WorldWideScience

Sample records for ancient horizontal gene

  1. Ancient horizontal gene transfer from bacteria enhances biosynthetic capabilities of fungi.

    Directory of Open Access Journals (Sweden)

    Imke Schmitt

    Full Text Available Polyketides are natural products with a wide range of biological functions and pharmaceutical applications. Discovery and utilization of polyketides can be facilitated by understanding the evolutionary processes that gave rise to the biosynthetic machinery and the natural product potential of extant organisms. Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of biosynthetic gene clusters. To explain the amount of homology in some polyketide synthases in unrelated organisms such as bacteria and fungi, interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the genes and the direction of the transfer remained elusive.We used comparative phylogenetics to infer the ancestor of a group of polyketide synthase genes involved in antibiotic and mycotoxin production. We aligned keto synthase domain sequences of all available fungal 6-methylsalicylic acid (6-MSA-type PKSs and their closest bacterial relatives. To assess the role of symbiotic fungi in the evolution of this gene we generated 24 6-MSA synthase sequence tags from lichen-forming fungi. Our results support an ancient horizontal gene transfer event from an actinobacterial source into ascomycete fungi, followed by gene duplication.Given that actinobacteria are unrivaled producers of biologically active compounds, such as antibiotics, it appears particularly promising to study biosynthetic genes of actinobacterial origin in fungi. The large number of 6-MSA-type PKS sequences found in lichen-forming fungi leads us hypothesize that the evolution of typical lichen compounds, such as orsellinic acid derivatives, was facilitated by the gain of this bacterial polyketide synthase.

  2. Horizontal gene transfer in chromalveolates

    Directory of Open Access Journals (Sweden)

    Bhattacharya Debashish

    2007-09-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT, the non-genealogical transfer of genetic material between different organisms, is considered a potentially important mechanism of genome evolution in eukaryotes. Using phylogenomic analyses of expressed sequence tag (EST data generated from a clonal cell line of a free living dinoflagellate alga Karenia brevis, we investigated the impact of HGT on genome evolution in unicellular chromalveolate protists. Results We identified 16 proteins that have originated in chromalveolates through ancient HGTs before the divergence of the genera Karenia and Karlodinium and one protein that was derived through a more recent HGT. Detailed analysis of the phylogeny and distribution of identified proteins demonstrates that eight have resulted from independent HGTs in several eukaryotic lineages. Conclusion Recurring intra- and interdomain gene exchange provides an important source of genetic novelty not only in parasitic taxa as previously demonstrated but as we show here, also in free-living protists. Investigating the tempo and mode of evolution of horizontally transferred genes in protists will therefore advance our understanding of mechanisms of adaptation in eukaryotes.

  3. Evolution of red algal plastid genomes: ancient architectures, introns, horizontal gene transfer, and taxonomic utility of plastid markers.

    Directory of Open Access Journals (Sweden)

    Jan Janouškovec

    Full Text Available Red algae have the most gene-rich plastid genomes known, but despite their evolutionary importance these genomes remain poorly sampled. Here we characterize three complete and one partial plastid genome from a diverse range of florideophytes. By unifying annotations across all available red algal plastid genomes we show they all share a highly compact and slowly-evolving architecture and uniquely rich gene complements. Both chromosome structure and gene content have changed very little during red algal diversification, and suggest that plastid-to nucleus gene transfers have been rare. Despite their ancient character, however, the red algal plastids also contain several unprecedented features, including a group II intron in a tRNA-Met gene that encodes the first example of red algal plastid intron maturase - a feature uniquely shared among florideophytes. We also identify a rare case of a horizontally-acquired proteobacterial operon, and propose this operon may have been recruited for plastid function and potentially replaced a nucleus-encoded plastid-targeted paralogue. Plastid genome phylogenies yield a fully resolved tree and suggest that plastid DNA is a useful tool for resolving red algal relationships. Lastly, we estimate the evolutionary rates among more than 200 plastid genes, and assess their usefulness for species and subspecies taxonomy by comparison to well-established barcoding markers such as cox1 and rbcL. Overall, these data demonstrates that red algal plastid genomes are easily obtainable using high-throughput sequencing of total genomic DNA, interesting from evolutionary perspectives, and promising in resolving red algal relationships at evolutionarily-deep and species/subspecies levels.

  4. Genomic Evidence of Chemotrophic Metabolisms in Deep-Dwelling Chloroflexi Conferred by Ancient Horizontal Gene Transfer Events

    Science.gov (United States)

    Momper, L. M.; Magnabosco, C.; Amend, J.; Osburn, M. R.; Fournier, G. P.

    2017-12-01

    The marine and terrestrial subsurface biospheres represent quite likely the largest reservoirs for life on Earth, directly impacting surface processes and global cycles throughout Earth's history. In the deep subsurface biosphere (DSB) organic carbon and energy are often extremely scarce. However, archaea and bacteria are able to persist in the DSB to at least 3.5 km below surface [1]. Understanding how they persist, and by what metabolisms they subsist, are key questions in this biosphere. To address these questions we investigated 5 global DSB environments: one legacy mine in South Dakota, USA, 3 mines in South Africa and marine fluids circulating beneath the Juan de Fuca Ridge. Boreholes within these mines provided access to fluids buried beneath the earth's surface and sampled depths down to 3.1 km. Geochemical data were collected concomitantly with DNA for metagenomic sequencing. We examined genomes of the ancient and deeply branching Chloroflexi for metabolic capabilities and interrogated the geochemical drivers behind those metabolisms with in situ thermodynamic modeling of reaction energetics. In total, 23 Chloroflexi genomes were identified and analyzed from the 5 subsurface sites. Genes for nitrate reduction (nar) and sulfite reduction (dsr) were found in many of the South Africa Chloroflexi but were absent from genomes collected in South Dakota. Indeed, nitrate reduction was among the most energetically favorable reactions in South African fluids (10-14 kJ cell-1 sec -1 per mol of reactant) and sulfur reduction with Fe2+ or H2 was also exergonic [2]. Conversely, genes for nitrite and nitrous oxide reduction (nrf, nir and nos) were found in genomes collected in South Dakota and Juan de Fuca, but not South Africa. We examined the origin of genes conferring these metabolisms in the Chloroflexi genomes. We discovered evidence for horizontal gene transfer (HGT) for all of these putative metabolisms. Retention of these genes in Chloroflexi lineages indicates

  5. Horizontal gene transfer and the evolution of transcriptionalregulation in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Price, Morgan N.; Dehal, Paramvir S.; Arkin, Adam P.

    2007-12-20

    Background: Most bacterial genes were acquired by horizontalgene transfer from other bacteria instead of being inherited bycontinuous vertical descent from an ancient ancestor}. To understand howthe regulation of these {acquired} genes evolved, we examined theevolutionary histories of transcription factors and of regulatoryinteractions from the model bacterium Escherichia coli K12. Results:Although most transcription factors have paralogs, these usually arose byhorizontal gene transfer rather than by duplication within the E. colilineage, as previously believed. In general, most neighbor regulators --regulators that are adjacent to genes that they regulate -- were acquiredby horizontal gene transfer, while most global regulators evolvedvertically within the gamma-Proteobacteria. Neighbor regulators wereoften acquired together with the adjacent operon that they regulate, sothe proximity might be maintained by repeated transfers (like "selfishoperons"). Many of the as-yet-uncharacterized (putative) regulators havealso been acquired together with adjacent genes, so we predict that theseare neighbor regulators as well. When we analyzed the histories ofregulatory interactions, we found that the evolution of regulation byduplication was rare, and surprisingly, many of the regulatoryinteractions that are shared between paralogs result from convergentevolution. Another surprise was that horizontally transferred genes aremore likely than other genes to be regulated by multiple regulators, andmost of this complex regulation probably evolved after the transfer.Conclusions: Our results highlight the rapid evolution of niche-specificgene regulation in bacteria.

  6. Risks from GMOs due to horizontal gene transfer.

    Science.gov (United States)

    Keese, Paul

    2008-01-01

    Horizontal gene transfer (HGT) is the stable transfer of genetic material from one organism to another without reproduction or human intervention. Transfer occurs by the passage of donor genetic material across cellular boundaries, followed by heritable incorporation to the genome of the recipient organism. In addition to conjugation, transformation and transduction, other diverse mechanisms of DNA and RNA uptake occur in nature. The genome of almost every organism reveals the footprint of many ancient HGT events. Most commonly, HGT involves the transmission of genes on viruses or mobile genetic elements. HGT first became an issue of public concern in the 1970s through the natural spread of antibiotic resistance genes amongst pathogenic bacteria, and more recently with commercial production of genetically modified (GM) crops. However, the frequency of HGT from plants to other eukaryotes or prokaryotes is extremely low. The frequency of HGT to viruses is potentially greater, but is restricted by stringent selection pressures. In most cases the occurrence of HGT from GM crops to other organisms is expected to be lower than background rates. Therefore, HGT from GM plants poses negligible risks to human health or the environment.

  7. Widespread of horizontal gene transfer in the human genome.

    Science.gov (United States)

    Huang, Wenze; Tsai, Lillian; Li, Yulong; Hua, Nan; Sun, Chen; Wei, Chaochun

    2017-04-04

    A fundamental concept in biology is that heritable material is passed from parents to offspring, a process called vertical gene transfer. An alternative mechanism of gene acquisition is through horizontal gene transfer (HGT), which involves movement of genetic materials between different species. Horizontal gene transfer has been found prevalent in prokaryotes but very rare in eukaryote. In this paper, we investigate horizontal gene transfer in the human genome. From the pair-wise alignments between human genome and 53 vertebrate genomes, 1,467 human genome regions (2.6 M bases) from all chromosomes were found to be more conserved with non-mammals than with most mammals. These human genome regions involve 642 known genes, which are enriched with ion binding. Compared to known horizontal gene transfer regions in the human genome, there were few overlapping regions, which indicated horizontal gene transfer is more common than we expected in the human genome. Horizontal gene transfer impacts hundreds of human genes and this study provided insight into potential mechanisms of HGT in the human genome.

  8. Widespread of horizontal gene transfer in the human genome

    OpenAIRE

    Huang, Wenze; Tsai, Lillian; Li, Yulong; Hua, Nan; Sun, Chen; Wei, Chaochun

    2017-01-01

    Background A fundamental concept in biology is that heritable material is passed from parents to offspring, a process called vertical gene transfer. An alternative mechanism of gene acquisition is through horizontal gene transfer (HGT), which involves movement of genetic materials between different species. Horizontal gene transfer has been found prevalent in prokaryotes but very rare in eukaryote. In this paper, we investigate horizontal gene transfer in the human genome. Results From the pa...

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

    Science.gov (United States)

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

    2009-01-01

    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

  10. Phylogenomic analysis demonstrates a pattern of rare and ancient horizontal gene transfer between plants and fungi.

    Science.gov (United States)

    Richards, Thomas A; Soanes, Darren M; Foster, Peter G; Leonard, Guy; Thornton, Christopher R; Talbot, Nicholas J

    2009-07-01

    Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries and is an important evolutionary phenomenon in the ancestry of many microbes. The role of HGT in plant evolutionary history is, however, largely unexplored. Here, we compare the genomes of six plant species with those of 159 prokaryotic and eukaryotic species and identify 1689 genes that show the highest similarity to corresponding genes from fungi. We constructed a phylogeny for all 1689 genes identified and all homolog groups available from the rice (Oryza sativa) genome (3177 gene families) and used these to define 14 candidate plant-fungi HGT events. Comprehensive phylogenetic analyses of these 14 data sets, using methods that account for site rate heterogeneity, demonstrated support for nine HGT events, demonstrating an infrequent pattern of HGT between plants and fungi. Five HGTs were fungi-to-plant transfers and four were plant-to-fungi HGTs. None of the fungal-to-plant HGTs involved angiosperm recipients. These results alter the current view of organismal barriers to HGT, suggesting that phagotrophy, the consumption of a whole cell by another, is not necessarily a prerequisite for HGT between eukaryotes. Putative functional annotation of the HGT candidate genes suggests that two fungi-to-plant transfers have added phenotypes important for life in a soil environment. Our study suggests that genetic exchange between plants and fungi is exceedingly rare, particularly among the angiosperms, but has occurred during their evolutionary history and added important metabolic traits to plant lineages.

  11. Effect of the environment on horizontal gene transfer between bacteria and archaea.

    Science.gov (United States)

    Fuchsman, Clara A; Collins, Roy Eric; Rocap, Gabrielle; Brazelton, William J

    2017-01-01

    Horizontal gene transfer, the transfer and incorporation of genetic material between different species of organisms, has an important but poorly quantified role in the adaptation of microbes to their environment. Previous work has shown that genome size and the number of horizontally transferred genes are strongly correlated. Here we consider how genome size confuses the quantification of horizontal gene transfer because the number of genes an organism accumulates over time depends on its evolutionary history and ecological context (e.g., the nutrient regime for which it is adapted). We investigated horizontal gene transfer between archaea and bacteria by first counting reciprocal BLAST hits among 448 bacterial and 57 archaeal genomes to find shared genes. Then we used the DarkHorse algorithm, a probability-based, lineage-weighted method (Podell & Gaasterland, 2007), to identify potential horizontally transferred genes among these shared genes. By removing the effect of genome size in the bacteria, we have identified bacteria with unusually large numbers of shared genes with archaea for their genome size. Interestingly, archaea and bacteria that live in anaerobic and/or high temperature conditions are more likely to share unusually large numbers of genes. However, high salt was not found to significantly affect the numbers of shared genes. Numbers of shared (genome size-corrected, reciprocal BLAST hits) and transferred genes (identified by DarkHorse) were strongly correlated. Thus archaea and bacteria that live in anaerobic and/or high temperature conditions are more likely to share horizontally transferred genes. These horizontally transferred genes are over-represented by genes involved in energy conversion as well as the transport and metabolism of inorganic ions and amino acids. Anaerobic and thermophilic bacteria share unusually large numbers of genes with archaea. This is mainly due to horizontal gene transfer of genes from the archaea to the bacteria. In

  12. Effect of the environment on horizontal gene transfer between bacteria and archaea

    Directory of Open Access Journals (Sweden)

    Clara A. Fuchsman

    2017-09-01

    Full Text Available Background Horizontal gene transfer, the transfer and incorporation of genetic material between different species of organisms, has an important but poorly quantified role in the adaptation of microbes to their environment. Previous work has shown that genome size and the number of horizontally transferred genes are strongly correlated. Here we consider how genome size confuses the quantification of horizontal gene transfer because the number of genes an organism accumulates over time depends on its evolutionary history and ecological context (e.g., the nutrient regime for which it is adapted. Results We investigated horizontal gene transfer between archaea and bacteria by first counting reciprocal BLAST hits among 448 bacterial and 57 archaeal genomes to find shared genes. Then we used the DarkHorse algorithm, a probability-based, lineage-weighted method (Podell & Gaasterland, 2007, to identify potential horizontally transferred genes among these shared genes. By removing the effect of genome size in the bacteria, we have identified bacteria with unusually large numbers of shared genes with archaea for their genome size. Interestingly, archaea and bacteria that live in anaerobic and/or high temperature conditions are more likely to share unusually large numbers of genes. However, high salt was not found to significantly affect the numbers of shared genes. Numbers of shared (genome size-corrected, reciprocal BLAST hits and transferred genes (identified by DarkHorse were strongly correlated. Thus archaea and bacteria that live in anaerobic and/or high temperature conditions are more likely to share horizontally transferred genes. These horizontally transferred genes are over-represented by genes involved in energy conversion as well as the transport and metabolism of inorganic ions and amino acids. Conclusions Anaerobic and thermophilic bacteria share unusually large numbers of genes with archaea. This is mainly due to horizontal gene transfer of

  13. The chromosomal organization of horizontal gene transfer in bacteria.

    Science.gov (United States)

    Oliveira, Pedro H; Touchon, Marie; Cury, Jean; Rocha, Eduardo P C

    2017-10-10

    Bacterial adaptation is accelerated by the acquisition of novel traits through horizontal gene transfer, but the integration of these genes affects genome organization. We found that transferred genes are concentrated in only ~1% of the chromosomal regions (hotspots) in 80 bacterial species. This concentration increases with genome size and with the rate of transfer. Hotspots diversify by rapid gene turnover; their chromosomal distribution depends on local contexts (neighboring core genes), and content in mobile genetic elements. Hotspots concentrate most changes in gene repertoires, reduce the trade-off between genome diversification and organization, and should be treasure troves of strain-specific adaptive genes. Most mobile genetic elements and antibiotic resistance genes are in hotspots, but many hotspots lack recognizable mobile genetic elements and exhibit frequent homologous recombination at flanking core genes. Overrepresentation of hotspots with fewer mobile genetic elements in naturally transformable bacteria suggests that homologous recombination and horizontal gene transfer are tightly linked in genome evolution.Horizontal gene transfer (HGT) is an important mechanism for genome evolution and adaptation in bacteria. Here, Oliveira and colleagues find HGT hotspots comprising  ~ 1% of the chromosomal regions in 80 bacterial species.

  14. Biological consequences of ancient gene acquisition and duplication in the large genome soil bacterium, ""solibacter usitatus"" strain Ellin6076

    Energy Technology Data Exchange (ETDEWEB)

    Challacombe, Jean F [Los Alamos National Laboratory; Eichorst, Stephanie A [Los Alamos National Laboratory; Xie, Gary [Los Alamos National Laboratory; Kuske, Cheryl R [Los Alamos National Laboratory; Hauser, Loren [ORNL; Land, Miriam [ORNL

    2009-01-01

    Bacterial genome sizes range from ca. 0.5 to 10Mb and are influenced by gene duplication, horizontal gene transfer, gene loss and other evolutionary processes. Sequenced genomes of strains in the phylum Acidobacteria revealed that 'Solibacter usistatus' strain Ellin6076 harbors a 9.9 Mb genome. This large genome appears to have arisen by horizontal gene transfer via ancient bacteriophage and plasmid-mediated transduction, as well as widespread small-scale gene duplications. This has resulted in an increased number of paralogs that are potentially ecologically important (ecoparalogs). Low amino acid sequence identities among functional group members and lack of conserved gene order and orientation in the regions containing similar groups of paralogs suggest that most of the paralogs were not the result of recent duplication events. The genome sizes of cultured subdivision 1 and 3 strains in the phylum Acidobacteria were estimated using pulsed-field gel electrophoresis to determine the prevalence of the large genome trait within the phylum. Members of subdivision 1 were estimated to have smaller genome sizes ranging from ca. 2.0 to 4.8 Mb, whereas members of subdivision 3 had slightly larger genomes, from ca. 5.8 to 9.9 Mb. It is hypothesized that the large genome of strain Ellin6076 encodes traits that provide a selective metabolic, defensive and regulatory advantage in the variable soil environment.

  15. Detection of Horizontal Gene Transfers from Phylogenetic Comparisons

    Science.gov (United States)

    Pylro, Victor Satler; Vespoli, Luciano de Souza; Duarte, Gabriela Frois; Yotoko, Karla Suemy Clemente

    2012-01-01

    Bacterial phylogenies have become one of the most important challenges for microbial ecology. This field started in the mid-1970s with the aim of using the sequence of the small subunit ribosomal RNA (16S) tool to infer bacterial phylogenies. Phylogenetic hypotheses based on other sequences usually give conflicting topologies that reveal different evolutionary histories, which in some cases may be the result of horizontal gene transfer events. Currently, one of the major goals of molecular biology is to understand the role that horizontal gene transfer plays in species adaptation and evolution. In this work, we compared the phylogenetic tree based on 16S with the tree based on dszC, a gene involved in the cleavage of carbon-sulfur bonds. Bacteria of several genera perform this survival task when living in environments lacking free mineral sulfur. The biochemical pathway of the desulphurization process was extensively studied due to its economic importance, since this step is expensive and indispensable in fuel production. Our results clearly show that horizontal gene transfer events could be detected using common phylogenetic methods with gene sequences obtained from public sequence databases. PMID:22675653

  16. Ancient Resistome.

    Science.gov (United States)

    Olaitan, Abiola Olumuyiwa; Rolain, Jean-Marc

    2016-08-01

    Antibiotic resistance is an ancient biological mechanism in bacteria, although its proliferation in our contemporary world has been amplified through antimicrobial therapy. Recent studies conducted on ancient environmental and human samples have uncovered numerous antibiotic-resistant bacteria and resistance genes. The resistance genes that have been reported from the analysis of ancient bacterial DNA include genes coding for several classes of antibiotics, such as glycopeptides, β-lactams, tetracyclines, and macrolides. The investigation of the resistome of ancient bacteria is a recent and emerging field of research, and technological advancements such as next-generation sequencing will further contribute to its growth. It is hoped that the knowledge gained from this research will help us to better understand the evolution of antibiotic resistance genes and will also be used in drug design as a proactive measure against antibiotic resistance.

  17. An Ancient Transkingdom Horizontal Transfer of Penelope-Like Retroelements from Arthropods to Conifers.

    Science.gov (United States)

    Lin, Xuan; Faridi, Nurul; Casola, Claudio

    2016-05-02

    Comparative genomics analyses empowered by the wealth of sequenced genomes have revealed numerous instances of horizontal DNA transfers between distantly related species. In eukaryotes, repetitive DNA sequences known as transposable elements (TEs) are especially prone to move across species boundaries. Such horizontal transposon transfers, or HTTs, are relatively common within major eukaryotic kingdoms, including animals, plants, and fungi, while rarely occurring across these kingdoms. Here, we describe the first case of HTT from animals to plants, involving TEs known as Penelope-like elements, or PLEs, a group of retrotransposons closely related to eukaryotic telomerases. Using a combination of in situ hybridization on chromosomes, polymerase chain reaction experiments, and computational analyses we show that the predominant PLE lineage, EN(+)PLEs, is highly diversified in loblolly pine and other conifers, but appears to be absent in other gymnosperms. Phylogenetic analyses of both protein and DNA sequences reveal that conifers EN(+)PLEs, or Dryads, form a monophyletic group clustering within a clade of primarily arthropod elements. Additionally, no EN(+)PLEs were detected in 1,928 genome assemblies from 1,029 nonmetazoan and nonconifer genomes from 14 major eukaryotic lineages. These findings indicate that Dryads emerged following an ancient horizontal transfer of EN(+)PLEs from arthropods to a common ancestor of conifers approximately 340 Ma. This represents one of the oldest known interspecific transmissions of TEs, and the most conspicuous case of DNA transfer between animals and plants. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution 2016. This work is written by US Government employees and is in the public domain in the US.

  18. A new computational method for the detection of horizontal gene transfer events.

    Science.gov (United States)

    Tsirigos, Aristotelis; Rigoutsos, Isidore

    2005-01-01

    In recent years, the increase in the amounts of available genomic data has made it easier to appreciate the extent by which organisms increase their genetic diversity through horizontally transferred genetic material. Such transfers have the potential to give rise to extremely dynamic genomes where a significant proportion of their coding DNA has been contributed by external sources. Because of the impact of these horizontal transfers on the ecological and pathogenic character of the recipient organisms, methods are continuously sought that are able to computationally determine which of the genes of a given genome are products of transfer events. In this paper, we introduce and discuss a novel computational method for identifying horizontal transfers that relies on a gene's nucleotide composition and obviates the need for knowledge of codon boundaries. In addition to being applicable to individual genes, the method can be easily extended to the case of clusters of horizontally transferred genes. With the help of an extensive and carefully designed set of experiments on 123 archaeal and bacterial genomes, we demonstrate that the new method exhibits significant improvement in sensitivity when compared to previously published approaches. In fact, it achieves an average relative improvement across genomes of between 11 and 41% compared to the Codon Adaptation Index method in distinguishing native from foreign genes. Our method's horizontal gene transfer predictions for 123 microbial genomes are available online at http://cbcsrv.watson.ibm.com/HGT/.

  19. Evolutionary change and phylogenetic relationships in light of horizontal gene transfer.

    Science.gov (United States)

    Boto, Luis

    2015-06-01

    Horizontal gene transfer has, over the past 25 years, become a part of evolutionary thinking. In the present paper I discuss horizontal gene transfer (HGT) in relation to contingency, natural selection, evolutionary change speed and the Tree-of-Life endeavour, with the aim of contributing to the understanding of the role of HGT in evolutionary processes. In addition, the challenges that HGT imposes on the current view of evolution are emphasized.

  20. Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification.

    Science.gov (United States)

    Ziesemer, Kirsten A; Mann, Allison E; Sankaranarayanan, Krithivasan; Schroeder, Hannes; Ozga, Andrew T; Brandt, Bernd W; Zaura, Egija; Waters-Rist, Andrea; Hoogland, Menno; Salazar-García, Domingo C; Aldenderfer, Mark; Speller, Camilla; Hendy, Jessica; Weston, Darlene A; MacDonald, Sandy J; Thomas, Gavin H; Collins, Matthew J; Lewis, Cecil M; Hofman, Corinne; Warinner, Christina

    2015-11-13

    To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341-534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon sequencing. Through comparisons of microbial taxonomic counts from paired amplicon (V3 U341F/534R) and shotgun sequencing datasets, we demonstrate that extensive length polymorphisms in the V3 region are a consistent and major cause of differential amplification leading to taxonomic bias in ancient microbiome reconstructions based on amplicon sequencing. We conclude that systematic amplification bias confounds attempts to accurately reconstruct microbiome taxonomic profiles from 16S rRNA V3 amplicon data generated using universal primers. Because in silico analysis indicates that alternative 16S rRNA hypervariable regions will present similar challenges, we advocate for the use of a shotgun metagenomics approach in ancient microbiome reconstructions.

  1. Establishing the validity of domestication genes using DNA from ancient chickens

    Science.gov (United States)

    Girdland Flink, Linus; Allen, Richard; Barnett, Ross; Malmström, Helena; Peters, Joris; Eriksson, Jonas; Andersson, Leif; Dobney, Keith

    2014-01-01

    Modern domestic plants and animals are subject to human-driven selection for desired phenotypic traits and behavior. Large-scale genetic studies of modern domestic populations and their wild relatives have revealed not only the genetic mechanisms underlying specific phenotypic traits, but also allowed for the identification of candidate domestication genes. Our understanding of the importance of these genes during the initial stages of the domestication process traditionally rests on the assumption that robust inferences about the past can be made on the basis of modern genetic datasets. A growing body of evidence from ancient DNA studies, however, has revealed that ancient and even historic populations often bear little resemblance to their modern counterparts. Here, we test the temporal context of selection on specific genetic loci known to differentiate modern domestic chickens from their extant wild ancestors. We extracted DNA from 80 ancient chickens excavated from 12 European archaeological sites, dated from ∼280 B.C. to the 18th century A.D. We targeted three unlinked genetic loci: the mitochondrial control region, a gene associated with yellow skin color (β-carotene dioxygenase 2), and a putative domestication gene thought to be linked to photoperiod and reproduction (thyroid-stimulating hormone receptor, TSHR). Our results reveal significant variability in both nuclear genes, suggesting that the commonality of yellow skin in Western breeds and the near fixation of TSHR in all modern chickens took place only in the past 500 y. In addition, mitochondrial variation has increased as a result of recent admixture with exotic breeds. We conclude by emphasizing the perils of inferring the past from modern genetic data alone. PMID:24753608

  2. Establishing the validity of domestication genes using DNA from ancient chickens.

    Science.gov (United States)

    Girdland Flink, Linus; Allen, Richard; Barnett, Ross; Malmström, Helena; Peters, Joris; Eriksson, Jonas; Andersson, Leif; Dobney, Keith; Larson, Greger

    2014-04-29

    Modern domestic plants and animals are subject to human-driven selection for desired phenotypic traits and behavior. Large-scale genetic studies of modern domestic populations and their wild relatives have revealed not only the genetic mechanisms underlying specific phenotypic traits, but also allowed for the identification of candidate domestication genes. Our understanding of the importance of these genes during the initial stages of the domestication process traditionally rests on the assumption that robust inferences about the past can be made on the basis of modern genetic datasets. A growing body of evidence from ancient DNA studies, however, has revealed that ancient and even historic populations often bear little resemblance to their modern counterparts. Here, we test the temporal context of selection on specific genetic loci known to differentiate modern domestic chickens from their extant wild ancestors. We extracted DNA from 80 ancient chickens excavated from 12 European archaeological sites, dated from ∼ 280 B.C. to the 18th century A.D. We targeted three unlinked genetic loci: the mitochondrial control region, a gene associated with yellow skin color (β-carotene dioxygenase 2), and a putative domestication gene thought to be linked to photoperiod and reproduction (thyroid-stimulating hormone receptor, TSHR). Our results reveal significant variability in both nuclear genes, suggesting that the commonality of yellow skin in Western breeds and the near fixation of TSHR in all modern chickens took place only in the past 500 y. In addition, mitochondrial variation has increased as a result of recent admixture with exotic breeds. We conclude by emphasizing the perils of inferring the past from modern genetic data alone.

  3. Horizontal Gene Transfers in Mycoplasmas (Mollicutes).

    Science.gov (United States)

    Citti, C; Dordet-Frisoni, E; Nouvel, L X; Kuo, C H; Baranowski, E

    2018-04-12

    The class Mollicutes (trivial name "mycoplasma") is composed of wall-less bacteria with reduced genomes whose evolution was long thought to be only driven by gene losses. Recent evidences of massive horizontal gene transfer (HGT) within and across species provided a new frame to understand the successful adaptation of these minimal bacteria to a broad range of hosts. Mobile genetic elements are being identified in a growing number of mycoplasma species, but integrative and conjugative elements (ICEs) are emerging as pivotal in HGT. While sharing common traits with other bacterial ICEs, such as their chromosomal integration and the use of a type IV secretion system to mediate horizontal dissemination, mycoplasma ICEs (MICEs) revealed unique features: their chromosomal integration is totally random and driven by a DDE recombinase related to the Mutator-like superfamily. Mycoplasma conjugation is not restricted to ICE transmission, but also involves the transfer of large chromosomal fragments that generates progenies with mosaic genomes, nearly every position of chromosome being mobile. Mycoplasmas have thus developed efficient ways to gain access to a considerable reservoir of genetic resources distributed among a vast number of species expanding the concept of minimal cell to the broader context of flowing information.

  4. Potential Effects of Horizontal Gene Exchange in the Human Gut.

    Science.gov (United States)

    Lerner, Aaron; Matthias, Torsten; Aminov, Rustam

    2017-01-01

    Many essential functions of the human body are dependent on the symbiotic microbiota, which is present at especially high numbers and diversity in the gut. This intricate host-microbe relationship is a result of the long-term coevolution between the two. While the inheritance of mutational changes in the host evolution is almost exclusively vertical, the main mechanism of bacterial evolution is horizontal gene exchange. The gut conditions, with stable temperature, continuous food supply, constant physicochemical conditions, extremely high concentration of microbial cells and phages, and plenty of opportunities for conjugation on the surfaces of food particles and host tissues, represent one of the most favorable ecological niches for horizontal gene exchange. Thus, the gut microbial system genetically is very dynamic and capable of rapid response, at the genetic level, to selection, for example, by antibiotics. There are many other factors to which the microbiota may dynamically respond including lifestyle, therapy, diet, refined food, food additives, consumption of pre- and probiotics, and many others. The impact of the changing selective pressures on gut microbiota, however, is poorly understood. Presumably, the gut microbiome responds to these changes by genetic restructuring of gut populations, driven mainly via horizontal gene exchange. Thus, our main goal is to reveal the role played by horizontal gene exchange in the changing landscape of the gastrointestinal microbiome and potential effect of these changes on human health in general and autoimmune diseases in particular.

  5. Potential Effects of Horizontal Gene Exchange in the Human Gut

    Directory of Open Access Journals (Sweden)

    Aaron Lerner

    2017-11-01

    Full Text Available Many essential functions of the human body are dependent on the symbiotic microbiota, which is present at especially high numbers and diversity in the gut. This intricate host–microbe relationship is a result of the long-term coevolution between the two. While the inheritance of mutational changes in the host evolution is almost exclusively vertical, the main mechanism of bacterial evolution is horizontal gene exchange. The gut conditions, with stable temperature, continuous food supply, constant physicochemical conditions, extremely high concentration of microbial cells and phages, and plenty of opportunities for conjugation on the surfaces of food particles and host tissues, represent one of the most favorable ecological niches for horizontal gene exchange. Thus, the gut microbial system genetically is very dynamic and capable of rapid response, at the genetic level, to selection, for example, by antibiotics. There are many other factors to which the microbiota may dynamically respond including lifestyle, therapy, diet, refined food, food additives, consumption of pre- and probiotics, and many others. The impact of the changing selective pressures on gut microbiota, however, is poorly understood. Presumably, the gut microbiome responds to these changes by genetic restructuring of gut populations, driven mainly via horizontal gene exchange. Thus, our main goal is to reveal the role played by horizontal gene exchange in the changing landscape of the gastrointestinal microbiome and potential effect of these changes on human health in general and autoimmune diseases in particular.

  6. Horizontal transfer of short and degraded DNA has evolutionary implications for microbes and eukaryotic sexual reproduction.

    Science.gov (United States)

    Overballe-Petersen, Søren; Willerslev, Eske

    2014-10-01

    Horizontal gene transfer in the form of long DNA fragments has changed our view of bacterial evolution. Recently, we discovered that such processes may also occur with the massive amounts of short and damaged DNA in the environment, and even with truly ancient DNA. Although it presently remains unclear how often it takes place in nature, horizontal gene transfer of short and damaged DNA opens up the possibility for genetic exchange across distinct species in both time and space. In this essay, we speculate on the potential evolutionary consequences of this phenomenon. We argue that it may challenge basic assumptions in evolutionary theory; that it may have distant origins in life's history; and that horizontal gene transfer should be viewed as an evolutionary strategy not only preceding but causally underpinning the evolution of sexual reproduction. © 2014 The Authors. BioEssays Published by WILEY Periodicals, Inc.

  7. Horizontal gene transfer of a plastid gene in the non-photosynthetic flowering plants Orobanche and Phelipanche (Orobanchaceae).

    Science.gov (United States)

    Park, Jeong-Mi; Manen, Jean-François; Schneeweiss, Gerald M

    2007-06-01

    Plastid sequences are among the most widely used in phylogenetic and phylogeographic studies in flowering plants, where they are usually assumed to evolve like non-recombining, uniparentally transmitted, single-copy genes. Among others, this assumption can be violated by intracellular gene transfer (IGT) within cells or by the exchange of genes across mating barriers (horizontal gene transfer, HGT). We report on HGT of a plastid region including rps2, trnL-F, and rbcL in a group of non-photosynthetic flowering plants. Species of the parasitic broomrape genus Phelipanche harbor two copies of rps2, a plastid ribosomal gene, one corresponding to the phylogenetic position of the respective species, the other being horizontally acquired from the related broomrape genus Orobanche. While the vertically transmitted copies probably reside within the plastid genome, the localization of the horizontally acquired copies is not known. With both donor and recipient being parasitic plants, a possible pathway for the exchange of genetic material is via a commonly attacked host.

  8. Detecting Horizontal Gene Transfer between Closely Related Taxa.

    Directory of Open Access Journals (Sweden)

    Orit Adato

    2015-10-01

    Full Text Available Horizontal gene transfer (HGT, the transfer of genetic material between organisms, is crucial for genetic innovation and the evolution of genome architecture. Existing HGT detection algorithms rely on a strong phylogenetic signal distinguishing the transferred sequence from ancestral (vertically derived genes in its recipient genome. Detecting HGT between closely related species or strains is challenging, as the phylogenetic signal is usually weak and the nucleotide composition is normally nearly identical. Nevertheless, there is a great importance in detecting HGT between congeneric species or strains, especially in clinical microbiology, where understanding the emergence of new virulent and drug-resistant strains is crucial, and often time-sensitive. We developed a novel, self-contained technique named Near HGT, based on the synteny index, to measure the divergence of a gene from its native genomic environment and used it to identify candidate HGT events between closely related strains. The method confirms candidate transferred genes based on the constant relative mutability (CRM. Using CRM, the algorithm assigns a confidence score based on "unusual" sequence divergence. A gene exhibiting exceptional deviations according to both synteny and mutability criteria, is considered a validated HGT product. We first employed the technique to a set of three E. coli strains and detected several highly probable horizontally acquired genes. We then compared the method to existing HGT detection tools using a larger strain data set. When combined with additional approaches our new algorithm provides richer picture and brings us closer to the goal of detecting all newly acquired genes in a particular strain.

  9. Horizontal gene transfer between Wolbachia and the mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Walker Thomas

    2009-01-01

    Full Text Available Abstract Background The evolutionary importance of horizontal gene transfer (HGT from Wolbachia endosymbiotic bacteria to their eukaryotic hosts is a topic of considerable interest and debate. Recent transfers of genome fragments from Wolbachia into insect chromosomes have been reported, but it has been argued that these fragments may be on an evolutionary trajectory to degradation and loss. Results We have discovered a case of HGT, involving two adjacent genes, between the genomes of Wolbachia and the currently Wolbachia-uninfected mosquito Aedes aegypti, an important human disease vector. The lower level of sequence identity between Wolbachia and insect, the transcription of all the genes involved, and the fact that we have identified homologs of the two genes in another Aedes species (Ae. mascarensis, suggest that these genes are being expressed after an extended evolutionary period since horizontal transfer, and therefore that the transfer has functional significance. The association of these genes with Wolbachia prophage regions also provides a mechanism for the transfer. Conclusion The data support the argument that HGT between Wolbachia endosymbiotic bacteria and their hosts has produced evolutionary innovation.

  10. Horizontal gene transfer between bacteria.

    Science.gov (United States)

    Heuer, Holger; Smalla, Kornelia

    2007-01-01

    Horizontal gene transfer (HGT) refers to the acquisition of foreign genes by organisms. The occurrence of HGT among bacteria in the environment is assumed to have implications in the risk assessment of genetically modified bacteria which are released into the environment. First, introduced genetic sequences from a genetically modified bacterium could be transferred to indigenous micro-organisms and alter their genome and subsequently their ecological niche. Second, the genetically modified bacterium released into the environment might capture mobile genetic elements (MGE) from indigenous micro-organisms which could extend its ecological potential. Thus, for a risk assessment it is important to understand the extent of HGT and genome plasticity of bacteria in the environment. This review summarizes the present state of knowledge on HGT between bacteria as a crucial mechanism contributing to bacterial adaptability and diversity. In view of the use of GM crops and microbes in agricultural settings, in this mini-review we focus particularly on the presence and role of MGE in soil and plant-associated bacteria and the factors affecting gene transfer.

  11. The interconnection between biofilm formation and horizontal gene transfer

    DEFF Research Database (Denmark)

    Madsen, Jonas Stenløkke; Burmølle, Mette; Hansen, Lars H.

    2012-01-01

    Recent research has revealed that horizontal gene transfer and biofilm formation are connected processes. Although published research investigating this interconnectedness is still limited, we will review this subject in order to highlight the potential of these observations because....... Biofilms, furthermore, promote plasmid stability and may enhance the host range of mobile genetic elements that are transferred horizontally. Plasmids, on the other hand, are very well suited to promote the evolution of social traits such as biofilm formation. This, essentially, transpires because plasmids...... of their believed importance in the understanding of the adaptation and subsequent evolution of social traits in bacteria. Here, we discuss current evidence for such interconnectedness centred on plasmids. Horizontal transfer rates are typically higher in biofilm communities compared with those in planktonic states...

  12. Collective evolution of cyanobacteria and cyanophages mediated by horizontal gene transfer

    Science.gov (United States)

    Shih, Hong-Yan; Rogers, Tim; Goldenfeld, Nigel

    We describe a model for how antagonistic predator-prey coevolution can lead to mutualistic adaptation to an environment, as a result of horizontal gene transfer. Our model is a simple description of ecosystems such as marine cyanobacteria and their predator cyanophages, which carry photosynthesis genes. These genes evolve more rapidly in the virosphere than the bacterial pan-genome, and thus the bacterial population could potentially benefit from phage predation. By modeling both the barrier to predation and horizontal gene transfer, we study this balance between individual sacrifice and collective benefits. The outcome is an emergent mutualistic coevolution of improved photosynthesis capability, benefiting both bacteria and phage. This form of multi-level selection can contribute to niche stratification in the cyanobacteria-phage ecosystem. This work is supported in part by a cooperative agreement with NASA, Grant NNA13AA91A/A0018.

  13. Ancestral genes can control the ability of horizontally acquired loci to confer new traits.

    Directory of Open Access Journals (Sweden)

    H Deborah Chen

    2011-07-01

    Full Text Available Horizontally acquired genes typically function as autonomous units conferring new abilities when introduced into different species. However, we reasoned that proteins preexisting in an organism might constrain the functionality of a horizontally acquired gene product if it operates on an ancestral pathway. Here, we determine how the horizontally acquired pmrD gene product activates the ancestral PmrA/PmrB two-component system in Salmonella enterica but not in the closely related bacterium Escherichia coli. The Salmonella PmrD protein binds to the phosphorylated PmrA protein (PmrA-P, protecting it from dephosphorylation by the PmrB protein. This results in transcription of PmrA-dependent genes, including those conferring polymyxin B resistance. We now report that the E. coli PmrD protein can activate the PmrA/PmrB system in Salmonella even though it cannot do it in E. coli, suggesting that these two species differ in an additional component controlling PmrA-P levels. We establish that the E. coli PmrB displays higher phosphatase activity towards PmrA-P than the Salmonella PmrB, and we identified a PmrB subdomain responsible for this property. Replacement of the E. coli pmrB gene with the Salmonella homolog was sufficient to render E. coli resistant to polymyxin B under PmrD-inducing conditions. Our findings provide a singular example whereby quantitative differences in the biochemical activities of orthologous ancestral proteins dictate the ability of a horizontally acquired gene product to confer species-specific traits. And they suggest that horizontally acquired genes can potentiate selection at ancestral loci.

  14. Horizontally Acquired Biosynthesis Genes Boost Coxiella burnetii's Physiology.

    Science.gov (United States)

    Moses, Abraham S; Millar, Jess A; Bonazzi, Matteo; Beare, Paul A; Raghavan, Rahul

    2017-01-01

    Coxiella burnetii , the etiologic agent of acute Q fever and chronic endocarditis, has a unique biphasic life cycle, which includes a metabolically active intracellular form that occupies a large lysosome-derived acidic vacuole. C. burnetii is the only bacterium known to thrive within such an hostile intracellular niche, and this ability is fundamental to its pathogenicity; however, very little is known about genes that facilitate Coxiella 's intracellular growth. Recent studies indicate that C. burnetii evolved from a tick-associated ancestor and that the metabolic capabilities of C. burnetii are different from that of Coxiella -like bacteria found in ticks. Horizontally acquired genes that allow C. burnetii to infect and grow within mammalian cells likely facilitated the host shift; however, because of its obligate intracellular replication, C. burnetii would have lost most genes that have been rendered redundant due to the availability of metabolites within the host cell. Based on these observations, we reasoned that horizontally derived biosynthetic genes that have been retained in the reduced genome of C. burnetii are ideal candidates to begin to uncover its intracellular metabolic requirements. Our analyses identified a large number of putative foreign-origin genes in C. burnetii , including tRNA Glu 2 that is potentially required for heme biosynthesis, and genes involved in the production of lipopolysaccharide-a virulence factor, and of critical metabolites such as fatty acids and biotin. In comparison to wild-type C. burnetii , a strain that lacks tRNA Glu 2 exhibited reduced growth, indicating its importance to Coxiella 's physiology. Additionally, by using chemical agents that block heme and biotin biosyntheses, we show that these pathways are promising targets for the development of new anti- Coxiella therapies.

  15. Horizontal gene transfer and nucleotide compositional anomaly in large DNA viruses

    Directory of Open Access Journals (Sweden)

    Ogata Hiroyuki

    2007-12-01

    Full Text Available Abstract Background DNA viruses have a wide range of genome sizes (5 kb up to 1.2 Mb, compared to 0.16 Mb to 1.5 Mb for obligate parasitic bacteria that do not correlate with their virulence or the taxonomic distribution of their hosts. The reasons for such large variation are unclear. According to the traditional view of viruses as gifted "gene pickpockets", large viral genome sizes could originate from numerous gene acquisitions from their hosts. We investigated this hypothesis by studying 67 large DNA viruses with genome sizes larger than 150 kb, including the recently characterized giant mimivirus. Given that horizontally transferred DNA often have anomalous nucleotide compositions differing from the rest of the genome, we conducted a detailed analysis of the inter- and intra-genome compositional properties of these viruses. We then interpreted their compositional heterogeneity in terms of possible causes, including strand asymmetry, gene function/expression, and horizontal transfer. Results We first show that the global nucleotide composition and nucleotide word usage of viral genomes are species-specific and distinct from those of their hosts. Next, we identified compositionally anomalous (cA genes in viral genomes, using a method based on Bayesian inference. The proportion of cA genes is highly variable across viruses and does not exhibit a significant correlation with genome size. The vast majority of the cA genes were of unknown function, lacking homologs in the databases. For genes with known homologs, we found a substantial enrichment of cA genes in specific functional classes for some of the viruses. No significant association was found between cA genes and compositional strand asymmetry. A possible exogenous origin for a small fraction of the cA genes could be confirmed by phylogenetic reconstruction. Conclusion At odds with the traditional dogma, our results argue against frequent genetic transfers to large DNA viruses from their

  16. Horizontal Gene Transfer Contributes to the Evolution of Arthropod Herbivory.

    Science.gov (United States)

    Wybouw, Nicky; Pauchet, Yannick; Heckel, David G; Van Leeuwen, Thomas

    2016-06-27

    Within animals, evolutionary transition toward herbivory is severely limited by the hostile characteristics of plants. Arthropods have nonetheless counteracted many nutritional and defensive barriers imposed by plants and are currently considered as the most successful animal herbivores in terrestrial ecosystems. We gather a body of evidence showing that genomes of various plant feeding insects and mites possess genes whose presence can only be explained by horizontal gene transfer (HGT). HGT is the asexual transmission of genetic information between reproductively isolated species. Although HGT is known to have great adaptive significance in prokaryotes, its impact on eukaryotic evolution remains obscure. Here, we show that laterally transferred genes into arthropods underpin many adaptations to phytophagy, including efficient assimilation and detoxification of plant produced metabolites. Horizontally acquired genes and the traits they encode often functionally diversify within arthropod recipients, enabling the colonization of more host plant species and organs. We demonstrate that HGT can drive metazoan evolution by uncovering its prominent role in the adaptations of arthropods to exploit plants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. Characterization of an ancient lepidopteran lateral gene transfer.

    Directory of Open Access Journals (Sweden)

    David Wheeler

    Full Text Available Bacteria to eukaryote lateral gene transfers (LGT are an important potential source of material for the evolution of novel genetic traits. The explosion in the number of newly sequenced genomes provides opportunities to identify and characterize examples of these lateral gene transfer events, and to assess their role in the evolution of new genes. In this paper, we describe an ancient lepidopteran LGT of a glycosyl hydrolase family 31 gene (GH31 from an Enterococcus bacteria. PCR amplification between the LGT and a flanking insect gene confirmed that the GH31 was integrated into the Bombyx mori genome and was not a result of an assembly error. Database searches in combination with degenerate PCR on a panel of 7 lepidopteran families confirmed that the GH31 LGT event occurred deep within the Order approximately 65-145 million years ago. The most basal species in which the LGT was found is Plutella xylostella (superfamily: Yponomeutoidea. Array data from Bombyx mori shows that GH31 is expressed, and low dN/dS ratios indicates the LGT coding sequence is under strong stabilizing selection. These findings provide further support for the proposition that bacterial LGTs are relatively common in insects and likely to be an underappreciated source of adaptive genetic material.

  18. Incorporation of a horizontally transferred gene into an operon during cnidarian evolution.

    Directory of Open Access Journals (Sweden)

    Catherine E Dana

    Full Text Available Genome sequencing has revealed examples of horizontally transferred genes, but we still know little about how such genes are incorporated into their host genomes. We have previously reported the identification of a gene (flp that appears to have entered the Hydra genome through horizontal transfer. Here we provide additional evidence in support of our original hypothesis that the transfer was from a unicellular organism, and we show that the transfer occurred in an ancestor of two medusozoan cnidarian species. In addition we show that the gene is part of a bicistronic operon in the Hydra genome. These findings identify a new animal phylum in which trans-spliced leader addition has led to the formation of operons, and define the requirements for evolution of an operon in Hydra. The identification of operons in Hydra also provides a tool that can be exploited in the construction of transgenic Hydra strains.

  19. Horizontal gene transfer in an acid mine drainage microbial community.

    Science.gov (United States)

    Guo, Jiangtao; Wang, Qi; Wang, Xiaoqi; Wang, Fumeng; Yao, Jinxian; Zhu, Huaiqiu

    2015-07-04

    Horizontal gene transfer (HGT) has been widely identified in complete prokaryotic genomes. However, the roles of HGT among members of a microbial community and in evolution remain largely unknown. With the emergence of metagenomics, it is nontrivial to investigate such horizontal flow of genetic materials among members in a microbial community from the natural environment. Because of the lack of suitable methods for metagenomics gene transfer detection, microorganisms from a low-complexity community acid mine drainage (AMD) with near-complete genomes were used to detect possible gene transfer events and suggest the biological significance. Using the annotation of coding regions by the current tools, a phylogenetic approach, and an approximately unbiased test, we found that HGTs in AMD organisms are not rare, and we predicted 119 putative transferred genes. Among them, 14 HGT events were determined to be transfer events among the AMD members. Further analysis of the 14 transferred genes revealed that the HGT events affected the functional evolution of archaea or bacteria in AMD, and it probably shaped the community structure, such as the dominance of G-plasma in archaea in AMD through HGT. Our study provides a novel insight into HGT events among microorganisms in natural communities. The interconnectedness between HGT and community evolution is essential to understand microbial community formation and development.

  20. Dynamic expression of ancient and novel molluscan shell genes during ecological transitions

    Directory of Open Access Journals (Sweden)

    Wörheide Gert

    2007-09-01

    Full Text Available Abstract Background The Mollusca constitute one of the most morphologically and ecologically diverse metazoan phyla, occupying a wide range of marine, terrestrial and freshwater habitats. The evolutionary success of the molluscs can in part be attributed to the evolvability of the external shell. Typically, the shell first forms during embryonic and larval development, changing dramatically in shape, colour and mineralogical composition as development and maturation proceeds. Major developmental transitions in shell morphology often correlate with ecological transitions (e.g. from a planktonic to benthic existence at metamorphosis. While the genes involved in molluscan biomineralisation are beginning to be identified, there is little understanding of how these are developmentally regulated, or if the same genes are operational at different stages of the mollusc's life. Results Here we relate the developmental expression of nine genes in the tissue responsible for shell production – the mantle – to ecological transitions that occur during the lifetime of the tropical abalone Haliotis asinina (Vetigastropoda. Four of these genes encode evolutionarily ancient proteins, while four others encode secreted proteins with little or no identity to known proteins. Another gene has been previously described from the mantle of another haliotid vetigastropod. All nine genes display dynamic spatial and temporal expression profiles within the larval shell field and juvenile mantle. Conclusion These expression data reflect the regulatory complexity that underlies molluscan shell construction from larval stages to adulthood, and serves to highlight the different ecological demands placed on each stage. The use of both ancient and novel genes in all stages of shell construction also suggest that a core set of shell-making genes was provided by a shared metazoan ancestor, which has been elaborated upon to produce the range of molluscan shell types we see today.

  1. Horizontal acquisition of a hypoxia-responsive molybdenum cofactor biosynthesis pathway contributed to Mycobacterium tuberculosis pathoadaptation.

    Science.gov (United States)

    Levillain, Florence; Poquet, Yannick; Mallet, Ludovic; Mazères, Serge; Marceau, Michael; Brosch, Roland; Bange, Franz-Christoph; Supply, Philip; Magalon, Axel; Neyrolles, Olivier

    2017-11-01

    The unique ability of the tuberculosis (TB) bacillus, Mycobacterium tuberculosis, to persist for long periods of time in lung hypoxic lesions chiefly contributes to the global burden of latent TB. We and others previously reported that the M. tuberculosis ancestor underwent massive episodes of horizontal gene transfer (HGT), mostly from environmental species. Here, we sought to explore whether such ancient HGT played a part in M. tuberculosis evolution towards pathogenicity. We were interested by a HGT-acquired M. tuberculosis-specific gene set, namely moaA1-D1, which is involved in the biosynthesis of the molybdenum cofactor. Horizontal acquisition of this gene set was striking because homologues of these moa genes are present all across the Mycobacterium genus, including in M. tuberculosis. Here, we discovered that, unlike their paralogues, the moaA1-D1 genes are strongly induced under hypoxia. In vitro, a M. tuberculosis moaA1-D1-null mutant has an impaired ability to respire nitrate, to enter dormancy and to survive in oxygen-limiting conditions. Conversely, heterologous expression of moaA1-D1 in the phylogenetically closest non-TB mycobacterium, Mycobacterium kansasii, which lacks these genes, improves its capacity to respire nitrate and grants it with a marked ability to survive oxygen depletion. In vivo, the M. tuberculosis moaA1-D1-null mutant shows impaired survival in hypoxic granulomas in C3HeB/FeJ mice, but not in normoxic lesions in C57BL/6 animals. Collectively, our results identify a novel pathway required for M. tuberculosis resistance to host-imposed stress, namely hypoxia, and provide evidence that ancient HGT bolstered M. tuberculosis evolution from an environmental species towards a pervasive human-adapted pathogen.

  2. The Bacterium That Got Infected by a Cow! - Horizontal Gene

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 1. The Bacterium That Got Infected by a Cow! - Horizontal Gene Transfer and Evolution. Saurabh Dhawan Tomás John Ryan. General Article Volume 12 Issue 1 January 2007 pp 49-59 ...

  3. Involvement of β-carbonic anhydrase (β-CA) genes in bacterial genomic islands and horizontal transfer to protists.

    Science.gov (United States)

    Zolfaghari Emameh, Reza; Barker, Harlan R; Hytönen, Vesa P; Parkkila, Seppo

    2018-05-25

    Genomic islands (GIs) are a type of mobile genetic element (MGE) that are present in bacterial chromosomes. They consist of a cluster of genes which produce proteins that contribute to a variety of functions, including, but not limited to, regulation of cell metabolism, anti-microbial resistance, pathogenicity, virulence, and resistance to heavy metals. The genes carried in MGEs can be used as a trait reservoir in times of adversity. Transfer of genes using MGEs, occurring outside of reproduction, is called horizontal gene transfer (HGT). Previous literature has shown that numerous HGT events have occurred through endosymbiosis between prokaryotes and eukaryotes.Beta carbonic anhydrase (β-CA) enzymes play a critical role in the biochemical pathways of many prokaryotes and eukaryotes. We have previously suggested horizontal transfer of β-CA genes from plasmids of some prokaryotic endosymbionts to their protozoan hosts. In this study, we set out to identify β-CA genes that might have transferred between prokaryotic and protist species through HGT in GIs. Therefore, we investigated prokaryotic chromosomes containing β-CA-encoding GIs and utilized multiple bioinformatics tools to reveal the distinct movements of β-CA genes among a wide variety of organisms. Our results identify the presence of β-CA genes in GIs of several medically and industrially relevant bacterial species, and phylogenetic analyses reveal multiple cases of likely horizontal transfer of β-CA genes from GIs of ancestral prokaryotes to protists. IMPORTANCE The evolutionary process is mediated by mobile genetic elements (MGEs), such as genomic islands (GIs). A gene or set of genes in the GIs are exchanged between and within various species through horizontal gene transfer (HGT). Based on the crucial role that GIs can play in bacterial survival and proliferation, they were introduced as the environmental- and pathogen-associated factors. Carbonic anhydrases (CAs) are involved in many critical

  4. An allele of an ancestral transcription factor dependent on a horizontally acquired gene product.

    Science.gov (United States)

    Chen, H Deborah; Jewett, Mollie W; Groisman, Eduardo A

    2012-01-01

    Changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. In bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. Here, we identify an allele of the ancestral transcription factor PmrA that requires the horizontally acquired pmrD gene product to promote gene expression. We determined that a single amino acid difference between the PmrA proteins from the human adapted Salmonella enterica serovar Paratyphi B and the broad host range S. enterica serovar Typhimurium rendered transcription of PmrA-activated genes dependent on the PmrD protein in the former but not the latter serovar. Bacteria harboring the serovar Typhimurium allele exhibited polymyxin B resistance under PmrA- or under PmrA- and PmrD-inducing conditions. By contrast, isogenic strains with the serovar Paratyphi B allele displayed PmrA-regulated polymyxin B resistance only when experiencing activating conditions for both PmrA and PmrD. We establish that the two PmrA orthologs display quantitative differences in several biochemical properties. Strains harboring the serovar Paratyphi B allele showed enhanced biofilm formation, a property that might promote serovar Paratyphi B's chronic infection of the gallbladder. Our findings illustrate how subtle differences in ancestral genes can impact the ability of horizontally acquired genes to confer new properties.

  5. Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification

    NARCIS (Netherlands)

    Ziesemer, K.A.; Mann, A.E.; Sankaranarayanan, K.; Schroeder, H.; Ozga, A.T.; Brandt, B.W.; Zaura, E.; Waters-Rist, A.; Hoogland, M.; Salazar-García, D.C.; Aldenderfer, M.; Speller, C.; Hendy, J.; Weston, D.A.; MacDonald, S.J.; Thomas, G.H.; Collins, M.J.; Lewis, C.M.; Hofman, C.; Warinner, C.

    2015-01-01

    To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341-534) of this

  6. Evidence of recent interkingdom horizontal gene transfer between bacteria and Candida parapsilosis

    Directory of Open Access Journals (Sweden)

    Butler Geraldine

    2008-06-01

    Full Text Available Abstract Background To date very few incidences of interdomain gene transfer into fungi have been identified. Here, we used the emerging genome sequences of Candida albicans WO-1, Candida tropicalis, Candida parapsilosis, Clavispora lusitaniae, Pichia guilliermondii, and Lodderomyces elongisporus to identify recent interdomain HGT events. We refer to these as CTG species because they translate the CTG codon as serine rather than leucine, and share a recent common ancestor. Results Phylogenetic and syntenic information infer that two C. parapsilosis genes originate from bacterial sources. One encodes a putative proline racemase (PR. Phylogenetic analysis also infers that there were independent transfers of bacterial PR enzymes into members of the Pezizomycotina, and protists. The second HGT gene in C. parapsilosis belongs to the phenazine F (PhzF superfamily. Most CTG species also contain a fungal PhzF homolog. Our phylogeny suggests that the CTG homolog originated from an ancient HGT event, from a member of the proteobacteria. An analysis of synteny suggests that C. parapsilosis has lost the endogenous fungal form of PhzF, and subsequently reacquired it from a proteobacterial source. There is evidence that Schizosaccharomyces pombe and Basidiomycotina also obtained a PhzF homolog through HGT. Conclusion Our search revealed two instances of well-supported HGT from bacteria into the CTG clade, both specific to C. parapsilosis. Therefore, while recent interkingdom gene transfer has taken place in the CTG lineage, its occurrence is rare. However, our analysis will not detect ancient gene transfers, and we may have underestimated the global extent of HGT into CTG species.

  7. Resurrecting ancestral genes in bacteria to interpret ancient biosignatures

    Science.gov (United States)

    Kacar, Betul; Guy, Lionel; Smith, Eric; Baross, John

    2017-11-01

    Two datasets, the geologic record and the genetic content of extant organisms, provide complementary insights into the history of how key molecular components have shaped or driven global environmental and macroevolutionary trends. Changes in global physico-chemical modes over time are thought to be a consistent feature of this relationship between Earth and life, as life is thought to have been optimizing protein functions for the entirety of its approximately 3.8 billion years of history on the Earth. Organismal survival depends on how well critical genetic and metabolic components can adapt to their environments, reflecting an ability to optimize efficiently to changing conditions. The geologic record provides an array of biologically independent indicators of macroscale atmospheric and oceanic composition, but provides little in the way of the exact behaviour of the molecular components that influenced the compositions of these reservoirs. By reconstructing sequences of proteins that might have been present in ancient organisms, we can downselect to a subset of possible sequences that may have been optimized to these ancient environmental conditions. How can one use modern life to reconstruct ancestral behaviours? Configurations of ancient sequences can be inferred from the diversity of extant sequences, and then resurrected in the laboratory to ascertain their biochemical attributes. One way to augment sequence-based, single-gene methods to obtain a richer and more reliable picture of the deep past, is to resurrect inferred ancestral protein sequences in living organisms, where their phenotypes can be exposed in a complex molecular-systems context, and then to link consequences of those phenotypes to biosignatures that were preserved in the independent historical repository of the geological record. As a first step beyond single-molecule reconstruction to the study of functional molecular systems, we present here the ancestral sequence reconstruction of the

  8. CRISPR-cas-mediated phage resistance enhances horizontal gene transfer by transduction

    NARCIS (Netherlands)

    Watson, Bridget N.J.; Staals, Raymond H.J.; Fineran, Peter C.

    2018-01-01

    A powerful contributor to prokaryotic evolution is horizontal gene transfer (HGT) through transformation, conjugation, and transduction, which can be advantageous, neutral, or detrimental to fitness. Bacteria and archaea control HGT and phage infection through CRISPR-Cas (clustered regularly

  9. Horizontal gene transfer and mobile genetic elements in marine systems.

    Science.gov (United States)

    Sobecky, Patricia A; Hazen, Tracy H

    2009-01-01

    The pool of mobile genetic elements (MGE) in microbial communities consists of viruses, plasmids, and associated elements (insertion sequences, transposons, and integrons) that are either self-transmissible or use mobile plasmids and viruses as vehicles for their dissemination. This mobilome facilitates the horizontal transfer of genes that promote the evolution and adaptation of microbial communities. Efforts to characterize MGEs from microbial populations resident in a variety of ecological habitats have revealed a surprisingly novel and seemingly untapped biodiversity. To better understand the impact of horizontal gene transfer (HGT), as well as the agents that promote HGT in marine ecosystems and to determine whether or not environmental parameters can effect the composition and structure of the mobilome in marine microbial communities, information on the distribution, diversity, and ecological traits of the marine mobilome is presented. In this chapter we discuss recent insights gained from different methodological approaches used to characterize the biodiversity and ecology of MGE in marine environments and their contributions to HGT. In addition, we present case studies that highlight specific HGT examples in coastal, open-ocean, and deep-sea marine ecosystems.

  10. Lateral Gene Transfer Dynamics in the Ancient Bacterial Genus Streptomyces

    Directory of Open Access Journals (Sweden)

    Bradon R. McDonald

    2017-06-01

    Full Text Available Lateral gene transfer (LGT profoundly shapes the evolution of bacterial lineages. LGT across disparate phylogenetic groups and genome content diversity between related organisms suggest a model of bacterial evolution that views LGT as rampant and promiscuous. It has even driven the argument that species concepts and tree-based phylogenetics cannot be applied to bacteria. Here, we show that acquisition and retention of genes through LGT are surprisingly rare in the ubiquitous and biomedically important bacterial genus Streptomyces. Using a molecular clock, we estimate that the Streptomyces bacteria are ~380 million years old, indicating that this bacterial genus is as ancient as land vertebrates. Calibrating LGT rate to this geologic time span, we find that on average only 10 genes per million years were acquired and subsequently maintained. Over that same time span, Streptomyces accumulated thousands of point mutations. By explicitly incorporating evolutionary timescale into our analyses, we provide a dramatically different view on the dynamics of LGT and its impact on bacterial evolution.

  11. Horizontal gene transfer in silkworm, Bombyx mori

    Science.gov (United States)

    2011-01-01

    Background The domesticated silkworm, Bombyx mori, is the model insect for the order Lepidoptera, has economically important values, and has gained some representative behavioral characteristics compared to its wild ancestor. The genome of B. mori has been fully sequenced while function analysis of BmChi-h and BmSuc1 genes revealed that horizontal gene transfer (HGT) maybe bestow a clear selective advantage to B. mori. However, the role of HGT in the evolutionary history of B. mori is largely unexplored. In this study, we compare the whole genome of B. mori with those of 382 prokaryotic and eukaryotic species to investigate the potential HGTs. Results Ten candidate HGT events were defined in B. mori by comprehensive sequence analysis using Maximum Likelihood and Bayesian method combining with EST checking. Phylogenetic analysis of the candidate HGT genes suggested that one HGT was plant-to- B. mori transfer while nine were bacteria-to- B. mori transfer. Furthermore, functional analysis based on expression, coexpression and related literature searching revealed that several HGT candidate genes have added important characters, such as resistance to pathogen, to B. mori. Conclusions Results from this study clearly demonstrated that HGTs play an important role in the evolution of B. mori although the number of HGT events in B. mori is in general smaller than those of microbes and other insects. In particular, interdomain HGTs in B. mori may give rise to functional, persistent, and possibly evolutionarily significant new genes. PMID:21595916

  12. Identification of horizontally transferred genes in the genus Colletotrichum reveals a steady tempo of bacterial to fungal gene transfer.

    Science.gov (United States)

    Jaramillo, Vinicio D Armijos; Sukno, Serenella A; Thon, Michael R

    2015-01-02

    Horizontal gene transfer (HGT) is the stable transmission of genetic material between organisms by means other than vertical inheritance. HGT has an important role in the evolution of prokaryotes but is relatively rare in eukaryotes. HGT has been shown to contribute to virulence in eukaryotic pathogens. We studied the importance of HGT in plant pathogenic fungi by identifying horizontally transferred genes in the genomes of three members of the genus Colletotrichum. We identified eleven HGT events from bacteria into members of the genus Colletotrichum or their ancestors. The HGT events include genes involved in amino acid, lipid and sugar metabolism as well as lytic enzymes. Additionally, the putative minimal dates of transference were calculated using a time calibrated phylogenetic tree. This analysis reveals a constant flux of genes from bacteria to fungi throughout the evolution of subphylum Pezizomycotina. Genes that are typically transferred by HGT are those that are constantly subject to gene duplication and gene loss. The functions of some of these genes suggest roles in niche adaptation and virulence. We found no evidence of a burst of HGT events coinciding with major geological events. In contrast, HGT appears to be a constant, albeit rare phenomenon in the Pezizomycotina, occurring at a steady rate during their evolution.

  13. Cancer tumors as Metazoa 1.0: tapping genes of ancient ancestors

    International Nuclear Information System (INIS)

    Davies, P C W; Lineweaver, C H

    2011-01-01

    The genes of cellular cooperation that evolved with multicellularity about a billion years ago are the same genes that malfunction to cause cancer. We hypothesize that cancer is an atavistic condition that occurs when genetic or epigenetic malfunction unlocks an ancient 'toolkit' of pre-existing adaptations, re-establishing the dominance of an earlier layer of genes that controlled loose-knit colonies of only partially differentiated cells, similar to tumors. The existence of such a toolkit implies that the progress of the neoplasm in the host organism differs distinctively from normal Darwinian evolution. Comparative genomics and the phylogeny of basal metazoans, opisthokonta and basal multicellular eukaryotes should help identify the relevant genes and yield the order in which they evolved. This order will be a rough guide to the reverse order in which cancer develops, as mutations disrupt the genes of cellular cooperation. Our proposal is consistent with current understanding of cancer and explains the paradoxical rapidity with which cancer acquires a suite of mutually-supportive complex abilities. Finally we make several predictions and suggest ways to test this model

  14. Adaptive Horizontal Gene Transfers between Multiple Cheese-Associated Fungi.

    Science.gov (United States)

    Ropars, Jeanne; Rodríguez de la Vega, Ricardo C; López-Villavicencio, Manuela; Gouzy, Jérôme; Sallet, Erika; Dumas, Émilie; Lacoste, Sandrine; Debuchy, Robert; Dupont, Joëlle; Branca, Antoine; Giraud, Tatiana

    2015-10-05

    Domestication is an excellent model for studies of adaptation because it involves recent and strong selection on a few, identified traits [1-5]. Few studies have focused on the domestication of fungi, with notable exceptions [6-11], despite their importance to bioindustry [12] and to a general understanding of adaptation in eukaryotes [5]. Penicillium fungi are ubiquitous molds among which two distantly related species have been independently selected for cheese making-P. roqueforti for blue cheeses like Roquefort and P. camemberti for soft cheeses like Camembert. The selected traits include morphology, aromatic profile, lipolytic and proteolytic activities, and ability to grow at low temperatures, in a matrix containing bacterial and fungal competitors [13-15]. By comparing the genomes of ten Penicillium species, we show that adaptation to cheese was associated with multiple recent horizontal transfers of large genomic regions carrying crucial metabolic genes. We identified seven horizontally transferred regions (HTRs) spanning more than 10 kb each, flanked by specific transposable elements, and displaying nearly 100% identity between distant Penicillium species. Two HTRs carried genes with functions involved in the utilization of cheese nutrients or competition and were found nearly identical in multiple strains and species of cheese-associated Penicillium fungi, indicating recent selective sweeps; they were experimentally associated with faster growth and greater competitiveness on cheese and contained genes highly expressed in the early stage of cheese maturation. These findings have industrial and food safety implications and improve our understanding of the processes of adaptation to rapid environmental changes. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

    Science.gov (United States)

    Danchin, Etienne G.J.; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Da Rocha, Martine; Bajew, Simon; Neilson, Roy; Sokolova (Guzeeva), Elena; Da Silva, Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Johannes; Jones, John T.

    2017-01-01

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq) to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus, representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus, respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum. PMID:29065523

  16. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes.

    Science.gov (United States)

    Danchin, Etienne G J; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Da Rocha, Martine; Bajew, Simon; Neilson, Roy; Guzeeva, Elena Sokolova; Da Silva, Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Johannes; Jones, John T; den Akker, Sebastian Eves-van

    2017-10-23

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq) to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus , representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus , respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum.

  17. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

    Directory of Open Access Journals (Sweden)

    Etienne G.J. Danchin

    2017-10-01

    Full Text Available Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus, representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus, respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum.

  18. Cellular automata-based artificial life system of horizontal gene transfer

    Directory of Open Access Journals (Sweden)

    Ji-xin Liu

    2016-02-01

    Full Text Available Mutation and natural selection is the core of Darwin's idea about evolution. Many algorithms and models are based on this idea. However, in the evolution of prokaryotes, more and more researches have indicated that horizontal gene transfer (HGT would be much more important and universal than the authors had imagined. Owing to this mechanism, the prokaryotes not only become adaptable in nearly any environment on Earth, but also form a global genetic bank and a super communication network with all the genes of the prokaryotic world. Under this background, they present a novel cellular automata model general gene transfer to simulate and study the vertical gene transfer and HGT in the prokaryotes. At the same time, they use Schrodinger's life theory to formulate some evaluation indices and to discuss the intelligence and cognition of prokaryotes which is derived from HGT.

  19. A Preliminary List of Horizontally Transferred Genes in Prokaryotes Determined by Tree Reconstruction and Reconciliation

    Directory of Open Access Journals (Sweden)

    Hyeonsoo Jeong

    2017-08-01

    Full Text Available Genome-wide global detection of genes involved in horizontal gene transfer (HGT remains an active area of research in medical microbiology and evolutionary genomics. Utilizing the explicit evolutionary method of comparing topologies of a total of 154,805 orthologous gene trees against corresponding 16S rRNA “reference” trees, we previously detected a total of 660,894 candidate HGT events in 2,472 completely-sequenced prokaryotic genomes. Here, we report an HGT-index for each individual gene-reference tree pair reconciliation, representing the total number of detected HGT events on the gene tree divided by the total number of genomes (taxa member of that tree. HGT-index is thus a simple measure indicating the sensitivity of prokaryotic genes to participate (or not participate in HGT. Our preliminary list provides HGT-indices for a total of 69,365 genes (detected in >10 and <50% available prokaryotic genomes that are involved in a wide range of biological processes such as metabolism, information, and bacterial response to environment. Identification of horizontally-derived genes is important to combat antibiotic resistance and is a step forward toward reconstructions of improved phylogenies describing the history of life. Our effort is thus expected to benefit ongoing research in the fields of clinical microbiology and evolutionary biology.

  20. Evolutionary maintenance of selfish homing endonuclease genes in the absence of horizontal transfer.

    Science.gov (United States)

    Yahara, Koji; Fukuyo, Masaki; Sasaki, Akira; Kobayashi, Ichizo

    2009-11-03

    Homing endonuclease genes are "selfish" mobile genetic elements whose endonuclease promotes the spread of its own gene by creating a break at a specific target site and using the host machinery to repair the break by copying and inserting the gene at this site. Horizontal transfer across the boundary of a species or population within which mating takes place has been thought to be necessary for their evolutionary persistence. This is based on the assumption that they will become fixed in a host population, where opportunities of homing will disappear, and become susceptible to degeneration. To test this hypothesis, we modeled behavior of a homing endonuclease gene that moves during meiosis through double-strand break repair. We mathematically explored conditions for persistence of the homing endonuclease gene and elucidated their parameter dependence as phase diagrams. We found that, if the cost of the pseudogene is lower than that of the homing endonuclease gene, the 2 forms can persist in a population through autonomous periodic oscillation. If the cost of the pseudogene is higher, 2 types of dynamics appear that enable evolutionary persistence: bistability dependent on initial frequency or fixation irrespective of initial frequency. The prediction of long persistence in the absence of horizontal transfer was confirmed by stochastic simulations in finite populations. The average time to extinction of the endonuclease gene was found to be thousands of meiotic generations or more based on realistic parameter values. These results provide a solid theoretical basis for an understanding of these and other extremely selfish elements.

  1. Tamil merchant in ancient Mesopotamia.

    Directory of Open Access Journals (Sweden)

    Malliya Gounder Palanichamy

    Full Text Available Recent analyses of ancient Mesopotamian mitochondrial genomes have suggested a genetic link between the Indian subcontinent and Mesopotamian civilization. There is no consensus on the origin of the ancient Mesopotamians. They may be descendants of migrants, who founded regional Mesopotamian groups like that of Terqa or they may be merchants who were involved in trans Mesopotamia trade. To identify the Indian source population showing linkage to the ancient Mesopotamians, we screened a total of 15,751 mitochondrial DNAs (11,432 from the literature and 4,319 from this study representing all major populations of India. Our results although suggest that south India (Tamil Nadu and northeast India served as the source of the ancient Mesopotamian mtDNA gene pool, mtDNA of these ancient Mesopotamians probably contributed by Tamil merchants who were involved in the Indo-Roman trade.

  2. Role of Horizontal Gene Transfer in the Evolution of Plant Parasitism Among Nematodes

    NARCIS (Netherlands)

    Mitreva, M.; Smant, G.; Helder, J.

    2009-01-01

    Horizontal gene transfer (HGT) implies the non-sexual exchange of genetic material between species ¿ in some cases even across kingdoms. Although common among Bacteria and Archaea, HGTs from pro- to eukaryotes and between eukaryotes were thought to be extremely rare. Recent studies on intracellular

  3. Phylogenetic inference in Rafflesiales: the influence of rate heterogeneity and horizontal gene transfer

    Directory of Open Access Journals (Sweden)

    Vidal-Russell Romina

    2004-10-01

    Full Text Available Abstract Background The phylogenetic relationships among the holoparasites of Rafflesiales have remained enigmatic for over a century. Recent molecular phylogenetic studies using the mitochondrial matR gene placed Rafflesia, Rhizanthes and Sapria (Rafflesiaceae s. str. in the angiosperm order Malpighiales and Mitrastema (Mitrastemonaceae in Ericales. These phylogenetic studies did not, however, sample two additional groups traditionally classified within Rafflesiales (Apodantheaceae and Cytinaceae. Here we provide molecular phylogenetic evidence using DNA sequence data from mitochondrial and nuclear genes for representatives of all genera in Rafflesiales. Results Our analyses indicate that the phylogenetic affinities of the large-flowered clade and Mitrastema, ascertained using mitochondrial matR, are congruent with results from nuclear SSU rDNA when these data are analyzed using maximum likelihood and Bayesian methods. The relationship of Cytinaceae to Malvales was recovered in all analyses. Relationships between Apodanthaceae and photosynthetic angiosperms varied depending upon the data partition: Malvales (3-gene, Cucurbitales (matR or Fabales (atp1. The latter incongruencies suggest that horizontal gene transfer (HGT may be affecting the mitochondrial gene topologies. The lack of association between Mitrastema and Ericales using atp1 is suggestive of HGT, but greater sampling within eudicots is needed to test this hypothesis further. Conclusions Rafflesiales are not monophyletic but composed of three or four independent lineages (families: Rafflesiaceae, Mitrastemonaceae, Apodanthaceae and Cytinaceae. Long-branch attraction appears to be misleading parsimony analyses of nuclear small-subunit rDNA data, but model-based methods (maximum likelihood and Bayesian analyses recover a topology that is congruent with the mitochondrial matR gene tree, thus providing compelling evidence for organismal relationships. Horizontal gene transfer appears to

  4. Characterization of two catalase-peroxidase-encoding genes in Fusarium verticillioides reveals differential responses to in vitro versus in planta oxidative challenges

    Science.gov (United States)

    Catalase/peroxidases (KatGs) are a superfamily of reactive oxygen species (ROS)-degrading enzymes believed to be horizontally acquired by ancient Ascomycota from bacteria. Subsequent gene duplication resulted in two KatG paralogs in ascomycetes: the widely distributed intracellular KatG1 group, and ...

  5. Horizontal gene transfers with or without cell fusions in all categories of the living matter.

    Science.gov (United States)

    Sinkovics, Joseph G

    2011-01-01

    This article reviews the history of widespread exchanges of genetic segments initiated over 3 billion years ago, to be part of their life style, by sphero-protoplastic cells, the ancestors of archaea, prokaryota, and eukaryota. These primordial cells shared a hostile anaerobic and overheated environment and competed for survival. "Coexist with, or subdue and conquer, expropriate its most useful possessions, or symbiose with it, your competitor" remain cellular life's basic rules. This author emphasizes the role of viruses, both in mediating cell fusions, such as the formation of the first eukaryotic cell(s) from a united crenarchaeon and prokaryota, and the transfer of host cell genes integrated into viral (phages) genomes. After rising above the Darwinian threshold, rigid rules of speciation and vertical inheritance in the three domains of life were established, but horizontal gene transfers with or without cell fusions were never abolished. The author proves with extensive, yet highly selective documentation, that not only unicellular microorganisms, but the most complex multicellular entities of the highest ranks resort to, and practice, cell fusions, and donate and accept horizontally (laterally) transferred genes. Cell fusions and horizontally exchanged genetic materials remain the fundamental attributes and inherent characteristics of the living matter, whether occurring accidentally or sought after intentionally. These events occur to cells stagnating for some 3 milliard years at a lower yet amazingly sophisticated level of evolution, and to cells achieving the highest degree of differentiation, and thus functioning in dependence on the support of a most advanced multicellular host, like those of the human brain. No living cell is completely exempt from gene drains or gene insertions.

  6. Ancient origin and gene mosaicism of the progenitor of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    M Cristina Gutierrez

    2005-09-01

    Full Text Available The highly successful human pathogen Mycobacterium tuberculosis has an extremely low level of genetic variation, which suggests that the entire population resulted from clonal expansion following an evolutionary bottleneck around 35,000 y ago. Here, we show that this population constitutes just the visible tip of a much broader progenitor species, whose extant representatives are human isolates of tubercle bacilli from East Africa. In these isolates, we detected incongruence among gene phylogenies as well as mosaic gene sequences, whose individual elements are retrieved in classical M. tuberculosis. Therefore, despite its apparent homogeneity, the M. tuberculosis genome appears to be a composite assembly resulting from horizontal gene transfer events predating clonal expansion. The amount of synonymous nucleotide variation in housekeeping genes suggests that tubercle bacilli were contemporaneous with early hominids in East Africa, and have thus been coevolving with their human host much longer than previously thought. These results open novel perspectives for unraveling the molecular bases of M. tuberculosis evolutionary success.

  7. Two Horizontally Transferred Xenobiotic Resistance Gene Clusters Associated with Detoxification of Benzoxazolinones by Fusarium Species

    Science.gov (United States)

    Glenn, Anthony E.; Davis, C. Britton; Gao, Minglu; Gold, Scott E.; Mitchell, Trevor R.; Proctor, Robert H.; Stewart, Jane E.; Snook, Maurice E.

    2016-01-01

    Microbes encounter a broad spectrum of antimicrobial compounds in their environments and often possess metabolic strategies to detoxify such xenobiotics. We have previously shown that Fusarium verticillioides, a fungal pathogen of maize known for its production of fumonisin mycotoxins, possesses two unlinked loci, FDB1 and FDB2, necessary for detoxification of antimicrobial compounds produced by maize, including the γ-lactam 2-benzoxazolinone (BOA). In support of these earlier studies, microarray analysis of F. verticillioides exposed to BOA identified the induction of multiple genes at FDB1 and FDB2, indicating the loci consist of gene clusters. One of the FDB1 cluster genes encoded a protein having domain homology to the metallo-β-lactamase (MBL) superfamily. Deletion of this gene (MBL1) rendered F. verticillioides incapable of metabolizing BOA and thus unable to grow on BOA-amended media. Deletion of other FDB1 cluster genes, in particular AMD1 and DLH1, did not affect BOA degradation. Phylogenetic analyses and topology testing of the FDB1 and FDB2 cluster genes suggested two horizontal transfer events among fungi, one being transfer of FDB1 from Fusarium to Colletotrichum, and the second being transfer of the FDB2 cluster from Fusarium to Aspergillus. Together, the results suggest that plant-derived xenobiotics have exerted evolutionary pressure on these fungi, leading to horizontal transfer of genes that enhance fitness or virulence. PMID:26808652

  8. Evolution of Phototrophy in the Chloroflexi Phylum Driven by Horizontal Gene Transfer

    Directory of Open Access Journals (Sweden)

    Lewis M. Ward

    2018-02-01

    Full Text Available The evolutionary mechanisms behind the extant distribution of photosynthesis is a point of substantial contention. Hypotheses range from the presence of phototrophy in the last universal common ancestor and massive gene loss in most lineages, to a later origin in Cyanobacteria followed by extensive horizontal gene transfer into the extant phototrophic clades, with intermediate scenarios that incorporate aspects of both end-members. Here, we report draft genomes of 11 Chloroflexi: the phototrophic Chloroflexia isolate Kouleothrix aurantiaca as well as 10 genome bins recovered from metagenomic sequencing of microbial mats found in Japanese hot springs. Two of these metagenome bins encode photrophic reaction centers and several of these bins form a metabolically diverse, monophyletic clade sister to the Anaerolineae class that we term Candidatus Thermofonsia. Comparisons of organismal (based on conserved ribosomal and phototrophy (reaction center and bacteriochlorophyll synthesis protein phylogenies throughout the Chloroflexi demonstrate that two new lineages acquired phototrophy independently via horizontal gene transfer (HGT from different ancestral donors within the classically phototrophic Chloroflexia class. These results illustrate a complex history of phototrophy within this group, with metabolic innovation tied to HGT. These observations do not support simple hypotheses for the evolution of photosynthesis that require massive character loss from many clades; rather, HGT appears to be the defining mechanic for the distribution of phototrophy in many of the extant clades in which it appears.

  9. Phylogenetic study of Geitlerinema and Microcystis (Cyanobacteria) using PC-IGS and 16S-23S ITS as markers: investigation of horizontal gene transfer.

    Science.gov (United States)

    Piccin-Santos, Viviane; Brandão, Marcelo Mendes; Bittencourt-Oliveira, Maria Do Carmo

    2014-08-01

    Selection of genes that have not been horizontally transferred for prokaryote phylogenetic inferences is regarded as a challenging task. The markers internal transcribed spacer of ribosomal genes (16S-23S ITS) and phycocyanin intergenic spacer (PC-IGS), based on the operons of ribosomal and phycocyanin genes respectively, are among the most used markers in cyanobacteria. The region of the ribosomal genes has been considered stable, whereas the phycocyanin operon may have undergone horizontal transfer. To investigate the occurrence of horizontal transfer of PC-IGS, phylogenetic trees of Geitlerinema and Microcystis strains were generated using PC-IGS and 16S-23S ITS and compared. Phylogenetic trees based on the two markers were mostly congruent for Geitlerinema and Microcystis, indicating a common evolutionary history among ribosomal and phycocyanin genes with no evidence for horizontal transfer of PC-IGS. Thus, PC-IGS is a suitable marker, along with 16S-23S ITS for phylogenetic studies of cyanobacteria. © 2014 Phycological Society of America.

  10. Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution.

    Science.gov (United States)

    Clarke, Thomas H; Garb, Jessica E; Hayashi, Cheryl Y; Arensburger, Peter; Ayoub, Nadia A

    2015-06-08

    The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  11. Horizontal gene transfer of acetyltransferases, invertases and chorismate mutases from different bacteria to diverse recipients.

    Science.gov (United States)

    Noon, Jason B; Baum, Thomas J

    2016-04-12

    Hoplolaimina plant-parasitic nematodes (PPN) are a lineage of animals with many documented cases of horizontal gene transfer (HGT). In a recent study, we reported on three likely HGT candidate genes in the soybean cyst nematode Heterodera glycines, all of which encode secreted candidate effectors with putative functions in the host plant. Hg-GLAND1 is a putative GCN5-related N-acetyltransferase (GNAT), Hg-GLAND13 is a putative invertase (INV), and Hg-GLAND16 is a putative chorismate mutase (CM), and blastp searches of the non-redundant database resulted in highest similarity to bacterial sequences. Here, we searched nematode and non-nematode sequence databases to identify all the nematodes possible that contain these three genes, and to formulate hypotheses about when they most likely appeared in the phylum Nematoda. We then performed phylogenetic analyses combined with model selection tests of alternative models of sequence evolution to determine whether these genes were horizontally acquired from bacteria. Mining of nematode sequence databases determined that GNATs appeared in Hoplolaimina PPN late in evolution, while both INVs and CMs appeared before the radiation of the Hoplolaimina suborder. Also, Hoplolaimina GNATs, INVs and CMs formed well-supported clusters with different rhizosphere bacteria in the phylogenetic trees, and the model selection tests greatly supported models of HGT over descent via common ancestry. Surprisingly, the phylogenetic trees also revealed additional, well-supported clusters of bacterial GNATs, INVs and CMs with diverse eukaryotes and archaea. There were at least eleven and eight well-supported clusters of GNATs and INVs, respectively, from different bacteria with diverse eukaryotes and archaea. Though less frequent, CMs from different bacteria formed supported clusters with multiple different eukaryotes. Moreover, almost all individual clusters containing bacteria and eukaryotes or archaea contained species that inhabit very similar

  12. Phylogeographic support for horizontal gene transfer involving sympatric bruchid species

    Directory of Open Access Journals (Sweden)

    Grill Andrea

    2006-07-01

    Full Text Available Abstract Background We report on the probable horizontal transfer of a mitochondrial gene, cytb, between species of Neotropical bruchid beetles, in a zone where these species are sympatric. The bruchid beetles Acanthoscelides obtectus, A. obvelatus, A. argillaceus and Zabrotes subfasciatus develop on various bean species in Mexico. Whereas A. obtectus and A. obvelatus develop on Phaseolus vulgaris in the Mexican Altiplano, A. argillaceus feeds on P. lunatus in the Pacific coast. The generalist Z. subfasciatus feeds on both bean species, and is sympatric with A. obtectus and A. obvelatus in the Mexican Altiplano, and with A. argillaceus in the Pacific coast. In order to assess the phylogenetic position of these four species, we amplified and sequenced one nuclear (28S rRNA and two mitochondrial (cytb, COI genes. Results Whereas species were well segregated in topologies obtained for COI and 28S rRNA, an unexpected pattern was obtained in the cytb phylogenetic tree. In this tree, individuals from A. obtectus and A. obvelatus, as well as Z. subfasciatus individuals from the Mexican Altiplano, clustered together in a unique little variable monophyletic unit. In contrast, A. argillaceus and Z. subfasciatus individuals from the Pacific coast clustered in two separated clades, identically to the pattern obtained for COI and 28S rRNA. An additional analysis showed that Z. subfasciatus individuals from the Mexican Altiplano also possessed the cytb gene present in individuals of this species from the Pacific coast. Zabrotes subfasciatus individuals from the Mexican Altiplano thus demonstrated two cytb genes, an "original" one and an "infectious" one, showing 25% of nucleotide divergence. The "infectious" cytb gene seems to be under purifying selection and to be expressed in mitochondria. Conclusion The high degree of incongruence of the cytb tree with patterns for other genes is discussed in the light of three hypotheses: experimental contamination

  13. Phylogeographic support for horizontal gene transfer involving sympatric bruchid species.

    Science.gov (United States)

    Alvarez, Nadir; Benrey, Betty; Hossaert-McKey, Martine; Grill, Andrea; McKey, Doyle; Galtier, Nicolas

    2006-07-27

    We report on the probable horizontal transfer of a mitochondrial gene, cytb, between species of Neotropical bruchid beetles, in a zone where these species are sympatric. The bruchid beetles Acanthoscelides obtectus, A. obvelatus, A. argillaceus and Zabrotes subfasciatus develop on various bean species in Mexico. Whereas A. obtectus and A. obvelatus develop on Phaseolus vulgaris in the Mexican Altiplano, A. argillaceus feeds on P. lunatus in the Pacific coast. The generalist Z. subfasciatus feeds on both bean species, and is sympatric with A. obtectus and A. obvelatus in the Mexican Altiplano, and with A. argillaceus in the Pacific coast. In order to assess the phylogenetic position of these four species, we amplified and sequenced one nuclear (28S rRNA) and two mitochondrial (cytb, COI) genes. Whereas species were well segregated in topologies obtained for COI and 28S rRNA, an unexpected pattern was obtained in the cytb phylogenetic tree. In this tree, individuals from A. obtectus and A. obvelatus, as well as Z. subfasciatus individuals from the Mexican Altiplano, clustered together in a unique little variable monophyletic unit. In contrast, A. argillaceus and Z. subfasciatus individuals from the Pacific coast clustered in two separated clades, identically to the pattern obtained for COI and 28S rRNA. An additional analysis showed that Z. subfasciatus individuals from the Mexican Altiplano also possessed the cytb gene present in individuals of this species from the Pacific coast. Zabrotes subfasciatus individuals from the Mexican Altiplano thus demonstrated two cytb genes, an "original" one and an "infectious" one, showing 25% of nucleotide divergence. The "infectious" cytb gene seems to be under purifying selection and to be expressed in mitochondria. The high degree of incongruence of the cytb tree with patterns for other genes is discussed in the light of three hypotheses: experimental contamination, hybridization, and pseudogenisation. However, none of these

  14. Operon Formation is Driven by Co-Regulation and Not by Horizontal Gene Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Price, Morgan N.; Huang, Katherine H.; Arkin, Adam P.; Alm, Eric J.

    2005-04-12

    Although operons are often subject to horizontal gene transfer (HGT), non-HGT genes are particularly likely to be in operons. To resolve this apparent discrepancy and to determine whether HGT is involved in operon formation, we examined the evolutionary history of the genes and operons in Escherichia coli K12. We show that genes that have homologs in distantly related bacteria but not in close relatives of E. coli (indicating HGTi) form new operons at about the same rates as native genes. Furthermore, genes in new operons are no more likely than other genes to have phylogenetic trees that are inconsistent with the species tree. In contrast, essential genes and ubiquitous genes without paralogs (genes believed to undergo HGT rarely) often form new operons. We conclude that HGT is not associated with operon formation, but instead promotes the prevalence of pre-existing operons. To explain operon formation, we propose that new operons reduce the amount of regulatory information required to specify optimal expression patterns. Consistent with this hypothesis, operons have greater amounts of conserved regulatory sequences than do individually transcribed genes.

  15. Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment

    Directory of Open Access Journals (Sweden)

    Takenaka Akio

    2006-02-01

    Full Text Available Abstract Background The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants was studied using ciliate Expressed Sequence Tags (ESTs. More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and Epidinium ecaudatum and the order Vestibuliferida, previously called Holotricha (Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminantium. Results A comparison of the sequences with the completely sequenced genomes of Eukaryotes and Prokaryotes, followed by large-scale construction and analysis of phylogenies, identified 148 ciliate genes that specifically cluster with genes from the Bacteria and Archaea. The phylogenetic clustering with bacterial genes, coupled with the absence of close relatives of these genes in the Ciliate Tetrahymena thermophila, indicates that they have been acquired via Horizontal Gene Transfer (HGT after the colonization of the gut by the rumen Ciliates. Conclusion Among the HGT candidates, we found an over-representation (>75% of genes involved in metabolism, specifically in the catabolism of complex carbohydrates, a rich food source in the rumen. We propose that the acquisition of these genes has greatly facilitated the Ciliates' colonization of the rumen providing evidence for the role of HGT in the adaptation to new niches.

  16. Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment.

    Science.gov (United States)

    Ricard, Guénola; McEwan, Neil R; Dutilh, Bas E; Jouany, Jean-Pierre; Macheboeuf, Didier; Mitsumori, Makoto; McIntosh, Freda M; Michalowski, Tadeusz; Nagamine, Takafumi; Nelson, Nancy; Newbold, Charles J; Nsabimana, Eli; Takenaka, Akio; Thomas, Nadine A; Ushida, Kazunari; Hackstein, Johannes H P; Huynen, Martijn A

    2006-02-10

    The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants) was studied using ciliate Expressed Sequence Tags (ESTs). More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and Epidinium ecaudatum) and the order Vestibuliferida, previously called Holotricha (Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminantium). A comparison of the sequences with the completely sequenced genomes of Eukaryotes and Prokaryotes, followed by large-scale construction and analysis of phylogenies, identified 148 ciliate genes that specifically cluster with genes from the Bacteria and Archaea. The phylogenetic clustering with bacterial genes, coupled with the absence of close relatives of these genes in the Ciliate Tetrahymena thermophila, indicates that they have been acquired via Horizontal Gene Transfer (HGT) after the colonization of the gut by the rumen Ciliates. Among the HGT candidates, we found an over-representation (>75%) of genes involved in metabolism, specifically in the catabolism of complex carbohydrates, a rich food source in the rumen. We propose that the acquisition of these genes has greatly facilitated the Ciliates' colonization of the rumen providing evidence for the role of HGT in the adaptation to new niches.

  17. Assessing the fidelity of ancient DNA sequences amplified from nuclear genes

    DEFF Research Database (Denmark)

    Binladen, Jonas; Wiuf, Carsten Henrik; Gilbert, M. Thomas P.

    2006-01-01

    To date, the field of ancient DNA has relied almost exclusively on mitochondrial DNA (mtDNA) sequences. However, a number of recent studies have reported the successful recovery of ancient nuclear DNA (nuDNA) sequences, thereby allowing the characterization of genetic loci directly involved...... in phenotypic traits of extinct taxa. It is well documented that postmortem damage in ancient mtDNA can lead to the generation of artifactual sequences. However, as yet no one has thoroughly investigated the damage spectrum in ancient nuDNA. By comparing clone sequences from 23 fossil specimens, recovered from...... adenine), respectively. Type 2 transitions are by far the most dominant and increase relative to those of type 1 with damage load. The results suggest that the deamination of cytosine (and 5-methyl cytosine) to uracil (and thymine) is the main cause of miscoding lesions in both ancient mtDNA and nu...

  18. Extensive horizontal transfer of core genome genes between two Lactobacillus species found in the gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Maguin Emmanuelle

    2007-08-01

    Full Text Available Abstract Background While genes that are conserved between related bacterial species are usually thought to have evolved along with the species, phylogenetic trees reconstructed for individual genes may contradict this picture and indicate horizontal gene transfer. Individual trees are often not resolved with high confidence, however, and in that case alternative trees are generally not considered as contradicting the species tree, although not confirming it either. Here we conduct an in-depth analysis of 401 protein phylogenetic trees inferred with varying levels of confidence for three lactobacilli from the acidophilus complex. At present the relationship between these bacteria, isolated from environments as diverse as the gastrointestinal tract (Lactobacillus acidophilus and Lactobacillus johnsonii and yogurt (Lactobacillus delbrueckii ssp. bulgaricus, is ambiguous due to contradictory phenotypical and 16S rRNA based classifications. Results Among the 401 phylogenetic trees, those that could be reconstructed with high confidence support the 16S-rRNA tree or one alternative topology in an astonishing 3:2 ratio, while the third possible topology is practically absent. Lowering the confidence threshold for trees to be taken into consideration does not significantly affect this ratio, and therefore suggests that gene transfer may have affected as much as 40% of the core genome genes. Gene function bias suggests that the 16S rRNA phylogeny of the acidophilus complex, which indicates that L. acidophilus and L. delbrueckii ssp. bulgaricus are the closest related of these three species, is correct. A novel approach of comparison of interspecies protein divergence data employed in this study allowed to determine that gene transfer most likely took place between the lineages of the two species found in the gastrointestinal tract. Conclusion This case-study reports an unprecedented level of phylogenetic incongruence, presumably resulting from extensive

  19. Horizontal Transfer of Tetracycline Resistance Genes in the Subsurface of a Poultry Farm

    Science.gov (United States)

    You, Y.; Ward, M.; Hilpert, M.

    2008-12-01

    Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoirs of antibiotic resistant bacteria and antibiotic resistance genes. At a poultry farm, we, together with Mr.~James Doolittle from USDA, measured the apparent subsurface electrical conductivity (ECa) using a EM38 meter. The resulting ECaR) associated with the poultry farm due to the fact that tetracycline (Tc) is one of the most frequently used antibiotics in food animal production and therefore is probably used at this farm. Soil and aquifer samples were taken from the farm. TcR bacteria were detected, with higher concentrations in the top layer of soil than in the aquifer. TcR bacteria were then enriched from a soil sample, and two classes of TcR genes were detected: tet(M) genes encoding ribosomal protection proteins and tet(L) genes encoding tet efflux pumps. Sequences of the PCR products were compared to known tet(M) and tet(L) genes in GenBank using BLASTN. Phylogenetic trees were also built based on the sequence information. The tet(M) genes found in our soil sample were highly similar to those located on transposons. In a soil microcosm experiment, we used the aforementioned soil sample as incubation medium as well as genetic donor (TcR soil bacteria), and a green fluorescent strain of E. coli as a model genetic recipient to study horizontal transfer of TcR genes from soil bacteria to naïve bacteria. Concentrations of inoculated E. coli were continuously monitored for 15 days, TcR E. coli isolated, and colony PCR performed. The tet(M) genes were found to be transferred to naïve E. coli. The highest horizontal transfer ratio, 0.62 transconjugant per recipient, was observed when Tc was supplemented to a soil microcosm at a concentration of 140 μg/kg soil. Modeling is also ongoing to obtain a better understanding of this complex phenomenon.

  20. Root parasitic plant Orobanche aegyptiaca and shoot parasitic plant Cuscuta australis obtained Brassicaceae-specific strictosidine synthase-like genes by horizontal gene transfer.

    Science.gov (United States)

    Zhang, Dale; Qi, Jinfeng; Yue, Jipei; Huang, Jinling; Sun, Ting; Li, Suoping; Wen, Jian-Fan; Hettenhausen, Christian; Wu, Jinsong; Wang, Lei; Zhuang, Huifu; Wu, Jianqiang; Sun, Guiling

    2014-01-13

    Besides gene duplication and de novo gene generation, horizontal gene transfer (HGT) is another important way of acquiring new genes. HGT may endow the recipients with novel phenotypic traits that are important for species evolution and adaption to new ecological niches. Parasitic systems expectedly allow the occurrence of HGT at relatively high frequencies due to their long-term physical contact. In plants, a number of HGT events have been reported between the organelles of parasites and the hosts, but HGT between host and parasite nuclear genomes has rarely been found. A thorough transcriptome screening revealed that a strictosidine synthase-like (SSL) gene in the root parasitic plant Orobanche aegyptiaca and the shoot parasitic plant Cuscuta australis showed much higher sequence similarities with those in Brassicaceae than with those in their close relatives, suggesting independent gene horizontal transfer events from Brassicaceae to these parasites. These findings were strongly supported by phylogenetic analysis and their identical unique amino acid residues and deletions. Intriguingly, the nucleus-located SSL genes in Brassicaceae belonged to a new member of SSL gene family, which were originated from gene duplication. The presence of introns indicated that the transfer occurred directly by DNA integration in both parasites. Furthermore, positive selection was detected in the foreign SSL gene in O. aegyptiaca but not in C. australis. The expression of the foreign SSL genes in these two parasitic plants was detected in multiple development stages and tissues, and the foreign SSL gene was induced after wounding treatment in C. australis stems. These data imply that the foreign genes may still retain certain functions in the recipient species. Our study strongly supports that parasitic plants can gain novel nuclear genes from distantly related host species by HGT and the foreign genes may execute certain functions in the new hosts.

  1. Microbial survival strategies in ancient permafrost: insights from metagenomics.

    Science.gov (United States)

    Mackelprang, Rachel; Burkert, Alexander; Haw, Monica; Mahendrarajah, Tara; Conaway, Christopher H; Douglas, Thomas A; Waldrop, Mark P

    2017-10-01

    In permafrost (perennially frozen ground) microbes survive oligotrophic conditions, sub-zero temperatures, low water availability and high salinity over millennia. Viable life exists in permafrost tens of thousands of years old but we know little about the metabolic and physiological adaptations to the challenges presented by life in frozen ground over geologic time. In this study we asked whether increasing age and the associated stressors drive adaptive changes in community composition and function. We conducted deep metagenomic and 16 S rRNA gene sequencing across a Pleistocene permafrost chronosequence from 19 000 to 33 000 years before present (kyr). We found that age markedly affected community composition and reduced diversity. Reconstruction of paleovegetation from metagenomic sequence suggests vegetation differences in the paleo record are not responsible for shifts in community composition and function. Rather, we observed shifts consistent with long-term survival strategies in extreme cryogenic environments. These include increased reliance on scavenging detrital biomass, horizontal gene transfer, chemotaxis, dormancy, environmental sensing and stress response. Our results identify traits that may enable survival in ancient cryoenvironments with no influx of energy or new materials.

  2. Fatty acid-binding protein genes of the ancient, air-breathing, ray-finned fish, spotted gar (Lepisosteus oculatus).

    Science.gov (United States)

    Venkatachalam, Ananda B; Fontenot, Quenton; Farrara, Allyse; Wright, Jonathan M

    2018-03-01

    With the advent of high-throughput DNA sequencing technology, the genomic sequence of many disparate species has led to the relatively new discipline of genomics, the study of genome structure, function and evolution. Much work has been focused on the role of whole genome duplications (WGD) in the architecture of extant vertebrate genomes, particularly those of teleost fishes which underwent a WGD early in the teleost radiation >230 million years ago (mya). Our past work has focused on the fate of duplicated copies of a multigene family coding for the intracellular lipid-binding protein (iLBP) genes in the teleost fishes. To define the evolutionary processes that determined the fate of duplicated genes and generated the structure of extant fish genomes, however, requires comparative genomic analysis with a fish lineage that diverged before the teleost WGD, such as the spotted gar (Lepisosteus oculatus), an ancient, air-breathing, ray-finned fish. Here, we describe the genomic organization, chromosomal location and tissue-specific expression of a subfamily of the iLBP genes that code for fatty acid-binding proteins (Fabps) in spotted gar. Based on this work, we have defined the minimum suite of fabp genes prior to their duplication in the teleost lineages ~230-400 mya. Spotted gar, therefore, serves as an appropriate outgroup, or ancestral/ancient fish, that did not undergo the teleost-specific WGD. As such, analyses of the spatio-temporal regulation of spotted gar genes provides a foundation to determine whether the duplicated fabp genes have been retained in teleost genomes owing to either sub- or neofunctionalization. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Biochemical diversification through foreign gene expression in bdelloid rotifers.

    Directory of Open Access Journals (Sweden)

    Chiara Boschetti

    Full Text Available Bdelloid rotifers are microinvertebrates with unique characteristics: they have survived tens of millions of years without sexual reproduction; they withstand extreme desiccation by undergoing anhydrobiosis; and they tolerate very high levels of ionizing radiation. Recent evidence suggests that subtelomeric regions of the bdelloid genome contain sequences originating from other organisms by horizontal gene transfer (HGT, of which some are known to be transcribed. However, the extent to which foreign gene expression plays a role in bdelloid physiology is unknown. We address this in the first large scale analysis of the transcriptome of the bdelloid Adineta ricciae: cDNA libraries from hydrated and desiccated bdelloids were subjected to massively parallel sequencing and assembled transcripts compared against the UniProtKB database by blastx to identify their putative products. Of ~29,000 matched transcripts, ~10% were inferred from blastx matches to be horizontally acquired, mainly from eubacteria but also from fungi, protists, and algae. After allowing for possible sources of error, the rate of HGT is at least 8%-9%, a level significantly higher than other invertebrates. We verified their foreign nature by phylogenetic analysis and by demonstrating linkage of foreign genes with metazoan genes in the bdelloid genome. Approximately 80% of horizontally acquired genes expressed in bdelloids code for enzymes, and these represent 39% of enzymes in identified pathways. Many enzymes encoded by foreign genes enhance biochemistry in bdelloids compared to other metazoans, for example, by potentiating toxin degradation or generation of antioxidants and key metabolites. They also supplement, and occasionally potentially replace, existing metazoan functions. Bdelloid rotifers therefore express horizontally acquired genes on a scale unprecedented in animals, and foreign genes make a profound contribution to their metabolism. This represents a potential

  4. SL1 RNA gene recovery from Enterobius vermicularis ancient DNA in pre-Columbian human coprolites.

    Science.gov (United States)

    Iñiguez, Alena Mayo; Reinhard, Karl; Carvalho Gonçalves, Marcelo Luiz; Ferreira, Luiz Fernando; Araújo, Adauto; Paulo Vicente, Ana Carolina

    2006-11-01

    Enterobius vermicularis, pinworm, is one of the most common helminths worldwide, infecting nearly a billion people at all socio-economic levels. In prehistoric populations the paleoparasitological findings show a pinworm homogeneous distribution among hunter-gatherers in North America, intensified with the advent of agriculture. This same increase also occurred in the transition from nomad hunter-gatherers to sedentary farmers in South America, although E. vermicularis infection encompasses only the ancient Andean peoples, with no record among the pre-Colombian populations in the South American lowlands. However, the outline of pinworm paleoepidemiology has been supported by microscopic finding of eggs recovered from coprolites. Since molecular techniques are precise and sensitive in detecting pathogen ancient DNA (aDNA), and also could provide insights into the parasite evolutionary history, in this work we have performed a molecular paleoparasitological study of E. vermicularis. aDNA was recovered and pinworm 5S rRNA spacer sequences were determined from pre-Columbian coprolites (4110 BC-AD 900) from four different North and South American archaeological sites. The sequence analysis confirmed E. vermicularis identity and revealed a similarity among ancient and modern sequences. Moreover, polymorphisms were identified at the relative positions 160, 173 and 180, in independent coprolite samples from Tulán, San Pedro de Atacama, Chile (1080-950 BC). We also verified the presence of peculiarities (Splicing leader (SL1) RNA sequence, spliced donor site, the Sm antigen biding site, and RNA secondary structure) which characterise the SL1 RNA gene. The analysis shows that the SL1 RNA gene of contemporary pinworms was present in pre-Columbian E. vermicularis by 6110 years ago. We were successful in detecting E. vermicularis aDNA even in coprolites without direct microscopic evidence of the eggs, improving the diagnosis of helminth infections in the past and further

  5. CysQ of , a Protozoa, May Have Been Acquired from Bacteria by Horizontal Gene Transfer

    Directory of Open Access Journals (Sweden)

    Ji Young Lee

    2012-03-01

    Full Text Available Horizontal gene transfer (HGT is the movement of genetic material between kingdoms and is considered to play a positive role in adaptation. Cryptosporidium parvum is a parasitic protozoan that causes an infectious disease. Its genome sequencing reported 14 bacteria-like proteins in the nuclear genome. Among them, cgd2_1810, which has been annotated as CysQ, a sulfite synthesis pathway protein, is listed as one of the candidates of genes horizontally transferred from bacterial origin. In this report, we examined this issue using phylogenetic analysis. Our BLAST search showed that C. parvum CysQ protein had the highest similarity with that of proteobacteria. Analysis with NCBI's Conserved Domain Tree showed phylogenetic incongruence, in that C. parvum CysQ protein was located within a branch of proteobacteria in the cd01638 domain, a bacterial member of the inositol monophosphatase family. According to Kyoto Encyclopedia of Genes and Genomes (KEGG pathway, the sulfate assimilation pathway, where CysQ plays an important role, is well conserved in most eukaryotes as well as prokaryotes. However, the Apicomplexa, including C. parvum, largely lack orthologous genes of the pathway, suggesting its loss in those protozoan lineages. Therefore, we conclude that C. parvum regained cysQ from proteobacteria by HGT, although its functional role is elusive.

  6. What tangled web: barriers to rampant horizontal gene transfer.

    Science.gov (United States)

    Kurland, Charles G

    2005-07-01

    Dawkins in his The Selfish Gene(1) quite aptly applies the term "selfish" to parasitic repetitive DNA sequences endemic to eukaryotic genomes, especially vertebrates. Doolittle and Sapienza(2) as well as Orgel and Crick(3) enlivened this notion of selfish DNA with the identification of such repetitive sequences as remnants of mobile elements such as transposons. In addition, Orgel and Crick(3) associated parasitic DNA with a potential to outgrow their host genomes by propagating both vertically via conventional genome replication as well as infectiously by horizontal gene transfer (HGT) to other genomes. Still later, Doolittle(4) speculated that unchecked HGT between unrelated genomes so complicates phylogeny that the conventional representation of a tree of life would have to be replaced by a thicket or a web of life.(4) In contrast, considerable data now show that reconstructions based on whole genome sequences are consistent with the conventional "tree of life".(5-10) Here, we identify natural barriers that protect modern genome populations from the inroads of rampant HGT. Copyright (c) 2005 Wiley Periodicals, Inc.

  7. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters.

    Science.gov (United States)

    Miller, Jennifer H; Novak, John T; Knocke, William R; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1-a Pseudomonas sp.) and thermophilic (Iso T10-a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457-0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130-0.486, P = 0.075-0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and/or horizontal gene

  8. Detection of horizontal transfer of individual genes by anomalous oligomer frequencies

    Directory of Open Access Journals (Sweden)

    Elhai Jeff

    2012-06-01

    Full Text Available Abstract Background Understanding the history of life requires that we understand the transfer of genetic material across phylogenetic boundaries. Detecting genes that were acquired by means other than vertical descent is a basic step in that process. Detection by discordant phylogenies is computationally expensive and not always definitive. Many have used easily computed compositional features as an alternative procedure. However, different compositional methods produce different predictions, and the effectiveness of any method is not well established. Results The ability of octamer frequency comparisons to detect genes artificially seeded in cyanobacterial genomes was markedly increased by using as a training set those genes that are highly conserved over all bacteria. Using a subset of octamer frequencies in such tests also increased effectiveness, but this depended on the specific target genome and the source of the contaminating genes. The presence of high frequency octamers and the GC content of the contaminating genes were important considerations. A method comprising best practices from these tests was devised, the Core Gene Similarity (CGS method, and it performed better than simple octamer frequency analysis, codon bias, or GC contrasts in detecting seeded genes or naturally occurring transposons. From a comparison of predictions with phylogenetic trees, it appears that the effectiveness of the method is confined to horizontal transfer events that have occurred recently in evolutionary time. Conclusions The CGS method may be an improvement over existing surrogate methods to detect genes of foreign origin.

  9. Phylogenetic analysis of ferlin genes reveals ancient eukaryotic origins

    Directory of Open Access Journals (Sweden)

    Lek Monkol

    2010-07-01

    reproduction-related divergence and specialization of species-specific functions within their genus. Conclusions Our phylogenetic studies provide evolutionary insight into the ferlin gene family. We highlight the existence of ferlin-like proteins throughout eukaryotic evolution, from unicellular phytoplankton and apicomplexan parasites, through to humans. We characterise the preservation of ferlin structural motifs, not only of C2 domains, but also the more poorly characterised ferlin-specific motifs representing the DysF, FerA and FerB domains. Our data suggest an ancient role of ferlin proteins, with lessons from vertebrate biology and human disease suggesting a role relating to vesicle fusion and plasma membrane specialization.

  10. Study on kinetic degradation in soil and horizontal transfer of bt gene by 35S isotopic tracing method

    International Nuclear Information System (INIS)

    Wang Haiyan; Zhang Yanfei; Ye Qingfu

    2012-01-01

    In this study, 35 S isotopic tracing method was applied to investigate kinetic degradation of bt gene from Bt transgenic rice TT51 in two different soil and possibility of its horizontal transfer into soil bacteria as well. Results showed that, during 30 d of aerobic incubation, it was indicated that 35 S-Bt gene was not horizontally transferred into soil microorganisms. The aerobic soil degradation dynamics significantly followed a first-order dissipation pattern for bt gene. After 30 d of incubation, the amount of bt gene reached 9.32% of applied radioactivity for the fluvio-marine yellow loamy soil and 9.92% for the fluvio-aquatic soil, respectively. The half-lives in two soils were 3.53 d for the former soil and 5. 77 d for the latter soil, which means that bt gene was more easily degradable in the weak acidic soil. The use of 35 S labeling proved to be valuable; it served the purpose of validating the rigorousness of experimental protocols, and provided insights into the soil environmental safety assessment for Bt transgenic rice. (authors)

  11. Linen in Ancient Egypt

    Directory of Open Access Journals (Sweden)

    dr.Rehab Mahmoud Ahmed Elsharnouby

    2014-01-01

    Full Text Available Egypt was famous through the Ancient Near East for both weaving linen cloth and the produced quantities. Cloth was sent as expensive gifts from one king to another and given to a laborer as wages in return for his work. Cloth was regarded as an essential element in everyday life as it could be used for everything: clothing, bedding, trappings for animals, or sails of a ship. It was in fact one of the most widely used item throughout Ancient Egypt. Although other textile fibers were used in Pharaonic Egypt, namely, sheep's wool, goat hair and a form of coir, the majority of textiles were made from the plant Linum usitatissimum, flax. Cloth made from this fiber is defined as linen. The research starts with a brief definition of the flax, and then reviews the scenes representing the sowing and the harvesting of its seeds. It also focuses on the way of removing the seeds heads, the preparing of the flax for spinning: retting, beating and scutching. After that, it deals with transforming flax into orderly lengths, and rolling it into balls or coils. The researcher as well studies the Ancient Egyptian spinning techniques: grasped spindle, support spindle and drop spinning; the different types of weaving: tabby weaves, basket weaves, tapestry weaves and warps-patterned weave and the types of looms that were in use in Egypt, namely, the horizontal and vertical looms.

  12. Lateral Gene Transfer Dynamics in the Ancient Bacterial Genus Streptomyces.

    Science.gov (United States)

    McDonald, Bradon R; Currie, Cameron R

    2017-06-06

    Lateral gene transfer (LGT) profoundly shapes the evolution of bacterial lineages. LGT across disparate phylogenetic groups and genome content diversity between related organisms suggest a model of bacterial evolution that views LGT as rampant and promiscuous. It has even driven the argument that species concepts and tree-based phylogenetics cannot be applied to bacteria. Here, we show that acquisition and retention of genes through LGT are surprisingly rare in the ubiquitous and biomedically important bacterial genus Streptomyces Using a molecular clock, we estimate that the Streptomyces bacteria are ~380 million years old, indicating that this bacterial genus is as ancient as land vertebrates. Calibrating LGT rate to this geologic time span, we find that on average only 10 genes per million years were acquired and subsequently maintained. Over that same time span, Streptomyces accumulated thousands of point mutations. By explicitly incorporating evolutionary timescale into our analyses, we provide a dramatically different view on the dynamics of LGT and its impact on bacterial evolution. IMPORTANCE Tree-based phylogenetics and the use of species as units of diversity lie at the foundation of modern biology. In bacteria, these pillars of evolutionary theory have been called into question due to the observation of thousands of lateral gene transfer (LGT) events within and between lineages. Here, we show that acquisition and retention of genes through LGT are exceedingly rare in the bacterial genus Streptomyces , with merely one gene acquired in Streptomyces lineages every 100,000 years. These findings stand in contrast to the current assumption of rampant genetic exchange, which has become the dominant hypothesis used to explain bacterial diversity. Our results support a more nuanced understanding of genetic exchange, with LGT impacting evolution over short timescales but playing a significant role over long timescales. Deeper understanding of LGT provides new

  13. Experimental Evolution of Escherichia coli Harboring an Ancient Translation Protein.

    Science.gov (United States)

    Kacar, Betül; Ge, Xueliang; Sanyal, Suparna; Gaucher, Eric A

    2017-03-01

    The ability to design synthetic genes and engineer biological systems at the genome scale opens new means by which to characterize phenotypic states and the responses of biological systems to perturbations. One emerging method involves inserting artificial genes into bacterial genomes and examining how the genome and its new genes adapt to each other. Here we report the development and implementation of a modified approach to this method, in which phylogenetically inferred genes are inserted into a microbial genome, and laboratory evolution is then used to examine the adaptive potential of the resulting hybrid genome. Specifically, we engineered an approximately 700-million-year-old inferred ancestral variant of tufB, an essential gene encoding elongation factor Tu, and inserted it in a modern Escherichia coli genome in place of the native tufB gene. While the ancient homolog was not lethal to the cell, it did cause a twofold decrease in organismal fitness, mainly due to reduced protein dosage. We subsequently evolved replicate hybrid bacterial populations for 2000 generations in the laboratory and examined the adaptive response via fitness assays, whole genome sequencing, proteomics, and biochemical assays. Hybrid lineages exhibit a general adaptive strategy in which the fitness cost of the ancient gene was ameliorated in part by upregulation of protein production. Our results suggest that an ancient-modern recombinant method may pave the way for the synthesis of organisms that exhibit ancient phenotypes, and that laboratory evolution of these organisms may prove useful in elucidating insights into historical adaptive processes.

  14. Horizontal transfer of a eukaryotic plastid-targeted protein gene to cyanobacteria

    Directory of Open Access Journals (Sweden)

    Keeling Patrick J

    2007-06-01

    Full Text Available Abstract Background Horizontal or lateral transfer of genetic material between distantly related prokaryotes has been shown to play a major role in the evolution of bacterial and archaeal genomes, but exchange of genes between prokaryotes and eukaryotes is not as well understood. In particular, gene flow from eukaryotes to prokaryotes is rarely documented with strong support, which is unusual since prokaryotic genomes appear to readily accept foreign genes. Results Here, we show that abundant marine cyanobacteria in the related genera Synechococcus and Prochlorococcus acquired a key Calvin cycle/glycolytic enzyme from a eukaryote. Two non-homologous forms of fructose bisphosphate aldolase (FBA are characteristic of eukaryotes and prokaryotes respectively. However, a eukaryotic gene has been inserted immediately upstream of the ancestral prokaryotic gene in several strains (ecotypes of Synechococcus and Prochlorococcus. In one lineage this new gene has replaced the ancestral gene altogether. The eukaryotic gene is most closely related to the plastid-targeted FBA from red algae. This eukaryotic-type FBA once replaced the plastid/cyanobacterial type in photosynthetic eukaryotes, hinting at a possible functional advantage in Calvin cycle reactions. The strains that now possess this eukaryotic FBA are scattered across the tree of Synechococcus and Prochlorococcus, perhaps because the gene has been transferred multiple times among cyanobacteria, or more likely because it has been selectively retained only in certain lineages. Conclusion A gene for plastid-targeted FBA has been transferred from red algae to cyanobacteria, where it has inserted itself beside its non-homologous, functional analogue. Its current distribution in Prochlorococcus and Synechococcus is punctate, suggesting a complex history since its introduction to this group.

  15. Horizontal gene transfer versus biostimulation: A strategy for bioremediation in Goa.

    Science.gov (United States)

    Pasumarthi, Rajesh; Mutnuri, Srikanth

    2016-12-15

    Bioaugmentation, Biostimulation and Horizontal gene transfer (HGT) of catabolic genes have been proven for their role in bioremediation of hydrocarbons. It also has been proved that selection of either biostimulation or bioremediation varies for every contaminated site. The reliability of HGT compared to biostimulation and bioremediation was not tested. The present study focuses on reliability of biostimulatiion, bioaugmentation and HGT during biodegradation of Diesel oil and Non aqueous phase liquids (NAPL). Pseudomonas aeruginosa (AEBBITS1) having alkB and NDO genes was used for bioaugmentation and the experiment was conducted using seawater as medium. Based on Gas chromatography results diesel was found to be degraded to 100% in both presence and absence of AEBBITS1. Denturing gradient gel electrophoresis result showed same pattern in presence and absence of AEBBITS1 indicating no HGT. NAPL degradation was found to be more by Biostimulated Bioaugmentation compared to biostimulation and bioaugmentation alone. This proves that biostimulated bioaugmentation is better strategy for oil contamination (tarabll) in Velsao beach, Goa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Horizontal transfer of a nitrate assimilation gene cluster and ecological transitions in fungi: a phylogenetic study.

    Directory of Open Access Journals (Sweden)

    Jason C Slot

    Full Text Available High affinity nitrate assimilation genes in fungi occur in a cluster (fHANT-AC that can be coordinately regulated. The clustered genes include nrt2, which codes for a high affinity nitrate transporter; euknr, which codes for nitrate reductase; and NAD(PH-nir, which codes for nitrite reductase. Homologs of genes in the fHANT-AC occur in other eukaryotes and prokaryotes, but they have only been found clustered in the oomycete Phytophthora (heterokonts. We performed independent and concatenated phylogenetic analyses of homologs of all three genes in the fHANT-AC. Phylogenetic analyses limited to fungal sequences suggest that the fHANT-AC has been transferred horizontally from a basidiomycete (mushrooms and smuts to an ancestor of the ascomycetous mold Trichoderma reesei. Phylogenetic analyses of sequences from diverse eukaryotes and eubacteria, and cluster structure, are consistent with a hypothesis that the fHANT-AC was assembled in a lineage leading to the oomycetes and was subsequently transferred to the Dikarya (Ascomycota+Basidiomycota, which is a derived fungal clade that includes the vast majority of terrestrial fungi. We propose that the acquisition of high affinity nitrate assimilation contributed to the success of Dikarya on land by allowing exploitation of nitrate in aerobic soils, and the subsequent transfer of a complete assimilation cluster improved the fitness of T. reesei in a new niche. Horizontal transmission of this cluster of functionally integrated genes supports the "selfish operon" hypothesis for maintenance of gene clusters.

  17. Horizontal Acquisition and Transcriptional Integration of Novel Genes in Mosquito-Associated Spiroplasma.

    Science.gov (United States)

    Lo, Wen-Sui; Kuo, Chih-Horng

    2017-12-01

    Genetic differentiation among symbiotic bacteria is important in shaping biodiversity. The genus Spiroplasma contains species occupying diverse niches and is a model system for symbiont evolution. Previous studies have established that two mosquito-associated species have diverged extensively in their carbohydrate metabolism genes despite having a close phylogenetic relationship. Notably, although the commensal Spiroplasma diminutum lacks identifiable pathogenicity factors, the pathogenic Spiroplasma taiwanense was found to have acquired a virulence factor glpO and its associated genes through horizontal transfer. However, it is unclear if these acquired genes have been integrated into the regulatory network. In this study, we inferred the gene content evolution in these bacteria, as well as examined their transcriptomes in response to glucose availability. The results indicated that both species have many more gene acquisitions from the Mycoides-Entomoplasmataceae clade, which contains several important pathogens of ruminants, than previously thought. Moreover, several acquired genes have higher expression levels than the vertically inherited homologs, indicating possible functional replacement. Finally, the virulence factor and its functionally linked genes in S. taiwanense were up-regulated in response to glucose starvation, suggesting that these acquired genes are under expression regulation and the pathogenicity may be a stress response. In summary, although differential gene losses are a major process for symbiont divergence, gene gains are critical in counteracting genome degradation and driving diversification among facultative symbionts. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Plant nodulation inducers enhance horizontal gene transfer of Azorhizobium caulinodans symbiosis island.

    Science.gov (United States)

    Ling, Jun; Wang, Hui; Wu, Ping; Li, Tao; Tang, Yu; Naseer, Nawar; Zheng, Huiming; Masson-Boivin, Catherine; Zhong, Zengtao; Zhu, Jun

    2016-11-29

    Horizontal gene transfer (HGT) of genomic islands is a driving force of bacterial evolution. Many pathogens and symbionts use this mechanism to spread mobile genetic elements that carry genes important for interaction with their eukaryotic hosts. However, the role of the host in this process remains unclear. Here, we show that plant compounds inducing the nodulation process in the rhizobium-legume mutualistic symbiosis also enhance the transfer of symbiosis islands. We demonstrate that the symbiosis island of the Sesbania rostrata symbiont, Azorhizobium caulinodans, is an 87.6-kb integrative and conjugative element (ICE Ac ) that is able to excise, form a circular DNA, and conjugatively transfer to a specific site of gly-tRNA gene of other rhizobial genera, expanding their host range. The HGT frequency was significantly increased in the rhizosphere. An ICE Ac -located LysR-family transcriptional regulatory protein AhaR triggered the HGT process in response to plant flavonoids that induce the expression of nodulation genes through another LysR-type protein, NodD. Our study suggests that rhizobia may sense rhizosphere environments and transfer their symbiosis gene contents to other genera of rhizobia, thereby broadening rhizobial host-range specificity.

  19. In silico prediction of horizontal gene transfer events in Lactobacillus bulgaricus and Streptococcus thermophilus reveals protocooperation in yogurt manufacturing.

    Science.gov (United States)

    Liu, Mengjin; Siezen, Roland J; Nauta, Arjen

    2009-06-01

    Lactobacillus bulgaricus and Streptococcus thermophilus, used in yogurt starter cultures, are well known for their stability and protocooperation during their coexistence in milk. In this study, we show that a close interaction between the two species also takes place at the genetic level. We performed an in silico analysis, combining gene composition and gene transfer mechanism-associated features, and predicted horizontally transferred genes in both L. bulgaricus and S. thermophilus. Putative horizontal gene transfer (HGT) events that have occurred between the two bacterial species include the transfer of exopolysaccharide (EPS) biosynthesis genes, transferred from S. thermophilus to L. bulgaricus, and the gene cluster cbs-cblB(cglB)-cysE for the metabolism of sulfur-containing amino acids, transferred from L. bulgaricus or Lactobacillus helveticus to S. thermophilus. The HGT event for the cbs-cblB(cglB)-cysE gene cluster was analyzed in detail, with respect to both evolutionary and functional aspects. It can be concluded that during the coexistence of both yogurt starter species in a milk environment, agonistic coevolution at the genetic level has probably been involved in the optimization of their combined growth and interactions.

  20. An ancient trans-kingdom horizontal transfer of Penelope -like retroelements from arthropods to conifers

    Science.gov (United States)

    Xuan Lin; Nurul Faridi; Claudio Casola

    2016-01-01

    Comparative genomics analyses empowered by the wealth of sequenced genomes have revealed numerous instances of horizontal DNA transfers between distantly related species. In  eukaryotes, repetitive DNA sequences known as transposable elements (TEs) are especially prone to  move across species boundaries. Such horizontal transposon transfers, or HTTs, are relatively  ...

  1. Ancient genes establish stress-induced mutation as a hallmark of cancer.

    Science.gov (United States)

    Cisneros, Luis; Bussey, Kimberly J; Orr, Adam J; Miočević, Milica; Lineweaver, Charles H; Davies, Paul

    2017-01-01

    Cancer is sometimes depicted as a reversion to single cell behavior in cells adapted to live in a multicellular assembly. If this is the case, one would expect that mutation in cancer disrupts functional mechanisms that suppress cell-level traits detrimental to multicellularity. Such mechanisms should have evolved with or after the emergence of multicellularity. This leads to two related, but distinct hypotheses: 1) Somatic mutations in cancer will occur in genes that are younger than the emergence of multicellularity (1000 million years [MY]); and 2) genes that are frequently mutated in cancer and whose mutations are functionally important for the emergence of the cancer phenotype evolved within the past 1000 million years, and thus would exhibit an age distribution that is skewed to younger genes. In order to investigate these hypotheses we estimated the evolutionary ages of all human genes and then studied the probability of mutation and their biological function in relation to their age and genomic location for both normal germline and cancer contexts. We observed that under a model of uniform random mutation across the genome, controlled for gene size, genes less than 500 MY were more frequently mutated in both cases. Paradoxically, causal genes, defined in the COSMIC Cancer Gene Census, were depleted in this age group. When we used functional enrichment analysis to explain this unexpected result we discovered that COSMIC genes with recessive disease phenotypes were enriched for DNA repair and cell cycle control. The non-mutated genes in these pathways are orthologous to those underlying stress-induced mutation in bacteria, which results in the clustering of single nucleotide variations. COSMIC genes were less common in regions where the probability of observing mutational clusters is high, although they are approximately 2-fold more likely to harbor mutational clusters compared to other human genes. Our results suggest this ancient mutational response to

  2. Effect of genomic location on horizontal transfer of a recombinant gene cassette between Pseudomonas strains in the rhizosphere and spermosphere of barley seedlings

    DEFF Research Database (Denmark)

    Sengelov, G.; Kristensen, K. J.; Sørensen, Anders Morten Hay

    2001-01-01

    , horizontal transfer of a recombinant gene cassette inserted into the chromosome of a Pseudomonas strutzeri strain, into a mobilizable plasmid (pAGM42), and into a conjugative plasmid (pKJK5) isolated from barley rhizosphere was investigated. Horizontal transfer efficiencies of the gene cassette inserted...... efficiencies were up to 4.36 x 10(-3) transconjugants/(donors x recipients)(1/2). Transfer of chromosomal encoded genes could not be detected in the microcosms by conjugation or transformation. However, transformation did occur by using the same bacterial strains under laboratory conditions. The rhizosphere...

  3. Real-time PCR detection of Fe-type nitrile hydratase genes from environmental isolates suggests horizontal gene transfer between multiple genera.

    Science.gov (United States)

    Coffey, Lee; Owens, Erica; Tambling, Karen; O'Neill, David; O'Connor, Laura; O'Reilly, Catherine

    2010-11-01

    Nitriles are widespread in the environment as a result of biological and industrial activity. Nitrile hydratases catalyse the hydration of nitriles to the corresponding amide and are often associated with amidases, which catalyze the conversion of amides to the corresponding acids. Nitrile hydratases have potential as biocatalysts in bioremediation and biotransformation applications, and several successful examples demonstrate the advantages. In this work a real-time PCR assay was designed for the detection of Fe-type nitrile hydratase genes from environmental isolates purified from nitrile-enriched soils and seaweeds. Specific PCR primers were also designed for amplification and sequencing of the genes. Identical or highly homologous nitrile hydratase genes were detected from isolates of numerous genera from geographically diverse sites, as were numerous novel genes. The genes were also detected from isolates of genera not previously reported to harbour nitrile hydratases. The results provide further evidence that many bacteria have acquired the genes via horizontal gene transfer. The real-time PCR assay should prove useful in searching for nitrile hydratases that could have novel substrate specificities and therefore potential in industrial applications.

  4. Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment.

    NARCIS (Netherlands)

    Ricard, G.N.S.; McEwan, N.R.; Dutilh, B.E.; Jouany, J.P.; Macheboeuf, D.; Mitsumori, M.; McIntosh, F.M.; Michalowski, T.; Nagamine, T.; Nelson, N.; Newbold, C.J.; Nsabimana, E.; Takenaka, A; Thomas, N.A.; Ushida, K.; Hackstein, J.H.P.; Huynen, M.A.

    2006-01-01

    BACKGROUND: The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants) was studied using ciliate Expressed Sequence Tags (ESTs). More than 4000 ESTs were sequenced from representatives of the two major

  5. Positive selection and ancient duplications in the evolution of class B floral homeotic genes of orchids and grasses

    Directory of Open Access Journals (Sweden)

    Koch Marcus A

    2009-04-01

    Full Text Available Abstract Background Positive selection is recognized as the prevalence of nonsynonymous over synonymous substitutions in a gene. Models of the functional evolution of duplicated genes consider neofunctionalization as key to the retention of paralogues. For instance, duplicate transcription factors are specifically retained in plant and animal genomes and both positive selection and transcriptional divergence appear to have played a role in their diversification. However, the relative impact of these two factors has not been systematically evaluated. Class B MADS-box genes, comprising DEF-like and GLO-like genes, encode developmental transcription factors essential for establishment of perianth and male organ identity in the flowers of angiosperms. Here, we contrast the role of positive selection and the known divergence in expression patterns of genes encoding class B-like MADS-box transcription factors from monocots, with emphasis on the family Orchidaceae and the order Poales. Although in the monocots these two groups are highly diverse and have a strongly canalized floral morphology, there is no information on the role of positive selection in the evolution of their distinctive flower morphologies. Published research shows that in Poales, class B-like genes are expressed in stamens and in lodicules, the perianth organs whose identity might also be specified by class B-like genes, like the identity of the inner tepals of their lily-like relatives. In orchids, however, the number and pattern of expression of class B-like genes have greatly diverged. Results The DEF-like genes from Orchidaceae form four well-supported, ancient clades of orthologues. In contrast, orchid GLO-like genes form a single clade of ancient orthologues and recent paralogues. DEF-like genes from orchid clade 2 (OMADS3-like genes are under less stringent purifying selection than the other orchid DEF-like and GLO-like genes. In comparison with orchids, purifying selection

  6. Accounting for horizontal gene transfers explains conflicting hypotheses regarding the position of aquificales in the phylogeny of Bacteria

    Directory of Open Access Journals (Sweden)

    Gouy Manolo

    2008-10-01

    Full Text Available Abstract Background Despite a large agreement between ribosomal RNA and concatenated protein phylogenies, the phylogenetic tree of the bacterial domain remains uncertain in its deepest nodes. For instance, the position of the hyperthermophilic Aquificales is debated, as their commonly observed position close to Thermotogales may proceed from horizontal gene transfers, long branch attraction or compositional biases, and may not represent vertical descent. Indeed, another view, based on the analysis of rare genomic changes, places Aquificales close to epsilon-Proteobacteria. Results To get a whole genome view of Aquifex relationships, all trees containing sequences from Aquifex in the HOGENOM database were surveyed. This study revealed that Aquifex is most often found as a neighbour to Thermotogales. Moreover, informational genes, which appeared to be less often transferred to the Aquifex lineage than non-informational genes, most often placed Aquificales close to Thermotogales. To ensure these results did not come from long branch attraction or compositional artefacts, a subset of carefully chosen proteins from a wide range of bacterial species was selected for further scrutiny. Among these genes, two phylogenetic hypotheses were found to be significantly more likely than the others: the most likely hypothesis placed Aquificales as a neighbour to Thermotogales, and the second one with epsilon-Proteobacteria. We characterized the genes that supported each of these two hypotheses, and found that differences in rates of evolution or in amino-acid compositions could not explain the presence of two incongruent phylogenetic signals in the alignment. Instead, evidence for a large Horizontal Gene Transfer between Aquificales and epsilon-Proteobacteria was found. Conclusion Methods based on concatenated informational proteins and methods based on character cladistics led to different conclusions regarding the position of Aquificales because this lineage

  7. Horizontal acquisition of multiple mitochondrial genes from a parasitic plant followed by gene conversion with host mitochondrial genes

    Science.gov (United States)

    2010-01-01

    Background Horizontal gene transfer (HGT) is relatively common in plant mitochondrial genomes but the mechanisms, extent and consequences of transfer remain largely unknown. Previous results indicate that parasitic plants are often involved as either transfer donors or recipients, suggesting that direct contact between parasite and host facilitates genetic transfer among plants. Results In order to uncover the mechanistic details of plant-to-plant HGT, the extent and evolutionary fate of transfer was investigated between two groups: the parasitic genus Cuscuta and a small clade of Plantago species. A broad polymerase chain reaction (PCR) survey of mitochondrial genes revealed that at least three genes (atp1, atp6 and matR) were recently transferred from Cuscuta to Plantago. Quantitative PCR assays show that these three genes have a mitochondrial location in the one species line of Plantago examined. Patterns of sequence evolution suggest that these foreign genes degraded into pseudogenes shortly after transfer and reverse transcription (RT)-PCR analyses demonstrate that none are detectably transcribed. Three cases of gene conversion were detected between native and foreign copies of the atp1 gene. The identical phylogenetic distribution of the three foreign genes within Plantago and the retention of cytidines at ancestral positions of RNA editing indicate that these genes were probably acquired via a single, DNA-mediated transfer event. However, samplings of multiple individuals from two of the three species in the recipient Plantago clade revealed complex and perplexing phylogenetic discrepancies and patterns of sequence divergence for all three of the foreign genes. Conclusions This study reports the best evidence to date that multiple mitochondrial genes can be transferred via a single HGT event and that transfer occurred via a strictly DNA-level intermediate. The discovery of gene conversion between co-resident foreign and native mitochondrial copies suggests

  8. Horizontal acquisition of multiple mitochondrial genes from a parasitic plant followed by gene conversion with host mitochondrial genes

    Directory of Open Access Journals (Sweden)

    Hao Weilong

    2010-12-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT is relatively common in plant mitochondrial genomes but the mechanisms, extent and consequences of transfer remain largely unknown. Previous results indicate that parasitic plants are often involved as either transfer donors or recipients, suggesting that direct contact between parasite and host facilitates genetic transfer among plants. Results In order to uncover the mechanistic details of plant-to-plant HGT, the extent and evolutionary fate of transfer was investigated between two groups: the parasitic genus Cuscuta and a small clade of Plantago species. A broad polymerase chain reaction (PCR survey of mitochondrial genes revealed that at least three genes (atp1, atp6 and matR were recently transferred from Cuscuta to Plantago. Quantitative PCR assays show that these three genes have a mitochondrial location in the one species line of Plantago examined. Patterns of sequence evolution suggest that these foreign genes degraded into pseudogenes shortly after transfer and reverse transcription (RT-PCR analyses demonstrate that none are detectably transcribed. Three cases of gene conversion were detected between native and foreign copies of the atp1 gene. The identical phylogenetic distribution of the three foreign genes within Plantago and the retention of cytidines at ancestral positions of RNA editing indicate that these genes were probably acquired via a single, DNA-mediated transfer event. However, samplings of multiple individuals from two of the three species in the recipient Plantago clade revealed complex and perplexing phylogenetic discrepancies and patterns of sequence divergence for all three of the foreign genes. Conclusions This study reports the best evidence to date that multiple mitochondrial genes can be transferred via a single HGT event and that transfer occurred via a strictly DNA-level intermediate. The discovery of gene conversion between co-resident foreign and native

  9. Beyond Agrobacterium-Mediated Transformation: Horizontal Gene Transfer from Bacteria to Eukaryotes.

    Science.gov (United States)

    Lacroix, Benoît; Citovsky, Vitaly

    2018-03-03

    Besides the massive gene transfer from organelles to the nuclear genomes, which occurred during the early evolution of eukaryote lineages, the importance of horizontal gene transfer (HGT) in eukaryotes remains controversial. Yet, increasing amounts of genomic data reveal many cases of bacterium-to-eukaryote HGT that likely represent a significant force in adaptive evolution of eukaryotic species. However, DNA transfer involved in genetic transformation of plants by Agrobacterium species has traditionally been considered as the unique example of natural DNA transfer and integration into eukaryotic genomes. Recent discoveries indicate that the repertoire of donor bacterial species and of recipient eukaryotic hosts potentially are much wider than previously thought, including donor bacterial species, such as plant symbiotic nitrogen-fixing bacteria (e.g., Rhizobium etli) and animal bacterial pathogens (e.g., Bartonella henselae, Helicobacter pylori), and recipient species from virtually all eukaryotic clades. Here, we review the molecular pathways and potential mechanisms of these trans-kingdom HGT events and discuss their utilization in biotechnology and research.

  10. In Silico Prediction of Horizontal Gene Transfer Events in Lactobacillus bulgaricus and Streptococcus thermophilus Reveals Protocooperation in Yogurt Manufacturing▿ †

    Science.gov (United States)

    Liu, Mengjin; Siezen, Roland J.; Nauta, Arjen

    2009-01-01

    Lactobacillus bulgaricus and Streptococcus thermophilus, used in yogurt starter cultures, are well known for their stability and protocooperation during their coexistence in milk. In this study, we show that a close interaction between the two species also takes place at the genetic level. We performed an in silico analysis, combining gene composition and gene transfer mechanism-associated features, and predicted horizontally transferred genes in both L. bulgaricus and S. thermophilus. Putative horizontal gene transfer (HGT) events that have occurred between the two bacterial species include the transfer of exopolysaccharide (EPS) biosynthesis genes, transferred from S. thermophilus to L. bulgaricus, and the gene cluster cbs-cblB(cglB)-cysE for the metabolism of sulfur-containing amino acids, transferred from L. bulgaricus or Lactobacillus helveticus to S. thermophilus. The HGT event for the cbs-cblB(cglB)-cysE gene cluster was analyzed in detail, with respect to both evolutionary and functional aspects. It can be concluded that during the coexistence of both yogurt starter species in a milk environment, agonistic coevolution at the genetic level has probably been involved in the optimization of their combined growth and interactions. PMID:19395564

  11. Complete genome sequence of Brachyspira intermedia reveals unique genomic features in Brachyspira species and phage-mediated horizontal gene transfer

    Science.gov (United States)

    2011-01-01

    Background Brachyspira spp. colonize the intestines of some mammalian and avian species and show different degrees of enteropathogenicity. Brachyspira intermedia can cause production losses in chickens and strain PWS/AT now becomes the fourth genome to be completed in the genus Brachyspira. Results 15 classes of unique and shared genes were analyzed in B. intermedia, B. murdochii, B. hyodysenteriae and B. pilosicoli. The largest number of unique genes was found in B. intermedia and B. murdochii. This indicates the presence of larger pan-genomes. In general, hypothetical protein annotations are overrepresented among the unique genes. A 3.2 kb plasmid was found in B. intermedia strain PWS/AT. The plasmid was also present in the B. murdochii strain but not in nine other Brachyspira isolates. Within the Brachyspira genomes, genes had been translocated and also frequently switched between leading and lagging strands, a process that can be followed by different AT-skews in the third positions of synonymous codons. We also found evidence that bacteriophages were being remodeled and genes incorporated into them. Conclusions The accessory gene pool shapes species-specific traits. It is also influenced by reductive genome evolution and horizontal gene transfer. Gene-transfer events can cross both species and genus boundaries and bacteriophages appear to play an important role in this process. A mechanism for horizontal gene transfer appears to be gene translocations leading to remodeling of bacteriophages in combination with broad tropism. PMID:21816042

  12. The advantages and disadvantages of horizontal gene transfer and the emergence of the first species

    Directory of Open Access Journals (Sweden)

    Higgs Paul G

    2011-01-01

    Full Text Available Abstract Background Horizontal Gene Transfer (HGT is beneficial to a cell if the acquired gene confers a useful function, but is detrimental if the gene has no function, if it is incompatible with existing genes, or if it is a selfishly replicating mobile element. If the balance of these effects is beneficial on average, we would expect cells to evolve high rates of acceptance of horizontally transferred genes, whereas if it is detrimental, cells should reduce the rate of HGT as far as possible. It has been proposed that the rate of HGT was very high in the early stages of prokaryotic evolution, and hence there were no separate lineages of organisms. Only when the HGT rate began to fall, would lineages begin to emerge with their own distinct sets of genes. Evolution would then become more tree-like. This phenomenon has been called the Darwinian Threshold. Results We study a model for genome evolution that incorporates both beneficial and detrimental effects of HGT. We show that if rate of gene loss during genome replication is high, as was probably the case in the earliest genomes before the time of the last universal common ancestor, then a high rate of HGT is favourable. HGT leads to the rapid spread of new genes and allows the build-up of larger, fitter genomes than could be achieved by purely vertical inheritance. In contrast, if the gene loss rate is lower, as in modern prokaryotes, then HGT is, on average, unfavourable. Conclusions Modern cells should therefore evolve to reduce HGT if they can, although the prevalence of independently replicating mobile elements and viruses may mean that cells cannot avoid HGT in practice. In the model, natural selection leads to gradual improvement of the replication accuracy and gradual decrease in the optimal rate of HGT. By clustering genomes based on gene content, we show that there are no separate lineages of organisms when the rate of HGT is high; however, as the rate of HGT decreases, a tree

  13. Plasmid transfer by conjugation as a possible route of horizontal gene transfer and recombination in Xylella fastidiosa

    Science.gov (United States)

    Horizontal gene transfer is an important component of evolution and adaptation of bacterial species. Xylella fastidiosa has the ability to incorporate exogenous DNA into its genome by homologous recombination at relatively high rates. This genetic recombination is believed to play a role in adaptati...

  14. Role of horizontal gene transfer as a control on the coevolution of ribosomal proteins and the genetic code

    Energy Technology Data Exchange (ETDEWEB)

    Woese, Carl R.; Goldenfeld, Nigel; Luthey-Schulten, Zaida

    2011-03-31

    Our main goal is to develop the conceptual and computational tools necessary to understand the evolution of the universal processes of translation and replication and to identify events of horizontal gene transfer that occurred within the components. We will attempt to uncover the major evolutionary transitions that accompanied the development of protein synthesis by the ribosome and associated components of the translation apparatus. Our project goes beyond standard genomic approaches to explore homologs that are represented at both the structure and sequence level. Accordingly, use of structural phylogenetic analysis allows us to probe further back into deep evolutionary time than competing approaches, permitting greater resolution of primitive folds and structures. Specifically, our work focuses on the elements of translation, ranging from the emergence of the canonical genetic code to the evolution of specific protein folds, mediated by the predominance of horizontal gene transfer in early life. A unique element of this study is the explicit accounting for the impact of phenotype selection on translation, through a coevolutionary control mechanism. Our work contributes to DOE mission objectives through: (1) sophisticated computer simulation of protein dynamics and evolution, and the further refinement of techniques for structural phylogeny, which complement sequence information, leading to improved annotation of genomic databases; (2) development of evolutionary approaches to exploring cellular function and machinery in an integrated way; and (3) documentation of the phenotype interaction with translation over evolutionary time, reflecting the system response to changing selection pressures through horizontal gene transfer.

  15. Horizontal Gene Acquisitions, Mobile Element Proliferation, and Genome Decay in the Host-Restricted Plant Pathogen Erwinia Tracheiphila

    Science.gov (United States)

    Shapiro, Lori R.; Scully, Erin D.; Straub, Timothy J.; Park, Jihye; Stephenson, Andrew G.; Beattie, Gwyn A.; Gleason, Mark L.; Kolter, Roberto; Coelho, Miguel C.; De Moraes, Consuelo M.; Mescher, Mark C.; Zhaxybayeva, Olga

    2016-01-01

    Modern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. Here, we present the genome sequence of six strains of the cucurbit bacterial wilt pathogen Erwinia tracheiphila (Enterobacteriaceae) isolated from infected squash plants in New York, Pennsylvania, Kentucky, and Michigan. These genomes exhibit a high proportion of recent horizontal gene acquisitions, invasion and remarkable amplification of mobile genetic elements, and pseudogenization of approximately 20% of the coding sequences. These genome attributes indicate that E. tracheiphila recently emerged as a host-restricted pathogen. Furthermore, chromosomal rearrangements associated with phage and transposable element proliferation contribute to substantial differences in gene content and genetic architecture between the six E. tracheiphila strains and other Erwinia species. Together, these data lead us to hypothesize that E. tracheiphila has undergone recent evolution through both genome decay (pseudogenization) and genome expansion (horizontal gene transfer and mobile element amplification). Despite evidence of dramatic genomic changes, the six strains are genetically monomorphic, suggesting a recent population bottleneck and emergence into E. tracheiphila’s current ecological niche. PMID:26992913

  16. Screening a novel Na+/H+ antiporter gene from a metagenomic library of halophiles colonizing in the Dagong Ancient Brine Well in China.

    Science.gov (United States)

    Xiang, Wenliang; Zhang, Jie; Li, Lin; Liang, Huazhong; Luo, Hai; Zhao, Jian; Yang, Zhirong; Sun, Qun

    2010-05-01

    Metagenomic DNA libraries constructed from the Dagong Ancient Brine Well were screened for genes with Na(+)/H(+) antiporter activity on the antiporter-deficient Escherichia coli KNabc strain. One clone with a stable Na(+)-resistant phenotype was obtained and its Na(+)/H(+) antiporter gene was sequenced and designated as m-nha. The deduced amino acid sequence of M-Nha protein consists of 523 residues with a calculated molecular weight of 58 147 Da and a pI of 5.50, which is homologous with NhaH from Halobacillus dabanensis D-8(T) (92%) and Halobacillus aidingensis AD-6(T) (86%), and with Nhe2 from Bacillus sp. NRRL B-14911 (64%). It had a hydropathy profile with 10 putative transmembrane domains and a long carboxyl terminal hydrophilic tail of 140 amino acid residues, similar to Nhap from Synechocystis sp. and Aphanothece halophytica, as well as NhaG from Bacillus subtilis. The m-nha gene in the antiporter-negative mutant E. coli KNabc conferred resistance to Na(+) and the ability to grow under alkaline conditions. The difference in amino acid sequence and the putative secondary structure suggested that the m-nha isolated from the Dagong Ancient Brine Well in this study was a novel Na(+)/H(+) antiporter gene.

  17. Untangling hybrid phylogenetic signals: horizontal gene transfer and artifacts of phylogenetic reconstruction.

    Science.gov (United States)

    Beiko, Robert G; Ragan, Mark A

    2009-01-01

    Phylogenomic methods can be used to investigate the tangled evolutionary relationships among genomes. Building 'all the trees of all the genes' can potentially identify common pathways of horizontal gene transfer (HGT) among taxa at varying levels of phylogenetic depth. Phylogenetic affinities can be aggregated and merged with the information about genetic linkage and biochemical function to examine hypotheses of adaptive evolution via HGT. Additionally, the use of many genetic data sets increases the power of statistical tests for phylogenetic artifacts. However, large-scale phylogenetic analyses pose several challenges, including the necessary abandonment of manual validation techniques, the need to translate inferred phylogenetic discordance into inferred HGT events, and the challenges involved in aggregating results from search-based inference methods. In this chapter we describe a tree search procedure to recover the most parsimonious pathways of HGT, and examine some of the assumptions that are made by this method.

  18. Dissemination of antimicrobial resistance in microbial ecosystems through horizontal gene transfer

    Directory of Open Access Journals (Sweden)

    Christian Johannes Hendrik Von Wintersdorff

    2016-02-01

    Full Text Available The emergence and spread of antibiotic resistance among pathogenic bacteria has been a rising problem for public health in recent decades. It is becoming increasingly recognized that not only antibiotic resistance genes (ARGs encountered in clinical pathogens are of relevance, but rather, all pathogenic, commensal as well as environmental bacteria – and also mobile genetic elements and bacteriophages – form a reservoir of ARGs (the resistome from which pathogenic bacteria can acquire resistance via horizontal gene transfer (HGT. HGT has caused antibiotic resistance to spread from commensal and environmental species to pathogenic ones, as has been shown for some clinically important ARGs. Of the three canonical mechanisms of HGT, conjugation is thought to have the greatest influence on the dissemination of ARGs. While transformation and transduction are deemed less important, recent discoveries suggest their role may be larger than previously thought. Understanding the extent of the resistome and how its mobilization to pathogenic bacteria takes place is essential for efforts to control the dissemination of these genes. Here, we will discuss the concept of the resistome, provide examples of HGT of clinically relevant ARGs and present an overview of the current knowledge of the contributions the various HGT mechanisms make to the spread of antibiotic resistance.

  19. Horizontal gene transfer confers adaptive advantages to phytopathogenic fungi: a case study of catalase-peroxidase in Fusarium verticillioides

    Science.gov (United States)

    Horizontal gene transfer (HGT), the exchange and stable integration of genetic material between different evolutionary lineages, is widely observed in fungi. We hypothesize that successful stabilization of HGT elements provides adaptive advantages (e.g., virulence). Catalase/peroxidases (KatGs) are ...

  20. AS3MT-mediated tolerance to arsenic evolved by multiple independent horizontal gene transfers from bacteria to eukaryotes

    DEFF Research Database (Denmark)

    Palmgren, Michael; Engström, Karin; Hallström, Björn M.

    2017-01-01

    the evolutionary origin of AS3MT and assessed the ability of different genotypes to produce methylated arsenic metabolites. Phylogenetic analysis suggests that multiple, independent horizontal gene transfers between different bacteria, and from bacteria to eukaryotes, increased tolerance to environmental arsenic...

  1. Dynamic evolution of Geranium mitochondrial genomes through multiple horizontal and intracellular gene transfers.

    Science.gov (United States)

    Park, Seongjun; Grewe, Felix; Zhu, Andan; Ruhlman, Tracey A; Sabir, Jamal; Mower, Jeffrey P; Jansen, Robert K

    2015-10-01

    The exchange of genetic material between cellular organelles through intracellular gene transfer (IGT) or between species by horizontal gene transfer (HGT) has played an important role in plant mitochondrial genome evolution. The mitochondrial genomes of Geraniaceae display a number of unusual phenomena including highly accelerated rates of synonymous substitutions, extensive gene loss and reduction in RNA editing. Mitochondrial DNA sequences assembled for 17 species of Geranium revealed substantial reduction in gene and intron content relative to the ancestor of the Geranium lineage. Comparative analyses of nuclear transcriptome data suggest that a number of these sequences have been functionally relocated to the nucleus via IGT. Evidence for rampant HGT was detected in several Geranium species containing foreign organellar DNA from diverse eudicots, including many transfers from parasitic plants. One lineage has experienced multiple, independent HGT episodes, many of which occurred within the past 5.5 Myr. Both duplicative and recapture HGT were documented in Geranium lineages. The mitochondrial genome of Geranium brycei contains at least four independent HGT tracts that are absent in its nearest relative. Furthermore, G. brycei mitochondria carry two copies of the cox1 gene that differ in intron content, providing insight into contrasting hypotheses on cox1 intron evolution. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  2. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

    NARCIS (Netherlands)

    Danchin, Etienne G.J.; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Rocha, Da Martine; Bajew, Simon; Neilson, Roy; Sokolova, Elena; Silva, Da Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Hans; Jones, John T.; Eves-van den Akker, Sebastian

    2017-01-01

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been

  3. High-resolution analysis of cytosine methylation in ancient DNA.

    Directory of Open Access Journals (Sweden)

    Bastien Llamas

    Full Text Available Epigenetic changes to gene expression can result in heritable phenotypic characteristics that are not encoded in the DNA itself, but rather by biochemical modifications to the DNA or associated chromatin proteins. Interposed between genes and environment, these epigenetic modifications can be influenced by environmental factors to affect phenotype for multiple generations. This raises the possibility that epigenetic states provide a substrate for natural selection, with the potential to participate in the rapid adaptation of species to changes in environment. Any direct test of this hypothesis would require the ability to measure epigenetic states over evolutionary timescales. Here we describe the first single-base resolution of cytosine methylation patterns in an ancient mammalian genome, by bisulphite allelic sequencing of loci from late Pleistocene Bison priscus remains. Retrotransposons and the differentially methylated regions of imprinted loci displayed methylation patterns identical to those derived from fresh bovine tissue, indicating that methylation patterns are preserved in the ancient DNA. Our findings establish the biochemical stability of methylated cytosines over extensive time frames, and provide the first direct evidence that cytosine methylation patterns are retained in DNA from ancient specimens. The ability to resolve cytosine methylation in ancient DNA provides a powerful means to study the role of epigenetics in evolution.

  4. Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment

    OpenAIRE

    Ricard, Guénola; McEwan, Neil R; Dutilh, Bas E; Jouany, Jean-Pierre; Macheboeuf, Didier; Mitsumori, Makoto; McIntosh, Freda M; Michalowski, Tadeusz; Nagamine, Takafumi; Nelson, Nancy; Newbold, Charles J; Nsabimana, Eli; Takenaka, Akio; Thomas, Nadine A; Ushida, Kazunari

    2006-01-01

    Abstract Background The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants) was studied using ciliate Expressed Sequence Tags (ESTs). More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and...

  5. Ancient expansion of the hox cluster in lepidoptera generated four homeobox genes implicated in extra-embryonic tissue formation.

    Directory of Open Access Journals (Sweden)

    Laura Ferguson

    2014-10-01

    Full Text Available Gene duplications within the conserved Hox cluster are rare in animal evolution, but in Lepidoptera an array of divergent Hox-related genes (Shx genes has been reported between pb and zen. Here, we use genome sequencing of five lepidopteran species (Polygonia c-album, Pararge aegeria, Callimorpha dominula, Cameraria ohridella, Hepialus sylvina plus a caddisfly outgroup (Glyphotaelius pellucidus to trace the evolution of the lepidopteran Shx genes. We demonstrate that Shx genes originated by tandem duplication of zen early in the evolution of large clade Ditrysia; Shx are not found in a caddisfly and a member of the basally diverging Hepialidae (swift moths. Four distinct Shx genes were generated early in ditrysian evolution, and were stably retained in all descendent Lepidoptera except the silkmoth which has additional duplications. Despite extensive sequence divergence, molecular modelling indicates that all four Shx genes have the potential to encode stable homeodomains. The four Shx genes have distinct spatiotemporal expression patterns in early development of the Speckled Wood butterfly (Pararge aegeria, with ShxC demarcating the future sites of extraembryonic tissue formation via strikingly localised maternal RNA in the oocyte. All four genes are also expressed in presumptive serosal cells, prior to the onset of zen expression. Lepidopteran Shx genes represent an unusual example of Hox cluster expansion and integration of novel genes into ancient developmental regulatory networks.

  6. Et tu, Brute? Not Even Intracellular Mutualistic Symbionts Escape Horizontal Gene Transfer

    Directory of Open Access Journals (Sweden)

    Sergio López-Madrigal

    2017-09-01

    Full Text Available Many insect species maintain mutualistic relationships with endosymbiotic bacteria. In contrast to their free-living relatives, horizontal gene transfer (HGT has traditionally been considered rare in long-term endosymbionts. Nevertheless, meta-omics exploration of certain symbiotic models has unveiled an increasing number of bacteria-bacteria and bacteria-host genetic transfers. The abundance and function of transferred loci suggest that HGT might play a major role in the evolution of the corresponding consortia, enhancing their adaptive value or buffering detrimental effects derived from the reductive evolution of endosymbionts’ genomes. Here, we comprehensively review the HGT cases recorded to date in insect-bacteria mutualistic consortia, and discuss their impact on the evolutionary success of these associations.

  7. Nuclear counterparts of the cytoplasmic mitochondrial 12S rRNA gene: a problem of ancient DNA and molecular phylogenies.

    Science.gov (United States)

    van der Kuyl, A C; Kuiken, C L; Dekker, J T; Perizonius, W R; Goudsmit, J

    1995-06-01

    Monkey mummy bones and teeth originating from the North Saqqara Baboon Galleries (Egypt), soft tissue from a mummified baboon in a museum collection, and nineteenth/twentieth-century skin fragments from mangabeys were used for DNA extraction and PCR amplification of part of the mitochondrial 12S rRNA gene. Sequences aligning with the 12S rRNA gene were recovered but were only distantly related to contemporary monkey mitochondrial 12S rRNA sequences. However, many of these sequences were identical or closely related to human nuclear DNA sequences resembling mitochondrial 12S rRNA (isolated from a cell line depleted in mitochondria) and therefore have to be considered contamination. Subsequently in a separate study we were able to recover genuine mitochondrial 12S rRNA sequences from many extant species of nonhuman Old World primates and sequences closely resembling the human nuclear integrations. Analysis of all sequences by the neighbor-joining (NJ) method indicated that mitochondrial DNA sequences and their nuclear counterparts can be divided into two distinct clusters. One cluster contained all temporary cytoplasmic mitochondrial DNA sequences and approximately half of the monkey nuclear mitochondriallike sequences. A second cluster contained most human nuclear sequences and the other half of monkey nuclear sequences with a separate branch leading to human and gorilla mitochondrial and nuclear sequences. Sequences recovered from ancient materials were equally divided between the two clusters. These results constitute a warning for when working with ancient DNA or performing phylogenetic analysis using mitochondrial DNA as a target sequence: Nuclear counterparts of mitochondrial genes may lead to faulty interpretation of results.

  8. Mainstreams of horizontal gene exchange in enterobacteria: consideration of the outbreak of enterohemorrhagic E. coli O104:H4 in Germany in 2011.

    Directory of Open Access Journals (Sweden)

    Oliver Bezuidt

    Full Text Available BACKGROUND: Escherichia coli O104:H4 caused a severe outbreak in Europe in 2011. The strain TY-2482 sequenced from this outbreak allowed the discovery of its closest relatives but failed to resolve ways in which it originated and evolved. On account of the previous statement, may we expect similar upcoming outbreaks to occur recurrently or spontaneously in the future? The inability to answer these questions shows limitations of the current comparative and evolutionary genomics methods. PRINCIPAL FINDINGS: The study revealed oscillations of gene exchange in enterobacteria, which originated from marine γ-Proteobacteria. These mobile genetic elements have become recombination hotspots and effective 'vehicles' ensuring a wide distribution of successful combinations of fitness and virulence genes among enterobacteria. Two remarkable peculiarities of the strain TY-2482 and its relatives were observed: i retaining the genetic primitiveness by these strains as they somehow avoided the main fluxes of horizontal gene transfer which effectively penetrated other enetrobacteria; ii acquisition of antibiotic resistance genes in a plasmid genomic island of β-Proteobacteria origin which ontologically is unrelated to the predominant genomic islands of enterobacteria. CONCLUSIONS: Oscillations of horizontal gene exchange activity were reported which result from a counterbalance between the acquired resistance of bacteria towards existing mobile vectors and the generation of new vectors in the environmental microflora. We hypothesized that TY-2482 may originate from a genetically primitive lineage of E. coli that has evolved in confined geographical areas and brought by human migration or cattle trade onto an intersection of several independent streams of horizontal gene exchange. Development of a system for monitoring the new and most active gene exchange events was proposed.

  9. Ancient connection between NKL genes and the mesoderm? Insights from Tlx expression in a ctenophore.

    Science.gov (United States)

    Derelle, Romain; Manuel, Michaël

    2007-04-01

    In recent years, evo-devo studies on non-bilaterian metazoans have improved our understanding of the early evolution of animal body plans. In particular, works on cnidarians suggested that contrary to classical views, the mesoderm originated far before the emergence of the Bilateria. In this context, a synthesis of genomic and functional data concerning the Antennapedia (Antp) superclass of homeobox genes suggested that early in animal evolution, each of the three germ layers was under the control of one cluster of Antp genes. In particular, the patterning and differentiation of the mesoderm was under the control of the NKL cluster. The ctenophores stand as a key taxon with respect to such issues because unlike other non-bilaterian phyla, their intermediate germ layer satisfies the strict embryological definition of a mesoderm. For that reason, we investigated the only known member of the NKL group in Ctenophora, a gene previously isolated from Pleurobrachia and attributed to the Tlx family. In our analysis of the NKL group, this ctenophore gene branches as the sister-group of bilaterian Tlx genes, but without statistical support. The expression pattern of this gene was revealed by in situ hybridisation in the adult ctenophore. The expression territories of PpiTlx are predominantly ectodermal, in two distinct types of ciliated epidermal cells and in one category of gland cells. We also identified a probable endodermal site of expression. Because we failed to detect any mesodermal expression, the results do not provide support to the hypothesis of an ancient functional association between the NKL group and the mesoderm.

  10. H-NS Facilitates Sequence Diversification of Horizontally Transferred DNAs during Their Integration in Host Chromosomes.

    OpenAIRE

    Koichi Higashi; Toru Tobe; Akinori Kanai; Ebru Uyar; Shu Ishikawa; Yutaka Suzuki; Naotake Ogasawara; Ken Kurokawa; Taku Oshima

    2016-01-01

    Bacteria can acquire new traits through horizontal gene transfer. Inappropriate expression of transferred genes, however, can disrupt the physiology of the host bacteria. To reduce this risk, Escherichia coli expresses the nucleoid-associated protein, H-NS, which preferentially binds to horizontally transferred genes to control their expression. Once expression is optimized, the horizontally transferred genes may actually contribute to E. coli survival in new habitats. Therefore, we investiga...

  11. Pathogens and host immunity in the ancient human oral cavity

    DEFF Research Database (Denmark)

    Warinner, Christina; Rodrigues, João F Matias; Vyas, Rounak

    2014-01-01

    Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral...... cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction...... calculus permits the simultaneous investigation of pathogen activity, host immunity and diet, thereby extending direct investigation of common diseases into the human evolutionary past....

  12. Two Ancient Gene Families Are Critical for Maintenance of the Mammalian Skin Barrier in Postnatal Life.

    Science.gov (United States)

    Cangkrama, Michael; Darido, Charbel; Georgy, Smitha R; Partridge, Darren; Auden, Alana; Srivastava, Seema; Wilanowski, Tomasz; Jane, Stephen M

    2016-07-01

    The skin barrier is critical for mammalian survival in the terrestrial environment, affording protection against fluid loss, microbes, toxins, and UV exposure. Many genes indispensable for barrier formation in the embryo have been identified, but loss of these genes in adult mice does not induce barrier regression. We describe a complex regulatory network centered on two ancient gene families, the grainyhead-like (Grhl) transcription factors and the protein cross-linking enzymes (tissue transglutaminases [Tgms]), which are essential for skin permeability barrier maintenance in adult mice. Embryonic deletion of Grhl3 induces loss of Tgm1 expression, which disrupts the cornified envelope, thus preventing permeability barrier formation leading to neonatal death. However, gene deletion of Grhl3 in adult mice does not disrupt the preformed barrier, with cornified envelope integrity maintained by Grhl1 and Tgm5, which are up-regulated in response to postnatal loss of Grhl3. Concomitant deletion of both Grhl factors in adult mice induced loss of Tgm1 and Tgm5 expression, perturbation of the cornified envelope, and complete permeability barrier regression that was incompatible with life. These findings define the molecular safeguards for barrier function that accompany the transition from intrauterine to terrestrial life. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  13. An ancient duplication of exon 5 in the Snap25 gene is required for complex neuronal development/function.

    Directory of Open Access Journals (Sweden)

    Jenny U Johansson

    2008-11-01

    Full Text Available Alternative splicing is an evolutionary innovation to create functionally diverse proteins from a limited number of genes. SNAP-25 plays a central role in neuroexocytosis by bridging synaptic vesicles to the plasma membrane during regulated exocytosis. The SNAP-25 polypeptide is encoded by a single copy gene, but in higher vertebrates a duplication of exon 5 has resulted in two mutually exclusive splice variants, SNAP-25a and SNAP-25b. To address a potential physiological difference between the two SNAP-25 proteins, we generated gene targeted SNAP-25b deficient mouse mutants by replacing the SNAP-25b specific exon with a second SNAP-25a equivalent. Elimination of SNAP-25b expression resulted in developmental defects, spontaneous seizures, and impaired short-term synaptic plasticity. In adult mutants, morphological changes in hippocampus and drastically altered neuropeptide expression were accompanied by severe impairment of spatial learning. We conclude that the ancient exon duplication in the Snap25 gene provides additional SNAP-25-function required for complex neuronal processes in higher eukaryotes.

  14. Recombination and horizontal transfer of nodulation and ACC deaminase (acdS) genes within Alpha- and Betaproteobacteria nodulating legumes of the Cape Fynbos biome.

    Science.gov (United States)

    Lemaire, Benny; Van Cauwenberghe, Jannick; Chimphango, Samson; Stirton, Charles; Honnay, Olivier; Smets, Erik; Muasya, A Muthama

    2015-11-01

    The goal of this work is to study the evolution and the degree of horizontal gene transfer (HGT) within rhizobial genera of both Alphaproteobacteria (Mesorhizobium, Rhizobium) and Betaproteobacteria (Burkholderia), originating from South African Fynbos legumes. By using a phylogenetic approach and comparing multiple chromosomal and symbiosis genes, we revealed conclusive evidence of high degrees of horizontal transfer of nodulation genes among closely related species of both groups of rhizobia, but also among species with distant genetic backgrounds (Rhizobium and Mesorhizobium), underscoring the importance of lateral transfer of symbiosis traits as an important evolutionary force among rhizobia of the Cape Fynbos biome. The extensive exchange of symbiosis genes in the Fynbos is in contrast with a lack of significant events of HGT among Burkholderia symbionts from the South American Cerrado and Caatinga biome. Furthermore, homologous recombination among selected housekeeping genes had a substantial impact on sequence evolution within Burkholderia and Mesorhizobium. Finally, phylogenetic analyses of the non-symbiosis acdS gene in Mesorhizobium, a gene often located on symbiosis islands, revealed distinct relationships compared to the chromosomal and symbiosis genes, suggesting a different evolutionary history and independent events of gene transfer. The observed events of HGT and incongruence between different genes necessitate caution in interpreting topologies from individual data types. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Ancient mitogenomics

    DEFF Research Database (Denmark)

    Ho, Simon Y. W.; Gilbert, Tom

    2010-01-01

    the technical challenges that face researchers in the field. We catalogue the diverse sequencing methods and source materials used to obtain ancient mitogenomic sequences, summarise the associated genetic and phylogenetic studies that have been conducted, and evaluate the future prospects of the field.......The mitochondrial genome has been the traditional focus of most research into ancient DNA, owing to its high copy number and population-level variability. Despite this long-standing interest in mitochondrial DNA, it was only in 2001 that the first complete ancient mitogenomic sequences were...... obtained. As a result of various methodological developments, including the introduction of high-throughput sequencing techniques, the total number of ancient mitogenome sequences has increased rapidly over the past few years. In this review, we present a brief history of ancient mitogenomics and describe...

  16. The prevalence of gene duplications and their ancient origin in Rhodobacter sphaeroides 2.4.1

    Directory of Open Access Journals (Sweden)

    Cho Hyuk

    2010-12-01

    Full Text Available Abstract Background Rhodobacter sphaeroides 2.4.1 is a metabolically versatile organism that belongs to α-3 subdivision of Proteobacteria. The present study was to identify the extent, history, and role of gene duplications in R. sphaeroides 2.4.1, an organism that possesses two chromosomes. Results A protein similarity search (BLASTP identified 1247 orfs (~29.4% of the total protein coding orfs that are present in 2 or more copies, 37.5% (234 gene-pairs of which exist in duplicate copies. The distribution of the duplicate gene-pairs in all Clusters of Orthologous Groups (COGs differed significantly when compared to the COG distribution across the whole genome. Location plots revealed clusters of gene duplications that possessed the same COG classification. Phylogenetic analyses were performed to determine a tree topology predicting either a Type-A or Type-B phylogenetic relationship. A Type-A phylogenetic relationship shows that a copy of the protein-pair matches more with an ortholog from a species closely related to R. sphaeroides while a Type-B relationship predicts the highest match between both copies of the R. sphaeroides protein-pair. The results revealed that ~77% of the proteins exhibited a Type-A phylogenetic relationship demonstrating the ancient origin of these gene duplications. Additional analyses on three other strains of R. sphaeroides revealed varying levels of gene loss and retention in these strains. Also, analyses on common gene pairs among the four strains revealed that these genes experience similar functional constraints and undergo purifying selection. Conclusions Although the results suggest that the level of gene duplication in organisms with complex genome structuring (more than one chromosome seems to be not markedly different from that in organisms with only a single chromosome, these duplications may have aided in genome reorganization in this group of eubacteria prior to the formation of R. sphaeroides as gene

  17. Background Adjusted Alignment-Free Dissimilarity Measures Improve the Detection of Horizontal Gene Transfer

    Directory of Open Access Journals (Sweden)

    Kujin Tang

    2018-04-01

    Full Text Available Horizontal gene transfer (HGT plays an important role in the evolution of microbial organisms including bacteria. Alignment-free methods based on single genome compositional information have been used to detect HGT. Currently, Manhattan and Euclidean distances based on tetranucleotide frequencies are the most commonly used alignment-free dissimilarity measures to detect HGT. By testing on simulated bacterial sequences and real data sets with known horizontal transferred genomic regions, we found that more advanced alignment-free dissimilarity measures such as CVTree and d2* that take into account the background Markov sequences can solve HGT detection problems with significantly improved performance. We also studied the influence of different factors such as evolutionary distance between host and donor sequences, size of sliding window, and host genome composition on the performances of alignment-free methods to detect HGT. Our study showed that alignment-free methods can predict HGT accurately when host and donor genomes are in different order levels. Among all methods, CVTree with word length of 3, d2* with word length 3, Markov order 1 and d2* with word length 4, Markov order 1 outperform others in terms of their highest F1-score and their robustness under the influence of different factors.

  18. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  19. A comprehensive aligned nifH gene database: a multipurpose tool for studies of nitrogen-fixing bacteria.

    Science.gov (United States)

    Gaby, John Christian; Buckley, Daniel H

    2014-01-01

    We describe a nitrogenase gene sequence database that facilitates analysis of the evolution and ecology of nitrogen-fixing organisms. The database contains 32 954 aligned nitrogenase nifH sequences linked to phylogenetic trees and associated sequence metadata. The database includes 185 linked multigene entries including full-length nifH, nifD, nifK and 16S ribosomal RNA (rRNA) gene sequences. Evolutionary analyses enabled by the multigene entries support an ancient horizontal transfer of nitrogenase genes between Archaea and Bacteria and provide evidence that nifH has a different history of horizontal gene transfer from the nifDK enzyme core. Further analyses show that lineages in nitrogenase cluster I and cluster III have different rates of substitution within nifD, suggesting that nifD is under different selection pressure in these two lineages. Finally, we find that that the genetic divergence of nifH and 16S rRNA genes does not correlate well at sequence dissimilarity values used commonly to define microbial species, as stains having <3% sequence dissimilarity in their 16S rRNA genes can have up to 23% dissimilarity in nifH. The nifH database has a number of uses including phylogenetic and evolutionary analyses, the design and assessment of primers/probes and the evaluation of nitrogenase sequence diversity. Database URL: http://www.css.cornell.edu/faculty/buckley/nifh.htm.

  20. Did the ancient Egyptians migrate to ancient Nigeria?

    Directory of Open Access Journals (Sweden)

    Jock M. Agai

    2014-01-01

    Full Text Available Literatures concerning the history of West African peoples published from 1900 to 1970 debate�the possible migrations of the Egyptians into West Africa. Writers like Samuel Johnson and�Lucas Olumide believe that the ancient Egyptians penetrated through ancient Nigeria but Leo�Frobenius and Geoffrey Parrinder frowned at this opinion. Using the works of these early�20th century writers of West African history together with a Yoruba legend which teaches�about the origin of their earliest ancestor(s, this researcher investigates the theories that the�ancient Egyptians had contact with the ancient Nigerians and particularly with the Yorubas.Intradisciplinary and/or interdisciplinary implications: There is an existing ideology�amongst the Yorubas and other writers of Yoruba history that the original ancestors of�the Yorubas originated in ancient Egypt hence there was migration between Egypt and�Yorubaland. This researcher contends that even if there was migration between Egypt and�Nigeria, such migration did not take place during the predynastic and dynastic period as�speculated by some scholars. The subject is open for further research.

  1. From gene trees to organismal phylogeny in prokaryotes: the case of the gamma-Proteobacteria.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Lerat

    2003-10-01

    Full Text Available The rapid increase in published genomic sequences for bacteria presents the first opportunity to reconstruct evolutionary events on the scale of entire genomes. However, extensive lateral gene transfer (LGT may thwart this goal by preventing the establishment of organismal relationships based on individual gene phylogenies. The group for which cases of LGT are most frequently documented and for which the greatest density of complete genome sequences is available is the gamma-Proteobacteria, an ecologically diverse and ancient group including free-living species as well as pathogens and intracellular symbionts of plants and animals. We propose an approach to multigene phylogeny using complete genomes and apply it to the case of the gamma-Proteobacteria. We first applied stringent criteria to identify a set of likely gene orthologs and then tested the compatibilities of the resulting protein alignments with several phylogenetic hypotheses. Our results demonstrate phylogenetic concordance among virtually all (203 of 205 of the selected gene families, with each of the exceptions consistent with a single LGT event. The concatenated sequences of the concordant families yield a fully resolved phylogeny. This topology also received strong support in analyses aimed at excluding effects of heterogeneity in nucleotide base composition across lineages. Our analysis indicates that single-copy orthologous genes are resistant to horizontal transfer, even in ancient bacterial groups subject to high rates of LGT. This gene set can be identified and used to yield robust hypotheses for organismal phylogenies, thus establishing a foundation for reconstructing the evolutionary transitions, such as gene transfer, that underlie diversity in genome content and organization.

  2. Phylogenetic detection of horizontal gene transfer during the step-wise genesis of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Turenne Christine

    2009-08-01

    Full Text Available Abstract Background In the past decade, the availability of complete genome sequence data has greatly facilitated comparative genomic research aimed at addressing genetic variability within species. More recently, analysis across species has become feasible, especially in genera where genome sequencing projects of multiple species have been initiated. To understand the genesis of the pathogen Mycobacterium tuberculosis within a genus where the majority of species are harmless environmental organisms, we have used genome sequence data from 16 mycobacteria to look for evidence of horizontal gene transfer (HGT associated with the emergence of pathogenesis. First, using multi-locus sequence analysis (MLSA of 20 housekeeping genes across these species, we derived a phylogeny that serves as the basis for HGT assignments. Next, we performed alignment searches for the 3989 proteins of M. tuberculosis H37Rv against 15 other mycobacterial genomes, generating a matrix of 59835 comparisons, to look for genetic elements that were uniquely found in M. tuberculosis and closely-related pathogenic mycobacteria. To assign when foreign genes were likely acquired, we designed a bioinformatic program called mycoHIT (mycobacterial homologue investigation tool to analyze these data in conjunction with the MLSA-based phylogeny. Results The bioinformatic screen predicted that 137 genes had been acquired by HGT at different phylogenetic strata; these included genes coding for metabolic functions and modification of mycobacterial lipids. For the majority of these genes, corroborating evidence of HGT was obtained, such as presence of phage or plasmid, and an aberrant GC%. Conclusion M. tuberculosis emerged through vertical inheritance along with the step-wise addition of genes acquired via HGT events, a process that may more generally describe the evolution of other pathogens.

  3. Insights into horizontal acquisition patterns of dormancy and ...

    Indian Academy of Sciences (India)

    2016-07-22

    Jul 22, 2016 ... ed the horizontal acquisition of fatty acid synthesis genes from α-proteobacteria .... of the genes related to fatty acid, polyketide or lipoprotein metabolism in M. ..... Basic local alignment search tool. J. Mol. Biol. 215 403–410.

  4. Análisis de transferencia horizontal de genes en ensayos de biorremediación con grasas recalcitrantes

    Directory of Open Access Journals (Sweden)

    Catalina Rozo

    2010-01-01

    Full Text Available El empleo de microorganismos como herramienta para la mineralización de contaminantes orgánicos es una práctica que ha tomado mucha fuerza gracias a su eficiencia y bajo costo. La transferencia horizontal vía conjugación de genes es un requerimiento básico para optimizar procesos de biorremediación, por esta razón, además de conocer la diversidad metabólica es fundamental entender las interacciones que ocurren en una comunidad bacteriana para potenciar los procesos de biorremediación en campo. En este estudio se busca evaluar el potencial de transferencia horizontal (TH, tanto in vitro como en microcosmos de suelo, de aislamientos de bacterias obtenidas de un pasivo ambiental de grasas provenientes de la explotación carbonífera del Cerrejón. Inicialmente se agruparon los aislamientos de acuerdo con sus patrones de resistencia a antibióticos: ampicilina, cloramfenicol, gentamicina, tetraciclina y kanamicina. El potencial de TH de las cepas Vlf4, Ot3, Ot6, Pgt4, Blf11 y Vlf13 fue evaluado in vitro en medio sólido Luria-Bertani (LB donde se obtuvieron nuevos fenotipos a partir de los cruces Vlf13xOt6 y Pgt4xOt6, el nuevo fenotipo indica resistencia a los dos marcadores (ampR, kanR y su morfología sugiere que el receptor, en los dos casos, es la cepa Ot6. Los parentales Vlf13, Pgt4 y Ot6 fueron identificados por amplificación del gen RNAr 16S como Pseudomonas sp., Pseudomonas sp. y Chryseobacterium sp., respectivamente, y los transconjugantes como Chryseobacterium sp. Posteriormente, estos dos cruces fueron sometidos a ensayos de transferencia horizontal en microcosmos de suelos, donde se hizo evidente nuevamente la presencia de TH a una menor tasa. Los resultados obtenidos indican la posibilidad de un potencial de transferencia horizontal de genes entre los aislamientos seleccionados, dando lugar a la probabilidad de formular en futuros estudios un consorcio de bacterias que demuestran tener esta ventaja adaptativa.

  5. The importance of studying inherited hematological disorders in ancient Anatolian populations

    Directory of Open Access Journals (Sweden)

    Yeşim Doğan Alakoç

    2011-12-01

    Full Text Available Before analysis of DNA from ancient remains was possible, anthropologists studied evolution and migration patterns using data obtained from population genetic studies on modern populations combined with data obtained from morphological evaluations of ancient remains. Currently, DNA analysis of ancient populations is making a valuable contribution to these efforts. Researchers that perform ancient DNA analysis prefer to study polymorphisms on the Y chromosome or mitochondrial DNA because the results are easier to statistically evaluate. To evaluate polymorphisms on diploid genomes, which are more informative, only mutations that have been extensively examined in modern populations should be chosen. The most extensively evaluated mutations are those related to prevalent inherited disorders. As such, beta-thalassemia, sickle cell anemia, FVL mutation of globin and the factor V genes are good candidates for DNA studies in ancient populations. These mutations are common in Anatolia, host to many civilizations since the Paleolithic period. This history makes Anatolia a good place for conducting research that could enhance our understanding of human evolution and migration patterns.

  6. Sequence diversities of serine-aspartate repeat genes among Staphylococcus aureus isolates from different hosts presumably by horizontal gene transfer.

    Directory of Open Access Journals (Sweden)

    Huping Xue

    Full Text Available BACKGROUND: Horizontal gene transfer (HGT is recognized as one of the major forces for bacterial genome evolution. Many clinically important bacteria may acquire virulence factors and antibiotic resistance through HGT. The comparative genomic analysis has become an important tool for identifying HGT in emerging pathogens. In this study, the Serine-Aspartate Repeat (Sdr family has been compared among different sources of Staphylococcus aureus (S. aureus to discover sequence diversities within their genomes. METHODOLOGY/PRINCIPAL FINDINGS: Four sdr genes were analyzed for 21 different S. aureus strains and 218 mastitis-associated S. aureus isolates from Canada. Comparative genomic analyses revealed that S. aureus strains from bovine mastitis (RF122 and mastitis isolates in this study, ovine mastitis (ED133, pig (ST398, chicken (ED98, and human methicillin-resistant S. aureus (MRSA (TCH130, MRSA252, Mu3, Mu50, N315, 04-02981, JH1 and JH9 were highly associated with one another, presumably due to HGT. In addition, several types of insertion and deletion were found in sdr genes of many isolates. A new insertion sequence was found in mastitis isolates, which was presumably responsible for the HGT of sdrC gene among different strains. Moreover, the sdr genes could be used to type S. aureus. Regional difference of sdr genes distribution was also indicated among the tested S. aureus isolates. Finally, certain associations were found between sdr genes and subclinical or clinical mastitis isolates. CONCLUSIONS: Certain sdr gene sequences were shared in S. aureus strains and isolates from different species presumably due to HGT. Our results also suggest that the distributional assay of virulence factors should detect the full sequences or full functional regions of these factors. The traditional assay using short conserved regions may not be accurate or credible. These findings have important implications with regard to animal husbandry practices that may

  7. Aerobic lineage of the oxidative stress response protein rubrerythrin emerged in an ancient microaerobic, (hyperthermophilic environment

    Directory of Open Access Journals (Sweden)

    Juan Pablo Cardenas

    2016-11-01

    Full Text Available Rubrerythrins (RBRs are non-heme di-iron proteins belonging to the ferritin-like superfamily (FLSF. They are involved in oxidative stress defense as peroxide scavengers in a wide range of organisms. The vast majority of RBRs, including classical forms of this protein, contain a C-terminal rubredoxin-like domain involved in electron transport that is used during catalysis in anaerobic conditions. Rubredoxin is an ancient and large protein family of short length (<100 residues that contains a Fe-S center involved in electron transfer. However, functional forms of the enzyme lacking the rubredoxin-like domain have been reported (e.g., sulerythrin and ferriperoxin. In this study, phylogenomic evidence is presented that suggests that a complete lineage of rubrerythrins, lacking the rubredoxin-like domain, arose in an ancient microaerobic and (hyperthermophilic environments in the ancestors of the Archaea Thermoproteales and Sulfolobales. This lineage (termed the aerobic-type lineage subsequently evolved to become adapted to environments with progressively lower temperatures and higher oxygen concentrations via the acquisition of two co-localized genes, termed DUF3501 and RFO, encoding a conserved protein of unknown function and a predicted Fe-S oxidoreductase respectively. Proposed Horizontal Gene Transfer (HGT events from these archaeal ancestors to Bacteria expanded the opportunities for further evolution of this RBR including adaption to lower temperatures. The second lineage (termed the cyanobacterial lineage is proposed to have evolved in cyanobacterial ancestors, maybe in direct response to the production of oxygen via oxygenic photosynthesis during the Great Oxygen Event (GOE. It is hypothesized that both lineages of RBR emerged in a largely anaerobic world with whiffs of oxygen and that their subsequent independent evolutionary trajectories allowed microorganisms to transition from this anaerobic world to an aerobic one.

  8. Comparative genomics reveals cotton-specific virulence factors in flexible genomic regions in Verticillium dahliae and evidence of horizontal gene transfer from Fusarium.

    Science.gov (United States)

    Chen, Jie-Yin; Liu, Chun; Gui, Yue-Jing; Si, Kai-Wei; Zhang, Dan-Dan; Wang, Jie; Short, Dylan P G; Huang, Jin-Qun; Li, Nan-Yang; Liang, Yong; Zhang, Wen-Qi; Yang, Lin; Ma, Xue-Feng; Li, Ting-Gang; Zhou, Lei; Wang, Bao-Li; Bao, Yu-Ming; Subbarao, Krishna V; Zhang, Geng-Yun; Dai, Xiao-Feng

    2018-01-01

    Verticillium dahliae isolates are most virulent on the host from which they were originally isolated. Mechanisms underlying these dominant host adaptations are currently unknown. We sequenced the genome of V. dahliae Vd991, which is highly virulent on its original host, cotton, and performed comparisons with the reference genomes of JR2 (from tomato) and VdLs.17 (from lettuce). Pathogenicity-related factor prediction, orthology and multigene family classification, transcriptome analyses, phylogenetic analyses, and pathogenicity experiments were performed. The Vd991 genome harbored several exclusive, lineage-specific (LS) genes within LS regions (LSRs). Deletion mutants of the seven genes within one LSR (G-LSR2) in Vd991 were less virulent only on cotton. Integration of G-LSR2 genes individually into JR2 and VdLs.17 resulted in significantly enhanced virulence on cotton but did not affect virulence on tomato or lettuce. Transcription levels of the seven LS genes in Vd991 were higher during the early stages of cotton infection, as compared with other hosts. Phylogenetic analyses suggested that G-LSR2 was acquired from Fusarium oxysporum f. sp. vasinfectum through horizontal gene transfer. Our results provide evidence that horizontal gene transfer from Fusarium to Vd991 contributed significantly to its adaptation to cotton and may represent a significant mechanism in the evolution of an asexual plant pathogen. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  9. Insights on the Horizontal Gene Transfer of Carbapenemase Determinants in the Opportunistic Pathogen Acinetobacter baumannii

    Science.gov (United States)

    Da Silva, Gabriela Jorge; Domingues, Sara

    2016-01-01

    Horizontal gene transfer (HGT) is a driving force to the evolution of bacteria. The fast emergence of antimicrobial resistance reflects the ability of genetic adaptation of pathogens. Acinetobacter baumannii has emerged in the last few decades as an important opportunistic nosocomial pathogen, in part due to its high capacity of acquiring resistance to diverse antibiotic families, including to the so-called last line drugs such as carbapenems. The rampant selective pressure and genetic exchange of resistance genes hinder the effective treatment of resistant infections. A. baumannii uses all the resistance mechanisms to survive against carbapenems but production of carbapenemases are the major mechanism, which may act in synergy with others. A. baumannii appears to use all the mechanisms of gene dissemination. Beyond conjugation, the mostly reported recent studies point to natural transformation, transduction and outer membrane vesicles-mediated transfer as mechanisms that may play a role in carbapenemase determinants spread. Understanding the genetic mobilization of carbapenemase genes is paramount in preventing their dissemination. Here we review the carbapenemases found in A. baumannii and present an overview of the current knowledge of contributions of the various HGT mechanisms to the molecular epidemiology of carbapenem resistance in this relevant opportunistic pathogen. PMID:27681923

  10. Fluorescence recovery allows theimplementation of a fluorescence reporter gene platform applicable for the detection and quantification of horizontal gene transfer in anoxic environments

    DEFF Research Database (Denmark)

    Pinilla-Redondo, Rafael; Riber, Leise; Sørensen, Søren Johannes

    2018-01-01

    H limitations, and provide experimental tools that will help broaden its horizon of application to other fields.IMPORTANCEMany anaerobic environments, like the gastrointestinal tract, anaerobic digesters, and the interiors of dense biofilms, have been shown to be hotspots for horizontal gene transfer (HGT......). Despite the increasing wealth of reports warning about the alarming spread of antibiotic resistance determinants, to date, HGT studies mainly rely on cultivation-based methods. Unfortunately, the relevance of these studies is often questionable, as only a minor fraction of bacteria can be cultivated...

  11. Inter-replicon Gene Flow Contributes to Transcriptional Integration in the Sinorhizobium meliloti Multipartite Genome.

    Science.gov (United States)

    diCenzo, George C; Wellappili, Deelaka; Golding, G Brian; Finan, Turlough M

    2018-05-04

    Integration of newly acquired genes into existing regulatory networks is necessary for successful horizontal gene transfer (HGT). Ten percent of bacterial species contain at least two DNA replicons over 300 kilobases in size, with the secondary replicons derived predominately through HGT. The Sinorhizobium meliloti genome is split between a 3.7 Mb chromosome, a 1.7 Mb chromid consisting largely of genes acquired through ancient HGT, and a 1.4 Mb megaplasmid consisting primarily of recently acquired genes. Here, RNA-sequencing is used to examine the transcriptional consequences of massive, synthetic genome reduction produced through the removal of the megaplasmid and/or the chromid. Removal of the pSymA megaplasmid influenced the transcription of only six genes. In contrast, removal of the chromid influenced expression of ∼8% of chromosomal genes and ∼4% of megaplasmid genes. This was mediated in part by the loss of the ETR DNA region whose presence on pSymB is due to a translocation from the chromosome. No obvious functional bias among the up-regulated genes was detected, although genes with putative homologs on the chromid were enriched. Down-regulated genes were enriched in motility and sensory transduction pathways. Four transcripts were examined further, and in each case the transcriptional change could be traced to loss of specific pSymB regions. In particularly, a chromosomal transporter was induced due to deletion of bdhA likely mediated through 3-hydroxybutyrate accumulation. These data provide new insights into the evolution of the multipartite bacterial genome, and more generally into the integration of horizontally acquired genes into the transcriptome. Copyright © 2018 diCenzo, et al.

  12. Inter-replicon Gene Flow Contributes to Transcriptional Integration in the Sinorhizobium meliloti Multipartite Genome

    Directory of Open Access Journals (Sweden)

    George C. diCenzo

    2018-05-01

    Full Text Available Integration of newly acquired genes into existing regulatory networks is necessary for successful horizontal gene transfer (HGT. Ten percent of bacterial species contain at least two DNA replicons over 300 kilobases in size, with the secondary replicons derived predominately through HGT. The Sinorhizobium meliloti genome is split between a 3.7 Mb chromosome, a 1.7 Mb chromid consisting largely of genes acquired through ancient HGT, and a 1.4 Mb megaplasmid consisting primarily of recently acquired genes. Here, RNA-sequencing is used to examine the transcriptional consequences of massive, synthetic genome reduction produced through the removal of the megaplasmid and/or the chromid. Removal of the pSymA megaplasmid influenced the transcription of only six genes. In contrast, removal of the chromid influenced expression of ∼8% of chromosomal genes and ∼4% of megaplasmid genes. This was mediated in part by the loss of the ETR DNA region whose presence on pSymB is due to a translocation from the chromosome. No obvious functional bias among the up-regulated genes was detected, although genes with putative homologs on the chromid were enriched. Down-regulated genes were enriched in motility and sensory transduction pathways. Four transcripts were examined further, and in each case the transcriptional change could be traced to loss of specific pSymB regions. In particularly, a chromosomal transporter was induced due to deletion of bdhA likely mediated through 3-hydroxybutyrate accumulation. These data provide new insights into the evolution of the multipartite bacterial genome, and more generally into the integration of horizontally acquired genes into the transcriptome.

  13. Insights into Modern Human Prehistory Using Ancient Genomes.

    Science.gov (United States)

    Yang, Melinda A; Fu, Qiaomei

    2018-03-01

    The genetic relationship of past modern humans to today's populations and each other was largely unknown until recently, when advances in ancient DNA sequencing allowed for unprecedented analysis of the genomes of these early people. These ancient genomes reveal new insights into human prehistory not always observed studying present-day populations, including greater details on the genetic diversity, population structure, and gene flow that characterized past human populations, particularly in early Eurasia, as well as increased insight on the relationship between archaic and modern humans. Here, we review genetic studies on ∼45000- to 7500-year-old individuals associated with mainly preagricultural cultures found in Eurasia, the Americas, and Africa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Mt-rps3 is an ancient gene which provides insight into the evolution of fungal mitochondrial genomes.

    Science.gov (United States)

    Korovesi, Artemis G; Ntertilis, Maria; Kouvelis, Vassili N

    2018-05-12

    The nuclear ribosomal protein S3 (Rps3) is implicated in the assembly of the ribosomal small subunit. Fungi and plants present a gene copy in their mitochondrial (mt) genomes. An analysis of 303 complete fungal mt genomes showed that, when rps3 is found, it is either a free-standing gene or an anchored gene within the omega intron of the rnl gene. Early divergent fungi, Basidiomycota and all yeasts but the CTG group belong to the first case, and Pezizomycotina to the second. Its position, size and genetic code employed are conserved within species of the same Order. Size variability is attributed to different number of repeats. These repeats consist of AT-rich sequences. MtRps3 proteins lack the KH domain, necessary for binding to rRNA, in their N-terminal region. Their C-terminal region is conserved in all Domains of life. Phylogenetic analysis showed that nuclear and mt Rps3 proteins are descendants of archaeal and a-proteobacterial homologues, respectively. Thus, fungal mt-rps3 gene is an ancient gene which evolved within the endosymbiotic model and presents different evolutionary routes: (a) coming from a-proteobacteria, it was relocated to another region of the mt genome, (b) via its insertion to the omega intron, it was transferred to the nucleus and/or got lost, and (c) it was re-routed to the mt genome again. Today, Basidiomycota and Saccharomycetales seem to follow the first evolutionary route and almost all Pezizomycotina support the second scenario with their exceptions being the result of the third scenario, i.e., the gene's re-entry to the mt genome. Copyright © 2018. Published by Elsevier Inc.

  15. Modeling horizontal gene transfer (HGT in the gut of the Chagas disease vector Rhodnius prolixus

    Directory of Open Access Journals (Sweden)

    Durvasula Ravi V

    2011-05-01

    Full Text Available Abstract Background Paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. When applied to control of Chagas disease, the symbiont bacterium Rhodococcus rhodnii, resident in the gut lumen of the triatomine vector Rhodnius prolixus (Hemiptera: Reduviidae, is transformed to export cecropin A, an insect immune peptide. Cecropin A is active against Trypanosoma cruzi, the causative agent of Chagas disease. While proof of concept has been achieved in laboratory studies, a rigorous and comprehensive risk assessment is required prior to consideration of field release. An important part of this assessment involves estimating probability of transgene horizontal transfer to environmental organisms (HGT. This article presents a two-part risk assessment methodology: a theoretical model predicting HGT in the gut of R. prolixus from the genetically transformed symbiont R. rhodnii to a closely related non-target bacterium, Gordona rubropertinctus, in the absence of selection pressure, and a series of laboratory trials designed to test the model. Results The model predicted an HGT frequency of less than 1.14 × 10-16 per 100,000 generations at the 99% certainty level. The model was iterated twenty times, with the mean of the ten highest outputs evaluated at the 99% certainty level. Laboratory trials indicated no horizontal gene transfer, supporting the conclusions of the model. Conclusions The model treats HGT as a composite event, the probability of which is determined by the joint probability of three independent events: gene transfer through the modalities of transformation, transduction, and conjugation. Genes are represented in matrices and Monte Carlo method and Markov chain analysis are used to simulate and evaluate environmental conditions. The model is intended as a risk assessment instrument and predicts HGT frequency of less than 1.14 × 10-16 per 100,000 generations. With laboratory studies that

  16. Inferring the palaeoenvironment of ancient bacteria on the basis of resurrected proteins

    Science.gov (United States)

    Gaucher, Eric A.; Thomson, J. Michael; Burgan, Michelle F.; Benner, Steven A.

    2003-01-01

    Features of the physical environment surrounding an ancestral organism can be inferred by reconstructing sequences of ancient proteins made by those organisms, resurrecting these proteins in the laboratory, and measuring their properties. Here, we resurrect candidate sequences for elongation factors of the Tu family (EF-Tu) found at ancient nodes in the bacterial evolutionary tree, and measure their activities as a function of temperature. The ancient EF-Tu proteins have temperature optima of 55-65 degrees C. This value seems to be robust with respect to uncertainties in the ancestral reconstruction. This suggests that the ancient bacteria that hosted these particular genes were thermophiles, and neither hyperthermophiles nor mesophiles. This conclusion can be compared and contrasted with inferences drawn from an analysis of the lengths of branches in trees joining proteins from contemporary bacteria, the distribution of thermophily in derived bacterial lineages, the inferred G + C content of ancient ribosomal RNA, and the geological record combined with assumptions concerning molecular clocks. The study illustrates the use of experimental palaeobiochemistry and assumptions about deep phylogenetic relationships between bacteria to explore the character of ancient life.

  17. Polygalacturonase from Sitophilus oryzae: Possible horizontal transfer of a pectinase gene from fungi to weevils

    Directory of Open Access Journals (Sweden)

    Zhicheng Shen

    2003-08-01

    Full Text Available Endo-polygalacturonase, one of the group of enzymes known collectively as pectinases, is widely distributed in bacteria, plants and fungi. The enzyme has also been found in several weevil species and a few other insects, such as aphids, but not in Drosophila melanogaster, Anopheles gambiae, or Caenorhabditis elegans or, as far as is known, in any more primitive animal species. What, then, is the genetic origin of the polygalacturonases in weevils? Since some weevil species harbor symbiotic microorganisms, it has been suggested, reasonably, that the symbionts' genomes of both aphids and weevils, rather than the insects' genomes, could encode polygalacturonase. We report here the cloning of a cDNA that encodes endo-polygalacturonase in the rice weevil, Sitophilus oryzae (L., and investigations based on the cloned cDNA. Our results, which include analysis of genes in antibiotic-treated rice weevils, indicate that the enzyme is, in fact, encoded by the insect genome. Given the apparent absence of the gene in much of the rest of the animal kingdom, it is therefore likely that the rice weevil polygalacturonase gene was incorporated into the weevil's genome by horizontal transfer, possibly from a fungus.

  18. Exploring Ancient Skies A Survey of Ancient and Cultural Astronomy

    CERN Document Server

    Kelley, David H

    2011-01-01

    Exploring Ancient Skies brings together the methods of archaeology and the insights of modern astronomy to explore the science of astronomy as it was practiced in various cultures prior to the invention of the telescope. The book reviews an enormous and growing body of literature on the cultures of the ancient Mediterranean, the Far East, and the New World (particularly Mesoamerica), putting the ancient astronomical materials into their archaeological and cultural contexts. The authors begin with an overview of the field and proceed to essential aspects of naked-eye astronomy, followed by an examination of specific cultures. The book concludes by taking into account the purposes of ancient astronomy: astrology, navigation, calendar regulation, and (not least) the understanding of our place and role in the universe. Skies are recreated to display critical events as they would have appeared to ancient observers—events such as the supernova of 1054 A.D., the "lion horoscope," and the Star of Bethlehem. Explori...

  19. An acyltransferase gene that putatively functions in anthocyanin modification was horizontally transferred from Fabaceae into the genus Cuscuta

    Directory of Open Access Journals (Sweden)

    Ting Sun

    2016-06-01

    Full Text Available Horizontal gene transfer (HGT refers to the flow of genetic materials to non-offspring, and occasionally HGT in plants can improve the adaptation of organisms in new niches due to expanded metabolic capability. Anthocyanins are an important group of water-soluble red, purple, or blue secondary metabolites, whose diversity results from modification after the main skeleton biosynthesis. Cuscuta is a stem holoparasitic genus, whose members form direct connection with hosts to withdraw water, nutrients, and macromolecules. Such intimate association is thought to increase the frequency of HGT. By transcriptome screening for foreign genes in Cuscuta australis, we discovered that one gene encoding a putative anthocyanin acyltransferase gene of the BAHD family, which is likely to be involved in anthocyanin modification, was acquired by C. australis from Fabaceae through HGT. The anthocyanin acyltransferase-like (AT-like gene was confirmed to be present in the genome assembly of C. australis and the transcriptomes of Cuscuta pentagona. The higher transcriptional level in old stems is consistent with its putative function in secondary metabolism by stabilizing anthocyanin at neutral pH and thus HGT of this AT-like gene may have improved biotic and abiotic resistance of Cuscuta.

  20. Ancient genomes

    OpenAIRE

    Hoelzel, A Rus

    2005-01-01

    Ever since its invention, the polymerase chain reaction has been the method of choice for work with ancient DNA. In an application of modern genomic methods to material from the Pleistocene, a recent study has instead undertaken to clone and sequence a portion of the ancient genome of the cave bear.

  1. Updated clusters of orthologous genes for Archaea: a complex ancestor of the Archaea and the byways of horizontal gene transfer

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2012-12-01

    Full Text Available Abstract Background Collections of Clusters of Orthologous Genes (COGs provide indispensable tools for comparative genomic analysis, evolutionary reconstruction and functional annotation of new genomes. Initially, COGs were made for all complete genomes of cellular life forms that were available at the time. However, with the accumulation of thousands of complete genomes, construction of a comprehensive COG set has become extremely computationally demanding and prone to error propagation, necessitating the switch to taxon-specific COG collections. Previously, we reported the collection of COGs for 41 genomes of Archaea (arCOGs. Here we present a major update of the arCOGs and describe evolutionary reconstructions to reveal general trends in the evolution of Archaea. Results The updated version of the arCOG database incorporates 91% of the pangenome of 120 archaea (251,032 protein-coding genes altogether into 10,335 arCOGs. Using this new set of arCOGs, we performed maximum likelihood reconstruction of the genome content of archaeal ancestral forms and gene gain and loss events in archaeal evolution. This reconstruction shows that the last Common Ancestor of the extant Archaea was an organism of greater complexity than most of the extant archaea, probably with over 2,500 protein-coding genes. The subsequent evolution of almost all archaeal lineages was apparently dominated by gene loss resulting in genome streamlining. Overall, in the evolution of Archaea as well as a representative set of bacteria that was similarly analyzed for comparison, gene losses are estimated to outnumber gene gains at least 4 to 1. Analysis of specific patterns of gene gain in Archaea shows that, although some groups, in particular Halobacteria, acquire substantially more genes than others, on the whole, gene exchange between major groups of Archaea appears to be largely random, with no major ‘highways’ of horizontal gene transfer. Conclusions The updated collection

  2. AST: an automated sequence-sampling method for improving the taxonomic diversity of gene phylogenetic trees.

    Science.gov (United States)

    Zhou, Chan; Mao, Fenglou; Yin, Yanbin; Huang, Jinling; Gogarten, Johann Peter; Xu, Ying

    2014-01-01

    A challenge in phylogenetic inference of gene trees is how to properly sample a large pool of homologous sequences to derive a good representative subset of sequences. Such a need arises in various applications, e.g. when (1) accuracy-oriented phylogenetic reconstruction methods may not be able to deal with a large pool of sequences due to their high demand in computing resources; (2) applications analyzing a collection of gene trees may prefer to use trees with fewer operational taxonomic units (OTUs), for instance for the detection of horizontal gene transfer events by identifying phylogenetic conflicts; and (3) the pool of available sequences is biased towards extensively studied species. In the past, the creation of subsamples often relied on manual selection. Here we present an Automated sequence-Sampling method for improving the Taxonomic diversity of gene phylogenetic trees, AST, to obtain representative sequences that maximize the taxonomic diversity of the sampled sequences. To demonstrate the effectiveness of AST, we have tested it to solve four problems, namely, inference of the evolutionary histories of the small ribosomal subunit protein S5 of E. coli, 16 S ribosomal RNAs and glycosyl-transferase gene family 8, and a study of ancient horizontal gene transfers from bacteria to plants. Our results show that the resolution of our computational results is almost as good as that of manual inference by domain experts, hence making the tool generally useful to phylogenetic studies by non-phylogeny specialists. The program is available at http://csbl.bmb.uga.edu/~zhouchan/AST.php.

  3. No evidence of inhibition of horizontal gene transfer by CRISPR-Cas on evolutionary timescales.

    Science.gov (United States)

    Gophna, Uri; Kristensen, David M; Wolf, Yuri I; Popa, Ovidiu; Drevet, Christine; Koonin, Eugene V

    2015-09-01

    The CRISPR (clustered, regularly, interspaced, short, palindromic repeats)-Cas (CRISPR-associated genes) systems of archaea and bacteria provide adaptive immunity against viruses and other selfish elements and are believed to curtail horizontal gene transfer (HGT). Limiting acquisition of new genetic material could be one of the sources of the fitness cost of CRISPR-Cas maintenance and one of the causes of the patchy distribution of CRISPR-Cas among bacteria, and across environments. We sought to test the hypothesis that the activity of CRISPR-Cas in microbes is negatively correlated with the extent of recent HGT. Using three independent measures of HGT, we found no significant dependence between the length of CRISPR arrays, which reflects the activity of the immune system, and the estimated number of recent HGT events. In contrast, we observed a significant negative dependence between the estimated extent of HGT and growth temperature of microbes, which could be explained by the lower genetic diversity in hotter environments. We hypothesize that the relevant events in the evolution of resistance to mobile elements and proclivity for HGT, to which CRISPR-Cas systems seem to substantially contribute, occur on the population scale rather than on the timescale of species evolution.

  4. Horizontal transfer, not duplication, drives the expansion of protein families in prokaryotes.

    Directory of Open Access Journals (Sweden)

    Todd J Treangen

    2011-01-01

    Full Text Available Gene duplication followed by neo- or sub-functionalization deeply impacts the evolution of protein families and is regarded as the main source of adaptive functional novelty in eukaryotes. While there is ample evidence of adaptive gene duplication in prokaryotes, it is not clear whether duplication outweighs the contribution of horizontal gene transfer in the expansion of protein families. We analyzed closely related prokaryote strains or species with small genomes (Helicobacter, Neisseria, Streptococcus, Sulfolobus, average-sized genomes (Bacillus, Enterobacteriaceae, and large genomes (Pseudomonas, Bradyrhizobiaceae to untangle the effects of duplication and horizontal transfer. After removing the effects of transposable elements and phages, we show that the vast majority of expansions of protein families are due to transfer, even among large genomes. Transferred genes--xenologs--persist longer in prokaryotic lineages possibly due to a higher/longer adaptive role. On the other hand, duplicated genes--paralogs--are expressed more, and, when persistent, they evolve slower. This suggests that gene transfer and gene duplication have very different roles in shaping the evolution of biological systems: transfer allows the acquisition of new functions and duplication leads to higher gene dosage. Accordingly, we show that paralogs share most protein-protein interactions and genetic regulators, whereas xenologs share very few of them. Prokaryotes invented most of life's biochemical diversity. Therefore, the study of the evolution of biology systems should explicitly account for the predominant role of horizontal gene transfer in the diversification of protein families.

  5. Pathogens and host immunity in the ancient human oral cavity

    Science.gov (United States)

    Warinner, Christina; Matias Rodrigues, João F.; Vyas, Rounak; Trachsel, Christian; Shved, Natallia; Grossmann, Jonas; Radini, Anita; Hancock, Y.; Tito, Raul Y.; Fiddyment, Sarah; Speller, Camilla; Hendy, Jessica; Charlton, Sophy; Luder, Hans Ulrich; Salazar-García, Domingo C.; Eppler, Elisabeth; Seiler, Roger; Hansen, Lars; Samaniego Castruita, José Alfredo; Barkow-Oesterreicher, Simon; Teoh, Kai Yik; Kelstrup, Christian; Olsen, Jesper V.; Nanni, Paolo; Kawai, Toshihisa; Willerslev, Eske; von Mering, Christian; Lewis, Cecil M.; Collins, Matthew J.; Gilbert, M. Thomas P.; Rühli, Frank; Cappellini, Enrico

    2014-01-01

    Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize: (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) the first evidence of ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, “red-complex” pathogens, and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental calculus permits the simultaneous investigation of pathogen activity, host immunity, and diet, thereby extending the direct investigation of common diseases into the human evolutionary past. PMID:24562188

  6. Apps for Ancient Civilizations

    Science.gov (United States)

    Thompson, Stephanie

    2011-01-01

    This project incorporates technology and a historical emphasis on science drawn from ancient civilizations to promote a greater understanding of conceptual science. In the Apps for Ancient Civilizations project, students investigate an ancient culture to discover how people might have used science and math smartphone apps to make their lives…

  7. Integrating Horizontal Gene Transfer and Common Descent to Depict Evolution and Contrast It with “Common Design”1

    Science.gov (United States)

    GUILLERMO PAZ-Y-MIÑO-C; ESPINOSA, AVELINA

    2016-01-01

    Horizontal gene transfer (HGT) and common descent interact in space and time. Because events of HGT co-occur with phylogenetic evolution, it is difficult to depict evolutionary patterns graphically. Tree-like representations of life’s diversification are useful, but they ignore the significance of HGT in evolutionary history, particularly of unicellular organisms, ancestors of multicellular life. Here we integrate the reticulated-tree model, ring of life, symbiogenesis whole-organism model, and eliminative pattern pluralism to represent evolution. Using Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), a bifunctional enzyme in the glycolytic pathway of amoeba, we illustrate how EhADH2 could be the product of both horizontally acquired features from ancestral prokaryotes (i.e. aldehyde dehydrogenase [ALDH] and alcohol dehydrogenase [ADH]), and subsequent functional integration of these enzymes into EhADH2, which is now inherited by amoeba via common descent. Natural selection has driven the evolution of EhADH2 active sites, which require specific amino acids (cysteine 252 in the ALDH domain; histidine 754 in the ADH domain), iron- and NAD+ as cofactors, and the substrates acetyl-CoA for ALDH and acetaldehyde for ADH. Alternative views invoking “common design” (i.e. the non-naturalistic emergence of major taxa independent from ancestry) to explain the interaction between horizontal and vertical evolution are unfounded. PMID:20021546

  8. Horizontal gene acquisition of Liberibacter plant pathogens from a bacteriome-confined endosymbiont of their psyllid vector.

    Directory of Open Access Journals (Sweden)

    Atsushi Nakabachi

    Full Text Available he Asian citrus psyllid Diaphorina citri is a notorious agricultural pest that transmits the phloem-inhabiting alphaproteobacterial 'Candidatus Liberibacter asiaticus' and allied plant pathogens, which cause the devastating citrus disease called Huanglongbing or greening disease. D. citri harbors two distinct bacterial mutualists in the symbiotic organ called bacteriome: the betaproteobacterium 'Candidatus Profftella armatura' in the syncytial cytoplasm at the center of the bacteriome, and the gammaproteobacterium 'Candidatus Carsonella ruddii' in uninucleate bacteriocytes. Here we report that a putative amino acid transporter LysE of Profftella forms a highly supported clade with proteins of L. asiaticus, L. americanus, and L. solanacearum. L. crescens, the most basal Liberibacter lineage currently known, lacked the corresponding gene. The Profftella-Liberibacter subclade of LysE formed a clade with proteins from betaproteobacteria of the order Burkholderiales, to which Profftella belongs. This phylogenetic pattern favors the hypothesis that the Liberibacter lineage acquired the gene from the Profftella lineage via horizontal gene transfer (HGT after L. crescens diverged from other Liberibacter lineages. K A/K S analyses further supported the hypothesis that the genes encoded in the Liberibacter genomes are functional. These findings highlight the possible evolutionary importance of HGT between plant pathogens and their insect vector's symbionts that are confined in the symbiotic organ and seemingly sequestered from external microbial populations.

  9. Horizontal gene transfer from macrophages to ischemic muscles upon delivery of naked DNA with Pluronic block copolymers.

    Science.gov (United States)

    Mahajan, Vivek; Gaymalov, Zagit; Alakhova, Daria; Gupta, Richa; Zucker, Irving H; Kabanov, Alexander V

    2016-01-01

    Intramuscular administration of plasmid DNA (pDNA) with non-ionic Pluronic block copolymers increases gene expression in injected muscles and lymphoid organs. We studied the role of immune cells in muscle transfection upon inflammation. Local inflammation in murine hind limb ischemia model (MHLIM) drastically increased DNA, RNA and expressed protein levels in ischemic muscles injected with pDNA/Pluronic. The systemic inflammation (MHLIM or peritonitis) also increased expression of pDNA/Pluronic in the muscles. When pDNA/Pluronic was injected in ischemic muscles the reporter gene, Green Fluorescent Protein (GFP) co-localized with desmin(+) muscle fibers and CD11b(+) macrophages (MØs), suggesting transfection of MØs along with the muscle cells. P85 enhanced (∼ 4 orders) transfection of MØs with pDNA in vitro. Moreover, adoptively transferred MØs were shown to pass the transgene to inflamed muscle cells in MHLIM. Using a co-culture of myotubes (MTs) and transfected MØs expressing a reporter gene under constitutive (cmv-luciferase) or muscle specific (desmin-luciferase) promoter we demonstrated that P85 enhances horizontal gene transfer from MØ to MTs. Therefore, MØs can play an important role in muscle transfection with pDNA/Pluronic during inflammation, with both inflammation and Pluronic contributing to the increased gene expression. pDNA/Pluronic has potential for therapeutic gene delivery in muscle pathologies that involve inflammation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Alienness: Rapid Detection of Candidate Horizontal Gene Transfers across the Tree of Life

    Directory of Open Access Journals (Sweden)

    Corinne Rancurel

    2017-09-01

    Full Text Available Horizontal gene transfer (HGT is the transmission of genes between organisms by other means than parental to offspring inheritance. While it is prevalent in prokaryotes, HGT is less frequent in eukaryotes and particularly in Metazoa. Here, we propose Alienness, a taxonomy-aware web application available at http://alienness.sophia.inra.fr. Alienness parses BLAST results against public libraries to rapidly identify candidate HGT in any genome of interest. Alienness takes as input the result of a BLAST of a whole proteome of interest against any National Center for Biotechnology Information (NCBI protein library. The user defines recipient (e.g., Metazoa and donor (e.g., bacteria, fungi branches of interest in the NCBI taxonomy. Based on the best BLAST E-values of candidate donor and recipient taxa, Alienness calculates an Alien Index (AI for each query protein. An AI > 0 indicates a better hit to candidate donor than recipient taxa and a possible HGT. Higher AI represent higher gap of E-values between candidate donor and recipient and a more likely HGT. We confirmed the accuracy of Alienness on phylogenetically confirmed HGT of non-metazoan origin in plant-parasitic nematodes. Alienness scans whole proteomes to rapidly identify possible HGT in any species of interest and thus fosters exploration of HGT more easily and largely across the tree of life.

  11. Signatures of Low-Mo Ancient Ocean May be Preserved in Cyanobacterial Genomes

    Science.gov (United States)

    Glass, J. B.; Wolfe-Simon, F. L.; Poret-Peterson, A. T.; Anbar, A. D.

    2010-04-01

    Before 800 million years ago, Mo was scarce in the ocean. We present evidence that primitive cyanobacteria store Mo using a protein called "Mop." Mop genes preserved in modern genomes may be signatures of the imprint of ancient Mo limitation.

  12. In situ detection of horizontal transfer of mobile genetic elements

    DEFF Research Database (Denmark)

    Haagensen, Janus Anders Juul; Hansen, Susse Kirkelund; Johansen, Tove

    2002-01-01

    . The obtained data show that the several different types of fluorescent reporters, which are now available, allow more informative in situ investigations of horizontal gene transfer to be carried out, and by combining these genes with various expression systems it is possible to simultaneously monitor donor...

  13. The Drosophila melanogaster methuselah gene: a novel gene with ancient functions.

    Directory of Open Access Journals (Sweden)

    Ana Rita Araújo

    Full Text Available The Drosophila melanogaster G protein-coupled receptor gene, methuselah (mth, has been described as a novel gene that is less than 10 million years old. Nevertheless, it shows a highly specific expression pattern in embryos, larvae, and adults, and has been implicated in larval development, stress resistance, and in the setting of adult lifespan, among others. Although mth belongs to a gene subfamily with 16 members in D. melanogaster, there is no evidence for functional redundancy in this subfamily. Therefore, it is surprising that a novel gene influences so many traits. Here, we explore the alternative hypothesis that mth is an old gene. Under this hypothesis, in species distantly related to D. melanogaster, there should be a gene with features similar to those of mth. By performing detailed phylogenetic, synteny, protein structure, and gene expression analyses we show that the D. virilis GJ12490 gene is the orthologous of mth in species distantly related to D. melanogaster. We also show that, in D. americana (a species of the virilis group of Drosophila, a common amino acid polymorphism at the GJ12490 orthologous gene is significantly associated with developmental time, size, and lifespan differences. Our results imply that GJ12490 orthologous genes are candidates for developmental time and lifespan differences in Drosophila in general.

  14. A study on provenance relation between Jiaotanxia ancient Guan porcelain and Qingliangsi ancient Ru porcelain by NAA

    International Nuclear Information System (INIS)

    Li Rongwu; Feng Songlin; Huang Zhongxiang; Jia Xiuqin

    2004-01-01

    11 samples of ancient Chinese Ru porcelain from Qingliangsi kiln, 23 samples of ancient Chinese Guan porcelain from Jiaotanxia kiln and 4 samples of modern archaized Guan porcelain were obtained to determine the contents of elements in each of them by neutron activation analysis (NAA). The NAA data were further analyzed using fuzzy cluster analysis to obtain the fuzzy cluster trend diagrams for the bodies' samples and the glazes samples respectively. The analysis shows that the raw material origins of the Jiaotanxia ancient Chinese Guan porcelain bodies samples are very concentrated; those of the Qingliangsi ancient Chinese Ru porcelain bodies samples are a little dispersed; those of ancient Chinese Guan porcelain glazes samples are relatively concentrated; those of ancient Chinese Ru porcelain glazes samples are dispersed; and the origins of the raw material of ancient Chinese Guan porcelain glazes samples are obviously different from those of ancient Chinese Ru porcelain glazes samples. The bodies samples and glazes samples of Jiaotanxia ancient Chinese Guan porcelain and those of Qingliangsi ancient Chinese Ru porcelain have some difference but can be compared with each other. (authors)

  15. A horizontal gene transfer at the origin of phenylpropanoid metabolism: a key adaptation of plants to land.

    Science.gov (United States)

    Emiliani, Giovanni; Fondi, Marco; Fani, Renato; Gribaldo, Simonetta

    2009-02-16

    The pioneering ancestor of land plants that conquered terrestrial habitats around 500 million years ago had to face dramatic stresses including UV radiation, desiccation, and microbial attack. This drove a number of adaptations, among which the emergence of the phenylpropanoid pathway was crucial, leading to essential compounds such as flavonoids and lignin. However, the origin of this specific land plant secondary metabolism has not been clarified. We have performed an extensive analysis of the taxonomic distribution and phylogeny of Phenylalanine Ammonia Lyase (PAL), which catalyses the first and essential step of the general phenylpropanoid pathway, leading from phenylalanine to p-Coumaric acid and p-Coumaroyl-CoA, the entry points of the flavonoids and lignin routes. We obtained robust evidence that the ancestor of land plants acquired a PAL via horizontal gene transfer (HGT) during symbioses with soil bacteria and fungi that are known to have established very early during the first steps of land colonization. This horizontally acquired PAL represented then the basis for further development of the phenylpropanoid pathway and plant radiation on terrestrial environments. Our results highlight a possible crucial role of HGT from soil bacteria in the path leading to land colonization by plants and their subsequent evolution. The few functional characterizations of sediment/soil bacterial PAL (production of secondary metabolites with powerful antimicrobial activity or production of pigments) suggest that the initial advantage of this horizontally acquired PAL in the ancestor of land plants might have been either defense against an already developed microbial community and/or protection against UV.

  16. Horizontal gene transfer: essentiality and evolvability in prokaryotes, and roles in evolutionary transitions [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Eugene V. Koonin

    2016-07-01

    Full Text Available The wide spread of gene exchange and loss in the prokaryotic world has prompted the concept of ‘lateral genomics’ to the point of an outright denial of the relevance of phylogenetic trees for evolution. However, the pronounced coherence congruence of the topologies of numerous gene trees, particularly those for (nearly universal genes, translates into the notion of a statistical tree of life (STOL, which reflects a central trend of vertical evolution. The STOL can be employed as a framework for reconstruction of the evolutionary processes in the prokaryotic world. Quantitatively, however, horizontal gene transfer (HGT dominates microbial evolution, with the rate of gene gain and loss being comparable to the rate of point mutations and much greater than the duplication rate. Theoretical models of evolution suggest that HGT is essential for the survival of microbial populations that otherwise deteriorate due to the Muller’s ratchet effect. Apparently, at least some bacteria and archaea evolved dedicated vehicles for gene transfer that evolved from selfish elements such as plasmids and viruses. Recent phylogenomic analyses suggest that episodes of massive HGT were pivotal for the emergence of major groups of organisms such as multiple archaeal phyla as well as eukaryotes. Similar analyses appear to indicate that, in addition to donating hundreds of genes to the emerging eukaryotic lineage, mitochondrial endosymbiosis severely curtailed HGT. These results shed new light on the routes of evolutionary transitions, but caution is due given the inherent uncertainty of deep phylogenies.

  17. An exceptional horizontal gene transfer in plastids: gene replacement by a distant bacterial paralog and evidence that haptophyte and cryptophyte plastids are sisters

    Directory of Open Access Journals (Sweden)

    Palmer Jeffrey D

    2006-09-01

    Full Text Available Abstract Background Horizontal gene transfer (HGT to the plant mitochondrial genome has recently been shown to occur at a surprisingly high rate; however, little evidence has been found for HGT to the plastid genome, despite extensive sequencing. In this study, we analyzed all genes from sequenced plastid genomes to unearth any neglected cases of HGT and to obtain a measure of the overall extent of HGT to the plastid. Results Although several genes gave strongly supported conflicting trees under certain conditions, we are confident of HGT in only a single case beyond the rubisco HGT already reported. Most of the conflicts involved near neighbors connected by long branches (e.g. red algae and their secondary hosts, where phylogenetic methods are prone to mislead. However, three genes – clpP, ycf2, and rpl36 – provided strong support for taxa moving far from their organismal position. Further taxon sampling of clpP and ycf2 resulted in rejection of HGT due to long-branch attraction and a serious error in the published plastid genome sequence of Oenothera elata, respectively. A single new case, a bacterial rpl36 gene transferred into the ancestor of the cryptophyte and haptophyte plastids, appears to be a true HGT event. Interestingly, this rpl36 gene is a distantly related paralog of the rpl36 type found in other plastids and most eubacteria. Moreover, the transferred gene has physically replaced the native rpl36 gene, yet flanking genes and intergenic regions show no sign of HGT. This suggests that gene replacement somehow occurred by recombination at the very ends of rpl36, without the level and length of similarity normally expected to support recombination. Conclusion The rpl36 HGT discovered in this study is of considerable interest in terms of both molecular mechanism and phylogeny. The plastid acquisition of a bacterial rpl36 gene via HGT provides the first strong evidence for a sister-group relationship between haptophyte and

  18. An exceptional horizontal gene transfer in plastids: gene replacement by a distant bacterial paralog and evidence that haptophyte and cryptophyte plastids are sisters

    Science.gov (United States)

    Rice, Danny W; Palmer, Jeffrey D

    2006-01-01

    Background Horizontal gene transfer (HGT) to the plant mitochondrial genome has recently been shown to occur at a surprisingly high rate; however, little evidence has been found for HGT to the plastid genome, despite extensive sequencing. In this study, we analyzed all genes from sequenced plastid genomes to unearth any neglected cases of HGT and to obtain a measure of the overall extent of HGT to the plastid. Results Although several genes gave strongly supported conflicting trees under certain conditions, we are confident of HGT in only a single case beyond the rubisco HGT already reported. Most of the conflicts involved near neighbors connected by long branches (e.g. red algae and their secondary hosts), where phylogenetic methods are prone to mislead. However, three genes – clpP, ycf2, and rpl36 – provided strong support for taxa moving far from their organismal position. Further taxon sampling of clpP and ycf2 resulted in rejection of HGT due to long-branch attraction and a serious error in the published plastid genome sequence of Oenothera elata, respectively. A single new case, a bacterial rpl36 gene transferred into the ancestor of the cryptophyte and haptophyte plastids, appears to be a true HGT event. Interestingly, this rpl36 gene is a distantly related paralog of the rpl36 type found in other plastids and most eubacteria. Moreover, the transferred gene has physically replaced the native rpl36 gene, yet flanking genes and intergenic regions show no sign of HGT. This suggests that gene replacement somehow occurred by recombination at the very ends of rpl36, without the level and length of similarity normally expected to support recombination. Conclusion The rpl36 HGT discovered in this study is of considerable interest in terms of both molecular mechanism and phylogeny. The plastid acquisition of a bacterial rpl36 gene via HGT provides the first strong evidence for a sister-group relationship between haptophyte and cryptophyte plastids to the

  19. Phylogeny Reconstruction with Alignment-Free Method That Corrects for Horizontal Gene Transfer.

    Directory of Open Access Journals (Sweden)

    Raquel Bromberg

    2016-06-01

    Full Text Available Advances in sequencing have generated a large number of complete genomes. Traditionally, phylogenetic analysis relies on alignments of orthologs, but defining orthologs and separating them from paralogs is a complex task that may not always be suited to the large datasets of the future. An alternative to traditional, alignment-based approaches are whole-genome, alignment-free methods. These methods are scalable and require minimal manual intervention. We developed SlopeTree, a new alignment-free method that estimates evolutionary distances by measuring the decay of exact substring matches as a function of match length. SlopeTree corrects for horizontal gene transfer, for composition variation and low complexity sequences, and for branch-length nonlinearity caused by multiple mutations at the same site. We tested SlopeTree on 495 bacteria, 73 archaea, and 72 strains of Escherichia coli and Shigella. We compared our trees to the NCBI taxonomy, to trees based on concatenated alignments, and to trees produced by other alignment-free methods. The results were consistent with current knowledge about prokaryotic evolution. We assessed differences in tree topology over different methods and settings and found that the majority of bacteria and archaea have a core set of proteins that evolves by descent. In trees built from complete genomes rather than sets of core genes, we observed some grouping by phenotype rather than phylogeny, for instance with a cluster of sulfur-reducing thermophilic bacteria coming together irrespective of their phyla. The source-code for SlopeTree is available at: http://prodata.swmed.edu/download/pub/slopetree_v1/slopetree.tar.gz.

  20. Phylogeny Reconstruction with Alignment-Free Method That Corrects for Horizontal Gene Transfer

    Science.gov (United States)

    Grishin, Nick V.; Otwinowski, Zbyszek

    2016-01-01

    Advances in sequencing have generated a large number of complete genomes. Traditionally, phylogenetic analysis relies on alignments of orthologs, but defining orthologs and separating them from paralogs is a complex task that may not always be suited to the large datasets of the future. An alternative to traditional, alignment-based approaches are whole-genome, alignment-free methods. These methods are scalable and require minimal manual intervention. We developed SlopeTree, a new alignment-free method that estimates evolutionary distances by measuring the decay of exact substring matches as a function of match length. SlopeTree corrects for horizontal gene transfer, for composition variation and low complexity sequences, and for branch-length nonlinearity caused by multiple mutations at the same site. We tested SlopeTree on 495 bacteria, 73 archaea, and 72 strains of Escherichia coli and Shigella. We compared our trees to the NCBI taxonomy, to trees based on concatenated alignments, and to trees produced by other alignment-free methods. The results were consistent with current knowledge about prokaryotic evolution. We assessed differences in tree topology over different methods and settings and found that the majority of bacteria and archaea have a core set of proteins that evolves by descent. In trees built from complete genomes rather than sets of core genes, we observed some grouping by phenotype rather than phylogeny, for instance with a cluster of sulfur-reducing thermophilic bacteria coming together irrespective of their phyla. The source-code for SlopeTree is available at: http://prodata.swmed.edu/download/pub/slopetree_v1/slopetree.tar.gz. PMID:27336403

  1. Protein Homeostasis Imposes a Barrier on Functional Integration of Horizontally Transferred Genes in Bacteria.

    Science.gov (United States)

    Bershtein, Shimon; Serohijos, Adrian W R; Bhattacharyya, Sanchari; Manhart, Michael; Choi, Jeong-Mo; Mu, Wanmeng; Zhou, Jingwen; Shakhnovich, Eugene I

    2015-10-01

    Horizontal gene transfer (HGT) plays a central role in bacterial evolution, yet the molecular and cellular constraints on functional integration of the foreign genes are poorly understood. Here we performed inter-species replacement of the chromosomal folA gene, encoding an essential metabolic enzyme dihydrofolate reductase (DHFR), with orthologs from 35 other mesophilic bacteria. The orthologous inter-species replacements caused a marked drop (in the range 10-90%) in bacterial growth rate despite the fact that most orthologous DHFRs are as stable as E.coli DHFR at 37°C and are more catalytically active than E. coli DHFR. Although phylogenetic distance between E. coli and orthologous DHFRs as well as their individual molecular properties correlate poorly with growth rates, the product of the intracellular DHFR abundance and catalytic activity (kcat/KM), correlates strongly with growth rates, indicating that the drop in DHFR abundance constitutes the major fitness barrier to HGT. Serial propagation of the orthologous strains for ~600 generations dramatically improved growth rates by largely alleviating the fitness barriers. Whole genome sequencing and global proteome quantification revealed that the evolved strains with the largest fitness improvements have accumulated mutations that inactivated the ATP-dependent Lon protease, causing an increase in the intracellular DHFR abundance. In one case DHFR abundance increased further due to mutations accumulated in folA promoter, but only after the lon inactivating mutations were fixed in the population. Thus, by apparently distinguishing between self and non-self proteins, protein homeostasis imposes an immediate and global barrier to the functional integration of foreign genes by decreasing the intracellular abundance of their products. Once this barrier is alleviated, more fine-tuned evolution occurs to adjust the function/expression of the transferred proteins to the constraints imposed by the intracellular

  2. Protein Homeostasis Imposes a Barrier on Functional Integration of Horizontally Transferred Genes in Bacteria.

    Directory of Open Access Journals (Sweden)

    Shimon Bershtein

    2015-10-01

    Full Text Available Horizontal gene transfer (HGT plays a central role in bacterial evolution, yet the molecular and cellular constraints on functional integration of the foreign genes are poorly understood. Here we performed inter-species replacement of the chromosomal folA gene, encoding an essential metabolic enzyme dihydrofolate reductase (DHFR, with orthologs from 35 other mesophilic bacteria. The orthologous inter-species replacements caused a marked drop (in the range 10-90% in bacterial growth rate despite the fact that most orthologous DHFRs are as stable as E.coli DHFR at 37°C and are more catalytically active than E. coli DHFR. Although phylogenetic distance between E. coli and orthologous DHFRs as well as their individual molecular properties correlate poorly with growth rates, the product of the intracellular DHFR abundance and catalytic activity (kcat/KM, correlates strongly with growth rates, indicating that the drop in DHFR abundance constitutes the major fitness barrier to HGT. Serial propagation of the orthologous strains for ~600 generations dramatically improved growth rates by largely alleviating the fitness barriers. Whole genome sequencing and global proteome quantification revealed that the evolved strains with the largest fitness improvements have accumulated mutations that inactivated the ATP-dependent Lon protease, causing an increase in the intracellular DHFR abundance. In one case DHFR abundance increased further due to mutations accumulated in folA promoter, but only after the lon inactivating mutations were fixed in the population. Thus, by apparently distinguishing between self and non-self proteins, protein homeostasis imposes an immediate and global barrier to the functional integration of foreign genes by decreasing the intracellular abundance of their products. Once this barrier is alleviated, more fine-tuned evolution occurs to adjust the function/expression of the transferred proteins to the constraints imposed by the

  3. Evidence of recent interspecies horizontal gene transfer regarding nucleopolyhedrovirus infection of Spodoptera frugiperda.

    Science.gov (United States)

    Barrera, Gloria Patricia; Belaich, Mariano Nicolás; Patarroyo, Manuel Alfonso; Villamizar, Laura Fernanda; Ghiringhelli, Pablo Daniel

    2015-11-25

    Baculoviruses are insect-associated viruses carrying large, circular double-stranded-DNA genomes with significant biotechnological applications such as biological pest control, recombinant protein production, gene delivery in mammals and as a model of DNA genome evolution. These pathogens infect insects from the orders Lepidoptera, Hymenoptera and Diptera, and have high species diversity which is expressed in their diverse biological properties including morphology, virulence or pathogenicity. Spodoptera frugiperda (Lepidoptera: Noctuidae), the fall armyworm, represents a significant pest for agriculture in America; it is a host for baculoviruses such as the Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) (Colombia strain, genotype A) having been classified as a Group II alphabaculovirus making it a very attractive target for bioinsecticidal use. Genome analysis by pyrosequencing revealed that SfMNPV ColA has 145 ORFs, 2 of which were not present in the other sequenced genotypes of the virus (SfMNPV-NicB, SfMNPV-NicG, SfMNPV-19 and SfMNPV-3AP2). An in-depth bioinformatics study showed that ORF023 and ORF024 were acquired by a recent homologous recombination process between Spodoptera frugiperda and Spodoptera litura (the Oriental leafworm moth) nucleopolyhedroviruses. Auxiliary genes are numerous in the affected locus which has a homologous region (hr3), a repetitive sequence associated with genome replication which became lost in SfColA along with 1 ORF. Besides, the mRNAs associated with two acquired genes appeared in the virus' life-cycle during the larval stage. Predictive studies concerning the theoretical proteins identified that ORF023 protein would be a phosphatase involved in DNA repair and that the ORF024 protein would be a membrane polypeptide associated with cell transport. The SfColA genome was thus revealed to be a natural recombinant virus showing evidence of recent horizontal gene transfer between different baculovirus species occurring

  4. Detection of 400-year-old Yersinia pestis DNA in human dental pulp: an approach to the diagnosis of ancient septicemia.

    Science.gov (United States)

    Drancourt, M; Aboudharam, G; Signoli, M; Dutour, O; Raoult, D

    1998-10-13

    Ancient septicemic plague epidemics were reported to have killed millions of people for 2 millenniums. However, confident diagnosis of ancient septicemia solely on the basis of historical clinical observations is not possible. The lack of suitable infected material has prevented direct demonstration of ancient septicemia; thus, the history of most infections such as plague remains hypothetical. The durability of dental pulp, together with its natural sterility, makes it a suitable material on which to base such research. We hypothesized that it would be a lasting refuge for Yersinia pestis, the plague agent. DNA extracts were made from the dental pulp of 12 unerupted teeth extracted from skeletons excavated from 16th and 18th century French graves of persons thought to have died of plague ("plague teeth") and from 7 ancient negative control teeth. PCRs incorporating ancient DNA extracts and primers specific for the human beta-globin gene demonstrated the absence of inhibitors in these preparations. The incorporation of primers specific for Y. pestis rpoB (the RNA polymerase beta-subunit-encoding gene) and the recognized virulence-associated pla (the plasminogen activator-encoding gene) repeatedly yielded products that had a nucleotide sequence indistinguishable from that of modern day isolates of the bacterium. The specific pla sequence was obtained from 6 of 12 plague skeleton teeth but 0 of 7 negative controls (P plague was achieved for historically identified victims, and we have confirmed the presence of the disease at the end of 16th century in France. Dental pulp is an attractive target in the quest to determine the etiology of septicemic illnesses detected in ancient corpses. Molecular techniques could be applied to this material to resolve historical outbreaks.

  5. Gene loss and horizontal gene transfer contributed to the genome evolution of the extreme acidophile Ferrovum

    Directory of Open Access Journals (Sweden)

    Sophie Roxana Ullrich

    2016-05-01

    Full Text Available Acid mine drainage (AMD, associated with active and abandoned mining sites, is a habitat for acidophilic microorganisms that gain energy from the oxidation of reduced sulfur compounds and ferrous iron and that thrive at pH below 4. Members of the recently proposed genus Ferrovum are the first acidophilic iron oxidizers to be described within the Betaproteobacteria. Although they have been detected as typical community members in AMD habitats worldwide, knowledge of their phylogenetic and metabolic diversity is scarce. Genomics approaches appear to be most promising in addressing this lacuna since isolation and cultivation of Ferrovum has proven to be extremely difficult and has so far only been successful for the designated type strain Ferrovum myxofaciens P3G. In this study, the genomes of two novel strains of Ferrovum (PN-J185 and Z-31 derived from water samples of a mine water treatment plant were sequenced. These genomes were compared with those of Ferrovum sp. JA12 that also originated from the mine water treatment plant, and of the type strain (P3G. Phylogenomic scrutiny suggests that the four strains represent three Ferrovum species that cluster in two groups (1 and 2. Comprehensive analysis of their predicted metabolic pathways revealed that these groups harbor characteristic metabolic profiles, notably with respect to motility, chemotaxis, nitrogen metabolism, biofilm formation and their potential strategies to cope with the acidic environment. For example, while the F. myxofaciens strains (group 1 appear to be motile and diazotrophic, the non-motile group 2 strains have the predicted potential to use a greater variety of fixed nitrogen sources. Furthermore, analysis of their genome synteny provides first insights into their genome evolution, suggesting that horizontal gene transfer and genome reduction in the group 2 strains by loss of genes encoding complete metabolic pathways or physiological features contributed to the observed

  6. Assessment of the horizontal transfer of functional genes as a suitable approach for evaluation of the bioremediation potential of petroleum-contaminated sites: a mini-review.

    Science.gov (United States)

    Shahi, Aiyoub; Ince, Bahar; Aydin, Sevcan; Ince, Orhan

    2017-06-01

    Petroleum sludge contains recalcitrant residuals. These compounds because of being toxic to humans and other organism are of the major concerns. Therefore, petroleum sludge should be safely disposed. Physicochemical methods which are used by this sector are mostly expensive and need complex devices. Bioremediation methods because of being eco-friendly and cost-effective overcome most of the limitations of physicochemical treatments. Microbial strains capable to degrade petroleum hydrocarbons are practically present in all soils and sediments and their population density increases in contact with contaminants. Bacterial strains cannot degrade alone all kinds of petroleum hydrocarbons, rather microbial consortium should collaborate with each other for degradation of petroleum hydrocarbon mixtures. Horizontal transfer of functional genes between bacteria plays an important role in increasing the metabolic potential of the microbial community. Therefore, selecting a suitable degrading gene and tracking its horizontal transfer would be a useful approach to evaluate the bioremediation process and to assess the bioremediation potential of contaminated sites.

  7. H-NS Facilitates Sequence Diversification of Horizontally Transferred DNAs during Their Integration in Host Chromosomes.

    Directory of Open Access Journals (Sweden)

    Koichi Higashi

    2016-01-01

    Full Text Available Bacteria can acquire new traits through horizontal gene transfer. Inappropriate expression of transferred genes, however, can disrupt the physiology of the host bacteria. To reduce this risk, Escherichia coli expresses the nucleoid-associated protein, H-NS, which preferentially binds to horizontally transferred genes to control their expression. Once expression is optimized, the horizontally transferred genes may actually contribute to E. coli survival in new habitats. Therefore, we investigated whether and how H-NS contributes to this optimization process. A comparison of H-NS binding profiles on common chromosomal segments of three E. coli strains belonging to different phylogenetic groups indicated that the positions of H-NS-bound regions have been conserved in E. coli strains. The sequences of the H-NS-bound regions appear to have diverged more so than H-NS-unbound regions only when H-NS-bound regions are located upstream or in coding regions of genes. Because these regions generally contain regulatory elements for gene expression, sequence divergence in these regions may be associated with alteration of gene expression. Indeed, nucleotide substitutions in H-NS-bound regions of the ybdO promoter and coding regions have diversified the potential for H-NS-independent negative regulation among E. coli strains. The ybdO expression in these strains was still negatively regulated by H-NS, which reduced the effect of H-NS-independent regulation under normal growth conditions. Hence, we propose that, during E. coli evolution, the conservation of H-NS binding sites resulted in the diversification of the regulation of horizontally transferred genes, which may have facilitated E. coli adaptation to new ecological niches.

  8. H-NS Facilitates Sequence Diversification of Horizontally Transferred DNAs during Their Integration in Host Chromosomes.

    Science.gov (United States)

    Higashi, Koichi; Tobe, Toru; Kanai, Akinori; Uyar, Ebru; Ishikawa, Shu; Suzuki, Yutaka; Ogasawara, Naotake; Kurokawa, Ken; Oshima, Taku

    2016-01-01

    Bacteria can acquire new traits through horizontal gene transfer. Inappropriate expression of transferred genes, however, can disrupt the physiology of the host bacteria. To reduce this risk, Escherichia coli expresses the nucleoid-associated protein, H-NS, which preferentially binds to horizontally transferred genes to control their expression. Once expression is optimized, the horizontally transferred genes may actually contribute to E. coli survival in new habitats. Therefore, we investigated whether and how H-NS contributes to this optimization process. A comparison of H-NS binding profiles on common chromosomal segments of three E. coli strains belonging to different phylogenetic groups indicated that the positions of H-NS-bound regions have been conserved in E. coli strains. The sequences of the H-NS-bound regions appear to have diverged more so than H-NS-unbound regions only when H-NS-bound regions are located upstream or in coding regions of genes. Because these regions generally contain regulatory elements for gene expression, sequence divergence in these regions may be associated with alteration of gene expression. Indeed, nucleotide substitutions in H-NS-bound regions of the ybdO promoter and coding regions have diversified the potential for H-NS-independent negative regulation among E. coli strains. The ybdO expression in these strains was still negatively regulated by H-NS, which reduced the effect of H-NS-independent regulation under normal growth conditions. Hence, we propose that, during E. coli evolution, the conservation of H-NS binding sites resulted in the diversification of the regulation of horizontally transferred genes, which may have facilitated E. coli adaptation to new ecological niches.

  9. The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters

    DEFF Research Database (Denmark)

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca

    2015-01-01

    . aeruginosa O12 OSA gene cluster, an antibiotic resistance determinant (gyrAC248T), and other genes that have been transferred between P. aeruginosa strains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related to P...... in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how the P. aeruginosa OSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83 P....... aeruginosa strains and their serotypes. While most serotypes were closely linked to the core genome phylogeny, we observed horizontal exchange of OSA biosynthesis genes among phylogenetically distinct P. aeruginosa strains. Specifically, we identified a "serotype island" ranging from 62 kb to 185 kb containing the P...

  10. Phylogenetic analysis of bacterial and archaeal arsC gene sequences suggests an ancient, common origin for arsenate reductase

    Directory of Open Access Journals (Sweden)

    Dugas Sandra L

    2003-07-01

    Full Text Available Abstract Background The ars gene system provides arsenic resistance for a variety of microorganisms and can be chromosomal or plasmid-borne. The arsC gene, which codes for an arsenate reductase is essential for arsenate resistance and transforms arsenate into arsenite, which is extruded from the cell. A survey of GenBank shows that arsC appears to be phylogenetically widespread both in organisms with known arsenic resistance and those organisms that have been sequenced as part of whole genome projects. Results Phylogenetic analysis of aligned arsC sequences shows broad similarities to the established 16S rRNA phylogeny, with separation of bacterial, archaeal, and subsequently eukaryotic arsC genes. However, inconsistencies between arsC and 16S rRNA are apparent for some taxa. Cyanobacteria and some of the γ-Proteobacteria appear to possess arsC genes that are similar to those of Low GC Gram-positive Bacteria, and other isolated taxa possess arsC genes that would not be expected based on known evolutionary relationships. There is no clear separation of plasmid-borne and chromosomal arsC genes, although a number of the Enterobacteriales (γ-Proteobacteria possess similar plasmid-encoded arsC sequences. Conclusion The overall phylogeny of the arsenate reductases suggests a single, early origin of the arsC gene and subsequent sequence divergence to give the distinct arsC classes that exist today. Discrepancies between 16S rRNA and arsC phylogenies support the role of horizontal gene transfer (HGT in the evolution of arsenate reductases, with a number of instances of HGT early in bacterial arsC evolution. Plasmid-borne arsC genes are not monophyletic suggesting multiple cases of chromosomal-plasmid exchange and subsequent HGT. Overall, arsC phylogeny is complex and is likely the result of a number of evolutionary mechanisms.

  11. Algorithms for computing parsimonious evolutionary scenarios for genome evolution, the last universal common ancestor and dominance of horizontal gene transfer in the evolution of prokaryotes

    Directory of Open Access Journals (Sweden)

    Galperin Michael Y

    2003-01-01

    Full Text Available Abstract Background Comparative analysis of sequenced genomes reveals numerous instances of apparent horizontal gene transfer (HGT, at least in prokaryotes, and indicates that lineage-specific gene loss might have been even more common in evolution. This complicates the notion of a species tree, which needs to be re-interpreted as a prevailing evolutionary trend, rather than the full depiction of evolution, and makes reconstruction of ancestral genomes a non-trivial task. Results We addressed the problem of constructing parsimonious scenarios for individual sets of orthologous genes given a species tree. The orthologous sets were taken from the database of Clusters of Orthologous Groups of proteins (COGs. We show that the phyletic patterns (patterns of presence-absence in completely sequenced genomes of almost 90% of the COGs are inconsistent with the hypothetical species tree. Algorithms were developed to reconcile the phyletic patterns with the species tree by postulating gene loss, COG emergence and HGT (the latter two classes of events were collectively treated as gene gains. We prove that each of these algorithms produces a parsimonious evolutionary scenario, which can be represented as mapping of loss and gain events on the species tree. The distribution of the evolutionary events among the tree nodes substantially depends on the underlying assumptions of the reconciliation algorithm, e.g. whether or not independent gene gains (gain after loss after gain are permitted. Biological considerations suggest that, on average, gene loss might be a more likely event than gene gain. Therefore different gain penalties were used and the resulting series of reconstructed gene sets for the last universal common ancestor (LUCA of the extant life forms were analysed. The number of genes in the reconstructed LUCA gene sets grows as the gain penalty increases. However, qualitative examination of the LUCA versions reconstructed with different gain penalties

  12. A sensitive, support-vector-machine method for the detection of horizontal gene transfers in viral, archaeal and bacterial genomes.

    Science.gov (United States)

    Tsirigos, Aristotelis; Rigoutsos, Isidore

    2005-01-01

    In earlier work, we introduced and discussed a generalized computational framework for identifying horizontal transfers. This framework relied on a gene's nucleotide composition, obviated the need for knowledge of codon boundaries and database searches, and was shown to perform very well across a wide range of archaeal and bacterial genomes when compared with previously published approaches, such as Codon Adaptation Index and C + G content. Nonetheless, two considerations remained outstanding: we wanted to further increase the sensitivity of detecting horizontal transfers and also to be able to apply the method to increasingly smaller genomes. In the discussion that follows, we present such a method, Wn-SVM, and show that it exhibits a very significant improvement in sensitivity compared with earlier approaches. Wn-SVM uses a one-class support-vector machine and can learn using rather small training sets. This property makes Wn-SVM particularly suitable for studying small-size genomes, similar to those of viruses, as well as the typically larger archaeal and bacterial genomes. We show experimentally that the new method results in a superior performance across a wide range of organisms and that it improves even upon our own earlier method by an average of 10% across all examined genomes. As a small-genome case study, we analyze the genome of the human cytomegalovirus and demonstrate that Wn-SVM correctly identifies regions that are known to be conserved and prototypical of all beta-herpesvirinae, regions that are known to have been acquired horizontally from the human host and, finally, regions that had not up to now been suspected to be horizontally transferred. Atypical region predictions for many eukaryotic viruses, including the alpha-, beta- and gamma-herpesvirinae, and 123 archaeal and bacterial genomes, have been made available online at http://cbcsrv.watson.ibm.com/HGT_SVM/.

  13. Ancient Greek with Thrasymachus: A Web Site for Learning Ancient Greek.

    Science.gov (United States)

    Barker, Alison

    2001-01-01

    Discusses a project that was begun as an attempt by two teachers of Ancient Greek to provide supplementary materials to accompany "Thrasymachus," a first-year textbook for learning ancient Greek. Provides a brief history and description of the project, the format of each chapter, a chronology for completion of materials for each chapter in the…

  14. Ancient genomics

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Allentoft, Morten Erik; Avila Arcos, Maria del Carmen

    2015-01-01

    throughput of next generation sequencing platforms and the ability to target short and degraded DNA molecules. Many ancient specimens previously unsuitable for DNA analyses because of extensive degradation can now successfully be used as source materials. Additionally, the analytical power obtained...... by increasing the number of sequence reads to billions effectively means that contamination issues that have haunted aDNA research for decades, particularly in human studies, can now be efficiently and confidently quantified. At present, whole genomes have been sequenced from ancient anatomically modern humans...

  15. Distribution of tetracycline resistance genes in anaerobic treatment of waste sludge: The role of pH in regulating tetracycline resistant bacteria and horizontal gene transfer.

    Science.gov (United States)

    Huang, Haining; Chen, Yinguang; Zheng, Xiong; Su, Yinglong; Wan, Rui; Yang, Shouye

    2016-10-01

    Although pH value has been widely regarded as an important factor that affects resource recovery of waste sludge, the potential influence of diverse pHs on the distribution of tetracycline resistance genes (TRGs) during sludge anaerobic treatment is largely unknown. Here we reported that in the range of pH 4-10, 0.58-1.18 log unit increase of target TRGs was observed at pH 4, compared with that at pH 7, while 0.70-1.31 log unit further removal were obtained at pH 10. Mechanism study revealed that varied pHs not only altered the community structures of tetracycline resistant bacteria (TRB), but also changed their relative abundances, benefitting the propagation (acidic pHs) or attenuation (alkaline pHs) of TRB. Further investigation indicated that the amount and gene-possessing abilities of key genetic vectors for horizontal TRGs transfer were greatly promoted at acidic pHs but restricted under alkaline conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Cloning the uteroglobin gene promoter from the relic volcano rabbit (Romerolagus diazi) reveals an ancient estrogen-response element.

    Science.gov (United States)

    Acosta-MontesdeOca, Adriana; Zariñán, Teresa; Macías, Héctor; Pérez-Solís, Marco A; Ulloa-Aguirre, Alfredo; Gutiérrez-Sagal, Rubén

    2012-05-01

    To gain further insight on the estrogen-dependent transcriptional regulation of the uteroglobin (UG) gene, we cloned the 5'-flanking region of the UG gene from the phylogenetically ancient volcano rabbit (Romerolagus diazi; Rd). The cloned region spans 812 base pairs (bp; -812/-1) and contains a noncanonical TATA box (TACA). The translation start site is 48 bp downstream from the putative transcription initiation site (AGA), and is preceded by a consensus Kozak box. Comparison of the Rd-UG gene with that previously isolated from rabbits (Oryctolagus cuniculus) showed 93% in sequence identity as well as a number of conserved cis-acting elements, including the estrogen-response element (ERE; -265/-251), which differs from the consensus by two nucleotides. In MCF-7 cells, 17β-estradiol (E(2)) induced transcription of a luciferase reporter driven by the Rd-UG promoter in a similar manner as in an equivalent rabbit UG reporter; the Rd-UG promoter was 30% more responsive to E(2) than the rabbit promoter. Mutagenesis studies on the Rd-ERE confirmed this cis-element as a target of E(2) as two luciferase mutant reporters of the Rd-promoter, one with the rabbit and the other with the consensus ERE, were more responsive to the hormone than the wild-type reporter. Gel shift and super-shift assays showed that estrogen receptor-α indeed binds to the imperfect palindromic sequence of the Rd-ERE. Copyright © 2012 Wiley Periodicals, Inc.

  17. Ancient Pbx-Hox signatures define hundreds of vertebrate developmental enhancers

    Directory of Open Access Journals (Sweden)

    Parker Hugo J

    2011-12-01

    Full Text Available Abstract Background Gene regulation through cis-regulatory elements plays a crucial role in development and disease. A major aim of the post-genomic era is to be able to read the function of cis-regulatory elements through scrutiny of their DNA sequence. Whilst comparative genomics approaches have identified thousands of putative regulatory elements, our knowledge of their mechanism of action is poor and very little progress has been made in systematically de-coding them. Results Here, we identify ancient functional signatures within vertebrate conserved non-coding elements (CNEs through a combination of phylogenetic footprinting and functional assay, using genomic sequence from the sea lamprey as a reference. We uncover a striking enrichment within vertebrate CNEs for conserved binding-site motifs of the Pbx-Hox hetero-dimer. We further show that these predict reporter gene expression in a segment specific manner in the hindbrain and pharyngeal arches during zebrafish development. Conclusions These findings evoke an evolutionary scenario in which many CNEs evolved early in the vertebrate lineage to co-ordinate Hox-dependent gene-regulatory interactions that pattern the vertebrate head. In a broader context, our evolutionary analyses reveal that CNEs are composed of tightly linked transcription-factor binding-sites (TFBSs, which can be systematically identified through phylogenetic footprinting approaches. By placing a large number of ancient vertebrate CNEs into a developmental context, our findings promise to have a significant impact on efforts toward de-coding gene-regulatory elements that underlie vertebrate development, and will facilitate building general models of regulatory element evolution.

  18. Single cell genomics indicates horizontal gene transfer and viral infections in a deep subsurface Firmicutes population

    Directory of Open Access Journals (Sweden)

    Jessica eLabonté

    2015-04-01

    Full Text Available A major fraction of Earth's prokaryotic biomass dwells in the deep subsurface, where cellular abundances per volume of sample are lower, metabolism is slower, and generation times are longer than those in surface terrestrial and marine environments. How these conditions impact biotic interactions and evolutionary processes is largely unknown. Here we employed single cell genomics to analyze cell-to-cell genome content variability and signatures of horizontal gene transfer (HGT and viral infections in five cells of Candidatus Desulforudis audaxviator, which were collected from a three km-deep fracture water in the 2.9 Ga-old Witwatersrand Basin of South Africa. Between 0 and 32 % of genes recovered from single cells were not present in the original, metagenomic assembly of Desulforudis, which was obtained from a neighboring subsurface fracture. We found a transposable prophage, a retron, multiple clustered regularly interspaced short palindromic repeats (CRISPRs and restriction-modification systems, and an unusually high frequency of transposases in the analyzed single cell genomes. This indicates that recombination, HGT and viral infections are prevalent evolutionary events in the studied population of microorganisms inhabiting a highly stable deep subsurface environment.

  19. Insights into horizontal acquisition patterns of dormancy and ...

    Indian Academy of Sciences (India)

    Horizontal Gene Transfer (HGT) events, initially thought to be rare in Mycobacterium tuberculosis, have recentlybeen shown to be involved in the acquisition of virulence operons in M. tuberculosis. We have developed a newpartitioning framework based HGT prediction algorithm, called Grid3M, and applied the same for the ...

  20. A horizontal gene transfer at the origin of phenylpropanoid metabolism: a key adaptation of plants to land

    Directory of Open Access Journals (Sweden)

    Gribaldo Simonetta

    2009-02-01

    Full Text Available Abstract Background The pioneering ancestor of land plants that conquered terrestrial habitats around 500 million years ago had to face dramatic stresses including UV radiation, desiccation, and microbial attack. This drove a number of adaptations, among which the emergence of the phenylpropanoid pathway was crucial, leading to essential compounds such as flavonoids and lignin. However, the origin of this specific land plant secondary metabolism has not been clarified. Results We have performed an extensive analysis of the taxonomic distribution and phylogeny of Phenylalanine Ammonia Lyase (PAL, which catalyses the first and essential step of the general phenylpropanoid pathway, leading from phenylalanine to p-Coumaric acid and p-Coumaroyl-CoA, the entry points of the flavonoids and lignin routes. We obtained robust evidence that the ancestor of land plants acquired a PAL via horizontal gene transfer (HGT during symbioses with soil bacteria and fungi that are known to have established very early during the first steps of land colonization. This horizontally acquired PAL represented then the basis for further development of the phenylpropanoid pathway and plant radiation on terrestrial environments. Conclusion Our results highlight a possible crucial role of HGT from soil bacteria in the path leading to land colonization by plants and their subsequent evolution. The few functional characterizations of sediment/soil bacterial PAL (production of secondary metabolites with powerful antimicrobial activity or production of pigments suggest that the initial advantage of this horizontally acquired PAL in the ancestor of land plants might have been either defense against an already developed microbial community and/or protection against UV. Reviewers This article was reviewed by Purificación López-García, Janet Siefert, and Eugene Koonin.

  1. Balancing Acts Between Ancient and Modern Cities: The Ancient Greek Cities Project of C. A. Doxiadis

    Directory of Open Access Journals (Sweden)

    Mantha Zarmakoupi

    2015-12-01

    Full Text Available This paper examines the inception and development of the Ancient Greek Cities (AGC research project (1963–77 of Constantinos A. Doxiadis and addresses the novelty of its methodological approach to the study of classical urbanism. With the AGC project, Doxiadis launched a comprehensive study of the ancient Greek built environment to provide an overview of the factors involved in its shaping. The project produced 24 published volumes — the first two laying out the historical and methodological parameters of the ensuing 22 monographs with case studies — as well as 12 unpublished manuscripts, and through international conferences initiated a wider dialogue on ancient cities beyond the classical Greek world. It was the first interdisciplinary study that attempted to tackle the environmental factors, together with the social and economic ones, underpinning the creation, development and operation of ancient Greek cities. Doxiadis’s innovative approach to the analysis of the ancient city was indebted to his practice as an architect and town planner and was informed by his theory of Ekistics. His purpose was to identify the urban planning principles of ancient Greek settlements in order to employ them in his projects. This paper examines the concept and methodology of the AGC project as well as the ways in which Doxiadis used the study of ancient cities in relation to his contemporary urban/architectural agendas, and explains this important moment in the historiography of ancient Greek urbanism.

  2. Ancient Transposable Elements Transformed the Uterine Regulatory Landscape and Transcriptome during the Evolution of Mammalian Pregnancy

    Directory of Open Access Journals (Sweden)

    Vincent J. Lynch

    2015-02-01

    Full Text Available A major challenge in biology is determining how evolutionarily novel characters originate; however, mechanistic explanations for the origin of new characters are almost completely unknown. The evolution of pregnancy is an excellent system in which to study the origin of novelties because mammals preserve stages in the transition from egg laying to live birth. To determine the molecular bases of this transition, we characterized the pregnant/gravid uterine transcriptome from tetrapods to trace the evolutionary history of uterine gene expression. We show that thousands of genes evolved endometrial expression during the origins of mammalian pregnancy, including genes that mediate maternal-fetal communication and immunotolerance. Furthermore, thousands of cis-regulatory elements that mediate decidualization and cell-type identity in decidualized stromal cells are derived from ancient mammalian transposable elements (TEs. Our results indicate that one of the defining mammalian novelties evolved from DNA sequences derived from ancient mammalian TEs co-opted into hormone-responsive regulatory elements distributed throughout the genome.

  3. Genes, Genomes, and Assemblages of Modern Anoxygenic Photosynthetic Cyanobacteria as Proxies for Ancient Cyanobacteria

    Science.gov (United States)

    Grim, S. L.; Dick, G.

    2015-12-01

    Oxygenic photosynthetic (OP) cyanobacteria were responsible for the production of O2 during the Proterozoic. However, the extent and degree of oxygenation of the atmosphere and oceans varied for over 2 Ga after OP cyanobacteria first appeared in the geologic record. Cyanobacteria capable of anoxygenic photosynthesis (AP) may have altered the trajectory of oxygenation, yet the scope of their role in the Proterozoic is not well known. Modern cyanobacterial populations from Middle Island Sinkhole (MIS), Michigan and a handful of cultured cyanobacterial strains, are capable of OP and AP. With their metabolic versatility, these microbes may approximate ancient cyanobacterial assemblages that mediated Earth's oxygenation. To better characterize the taxonomic and genetic signatures of these modern AP/OP cyanobacteria, we sequenced 16S rRNA genes and conducted 'omics analyses on cultured strains, lab mesocosms, and MIS cyanobacterial mat samples collected over multiple years from May to September. Diversity in the MIS cyanobacterial mat is low, with one member of Oscillatoriales dominating at all times. However, Planktothrix members are more abundant in the cyanobacterial community in late summer and fall. The shift in cyanobacterial community composition may be linked to seasonally changing light intensity. In lab mesocosms of MIS microbial mat, we observed a shift in dominant cyanobacterial groups as well as the emergence of Chlorobium, bacteria that specialize in AP. These shifts in microbial community composition and metabolism are likely in response to changing environmental parameters such as the availability of light and sulfide. Further research is needed to understand the impacts of the changing photosynthetic community on oxygen production and the entire microbial consortium. Our study connects genes and genomes of AP cyanobacteria to their environment, and improves understanding of cyanobacterial metabolic strategies that may have shaped Earth's redox evolution.

  4. Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary

    Science.gov (United States)

    Almathen, Faisal; Charruau, Pauline; Mohandesan, Elmira; Mwacharo, Joram M.; Orozco-terWengel, Pablo; Pitt, Daniel; Abdussamad, Abdussamad M.; Uerpmann, Margarethe; Uerpmann, Hans-Peter; De Cupere, Bea; Magee, Peter; Alnaqeeb, Majed A.; Salim, Bashir; Raziq, Abdul; Dessie, Tadelle; Abdelhadi, Omer M.; Banabazi, Mohammad H.; Al-Eknah, Marzook; Walzer, Chris; Faye, Bernard; Hofreiter, Michael; Peters, Joris; Hanotte, Olivier

    2016-01-01

    Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species’ range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the “restocking from the wild” hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments. PMID:27162355

  5. Elusive Origins of the Extra Genes in Aspergillus oryzae

    Science.gov (United States)

    Khaldi, Nora; Wolfe, Kenneth H.

    2008-01-01

    The genome sequence of Aspergillus oryzae revealed unexpectedly that this species has approximately 20% more genes than its congeneric species A. nidulans and A. fumigatus. Where did these extra genes come from? Here, we evaluate several possible causes of the elevated gene number. Many gene families are expanded in A. oryzae relative to A. nidulans and A. fumigatus, but we find no evidence of ancient whole-genome duplication or other segmental duplications, either in A. oryzae or in the common ancestor of the genus Aspergillus. We show that the presence of divergent pairs of paralogs is a feature peculiar to A. oryzae and is not shared with A. nidulans or A. fumigatus. In phylogenetic trees that include paralog pairs from A. oryzae, we frequently find that one of the genes in a pair from A. oryzae has the expected orthologous relationship with A. nidulans, A. fumigatus and other species in the subphylum Eurotiomycetes, whereas the other A. oryzae gene falls outside this clade but still within the Ascomycota. We identified 456 such gene pairs in A. oryzae. Further phylogenetic analysis did not however indicate a single consistent evolutionary origin for the divergent members of these pairs. Approximately one-third of them showed phylogenies that are suggestive of horizontal gene transfer (HGT) from Sordariomycete species, and these genes are closer together in the A. oryzae genome than expected by chance, but no unique Sordariomycete donor species was identifiable. The postulated HGTs from Sordariomycetes still leave the majority of extra A. oryzae genes unaccounted for. One possible explanation for our observations is that A. oryzae might have been the recipient of many separate HGT events from diverse donors. PMID:18725939

  6. Elusive origins of the extra genes in Aspergillus oryzae.

    Directory of Open Access Journals (Sweden)

    Nora Khaldi

    Full Text Available The genome sequence of Aspergillus oryzae revealed unexpectedly that this species has approximately 20% more genes than its congeneric species A. nidulans and A. fumigatus. Where did these extra genes come from? Here, we evaluate several possible causes of the elevated gene number. Many gene families are expanded in A. oryzae relative to A. nidulans and A. fumigatus, but we find no evidence of ancient whole-genome duplication or other segmental duplications, either in A. oryzae or in the common ancestor of the genus Aspergillus. We show that the presence of divergent pairs of paralogs is a feature peculiar to A. oryzae and is not shared with A. nidulans or A. fumigatus. In phylogenetic trees that include paralog pairs from A. oryzae, we frequently find that one of the genes in a pair from A. oryzae has the expected orthologous relationship with A. nidulans, A. fumigatus and other species in the subphylum Eurotiomycetes, whereas the other A. oryzae gene falls outside this clade but still within the Ascomycota. We identified 456 such gene pairs in A. oryzae. Further phylogenetic analysis did not however indicate a single consistent evolutionary origin for the divergent members of these pairs. Approximately one-third of them showed phylogenies that are suggestive of horizontal gene transfer (HGT from Sordariomycete species, and these genes are closer together in the A. oryzae genome than expected by chance, but no unique Sordariomycete donor species was identifiable. The postulated HGTs from Sordariomycetes still leave the majority of extra A. oryzae genes unaccounted for. One possible explanation for our observations is that A. oryzae might have been the recipient of many separate HGT events from diverse donors.

  7. Horizontal transfer of a subtilisin gene from plants into an ancestor of the plant pathogenic fungal genus Colletotrichum.

    Science.gov (United States)

    Armijos Jaramillo, Vinicio Danilo; Vargas, Walter Alberto; Sukno, Serenella Ana; Thon, Michael R

    2013-01-01

    The genus Colletotrichum contains a large number of phytopathogenic fungi that produce enormous economic losses around the world. The effect of horizontal gene transfer (HGT) has not been studied yet in these organisms. Inter-Kingdom HGT into fungal genomes has been reported in the past but knowledge about the HGT between plants and fungi is particularly limited. We describe a gene in the genome of several species of the genus Colletotrichum with a strong resemblance to subtilisins typically found in plant genomes. Subtilisins are an important group of serine proteases, widely distributed in all of the kingdoms of life. Our hypothesis is that the gene was acquired by Colletotrichum spp. through (HGT) from plants to a Colletotrichum ancestor. We provide evidence to support this hypothesis in the form of phylogenetic analyses as well as a characterization of the similarity of the subtilisin at the primary, secondary and tertiary structural levels. The remarkable level of structural conservation of Colletotrichum plant-like subtilisin (CPLS) with plant subtilisins and the differences with the rest of Colletotrichum subtilisins suggests the possibility of molecular mimicry. Our phylogenetic analysis indicates that the HGT event would have occurred approximately 150-155 million years ago, after the divergence of the Colletotrichum lineage from other fungi. Gene expression analysis shows that the gene is modulated during the infection of maize by C. graminicola suggesting that it has a role in plant disease. Furthermore, the upregulation of the CPLS coincides with the downregulation of several plant genes encoding subtilisins. Based on the known roles of subtilisins in plant pathogenic fungi and the gene expression pattern that we observed, we postulate that the CPLSs have an important role in plant infection.

  8. A guide to ancient protein studies

    DEFF Research Database (Denmark)

    Hendy, Jessica; Welker, Frido; Demarchi, Beatrice

    2018-01-01

    Palaeoproteomics is an emerging neologism used to describe the application of mass spectrometry-based approaches to the study of ancient proteomes. As with palaeogenomics (the study of ancient DNA), it intersects evolutionary biology, archaeology and anthropology, with applications ranging from....... Additionally, in contrast to the ancient DNA community, no consolidated guidelines have been proposed by which researchers, reviewers and editors can evaluate palaeoproteomics data, in part due to the novelty of the field. Here we present a series of precautions and standards for ancient protein research...

  9. Aiding the Interpretation of Ancient Documents

    DEFF Research Database (Denmark)

    Roued-Cunliffe, Henriette

    How can Decision Support System (DSS) software aid the interpretation process involved in the reading of ancient documents? This paper discusses the development of a DSS prototype for the reading of ancient texts. In this context the term ‘ancient documents’ is used to describe mainly Greek...... tool it is important first to comprehend the interpretation process involved in reading ancient documents. This is not a linear process but rather a recursive process where the scholar moves between different levels of reading, such as ‘understanding the meaning of a character’ or ‘understanding...

  10. Medicine in Ancient Assur

    DEFF Research Database (Denmark)

    Arbøll, Troels Pank

    This dissertation is a microhistorical study of a single individual named Kiṣir-Aššur who practiced medicine in the ancient city of Assur (modern northern Iraq) in the 7th century BCE. The study provides the first detailed analysis of one healer’s education and practice in ancient Mesopotamia...

  11. The eye and its diseases in Ancient Egypt

    DEFF Research Database (Denmark)

    Andersen, S. Ry

    1997-01-01

    Ophthalmology, History of ophthalmology, eyes in the Ancient Egypt, eye disease in Ancient Egypt, porotic hyperostosis, mummification......Ophthalmology, History of ophthalmology, eyes in the Ancient Egypt, eye disease in Ancient Egypt, porotic hyperostosis, mummification...

  12. Ancient Chinese Precedents in China

    National Research Council Canada - National Science Library

    Geddis, Robert

    1999-01-01

    ... classics from ancient china. The assumption is that since China's political and military leaders state openly that their strategy is based on traditional Chinese strategic concepts, a study of ancient classics on strategy...

  13. Trans-kingdom horizontal DNA transfer from bacteria to yeast is highly plastic due to natural polymorphisms in auxiliary nonessential recipient genes.

    Directory of Open Access Journals (Sweden)

    Kazuki Moriguchi

    Full Text Available With the rapid accumulation of genomic information from various eukaryotes in the last decade, genes proposed to have been derived from recent horizontal gene transfer (HGT events have been reported even in non-phagotrophic unicellular and multicellular organisms, but the molecular pathways underlying HGT remain to be explained. The development of in vitro HGT detection systems, which permit the molecular and genetic analyses of donor and recipient organisms and quantify HGT, are helpful in order to gain insight into mechanisms that may contribute to contemporary HGT events or may have contributed to past HGT events. We applied a horizontal DNA transfer system model based on conjugal gene transfer called trans-kingdom conjugation (TKC from the prokaryote Escherichia coli to the eukaryote Saccharomyces cerevisiae, and assessed whether and to what extent genetic variations in the eukaryotic recipient affect its receptivity to TKC. Strains from a collection of 4,823 knock-out mutants of S. cerevisiae MAT-α haploids were tested for their individual TKC receptivity. Two types of mutants, an ssd1 mutant and respiratory mutants, which are also found in experimental strains and in nature widely, were identified as highly receptive mutants. The TKC efficiency for spontaneously accrued petite (rho (-/0 mutants of the functional allele (SSD1-V strain showed increased receptivity. The TKC efficiency of the ssd1Δ mutant was 36% for bacterial conjugation, while that of the petite/ssd1Δ double mutants was even higher (220% in average compared to bacterial conjugation. This increased TKC receptivity was also observed when other conjugal transfer systems were applied and the donor bacterium was changed to Agrobacterium tumefaciens. These results support the idea that the genomes of certain eukaryotes have been exposed to exogenous DNA more frequently and continuously than previously thought.

  14. Molecular evidence for ongoing complementarity and horizontal gene transfer in endosymbiotic systems of mealybugs

    Directory of Open Access Journals (Sweden)

    Sergio eLópez-Madrigal

    2014-08-01

    Full Text Available Intracellular bacterial supply of essential amino acids is common among sap-feeding insects, thus complementing the scarcity of nitrogenous compounds in plant phloem. This is also the role of the two mealybug endosymbiotic systems whose genomes have been sequenced. In the nested endosymbiotic system from Planococcus citri (Pseudococcinae, Candidatus Tremblaya princeps and Candidatus Moranella endobia cooperate to synthesize essential amino acids, while in Phenacoccus avenae (Phenacoccinae this function is performed by its single endosymbiont Candidatus Tremblaya phenacola. However, little is known regarding the evolution of essential amino acid supplementation strategies in other mealybug systems. To address this knowledge gap, we screened for the presence of six selected loci involved in essential amino acid biosynthesis in five additional mealybug species. We found evidence of ongoing complementarity among endosymbionts from insects of subfamily Pseudococcinae, as well as horizontal gene transfer affecting endosymbionts from insects of family Phenacoccinae, providing a more comprehensive picture of the evolutionary history of these endosymbiotic systems. Additionally, we report two diagnostic motifs to help identify invasive mealybug species.

  15. Evolutionary novelty in gravity sensing through horizontal gene transfer and high-order protein assembly.

    Directory of Open Access Journals (Sweden)

    Tu Anh Nguyen

    2018-04-01

    Full Text Available Horizontal gene transfer (HGT can promote evolutionary adaptation by transforming a species' relationship to the environment. In most well-understood cases of HGT, acquired and donor functions appear to remain closely related. Thus, the degree to which HGT can lead to evolutionary novelties remains unclear. Mucorales fungi sense gravity through the sedimentation of vacuolar protein crystals. Here, we identify the octahedral crystal matrix protein (OCTIN. Phylogenetic analysis strongly supports acquisition of octin by HGT from bacteria. A bacterial OCTIN forms high-order periplasmic oligomers, and inter-molecular disulphide bonds are formed by both fungal and bacterial OCTINs, suggesting that they share elements of a conserved assembly mechanism. However, estimated sedimentation velocities preclude a gravity-sensing function for the bacterial structures. Together, our data suggest that HGT from bacteria into the Mucorales allowed a dramatic increase in assembly scale and emergence of the gravity-sensing function. We conclude that HGT can lead to evolutionary novelties that emerge depending on the physiological and cellular context of protein assembly.

  16. Dwarfs in ancient Egypt.

    Science.gov (United States)

    Kozma, Chahira

    2006-02-15

    Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities. Copyright (c) 2005 Wiley-Liss, Inc.

  17. Horizontal gene transfer and bacterial diversity

    Indian Academy of Sciences (India)

    Unknown

    This review discusses how the recent influx of complete chromosomal sequences of various ... enteric bacteria, a great deal of phenotypic diversity among species is ..... E V 1998 Evidence for massive gene exchange between archaeal and ...

  18. Horizontal transmission of malignancy: in-vivo fusion of human lymphomas with hamster stroma produces tumors retaining human genes and lymphoid pathology.

    Directory of Open Access Journals (Sweden)

    David M Goldenberg

    Full Text Available We report the in-vivo fusion of two Hodgkin lymphomas with golden hamster cheek pouch cells, resulting in serially-transplanted (over 5-6 years GW-532 and GW-584 heterosynkaryon tumor cells displaying both human and hamster DNA (by FISH, lymphoma-like morphology, aggressive metastasis, and retention of 7 human genes (CD74, CXCR4, CD19, CD20, CD71, CD79b, and VIM out of 24 tested by PCR. The prevalence of B-cell restricted genes (CD19, CD20, and CD79b suggests that this uniform population may be the clonal initiating (malignant cells of Hodgkin lymphoma, despite their not showing translation to their respective proteins by immunohistochemical analysis. This is believed to be the first report of in-vivo cell-cell fusion of human lymphoma and rodent host cells, and may be a method to disclose genes regulating both organoid and metastasis signatures, suggesting that the horizontal transfer of tumor DNA to adjacent stromal cells may be implicated in tumor heterogeneity and progression. The B-cell gene signature of the hybrid xenografts suggests that Hodgkin lymphoma, or its initiating cells, is a B-cell malignancy.

  19. Toward a new history and geography of human genes informed by ancient DNA.

    Science.gov (United States)

    Pickrell, Joseph K; Reich, David

    2014-09-01

    Genetic information contains a record of the history of our species, and technological advances have transformed our ability to access this record. Many studies have used genome-wide data from populations today to learn about the peopling of the globe and subsequent adaptation to local conditions. Implicit in this research is the assumption that the geographic locations of people today are informative about the geographic locations of their ancestors in the distant past. However, it is now clear that long-range migration, admixture, and population replacement subsequent to the initial out-of-Africa expansion have altered the genetic structure of most of the world's human populations. In light of this we argue that it is time to critically reevaluate current models of the peopling of the globe, as well as the importance of natural selection in determining the geographic distribution of phenotypes. We specifically highlight the transformative potential of ancient DNA. By accessing the genetic make-up of populations living at archaeologically known times and places, ancient DNA makes it possible to directly track migrations and responses to natural selection. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Ancient Biomolecules and Evolutionary Inference

    DEFF Research Database (Denmark)

    Cappellini, Enrico; Prohaska, Ana; Racimo, Fernando

    2018-01-01

    Over the last decade, studies of ancient biomolecules-particularly ancient DNA, proteins, and lipids-have revolutionized our understanding of evolutionary history. Though initially fraught with many challenges, the field now stands on firm foundations. Researchers now successfully retrieve nucleo...

  1. EuGI: a novel resource for studying genomic islands to facilitate horizontal gene transfer detection in eukaryotes.

    Science.gov (United States)

    Clasen, Frederick Johannes; Pierneef, Rian Ewald; Slippers, Bernard; Reva, Oleg

    2018-05-03

    Genomic islands (GIs) are inserts of foreign DNA that have potentially arisen through horizontal gene transfer (HGT). There are evidences that GIs can contribute significantly to the evolution of prokaryotes. The acquisition of GIs through HGT in eukaryotes has, however, been largely unexplored. In this study, the previously developed GI prediction tool, SeqWord Gene Island Sniffer (SWGIS), is modified to predict GIs in eukaryotic chromosomes. Artificial simulations are used to estimate ratios of predicting false positive and false negative GIs by inserting GIs into different test chromosomes and performing the SWGIS v2.0 algorithm. Using SWGIS v2.0, GIs are then identified in 36 fungal, 22 protozoan and 8 invertebrate genomes. SWGIS v2.0 predicts GIs in large eukaryotic chromosomes based on the atypical nucleotide composition of these regions. Averages for predicting false negative and false positive GIs were 20.1% and 11.01% respectively. A total of 10,550 GIs were identified in 66 eukaryotic species with 5299 of these GIs coding for at least one functional protein. The EuGI web-resource, freely accessible at http://eugi.bi.up.ac.za , was developed that allows browsing the database created from identified GIs and genes within GIs through an interactive and visual interface. SWGIS v2.0 along with the EuGI database, which houses GIs identified in 66 different eukaryotic species, and the EuGI web-resource, provide the first comprehensive resource for studying HGT in eukaryotes.

  2. Ancient and Current Chaos Theories

    Directory of Open Access Journals (Sweden)

    Güngör Gündüz

    2006-07-01

    Full Text Available Chaos theories developed in the last three decades have made very important contributions to our understanding of dynamical systems and natural phenomena. The meaning of chaos in the current theories and in the past is somewhat different from each other. In this work, the properties of dynamical systems and the evolution of chaotic systems were discussed in terms of the views of ancient philosophers. The meaning of chaos in Anaximenes’ philosophy and its role in the Ancient natural philosophy has been discussed in relation to other natural philosophers such as of Anaximander, Parmenides, Heraclitus, Empedocles, Leucippus (i.e. atomists and Aristotle. In addition, the fundamental concepts of statistical mechanics and the current chaos theories were discussed in relation to the views in Ancient natural philosophy. The roots of the scientific concepts such as randomness, autocatalysis, nonlinear growth, information, pattern, etc. in the Ancient natural philosophy were investigated.

  3. Lightning-triggered electroporation and electrofusion as possible contributors to natural horizontal gene transfer.

    Science.gov (United States)

    Kotnik, Tadej

    2013-09-01

    Phylogenetic studies show that horizontal gene transfer (HGT) is a significant contributor to genetic variability of prokaryotes, and was perhaps even more abundant during the early evolution. Hitherto, research of natural HGT has mainly focused on three mechanisms of DNA transfer: conjugation, natural competence, and viral transduction. This paper discusses the feasibility of a fourth such mechanism--cell electroporation and/or electrofusion triggered by atmospheric electrostatic discharges (lightnings). A description of electroporation as a phenomenon is followed by a review of experimental evidence that electroporation of prokaryotes in aqueous environments can result in release of non-denatured DNA, as well as uptake of DNA from the surroundings and transformation. Similarly, a description of electrofusion is followed by a review of experiments showing that prokaryotes devoid of cell wall can electrofuse into hybrids expressing the genes of their both precursors. Under sufficiently fine-tuned conditions, electroporation and electrofusion are efficient tools for artificial transformation and hybridization, respectively, but the quantitative analysis developed here shows that conditions for electroporation-based DNA release, DNA uptake and transformation, as well as for electrofusion are also present in many natural aqueous environments exposed to lightnings. Electroporation is thus a plausible contributor to natural HGT among prokaryotes, and could have been particularly important during the early evolution, when the other mechanisms might have been scarcer or nonexistent. In modern prokaryotes, natural absence of the cell wall is rare, but it is reasonable to assume that the wall has formed during a certain stage of evolution, and at least prior to this, electrofusion could also have contributed to natural HGT. The concluding section outlines several guidelines for assessment of the feasibility of lightning-triggered HGT. © 2013 Elsevier B.V. All rights

  4. Classification of ancient mammal individuals using dental pulp MALDI-TOF MS peptide profiling.

    Directory of Open Access Journals (Sweden)

    Thi-Nguyen-Ny Tran

    Full Text Available BACKGROUND: The classification of ancient animal corpses at the species level remains a challenging task for forensic scientists and anthropologists. Severe damage and mixed, tiny pieces originating from several skeletons may render morphological classification virtually impossible. Standard approaches are based on sequencing mitochondrial and nuclear targets. METHODOLOGY/PRINCIPAL FINDINGS: We present a method that can accurately classify mammalian species using dental pulp and mass spectrometry peptide profiling. Our work was organized into three successive steps. First, after extracting proteins from the dental pulp collected from 37 modern individuals representing 13 mammalian species, trypsin-digested peptides were used for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. The resulting peptide profiles accurately classified every individual at the species level in agreement with parallel cytochrome b gene sequencing gold standard. Second, using a 279-modern spectrum database, we blindly classified 33 of 37 teeth collected in 37 modern individuals (89.1%. Third, we classified 10 of 18 teeth (56% collected in 15 ancient individuals representing five mammal species including human, from five burial sites dating back 8,500 years. Further comparison with an upgraded database comprising ancient specimen profiles yielded 100% classification in ancient teeth. Peptide sequencing yield 4 and 16 different non-keratin proteins including collagen (alpha-1 type I and alpha-2 type I in human ancient and modern dental pulp, respectively. CONCLUSIONS/SIGNIFICANCE: Mass spectrometry peptide profiling of the dental pulp is a new approach that can be added to the arsenal of species classification tools for forensics and anthropology as a complementary method to DNA sequencing. The dental pulp is a new source for collagen and other proteins for the species classification of modern and ancient mammal individuals.

  5. Classification of Ancient Mammal Individuals Using Dental Pulp MALDI-TOF MS Peptide Profiling

    Science.gov (United States)

    Tran, Thi-Nguyen-Ny; Aboudharam, Gérard; Gardeisen, Armelle; Davoust, Bernard; Bocquet-Appel, Jean-Pierre; Flaudrops, Christophe; Belghazi, Maya; Raoult, Didier; Drancourt, Michel

    2011-01-01

    Background The classification of ancient animal corpses at the species level remains a challenging task for forensic scientists and anthropologists. Severe damage and mixed, tiny pieces originating from several skeletons may render morphological classification virtually impossible. Standard approaches are based on sequencing mitochondrial and nuclear targets. Methodology/Principal Findings We present a method that can accurately classify mammalian species using dental pulp and mass spectrometry peptide profiling. Our work was organized into three successive steps. First, after extracting proteins from the dental pulp collected from 37 modern individuals representing 13 mammalian species, trypsin-digested peptides were used for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. The resulting peptide profiles accurately classified every individual at the species level in agreement with parallel cytochrome b gene sequencing gold standard. Second, using a 279–modern spectrum database, we blindly classified 33 of 37 teeth collected in 37 modern individuals (89.1%). Third, we classified 10 of 18 teeth (56%) collected in 15 ancient individuals representing five mammal species including human, from five burial sites dating back 8,500 years. Further comparison with an upgraded database comprising ancient specimen profiles yielded 100% classification in ancient teeth. Peptide sequencing yield 4 and 16 different non-keratin proteins including collagen (alpha-1 type I and alpha-2 type I) in human ancient and modern dental pulp, respectively. Conclusions/Significance Mass spectrometry peptide profiling of the dental pulp is a new approach that can be added to the arsenal of species classification tools for forensics and anthropology as a complementary method to DNA sequencing. The dental pulp is a new source for collagen and other proteins for the species classification of modern and ancient mammal individuals. PMID:21364886

  6. The house spider genome reveals an ancient whole-genome duplication during arachnid evolution.

    Science.gov (United States)

    Schwager, Evelyn E; Sharma, Prashant P; Clarke, Thomas; Leite, Daniel J; Wierschin, Torsten; Pechmann, Matthias; Akiyama-Oda, Yasuko; Esposito, Lauren; Bechsgaard, Jesper; Bilde, Trine; Buffry, Alexandra D; Chao, Hsu; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dugan, Shannon; Eibner, Cornelius; Extavour, Cassandra G; Funch, Peter; Garb, Jessica; Gonzalez, Luis B; Gonzalez, Vanessa L; Griffiths-Jones, Sam; Han, Yi; Hayashi, Cheryl; Hilbrant, Maarten; Hughes, Daniel S T; Janssen, Ralf; Lee, Sandra L; Maeso, Ignacio; Murali, Shwetha C; Muzny, Donna M; Nunes da Fonseca, Rodrigo; Paese, Christian L B; Qu, Jiaxin; Ronshaugen, Matthew; Schomburg, Christoph; Schönauer, Anna; Stollewerk, Angelika; Torres-Oliva, Montserrat; Turetzek, Natascha; Vanthournout, Bram; Werren, John H; Wolff, Carsten; Worley, Kim C; Bucher, Gregor; Gibbs, Richard A; Coddington, Jonathan; Oda, Hiroki; Stanke, Mario; Ayoub, Nadia A; Prpic, Nikola-Michael; Flot, Jean-François; Posnien, Nico; Richards, Stephen; McGregor, Alistair P

    2017-07-31

    The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.

  7. Effect of Duplicate Genes on Mouse Genetic Robustness: An Update

    Directory of Open Access Journals (Sweden)

    Zhixi Su

    2014-01-01

    Full Text Available In contrast to S. cerevisiae and C. elegans, analyses based on the current knockout (KO mouse phenotypes led to the conclusion that duplicate genes had almost no role in mouse genetic robustness. It has been suggested that the bias of mouse KO database toward ancient duplicates may possibly cause this knockout duplicate puzzle, that is, a very similar proportion of essential genes (PE between duplicate genes and singletons. In this paper, we conducted an extensive and careful analysis for the mouse KO phenotype data and corroborated a strong effect of duplicate genes on mouse genetics robustness. Moreover, the effect of duplicate genes on mouse genetic robustness is duplication-age dependent, which holds after ruling out the potential confounding effect from coding-sequence conservation, protein-protein connectivity, functional bias, or the bias of duplicates generated by whole genome duplication (WGD. Our findings suggest that two factors, the sampling bias toward ancient duplicates and very ancient duplicates with a proportion of essential genes higher than that of singletons, have caused the mouse knockout duplicate puzzle; meanwhile, the effect of genetic buffering may be correlated with sequence conservation as well as protein-protein interactivity.

  8. Horizontal antimicrobial resistance transfer drives epidemics of multiple Shigella species.

    Science.gov (United States)

    Baker, Kate S; Dallman, Timothy J; Field, Nigel; Childs, Tristan; Mitchell, Holly; Day, Martin; Weill, François-Xavier; Lefèvre, Sophie; Tourdjman, Mathieu; Hughes, Gwenda; Jenkins, Claire; Thomson, Nicholas

    2018-04-13

    Horizontal gene transfer has played a role in developing the global public health crisis of antimicrobial resistance (AMR). However, the dynamics of AMR transfer through bacterial populations and its direct impact on human disease is poorly elucidated. Here, we study parallel epidemic emergences of multiple Shigella species, a priority AMR organism, in men who have sex with men to gain insight into AMR emergence and spread. Using genomic epidemiology, we show that repeated horizontal transfer of a single AMR plasmid among Shigella enhanced existing and facilitated new epidemics. These epidemic patterns contrasted with slighter, slower increases in disease caused by organisms with vertically inherited (chromosomally encoded) AMR. This demonstrates that horizontal transfer of AMR directly affects epidemiological outcomes of globally important AMR pathogens and highlights the need for integration of genomic analyses into all areas of AMR research, surveillance and management.

  9. Radiocarbon dating of ancient Japanese documents

    International Nuclear Information System (INIS)

    Oda, H.

    2001-01-01

    History is a reconstruction of past human activity, evidence of which is remained in the form of documents or relics. For the reconstruction of historic period, the radiocarbon dating of ancient documents provides important information. Although radiocarbon age is converted into calendar age with the calibration curve, the calibrated radiocarbon age is still different from the historical age when the document was written. The difference is known as 'old wood effect' for wooden cultural property. The discrepancy becomes more serious problem for recent sample which requires more accurate age determination. Using Tandetron accelerator mass spectrometer at Nagoya University, we have measured radiocarbon ages of Japanese ancient documents, sutras and printed books written dates of which are clarified from the paleographic standpoint. The purpose is to clarify the relation between calibrated radiocarbon age and historical age of ancient Japanese document by AMS radiocarbon dating. This paper reports 23 radiocarbon ages of ancient Japanese documents, sutras and printed books. The calibrated radiocarbon ages are in good agreement with the corresponding historical ages. It was shown by radiocarbon dating of the ancient documents that Japanese paper has little gap by 'old wood effect'; accordingly, ancient Japanese paper is a suitable sample for radiocarbon dating of recent historic period. (author)

  10. Antibiotic Resistance Genetic Markers and Integrons in White Soft Cheese: Aspects of Clinical Resistome and Potentiality of Horizontal Gene Transfer.

    Science.gov (United States)

    de Paula, Ana Caroline L; Medeiros, Julliane D; de Azevedo, Analice C; de Assis Chagas, Jéssica M; da Silva, Vânia L; Diniz, Cláudio G

    2018-02-19

    Antibiotic resistance poses an important threat to global public health and has become a challenge to modern medicine. The occurrence of antibiotic-resistant bacteria in a broad range of foods has led to a growing concern about the impact that food may have as a reservoir of antibiotic resistance genes. Considering Minas Frescal Cheese (MFC)-a typical Brazilian white soft cheese-and its economic and cultural values, in this study, medically relevant antimicrobial-resistance genetic markers (AR genes) were screened, and the occurrence of integrons were evaluated in manufactured MFC using culture-independent approaches. Through a fingerprinting analysis, the tested MFCs were brand-clustered, indicating reproducibility along the production chain. A common core of resistance markers in all brands evaluated and related antimicrobials such as β-lactams, tetracyclines, quinolones, and sulfonamide was detected. Several other markers, including efflux pumps and aminoglycosides-resistance were distributed among brands. Class 1 and 2 integrons were observed, respectively, in 77% and 97% of the samples. The presence of AR genes is of special interest due to their clinical relevance. Taken together, the data may suggest that the production chain of MFC might contribute to the spread of putative drug-resistant bacteria, which could greatly impact human health. Furthermore, detection of class 1 and class 2 integrons in MFC has led to discussions about resistance gene spread in this traditional cheese, providing evidence of potential horizontal transfer of AR genes to human gut microbiota.

  11. Antibiotic Resistance Genetic Markers and Integrons in White Soft Cheese: Aspects of Clinical Resistome and Potentiality of Horizontal Gene Transfer

    Directory of Open Access Journals (Sweden)

    Ana Caroline L. de Paula

    2018-02-01

    Full Text Available Antibiotic resistance poses an important threat to global public health and has become a challenge to modern medicine. The occurrence of antibiotic-resistant bacteria in a broad range of foods has led to a growing concern about the impact that food may have as a reservoir of antibiotic resistance genes. Considering Minas Frescal Cheese (MFC—a typical Brazilian white soft cheese—and its economic and cultural values, in this study, medically relevant antimicrobial-resistance genetic markers (AR genes were screened, and the occurrence of integrons were evaluated in manufactured MFC using culture-independent approaches. Through a fingerprinting analysis, the tested MFCs were brand-clustered, indicating reproducibility along the production chain. A common core of resistance markers in all brands evaluated and related antimicrobials such as β-lactams, tetracyclines, quinolones, and sulfonamide was detected. Several other markers, including efflux pumps and aminoglycosides-resistance were distributed among brands. Class 1 and 2 integrons were observed, respectively, in 77% and 97% of the samples. The presence of AR genes is of special interest due to their clinical relevance. Taken together, the data may suggest that the production chain of MFC might contribute to the spread of putative drug-resistant bacteria, which could greatly impact human health. Furthermore, detection of class 1 and class 2 integrons in MFC has led to discussions about resistance gene spread in this traditional cheese, providing evidence of potential horizontal transfer of AR genes to human gut microbiota.

  12. Authenticity in ancient DNA studies

    DEFF Research Database (Denmark)

    Gilbert, M Thomas P; Willerslev, Eske

    2006-01-01

    Ancient DNA studies represent a powerful tool that can be used to obtain genetic insights into the past. However, despite the publication of large numbers of apparently successful ancient DNA studies, a number of problems exist with the field that are often ignored. Therefore, questions exist as ...

  13. The History and Practice of Ancient Astronomy

    CERN Document Server

    Evans, James

    1998-01-01

    The History and Practice of Ancient Astronomy combines new scholarship with hands-on science to bring readers into direct contact with the work of ancient astronomers. While tracing ideas from ancient Babylon to sixteenth-century Europe, the book places its greatest emphasis on the Greek period, when astronomers developed the geometric and philosophical ideas that have determined the subsequent character of Western astronomy. The author approaches this history through the concrete details of ancient astronomical practice. Carefully organized and generously illustrated, the book can teach reade

  14. An investigation into the ancient abortion laws: comparing ancient Persia with ancient Greece and Rome.

    Science.gov (United States)

    Yarmohammadi, Hassan; Zargaran, Arman; Vatanpour, Azadeh; Abedini, Ehsan; Adhami, Siamak

    2013-01-01

    Since the dawn of medicine, medical rights and ethics have always been one of mankind's concerns. In any civilisation, attention paid to medical laws and ethics depends on the progress of human values and the advancement of medical science. The history of various civilisations teaches that each had its own views on medical ethics, but most had something in common. Ancient civilisations such as Greece, Rome, or Assyria did not consider the foetus to be alive and therefore to have human rights. In contrast, ancient Persians valued the foetus as a living person equal to others. Accordingly, they brought laws against abortion, even in cases of sexual abuse. Furthermore, abortion was considered to be a murder and punishments were meted out to the mother, father, and the person performing it.

  15. The Ancient Greece's roots of Olimpism

    Directory of Open Access Journals (Sweden)

    Bubka Sergej Nazarovich

    2011-10-01

    Full Text Available The paper focused on the phenomena of sport in Ancient Greece along with history, traditions, religion, education, culture and art. Economic and political conditions are analysed which promote or hamper development of Olympic Games in Ancient Greece. Exceptional stability of Ancient Olympic games during more than eleven centuries are noted as well as their influence on the life of Greek polices of those days. Hellenistic period needs of individual consideration.

  16. Urology and the scientific method in ancient Egypt.

    Science.gov (United States)

    Gordetsky, Jennifer; O'Brien, Jeanne

    2009-03-01

    To examine the practice of urology in ancient Egypt using various sources, including the Edwin Smith and Ebers Papyri. The sources of knowledge of ancient Egyptian medicine include medical papyri, paleopathology, art, and hieroglyphic carvings. A brief overview of the medical system in ancient Egypt was completed, in addition to an examination of the training and specialization of the physician in the ancient world. Urologic diseases treated in ancient Egypt and some of the first documented urologic surgeries are presented. Finally, we studied the role of the physician-priest and the intertwined use of religion and magic in ancient Egyptian medicine. The same medical conditions urologists treat in the office today were methodically documented thousands of years ago. Medical papyri show evidence that the ancient Egyptians practiced medicine using a scientific method based on the clinical observation of disease. This has been exemplified by the Edwin Smith Surgical Papyrus, a collection of surgical cases that gives a diagnosis, treatment, and prognosis for each ailment, and the discovery of medical specialization in ancient Egypt, giving us perhaps the world's first urologists. Intertwined with the scientific method was also the rich mysticism and religion of ancient Egypt, which were integral components of the healing process. We present an overview of the practice of urology in ancient Egypt, in terms of both pharmacologic and surgical intervention, as well as with a look into the religion of medicine practiced at that time.

  17. Sobre el papel del sistema SOS, la recombinación y el intercambio horizontal de genes en la evolución bacteriana

    OpenAIRE

    Rodríguez Beltrán, Jerónimo

    2015-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 06-11-2015 El principal objetivo de esta tesis ha sido cuantificar y ampliar el conocimiento sobre los diferentes sistemas evolutivos implicados en el control de la tasa adaptativa en los seres vivos, usando para ello la bacteria modelo E. coli. La mutación, la recombinación y la transferencia horizontal de genes son los mecanismos más prominentes d...

  18. Genome Comparison of Erythromycin Resistant Campylobacter from Turkeys Identifies Hosts and Pathways for Horizontal Spread of erm(B Genes

    Directory of Open Access Journals (Sweden)

    Diego Florez-Cuadrado

    2017-11-01

    Full Text Available Pathogens in the genus Campylobacter are the most common cause of food-borne bacterial gastro-enteritis. Campylobacteriosis, caused principally by Campylobacter jejuni and Campylobacter coli, is transmitted to humans by food of animal origin, especially poultry. As for many pathogens, antimicrobial resistance in Campylobacter is increasing at an alarming rate. Erythromycin prescription is the treatment of choice for clinical cases requiring antimicrobial therapy but this is compromised by mobility of the erythromycin resistance gene erm(B between strains. Here, we evaluate resistance to six antimicrobials in 170 Campylobacter isolates (133 C. coli and 37 C. jejuni from turkeys. Erythromycin resistant isolates (n = 85; 81 C. coli and 4 C. jejuni were screened for the presence of the erm(B gene, that has not previously been identified in isolates from turkeys. The genomes of two positive C. coli isolates were sequenced and in both isolates the erm(B gene clustered with resistance determinants against aminoglycosides plus tetracycline, including aad9, aadE, aph(2″-IIIa, aph(3′-IIIa, and tet(O genes. Comparative genomic analysis identified identical erm(B sequences among Campylobacter from turkeys, Streptococcus suis from pigs and Enterococcus faecium and Clostridium difficile from humans. This is consistent with multiple horizontal transfer events among different bacterial species colonizing turkeys. This example highlights the potential for dissemination of antimicrobial resistance across bacterial species boundaries which may compromise their effectiveness in antimicrobial therapy.

  19. Science and Library in the Ancient Age

    Directory of Open Access Journals (Sweden)

    Hasan Sacit Keseroğlu

    2016-09-01

    Full Text Available Science assumes its contemporary identity as a result of the stages of magic, religion and reason. The religious stage starts with the invention of writing and this stage leaves its place to reason with Thales in Ancient Greece. Knowledge eludes from religious beliefs. Ways to reach accurate, reliable and realistic knowledge are sought, along with the answer for what knowledge is. Therefore, beginning of the science is taken into consideration together with science and philosophy. The purpose of this study is to approach knowledge and science of the ancient age in Mesopotamia, Egypt and Ancient Greece in general terms and to determine the relationship between the knowledge produced in those places and libraries established. The hypothesis has been determined as “Egypt and Mesopotamia at the starting point of the history of science and science, and libraries in Ancient Greece have developed parallelly to each other.” The scope of the study has been limited to Mesopotamia, Egypt and Ancient Greece; and Ancient Greece has been explained, with descriptive method, in the frame of the topics of Ionia, Athens, Hellenistic Period and Rome. Many archives and libraries have been established in the ancient age. The difference between an archive and a library has been mentioned first, and then, various libraries have been introduced such as Nineveh in Mesopotamia, Alexandria in Ancient Greece and many others in Egypt. It has been clearly distinguished that there had been a very tight relationship between knowledge production and library, especially with the Library of Alexandria.

  20. Paleo-Environmental Reconstruction Using Ancient DNA

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Winther

    The aim of this thesis has been to investigate and expand the methodology and applicability for using ancient DNA deposited in lake sediments to detect and determine its genetic sources for paleo-environmental reconstruction. The aim was furthermore to put this tool into an applicable context...... solving other scientifically interesting questions. Still in its childhood, ancient environmental DNA research has a large potential for still developing, improving and discovering its possibilities and limitations in different environments and for identifying various organisms, both in terms...... research on ancient and modern environmental DNA (Paper 1), secondly by setting up a comparative study (Paper 2) to investigate how an ancient plant DNA (mini)-barcode can reflect other traditional methods (e.g. pollen and macrofossils) for reconstructing floristic history. In prolongation of the results...

  1. AN INTERESTING CASE OF ANCIENT SCHWANNOMA

    Directory of Open Access Journals (Sweden)

    Binu

    2015-01-01

    Full Text Available INTRODUCTION : Schwannoma is a common benign tumour of nerve sheath. Degenerating type of schwannoma is called ancient schwannoma. Ancient schwannomas of scalp are rare and are often misdiagnosed as sebaceous cyst or dermoid cyst. CASE REPORT : We present a thirty two year old male presented with scalp swel ling of eight years duration. X - ray showed no intracranial extension. He underwent excision of the tumour and histopathology was reported as ancient schwannoma. DISCUSSION : Histopathologically , ancient schwannomas charecterised by cellular Antoni type A ar eas and less cellular Antoni type - B areas. 9 th , 7 th , 11 th , 5 th and 4 th cranial nerves are often affected and may be associated with multiple neuro fibramatosis (Von - Recklinghausen’s disease. Impact : Case is presented for its rarity and possible pre - operative misdiagnosis

  2. Inferring Allele Frequency Trajectories from Ancient DNA Indicates That Selection on a Chicken Gene Coincided with Changes in Medieval Husbandry Practices.

    Science.gov (United States)

    Loog, Liisa; Thomas, Mark G; Barnett, Ross; Allen, Richard; Sykes, Naomi; Paxinos, Ptolemaios D; Lebrasseur, Ophélie; Dobney, Keith; Peters, Joris; Manica, Andrea; Larson, Greger; Eriksson, Anders

    2017-08-01

    Ancient DNA provides an opportunity to infer the drivers of natural selection by linking allele frequency changes to temporal shifts in environment or cultural practices. However, analyses have often been hampered by uneven sampling and uncertainties in sample dating, as well as being confounded by demographic processes. Here, we present a Bayesian statistical framework for quantifying the timing and strength of selection using ancient DNA that explicitly addresses these challenges. We applied this method to time series data for two loci: TSHR and BCDO2, both hypothesised to have undergone strong and recent selection in domestic chickens. The derived variant in TSHR, associated with reduced aggression to conspecifics and faster onset of egg laying, shows strong selection beginning around 1,100 years ago, coincident with archaeological evidence for intensified chicken production and documented changes in egg and chicken consumption. To our knowledge, this is the first example of preindustrial domesticate trait selection in response to a historically attested cultural shift in food preference. For BCDO2, we find support for selection, but demonstrate that the recent rise in allele frequency could also have been driven by gene flow from imported Asian chickens during more recent breed formations. Our findings highlight that traits found ubiquitously in modern domestic species may not necessarily have originated during the early stages of domestication. In addition, our results demonstrate the importance of precise estimation of allele frequency trajectories through time for understanding the drivers of selection. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. On Ancient Babylonian Algebra and Geometry

    Indian Academy of Sciences (India)

    ber system prevalent during the ancient Mesopotamian civilization. In this article, we study the ... civilization provides a better insight into the thought processes of the ancient Babylonian mathematicians. In this context, consider the following ...

  4. Recurrent invasion and extinction of a selfish gene.

    Science.gov (United States)

    Goddard, M R; Burt, A

    1999-11-23

    Homing endonuclease genes show super-Mendelian inheritance, which allows them to spread in populations even when they are of no benefit to the host organism. To test the idea that regular horizontal transmission is necessary for the long-term persistence of these genes, we surveyed 20 species of yeasts for the omega-homing endonuclease gene and associated group I intron. The status of omega could be categorized into three states (functional, nonfunctional, or absent), and status was not clustered on the host phylogeny. Moreover, the phylogeny of omega differed significantly from that of the host, strong evidence of horizontal transmission. Further analyses indicate that horizontal transmission is more common than transposition, and that it occurs preferentially between closely related species. Parsimony analysis and coalescent theory suggest that there have been 15 horizontal transmission events in the ancestry of our yeast species, through simulations indicate that this value is probably an underestimate. Overall, the data support a cyclical model of invasion, degeneration, and loss, followed by reinvasion, and each of these transitions is estimated to occur about once every 2 million years. The data are thus consistent with the idea that frequent horizontal transmission is necessary for the long-term persistence of homing endonuclease genes, and further, that this requirement limits these genes to organisms with easily accessible germ lines. The data also show that mitochondrial DNA sequences are transferred intact between yeast species; if other genes do not show such high levels of horizontal transmission, it would be due to lack of selection, rather than lack of opportunity.

  5. Ancient Biomolecules and Evolutionary Inference.

    Science.gov (United States)

    Cappellini, Enrico; Prohaska, Ana; Racimo, Fernando; Welker, Frido; Pedersen, Mikkel Winther; Allentoft, Morten E; de Barros Damgaard, Peter; Gutenbrunner, Petra; Dunne, Julie; Hammann, Simon; Roffet-Salque, Mélanie; Ilardo, Melissa; Moreno-Mayar, J Víctor; Wang, Yucheng; Sikora, Martin; Vinner, Lasse; Cox, Jürgen; Evershed, Richard P; Willerslev, Eske

    2018-04-25

    Over the last decade, studies of ancient biomolecules-particularly ancient DNA, proteins, and lipids-have revolutionized our understanding of evolutionary history. Though initially fraught with many challenges, the field now stands on firm foundations. Researchers now successfully retrieve nucleotide and amino acid sequences, as well as lipid signatures, from progressively older samples, originating from geographic areas and depositional environments that, until recently, were regarded as hostile to long-term preservation of biomolecules. Sampling frequencies and the spatial and temporal scope of studies have also increased markedly, and with them the size and quality of the data sets generated. This progress has been made possible by continuous technical innovations in analytical methods, enhanced criteria for the selection of ancient samples, integrated experimental methods, and advanced computational approaches. Here, we discuss the history and current state of ancient biomolecule research, its applications to evolutionary inference, and future directions for this young and exciting field. Expected final online publication date for the Annual Review of Biochemistry Volume 87 is June 20, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  6. Trepanation in Ancient China.

    Science.gov (United States)

    Hobert, Leah; Binello, Emanuela

    2017-05-01

    Trepanation, the process of making a burr hole in the skull to access the brain, is an ancient form of a primitive craniotomy. There is widespread evidence of contributions made to this practice by ancient civilizations in Europe, Africa, and South America, where archaeologists have unearthed thousands of trepanned skulls dating back to the Neolithic period. Little is known about trepanation in China, and it is commonly believed that the Chinese used only traditional Chinese medicine and nonsurgical methods for treating brain injuries. However, a thorough analysis of the available archeological and literary evidence reveals that trepanation was widely practiced throughout China thousands of years ago. A significant number of trepanned Chinese skulls have been unearthed showing signs of healing and suggesting that patients survived after surgery. Trepanation was likely performed for therapeutic and spiritual reasons. Medical and historical works from Chinese literature contain descriptions of primitive neurosurgical procedures, including stories of surgeons, such as the legendary Hua Tuo, and surgical techniques used for the treatment of brain pathologies. The lack of translation of Chinese reports into the English language and the lack of publications on this topic in the English language may have contributed to the misconception that ancient China was devoid of trepanation. This article summarizes the available evidence attesting to the performance of successful primitive cranial surgery in ancient China. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Mechanisms in ancient Chinese books with illustrations

    CERN Document Server

    Hsiao, Kuo-Hung

    2014-01-01

    This book presents a unique approach for studying mechanisms and machines with drawings that were depicted unclearly in ancient Chinese books. The historical, cultural and technical backgrounds of the mechanisms are explained, and various mechanisms described and illustrated in ancient books are introduced. By utilizing the idea for the conceptual design of modern mechanisms, all feasible designs of ancient mechanisms with uncertain members and joints that meet the technical standards of the subjects’ time periods are synthesized systematically. Ancient Chinese crossbows (the original crossbow and repeating crossbows), textile mechanisms (silk-reeling mechanism, spinning mechanisms, and looms), and many other artisan's tool mechanisms are used as illustrated examples.  Such an approach provides a logical method for the reconstruction designs of ancient mechanisms with uncertain structures. It also provides an innovative direction for researchers to further identify the original structures of mechanisms...

  8. Endocrinology in ancient Sparta.

    Science.gov (United States)

    Tsoulogiannis, Ioannis N; Spandidos, Demetrios A

    2007-01-01

    This article attempts to analyze the crucial link between the plant Agnus castus and human health, particularly hormonal status, with special reference to the needs of the society of ancient Sparta. The ancient Spartans used Agnus both as a cure for infertility and as a remedy to treat battle wounds. These special properties were recognized by the sanctuary of Asclepios Agnita, which was located in Sparta, as well as by medical practitioners in Sparta during the classical, Hellenistic and Roman ages.

  9. Application of neutron activation analysis in study of ancient ceramics

    International Nuclear Information System (INIS)

    Li Guoxia; Zhao Weijuan; Gao Zhengyao; Xie Jianzhong; Huang Zhongxiang; Jia Xiuqin; Han Song

    2000-01-01

    Trace-elements in ancient ceramics and imitative ancient ceramics were determined by neutron activation analysis (NAA). The NAA data are then analyzed by fuzzy cluster method and the trend cluster diagram is obtained. The raw material sources of ancient ceramics and imitative ancient ceramics are determined. The path for improving quality of imitative ancient ceramics is found

  10. Comparative scaffolding and gap filling of ancient bacterial genomes applied to two ancient Yersinia pestis genomes

    Science.gov (United States)

    Doerr, Daniel; Chauve, Cedric

    2017-01-01

    Yersinia pestis is the causative agent of the bubonic plague, a disease responsible for several dramatic historical pandemics. Progress in ancient DNA (aDNA) sequencing rendered possible the sequencing of whole genomes of important human pathogens, including the ancient Y. pestis strains responsible for outbreaks of the bubonic plague in London in the 14th century and in Marseille in the 18th century, among others. However, aDNA sequencing data are still characterized by short reads and non-uniform coverage, so assembling ancient pathogen genomes remains challenging and often prevents a detailed study of genome rearrangements. It has recently been shown that comparative scaffolding approaches can improve the assembly of ancient Y. pestis genomes at a chromosome level. In the present work, we address the last step of genome assembly, the gap-filling stage. We describe an optimization-based method AGapEs (ancestral gap estimation) to fill in inter-contig gaps using a combination of a template obtained from related extant genomes and aDNA reads. We show how this approach can be used to refine comparative scaffolding by selecting contig adjacencies supported by a mix of unassembled aDNA reads and comparative signal. We applied our method to two Y. pestis data sets from the London and Marseilles outbreaks, for which we obtained highly improved genome assemblies for both genomes, comprised of, respectively, five and six scaffolds with 95 % of the assemblies supported by ancient reads. We analysed the genome evolution between both ancient genomes in terms of genome rearrangements, and observed a high level of synteny conservation between these strains. PMID:29114402

  11. Retroviral DNA Sequences as a Means for Determining Ancient Diets.

    Directory of Open Access Journals (Sweden)

    Jessica I Rivera-Perez

    Full Text Available For ages, specialists from varying fields have studied the diets of the primeval inhabitants of our planet, detecting diet remains in archaeological specimens using a range of morphological and biochemical methods. As of recent, metagenomic ancient DNA studies have allowed for the comparison of the fecal and gut microbiomes associated to archaeological specimens from various regions of the world; however the complex dynamics represented in those microbial communities still remain unclear. Theoretically, similar to eukaryote DNA the presence of genes from key microbes or enzymes, as well as the presence of DNA from viruses specific to key organisms, may suggest the ingestion of specific diet components. In this study we demonstrate that ancient virus DNA obtained from coprolites also provides information reconstructing the host's diet, as inferred from sequences obtained from pre-Columbian coprolites. This depicts a novel and reliable approach to determine new components as well as validate the previously suggested diets of extinct cultures and animals. Furthermore, to our knowledge this represents the first description of the eukaryotic viral diversity found in paleofaeces belonging to pre-Columbian cultures.

  12. Geologically ancient DNA: fact or artefact?

    DEFF Research Database (Denmark)

    Hebsgaard, Martin Bay; Phillips, Matthew J.; Willerslev, Eske

    2005-01-01

    Studies continue to report ancient DNA sequences and viable microbial cells that are many millions of years old. In this paper we evaluate some of the most extravagant claims of geologically ancient DNA. We conclude that although exciting, the reports suffer from inadequate experimental setup and...

  13. The conscious of Nightmares in ancient China

    OpenAIRE

    西林, 眞紀子

    2006-01-01

    The analaysis concerns Nightmares in ancient China. People in ancient China were very afraid of Nightmares. Nightmares are described in the『春秋左氏傳』etc. The exocis Nightmares is described in the『周禮』. The ceremony "難" of exocis Nightmares in the『禮記』. In the characters Meng (夢) had the conscious of Nightmares in ancient China. The analaysis is about the characters 'Meng', about the characters of the relationship 'Meng'

  14. Unriddling of ancient-medieval culture by PIXE

    International Nuclear Information System (INIS)

    Uda, M.

    1997-01-01

    Some examples are given for unriddling of ancient-medieval culture by PIXE. Effectiveness of PIXE to analyze art and archaeological objects is also explained. Objects employed here are 1) red, yellow, blue and white pigments painted on sun-dried bricks excavated in Egypt, 2) ancient glass beads used in the Near East, 3) South American mummy hair, 4) ancient slag excavated from Kansai-district, Japan 5) ink used by Galileo Galilei and 6) Renaissance style enameled gold jewelry. (author)

  15. Heavy crude production from shallow formations: long horizontal wells versus horizontal fractures

    Energy Technology Data Exchange (ETDEWEB)

    Valko, P.; Economides, M. J. [Texas A and M Univ., TX (United States)

    1998-12-31

    The feasibility of producing heavy oil from shallow formations using either horizontal wells or short horizontal wells fractured horizontally is demonstrated. The problem of optimum proppant placement is solved in two steps. In step one, the finite productivity performance is considered in general terms showing that the performance is a function of two dimensionless parameters. Following derivation of optimum conditions, the solution is applied to the horizontal fracture consideration. The limiting factor is that to create an effective finite conductivity fracture, the dimensionless fracture conductivity must be on the order of unity, a fracture that is difficult to realize in higher permeability formations. The best candidates for the suggested configuration are shallow or moderate formations, or formations otherwise proven to accept horizontal fractures, and formations with low permeability/viscosity ratio. 7 refs., 2 tabs., 10 figs., 2 appendices.

  16. A Horizontally Transferred Autonomous Helitron Became a Full Polydnavirus Segment in Cotesia vestalis

    Directory of Open Access Journals (Sweden)

    Pedro Heringer

    2017-12-01

    Full Text Available Bracoviruses associate symbiotically with thousands of parasitoid wasp species in the family Braconidae, working as virulence gene vectors, and allowing the development of wasp larvae within hosts. These viruses are composed of multiple DNA circles that are packaged into infective particles, and injected together with wasp’s eggs during parasitization. One of the viral segments of Cotesia vestalis bracovirus contains a gene that has been previously described as a helicase of unknown origin. Here, we demonstrate that this gene is a Rep/Helicase from an intact Helitron transposable element that covers the viral segment almost entirely. We also provide evidence that this element underwent at least two horizontal transfers, which appear to have occurred consecutively: first from a Drosophila host ancestor to the genome of the parasitoid wasp C. vestalis and its bracovirus, and then from C. vestalis to a lepidopteran host (Bombyx mori. Our results reinforce the idea of parasitoid wasps as frequent agents of horizontal transfers in eukaryotes. Additionally, this Helitron-bracovirus segment is the first example of a transposable element that effectively became a whole viral circle.

  17. Sub-inhibitory concentrations of heavy metals facilitate the horizontal transfer of plasmid-mediated antibiotic resistance genes in water environment.

    Science.gov (United States)

    Zhang, Ye; Gu, April Z; Cen, Tianyu; Li, Xiangyang; He, Miao; Li, Dan; Chen, Jianmin

    2018-06-01

    Although widespread antibiotic resistance has been mostly attributed to the selective pressure generated by overuse and misuse of antibiotics, recent growing evidence suggests that chemicals other than antibiotics, such as certain metals, can also select and stimulate antibiotic resistance via both co-resistance and cross-resistance mechanisms. For instance, tetL, merE, and oprD genes are resistant to both antibiotics and metals. However, the potential de novo resistance induced by heavy metals at environmentally-relevant low concentrations (much below theminimum inhibitory concentrations [MICs], also referred as sub-inhibitory) has hardly been explored. This study investigated and revealed that heavy metals, namely Cu(II), Ag(I), Cr(VI), and Zn(II), at environmentally-relevant and sub-inhibitory concentrations, promoted conjugative transfer of antibiotic resistance genes (ARGs) between E. coli strains. The mechanisms of this phenomenon were further explored, which involved intracellular reactive oxygen species (ROS) formation, SOS response, increased cell membrane permeability, and altered expression of conjugation-relevant genes. These findings suggest that sub-inhibitory levels of heavy metals that widely present in various environments contribute to the resistance phenomena via facilitating horizontal transfer of ARGs. This study provides evidence from multiple aspects implicating the ecological effect of low levels of heavy metals on antibiotic resistance dissemination and highlights the urgency of strengthening efficacious policy and technology to control metal pollutants in the environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Reconstructing ancient genomes and epigenomes

    DEFF Research Database (Denmark)

    Orlando, Ludovic Antoine Alexandre; Gilbert, M. Thomas P.; Willerslev, Eske

    2015-01-01

    DNA studies have now progressed to whole-genome sequencing for an increasing number of ancient individuals and extinct species, as well as to epigenomic characterization. Such advances have enabled the sequencing of specimens of up to 1 million years old, which, owing to their extensive DNA damage...... and contamination, were previously not amenable to genetic analyses. In this Review, we discuss these varied technical challenges and solutions for sequencing ancient genomes and epigenomes....

  19. [Ancient Greek in modern language of medicine].

    Science.gov (United States)

    Marković, Vera

    2007-01-01

    In order to standardize language of medicine, it is essential to have a good command of ancient Greek and Latin. We cannot deny a huge impact of ancient Greek medicine on medical terminology. Compounds of Greek origin related to terms for organs, illnesses, inflammations, surgical procedures etc. have been listed as examples. They contain Greek prefixes and suffixes transcribed into Latin and they have been analysed. It may be concluded that the modern language of medicine basically represents the ancient Greek language transcribed into Latin.

  20. Deep sequencing of RNA from ancient maize kernels

    DEFF Research Database (Denmark)

    Fordyce, Sarah Louise; Avila Arcos, Maria del Carmen; Rasmussen, Morten

    2013-01-01

    The characterization of biomolecules from ancient samples can shed otherwise unobtainable insights into the past. Despite the fundamental role of transcriptomal change in evolution, the potential of ancient RNA remains unexploited - perhaps due to dogma associated with the fragility of RNA. We hy...... maize kernels. The results suggest that ancient seed transcriptomics may offer a powerful new tool with which to study plant domestication....

  1. The provenance investigation on ancient chinese Ru porcelains by NAA

    International Nuclear Information System (INIS)

    Gao Zhengyao; Wang Jie; Chen Songhua

    1997-01-01

    The 28 samples of glazes and bodies of ancient Chinese Ru porcelains are analyzed by neutron activation. The 36 element contents in each sample are determined. The neutron activation analysis (NAA) data are analyzed by fuzzy cluster. The trend cluster diagram is obtained. The result shows that the ancient Chinese Ru porcelains were most probably from the same raw material source though they were from different time, fired in different kilns and in different colors. The near provenance relation between ancient Jun porcelain and ancient Ru porcelain is preliminarily analyzed. The two modern Ru porcelains approximate to ancient Ru porcelains, one becomes estranged from ancient Ru porcelains. Jingdezhen porcelain is unconcerned with Ru porcelains

  2. Ancient Egyptian Medicine: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Samuel Adu-Gyamfi

    2015-12-01

    Full Text Available Our present day knowledge in the area of medicine in Ancient Egypt has been severally sourced from medical papyri several of which have been deduced and analyzed by different scholars. For educational purposes it is always imperative to consult different literature or sources in the teaching of ancient Egypt and medicine in particular. To avoid subjectivity the author has found the need to re-engage the efforts made by several scholars in adducing evidences from medical papyri. In the quest to re-engage the efforts of earlier writers and commentaries on the medical papyri, we are afforded the opportunity to be informed about the need to ask further questions to enable us to construct or reconstruct both past and modern views on ancient Egyptian medical knowledge. It is this vocation the author sought to pursue in the interim, through a preliminary review, to highlight, comment and reinvigorate in the reader or researcher the need for a continuous engagement of some pertinent documentary sources on Ancient Egyptian medical knowledge for educational and research purposes. The study is based on qualitative review of published literature. The selection of those articles as sources was based on the focus of the review, in order to purposively select and comment on articles that were published based either on information from a medical papyrus or focused on medical specialization among the ancient Egyptians as well as ancient Egyptian knowledge on diseases and medicine. It was found that the Egyptians developed relatively sophisticated medical practices covering significant medical fields such as herbal medicine, gynecology and obstetrics, anatomy and physiology, mummification and even the preliminary form of surgery. These practices, perhaps, were developed as remedies for the prevailing diseases and the accidents that might have occurred during the construction of their giant pyramids. It must be stated that they were not without flaws. Also, the

  3. Ancient Greek in modern language of medicine

    Directory of Open Access Journals (Sweden)

    Marković Vera

    2007-01-01

    Full Text Available In order to standardize language of medicine, it is essential to have a good command of ancient Greek and Latin. We cannot deny a huge impact of ancient Greek medicine on medical terminology. Compounds of Greek origin related to terms for organs, illnesses, inflammations, surgical procedures etc. have been listed as examples. They contain Greek prefixes and suffixes transcribed into Latin and they have been analyzed. It may be concluded that the modern language of medicine basically represents the ancient Greek language transcribed into Latin.

  4. The characterization of Helicobacter pylori DNA associated with ancient human remains recovered from a Canadian glacier.

    Directory of Open Access Journals (Sweden)

    Treena Swanston

    2011-02-01

    Full Text Available Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of nearly half of the world's population. Genotypic characterization of H. pylori strains involves the analysis of virulence-associated genes, such as vacA, which has multiple alleles. Previous phylogenetic analyses have revealed a connection between modern H. pylori strains and the movement of ancient human populations. In this study, H. pylori DNA was amplified from the stomach tissue of the Kwäday Dän Ts'ìnchi individual. This ancient individual was recovered from the Samuel Glacier in Tatshenshini-Alsek Park, British Columbia, Canada on the traditional territory of the Champagne and Aishihik First Nations and radiocarbon dated to a timeframe of approximately AD 1670 to 1850. This is the first ancient H. pylori strain to be characterized with vacA sequence data. The Tatshenshini H. pylori strain has a potential hybrid vacA m2a/m1d middle (m region allele and a vacA s2 signal (s region allele. A vacA s2 allele is more commonly identified with Western strains, and this suggests that European strains were present in northwestern Canada during the ancient individual's time. Phylogenetic analysis indicated that the vacA m1d region of the ancient strain clusters with previously published novel Native American strains that are closely related to Asian strains. This indicates a past connection between the Kwäday Dän Ts'ìnchi individual and the ancestors who arrived in the New World thousands of years ago.

  5. Selfish operons: the evolutionary impact of gene clustering in prokaryotes and eukaryotes.

    Science.gov (United States)

    Lawrence, J

    1999-12-01

    The Selfish Operon Model postulates that the organization of bacterial genes into operons is beneficial to the constituent genes in that proximity allows horizontal cotransfer of all genes required for a selectable phenotype; eukaryotic operons formed for very different reasons. Horizontal transfer of selfish operons most probably promotes bacterial diversification.

  6. Horizontal wells in subsurface remediation

    International Nuclear Information System (INIS)

    Losonsky, G.; Beljin, M.S.

    1992-01-01

    This paper reports on horizontal wells which offer an effective alternative to vertical wells in various environmental remediation technologies. Hydrogeological advantages of horizontal wells over vertical wells include a larger zone of influence, greater screen length, higher specific capacity and lower groundwater screen entrance velocity. Because of these advantages, horizontal wells can reduce treatment time and costs of groundwater recovery (pump-and-treat), in situ groundwater aeration (sparging) and soil gas extraction (vacuum extraction). Horizontal wells are also more effective than vertical wells in landfill leachate collection (under-drains), bioremediation, and horizontal grout injection

  7. Suicide in ancient Greece.

    Science.gov (United States)

    Laios, K; Tsoukalas, G; Kontaxaki, M-I; Karamanou, M; Androutsos, G

    2014-01-01

    The theme of suicide appears several times in ancient Greek literature. However, each such reference acquires special significance depending on the field from which it originates. Most of the information found in mythology, but the suicide in a mythological tale, although in terms of motivation and mental situation of heroes may be in imitation of similar incidents of real life, in fact is linked with the principles of the ancient Greek religion. In ancient drama and mainly in tragedies suicide conduces to the tragic hypostasis of the heroes and to the evolution of the plot and also is a tool in order to be presented the ideas of poets for the relations of the gods, the relation among gods and men and the relation among the men. In ancient Greek philosophy there were the deniers of suicide, who were more concerned about the impact of suicide on society and also these who accepted it, recognizing the right of the individual to put an end to his life, in order to avoid personal misfortunes. Real suicides will be found mostly from historical sources, but most of them concern leading figures of the ancient world. Closer to the problem of suicide in the everyday life of antiquity are ancient Greek medicines, who studied the phenomenon more general without references to specific incidents. Doctors did not approve in principal the suicide and dealt with it as insane behavior in the development of the mental diseases, of melancholia and mania. They considered that the discrepancy of humors in the organ of logic in the human body will cause malfunction, which will lead to the absurdity and consequently to suicide, either due to excessive concentration of black bile in melancholia or due to yellow bile in mania. They believed that greater risk to commit suicide had women, young people and the elderly. As therapy they used the drugs of their time with the intention to induce calm and repression in the ill person, therefore they mainly used mandragora. In general, we would say

  8. Exploring Ancient Skies An Encyclopedic Survey of Archaeoastronomy

    CERN Document Server

    Kelley, David H

    2005-01-01

    Exploring Ancient Skies brings together the methods of archaeology and the insights of modern astronomy to explore the science of astronomy as it was practiced in various cultures prior to the invention of the telescope. The book reviews an enormous and growing body of literature on the cultures of the ancient Mediterranean, the Far East, and the New World (particularly Mesoamerica), putting the ancient astronomical materials into their archaeological and cultural contexts. The authors begin with an overview of the field and proceed to essential aspects of naked-eye astronomy, followed by an examination of specific cultures. The book concludes by taking into account the purposes of ancient astronomy: astrology, navigation, calendar regulation, and (not least) the understanding of our place and role in the universe. Skies are recreated to display critical events as they would have appeared to ancient observers - events such as the supernova of 1054, the 'lion horoscope' or the 'Star of Bethlehem.' Exploring An...

  9. Phylogenetic diversity of Pasteurellaceae and horizontal gene transfer of leukotoxin in wild and domestic sheep.

    Science.gov (United States)

    Kelley, Scott T; Cassirer, E Frances; Weiser, Glen C; Safaee, Shirin

    2007-01-01

    Wild and domestic animal populations are known to be sources and reservoirs of emerging diseases. There is also a growing recognition that horizontal genetic transfer (HGT) plays an important role in bacterial pathogenesis. We used molecular phylogenetic methods to assess diversity and cross-transmission rates of Pasteurellaceae bacteria in populations of bighorn sheep, Dall's sheep, domestic sheep and domestic goats. Members of the Pasteurellaceae cause an array of deadly illnesses including bacterial pneumonia known as "pasteurellosis", a particularly devastating disease for bighorn sheep. A phylogenetic analysis of a combined dataset of two RNA genes (16S ribosomal RNA and RNAse P RNA) revealed remarkable evolutionary diversity among Pasteurella trehalosi and Mannheimia (Pasteurella) haemolytica bacteria isolated from sheep and goats. Several phylotypes appeared to associate with particular host species, though we found numerous instances of apparent cross-transmission among species and populations. Statistical analyses revealed that host species, geographic locale and biovariant classification, but not virulence, correlated strongly with Pasteurellaceae phylogeny. Sheep host species correlated with P. trehalosi isolates phylogeny (PTP test; P=0.002), but not with the phylogeny of M. haemolytica isolates, suggesting that P. trehalosi bacteria may be more host specific. With regards to populations within species, we also discovered a strong correlation between geographic locale and isolate phylogeny in the Rocky Mountain bighorn sheep (PTP test; P=0.001). We also investigated the potential for HGT of the leukotoxin A (lktA) gene, which produces a toxin that plays an integral role in causing disease. Comparative analysis of the combined RNA gene phylogeny and the lktA phylogenies revealed considerable incongruence between the phylogenies, suggestive of HGT. Furthermore, we found identical lktA alleles in unrelated bacterial species, some of which had been isolated

  10. In Silico Gene-Level Evolution Explains Microbial Population Diversity through Differential Gene Mobility

    NARCIS (Netherlands)

    van Dijk, Bram; Hogeweg, P.

    2016-01-01

    Microbial communities can show astonishing ecological and phylogenetic diversity. What is the role of pervasive horizontal gene transfer (HGT) in shaping this diversity in the presence of clonally expanding "killer strains"? Does HGT of antibiotic production and resistance genes erase phylogenetic

  11. Twins in Ancient Greece: a synopsis.

    Science.gov (United States)

    Malamitsi-Puchner, Ariadne

    2016-01-01

    This brief outline associates twins with several aspects of life in Ancient Greece. In Greek mythology twins caused ambivalent reactions and were believed to have ambivalent feelings for each other. Very often, they were viewed as the representatives of the dualistic nature of the universe. Heteropaternal superfecundation, which dominates in ancient myths, explains on one hand, the god-like qualities and, on the other hand, the mortal nature of many twins. An assumption is presented that legends referring to twins might reflect the territorial expansions of Ancient Greeks in Northern Mediterranean, around the Black Sea, in Asia Minor, as well as North East Africa. In conclusion, in Greek antiquity, twins have been used as transitional figures between myth and reality.

  12. Nitrogen removal and its relationship with the nitrogen-cycle genes and microorganisms in the horizontal subsurface flow constructed wetlands with different design parameters.

    Science.gov (United States)

    Chen, Jun; Ying, Guang-Guo; Liu, You-Sheng; Wei, Xiao-Dong; Liu, Shuang-Shuang; He, Liang-Ying; Yang, Yong-Qiang; Chen, Fan-Rong

    2017-07-03

    This study aims to investigate nitrogen removal and its relationship with the nitrogen-cycle genes and microorganisms in the horizontal subsurface flow constructed wetlands (CWs) with different design parameters. Twelve mesocosm-scale CWs with four substrates and three hydraulic loading rates were set up in the outdoor. The result showed the CWs with zeolite as substrate and HLR of 20 cm/d were selected as the best choice for the TN and NH 3 -N removal. It was found that the single-stage mesocosm-scale CWs were incapable to achieve high removals of TN and NH 3 -N due to inefficient nitrification process in the systems. This was demonstrated by the lower abundance of the nitrification genes (AOA and AOB) than the denitrification genes (nirK and nirS), and the less diverse nitrification microorganisms than the denitrification microorganisms in the CWs. The results also show that microorganism community structure including nitrogen-cycle microorganisms in the constructed wetland systems was affected by the design parameters especially the substrate type. These findings show that nitrification is a limiting factor for the nitrogen removal by CWs.

  13. The Ancient Kemetic Roots of Library and Information Science.

    Science.gov (United States)

    Zulu, Itibari M.

    This paper argues that the ancient people of Kemet (Egypt), "the black land," built and operated the first major libraries and institutions of higher education in the world. Topics of discussion include the Ancient Egyptians as an African people; a chronology of Ancient Kemet; literature in Kemet; a history of Egyptian Librarianship; the…

  14. Wall paintings facies and their possible genetic correlates in the ancient Pompeii: A bio-anthropologic message from the past?

    Science.gov (United States)

    Ponti, Giovanni; Manfredini, Marco; Ruini, Cristel

    2016-09-10

    The figurative arts and precisely the ancient Pompeian wall paintings portraits can provide an additional source of information in supplementing bio-anthropological studies. There are several genetic diseases with a wide spectrum of congenital bone stigmata in association to distinctive facial features. Gorlin-Goltz syndrome, also named nevoid basal cell carcinoma syndrome, is an autosomal dominant syndrome characterized by unusual skeletal changes, such as macrocephaly, facial asymmetry, hypertelorism, frontal and parietal bossing caused by germline mutations of the gene PTCH1. The Gorlin syndrome, clinically defined in 1963, existed during Dynastic Egyptian times, as revealed by a spectrum of skeletal findings compatible with the syndrome in mummies dating back to three thousand years ago and, most likely, in the ancient population of Pompeii. In the present research, we discuss the potential relationship between Pompeian wall paintings portrait and the cranio-metric bone changes revealed among the Pompeian skull collections assuming that the ancient portraits can constitute an important tool that should be strictly integrated with osteologic and biomolecular data in order to argue a syndromic diagnosis in ancient population. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Ancient and modern women in the "Woman's World".

    Science.gov (United States)

    Hurst, Isobel

    2009-01-01

    Under the editorship of Oscar Wilde, the "Woman's World" exemplified the popular dissemination of Hellenism through periodical culture. Addressing topics such as marriage, politics, and education in relation to the lives of women in the ancient world, the magazine offered an unfamiliar version of the reception of ancient Greece and Rome in late-Victorian aestheticism, one that was accessible to a wide readership because it was often based on images rather than texts. The classical scholar Jane Ellen Harrison addressed herself to this audience of women readers, discussing the similarities between modern collegiate life and the "woman's world" that enabled Sappho to flourish in ancient Greece. The "Woman's World" thus questions gender stereotypes by juxtaposing ancient and modern women, implicitly endorsing varied models of womanhood.

  16. Defining Astrology in Ancient and Classical History

    Science.gov (United States)

    Campion, Nicholas

    2015-05-01

    Astrology in the ancient and classical worlds can be partly defined by its role, and partly by the way in which scholars spoke about it. The problem is complicated by the fact that the word is Greek - it has no Babylonian or Egyptian cognates - and even in Greece it was interchangeable with its cousin, 'astronomy'. Yet if we are to understand the role of the sky, stars and planets in culture, debates about the nature of ancient astrology, by both classical and modern scholars, must be taken into account. This talk will consider modern scholars' typologies of ancient astrology, together with ancient debates from Cicero in the 1st century BC, to Plotinus (204/5-270 AD) and Isidore of Seville (c. 560 - 4 April 636). It will consider the implications for our understanding of astronomy's role in culture, and conclude that in the classical period astrology may be best understood through its diversity and allegiance to competing philosophies, and that its functions were therefore similarly varied.

  17. The fingerprint element analysis on provenance of ancient chinese Jun porcelain

    International Nuclear Information System (INIS)

    Gao Zhengyao; Chen Songhua; Wang Jie; Huang Zhongxiang; Jia Xiuqin; Han Song

    1997-01-01

    Forty-three samples of ancient Jun porcelains and so on were chosen. Neutron activation analysis (NAA) was used to measure the 36 trace elements in every sample. Seven elements were chosen as the 'fingerprint elements'. The provenance of the glazes and bodies of ancient Chinese Jun porcelain were investigated by the fingerprint element analysis method. The result shows that although the ancient Chinese Jun porcelain samples have been leapt over six hundred years, and glaze colors are utterly different and are from many different kilns, there are long term, stable and same mainly raw material source. The near provenance relation between ancient Jun porcelain and ancient Ru porcelain is preliminarily analyzed. A few modern Jun porcelains approximate from ancient Jun porcelains, the majority become estranged from ancient Jun porcelain

  18. Microanalysis study on ancient Wiangkalong Pottery

    Science.gov (United States)

    Won-in, K.; Tancharakorn, S.; Dararutana, P.

    2017-09-01

    Wiangkalong is one of major ceramic production cities in northern of Thailand, once colonized by the ancient Lanna Kingdom (1290 A.D.). Ancient Wiangkalong potteries were produced with shapes and designs as similar as those of the Chinese Yuan and Ming Dynasties. Due to the complex nature of materials and objects, extremely sensitive, spatially resolved, multi-elemental and versatile analytical instruments using non-destructive and non-sampling methods to analyze theirs composition are need. In this work, micro-beam X-ray fluorescence spectroscopy based on synchrotron radiation was firstly used to characterize the elemental composition of the ancient Wiangkalong pottery. The results showed the variations in elemental composition of the body matrix, the glaze and the underglaze painting, such as K, Ca, Ti, V, Cr, Mn and Fe.

  19. Vertical and horizontal distribution of sediment nitrite-dependent methane-oxidizing organisms in a mesotrophic freshwater reservoir.

    Science.gov (United States)

    Long, Yan; Liu, Changbao; Lin, Hengliang; Li, Ningning; Guo, Qingwei; Xie, Shuguang

    2017-06-01

    In the present study, we investigated the spatial change of sediment nitrite-dependent anaerobic methane-oxidizing (n-damo) organisms in the mesotrophic freshwater Gaozhou Reservoir (6 different sampling locations and 2 sediment depths (0-5 cm, 5-10 cm)), one of the largest drinking water reservoirs in China. The abundance of sediment n-damo bacteria was quantified using quantitative polymerase chain reaction assay, while the richness, diversity, and composition of n-damo pmoA gene sequences were characterized using clone library analysis. Vertical and horizontal changes in sediment n-damo bacterial abundance occurred in Gaozhou Reservoir, with 1.37 × 10 5 to 8.24 × 10 5 n-damo 16S rRNA gene copies per gram of dry sediment. Considerable horizontal and vertical variations of n-damo pmoA gene diversity (Shannon index = 0.32-2.50) and composition also occurred in this reservoir. Various types of sediment n-damo pmoA genes existed in Gaozhou Reservoir. A small proportion of n-damo pmoA gene sequences (19.1%) were related to those recovered from "Candidatus Methylomirabilis oxyfera". Our results suggested that sediment n-damo pmoA gene diversity might be regulated by nitrite, while n-damo pmoA gene richness might be governed by multiple environmental factors, including total organic carbon, total phosphorus, nitrite, and total nitrogen.

  20. Legacy of the Ancient World: An Educational Guide. Understanding Ancient Culture through Art at the Tampa Museum of Art.

    Science.gov (United States)

    Whitelaw, R. Lynn

    Among the many contributions made by Ancient Greeks and Romans to contemporary life, are those which influence art, architecture, literature, philosophy, mathematics and science, theater, athletics, religion, and the founding of democracy. The Tampa Museum of Art's classical collection offers a unique opportunity to learn about Ancient Greeks and…

  1. GENERATION OF GEOMETRIC ORNAMENTS IN ANCIENT MOSAIC ART

    Directory of Open Access Journals (Sweden)

    SASS Ludmila

    2015-06-01

    Full Text Available The paper examines geometrical ornaments from ancient mosaic.We studied the geometric generation by using Computer Aided Graphics for three examples of ancient mosaic: a mosaic of Ancient Corinth, a mosaic of the sacred geometry Flower of Life (exposed in the National Museum of Israel and a mosaic of fortress Masada - Israel. The technique of drawing ancient mosaic is recomposed using computer aided graphics. A program has been developed that can help draw a petal-type arc (semicircle of the mosaic that is the Byzantine church of Masada. Based on these mosaics, other variants of aesthetic images in monochrome or black and white and polychrome were drawn, all of which can be materialized in decorative art to embellish various surfaces: walls, floors, pools, fountains, etc.

  2. Co-evolution of secondary metabolite gene clusters and their host

    DEFF Research Database (Denmark)

    Kjærbølling, Inge; Vesth, Tammi Camilla; Frisvad, Jens Christian

    Secondary metabolite gene cluster evolution is mainly driven by two events: gene duplication and annexation and horizontal gene transfer. Here we use comparative genomics of Aspergillus species to investigate the evolution of secondary metabolite (SM) gene clusters across a wide spectrum of speci....... We investigate the dynamic evolutionary relationship between the cluster and the host by examining the genes within the cluster and the number of homologous genes found within the host and in closely related species.......Secondary metabolite gene cluster evolution is mainly driven by two events: gene duplication and annexation and horizontal gene transfer. Here we use comparative genomics of Aspergillus species to investigate the evolution of secondary metabolite (SM) gene clusters across a wide spectrum of species...

  3. Ancient Exaptation of a CORE-SINE Retroposon into a Highly Conserved Mammalian Neuronal Enhancer of the Proopiomelanocortin Gene

    Science.gov (United States)

    Bumaschny, Viviana F; Low, Malcolm J; Rubinstein, Marcelo

    2007-01-01

    The proopiomelanocortin gene (POMC) is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5′ distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE) retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution. PMID:17922573

  4. Ancient exaptation of a CORE-SINE retroposon into a highly conserved mammalian neuronal enhancer of the proopiomelanocortin gene.

    Directory of Open Access Journals (Sweden)

    Andrea M Santangelo

    2007-10-01

    Full Text Available The proopiomelanocortin gene (POMC is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5' distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution.

  5. Horizontal transfer generates genetic variation in an asexual pathogen

    Directory of Open Access Journals (Sweden)

    Xiaoqiu Huang

    2014-10-01

    Full Text Available There are major gaps in the understanding of how genetic variation is generated in the asexual pathogen Verticillium dahliae. On the one hand, V. dahliae is a haploid organism that reproduces clonally. On the other hand, single-nucleotide polymorphisms and chromosomal rearrangements were found between V. dahliae strains. Lineage-specific (LS regions comprising about 5% of the genome are highly variable between V. dahliae strains. Nonetheless, it is unknown whether horizontal gene transfer plays a major role in generating genetic variation in V. dahliae. Here, we analyzed a previously sequenced V. dahliae population of nine strains from various geographical locations and hosts. We found highly homologous elements in LS regions of each strain; LS regions of V. dahliae strain JR2 are much richer in highly homologous elements than the core genome. In addition, we discovered, in LS regions of JR2, several structural forms of nonhomologous recombination, and two or three homologous sequence types of each form, with almost each sequence type present in an LS region of another strain. A large section of one of the forms is known to be horizontally transferred between V. dahliae strains. We unexpectedly found that 350 kilobases of dynamic LS regions were much more conserved than the core genome between V. dahliae and a closely related species (V. albo-atrum, suggesting that these LS regions were horizontally transferred recently. Our results support the view that genetic variation in LS regions is generated by horizontal transfer between strains, and by chromosomal reshuffling reported previously.

  6. News from the west: ancient DNA from a French megalithic burial chamber.

    Science.gov (United States)

    Deguilloux, Marie-France; Soler, Ludovic; Pemonge, Marie-Hélène; Scarre, Chris; Joussaume, Roger; Laporte, Luc

    2011-01-01

    Recent paleogenetic studies have confirmed that the spread of the Neolithic across Europe was neither genetically nor geographically uniform. To extend existing knowledge of the mitochondrial European Neolithic gene pool, we examined six samples of human skeletal material from a French megalithic long mound (c.4200 cal BC). We retrieved HVR-I sequences from three individuals and demonstrated that in the Neolithic period the mtDNA haplogroup N1a, previously only known in central Europe, was as widely distributed as western France. Alternative scenarios are discussed in seeking to explain this result, including Mesolithic ancestry, Neolithic demic diffusion, and long-distance matrimonial exchanges. In light of the limited Neolithic ancient DNA (aDNA) data currently available, we observe that all three scenarios appear equally consistent with paleogenetic and archaeological data. In consequence, we advocate caution in interpreting aDNA in the context of the Neolithic transition in Europe. Nevertheless, our results strengthen conclusions demonstrating genetic discontinuity between modern and ancient Europeans whether through migration, demographic or selection processes, or social practices. Copyright © 2010 Wiley-Liss, Inc.

  7. Vertical and horizontal subsidiarity

    Directory of Open Access Journals (Sweden)

    Ivan V. Daniluk

    2016-02-01

    Full Text Available This article makes an attempt to analyze the principle of subsidiarity in its two main manifestations, namely vertical and horizontal, to outline the principles of relations between the state and regions within the vertical subsidiarity, and features a collaboration of the government and civil society within the horizontal subsidiarity. Scientists identify two types, or two levels of the subsidiarity principle: vertical subsidiarity and horizontal subsidiarity. First, vertical subsidiarity (or territorial concerning relations between the state and other levels of subnational government, such as regions and local authorities; second, horizontal subsidiarity (or functional concerns the relationship between state and citizen (and civil society. Vertical subsidiarity expressed in the context of the distribution of administrative responsibilities to the appropriate higher level lower levels relative to the state structure, ie giving more powers to local government. However, state intervention has subsidiary-lower action against local authorities in cases of insolvency last cope on their own, ie higher organisms intervene only if the duties are less authority is insufficient to achieve the goals. Horizontal subsidiarity is within the relationship between power and freedom, and is based on the assumption that the concern for the common good and the needs of common interest community, able to solve community members (as individuals and citizens’ associations and role of government, in accordance horizontal subsidiarity comes to attracting features subsidiarity assistance, programming, coordination and possibly control.

  8. Genetic diversity among ancient Nordic populations

    DEFF Research Database (Denmark)

    Melchior, Linea Cecilie; Lynnerup, Niels; Siegismund, Hans Redlef

    2010-01-01

    , the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two...... the ancient Danes (average 13%) than among extant Danes and Scandinavians ( approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic...... samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least...

  9. Damage and repair of ancient DNA

    DEFF Research Database (Denmark)

    Mitchell, David; Willerslev, Eske; Hansen, Anders

    2005-01-01

    degradation, these studies are limited to species that lived within the past 10(4)-10(5) years (Late Pleistocene), although DNA sequences from 10(6) years have been reported. Ancient DNA (aDNA) has been used to study phylogenetic relationships of protists, fungi, algae, plants, and higher eukaryotes...... such as extinct horses, cave bears, the marsupial wolf, the moa, and Neanderthal. In the past few years, this technology has been extended to the study of infectious disease in ancient Egyptian and South American mummies, the dietary habits of ancient animals, and agricultural practices and population dynamics......, and extensive degradation. In the course of this review, we will discuss the current aDNA literature describing the importance of aDNA studies as they relate to important biological questions and the difficulties associated with extracting useful information from highly degraded and damaged substrates derived...

  10. Testing of Alignment Parameters for Ancient Samples: Evaluating and Optimizing Mapping Parameters for Ancient Samples Using the TAPAS Tool

    Directory of Open Access Journals (Sweden)

    Ulrike H. Taron

    2018-03-01

    Full Text Available High-throughput sequence data retrieved from ancient or other degraded samples has led to unprecedented insights into the evolutionary history of many species, but the analysis of such sequences also poses specific computational challenges. The most commonly used approach involves mapping sequence reads to a reference genome. However, this process becomes increasingly challenging with an elevated genetic distance between target and reference or with the presence of contaminant sequences with high sequence similarity to the target species. The evaluation and testing of mapping efficiency and stringency are thus paramount for the reliable identification and analysis of ancient sequences. In this paper, we present ‘TAPAS’, (Testing of Alignment Parameters for Ancient Samples, a computational tool that enables the systematic testing of mapping tools for ancient data by simulating sequence data reflecting the properties of an ancient dataset and performing test runs using the mapping software and parameter settings of interest. We showcase TAPAS by using it to assess and improve mapping strategy for a degraded sample from a banded linsang (Prionodon linsang, for which no closely related reference is currently available. This enables a 1.8-fold increase of the number of mapped reads without sacrificing mapping specificity. The increase of mapped reads effectively reduces the need for additional sequencing, thus making more economical use of time, resources, and sample material.

  11. Moessbauer studies on ancient Jizhon plain Temmoku porcelains

    International Nuclear Information System (INIS)

    Yu Zhengfang; Zheng Yufang; Lin Yongqiang

    1994-01-01

    Three kinds of ancient Jizhou plain Temmoku wares and their several ware-making raw materials were studied by means of X-ray diffraction (XRD) and Moessbauer spectroscopy. The firing technique of ancient Jizhou Temmoku porcelains is discussed. (orig.)

  12. Improved waterflooding efficiency by horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Popa, C. G. [Petroleum and Gas Univ., Ploesti (Romania); Clipea, M. [SNP Petrom SA, ICPT Campina (Romania)

    1998-12-31

    The influence of well pattern involving the use of horizontal wells on the overall efficiency of the waterflooding process was analyzed. Three different scenarios were examined: (1) a pattern of using two parallel horizontal wells, one for injection, the other for production, (2) a pattern of one horizontal well for water injection and several vertical wells for production, and (3) a pattern of using vertical wells for injection and one horizontal well for production. In each case, the waterflooding process was simulated using a two phase two dimensional numerical model. Results showed that the pressure loss along the horizontal section had a large influence on the sweep efficiency whether the horizontal well was used for injection or production. Overall, the most successful combination appeared to be using vertical wells for injection and horizontal wells for production. 4 refs., 1 tab., 15 figs.

  13. Tracking down human contamination in ancient human teeth

    DEFF Research Database (Denmark)

    Sampietro, María Lourdes; Gilbert, M Thomas P; Lao, Oscar

    2006-01-01

    DNA sequences can be used to support data authenticity is misleading in scenarios where the presence of old contaminant sequences is possible. We argue therefore that the typing of those involved in the manipulation of the ancient human specimens is critical in order to ensure that generated results......DNA contamination arising from the manipulation of ancient calcified tissue samples is a poorly understood, yet fundamental, problem that affects the reliability of ancient DNA (aDNA) studies. We have typed the mitochondrial DNA hypervariable region I of the only 6 people involved in the excavation...

  14. Detecting Ancient Tuberculosis

    Directory of Open Access Journals (Sweden)

    Angela M. Gernaey

    1998-12-01

    Full Text Available Some diseases have played a more significant role in human development than others. Here we describe the results of a trial to diagnose ancient tuberculosis using chemical methods. Palaeo-epidemiological studies of the disease are compromised, but it has become apparent that tuberculosis (TB is a 'population-density dependent' disease. From modern studies, it is also apparent that the prevalence of TB can be used as an indicator of the level of poverty within the studied population. Mid-shaft rib samples from articulated individuals recovered from the former Newcastle Infirmary Burial Ground (1753-1845 AD were examined for mycolic acids that are species-specific for Mycobacterium tuberculosis. The 24% of ribs positive for mycolic acids correlated with the documented 27% tuberculosis prevalence. Mycolic acid biomarkers have the potential to provide an accurate trace of the palaeo-epidemiology of tuberculosis in ancient populations, thereby providing an indication of the overall level of poverty - a useful adjunct for archaeology.

  15. The ancient Virus World and evolution of cells

    Directory of Open Access Journals (Sweden)

    Dolja Valerian V

    2006-09-01

    Full Text Available Abstract Background Recent advances in genomics of viruses and cellular life forms have greatly stimulated interest in the origins and evolution of viruses and, for the first time, offer an opportunity for a data-driven exploration of the deepest roots of viruses. Here we briefly review the current views of virus evolution and propose a new, coherent scenario that appears to be best compatible with comparative-genomic data and is naturally linked to models of cellular evolution that, from independent considerations, seem to be the most parsimonious among the existing ones. Results Several genes coding for key proteins involved in viral replication and morphogenesis as well as the major capsid protein of icosahedral virions are shared by many groups of RNA and DNA viruses but are missing in cellular life forms. On the basis of this key observation and the data on extensive genetic exchange between diverse viruses, we propose the concept of the ancient virus world. The virus world is construed as a distinct contingent of viral genes that continuously retained its identity throughout the entire history of life. Under this concept, the principal lineages of viruses and related selfish agents emerged from the primordial pool of primitive genetic elements, the ancestors of both cellular and viral genes. Thus, notwithstanding the numerous gene exchanges and acquisitions attributed to later stages of evolution, most, if not all, modern viruses and other selfish agents are inferred to descend from elements that belonged to the primordial genetic pool. In this pool, RNA viruses would evolve first, followed by retroid elements, and DNA viruses. The Virus World concept is predicated on a model of early evolution whereby emergence of substantial genetic diversity antedates the advent of full-fledged cells, allowing for extensive gene mixing at this early stage of evolution. We outline a scenario of the origin of the main classes of viruses in conjunction

  16. Fingerprint elements scatter analysis on ancient chinese Ru porcelains samples

    International Nuclear Information System (INIS)

    Gao Zhengyao; Wang Jie; Chen Xiande

    1997-01-01

    Altogether 28 samples, mainly including glazes and bodies of ancient Chinese Ru porcelain, were analyzed by NAA technique and the contents of 36 elements were compared. The scatter analysis for nine fingerprint-elements indicates that almost all ancient Chinese Ru porcelain samples had nearly identical and long-term stable source of raw materials although they were fired in different kilns, at varying time and with distinct colors, and moreover, the source of raw materials for modern Ru porcelain seems to approach that for ancient one. The close provenance relation between ancient Jun porcelain and ancient Ru porcelain is also preliminarily verified. The glaze material of Jingdezhen white porcelain is totally different from all other samples. It shows that the former came from a separate source

  17. Deciphering Equine Evolution and Spatial Ancestry with Ancient Data

    DEFF Research Database (Denmark)

    Jónsson, Hákon

    High-throughput sequencing has opened ancient DNA research to genomics, revolutionizing the amount of genetic information retrievable from archaeological and paleontological remains. Paleogenomics is still in infancy and requires substantial improvements in computational methods tailored to the s......High-throughput sequencing has opened ancient DNA research to genomics, revolutionizing the amount of genetic information retrievable from archaeological and paleontological remains. Paleogenomics is still in infancy and requires substantial improvements in computational methods tailored...... in the analysis of environmental bacterial sequences, which generally dominate ancient DNA extracts, and in the first pipeline completely devoted to the computational analysis of raw ancient DNA sequences. We then develop a spatially explicit method for determining which extant populations show the greatest...... genetic anity to ancient individuals, which often represents the key question in human paleogenomic projects. We applied the computational infrastructure developed to complete the genomic characterization of extant members of the genus Equus, which is composed of horses, asses and zebras. We sequenced...

  18. Dreams in ancient Greek Medicine.

    Science.gov (United States)

    Laios, K; Moschos, M M; Koukaki, E; Vasilopoulos, E; Karamanou, M; Kontaxaki, M-I; Androutsos, G

    2016-01-01

    Dreams preoccupied the Greek and Roman world in antiquity, therefore they had a prominent role in social, philosophical, religious, historical and political life of those times. They were considered as omens and prophetic signs of future events in private and public life, and that was particularly accentuated when elements of actions which took place in the plot of dreams were associated directly or indirectly with real events. This is why it was important to use them in divination, and helped the growth of superstition and folklore believes. Medicine as a science and an anthropocentric art, could not ignore the importance of dreams, having in mind their popularity in antiquity. In ancient Greek medicine dreams can be divided into two basic categories. In the first one -which is related to religious medicine-dreams experienced by religionists are classified, when resorted to great religious sanctuaries such as those of Asclepius (Asclepieia) and Amphiaraos (Amfiaraeia). These dreams were the essential element for healing in this form of religious medicine, because after pilgrims underwent purifications they went to sleep in a special dwelling of the sanctuaries called "enkoimeterion" (Greek: the place to sleep) so that the healing god would come to their dreams either to cure them or to suggest treatment. In ancient Greek literature there are many reports of these experiences, but if there may be phenomena of self-suggestion, or they could be characterized as propaganda messages from the priesthood of each sanctuary for advertising purposes. The other category concerns the references about dreams found in ancient Greek medical literature, where one can find the attempts of ancient Greek physicians to interpret these dreams in a rational way as sings either of a corporal disease or of psychological distress. This second category will be the object of our study. Despite the different ways followed by each ancient Greek physician in order to explain dreams, their

  19. Lake Tanganyika--a 'melting pot' of ancient and young cichlid lineages (Teleostei: Cichlidae?

    Directory of Open Access Journals (Sweden)

    Juliane D Weiss

    Full Text Available A long history of research focused on the East Africa cichlid radiations (EAR revealed discrepancies between mtDNA and nuclear phylogenies, suggesting that interspecific hybridisation may have been significant during the radiation of these fishes. The approximately 250 cichlid species of Lake Tanganyika have their roots in a monophyletic African cichlid assemblage, but controversies remain about the precise phylogenetic origin and placement of different lineages and consequently about L. Tanganyika colonization scenarios. 3312 AFLP loci and the mitochondrial ND2 gene were genotyped for 91 species representing almost all major lacustrine and riverine haplotilapiine east African cichlid lineages with a focus on L. Tanganyika endemics. Explicitly testing for the possibility of ancient hybridisation events, a comprehensive phylogenetic network hypothesis is proposed for the origin and diversification of L. Tanganyika cichlids. Inference of discordant phylogenetic signal strongly suggests that the genomes of two endemic L. Tanganyika tribes, Eretmodini and Tropheini, are composed of an ancient mixture of riverine and lacustrine lineages. For the first time a strong monophyly signal of all non-haplochromine mouthbrooding species endemic to L. Tanganyika ("ancient mouthbrooders" was detected. Further, in the genomes of early diverging L. Tanganyika endemics Trematocarini, Bathybatini, Hemibatini and Boulengerochromis genetic components of other lineages belonging to the East African Radiation appear to be present. In combination with recent palaeo-geological results showing that tectonic activity in the L. Tanganyika region resulted in highly dynamic and heterogeneous landscape evolution over the Neogene and Pleistocene, the novel phylogenetic data render a single lacustrine basin as the geographical cradle of the endemic L. Tanganyika cichlid lineages unlikely. Instead a scenario of a pre-rift origin of several independent L. Tanganyika precursor

  20. ISSR diversity and genetic differentiation of ancient tea (camellia sinensis var. assamica) plantations from China: implications for precious tea germplasm conservation

    International Nuclear Information System (INIS)

    Huang, X.Q.; Ji, P.Z.; Li, H.; Zhang, J.; Gao, L.Z.; Cheng, Z.Q.

    2011-01-01

    Over 10 centuries, ancient cultivated tea populations (Camellia sinensis var. assamica) are still planted merely in Yunnan province of China. Genetic diversity and differentiation were examined in 10 ancient tea plantations by using ISSR markers. The average genetic diversity within populations, estimated with Nei's genetic diversity (HE), was approximately 0.2809, while Shannon indices (HO) was 0.4179. The percentage of polymorphic loci (P) of the 10 populations ranged from 56.5% to 90.91%. We found a moderate level of genetic differentiation among population as evidenced by the coefficients of gene differentiation (Gst) of 0.3911 and the analysis of molecular variance (AMOVA) of 39.70%. The result could be explained by the nature of highly out crossing in the tea species as well as serious habitat fragmentation. Finally, conservation strategies were discussed to protect these ancient tea populations, including in situ reserve settings and ex situ germplasm sampling. (author)

  1. Ancient DNA and Forensics Mutual Benefits a Practical Sampling and Laboratory Guide Through a Virtual Ancient DNA Study

    Directory of Open Access Journals (Sweden)

    Jan Cemper-Kiesslich

    2014-09-01

    In this review the authors give a general overview on the field of ancient DNA analysis focussing of the potentials and limits, fields of application, requirements for samples, laboratory setup, reaction design and equipment as well as a brief outlook on current developments, future perspectives and potential cross links with associated scientific disciplines. Key words: Human DNA, Ancient DNA, Forensic DNA typing, Molecular archaeology, Application.

  2. CHANT (CHinese ANcient Texts): a comprehensive database of all ancient Chinese texts up to 600 AD

    OpenAIRE

    Ho, Che Wah

    2006-01-01

    The CHinese ANcient Texts (CHANT) database is a long-term project which began in 1988 to build up a comprehensive database of all ancient Chinese texts up to the sixth century AD. The project is near completion and the entire database, which includes both traditional and excavated materials, will be released on the CHANT Web site (www.chant.org) in mid-2002. With more than a decade of experience in establishing an electronic Chinese literary database, we have gained much insight useful to the...

  3. The patterning of retinal horizontal cells: normalizing the regularity index enhances the detection of genomic linkage

    Directory of Open Access Journals (Sweden)

    Patrick W. Keeley

    2014-10-01

    Full Text Available Retinal neurons are often arranged as non-random distributions called mosaics, as their somata minimize proximity to neighboring cells of the same type. The horizontal cells serve as an example of such a mosaic, but little is known about the developmental mechanisms that underlie their patterning. To identify genes involved in this process, we have used three different spatial statistics to assess the patterning of the horizontal cell mosaic across a panel of genetically distinct recombinant inbred strains. To avoid the confounding effect cell density, which varies two-fold across these different strains, we computed the real/random regularity ratio, expressing the regularity of a mosaic relative to a randomly distributed simulation of similarly sized cells. To test whether this latter statistic better reflects the variation in biological processes that contribute to horizontal cell spacing, we subsequently compared the genetic linkage for each of these two traits, the regularity index and the real/random regularity ratio, each computed from the distribution of nearest neighbor (NN distances and from the Voronoi domain (VD areas. Finally, we compared each of these analyses with another index of patterning, the packing factor. Variation in the regularity indexes, as well as their real/random regularity ratios, and the packing factor, mapped quantitative trait loci (QTL to the distal ends of Chromosomes 1 and 14. For the NN and VD analyses, we found that the degree of linkage was greater when using the real/random regularity ratio rather than the respective regularity index. Using informatic resources, we narrow the list of prospective genes positioned at these two intervals to a small collection of six genes that warrant further investigation to determine their potential role in shaping the patterning of the horizontal cell mosaic.

  4. Ancient signals: comparative genomics of plant MAPK and MAPKK gene families

    DEFF Research Database (Denmark)

    Hamel, Louis-Philippe; Nicole, Marie-Claude; Sritubtim, Somrudee

    2006-01-01

    MAPK signal transduction modules play crucial roles in regulating many biological processes in plants, and their components are encoded by highly conserved genes. The recent availability of genome sequences for rice and poplar now makes it possible to examine how well the previously described...... Arabidopsis MAPK and MAPKK gene family structures represent the broader evolutionary situation in plants, and analysis of gene expression data for MPK and MKK genes in all three species allows further refinement of those families, based on functionality. The Arabidopsis MAPK nomenclature appears sufficiently...

  5. Genome-wide analysis of the MYB gene family in physic nut (Jatropha curcas L.).

    Science.gov (United States)

    Zhou, Changpin; Chen, Yanbo; Wu, Zhenying; Lu, Wenjia; Han, Jinli; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

    2015-11-01

    The MYB proteins comprise one of the largest transcription factor families in plants, and play key roles in regulatory networks controlling development, metabolism, and stress responses. A total of 125 MYB genes (JcMYB) have been identified in the physic nut (Jatropha curcas L.) genome, including 120 2R-type MYB, 4 3R-MYB, and 1 4R-MYB genes. Based on exon-intron arrangement of MYBs from both lower (Physcomitrella patens) and higher (physic nut, Arabidopsis, and rice) plants, we can classify plant MYB genes into ten groups (MI-X), except for MIX genes which are nonexistent in higher plants. We also observed that MVIII genes may be one of the most ancient MYB types which consist of both R2R3- and 3R-MYB genes. Most MYB genes (76.8% in physic nut) belong to the MI group which can be divided into 34 subgroups. The JcMYB genes were nonrandomly distributed on its 11 linkage groups (LGs). The expansion of MYB genes across several subgroups was observed and resulted from genome triplication of ancient dicotyledons and from both ancient and recent tandem duplication events in the physic nut genome. The expression patterns of several MYB duplicates in the physic nut showed differences in four tissues (root, stem, leaf, and seed), and 34 MYB genes responded to at least one abiotic stressor (drought, salinity, phosphate starvation, and nitrogen starvation) in leaves and/or roots based on the data analysis of digital gene expression tags. Overexpression of the JcMYB001 gene in Arabidopsis increased its sensitivity to drought and salinity stresses. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Geo electrical Resistivity Survey for Ancient Tunnel Detection at Bukit Tenggek, Setiu, Terengganu

    International Nuclear Information System (INIS)

    Siti Nazira Masrom; Mohd Hariri Arifin; Abd Rahim Harun; Abdul Rahim Samsudin

    2011-01-01

    Geo electrical resistivity survey was conducted in the Bukit Tenggek, Setiu, Terengganu to detect the possible existence of an ancient tunnel which is believed to be in the area. Geo electrical resistivity method was found very effective in searching for archaeological exploration and underground structures (tunnels and artifacts). Geo electrical resistivity survey was carried out using Terrameter ABEM SAS1000 and Wenner array electrode configuration. The survey area is located in a damp valley with a stream across the region. 2-D resistivity image showed the existence of anomalies in several areas that can be associated with the structure. Low resistivity value represents the estimated existence of the old tunnel, while isolated rounded anomalies are believed to be associated with barrels/artifacts. 3-D resistivity profiles, shows anomalies that may be caused by the existence of a horizontal and two vertical tunnels (shaft). However, the drillings work need to be done to figure out the exact cause of these anomalies. (author)

  7. Ancient DNA analysis of dental calculus.

    Science.gov (United States)

    Weyrich, Laura S; Dobney, Keith; Cooper, Alan

    2015-02-01

    Dental calculus (calcified tartar or plaque) is today widespread on modern human teeth around the world. A combination of soft starchy foods, changing acidity of the oral environment, genetic pre-disposition, and the absence of dental hygiene all lead to the build-up of microorganisms and food debris on the tooth crown, which eventually calcifies through a complex process of mineralisation. Millions of oral microbes are trapped and preserved within this mineralised matrix, including pathogens associated with the oral cavity and airways, masticated food debris, and other types of extraneous particles that enter the mouth. As a result, archaeologists and anthropologists are increasingly using ancient human dental calculus to explore broad aspects of past human diet and health. Most recently, high-throughput DNA sequencing of ancient dental calculus has provided valuable insights into the evolution of the oral microbiome and shed new light on the impacts of some of the major biocultural transitions on human health throughout history and prehistory. Here, we provide a brief historical overview of archaeological dental calculus research, and discuss the current approaches to ancient DNA sampling and sequencing. Novel applications of ancient DNA from dental calculus are discussed, highlighting the considerable scope of this new research field for evolutionary biology and modern medicine. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Truth Obviousness in Ancient Greek Philosophy

    Directory of Open Access Journals (Sweden)

    Halyna I. Budz

    2013-01-01

    Full Text Available The article examines the features of the axiomatic approach to the truth understanding in ancient Greek philosophy. Truth in the works by ancient philosophers has axiomatic essence, basing on divine origin of truth. As the truth has a divine origin, it is in reality. The reality, created by Gods is the solemn reality. Therefore, understanding of reality by man is the display of divine reality, which is true and clever. In of the context of ancient Greek philosophy, to know truth is to know something, existing in reality, in other words, something, truly existing, eternal reality. Consequently, to know truth is it to know the substantial reality base. That’s why the justification of the reality origin is the axiomatic doctrine of truth at the same time, because only fundamental principle “truly” exists and is the truth itself. The idea of fundamental principle in ancient Greek philosophy is the axiom, universal principle, which is the base of reality as a substance from ontological perspective and is realized as the truth from gnosiological perspective. Fundamental principle, as Greeks understand it, coincides with the truth, in other words, reality and thinking are identical. The idea of reality source is the universal criterion of world perception at the same time, in other words, it is the truth, which is perceived axiomatically.

  9. Colour Perception in Ancient World

    Science.gov (United States)

    Nesterov, D. I.; Fedorova, M. Yu

    2017-11-01

    How did the human thought form the surrounding color information into the persistent semantic images of a mythological, pseudoscientific and religious nature? The concepts associated with colour perception are suggested. The existence of colour environment does not depend on the human consciousness. The colour culture formation is directly related to the level of the human consciousness development and the possibility to influence the worldview and culture. The colour perception of a person goes through the stages similar to the development of colour vision in a child. Like any development, the colour consciousness has undergone stages of growth and decline, evolution and stagnation. The way of life and difficult conditions for existence made their own adjustments to the development of the human perception of the surrounding world. Wars have been both a powerful engine of progress in all spheres of life and a great destructive force demolishing the already created and preserved heritage. The surrounding world has always been interesting for humans, evoked images and fantasies in the consciousness of ancient people. Unusual and inexplicable natural phenomena spawned numerous legends and myths which was reflected in the ancient art and architecture and, accordingly, in a certain manifestation of colour in the human society. The colour perception of the ancient man, his pragmatic, utilitarian attitude to colour is considered as well as the influence of dependence on external conditions of existence and their reflection in the colour culture of antiquity. “Natural Science” conducts research in the field of the colour nature and their authorial interpretation of the Hellenic period. Several authorial concepts of the ancient world have been considered.

  10. Horizontal drilling assessment in Western Canada

    International Nuclear Information System (INIS)

    Catania, Peter; Wilson, Malcolm

    1999-01-01

    The first horizontal well was drilled in Saskatchewan in 1987. Since then, the number of horizontal wells drilled has escalated rapidly, averaging approximately 500 per year since 1993. When combined with horizontal wells drilled in Alberta, the major Canadian oil-producing province, the total number drilled in 1995 was 978. This total exceeds the National Energy Board (NEB) projected maximum of 816 wells per year. The NEB projections were based on a break-even point for the drilling of horizontal wells of a return of CDN $285,000 using a discount rate of 15%. This corresponded to a cumulative production from each individual well of some 11,000 m 3 . The introduction of a royalty-free production volume of 12,000 m 3 per horizontal well in Saskatchewan was instrumental in stimulating the rapid expansion in the use of horizontal wells and helping Canada to exceed the forecasted drilling level. Within Saskatchewan, daily production from 1964 active horizontal wells is in excess of 20,000 m 3 . Comparative analysis indicates that the average daily production per well has increased from approximately by 40% with the advent of horizontal wells. In total production terms, provincial production has increased from 11.7 million cubic metres in 1989 to 20.9 million m 3 in 1996. This represents an increase of almost 79% based primarily on the extensive use of horizontal wells. In 1996, horizontal wells produced 36% of the province's oil from 12% of the active wells. In the southeastern producing areas of Saskatchewan, the Williston Basin, declining oil-production has jumped 100%, with horizontal wells accounting for approximately 50% of total regional production. Pay zones in this areas, as in most of the province, tend to be relatively thin, with net pay frequently less that 5 m. The modest investment of some CDN $5 million in government research funding 10 years ago to stimulate the development of horizontal wells, combined with a favourable royalty structure, has been at

  11. Dacic Ancient Astronomical Research in Sarmizegetuza

    Directory of Open Access Journals (Sweden)

    Emanuel George Oprea

    2015-11-01

    Full Text Available The actual Romanian territory belongs to Carpatho-Danubian Space and to Ancient Europe. The Ancient European Society was a vast cultural entity based on a theocratic, matriarchal society, peaceful and art creating.Temples of Sarmizegetusa have given rise to several theories over time, proven by historians with the most diverse arguments. The largest complex of temples and sanctuaries was founded in Sarmizegetusa Regia, the Dacian’s main fortress and ancient capital of Dacia in the time of King Decebalus. The mysterious form of settlements has led researchers to the conclusion that the locations were astronomical observation shrines. Among the places of Dacian worship in Orastie Mountains the most impressive is the Great Circular Sanctuary, used to perform some celestial observations, and also as original solar calendar. This paper had the purpose to re-discover the Dacian Civilization and Dacian cosmogony based on the accumulated knowledge upon our country’s past.

  12. Did the ancient egyptians discover Algol?

    Science.gov (United States)

    Jetsu, L.; Porceddu, S.; Porceddu, S.; Lyytinen, J.; Kajatkari, P.; Markkanen, T.; Toivari-Viitala, J.

    2013-02-01

    Fabritius discovered the first variable star, Mira, in 1596. Holwarda determined the 11 months period of Mira in 1638. Montanari discovered the next variable star, Algol, in 1669. Its period, 2.867 days, was determined by Goodricke (178). Algol was associated with demon-like creatures, "Gorgon" in ancient Greek and "ghoul" in ancient Arab mythology. This indicates that its variability was discovered much before 1669 (Wilk 1996), but this mythological evidence is ambiguous (Davis 1975). For thousands of years, the Ancient Egyptian Scribes (AES) observed stars for timekeeping in a region, where there are nearly 300 clear nights a year. We discovered a significant periodicity of 2.850 days in their calendar for lucky and unlucky days dated to 1224 BC, "the Cairo Calendar". Several astrophysical and astronomical tests supported our conclusion that this was the period of Algol three millennia ago. The "ghoulish habits" of Algol could explain this 0.017 days period increase (Battersby 2012).

  13. Comparative Screening of Digestion Tract Toxic Genes in Proteus mirabilis.

    Science.gov (United States)

    Shi, Xiaolu; Lin, Yiman; Qiu, Yaqun; Li, Yinghui; Jiang, Min; Chen, Qiongcheng; Jiang, Yixiang; Yuan, Jianhui; Cao, Hong; Hu, Qinghua; Huang, Shenghe

    2016-01-01

    Proteus mirabilis is a common urinary tract pathogen, and may induce various inflammation symptoms. Its notorious ability to resist multiple antibiotics and to form urinary tract stones makes its treatment a long and painful process, which is further challenged by the frequent horizontal gene transferring events in P. mirabilis genomes. Three strains of P. mirabilis C02011/C04010/C04013 were isolated from a local outbreak of a food poisoning event in Shenzhen, China. Our hypothesis is that new genes may have been acquired horizontally to exert the digestion tract infection and toxicity. The functional characterization of these three genomes shows that each of them independently acquired dozens of virulent genes horizontally from the other microbial genomes. The representative strain C02011 induces the symptoms of both vomit and diarrhea, and has recently acquired a complete type IV secretion system and digestion tract toxic genes from the other bacteria.

  14. Massive gene swamping among cheese-making Penicillium fungi

    Directory of Open Access Journals (Sweden)

    Jeanne Ropars

    2015-03-01

    Full Text Available Horizontal gene transfers (HGT, i.e., the transmission of genetic material between species not directly attributable to meiotic gene exchange, have long been acknowledged as a major driver of prokaryotic evolution and is increasingly recognized as an important source of adaptation in eukaryotes. In fungi in particular, many convincing examples of HGT have been reported to confer selective advantages on the recipient fungal host, either promoting fungal pathogenicity on plants or increasing their toxicity by the acquisition of secondary metabolic clusters, resulting in adaptation to new niches and in some cases eventually even in speciation. These horizontal gene transfers involve single genes, complete metabolic pathways or even entire chromosomes. A recent study has uncovered multiple recent horizontal transfers of a 575 kb genomic island in cheese Penicillium fungi, representing ca. 2% of the Penicillium roqueforti’s genome, that may confer selective advantage in the competing cheese environment where bacteria and fungi occur. Novel phylogenomic methods are being developed, revealing massive HGT among fungi. Altogether, these recent studies indicate that HGT is a crucial mechanism of rapid adaptation, even among eukaryotes.

  15. Deep sequencing revealed molecular signature of horizontal gene transfer of plant like transcripts in the mosquito Anopheles culicifacies: an evolutionary puzzle [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Punita Sharma

    2015-12-01

    Full Text Available In prokaryotes, horizontal gene transfer (HGT has been regarded as an important evolutionary drive to acquire and retain beneficial genes for their survival in diverse ecologies. However, in eukaryotes, the functional role of HGTs remains questionable, although current genomic tools are providing increased evidence of acquisition of novel traits within non-mating metazoan species. Here, we provide another transcriptomic evidence for the acquisition of massive plant genes in the mosquito, Anopheles culicifacies. Our multiple experimental validations including genomic PCR, RT-PCR, real-time PCR, immuno-blotting and immuno-florescence microscopy, confirmed that plant like transcripts (PLTs are of mosquito origin and may encode functional proteins. A comprehensive molecular analysis of the PLTs and ongoing metagenomic analysis of salivary microbiome provide initial clues that mosquitoes may have survival benefits through the acquisition of nuclear as well as chloroplast encoded plant genes. Our findings of PLTs further support the similar questionable observation of HGTs in other higher organisms, which is still a controversial and debatable issue in the community of evolutionists. We believe future understanding of the underlying mechanism of the feeding associated molecular responses may shed new insights in the functional role of PLTs in the mosquito.

  16. Comparative analysis of the full genome of Helicobacter pylori isolate Sahul64 identifies genes of high divergence.

    Science.gov (United States)

    Lu, Wei; Wise, Michael J; Tay, Chin Yen; Windsor, Helen M; Marshall, Barry J; Peacock, Christopher; Perkins, Tim

    2014-03-01

    Isolates of Helicobacter pylori can be classified phylogeographically. High genetic diversity and rapid microevolution are a hallmark of H. pylori genomes, a phenomenon that is proposed to play a functional role in persistence and colonization of diverse human populations. To provide further genomic evidence in the lineage of H. pylori and to further characterize diverse strains of this pathogen in different human populations, we report the finished genome sequence of Sahul64, an H. pylori strain isolated from an indigenous Australian. Our analysis identified genes that were highly divergent compared to the 38 publically available genomes, which include genes involved in the biosynthesis and modification of lipopolysaccharide, putative prophage genes, restriction modification components, and hypothetical genes. Furthermore, the virulence-associated vacA locus is a pseudogene and the cag pathogenicity island (cagPAI) is not present. However, the genome does contain a gene cluster associated with pathogenicity, including dupA. Our analysis found that with the addition of Sahul64 to the 38 genomes, the core genome content of H. pylori is reduced by approximately 14% (∼170 genes) and the pan-genome has expanded from 2,070 to 2,238 genes. We have identified three putative horizontally acquired regions, including one that is likely to have been acquired from the closely related Helicobacter cetorum prior to speciation. Our results suggest that Sahul64, with the absence of cagPAI, highly divergent cell envelope proteins, and a predicted nontransportable VacA protein, could be more highly adapted to ancient indigenous Australian people but with lower virulence potential compared to other sequenced and cagPAI-positive H. pylori strains.

  17. Evolutionary Significance of Wolbachia-to-Animal Horizontal Gene Transfer: Female Sex Determination and the f Element in the Isopod Armadillidium vulgare.

    Science.gov (United States)

    Cordaux, Richard; Gilbert, Clément

    2017-07-21

    An increasing number of horizontal gene transfer (HGT) events from bacteria to animals have been reported in the past years, many of which involve Wolbachia bacterial endosymbionts and their invertebrate hosts. Most transferred Wolbachia genes are neutrally-evolving fossils embedded in host genomes. A remarkable case of Wolbachia HGT for which a clear evolutionary significance has been demonstrated is the " f element", a nuclear Wolbachia insert involved in female sex determination in the terrestrial isopod Armadillidium vulgare . The f element represents an instance of bacteria-to-animal HGT that has occurred so recently that it was possible to infer the donor (feminizing Wolbachia closely related to the w VulC Wolbachia strain of A. vulgare ) and the mechanism of integration (a nearly complete genome inserted by micro-homology-mediated recombination). In this review, we summarize our current knowledge of the f element and discuss arising perspectives regarding female sex determination, unstable inheritance, population dynamics and the molecular evolution of the f element. Overall, the f element unifies three major areas in evolutionary biology: symbiosis, HGT and sex determination. Its characterization highlights the tremendous impact sex ratio distorters can have on the evolution of sex determination mechanisms and sex chromosomes in animals and plants.

  18. Evolutionary Significance of Wolbachia-to-Animal Horizontal Gene Transfer: Female Sex Determination and the f Element in the Isopod Armadillidium vulgare

    Directory of Open Access Journals (Sweden)

    Richard Cordaux

    2017-07-01

    Full Text Available An increasing number of horizontal gene transfer (HGT events from bacteria to animals have been reported in the past years, many of which involve Wolbachia bacterial endosymbionts and their invertebrate hosts. Most transferred Wolbachia genes are neutrally-evolving fossils embedded in host genomes. A remarkable case of Wolbachia HGT for which a clear evolutionary significance has been demonstrated is the “f element”, a nuclear Wolbachia insert involved in female sex determination in the terrestrial isopod Armadillidium vulgare. The f element represents an instance of bacteria-to-animal HGT that has occurred so recently that it was possible to infer the donor (feminizing Wolbachia closely related to the wVulC Wolbachia strain of A. vulgare and the mechanism of integration (a nearly complete genome inserted by micro-homology-mediated recombination. In this review, we summarize our current knowledge of the f element and discuss arising perspectives regarding female sex determination, unstable inheritance, population dynamics and the molecular evolution of the f element. Overall, the f element unifies three major areas in evolutionary biology: symbiosis, HGT and sex determination. Its characterization highlights the tremendous impact sex ratio distorters can have on the evolution of sex determination mechanisms and sex chromosomes in animals and plants.

  19. Ancient Wisdom, Applied Knowledge for a Sustainable Future

    Science.gov (United States)

    Peterson, K.; Philippe, R. Elde; Dardar, T. M. Elde

    2017-12-01

    Ancient wisdom informs traditional knowledges that guide Indigenous communities on how to interact with the world. These knowledges and the ancient wisdom have been the life-giving forces that have prevented the complete genocide of Indigenous peoples, and is also the wisdom that is rejuvenating ancient ways that will take the world into a future that embraces the seventh generation philosophy.. Western scientists and agency representatives are learning from the work and wisdom of Native Americans. This presentation will share the ways in which the representatives of two Tribes along the coast of Louisiana have been helping to educate and apply their work with Western scientists.

  20. Radiocarbon ages of Sorori ancient rice of Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong Ja, E-mail: kjkim@kigam.re.kr [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Lee, Yung-Jo; Woo, Jong-Yoon [Institute of Korean Prehistory, Cheongju (Korea, Republic of); Jull, A.J. Timothy [NSF Arizona AMS Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2013-01-15

    Samples of Sorori ancient rice were excavated in 1998 from the Sorori Paleolithic site located at Sorori, Oksan-myeon, Cheong-won County in Chungcheongbuk-do, Korea. We have made new radiocarbon measurements for Sorori samples in 2009 at the NSF Arizona AMS Laboratory. Both ancient rice samples and surrounded peat from the Sorori site were dated. The AMS results confirmed that the ages of the rice and peat soil were 12,520 {+-} 150 and 12,552 {+-} 90 BP, respectively. These radiocarbon ages are consistent with the previously published data of quasi rice measured at Seoul National University and confirm that the Sorori rice is the oldest ancient rice currently reported.

  1. Cell-specific cre recombinase expression allows selective ablation of glutamate receptors from mouse horizontal cells.

    Directory of Open Access Journals (Sweden)

    Sebastian Ströh

    Full Text Available In the mouse retina, horizontal cells form an electrically coupled network and provide feedback signals to photoreceptors and feedforward signals to bipolar cells. Thereby, horizontal cells contribute to gain control at the first visual synapse and to the antagonistic organization of bipolar and ganglion cell receptive fields. However, the nature of horizontal cell output remains a matter of debate, just as the exact contribution of horizontal cells to center-surround antagonism. To facilitate studying horizontal cell function, we developed a knockin mouse line which allows ablating genes exclusively in horizontal cells. This knockin line expresses a Cre recombinase under the promoter of connexin57 (Cx57, a gap junction protein only expressed in horizontal cells. Consistently, in Cx57+/Cre mice, Cre recombinase is expressed in almost all horizontal cells (>99% and no other retinal neurons. To test Cre activity, we crossbred Cx57+/Cre mice with a mouse line in which exon 11 of the coding sequence for the ionotropic glutamate receptor subunit GluA4 was flanked by two loxP sites (GluA4fl/fl. In GluA4fl/fl:Cx57+/Cre mice, GluA4 immunoreactivity was significantly reduced (∼ 50% in the outer retina where horizontal cells receive photoreceptor inputs, confirming the functionality of the Cre/loxP system. Whole-cell patch-clamp recordings from isolated horizontal cell somata showed a reduction of glutamate-induced inward currents by ∼ 75%, suggesting that the GluA4 subunit plays a major role in mediating photoreceptor inputs. The persistent current in GluA4-deficient cells is mostly driven by AMPA and to a very small extent by kainate receptors as revealed by application of the AMPA receptor antagonist GYKI52466 and concanavalin A, a potentiator of kainate receptor-mediated currents. In summary, the Cx57+/Cre mouse line provides a versatile tool for studying horizontal cell function. GluA4fl/fl:Cx57+/Cre mice, in which horizontal cells receive less

  2. Cell-Specific Cre Recombinase Expression Allows Selective Ablation of Glutamate Receptors from Mouse Horizontal Cells

    Science.gov (United States)

    Janssen-Bienhold, Ulrike; Schultz, Konrad; Cimiotti, Kerstin; Weiler, Reto; Willecke, Klaus; Dedek, Karin

    2013-01-01

    In the mouse retina, horizontal cells form an electrically coupled network and provide feedback signals to photoreceptors and feedforward signals to bipolar cells. Thereby, horizontal cells contribute to gain control at the first visual synapse and to the antagonistic organization of bipolar and ganglion cell receptive fields. However, the nature of horizontal cell output remains a matter of debate, just as the exact contribution of horizontal cells to center-surround antagonism. To facilitate studying horizontal cell function, we developed a knockin mouse line which allows ablating genes exclusively in horizontal cells. This knockin line expresses a Cre recombinase under the promoter of connexin57 (Cx57), a gap junction protein only expressed in horizontal cells. Consistently, in Cx57+/Cre mice, Cre recombinase is expressed in almost all horizontal cells (>99%) and no other retinal neurons. To test Cre activity, we crossbred Cx57+/Cre mice with a mouse line in which exon 11 of the coding sequence for the ionotropic glutamate receptor subunit GluA4 was flanked by two loxP sites (GluA4fl/fl). In GluA4fl/fl:Cx57+/Cre mice, GluA4 immunoreactivity was significantly reduced (∼50%) in the outer retina where horizontal cells receive photoreceptor inputs, confirming the functionality of the Cre/loxP system. Whole-cell patch-clamp recordings from isolated horizontal cell somata showed a reduction of glutamate-induced inward currents by ∼75%, suggesting that the GluA4 subunit plays a major role in mediating photoreceptor inputs. The persistent current in GluA4-deficient cells is mostly driven by AMPA and to a very small extent by kainate receptors as revealed by application of the AMPA receptor antagonist GYKI52466 and concanavalin A, a potentiator of kainate receptor-mediated currents. In summary, the Cx57+/Cre mouse line provides a versatile tool for studying horizontal cell function. GluA4fl/fl:Cx57+/Cre mice, in which horizontal cells receive less excitatory input

  3. An Ancient Inca Tax and Metallurgy in Peru

    Science.gov (United States)

    Journal of Chemical Education, 2007

    2007-01-01

    The discovery of ancient Inca tax rulers and other metallurgical objects in Peru show that the ancient civilizations of the country smelted metals. The analysis shows that the smelters in Peru switched from the production of copper to silver after a tax was imposed on them by the Inca rulers.

  4. Neutron activation analysis of some ancient and modern Chinese Jun Porcelain samples

    International Nuclear Information System (INIS)

    Gao Zhengyao; Wang Jie; Chen Songhua; Huang Zhongxiang; Han Song; Jia Xiuqin

    1997-01-01

    Up to 43 glaze and body samples of ancient and modern Chinese Jun Porcelain and other porcelain are chosen and contents of 36 elements for each sample are determined by NAA. The NAA data are then analysed by the fuzzy cluster method. The result shows that although the ancient Jun Porcelain samples span leaped 600 years and are from different kilns and their glaze colors are utterly different, they have a long-term, stable and mainly the same supply of raw material. The relation between ancient Jun Porcelain and ancient Ru Porcelain is also preliminarily analysed. It is found that only few modern Jun Porcelain samples are similar to ancient Jun Porcelain but the majority of them are different from ancient ones

  5. Reconstructing an Ancient Wonder.

    Science.gov (United States)

    Imhof, Christopher J.

    2001-01-01

    Describes a Montessori class project involving the building of a model of the ancient Briton monument, Stonehenge. Illustrates how the flexibility of the Montessori elementary curriculum encourages children to make their own toys and learn from the process. (JPB)

  6. Ancient DNA provides new insight into the maternal lineages and domestication of Chinese donkeys.

    Science.gov (United States)

    Han, Lu; Zhu, Songbiao; Ning, Chao; Cai, Dawei; Wang, Kai; Chen, Quanjia; Hu, Songmei; Yang, Junkai; Shao, Jing; Zhu, Hong; Zhou, Hui

    2014-11-30

    The donkey (Equus asinus) is an important domestic animal that provides a reliable source of protein and method of transportation for many human populations. However, the process of domestication and the dispersal routes of the Chinese donkey are still unclear, as donkey remains are sparse in the archaeological record and often confused with horse remains. To explore the maternal origins and dispersal route of Chinese donkeys, both mitochondrial DNA D-loop and cytochrome b gene fragments of 21 suspected donkey remains from four archaeological sites in China were amplified and sequenced. Molecular methods of species identification show that 17 specimens were donkeys and three samples had the maternal genetic signature of horses. One sample that dates to about 20,000 years before present failed to amplify. In this study, the phylogenetic analysis reveals that ancient Chinese donkeys have high mitochondrial DNA diversity and two distinct mitochondrial maternal lineages, known as the Somali and Nubian lineages. These results indicate that the maternal origin of Chinese domestic donkeys was probably related to the African wild ass, which includes the Nubian wild ass (Equus africanus africanus) and the Somali wild ass (Equus africanus somaliensis). Combined with historical records, the results of this study implied that domestic donkeys spread into west and north China before the emergence of the Han dynasty. The number of Chinese domestic donkeys had increased primarily to meet demand for the expansion of trade, and they were likely used as commodities or for shipping goods along the Silk Road during the Tang Dynasty, when the Silk Road reached its golden age. This study is the first to provide valuable ancient animal DNA evidence for early trade between African and Asian populations. The ancient DNA analysis of Chinese donkeys also sheds light on the dynamic process of the maternal origin, domestication, and dispersal route of ancient Chinese donkeys.

  7. Mitogenomic analyses from ancient DNA

    DEFF Research Database (Denmark)

    Paijmans, Johanna L. A.; Gilbert, Tom; Hofreiter, Michael

    2013-01-01

    The analysis of ancient DNA is playing an increasingly important role in conservation genetic, phylogenetic and population genetic analyses, as it allows incorporating extinct species into DNA sequence trees and adds time depth to population genetics studies. For many years, these types of DNA...... analyses (whether using modern or ancient DNA) were largely restricted to the analysis of short fragments of the mitochondrial genome. However, due to many technological advances during the past decade, a growing number of studies have explored the power of complete mitochondrial genome sequences...... yielded major progress with regard to both the phylogenetic positions of extinct species, as well as resolving population genetics questions in both extinct and extant species....

  8. Ancient Egypt in our Cultural Heritage?

    Directory of Open Access Journals (Sweden)

    Vera Vasiljević

    2016-02-01

    Full Text Available Inspiration derived from ancient Egypt is usually expressed through the Egyptian motifs in arts and popular culture of the 19th and 20th centuries, as well as through the non-scientific interpretations of the culture, very much based upon the Renaissance ones. The number and variety of material and non-material traces of this fascination are most expressed in the countries where, along with the early support for the institutional development of Egyptology, there existed economically potent educated middle classes (Western and Central Europe, USA, but may also be traced elsewhere. The public fascination by ancient Egypt has not ceased by the times of foundation of Egyptology, marked by the decipherment of the hieroglyphic script in 1822. Until the end of the 20th century Egyptologists have rarely dealt with the prelude to their discipline, limiting their interest to the critical approach to ancient sources and to noting the attempts to interpret the hieroglyphic script and the function of pyramids. However, the rising importance of the reception studies in other disciplines raised the interest of Egyptologists for the "fascination of Egypt", thus changing the status of various modes of expressing "Egyptomania" – they have thus become a part of the cultural heritage, registered, documented, preserved and studied. The research of this kind is only beginning in Serbia. The line of inquiry enhances the knowledge of the scope, manifestations and roles of the interest in Egypt, not limited by the national or political borders. On the other hand, the existence of the cultural heritage similar to the wider European view of ancient Egypt – short remarks by Jerotej Račanin, Kandor by Atanasije Stojković, the usage of architectural motifs derived from Egypt, the emergence of small private collections, to mention several early examples – all show that the research into the reception of ancient Egypt may contribute to the knowledge about the history

  9. The rights of patients as consumers: An ancient view.

    Science.gov (United States)

    Barapatre, Nishant Bhimraj; Joglekar, Vishnu Prabhakar

    2016-01-01

    As far as the rights of consumers are concerned, the International Organization of Consumer's Union (IOCU) in 1983 has specified about the eight rights of a consumer. The Consumer Protection Act (CPA), 1986 then prescribed six "Rights of Consumers," which are protected under the act. However, these rights can be observed in the ancient Indian texts such as Brihat-trayee , Narad Smruti , and Kautilya Arthashastra ., in the form of rights given to patients. For the purpose of present study, the implemented methodology includes - (1) study of the consumer rights described by IOCU and CPA, (2) detailed review of literature for observance of replication of these consumer rights in the ancient Indian texts and (3) a comparative study of the present consumer rights with the rights of patients observed in ancient Indian texts. This study shows that the substance of consumer rights is not a recent evolution, but the foundation of these rights has been laid well beforehand in the ancient times, which were provided to the patients by medical profession as well as by the rulers. The current scenario of protection of consumer rights is the replication of this ancient practice only.

  10. Ancient Human Parasites in Ethnic Chinese Populations.

    Science.gov (United States)

    Yeh, Hui-Yuan; Mitchell, Piers D

    2016-10-01

    Whilst archaeological evidence for many aspects of life in ancient China is well studied, there has been much less interest in ancient infectious diseases, such as intestinal parasites in past Chinese populations. Here, we bring together evidence from mummies, ancient latrines, and pelvic soil from burials, dating from the Neolithic Period to the Qing Dynasty, in order to better understand the health of the past inhabitants of China and the diseases endemic in the region. Seven species of intestinal parasite have been identified, namely roundworm, whipworm, Chinese liver fluke, oriental schistosome, pinworm, Taenia sp. tapeworm, and the intestinal fluke Fasciolopsis buski . It was found that in the past, roundworm, whipworm, and Chinese liver fluke appear to have been much more common than the other species. While roundworm and whipworm remained common into the late 20th century, Chinese liver fluke seems to have undergone a marked decline in its prevalence over time. The iconic transport route known as the Silk Road has been shown to have acted as a vector for the transmission of ancient diseases, highlighted by the discovery of Chinese liver fluke in a 2,000 year-old relay station in northwest China, 1,500 km outside its endemic range.

  11. Evidence of ancient genome reduction in red algae (Rhodophyta).

    Science.gov (United States)

    Qiu, Huan; Price, Dana C; Yang, Eun Chan; Yoon, Hwan Su; Bhattacharya, Debashish

    2015-08-01

    Red algae (Rhodophyta) comprise a monophyletic eukaryotic lineage of ~6,500 species with a fossil record that extends back 1.2 billion years. A surprising aspect of red algal evolution is that sequenced genomes encode a relatively limited gene inventory (~5-10 thousand genes) when compared with other free-living algae or to other eukaryotes. This suggests that the common ancestor of red algae may have undergone extensive genome reduction, which can result from lineage specialization to a symbiotic or parasitic lifestyle or adaptation to an extreme or oligotrophic environment. We gathered genome and transcriptome data from a total of 14 red algal genera that represent the major branches of this phylum to study genome evolution in Rhodophyta. Analysis of orthologous gene gains and losses identifies two putative major phases of genome reduction: (i) in the stem lineage leading to all red algae resulting in the loss of major functions such as flagellae and basal bodies, the glycosyl-phosphatidylinositol anchor biosynthesis pathway, and the autophagy regulation pathway; and (ii) in the common ancestor of the extremophilic Cyanidiophytina. Red algal genomes are also characterized by the recruitment of hundreds of bacterial genes through horizontal gene transfer that have taken on multiple functions in shared pathways and have replaced eukaryotic gene homologs. Our results suggest that Rhodophyta may trace their origin to a gene depauperate ancestor. Unlike plants, it appears that a limited gene inventory is sufficient to support the diversification of a major eukaryote lineage that possesses sophisticated multicellular reproductive structures and an elaborate triphasic sexual cycle. © 2015 Phycological Society of America.

  12. Non-destructive sampling of ancient insect DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Elias, Scott; Gilbert, Tom

    2009-01-01

    BACKGROUND: A major challenge for ancient DNA (aDNA) studies on insect remains is that sampling procedures involve at least partial destruction of the specimens. A recent extraction protocol reveals the possibility of obtaining DNA from past insect remains without causing visual morphological...... of 77-204 base pairs (-bp) in size using species-specific and general insect primers. CONCLUSION/SIGNIFICANCE: The applied non-destructive DNA extraction method shows promising potential on insect museum specimens of historical age as far back as AD 1820, but less so on the ancient permafrost......-preserved insect fossil remains tested, where DNA was obtained from samples up to ca. 26,000 years old. The non-frozen sediment DNA approach appears to have great potential for recording the former presence of insect taxa not normally preserved as macrofossils and opens new frontiers in research on ancient...

  13. Applied investigation of Moessbauer effect for the famous ancient chinese porcelains

    International Nuclear Information System (INIS)

    Gao Zhengyao; Chen Songhua; Shen Zuocheng

    1996-10-01

    The famous Ru porcelain, Jun porcelain and Guan porcelain of Song Dynasty and Yuan Dynasty are analyzed. The Moessbauer parameters of the ancient porcelains and the imitative ancient porcelains are compared. The firing techniques, coloring mechanism and microstructures of the ancient Chinese porcelains have been discussed. (7 figs., 4 tabs.)

  14. Ancient Chinese literature reveals pathways of eggplant domestication.

    Science.gov (United States)

    Wang, Jin-Xiu; Gao, Tian-Gang; Knapp, Sandra

    2008-12-01

    Changes in key traits occurring during the processes of plant domestication have long been subjects of debate. Only in the case of genetic analysis or with extensive plant remains can specific sets of changes be documented. Historical details of the plant domestication processes are rare and other evidence of morphological change can be difficult to obtain, especially for those vegetables that lack a substantial body of archaeological data. Botanical records chronicled in the ancient literature of established ancient civilizations, such as that of China, are invaluable resources for the study and understanding of the process of plant domestication. Here, the considerable body of ancient Chinese literature is used to explore the domestication process that has occurred with the eggplant (Solanum melongena), an important vegetable in Old World. Information about eggplant domestication in the ancient Chinese literature was retrieved using a variety of methods. The information obtained was then sorted by taxon, examined and taxonomic identifications verified. It was found that the earliest record of the eggplant documented in ancient Chinese literature was in a work from 59 bc. As far as is known, this is the earliest reliable and accurately dated record of eggplant in cultivation. The analysis reveals that the process of domestication of the eggplant in China involved three principal aspects of fruit quality: size, shape and taste. These traits were actively and gradually selected; fruit size changed from small to large, taste changed from not palatable to what was termed at the time sweetish, and that over time, a wider variety of fruit shapes was cultivated. The results indicate that, in addition to data gleaned from archaeology and genetics, evidence as to changes in key traits occurring during the process of plant domestication and selective forces responsible for these changes can be traced through the ancient literature in some civilizations.

  15. Notions of "Rhetoric as Epistemic" in Ancient Greece.

    Science.gov (United States)

    Benoit, William L.

    The notion that rhetoric (and to a lesser extent, argument) is epistemic is an increasingly popular one today, although it can be traced to ancient Greece. The notion holds that rhetoric, or the art of persuasion, creates and shapes knowledge. Two ancient authors--Aristophanes and Plato--provide evidence that others had notions of rhetoric as…

  16. Surgical history of ancient China: Part 2.

    Science.gov (United States)

    Fu, Louis

    2010-03-01

    In this second part of ancient Chinese surgical history, the practice of bone setting in China began around 3000 years ago. Throughout this period, significant progress was made, some highlights of which are cited. These methods, comparable with Western orthopaedic technique, are still being practised today. In conclusion, the possible reasons for the lack of advancement in operative surgery are discussed, within context of the cultural, social and religious background of ancient China.

  17. Social Norms in the Ancient Athenian Courts

    OpenAIRE

    Lanni, Adriaan M.

    2013-01-01

    Ancient Athens was a remarkably peaceful and well-ordered society by both ancient and contemporary standards. Scholars typically attribute Athens’ success to internalized norms and purely informal enforcement mechanisms. This article argues that the formal Athenian court system played a vital role in maintaining order by enforcing informal norms. This peculiar approach to norm enforcement compensated for apparent weaknesses in the state system of coercion. It mitigated the effects of under-e...

  18. Musical ensembles in Ancient Mesapotamia

    NARCIS (Netherlands)

    Krispijn, T.J.H.; Dumbrill, R.; Finkel, I.

    2010-01-01

    Identification of musical instruments from ancient Mesopotamia by comparing musical ensembles attested in Sumerian and Akkadian texts with depicted ensembles. Lexicographical contributions to the Sumerian and Akkadian lexicon.

  19. history repeats itself : saddam and the ancient mesopotamian royal

    African Journals Online (AJOL)

    harkhu

    ancient Mesopotamia (present day Iraq)2, from the fourth millennium3 until its incorporation into the ..... aspects of Mesopotamian culture that could not be separated from the other. Saddam, on the ..... site of ancient Babylon. Large parts of the ...

  20. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  1. Health benefits of ancient grains. Comparison among bread made with ancient, heritage and modern grain flours in human cultured cells.

    Science.gov (United States)

    Valli, Veronica; Taccari, Annalisa; Di Nunzio, Mattia; Danesi, Francesca; Bordoni, Alessandra

    2018-05-01

    Nowadays the higher nutritional value of whole grains compared to refined grains is recognized. In the last decade, there has been a renewed interest in the ancient wheat varieties for producing high-value food products with enhanced health benefits. This study compared two ancient grains, two heritage grains, and four modern grains grown in the same agronomic conditions considering not only their chemical characteristics, but also their biological effects. Whole grain flours were obtained and used to make bread. Bread was in vitro digested, the digesta were supplemented to HepG2 cells, and the biological effects of supplementation were evaluated. In addition, cells previously supplemented with the different digested bread types were then exposed to inflammatory agents to evidence possible protective effects of the pre-treatments. Despite the impossibility to discriminate bread made with different grains based on their chemical composition, results herein reported evidence that their supplementation to cultured cells exerts different effects, confirming the potential health benefits of ancient grains. This research represents an advancement for the evaluation of the apparent positive effects of ancient grains and the formulation of cereal-based products with added nutritional value. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. What can we learn from tobacco and other Solanaceae about horizontal DNA transfer?

    Czech Academy of Sciences Publication Activity Database

    Talianová, Martina; Janoušek, Bohuslav

    2011-01-01

    Roč. 98, č. 8 (2011), s. 1231-1242 ISSN 0002-9122 R&D Projects: GA ČR(CZ) GA521/08/0932; GA ČR(CZ) GD204/09/H002 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Agrobacterium * grafting * horizontal gene transfer Subject RIV: BO - Biophysics Impact factor: 2.664, year: 2011

  3. The contribution of microbial mats to the arsenic geochemistry of an ancient gold mine

    International Nuclear Information System (INIS)

    Drewniak, Lukasz; Maryan, Natalia; Lewandowski, Wiktor; Kaczanowski, Szymon; Sklodowska, Aleksandra

    2012-01-01

    The ancient Zloty Stok (SW Poland) gold mine is such an environment, where different microbial communities, able to utilize inorganic arsenic species As(III) and As(V), are found. The purpose of the present study was to (i) estimate prokaryotic diversity in the microbial mats in bottom sediments of this gold mine, (ii) identify microorganisms that can metabolize arsenic, and (iii) estimate their potential role in the arsenic geochemistry of the mine and in the environment. The oxidation/reduction experiments showed that the microbial mat community may significantly contribute to arsenic contamination in groundwater. The presence of both arsenite oxidizing and dissimilatory arsenate reducing bacteria in the mat was confirmed by the detection of arsenite oxidase and dissimilatory arsenate reductase genes, respectively. This work also demonstrated that microorganisms utilizing other compounds that naturally co-occur with arsenic are present within the microbial mat community and may contribute to the arsenic geochemistry in the environment. - Highlights: ► The microbial mats from this ancient gold mine are highly diverse community. ► As(III) oxidizing and As(V) reducing bacteria are present in the mats. ► As redox transformations are linked to the metabolism of microbial mats bacteria. ► Microbial mats play a crucial role in the As biogeochemical cycle within the mine. - The microbial mats from this ancient gold mine can mediate oxidation/reduction reaction of arsenic and in this way may significantly contribute to arsenic contamination in groundwater.

  4. Dating ancient Chinese celadon porcelain by neutron activation analysis and bayesian classification

    International Nuclear Information System (INIS)

    Xie Guoxi; Feng Songlin; Feng Xiangqian; Zhu Jihao; Yan Lingtong; Li Li

    2009-01-01

    Dating ancient Chinese porcelain is one of the most important and difficult problems in porcelain archaeological field. Eighteen elements in bodies of ancient celadon porcelains fired in Southern Song to Yuan period (AD 1127-1368) and Ming dynasty (AD 1368-1644), including La, Sm, U, Ce, etc., were determined by neutron activation analysis (NAA). After the outliers of experimental data were excluded and multivariate normal distribution was tested, and Bayesian classification was used for dating of 165 ancient celadon porcelain samples. The results show that 98.2% of total ancient celadon porcelain samples are classified correctly. It means that NAA and Bayesian classification are very useful for dating ancient porcelain. (authors)

  5. Second-harmonic generation imaging of collagen in ancient bone.

    Science.gov (United States)

    Thomas, B; McIntosh, D; Fildes, T; Smith, L; Hargrave, F; Islam, M; Thompson, T; Layfield, R; Scott, D; Shaw, B; Burrell, C L; Gonzalez, S; Taylor, S

    2017-12-01

    Second-harmonic generation imaging (SHG) captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  6. Ancient ports of Kalinga

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.

    which plied between Kalinga and south east Asian countries. Nanda Raja, is said to have attacked Kalinga with the intention of getting access to the sea for the landlocked Kingdom of Magadha (Bihar). The ancient texa Artha Sastra (3rd-4th century B...

  7. The doubly conditioned frequency spectrum does not distinguish between ancient population structure and hybridization

    KAUST Repository

    Eriksson, Anders

    2014-03-13

    Distinguishing between hybridization and population structure in the ancestral species is a key challenge in our understanding of how permeable species boundaries are to gene flow. The doubly conditioned frequency spectrum (dcfs) has been argued to be a powerful metric to discriminate between these two explanations, and it was used to argue for hybridization between Neandertal and anatomically modern humans. The shape of the observed dcfs for these two species cannot be reproduced by a model that represents ancient population structure in Africa with two populations, while adding hybridization produces realistic shapes. In this letter, we show that this result is a consequence of the spatial coarseness of the demographic model and that a spatially structured stepping stone model can generate realistic dcfs without hybridization. This result highlights how inferences on hybridization between recently diverged species can be strongly affected by the choice of how population structure is represented in the underlying demographic model. We also conclude that the dcfs has limited power in distinguishing between the signals left by hybridization and ancient structure. 2014 The Author.

  8. The doubly conditioned frequency spectrum does not distinguish between ancient population structure and hybridization

    KAUST Repository

    Eriksson, Anders; Manica, Andrea

    2014-01-01

    Distinguishing between hybridization and population structure in the ancestral species is a key challenge in our understanding of how permeable species boundaries are to gene flow. The doubly conditioned frequency spectrum (dcfs) has been argued to be a powerful metric to discriminate between these two explanations, and it was used to argue for hybridization between Neandertal and anatomically modern humans. The shape of the observed dcfs for these two species cannot be reproduced by a model that represents ancient population structure in Africa with two populations, while adding hybridization produces realistic shapes. In this letter, we show that this result is a consequence of the spatial coarseness of the demographic model and that a spatially structured stepping stone model can generate realistic dcfs without hybridization. This result highlights how inferences on hybridization between recently diverged species can be strongly affected by the choice of how population structure is represented in the underlying demographic model. We also conclude that the dcfs has limited power in distinguishing between the signals left by hybridization and ancient structure. 2014 The Author.

  9. Ancient Greek in modern language of medicine

    OpenAIRE

    Marković Vera

    2007-01-01

    In order to standardize language of medicine, it is essential to have a good command of ancient Greek and Latin. We cannot deny a huge impact of ancient Greek medicine on medical terminology. Compounds of Greek origin related to terms for organs, illnesses, inflammations, surgical procedures etc. have been listed as examples. They contain Greek prefixes and suffixes transcribed into Latin and they have been analyzed. It may be concluded that the modern language of medicine basically represent...

  10. From ancient Greek Logos to European rationality

    OpenAIRE

    APOSTOLOPOULOU GEORGIA

    2016-01-01

    Because of history, culture, and politics, European identity has its archetypical elements in ancient Greek culture. Ancient Greek philosophy brought Logos to fore and defined it as the crucial problem and the postulate of the human. We translate the Greek term Logos in English as reason or rationality. These terms, however, do not cover the semantic field of Logos since this includes, among other things, order of being, ground, language, argument etc. The juxtaposition of Logos (reason) to m...

  11. An ancient spliceosomal intron in the ribosomal protein L7a gene (Rpl7a of Giardia lamblia

    Directory of Open Access Journals (Sweden)

    Gray Michael W

    2005-08-01

    Full Text Available Abstract Background Only one spliceosomal-type intron has previously been identified in the unicellular eukaryotic parasite, Giardia lamblia (a diplomonad. This intron is only 35 nucleotides in length and is unusual in possessing a non-canonical 5' intron boundary sequence, CT, instead of GT. Results We have identified a second spliceosomal-type intron in G. lamblia, in the ribosomal protein L7a gene (Rpl7a, that possesses a canonical GT 5' intron boundary sequence. A comparison of the two known Giardia intron sequences revealed extensive nucleotide identity at both the 5' and 3' intron boundaries, similar to the conserved sequence motifs recently identified at the boundaries of spliceosomal-type introns in Trichomonas vaginalis (a parabasalid. Based on these observations, we searched the partial G. lamblia genome sequence for these conserved features and identified a third spliceosomal intron, in an unassigned open reading frame. Our comprehensive analysis of the Rpl7a intron in other eukaryotic taxa demonstrates that it is evolutionarily conserved and is an ancient eukaryotic intron. Conclusion An analysis of the phylogenetic distribution and properties of the Rpl7a intron suggests its utility as a phylogenetic marker to evaluate particular eukaryotic groupings. Additionally, analysis of the G. lamblia introns has provided further insight into some of the conserved and unique features possessed by the recently identified spliceosomal introns in related organisms such as T. vaginalis and Carpediemonas membranifera.

  12. Insights into recent and ancient trends in the co-evolution of Earth and life as revealed by microbial genomics

    Science.gov (United States)

    Anderson, R. E.; Huber, J. A.; Parsons, C.; Stüeken, E.

    2017-12-01

    Since the origin of life over 4 billion years ago, life has fundamentally altered the habitability of Earth. Similarly, the environment molds the evolutionary trajectory of life itself through natural selection. Microbial genomes retain a "memory" of the co-evolution of life and Earth and can be analyzed to better understand trends and events in both the recent and distant past. To examine evolutionary trends in the more recent past, we have used metagenomics analyses to investigate which environmental factors play the strongest role in driving the evolution of microbes in deep-sea hydrothermal vents, which are thought to have been important habitats in the earliest stages of life's evolution. We have shown that microbial populations in a deep, basalt-hosted system appear to be under stronger purifying selection than populations inhabiting a cooler serpentinizing system less than 20 km away, suggesting that environmental context and geochemistry have an important impact on evolutionary rates and trends. We also found evidence that viruses play an important role in driving evolution in these habitats. Changing environmental conditions may also effect long-term evolutionary trends in Earth's distant past, as revealed by comparative genomics. By reconciling phylogenetic trees for microbial species with trees of metabolic genes, we can determine approximately when crucial metabolic genes began to spread across the tree of life through horizontal gene transfer. Using these methods, we conducted an analysis of the relative timing of the spread of genes related to the nitrogen cycle. Our results indicate that the rate of horizontal gene transfer for important genes related to denitrification increased after the Great Oxidation Event, concurrent with geochemical evidence for increasing availability of nitrate, suggesting that the oxygenation of the atmosphere and surface ocean may have been an important determining factor for the spread of denitrification genes across the

  13. Ancient analogues concerning stability and durability of cementitious wasteform

    International Nuclear Information System (INIS)

    Jiang, W.; Roy, D.M.

    1994-01-01

    The history of cementitious materials goes back to ancient times. The Greeks and Romans used calcined limestone and later developed pozzolanic cement by grinding together lime and volcanic ash called open-quotes pozzolanclose quotes which was first found near Port Pozzuoli, Italy. The ancient Chinese used lime-pozzolanic mixes to build the Great Wall. The ancient Egyptians used calcined impure gypsum to build the Great Pyramid of Cheops. The extraordinary stability and durability of these materials has impressed us, when so much dramatically damaged infrastructure restored by using modern portland cement now requires rebuilding. Stability and durability of cementitious materials have attracted intensive research interest and contractors' concerns, as does immobilization of radioactive and hazardous industrial waste in cementitious materials. Nuclear waste pollution of the environment and an acceptable solution for waste management and disposal constitute among the most important public concerns. The analogy of ancient cementitious materials to modern Portland cement could give us some clues to study their stability and durability. This present study examines selected results of studies of ancient building materials from France, Italy, China, and Egypt, combined with knowledge obtained from the behavior of modern portland cement to evaluate the potential for stability and durability of such materials in nuclear waste forms

  14. Setting the stage - building and working in an ancient DNA laboratory.

    Science.gov (United States)

    Knapp, Michael; Clarke, Andrew C; Horsburgh, K Ann; Matisoo-Smith, Elizabeth A

    2012-01-20

    With the introduction of next generation high throughput sequencing in 2005 and the resulting revolution in genetics, ancient DNA research has rapidly developed from an interesting but marginal field within evolutionary biology into one that can contribute significantly to our understanding of evolution in general and the development of our own species in particular. While the amount of sequence data available from ancient human, other animal and plant remains has increased dramatically over the past five years, some key limitations of ancient DNA research remain. Most notably, reduction of contamination and the authentication of results are of utmost importance. A number of studies have addressed different aspects of sampling, DNA extraction and DNA manipulation in order to establish protocols that most efficiently generate reproducible and authentic results. As increasing numbers of researchers from different backgrounds become interested in using ancient DNA technology to address key questions, the need for practical guidelines on how to construct and use an ancient DNA facility arises. The aim of this article is therefore to provide practical tips for building a state-of-the-art ancient DNA facility. It is intended to help researchers new to the field of ancient DNA research generally, and those considering the application of next generation sequencing, in their planning process. Copyright © 2011 Elsevier GmbH. All rights reserved.

  15. Functional Characterization of Bacteria Isolated from Ancient Arctic Soil Exposes Diverse Resistance Mechanisms to Modern Antibiotics

    Science.gov (United States)

    Perron, Gabriel G.; Whyte, Lyle; Turnbaugh, Peter J.; Goordial, Jacqueline; Hanage, William P.; Dantas, Gautam; Desai, Michael M.

    2015-01-01

    Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes. PMID:25807523

  16. Environmental Bacteriophages of the Emerging Enterobacterial Phytopathogen, Dickeya solani, Show Genomic Conservation and Capacity for Horizontal Gene Transfer between Their Bacterial Hosts

    Directory of Open Access Journals (Sweden)

    Andrew Day

    2017-08-01

    Full Text Available Dickeya solani is an economically important phytopathogen widespread in mainland Europe that can reduce potato crop yields by 25%. There are no effective environmentally-acceptable chemical systems available for diseases caused by Dickeya. Bacteriophages have been suggested for use in biocontrol of this pathogen in the field, and limited field trials have been conducted. To date only a small number of bacteriophages capable of infecting D. solani have been isolated and characterized, and so there is a need to expand the repertoire of phages that may have potential utility in phage therapy strategies. Here we describe 67 bacteriophages from environmental sources, the majority of which are members of the viral family Myoviridae. Full genomic sequencing of two isolates revealed a high degree of DNA identity with D. solani bacteriophages isolated in Europe in the past 5 years, suggesting a wide ecological distribution of this phage family. Transduction experiments showed that the majority of the new environmental bacteriophages are capable of facilitating efficient horizontal gene transfer. The possible risk of unintentional transfer of virulence or antibiotic resistance genes between hosts susceptible to transducing phages cautions against their environmental use for biocontrol, until specific phages are fully tested for transduction capabilities.

  17. The provenance study of Chinese ancient architectonical colored glaze by INAA

    International Nuclear Information System (INIS)

    Cheng Lin; Feng Songlin; Li Rongwu; Lue Zhirong; Li Guoxia

    2008-01-01

    The colored glazes are very popular and famous in Chinese ancient architectures. In order to exactly locate the provenance of ancient architectonical colored glazes, 196 pieces of ancient colored glaze bodies and porcelain bodies fired in Xiyue Temple and Lidipo kiln are analyzed by INAA. The results of factor analysis and some archaeological questions are reported and discussed in this paper

  18. The provenance study of Chinese ancient architectonical colored glaze by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Lin [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Radiation Center, Beijing Normal University, Beijing 100875 (China); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: chenglin@bnu.edu.cn; Feng Songlin [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li Rongwu [Department of Physics, Beijing Normal University, Beijing 100049 (China); Lue Zhirong [Shan' xi Provincial Institute of Cultural Relics and Archaeology, Xi' an 710054 (China); Li Guoxia [Institute of Physical Engineering, Zhengzhou University, Zhengzhou 450052 (China)

    2008-12-15

    The colored glazes are very popular and famous in Chinese ancient architectures. In order to exactly locate the provenance of ancient architectonical colored glazes, 196 pieces of ancient colored glaze bodies and porcelain bodies fired in Xiyue Temple and Lidipo kiln are analyzed by INAA. The results of factor analysis and some archaeological questions are reported and discussed in this paper.

  19. Single gene retrieval from thermally degraded DNA

    Indian Academy of Sciences (India)

    To simulate single gene retrieval from ancient DNA, several related factors have been investigated. By monitoring a 889 bp polymerase chain reaction (PCR) product and genomic DNA degradation, we find that heat and oxygen (especially heat) are both crucial factors influencing DNA degradation. The heat influence ...

  20. Horizontal drilling under Lake Erie

    Energy Technology Data Exchange (ETDEWEB)

    Meller, R.

    2001-07-01

    Drilling oil wells under Lake Erie calls for horizontal drilling wells to be drilled from shore out into the pay-zone under the lake. The nature and characteristics of horizontal wells as compared to vertical wells are explored. Considerations that have to be taken into account in drilling horizontal wells are explained (the degree of curvature, drilling fluid quality, geosteering in the pay-zone, steering instrumentation, measurements while drilling (MWD), logging while drilling (LWD)). The concept and reasons for extended reach wells are outlined, along with characteristic features of multilateral wells.

  1. Resurrecting ancient animal genomes: the extinct moa and more.

    Science.gov (United States)

    Huynen, Leon; Millar, Craig D; Lambert, David M

    2012-08-01

    Recently two developments have had a major impact on the field of ancient DNA (aDNA). First, new advances in DNA sequencing, in combination with improved capture/enrichment methods, have resulted in the recovery of orders of magnitude more DNA sequence data from ancient animals. Second, there has been an increase in the range of tissue types employed in aDNA. Hair in particular has proven to be very successful as a source of DNA because of its low levels of contamination and high level of ancient endogenous DNA. These developments have resulted in significant advances in our understanding of recently extinct animals: namely their evolutionary relationships, physiology, and even behaviour. Hair has been used to recover the first complete ancient nuclear genome, that of the extinct woolly mammoth, which then facilitated the expression and functional analysis of haemoglobins. Finally, we speculate on the consequences of these developments for the possibility of recreating extinct animals. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. PIXE study on ancient pottery from Chinese Shanghai area

    International Nuclear Information System (INIS)

    Cheng, H.S.; Zhang, Z.Q.; Song, J.; Gao, M.H.; Zhu, D.; Lin, J.W.; Feng, S.L.

    2006-01-01

    Shanghai is the largest city in China, and it also has a very long history. Archaeologists have found that six thousand yeas ago, there were ancient people living at Songze, Qingpu County, Shanghai. This paper reports the study of ancient potteries unearthed from the Guangfulin site located at Songjiang, Shanghai. The potteries unearthed from Guangfulin site belonged to two different culture types: the Liangzhu culture type (local culture) and a new culture, which might be derived from elsewhere. PIXE has been used to measure the chemical compositions of samples and factor analysis was used. Experimental results show that the compositions of the pottery from the two phases are different from each other. It means that the raw materials used to make the ancient pottery originate from different places. This results support the idea suggested by archaeologists that a group of ancient people migrated to the Shanghai area from some other place 4000 years ago

  3. X-ray analysis of pigments on ancient Egyptian monuments

    International Nuclear Information System (INIS)

    Uda, M.; Sassa, S.; Yoshioka, T.

    1999-01-01

    Ancient pigments were analyzed using PIXE and XRD methods in the laboratory, which were painted on ancient Egyptian monuments. On the other hand, those on monuments remaining with entire shape were investigated using the hand-held type of an XRF spectrometer and an X-ray diffractometer in the field. For the laboratory experiment, several wall fragments of the Malqata palace in ancient Egypt (18th Dynasty, ca. 1390 B.C.) were investigated. In the field experiment, the block of Ramesses II (19th Dynasty, ca. 1270 B.C.), the Wooden Coffin of Neb-sny (18th Dynasty, ca. 1400 B.C.), the Funerary Stele of Amenemhat (11th Dynasty, ca. 2000 B.C.), and the painted walls of the Tomb of Userhat (18th Dynasty, ca. 1400 B.C.) were investigated. From white and blue colored parts, huntite and Egyptian blue were found, respectively, which are a very rare mineral and an artificial pigment prepared only in ancient Egypt, respectively. (author)

  4. X-ray analysis of pigments on ancient Egyptian monuments

    Energy Technology Data Exchange (ETDEWEB)

    Uda, M.; Sassa, S.; Yoshioka, T. [Waseda Univ., Department of Materials Science and Engineering, Tokyo (JP)] [and others

    1999-07-01

    Ancient pigments were analyzed using PIXE and XRD methods in the laboratory, which were painted on ancient Egyptian monuments. On the other hand, those on monuments remaining with entire shape were investigated using the hand-held type of an XRF spectrometer and an X-ray diffractometer in the field. For the laboratory experiment, several wall fragments of the Malqata palace in ancient Egypt (18th Dynasty, ca. 1390 B.C.) were investigated. In the field experiment, the block of Ramesses II (19th Dynasty, ca. 1270 B.C.), the Wooden Coffin of Neb-sny (18th Dynasty, ca. 1400 B.C.), the Funerary Stele of Amenemhat (11th Dynasty, ca. 2000 B.C.), and the painted walls of the Tomb of Userhat (18th Dynasty, ca. 1400 B.C.) were investigated. From white and blue colored parts, huntite and Egyptian blue were found, respectively, which are a very rare mineral and an artificial pigment prepared only in ancient Egypt, respectively. (author)

  5. Second-harmonic generation imaging of collagen in ancient bone

    Directory of Open Access Journals (Sweden)

    B. Thomas

    2017-12-01

    Full Text Available Second-harmonic generation imaging (SHG captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  6. Divergence and Conservative Evolution of XTNX Genes in Land Plants

    Directory of Open Access Journals (Sweden)

    Yan-Mei Zhang

    2017-10-01

    Full Text Available The Toll-interleukin-1 receptor (TIR and Nucleotide-binding site (NBS domains are two major components of the TIR-NBS-leucine-rich repeat family plant disease resistance genes. Extensive functional and evolutionary studies have been performed on these genes; however, the characterization of a small group of genes that are composed of atypical TIR and NBS domains, namely XTNX genes, is limited. The present study investigated this specific gene family by conducting genome-wide analyses of 59 green plant genomes. A total of 143 XTNX genes were identified in 51 of the 52 land plant genomes, whereas no XTNX gene was detected in any green algae genomes, which indicated that XTNX genes originated upon emergence of land plants. Phylogenetic analysis revealed that the ancestral XTNX gene underwent two rounds of ancient duplications in land plants, which resulted in the formation of clades I/II and clades IIa/IIb successively. Although clades I and IIb have evolved conservatively in angiosperms, the motif composition difference and sequence divergence at the amino acid level suggest that functional divergence may have occurred since the separation of the two clades. In contrast, several features of the clade IIa genes, including the absence in the majority of dicots, the long branches in the tree, the frequent loss of ancestral motifs, and the loss of expression in all detected tissues of Zea mays, all suggest that the genes in this lineage might have undergone pseudogenization. This study highlights that XTNX genes are a gene family originated anciently in land plants and underwent specific conservative pattern in evolution.

  7. Horizontal Transfer of Small RNAs To and From Plants

    Directory of Open Access Journals (Sweden)

    Lu eHan

    2015-12-01

    Full Text Available Genetic information is traditionally thought to be transferred from parents to offspring. However, there is evidence indicating that gene transfer can also occur from microbes to higher species, such as plants, invertebrates and vertebrates. This horizontal transfer can be carried out by small RNAs (sRNAs. sRNAs have been recently reported to move across kingdoms as mobile signals, spreading silencing information toward targeted genes. sRNAs, especially microRNAs (miRNAs and small interfering RNAs (siRNAs, are non-coding molecules that control gene expression at the transcriptional or post-transcriptional level. Some sRNAs act in a cross-kingdom manner between animals and their parasites, but little is known about such sRNAs associated with plants. In this report, we provide a brief introduction to miRNAs that are transferred from plants to mammals/viruses and siRNAs that are transferred from microbes to plants. Both miRNAs and siRNAs can exert corresponding functions in the target organisms. Additionally, we provide information concerning a host-induced gene silencing (HIGS system as a potential application that utilizes the transgenic trafficking of RNA molecules to silence the genes of interacting organisms. Moreover, we lay out the controversial views regarding cross-kingdom miRNAs and call for better methodology and experimental design to confirm this unique function of miRNAs.

  8. Creative Ventures: Ancient Civilizations.

    Science.gov (United States)

    Stark, Rebecca

    The open-ended activities in this book are designed to extend the imagination and creativity of students and encourage students to examine their feelings and values about historic eras. Civilizations addressed include ancient Egypt, Greece, Rome, Mayan, Stonehenge, and Mesopotamia. The activities focus upon the cognitive and affective pupil…

  9. Penile representations in ancient Greek art.

    Science.gov (United States)

    Rempelakos, L; Tsiamis, C; Poulakou-Rebelakou, E

    2013-12-01

    The presentation of the cult of phallus in ancient Greece and the artistic appearance of the phenomenon on vase figures and statues, as indicative of the significant role of the male genitalia in all fertility ceremonies. The examination of a great number of penile representations from the ancient Greek pottery and sculpture and the review of the ancient theater plays (satiric dramas and comedies ). Phallus in artistic representation is connected either with gods of fertility, such as the goat-footed and horned Pan or the ugly dwarf Priapus or the semi-animal nailed figures Satyrs, devotees of the god Dionysus accompanying him in all ritual orgiastic celebrations. Phallus also symbolizes good luck, health and sexuality: people bear or wear artificial phalli exactly like the actors as part of their costume or carry huge penises during the festive ritual processions. On the contrary, the Olympic gods or the ordinary mortals are not imaged ithyphallic; the ideal type of male beauty epitomized in classical sculpture, normally depicts genitals of average or less than average size. It is noteworthy that many of these images belong to athletes during or immediately after hard exercise with the penis shrunk. The normal size genitalia may have been simply a convention to distinguish normal people from the gods of sexuality and fertility, protectors of the reproductive process of Nature. The representation of the over-sized and erected genitalia on vase figures or statues of ancient Greek art is related to fertility gods such as Priapus, Pan and Satyrs and there is strong evidence that imagination and legend were replacing the scientific achievements in the field of erectile function for many centuries.

  10. Medicine and psychiatry in Western culture: Ancient Greek myths and modern prejudices

    Directory of Open Access Journals (Sweden)

    Clementi Nicoletta

    2009-10-01

    Full Text Available Abstract The origins of Western culture extensively relate to Ancient Greek culture. While many ancient cultures have contributed to our current knowledge about medicine and the origins of psychiatry, the Ancient Greeks were among the best observers of feelings and moods patients expressed towards medicine and toward what today is referred to as 'psychopathology'. Myths and religious references were used to explain what was otherwise impossible to understand or be easily communicated. Most ancient myths focus on ambiguous feelings patients may have had towards drugs, especially psychotropic ones. Interestingly, such prejudices are common even today. Recalling ancient findings and descriptions made using myths could represent a valuable knowledge base for modern physicians, especially for psychiatrists and their patients, with the aim of better understanding each other and therefore achieving a better clinical outcome. This paper explores many human aspects and feelings towards doctors and their cures, referring to ancient myths and focusing on the perception of mental illness.

  11. Ancient Egypt

    Science.gov (United States)

    Swamy, Ashwin Balegar

    This thesis involves development of an interactive GIS (Geographic Information System) based application, which gives information about the ancient history of Egypt. The astonishing architecture, the strange burial rituals and their civilization were some of the intriguing questions that motivated me towards developing this application. The application is a historical timeline starting from 3100 BC, leading up to 664 BC, focusing on the evolution of the Egyptian dynasties. The tool holds information regarding some of the famous monuments which were constructed during that era and also about the civilizations that co-existed. It also provides details about the religions followed by their kings. It also includes the languages spoken during those periods. The tool is developed using JAVA, a programing language and MOJO (Map Objects Java Objects) a product of ESRI (Environmental Science Research Institute) to create map objects, to provide geographic information. JAVA Swing is used for designing the user interface. HTML (Hyper Text Markup Language) pages are created to provide the user with more information related to the historic period. CSS (Cascade Style Sheets) and JAVA Scripts are used with HTML5 to achieve creative display of content. The tool is kept simple and easy for the user to interact with. The tool also includes pictures and videos for the user to get a feel of the historic period. The application is built to motivate people to know more about one of the prominent and ancient civilization of the Mediterranean world.

  12. The emergence and fate of horizontally acquired genes in Escherichia coli

    NARCIS (Netherlands)

    Passel, van M.W.J.; Marri, P.R.; Ochman, H.

    2008-01-01

    Bacterial species, and even strains within species, can vary greatly in their gene contents and metabolic capabilities. We examine the evolution of this diversity by assessing the distribution and ancestry of each gene in 13 sequenced isolates of Escherichia coli and Shigella. We focus on the

  13. Originating relation studies on ancient porcelains of chines Ru and Jun by NAA

    International Nuclear Information System (INIS)

    Zhao Weijuan; Xie Jianzhong; Gao Zhengyao; Li Guoxia; Li Rongwu; Zhang Bin

    2002-01-01

    50 samples of glazes and bodies of the ancient Chinese Ru porcelain, Jun porcelain and imitative ancient ceramics were analyzed by neutron activation analysis (NAA). The contents of 36 elements in each sample were measured. The NAA data were statistically treated by fuzzy cluster method and the trend cluster diagram was obtained. Their classes and raw material sources were determined. The results show that although these samples spanned hundreds of years, came from different kilns and had different glazes colors, the bodies of the ancient Chinese Ru porcelain and Jun porcelain belong to the same kind, the glazes of the ancient Chinese Ru porcelain is similar to the glazes of the ancient Chinese Jun porcelain. The originating places of the body raw material were concentrated, and that of the glaze raw materials were scattered, the source of the glaze raw material covered that the body raw material. The ancient Chinese Ru porcelain and Jun porcelain have basically the same raw material sources and the sources of raw material are stable in long time. It is found that most modern Jun porcelain samples are similar to the ancient Chinese Jun porcelain. Two modern Ru porcelain samples are similar to the ancient Chinese Ru porcelain, but another one drifts apart from the ancient Chinese Ru porcelain. Jingdezhen porcelain has no relation to Ru porcelain and Jun porcelain

  14. Molecular analysis of ancient caries

    Science.gov (United States)

    Simón, Marc; Montiel, Rafael; Smerling, Andrea; Solórzano, Eduvigis; Díaz, Nancy; Álvarez-Sandoval, Brenda A.; Jiménez-Marín, Andrea R.; Malgosa, Assumpció

    2014-01-01

    An 84 base pair sequence of the Streptococcus mutans virulence factor, known as dextranase, has been obtained from 10 individuals from the Bronze Age to the Modern Era in Europe and from before and after the colonization in America. Modern samples show four polymorphic sites that have not been found in the ancient samples studied so far. The nucleotide and haplotype diversity of this region have increased over time, which could be reflecting the footprint of a population expansion. While this segment has apparently evolved according to neutral evolution, we have been able to detect one site that is under positive selection pressure both in present and past populations. This study is a first step to study the evolution of this microorganism, analysed using direct evidence obtained from ancient remains. PMID:25056622

  15. The TL dating of ancient porcelain

    International Nuclear Information System (INIS)

    Leung, P.L.; Stokes, M.J.; Wang Weida; Xia Junding; Zhou Zhixin

    1997-01-01

    The age determination of ancient porcelain using the pre-dose technique in TL dating was reported. The variation of beta dose with depth below the surface of the porcelain slice, the thermal activation characteristic (TAC) for 110 degree C peak, the measurement of paleodose and the estimation of annual dose were studied. The results show that this technique is suitable for authenticity testing of ancient porcelain, but both accuracy and precision for porcelain dating are worse than those for pottery, because porcelain differs from pottery on composition, structure and firing temperature. Besides, some complicated factors in the pre-dose technique would be the possible cause of the greater errors

  16. TREATMENT OF FRACTURES IN ANCIENT EGYPT

    Directory of Open Access Journals (Sweden)

    Z. K. Bashurov

    2012-01-01

    Full Text Available The most complete information about the medicine in Ancient Egypt two papyrus provided: a large medical papyrus of G. Ebers and papyrus about the surgery of E. Smith. Smith’s papyrus is of particular interest as it contains the information on the status of surgery in Ancient Egypt. Papyrus consists of descriptions of the clinical cases. To the present time, 48 cases have survived; it is arranged in order of location - from the head down to the feet. Orthopedic deformities were reflected in the figures on the walls of the pyramids and temples as well as the description of the mummies and archaeological finds.

  17. Issue of Separation of Powers in Ancient Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Javid

    2012-03-01

    Full Text Available Cotemporary public law in Iran cannot ignore the elements of its identity in the past. Although analysis of public law issue in ancient Iran, the most researchers to be considered so it is not easy to speak about separation of powers, the part of the body of public law in the Iran primary governments but this article constants on hypothesis which with think and assimilation in history of ancient Iran which can laying the groundwork of strengthening people rights and limitation of authority's governors with emphasis on three periods of governorship on ancient Iran .for example Hakhamaneshian, Ashkanian and Sasanian. This article intent to clear haw can in these periods, the primary figure and foundation of separation of powers and functions division in body of previous governments of Iran to be observed.

  18. Application of nuclear analysis techniques in ancient chinese porcelain

    International Nuclear Information System (INIS)

    Feng Songlin; Xu Qing; Feng Xiangqian; Lei Yong; Cheng Lin; Wang Yanqing

    2005-01-01

    Ancient ceramic was fired with porcelain clay. It contains various provenance information and age characteristic. It is the scientific foundation of studying Chinese porcelain to analyze and research the ancient ceramic with modern analysis methods. According to the property of nuclear analysis technique, its function and application are discussed. (authors)

  19. History through Art and Architecture: Ancient Greek Architecture [and] Ancient Greek Sculpture. Teacher's Manual.

    Science.gov (United States)

    Campbell, Ann

    This document consists of two teaching manuals designed to accompany a commercially-available "multicultural, interdisciplinary video program," consisting of four still videotape programs (72 minutes, 226 frames), one teaching poster, and these two manuals. "Teacher's Manual: Ancient Greek Architecture" covers: "Ancient…

  20. Penetrating particles in horizontal air showers

    International Nuclear Information System (INIS)

    Wohlenberg, J.; Boehm, E.

    1975-01-01

    Particle density and arrival time of muons has been measured in Horizontal Air Showers. 5,600 showers have been recorded in 7,800 hours. Using stringent selection criteria 155 showers have been found horizontal (zenith angle larger 70 0 ) in the size range 4.1 > lg N > 5.5. The muons observed in these showers can be explained by purely electromagnetic origin of horizontal showers. (orig.) [de

  1. Ancient Egypt: Personal Perspectives.

    Science.gov (United States)

    Wolinski, Arelene

    This teacher resource book provides information on ancient Egypt via short essays, photographs, maps, charts, and drawings. Egyptian social and religious life, including writing, art, architecture, and even the practice of mummification, is conveniently summarized for the teacher or other practitioner in a series of one to three page articles with…

  2. Ancient literature in the teaching of the Ljubljana jesuits

    Directory of Open Access Journals (Sweden)

    Nada Grošelj

    2004-12-01

    Full Text Available Members of the Jesuit Order came to Ljubljana in 1597, founding a »gymnasium« and later expanding it with a semi-university. In contrast to certain other orders, they fostered the classics, as is evidenced by their teaching, scholarly research, and literary composition. The scholarly work of the Jesuits active in present-day Slovenia was mostly concentrated on ancient philosophy, as is shown in the second section of this paper. Their teaching, on the other hand, included both classroom lessons and more creative activities, such as the writing and staging of school plays. The Jesuit school system with its six gymnasium classes is described in the first section of the paper, and the school curriculum (based almost exclusively on the teaching of Latin literature and methods in the third. The fourth section presents the documents relating to the final gymnasium examinations in ancient literature which took place in Ljubljana, with a survey of the contents of the questions. The fifth section outlines the characteristics of Jesuit school drama. The plays performed in Ljubljana are lost, but, judging by the preserved titles and synopses, ancient themes appear to have been relatively rare. Nevertheless, the paper succeeds in isolating seventeen works (discussed in the sixth section which must have either utilised plots from ancient literature or drawn inspiration from ancient stock characters and rhetoric.

  3. Ancient migratory events in the Middle East: new clues from the Y-chromosome variation of modern Iranians.

    Directory of Open Access Journals (Sweden)

    Viola Grugni

    Full Text Available Knowledge of high resolution Y-chromosome haplogroup diversification within Iran provides important geographic context regarding the spread and compartmentalization of male lineages in the Middle East and southwestern Asia. At present, the Iranian population is characterized by an extraordinary mix of different ethnic groups speaking a variety of Indo-Iranian, Semitic and Turkic languages. Despite these features, only few studies have investigated the multiethnic components of the Iranian gene pool. In this survey 938 Iranian male DNAs belonging to 15 ethnic groups from 14 Iranian provinces were analyzed for 84 Y-chromosome biallelic markers and 10 STRs. The results show an autochthonous but non-homogeneous ancient background mainly composed by J2a sub-clades with different external contributions. The phylogeography of the main haplogroups allowed identifying post-glacial and Neolithic expansions toward western Eurasia but also recent movements towards the Iranian region from western Eurasia (R1b-L23, Central Asia (Q-M25, Asia Minor (J2a-M92 and southern Mesopotamia (J1-Page08. In spite of the presence of important geographic barriers (Zagros and Alborz mountain ranges, and the Dasht-e Kavir and Dash-e Lut deserts which may have limited gene flow, AMOVA analysis revealed that language, in addition to geography, has played an important role in shaping the nowadays Iranian gene pool. Overall, this study provides a portrait of the Y-chromosomal variation in Iran, useful for depicting a more comprehensive history of the peoples of this area as well as for reconstructing ancient migration routes. In addition, our results evidence the important role of the Iranian plateau as source and recipient of gene flow between culturally and genetically distinct populations.

  4. Sin, Punishment And Forgiveness In Ancient Greek Religion: A ...

    African Journals Online (AJOL)

    This paper looks in particular at the special sin of hubris in ancient Greek religious thought. It examines what constitutes hubris and some cases in which hubris has been committed and punished. It demonstrates with examples that hubris is an unforgivable sin in ancient Greek religion and examines the reasons for this ...

  5. Translation: an example from ancient Chinese to modern Chinese

    NARCIS (Netherlands)

    Liu, X; Hoede, C.

    2002-01-01

    In this paper, we gave an idea of translation by means of knowledge graph theory from ancient Chinese to modern Chinese, by using an example story. Actually, we give the details of the method of translation from ancient Chinese to modern Chinese step by step as carried out by hand. From the example,

  6. Horizontal violence in Nursing

    Directory of Open Access Journals (Sweden)

    Tsimoulaki Evangelia

    2017-01-01

    Full Text Available One’s effort to clarify the definition of horizontal labour violence is of great importance, due to the variety of definitions that are mentioned in the worldwide scientific literature. Furthermore, the reference of multiple forms of such violence herein the nurse professional group is challenging, as well. Another fact of great importance is that, any form of professional violence (horizontal violence, horizontal mobbing in the work place environment can be possibly escalated and include even physical abuse (Bullying, besides the psychological and emotional impact for the victim. The definitions of Horizontal violence, Mobbing and Bullying, include a repeated negative behaviour emanating from at least one “predator” towards at least one “victim”, with work status differences and the existence or lack of physical abuse (Bullying. Horizontal violence is a hostile, aggressive and harmful behaviour which is either overt or concealed and is pointed from an individual to another individual of the same working rank and causes intense emotional pain at the victim. The manifestations vary from humiliating tasks assignment or the victim’s efforts undermining to clearly aggressive behaviors (criticism, intimidation, sarcasm etc.. The reason behind this phenomenon is multifactorial extended not only towards the working environment but also to the personal characteristics of the “predator” as well as the possible “victim”. The researchers emphasize the high incidence of the phenomenon, as well as the cost that is induced by the violent behaviors to both the health professionals and the hospital. Finally, they point out the paradox of the presence of violence inside a system that is designed to promote health.

  7. Paraoxonases: ancient substrate hunters and their evolving role in ischemic heart disease.

    Science.gov (United States)

    Martinelli, Nicola; Consoli, Letizia; Girelli, Domenico; Grison, Elisa; Corrocher, Roberto; Olivieri, Oliviero

    2013-01-01

    Interest in the role of paraoxonases (PON) in cardiovascular research has increased substantially over the past two decades. These multifaceted and pleiotropic enzymes are encoded by three highly conserved genes (PON1, PON2, and PON3) located on chromosome 7q21.3-22.1. Phylogenetic analysis suggests that PON2 is the ancient gene from which PON1 and PON3 arose via gene duplication. Although PON are primarily lactonases with overlapping, but distinct specificities, their physiologic substrates remain poorly characterized. The most interesting characteristic of PON, however, is their multifunctional roles in various biochemical pathways. These include protection against oxidative damage and lipid peroxidation, contribution to innate immunity, detoxification of reactive molecules, bioactivation of drugs, modulation of endoplasmic reticulum stress, and regulation of cell proliferation/apoptosis. In general, PON appear as "hunters" of old and new substrates often involved in athero- and thrombogenesis. Although reduced PON activity appears associated with increased cardiovascular risk, the correlation between PON genotype and ischemic heart disease remains controversial. In this review, we examine the biochemical pathways impacted by these unique enzymes and investigate the potential use of PON as diagnostic tools and their impact on development of future therapeutic strategies.

  8. Horizontal steam generator thermal-hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O. [SKODA Praha Company, Prague (Czechoslovakia); Doubek, M. [Czech Technical Univ., Prague (Czechoslovakia)

    1995-09-01

    Horizontal steam generators are typical components of nuclear power plants with pressure water reactor type VVER. Thermal-hydraulic behavior of horizontal steam generators is very different from the vertical U-tube steam generator, which has been extensively studied for several years. To contribute to the understanding of the horizontal steam generator thermal-hydraulics a computer program for 3-D steady state analysis of the PGV-1000 steam generator has been developed. By means of this computer program, a detailed thermal-hydraulic and thermodynamic study of the horizontal steam generator PGV-1000 has been carried out and a set of important steam generator characteristics has been obtained. The 3-D distribution of the void fraction and 3-D level profile as functions of load and secondary side pressure have been investigated and secondary side volumes and masses as functions of load and pressure have been evaluated. Some of the interesting results of calculations are presented in the paper.

  9. Determination of ancient ceramics reference material by neutron activation analysis

    International Nuclear Information System (INIS)

    Li Huhou; Sun Jingxin; Wang Yuqi; Lu Liangcai

    1986-01-01

    Contents of trace elements in the reference material of ancient ceramics (KPS-1) were determined by means of activation analysis, using thermal neutron irradiation produced in nuclear reactor. KPS-1 favoured the analysis of ancient ceramics because it had not only many kinds of element but also appropriate contents of composition. The values presented here are reliable within the experimental precision, and have shown that the reference material had a good homogeneity. So KPS-1 can be used as a suitable reference material for the ancient ceramics analysis

  10. A horizontally gene transferred copper resistance locus confers hyper‐resistance to antibacterial copper toxicity and enables survival of community acquired methicillin resistant Staphylococcus aureus USA300 in macrophages

    Science.gov (United States)

    Purves, Joanne; Thomas, Jamie; Riboldi, Gustavo P.; Zapotoczna, Marta; Tarrant, Emma; Andrew, Peter W.; Londoño, Alejandra; Planet, Paul J.; Geoghegan, Joan A.; Waldron, Kevin J.

    2018-01-01

    Summary Excess copper is highly toxic and forms part of the host innate immune system's antibacterial arsenal, accumulating at sites of infection and acting within macrophages to kill engulfed pathogens. We show for the first time that a novel, horizontally gene transferred copper resistance locus (copXL), uniquely associated with the SCCmec elements of the highly virulent, epidemic, community acquired methicillin resistant Staphylococcus aureus (CA‐MRSA) USA300, confers copper hyper‐resistance. These genes are additional to existing core genome copper resistance mechanisms, and are not found in typical S. aureus lineages, but are increasingly identified in emerging pathogenic isolates. Our data show that CopX, a putative P1B‐3‐ATPase efflux transporter, and CopL, a novel lipoprotein, confer copper hyper‐resistance compared to typical S. aureus strains. The copXL genes form an operon that is tightly repressed in low copper environments by the copper regulator CsoR. Significantly, CopX and CopL are important for S. aureus USA300 intracellular survival within macrophages. Therefore, the emergence of new S. aureus clones with the copXL locus has significant implications for public health because these genes confer increased resistance to antibacterial copper toxicity, enhancing bacterial fitness by altering S. aureus interaction with innate immunity. PMID:29521441

  11. Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local

    Science.gov (United States)

    Ros, Rosa M.

    2009-12-01

    The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)

  12. Ancient DNA reveals genetic connections between early Di-Qiang and Han Chinese.

    Science.gov (United States)

    Li, Jiawei; Zeng, Wen; Zhang, Ye; Ko, Albert Min-Shan; Li, Chunxiang; Zhu, Hong; Fu, Qiaomei; Zhou, Hui

    2017-12-04

    Ancient Di-Qiang people once resided in the Ganqing region of China, adjacent to the Central Plain area from where Han Chinese originated. While gene flow between the Di-Qiang and Han Chinese has been proposed, there is no evidence to support this view. Here we analyzed the human remains from an early Di-Qiang site (Mogou site dated ~4000 years old) and compared them to other ancient DNA across China, including an early Han-related site (Hengbei site dated ~3000 years old) to establish the underlying genetic relationship between the Di-Qiang and ancestors of Han Chinese. We found Mogou mtDNA haplogroups were highly diverse, comprising 14 haplogroups: A, B, C, D (D*, D4, D5), F, G, M7, M8, M10, M13, M25, N*, N9a, and Z. In contrast, Mogou males were all Y-DNA haplogroup O3a2/P201; specifically one male was further assigned to O3a2c1a/M117 using targeted unique regions on the non-recombining region of the Y-chromosome. We compared Mogou to 7 other ancient and 38 modern Chinese groups, in a total of 1793 individuals, and found that Mogou shared close genetic distances with Taojiazhai (a more recent Di-Qiang population), Hengbei, and Northern Han. We modeled their interactions using Approximate Bayesian Computation, and support was given to a potential admixture of ~13-18% between the Mogou and Northern Han around 3300-3800 years ago. Mogou harbors the earliest genetically identifiable Di-Qiang, ancestral to the Taojiazhai, and up to ~33% paternal and ~70% of its maternal haplogroups could be found in present-day Northern Han Chinese.

  13. A new look at old bread: ancient Egyptian baking

    Directory of Open Access Journals (Sweden)

    Delwen Samuel

    1999-11-01

    Full Text Available Despite abundant archaeological, pictorial and textual evidence of ancient Egyptian life and death, we have little detailed information about the staple diet of most of the population. Now experimental work by a postdoctoral Wellcome Research Fellow in Bioarchaeology at the Institute is revealing how the ancient Egyptians made their daily bread.

  14. Intraosseous neurilemmoma of the mandible: Report of a rare ancient type

    OpenAIRE

    Gholamreza Jahanshahi; Abbas Haghighat; Faezeh Azmoodeh

    2011-01-01

    The neurilemmoma is a benign neoplasm of Schwann cell origin. One of the histopathologic subtypes of this tumor is ancient schwannoma which is characterized by degenerative alterations including cystic change, calcification, hemorrhage, and hyalinization. Intraosseous schwannomas especially ancient ones are rare tumors. Here we present a case of intraosseous ancient schwannoma in the lower jaw of an 11-year-old girl which caused a non-tender expansion. Radiographic examination showed a well-c...

  15. Alternative haplotypes of antigen processing genes in zebrafish diverged early in vertebrate evolution

    Science.gov (United States)

    McConnell, Sean C.; Hernandez, Kyle M.; Wcisel, Dustin J.; Kettleborough, Ross N.; Stemple, Derek L.; Andrade, Jorge; de Jong, Jill L. O.

    2016-01-01

    Antigen processing and presentation genes found within the MHC are among the most highly polymorphic genes of vertebrate genomes, providing populations with diverse immune responses to a wide array of pathogens. Here, we describe transcriptome, exome, and whole-genome sequencing of clonal zebrafish, uncovering the most extensive diversity within the antigen processing and presentation genes of any species yet examined. Our CG2 clonal zebrafish assembly provides genomic context within a remarkably divergent haplotype of the core MHC region on chromosome 19 for six expressed genes not found in the zebrafish reference genome: mhc1uga, proteasome-β 9b (psmb9b), psmb8f, and previously unknown genes psmb13b, tap2d, and tap2e. We identify ancient lineages for Psmb13 within a proteasome branch previously thought to be monomorphic and provide evidence of substantial lineage diversity within each of three major trifurcations of catalytic-type proteasome subunits in vertebrates: Psmb5/Psmb8/Psmb11, Psmb6/Psmb9/Psmb12, and Psmb7/Psmb10/Psmb13. Strikingly, nearby tap2 and MHC class I genes also retain ancient sequence lineages, indicating that alternative lineages may have been preserved throughout the entire MHC pathway since early diversification of the adaptive immune system ∼500 Mya. Furthermore, polymorphisms within the three MHC pathway steps (antigen cleavage, transport, and presentation) are each predicted to alter peptide specificity. Lastly, comparative analysis shows that antigen processing gene diversity is far more extensive than previously realized (with ancient coelacanth psmb8 lineages, shark psmb13, and tap2t and psmb10 outside the teleost MHC), implying distinct immune functions and conserved roles in shaping MHC pathway evolution throughout vertebrates. PMID:27493218

  16. Ancient DNA from marine mammals

    DEFF Research Database (Denmark)

    Foote, Andrew David; Hofreiter, Michael; Morin, Philip A.

    2012-01-01

    such as bone, tooth, baleen, skin, fur, whiskers and scrimshaw using ancient DNA (aDNA) approaches provide an oppor- tunity for investigating such changes over evolutionary and ecological timescales. Here, we review the application of aDNA techniques to the study of marine mammals. Most of the studies have...... focused on detecting changes in genetic diversity following periods of exploitation and environmental change. To date, these studies have shown that even small sample sizes can provide useful information on historical genetic diversity. Ancient DNA has also been used in investigations of changes...... in distribution and range of marine mammal species; we review these studies and discuss the limitations of such ‘presence only’ studies. Combining aDNA data with stable isotopes can provide further insights into changes in ecology and we review past studies and suggest future potential applications. We also...

  17. Sorting through the chaff, nDNA gene trees for phylogenetic inference and hybrid identification of annual sunflowers (Helianthus sect. Helianthus).

    Science.gov (United States)

    Moody, Michael L; Rieseberg, Loren H

    2012-07-01

    The annual sunflowers (Helianthus sect. Helianthus) present a formidable challenge for phylogenetic inference because of ancient hybrid speciation, recent introgression, and suspected issues with deep coalescence. Here we analyze sequence data from 11 nuclear DNA (nDNA) genes for multiple genotypes of species within the section to (1) reconstruct the phylogeny of this group, (2) explore the utility of nDNA gene trees for detecting hybrid speciation and introgression; and (3) test an empirical method of hybrid identification based on the phylogenetic congruence of nDNA gene trees from tightly linked genes. We uncovered considerable topological heterogeneity among gene trees with or without three previously identified hybrid species included in the analyses, as well as a general lack of reciprocal monophyly of species. Nonetheless, partitioned Bayesian analyses provided strong support for the reciprocal monophyly of all species except H. annuus (0.89 PP), the most widespread and abundant annual sunflower. Previous hypotheses of relationships among taxa were generally strongly supported (1.0 PP), except among taxa typically associated with H. annuus, apparently due to the paraphyly of the latter in all gene trees. While the individual nDNA gene trees provided a useful means for detecting recent hybridization, identification of ancient hybridization was problematic for all ancient hybrid species, even when linkage was considered. We discuss biological factors that affect the efficacy of phylogenetic methods for hybrid identification.

  18. Ancient origin of placental expression in the growth hormone genes of anthropoid primates.

    Science.gov (United States)

    Papper, Zack; Jameson, Natalie M; Romero, Roberto; Weckle, Amy L; Mittal, Pooja; Benirschke, Kurt; Santolaya-Forgas, Joaquin; Uddin, Monica; Haig, David; Goodman, Morris; Wildman, Derek E

    2009-10-06

    In anthropoid primates, growth hormone (GH) genes have undergone at least 2 independent locus expansions, one in platyrrhines (New World monkeys) and another in catarrhines (Old World monkeys and apes). In catarrhines, the GH cluster has a pituitary-expressed gene called GH1; the remaining GH genes include placental GHs and placental lactogens. Here, we provide cDNA sequence evidence that the platyrrhine GH cluster also includes at least 3 placenta expressed genes and phylogenetic evidence that placenta expressed anthropoid GH genes have undergone strong adaptive evolution, whereas pituitary-expressed GH genes have faced strict functional constraint. Our phylogenetic evidence also points to lineage-specific gene gain and loss in early placental mammalian evolution, with at least three copies of the GH gene present at the time of the last common ancestor (LCA) of primates, rodents, and laurasiatherians. Anthropoid primates and laurasiatherians share gene descendants of one of these three copies, whereas rodents and strepsirrhine primates each maintain a separate copy. Eight of the amino-acid replacements that occurred on the lineage leading to the LCA of extant anthropoids have been implicated in GH signaling at the maternal-fetal interface. Thus, placental expression of GH may have preceded the separate series of GH gene duplications that occurred in catarrhines and platyrrhines (i.e., the roles played by placenta-expressed GHs in human pregnancy may have a longer evolutionary history than previously appreciated).

  19. Mineralization of the ancient hydrogeological conditions in the northeast of Ordos basin

    International Nuclear Information System (INIS)

    Gao Junyi

    2012-01-01

    Ordos basin, North East, to the Eocene as a turning point, in the generation of the ancient hydrogeological conditions have distinct changes experienced at least two ancient evolution of hydrogeological conditions, that is closed in the early flow into basin Late open drain basin. Closed in the early period of the inner flow basin, since the purpose of layer deposition, the direction of the ancient hydrodynamic interlayer oxidation is consistent with the direction of oxidation. Hydrogeological conditions of the ancient point of view, in the Ordos basin, North East looking for interlayer oxidation zone type uranium has a guiding role. (author)

  20. Anticancer activity of botanical compounds in ancient fermented beverages (review).

    Science.gov (United States)

    McGovern, P E; Christofidou-Solomidou, M; Wang, W; Dukes, F; Davidson, T; El-Deiry, W S

    2010-07-01

    Humans around the globe probably discovered natural remedies against disease and cancer by trial and error over the millennia. Biomolecular archaeological analyses of ancient organics, especially plants dissolved or decocted as fermented beverages, have begun to reveal the preliterate histories of traditional pharmacopeias, which often date back thousands of years earlier than ancient textual, ethnohistorical, and ethnological evidence. In this new approach to drug discovery, two case studies from ancient Egypt and China illustrate how ancient medicines can be reconstructed from chemical and archaeological data and their active compounds delimited for testing their anticancer and other medicinal effects. Specifically, isoscopoletin from Artemisia argyi, artemisinin from Artemisia annua, and the latter's more easily assimilated semi-synthetic derivative, artesunate, showed the greatest activity in vitro against lung and colon cancers. In vivo tests of these compounds previously unscreened against lung and pancreatic cancers are planned for the future.

  1. Next Generation Sequencing of Ancient DNA: Requirements, Strategies and Perspectives

    Directory of Open Access Journals (Sweden)

    Michael Knapp

    2010-07-01

    Full Text Available The invention of next-generation-sequencing has revolutionized almost all fields of genetics, but few have profited from it as much as the field of ancient DNA research. From its beginnings as an interesting but rather marginal discipline, ancient DNA research is now on its way into the centre of evolutionary biology. In less than a year from its invention next-generation-sequencing had increased the amount of DNA sequence data available from extinct organisms by several orders of magnitude. Ancient DNA  research is now not only adding a temporal aspect to evolutionary studies and allowing for the observation of evolution in real time, it also provides important data to help understand the origins of our own species. Here we review progress that has been made in next-generation-sequencing of ancient DNA over the past five years and evaluate sequencing strategies and future directions.

  2. Cosmologies of the ancient Mediterranean world

    Directory of Open Access Journals (Sweden)

    John T. Fitzgerald

    2013-07-01

    Full Text Available Cosmology is concerned with the order of the universe and seeks to provide an account, not only of that order, but also of the mind or reason behind it. In antiquity, the cosmos was usually understood religiously, such that the cosmologies of the ancient Mediterranean world were either religious in nature or constituted a reaction to a religiously conceived understanding of the structures of the universe. The oldest form in which ancient cosmologies occur is myth, which, owing to its elasticity as a form, enabled them to be appropriated, adapted and used by different groups. In addition, different cosmologies co-existed within the same ancient culture, each having an authoritative status. This article provides an introductory overview of these cosmological myths and argues that a comparative approach is the most fruitful way to study them. Emphasis is given to certain prominent cosmological topics, including theogony (the genesis of the divine or the relationship of the divine to the cosmos, cosmogony (the genesis of the cosmos, and anthropogony (the origin of humans within the cosmos. Although these myths vary greatly in terms of content and how they envision the origin of the cosmos, many of them depict death as part of the structure of the universe.

  3. Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.

    Science.gov (United States)

    Li, Yi-Han; Ahmed, Muhammad Z; Li, Shao-Jian; Lv, Ning; Shi, Pei-Qiong; Chen, Xiao-Sheng; Qiu, Bao-Li

    2017-12-01

    A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Horizontal transfer of potential mobile units in phytoplasmas.

    Science.gov (United States)

    Ku, Chuan; Lo, Wen-Sui; Kuo, Chih-Horng

    2013-09-01

    Phytoplasmas are uncultivated phytopathogenic bacteria that cause diseases in a wide range of economically important plants. Through secretion of effector proteins, they are able to manipulate their plant hosts to facilitate their multiplication and dispersal by insect vectors. The genome sequences of several phytoplasmas have been characterized to date and a group of putative composite transposons called potential mobile units (PMUs) are found in these highly reduced genomes. Recently, our team reported the genome sequence and comparative analysis of a peanut witches' broom (PnWB) phytoplasma, the first representative of the phytoplasma 16SrII group. Comparisons between the species phylogeny and the phylogenies of the PMU genes revealed that the PnWB PMU is likely to have been transferred from the 16SrI group. This indicates that PMUs are not only the DNA unit for transposition within a genome, but also for horizontal transfer among divergent phytoplasma lineages. Given the association of PMUs with effector genes, the mobility of PMUs across genomes has important implications for phytoplasma ecology and evolution.

  5. Co-Option and De Novo Gene Evolution Underlie Molluscan Shell Diversity

    Science.gov (United States)

    Aguilera, Felipe; McDougall, Carmel

    2017-01-01

    Abstract Molluscs fabricate shells of incredible diversity and complexity by localized secretions from the dorsal epithelium of the mantle. Although distantly related molluscs express remarkably different secreted gene products, it remains unclear if the evolution of shell structure and pattern is underpinned by the differential co-option of conserved genes or the integration of lineage-specific genes into the mantle regulatory program. To address this, we compare the mantle transcriptomes of 11 bivalves and gastropods of varying relatedness. We find that each species, including four Pinctada (pearl oyster) species that diverged within the last 20 Ma, expresses a unique mantle secretome. Lineage- or species-specific genes comprise a large proportion of each species’ mantle secretome. A majority of these secreted proteins have unique domain architectures that include repetitive, low complexity domains (RLCDs), which evolve rapidly, and have a proclivity to expand, contract and rearrange in the genome. There are also a large number of secretome genes expressed in the mantle that arose before the origin of gastropods and bivalves. Each species expresses a unique set of these more ancient genes consistent with their independent co-option into these mantle gene regulatory networks. From this analysis, we infer lineage-specific secretomes underlie shell diversity, and include both rapidly evolving RLCD-containing proteins, and the continual recruitment and loss of both ancient and recently evolved genes into the periphery of the regulatory network controlling gene expression in the mantle epithelium. PMID:28053006

  6. Printing Ancient Terracotta Warriors

    Science.gov (United States)

    Gadecki, Victoria L.

    2010-01-01

    Standing in awe in Xian, China, at the Terra Cotta warrior archaeological site, the author thought of sharing this experience and excitement with her sixth-grade students. She decided to let her students carve patterns of the ancient soldiers to understand their place in Chinese history. They would make block prints and print multiple soldiers on…

  7. Similar sponge-associated bacteria can be acquired via both vertical and horizontal transmission

    DEFF Research Database (Denmark)

    Sipkema, Detmer; de Caralt, Sònia; Morillo, Jose A

    2015-01-01

    Marine sponges host diverse communities of microorganisms that are often vertically transmitted from mother to oocyte or embryo. Horizontal transmission has often been proposed to co-occur in marine sponges, but the mechanism is poorly understood. To assess the impact of the mode of transmission...... on the microbial assemblages of sponges, we analysed the microbiota in sympatric sponges that have previously been reported to acquire bacteria via either vertical (Corticium candelabrum and Crambe crambe) or horizontal transmission (Petrosia ficiformis). The comparative study was performed by PCR......-DGGE and pyrosequencing of barcoded PCR-amplified 16S rRNA gene fragments. We found that P. ficiformis and C. candelabrum each harbor their own species-specific bacteria, but they are similar to other high-microbial-abundance sponges, while the low-microbial-abundance sponge C. crambe hosts microbiota of a very different...

  8. HORIZONTAL WELL DRILL-IN FLUIDS

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1998-12-01

    Full Text Available Main objective of horizontal driling is to place a drain-hole for a long distance within the pay zone to enhance productivity or injectivity. In drilling horizontal wells, more serious problems appear than in drilling vertical wells. These problems are: poor hole cleaning, excessive torque and drag, hole filling, pipe stucking, wellbore instability, loss of circulation, formation damage, poor cement job, and difficulties at logging jobs. From that reason, successful drilling and production of horizontal well depends largely on the fluid used during drilling and completion phases. Several new fluids, that fulfill some or all of required properties (hole cleaning, cutting suspension, good lubrication, and relative low formation damage, are presented in this paper.

  9. Productivity and injectivity of horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Khalid

    2000-03-06

    One of the key issues addressed was pressure drop in long horizontal wells and its influence on well performance. Very little information is available in the literature on flow in pipes with influx through pipe walls. Virtually all of this work has been in small diameter pipes and with single-phase flow. In order to address this problem new experimental data on flow in horizontal and near horizontal wells have been obtained. Experiments were conducted at an industrial facility on typical 6 1/8 ID, 100 feet long horizontal well model. The new data along with available information in the literature have been used to develop new correlations and mechanistic models. Thus it is now possible to predict, within reasonable accuracy, the effect of influx through the well on pressure drop in the well.

  10. Application of Ancient DNA Methods to the Study of the Transatlantic Slave Trade

    DEFF Research Database (Denmark)

    Sandoval Velasco, Marcela

    As one of a limited number of biomolecules recording evolutionary events, DNA provides an unparalleled means of investigating genetic processes. Over three decades, ancient DNA research has matured in many ways, growing alongside technological and methodological advancements. However, due to DNA...... means of investigating genetic processes. Over three decades, ancient DNA research has matured in many ways, growing alongside technological and methodological advancements. However, due to DNA preservation, degradation and contamination, ancient DNA research presents significant limitations...... preservation, degradation and contamination, ancient DNA research presents significant limitations and challenges. Until recently, it was thought that DNA did not survive more than few hundred thousand years, and that it was impossible to retrieve whole genome data from ancient samples preserved under...

  11. The building stones of ancient Egypt a gift of its geology

    Science.gov (United States)

    Klemm, Dietrich D.; Klemm, Rosemarie

    2001-08-01

    Building stones and clay-rich Nile mud were ancient Egypt's main raw construction materials. While the mud was easily accessible along the Nile river valley, the immense quantities of the different stone materials used for construction of the famous pyramids, precious temples and tombs needed a systematic quarrying organization, well arranged transport logistics over extreme distances and a high standard of stone masonry. The petrography, occurrence, and main applications of the 11 most popular stone types used in ancient Egypt are described in this contribution. Rough estimates of the scale of this mining activity, based on the volume of many different ancient quarry sites, all over Egypt, reveal that the monuments known today represent only a small fraction of the amount of building stones mined during the long, ancient Egyptian history.

  12. Contribution of horizontal gene transfer to the emergence of VIM-4 carbapenemase producer Enterobacteriaceae in Kuwait

    Directory of Open Access Journals (Sweden)

    Sonnevend Á

    2017-12-01

    . Monitoring of such events is of high importance as the interference with the spread of mobile genetic elements may represent a formidable challenge to infection control. Keywords: Enterobacteriaceae, VIM carbapenemase, horizontal gene transfer, multidrug resistance, Middle East

  13. Indication of Horizontal DNA Gene Transfer by Extracellular Vesicles.

    Directory of Open Access Journals (Sweden)

    Stefanie Fischer

    Full Text Available The biological relevance of extracellular vesicles (EV in intercellular communication has been well established. Thus far, proteins and RNA were described as main cargo. Here, we show that EV released from human bone marrow derived mesenchymal stromal cells (BM-hMSC also carry high-molecular DNA in addition. Extensive EV characterization revealed this DNA mainly associated with the outer EV membrane and to a smaller degree also inside the EV. Our EV purification protocol secured that DNA is not derived from apoptotic or necrotic cells. To analyze the relevance of EV-associated DNA we lentivirally transduced Arabidopsis thaliana-DNA (A.t.-DNA as indicator into BM-hMSC and generated EV. Using quantitative polymerase chain reaction (qPCR techniques we detected high copy numbers of A.t.-DNA in EV. In recipient hMSC incubated with tagged EV for two weeks we identified A.t.-DNA transferred to recipient cells. Investigation of recipient cell DNA using quantitative PCR and verification of PCR-products by sequencing suggested stable integration of A.t.-DNA. In conclusion, for the first time our proof-of-principle experiments point to horizontal DNA transfer into recipient cells via EV. Based on our results we assume that eukaryotic cells are able to exchange genetic information in form of DNA extending the known cargo of EV by genomic DNA. This mechanism might be of relevance in cancer but also during cell evolution and development.

  14. Views of Ancient Egypt. Teacher's Guide. School Arts: Looking/Learning.

    Science.gov (United States)

    Downs, Linda; Brenner, Carla

    This teaching guide discusses ancient Egyptian culture, the lithographs made by Napoleon's scientists in 1798-99 to study and record every aspect of Egypt, the world's subsequent fascination with Egypt, ancient Egyptian architecture, Egyptian writing, and archeologists' illustrations of Egypt. The guide suggests activities for elementary school,…

  15. Origination of an X-linked testes chimeric gene by illegitimate recombination in Drosophila.

    Directory of Open Access Journals (Sweden)

    J Roman Arguello

    2006-05-01

    Full Text Available The formation of chimeric gene structures provides important routes by which novel proteins and functions are introduced into genomes. Signatures of these events have been identified in organisms from wide phylogenic distributions. However, the ability to characterize the early phases of these evolutionary processes has been difficult due to the ancient age of the genes or to the limitations of strictly computational approaches. While examples involving retrotransposition exist, our understanding of chimeric genes originating via illegitimate recombination is limited to speculations based on ancient genes or transfection experiments. Here we report a case of a young chimeric gene that has originated by illegitimate recombination in Drosophila. This gene was created within the last 2-3 million years, prior to the speciation of Drosophila simulans, Drosophila sechellia, and Drosophila mauritiana. The duplication, which involved the Bällchen gene on Chromosome 3R, was partial, removing substantial 3' coding sequence. Subsequent to the duplication onto the X chromosome, intergenic sequence was recruited into the protein-coding region creating a chimeric peptide with approximately 33 new amino acid residues. In addition, a novel intron-containing 5' UTR and novel 3' UTR evolved. We further found that this new X-linked gene has evolved testes-specific expression. Following speciation of the D. simulans complex, this novel gene evolved lineage-specifically with evidence for positive selection acting along the D. simulans branch.

  16. Vascular plants promote ancient peatland carbon loss with climate warming.

    Science.gov (United States)

    Walker, Tom N; Garnett, Mark H; Ward, Susan E; Oakley, Simon; Bardgett, Richard D; Ostle, Nicholas J

    2016-05-01

    Northern peatlands have accumulated one third of the Earth's soil carbon stock since the last Ice Age. Rapid warming across northern biomes threatens to accelerate rates of peatland ecosystem respiration. Despite compensatory increases in net primary production, greater ecosystem respiration could signal the release of ancient, century- to millennia-old carbon from the peatland organic matter stock. Warming has already been shown to promote ancient peatland carbon release, but, despite the key role of vegetation in carbon dynamics, little is known about how plants influence the source of peatland ecosystem respiration. Here, we address this issue using in situ (14)C measurements of ecosystem respiration on an established peatland warming and vegetation manipulation experiment. Results show that warming of approximately 1 °C promotes respiration of ancient peatland carbon (up to 2100 years old) when dwarf-shrubs or graminoids are present, an effect not observed when only bryophytes are present. We demonstrate that warming likely promotes ancient peatland carbon release via its control over organic inputs from vascular plants. Our findings suggest that dwarf-shrubs and graminoids prime microbial decomposition of previously 'locked-up' organic matter from potentially deep in the peat profile, facilitating liberation of ancient carbon as CO2. Furthermore, such plant-induced peat respiration could contribute up to 40% of ecosystem CO2 emissions. If consistent across other subarctic and arctic ecosystems, this represents a considerable fraction of ecosystem respiration that is currently not acknowledged by global carbon cycle models. Ultimately, greater contribution of ancient carbon to ecosystem respiration may signal the loss of a previously stable peatland carbon pool, creating potential feedbacks to future climate change. © 2016 John Wiley & Sons Ltd.

  17. Performance of horizontal versus vertical vapor extraction wells

    International Nuclear Information System (INIS)

    Birdsell, K.H.; Roseberg, N.D.; Edlund, K.M.

    1994-06-01

    Vapor extraction wells used for site remediation of volatile organic chemicals in the vadose zone are typically vertical wells. Over the past few years, there has been an increased interest in horizontal wells for environmental remediation. Despite the interest and potential benefits of horizontal wells, there has been little study of the relative performance of horizontal and vertical vapor extraction wells. This study uses numerical simulations to investigate the relative performance of horizontal versus vertical vapor extraction wells under a variety of conditions. The most significant conclusion that can be drawn from this study is that in a homogeneous medium, a single, horizontal vapor extraction well outperforms a single, vertical vapor extraction well (with surface capping) only for long, linear plumes. Guidelines are presented regarding the use of horizontal wells

  18. Quantification and presence of human ancient DNA in burial place ...

    African Journals Online (AJOL)

    Quantification and presence of human ancient DNA in burial place remains of Turkey using real time polymerase chain reaction. ... A published real-time PCR assay, which allows for the combined analysis of nuclear or ancient DNA and mitochondrial DNA, was modified. This approach can be used for recovering DNA from ...

  19. Characterization of the bovine pregnancy-associated glycoprotein gene family – analysis of gene sequences, regulatory regions within the promoter and expression of selected genes

    Directory of Open Access Journals (Sweden)

    Walker Angela M

    2009-04-01

    Full Text Available Abstract Background The Pregnancy-associated glycoproteins (PAGs belong to a large family of aspartic peptidases expressed exclusively in the placenta of species in the Artiodactyla order. In cattle, the PAG gene family is comprised of at least 22 transcribed genes, as well as some variants. Phylogenetic analyses have shown that the PAG family segregates into 'ancient' and 'modern' groupings. Along with sequence differences between family members, there are clear distinctions in their spatio-temporal distribution and in their relative level of expression. In this report, 1 we performed an in silico analysis of the bovine genome to further characterize the PAG gene family, 2 we scrutinized proximal promoter sequences of the PAG genes to evaluate the evolution pressures operating on them and to identify putative regulatory regions, 3 we determined relative transcript abundance of selected PAGs during pregnancy and, 4 we performed preliminary characterization of the putative regulatory elements for one of the candidate PAGs, bovine (bo PAG-2. Results From our analysis of the bovine genome, we identified 18 distinct PAG genes and 14 pseudogenes. We observed that the first 500 base pairs upstream of the translational start site contained multiple regions that are conserved among all boPAGs. However, a preponderance of conserved regions, that harbor recognition sites for putative transcriptional factors (TFs, were found to be unique to the modern boPAG grouping, but not the ancient boPAGs. We gathered evidence by means of Q-PCR and screening of EST databases to show that boPAG-2 is the most abundant of all boPAG transcripts. Finally, we provided preliminary evidence for the role of ETS- and DDVL-related TFs in the regulation of the boPAG-2 gene. Conclusion PAGs represent a relatively large gene family in the bovine genome. The proximal promoter regions of these genes display differences in putative TF binding sites, likely contributing to observed

  20. An Evaluation of the Historical Importance of Fertility and Its Reflection in Ancient Mythology.

    Science.gov (United States)

    Behjati-Ardakani, Zohreh; Akhondi, Mohammad Mehdi; Mahmoodzadeh, Homa; Hosseini, Seyed Hasan

    2016-01-01

    Myths are reflective of human concerns and needs during ancient times. By reviewing them, it turns out that many human problems today, have a historical background. Among the main themes of ancient mythologies, fertility and reproduction have various representations in ancient civilizations. The purpose of this paper was to review myths and common symbols of fertility and reproduction in ancient civilizations and evaluate the reasons of their continuous importance in different cultures. The data in this review study was obtained by scrutinizing the related literature. The gathered data indicated the multiplicity and variety of fertility symbols in ancient myths. Most ancient fertility symbols were inspired by the nature and some of them like earth and water were common in mythology of different civilizations. Therefore, the symbols consolidate the concept of conformity between human reproductive concerns and the nature's necessities.

  1. Ancient tombs in China and shallow land disposal of low-intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Huang, Y.; Gu, C.

    1987-01-01

    The paper summerises the experiences of ancient tombs in China on tomb siting, configuration of tombs, backfilling materials, civil engineering techniques, sealing (or airlight) techniques, drainage system, antiseptic techniques and so on based upon site investigation. Comparison between ancient tombs in China and shallow land disposal of radioactive wastes has been made. The authors point out that the brilliant achievements of ancient tombs in China in keeping ancient corpses and funeral objects is a historical evidence for safety of shallow land disposal of radioactive wastes, and that the main experiences of ancient tombs can be used for reference to shallow land disposal of radioactive wastes

  2. Genetic Drift. The ancient Egyptian dwarfs of the Walters Art Museum.

    Science.gov (United States)

    Kozma, Chahira

    2010-10-01

    The ancient Egyptians left an impressive artistic legacy documenting many aspects of their society including the existence of dwarfs as highly valued members. In previous publications in the Journal, I discussed dwarfs and skeletal dysplasia in ancient Egypt. In this study, I examined the ancient Egyptian representations of dwarfs of the Walters Art Museum in Baltimore, Maryland. One of the highlights of the collection is a group of five ivory figurines from Predynastic Times (pre 3500-3100 BCE) depicting a couple, a man with a child, and two females. Representations from other periods include ordinary as well as dwarf deities. The dwarf gods, Bes and Ptah, are frequently depicted holding or biting snakes or standing on crocodiles symbolizing their ability to ward off dangers. A couple of statuettes from the Greco-Roman Period that, in contrast to earlier Egyptian Periods, depict harsh physical anomalies, twisted bodies, and facial pain. The artistic impression can be interpreted as either tragic or humorous. The grotesque depiction of dwarfs during the Greco-Roman Period in ancient Egypt is believed to be due to a greater infusion of Hellenistic influence. This study provides a microcosm of the legacy of dwarfs in ancient Egypt and supports the premise that dwarfs were accepted and integrated in the ancient Egyptian society, and with a few exceptions, their disorder was not depicted as a physical handicap. Copyright © 2010 Wiley-Liss, Inc.

  3. Implications of Nash Bargaining for Horizontal Industry Integration

    OpenAIRE

    Richard E. Just; Siddhartha Mitra; Sinaia Netanyahu

    2005-01-01

    This article shows how horizontal industry integration can arise from transferable asymmetry of technologies and endowments. The Nash bargaining solution suggests that greater technological diversity among coordinating parties yields greater gains from horizontal integration. The framework fits the case where a firm with a superior technology franchises the technology by horizontal integration. The results appear to fit hog production where integration has been primarily horizontal and, in pa...

  4. Research of Ancient Architectures in Jin-Fen Area Based on GIS&BIM Technology

    Science.gov (United States)

    Jia, Jing; Zheng, Qiuhong; Gao, Huiying; Sun, Hai

    2017-05-01

    The number of well-preserved ancient buildings located in Shanxi Province, enjoying the absolute maximum proportion of ancient architectures in China, is about 18418, among which, 9053 buildings have the structural style of wood frame. The value of the application of BIM (Building Information Modeling) and GIS (Geographic Information System) is gradually probed and testified in the corresponding fields of ancient architecture’s spatial distribution information management, routine maintenance and special conservation & restoration, the evaluation and simulation of related disasters, such as earthquake. The research objects are ancient architectures in JIN-FEN area, which were first investigated by Sicheng LIANG and recorded in his work of “Chinese ancient architectures survey report”. The research objects, i.e. the ancient architectures in Jin-Fen area include those in Sicheng LIANG’s investigation, and further adjustments were made through authors’ on-site investigation and literature searching & collection. During this research process, the spatial distributing Geodatabase of research objects is established utilizing GIS. The BIM components library for ancient buildings is formed combining on-site investigation data and precedent classic works, such as “Yingzao Fashi”, a treatise on architectural methods in Song Dynasty, “Yongle Encyclopedia” and “Gongcheng Zuofa Zeli”, case collections of engineering practice, by the Ministry of Construction of Qing Dynasty. A building of Guangsheng temple in Hongtong county is selected as an example to elaborate the BIM model construction process based on the BIM components library for ancient buildings. Based on the foregoing work results of spatial distribution data, attribute data of features, 3D graphic information and parametric building information model, the information management system for ancient architectures in Jin-Fen Area, utilizing GIS&BIM technology, could be constructed to support the

  5. Ancient woodland boundaries in Europe

    Czech Academy of Sciences Publication Activity Database

    Szabó, Péter

    2010-01-01

    Roč. 36, č. 2 (2010), s. 205-214 ISSN 0305-7488 R&D Projects: GA AV ČR IAA600050812 Institutional research plan: CEZ:AV0Z60050516 Keywords : ancient woodland * historical ecology * landscape archaeology Subject RIV: EF - Botanics Impact factor: 0.983, year: 2010

  6. Application of NAA in the sort discrimination of the ancient porcelains

    International Nuclear Information System (INIS)

    Jia Xiuqin; Huang Zhongxiang; Han Song

    2002-01-01

    The neutron activation analysis is applied for analyzing the rare earth elements (REE) and trace elements in the ancient porcelains of Yao Zhou and Ru. The results show that there are differences or even significant differences between glazes and roughcasts of these two ancient porcelains in the gross amounts of REE, normalized diagrams of REE and characteristics of trace element contents, which reflecting the composition differences in glazes and roughcasts of the two kinds of porcelains. Thus, the contents of REE and trace elements can be taken for discriminating the ancient porcelains

  7. Ancient Terrestrial Carbon: Lost and Found

    Science.gov (United States)

    Freeman, K. H.

    2017-12-01

    Carbon fluxes in terrestrial environments dominate the global carbon cycle. The fluxes of terrestrial carbon are strongly tied to regional climate due to the influences of temperature, water, and nutrient dynamics on plant productivity. However, climate also influences the destruction of terrestrial organic matter, through weathering, erosion, and biomass loss via fire and oxidative microbial processes. Organic geochemical methods enable us to interrogate past terrestrial carbon dynamics and learn how continental processes might accelerate, or mitigate carbon transfer to the atmosphere, and the associated greenhouse warming. Terrestrial soil systems represent the weathering rind of the continents, and are inherently non-depositional and erosive. The production, transport, and depositional processes affecting organics in continental settings each impart their own biases on the amount and characteristics of preserved carbon. Typically, the best archives for biomarker records are sediments in ancient lakes or subaqueous fans, which represents a preservation bias that tends to favor wetter environments. Paleosols, or ancient soils, formed under depositional conditions that, for one reason or another, truncated soil ablation, erosion, or other loss processes. In modern soils, widely ranging organic carbon abundances are almost always substantially greater than the trace amounts of carbon left behind in ancient soils. Even so, measureable amounts of organic biomarkers persist in paleosols. We have been investigating processes that preserve soil organic carbon on geologic timescales, and how these mechanisms may be sensitive to past climate change. Climate-linked changes in temperature, moisture, pH, and weathering processes can impact carbon preservation via organo-mineral sorption, soil biogeochemistry, and stability based on the physical and chemical properties of organic compounds. These will be discussed and illustrated with examples from our studies of Cenozoic

  8. Vertical microbial community variability of carbonate-based cones may provide insight into ancient conical stromatolite formation

    Science.gov (United States)

    Bradley, James; Daille, Leslie; Trivedi, Christopher; Bojanowski, Caitlin; Nunn, Heather; Stamps, Blake; Johnson, Hope; Stevenson, Bradley; Berelson, Will; Corsetti, Frank; Spear, John

    2016-04-01

    Stromatolite morphogenesis is poorly understood, and the process by which microbial mats become mineralized is a primary question in microbialite formation. Ancient conical stromatolites are primarily carbonate-based whereas the few modern analogues in hot springs are either non-mineralized or mineralized by silica. A team from the 2015 International GeoBiology Course investigated carbonate-rich microbial cones from near Little Hot Creek (LHC), Long Valley Caldera, California, to investigate how conical stromatolites might form in a hot spring carbonate system. The cones rise up from a layered microbial mat on the east side of a 45° C pool with very low flow that is super-saturated with respect to CaCO3. Cone structures are 8-30 mm in height, are rigid and do not deform when removed from the pool. Morphological characterization through environmental scanning electronic microscopy revealed that the cone structure is maintained by a matrix of intertwining microbial filaments around carbonate grains. This matrix gives rise to cone-filaments that are arranged vertically or horizontally, and provides further stability to the cone. Preliminary 16S rRNA gene analysis indicated variability of community composition between different vertical levels of the cone. The cone tip had comparatively greater abundance of filamentous cyanobacteria including Leptolingbya, Phormidium and Isosphaera and fewer heterotrophs (e.g. Chloroflexi) compared to the cone bottom. This supports the hypothesis that cone formation may depend on the differential abundance of the microbial community and their potential functional roles. Metagenomic analyses of the cones revealed potential genes related to chemotaxis and motility. Specifically, a genomic bin identified as a member of the genus Isosphaera contained an hmp chemotaxis operon implicated in gliding motility in the cyanobacterium Nostoc punctiforme. Isosphaera is a Planctomycete shown to have phototactic capabilities, and may play a role in

  9. Peopling the past: New perspectives on the ancient Maya

    OpenAIRE

    Robin, Cynthia

    2001-01-01

    The new direction in Maya archaeology is toward achieving a greater understanding of people and their roles and their relations in the past. To answer emerging humanistic questions about ancient people's lives Mayanists are increasingly making use of new and existing scientific methods from archaeology and other disciplines. Maya archaeology is bridging the divide between the humanities and sciences to answer questions about ancient people previously considered bey...

  10. Neutral polymorphisms in putative housekeeping genes and tandem repeats unravels the population genetics and evolutionary history of Plasmodium vivax in India.

    Directory of Open Access Journals (Sweden)

    Surendra K Prajapati

    Full Text Available The evolutionary history and age of Plasmodium vivax has been inferred as both recent and ancient by several studies, mainly using mitochondrial genome diversity. Here we address the age of P. vivax on the Indian subcontinent using selectively neutral housekeeping genes and tandem repeat loci. Analysis of ten housekeeping genes revealed a substantial number of SNPs (n = 75 from 100 P. vivax isolates collected from five geographical regions of India. Neutrality tests showed a majority of the housekeeping genes were selectively neutral, confirming the suitability of housekeeping genes for inferring the evolutionary history of P. vivax. In addition, a genetic differentiation test using housekeeping gene polymorphism data showed a lack of geographical structuring between the five regions of India. The coalescence analysis of the time to the most recent common ancestor estimate yielded an ancient TMRCA (232,228 to 303,030 years and long-term population history (79,235 to 104,008 of extant P. vivax on the Indian subcontinent. Analysis of 18 tandem repeat loci polymorphisms showed substantial allelic diversity and heterozygosity per locus, and analysis of potential bottlenecks revealed the signature of a stable P. vivax population, further corroborating our ancient age estimates. For the first time we report a comparable evolutionary history of P. vivax inferred by nuclear genetic markers (putative housekeeping genes to that inferred from mitochondrial genome diversity.

  11. Neutral polymorphisms in putative housekeeping genes and tandem repeats unravels the population genetics and evolutionary history of Plasmodium vivax in India.

    Science.gov (United States)

    Prajapati, Surendra K; Joshi, Hema; Carlton, Jane M; Rizvi, M Alam

    2013-01-01

    The evolutionary history and age of Plasmodium vivax has been inferred as both recent and ancient by several studies, mainly using mitochondrial genome diversity. Here we address the age of P. vivax on the Indian subcontinent using selectively neutral housekeeping genes and tandem repeat loci. Analysis of ten housekeeping genes revealed a substantial number of SNPs (n = 75) from 100 P. vivax isolates collected from five geographical regions of India. Neutrality tests showed a majority of the housekeeping genes were selectively neutral, confirming the suitability of housekeeping genes for inferring the evolutionary history of P. vivax. In addition, a genetic differentiation test using housekeeping gene polymorphism data showed a lack of geographical structuring between the five regions of India. The coalescence analysis of the time to the most recent common ancestor estimate yielded an ancient TMRCA (232,228 to 303,030 years) and long-term population history (79,235 to 104,008) of extant P. vivax on the Indian subcontinent. Analysis of 18 tandem repeat loci polymorphisms showed substantial allelic diversity and heterozygosity per locus, and analysis of potential bottlenecks revealed the signature of a stable P. vivax population, further corroborating our ancient age estimates. For the first time we report a comparable evolutionary history of P. vivax inferred by nuclear genetic markers (putative housekeeping genes) to that inferred from mitochondrial genome diversity.

  12. Homosexuality according to ancient Greek physicians.

    Science.gov (United States)

    Laios, K; Moschos, M M; Koukaki, E; Kontaxaki, M-I; Androutsos, G

    2017-01-01

    Homosexuality and pedophilia in ancient Greece greatly concerned many researchers who were mainly interested in highlighting the social aspect of this phenomenon in ancient Greek society. An important source on the subject was the paintings of a man and his lover in attic black and red figured pottery, up to the end of the 5th century BC. Another main source was the information that derived from the texts of ancient Greek literature, especially poetry. Homosexuality was not only referring to relationships between males, but it was also manifested in lesbian love. It is believed that in the Homeric world homosexuality was not favored. In Greek society of the archaic period, the restriction of women at home, the satisfaction of sexual needs with courtesans, the marriage for the purpose of maintaining and managing the property, put women aside, marginalizing them in terms of social life, impeding the cultivation of emotional relationships between sexes. At the same time, in the society of those times, the aristocratic ideal, the constant communication of men during military training and the war, the male nudity in sports and the promotion of beauty and bravery in athletic contests, as well as the gatherings and the entertainment of men at the symposia, created a suitable substrate in which male homosexuality could develop. In this context, pedophile relationships were developed mainly during the archaic period, as recorded on vase paintings, where a mature man developed a special relationship with a teenager of the same social class. The mature man had the role of mentor for the juvenile, he would look after him and cover his living expenses and education cost. In this relationship, exhibiting predominantly the social dimension of an initiation process and introduction to adult life, the erotic homosexual intercourse could find a place to flourish. The above-mentioned relationship could not last forever, given that this would later transform into an emotional

  13. The study of human Y chromosome variation through ancient DNA.

    Science.gov (United States)

    Kivisild, Toomas

    2017-05-01

    High throughput sequencing methods have completely transformed the study of human Y chromosome variation by offering a genome-scale view on genetic variation retrieved from ancient human remains in context of a growing number of high coverage whole Y chromosome sequence data from living populations from across the world. The ancient Y chromosome sequences are providing us the first exciting glimpses into the past variation of male-specific compartment of the genome and the opportunity to evaluate models based on previously made inferences from patterns of genetic variation in living populations. Analyses of the ancient Y chromosome sequences are challenging not only because of issues generally related to ancient DNA work, such as DNA damage-induced mutations and low content of endogenous DNA in most human remains, but also because of specific properties of the Y chromosome, such as its highly repetitive nature and high homology with the X chromosome. Shotgun sequencing of uniquely mapping regions of the Y chromosomes to sufficiently high coverage is still challenging and costly in poorly preserved samples. To increase the coverage of specific target SNPs capture-based methods have been developed and used in recent years to generate Y chromosome sequence data from hundreds of prehistoric skeletal remains. Besides the prospects of testing directly as how much genetic change in a given time period has accompanied changes in material culture the sequencing of ancient Y chromosomes allows us also to better understand the rate at which mutations accumulate and get fixed over time. This review considers genome-scale evidence on ancient Y chromosome diversity that has recently started to accumulate in geographic areas favourable to DNA preservation. More specifically the review focuses on examples of regional continuity and change of the Y chromosome haplogroups in North Eurasia and in the New World.

  14. On the Development and Evolution of Astronomy in ancient Egypt

    Science.gov (United States)

    Maravelias, S. E.

    In the present paper the development and evolution of astronomy in = Ancient Egypt are briefly examined. Emphasis is given to the = applications of astronomy on: (i) the orientation of temples and = pyramids, and the subsequent determination of the year; (ii) the = reorientation of temples --after the lapse of several centuries-- (due = to the fact that the priesthood was empirically aware of the precession = of equinoxes, and the subsequent use of this very fact in order to = estimate the archaeological age of temples, tombs and pyramids; (iii) = the heliacal rising of Sirius, which was used by ancient = priests-astronomers in order to fix the New Year's Day and determine the = seasons of the civil year, although the discre pancy of the Sothic cycle = in their calendrical system was not seriously taken into account. = Finally the conclusion put forward is that astronomy in Ancient Egypt = never reached the grounds of pure science (as in Ancient Greece), at = least before the Ptolemaic era, but always remained under the influence = of traditionalism and mythology pertaining more to the sphere of = religion and dogma.

  15. In situ bioremediation via horizontal wells

    International Nuclear Information System (INIS)

    Hazen, T.C.; Looney, B.B.; Enzien, M.; Dougherty, J.M.; Wear, J.; Fliermans, C.B.; Eddy, C.A.

    1993-01-01

    The test consisted of methane mixed with air into the contaminated aquifer via a horizontal well and extraction from the vadose zone via a parallel horizontal well. This configuration has the advantage of simultaneously stimulating methanotrophic activity in both the groundwater and vadose zone, and inhibiting spread of the contaminant plume. Groundwater was monitored biweekly from 13 wells for a variety of chemical and microbiological parameters. Groundwater from wells in affected areas showed increases in methanotrophs of more than 1 order of magnitude every 2 weeks for several weeks after 1% methane-in-air injection was started. Some wells had increases as much as 7 orders of magnitude. Simultaneous with the increase in methanotrophs was a decrease in water and soil gas concentrations of trichloroethylene (TCE) and tetrachloroethane (PCE). Two wells declined in TCE/PCE concentration in the water by more than 90% to below 2 ppb. All of the wells in the affected zone showed significant decreases in contaminants in less than one month. Chloride concentrations in the water were inversely correlated with TCE/PCE concentration. Four of five vadose zone piezometers declined from concentration as high as 10,000 ppm to less than 5 ppm in less than 6 weeks. The fifth cluster also declined by more than 95%. After only three months on injection, a decline in TCE/PCE in the sediment of more than 30% was also observed, with TCE/PCE being undetectable in most sediments at the end of the 14-month test. Gene probes and direct isolation from the water and sediment revealed that the right types of methanotrophs were being stimulated and that isolates could degrade TCE at a high rate

  16. Medicine and psychiatry in Western culture: among Ancient Greek myths and modern prejudices.

    Science.gov (United States)

    Fornaro, Michele; Clementi, Nicoletta; Fornaro, Pantaleo

    2009-01-01

    While many ancient cultures contributed to our current knowledge about medicine and psychiatry origins, Ancient Greeks were among the best observers of feelings and moods patients could express toward medicine and toward what today referred as "psychopathology". Myths and religious references were used to explain what elsewhere impossible to understand or easily communicated. Most of ancient myths focus on ambiguous feelings patients could have towards drugs, especially psychotropic ones. Interestingly, such prejudices are common yet today. Recalling ancient findings and descriptions made using myths, should represent a valuable knowledge for modern physicians, especially for psychiatrists, and their patients, with the aim of better understanding each other and therefore achieving a better clinical outcome. The paper explores many human aspects and feelings toward doctors and their cures, referring to ancient myths, focusing on the perception of mental illness.

  17. ARCHAEOLOGICAL AND GEOLOGICAL CONCEPTS ON THE TOPIC OF ANCIENT MINING

    Directory of Open Access Journals (Sweden)

    Prentiss de JESUS

    2015-12-01

    Full Text Available Geological and archaeological research on ancient mining and metallurgy are actually targeting the same goals: understanding the nature and value of a mining operation. Geologists are intent on locating and qualifying ores and minerals for future use, whereas archaeologists strive to link ores to relevant historic and prehistoric metal artifacts and activities. This article discusses research into ancient Anatolian metallurgy by underscoring the overlap between geological and archeological practices. The work of archaeologists and geologists can be mutually beneficial through a close collaboration on the collection and analysis of field data. Their accumulated and combined knowledge would accelerate the progress towards placing ancient mining activities in a chronological and meaningful context.

  18. Cathair Crobh Dearg: From Ancient Beliefs to the Rounds 2017

    Directory of Open Access Journals (Sweden)

    Frédéric Armao

    2017-10-01

    Full Text Available This paper will study the case of the stone enclosure of Cathair Crobh Dearg, Co. Kerry (also referred to as the City and Dá Chích Anann (or the Paps of Anu, the twin mountains that can be seen from the enclosure. The site is mentioned in ancient mythological texts as well as more modern accounts in connection with the Irish festival of Bealtaine, in early May. The author relied on archaeological evidence, an analysis of ancient documents, a number of manuscripts from the Irish National Folklore Collection, as well as personal visits to the site in order to try and understand the nature, and possibly origin, of both contemporary rituals and ancient beliefs.

  19. On the acoustics of ancient Greek and Roman theaters.

    Science.gov (United States)

    Farnetani, Andrea; Prodi, Nicola; Pompoli, Roberto

    2008-09-01

    The interplay of architecture and acoustics is remarkable in ancient Greek and Roman theaters. Frequently they are nowadays lively performance spaces and the knowledge of the sound field inside them is still an issue of relevant importance. Even if the transition from Greek to Roman theaters can be described with a great architectural detail, a comprehensive and objective approach to the two types of spaces from the acoustical point of view is available at present only as a computer model study [P. Chourmouziadou and J. Kang, "Acoustic evolution of ancient Greek and Roman theaters," Appl. Acoust. 69, re (2007)]. This work addresses the same topic from the experimental point of view, and its aim is to provide a basis to the acoustical evolution from Greek to Roman theater design. First, by means of in situ and scale model measurements, the most important features of the sound field in ancient theaters are clarified and discussed. Then it has been possible to match quantitatively the role of some remarkable architectural design variables with acoustics, and it is seen how this criterion can be used effectively to define different groups of ancient theaters. Finally some more specific wave phenomena are addressed and discussed.

  20. Application of PIXE to study ancient Iranian silver coins

    Energy Technology Data Exchange (ETDEWEB)

    Oliaiy, P.; Shokouhi, F.; Lamehi-Rachti, M.; Rahighi, J. [Van de Graaff Laboratory, AEOI, Tehran (Iran); Andami, P.; Dilmaghani, J.; Etezadi, M. [Tamashagah-e-Pool, General Office of Museums, MDFIR, Tehran (Iran)

    1999-07-01

    Ancient Iranian silver coins minted in various parts of the ancient Iran from Transoxiana to Mesopotamia over a time span of 460 years (247BC-208AD) during Parthians dynasty were analysed by PIXE with a 2.2 MeV proton beam. Forty seven silver coins owned by Tamashagah-e-Pool (museum of money) in Tehran were examined in this study. The possible correlation between the composition of coins and the minting time or the minting location of coins has been the prime objective of the present study. Elemental analysis of ancient coins could also reveal the direct relation with the political and economical situation and also with the metallurgy of the minting time. Results on the contents of principal component elements (Fe, Ni, Cu, As, Br, Ag, Sn, Sb, Ba, Au and Pb) are presented and discussed. (author)

  1. RNA interference: learning gene knock-down from cell physiology

    Directory of Open Access Journals (Sweden)

    Provenzano Maurizio

    2004-11-01

    Full Text Available Summary Over the past decade RNA interference (RNAi has emerged as a natural mechanism for silencing gene expression. This ancient cellular antiviral response can be exploited to allow specific inhibition of the function of any chosen target gene. RNAi is proving to be an invaluable research tool, allowing much more rapid characterization of the function of known genes. More importantly, RNAi technology considerably bolsters functional genomics to aid in the identification of novel genes involved in disease processes. This review briefly describes the molecular principles underlying the biology of RNAi phenomenon and discuss the main technical issues regarding optimization of RNAi experimental design.

  2. RNA interference: learning gene knock-down from cell physiology

    Science.gov (United States)

    Mocellin, Simone; Provenzano, Maurizio

    2004-01-01

    Over the past decade RNA interference (RNAi) has emerged as a natural mechanism for silencing gene expression. This ancient cellular antiviral response can be exploited to allow specific inhibition of the function of any chosen target gene. RNAi is proving to be an invaluable research tool, allowing much more rapid characterization of the function of known genes. More importantly, RNAi technology considerably bolsters functional genomics to aid in the identification of novel genes involved in disease processes. This review briefly describes the molecular principles underlying the biology of RNAi phenomenon and discuss the main technical issues regarding optimization of RNAi experimental design. PMID:15555080

  3. Tradition and Creativity. Toward a Study of Intericonicity in Ancient Egyptian Art

    OpenAIRE

    Laboury, Dimitri

    2017-01-01

    Although a key-concept in Art historical discourse and reasoning, creativity has almost always been avoided as an issue in the discussion of Ancient Egyptian Art, as if the notion was simply irrelevant in such a context. This surprising phenomenon has clearly deep roots in the history of the western vision of Ancient Egyptian Art (and civilization). Nonetheless, the investigation of some (actually quite rare) cases of true copies in Ancient Egyptian Art reveals that creativity operated within...

  4. Accidental genetic engineers: horizontal sequence transfer from parasitoid wasps to their Lepidopteran hosts.

    Directory of Open Access Journals (Sweden)

    Sean E Schneider

    Full Text Available We show here that 105 regions in two Lepidoptera genomes appear to derive from horizontally transferred wasp DNA. We experimentally verified the presence of two of these sequences in a diverse set of silkworm (Bombyx mori genomes. We hypothesize that these horizontal transfers are made possible by the unusual strategy many parasitoid wasps employ of injecting hosts with endosymbiotic polydnaviruses to minimize the host's defense response. Because these virus-like particles deliver wasp DNA to the cells of the host, there has been much interest in whether genetic information can be permanently transferred from the wasp to the host. Two transferred sequences code for a BEN domain, known to be associated with polydnaviruses and transcriptional regulation. These findings represent the first documented cases of horizontal transfer of genes between two organisms by a polydnavirus. This presents an interesting evolutionary paradigm in which host species can acquire new sequences from parasitoid wasps that attack them. Hymenoptera and Lepidoptera diverged ∼300 MYA, making this type of event a source of novel sequences for recipient species. Unlike many other cases of horizontal transfer between two eukaryote species, these sequence transfers can be explained without the need to invoke the sequences 'hitchhiking' on a third organism (e.g. retrovirus capable of independent reproduction. The cellular machinery necessary for the transfer is contained entirely in the wasp genome. The work presented here is the first such discovery of what is likely to be a broader phenomenon among species affected by these wasps.

  5. Horizontal transmission of the Leningrad-Zagreb mumps vaccine strain: a report of six symptomatic cases of parotitis and one case of meningitis.

    Science.gov (United States)

    Atrasheuskaya, Alina; Kulak, Mikhail; Fisenko, Elena G; Karpov, Igor; Ignatyev, George; Atrasheuskaya, Alena

    2012-08-03

    Here we report horizontal symptomatic transmission of the Leningrad-Zagreb (L-Zagreb) mumps vaccine virus. Children who were the source of transmission had been vaccinated with the MMR vaccine (Serum Institute of India) contained L-Zagreb mumps virus. This is the first report of horizontal symptomatic transmission of this vaccine. The etiology of all seven contact cases was confirmed by epidemiological linking, serology and by F, SH, NP and HN mumps virus genes sequencing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Ancient Origin of the Tryptophan Operon and the Dynamics of Evolutionary Change†

    Science.gov (United States)

    Xie, Gary; Keyhani, Nemat O.; Bonner; Jensen, Roy A.

    2003-01-01

    The seven conserved enzymatic domains required for tryptophan (Trp) biosynthesis are encoded in seven genetic regions that are organized differently (whole-pathway operons, multiple partial-pathway operons, and dispersed genes) in prokaryotes. A comparative bioinformatics evaluation of the conservation and organization of the genes of Trp biosynthesis in prokaryotic operons should serve as an excellent model for assessing the feasibility of predicting the evolutionary histories of genes and operons associated with other biochemical pathways. These comparisons should provide a better understanding of possible explanations for differences in operon organization in different organisms at a genomics level. These analyses may also permit identification of some of the prevailing forces that dictated specific gene rearrangements during the course of evolution. Operons concerned with Trp biosynthesis in prokaryotes have been in a dynamic state of flux. Analysis of closely related organisms among the Bacteria at various phylogenetic nodes reveals many examples of operon scission, gene dispersal, gene fusion, gene scrambling, and gene loss from which the direction of evolutionary events can be deduced. Two milestone evolutionary events have been mapped to the 16S rRNA tree of Bacteria, one splitting the operon in two, and the other rejoining it by gene fusion. The Archaea, though less resolved due to a lesser genome representation, appear to exhibit more gene scrambling than the Bacteria. The trp operon appears to have been an ancient innovation; it was already present in the common ancestor of Bacteria and Archaea. Although the operon has been subjected, even in recent times, to dynamic changes in gene rearrangement, the ancestral gene order can be deduced with confidence. The evolutionary history of the genes of the pathway is discernible in rough outline as a vertical line of descent, with events of lateral gene transfer or paralogy enriching the analysis as interesting

  7. Ancient origin of the tryptophan operon and the dynamics of evolutionary change.

    Science.gov (United States)

    Xie, Gary; Keyhani, Nemat O; Bonner, Carol A; Jensen, Roy A

    2003-09-01

    The seven conserved enzymatic domains required for tryptophan (Trp) biosynthesis are encoded in seven genetic regions that are organized differently (whole-pathway operons, multiple partial-pathway operons, and dispersed genes) in prokaryotes. A comparative bioinformatics evaluation of the conservation and organization of the genes of Trp biosynthesis in prokaryotic operons should serve as an excellent model for assessing the feasibility of predicting the evolutionary histories of genes and operons associated with other biochemical pathways. These comparisons should provide a better understanding of possible explanations for differences in operon organization in different organisms at a genomics level. These analyses may also permit identification of some of the prevailing forces that dictated specific gene rearrangements during the course of evolution. Operons concerned with Trp biosynthesis in prokaryotes have been in a dynamic state of flux. Analysis of closely related organisms among the Bacteria at various phylogenetic nodes reveals many examples of operon scission, gene dispersal, gene fusion, gene scrambling, and gene loss from which the direction of evolutionary events can be deduced. Two milestone evolutionary events have been mapped to the 16S rRNA tree of Bacteria, one splitting the operon in two, and the other rejoining it by gene fusion. The Archaea, though less resolved due to a lesser genome representation, appear to exhibit more gene scrambling than the Bacteria. The trp operon appears to have been an ancient innovation; it was already present in the common ancestor of Bacteria and Archaea. Although the operon has been subjected, even in recent times, to dynamic changes in gene rearrangement, the ancestral gene order can be deduced with confidence. The evolutionary history of the genes of the pathway is discernible in rough outline as a vertical line of descent, with events of lateral gene transfer or paralogy enriching the analysis as interesting

  8. Lampreys, the jawless vertebrates, contain only two ParaHox gene clusters.

    Science.gov (United States)

    Zhang, Huixian; Ravi, Vydianathan; Tay, Boon-Hui; Tohari, Sumanty; Pillai, Nisha E; Prasad, Aravind; Lin, Qiang; Brenner, Sydney; Venkatesh, Byrappa

    2017-08-22

    ParaHox genes ( Gsx , Pdx , and Cdx ) are an ancient family of developmental genes closely related to the Hox genes. They play critical roles in the patterning of brain and gut. The basal chordate, amphioxus, contains a single ParaHox cluster comprising one member of each family, whereas nonteleost jawed vertebrates contain four ParaHox genomic loci with six or seven ParaHox genes. Teleosts, which have experienced an additional whole-genome duplication, contain six ParaHox genomic loci with six ParaHox genes. Jawless vertebrates, represented by lampreys and hagfish, are the most ancient group of vertebrates and are crucial for understanding the origin and evolution of vertebrate gene families. We have previously shown that lampreys contain six Hox gene loci. Here we report that lampreys contain only two ParaHox gene clusters (designated as α- and β-clusters) bearing five ParaHox genes ( Gsxα , Pdxα , Cdxα , Gsxβ , and Cdxβ ). The order and orientation of the three genes in the α-cluster are identical to that of the single cluster in amphioxus. However, the orientation of Gsxβ in the β-cluster is inverted. Interestingly, Gsxβ is expressed in the eye, unlike its homologs in jawed vertebrates, which are expressed mainly in the brain. The lamprey Pdxα is expressed in the pancreas similar to jawed vertebrate Pdx genes, indicating that the pancreatic expression of Pdx was acquired before the divergence of jawless and jawed vertebrate lineages. It is likely that the lamprey Pdxα plays a crucial role in pancreas specification and insulin production similar to the Pdx of jawed vertebrates.

  9. Peopling the past: new perspectives on the ancient Maya.

    Science.gov (United States)

    Robin, C

    2001-01-02

    The new direction in Maya archaeology is toward achieving a greater understanding of people and their roles and their relations in the past. To answer emerging humanistic questions about ancient people's lives Mayanists are increasingly making use of new and existing scientific methods from archaeology and other disciplines. Maya archaeology is bridging the divide between the humanities and sciences to answer questions about ancient people previously considered beyond the realm of archaeological knowledge.

  10. What tangled web: barriers to rampant horizontal gene transfer

    OpenAIRE

    Kurland, Charles

    2005-01-01

    Dawkins in his The Selfish Gene(1) quite aptly applies the term "selfish" to parasitic repetitive DNA sequences endemic to eukaryotic genomes, especially vertebrates. Doolittle and Sapienza (2) as well as Orgel and Crick (3) enlivened this notion of selfish DNA with the identification of such repetitive sequences as remnants of mobile elements such as transposons. In addition, Orgel and Crick (3) associated parasitic DNA with a potential to outgrow their host genomes by propagating ...

  11. Small horizontal emittance in the TESLA damping ring

    International Nuclear Information System (INIS)

    Decking, W.

    2001-01-01

    The present TESLA damping ring is designed for a normalized horizontal emittance of 8x10 -6 m. γ-γ collisions at the TESLA linear collider will benefit from a further decrease of the horizontal emittance. This paper reviews the processes which limit the horizontal emittance in the damping ring. Preliminary estimates on the smallest horizontal emittance for the present TESLA damping ring design as well as an ultimate limit of the emittance reachable with the TESLA damping ring concept will be given

  12. Perseus Project: Interactive Teaching and Research Tools for Ancient Greek Civilization.

    Science.gov (United States)

    Crane, Gregory; Harward, V. Judson

    1987-01-01

    Describes the Perseus Project, an educational program utilizing computer technology to study ancient Greek civilization. Including approximately 10 percent of all ancient literature and visual information on architecture, sculpture, ceramics, topography, and archaeology, the project spans a range of disciplines. States that Perseus fuels student…

  13. Ancient tombs in China and shallow ground burial of solid low-intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Huang Yawen; Gu Cunli

    1987-01-01

    Having reviewed the experiences with ancient tombs in China, particularly the experiences with tomb siting, configuration of tombs, backfilling materials, civil engineering techniques, sealing techniques, drainage system, antiseptic techniques, a comparison between the ancient tombs and the shallow ground burial of solid radioactive wastes is made. The authors believe that the brilliant achievements of ancient tombs in China in keeping ancient corpses and funeral objects are a historical evidence for safety of shallow ground burial of radioactive wastes, and that the main experiences with the ancient tombs may be useful to shallow ground burial of solid radioactive wastes

  14. Reconciliation of Gene and Species Trees

    Directory of Open Access Journals (Sweden)

    L. Y. Rusin

    2014-01-01

    Full Text Available The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree.

  15. Trace elements measurement by PIXE in the appraisal of the ancient potteries

    International Nuclear Information System (INIS)

    Zhang, Z.Q.; Cheng, H.S.; Xia, H.N.; Jiang, J.C.; Gao, M.H.; Yang, F.J.

    2002-01-01

    Fifty pieces of pottery samples were collected from two domains with different types of ancient Sino-civilization. The concentrations of trace elements Cr, Ni, Cu, Zn, Pb, Rb, Sr, Y and Zr were measured by proton-induced X-ray emission technique. Multivariate statistical processing of the results allows us to locate the provenance of the ancient potteries. The experimental results also show that the relative trace element contents Ni-Rb-Zr are useful for distinguishing these two types of Chinese ancient potteries

  16. Ancient deuterostome origins of vertebrate brain signalling centres.

    Science.gov (United States)

    Pani, Ariel M; Mullarkey, Erin E; Aronowicz, Jochanan; Assimacopoulos, Stavroula; Grove, Elizabeth A; Lowe, Christopher J

    2012-03-14

    Neuroectodermal signalling centres induce and pattern many novel vertebrate brain structures but are absent, or divergent, in invertebrate chordates. This has led to the idea that signalling-centre genetic programs were first assembled in stem vertebrates and potentially drove morphological innovations of the brain. However, this scenario presumes that extant cephalochordates accurately represent ancestral chordate characters, which has not been tested using close chordate outgroups. Here we report that genetic programs homologous to three vertebrate signalling centres-the anterior neural ridge, zona limitans intrathalamica and isthmic organizer-are present in the hemichordate Saccoglossus kowalevskii. Fgf8/17/18 (a single gene homologous to vertebrate Fgf8, Fgf17 and Fgf18), sfrp1/5, hh and wnt1 are expressed in vertebrate-like arrangements in hemichordate ectoderm, and homologous genetic mechanisms regulate ectodermal patterning in both animals. We propose that these genetic programs were components of an unexpectedly complex, ancient genetic regulatory scaffold for deuterostome body patterning that degenerated in amphioxus and ascidians, but was retained to pattern divergent structures in hemichordates and vertebrates. © 2012 Macmillan Publishers Limited. All rights reserved

  17. Spondylolysis and the sacro-horizontal angle in athletes

    International Nuclear Information System (INIS)

    Swaerd, L.; Hellstroem, M.; Jacobsson, B.; Peterson, L.; Sahlgrenska Sjukhuset, Goeteborg; King Faisal Specialist Hospital and Research Centre, Riyadh

    1989-01-01

    The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.)

  18. Spondylolysis and the sacro-horizontal angle in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Swaerd, L.; Hellstroem, M.; Jacobsson, B.; Peterson, L. (Oestra Sjukhuset, Goeteborg (Sweden). Dept. of Orthopaedics; Sahlgrenska Sjukhuset, Goeteborg (Sweden). Dept. of Diagnostic Radiology; King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Radiology)

    The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.).

  19. Sex and Gender Related Health Status Differences in Ancient and Contemporary Skeletal Populations

    Directory of Open Access Journals (Sweden)

    Velissaria Vanna

    2007-11-01

    Full Text Available Human skeletal and dental remains are an invaluable source of information for interpreting the way of life of past people and also provide the only direct evidence of non-living populations’ health status. This research paper discusses the sex-related health differences observed in two skeletal populations from Greece, an ancient and a modern, by employing multiple health indicators, and aims at determining the biological and possible social factors that contribute to this variation. Particular emphasis is given to the importance of hypotheses-driven, population-based studies of human remains as the most effective means of reconstructing life in the past. The results showed that fracture ('ancient': females 0.08%, males 0.12%; 'modern': females 0.38%, males 0.19% and osteoarthritis ('ancient': females 0.7%, males: 3.0%; 'modern': females 4.4%, males 3.2% frequencies were higher for male individuals than females in the ancient population, which can be explained by greater engagement in strenuous and risky activity. Dental caries ('ancient': females 1.2%, males 1.8%; 'modern': females 23.6%, males 17.4% and ante-mortem tooth loss ('ancient': females 12.3%, males 7.7%; 'modern': females 69.5%, males 49.5% rates were higher for females than males (with the exception of the almost equal caries rates for the ancient population, most likely due to hormonal fluctuations, saliva content and flow, because female teeth erupt earlier and also perhaps as a result of differences in dietary habits. Periodontitis levels were more elevated in males ('ancient': females 9.6%, males 30.1%; 'modern': females 29.1%, males 38.3%, possibly due to poor oral hygiene practices and excessive masticatory loading. Dental enamel defects rates showed that in the ancient population, males had more chances of surviving childhood stress than females (females 19.5%, males 20.0%, whereas, in the modern population, the exact opposite was the case (females 6.1%, males 22.7%.

  20. Intraosseous neurilemmoma of the mandible: report of a rare ancient type.

    Science.gov (United States)

    Jahanshahi, Gholamreza; Haghighat, Abbas; Azmoodeh, Faezeh

    2011-01-01

    The neurilemmoma is a benign neoplasm of Schwann cell origin. One of the histopathologic subtypes of this tumor is ancient schwannoma which is characterized by degenerative alterations including cystic change, calcification, hemorrhage, and hyalinization.Intraosseous schwannomas especially ancient ones are rare tumors. Here we present a case of intraosseous ancient schwannoma in the lower jaw of an 11-year-old girl which caused a non-tender expansion. Radiographic examination showed a well-circumscribed, unilocular radiolucent lesion with thin sclerotic borders in the mandibular body and the ramus. Histopathologic examination of the incisional biopsy showed areas of typical Antoni A with verocay bodies and Antoni B that was strongly suggestive of a schwannoma. Complete excision of the lesion was done under general anesthesia. The histopathologic examination confirmed the primary diagnosis and also degenerative changes such as hyalinization and calcification. Based on these findings, the diagnosis of ancient schwannoma was made. No recurrence was observed in the follow-up examination after 3 months.

  1. Feature recognition and detection for ancient architecture based on machine vision

    Science.gov (United States)

    Zou, Zheng; Wang, Niannian; Zhao, Peng; Zhao, Xuefeng

    2018-03-01

    Ancient architecture has a very high historical and artistic value. The ancient buildings have a wide variety of textures and decorative paintings, which contain a lot of historical meaning. Therefore, the research and statistics work of these different compositional and decorative features play an important role in the subsequent research. However, until recently, the statistics of those components are mainly by artificial method, which consumes a lot of labor and time, inefficiently. At present, as the strong support of big data and GPU accelerated training, machine vision with deep learning as the core has been rapidly developed and widely used in many fields. This paper proposes an idea to recognize and detect the textures, decorations and other features of ancient building based on machine vision. First, classify a large number of surface textures images of ancient building components manually as a set of samples. Then, using the convolution neural network to train the samples in order to get a classification detector. Finally verify its precision.

  2. Attitudes to Ancient Greek in Three Schools: A Case Study

    Science.gov (United States)

    Foster, Frances

    2018-01-01

    This study comes in response to recent changes in UK policy, whereby Ancient Greek and Latin have been included alongside modern languages as part of the curriculum at Key Stage 2. It aims to understand how Ancient Greek is surviving and thriving in three different types of schools. After a short overview of the history of Greek teaching in the…

  3. Horizontal alveolar bone loss: A periodontal orphan

    Science.gov (United States)

    Jayakumar, A.; Rohini, S.; Naveen, A.; Haritha, A.; Reddy, Krishnanjeneya

    2010-01-01

    Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician’s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs) (of patients diagnosed with chronic periodontitis and seeking periodontal care), which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm) or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36%) OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2%) teeth, and vertical defects were found only in 264 (7.8%) of the teeth, which was statistically significant (P<.001). Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3%) have addressed vertical bone loss, and 18 (3.7%) have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment modalities for

  4. Preliminary Study of Ancient Town Protection and Rural Tourism Development of Caoshi Town in Hengdong County, Hunan Province

    OpenAIRE

    Liu, Tian-zhao; Yang, Zai-tian; Liu Pei-lin

    2012-01-01

    The typical style and features of mountains and waters in Caoshi Ancient Town, have hitherto been well preserved. Caoshi Ancient Town boasts superior base of the natural eco-environment and deep-rooted background of regional culture, where mountains, waters, shoals, towns and other landscape elements are merged harmoniously, the transportation and geographical conditions have been fundamentally changed. Ancient towns, old temples, ancient forests, ancient wells and ancient piers are unique in...

  5. Problem-oriented approach to Ancient philosophy

    Directory of Open Access Journals (Sweden)

    Berstov, Igor

    2007-06-01

    Full Text Available Igor Berestov and Marina Wolf of the Institute of philosophy and law, Novosibirsk, discuss various methodological difficulties typical of studies in the history of Ancient Greek philosophy and try to develop their own problem-oriented approach.

  6. comparative evaluation of pressure distribution between horizontal

    African Journals Online (AJOL)

    user

    This paper presents comparative analysis between the pressure behavior of ... Green and source function were used to evaluate the performance of horizontal well and ..... Superscript. ' derivative. D = dimensionless. h = horizontal. = change.

  7. DNA typing of ancient parasite eggs from environmental samples identifies human and animal worm infections in Viking-age settlement.

    Science.gov (United States)

    Søe, Martin Jensen; Nejsum, Peter; Fredensborg, Brian Lund; Kapel, Christian Moliin Outzen

    2015-02-01

    Ancient parasite eggs were recovered from environmental samples collected at a Viking-age settlement in Viborg, Denmark, dated 1018-1030 A.D. Morphological examination identified Ascaris sp., Trichuris sp., and Fasciola sp. eggs, but size and shape did not allow species identification. By carefully selecting genetic markers, PCR amplification and sequencing of ancient DNA (aDNA) isolates resulted in identification of: the human whipworm, Trichuris trichiura , using SSUrRNA sequence homology; Ascaris sp. with 100% homology to cox1 haplotype 07; and Fasciola hepatica using ITS1 sequence homology. The identification of T. trichiura eggs indicates that human fecal material is present and, hence, that the Ascaris sp. haplotype 07 was most likely a human variant in Viking-age Denmark. The location of the F. hepatica finding suggests that sheep or cattle are the most likely hosts. Further, we sequenced the Ascaris sp. 18S rRNA gene in recent isolates from humans and pigs of global distribution and show that this is not a suited marker for species-specific identification. Finally, we discuss ancient parasitism in Denmark and the implementation of aDNA analysis methods in paleoparasitological studies. We argue that when employing species-specific identification, soil samples offer excellent opportunities for studies of human parasite infections and of human and animal interactions of the past.

  8. The value of ancient architecture for educational program of masters of architectural space design

    Directory of Open Access Journals (Sweden)

    Prishchepa Aleksandr

    2017-01-01

    Full Text Available The existence of archaeological sites of ancient Greek colony-towns and medieval fortresses gives a real insight into the interaction of all spheres of human activity in ancient times. Ancient Greek Emporium is a vivid example of the architecture, art, archaeology and urban planning synthesis. Archaeological excavations provide an opportunity to study the artefacts of the ancient world belonging to several fields, such as sculpture, decorative arts, fashion design and household. Studying history of archaeology right on the place of excavation of an ancient city masters can imagine the scale of buildings, streets layout and location of business, administrative and residential buildings. It allows students to form professional way of thinking in a short period in order to gather the material and work on the master thesis.

  9. NIMI TANTRA (Opthalmology of Ancient India).

    Science.gov (United States)

    Ramachandran, C K

    1984-04-01

    The art of opthalmology was well developed in ancient India and was known as Nimi Tantra. In this paper the author presents the main features of Nimi Tantra an authoritative treatises written by Nimi, a prominent opthalmologist of his time.

  10. NIMI TANTRA (Opthalmology of Ancient India)

    OpenAIRE

    Ramachandran, C.K.

    1984-01-01

    The art of opthalmology was well developed in ancient India and was known as Nimi Tantra. In this paper the author presents the main features of Nimi Tantra an authoritative treatises written by Nimi, a prominent opthalmologist of his time.

  11. Balancing selection on a regulatory region exhibiting ancient variation that predates human-neandertal divergence.

    Directory of Open Access Journals (Sweden)

    Omer Gokcumen

    2013-04-01

    Full Text Available Ancient population structure shaping contemporary genetic variation has been recently appreciated and has important implications regarding our understanding of the structure of modern human genomes. We identified a ∼36-kb DNA segment in the human genome that displays an ancient substructure. The variation at this locus exists primarily as two highly divergent haplogroups. One of these haplogroups (the NE1 haplogroup aligns with the Neandertal haplotype and contains a 4.6-kb deletion polymorphism in perfect linkage disequilibrium with 12 single nucleotide polymorphisms (SNPs across diverse populations. The other haplogroup, which does not contain the 4.6-kb deletion, aligns with the chimpanzee haplotype and is likely ancestral. Africans have higher overall pairwise differences with the Neandertal haplotype than Eurasians do for this NE1 locus (p<10⁻¹⁵. Moreover, the nucleotide diversity at this locus is higher in Eurasians than in Africans. These results mimic signatures of recent Neandertal admixture contributing to this locus. However, an in-depth assessment of the variation in this region across multiple populations reveals that African NE1 haplotypes, albeit rare, harbor more sequence variation than NE1 haplotypes found in Europeans, indicating an ancient African origin of this haplogroup and refuting recent Neandertal admixture. Population genetic analyses of the SNPs within each of these haplogroups, along with genome-wide comparisons revealed significant FST (p = 0.00003 and positive Tajima's D (p = 0.00285 statistics, pointing to non-neutral evolution of this locus. The NE1 locus harbors no protein-coding genes, but contains transcribed sequences as well as sequences with putative regulatory function based on bioinformatic predictions and in vitro experiments. We postulate that the variation observed at this locus predates Human-Neandertal divergence and is evolving under balancing selection, especially among European

  12. Research of Ancient Architectures in Jin-Fen Area Based on GIS and BIM Technology

    International Nuclear Information System (INIS)

    Jia, Jing; Zheng, Qiuhong; Gao, Huiying; Sun, Hai

    2017-01-01

    The number of well-preserved ancient buildings located in Shanxi Province, enjoying the absolute maximum proportion of ancient architectures in China, is about 18418, among which, 9053 buildings have the structural style of wood frame. The value of the application of BIM (Building Information Modeling) and GIS (Geographic Information System) is gradually probed and testified in the corresponding fields of ancient architecture’s spatial distribution information management, routine maintenance and special conservation and restoration, the evaluation and simulation of related disasters, such as earthquake. The research objects are ancient architectures in JIN-FEN area, which were first investigated by Sicheng LIANG and recorded in his work of “Chinese ancient architectures survey report”. The research objects, i.e. the ancient architectures in Jin-Fen area include those in Sicheng LIANG’s investigation, and further adjustments were made through authors’ on-site investigation and literature searching and collection. During this research process, the spatial distributing Geodatabase of research objects is established utilizing GIS. The BIM components library for ancient buildings is formed combining on-site investigation data and precedent classic works, such as “Yingzao Fashi”, a treatise on architectural methods in Song Dynasty, “Yongle Encyclopedia” and “Gongcheng Zuofa Zeli”, case collections of engineering practice, by the Ministry of Construction of Qing Dynasty. A building of Guangsheng temple in Hongtong county is selected as an example to elaborate the BIM model construction process based on the BIM components library for ancient buildings. Based on the foregoing work results of spatial distribution data, attribute data of features, 3D graphic information and parametric building information model, the information management system for ancient architectures in Jin-Fen Area, utilizing GIS and BIM technology, could be constructed to support

  13. The development of Canadian leadership in horizontal drilling technology

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, J R

    1989-01-01

    Horizontal wells are of increasing interest in the oil and gas industry, as is evident from the increase in the numbers of such wells being drilled. Horizontal well technology is used to improve production rates, notably in low permeability formations; to capture reserves if a reservoir is not economic using non-horizontal wells; to manage breakthrough of sweep fluids and increase sweep efficiency; and to extend the areal reach from a single surface location, especially in offshore production. The types of horizontal wells, differentiated on the basis of how quickly the well becomes horizontal, are briefly outlined and a short history of horizontal wells is presented. Canadian accomplishments in this field are then described, including steerable drilling systems, measurement-while-drilling systems, management of hole drag and torque, and well completion techniques. About 25 horizontal wells are forecast to be drilled in Canada in 1989, indicating the favorable future of this technology. 2 figs., 5 tabs.

  14. The Phenomenon of Pathological Dissociation in the Ancient Chinese Medicine Literature.

    Science.gov (United States)

    Fung, Hong Wang

    2018-01-01

    Dissociative symptoms and disorders have been reported in many different cultures. If pathological dissociation is naturally occurring and related to adverse experiences, such phenomena should have been witnessed and portrayed before the modern age. To investigate whether this is the case, the author made use of the rich ancient Chinese medicine literature and looked for descriptions of pathological dissociation in medical documents written by ancient Chinese medical practitioners. In this paper, the author presents six cases selected from the ancient Chinese medicine literature. The phenomenon of pathological dissociation is observed in these cases. This is the first report of case descriptions of pathological dissociation documented in Chinese cultures before 1900.

  15. The horizontal plane appearances of scoliosis

    DEFF Research Database (Denmark)

    Illés, Tamás S.; Burkus, Máté; Somoskeőy, Szabolcs

    2017-01-01

    Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two-/three-dimen......Purpose: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. Methods: We used an EOS two...... cases of a normal spine and a thoracic scoliosis are presented. Results: For a normal spine, vector projections in the transverse plane are aligned with the posterior-anterior anatomical axis. For a scoliotic spine, vector projections in the horizontal plane provide information on the lateral...... decompensation of the spine and the lateral displacement of vertebrae. In the horizontal plane view, vertebral rotation and projections of the sagittal curves can also be analyzed simultaneously. Conclusions: The use of posterior-anterior vertebral vector facilitates the understanding of the 3D nature...

  16. Modelling human agency in ancient irrigation

    NARCIS (Netherlands)

    Ertsen, M.W.

    2011-01-01

    Human activity is key in understanding ancient irrigation systems. Results of short term actions build up over time, affecting civilizations on larger temporal and spatial scales. Irrigation systems, with their many entities, social and physical, their many interactions within a changing environment

  17. Statistical guidelines for detecting past population shifts using ancient DNA

    DEFF Research Database (Denmark)

    Mourier, Tobias; Ho, Simon Y. W.; Gilbert, Tom

    2012-01-01

    Populations carry a genetic signal of their demographic past, providing an opportunity for investigating the processes that shaped their evolution. Our ability to infer population histories can be enhanced by including ancient DNA data. Using serial-coalescent simulations and a range of both...... quantitative and temporal sampling schemes, we test the power of ancient mitochondrial sequences and nuclear single-nucleotide polymorphisms (SNPs) to detect past population bottlenecks. Within our simulated framework, mitochondrial sequences have only limited power to detect subtle bottlenecks and/or fast...... results provide useful guidelines for scaling sampling schemes and for optimizing our ability to infer past population dynamics. In addition, our results suggest that many ancient DNA studies may face power issues in detecting moderate demographic collapses and/or highly dynamic demographic shifts when...

  18. A decision support system for the reading of ancient documents

    DEFF Research Database (Denmark)

    Roued-Cunliffe, Henriette

    2011-01-01

    The research presented in this thesis is based in the Humanities discipline of Ancient History and begins by attempting to understand the interpretation process involved in reading ancient documents and how this process can be aided by computer systems such as Decision Support Systems (DSS...... this process in the five areas: remembering complex reasoning, searching huge datasets, international collaboration, publishing editions, and image enhancement. This research contains a large practical element involving the development of a DSS prototype. The prototype is used to illustrate how a DSS......, by remembering complex reasoning, can aid the process of interpretation that is reading ancient documents. It is based on the idea that the interpretation process goes through a network of interpretation. The network of interpretation illustrates a recursive process where scholars move between reading levels...

  19. Horizontal gaze palsy and progressive scoliosis in a patient with congenital esotropia and inability to abduct. A case report.

    Science.gov (United States)

    Fernández-Vega Cueto, A; Rodríguez-Ezcurra, J J; Rodríguez-Maiztegui, I

    2016-12-01

    The case is presented on a 4- year-old child with congenital esotropia, limitation of abduction, cross-fixation, and thoracolumbar scoliosis. Genetic testing of ROBO3 gene confirmed the diagnosis of horizontal gaze palsy and scoliosis (HGPSS) DISCUSSION: HGPPS is a rare congenital disorder characterised by absence of conjugate horizontal eye movements and progressive scoliosis developed in childhood and adolescence. We highlight this motility disorder as a part of the differential diagnosis of early childhood esotropia with cross- fixation and limitation of abduction. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Lipids of aquatic sediments, recent and ancient

    Science.gov (United States)

    Eglinton, G.; Hajibrahim, S. K.; Maxwell, J. R.; Quirke, J. M. E.; Shaw, G. J.; Volkman, J. K.; Wardroper, A. M. K.

    1979-01-01

    Computerized gas chromatography-mass spectrometry (GC-MS) is now an essential tool in the analysis of the complex mixtures of lipids (geolipids) encountered in aquatic sediments, both 'recent' (less than 1 million years old) and ancient. The application of MS, and particularly GC-MS, has been instrumental in the rapid development of organic geochemistry and environmental organic chemistry in recent years. The techniques used have resulted in the identification of numerous compounds of a variety of types in sediments. Most attention has been concentrated on molecules of limited size, mainly below 500 molecular mass, and of limited functionality, for examples, hydrocarbons, fatty acids and alcohols. Examples from recent studies (at Bristol) of contemporary, 'recent' and ancient sediments are presented and discussed.

  1. AMS radiocarbon dating of ancient Japanese sutras

    CERN Document Server

    Oda, H; Nakamura, T; Fujita, K

    2000-01-01

    Radiocarbon ages of ancient Japanese sutras whose historical ages were known paleographically were measured by means of accelerator mass spectrometry (AMS). Calibrated radiocarbon ages of five samples were consistent with the corresponding historical ages; the 'old wood effect' is negligible for ancient Japanese sutras. Japanese paper has been made from fresh branches grown within a few years and the interval from trimming off the branches to writing sutra on the paper is within one year. The good agreement between the calibrated radiocarbon ages and the historical ages is supported by such characteristics of Japanese paper. It is indicated in this study that Japanese sutra is a suitable sample for radiocarbon dating in the historic period because of little gap by 'old wood effect'.

  2. AMS radiocarbon dating of ancient Japanese sutras

    International Nuclear Information System (INIS)

    Oda, Hirotaka; Yoshizawa, Yasukazu; Nakamura, Toshio; Fujita, Keiko

    2000-01-01

    Radiocarbon ages of ancient Japanese sutras whose historical ages were known paleographically were measured by means of accelerator mass spectrometry (AMS). Calibrated radiocarbon ages of five samples were consistent with the corresponding historical ages; the 'old wood effect' is negligible for ancient Japanese sutras. Japanese paper has been made from fresh branches grown within a few years and the interval from trimming off the branches to writing sutra on the paper is within one year. The good agreement between the calibrated radiocarbon ages and the historical ages is supported by such characteristics of Japanese paper. It is indicated in this study that Japanese sutra is a suitable sample for radiocarbon dating in the historic period because of little gap by 'old wood effect'

  3. Ancient balancing selection at tan underlies female colour dimorphism in Drosophila erecta.

    Science.gov (United States)

    Yassin, Amir; Bastide, Héloïse; Chung, Henry; Veuille, Michel; David, Jean R; Pool, John E

    2016-01-18

    Dimorphic traits are ubiquitous in nature, but the evolutionary factors leading to dimorphism are largely unclear. We investigate a potential case of sexual mimicry in Drosophila erecta, in which females show contrasting resemblance to males. We map the genetic basis of this sex-limited colour dimorphism to a region containing the gene tan. We find a striking signal of ancient balancing selection at the 'male-specific enhancer' of tan, with exceptionally high sequence divergence between light and dark alleles, suggesting that this dimorphism has been adaptively maintained for millions of years. Using transgenic reporter assays, we confirm that these enhancer alleles encode expression differences that are predicted to generate this pigmentation dimorphism. These results are compatible with the theoretical prediction that divergent phenotypes maintained by selection can evolve simple genetic architectures.

  4. Genome-wide analysis of the GRAS gene family in physic nut (Jatropha curcas L.).

    Science.gov (United States)

    Wu, Z Y; Wu, P Z; Chen, Y P; Li, M R; Wu, G J; Jiang, H W

    2015-12-29

    GRAS proteins play vital roles in plant growth and development. Physic nut (Jatropha curcas L.) was found to have a total of 48 GRAS family members (JcGRAS), 15 more than those found in Arabidopsis. The JcGRAS genes were divided into 12 subfamilies or 15 ancient monophyletic lineages based on the phylogenetic analysis of GRAS proteins from both flowering and lower plants. The functions of GRAS genes in 9 subfamilies have been reported previously for several plants, while the genes in the remaining 3 subfamilies were of unknown function; we named the latter families U1 to U3. No member of U3 subfamily is present in Arabidopsis and Poaceae species according to public genome sequence data. In comparison with the number of GRAS genes in Arabidopsis, more were detected in physic nut, resulting from the retention of many ancient GRAS subfamilies and the formation of tandem repeats during evolution. No evidence of recent duplication among JcGRAS genes was observed in physic nut. Based on digital gene expression data, 21 of the 48 genes exhibited differential expression in four tissues analyzed. Two members of subfamily U3 were expressed only in buds and flowers, implying that they may play specific roles. Our results provide valuable resources for future studies on the functions of GRAS proteins in physic nut.

  5. MITEs in the promoters of effector genes allow prediction of novel virulence genes in Fusarium oxysporum

    NARCIS (Netherlands)

    Schmidt, S.M.; Houterman, P.M.; Schreiver, I.; Ma, L.; Amyotte, S.; Chellappan, B.; Boeren, S.; Takken, F.L.W.; Rep, M.

    2013-01-01

    Background The plant-pathogenic fungus Fusarium oxysporum f.sp.lycopersici (Fol) has accessory, lineage-specific (LS) chromosomes that can be transferred horizontally between strains. A single LS chromosome in the Fol4287 reference strain harbors all known Fol effector genes. Transfer of this

  6. Comparing particle-size distributions in modern and ancient sand-bed rivers

    Science.gov (United States)

    Hajek, E. A.; Lynds, R. M.; Huzurbazar, S. V.

    2011-12-01

    Particle-size distributions yield valuable insight into processes controlling sediment supply, transport, and deposition in sedimentary systems. This is especially true in ancient deposits, where effects of changing boundary conditions and autogenic processes may be detected from deposited sediment. In order to improve interpretations in ancient deposits and constrain uncertainty associated with new methods for paleomorphodynamic reconstructions in ancient fluvial systems, we compare particle-size distributions in three active sand-bed rivers in central Nebraska (USA) to grain-size distributions from ancient sandy fluvial deposits. Within the modern rivers studied, particle-size distributions of active-layer, suspended-load, and slackwater deposits show consistent relationships despite some morphological and sediment-supply differences between the rivers. In particular, there is substantial and consistent overlap between bed-material and suspended-load distributions, and the coarsest material found in slackwater deposits is comparable to the coarse fraction of suspended-sediment samples. Proxy bed-load and slackwater-deposit samples from the Kayenta Formation (Lower Jurassic, Utah/Colorado, USA) show overlap similar to that seen in the modern rivers, suggesting that these deposits may be sampled for paleomorphodynamic reconstructions, including paleoslope estimation. We also compare grain-size distributions of channel, floodplain, and proximal-overbank deposits in the Willwood (Paleocene/Eocene, Bighorn Basin, Wyoming, USA), Wasatch (Paleocene/Eocene, Piceance Creek Basin, Colorado, USA), and Ferris (Cretaceous/Paleocene, Hanna Basin, Wyoming, USA) formations. Grain-size characteristics in these deposits reflect how suspended- and bed-load sediment is distributed across the floodplain during channel avulsion events. In order to constrain uncertainty inherent in such estimates, we evaluate uncertainty associated with sample collection, preparation, analytical

  7. Nannochloropsis genomes reveal evolution of microalgal oleaginous traits.

    Directory of Open Access Journals (Sweden)

    Dongmei Wang

    2014-01-01

    Full Text Available Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains and one time-series transcriptome dataset for triacylglycerol (TAG synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2 in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels.

  8. [On the issue of healers of the Ancient China].

    Science.gov (United States)

    Lazarenko, V G

    2010-01-01

    The article is devoted to the first physicians of the Ancient China--I-Ing (XVII-XVI centuries BC) and I-Ho (VI-V centuries BC). On the basis of the investigation of the ancient sources the significant input of the mentioned physicians into the development of the traditional Chinese medicine, dietetics and diet therapy included is testified. In addition, their scientific approach to the issues of diagnostics and treatment on the basis of applying the natural philosophy principles of Yin-Yan and Y-Sin is demonstrated.

  9. Horizontal drilling in Miocene thin sand of Lake Maracaibo

    Energy Technology Data Exchange (ETDEWEB)

    Partidas, C. [PDVSA Exploration and Production (Venezuela)

    1998-12-31

    Horizontal drilling in the mature Lake Maracaibo field in Venezuela as a means of stimulating production are discussed. The Miocene sand where the horizontal well technology was applied, presented a number of intervals of unconsolidated sand of varied continuity, pay intervals at ten to twenty feet thickness, and reservoir pressures mostly at hydrostatic or below hydrostatic values. This paper evaluates a horizontal drilling program in the Lagunallis Lago Production Unit of Maracaibo, involving 91 wells to date (since 1995). When assessed in economic terms, results indicate that horizontal wells are a better economic alternative than vertical wells. The same results also showed that drainage from thin sand reservoirs resulted in better production with horizontal well technology than production from vertical wells. Payout was less than two years for 50 per cent of the horizontal wells while 40 per cent had payouts of between two and four years. Profit to investment ratio was greater than two in the case of about 70 per cent of the horizontal wells drilled in 1996. 2 tabs., 10 figs.

  10. The potential for biologically catalyzed anaerobic methane oxidation on ancient Mars.

    Science.gov (United States)

    Marlow, Jeffrey J; Larowe, Douglas E; Ehlmann, Bethany L; Amend, Jan P; Orphan, Victoria J

    2014-04-01

    This study examines the potential for the biologically mediated anaerobic oxidation of methane (AOM) coupled to sulfate reduction on ancient Mars. Seven distinct fluids representative of putative martian groundwater were used to calculate Gibbs energy values in the presence of dissolved methane under a range of atmospheric CO2 partial pressures. In all scenarios, AOM is exergonic, ranging from -31 to -135 kJ/mol CH4. A reaction transport model was constructed to examine how environmentally relevant parameters such as advection velocity, reactant concentrations, and biomass production rate affect the spatial and temporal dependences of AOM reaction rates. Two geologically supported models for ancient martian AOM are presented: a sulfate-rich groundwater with methane produced from serpentinization by-products, and acid-sulfate fluids with methane from basalt alteration. The simulations presented in this study indicate that AOM could have been a feasible metabolism on ancient Mars, and fossil or isotopic evidence of this metabolic pathway may persist beneath the surface and in surface exposures of eroded ancient terrains.

  11. Earthquake Archaeology: a case study from Ancient Cnidus

    Science.gov (United States)

    Stewart, I. S.; Altunel, E.; Piccardi, L.

    2003-04-01

    Ancient earthquakes can leave their mark in the mythical practices and literary accounts of ancient peoples, the stratigraphy of their site histories, and the structural integrity of their constructions. The ancient Greek/Roman city of Cnidus in southwestern Turkey records all three. A spectacular exposed fault plane cliff bordering the northern edge of the city appears to have been an important revered site, bearing votive niches carved into the near-vertical slip plane and associated with a Sanctuary of Demeter that implies a connection to the underworld. Stratigraphic evidence for earthquake faulting can be found in the form of a destruction horizon of contorted soil, relics and human remains exposed in the original excavations of the Sanctuary of Demeter by Sir Charles Newton (1857-58) and in a destruction horizon of burnt soil and bone uncovered by the ongoing excavation of a colonnaded street. Structural damage to constructions is widespread across the site, with warped and offset walls in the Sanctuary of Demeter, collapsed buildings in several places, and a parallel arrangement of fallen columns in the colonnaded street. The most remarkable structural evidence for fault activity, however, is the rupture of the ancient city's famous Round Temple of Aphrodite, whose podium reveals a history of damage and which is unambiguously displaced across a bedrock fault. While these phenomena are equivocal when viewed in isolation, collectively they imply at least two damaging earthquakes at the site, one (possibly both) of which ruptured along the fault on which the city is found. The Cnidus case study highlights how reliable identification of archaeoseismic damage relies on compiling an assemblage of indicators rather than the discovery of a diagnostic "smoking gun".

  12. Geomorphic reconstructions in the environs of ancient troy.

    Science.gov (United States)

    Kraft, J C; Kayan, I; Erol, O

    1980-08-15

    Sea level rise, deltaic progradation, and floodplain aggradation have changed the landscape in the vicinity of ancient Troy during the past 10,000 years. With the waning of the last major world glaciation and resultant sea level rise and fluctuation, a marine embayment protruded nearly 10 ki