition, potential regulatory elements could be inserted at the 3' end using the BamH1 site. This plasmid provides a great deal of flexibility in designing constructs which facilitate ras p21 expression in different cell types, either by transfection in vitro or in transgenic mice in vivo.

  19. The genome of the polar eukaryotic microalga Coccomyxa subellipsoidea reveals traits of cold adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, Guillaume; Agarkova, Irina; Grimwood, Jane; Kuo, Alan; Brueggeman, Andrew; Dunigan, David D.; Gurnon, James; Ladunga, Istvan; Lindquist, Erika; Lucas, Susan; Pangilinan, Jasmyn; Proschold, Thomas; Salamov, Asaf; Schmutz, Jeremy; Weeks, Donald; Tamada, Takashi; Lomsadze, Alexandre; Borodovsky, Mark; Claverie, Jean-Michel; Grigoriev, Igor V.; Van Etten, James L.

    2012-02-13

    Background Little is known about the mechanisms of adaptation of life to the extreme environmental conditions encountered in polar regions. Here we present the genome sequence of a unicellular green alga from the division chlorophyta, Coccomyxa subellipsoidea C-169, which we will hereafter refer to as C-169. This is the first eukaryotic microorganism from a polar environment to have its genome sequenced. Results The 48.8 Mb genome contained in 20 chromosomes exhibits significant synteny conservation with the chromosomes of its relatives Chlorella variabilis and Chlamydomonas reinhardtii. The order of the genes is highly reshuffled within synteny blocks, suggesting that intra-chromosomal rearrangements were more prevalent than inter-chromosomal rearrangements. Remarkably, Zepp retrotransposons occur in clusters of nested elements with strictly one cluster per chromosome probably residing at the centromere. Several protein families overrepresented in C. subellipsoidae include proteins involved in lipid metabolism, transporters, cellulose synthases and short alcohol dehydrogenases. Conversely, C-169 lacks proteins that exist in all other sequenced chlorophytes, including components of the glycosyl phosphatidyl inositol anchoring system, pyruvate phosphate dikinase and the photosystem 1 reaction center subunit N (PsaN). Conclusions We suggest that some of these gene losses and gains could have contributed to adaptation to low temperatures. Comparison of these genomic features with the adaptive strategies of psychrophilic microbes suggests that prokaryotes and eukaryotes followed comparable evolutionary routes to adapt to cold environments.

  20. Eukaryotic ribosomes that lack a 5.8S RNA

    Science.gov (United States)

    Vossbrinck, C. R.; Woese, C. R.

    1986-01-01

    The 5.8S ribosomal RNA is believed to be a universal eukaryotic characteristic. It has no (size) counterpart among the prokaryotes, although its sequence is homologous with the first 150 or so nucleotides of the prokaryotic large subunit (23S) ribosomal RNA. An exception to this rule is reported here. The microsporidian Vairimorpha necatrix is a eukaryote that has no 5.8S rRNA. As in the prokaryotes, it has a single large subunit rRNA, whose 5-prime region corresponds to the 5.8S rRNA.

  1. Regulation of eukaryotic DNA replication and nuclear structure

    Institute of Scientific and Technical Information of China (English)

    WUJIARUI

    1999-01-01

    In eukaryote,nuclear structure is a key component for the functions of eukaryotic cells.More and more evidences show that the nuclear structure plays important role in regulating DNA replication.The nuclear structure provides a physical barrier for the replication licensing,participates in the decision where DNA replication initiates,and organizes replication proteins as replication factory for DNA replication.Through these works,new concepts on the regulation of DNA replication have emerged,which will be discussed in this minireview.

  2. Application of high-resolution capillary array electrophoresis with automated fraction collection for GeneCalling analysis of the yeast genomic DNA

    Czech Academy of Sciences Publication Activity Database

    Berka, J.; Ruiz-Martinez, M. C.; Hammond, R.; Minarik, M.; Foret, František; Sosic, Z.; Klepárník, Karel; Karger, B. L.

    2003-01-01

    Roč. 24, č. 4 (2003), s. 639-647. ISSN 0173-0835 R&D Projects: GA ČR GA203/00/0772; GA ČR GA303/00/0928 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary array * fraction collection * gene expression profiling Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.040, year: 2003

  3. Eukaryote-to-eukaryote gene transfer events revealed by the genome sequence of the wine yeast Saccharomyces cerevisiae EC1118

    OpenAIRE

    Novo, Maite; Bigey, Frederic; Beyne, Emmanuelle; Galeote, Virginie; Gavory, Frédérick; Mallet, Sandrine; Cambon, Brigitte; Legras, Jean Luc; Wincker, Patrick; Casaregola, Serge; Dequin, Sylvie

    2009-01-01

    Saccharomyces cerevisiae has been used for millennia in winemaking, but little is known about the selective forces acting on the wine yeast genome. We sequenced the complete genome of the diploid commercial wine yeast EC1118, resulting in an assembly of 31 scaffolds covering 97% of the S288c reference genome. The wine yeast differed strikingly from the other S. cerevisiae isolates in possessing 3 unique large regions, 2 of which were subtelomeric, the other being inserted within an EC1...

  4. Heat degradation of eukaryotic and bacterial DNA: an experimental model for paleomicrobiology

    Directory of Open Access Journals (Sweden)

    Nguyen-Hieu Tung

    2012-09-01

    Full Text Available Abstract Background Theoretical models suggest that DNA degradation would sharply limit the PCR-based detection of both eukaryotic and prokaryotic DNA within ancient specimens. However, the relative extent of decay of eukaryote and prokaryote DNA over time is a matter of debate. In this study, the murine macrophage cell line J774, alone or infected with Mycobacterium smegmatis bacteria, were killed after exposure to 90°C dry heat for intervals ranging from 1 to 48 h in order to compare eukaryotic cells, extracellular bacteria and intracellular bacteria. The sizes of the resulting mycobacterial rpoB and murine rpb2 homologous gene fragments were then determined by real-time PCR and fluorescent probing. Findings The cycle threshold (Ct values of PCR-amplified DNA fragments from J774 cells and the M. smegmatis negative controls (without heat exposure varied from 26–33 for the J774 rpb2 gene fragments and from 24–29 for M. smegmatis rpoB fragments. After 90°C dry heat incubation for up to 48 h, the Ct values of test samples increased relative to those of the controls for each amplicon size. For each dry heat exposure time, the Ct values of the 146-149-bp fragments were lower than those of 746-747-bp fragments. During the 4- to 24-h dry heat incubation, the non-infected J774 cell DNA was degraded into 597-bp rpb2 fragments. After 48 h, however, only 450-bp rpb2 fragments of both non-infected and infected J774 cells could be amplified. In contrast, the 746-bp rpoB fragments of M. smegmatis DNA could be amplified after the 48-h dry heat exposure in all experiments. Infected and non-infected J774 cell DNA was degraded more rapidly than M. smegmatis DNA after dry heat exposure (ANOVA test, p  Conclusion In this study, mycobacterial DNA was more resistant to dry-heat stress than eukaryotic DNA. Therefore, the detection of large, experimental, ancient mycobacterial DNA fragments is a suitable approach for paleomicrobiological studies.

  5. PPVVP2基因与PCV2ORF2不同抗原表位重组真核表达载体的构建及其免疫原性%Construction and immune efficacy of eukaryotic expression vectors of PPV VP2 gene with different antigen epitopes of PCV20RF2 gene

    Institute of Scientific and Technical Information of China (English)

    徐志文; 郭万柱; 唐玉香; 朱玲; 陈燕凌; 徐凯; 梅淼

    2011-01-01

    To investigate the immune efficacy of recombinant plasmids of PPV VP2 with different antigen epitopes of PCV20RF2,the antigen epitope of A(117-131 aa),B(157-183 aa),C(165-200 aa) and VP2 gene were obtained by PCR from PCV2 SC strain and PPV SC-1 strain respectively, and three recombinant plasmids including pCI -A-VP2, pCI-B-VP2,pCI-C-VP2 were constructed separately. Three recombinant plasmids were transferred into MDBK cells respectively,and examined by indirect immunofluorescence technology. Female mice were inoculated with the recombinant plasmids respectively,and the immune efficacy was detected by the MTT assay, FCM and ELISA. Fluorescence was ob- served in the cells after transfection with pCI -A-VP2, pCI-B-VP2, pCI-C-VP2. The immune efficacy of three recombinant plasmids was significantly higher than the negative control group and pCI-B-VP2 was the highest among the three plasmids. It indicated that antigen epitopes B of PCV20RF2 can be used to study the two joint vaccines with other virus.%为了研究PCV2ORF2的不同抗原表位重组PPVVP2基因真核表达质粒的体外表达情况与免疫原性,分别以PCV2SC株和PPVSC-1株为模板,扩增PCV2ORF2的抗原表位基因A、B、c(A:117~131aa,B:157~183aa,C:165~200aa)和PPVVP2基因。将A、B、C基因分别与PPVVP2基因串联,并插入到pCI真核表达载体中,构建了能同时表达PPVVP2蛋白和PCV20RF2抗原表位的重组质粒pCI—A—VP2、pCI13-Vp2、pCI—C—VP2。将重组真核表达质粒转染MDBK细胞,用间接免疫荧光试验检测各个质粒在细胞中的表达情况;并将其免疫小鼠,采用MTT比色法、流式细胞术和ELISA法检测免疫效果。结果显示,3种重组表达质粒转染细胞48h后都能检测到较强的免疫荧光;免疫小鼠后14~42d诱导的T淋巴细胞转化效率、CD4+/CD8+细胞比值以及PPV和PCV2抗体均显著高于对照组,且pCI—13-VP2免疫效率高于

  6. The Oxytricha trifallax macronuclear genome: a complex eukaryotic genome with 16,000 tiny chromosomes.

    Directory of Open Access Journals (Sweden)

    Estienne C Swart

    Full Text Available The macronuclear genome of the ciliate Oxytricha trifallax displays an extreme and unique eukaryotic genome architecture with extensive genomic variation. During sexual genome development, the expressed, somatic macronuclear genome is whittled down to the genic portion of a small fraction (∼5% of its precursor "silent" germline micronuclear genome by a process of "unscrambling" and fragmentation. The tiny macronuclear "nanochromosomes" typically encode single, protein-coding genes (a small portion, 10%, encode 2-8 genes, have minimal noncoding regions, and are differentially amplified to an average of ∼2,000 copies. We report the high-quality genome assembly of ∼16,000 complete nanochromosomes (∼50 Mb haploid genome size that vary from 469 bp to 66 kb long (mean ∼3.2 kb and encode ∼18,500 genes. Alternative DNA fragmentation processes ∼10% of the nanochromosomes into multiple isoforms that usually encode complete genes. Nucleotide diversity in the macronucleus is very high (SNP heterozygosity is ∼4.0%, suggesting that Oxytricha trifallax may have one of the largest known effective population sizes of eukaryotes. Comparison to other ciliates with nonscrambled genomes and long macronuclear chromosomes (on the order of 100 kb suggests several candidate proteins that could be involved in genome rearrangement, including domesticated MULE and IS1595-like DDE transposases. The assembly of the highly fragmented Oxytricha macronuclear genome is the first completed genome with such an unusual architecture. This genome sequence provides tantalizing glimpses into novel molecular biology and evolution. For example, Oxytricha maintains tens of millions of telomeres per cell and has also evolved an intriguing expansion of telomere end-binding proteins. In conjunction with the micronuclear genome in progress, the O. trifallax macronuclear genome will provide an invaluable resource for investigating programmed genome rearrangements, complementing

  7. Computación evolutiva y aprendizaje automático para la inferencia, modelado y simulación de redes regulatorias de genes

    OpenAIRE

    Carballido, Jessica Andrea; Ponzoni, Ignacio; Gallo, Cristian Andrés

    2009-01-01

    Los alcances principales de esta línea de I/D consisten en diseñar técnicas computacionales que asistan a expertos en bioinformática en la obtención de nuevos conocimientos sobre el funcionamiento de los mecanismos de regulación existentes a nivel molecular en los organismos biológicos. Más específicamente, se busca desarrollar sistemas de software que asistan en la reconstrucción (o descubrimiento) de la estructura relacional presente en las redes regulatorias de genes.

  8. Automated stopcock actuator

    OpenAIRE

    Vandehey, N. T.; O'Neil, J.P.

    2015-01-01

    Introduction We have developed a low-cost stopcock valve actuator for radiochemistry automation built using a stepper motor and an Arduino, an open-source single-board microcontroller. The con-troller hardware can be programmed to run by serial communication or via two 5–24 V digital lines for simple integration into any automation control system. This valve actuator allows for automated use of a single, disposable stopcock, providing a number of advantages over stopcock manifold systems ...

  9. The Adaptive Automation Design

    OpenAIRE

    Calefato, Caterina; Montanari, Roberto; TESAURI, Francesco

    2008-01-01

    After considering the positive effects of adaptive automation implementation, this chapter focuses on two partly overlapping phenomena: on the one hand, the role of trust in automation is considered, particularly as to the effects of overtrust and mistrust in automation's reliability; on the other hand, long-term lack of exercise on specific operation may lead users to skill deterioration. As a future work, it will be interesting and challenging to explore the conjunction of adaptive automati...

  10. Service functional test automation

    OpenAIRE

    Hillah, Lom Messan; Maesano, Ariele-Paolo; Rosa, Fabio; Maesano, Libero; Lettere, Marco; Fontanelli, Riccardo

    2015-01-01

    This paper presents the automation of the functional test of services (black-box testing) and services architectures (grey-box testing) that has been developed by the MIDAS project and is accessible on the MIDAS SaaS. In particular, the paper illustrates the solutions of tough functional test automation problems such as: (i) the configuration of the automated test execution system against large and complex services architectures, (ii) the constraint-based test input generation, (iii) the spec...

  11. Plant and animal glycolate oxidases have a common eukaryotic ancestor and convergently duplicated to evolve long-chain 2-hydroxy acid oxidases.

    Science.gov (United States)

    Esser, Christian; Kuhn, Anke; Groth, Georg; Lercher, Martin J; Maurino, Veronica G

    2014-05-01

    Glycolate oxidase (GOX) is a crucial enzyme of plant photorespiration. The encoding gene is thought to have originated from endosymbiotic gene transfer between the eukaryotic host and the cyanobacterial endosymbiont at the base of plantae. However, animals also possess GOX activities. Plant and animal GOX belong to the gene family of (L)-2-hydroxyacid-oxidases ((L)-2-HAOX). We find that all (L)-2-HAOX proteins in animals and archaeplastida go back to one ancestral eukaryotic sequence; the sole exceptions are green algae of the chlorophyta lineage. Chlorophyta replaced the ancestral eukaryotic (L)-2-HAOX with a bacterial ortholog, a lactate oxidase that may have been obtained through the primary endosymbiosis at the base of plantae; independent losses of this gene may explain its absence in other algal lineages (glaucophyta, rhodophyta, and charophyta). We also show that in addition to GOX, plants possess (L)-2-HAOX proteins with different specificities for medium- and long-chain hydroxyacids (lHAOX), likely involved in fatty acid and protein catabolism. Vertebrates possess lHAOX proteins acting on similar substrates as plant lHAOX; however, the existence of GOX and lHAOX subfamilies in both plants and animals is not due to shared ancestry but is the result of convergent evolution in the two most complex eukaryotic lineages. On the basis of targeting sequences and predicted substrate specificities, we conclude that the biological role of plantae (L)-2-HAOX in photorespiration evolved by co-opting an existing peroxisomal protein. PMID:24408912

  12. A Eukaryotic-Type Serine/Threonine Protein Kinase Is Required for Biofilm Formation, Genetic Competence, and Acid Resistance in Streptococcus mutans

    OpenAIRE

    Hussain, H.; Branny, P.; Allan, E.

    2006-01-01

    We report an operon encoding a eukaryotic-type serine/threonine protein kinase (STPK) and its cognate phosphatase (STPP) in Streptococcus mutans. Mutation of the gene encoding the STPK produced defects in biofilm formation, genetic competence, and acid resistance, determinants important in caries pathogenesis.

  13. Characterization of prokaryotic and eukaryotic promoters usinghidden Markov models

    DEFF Research Database (Denmark)

    Pedersen, Anders Gorm; Baldi, Pierre; Brunak, Søren;

    1996-01-01

    In this paper we utilize hidden Markov models (HMMs) and information theory to analyze prokaryotic and eukaryotic promoters. We perform this analysis with special emphasis on the fact that promoters are divided into a number of different classes, depending on which polymerase-associated factors...

  14. Reconsidering DNA Polymerases at the Replication Fork in Eukaryotes

    OpenAIRE

    Stillman, Bruce

    2015-01-01

    The distribution of DNA polymerase activities at the eukaryotic DNA replication fork was “established,” but recent genetic studies in this issue of Molecular Cell raise questions about which polymerases are copying the leading and lagging strand templates (Johnson et al, 2015).

  15. Abundance of eukaryotic microbes in the deep subtropical North Atlantic

    NARCIS (Netherlands)

    Morgan-Smith, D.; Herndl, G.J.; van Aken, H.M.; Bochdansky, A.B.

    2011-01-01

    The meso- and bathypelagic ocean comprises the largest habitat on earth, yet we know very little about the distribution and activity of protists in this environment. These small eukaryotes are responsible for controlling bacterial abundance in the surface ocean and are major players in the material

  16. Geminin: a major DNA replication safeguard in higher eukaryotes

    DEFF Research Database (Denmark)

    Melixetian, Marina; Helin, Kristian

    2004-01-01

    Eukaryotes have evolved multiple mechanisms to restrict DNA replication to once per cell cycle. These mechanisms prevent relicensing of origins of replication after initiation of DNA replication in S phase until the end of mitosis. Most of our knowledge of mechanisms controlling prereplication...

  17. Characterization of prokaryotic and eukaryotic promoters using hidden Markov models

    DEFF Research Database (Denmark)

    Pedersen, Anders Gorm; Baldi, P.; Chauvin, Y.;

    1996-01-01

    In this paper we utilize hidden Markov models (HMMs) and information theory to analyze prokaryotic and eukaryotic promoters. We perform this analysis with special emphasis on the fact that promoters are divided into a number of different classes, depending on which polymerase-associated factors...

  18. Magnetic Decoration and Labeling of Prokaryotic and Eukaryotic Cells

    Czech Academy of Sciences Publication Activity Database

    Šafařík, Ivo; Maděrová, Zdeňka; Pospišková, K.; Horská, Kateřina; Šafaříková, Miroslava

    Cambridge: Royal society of chemistry, 2014 - (Fakhrullin, R.; Choi, I.; Lvov, Y.), s. 185-215 ISBN 978-1-84973-902-3 R&D Projects: GA MŠk(CZ) LD13023; GA ČR(CZ) GAP503/11/2263 Institutional support: RVO:67179843 Keywords : eukaryotic cells * nanoparticles * microparticles * organic and inorganic xenobiotics Subject RIV: DJ - Water Pollution ; Quality

  19. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae

    NARCIS (Netherlands)

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments.Cyanobacteria are promising host organisms for

  20. Selenocystamine improves protein accumulation in chloroplasts of eukaryotic green algae

    OpenAIRE

    Ferreira-Camargo, Livia S; Tran, Miller; Beld, Joris; Burkart, Michael D.; Mayfield, Stephen P

    2015-01-01

    Eukaryotic green algae have become an increasingly popular platform for recombinant proteins production. In particular, Chlamydomonas reinhardtii, has garnered increased attention for having the necessary biochemical machinery to produce vaccines, human antibodies and next generation cancer targeting immunotoxins. While it has been shown that chloroplasts contain chaperones, peptidyl prolylisomerases and protein disulfide isomerases that facilitate these complex proteins folding and assembly,...

  1. Uncoupling of Sister Replisomes during Eukaryotic DNA Replication

    NARCIS (Netherlands)

    Yardimci, Hasan; Loveland, Anna B.; Habuchi, Satoshi; van Oijen, Antoine M.; Walter, Johannes C.

    2010-01-01

    The duplication of eukaryotic genomes involves the replication of DNA from multiple origins of replication. In S phase, two sister replisomes assemble at each active origin, and they replicate DNA in opposite directions. Little is known about the functional relationship between sister replisomes. So

  2. Nitrate storage and dissimilatory nitrate reduction by eukaryotic microbes

    DEFF Research Database (Denmark)

    Kamp, Anja; Høgslund, Signe; Risgaard-Petersen, Nils; Stief, Peter

    2015-01-01

    storage and dissimilatory nitrate reduction by diverse marine eukaryotes placed into an eco-physiological context. The advantage of intracellular nitrate storage for anaerobic energy conservation in oxygen-depleted habitats is explained and the life style enabled by this metabolic trait is described. A...

  3. The biology of eukaryotic promoter prediction - a review

    DEFF Research Database (Denmark)

    Pedersen, Anders Gorm; Baldi, Pierre; Chauvin, Yves;

    1999-01-01

    Computational prediction of eukaryotic promoters from the nucleotide sequence is one of the most attractive problems in sequence analysis today, but it is also a very difficult one. Thus, current methods predict in the order of one promoter per kilobase in human DNA, while the average distance...

  4. The biology of eukaryotic promoter prediction - a review

    DEFF Research Database (Denmark)

    Pedersen, Anders Gorm; Baldi, Pierre; Chauvin, Yves; Brunak, Søren

    Computational prediction of eukaryotic promoters from the nucleotide sequence is one of the most attractive problems in sequence analysis today, but it is also a very difficult one. Thus, current methods predict in the order of one promoter per kilobase in human DNA, while the average distance...

  5. Automated Weather Observing System

    Data.gov (United States)

    Department of Transportation — The Automated Weather Observing System (AWOS) is a suite of sensors, which measure, collect, and disseminate weather data to help meteorologists, pilots, and flight...

  6. Laboratory Automation and Middleware.

    Science.gov (United States)

    Riben, Michael

    2015-06-01

    The practice of surgical pathology is under constant pressure to deliver the highest quality of service, reduce errors, increase throughput, and decrease turnaround time while at the same time dealing with an aging workforce, increasing financial constraints, and economic uncertainty. Although not able to implement total laboratory automation, great progress continues to be made in workstation automation in all areas of the pathology laboratory. This report highlights the benefits and challenges of pathology automation, reviews middleware and its use to facilitate automation, and reviews the progress so far in the anatomic pathology laboratory. PMID:26065792

  7. Automated cloning methods.; TOPICAL

    International Nuclear Information System (INIS)

    Argonne has developed a series of automated protocols to generate bacterial expression clones by using a robotic system designed to be used in procedures associated with molecular biology. The system provides plate storage, temperature control from 4 to 37 C at various locations, and Biomek and Multimek pipetting stations. The automated system consists of a robot that transports sources from the active station on the automation system. Protocols for the automated generation of bacterial expression clones can be grouped into three categories (Figure 1). Fragment generation protocols are initiated on day one of the expression cloning procedure and encompass those protocols involved in generating purified coding region (PCR)

  8. Construction of human microRNA-21 eukaryotic overexpression vector and its up-regulation of c-myc gene expression in HepG2 .2 .15 cells%人microRNA-21真核过表达载体的构建及其在 HepG2.2.15细胞中上调c-myc基因的表达

    Institute of Scientific and Technical Information of China (English)

    林永敏; 任广立; 张卫云; 蔡启茵; 谢聪; 马恒颢

    2016-01-01

    Objective To construct the miRNA‐21 eukaryotic overexpression vector pmR‐21 and to explore its regulation effect on the expression of c‐myc gene in HepG2 .2 .15 cells .Methods The miRNA‐21 precursor gene fragment pre‐miRNA‐21 was amplified by PCR ,then connected to the pmR‐mCherry plasmid vector after double enzyme digestion ,the accuracy of the recombi‐nant vector was verified by double enzyme digestion and sequencing ;then the recombinant vector was transfected into HepG2 .2 .15 cells ,the fluorescent protein expression was observed under the fluorescence microscopy at 24 h and the transfection efficiency was detected by flow cytometry ;the expression of miRNA‐21 was evaluated by real‐time quantitative PCR;at 72 h after transfection ,the expression levels of c‐myc gene were detected by RT‐PCR and Western blot ;CCK‐8 was used to detect the cell proliferation in each group .Results The double enzyme digestion and Western blot verified that the target gene fragment was inserted into the pmR‐mCherry vector;at 24 h after transfection ,intracellular strong fluorescence was seen ,the transfection efficiency was higher than 50% ;miRNA‐21 expression level of the pmR‐21 recombinant vector group was significantly increased;c‐myc gene expression was increased in the pmR‐21 recombinant vector group at 72 h after transfection ,the cell proliferation in the pmR‐21 recombinant group was faster than that in the control group(P<0 .05) .Conclusion The pmR‐21 eukaryotic overexpression vector is successfully con‐structed ,this recombinant vector can express miRNA‐21 stably ;miRNA‐21 can up‐regulate c‐myc gene expression ,c‐myc gene is one of miR‐21′s targets for playing a cancer‐promoting action .%目的:构建人微小RNA‐21(microRNA‐21,miRNA‐21)真核过表达载体pmR‐21,探讨其在 HepG2.2.15细胞中对c‐myc基因表达的调控作用。方法 PCR扩增miRNA‐21的

  9. DNA polymerase ζ: new insight into eukaryotic mutagenesis and mammalian embryonic development

    Institute of Scientific and Technical Information of China (English)

    Feng Zhu; Ming Zhang

    2003-01-01

    Information about the mechanisms that generate mutationsin eukaryotes is likely to be useful for understanding humanhealth concerns, such as genotoxicity and cancer.Eukaryotic mutagenesis is largely the outcome of attacksby' endogenous and environmental agents. Except for DNArepair, cell cycle checkpoints and DNA damage avoidance,cells have also evolved DNA damage tolerance mechanism,by which lesion-targeted mutation might occur in thegenome during replication by specific DNA polymerases tobypass the lesions (translesion DNA synthesis, TLS), ormutation on undamaged DNA templates (untargetedmutation) might be induced. DNA polymerase ζ (poiζ),which was found firstly in budding yeast Saccharomycescerevisiae and consists of catalytic subunit scRev3 and stimulating subunit scRev7, has Received more attention in recent years. Poi ζ is a member of DNA polymerase δsubfamily, which belongs to DNA polymerase B family, and exists in almost all eukaryotes. Human homolog of the scRev3gene is located in chromosome region 6q21, and the mouse equivalent maps to chromosome 10, distal to the c-myb gene and close to the Macs gene. Alternative splicing, upstream out-of frame ATG can be found in yeast scRev3, mouse and human homologs. Furthermore, the sequence from 253-323 immediate upstream of the AUG initiator codon has the potential to form a stem-loop hairpin secondary structure in REV3 mRNA, suggesting that human REV3 protein may be expressed at low levels in human cells under normal growth conditions. The functional domain analysis showed that yeast Rev3-980 tyrosine in conserved region II is at the polymerase active site. Human REV3 amino acid residues 1 776-2 195 provide a REV7binding domain, and REV7 amino acid residues 1-211provide a bind domain for REV1, REV3 and REV7 itself.More interestingly, REV7 interacts with hMAD2 and therefore might function in the cell cycle control by affecting the activation of APC (anaphase promoting complex).Currently it has been known that

  10. 甜菜 M14品系硫氧还蛋白过氧化物酶(BvM14-Tpx)基因在原核及真核细胞中的抗氧化及抗盐能力分析%Oxidation resistance and salt resistance analysis of Thioredoxin peroxidase (BvM14-Tpx) gene from Sugar Beet M14 line in transgenic prokaryotic and eukaryotic cells

    Institute of Scientific and Technical Information of China (English)

    赵晨曦; 南景东; 马春泉; 于冰; 陈思学; 李海英

    2015-01-01

    Sugar beet monosomic addition line M14 was obtained from the intercross between a cultivated species Beta vulgaris L .and a wild species Beta corollif lora Zoss . It contains the Beta vulgaris L . genome with the addition of chromosome 9 of Beta corollif lora Zoss . The M14 line has exhibited the characteristics of stress tolerance and apomixes .Previously ,a cDNA whole length of the BvM14-Tpx gene which coded for thioredoxin peroxidase was obtained by RACE .It was reported that the Tpx gene was involved in the removal of the various peroxide reaction so as to improve the resistance of plants . In this study ,the E.coli expression system of BvM14-Tpx gene was built . The growth curve of E.coli BL21 (DE3) bacteria transferring BvM14-Tpx gene was measured under the stress of H2O2 .The results showed that transgenic E. coli strains entered growing period 1 h earlier than the control strains , suggesting that BvM14-Tpx genes can ease the inhibition of H2O2 on the growth of E.coli .And the eukaryotic expression system of BvM14-Tpx gene was built . The results of transgenic Saccharomyces cerevisiae under H2O2 and NaCl stress , showed that transgenic yeast grown better than the control , suggesting that Bv M14-T p x can improve the salt tolerance ability of transgenic yeast .%甜菜M 14品系是在栽培甜菜染色体基础上附加了野生白花甜菜第9号染色体的单体附加系,具有抗逆、无融合生殖等优异特性。在前期工作中,通过 RACE技术获得了甜菜 M14品系硫氧还蛋白过氧化物酶(Thioredoxin peroxidase , Tpx)编码基因 BvM14-Tpx的cDNA全长,此基因参与各种过氧化物的清除反应从而提高植物的抗逆性。构建了 BvM14-Tpx 基因的大肠杆菌表达体系,对转 BvM14-Tpx基因的大肠杆菌BL21(DE3)菌体在H2 O2胁迫下的生长曲线进行了测定,结果显示转基因菌株比对照菌株提前1 h进入生长期,说明BvM14-Tpx基因能够缓解H2O2对大肠杆菌生长的

  11. Evolutionary constraints of phosphorylation in eukaryotes, prokaryotes, and mitochondria.

    Science.gov (United States)

    Gnad, Florian; Forner, Francesca; Zielinska, Dorota F; Birney, Ewan; Gunawardena, Jeremy; Mann, Matthias

    2010-12-01

    High accuracy mass spectrometry has proven to be a powerful technology for the large scale identification of serine/threonine/tyrosine phosphorylation in the living cell. However, despite many described phosphoproteomes, there has been no comparative study of the extent of phosphorylation and its evolutionary conservation in all domains of life. Here we analyze the results of phosphoproteomics studies performed with the same technology in a diverse set of organisms. For the most ancient organisms, the prokaryotes, only a few hundred proteins have been found to be phosphorylated. Applying the same technology to eukaryotic species resulted in the detection of thousands of phosphorylation events. Evolutionary analysis shows that prokaryotic phosphoproteins are preferentially conserved in all living organisms, whereas-site specific phosphorylation is not. Eukaryotic phosphosites are generally more conserved than their non-phosphorylated counterparts (with similar structural constraints) throughout the eukaryotic domain. Yeast and Caenorhabditis elegans are two exceptions, indicating that the majority of phosphorylation events evolved after the divergence of higher eukaryotes from yeast and reflecting the unusually large number of nematode-specific kinases. Mitochondria present an interesting intermediate link between the prokaryotic and eukaryotic domains. Applying the same technology to this organelle yielded 174 phosphorylation sites mapped to 74 proteins. Thus, the mitochondrial phosphoproteome is similarly sparse as the prokaryotic phosphoproteomes. As expected from the endosymbiotic theory, phosphorylated as well as non-phosphorylated mitochondrial proteins are significantly conserved in prokaryotes. However, mitochondrial phosphorylation sites are not conserved throughout prokaryotes, consistent with the notion that serine/threonine phosphorylation in prokaryotes occurred relatively recently in evolution. Thus, the phosphoproteome reflects major events in the

  12. Eukaryotic microorganisms in cold environments. Examples from Pyrenean glaciers

    Directory of Open Access Journals (Sweden)

    CristinaCid

    2013-03-01

    Full Text Available Little is known about the viability of eukaryotic microorganisms preserved in icy regions. Here we report on the diversity of microbial eukaryotes in ice samples derived from four Pyrenean glaciers. The species composition of eukaryotic communities in these glaciers is unknown mostly because of the presence of a multi-year ice cap, and it is not clear whether they harbor the same populations. The recent deglaciation of these areas is allowing an easy access to glacial layers that correspond to the “Little Ice Age” although some isolated deposits are attributed to previous glacial cycles. In this study, we use molecular 18S rRNA-based approaches to characterize some of the microbial eukaryotic populations associated with Pyrenean glaciers. Firstly, we performed a chemical and microscopical characterization of ice samples. Secondly, molecular analyses revealed interesting protist genetic diversity in glaciers. In order to understand the microbial composition of the ice samples the eukaryotic communities resident in the glacial samples were examined by amplifying community DNA and constructing clone libraries with 18S rRNA primers. After removal of potential chimeric sequences and derreplication of identical sequences, phylogenetic analysis demonstrated that several different protists could be identified. Protist diversity was more phylum rich in Aneto and Monte Perdido glaciers. The dominant taxonomic groups across all samples (> 1 % of all sequences were Viridiplantae and Rhizaria. Significant variations in relative abundances of protist phyla between higher and lower glaciers were observed. At the genus level, significant differences were also recorded for the dominant genera Chloromonas, Raphidonema , Heteromita , Koliella and Bodomorpha. In addition, protist community structure showed significant differences between glaciers. The relative abundances of protist groups at different taxonomic levels correlated with the altitude and area of

  13. Rapid quantification and taxonomic classification of environmentalDNA from both prokaryotic and eukaryotic origins using a microarray

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, Todd Z.; Stone, Carol E.; Murray, Sonya R.; Moberg,Jordan P.; Andersen, Gary L.

    2005-02-22

    A microarray has been designed using 62,358 probes matched to both prokaryotic and eukaryotic small-subunit ribosomal RNA genes. The array categorized environmental DNA to specific phylogenetic clusters in under 9 h. To a background of DNA generated from natural outdoor aerosols, known quantities of rRNA gene copies from distinct organisms were added producing corresponding hybridization intensity scores that correlated well with their concentrations (r=0.917). Reproducible differences in microbial community composition were observed by altering the genomic DNA extraction method. Notably, gentle extractions produced peak intensities for Mycoplasmatales and Burkholderiales, whereas a vigorous disruption produced peak intensities for Vibrionales,Clostridiales, and Bacillales.

  14. Fusión automática de imágenes a través de la obtención de sinogramas

    OpenAIRE

    Manuel Guillermo Forero; Marcela González

    2011-01-01

    El desarrollo de técnicas de fusión tiene un alto costo computacional y demandan, por el uso que de ellas se da, excelentes resultados. Este trabajo compara la aplicación de dos técnicas de retroproyección (proyección de máxima intensidad y promedio) para la obtención de sinogramas, los cuales serán utilizados como herramienta analítica dentro del procedimiento, junto con un par de métodos de correlación que permiten fusionar dos imágenes del mismo tipo; estos resultados constituyen el materi...

  15. Searching for eukaryotic life preserved in Antarctic permafrost

    Science.gov (United States)

    Onofri, Silvano; Zucconi, Laura; Selbmann, Laura; Ripa, Caterina; Frisvad, Jens Christian; Guglielmin, Mauro; Turchetti, Benedetta; Buzzini, Pietro

    Permafrost is defined as a soil remaining at 0 C or below throughout two or more consecutive years. Mainly present in polar areas, it occurs in all ice-free areas of Continental Antarc-tica. With the evidences of the possible presence of water ice below the surface of Mars and Moon, permafrost is now considered a possible reservoir of prokaryotic and eukaryotic spores outside the Earth. Cultivable fungi and yeasts have been isolated from Antarctic permafrost collected at different depths (233, 316 and 335 cm) in the McMurdo Dry Valleys, the largest ice-free area in Antarctica, and identified with cultural, physiological and molecular methods. Filamentous fungi belonged to the genera Penicillium, Eurotium, Cladosporium, Alternaria, Engyodonthium, Cordiceps, Rhizopus, Aureobasidium, whereas yeasts belonged to the genera Cryptococcus and Sporidiobolus. Penicillia were the most represented, and the most frequently recorded species were Penicillium palitans and P. chrysogenum. Most of the species found have been already recorded in Antarctic ecosystems as well as in other cold habitats (Onofri et al., 2007); for Eurotium amstelodami and Cryptococcus stepposus these are the first isolations in Antarctica. All the filamentous fungal isolates can be defined as mesophilic having optimal growth temperatures at 20-25 C and poor growth at 0 C after prolonged incubation. All the yeast isolates grew within a wide range of temperature (from 4 to 25 C). The molecular anal-yses based on the ITS rDNA sequences, for filamentous fungi, and on D1/D2 domain of LSU rRNA gene and ITS sequences for yeasts, revealed that these genotypes do not deviate from the global gene pool of microorganisms commonly spreading worldwide at present. Annual mean permafrost temperature (MAPT) in the sampling area was -18.8 C in 2008, with daily fluctuations lower than 1 C/day at 1 m of depth, but less 0.5 C/year at the depth of 17 m (Guglielmin pers. com.), and maximum thaw depth not exceeding 1 m

  16. Eukaryotes dominate new production in the Sargasso Sea

    Science.gov (United States)

    Fawcett, S. E.; Lomas, M. W.; Ward, B. B.; Casey, J. R.; Sigman, D. M.

    2010-12-01

    The vast subtropical ocean gyres are considered unproductive “deserts” due to the extremely low concentrations of essential nutrients in their sunlit surface waters. Because of intense upper ocean stratification, phytoplankton growth in the subtropical gyres is limited by the slow supply of nitrate from below, and is assumed to be supported predominantly by “regenerated” nitrogen (N): ammonium and other reduced N sources recycled in surface waters. The phytoplankton assemblage of the subtropical Sargasso Sea is dominated by the prokaryotic cyanobacteria, Prochlorococcus and Synechococcus, which occur in very high cell numbers compared to the rarer, and usually larger, eukaryotic algae. Coupling flow cytometry and a new high-sensitivity method for N isotope analysis, we measure the 15N/14N of major phytoplankton taxa and other biologically distinct particle populations collected from the surface waters of the Sargasso Sea during the stratified summer period. We find that the cyanobacteria and eukaryotic phytoplankton show distinct N isotope signatures, indicating that they utilize different sources of N for growth. Prochlorococcus and Synechococcus have a uniformly low 15N/14N, consistent with the expectation that these phytoplankton rely on regenerated N. However, the 15N/14N of eukaryotic phytoplankton is higher and more variable, with a mean 15N/14N comparable to the new nitrate supply from below, indicating that eukaryotes dominate the consumption of this nitrate and rely on it for more than half of their N requirement. Using our measured 15N/14N values for the various sorted autotrophic populations, we calculate eukaryote-specific summer f-ratios of 0.6-0.67 and total community summer f-ratios of 0.15-0.23. These values are higher than those based on comparison of primary production and sediment-trap derived organic carbon (C) export, and agree well with annual f-ratio estimates implied by geochemical tracers. The high 15N/14N of eukaryotic biomass can

  17. Re-evaluating the green versus red signal in eukaryotes with secondary plastid of red algal origin

    KAUST Repository

    Burki, Fabien

    2012-05-16

    The transition from endosymbiont to organelle in eukaryotic cells involves the transfer of significant numbers of genes to the host genomes, a process known as endosymbiotic gene transfer (EGT). In the case of plastid organelles, EGTs have been shown to leave a footprint in the nuclear genome that can be indicative of ancient photosynthetic activity in present-day plastid-lacking organisms, or even hint at the existence of cryptic plastids. Here,we evaluated the impact of EGTon eukaryote genomes by reanalyzing the recently published EST dataset for Chromera velia, an interesting test case of a photosynthetic alga closely related to apicomplexan parasites. Previously, 513 genes were reported to originate from red and green algae in a 1:1 ratio. In contrast, by manually inspecting newly generated trees indicating putative algal ancestry, we recovered only 51 genes congruent with EGT, of which 23 and 9 were of red and green algal origin, respectively,whereas 19 were ambiguous regarding the algal provenance.Our approach also uncovered 109 genes that branched within a monocot angiosperm clade, most likely representing a contamination. We emphasize the lack of congruence and the subjectivity resulting from independent phylogenomic screens for EGT, which appear to call for extreme caution when drawing conclusions for major evolutionary events. 2012 The Author(s).

  18. Library Automation Style Guide.

    Science.gov (United States)

    Gaylord Bros., Liverpool, NY.

    This library automation style guide lists specific terms and names often used in the library automation industry. The terms and/or acronyms are listed alphabetically and each is followed by a brief definition. The guide refers to the "Chicago Manual of Style" for general rules, and a notes section is included for the convenience of individual…

  19. Automation in Warehouse Development

    NARCIS (Netherlands)

    Hamberg, R.; Verriet, J.

    2012-01-01

    The warehouses of the future will come in a variety of forms, but with a few common ingredients. Firstly, human operational handling of items in warehouses is increasingly being replaced by automated item handling. Extended warehouse automation counteracts the scarcity of human operators and support

  20. Automate functional testing

    Directory of Open Access Journals (Sweden)

    Ramesh Kalindri

    2014-06-01

    Full Text Available Currently, software engineers are increasingly turning to the option of automating functional tests, but not always have successful in this endeavor. Reasons range from low planning until over cost in the process. Some principles that can guide teams in automating these tests are described in this article.

  1. Elucidating the composition and conservation of the autophagy pathway in photosynthetic eukaryotes.

    Science.gov (United States)

    Shemi, Adva; Ben-Dor, Shifra; Vardi, Assaf

    2015-04-01

    Aquatic photosynthetic eukaryotes represent highly diverse groups (green, red, and chromalveolate algae) derived from multiple endosymbiosis events, covering a wide spectrum of the tree of life. They are responsible for about 50% of the global photosynthesis and serve as the foundation for oceanic and fresh water food webs. Although the ecophysiology and molecular ecology of some algal species are extensively studied, some basic aspects of algal cell biology are still underexplored. The recent wealth of genomic resources from algae has opened new frontiers to decipher the role of cell signaling pathways and their function in an ecological and biotechnological context. Here, we took a bioinformatic approach to explore the distribution and conservation of TOR and autophagy-related (ATG) proteins (Atg in yeast) in diverse algal groups. Our genomic analysis demonstrates conservation of TOR and ATG proteins in green algae. In contrast, in all 5 available red algal genomes, we could not detect the sequences that encode for any of the 17 core ATG proteins examined, albeit TOR and its interacting proteins are conserved. This intriguing data suggests that the autophagy pathway is not conserved in red algae as it is in the entire eukaryote domain. In contrast, chromalveolates, despite being derived from the red-plastid lineage, retain and express ATG genes, which raises a fundamental question regarding the acquisition of ATG genes during algal evolution. Among chromalveolates, Emiliania huxleyi (Haptophyta), a bloom-forming coccolithophore, possesses the most complete set of ATG genes, and may serve as a model organism to study autophagy in marine protists with great ecological significance. PMID:25915714

  2. [Expression and identification of eukaryotic expression vectors of Brucella melitensis lipoprotein OMP19].

    Science.gov (United States)

    He, Zuoping; Luo, Peifang; Hu, Feihuan; Weng, Yunceng; Wang, Wenjing; Li, Chengyao

    2016-04-01

    Objective To construct eukaryotic expression vectors carrying Brucella melitensis outer membrane protein 19 (OMP19), express them in transfected Huh7.5.1 and JEG-3 cells, and analyze their role in cell apoptosis. Methods Brucella melitensis lipidated OMP19 (L-OMP19) gene and unlipidated OMP19 (U-OMP19) gene were amplified by PCR and inserted into the vector pZeroBack/blunt. The correct L-OMP19 and U-OMP19 genes verified by XbaI and BamHI double digestion and sequencing were cloned into the lentivirus expression vector pHAGE-CMV-MCS-IZsGreen to construct vectors pHAGE-L-OMP19 and pHAGE-U-OMP19, which were separately transfected into 293FT cells, Huh7.5.1 and JEG-3 cells. L-OMP19 and U-OMP19 in the cells were detected by Western blotting and immunofluorescence technique. Flow cytometry combined with annexin V-PE/7-AAD staining was used to detect the cell apoptosis. Results The lentiviral vectors pHAGE-L-OMP19 and pHAGE-U-OMP19 were constructed correctly and the recombinant lipoproteins L-OMP19 and U-OMP19 expressed in the above cells were well recognized by the specific antibodies against L-OMP19 in Western blotting and immunofluorescence technique. L-OMP19 and U-OMP19 induced JEG-3 cell death, but did not induce the apoptosis of Huh7.5.1 cells. Conclusion The eukaryotic expression vectors of L-OMP19 and U-OMP19 have been constructed successfully. Recombinant lipoproteins L-OMP19 and U-OMP19 expressed in cells have a good antigenicity, which could be used as experimental materials for the research on the relationship between host cells and lipoproteins in Brucella infection. PMID:27053612

  3. Automation in Immunohematology

    Directory of Open Access Journals (Sweden)

    Meenu Bajpai

    2012-01-01

    Full Text Available There have been rapid technological advances in blood banking in South Asian region over the past decade with an increasing emphasis on quality and safety of blood products. The conventional test tube technique has given way to newer techniques such as column agglutination technique, solid phase red cell adherence assay, and erythrocyte-magnetized technique. These new technologies are adaptable to automation and major manufacturers in this field have come up with semi and fully automated equipments for immunohematology tests in the blood bank. Automation improves the objectivity and reproducibility of tests. It reduces human errors in patient identification and transcription errors. Documentation and traceability of tests, reagents and processes and archiving of results is another major advantage of automation. Shifting from manual methods to automation is a major undertaking for any transfusion service to provide quality patient care with lesser turnaround time for their ever increasing workload. This article discusses the various issues involved in the process.

  4. Automated model building

    CERN Document Server

    Caferra, Ricardo; Peltier, Nicholas

    2004-01-01

    This is the first book on automated model building, a discipline of automated deduction that is of growing importance Although models and their construction are important per se, automated model building has appeared as a natural enrichment of automated deduction, especially in the attempt to capture the human way of reasoning The book provides an historical overview of the field of automated deduction, and presents the foundations of different existing approaches to model construction, in particular those developed by the authors Finite and infinite model building techniques are presented The main emphasis is on calculi-based methods, and relevant practical results are provided The book is of interest to researchers and graduate students in computer science, computational logic and artificial intelligence It can also be used as a textbook in advanced undergraduate courses

  5. Automation in Warehouse Development

    CERN Document Server

    Verriet, Jacques

    2012-01-01

    The warehouses of the future will come in a variety of forms, but with a few common ingredients. Firstly, human operational handling of items in warehouses is increasingly being replaced by automated item handling. Extended warehouse automation counteracts the scarcity of human operators and supports the quality of picking processes. Secondly, the development of models to simulate and analyse warehouse designs and their components facilitates the challenging task of developing warehouses that take into account each customer’s individual requirements and logistic processes. Automation in Warehouse Development addresses both types of automation from the innovative perspective of applied science. In particular, it describes the outcomes of the Falcon project, a joint endeavour by a consortium of industrial and academic partners. The results include a model-based approach to automate warehouse control design, analysis models for warehouse design, concepts for robotic item handling and computer vision, and auton...

  6. Advances in inspection automation

    Science.gov (United States)

    Weber, Walter H.; Mair, H. Douglas; Jansen, Dion; Lombardi, Luciano

    2013-01-01

    This new session at QNDE reflects the growing interest in inspection automation. Our paper describes a newly developed platform that makes the complex NDE automation possible without the need for software programmers. Inspection tasks that are tedious, error-prone or impossible for humans to perform can now be automated using a form of drag and drop visual scripting. Our work attempts to rectify the problem that NDE is not keeping pace with the rest of factory automation. Outside of NDE, robots routinely and autonomously machine parts, assemble components, weld structures and report progress to corporate databases. By contrast, components arriving in the NDT department typically require manual part handling, calibrations and analysis. The automation examples in this paper cover the development of robotic thickness gauging and the use of adaptive contour following on the NRU reactor inspection at Chalk River.

  7. Extracellular DNA amplicon sequencing reveals high levels of benthic eukaryotic diversity in the central Red Sea

    KAUST Repository

    Pearman, John K.

    2015-11-01

    The present study aims to characterize the benthic eukaryotic biodiversity patterns at a coarse taxonomic level in three areas of the central Red Sea (a lagoon, an offshore area in Thuwal and a shallow coastal area near Jeddah) based on extracellular DNA. High-throughput amplicon sequencing targeting the V9 region of the 18S rRNA gene was undertaken for 32 sediment samples. High levels of alpha-diversity were detected with 16,089 operational taxonomic units (OTUs) being identified. The majority of the OTUs were assigned to Metazoa (29.2%), Alveolata (22.4%) and Stramenopiles (17.8%). Stramenopiles (Diatomea) and Alveolata (Ciliophora) were frequent in a lagoon and in shallower coastal stations, whereas metazoans (Arthropoda: Maxillopoda) were dominant in deeper offshore stations. Only 24.6% of total OTUs were shared among all areas. Beta-diversity was generally lower between the lagoon and Jeddah (nearshore) than between either of those and the offshore area, suggesting a nearshore–offshore biodiversity gradient. The current approach allowed for a broad-range of benthic eukaryotic biodiversity to be analysed with significantly less labour than would be required by other traditional taxonomic approaches. Our findings suggest that next generation sequencing techniques have the potential to provide a fast and standardised screening of benthic biodiversity at large spatial and temporal scales.

  8. Programmable Site-Specific Nucleases for Targeted Genome Engineering in Higher Eukaryotes.

    Science.gov (United States)

    Govindan, Ganesan; Ramalingam, Sivaprakash

    2016-11-01

    Recent advances in the targeted genome engineering enable molecular biologists to generate sequence specific modifications with greater efficiency and higher specificity in complex eukaryotic genomes. Programmable site-specific DNA cleavage reagents and cellular DNA repair mechanisms have made this possible. These reagents have become powerful tools for delivering a site-specific genomic double-strand break (DSB) at the desired chromosomal locus, which produces sequence alterations through error-prone non-homologous end joining (NHEJ) resulting in gene inactivations/knockouts. Alternatively, the DSB can be repaired through homology-directed repair (HDR) using a donor DNA template, which leads to the introduction of desired sequence modifications at the predetermined site. Here, we summarize the role of three classes of nucleases; zinc finger nucleases (ZFNs), transcription activator like effector nucleases (TALENs), and clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) system in achieving targeted genome modifications. Further, we discuss the progress towards the applications of programmable site-specific nucleases (SSNs) in treating human diseases and other biological applications in economically important higher eukaryotic organisms such as plants and livestock. J. Cell. Physiol. 231: 2380-2392, 2016. © 2016 Wiley Periodicals, Inc. PMID:26945523

  9. Pyrosequencing assessment of prokaryotic and eukaryotic diversity in biofilm communities from a French river.

    Science.gov (United States)

    Bricheux, Geneviève; Morin, Loïc; Le Moal, Gwenaël; Coffe, Gérard; Balestrino, Damien; Charbonnel, Nicolas; Bohatier, Jacques; Forestier, Christiane

    2013-06-01

    Despite the recent and significant increase in the study of aquatic microbial communities, little is known about the microbial diversity of complex ecosystems such as running waters. This study investigated the biodiversity of biofilm communities formed in a river with 454 Sequencing™. This river has the particularity of integrating both organic and microbiological pollution, as receiver of agricultural pollution in its upstream catchment area and urban pollution through discharges of the wastewater treatment plant of the town of Billom. Different regions of the small subunit (SSU) ribosomal RNA gene were targeted using nine pairs of primers, either universal or specific for bacteria, eukarya, or archaea. Our aim was to characterize the widest range of rDNA sequences using different sets of polymerase chain reaction (PCR) primers. A first look at reads abundance revealed that a large majority (47-48%) were rare sequences (<5 copies). Prokaryotic phyla represented the species richness, and eukaryotic phyla accounted for a small part. Among the prokaryotic phyla, Proteobacteria (beta and alpha) predominated, followed by Bacteroidetes together with a large number of nonaffiliated bacterial sequences. Bacillariophyta plastids were abundant. The remaining bacterial phyla, Verrucomicrobia and Cyanobacteria, made up the rest of the bulk biodiversity. The most abundant eukaryotic phyla were annelid worms, followed by Diatoms, and Chlorophytes. These latter phyla attest to the abundance of plastids and the importance of photosynthetic activity for the biofilm. These findings highlight the existence and plasticity of multiple trophic levels within these complex biological systems. PMID:23520129

  10. Mussel biofiltration effects on attached bacteria and unicellular eukaryotes in fish-rearing seawater

    Science.gov (United States)

    Voudanta, Eleni; Monchy, Sebastién; Delegrange, Alice; Vincent, Dorothée; Genitsaris, Savvas; Christaki, Urania

    2016-01-01

    Mussel biofiltration is a widely used approach for the mitigation of aquaculture water. In this study, we investigated the effect of mussel biofiltration on the communities of particle-associated bacteria and unicellular eukaryotes in a sea bass aquaculture in southern North Sea. We assessed the planktonic community changes before and after biofiltration based on the diversity of the 16S and 18S rRNA genes by using next generation sequencing technologies. Although there was no overall reduction in the operational taxonomic units (OTU) numbers between the control (no mussels) and the test (with mussels) tanks, a clear reduction in the relative abundance of the top three most dominant OTUs in every sampling time was observed, ranging between 2–28% and 16–82% for Bacteria and Eukarya, respectively. The bacterial community was dominated by OTUs related to phytoplankton blooms and/or high concentrations of detritus. Among the eukaryotes, several fungal and parasitic groups were found. Their relative abundance in most cases was also reduced from the control to the test tanks; a similar decreasing pattern was also observed for both major higher taxa and functional (trophic) groups. Overall, this study showed the effectiveness of mussel biofiltration on the decrease of microbiota abundance and diversity in seawater fueling fish farms. PMID:27069786

  11. Depth shapes α- and β-diversities of microbial eukaryotes in surficial sediments of coastal ecosystems.

    Science.gov (United States)

    Gong, Jun; Shi, Fei; Ma, Bin; Dong, Jun; Pachiadaki, Maria; Zhang, Xiaoli; Edgcomb, Virginia P

    2015-10-01

    Little is known about the relative influence of historic processes and environmental gradients on shaping the diversity of single-celled eukaryotes in marine benthos. By combining pyrosequencing of 18S ribosomal RNA genes with data on multiple environmental factors, we investigated the diversity of microeukaryotes in surficial sediments of three basins of the Yellow Sea Large Marine Ecosystem. A considerable proportion (about 20%) of reads was affiliated with known parasitoid protists. Dinophyta and Ciliophora appeared dominant in terms of relative proportion of reads and operational taxonomic unit (OTU) richness. Overall, OTU richness of benthic microeukaryotes decreased with increasing water depth and decreasing pH. While community composition was significantly different among basins, partial Mantel tests indicated a depth-decay pattern of community similarity, whereby water depth, rather than geographic distance or environment, shaped β-diversity of benthic microeukaryotes (including both the abundant and the rare biosphere) on a regional scale. Similar hydrographic and mineralogical factors contributed to the biogeography of both the abundant and the rare OTUs. The trace metal vanadium had a significant effect on the biogeography of the rare biosphere. Our study sheds new light on the composition, diversity patterns and underlying mechanisms of single-celled eukaryote distribution in surficial sediments of coastal oceans. PMID:25581721

  12. Extracellular DNA amplicon sequencing reveals high levels of benthic eukaryotic diversity in the central Red Sea.

    Science.gov (United States)

    Pearman, John K; Irigoien, Xabier; Carvalho, Susana

    2016-04-01

    The present study aims to characterize the benthic eukaryotic biodiversity patterns at a coarse taxonomic level in three areas of the central Red Sea (a lagoon, an offshore area in Thuwal and a shallow coastal area near Jeddah) based on extracellular DNA. High-throughput amplicon sequencing targeting the V9 region of the 18S rRNA gene was undertaken for 32 sediment samples. High levels of alpha-diversity were detected with 16,089 operational taxonomic units (OTUs) being identified. The majority of the OTUs were assigned to Metazoa (29.2%), Alveolata (22.4%) and Stramenopiles (17.8%). Stramenopiles (Diatomea) and Alveolata (Ciliophora) were frequent in a lagoon and in shallower coastal stations, whereas metazoans (Arthropoda: Maxillopoda) were dominant in deeper offshore stations. Only 24.6% of total OTUs were shared among all areas. Beta-diversity was generally lower between the lagoon and Jeddah (nearshore) than between either of those and the offshore area, suggesting a nearshore-offshore biodiversity gradient. The current approach allowed for a broad-range of benthic eukaryotic biodiversity to be analysed with significantly less labour than would be required by other traditional taxonomic approaches. Our findings suggest that next generation sequencing techniques have the potential to provide a fast and standardised screening of benthic biodiversity at large spatial and temporal scales. PMID:26525270

  13. Living at the Limits: Evidence for Microbial Eukaryotes Thriving under Pressure in Deep Anoxic, Hypersaline Habitats

    Directory of Open Access Journals (Sweden)

    Thorsten Stoeck

    2014-01-01

    Full Text Available The advent of molecular tools in microbial ecology paved the way to exploit the diversity of microbes in extreme environments. Here, we review these tools as applied in one of the most polyextreme habitats known on our planet, namely, deep hypersaline anoxic basins (DHABs, located at ca. 3000–3500 m depth in the Eastern Mediterranean Sea. Molecular gene signatures amplified from environmental DHAB samples identified a high degree of genetic novelty, as well as distinct communities in the DHABs. Canonical correspondence analyses provided strong evidence that salinity, ion composition, and anoxia were the strongest selection factors shaping protistan community structures, largely preventing cross-colonization among the individual basins. Thus, each investigated basin represents a unique habitat (“isolated islands of evolution”, making DHABs ideal model sites to test evolutionary hypotheses. Fluorescence in situ hybridization assays using specifically designed probes revealed that the obtained genetic signatures indeed originated from indigenous polyextremophiles. Electron microscopy imaging revealed unknown ciliates densely covered with prokaryote ectosymbionts, which may enable adaptations of eukaryotes to DHAB conditions. The research reviewed here significantly advanced our knowledge on polyextremophile eukaryotes, which are excellent models for a number of biological research areas, including ecology, diversity, biotechnology, evolutionary research, physiology, and astrobiology.

  14. MutL homologs in restriction-modification systems and the origin of eukaryotic MORC ATPases

    Directory of Open Access Journals (Sweden)

    Aravind L

    2008-03-01

    Full Text Available Abstract The provenance and biochemical roles of eukaryotic MORC proteins have remained poorly understood since the discovery of their prototype MORC1, which is required for meiotic nuclear division in animals. The MORC family contains a combination of a gyrase, histidine kinase, and MutL (GHKL and S5 domains that together constitute a catalytically active ATPase module. We identify the prokaryotic MORCs and establish that the MORC family belongs to a larger radiation of several families of GHKL proteins (paraMORCs in prokaryotes. Using contextual information from conserved gene neighborhoods we show that these proteins primarily function in restriction-modification systems, in conjunction with diverse superfamily II DNA helicases and endonucleases. The common ancestor of these GHKL proteins, MutL and topoisomerase ATPase modules appears to have catalyzed structural reorganization of protein complexes and concomitant DNA-superstructure manipulations along with fused or standalone nuclease domains. Furthermore, contextual associations of the prokaryotic MORCs and their relatives suggest that their eukaryotic counterparts are likely to carry out chromatin remodeling by DNA superstructure manipulation in response to epigenetic signals such as histone and DNA methylation. Reviewers This article was reviewed by Arcady Mushegian and Gaspar Jekely.

  15. Replication and transcription on a collision course: eukaryotic regulation mechanisms and implications for DNA stability.

    Directory of Open Access Journals (Sweden)

    Alessandra eBrambati

    2015-04-01

    Full Text Available DNA replication and transcription are vital cellular processes during which the genetic information is copied into complementary DNA and RNA molecules. Highly complex machineries required for DNA and RNA synthesis compete for the same DNA template, therefore being on a collision course. Unscheduled replication-transcription clashes alter the gene transcription program and generate replication stress, reducing fork speed. Molecular pathways and mechanisms that minimize the conflict between replication and transcription have been extensively characterized in prokaryotic cells and recently identified also in eukaryotes. A pathological outcome of replication-transcription collisions is the formation of stable RNA:DNA hybrids in molecular structures called R-loops. Growing evidence suggests that R-loop accumulation promotes both genetic and epigenetic instability, thus severely affecting genome functionality. In the present review, we summarize the current knowledge related to replication and transcription conflicts in eukaryotes, their consequences on genome instability and the pathways involved in their resolution. These findings are relevant to clarify the molecular basis of cancer and neurodegenerative diseases.

  16. A multi-label predictor for identifying the subcellular locations of singleplex and multiplex eukaryotic proteins.

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    Full Text Available Subcellular locations of proteins are important functional attributes. An effective and efficient subcellular localization predictor is necessary for rapidly and reliably annotating subcellular locations of proteins. Most of existing subcellular localization methods are only used to deal with single-location proteins. Actually, proteins may simultaneously exist at, or move between, two or more different subcellular locations. To better reflect characteristics of multiplex proteins, it is highly desired to develop new methods for dealing with them. In this paper, a new predictor, called Euk-ECC-mPLoc, by introducing a powerful multi-label learning approach which exploits correlations between subcellular locations and hybridizing gene ontology with dipeptide composition information, has been developed that can be used to deal with systems containing both singleplex and multiplex eukaryotic proteins. It can be utilized to identify eukaryotic proteins among the following 22 locations: (1 acrosome, (2 cell membrane, (3 cell wall, (4 centrosome, (5 chloroplast, (6 cyanelle, (7 cytoplasm, (8 cytoskeleton, (9 endoplasmic reticulum, (10 endosome, (11 extracellular, (12 Golgi apparatus, (13 hydrogenosome, (14 lysosome, (15 melanosome, (16 microsome, (17 mitochondrion, (18 nucleus, (19 peroxisome, (20 spindle pole body, (21 synapse, and (22 vacuole. Experimental results on a stringent benchmark dataset of eukaryotic proteins by jackknife cross validation test show that the average success rate and overall success rate obtained by Euk-ECC-mPLoc were 69.70% and 81.54%, respectively, indicating that our approach is quite promising. Particularly, the success rates achieved by Euk-ECC-mPLoc for small subsets were remarkably improved, indicating that it holds a high potential for simulating the development of the area. As a user-friendly web-server, Euk-ECC-mPLoc is freely accessible to the public at the website http://levis.tongji.edu.cn:8080/bioinfo

  17. Molecular diagnosis of mucopolysaccharidosis Type II (Hunter syndrome) by automated sequencing and computer-assisted interpretation: Toward mutation mapping of the Iduronate-2-sulfatase gene

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, J.J.; Aronovich, E.L.; Braun, S.E.; Whitley, C.B. [Univ. of Minnesota Medical School, Minneapolis, MN (United States)

    1995-03-01

    Virtually all mutations causing Hunter syndrome (mucopolysaccharidosis type II) are expected to be new mutations. Therefore, as a means of molecular diagnosis, we developed a rapid method to sequence the entire iduronate-2-sulfatase (IDS) coding region. PCR amplicons representing the IDS cDNA were sequenced with an automatic instrument, and output was analyzed by computer-assisted interpretation of tracings, using Staden programs on a Sun computer. Mutations were found in 10 of 11 patients studied. Unique missense mutations were identified in five patients: H229Y (685{r_arrow}T, severe phenotype); P358R (1073C{r_arrow}G, severe); R468W (1402C{r_arrow}T, mild); P469H (1406C{r_arrow}A, mild); and Y523C (1568A{r_arrow}G, mild). Nonsense mutations were identified in two patients: R172X (514C{r_arrow}T, severe) and Q389X (1165C{r_arrow}T, severe). Two other patients with severe disease had insertions of 1 and 14 bp, in exons 3 and 6, respectively. In another patient with severe disease, the predominant (<95%) IDS message resulted from aberrant splicing, which skipped exon 3. In this last case, consensus sequences for splice sites in exon 3 were intact, but a 395C{r_arrow}G mutation was identified 24 bp upstream from the 3` splice of exon 3. This mutation created a cryptic 5` splice site with a better consensus sequence for 5` splice sites than the natural 5` splice site of intron 3. A minor population of the IDS message was processed by using this cryptic splice site; however, no correctly spliced message was detected in leukocytes from this patient. The mutational topology of the IDS gene is presented. 46 refs., 6 figs., 2 tabs.

  18. Inferring Ancestry : Mitochondrial Origins and Other Deep Branches in the Eukaryote Tree of Life

    OpenAIRE

    He, Ding

    2014-01-01

    There are ~12 supergroups of complex-celled organisms (eukaryotes), but relationships among them (including the root) remain elusive. For Paper I, I developed a dataset of 37 eukaryotic proteins of bacterial origin (euBac), representing the conservative protein core of the proto-mitochondrion. This gives a relatively short distance between ingroup (eukaryotes) and outgroup (mitochondrial progenitor), which is important for accurate rooting. The resulting phylogeny reconstructs three eukaryote...

  19. Energy metabolism among eukaryotic anaerobes in light of Proterozoic ocean chemistry

    OpenAIRE

    Mentel, Marek; Martin, William

    2008-01-01

    Recent years have witnessed major upheavals in views about early eukaryotic evolution. One very significant finding was that mitochondria, including hydrogenosomes and the newly discovered mitosomes, are just as ubiquitous and defining among eukaryotes as the nucleus itself. A second important advance concerns the readjustment, still in progress, about phylogenetic relationships among eukaryotic groups and the roughly six new eukaryotic supergroups that are currently at the focus of much atte...

  20. AGAPE (Automated Genome Analysis PipelinE for pan-genome analysis of Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Giltae Song

    Full Text Available The characterization and public release of genome sequences from thousands of organisms is expanding the scope for genetic variation studies. However, understanding the phenotypic consequences of genetic variation remains a challenge in eukaryotes due to the complexity of the genotype-phenotype map. One approach to this is the intensive study of model systems for which diverse sources of information can be accumulated and integrated. Saccharomyces cerevisiae is an extensively studied model organism, with well-known protein functions and thoroughly curated phenotype data. To develop and expand the available resources linking genomic variation with function in yeast, we aim to model the pan-genome of S. cerevisiae. To initiate the yeast pan-genome, we newly sequenced or re-sequenced the genomes of 25 strains that are commonly used in the yeast research community using advanced sequencing technology at high quality. We also developed a pipeline for automated pan-genome analysis, which integrates the steps of assembly, annotation, and variation calling. To assign strain-specific functional annotations, we identified genes that were not present in the reference genome. We classified these according to their presence or absence across strains and characterized each group of genes with known functional and phenotypic features. The functional roles of novel genes not found in the reference genome and associated with strains or groups of strains appear to be consistent with anticipated adaptations in specific lineages. As more S. cerevisiae strain genomes are released, our analysis can be used to collate genome data and relate it to lineage-specific patterns of genome evolution. Our new tool set will enhance our understanding of genomic and functional evolution in S. cerevisiae, and will be available to the yeast genetics and molecular biology community.

  1. Cas9-mediated targeting of viral RNA in eukaryotic cells

    OpenAIRE

    Price, Aryn A.; Sampson, Timothy R.; Ratner, Hannah K.; Grakoui, Arash; Weiss, David S

    2015-01-01

    The clustered, regularly interspaced, short palindromic repeats associated endonuclease, Cas9, has quickly become a revolutionary tool in genome engineering. Utilizing small guiding RNAs, Cas9 can be targeted to specific DNA sequences of interest, where it catalyzes DNA cleavage. We now demonstrate that Cas9 from the Gram-negative bacterium Francisella novicida (FnCas9) can be reprogrammed to target a specific RNA substrate, the genome of the +ssRNA virus, hepatitis C virus, in eukaryotic cel...

  2. Eukaryotic LYR Proteins Interact with Mitochondrial Protein Complexes

    OpenAIRE

    Heike Angerer

    2015-01-01

    In eukaryotic cells, mitochondria host ancient essential bioenergetic and biosynthetic pathways. LYR (leucine/tyrosine/arginine) motif proteins (LYRMs) of the Complex1_LYR-like superfamily interact with protein complexes of bacterial origin. Many LYR proteins function as extra subunits (LYRM3 and LYRM6) or novel assembly factors (LYRM7, LYRM8, ACN9 and FMC1) of the oxidative phosphorylation (OXPHOS) core complexes. Structural insights into complex I accessory subunits LYRM6 and LYRM3 have bee...

  3. Enzymes involved in organellar DNA replication in photosynthetic eukaryotes

    OpenAIRE

    Moriyama, Takashi; Sato, Naoki

    2014-01-01

    Plastids and mitochondria possess their own genomes. Although the replication mechanisms of these organellar genomes remain unclear in photosynthetic eukaryotes, several organelle-localized enzymes related to genome replication, including DNA polymerase, DNA primase, DNA helicase, DNA topoisomerase, single-stranded DNA maintenance protein, DNA ligase, primer removal enzyme, and several DNA recombination-related enzymes, have been identified. In the reference Eudicot plant Arabidopsis thaliana...

  4. Eukaryotic Systems Broaden the Scope of Synthetic Biology

    OpenAIRE

    Haynes, Karmella A.; Silver, Pamela A.

    2009-01-01

    Synthetic biology aims to engineer novel cellular functions by assembling well-characterized molecular parts (i.e., nucleic acids and proteins) into biological “devices” that exhibit predictable behavior. Recently, efforts in eukaryotic synthetic biology have sprung from foundational work in bacteria. Designing synthetic circuits to operate reliably in the context of differentiating and morphologically complex cells presents unique challenges and opportunities for progress in the field. This ...

  5. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    Directory of Open Access Journals (Sweden)

    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  6. Evolution of Copper Transporting ATPases in Eukaryotic Organisms

    OpenAIRE

    Gupta, Arnab; Lutsenko, Svetlana

    2012-01-01

    Copper is an essential nutrient for most life forms, however in excess it can be harmful. The ATP-driven copper pumps (Copper-ATPases) play critical role in living organisms by maintaining appropriate copper levels in cells and tissues. These evolutionary conserved polytopic membrane proteins are present in all phyla from simplest life forms (bacteria) to highly evolved eukaryotes (Homo sapiens). The presumed early function in metal detoxification remains the main function of Copper-ATPases i...

  7. Intracellular sterol transport in eukaryotes, a connection to mitochondrial function ?

    OpenAIRE

    Schneiter, Roger

    2007-01-01

    Eukaryotic cells synthesize sterols in the endoplasmatic reticulum (ER) from where it needs to be efficiently transported to the plasma membrane, which harbors not, vert, similar90% of the free sterol pool of the cell. Sterols that are being taken up from the environment, on the other hand, are transported back from the plasma membrane to the ER, where the free sterols are esterified to steryl esters. The molecular mechanisms that govern this bidirectional movement of sterols between the ER a...

  8. Hydrodynamics Versus Intracellular Coupling in the Synchronization of Eukaryotic Flagella

    Science.gov (United States)

    Quaranta, Greta; Aubin-Tam, Marie-Eve; Tam, Daniel

    2015-12-01

    The influence of hydrodynamic forces on eukaryotic flagella synchronization is investigated by triggering phase locking between a controlled external flow and the flagella of C. reinhardtii. Hydrodynamic forces required for synchronization are over an order of magnitude larger than hydrodynamic forces experienced in physiological conditions. Our results suggest that synchronization is due instead to coupling through cell internal fibers connecting the flagella. This conclusion is confirmed by observations of the vfl3 mutant, with impaired mechanical connection between the flagella.

  9. An overview of pre-ribosomal RNA processing in eukaryotes

    OpenAIRE

    Henras, Anthony K.; Plisson-Chastang, Célia; O'Donohue, Marie-Françoise; Chakraborty, Anirban; Gleizes, Pierre-Emmanuel

    2014-01-01

    Ribosomal RNAs are the most abundant and universal noncoding RNAs in living organisms. In eukaryotes, three of the four ribosomal RNAs forming the 40S and 60S subunits are borne by a long polycistronic pre-ribosomal RNA. A complex sequence of processing steps is required to gradually release the mature RNAs from this precursor, concomitant with the assembly of the 79 ribosomal proteins. A large set of trans-acting factors chaperone this process, including small nucleolar ribonucleoparticles. ...

  10. New thioredoxin targets in the unicellular photosynthetic eukaryote Chlamydomonas reinhardtii

    OpenAIRE

    Lemaire, Stéphane D.; Guillon, Blanche; Le Maréchal, Pierre; Keryer, Eliane; Miginiac-Maslow, Myroslawa; Decottignies, Paulette

    2004-01-01

    Proteomics were used to identify the proteins from the eukaryotic unicellular green alga Chlamydomonas reinhardtii that can be reduced by thioredoxin. These proteins were retained specifically on a thioredoxin affinity column made of a monocysteinic thioredoxin mutant able to form mixed disulfides with its targets. Of a total of 55 identified targets, 29 had been found previously in higher plants or Synechocystis, but 26 were new targets. Biochemical tests were performed on three of them, sho...

  11. Hijacking of eukaryotic functions by intracellular bacterial pathogens

    OpenAIRE

    Alonso, Ana; García del Portillo, Francisco

    2004-01-01

    Intracellular bacterial pathogens have evolved as a group of microorganisms endowed with weapons to hijack many biological processes of eukaryotic cells. This review discusses how these pathogens perturb diverse host cell functions, such as cytoskeleton dynamics and organelle vesicular trafficking. Alteration of the cytoskeleton is discussed in the context of the bacterial entry process (invasion), which occurs either by activation of membrane-located host receptors ("zipper" mechani...

  12. Structural and biomechanical basis of mitochondrial movement in eukaryotic cells

    OpenAIRE

    Wu M; Kalyanasundaram A; Zhu J

    2013-01-01

    Min Wu,1 Aruna Kalyanasundaram,2 Jie Zhu1 1Laboratory of Biomechanics and Engineering, Institute of Biophysics, College of Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China; 2College of Pharmacology, University of Illinois at Chicago, Chicago, IL, USA Abstract: Mitochondria serve as energy-producing organelles in eukaryotic cells. In addition to providing the energy supply for cells, the mitochondria are also involved in other processes, such as...

  13. Unraveling adaptation in eukaryotic pathways: lessons from protocells

    OpenAIRE

    De Palo, Giovanna; Robert G Endres

    2013-01-01

    Author Summary Adaptation is a common feature in sensory systems, well familiar to us from light and dark adaptation of our visual system. Biological cells, ranging from bacteria to complex eukaryotes, including single-cell organisms and human sensory receptors, adopt different strategies to fulfill this property. However, all of them require substantial amounts of energy to adapt. Here, we compare the different biological strategies and design two minimal models which allow adaptation withou...

  14. Contributions to the Proterozoic and Cambrian Evolution of Eukaryotes

    OpenAIRE

    Dong, Lin

    2007-01-01

    This thesis makes several contributions to improve our understanding of Proterozoic-Cambrian evolution of eukaryote life. Chapter 1 provides, for the first time, a quantitative characterization of the evolutionary trends of Proterozoic macroalgae. The analysis reveals that morphological disparity of Paleoproterozoic macroalgae was low but increased in the Mesoproterozoic and Ediacaran, with a plateau in between. There was also a significant increase in thallus surface/volume ratio and maxi...

  15. Enzymes involved in organellar DNA replication in photosynthetic eukaryotes

    Directory of Open Access Journals (Sweden)

    Takashi eMoriyama

    2014-09-01

    Full Text Available Plastids and mitochondria possess their own genomes. Although the replication mechanisms of these organellar genomes remain unclear in photosynthetic eukaryotes, several organelle-localized enzymes related to genome replication, including DNA polymerase, DNA primase, DNA helicase, DNA topoisomerase, single-stranded DNA maintenance protein, DNA ligase, primer removal enzyme, and several DNA recombination-related enzymes, have been identified. In the reference Eudicot plant Arabidopsis thaliana, the replication-related enzymes of plastids and mitochondria are similar because many of them are dual targeted to both organelles, whereas in the red alga Cyanidioschyzon merolae, plastids and mitochondria contain different replication machinery components. The enzymes involved in organellar genome replication in green plants and red algae were derived from different origins, including proteobacterial, cyanobacterial, and eukaryotic lineages. In the present review, we summarize the available data for enzymes related to organellar genome replication in green plants and red algae. In addition, based on the type and distribution of replication enzymes in photosynthetic eukaryotes, we discuss the transitional history of replication enzymes in the organelles of plants.

  16. Fungal evolutionary genomics provides insight into the mechanisms of adaptive divergence in eukaryotes.

    Science.gov (United States)

    Gladieux, Pierre; Ropars, Jeanne; Badouin, Hélène; Branca, Antoine; Aguileta, Gabriela; de Vienne, Damien M; Rodríguez de la Vega, Ricardo C; Branco, Sara; Giraud, Tatiana

    2014-02-01

    Fungi are ideal model organisms for dissecting the genomic bases of adaptive divergence in eukaryotes. They have simple morphologies and small genomes, occupy contrasting, well-identified ecological niches and tend to have short generation times, and many are amenable to experimental approaches. Fungi also display diverse lifestyles, from saprotrophs to pathogens or mutualists, and they play extremely important roles in both ecosystems and human activities, as wood decayers, mycorrhizal fungi, lichens, endophytes, plant and animal pathogens, and in fermentation or drug production. We review here recent insights into the patterns and mechanisms of adaptive divergence in fungi, including sources of divergence, genomic variation and, ultimately, speciation. We outline the various ecological sources of divergent selection and genomic changes, showing that gene loss and changes in gene expression and in genomic architecture are important adaptation processes, in addition to the more widely recognized processes of amino acid substitution and gene duplication. We also review recent findings regarding the interspecific acquisition of genomic variation and suggesting an important role for introgression, hybridization and horizontal gene transfers (HGTs). We show that transposable elements can mediate several of these genomic changes, thus constituting important factors for adaptation. Finally, we review the consequences of divergent selection in terms of speciation, arguing that genetic incompatibilities may not be as widespread as generally thought and that pleiotropy between adaptation and reproductive isolation is an important route of speciation in fungal pathogens. PMID:24341913

  17. Genomic reduction and evolution of novel genetic membranes and protein-targeting machinery in eukaryote-eukaryote chimaeras (meta-algae).

    OpenAIRE

    Cavalier-Smith, T.

    2003-01-01

    Chloroplasts originated just once, from cyanobacteria enslaved by a biciliate protozoan to form the plant kingdom (green plants, red and glaucophyte algae), but subsequently, were laterally transferred to other lineages to form eukaryote-eukaryote chimaeras or meta-algae. This process of secondary symbiogenesis (permanent merger of two phylogenetically distinct eukaryote cells) has left remarkable traces of its evolutionary role in the more complex topology of the membranes surrounding all no...

  18. Eukaryotic evolutionary transitions are associated with extreme codon bias in functionally-related proteins.

    Directory of Open Access Journals (Sweden)

    Nicholas J Hudson

    Full Text Available Codon bias in the genome of an organism influences its phenome by changing the speed and efficiency of mRNA translation and hence protein abundance. We hypothesized that differences in codon bias, either between-species differences in orthologous genes, or within-species differences between genes, may play an evolutionary role. To explore this hypothesis, we compared the genome-wide codon bias in six species that occupy vital positions in the Eukaryotic Tree of Life. We acquired the entire protein coding sequences for these organisms, computed the codon bias for all genes in each organism and explored the output for relationships between codon bias and protein function, both within- and between-lineages. We discovered five notable coordinated patterns, with extreme codon bias most pronounced in traits considered highly characteristic of a given lineage. Firstly, the Homo sapiens genome had stronger codon bias for DNA-binding transcription factors than the Saccharomyces cerevisiae genome, whereas the opposite was true for ribosomal proteins--perhaps underscoring transcriptional regulation in the origin of complexity. Secondly, both mammalian species examined possessed extreme codon bias in genes relating to hair--a tissue unique to mammals. Thirdly, Arabidopsis thaliana showed extreme codon bias in genes implicated in cell wall formation and chloroplast function--which are unique to plants. Fourthly, Gallus gallus possessed strong codon bias in a subset of genes encoding mitochondrial proteins--perhaps reflecting the enhanced bioenergetic efficiency in birds that co-evolved with flight. And lastly, the G. gallus genome had extreme codon bias for the Ciliary Neurotrophic Factor--which may help to explain their spontaneous recovery from deafness. We propose that extreme codon bias in groups of genes that encode functionally related proteins has a pathway-level energetic explanation.

  19. Improvement of Test Automation

    OpenAIRE

    Räsänen, Timo

    2013-01-01

    The purpose for this study was to find out how to ensure that the automated testing of MME in the Network Verification will continue smooth and reliable while using the in-house developed test automation framework. The goal of this thesis was to reveal the reasons of the currently challenging situation and to find the key elements to be improved in the MME testing carried by the test automation. Also a reason for the study was to get solutions as to how to change the current procedures and wa...

  20. Chef infrastructure automation cookbook

    CERN Document Server

    Marschall, Matthias

    2013-01-01

    Chef Infrastructure Automation Cookbook contains practical recipes on everything you will need to automate your infrastructure using Chef. The book is packed with illustrated code examples to automate your server and cloud infrastructure.The book first shows you the simplest way to achieve a certain task. Then it explains every step in detail, so that you can build your knowledge about how things work. Eventually, the book shows you additional things to consider for each approach. That way, you can learn step-by-step and build profound knowledge on how to go about your configuration management

  1. Metabarcoding improves detection of eukaryotes from early biofouling communities: implications for pest monitoring and pathway management.

    Science.gov (United States)

    Zaiko, Anastasija; Schimanski, Kate; Pochon, Xavier; Hopkins, Grant A; Goldstien, Sharyn; Floerl, Oliver; Wood, Susanna A

    2016-07-01

    In this experimental study the patterns in early marine biofouling communities and possible implications for surveillance and environmental management were explored using metabarcoding, viz. 18S ribosomal RNA gene barcoding in combination with high-throughput sequencing. The community structure of eukaryotic assemblages and the patterns of initial succession were assessed from settlement plates deployed in a busy port for one, five and 15 days. The metabarcoding results were verified with traditional morphological identification of taxa from selected experimental plates. Metabarcoding analysis identified > 400 taxa at a comparatively low taxonomic level and morphological analysis resulted in the detection of 25 taxa at varying levels of resolution. Despite the differences in resolution, data from both methods were consistent at high taxonomic levels and similar patterns in community shifts were observed. A high percentage of sequences belonging to genera known to contain non-indigenous species (NIS) were detected after exposure for only one day. PMID:27212415

  2. Origin of phagotrophic eukaryotes as social cheaters in microbial biofilms

    Directory of Open Access Journals (Sweden)

    Jékely Gáspár

    2007-01-01

    Full Text Available Abstract Background The origin of eukaryotic cells was one of the most dramatic evolutionary transitions in the history of life. It is generally assumed that eukaryotes evolved later then prokaryotes by the transformation or fusion of prokaryotic lineages. However, as yet there is no consensus regarding the nature of the prokaryotic group(s ancestral to eukaryotes. Regardless of this, a hardly debatable fundamental novel characteristic of the last eukaryotic common ancestor was the ability to exploit prokaryotic biomass by the ingestion of entire cells, i.e. phagocytosis. The recent advances in our understanding of the social life of prokaryotes may help to explain the origin of this form of total exploitation. Presentation of the hypothesis Here I propose that eukaryotic cells originated in a social environment, a differentiated microbial mat or biofilm that was maintained by the cooperative action of its members. Cooperation was costly (e.g. the production of developmental signals or an extracellular matrix but yielded benefits that increased the overall fitness of the social group. I propose that eukaryotes originated as selfish cheaters that enjoyed the benefits of social aggregation but did not contribute to it themselves. The cheaters later evolved into predators that lysed other cells and eventually became professional phagotrophs. During several cycles of social aggregation and dispersal the number of cheaters was contained by a chicken game situation, i.e. reproductive success of cheaters was high when they were in low abundance but was reduced when they were over-represented. Radical changes in cell structure, including the loss of the rigid prokaryotic cell wall and the development of endomembranes, allowed the protoeukaryotes to avoid cheater control and to exploit nutrients more efficiently. Cellular changes were buffered by both the social benefits and the protective physico-chemical milieu of the interior of biofilms. Symbiosis

  3. Leucine-Rich repeat receptor kinases are sporadically distributed in eukaryotic genomes

    Directory of Open Access Journals (Sweden)

    Diévart Anne

    2011-12-01

    Full Text Available Abstract Background Plant leucine-rich repeat receptor-like kinases (LRR-RLKs are receptor kinases that contain LRRs in their extracellular domain. In the last 15 years, many research groups have demonstrated major roles played by LRR-RLKs in plants during almost all developmental processes throughout the life of the plant and in defense/resistance against a large range of pathogens. Recently, a breakthrough has been made in this field that challenges the dogma of the specificity of plant LRR-RLKs. Results We analyzed ~1000 complete genomes and show that LRR-RK genes have now been identified in 8 non-plant genomes. We performed an exhaustive phylogenetic analysis of all of these receptors, revealing that all of the LRR-containing receptor subfamilies form lineage-specific clades. Our results suggest that the association of LRRs with RKs appeared independently at least four times in eukaryotic evolutionary history. Moreover, the molecular evolutionary history of the LRR-RKs found in oomycetes is reminiscent of the pattern observed in plants: expansion with amplification/deletion and evolution of the domain organization leading to the functional diversification of members of the gene family. Finally, the expression data suggest that oomycete LRR-RKs may play a role in several stages of the oomycete life cycle. Conclusions In view of the key roles that LRR-RLKs play throughout the entire lifetime of plants and plant-environment interactions, the emergence and expansion of this type of receptor in several phyla along the evolution of eukaryotes, and particularly in oomycete genomes, questions their intrinsic functions in mimicry and/or in the coevolution of receptors between hosts and pathogens.

  4. Automated Vehicles Symposium 2014

    CERN Document Server

    Beiker, Sven; Road Vehicle Automation 2

    2015-01-01

    This paper collection is the second volume of the LNMOB series on Road Vehicle Automation. The book contains a comprehensive review of current technical, socio-economic, and legal perspectives written by experts coming from public authorities, companies and universities in the U.S., Europe and Japan. It originates from the Automated Vehicle Symposium 2014, which was jointly organized by the Association for Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Burlingame, CA, in July 2014. The contributions discuss the challenges arising from the integration of highly automated and self-driving vehicles into the transportation system, with a focus on human factors and different deployment scenarios. This book is an indispensable source of information for academic researchers, industrial engineers, and policy makers interested in the topic of road vehicle automation.

  5. I-94 Automation FAQs

    Data.gov (United States)

    Department of Homeland Security — In order to increase efficiency, reduce operating costs and streamline the admissions process, U.S. Customs and Border Protection has automated Form I-94 at air and...

  6. Automated Vehicles Symposium 2015

    CERN Document Server

    Beiker, Sven

    2016-01-01

    This edited book comprises papers about the impacts, benefits and challenges of connected and automated cars. It is the third volume of the LNMOB series dealing with Road Vehicle Automation. The book comprises contributions from researchers, industry practitioners and policy makers, covering perspectives from the U.S., Europe and Japan. It is based on the Automated Vehicles Symposium 2015 which was jointly organized by the Association of Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Ann Arbor, Michigan, in July 2015. The topical spectrum includes, but is not limited to, public sector activities, human factors, ethical and business aspects, energy and technological perspectives, vehicle systems and transportation infrastructure. This book is an indispensable source of information for academic researchers, industrial engineers and policy makers interested in the topic of road vehicle automation.

  7. Hydrometeorological Automated Data System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of Hydrologic Development of the National Weather Service operates HADS, the Hydrometeorological Automated Data System. This data set contains the last...

  8. An automated Certification Authority

    CERN Document Server

    Shamardin, L V

    2002-01-01

    This note describe an approach to building an automated Certification Authority. It is compatible with basic requirements of RFC2527. It also supports Registration Authorities and Globus Toolkit grid-cert-renew automatic certificate renewal.

  9. Disassembly automation automated systems with cognitive abilities

    CERN Document Server

    Vongbunyong, Supachai

    2015-01-01

    This book presents a number of aspects to be considered in the development of disassembly automation, including the mechanical system, vision system and intelligent planner. The implementation of cognitive robotics increases the flexibility and degree of autonomy of the disassembly system. Disassembly, as a step in the treatment of end-of-life products, can allow the recovery of embodied value left within disposed products, as well as the appropriate separation of potentially-hazardous components. In the end-of-life treatment industry, disassembly has largely been limited to manual labor, which is expensive in developed countries. Automation is one possible solution for economic feasibility. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  10. Automated security management

    CERN Document Server

    Al-Shaer, Ehab; Xie, Geoffrey

    2013-01-01

    In this contributed volume, leading international researchers explore configuration modeling and checking, vulnerability and risk assessment, configuration analysis, and diagnostics and discovery. The authors equip readers to understand automated security management systems and techniques that increase overall network assurability and usability. These constantly changing networks defend against cyber attacks by integrating hundreds of security devices such as firewalls, IPSec gateways, IDS/IPS, authentication servers, authorization/RBAC servers, and crypto systems. Automated Security Managemen

  11. Automating Supplier Selection Procedures

    OpenAIRE

    Davidrajuh, Reggie

    2001-01-01

    This dissertation describes a methodology, tools, and implementation techniques of automating supplier selection procedures of a small and medium-sized agile virtual enterprise. Firstly, a modeling approach is devised that can be used to model the supplier selection procedures of an enterprise. This modeling approach divides the supplier selection procedures broadly into three stages, the pre-selection, selection, and post-selection stages. Secondly, a methodology is presented for automating ...

  12. Taiwan Automated Telescope Network

    OpenAIRE

    Shuhrat Ehgamberdiev; Alexander Serebryanskiy; Antonio Jimenez; Li-Han Wang; Ming-Tsung Sun; Javier Fernandez Fernandez; Dean-Yi Chou

    2010-01-01

    A global network of small automated telescopes, the Taiwan Automated Telescope (TAT) network, dedicated to photometric measurements of stellar pulsations, is under construction. Two telescopes have been installed in Teide Observatory, Tenerife, Spain and Maidanak Observatory, Uzbekistan. The third telescope will be installed at Mauna Loa Observatory, Hawaii, USA. Each system uses a 9-cm Maksutov-type telescope. The effective focal length is 225 cm, corresponding to an f-ratio of 25. The field...

  13. Automated Lattice Perturbation Theory

    Energy Technology Data Exchange (ETDEWEB)

    Monahan, Christopher

    2014-11-01

    I review recent developments in automated lattice perturbation theory. Starting with an overview of lattice perturbation theory, I focus on the three automation packages currently "on the market": HiPPy/HPsrc, Pastor and PhySyCAl. I highlight some recent applications of these methods, particularly in B physics. In the final section I briefly discuss the related, but distinct, approach of numerical stochastic perturbation theory.

  14. Automated functional software testing

    OpenAIRE

    Jelnikar, Kristina

    2009-01-01

    The following work describes an approach to software test automation of functional testing. In the introductory part we are introducing what testing problems development companies are facing. The second chapter describes some testing methods, what role does testing have in software development, some approaches to software development and the meaning of testing environment. Chapter 3 is all about test automation. After a brief historical presentation, we are demonstrating through s...

  15. Instant Sikuli test automation

    CERN Document Server

    Lau, Ben

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A concise guide written in an easy-to follow style using the Starter guide approach.This book is aimed at automation and testing professionals who want to use Sikuli to automate GUI. Some Python programming experience is assumed.

  16. A novel astaxanthin-binding photooxidative stress-inducible aqueous carotenoprotein from a eukaryotic microalga isolated from asphalt in midsummer.

    Science.gov (United States)

    Kawasaki, Shinji; Mizuguchi, Keisuke; Sato, Masaru; Kono, Tetsuya; Shimizu, Hirofumi

    2013-07-01

    Water-soluble orange carotenoid proteins (OCPs) that bind 3'-hydroxyechinenone are found in cyanobacteria, and are thought to play a key role in photoprotection. The distribution of OCPs in eukaryotes remains largely unknown. In this study, we identified a novel OCP that predominantly binds astaxanthin from a eukaryotic microalga, strain Ki-4, isolated from a dry surface of heated asphalt in midsummer. A purified astaxanthin-binding OCP, named AstaP, shows high solubility in water with an absorption peak at 484 nm, and possesses a heat-stable activity that quenches singlet oxygen. The deduced amino acid sequence of AstaP comprises an N-terminal hydrophobic signal peptide, fasciclin domains found in secreted and cell surface proteins, and N-linked glycosylation sites, the first example of a carotenoprotein among fasciclin family proteins. AstaP homologs of unknown function are distributed mainly in organisms from the hydrosphere, such as marine bacteria, cyanobacteria, sea anemone and eukaryotic microalgae; however, AstaP exhibits a unique extraordinarily high isoelectric point (pI) value among homologs. The gene encoding AstaP, as well as the AstaP peptide, is expressed abundantly under conditions of dehydration and salt stress in conjunction with high light exposure. As a unique aqueous carotenoprotein, AstaP will provide a novel function of OCPs in protection against extreme photooxidative stresses. PMID:23737502

  17. Identification of eukaryotic and prokaryotic methylthiotransferase for biosynthesis of 2-methylthio-N6-threonylcarbamoyladenosine in tRNA.

    Science.gov (United States)

    Arragain, Simon; Handelman, Samuel K; Forouhar, Farhad; Wei, Fan-Yan; Tomizawa, Kazuhito; Hunt, John F; Douki, Thierry; Fontecave, Marc; Mulliez, Etienne; Atta, Mohamed

    2010-09-10

    Bacterial and eukaryotic transfer RNAs have been shown to contain hypermodified adenosine, 2-methylthio-N(6)-threonylcarbamoyladenosine, at position 37 (A(37)) adjacent to the 3'-end of the anticodon, which is essential for efficient and highly accurate protein translation by the ribosome. Using a combination of bioinformatic sequence analysis and in vivo assay coupled to HPLC/MS technique, we have identified, from distinct sequence signatures, two methylthiotransferase (MTTase) subfamilies, designated as MtaB in bacterial cells and e-MtaB in eukaryotic and archaeal cells. Both subfamilies are responsible for the transformation of N(6)-threonylcarbamoyladenosine into 2-methylthio-N(6)-threonylcarbamoyladenosine. Recently, a variant within the human CDKAL1 gene belonging to the e-MtaB subfamily was shown to predispose for type 2 diabetes. CDKAL1 is thus the first eukaryotic MTTase identified so far. Using purified preparations of Bacillus subtilis MtaB (YqeV), a CDKAL1 bacterial homolog, we demonstrate that YqeV/CDKAL1 enzymes, as the previously studied MTTases MiaB and RimO, contain two [4Fe-4S] clusters. This work lays the foundation for elucidating the function of CDKAL1. PMID:20584901

  18. PRFdb: A database of computationally predicted eukaryotic programmed -1 ribosomal frameshift signals

    Directory of Open Access Journals (Sweden)

    Jacobs Jonathan L

    2008-07-01

    Full Text Available Abstract Background The Programmed Ribosomal Frameshift Database (PRFdb provides an interface to help researchers identify potential programmed -1 ribosomal frameshift (-1 PRF signals in eukaryotic genes or sequences of interest. Results To identify putative -1 PRF signals, sequences are first imported from whole genomes or datasets, e.g. the yeast genome project and mammalian gene collection. They are then filtered through multiple algorithms to identify potential -1 PRF signals as defined by a heptameric slippery site followed by an mRNA pseudoknot. The significance of each candidate -1 PRF signal is evaluated by comparing the predicted thermodynamic stability (ΔG° of the native mRNA sequence against a distribution of ΔG° values of a pool of randomized sequences derived from the original. The data have been compiled in a user-friendly, easily searchable relational database. Conclusion The PRFdB enables members of the research community to determine whether genes that they are investigating contain potential -1 PRF signals, and can be used as a metasource of information for cross referencing with other databases. It is available on the web at http://dinmanlab.umd.edu/prfdb.

  19. Construction of pVAX-WIF-1 Eukaryotic Expression Vector and Its Anti-tumor
Effect on Lung Cancer

    OpenAIRE

    An, Ning; Xinmei LUO; Sujuan YE; Wang, Yu; YANG, WEIHAN; Jiang, Qianqian; ZHU, WEN

    2015-01-01

    Background and objective WIF-1 is an important tumor-suppressing gene in lung cancer, and its encoding protein WIF-1 can reduce proliferation and promote apoptosis by inhibiting Wnt/β-catenin signaling in lung cancer. This study constructs a eukaryotic expression plasmid carrying WIF-1 using FDA-approved clinical plasmid pVAX and explores the anti-tumor effect of pVAX-WIF-1 on A549 lung cancer cells in vitro and vivo. Methods The DNA fragment of human WIF-1 coding sequence was amplified by PC...

  20. Comparative analysis of eukaryotic cell-free expression systems.

    Science.gov (United States)

    Hartsough, Emily M; Shah, Pankti; Larsen, Andrew C; Chaput, John C

    2015-09-01

    Cell-free protein synthesis (CFPS) allows researchers to rapidly generate functional proteins independent of cell culture. Although advances in eukaryotic lysates have increased the amount of protein that can be produced, the nuances of different translation systems lead to variability in protein production. To help overcome this problem, we have compared the relative yield and template requirements for three commonly used commercial cell-free translation systems: wheat germ extract (WGE), rabbit reticulocyte lysate (RRL), and HeLa cell lysate (HCL). Our results provide a general guide for researchers interested in using cell-free translation to generate recombinant protein for biomedical applications. PMID:26345507

  1. Micro-Eukaryotic Diversity in Hypolithons from Miers Valley, Antarctica

    Directory of Open Access Journals (Sweden)

    Don A. Cowan

    2013-02-01

    Full Text Available The discovery of extensive and complex hypolithic communities in both cold and hot deserts has raised many questions regarding their ecology, biodiversity and relevance in terms of regional productivity. However, most hypolithic research has focused on the bacterial elements of the community. This study represents the first investigation of micro-eukaryotic communities in all three hypolith types. Here we show that Antarctic hypoliths support extensive populations of novel uncharacterized bryophyta, fungi and protists and suggest that well known producer-decomposer-predator interactions may create the necessary conditions for hypolithic productivity in Antarctic deserts.

  2. Universal Temporal Profile of Replication Origin Activation in Eukaryotes

    Science.gov (United States)

    Goldar, Arach

    2011-03-01

    The complete and faithful transmission of eukaryotic genome to daughter cells involves the timely duplication of mother cell's DNA. DNA replication starts at multiple chromosomal positions called replication origin. From each activated replication origin two replication forks progress in opposite direction and duplicate the mother cell's DNA. While it is widely accepted that in eukaryotic organisms replication origins are activated in a stochastic manner, little is known on the sources of the observed stochasticity. It is often associated to the population variability to enter S phase. We extract from a growing Saccharomyces cerevisiae population the average rate of origin activation in a single cell by combining single molecule measurements and a numerical deconvolution technique. We show that the temporal profile of the rate of origin activation in a single cell is similar to the one extracted from a replicating cell population. Taking into account this observation we exclude the population variability as the origin of observed stochasticity in origin activation. We confirm that the rate of origin activation increases in the early stage of S phase and decreases at the latter stage. The population average activation rate extracted from single molecule analysis is in prefect accordance with the activation rate extracted from published micro-array data, confirming therefore the homogeneity and genome scale invariance of dynamic of replication process. All these observations point toward a possible role of replication fork to control the rate of origin activation.

  3. In silico ionomics segregates parasitic from free-living eukaryotes.

    Science.gov (United States)

    Greganova, Eva; Steinmann, Michael; Mäser, Pascal; Fankhauser, Niklaus

    2013-01-01

    Ion transporters are fundamental to life. Due to their ancient origin and conservation in sequence, ion transporters are also particularly well suited for comparative genomics of distantly related species. Here, we perform genome-wide ion transporter profiling as a basis for comparative genomics of eukaryotes. From a given predicted proteome, we identify all bona fide ion channels, ion porters, and ion pumps. Concentrating on unicellular eukaryotes (n = 37), we demonstrate that clustering of species according to their repertoire of ion transporters segregates obligate endoparasites (n = 23) on the one hand, from free-living species and facultative parasites (n = 14) on the other hand. This surprising finding indicates strong convergent evolution of the parasites regarding the acquisition and homeostasis of inorganic ions. Random forest classification identifies transporters of ammonia, plus transporters of iron and other transition metals, as the most informative for distinguishing the obligate parasites. Thus, in silico ionomics further underscores the importance of iron in infection biology and suggests access to host sources of nitrogen and transition metals to be selective forces in the evolution of parasitism. This finding is in agreement with the phenomenon of iron withholding as a primordial antimicrobial strategy of infected mammals. PMID:24048281

  4. Significance of calcium binding, tyrosine phosphorylation, and lysine trimethylation for the essential function of calmodulin in vertebrate cells analyzed in a novel gene replacement system

    DEFF Research Database (Denmark)

    Panina, Svetlana; Stephan, Alexander; la Cour, Jonas M;

    2012-01-01

    Calmodulin (CaM) was shown to be essential for survival of lower eukaryotes by gene deletion experiments. So far, no CaM gene deletion was reported in higher eukaryotes. In vertebrates, CaM is expressed from several genes, which encode an identical protein, making it difficult to generate a model...

  5. Automated Camera Calibration

    Science.gov (United States)

    Chen, Siqi; Cheng, Yang; Willson, Reg

    2006-01-01

    Automated Camera Calibration (ACAL) is a computer program that automates the generation of calibration data for camera models used in machine vision systems. Machine vision camera models describe the mapping between points in three-dimensional (3D) space in front of the camera and the corresponding points in two-dimensional (2D) space in the camera s image. Calibrating a camera model requires a set of calibration data containing known 3D-to-2D point correspondences for the given camera system. Generating calibration data typically involves taking images of a calibration target where the 3D locations of the target s fiducial marks are known, and then measuring the 2D locations of the fiducial marks in the images. ACAL automates the analysis of calibration target images and greatly speeds the overall calibration process.

  6. Automated telescope scheduling

    Science.gov (United States)

    Johnston, Mark D.

    1988-08-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  7. Construction of pVAX-WIF-1 Eukaryotic Expression Vector and Its Anti-tumor
Effect on Lung Cancer

    Directory of Open Access Journals (Sweden)

    Ning AN

    2015-07-01

    Full Text Available Background and objective WIF-1 is an important tumor-suppressing gene in lung cancer, and its encoding protein WIF-1 can reduce proliferation and promote apoptosis by inhibiting Wnt/β-catenin signaling in lung cancer. This study constructs a eukaryotic expression plasmid carrying WIF-1 using FDA-approved clinical plasmid pVAX and explores the anti-tumor effect of pVAX-WIF-1 on A549 lung cancer cells in vitro and vivo. Methods The DNA fragment of human WIF-1 coding sequence was amplified by PCR and was cloned into the multiple cloning sites of eukaryotic expression vector pVAX to construct pVAX-WIF-1. A recombinant plasmid was transfected into lung cancer A549 cells, and the expression of WIF-1 genes was verified by Western blot after transfection. Subsequently, the effect of pVAX-WIF-1 on cell apoptosis and proliferation was identified by MTT assay, staining A549 cells with Hoechst 3235, and flow cytometry. Finally, the A549 subcutaneous xenograft was established to detect the effect of pVAX-WIF-1 on lung tumor growth in vivo. Results The results of restriction enzyme digestion, PCR, and sequencing indicated that eukaryotic expression plasmid pVAX-WIF-1 was successfully constructed. The protein expression level of WIF-1 was increased in the transfected A549 cells. Further results showed that transfection with pVAX-WIF-1 significantly inhibited proliferation and promoted apoptosis in A549 cells. Moreover, pVAX-WIF-1 significantly inhibited the tumor growth of the A549 subcutaneous xenograft in vivo. Conclusion The recombinant eukaryotic expression vector pVAX-WIF-1 was successfully constructed. Transfection with pVAX-WIF-1 could significantly inhibit proliferation and promote apoptosis of lung cancer A549 cells and also effectively inhibit the tumor growth of the A549 subcutaneous xenograft in vivo. Our research can contribute to clinical applications of WIF-1 in lung cancer gene therapy.

  8. Myths in test automation

    OpenAIRE

    Jazmine Francis

    2015-01-01

    Myths in automation of software testing is an issue of discussion that echoes about the areas of service in validation of software industry. Probably, the first though that appears in knowledgeable reader would be Why this old topic again? What's New to discuss the matter? But, for the first time everyone agrees that undoubtedly automation testing today is not today what it used to be ten or fifteen years ago, because it has evolved in scope and magnitude. What began as a simple linear script...

  9. Automated phantom assay system

    International Nuclear Information System (INIS)

    This paper describes an automated phantom assay system developed for assaying phantoms spiked with minute quantities of radionuclides. The system includes a computer-controlled linear-translation table that positions the phantom at exact distances from a spectrometer. A multichannel analyzer (MCA) interfaces with a computer to collect gamma spectral data. Signals transmitted between the controller and MCA synchronize data collection and phantom positioning. Measured data are then stored on disk for subsequent analysis. The automated system allows continuous unattended operation and ensures reproducible results

  10. Horizontal gene transfer in plants.

    Science.gov (United States)

    Gao, Caihua; Ren, Xiaodong; Mason, Annaliese S; Liu, Honglei; Xiao, Meili; Li, Jiana; Fu, Donghui

    2014-03-01

    Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries. HGT often occurs in microbic and eukaryotic genomes. However, the pathways by which HGTs occur in multicellular eukaryotes, especially in plants, are not well understood. We systematically summarized more than ten possible pathways for HGT. The intimate contact which frequently occurs in parasitism, symbiosis, pathogen, epiphyte, entophyte, and grafting interactions could promote HGTs between two species. Besides these direct transfer methods, genes can be exchanged with a vector as a bridge: possible vectors include pollen, fungi, bacteria, viruses, viroids, plasmids, transposons, and insects. HGT, especially when involving horizontal transfer of transposable elements, is recognized as a significant force propelling genomic variation and biological innovation, playing an important functional and evolutionary role in both eukaryotic and prokaryotic genomes. We proposed possible mechanisms by which HGTs can occur, which is useful in understanding the genetic information exchange among distant species or distant cellular components. PMID:24132513

  11. A set of dual promoter vectors for high throughput cloning, screening, and protein expression in eukaryotic and prokaryotic systems from a single plasmid

    OpenAIRE

    Sinah Namita; Williams Charlotte A; Piper Robert C; Shields S

    2012-01-01

    Abstract Background The ability to produce the same recombinant protein in both prokaryotic and eukaryotic cells offers many experimental opportunities. However, the cloning of the same gene into multiple plasmids is required, which is time consuming, laborious and still may not produce soluble, stable protein in sufficient quantities. We have developed a set of expression vectors that allows for ligation-independent cloning and rapid functional screening for protein expression in both E. col...

  12. BC047440 antisense eukaryotic expression vectors inhibited HepG2 cell proliferation and suppressed xenograft tumorigenicity

    International Nuclear Information System (INIS)

    The biological functions of the BC047440 gene highly expressed by hepatocellular carcinoma (HCC) are unknown. The objective of this study was to reconstruct antisense eukaryotic expression vectors of the gene for inhibiting HepG2 cell proliferation and suppressing their xenograft tumorigenicity. The full-length BC047440 cDNA was cloned from human primary HCC by RT-PCR. BC047440 gene fragments were ligated with pMD18-T simple vectors and subsequent pcDNA3.1(+) plasmids to construct the recombinant antisense eukaryotic vector pcDNA3.1(+)BC047440AS. The endogenous BC047440 mRNA abundance in target gene-transfected, vector-transfected and naive HepG2 cells was semiquantitatively analyzed by RT-PCR and cell proliferation was measured by the MTT assay. Cell cycle distribution and apoptosis were profiled by flow cytometry. The in vivo xenograft experiment was performed on nude mice to examine the effects of antisense vector on tumorigenicity. BC047440 cDNA fragments were reversely inserted into pcDNA3.1(+) plasmids. The antisense vector significantly reduced the endogenous BC047440 mRNA abundance by 41% in HepG2 cells and inhibited their proliferation in vitro (P < 0.01). More cells were arrested by the antisense vector at the G1 phase in an apoptosis-independent manner (P = 0.014). Additionally, transfection with pcDNA3.1(+) BC047440AS significantly reduced the xenograft tumorigenicity in nude mice. As a novel cell cycle regulator associated with HCC, the BC047440 gene was involved in cell proliferation in vitro and xenograft tumorigenicity in vivo through apoptosis-independent mechanisms

  13. CONSTRUCTION AND IDENTIFICATION OF EUKARYOTIC VECTOR EXPRESSING SIRNA SPECIFIC FOR BACE

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective To generate eukaryotic expression vector of siRNA specific for β-site APP cleaving enzyme(BACE),and detect the interfering effect to the expression of BACE. Methods To clone the BACE targeting siRNA gene by PCR, the PCR products was inserted into the pUC19/EGFP-U6 plasmid. Then it was sub-cloned into the vector named pLXSN. The resultant plasmid was named pLXSN/EGFP-U6-siBACE, it was packaged into AmphoPack-293 cells by calcium phosphate transfection and collected the virus supernatant. The neuroblastoma cells SK-N-SH was infected with the pLXSN/EGFP-U6-siBACE retroviral vector, immunohistochemistry method was used to detect whether the pLXSN/EGFP-U6-siBACE infection can inhibit the expression of BACE of the neuroblastoma cells. Results The pLXSN/EGFP-U6-siBACE retroviral vector was constructed successfully and the siBACE can inhibit the BACE of the neuroblastma effectively. Conclusion The siRNA can inhibit the expression of the BACE gene, the endogenous production of BACE protein was decreased. It will lay the important foundation for using RNA technology to prevent the Alzheimer's disease.

  14. A general cloning system to selectively isolate any eukaryotic or prokaryotic genomic region in yeast

    Directory of Open Access Journals (Sweden)

    Barrett J Carl

    2003-04-01

    Full Text Available Abstract Background Transformation-associated recombination (TAR cloning in yeast is a unique method for selective isolation of large chromosomal fragments or entire genes from complex genomes. The technique involves homologous recombination, during yeast spheroplast transformation, between genomic DNA and a TAR vector that has short (~ 60 bp 5' and 3' gene targeting sequences (hooks. Result TAR cloning requires that the cloned DNA fragment carry at least one autonomously replicating sequence (ARS that can function as the origin of replication in yeast, which prevents wide application of the method. In this paper, we describe a novel TAR cloning system that allows isolation of genomic regions lacking yeast ARS-like sequences. ARS is inserted into the TAR vector along with URA3 as a counter-selectable marker. The hooks are placed between the TATA box and the transcription initiation site of URA3. Insertion of any sequence between hooks results in inactivation of URA3 expression. That inactivation confers resistance to 5-fluoroorotic acid, allowing selection of TAR cloning events against background vector recircularization events. Conclusion The new system greatly expands the area of application of TAR cloning by allowing isolation of any chromosomal region from eukaryotic and prokaryotic genomes regardless of the presence of autonomously replicating sequences.

  15. ATLs and BTLs, plant-specific and general eukaryotic structurally-related E3 ubiquitin ligases.

    Science.gov (United States)

    Guzmán, Plinio

    2014-02-01

    Major components of the ubiquitin proteasome system are the enzymes that operate on the transfer of ubiquitin to selected target substrate, known as ubiquitin ligases. The RING finger is a domain that is present in key classes of ubiquitin ligases. This domain coordinates the interaction with a suitable E2 conjugase and the transfer of ubiquitin from the E2 to protein targets. Additional domains coupled to the same polypeptide are important for modulating the function of these ubiquitin ligases. Plants contain several types of E3 ubiquitin ligases that in many cases have expanded as multigene families. Some families are specific to the plant lineage, whereas others may have a common ancestor among plants and other eukaryotic lineages. Arabidopsis Tóxicos en Levadura (ATLs) and BCA2 zinc finger ATLs (BTLs) are two families of ubiquitin ligases that share some common structural features. These are intronless genes that encode a highly related RING finger domain, and yet during evolutionary history, their mode of gene expansion and function is rather different. In each of these two families, the co-occurrence of transmembrane helices or C2/C2 (BZF finger) domains with a selected variation on the RING finger has been subjected to strong selection pressure in order to preserve their unique domain architectures during evolution. PMID:24388516

  16. FAM46 proteins are novel eukaryotic non-canonical poly(A) polymerases.

    Science.gov (United States)

    Kuchta, Krzysztof; Muszewska, Anna; Knizewski, Lukasz; Steczkiewicz, Kamil; Wyrwicz, Lucjan S; Pawlowski, Krzysztof; Rychlewski, Leszek; Ginalski, Krzysztof

    2016-05-01

    FAM46 proteins, encoded in all known animal genomes, belong to the nucleotidyltransferase (NTase) fold superfamily. All four human FAM46 paralogs (FAM46A, FAM46B, FAM46C, FAM46D) are thought to be involved in several diseases, with FAM46C reported as a causal driver of multiple myeloma; however, their exact functions remain unknown. By using a combination of various bioinformatics analyses (e.g. domain architecture, cellular localization) and exhaustive literature and database searches (e.g. expression profiles, protein interactors), we classified FAM46 proteins as active non-canonical poly(A) polymerases, which modify cytosolic and/or nuclear RNA 3' ends. These proteins may thus regulate gene expression and probably play a critical role during cell differentiation. A detailed analysis of sequence and structure diversity of known NTases possessing PAP/OAS1 SBD domain, combined with state-of-the-art comparative modelling, allowed us to identify potential active site residues responsible for catalysis and substrate binding. We also explored the role of single point mutations found in human cancers and propose that FAM46 genes may be involved in the development of other major malignancies including lung, colorectal, hepatocellular, head and neck, urothelial, endometrial and renal papillary carcinomas and melanoma. Identification of these novel enzymes taking part in RNA metabolism in eukaryotes may guide their further functional studies. PMID:27060136

  17. Network dynamics of eukaryotic LTR retroelements beyond phylogenetic trees

    Directory of Open Access Journals (Sweden)

    Bernad Lucia

    2009-11-01

    Full Text Available Abstract Background Sequencing projects have allowed diverse retroviruses and LTR retrotransposons from different eukaryotic organisms to be characterized. It is known that retroviruses and other retro-transcribing viruses evolve from LTR retrotransposons and that this whole system clusters into five families: Ty3/Gypsy, Retroviridae, Ty1/Copia, Bel/Pao and Caulimoviridae. Phylogenetic analyses usually show that these split into multiple distinct lineages but what is yet to be understood is how deep evolution occurred in this system. Results We combined phylogenetic and graph analyses to investigate the history of LTR retroelements both as a tree and as a network. We used 268 non-redundant LTR retroelements, many of them introduced for the first time in this work, to elucidate all possible LTR retroelement phylogenetic patterns. These were superimposed over the tree of eukaryotes to investigate the dynamics of the system, at distinct evolutionary times. Next, we investigated phenotypic features such as duplication and variability of amino acid motifs, and several differences in genomic ORF organization. Using this information we characterized eight reticulate evolution markers to construct phenotypic network models. Conclusion The evolutionary history of LTR retroelements can be traced as a time-evolving network that depends on phylogenetic patterns, epigenetic host-factors and phenotypic plasticity. The Ty1/Copia and the Ty3/Gypsy families represent the oldest patterns in this network that we found mimics eukaryotic macroevolution. The emergence of the Bel/Pao, Retroviridae and Caulimoviridae families in this network can be related with distinct inflations of the Ty3/Gypsy family, at distinct evolutionary times. This suggests that Ty3/Gypsy ancestors diversified much more than their Ty1/Copia counterparts, at distinct geological eras. Consistent with the principle of preferential attachment, the connectivities among phenotypic markers, taken as

  18. Automated conflict resolution issues

    Science.gov (United States)

    Wike, Jeffrey S.

    1991-01-01

    A discussion is presented of how conflicts for Space Network resources should be resolved in the ATDRSS era. The following topics are presented: a description of how resource conflicts are currently resolved; a description of issues associated with automated conflict resolution; present conflict resolution strategies; and topics for further discussion.

  19. Protokoller til Home Automation

    DEFF Research Database (Denmark)

    Kjær, Kristian Ellebæk

    2008-01-01

    computer, der kan skifte mellem foruddefinerede indstillinger. Nogle gange kan computeren fjernstyres over internettet, så man kan se hjemmets status fra en computer eller måske endda fra en mobiltelefon. Mens nævnte anvendelser er klassiske indenfor home automation, er yderligere funktionalitet dukket op...

  20. Myths in test automation

    Directory of Open Access Journals (Sweden)

    Jazmine Francis

    2015-01-01

    Full Text Available Myths in automation of software testing is an issue of discussion that echoes about the areas of service in validation of software industry. Probably, the first though that appears in knowledgeable reader would be Why this old topic again? What's New to discuss the matter? But, for the first time everyone agrees that undoubtedly automation testing today is not today what it used to be ten or fifteen years ago, because it has evolved in scope and magnitude. What began as a simple linear scripts for web applications today has a complex architecture and a hybrid framework to facilitate the implementation of testing applications developed with various platforms and technologies. Undoubtedly automation has advanced, but so did the myths associated with it. The change in perspective and knowledge of people on automation has altered the terrain. This article reflects the points of views and experience of the author in what has to do with the transformation of the original myths in new versions, and how they are derived; also provides his thoughts on the new generation of myths.

  1. Automated data model evaluation

    International Nuclear Information System (INIS)

    Modeling process is essential phase within information systems development and implementation. This paper presents methods and techniques for analysis and evaluation of data model correctness. Recent methodologies and development results regarding automation of the process of model correctness analysis and relations with ontology tools has been presented. Key words: Database modeling, Data model correctness, Evaluation

  2. Automated solvent concentrator

    Science.gov (United States)

    Griffith, J. S.; Stuart, J. L.

    1976-01-01

    Designed for automated drug identification system (AUDRI), device increases concentration by 100. Sample is first filtered, removing particulate contaminants and reducing water content of sample. Sample is extracted from filtered residue by specific solvent. Concentrator provides input material to analysis subsystem.

  3. ELECTROPNEUMATIC AUTOMATION EDUCATIONAL LABORATORY

    OpenAIRE

    Dolgorukov, S. O.; National Aviation University; Roman, B. V.; National Aviation University

    2013-01-01

    The article reflects current situation in education regarding mechatronics learning difficulties. Com-plex of laboratory test benches on electropneumatic automation are considered as a tool in advancing through technical science. Course of laboratory works developed to meet the requirement of efficient and reliable way of practical skills acquisition is regarded the simplest way for students to learn the ba-sics of mechatronics.

  4. Short RNA guides cleavage by eukaryotic RNase III.

    Directory of Open Access Journals (Sweden)

    Bruno Lamontagne

    Full Text Available In eukaryotes, short RNAs guide a variety of enzymatic activities that range from RNA editing to translation repression. It is hypothesized that pre-existing proteins evolved to bind and use guide RNA during evolution. However, the capacity of modern proteins to adopt new RNA guides has never been demonstrated. Here we show that Rnt1p, the yeast orthologue of the bacterial dsRNA-specific RNase III, can bind short RNA transcripts and use them as guides for sequence-specific cleavage. Target cleavage occurred at a constant distance from the Rnt1p binding site, leaving the guide RNA intact for subsequent cleavage. Our results indicate that RNase III may trigger sequence-specific RNA degradation independent of the RNAi machinery, and they open the road for a new generation of precise RNA silencing tools that do not trigger a dsRNA-mediated immune response.

  5. Synchronization of eukaryotic flagella in vivo: from two to thousands

    Science.gov (United States)

    Goldstein, Raymond E.

    2012-02-01

    From unicellular organisms as small as a few microns to the largest vertebrates on Earth, we find groups of beating flagella or cilia that exhibit striking spatiotemporal organization. This may take the form of precise frequency and phase locking, as frequently found in the swimming of green algae, or beating with long-wavelength phase modulations known as metachronal waves, seen in ciliates such as Paramecium and in our own respiratory systems. The remarkable similarity in the underlying molecular structure of flagella across the whole eukaryotic world leads naturally to the hypothesis that a similarly universal mechanism might be responsible for synchronization. Although this mechanism is poorly understood, one appealing hypothesis is that it results from hydrodynamic interactions between flagella. This talk will summarize recent work using the unicellular alga Chlamydomonas reinhardtii and its multicellular cousin Volvox carteri to study in detail the nature of flagellar synchronization and its possible hydrodynamic origins.

  6. Emergence of Synchronized Beating during the Regrowth of Eukaryotic Flagella

    Science.gov (United States)

    Goldstein, Raymond E.; Polin, Marco; Tuval, Idan

    2011-09-01

    A fundamental issue in the biology of eukaryotic flagella is the origin of synchronized beating observed in tissues and organisms containing multiple flagella. Recent studies of the biflagellate unicellular alga Chlamydomonas reinhardtii provided the first evidence that the interflagellar coupling responsible for synchronization is of hydrodynamic origin. To investigate this mechanism in detail, we study here synchronization in Chlamydomonas as its flagella slowly regrow after mechanically induced self-scission. The duration of synchronized intervals is found to be strongly dependent on flagellar length. Analysis within a stochastic model of coupled phase oscillators is used to extract the length dependence of the interflagellar coupling and the intrinsic beat frequencies of the two flagella. Physical and biological considerations that may explain these results are proposed.

  7. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave

    Science.gov (United States)

    Azua-Bustos, A.; Gonzalez-Silva, C.; Mancilla, R.A.; Salas, L.; Palma, R.E.; Wynne, J.J.; McKay, C.P.; Vicuna, R.

    2009-01-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert. ?? Springer Science + Business Media, LLC 2009.

  8. Biological Influence of Deuterium on Procariotic and Eukaryotic Cells

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2014-03-01

    Full Text Available Biologic influence of deuterium (D on cells of various taxonomic groups of prokaryotic and eukaryotic microorganisms realizing methylotrophic, chemoheterotrophic, photo-organotrophic, and photosynthetic ways of assimilation of carbon substrates are investigated at growth on media with heavy water (D2О. The method of step by step adaptation technique of cells to D2О was developed, consisting in plating of cells on 2 % agarose nutrient media containing increasing gradient of concentration of D2О (from 0 up to 98 % D2O and the subsequent selection of stable to D2O cells. In the result of that technique were obtained adapted to maximum concentration of D2O cells, biological material of which instead of hydrogen contained deuterium with levels of enrichment 92–97,5 at.% D.

  9. Prevention of DNA re-replication in eukaryotic cells

    Institute of Scientific and Technical Information of China (English)

    Lan N. Truong; Xiaohua Wu

    2011-01-01

    DNA replication is a highly regulated process involving a number of licensing and replication factors that function in a carefully orchestrated manner to faithfully replicate DNA during every cell cycle. Loss of proper licensing control leads to deregulated DNA replication including DNA re-replication, which can cause genome instability and tumorigenesis. Eukaryotic organisms have established several conserved mechanisms to prevent DNA re-replication and to counteract its potentially harmful effects. These mechanisms include tightly controlled regulation of licensing factors and activation of cell cycle and DNA damage checkpoints.Deregulated licensing control and its associated compromised checkpoints have both been observed in tumor cells, indicating that proper functioning of these pathways is essential for maintaining genome stability. In this review, we discuss the regulatory mechanisms of licensing control, the deleterious consequences when both licensing and checkpoints are compromised, and present possible mechanisms to prevent re-replication in order to maintain genome stability.

  10. Kinetic model of DNA replication in eukaryotic organisms

    CERN Document Server

    Herrick, J; Bensimon, A; Herrick, John; Bechhoefer, John; Bensimon, Aaron

    2001-01-01

    We formulate a kinetic model of DNA replication that quantitatively describes recent results on DNA replication in the in vitro system of Xenopus laevis prior to the mid-blastula transition. The model describes well a large amount of different data within a simple theoretical framework. This allows one, for the first time, to determine the parameters governing the DNA replication program in a eukaryote on a genome-wide basis. In particular, we have determined the frequency of origin activation in time and space during the cell cycle. Although we focus on a specific stage of development, this model can easily be adapted to describe replication in many other organisms, including budding yeast.

  11. Monitoring disulfide bond formation in the eukaryotic cytosol

    DEFF Research Database (Denmark)

    Østergaard, Henrik; Tachibana, Christine; Winther, Jakob R.

    2004-01-01

    Glutathione is the most abundant low molecular weight thiol in the eukaryotic cytosol. The compartment-specific ratio and absolute concentrations of reduced and oxidized glutathione (GSH and GSSG, respectively) are, however, not easily determined. Here, we present a glutathione-specific green...... fluorescent protein-based redox probe termed redox sensitive YFP (rxYFP). Using yeast with genetically manipulated GSSG levels, we find that rxYFP equilibrates with the cytosolic glutathione redox buffer. Furthermore, in vivo and in vitro data show the equilibration to be catalyzed by glutaredoxins and that...... conditions of high intracellular GSSG confer to these a new role as dithiol oxidases. For the first time a genetically encoded probe is used to determine the redox potential specifically of cytosolic glutathione. We find it to be -289 mV, indicating that the glutathione redox status is highly reducing and...

  12. Automating spectral measurements

    Science.gov (United States)

    Goldstein, Fred T.

    2008-09-01

    This paper discusses the architecture of software utilized in spectroscopic measurements. As optical coatings become more sophisticated, there is mounting need to automate data acquisition (DAQ) from spectrophotometers. Such need is exacerbated when 100% inspection is required, ancillary devices are utilized, cost reduction is crucial, or security is vital. While instrument manufacturers normally provide point-and-click DAQ software, an application programming interface (API) may be missing. In such cases automation is impossible or expensive. An API is typically provided in libraries (*.dll, *.ocx) which may be embedded in user-developed applications. Users can thereby implement DAQ automation in several Windows languages. Another possibility, developed by FTG as an alternative to instrument manufacturers' software, is the ActiveX application (*.exe). ActiveX, a component of many Windows applications, provides means for programming and interoperability. This architecture permits a point-and-click program to act as automation client and server. Excel, for example, can control and be controlled by DAQ applications. Most importantly, ActiveX permits ancillary devices such as barcode readers and XY-stages to be easily and economically integrated into scanning procedures. Since an ActiveX application has its own user-interface, it can be independently tested. The ActiveX application then runs (visibly or invisibly) under DAQ software control. Automation capabilities are accessed via a built-in spectro-BASIC language with industry-standard (VBA-compatible) syntax. Supplementing ActiveX, spectro-BASIC also includes auxiliary serial port commands for interfacing programmable logic controllers (PLC). A typical application is automatic filter handling.

  13. An Expanded Inventory of Conserved Meiotic Genes Provides Evidence for Sex in Trichomonas vaginalis

    OpenAIRE

    Shehre-Banoo Malik; Pightling, Arthur W.; Lauren M. Stefaniak; Schurko, Andrew M.; Logsdon, John M.

    2008-01-01

    Meiosis is a defining feature of eukaryotes but its phylogenetic distribution has not been broadly determined, especially among eukaryotic microorganisms (i.e. protists)-which represent the majority of eukaryotic 'supergroups'. We surveyed genomes of animals, fungi, plants and protists for meiotic genes, focusing on the evolutionarily divergent parasitic protist Trichomonas vaginalis. We identified homologs of 29 components of the meiotic recombination machinery, as well as the synaptonemal a...

  14. Arsonium-containing lipophosphoramides, poly-functional nano-carriers for simultaneous antibacterial action and eukaryotic cell transfection.

    Science.gov (United States)

    Le Gall, Tony; Berchel, Mathieu; Le Hir, Sophie; Fraix, Aurore; Salaün, Jean Yves; Férec, Claude; Lehn, Pierre; Jaffrès, Paul-Alain; Montier, Tristan

    2013-11-01

    Gene therapy of diseases like cystic fibrosis (CF) would consist of delivering a gene medicine towards the lungs via the respiratory tract into the target epithelial cells. Accordingly, poly-functional nano-carriers are required in order to overcome the various successive barriers of such a complex environment, such as airway colonization with bacterial strains. In this work, the antibacterial effectiveness of a series of cationic lipids is investigated before evaluating its compatibility with gene transfer into human bronchial epithelial cells. Among the various compounds considered, some bearing a trimethyl-arsonium headgroup demonstrate very potent biocide effects towards clinically relevant bacterial strains. In contrast to cationic lipids exhibiting no or insufficient antibacterial potency, arsonium-containing lipophosphoramides can simultaneously inhibit bacteria while delivering DNA into eukaryotic cells, as efficiently and safely as in absence of bacteria. Moreover, such vectors can demonstrate antibacterial activity in vitro while retaining high gene transfection efficiency to the nasal epithelium as well as to the lungs in mice in vivo. Arsonium-containing amphiphiles are the first synthetic compounds shown to achieve efficient gene delivery in the presence of bacteria, a property particularly suitable for gene therapy strategies under infected conditions such as within the airways of CF patients. PMID:23625809

  15. Automated identification of mitochondrial regions in complex intracellular space by texture analysis

    Science.gov (United States)

    Pham, Tuan D.

    2014-01-01

    Automated processing and quantification of biological images have been rapidly increasing the attention of researchers in image processing and pattern recognition because the roles of computerized image and pattern analyses are critical for new biological findings and drug discovery based on modern high-throughput and highcontent image screening. This paper presents a study of the automated detection of regions of mitochondria, which are a subcellular structure of eukaryotic cells, in microscopy images. The automated identification of mitochondria in intracellular space that is captured by the state-of-the-art combination of focused ion beam and scanning electron microscope imaging reported here is the first of its type. Existing methods and a proposed algorithm for texture analysis were tested with the real intracellular images. The high correction rate of detecting the locations of the mitochondria in a complex environment suggests the effectiveness of the proposed study.

  16. Gene gymnastics

    Science.gov (United States)

    Vijayachandran, Lakshmi S; Thimiri Govinda Raj, Deepak B; Edelweiss, Evelina; Gupta, Kapil; Maier, Josef; Gordeliy, Valentin; Fitzgerald, Daniel J; Berger, Imre

    2013-01-01

    Most essential activities in eukaryotic cells are catalyzed by large multiprotein assemblies containing up to ten or more interlocking subunits. The vast majority of these protein complexes are not easily accessible for high resolution studies aimed at unlocking their mechanisms, due to their low cellular abundance and high heterogeneity. Recombinant overproduction can resolve this bottleneck and baculovirus expression vector systems (BEVS) have emerged as particularly powerful tools for the provision of eukaryotic multiprotein complexes in high quality and quantity. Recently, synthetic biology approaches have begun to make their mark in improving existing BEVS reagents by de novo design of streamlined transfer plasmids and by engineering the baculovirus genome. Here we present OmniBac, comprising new custom designed reagents that further facilitate the integration of heterologous genes into the baculovirus genome for multiprotein expression. Based on comparative genome analysis and data mining, we herein present a blueprint to custom design and engineer the entire baculovirus genome for optimized production properties using a bottom-up synthetic biology approach. PMID:23328086

  17. Phylogenetic Relationships of 3/3 and 2/2 Hemoglobins in Archaeplastida Genomes to Bacterial and Other Eukaryote Hemoglobins

    Institute of Scientific and Technical Information of China (English)

    Serge N. Vinogradov; Iván Fernández; David Hoogewijs; Raúl Arredondo-Peter

    2011-01-01

    Land plants and algae form a supergroup, the Archaeplastida, believed to be monophyletic. We report the results of an analysis of the phylogeny of putative globins in the currently available genomes to bacterial and other eu-karyote hemoglobins (Hbs). Archaeplastida genomes have 3/3 and 2/2 Hbs, with the land plant genomes having group 2 2/2 Hbs, except for the unexpected occurrence of two group 1 2/2 Hbs in Ricinus communis. Bayesian analysis shows that plant 3/3 Hbs are related to vertebrate neuroglobins and bacterial flavohemoglobins (FHbs). We sought to define the bacterial groups, whose ancestors shared the precursors of Archaeplastida Hbs, via Bayesian and neighbor-joining anal-yses based on COBALTalignment of representative sets of bacterial 3/3 FHb-like globins and group 1 and 2 2/2 Hbs with the corresponding Archaeplastida Hbs. The results suggest that the Archaeplastida 3/3 and group 1 2/2 Hbs could have orig-inated from the horizontal gene transfers (HGTs) that accompanied the two generally accepted endosymbioses of a pro-teobacterium and a cyanobacterium with a eukaryote ancestor. In contrast, the origin of the group 2 2/2 Hbs unexpectedly appears to involve HGT from a bacterium ancestral to Chloroflexi, Deinococcales, Bacilli, and Actinomycetes. Furthermore,although intron positions and phases are mostly conserved among the land plant 3/3 and 2/2 globin genes, introns are absent in the algal 3/3 genes and intron positions and phases are highly variable in their 2/2 genes. Thus, introns are irrelevant to globin evolution in Archaeplastida.

  18. 登革2型病毒43株NS1基因的克隆及在真核细胞中的表达%Cloning and expression of dengue 2 virus NS1 gene in eukaryotic cells

    Institute of Scientific and Technical Information of China (English)

    胡志君; 杨敬; 赵卫; 杨佩英; 秦鄂德; 范宝昌; 耿丽卿; 于曼

    2001-01-01

    Objective:To investigate the correct expression of dengue 2 virus 43 strain NS1 gene in transfected BHK-21 cell. Methods:The D2-43 DNA fragment coding for signal peptide plus NS1 protein was cloned between KpnⅠ site and EcoR Ⅰ site of expression plamid pcDNA3.1. The obtained recombinant vector pcDNA-NS1 was transfected into BHK-21 cells with electroporation technique. After selection by G418, resistant clones were screened by RT-PCR and Western blotting test. Results:The RT-PCR results of four in five randomly selected cell clones were positive. Western blotting test showed that NS1 gene could be expressed in BHK-21 cells. Conclusions:NS1 protein was capable of being expressed and appropriately processed in pcDNA-NS1 transfected BHK-21 cells. The present results suggest the feasibility of NS1-based DNA immunization.%目的:研究含登革2型病毒43株(D2-43)NS1基因的重组质粒DNA在幼地鼠肾细胞BHK-21的表达。方法:将含信号肽的NS1基因片段插入到pcDNA3.1的KpnⅠ位点和EcoRⅠ位点之间,获得重组表达载体pcDNA-NS1。用电穿孔法将其导入BHK-21细胞,G418选择培养。挑取单细胞克隆,RT-PCR及蛋白质印迹法鉴定NS1基因的稳定表达。结果:在随机挑取的5个单细胞克隆中,有4个克隆的RT-PCR鉴定为阳性,蛋白质印迹结果表明NS1基因获得表达。结论:构建的pcDNA-NS1质粒在BHK-21细胞中有稳定表达,因此含NS1基因的该重组质粒DNA可用作核酸免疫。

  19. Improved expression systems for regulated expression in Salmonella infecting eukaryotic cells.

    Science.gov (United States)

    Medina, Carlos; Camacho, Eva María; Flores, Amando; Mesa-Pereira, Beatriz; Santero, Eduardo

    2011-01-01

    In this work we describe a series of improvements to the Salmonella-based salicylate-inducible cascade expression system comprised of a plasmid-borne expression module, where target gene expression is driven by the P(m) promoter governed by the XylS2 regulator, and a genome-integrated regulatory module controlled by the nahR/P(sal) system. We have constructed a set of high and low-copy number plasmids bearing modified versions of the expression module with a more versatile multiple cloning site and different combinations of the following elements: (i) the nasF transcriptional attenuator, which reduces basal expression levels, (ii) a strong ribosome binding site, and (iii) the Type III Secretion System (TTSS) signal peptide from the effector protein SspH2 to deliver proteins directly to the eukaryotic cytosol following bacterial infection of animal cells. We show that different expression module versions can be used to direct a broad range of protein production levels. Furthermore, we demonstrate that the efficient reduction of basal expression by the nasF attenuator allows the cloning of genes encoding highly cytotoxic proteins such as colicin E3 even in the absence of its immunity protein. Additionally, we show that the Salmonella TTSS is able to translocate most of the protein produced by this regulatory cascade to the cytoplasm of infected HeLa cells. Our results indicate that these vectors represent useful tools for the regulated overproduction of heterologous proteins in bacterial culture or in animal cells, for the cloning and expression of genes encoding toxic proteins and for pathogenesis studies. PMID:21829692

  20. Improved expression systems for regulated expression in Salmonella infecting eukaryotic cells.

    Directory of Open Access Journals (Sweden)

    Carlos Medina

    Full Text Available In this work we describe a series of improvements to the Salmonella-based salicylate-inducible cascade expression system comprised of a plasmid-borne expression module, where target gene expression is driven by the P(m promoter governed by the XylS2 regulator, and a genome-integrated regulatory module controlled by the nahR/P(sal system. We have constructed a set of high and low-copy number plasmids bearing modified versions of the expression module with a more versatile multiple cloning site and different combinations of the following elements: (i the nasF transcriptional attenuator, which reduces basal expression levels, (ii a strong ribosome binding site, and (iii the Type III Secretion System (TTSS signal peptide from the effector protein SspH2 to deliver proteins directly to the eukaryotic cytosol following bacterial infection of animal cells. We show that different expression module versions can be used to direct a broad range of protein production levels. Furthermore, we demonstrate that the efficient reduction of basal expression by the nasF attenuator allows the cloning of genes encoding highly cytotoxic proteins such as colicin E3 even in the absence of its immunity protein. Additionally, we show that the Salmonella TTSS is able to translocate most of the protein produced by this regulatory cascade to the cytoplasm of infected HeLa cells. Our results indicate that these vectors represent useful tools for the regulated overproduction of heterologous proteins in bacterial culture or in animal cells, for the cloning and expression of genes encoding toxic proteins and for pathogenesis studies.

  1. Automated Preferences Elicitation

    Czech Academy of Sciences Publication Activity Database

    Kárný, Miroslav; Guy, Tatiana Valentine

    Prague : Institute of Information Theory and Automation, 2011, s. 20-25. ISBN 978-80-903834-6-3. [The 2nd International Workshop od Decision Making with Multiple Imperfect Decision Makers. Held in Conjunction with the 25th Annual Conference on Neural Information Processing Systems (NIPS 2011). Sierra Nevada (ES), 16.12.2011-16.12.2011] R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0567 Institutional research plan: CEZ:AV0Z10750506 Keywords : elicitation * decision making * Bayesian decision making * fully probabilistic design Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2011/AS/karny-automated preferences elicitation.pdf

  2. Automated drawing generation system

    International Nuclear Information System (INIS)

    Since automated CAD drawing generation systems still require human intervention, improvements were focussed on an interactive processing section (data input and correcting operation) which necessitates a vast amount of work. As a result, human intervention was eliminated, the original objective of a computerized system. This is the first step taken towards complete automation. The effects of development and commercialization of the system are as described below. (1) The interactive processing time required for generating drawings was improved. It was determined that introduction of the CAD system has reduced the time required for generating drawings. (2) The difference in skills between workers preparing drawings has been eliminated and the quality of drawings has been made uniform. (3) The extent of knowledge and experience demanded of workers has been reduced. (author)

  3. Terminal automation system maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Coffelt, D.; Hewitt, J. [Engineered Systems Inc., Tempe, AZ (United States)

    1997-01-01

    Nothing has improved petroleum product loading in recent years more than terminal automation systems. The presence of terminal automation systems (TAS) at loading racks has increased operational efficiency and safety and enhanced their accounting and management capabilities. However, like all finite systems, they occasionally malfunction or fail. Proper servicing and maintenance can minimize this. And in the unlikely event a TAS breakdown does occur, prompt and effective troubleshooting can reduce its impact on terminal productivity. To accommodate around-the-clock loading at racks, increasingly unattended by terminal personnel, TAS maintenance, servicing and troubleshooting has become increasingly demanding. It has also become increasingly important. After 15 years of trial and error at petroleum and petrochemical storage and transfer terminals, a number of successful troubleshooting programs have been developed. These include 24-hour {open_quotes}help hotlines,{close_quotes} internal (terminal company) and external (supplier) support staff, and {open_quotes}layered{close_quotes} support. These programs are described.

  4. ATLAS Distributed Computing Automation

    CERN Document Server

    Schovancova, J; The ATLAS collaboration; Borrego, C; Campana, S; Di Girolamo, A; Elmsheuser, J; Hejbal, J; Kouba, T; Legger, F; Magradze, E; Medrano Llamas, R; Negri, G; Rinaldi, L; Sciacca, G; Serfon, C; Van Der Ster, D C

    2012-01-01

    The ATLAS Experiment benefits from computing resources distributed worldwide at more than 100 WLCG sites. The ATLAS Grid sites provide over 100k CPU job slots, over 100 PB of storage space on disk or tape. Monitoring of status of such a complex infrastructure is essential. The ATLAS Grid infrastructure is monitored 24/7 by two teams of shifters distributed world-wide, by the ATLAS Distributed Computing experts, and by site administrators. In this paper we summarize automation efforts performed within the ATLAS Distributed Computing team in order to reduce manpower costs and improve the reliability of the system. Different aspects of the automation process are described: from the ATLAS Grid site topology provided by the ATLAS Grid Information System, via automatic site testing by the HammerCloud, to automatic exclusion from production or analysis activities.

  5. Rapid automated nuclear chemistry

    International Nuclear Information System (INIS)

    Rapid Automated Nuclear Chemistry (RANC) can be thought of as the Z-separation of Neutron-rich Isotopes by Automated Methods. The range of RANC studies of fission and its products is large. In a sense, the studies can be categorized into various energy ranges from the highest where the fission process and particle emission are considered, to low energies where nuclear dynamics are being explored. This paper presents a table which gives examples of current research using RANC on fission and fission products. The remainder of this text is divided into three parts. The first contains a discussion of the chemical methods available for the fission product elements, the second describes the major techniques, and in the last section, examples of recent results are discussed as illustrations of the use of RANC

  6. Rapid automated nuclear chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, R.A.

    1979-05-31

    Rapid Automated Nuclear Chemistry (RANC) can be thought of as the Z-separation of Neutron-rich Isotopes by Automated Methods. The range of RANC studies of fission and its products is large. In a sense, the studies can be categorized into various energy ranges from the highest where the fission process and particle emission are considered, to low energies where nuclear dynamics are being explored. This paper presents a table which gives examples of current research using RANC on fission and fission products. The remainder of this text is divided into three parts. The first contains a discussion of the chemical methods available for the fission product elements, the second describes the major techniques, and in the last section, examples of recent results are discussed as illustrations of the use of RANC.

  7. Axonal transport of eukaryotic translation elongation factor 1α mRNA couples transcription in the nucleus to long-term facilitation at the synapse

    OpenAIRE

    Giustetto, Maurizio; Hegde, Ashok N.; Si, Kausik; Casadio, Andrea; Inokuchi, Kaoru; Pei, Wanzheng; Kandel, Eric R.; Schwartz, James H.

    2003-01-01

    Long-term synaptic plasticity requires both gene expression in the nucleus and local protein synthesis at synapses. The effector proteins that link molecular events in the cell body with local maintenance of synaptic strength are not known. We now show that treatment with serotonin (5-HT) that produces long-term facilitation induces the Aplysia eukaryotic translation elongation factor 1α (Ap-eEF1A) as a late gene that might serve this coupling function in sensory neurons. Although the transla...

  8. Automated Microbial Metabolism Laboratory

    Science.gov (United States)

    1973-01-01

    Development of the automated microbial metabolism laboratory (AMML) concept is reported. The focus of effort of AMML was on the advanced labeled release experiment. Labeled substrates, inhibitors, and temperatures were investigated to establish a comparative biochemical profile. Profiles at three time intervals on soil and pure cultures of bacteria isolated from soil were prepared to establish a complete library. The development of a strategy for the return of a soil sample from Mars is also reported.

  9. Components for automated microscopy

    Science.gov (United States)

    Determann, H.; Hartmann, H.; Schade, K. H.; Stankewitz, H. W.

    1980-12-01

    A number of devices, aiming at automated analysis of microscopic objects as regards their morphometrical parameters or their photometrical values, were developed. These comprise: (1) a device for automatic focusing tuned on maximum contrast; (2) a feedback system for automatic optimization of microscope illumination; and (3) microscope lenses with adjustable pupil distances for usage in the two previous devices. An extensive test program on histological and zytological applications proves the wide application possibilities of the autofocusing device.

  10. Automation of dissolution tests

    OpenAIRE

    Rolf Rolli

    2003-01-01

    Dissolution testing of drug formulations was introduced in the 1960s and accepted by health regulatory authorities in the 1970s. Since then, the importance of dissolution has grown rapidly as have the number of tests and demands in quality-control laboratories. Recent research works lead to the development of in-vitro dissolution tests as replacements for human and animal bioequivalence studies. For many years, a lot of time and effort has been invested in automation of dissolution tests. The...

  11. Automated uranium assays

    International Nuclear Information System (INIS)

    Precise, timely inventories of enriched uranium stocks are vital to help prevent the loss, theft, or diversion of this material for illicit use. A wet-chemistry analyzer has been developed at LLL to assist in these inventories by performing automated analyses of uranium samples from different stages in the nuclear fuel cycle. These assays offer improved accuracy, reduced costs, significant savings in manpower, and lower radiation exposure for personnel compared with present techniques

  12. Construction Automation and Robotics

    OpenAIRE

    Bock, Thomas

    2008-01-01

    Due to the high complexity of the construction process and the stagnating technological development a long-term preparation is necessary to adapt it to advanced construction methods. Architects, engineers and all other participants of the construction process have to be integrated in this adaptation process. The short- and long-term development of automation will take place step-by-step and will be oriented to the respective application and requirements. In the initial phase existing building...

  13. Shielded cells transfer automation

    International Nuclear Information System (INIS)

    Nuclear waste from shielded cells is removed, packaged, and transferred manually in many nuclear facilities. To reduce radiation exposure to operators, technological advances in remote handling and automation were employed. An industrial robot and a specially designed end effector, access port, and sealing machine were used to remotely bag waste containers out of a glove box. The system is operated from a control panel outside the work area via television cameras

  14. LINAC control automation system

    International Nuclear Information System (INIS)

    A 7 MeV Electron Beam Linear Accelerator (LINAC) being used for pulse radiolysis experiments at RC and CDD, B.A.R.C. has been automated with a PLC based control panel designed and developed by Computer Division, B.A.R.C.. The control panel after power on switches ON various units in a pre-defined sequence and intervals on a single turn of START key from OFF to ON position. The control panel also generates various ramp signals in a pre-defined sequence and rate and steady values and feeds to the LINAC bringing it to the ready for experiment condition. Similarly on a single turn of STOP key from OFF to ON position, the panel ramps down the various signals in pre-defined manners and makes OFF the various units in predefined sequence and timing providing safety to the machine. The steady values for various signals are on line settable as and when required so. This automation system relieves the operator from fatigue of time consuming manual ramping up or down of various signals and running around in four rooms for switching ON or OFF the various units enhancing efficiency and safety. This also facilitates the user scientist to do start up and shutdown operation in the absence of skilled operators and thus adds flexibility for working up to extended timing. This unit has been working satisfactorily since August 2002. For extraordinary condition automation to manual or vice versa change over has been provided. (author)

  15. Synchronization of Eukaryotic Flagella and the Evolution of Multicellularity

    Science.gov (United States)

    Goldstein, Raymond

    2009-03-01

    Flagella, among the most highly conserved structures in eukaryotes, are responsible for such tasks as fluid transport, motility and phototaxis, establishment of embryonic left-right asymmetry, and intercellular communication, and are thought to have played a key role in the development of multicellularity. These tasks are usually performed by the coordinated action of groups of flagella (from pairs to thousands), which display various types of spatio-temporal organization. The origin and quantitative characterization of flagellar synchronization has remained an important open problem, involving interplay between intracellular biochemistry and interflagellar mechanical/hydrodynamic coupling. The Volvocine green algae serve as useful model organisms for the study of these phenomena, as they form a lineage spanning from unicellular Chlamydomonas to germ-soma differentiated Volvox, having as many as 50,000 biflagellated surface somatic cells. In this talk I will describe extensive studies [1], using micromanipulation and high-speed imaging, of the flagellar synchronization of two key species - Chlamydomonas reinhardtii and Volvox carteri - over tens of thousands of cycles. With Chlamydomonas we find that the flagellar dynamics moves back and forth between a stochastic synchronized state consistent with a simple model of hydrodynamically coupled noisy oscillators, and a deterministic one driven by a large interflagellar frequency difference. These results reconcile previously contradictory studies, based on short observations, showing only one or the other of these two states, and, more importantly, show that the flagellar beat frequencies themselves are regulated by the cell. Moreover, high-resolution three-dimensional tracking of swimming cells provides strong evidence that these dynamical states are related to reorientation events in the trajectories, yielding a eukaryotic equivalent of the ``run and tumble'' motion of peritrichously flagellated bacteria. The degree

  16. Nitrogen fixation in eukaryotes – New models for symbiosis

    Directory of Open Access Journals (Sweden)

    Lockhart Peter

    2007-04-01

    Full Text Available Abstract Background Nitrogen, a component of many bio-molecules, is essential for growth and development of all organisms. Most nitrogen exists in the atmosphere, and utilisation of this source is important as a means of avoiding nitrogen starvation. However, the ability to fix atmospheric nitrogen via the nitrogenase enzyme complex is restricted to some bacteria. Eukaryotic organisms are only able to obtain fixed nitrogen through their symbiotic interactions with nitrogen-fixing prokaryotes. These symbioses involve a variety of host organisms, including animals, plants, fungi and protists. Results We have compared the morphological, physiological and molecular characteristics of nitrogen fixing symbiotic associations of bacteria and their diverse hosts. Special features of the interaction, e.g. vertical transmission of symbionts, grade of dependency of partners and physiological modifications have been considered in terms of extent of co-evolution and adaptation. Our findings are that, despite many adaptations enabling a beneficial partnership, most symbioses for molecular nitrogen fixation involve facultative interactions. However, some interactions, among them endosymbioses between cyanobacteria and diatoms, show characteristics that reveal a more obligate status of co-evolution. Conclusion Our review emphasises that molecular nitrogen fixation, a driving force for interactions and co-evolution of different species, is a widespread phenomenon involving many different organisms and ecosystems. The diverse grades of symbioses, ranging from loose associations to highly specific intracellular interactions, might themselves reflect the range of potential evolutionary fates for symbiotic partnerships. These include the extreme evolutionary modifications and adaptations that have accompanied the formation of organelles in eukaryotic cells: plastids and mitochondria. However, age and extensive adaptation of plastids and mitochondria complicate the

  17. Construction of Eukaryotic Expressing Plasmids Encoding HA and HA1 of Influenza A Virus and Their Transient Expression in HEK293 Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Weidong; LI Mingyuan; CAO Kang; YANG Jing; SHI Qiaofa; WANG Baoning; JIANG Zhonghua; LI Hong

    2006-01-01

    In order to explore the feasibility and protective efficiency of influenza DNA vaccine, we constructed eukaryotic expressing plasmids encoding HA and HA1 of influenza A virus (A/PR/8/34) and studied their expression in HEK293 cells. HA and HA1 genes were amplified by RT-PCR and cloned into pcDNA3. 1 (+) to generate pcDNA3. 1 (+)/HA and pcDNA3.1 (+)/HA1, respectively. After verification of the cloning fidelity by restriction endonuclease digestion, PCR, and sequencing, pcDNA3.1 (+)/HA and pcDNA3.1 (+)/HA1 were transfected into HEK293 cells using PolyFect Transfection Reagent. Immunofluorescence assay was used to detect the transient expressing cells. Fluorescence microscopy revealed strong expression of target gene in HEK293 cells transiently transfected with either pcDNA3. 1 (+)/HA or pcDNA3. 1 (+)/HA1. Therefore, the results confirm the successful construction of eukaryotic expressing plasmids capable of driving the eukaryotic expression of influenza virus antigen HA and HA1, which is likely to provide a basis for both further investigation of the mechanism of influenza viral infection and the development of influenza DNA vaccine.

  18. Newly identified and diverse plastid-bearing branch on the eukaryotic tree of life.

    Science.gov (United States)

    Kim, Eunsoo; Harrison, James W; Sudek, Sebastian; Jones, Meredith D M; Wilcox, Heather M; Richards, Thomas A; Worden, Alexandra Z; Archibald, John M

    2011-01-25

    The use of molecular methods is altering our understanding of the microbial biosphere and the complexity of the tree of life. Here, we report a newly discovered uncultured plastid-bearing eukaryotic lineage named the rappemonads. Phylogenies using near-complete plastid ribosomal DNA (rDNA) operons demonstrate that this group represents an evolutionarily distinct lineage branching with haptophyte and cryptophyte algae. Environmental DNA sequencing revealed extensive diversity at North Atlantic, North Pacific, and European freshwater sites, suggesting a broad ecophysiology and wide habitat distribution. Quantitative PCR analyses demonstrate that the rappemonads are often rare but can form transient blooms in the Sargasso Sea, where high 16S rRNA gene copies mL(-1) were detected in late winter. This pattern is consistent with these microbes being a member of the rare biosphere, whose constituents have been proposed to play important roles under ecosystem change. Fluorescence in situ hybridization revealed that cells from this unique lineage were 6.6 ± 1.2 × 5.7 ± 1.0 μm, larger than numerically dominant open-ocean phytoplankton, and appear to contain two to four plastids. The rappemonads are unique, widespread, putatively photosynthetic algae that are absent from present-day ecosystem models and current versions of the tree of life. PMID:21205890

  19. Cyanobacteria and Eukaryotic Algae Use Different Chemical Variants of Vitamin B12.

    Science.gov (United States)

    Helliwell, Katherine Emma; Lawrence, Andrew David; Holzer, Andre; Kudahl, Ulrich Johan; Sasso, Severin; Kräutler, Bernhard; Scanlan, David John; Warren, Martin James; Smith, Alison Gail

    2016-04-25

    Eukaryotic microalgae and prokaryotic cyanobacteria are the major components of the phytoplankton. Determining factors that govern growth of these primary producers, and how they interact, is therefore essential to understanding aquatic ecosystem productivity. Over half of microalgal species representing marine and freshwater habitats require for growth the corrinoid cofactor B12, which is synthesized de novo only by certain prokaryotes, including the majority of cyanobacteria. There are several chemical variants of B12, which are not necessarily functionally interchangeable. Cobalamin, the form bioavailable to humans, has as its lower axial ligand 5,6-dimethylbenzimidazole (DMB). Here, we show that the abundant marine cyanobacterium Synechococcus synthesizes only pseudocobalamin, in which the lower axial ligand is adenine. Moreover, bioinformatic searches of over 100 sequenced cyanobacterial genomes for B12 biosynthesis genes, including those involved in nucleotide loop assembly, suggest this is the form synthesized by cyanobacteria more broadly. We further demonstrate that pseudocobalamin is several orders of magnitude less bioavailable than cobalamin to several B12-dependent microalgae representing diverse lineages. This indicates that the two major phytoplankton groups use a different B12 currency. However, in an intriguing twist, some microalgal species can use pseudocobalamin if DMB is provided, suggesting that they are able to remodel the cofactor, whereas Synechococcus cannot. This species-specific attribute implicates algal remodelers as novel and keystone players of the B12 cycle, transforming our perception of the dynamics and complexity of the flux of this nutrient in aquatic ecosystems. PMID:27040778

  20. Cyanobacteria and Eukaryotic Algae Use Different Chemical Variants of Vitamin B12

    Science.gov (United States)

    Helliwell, Katherine Emma; Lawrence, Andrew David; Holzer, Andre; Kudahl, Ulrich Johan; Sasso, Severin; Kräutler, Bernhard; Scanlan, David John; Warren, Martin James; Smith, Alison Gail

    2016-01-01

    Summary Eukaryotic microalgae and prokaryotic cyanobacteria are the major components of the phytoplankton. Determining factors that govern growth of these primary producers, and how they interact, is therefore essential to understanding aquatic ecosystem productivity. Over half of microalgal species representing marine and freshwater habitats require for growth the corrinoid cofactor B12, which is synthesized de novo only by certain prokaryotes, including the majority of cyanobacteria. There are several chemical variants of B12, which are not necessarily functionally interchangeable. Cobalamin, the form bioavailable to humans, has as its lower axial ligand 5,6-dimethylbenzimidazole (DMB). Here, we show that the abundant marine cyanobacterium Synechococcus synthesizes only pseudocobalamin, in which the lower axial ligand is adenine. Moreover, bioinformatic searches of over 100 sequenced cyanobacterial genomes for B12 biosynthesis genes, including those involved in nucleotide loop assembly, suggest this is the form synthesized by cyanobacteria more broadly. We further demonstrate that pseudocobalamin is several orders of magnitude less bioavailable than cobalamin to several B12-dependent microalgae representing diverse lineages. This indicates that the two major phytoplankton groups use a different B12 currency. However, in an intriguing twist, some microalgal species can use pseudocobalamin if DMB is provided, suggesting that they are able to remodel the cofactor, whereas Synechococcus cannot. This species-specific attribute implicates algal remodelers as novel and keystone players of the B12 cycle, transforming our perception of the dynamics and complexity of the flux of this nutrient in aquatic ecosystems. PMID:27040778