Normalization of Complete Genome Characteristics: Application to Evolution from Primitive Organisms to Homo sapiens.

Science.gov (United States)

Sorimachi, Kenji; Okayasu, Teiji; Ohhira, Shuji

2015-04-01

Normalized nucleotide and amino acid contents of complete genome sequences can be visualized as radar charts. The shapes of these charts depict the characteristics of an organism's genome. The normalized values calculated from the genome sequence theoretically exclude experimental errors. Further, because normalization is independent of both target size and kind, this procedure is applicable not only to single genes but also to whole genomes, which consist of a huge number of different genes. In this review, we discuss the applications of the normalization of the nucleotide and predicted amino acid contents of complete genomes to the investigation of genome structure and to evolutionary research from primitive organisms to Homo sapiens. Some of the results could never have been obtained from the analysis of individual nucleotide or amino acid sequences but were revealed only after the normalization of nucleotide and amino acid contents was applied to genome research. The discovery that genome structure was homogeneous was obtained only after normalization methods were applied to the nucleotide or predicted amino acid contents of genome sequences. Normalization procedures are also applicable to evolutionary research. Thus, normalization of the contents of whole genomes is a useful procedure that can help to characterize organisms.

Using Genomics for Natural Product Structure Elucidation.

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Tietz, Jonathan I; Mitchell, Douglas A

2016-01-01

Natural products (NPs) are the most historically bountiful source of chemical matter for drug development-especially for anti-infectives. With insights gleaned from genome mining, interest in natural product discovery has been reinvigorated. An essential stage in NP discovery is structural elucidation, which sheds light not only on the chemical composition of a molecule but also its novelty, properties, and derivatization potential. The history of structure elucidation is replete with techniquebased revolutions: combustion analysis, crystallography, UV, IR, MS, and NMR have each provided game-changing advances; the latest such advance is genomics. All natural products have a genetic basis, and the ability to obtain and interpret genomic information for structure elucidation is increasingly available at low cost to non-specialists. In this review, we describe the value of genomics as a structural elucidation technique, especially from the perspective of the natural product chemist approaching an unknown metabolite. Herein we first introduce the databases and programs of interest to the natural products chemist, with an emphasis on those currently most suited for general usability. We describe strategies for linking observed natural product-linked phenotypes to their corresponding gene clusters. We then discuss techniques for extracting structural information from genes, illustrated with numerous case examples. We also provide an analysis of the biases and limitations of the field with recommendations for future development. Our overview is not only aimed at biologically-oriented researchers already at ease with bioinformatic techniques, but also, in particular, at natural product, organic, and/or medicinal chemists not previously familiar with genomic techniques.

Impact of nuclear organization and chromatin structure on DNA repair and genome stability

International Nuclear Information System (INIS)

Batte, Amandine

2016-01-01

The non-random organization of the eukaryotic cell nucleus and the folding of genome in chromatin more or less condensed can influence many functions related to DNA metabolism, including genome stability. Double-strand breaks (DSBs) are the most deleterious DNA damages for the cells. To preserve genome integrity, eukaryotic cells thus developed DSB repair mechanisms conserved from yeast to human, among which homologous recombination (HR) that uses an intact homologous sequence to repair a broken chromosome. HR can be separated in two sub-pathways: Gene Conversion (GC) transfers genetic information from one molecule to its homologous and Break Induced Replication (BIR) establishes a replication fork than can proceed until the chromosome end. My doctorate work was focused on the contribution of the chromatin context and 3D genome organization on DSB repair. In S. cerevisiae, nuclear organization and heterochromatin spreading at sub-telomeres can be modified through the overexpression of the Sir3 or sir3A2Q mutant proteins. We demonstrated that reducing the physical distance between homologous sequences increased GC rates, reinforcing the notion that homology search is a limiting step for recombination. We also showed that hetero-chromatinization of DSB site fine-tunes DSB resection, limiting the loss of the DSB ends required to perform homology search and complete HR. Finally, we noticed that the presence of heterochromatin at the donor locus decreased both GC and BIR efficiencies, probably by affecting strand invasion. This work highlights new regulatory pathways of DNA repair. (author) [fr

Functional Coverage of the Human Genome by Existing Structures, Structural Genomics Targets, and Homology Models.

Directory of Open Access Journals (Sweden)

2005-08-01

Full Text Available The bias in protein structure and function space resulting from experimental limitations and targeting of particular functional classes of proteins by structural biologists has long been recognized, but never continuously quantified. Using the Enzyme Commission and the Gene Ontology classifications as a reference frame, and integrating structure data from the Protein Data Bank (PDB, target sequences from the structural genomics projects, structure homology derived from the SUPERFAMILY database, and genome annotations from Ensembl and NCBI, we provide a quantified view, both at the domain and whole-protein levels, of the current and projected coverage of protein structure and function space relative to the human genome. Protein structures currently provide at least one domain that covers 37% of the functional classes identified in the genome; whole structure coverage exists for 25% of the genome. If all the structural genomics targets were solved (twice the current number of structures in the PDB, it is estimated that structures of one domain would cover 69% of the functional classes identified and complete structure coverage would be 44%. Homology models from existing experimental structures extend the 37% coverage to 56% of the genome as single domains and 25% to 31% for complete structures. Coverage from homology models is not evenly distributed by protein family, reflecting differing degrees of sequence and structure divergence within families. While these data provide coverage, conversely, they also systematically highlight functional classes of proteins for which structures should be determined. Current key functional families without structure representation are highlighted here; updated information on the "most wanted list" that should be solved is available on a weekly basis from http://function.rcsb.org:8080/pdb/function_distribution/index.html.

Elucidation of Operon Structures across Closely Related Bacterial Genomes

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Li, Guojun

2014-01-01

About half of the protein-coding genes in prokaryotic genomes are organized into operons to facilitate co-regulation during transcription. With the evolution of genomes, operon structures are undergoing changes which could coordinate diverse gene expression patterns in response to various stimuli during the life cycle of a bacterial cell. Here we developed a graph-based model to elucidate the diversity of operon structures across a set of closely related bacterial genomes. In the constructed graph, each node represents one orthologous gene group (OGG) and a pair of nodes will be connected if any two genes, from the corresponding two OGGs respectively, are located in the same operon as immediate neighbors in any of the considered genomes. Through identifying the connected components in the above graph, we found that genes in a connected component are likely to be functionally related and these identified components tend to form treelike topology, such as paths and stars, corresponding to different biological mechanisms in transcriptional regulation as follows. Specifically, (i) a path-structure component integrates genes encoding a protein complex, such as ribosome; and (ii) a star-structure component not only groups related genes together, but also reflects the key functional roles of the central node of this component, such as the ABC transporter with a transporter permease and substrate-binding proteins surrounding it. Most interestingly, the genes from organisms with highly diverse living environments, i.e., biomass degraders and animal pathogens of clostridia in our study, can be clearly classified into different topological groups on some connected components. PMID:24959722

Structurally Complex Organization of Repetitive DNAs in the Genome of Cobia (Rachycentron canadum).

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Costa, Gideão W W F; Cioffi, Marcelo de B; Bertollo, Luiz A C; Molina, Wagner F

2015-06-01

Repetitive DNAs comprise the largest fraction of the eukaryotic genome. They include microsatellites or simple sequence repeats (SSRs), which play an important role in the chromosome differentiation among fishes. Rachycentron canadum is the only representative of the family Rachycentridae. This species has been focused on several multidisciplinary studies in view of its important potential for marine fish farming. In the present study, distinct classes of repetitive DNAs, with emphasis on SSRs, were mapped in the chromosomes of this species to improve the knowledge of its genome organization. Microsatellites exhibited a diversified distribution, both dispersed in euchromatin and clustered in the heterochromatin. The multilocus location of SSRs strengthened the heterochromatin heterogeneity in this species, as suggested by some previous studies. The colocalization of SSRs with retrotransposons and transposons pointed to a close evolutionary relationship between these repetitive sequences. A number of heterochromatic regions highlighted a greater complex organization than previously supposed, harboring a diversity of repetitive elements. In this sense, there was also evidence of colocalization of active genetic regions and different classes of repetitive DNAs in a common heterochromatic region, which offers a potential opportunity for further researches regarding the interaction of these distinct fractions in fish genomes.

Genomic organization and evolution of the Atlantic salmon hemoglobin repertoire

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Phillips Ruth B

2010-10-01

Full Text Available Abstract Background The genomes of salmonids are considered pseudo-tetraploid undergoing reversion to a stable diploid state. Given the genome duplication and extensive biological data available for salmonids, they are excellent model organisms for studying comparative genomics, evolutionary processes, fates of duplicated genes and the genetic and physiological processes associated with complex behavioral phenotypes. The evolution of the tetrapod hemoglobin genes is well studied; however, little is known about the genomic organization and evolution of teleost hemoglobin genes, particularly those of salmonids. The Atlantic salmon serves as a representative salmonid species for genomics studies. Given the well documented role of hemoglobin in adaptation to varied environmental conditions as well as its use as a model protein for evolutionary analyses, an understanding of the genomic structure and organization of the Atlantic salmon α and β hemoglobin genes is of great interest. Results We identified four bacterial artificial chromosomes (BACs comprising two hemoglobin gene clusters spanning the entire α and β hemoglobin gene repertoire of the Atlantic salmon genome. Their chromosomal locations were established using fluorescence in situ hybridization (FISH analysis and linkage mapping, demonstrating that the two clusters are located on separate chromosomes. The BACs were sequenced and assembled into scaffolds, which were annotated for putatively functional and pseudogenized hemoglobin-like genes. This revealed that the tail-to-tail organization and alternating pattern of the α and β hemoglobin genes are well conserved in both clusters, as well as that the Atlantic salmon genome houses substantially more hemoglobin genes, including non-Bohr β globin genes, than the genomes of other teleosts that have been sequenced. Conclusions We suggest that the most parsimonious evolutionary path leading to the present organization of the Atlantic salmon

Genomic organization and evolution of the Atlantic salmon hemoglobin repertoire

Science.gov (United States)

2010-01-01

Background The genomes of salmonids are considered pseudo-tetraploid undergoing reversion to a stable diploid state. Given the genome duplication and extensive biological data available for salmonids, they are excellent model organisms for studying comparative genomics, evolutionary processes, fates of duplicated genes and the genetic and physiological processes associated with complex behavioral phenotypes. The evolution of the tetrapod hemoglobin genes is well studied; however, little is known about the genomic organization and evolution of teleost hemoglobin genes, particularly those of salmonids. The Atlantic salmon serves as a representative salmonid species for genomics studies. Given the well documented role of hemoglobin in adaptation to varied environmental conditions as well as its use as a model protein for evolutionary analyses, an understanding of the genomic structure and organization of the Atlantic salmon α and β hemoglobin genes is of great interest. Results We identified four bacterial artificial chromosomes (BACs) comprising two hemoglobin gene clusters spanning the entire α and β hemoglobin gene repertoire of the Atlantic salmon genome. Their chromosomal locations were established using fluorescence in situ hybridization (FISH) analysis and linkage mapping, demonstrating that the two clusters are located on separate chromosomes. The BACs were sequenced and assembled into scaffolds, which were annotated for putatively functional and pseudogenized hemoglobin-like genes. This revealed that the tail-to-tail organization and alternating pattern of the α and β hemoglobin genes are well conserved in both clusters, as well as that the Atlantic salmon genome houses substantially more hemoglobin genes, including non-Bohr β globin genes, than the genomes of other teleosts that have been sequenced. Conclusions We suggest that the most parsimonious evolutionary path leading to the present organization of the Atlantic salmon hemoglobin genes involves

Structure and genome organization of AFV2, a novel archaeal lipothrixvirus with unusual terminal and core structures

DEFF Research Database (Denmark)

Häring, Monika; Vestergaard, Gisle Alberg; Brügger, Kim

2005-01-01

A novel filamentous virus, AFV2, from the hyperthermophilic archaeal genus Acidianus shows structural similarity to lipothrixviruses but differs from them in its unusual terminal and core structures. The double-stranded DNA genome contains 31,787 bp and carries eight open reading frames homologous...

Genomic analysis of Xenopus organizer function

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Suhai Sándor

2006-06-01

Full Text Available Abstract Background Studies of the Xenopus organizer have laid the foundation for our understanding of the conserved signaling pathways that pattern vertebrate embryos during gastrulation. The two primary activities of the organizer, BMP and Wnt inhibition, can regulate a spectrum of genes that pattern essentially all aspects of the embryo during gastrulation. As our knowledge of organizer signaling grows, it is imperative that we begin knitting together our gene-level knowledge into genome-level signaling models. The goal of this paper was to identify complete lists of genes regulated by different aspects of organizer signaling, thereby providing a deeper understanding of the genomic mechanisms that underlie these complex and fundamental signaling events. Results To this end, we ectopically overexpress Noggin and Dkk-1, inhibitors of the BMP and Wnt pathways, respectively, within ventral tissues. After isolating embryonic ventral halves at early and late gastrulation, we analyze the transcriptional response to these molecules within the generated ectopic organizers using oligonucleotide microarrays. An efficient statistical analysis scheme, combined with a new Gene Ontology biological process annotation of the Xenopus genome, allows reliable and faithful clustering of molecules based upon their roles during gastrulation. From this data, we identify new organizer-related expression patterns for 19 genes. Moreover, our data sub-divides organizer genes into separate head and trunk organizing groups, which each show distinct responses to Noggin and Dkk-1 activity during gastrulation. Conclusion Our data provides a genomic view of the cohorts of genes that respond to Noggin and Dkk-1 activity, allowing us to separate the role of each in organizer function. These patterns demonstrate a model where BMP inhibition plays a largely inductive role during early developmental stages, thereby initiating the suites of genes needed to pattern dorsal tissues

Systematic determination of the mosaic structure of bacterial genomes: species backbone versus strain-specific loops

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Gendrault-Jacquemard A

2005-07-01

Full Text Available Abstract Background Public databases now contain multitude of complete bacterial genomes, including several genomes of the same species. The available data offers new opportunities to address questions about bacterial genome evolution, a task that requires reliable fine comparison data of closely related genomes. Recent analyses have shown, using pairwise whole genome alignments, that it is possible to segment bacterial genomes into a common conserved backbone and strain-specific sequences called loops. Results Here, we generalize this approach and propose a strategy that allows systematic and non-biased genome segmentation based on multiple genome alignments. Segmentation analyses, as applied to 13 different bacterial species, confirmed the feasibility of our approach to discern the 'mosaic' organization of bacterial genomes. Segmentation results are available through a Web interface permitting functional analysis, extraction and visualization of the backbone/loops structure of documented genomes. To illustrate the potential of this approach, we performed a precise analysis of the mosaic organization of three E. coli strains and functional characterization of the loops. Conclusion The segmentation results including the backbone/loops structure of 13 bacterial species genomes are new and available for use by the scientific community at the URL: http://genome.jouy.inra.fr/mosaic.

Improvisation in evolution of genes and genomes: whose structure is it anyway?

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Shakhnovich, Boris E; Shakhnovich, Eugene I

2008-06-01

Significant progress has been made in recent years in a variety of seemingly unrelated fields such as sequencing, protein structure prediction, and high-throughput transcriptomics and metabolomics. At the same time, new microscopic models have been developed that made it possible to analyze the evolution of genes and genomes from first principles. The results from these efforts enable, for the first time, a comprehensive insight into the evolution of complex systems and organisms on all scales--from sequences to organisms and populations. Every newly sequenced genome uncovers new genes, families, and folds. Where do these new genes come from? How do gene duplication and subsequent divergence of sequence and structure affect the fitness of the organism? What role does regulation play in the evolution of proteins and folds? Emerging synergism between data and modeling provides first robust answers to these questions.

In vivo genome-wide profiling of RNA secondary structure reveals novel regulatory features.

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Ding, Yiliang; Tang, Yin; Kwok, Chun Kit; Zhang, Yu; Bevilacqua, Philip C; Assmann, Sarah M

2014-01-30

RNA structure has critical roles in processes ranging from ligand sensing to the regulation of translation, polyadenylation and splicing. However, a lack of genome-wide in vivo RNA structural data has limited our understanding of how RNA structure regulates gene expression in living cells. Here we present a high-throughput, genome-wide in vivo RNA structure probing method, structure-seq, in which dimethyl sulphate methylation of unprotected adenines and cytosines is identified by next-generation sequencing. Application of this method to Arabidopsis thaliana seedlings yielded the first in vivo genome-wide RNA structure map at nucleotide resolution for any organism, with quantitative structural information across more than 10,000 transcripts. Our analysis reveals a three-nucleotide periodic repeat pattern in the structure of coding regions, as well as a less-structured region immediately upstream of the start codon, and shows that these features are strongly correlated with translation efficiency. We also find patterns of strong and weak secondary structure at sites of alternative polyadenylation, as well as strong secondary structure at 5' splice sites that correlates with unspliced events. Notably, in vivo structures of messenger RNAs annotated for stress responses are poorly predicted in silico, whereas mRNA structures of genes related to cell function maintenance are well predicted. Global comparison of several structural features between these two categories shows that the mRNAs associated with stress responses tend to have more single-strandedness, longer maximal loop length and higher free energy per nucleotide, features that may allow these RNAs to undergo conformational changes in response to environmental conditions. Structure-seq allows the RNA structurome and its biological roles to be interrogated on a genome-wide scale and should be applicable to any organism.

RNA 3D modules in genome-wide predictions of RNA 2D structure

DEFF Research Database (Denmark)

Theis, Corinna; Zirbel, Craig L; Zu Siederdissen, Christian Höner

2015-01-01

. These modules can, for example, occur inside structural elements which in RNA 2D predictions appear as internal loops. Hence one question is if the use of such RNA 3D information can improve the prediction accuracy of RNA secondary structure at a genome-wide level. Here, we use RNAz in combination with 3D......Recent experimental and computational progress has revealed a large potential for RNA structure in the genome. This has been driven by computational strategies that exploit multiple genomes of related organisms to identify common sequences and secondary structures. However, these computational...... approaches have two main challenges: they are computationally expensive and they have a relatively high false discovery rate (FDR). Simultaneously, RNA 3D structure analysis has revealed modules composed of non-canonical base pairs which occur in non-homologous positions, apparently by independent evolution...

Global organization of a positive-strand RNA virus genome.

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Baodong Wu

Full Text Available The genomes of plus-strand RNA viruses contain many regulatory sequences and structures that direct different viral processes. The traditional view of these RNA elements are as local structures present in non-coding regions. However, this view is changing due to the discovery of regulatory elements in coding regions and functional long-range intra-genomic base pairing interactions. The ∼4.8 kb long RNA genome of the tombusvirus tomato bushy stunt virus (TBSV contains these types of structural features, including six different functional long-distance interactions. We hypothesized that to achieve these multiple interactions this viral genome must utilize a large-scale organizational strategy and, accordingly, we sought to assess the global conformation of the entire TBSV genome. Atomic force micrographs of the genome indicated a mostly condensed structure composed of interconnected protrusions extending from a central hub. This configuration was consistent with the genomic secondary structure model generated using high-throughput selective 2'-hydroxyl acylation analysed by primer extension (i.e. SHAPE, which predicted different sized RNA domains originating from a central region. Known RNA elements were identified in both domain and inter-domain regions, and novel structural features were predicted and functionally confirmed. Interestingly, only two of the six long-range interactions known to form were present in the structural model. However, for those interactions that did not form, complementary partner sequences were positioned relatively close to each other in the structure, suggesting that the secondary structure level of viral genome structure could provide a basic scaffold for the formation of different long-range interactions. The higher-order structural model for the TBSV RNA genome provides a snapshot of the complex framework that allows multiple functional components to operate in concert within a confined context.

Gene organization inside replication domains in mammalian genomes

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Zaghloul, Lamia; Baker, Antoine; Audit, Benjamin; Arneodo, Alain

2012-11-01

We investigate the large-scale organization of human genes with respect to "master" replication origins that were previously identified as bordering nucleotide compositional skew domains. We separate genes in two categories depending on their CpG enrichment at the promoter which can be considered as a marker of germline DNA methylation. Using expression data in mouse, we confirm that CpG-rich genes are highly expressed in germline whereas CpG-poor genes are in a silent state. We further show that, whether tissue-specific or broadly expressed (housekeeping genes), the CpG-rich genes are over-represented close to the replication skew domain borders suggesting some coordination of replication and transcription. We also reveal that the transcription of the longest CpG-rich genes is co-oriented with replication fork progression so that the promoter of these transcriptionally active genes be located into the accessible open chromatin environment surrounding the master replication origins that border the replication skew domains. The observation of a similar gene organization in the mouse genome confirms the interplay of replication, transcription and chromatin structure as the cornerstone of mammalian genome architecture.

Hepatitis A Virus Genome Organization and Replication Strategy.

Science.gov (United States)

McKnight, Kevin L; Lemon, Stanley M

2018-04-02

Hepatitis A virus (HAV) is a positive-strand RNA virus classified in the genus Hepatovirus of the family Picornaviridae It is an ancient virus with a long evolutionary history and multiple features of its capsid structure, genome organization, and replication cycle that distinguish it from other mammalian picornaviruses. HAV proteins are produced by cap-independent translation of a single, long open reading frame under direction of an inefficient, upstream internal ribosome entry site (IRES). Genome replication occurs slowly and is noncytopathic, with transcription likely primed by a uridylated protein primer as in other picornaviruses. Newly produced quasi-enveloped virions (eHAV) are released from cells in a nonlytic fashion in a unique process mediated by interactions of capsid proteins with components of the host cell endosomal sorting complexes required for transport (ESCRT) system. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Structure and expression strategy of the genome of Culex pipiens densovirus, a mosquito densovirus with an ambisense organization.

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Baquerizo-Audiot, Elizabeth; Abd-Alla, Adly; Jousset, Françoise-Xavière; Cousserans, François; Tijssen, Peter; Bergoin, Max

2009-07-01

The genome of all densoviruses (DNVs) so far isolated from mosquitoes or mosquito cell lines consists of a 4-kb single-stranded DNA molecule with a monosense organization (genus Brevidensovirus, subfamily Densovirinae). We previously reported the isolation of a Culex pipiens DNV (CpDNV) that differs significantly from brevidensoviruses by (i) having a approximately 6-kb genome, (ii) lacking sequence homology, and (iii) lacking antigenic cross-reactivity with Brevidensovirus capsid polypeptides. We report here the sequence organization and transcription map of this virus. The cloned genome of CpDNV is 5,759 nucleotides (nt) long, and it possesses an inverted terminal repeat (ITR) of 285 nt and an ambisense organization of its genes. The nonstructural (NS) proteins NS-1, NS-2, and NS-3 are located in the 5' half of one strand and are organized into five open reading frames (ORFs) due to the split of both NS-1 and NS-2 into two ORFs. The ORF encoding capsid polypeptides is located in the 5' half of the complementary strand. The expression of NS proteins is controlled by two promoters, P7 and P17, driving the transcription of a 2.4-kb mRNA encoding NS-3 and of a 1.8-kb mRNA encoding NS-1 and NS-2, respectively. The two NS mRNAs species are spliced off a 53-nt sequence. Capsid proteins are translated from an unspliced 2.3-kb mRNA driven by the P88 promoter. CpDNV thus appears as a new type of mosquito DNV, and based on the overall organization and expression modalities of its genome, it may represent the prototype of a new genus of DNV.

Informational laws of genome structures

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Bonnici, Vincenzo; Manca, Vincenzo

2016-06-01

In recent years, the analysis of genomes by means of strings of length k occurring in the genomes, called k-mers, has provided important insights into the basic mechanisms and design principles of genome structures. In the present study, we focus on the proper choice of the value of k for applying information theoretic concepts that express intrinsic aspects of genomes. The value k = lg2(n), where n is the genome length, is determined to be the best choice in the definition of some genomic informational indexes that are studied and computed for seventy genomes. These indexes, which are based on information entropies and on suitable comparisons with random genomes, suggest five informational laws, to which all of the considered genomes obey. Moreover, an informational genome complexity measure is proposed, which is a generalized logistic map that balances entropic and anti-entropic components of genomes and is related to their evolutionary dynamics. Finally, applications to computational synthetic biology are briefly outlined.

DNA is structured as a linear "jigsaw puzzle" in the genomes of Arabidopsis, rice, and budding yeast.

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Liu, Yun-Hua; Zhang, Meiping; Wu, Chengcang; Huang, James J; Zhang, Hong-Bin

2014-01-01

Knowledge of how a genome is structured and organized from its constituent elements is crucial to understanding its biology and evolution. Here, we report the genome structuring and organization pattern as revealed by systems analysis of the sequences of three model species, Arabidopsis, rice and yeast, at the whole-genome and chromosome levels. We found that all fundamental function elements (FFE) constituting the genomes, including genes (GEN), DNA transposable elements (DTE), retrotransposable elements (RTE), simple sequence repeats (SSR), and (or) low complexity repeats (LCR), are structured in a nonrandom and correlative manner, thus leading to a hypothesis that the DNA of the species is structured as a linear "jigsaw puzzle". Furthermore, we showed that different FFE differ in their importance in the formation and evolution of the DNA jigsaw puzzle structure between species. DTE and RTE play more important roles than GEN, LCR, and SSR in Arabidopsis, whereas GEN and RTE play more important roles than LCR, SSR, and DTE in rice. The genes having multiple recognized functions play more important roles than those having single functions. These results provide useful knowledge necessary for better understanding genome biology and evolution of the species and for effective molecular breeding of rice.

Megabase replication domains along the human genome: relation to chromatin structure and genome organisation.

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Audit, Benjamin; Zaghloul, Lamia; Baker, Antoine; Arneodo, Alain; Chen, Chun-Long; d'Aubenton-Carafa, Yves; Thermes, Claude

2013-01-01

In higher eukaryotes, the absence of specific sequence motifs, marking the origins of replication has been a serious hindrance to the understanding of (i) the mechanisms that regulate the spatio-temporal replication program, and (ii) the links between origins activation, chromatin structure and transcription. In this chapter, we review the partitioning of the human genome into megabased-size replication domains delineated as N-shaped motifs in the strand compositional asymmetry profiles. They collectively span 28.3% of the genome and are bordered by more than 1,000 putative replication origins. We recapitulate the comparison of this partition of the human genome with high-resolution experimental data that confirms that replication domain borders are likely to be preferential replication initiation zones in the germline. In addition, we highlight the specific distribution of experimental and numerical chromatin marks along replication domains. Domain borders correspond to particular open chromatin regions, possibly encoded in the DNA sequence, and around which replication and transcription are highly coordinated. These regions also present a high evolutionary breakpoint density, suggesting that susceptibility to breakage might be linked to local open chromatin fiber state. Altogether, this chapter presents a compartmentalization of the human genome into replication domains that are landmarks of the human genome organization and are likely to play a key role in genome dynamics during evolution and in pathological situations.

2004 Structural, Function and Evolutionary Genomics

Energy Technology Data Exchange (ETDEWEB)

Douglas L. Brutlag Nancy Ryan Gray

2005-03-23

This Gordon conference will cover the areas of structural, functional and evolutionary genomics. It will take a systematic approach to genomics, examining the evolution of proteins, protein functional sites, protein-protein interactions, regulatory networks, and metabolic networks. Emphasis will be placed on what we can learn from comparative genomics and entire genomes and proteomes.

The footprint of metabolism in the organization of mammalian genomes

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Berná Luisa

2012-05-01

Full Text Available Abstract Background At present five evolutionary hypotheses have been proposed to explain the great variability of the genomic GC content among and within genomes: the mutational bias, the biased gene conversion, the DNA breakpoints distribution, the thermal stability and the metabolic rate. Several studies carried out on bacteria and teleostean fish pointed towards the critical role played by the environment on the metabolic rate in shaping the base composition of genomes. In mammals the debate is still open, and evidences have been produced in favor of each evolutionary hypothesis. Human genes were assigned to three large functional categories (as well as to the corresponding functional classes according to the KOG database: (i information storage and processing, (ii cellular processes and signaling, and (iii metabolism. The classification was extended to the organisms so far analyzed performing a reciprocal Blastp and selecting the best reciprocal hit. The base composition was calculated for each sequence of the whole CDS dataset. Results The GC3 level of the above functional categories was increasing from (i to (iii. This specific compositional pattern was found, as footprint, in all mammalian genomes, but not in frog and lizard ones. Comparative analysis of human versus both frog and lizard functional categories showed that genes involved in the metabolic processes underwent the highest GC3 increment. Analyzing the KOG functional classes of genes, again a well defined intra-genomic pattern was found in all mammals. Not only genes of metabolic pathways, but also genes involved in chromatin structure and dynamics, transcription, signal transduction mechanisms and cytoskeleton, showed an average GC3 level higher than that of the whole genome. In the case of the human genome, the genes of the aforementioned functional categories showed a high probability to be associated with the chromosomal bands. Conclusions In the light of different

Fine organization of genomic regions tagged to the 5S rDNA locus of the bread wheat 5B chromosome.

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Sergeeva, Ekaterina M; Shcherban, Andrey B; Adonina, Irina G; Nesterov, Michail A; Beletsky, Alexey V; Rakitin, Andrey L; Mardanov, Andrey V; Ravin, Nikolai V; Salina, Elena A

2017-11-14

The multigene family encoding the 5S rRNA, one of the most important structurally-functional part of the large ribosomal subunit, is an obligate component of all eukaryotic genomes. 5S rDNA has long been a favored target for cytological and phylogenetic studies due to the inherent peculiarities of its structural organization, such as the tandem arrays of repetitive units and their high interspecific divergence. The complex polyploid nature of the genome of bread wheat, Triticum aestivum, and the technically difficult task of sequencing clusters of tandem repeats mean that the detailed organization of extended genomic regions containing 5S rRNA genes remains unclear. This is despite the recent progress made in wheat genomic sequencing. Using pyrosequencing of BAC clones, in this work we studied the organization of two distinct 5S rDNA-tagged regions of the 5BS chromosome of bread wheat. Three BAC-clones containing 5S rDNA were identified in the 5BS chromosome-specific BAC-library of Triticum aestivum. Using the results of pyrosequencing and assembling, we obtained six 5S rDNA- containing contigs with a total length of 140,417 bp, and two sets (pools) of individual 5S rDNA sequences belonging to separate, but closely located genomic regions on the 5BS chromosome. Both regions are characterized by the presence of approximately 70-80 copies of 5S rDNA, however, they are completely different in their structural organization. The first region contained highly diverged short-type 5S rDNA units that were disrupted by multiple insertions of transposable elements. The second region contained the more conserved long-type 5S rDNA, organized as a single tandem array. FISH using probes specific to both 5S rDNA unit types showed differences in the distribution and intensity of signals on the chromosomes of polyploid wheat species and their diploid progenitors. A detailed structural organization of two closely located 5S rDNA-tagged genomic regions on the 5BS chromosome of bread

Genomic hypomethylation in the human germline associates with selective structural mutability in the human genome.

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Jian Li

Full Text Available The hotspots of structural polymorphisms and structural mutability in the human genome remain to be explained mechanistically. We examine associations of structural mutability with germline DNA methylation and with non-allelic homologous recombination (NAHR mediated by low-copy repeats (LCRs. Combined evidence from four human sperm methylome maps, human genome evolution, structural polymorphisms in the human population, and previous genomic and disease studies consistently points to a strong association of germline hypomethylation and genomic instability. Specifically, methylation deserts, the ~1% fraction of the human genome with the lowest methylation in the germline, show a tenfold enrichment for structural rearrangements that occurred in the human genome since the branching of chimpanzee and are highly enriched for fast-evolving loci that regulate tissue-specific gene expression. Analysis of copy number variants (CNVs from 400 human samples identified using a custom-designed array comparative genomic hybridization (aCGH chip, combined with publicly available structural variation data, indicates that association of structural mutability with germline hypomethylation is comparable in magnitude to the association of structural mutability with LCR-mediated NAHR. Moreover, rare CNVs occurring in the genomes of individuals diagnosed with schizophrenia, bipolar disorder, and developmental delay and de novo CNVs occurring in those diagnosed with autism are significantly more concentrated within hypomethylated regions. These findings suggest a new connection between the epigenome, selective mutability, evolution, and human disease.

GAAP: Genome-organization-framework-Assisted Assembly Pipeline for prokaryotic genomes.

Science.gov (United States)

Yuan, Lina; Yu, Yang; Zhu, Yanmin; Li, Yulai; Li, Changqing; Li, Rujiao; Ma, Qin; Siu, Gilman Kit-Hang; Yu, Jun; Jiang, Taijiao; Xiao, Jingfa; Kang, Yu

2017-01-25

Next-generation sequencing (NGS) technologies have greatly promoted the genomic study of prokaryotes. However, highly fragmented assemblies due to short reads from NGS are still a limiting factor in gaining insights into the genome biology. Reference-assisted tools are promising in genome assembly, but tend to result in false assembly when the assigned reference has extensive rearrangements. Herein, we present GAAP, a genome assembly pipeline for scaffolding based on core-gene-defined Genome Organizational Framework (cGOF) described in our previous study. Instead of assigning references, we use the multiple-reference-derived cGOFs as indexes to assist in order and orientation of the scaffolds and build a skeleton structure, and then use read pairs to extend scaffolds, called local scaffolding, and distinguish between true and chimeric adjacencies in the scaffolds. In our performance tests using both empirical and simulated data of 15 genomes in six species with diverse genome size, complexity, and all three categories of cGOFs, GAAP outcompetes or achieves comparable results when compared to three other reference-assisted programs, AlignGraph, Ragout and MeDuSa. GAAP uses both cGOF and pair-end reads to create assemblies in genomic scale, and performs better than the currently available reference-assisted assembly tools as it recovers more assemblies and makes fewer false locations, especially for species with extensive rearranged genomes. Our method is a promising solution for reconstruction of genome sequence from short reads of NGS.

Sequence-Based Analysis of Structural Organization and Composition of the Cultivated Sunflower (Helianthus annuus L.) Genome

Science.gov (United States)

Gill, Navdeep; Buti, Matteo; Kane, Nolan; Bellec, Arnaud; Helmstetter, Nicolas; Berges, Hélène; Rieseberg, Loren H.

2014-01-01

Sunflower is an important oilseed crop, as well as a model system for evolutionary studies, but its 3.6 gigabase genome has proven difficult to assemble, in part because of the high repeat content of its genome. Here we report on the sequencing, assembly, and analyses of 96 randomly chosen BACs from sunflower to provide additional information on the repeat content of the sunflower genome, assess how repetitive elements in the sunflower genome are organized relative to genes, and compare the genomic distribution of these repeats to that found in other food crops and model species. We also examine the expression of transposable element-related transcripts in EST databases for sunflower to determine the representation of repeats in the transcriptome and to measure their transcriptional activity. Our data confirm previous reports in suggesting that the sunflower genome is >78% repetitive. Sunflower repeats share very little similarity to other plant repeats such as those of Arabidopsis, rice, maize and wheat; overall 28% of repeats are “novel” to sunflower. The repetitive sequences appear to be randomly distributed within the sequenced BACs. Assuming the 96 BACs are representative of the genome as a whole, then approximately 5.2% of the sunflower genome comprises non TE-related genic sequence, with an average gene density of 18kbp/gene. Expression levels of these transposable elements indicate tissue specificity and differential expression in vegetative and reproductive tissues, suggesting that expressed TEs might contribute to sunflower development. The assembled BACs will also be useful for assessing the quality of several different draft assemblies of the sunflower genome and for annotating the reference sequence. PMID:24833511

Sequence-Based Analysis of Structural Organization and Composition of the Cultivated Sunflower (Helianthus annuus L. Genome

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Navdeep Gill

2014-04-01

Full Text Available Sunflower is an important oilseed crop, as well as a model system for evolutionary studies, but its 3.6 gigabase genome has proven difficult to assemble, in part because of the high repeat content of its genome. Here we report on the sequencing, assembly, and analyses of 96 randomly chosen BACs from sunflower to provide additional information on the repeat content of the sunflower genome, assess how repetitive elements in the sunflower genome are organized relative to genes, and compare the genomic distribution of these repeats to that found in other food crops and model species. We also examine the expression of transposable element-related transcripts in EST databases for sunflower to determine the representation of repeats in the transcriptome and to measure their transcriptional activity. Our data confirm previous reports in suggesting that the sunflower genome is >78% repetitive. Sunflower repeats share very little similarity to other plant repeats such as those of Arabidopsis, rice, maize and wheat; overall 28% of repeats are “novel” to sunflower. The repetitive sequences appear to be randomly distributed within the sequenced BACs. Assuming the 96 BACs are representative of the genome as a whole, then approximately 5.2% of the sunflower genome comprises non TE-related genic sequence, with an average gene density of 18kbp/gene. Expression levels of these transposable elements indicate tissue specificity and differential expression in vegetative and reproductive tissues, suggesting that expressed TEs might contribute to sunflower development. The assembled BACs will also be useful for assessing the quality of several different draft assemblies of the sunflower genome and for annotating the reference sequence.

De novo prediction of human chromosome structures: Epigenetic marking patterns encode genome architecture.

Science.gov (United States)

Di Pierro, Michele; Cheng, Ryan R; Lieberman Aiden, Erez; Wolynes, Peter G; Onuchic, José N

2017-11-14

Inside the cell nucleus, genomes fold into organized structures that are characteristic of cell type. Here, we show that this chromatin architecture can be predicted de novo using epigenetic data derived from chromatin immunoprecipitation-sequencing (ChIP-Seq). We exploit the idea that chromosomes encode a 1D sequence of chromatin structural types. Interactions between these chromatin types determine the 3D structural ensemble of chromosomes through a process similar to phase separation. First, a neural network is used to infer the relation between the epigenetic marks present at a locus, as assayed by ChIP-Seq, and the genomic compartment in which those loci reside, as measured by DNA-DNA proximity ligation (Hi-C). Next, types inferred from this neural network are used as an input to an energy landscape model for chromatin organization [Minimal Chromatin Model (MiChroM)] to generate an ensemble of 3D chromosome conformations at a resolution of 50 kilobases (kb). After training the model, dubbed Maximum Entropy Genomic Annotation from Biomarkers Associated to Structural Ensembles (MEGABASE), on odd-numbered chromosomes, we predict the sequences of chromatin types and the subsequent 3D conformational ensembles for the even chromosomes. We validate these structural ensembles by using ChIP-Seq tracks alone to predict Hi-C maps, as well as distances measured using 3D fluorescence in situ hybridization (FISH) experiments. Both sets of experiments support the hypothesis of phase separation being the driving process behind compartmentalization. These findings strongly suggest that epigenetic marking patterns encode sufficient information to determine the global architecture of chromosomes and that de novo structure prediction for whole genomes may be increasingly possible. Copyright © 2017 the Author(s). Published by PNAS.

Radiotaxons and reliability of a genome

International Nuclear Information System (INIS)

Korogodin, V.I.

1982-01-01

Radiosensitivity of cells (D 0 ) is considered with regard to the structural organization of the genome. The following terms are introduced: ''karyotaxon'', organisms with identical structural organization of the genome, and ''specific genome stability'' K=D 0 C, where C is the quantity of DNA in the cell nucleus; K is the amount of energy (eV) the sorption of which in DNA is necessary and sufficient for one elementary damage to occur. It was shown that Ksub(i)=const. within every karyotaxon ''i''. K 1 =100 eV for viruses, and K 4 =61000 eV for the highest level of genome organization (diploid eukaryotes including man). Potential mechanisms of increasing Ksub(i) with increasing level of genome organization and the role of this factor in evolution are discussed [ru

Genomics technologies to study structural variations in the grapevine genome

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Cardone Maria Francesca

2016-01-01

Full Text Available Grapevine is one of the most important crop plants in the world. Recently there was great expansion of genomics resources about grapevine genome, thus providing increasing efforts for molecular breeding. Current cultivars display a great level of inter-specific differentiation that needs to be investigated to reach a comprehensive understanding of the genetic basis of phenotypic differences, and to find responsible genes selected by cross breeding programs. While there have been significant advances in resolving the pattern and nature of single nucleotide polymorphisms (SNPs on plant genomes, few data are available on copy number variation (CNV. Furthermore association between structural variations and phenotypes has been described in only a few cases. We combined high throughput biotechnologies and bioinformatics tools, to reveal the first inter-varietal atlas of structural variation (SV for the grapevine genome. We sequenced and compared four table grape cultivars with the Pinot noir inbred line PN40024 genome as the reference. We detected roughly 8% of the grapevine genome affected by genomic variations. Taken into account phenotypic differences existing among the studied varieties we performed comparison of SVs among them and the reference and next we performed an in-depth analysis of gene content of polymorphic regions. This allowed us to identify genes showing differences in copy number as putative functional candidates for important traits in grapevine cultivation.

Organization and evolution of primate centromeric DNA from whole-genome shotgun sequence data.

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Can Alkan

2007-09-01

Full Text Available The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%-5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.

Organization and evolution of primate centromeric DNA from whole-genome shotgun sequence data.

Science.gov (United States)

Alkan, Can; Ventura, Mario; Archidiacono, Nicoletta; Rocchi, Mariano; Sahinalp, S Cenk; Eichler, Evan E

2007-09-01

The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%-5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.

Polytene Chromosomes - A Portrait of Functional Organization of the Drosophila Genome.

Science.gov (United States)

Zykova, Tatyana Yu; Levitsky, Victor G; Belyaeva, Elena S; Zhimulev, Igor F

2018-04-01

This mini-review is devoted to the problem genetic meaning of main polytene chromosome structures - bands and interbands. Generally, densely packed chromatin forms black bands, moderately condensed regions form grey loose bands, whereas decondensed regions of the genome appear as interbands. Recent progress in the annotation of the Drosophila genome and epigenome has made it possible to compare the banding pattern and the structural organization of genes, as well as their activity. This was greatly aided by our ability to establish the borders of bands and interbands on the physical map, which allowed to perform comprehensive side-by-side comparisons of cytology, genetic and epigenetic maps and to uncover the association between the morphological structures and the functional domains of the genome. These studies largely conclude that interbands 5'-ends of housekeeping genes that are active across all cell types. Interbands are enriched with proteins involved in transcription and nucleosome remodeling, as well as with active histone modifications. Notably, most of the replication origins map to interband regions. As for grey loose bands adjacent to interbands, they typically host the bodies of house-keeping genes. Thus, the bipartite structure composed of an interband and an adjacent grey band functions as a standalone genetic unit. Finally, black bands harbor tissue-specific genes with narrow temporal and tissue expression profiles. Thus, the uniform and permanent activity of interbands combined with the inactivity of genes in bands forms the basis of the universal banding pattern observed in various Drosophila tissues.

Short interspersed nuclear elements (SINEs) are abundant in Solanaceae and have a family-specific impact on gene structure and genome organization.

Science.gov (United States)

Seibt, Kathrin M; Wenke, Torsten; Muders, Katja; Truberg, Bernd; Schmidt, Thomas

2016-05-01

Short interspersed nuclear elements (SINEs) are highly abundant non-autonomous retrotransposons that are widespread in plants. They are short in size, non-coding, show high sequence diversity, and are therefore mostly not or not correctly annotated in plant genome sequences. Hence, comparative studies on genomic SINE populations are rare. To explore the structural organization and impact of SINEs, we comparatively investigated the genome sequences of the Solanaceae species potato (Solanum tuberosum), tomato (Solanum lycopersicum), wild tomato (Solanum pennellii), and two pepper cultivars (Capsicum annuum). Based on 8.5 Gbp sequence data, we annotated 82 983 SINE copies belonging to 10 families and subfamilies on a base pair level. Solanaceae SINEs are dispersed over all chromosomes with enrichments in distal regions. Depending on the genome assemblies and gene predictions, 30% of all SINE copies are associated with genes, particularly frequent in introns and untranslated regions (UTRs). The close association with genes is family specific. More than 10% of all genes annotated in the Solanaceae species investigated contain at least one SINE insertion, and we found genes harbouring up to 16 SINE copies. We demonstrate the involvement of SINEs in gene and genome evolution including the donation of splice sites, start and stop codons and exons to genes, enlargement of introns and UTRs, generation of tandem-like duplications and transduction of adjacent sequence regions. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Plastid genome structure and loss of photosynthetic ability in the parasitic genus Cuscuta.

Science.gov (United States)

Revill, Meredith J W; Stanley, Susan; Hibberd, Julian M

2005-09-01

The genus Cuscuta (dodder) is composed of parasitic plants, some species of which appear to be losing the ability to photosynthesize. A molecular phylogeny was constructed using 15 species of Cuscuta in order to assess whether changes in photosynthetic ability and alterations in structure of the plastid genome relate to phylogenetic position within the genus. The molecular phylogeny provides evidence for four major clades within Cuscuta. Although DNA blot analysis showed that Cuscuta species have smaller plastid genomes than tobacco, and that plastome size varied significantly even within one Cuscuta clade, dot blot analysis indicated that the dodders possess homologous sequence to 101 genes from the tobacco plastome. Evidence is provided for significant rates of DNA transfer from plastid to nucleus in Cuscuta. Size and structure of Cuscuta plastid genomes, as well as photosynthetic ability, appear to vary independently of position within the phylogeny, thus supporting the hypothesis that within Cuscuta photosynthetic ability and organization of the plastid genome are changing in an unco-ordinated manner.

Universal internucleotide statistics in full genomes: a footprint of the DNA structure and packaging?

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Mikhail I Bogachev

Full Text Available Uncovering the fundamental laws that govern the complex DNA structural organization remains challenging and is largely based upon reconstructions from the primary nucleotide sequences. Here we investigate the distributions of the internucleotide intervals and their persistence properties in complete genomes of various organisms from Archaea and Bacteria to H. Sapiens aiming to reveal the manifestation of the universal DNA architecture. We find that in all considered organisms the internucleotide interval distributions exhibit the same [Formula: see text]-exponential form. While in prokaryotes a single [Formula: see text]-exponential function makes the best fit, in eukaryotes the PDF contains additionally a second [Formula: see text]-exponential, which in the human genome makes a perfect approximation over nearly 10 decades. We suggest that this functional form is a footprint of the heterogeneous DNA structure, where the first [Formula: see text]-exponential reflects the universal helical pitch that appears both in pro- and eukaryotic DNA, while the second [Formula: see text]-exponential is a specific marker of the large-scale eukaryotic DNA organization.

The genomic organization of plant pathogenicity in Fusarium species

NARCIS (Netherlands)

Rep, M.; Kistler, H.C.

2010-01-01

Comparative genomics is a powerful tool to infer the molecular basis of fungal pathogenicity and its evolution by identifying differences in gene content and genomic organization between fungi with different hosts or modes of infection. Through comparative analysis, pathogenicity-related chromosomes

Azolla--a model organism for plant genomic studies.

Science.gov (United States)

Qiu, Yin-Long; Yu, Jun

2003-02-01

The aquatic ferns of the genus Azolla are nitrogen-fixing plants that have great potentials in agricultural production and environmental conservation. Azolla in many aspects is qualified to serve as a model organism for genomic studies because of its importance in agriculture, its unique position in plant evolution, its symbiotic relationship with the N2-fixing cyanobacterium, Anabaena azollae, and its moderate-sized genome. The goals of this genome project are not only to understand the biology of the Azolla genome to promote its applications in biological research and agriculture practice but also to gain critical insights about evolution of plant genomes. Together with the strategic and technical improvement as well as cost reduction of DNA sequencing, the deciphering of their genetic code is imminent.

Mycoplasma hyopneumoniae Transcription Unit Organization: Genome Survey and Prediction

Science.gov (United States)

Siqueira, Franciele Maboni; Schrank, Augusto; Schrank, Irene Silveira

2011-01-01

Mycoplasma hyopneumoniae is associated with swine respiratory diseases. Although gene organization and regulation are well known in many prokaryotic organisms, knowledge on mycoplasma is limited. This study performed a comparative analysis of three strains of M. hyopneumoniae (7448, J and 232), with a focus on genome organization and gene comparison for open read frame (ORF) cluster (OC) identification. An in silico analysis of gene organization demonstrated 117 OCs and 34 single ORFs in M. hyopneumoniae 7448 and J, while 116 OCs and 36 single ORFs were identified in M. hyopneumoniae 232. Genomic comparison revealed high synteny and conservation of gene order between the OCs defined for 7448 and J strains as well as for 7448 and 232 strains. Twenty-one OCs were chosen and experimentally confirmed by reverse transcription–PCR from M. hyopneumoniae 7448 genome, validating our prediction. A subset of the ORFs within an OC could be independently transcribed due to the presence of internal promoters. Our results suggest that transcription occurs in ‘run-on’ from an upstream promoter in M. hyopneumoniae, thus forming large ORF clusters (from 2 to 29 ORFs in the same orientation) and indicating a complex transcriptional organization. PMID:22086999

Universal Internucleotide Statistics in Full Genomes: A Footprint of the DNA Structure and Packaging?

OpenAIRE

Bogachev, Mikhail I.; Kayumov, Airat R.; Bunde, Armin

2014-01-01

Uncovering the fundamental laws that govern the complex DNA structural organization remains challenging and is largely based upon reconstructions from the primary nucleotide sequences. Here we investigate the distributions of the internucleotide intervals and their persistence properties in complete genomes of various organisms from Archaea and Bacteria to H. Sapiens aiming to reveal the manifestation of the universal DNA architecture. We find that in all considered organisms the internucleot...

Local chromatin structure of heterochromatin regulates repeated DNA stability, nucleolus structure, and genome integrity

Energy Technology Data Exchange (ETDEWEB)

Peng, Jamy C. [Univ. of California, Berkeley, CA (United States)

2007-01-01

Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) pathway. My thesis project investigates how heterochromatin formation and function impact nuclear architecture, repeated DNA organization, and genome stability in Drosophila melanogaster. H3K9me-based chromatin reduces extrachromosomal DNA formation; most likely by restricting the access of repair machineries to repeated DNAs. Reducing extrachromosomal ribosomal DNA stabilizes rDNA repeats and the nucleolus structure. H3K9me-based chromatin also inhibits DNA damage in heterochromatin. Cells with compromised heterochromatin structure, due to Su(var)3-9 or dcr-2 (a component of the RNAi pathway) mutations, display severe DNA damage in heterochromatin compared to wild type. In these mutant cells, accumulated DNA damage leads to chromosomal defects such as translocations, defective DNA repair response, and activation of the G2-M DNA repair and mitotic checkpoints that ensure cellular and animal viability. My thesis research suggests that DNA replication, repair, and recombination mechanisms in heterochromatin differ from those in

Insights into the genome structure and copy-number variation of Eimeria tenella

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Lim Lik-Sin

2012-08-01

Full Text Available Abstract Background Eimeria is a genus of parasites in the same phylum (Apicomplexa as human parasites such as Toxoplasma, Cryptosporidium and the malaria parasite Plasmodium. As an apicomplexan whose life-cycle involves a single host, Eimeria is a convenient model for understanding this group of organisms. Although the genomes of the Apicomplexa are diverse, that of Eimeria is unique in being composed of large alternating blocks of sequence with very different characteristics - an arrangement seen in no other organism. This arrangement has impeded efforts to fully sequence the genome of Eimeria, which remains the last of the major apicomplexans to be fully analyzed. In order to increase the value of the genome sequence data and aid in the effort to gain a better understanding of the Eimeria tenella genome, we constructed a whole genome map for the parasite. Results A total of 1245 contigs representing 70.0% of the whole genome assembly sequences (Wellcome Trust Sanger Institute were selected and subjected to marker selection. Subsequently, 2482 HAPPY markers were developed and typed. Of these, 795 were considered as usable markers, and utilized in the construction of a HAPPY map. Markers developed from chromosomally-assigned genes were then integrated into the HAPPY map and this aided the assignment of a number of linkage groups to their respective chromosomes. BAC-end sequences and contigs from whole genome sequencing were also integrated to improve and validate the HAPPY map. This resulted in an integrated HAPPY map consisting of 60 linkage groups that covers approximately half of the estimated 60 Mb genome. Further analysis suggests that the segmental organization first seen in Chromosome 1 is present throughout the genome, with repeat-poor (P regions alternating with repeat-rich (R regions. Evidence of copy-number variation between strains was also uncovered. Conclusions This paper describes the application of a whole genome mapping

Functional Insights from Structural Genomics

Energy Technology Data Exchange (ETDEWEB)

Forouhar,F.; Kuzin, A.; Seetharaman, J.; Lee, I.; Zhou, W.; Abashidze, M.; Chen, Y.; Montelione, G.; Tong, L.; et al

2007-01-01

Structural genomics efforts have produced structural information, either directly or by modeling, for thousands of proteins over the past few years. While many of these proteins have known functions, a large percentage of them have not been characterized at the functional level. The structural information has provided valuable functional insights on some of these proteins, through careful structural analyses, serendipity, and structure-guided functional screening. Some of the success stories based on structures solved at the Northeast Structural Genomics Consortium (NESG) are reported here. These include a novel methyl salicylate esterase with important role in plant innate immunity, a novel RNA methyltransferase (H. influenzae yggJ (HI0303)), a novel spermidine/spermine N-acetyltransferase (B. subtilis PaiA), a novel methyltransferase or AdoMet binding protein (A. fulgidus AF{_}0241), an ATP:cob(I)alamin adenosyltransferase (B. subtilis YvqK), a novel carboxysome pore (E. coli EutN), a proline racemase homolog with a disrupted active site (B. melitensis BME11586), an FMN-dependent enzyme (S. pneumoniae SP{_}1951), and a 12-stranded {beta}-barrel with a novel fold (V. parahaemolyticus VPA1032).

Multiscale modeling of three-dimensional genome

Science.gov (United States)

Zhang, Bin; Wolynes, Peter

The genome, the blueprint of life, contains nearly all the information needed to build and maintain an entire organism. A comprehensive understanding of the genome is of paramount interest to human health and will advance progress in many areas, including life sciences, medicine, and biotechnology. The overarching goal of my research is to understand the structure-dynamics-function relationships of the human genome. In this talk, I will be presenting our efforts in moving towards that goal, with a particular emphasis on studying the three-dimensional organization, the structure of the genome with multi-scale approaches. Specifically, I will discuss the reconstruction of genome structures at both interphase and metaphase by making use of data from chromosome conformation capture experiments. Computationally modeling of chromatin fiber at atomistic level from first principles will also be presented as our effort for studying the genome structure from bottom up.

Structural genomic variation in ischemic stroke

Science.gov (United States)

Matarin, Mar; Simon-Sanchez, Javier; Fung, Hon-Chung; Scholz, Sonja; Gibbs, J. Raphael; Hernandez, Dena G.; Crews, Cynthia; Britton, Angela; Wavrant De Vrieze, Fabienne; Brott, Thomas G.; Brown, Robert D.; Worrall, Bradford B.; Silliman, Scott; Case, L. Douglas; Hardy, John A.; Rich, Stephen S.; Meschia, James F.; Singleton, Andrew B.

2008-01-01

Technological advances in molecular genetics allow rapid and sensitive identification of genomic copy number variants (CNVs). This, in turn, has sparked interest in the function such variation may play in disease. While a role for copy number mutations as a cause of Mendelian disorders is well established, it is unclear whether CNVs may affect risk for common complex disorders. We sought to investigate whether CNVs may modulate risk for ischemic stroke (IS) and to provide a catalog of CNVs in patients with this disorder by analyzing copy number metrics produced as a part of our previous genome-wide single-nucleotide polymorphism (SNP)-based association study of ischemic stroke in a North American white population. We examined CNVs in 263 patients with ischemic stroke (IS). Each identified CNV was compared with changes identified in 275 neurologically normal controls. Our analysis identified 247 CNVs, corresponding to 187 insertions (76%; 135 heterozygous; 25 homozygous duplications or triplications; 2 heterosomic) and 60 deletions (24%; 40 heterozygous deletions;3 homozygous deletions; 14 heterosomic deletions). Most alterations (81%) were the same as, or overlapped with, previously reported CNVs. We report here the first genome-wide analysis of CNVs in IS patients. In summary, our study did not detect any common genomic structural variation unequivocally linked to IS, although we cannot exclude that smaller CNVs or CNVs in genomic regions poorly covered by this methodology may confer risk for IS. The application of genome-wide SNP arrays now facilitates the evaluation of structural changes through the entire genome as part of a genome-wide genetic association study. PMID:18288507

Multi-scale coding of genomic information: From DNA sequence to genome structure and function

International Nuclear Information System (INIS)

Arneodo, Alain; Vaillant, Cedric; Audit, Benjamin; Argoul, Francoise; D'Aubenton-Carafa, Yves; Thermes, Claude

2011-01-01

Understanding how chromatin is spatially and dynamically organized in the nucleus of eukaryotic cells and how this affects genome functions is one of the main challenges of cell biology. Since the different orders of packaging in the hierarchical organization of DNA condition the accessibility of DNA sequence elements to trans-acting factors that control the transcription and replication processes, there is actually a wealth of structural and dynamical information to learn in the primary DNA sequence. In this review, we show that when using concepts, methodologies, numerical and experimental techniques coming from statistical mechanics and nonlinear physics combined with wavelet-based multi-scale signal processing, we are able to decipher the multi-scale sequence encoding of chromatin condensation-decondensation mechanisms that play a fundamental role in regulating many molecular processes involved in nuclear functions.

Structural organization of poliovirus RNA replication is mediated by viral proteins of the P2 genomic region

International Nuclear Information System (INIS)

Bienz, K.; Egger, D.; Troxler, M.; Pasamontes, L.

1990-01-01

Transcriptionally active replication complexes bound to smooth membrane vesicles were isolated from poliovirus-infected cells. In electron microscopic, negatively stained preparations, the replication complex appeared as an irregularly shaped, oblong structure attached to several virus-induced vesicles of a rosettelike arrangement. Electron microscopic immunocytochemistry of such preparations demonstrated that the poliovirus replication complex contains the proteins coded by the P2 genomic region (P2 proteins) in a membrane-associated form. In addition, the P2 proteins are also associated with viral RNA, and they can be cross-linked to viral RNA by UV irradiation. Guanidine hydrochloride prevented the P2 proteins from becoming membrane bound but did not change their association with viral RNA. The findings allow the conclusion that the protein 2C or 2C-containing precursor(s) is responsible for the attachment of the viral RNA to the vesicular membrane and for the spatial organization of the replication complex necessary for its proper functioning in viral transcription. A model for the structure of the viral replication complex and for the function of the 2C-containing P2 protein(s) and the vesicular membranes is proposed

Simultaneous Structural Variation Discovery in Multiple Paired-End Sequenced Genomes

Science.gov (United States)

Hormozdiari, Fereydoun; Hajirasouliha, Iman; McPherson, Andrew; Eichler, Evan E.; Sahinalp, S. Cenk

Next generation sequencing technologies have been decreasing the costs and increasing the world-wide capacity for sequence production at an unprecedented rate, making the initiation of large scale projects aiming to sequence almost 2000 genomes [1]. Structural variation detection promises to be one of the key diagnostic tools for cancer and other diseases with genomic origin. In this paper, we study the problem of detecting structural variation events in two or more sequenced genomes through high throughput sequencing . We propose to move from the current model of (1) detecting genomic variations in single next generation sequenced (NGS) donor genomes independently, and (2) checking whether two or more donor genomes indeed agree or disagree on the variations (in this paper we name this framework Independent Structural Variation Discovery and Merging - ISV&M), to a new model in which we detect structural variation events among multiple genomes simultaneously.

Macromolecular structure determination in the post-genome era

CERN Document Server

Kuhn, P

2001-01-01

Recent advances in genetics, molecular biology and crystallographic instrumentation and methodology have led to a revolution in the field of Structural Molecular Biology (SMB). These combined advances have paved the way to a more complete and detailed understanding of the biological macromolecules that make up an organism, both in terms of their individual functions and also the interactions between them. In this paper we describe a large-scale, genomic approach to the three-dimensional structure determination of macromolecules and their complexes, using high-throughput methodology to streamline all aspects of the process. This task requires the development of automated high-intensity synchrotron beam lines for X-ray diffraction data collection from single crystal samples. Furthermore, these beam lines must be operated within a sophisticated software and hardware environment, which is capable of delivering a completely automated structure determination pipeline. The SMB resource at SSRL is developing a system...

Structural genomic variations and Parkinson's disease.

Science.gov (United States)

Bandrés-Ciga, Sara; Ruz, Clara; Barrero, Francisco J; Escamilla-Sevilla, Francisco; Pelegrina, Javier; Vives, Francisco; Duran, Raquel

2017-10-01

Parkinson's disease (PD) is the second most common neurodegenerative disease, whose prevalence is projected to be between 8.7 and 9.3 million by 2030. Until about 20 years ago, PD was considered to be the textbook example of a "non-genetic" disorder. Nowadays, PD is generally considered a multifactorial disorder that arises from the combination and complex interaction of genes and environmental factors. To date, a total of 7 genes including SNCA, LRRK2, PARK2, DJ-1, PINK 1, VPS35 and ATP13A2 have been seen to cause unequivocally Mendelian PD. Also, variants with incomplete penetrance in the genes LRRK2 and GBA are considered to be strong risk factors for PD worldwide. Although genetic studies have provided valuable insights into the pathogenic mechanisms underlying PD, the role of structural variation in PD has been understudied in comparison with other genomic variations. Structural genomic variations might substantially account for such genetic substrates yet to be discovered. The present review aims to provide an overview of the structural genomic variants implicated in the pathogenesis of PD.

High-throughput SHAPE analysis reveals structures in HIV-1 genomic RNA strongly conserved across distinct biological states.

Directory of Open Access Journals (Sweden)

Kevin A Wilkinson

2008-04-01

Full Text Available Replication and pathogenesis of the human immunodeficiency virus (HIV is tightly linked to the structure of its RNA genome, but genome structure in infectious virions is poorly understood. We invent high-throughput SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension technology, which uses many of the same tools as DNA sequencing, to quantify RNA backbone flexibility at single-nucleotide resolution and from which robust structural information can be immediately derived. We analyze the structure of HIV-1 genomic RNA in four biologically instructive states, including the authentic viral genome inside native particles. Remarkably, given the large number of plausible local structures, the first 10% of the HIV-1 genome exists in a single, predominant conformation in all four states. We also discover that noncoding regions functioning in a regulatory role have significantly lower (p-value < 0.0001 SHAPE reactivities, and hence more structure, than do viral coding regions that function as the template for protein synthesis. By directly monitoring protein binding inside virions, we identify the RNA recognition motif for the viral nucleocapsid protein. Seven structurally homologous binding sites occur in a well-defined domain in the genome, consistent with a role in directing specific packaging of genomic RNA into nascent virions. In addition, we identify two distinct motifs that are targets for the duplex destabilizing activity of this same protein. The nucleocapsid protein destabilizes local HIV-1 RNA structure in ways likely to facilitate initial movement both of the retroviral reverse transcriptase from its tRNA primer and of the ribosome in coding regions. Each of the three nucleocapsid interaction motifs falls in a specific genome domain, indicating that local protein interactions can be organized by the long-range architecture of an RNA. High-throughput SHAPE reveals a comprehensive view of HIV-1 RNA genome structure, and further

Structural dynamics of retroviral genome and the packaging.

Science.gov (United States)

Miyazaki, Yasuyuki; Miyake, Ariko; Nomaguchi, Masako; Adachi, Akio

2011-01-01

Retroviruses can cause diseases such as AIDS, leukemia, and tumors, but are also used as vectors for human gene therapy. All retroviruses, except foamy viruses, package two copies of unspliced genomic RNA into their progeny viruses. Understanding the molecular mechanisms of retroviral genome packaging will aid the design of new anti-retroviral drugs targeting the packaging process and improve the efficacy of retroviral vectors. Retroviral genomes have to be specifically recognized by the cognate nucleocapsid domain of the Gag polyprotein from among an excess of cellular and spliced viral mRNA. Extensive virological and structural studies have revealed how retroviral genomic RNA is selectively packaged into the viral particles. The genomic area responsible for the packaging is generally located in the 5' untranslated region (5' UTR), and contains dimerization site(s). Recent studies have shown that retroviral genome packaging is modulated by structural changes of RNA at the 5' UTR accompanied by the dimerization. In this review, we focus on three representative retroviruses, Moloney murine leukemia virus, human immunodeficiency virus type 1 and 2, and describe the molecular mechanism of retroviral genome packaging.

Structural determinants and mechanism of HIV-1 genome packaging.

Science.gov (United States)

Lu, Kun; Heng, Xiao; Summers, Michael F

2011-07-22

Like all retroviruses, the human immunodeficiency virus selectively packages two copies of its unspliced RNA genome, both of which are utilized for strand-transfer-mediated recombination during reverse transcription-a process that enables rapid evolution under environmental and chemotherapeutic pressures. The viral RNA appears to be selected for packaging as a dimer, and there is evidence that dimerization and packaging are mechanistically coupled. Both processes are mediated by interactions between the nucleocapsid domains of a small number of assembling viral Gag polyproteins and RNA elements within the 5'-untranslated region of the genome. A number of secondary structures have been predicted for regions of the genome that are responsible for packaging, and high-resolution structures have been determined for a few small RNA fragments and protein-RNA complexes. However, major questions regarding the RNA structures (and potentially the structural changes) that are responsible for dimeric genome selection remain unanswered. Here, we review efforts that have been made to identify the molecular determinants and mechanism of human immunodeficiency virus type 1 genome packaging. Copyright © 2011 Elsevier Ltd. All rights reserved.

Multi-scale structural community organisation of the human genome.

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Boulos, Rasha E; Tremblay, Nicolas; Arneodo, Alain; Borgnat, Pierre; Audit, Benjamin

2017-04-11

Structural interaction frequency matrices between all genome loci are now experimentally achievable thanks to high-throughput chromosome conformation capture technologies. This ensues a new methodological challenge for computational biology which consists in objectively extracting from these data the structural motifs characteristic of genome organisation. We deployed the fast multi-scale community mining algorithm based on spectral graph wavelets to characterise the networks of intra-chromosomal interactions in human cell lines. We observed that there exist structural domains of all sizes up to chromosome length and demonstrated that the set of structural communities forms a hierarchy of chromosome segments. Hence, at all scales, chromosome folding predominantly involves interactions between neighbouring sites rather than the formation of links between distant loci. Multi-scale structural decomposition of human chromosomes provides an original framework to question structural organisation and its relationship to functional regulation across the scales. By construction the proposed methodology is independent of the precise assembly of the reference genome and is thus directly applicable to genomes whose assembly is not fully determined.

The eukaryotic genome is structurally and functionally more like a social insect colony than a book.

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Qiu, Guo-Hua; Yang, Xiaoyan; Zheng, Xintian; Huang, Cuiqin

2017-11-01

Traditionally, the genome has been described as the 'book of life'. However, the metaphor of a book may not reflect the dynamic nature of the structure and function of the genome. In the eukaryotic genome, the number of centrally located protein-coding sequences is relatively constant across species, but the amount of noncoding DNA increases considerably with the increase of organismal evolutional complexity. Therefore, it has been hypothesized that the abundant peripheral noncoding DNA protects the genome and the central protein-coding sequences in the eukaryotic genome. Upon comparison with the habitation, sociality and defense mechanisms of a social insect colony, it is found that the genome is similar to a social insect colony in various aspects. A social insect colony may thus be a better metaphor than a book to describe the spatial organization and physical functions of the genome. The potential implications of the metaphor are also discussed.

Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome

NARCIS (Netherlands)

Collins, Ryan L; Brand, Harrison; Redin, Claire E.; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T.; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A.; Lucente, Diane; Levy, Brynn; Sanders, Jan-Stephan; Wapner, Ronald J.; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E.

2017-01-01

Background: Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. Results: We sequenced 689 participants with autism spectrum disorder (ASD) and other

Structural dynamics of retroviral genome and the packaging

Directory of Open Access Journals (Sweden)

Yasuyuki eMiyazaki

2011-12-01

Full Text Available Retroviruses can cause diseases such as AIDS, leukemia and tumors, but are also used as vectors for human gene therapy. All retroviruses, except foamy viruses, package two copies of unspliced genomic RNA into their progeny viruses. Understanding the molecular mechanisms of retroviral genome packaging will aid the design of new anti-retroviral drugs targeting the packaging process and improve the efficacy of retroviral vectors. Retroviral genomes have to be specifically recognized by the cognate nucleocapsid (NC domain of the Gag polyprotein from among an excess of cellular and spliced viral mRNA. Extensive virological and structural studies have revealed how retroviral genomic RNA is selectively packaged into the viral particles. The genomic area responsible for the packaging is generally located in the 5’ untranslated region (5’ UTR, and contains dimerization site(s. Recent studies have shown that retroviral genome packaging is modulated by structural changes of RNA at the 5’ UTR accompanied by the dimerization. In this review, we focus on three representative retroviruses, Moloney murine leukemia virus (MoMLV, human immunodeficiency virus type 1 (HIV-1 and 2 (HIV-2, and describe the molecular mechanism of retroviral genome packaging.

Genomic organization of plant aminopropyl transferases.

Science.gov (United States)

Rodríguez-Kessler, Margarita; Delgado-Sánchez, Pablo; Rodríguez-Kessler, Gabriela Theresia; Moriguchi, Takaya; Jiménez-Bremont, Juan Francisco

2010-07-01

Aminopropyl transferases like spermidine synthase (SPDS; EC 2.5.1.16), spermine synthase and thermospermine synthase (SPMS, tSPMS; EC 2.5.1.22) belong to a class of widely distributed enzymes that use decarboxylated S-adenosylmethionine as an aminopropyl donor and putrescine or spermidine as an amino acceptor to form in that order spermidine, spermine or thermospermine. We describe the analysis of plant genomic sequences encoding SPDS, SPMS, tSPMS and PMT (putrescine N-methyltransferase; EC 2.1.1.53). Genome organization (including exon size, gain and loss, as well as intron number, size, loss, retention, placement and phase, and the presence of transposons) of plant aminopropyl transferase genes were compared between the genomic sequences of SPDS, SPMS and tSPMS from Zea mays, Oryza sativa, Malus x domestica, Populus trichocarpa, Arabidopsis thaliana and Physcomitrella patens. In addition, the genomic organization of plant PMT genes, proposed to be derived from SPDS during the evolution of alkaloid metabolism, is illustrated. Herein, a particular conservation and arrangement of exon and intron sequences between plant SPDS, SPMS and PMT genes that clearly differs with that of ACL5 genes, is shown. The possible acquisition of the plant SPMS exon II and, in particular exon XI in the monocot SPMS genes, is a remarkable feature that allows their differentiation from SPDS genes. In accordance with our in silico analysis, functional complementation experiments of the maize ZmSPMS1 enzyme (previously considered to be SPDS) in yeast demonstrated its spermine synthase activity. Another significant aspect is the conservation of intron sequences among SPDS and PMT paralogs. In addition the existence of microsynteny among some SPDS paralogs, especially in P. trichocarpa and A. thaliana, supports duplication events of plant SPDS genes. Based in our analysis, we hypothesize that SPMS genes appeared with the divergence of vascular plants by a processes of gene duplication and the

Secure web book to store structural genomics research data.

Science.gov (United States)

Manjasetty, Babu A; Höppner, Klaus; Mueller, Uwe; Heinemann, Udo

2003-01-01

Recently established collaborative structural genomics programs aim at significantly accelerating the crystal structure analysis of proteins. These large-scale projects require efficient data management systems to ensure seamless collaboration between different groups of scientists working towards the same goal. Within the Berlin-based Protein Structure Factory, the synchrotron X-ray data collection and the subsequent crystal structure analysis tasks are located at BESSY, a third-generation synchrotron source. To organize file-based communication and data transfer at the BESSY site of the Protein Structure Factory, we have developed the web-based BCLIMS, the BESSY Crystallography Laboratory Information Management System. BCLIMS is a relational data management system which is powered by MySQL as the database engine and Apache HTTP as the web server. The database interface routines are written in Python programing language. The software is freely available to academic users. Here we describe the storage, retrieval and manipulation of laboratory information, mainly pertaining to the synchrotron X-ray diffraction experiments and the subsequent protein structure analysis, using BCLIMS.

Spatial organization of the budding yeast genome in the cell nucleus and identification of specific chromatin interactions from multi-chromosome constrained chromatin model.

Science.gov (United States)

Gürsoy, Gamze; Xu, Yun; Liang, Jie

2017-07-01

Nuclear landmarks and biochemical factors play important roles in the organization of the yeast genome. The interaction pattern of budding yeast as measured from genome-wide 3C studies are largely recapitulated by model polymer genomes subject to landmark constraints. However, the origin of inter-chromosomal interactions, specific roles of individual landmarks, and the roles of biochemical factors in yeast genome organization remain unclear. Here we describe a multi-chromosome constrained self-avoiding chromatin model (mC-SAC) to gain understanding of the budding yeast genome organization. With significantly improved sampling of genome structures, both intra- and inter-chromosomal interaction patterns from genome-wide 3C studies are accurately captured in our model at higher resolution than previous studies. We show that nuclear confinement is a key determinant of the intra-chromosomal interactions, and centromere tethering is responsible for the inter-chromosomal interactions. In addition, important genomic elements such as fragile sites and tRNA genes are found to be clustered spatially, largely due to centromere tethering. We uncovered previously unknown interactions that were not captured by genome-wide 3C studies, which are found to be enriched with tRNA genes, RNAPIII and TFIIS binding. Moreover, we identified specific high-frequency genome-wide 3C interactions that are unaccounted for by polymer effects under landmark constraints. These interactions are enriched with important genes and likely play biological roles.

Interrogating the druggable genome with structural informatics.

Science.gov (United States)

Hambly, Kevin; Danzer, Joseph; Muskal, Steven; Debe, Derek A

2006-08-01

Structural genomics projects are producing protein structure data at an unprecedented rate. In this paper, we present the Target Informatics Platform (TIP), a novel structural informatics approach for amplifying the rapidly expanding body of experimental protein structure information to enhance the discovery and optimization of small molecule protein modulators on a genomic scale. In TIP, existing experimental structure information is augmented using a homology modeling approach, and binding sites across multiple target families are compared using a clique detection algorithm. We report here a detailed analysis of the structural coverage for the set of druggable human targets, highlighting drug target families where the level of structural knowledge is currently quite high, as well as those areas where structural knowledge is sparse. Furthermore, we demonstrate the utility of TIP's intra- and inter-family binding site similarity analysis using a series of retrospective case studies. Our analysis underscores the utility of a structural informatics infrastructure for extracting drug discovery-relevant information from structural data, aiding researchers in the identification of lead discovery and optimization opportunities as well as potential "off-target" liabilities.

Visualization of RNA structure models within the Integrative Genomics Viewer.

Science.gov (United States)

Busan, Steven; Weeks, Kevin M

2017-07-01

Analyses of the interrelationships between RNA structure and function are increasingly important components of genomic studies. The SHAPE-MaP strategy enables accurate RNA structure probing and realistic structure modeling of kilobase-length noncoding RNAs and mRNAs. Existing tools for visualizing RNA structure models are not suitable for efficient analysis of long, structurally heterogeneous RNAs. In addition, structure models are often advantageously interpreted in the context of other experimental data and gene annotation information, for which few tools currently exist. We have developed a module within the widely used and well supported open-source Integrative Genomics Viewer (IGV) that allows visualization of SHAPE and other chemical probing data, including raw reactivities, data-driven structural entropies, and data-constrained base-pair secondary structure models, in context with linear genomic data tracks. We illustrate the usefulness of visualizing RNA structure in the IGV by exploring structure models for a large viral RNA genome, comparing bacterial mRNA structure in cells with its structure under cell- and protein-free conditions, and comparing a noncoding RNA structure modeled using SHAPE data with a base-pairing model inferred through sequence covariation analysis. © 2017 Busan and Weeks; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Genomic Organization of Zebrafish microRNAs

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Paydar Ima

2008-05-01

Full Text Available Abstract Background microRNAs (miRNAs are small (~22 nt non-coding RNAs that regulate cell movement, specification, and development. Expression of miRNAs is highly regulated, both spatially and temporally. Based on direct cloning, sequence conservation, and predicted secondary structures, a large number of miRNAs have been identified in higher eukaryotic genomes but whether these RNAs are simply a subset of a much larger number of noncoding RNA families is unknown. This is especially true in zebrafish where genome sequencing and annotation is not yet complete. Results We analyzed the zebrafish genome to identify the number and location of proven and predicted miRNAs resulting in the identification of 35 new miRNAs. We then grouped all 415 zebrafish miRNAs into families based on seed sequence identity as a means to identify possible functional redundancy. Based on genomic location and expression analysis, we also identified those miRNAs that are likely to be encoded as part of polycistronic transcripts. Lastly, as a resource, we compiled existing zebrafish miRNA expression data and, where possible, listed all experimentally proven mRNA targets. Conclusion Current analysis indicates the zebrafish genome encodes 415 miRNAs which can be grouped into 44 families. The largest of these families (the miR-430 family contains 72 members largely clustered in two main locations along chromosome 4. Thus far, most zebrafish miRNAs exhibit tissue specific patterns of expression.

Structural and functional analysis of the finished genome of the recently isolated toxic Anabaena sp. WA102.

Science.gov (United States)

Brown, Nathan M; Mueller, Ryan S; Shepardson, Jonathan W; Landry, Zachary C; Morré, Jeffrey T; Maier, Claudia S; Hardy, F Joan; Dreher, Theo W

2016-06-13

Very few closed genomes of the cyanobacteria that commonly produce toxic blooms in lakes and reservoirs are available, limiting our understanding of the properties of these organisms. A new anatoxin-a-producing member of the Nostocaceae, Anabaena sp. WA102, was isolated from a freshwater lake in Washington State, USA, in 2013 and maintained in non-axenic culture. The Anabaena sp. WA102 5.7 Mbp genome assembly has been closed with long-read, single-molecule sequencing and separately a draft genome assembly has been produced with short-read sequencing technology. The closed and draft genome assemblies are compared, showing a correlation between long repeats in the genome and the many gaps in the short-read assembly. Anabaena sp. WA102 encodes anatoxin-a biosynthetic genes, as does its close relative Anabaena sp. AL93 (also introduced in this study). These strains are distinguished by differences in the genes for light-harvesting phycobilins, with Anabaena sp. AL93 possessing a phycoerythrocyanin operon. Biologically relevant structural variants in the Anabaena sp. WA102 genome were detected only by long-read sequencing: a tandem triplication of the anaBCD promoter region in the anatoxin-a synthase gene cluster (not triplicated in Anabaena sp. AL93) and a 5-kbp deletion variant present in two-thirds of the population. The genome has a large number of mobile elements (160). Strikingly, there was no synteny with the genome of its nearest fully assembled relative, Anabaena sp. 90. Structural and functional genome analyses indicate that Anabaena sp. WA102 has a flexible genome. Genome closure, which can be readily achieved with long-read sequencing, reveals large scale (e.g., gene order) and local structural features that should be considered in understanding genome evolution and function.

CAGO: a software tool for dynamic visual comparison and correlation measurement of genome organization.

Directory of Open Access Journals (Sweden)

Yi-Feng Chang

Full Text Available CAGO (Comparative Analysis of Genome Organization is developed to address two critical shortcomings of conventional genome atlas plotters: lack of dynamic exploratory functions and absence of signal analysis for genomic properties. With dynamic exploratory functions, users can directly manipulate chromosome tracks of a genome atlas and intuitively identify distinct genomic signals by visual comparison. Signal analysis of genomic properties can further detect inconspicuous patterns from noisy genomic properties and calculate correlations between genomic properties across various genomes. To implement dynamic exploratory functions, CAGO presents each genome atlas in Scalable Vector Graphics (SVG format and allows users to interact with it using a SVG viewer through JavaScript. Signal analysis functions are implemented using R statistical software and a discrete wavelet transformation package waveslim. CAGO is not only a plotter for generating complex genome atlases, but also a platform for exploring genome atlases with dynamic exploratory functions for visual comparison and with signal analysis for comparing genomic properties across multiple organisms. The web-based application of CAGO, its source code, user guides, video demos, and live examples are publicly available and can be accessed at http://cbs.ym.edu.tw/cago.

Alignment-free comparative genomic screen for structured RNAs using coarse-grained secondary structure dot plots

DEFF Research Database (Denmark)

Kato, Yuki; Gorodkin, Jan; Havgaard, Jakob Hull

2017-01-01

. Methods: Here we present a fast and efficient method, DotcodeR, for detecting structurally similar RNAs in genomic sequences by comparing their corresponding coarse-grained secondary structure dot plots at string level. This allows us to perform an all-against-all scan of all window pairs from two genomes...... without alignment. Results: Our computational experiments with simulated data and real chromosomes demonstrate that the presented method has good sensitivity. Conclusions: DotcodeR can be useful as a pre-filter in a genomic comparative scan for structured RNAs....

Marine Genomics: A clearing-house for genomic and transcriptomic data of marine organisms

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Trent Harold F

2005-03-01

Full Text Available Abstract Background The Marine Genomics project is a functional genomics initiative developed to provide a pipeline for the curation of Expressed Sequence Tags (ESTs and gene expression microarray data for marine organisms. It provides a unique clearing-house for marine specific EST and microarray data and is currently available at http://www.marinegenomics.org. Description The Marine Genomics pipeline automates the processing, maintenance, storage and analysis of EST and microarray data for an increasing number of marine species. It currently contains 19 species databases (over 46,000 EST sequences that are maintained by registered users from local and remote locations in Europe and South America in addition to the USA. A collection of analysis tools are implemented. These include a pipeline upload tool for EST FASTA file, sequence trace file and microarray data, an annotative text search, automated sequence trimming, sequence quality control (QA/QC editing, sequence BLAST capabilities and a tool for interactive submission to GenBank. Another feature of this resource is the integration with a scientific computing analysis environment implemented by MATLAB. Conclusion The conglomeration of multiple marine organisms with integrated analysis tools enables users to focus on the comprehensive descriptions of transcriptomic responses to typical marine stresses. This cross species data comparison and integration enables users to contain their research within a marine-oriented data management and analysis environment.

Evolution of Genome Organization and Epigenetic Machineries ...

Indian Academy of Sciences (India)

48

The compact folded structure of bacterial genomic material is termed as nucleoid. The ... from pluripotent to the differentiated stage of a cell, there is a dramatic alteration both in the .... Sherratt, D.J. 2003 Bacterial Chromosome Dynamics.

Pathgroups, a dynamic data structure for genome reconstruction problems.

Science.gov (United States)

Zheng, Chunfang

2010-07-01

Ancestral gene order reconstruction problems, including the median problem, quartet construction, small phylogeny, guided genome halving and genome aliquoting, are NP hard. Available heuristics dedicated to each of these problems are computationally costly for even small instances. We present a data structure enabling rapid heuristic solution to all these ancestral genome reconstruction problems. A generic greedy algorithm with look-ahead based on an automatically generated priority system suffices for all the problems using this data structure. The efficiency of the algorithm is due to fast updating of the structure during run time and to the simplicity of the priority scheme. We illustrate with the first rapid algorithm for quartet construction and apply this to a set of yeast genomes to corroborate a recent gene sequence-based phylogeny. http://albuquerque.bioinformatics.uottawa.ca/pathgroup/Quartet.html chunfang313@gmail.com Supplementary data are available at Bioinformatics online.

The complete chloroplast genome sequence of Podocarpus lambertii: genome structure, evolutionary aspects, gene content and SSR detection.

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Leila do Nascimento Vieira

Full Text Available BACKGROUND: Podocarpus lambertii (Podocarpaceae is a native conifer from the Brazilian Atlantic Forest Biome, which is considered one of the 25 biodiversity hotspots in the world. The advancement of next-generation sequencing technologies has enabled the rapid acquisition of whole chloroplast (cp genome sequences at low cost. Several studies have proven the potential of cp genomes as tools to understand enigmatic and basal phylogenetic relationships at different taxonomic levels, as well as further probe the structural and functional evolution of plants. In this work, we present the complete cp genome sequence of P. lambertii. METHODOLOGY/PRINCIPAL FINDINGS: The P. lambertii cp genome is 133,734 bp in length, and similar to other sequenced cupressophytes, it lacks one of the large inverted repeat regions (IR. It contains 118 unique genes and one duplicated tRNA (trnN-GUU, which occurs as an inverted repeat sequence. The rps16 gene was not found, which was previously reported for the plastid genome of another Podocarpaceae (Nageia nagi and Araucariaceae (Agathis dammara. Structurally, P. lambertii shows 4 inversions of a large DNA fragment ∼20,000 bp compared to the Podocarpus totara cp genome. These unexpected characteristics may be attributed to geographical distance and different adaptive needs. The P. lambertii cp genome presents a total of 28 tandem repeats and 156 SSRs, with homo- and dipolymers being the most common and tri-, tetra-, penta-, and hexapolymers occurring with less frequency. CONCLUSION: The complete cp genome sequence of P. lambertii revealed significant structural changes, even in species from the same genus. These results reinforce the apparently loss of rps16 gene in Podocarpaceae cp genome. In addition, several SSRs in the P. lambertii cp genome are likely intraspecific polymorphism sites, which may allow highly sensitive phylogeographic and population structure studies, as well as phylogenetic studies of species of

Large differences in the genome organization of different plant Trypanosomatid parasites (Phytomonas spp.) reveal wide evolutionary divergences between taxa.

Science.gov (United States)

Marín, C; Dollet, M; Pagès, M; Bastien, P

2009-03-01

All currently known plant trypanosomes have been grouped in the genus Phytomonas spp., although they can differ greatly in terms of both their biological properties and effects upon the host. Those parasitizing the phloem sap are specifically associated with lethal syndromes in Latin America, such as, phloem necrosis of coffee, 'Hartrot' of coconut and 'Marchitez sorpresiva' of oil palm, that inflict considerable economic losses in endemic countries. The genomic organization of one group of Phytomonas (D) considered as representative of the genus has been published previously. The present work presents the genomic structure of two representative isolates from the pathogenic phloem-restricted group (H) of Phytomonas, analyzed by pulsed field gel electrophoresis followed by hybridization with chromosome-specific DNA markers. It came as a surprise to observe an extremely different genomic organization in this group as compared with that of group D. Most notably, the chromosome number is 7 in this group (with a genome size of 10 Mb) versus 21 in the group D (totalling 25 Mb). These data unravel an unsuspected genomic diversity within plant trypanosomatids, that may justify a further debate about their division into different genera.

Chromatin structure and evolution in the human genome

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Dunlop Malcolm G

2007-05-01

Full Text Available Abstract Background Evolutionary rates are not constant across the human genome but genes in close proximity have been shown to experience similar levels of divergence and selection. The higher-order organisation of chromosomes has often been invoked to explain such phenomena but previously there has been insufficient data on chromosome structure to investigate this rigorously. Using the results of a recent genome-wide analysis of open and closed human chromatin structures we have investigated the global association between divergence, selection and chromatin structure for the first time. Results In this study we have shown that, paradoxically, synonymous site divergence (dS at non-CpG sites is highest in regions of open chromatin, primarily as a result of an increased number of transitions, while the rates of other traditional measures of mutation (intergenic, intronic and ancient repeat divergence as well as SNP density are highest in closed regions of the genome. Analysis of human-chimpanzee divergence across intron-exon boundaries indicates that although genes in relatively open chromatin generally display little selection at their synonymous sites, those in closed regions show markedly lower divergence at their fourfold degenerate sites than in neighbouring introns and intergenic regions. Exclusion of known Exonic Splice Enhancer hexamers has little affect on the divergence observed at fourfold degenerate sites across chromatin categories; however, we show that closed chromatin is enriched with certain classes of ncRNA genes whose RNA secondary structure may be particularly important. Conclusion We conclude that, overall, non-CpG mutation rates are lowest in open regions of the genome and that regions of the genome with a closed chromatin structure have the highest background mutation rate. This might reflect lower rates of DNA damage or enhanced DNA repair processes in regions of open chromatin. Our results also indicate that dS is a poor

Evolutionary genomics and population structure of Entamoeba histolytica

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Koushik Das

2014-11-01

Full Text Available Amoebiasis caused by the gastrointestinal parasite Entamoeba histolytica has diverse disease outcomes. Study of genome and evolution of this fascinating parasite will help us to understand the basis of its virulence and explain why, when and how it causes diseases. In this review, we have summarized current knowledge regarding evolutionary genomics of E. histolytica and discussed their association with parasite phenotypes and its differential pathogenic behavior. How genetic diversity reveals parasite population structure has also been discussed. Queries concerning their evolution and population structure which were required to be addressed have also been highlighted. This significantly large amount of genomic data will improve our knowledge about this pathogenic species of Entamoeba.

Child Development and Structural Variation in the Human Genome

Science.gov (United States)

Zhang, Ying; Haraksingh, Rajini; Grubert, Fabian; Abyzov, Alexej; Gerstein, Mark; Weissman, Sherman; Urban, Alexander E.

2013-01-01

Structural variation of the human genome sequence is the insertion, deletion, or rearrangement of stretches of DNA sequence sized from around 1,000 to millions of base pairs. Over the past few years, structural variation has been shown to be far more common in human genomes than previously thought. Very little is currently known about the effects…

Macromolecular structure determination in the post-genome era

International Nuclear Information System (INIS)

Kuhn, P.; Soltis, S.M.

2001-01-01

Recent advances in genetics, molecular biology and crystallographic instrumentation and methodology have led to a revolution in the field of Structural Molecular Biology (SMB). These combined advances have paved the way to a more complete and detailed understanding of the biological macromolecules that make up an organism, both in terms of their individual functions and also the interactions between them. In this paper we describe a large-scale, genomic approach to the three-dimensional structure determination of macromolecules and their complexes, using high-throughput methodology to streamline all aspects of the process. This task requires the development of automated high-intensity synchrotron beam lines for X-ray diffraction data collection from single crystal samples. Furthermore, these beam lines must be operated within a sophisticated software and hardware environment, which is capable of delivering a completely automated structure determination pipeline. The SMB resource at SSRL is developing a system for the structure determination steps of this process, starting with the initial characterization of the frozen sample, followed by data collection, data reduction, phase determination, and model building. This paper focuses on the data collection elements of this high-throughput system

The SGC beyond structural genomics: redefining the role of 3D structures by coupling genomic stratification with fragment-based discovery.

Science.gov (United States)

Bradley, Anthony R; Echalier, Aude; Fairhead, Michael; Strain-Damerell, Claire; Brennan, Paul; Bullock, Alex N; Burgess-Brown, Nicola A; Carpenter, Elisabeth P; Gileadi, Opher; Marsden, Brian D; Lee, Wen Hwa; Yue, Wyatt; Bountra, Chas; von Delft, Frank

2017-11-08

The ongoing explosion in genomics data has long since outpaced the capacity of conventional biochemical methodology to verify the large number of hypotheses that emerge from the analysis of such data. In contrast, it is still a gold-standard for early phenotypic validation towards small-molecule drug discovery to use probe molecules (or tool compounds), notwithstanding the difficulty and cost of generating them. Rational structure-based approaches to ligand discovery have long promised the efficiencies needed to close this divergence; in practice, however, this promise remains largely unfulfilled, for a host of well-rehearsed reasons and despite the huge technical advances spearheaded by the structural genomics initiatives of the noughties. Therefore the current, fourth funding phase of the Structural Genomics Consortium (SGC), building on its extensive experience in structural biology of novel targets and design of protein inhibitors, seeks to redefine what it means to do structural biology for drug discovery. We developed the concept of a Target Enabling Package (TEP) that provides, through reagents, assays and data, the missing link between genetic disease linkage and the development of usefully potent compounds. There are multiple prongs to the ambition: rigorously assessing targets' genetic disease linkages through crowdsourcing to a network of collaborating experts; establishing a systematic approach to generate the protocols and data that comprise each target's TEP; developing new, X-ray-based fragment technologies for generating high quality chemical matter quickly and cheaply; and exploiting a stringently open access model to build multidisciplinary partnerships throughout academia and industry. By learning how to scale these approaches, the SGC aims to make structures finally serve genomics, as originally intended, and demonstrate how 3D structures systematically allow new modes of druggability to be discovered for whole classes of targets. © 2017 The

Genome organization in the nucleus: From dynamic measurements to a functional model.

Science.gov (United States)

Vivante, Anat; Brozgol, Eugene; Bronshtein, Irena; Garini, Yuval

2017-07-01

A biological system is by definition a dynamic environment encompassing kinetic processes that occur at different length scales and time ranges. To explore this type of system, spatial information needs to be acquired at different time scales. This means overcoming significant hurdles, including the need for stable and precise labeling of the required probes and the use of state of the art optical methods. However, to interpret the acquired data, biophysical models that can account for these biological mechanisms need to be developed. The structure and function of a biological system are closely related to its dynamic properties, thus further emphasizing the importance of identifying the rules governing the dynamics that cannot be directly deduced from information on the structure itself. In eukaryotic cells, tens of thousands of genes are packed in the small volume of the nucleus. The genome itself is organized in chromosomes that occupy specific volumes referred to as chromosome territories. This organization is preserved throughout the cell cycle, even though there are no sub-compartments in the nucleus itself. This organization, which is still not fully understood, is crucial for a large number of cellular functions such as gene regulation, DNA breakage repair and error-free cell division. Various techniques are in use today, including imaging, live cell imaging and molecular methods such as chromosome conformation capture (3C) methods to better understand these mechanisms. Live cell imaging methods are becoming well established. These include methods such as Single Particle Tracking (SPT), Continuous Photobleaching (CP), Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Correlation Spectroscopy (FCS) that are currently used for studying proteins, RNA, DNA, gene loci and nuclear bodies. They provide crucial information on its mobility, reorganization, interactions and binding properties. Here we describe how these dynamic methods can be used to

Gene Composer in a structural genomics environment

International Nuclear Information System (INIS)

Lorimer, Don; Raymond, Amy; Mixon, Mark; Burgin, Alex; Staker, Bart; Stewart, Lance

2011-01-01

For structural biology applications, protein-construct engineering is guided by comparative sequence analysis and structural information, which allow the researcher to better define domain boundaries for terminal deletions and nonconserved regions for surface mutants. A database software application called Gene Composer has been developed to facilitate construct design. The structural genomics effort at the Seattle Structural Genomics Center for Infectious Disease (SSGCID) requires the manipulation of large numbers of amino-acid sequences and the underlying DNA sequences which are to be cloned into expression vectors. To improve efficiency in high-throughput protein structure determination, a database software package, Gene Composer, has been developed which facilitates the information-rich design of protein constructs and their underlying gene sequences. With its modular workflow design and numerous graphical user interfaces, Gene Composer enables researchers to perform all common bioinformatics steps used in modern structure-guided protein engineering and synthetic gene engineering. An example of the structure determination of H1N1 RNA-dependent RNA polymerase PB2 subunit is given

Five Complete Chloroplast Genome Sequences from Diospyros: Genome Organization and Comparative Analysis.

Science.gov (United States)

Fu, Jianmin; Liu, Huimin; Hu, Jingjing; Liang, Yuqin; Liang, Jinjun; Wuyun, Tana; Tan, Xiaofeng

2016-01-01

Diospyros is the largest genus in Ebenaceae, comprising more than 500 species with remarkable economic value, especially Diospyros kaki Thunb., which has traditionally been an important food resource in China, Korea, and Japan. Complete chloroplast (cp) genomes from D. kaki, D. lotus L., D. oleifera Cheng., D. glaucifolia Metc., and Diospyros 'Jinzaoshi' were sequenced using Illumina sequencing technology. This is the first cp genome reported in Ebenaceae. The cp genome sequences of Diospyros ranged from 157,300 to 157,784 bp in length, presenting a typical quadripartite structure with two inverted repeats each separated by one large and one small single-copy region. For each cp genome, 134 genes were annotated, including 80 protein-coding, 31 tRNA, and 4 rRNA unique genes. In all, 179 repeats and 283 single sequence repeats were identified. Four hypervariable regions, namely, intergenic region of trnQ_rps16, trnV_ndhC, and psbD_trnT, and intron of ndhA, were identified in the Diospyros genomes. Phylogenetic analyses based on the whole cp genome, protein-coding, and intergenic and intron sequences indicated that D. oleifera is closely related to D. kaki and could be used as a model plant for future research on D. kaki; to our knowledge, this is proposed for the first time. Further, these analyses together with two large deletions (301 and 140 bp) in the cp genome of D. 'Jinzaoshi', support its placement as a new species in Diospyros. Both maximum parsimony and likelihood analyses for 19 taxa indicated the basal position of Ericales in asterids and suggested that Ebenaceae is monophyletic in Ericales.

Five Complete Chloroplast Genome Sequences from Diospyros: Genome Organization and Comparative Analysis.

Directory of Open Access Journals (Sweden)

Jianmin Fu

Full Text Available Diospyros is the largest genus in Ebenaceae, comprising more than 500 species with remarkable economic value, especially Diospyros kaki Thunb., which has traditionally been an important food resource in China, Korea, and Japan. Complete chloroplast (cp genomes from D. kaki, D. lotus L., D. oleifera Cheng., D. glaucifolia Metc., and Diospyros 'Jinzaoshi' were sequenced using Illumina sequencing technology. This is the first cp genome reported in Ebenaceae. The cp genome sequences of Diospyros ranged from 157,300 to 157,784 bp in length, presenting a typical quadripartite structure with two inverted repeats each separated by one large and one small single-copy region. For each cp genome, 134 genes were annotated, including 80 protein-coding, 31 tRNA, and 4 rRNA unique genes. In all, 179 repeats and 283 single sequence repeats were identified. Four hypervariable regions, namely, intergenic region of trnQ_rps16, trnV_ndhC, and psbD_trnT, and intron of ndhA, were identified in the Diospyros genomes. Phylogenetic analyses based on the whole cp genome, protein-coding, and intergenic and intron sequences indicated that D. oleifera is closely related to D. kaki and could be used as a model plant for future research on D. kaki; to our knowledge, this is proposed for the first time. Further, these analyses together with two large deletions (301 and 140 bp in the cp genome of D. 'Jinzaoshi', support its placement as a new species in Diospyros. Both maximum parsimony and likelihood analyses for 19 taxa indicated the basal position of Ericales in asterids and suggested that Ebenaceae is monophyletic in Ericales.

Structural biology at York Structural Biology Laboratory; laboratory information management systems for structural genomics

Czech Academy of Sciences Publication Activity Database

Dohnálek, Jan

2005-01-01

Roč. 12, č. 1 (2005), s. 3 ISSN 1211-5894. [Meeting of Structural Biologists /4./. 10.03.2005-12.03.2005, Nové Hrady] R&D Projects: GA MŠk(CZ) 1K05008 Keywords : structural biology * LIMS * structural genomics Subject RIV: CD - Macromolecular Chemistry

Structure-based inference of molecular functions of proteins of unknown function from Berkeley Structural Genomics Center

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung-Hou; Shin, Dong Hae; Hou, Jingtong; Chandonia, John-Marc; Das, Debanu; Choi, In-Geol; Kim, Rosalind; Kim, Sung-Hou

2007-09-02

Advances in sequence genomics have resulted in an accumulation of a huge number of protein sequences derived from genome sequences. However, the functions of a large portion of them cannot be inferred based on the current methods of sequence homology detection to proteins of known functions. Three-dimensional structure can have an important impact in providing inference of molecular function (physical and chemical function) of a protein of unknown function. Structural genomics centers worldwide have been determining many 3-D structures of the proteins of unknown functions, and possible molecular functions of them have been inferred based on their structures. Combined with bioinformatics and enzymatic assay tools, the successful acceleration of the process of protein structure determination through high throughput pipelines enables the rapid functional annotation of a large fraction of hypothetical proteins. We present a brief summary of the process we used at the Berkeley Structural Genomics Center to infer molecular functions of proteins of unknown function.

From structure prediction to genomic screens for novel non-coding RNAs

DEFF Research Database (Denmark)

Gorodkin, Jan; Hofacker, Ivo L.

2011-01-01

Abstract: Non-coding RNAs (ncRNAs) are receiving more and more attention not only as an abundant class of genes, but also as regulatory structural elements (some located in mRNAs). A key feature of RNA function is its structure. Computational methods were developed early for folding and prediction....... This and the increased amount of available genomes have made it possible to employ structure-based methods for genomic screens. The field has moved from folding prediction of single sequences to computational screens for ncRNAs in genomic sequence using the RNA structure as the main characteristic feature. Whereas early...... upon some of the concepts in current methods that have been applied in genomic screens for de novo RNA structures in searches for novel ncRNA genes and regulatory RNA structure on mRNAs. We discuss the strengths and weaknesses of the different strategies and how they can complement each other....

Molecular analysis and genomic organization of major DNA satellites in banana (Musa spp.).

Science.gov (United States)

Čížková, Jana; Hřibová, Eva; Humplíková, Lenka; Christelová, Pavla; Suchánková, Pavla; Doležel, Jaroslav

2013-01-01

Satellite DNA sequences consist of tandemly arranged repetitive units up to thousands nucleotides long in head-to-tail orientation. The evolutionary processes by which satellites arise and evolve include unequal crossing over, gene conversion, transposition and extra chromosomal circular DNA formation. Large blocks of satellite DNA are often observed in heterochromatic regions of chromosomes and are a typical component of centromeric and telomeric regions. Satellite-rich loci may show specific banding patterns and facilitate chromosome identification and analysis of structural chromosome changes. Unlike many other genomes, nuclear genomes of banana (Musa spp.) are poor in satellite DNA and the information on this class of DNA remains limited. The banana cultivars are seed sterile clones originating mostly from natural intra-specific crosses within M. acuminata (A genome) and inter-specific crosses between M. acuminata and M. balbisiana (B genome). Previous studies revealed the closely related nature of the A and B genomes, including similarities in repetitive DNA. In this study we focused on two main banana DNA satellites, which were previously identified in silico. Their genomic organization and molecular diversity was analyzed in a set of nineteen Musa accessions, including representatives of A, B and S (M. schizocarpa) genomes and their inter-specific hybrids. The two DNA satellites showed a high level of sequence conservation within, and a high homology between Musa species. FISH with probes for the satellite DNA sequences, rRNA genes and a single-copy BAC clone 2G17 resulted in characteristic chromosome banding patterns in M. acuminata and M. balbisiana which may aid in determining genomic constitution in interspecific hybrids. In addition to improving the knowledge on Musa satellite DNA, our study increases the number of cytogenetic markers and the number of individual chromosomes, which can be identified in Musa.

The Genomic Code: Genome Evolution and Potential Applications

KAUST Repository

Bernardi, Giorgio

2016-01-25

The genome of metazoans is organized according to a genomic code which comprises three laws: 1) Compositional correlations hold between contiguous coding and non-coding sequences, as well as among the three codon positions of protein-coding genes; these correlations are the consequence of the fact that the genomes under consideration consist of fairly homogeneous, long (≥200Kb) sequences, the isochores; 2) Although isochores are defined on the basis of purely compositional properties, GC levels of isochores are correlated with all tested structural and functional properties of the genome; 3) GC levels of isochores are correlated with chromosome architecture from interphase to metaphase; in the case of interphase the correlation concerns isochores and the three-dimensional “topological associated domains” (TADs); in the case of mitotic chromosomes, the correlation concerns isochores and chromosomal bands. Finally, the genomic code is the fourth and last pillar of molecular biology, the first three pillars being 1) the double helix structure of DNA; 2) the regulation of gene expression in prokaryotes; and 3) the genetic code.

Chromosome organizaton in simple and complex unicellular organisms.

Science.gov (United States)

O'Sullivan, Justin M

2011-01-01

The genomes of unicellular organisms form complex 3-dimensional structures. This spatial organization is hypothesized to have a significant role in genomic function. Spatial organization is not limited solely to the three-dimensional folding of the chromosome(s) in genomes but also includes genome positioning, and the folding and compartmentalization of any additional genetic material (e.g. episomes) present within complex genomes. In this comment, I will highlight similarities in the spatial organization of eukaryotic and prokaryotic unicellular genomes.

Structural proteomics of minimal organisms: conservation ofprotein fold usage and evolutionary implications

Energy Technology Data Exchange (ETDEWEB)

Chandonia, John-Marc; Kim, Sung-Hou

2006-03-15

Background: Determining the complete repertoire of proteinstructures for all soluble, globular proteins in a single organism hasbeen one of the major goals of several structural genomics projects inrecent years. Results: We report that this goal has nearly been reachedfor several "minimal organisms"--parasites or symbionts with reducedgenomes--for which over 95 percent of the soluble, globular proteins maynow be assigned folds, overall 3-D backbone structures. We analyze thestructures of these proteins as they relate to cellular functions, andcompare conservation off old usage between functional categories. We alsocompare patterns in the conservation off olds among minimal organisms andthose observed between minimal organisms and other bacteria. Conclusion:We find that proteins performing essential cellular functions closelyrelated to transcription and translation exhibit a higher degree ofconservation in fold usage than proteins in other functional categories.Folds related to transcription and translation functional categories werealso over represented in minimal organisms compared to otherbacteria.

Structured RNAs and synteny regions in the pig genome

DEFF Research Database (Denmark)

Anthon, Christian; Tafer, Hakim; Havgaard, Jakob H

2014-01-01

BACKGROUND: Annotating mammalian genomes for noncoding RNAs (ncRNAs) is nontrivial since far from all ncRNAs are known and the computational models are resource demanding. Currently, the human genome holds the best mammalian ncRNA annotation, a result of numerous efforts by several groups. However......, a more direct strategy is desired for the increasing number of sequenced mammalian genomes of which some, such as the pig, are relevant as disease models and production animals. RESULTS: We present a comprehensive annotation of structured RNAs in the pig genome. Combining sequence and structure...... lncRNA loci, 11 conflicts of annotation, and 3,183 ncRNA genes. The ncRNA genes comprise 359 miRNAs, 8 ribozymes, 185 rRNAs, 638 snoRNAs, 1,030 snRNAs, 810 tRNAs and 153 ncRNA genes not belonging to the here fore mentioned classes. When running the pipeline on a local shuffled version of the genome...

Visualizing conserved gene location across microbe genomes

Science.gov (United States)

Shaw, Chris D.

2009-01-01

This paper introduces an analysis-based zoomable visualization technique for displaying the location of genes across many related species of microbes. The purpose of this visualizatiuon is to enable a biologist to examine the layout of genes in the organism of interest with respect to the gene organization of related organisms. During the genomic annotation process, the ability to observe gene organization in common with previously annotated genomes can help a biologist better confirm the structure and function of newly analyzed microbe DNA sequences. We have developed a visualization and analysis tool that enables the biologist to observe and examine gene organization among genomes, in the context of the primary sequence of interest. This paper describes the visualization and analysis steps, and presents a case study using a number of Rickettsia genomes.

The DNA-encoded nucleosome organization of a eukaryotic genome.

Science.gov (United States)

Kaplan, Noam; Moore, Irene K; Fondufe-Mittendorf, Yvonne; Gossett, Andrea J; Tillo, Desiree; Field, Yair; LeProust, Emily M; Hughes, Timothy R; Lieb, Jason D; Widom, Jonathan; Segal, Eran

2009-03-19

Nucleosome organization is critical for gene regulation. In living cells this organization is determined by multiple factors, including the action of chromatin remodellers, competition with site-specific DNA-binding proteins, and the DNA sequence preferences of the nucleosomes themselves. However, it has been difficult to estimate the relative importance of each of these mechanisms in vivo, because in vivo nucleosome maps reflect the combined action of all influencing factors. Here we determine the importance of nucleosome DNA sequence preferences experimentally by measuring the genome-wide occupancy of nucleosomes assembled on purified yeast genomic DNA. The resulting map, in which nucleosome occupancy is governed only by the intrinsic sequence preferences of nucleosomes, is similar to in vivo nucleosome maps generated in three different growth conditions. In vitro, nucleosome depletion is evident at many transcription factor binding sites and around gene start and end sites, indicating that nucleosome depletion at these sites in vivo is partly encoded in the genome. We confirm these results with a micrococcal nuclease-independent experiment that measures the relative affinity of nucleosomes for approximately 40,000 double-stranded 150-base-pair oligonucleotides. Using our in vitro data, we devise a computational model of nucleosome sequence preferences that is significantly correlated with in vivo nucleosome occupancy in Caenorhabditis elegans. Our results indicate that the intrinsic DNA sequence preferences of nucleosomes have a central role in determining the organization of nucleosomes in vivo.

Hierarchical role for transcription factors and chromatin structure in genome organization along adipogenesis

DEFF Research Database (Denmark)

Sarusi Portuguez, Avital; Schwartz, Michal; Siersbaek, Rasmus

2017-01-01

The three dimensional folding of mammalian genomes is cell type specific and difficult to alter suggesting that it is an important component of gene regulation. However, given the multitude of chromatin-associating factors, the mechanisms driving the colocalization of active chromosomal domains...... by PPARγ and Lpin1, undergoes orchestrated reorganization during adipogenesis. Coupling the dynamics of genome architecture with multiple chromatin datasets indicated that among all the transcription factors (TFs) tested, RXR is central to genome reorganization at the beginning of adipogenesis...

Structural variation in two human genomes mapped at single-nucleotide resolution by whole genome de novo assembly

DEFF Research Database (Denmark)

Li, Yingrui; Zheng, Hancheng; Luo, Ruibang

2011-01-01

Here we use whole-genome de novo assembly of second-generation sequencing reads to map structural variation (SV) in an Asian genome and an African genome. Our approach identifies small- and intermediate-size homozygous variants (1-50 kb) including insertions, deletions, inversions and their precise...

From structure prediction to genomic screens for novel non-coding RNAs.

Science.gov (United States)

Gorodkin, Jan; Hofacker, Ivo L

2011-08-01

Non-coding RNAs (ncRNAs) are receiving more and more attention not only as an abundant class of genes, but also as regulatory structural elements (some located in mRNAs). A key feature of RNA function is its structure. Computational methods were developed early for folding and prediction of RNA structure with the aim of assisting in functional analysis. With the discovery of more and more ncRNAs, it has become clear that a large fraction of these are highly structured. Interestingly, a large part of the structure is comprised of regular Watson-Crick and GU wobble base pairs. This and the increased amount of available genomes have made it possible to employ structure-based methods for genomic screens. The field has moved from folding prediction of single sequences to computational screens for ncRNAs in genomic sequence using the RNA structure as the main characteristic feature. Whereas early methods focused on energy-directed folding of single sequences, comparative analysis based on structure preserving changes of base pairs has been efficient in improving accuracy, and today this constitutes a key component in genomic screens. Here, we cover the basic principles of RNA folding and touch upon some of the concepts in current methods that have been applied in genomic screens for de novo RNA structures in searches for novel ncRNA genes and regulatory RNA structure on mRNAs. We discuss the strengths and weaknesses of the different strategies and how they can complement each other.

Target Selection and Deselection at the Berkeley StructuralGenomics Center

Energy Technology Data Exchange (ETDEWEB)

Chandonia, John-Marc; Kim, Sung-Hou; Brenner, Steven E.

2005-03-22

At the Berkeley Structural Genomics Center (BSGC), our goalis to obtain a near-complete structural complement of proteins in theminimal organisms Mycoplasma genitalium and M. pneumoniae, two closelyrelated pathogens. Current targets for structure determination have beenselected in six major stages, starting with those predicted to be mosttractable to high throughput study and likely to yield new structuralinformation. We report on the process used to select these proteins, aswell as our target deselection procedure. Target deselection reducesexperimental effort by eliminating targets similar to those recentlysolved by the structural biology community or other centers. We measurethe impact of the 69 structures solved at the BSGC as of July 2004 onstructure prediction coverage of the M. pneumoniae and M. genitaliumproteomes. The number of Mycoplasma proteins for which thefold couldfirst be reliably assigned based on structures solved at the BSGC (24 M.pneumoniae and 21 M. genitalium) is approximately 25 percent of the totalresulting from work at all structural genomics centers and the worldwidestructural biology community (94 M. pneumoniae and 86M. genitalium)during the same period. As the number of structures contributed by theBSGC during that period is less than 1 percent of the total worldwideoutput, the benefits of a focused target selection strategy are apparent.If the structures of all current targets were solved, the percentage ofM. pneumoniae proteins for which folds could be reliably assigned wouldincrease from approximately 57 percent (391 of 687) at present to around80 percent (550 of 687), and the percentage of the proteome that could beaccurately modeled would increase from around 37 percent (254 of 687) toabout 64 percent (438 of 687). In M. genitalium, the percentage of theproteome that could be structurally annotated based on structures of ourremaining targets would rise from 72 percent (348 of 486) to around 76percent (371 of 486), with the

Functional RNA structures throughout the Hepatitis C Virus genome.

Science.gov (United States)

Adams, Rebecca L; Pirakitikulr, Nathan; Pyle, Anna Marie

2017-06-01

The single-stranded Hepatitis C Virus (HCV) genome adopts a set of elaborate RNA structures that are involved in every stage of the viral lifecycle. Recent advances in chemical probing, sequencing, and structural biology have facilitated analysis of RNA folding on a genome-wide scale, revealing novel structures and networks of interactions. These studies have underscored the active role played by RNA in every function of HCV and they open the door to new types of RNA-targeted therapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

The genomic organization of four b-1,4-endoglucanase genes in plant-parasitic cyst nematodes and its evolutionary implications.

NARCIS (Netherlands)

Yan, Y.; Smant, G.; Stokkermans, J.P.W.G.; Qin Ling,; Baum, T.J.; Schots, A.; Davis, E.L.

1998-01-01

The genomic organization of genes encoding -1,4-endoglucanases (cellulases) from the plant-parasitic cyst nematodes Heterodera glycines and Globodera rostochiensis (HG-eng1, Hg-eng2, GR-eng1, and GR-eng2) was investigated. HG-eng1 and GR-eng1 both contained eight introns and structural domains of

Genome3D: a UK collaborative project to annotate genomic sequences with predicted 3D structures based on SCOP and CATH domains.

Science.gov (United States)

Lewis, Tony E; Sillitoe, Ian; Andreeva, Antonina; Blundell, Tom L; Buchan, Daniel W A; Chothia, Cyrus; Cuff, Alison; Dana, Jose M; Filippis, Ioannis; Gough, Julian; Hunter, Sarah; Jones, David T; Kelley, Lawrence A; Kleywegt, Gerard J; Minneci, Federico; Mitchell, Alex; Murzin, Alexey G; Ochoa-Montaño, Bernardo; Rackham, Owen J L; Smith, James; Sternberg, Michael J E; Velankar, Sameer; Yeats, Corin; Orengo, Christine

2013-01-01

Genome3D, available at http://www.genome3d.eu, is a new collaborative project that integrates UK-based structural resources to provide a unique perspective on sequence-structure-function relationships. Leading structure prediction resources (DomSerf, FUGUE, Gene3D, pDomTHREADER, Phyre and SUPERFAMILY) provide annotations for UniProt sequences to indicate the locations of structural domains (structural annotations) and their 3D structures (structural models). Structural annotations and 3D model predictions are currently available for three model genomes (Homo sapiens, E. coli and baker's yeast), and the project will extend to other genomes in the near future. As these resources exploit different strategies for predicting structures, the main aim of Genome3D is to enable comparisons between all the resources so that biologists can see where predictions agree and are therefore more trusted. Furthermore, as these methods differ in whether they build their predictions using CATH or SCOP, Genome3D also contains the first official mapping between these two databases. This has identified pairs of similar superfamilies from the two resources at various degrees of consensus (532 bronze pairs, 527 silver pairs and 370 gold pairs).

Statistical properties of thermodynamically predicted RNA secondary structures in viral genomes

Science.gov (United States)

Spanò, M.; Lillo, F.; Miccichè, S.; Mantegna, R. N.

2008-10-01

By performing a comprehensive study on 1832 segments of 1212 complete genomes of viruses, we show that in viral genomes the hairpin structures of thermodynamically predicted RNA secondary structures are more abundant than expected under a simple random null hypothesis. The detected hairpin structures of RNA secondary structures are present both in coding and in noncoding regions for the four groups of viruses categorized as dsDNA, dsRNA, ssDNA and ssRNA. For all groups, hairpin structures of RNA secondary structures are detected more frequently than expected for a random null hypothesis in noncoding rather than in coding regions. However, potential RNA secondary structures are also present in coding regions of dsDNA group. In fact, we detect evolutionary conserved RNA secondary structures in conserved coding and noncoding regions of a large set of complete genomes of dsDNA herpesviruses.

Genomic organization of the rat alpha 2u-globulin gene cluster.

Science.gov (United States)

McFadyen, D A; Addison, W; Locke, J

1999-05-01

The alpha 2u-globulin are a group of similar proteins, belonging to the lipocalin superfamily of proteins, that are synthesized in a subset of secretory tissues in rats. The many alpha 2u-globulin isoforms are encoded by a multigene family that exhibits extensive homology. Despite a high degree of sequence identity, individual family members show diverse expression patterns involving complex hormonal, tissue-specific, and developmental regulation. Analysis suggests that there are approximately 20 alpha 2u-globulin genes in the rat genome. We have used fluorescence in situ hybridization (FISH) to show that the alpha 2u-globulin genes are clustered at a single site on rat Chromosome (Chr) 5 (5q22-24). Southern blots of rat genomic DNA separated by pulsed field gel electrophoresis indicated that the alpha 2u-globulin genes are contained on two NruI fragments with a total size of 880 kbp. Analysis of three P1 clones containing alpha 2u-globulin genes indicated that the alpha 2u-globulin genes are tandemly arranged in a head-to-tail fashion. The organization of the alpha 2u-globulin genes in the rat as a tandem array of single genes differs from the homologous major urinary protein genes in the mouse, which are organized as tandem arrays of divergently oriented gene pairs. The structure of these gene clusters may have consequences for the proposed function, as a pheromone transporter, for the protein products encoded by these genes.

From structure prediction to genomic screens for novel non-coding RNAs.

Directory of Open Access Journals (Sweden)

Jan Gorodkin

2011-08-01

Full Text Available Non-coding RNAs (ncRNAs are receiving more and more attention not only as an abundant class of genes, but also as regulatory structural elements (some located in mRNAs. A key feature of RNA function is its structure. Computational methods were developed early for folding and prediction of RNA structure with the aim of assisting in functional analysis. With the discovery of more and more ncRNAs, it has become clear that a large fraction of these are highly structured. Interestingly, a large part of the structure is comprised of regular Watson-Crick and GU wobble base pairs. This and the increased amount of available genomes have made it possible to employ structure-based methods for genomic screens. The field has moved from folding prediction of single sequences to computational screens for ncRNAs in genomic sequence using the RNA structure as the main characteristic feature. Whereas early methods focused on energy-directed folding of single sequences, comparative analysis based on structure preserving changes of base pairs has been efficient in improving accuracy, and today this constitutes a key component in genomic screens. Here, we cover the basic principles of RNA folding and touch upon some of the concepts in current methods that have been applied in genomic screens for de novo RNA structures in searches for novel ncRNA genes and regulatory RNA structure on mRNAs. We discuss the strengths and weaknesses of the different strategies and how they can complement each other.

Approaching the sequential and three-dimensional organization of Archaea, Bacteria and Eukarya genomes. Dynamic Organization of Nuclear Function

NARCIS (Netherlands)

T.A. Knoch (Tobias); M. Göker (Markus); R. Lohner (Rudolf); J. Langowski (Jörg)

2002-01-01

textabstractThe largely unresolved sequential organization, i.e. the relations within DNA sequences, and its connection to the three-dimensional organization of genomes was investigated by correlation analyses of completely sequenced chromosomes from Viroids, Archaea, Bacteria, Arabidopsis

3D modeling of genome macroorganization on the basis of its structural changes after action of radiation

International Nuclear Information System (INIS)

Aleksandrov, I.D.; Aleksandrova, M.V.; Zaikin, N.S.; Koren'kov, V.V.; Pervushova, O.V.; Stepanenko, V.A.

2006-01-01

At present, after 120 years of the theoretical and experimental works, the issue of the genome macroarchitecture as the highest level of interphase chromosome organization in somatic cell nuclei remains still unresolved. The problem of the spatial arrangement of interphase chromosomes in haploid germ cells has never even been studied. A 3D simulation of packaging of the entire second chromosome in Drosophila mature sperms has been performed by using mathematical approaches and visualization methods to present macromolecular structure data. As genetic markers for simulation, frequency and location of the second inversion breakpoints for 72 structural υg mutants induced by ionizing radiation were used supposing that both ends of each inversion are topologically brought together forming loop of appropriate size. For the account of a degree of spatial affinity and visualization of chromosomal loops modern 3D-modeling methods with application of splines, libraries OpenGL, language Delphi, program Gmax were used. According to the model proposed, the entire second chromosome within mature sperm nuclei seems to be packaged in the form of a megarosette-loop structure which may be a basic principle of organization of the genome macro-architecture in animal haploid germ cells

Human Ro60 (SSA2) genomic organization and sequence alterations, examined in cutaneous lupus erythematosus.

Science.gov (United States)

Millard, T P; Ashton, G H S; Kondeatis, E; Vaughan, R W; Hughes, G R V; Khamashta, M A; Hawk, J L M; McGregor, J M; McGrath, J A

2002-02-01

The Ro 60 kDa protein (Ro60 or SSA2) is the major component of the Ro ribonucleoprotein (Ro RNP) complex, to which an immune response is a specific feature of several autoimmune diseases. The genomic organization and any sequence variation within the DNA encoding Ro60 are unknown. To characterize the Ro60 gene structure and to assess whether any sequence alterations might be associated with serum anti-Ro antibody in subacute cutaneous lupus erythematosus (SCLE), thus potentially providing new insight into disease pathogenesis. The cDNA sequence for Ro60 was obtained from the NCBI database and used for a BLAST search for a clone containing the entire genomic sequence. The intron-exon borders were confirmed by designing intronic primer pairs to flank each exon, which were then used to amplify genomic DNA for automated sequencing from 36 caucasian patients with SCLE (anti-Ro positive) and 49 with discoid LE (DLE, anti-Ro negative), in addition to 36 healthy caucasian controls. Heteroduplex analysis of polymerase chain reaction (PCR) products from patients and controls spanning all Ro60 exons (1-8) revealed a common bandshift in the PCR products spanning exon 7. Sequencing of the corresponding PCR products demonstrated an A > G substitution at nucleotide position 1318-7, within the consensus acceptor splice site of exon 7 (GenBank XM001901). The allele frequencies were major allele A (0.71) and minor allele G (0.29) in 72 control chromosomes, with no significant differences found between SCLE patients, DLE patients and controls. The genomic organization of the DNA encoding the Ro60 protein is described, including a common polymorphism within the consensus acceptor splice site of exon 7. Our delineation of a strategy for the genomic amplification of Ro60 forms a basis for further examination of the pathological functions of the Ro RNP in autoimmune disease.

DNA Extraction Protocols for Whole-Genome Sequencing in Marine Organisms.

Science.gov (United States)

Panova, Marina; Aronsson, Henrik; Cameron, R Andrew; Dahl, Peter; Godhe, Anna; Lind, Ulrika; Ortega-Martinez, Olga; Pereyra, Ricardo; Tesson, Sylvie V M; Wrange, Anna-Lisa; Blomberg, Anders; Johannesson, Kerstin

2016-01-01

The marine environment harbors a large proportion of the total biodiversity on this planet, including the majority of the earths' different phyla and classes. Studying the genomes of marine organisms can bring interesting insights into genome evolution. Today, almost all marine organismal groups are understudied with respect to their genomes. One potential reason is that extraction of high-quality DNA in sufficient amounts is challenging for many marine species. This is due to high polysaccharide content, polyphenols and other secondary metabolites that will inhibit downstream DNA library preparations. Consequently, protocols developed for vertebrates and plants do not always perform well for invertebrates and algae. In addition, many marine species have large population sizes and, as a consequence, highly variable genomes. Thus, to facilitate the sequence read assembly process during genome sequencing, it is desirable to obtain enough DNA from a single individual, which is a challenge in many species of invertebrates and algae. Here, we present DNA extraction protocols for seven marine species (four invertebrates, two algae, and a marine yeast), optimized to provide sufficient DNA quality and yield for de novo genome sequencing projects.

Coordination of genomic structure and transcription by the main bacterial nucleoid-associated protein HU

Science.gov (United States)

Berger, Michael; Farcas, Anca; Geertz, Marcel; Zhelyazkova, Petya; Brix, Klaudia; Travers, Andrew; Muskhelishvili, Georgi

2010-01-01

The histone-like protein HU is a highly abundant DNA architectural protein that is involved in compacting the DNA of the bacterial nucleoid and in regulating the main DNA transactions, including gene transcription. However, the coordination of the genomic structure and function by HU is poorly understood. Here, we address this question by comparing transcript patterns and spatial distributions of RNA polymerase in Escherichia coli wild-type and hupA/B mutant cells. We demonstrate that, in mutant cells, upregulated genes are preferentially clustered in a large chromosomal domain comprising the ribosomal RNA operons organized on both sides of OriC. Furthermore, we show that, in parallel to this transcription asymmetry, mutant cells are also impaired in forming the transcription foci—spatially confined aggregations of RNA polymerase molecules transcribing strong ribosomal RNA operons. Our data thus implicate HU in coordinating the global genomic structure and function by regulating the spatial distribution of RNA polymerase in the nucleoid. PMID:20010798

Implications of structural genomics target selection strategies: Pfam5000, whole genome, and random approaches

Energy Technology Data Exchange (ETDEWEB)

Chandonia, John-Marc; Brenner, Steven E.

2004-07-14

The structural genomics project is an international effort to determine the three-dimensional shapes of all important biological macromolecules, with a primary focus on proteins. Target proteins should be selected according to a strategy which is medically and biologically relevant, of good value, and tractable. As an option to consider, we present the Pfam5000 strategy, which involves selecting the 5000 most important families from the Pfam database as sources for targets. We compare the Pfam5000 strategy to several other proposed strategies that would require similar numbers of targets. These include including complete solution of several small to moderately sized bacterial proteomes, partial coverage of the human proteome, and random selection of approximately 5000 targets from sequenced genomes. We measure the impact that successful implementation of these strategies would have upon structural interpretation of the proteins in Swiss-Prot, TrEMBL, and 131 complete proteomes (including 10 of eukaryotes) from the Proteome Analysis database at EBI. Solving the structures of proteins from the 5000 largest Pfam families would allow accurate fold assignment for approximately 68 percent of all prokaryotic proteins (covering 59 percent of residues) and 61 percent of eukaryotic proteins (40 percent of residues). More fine-grained coverage which would allow accurate modeling of these proteins would require an order of magnitude more targets. The Pfam5000 strategy may be modified in several ways, for example to focus on larger families, bacterial sequences, or eukaryotic sequences; as long as secondary consideration is given to large families within Pfam, coverage results vary only slightly. In contrast, focusing structural genomics on a single tractable genome would have only a limited impact in structural knowledge of other proteomes: a significant fraction (about 30-40 percent of the proteins, and 40-60 percent of the residues) of each proteome is classified in small

Mitochondrial Genome Sequences and Structures Aid in the Resolution of Piroplasmida phylogeny

Science.gov (United States)

Marr, Henry S.; Tarigo, Jaime L.; Cohn, Leah A.; Bird, David M.; Scholl, Elizabeth H.; Levy, Michael G.; Wiegmann, Brian M.; Birkenheuer, Adam J.

2016-01-01

The taxonomy of the order Piroplasmida, which includes a number of clinically and economically relevant organisms, is a hotly debated topic amongst parasitologists. Three genera (Babesia, Theileria, and Cytauxzoon) are recognized based on parasite life cycle characteristics, but molecular phylogenetic analyses of 18S sequences have suggested the presence of five or more distinct Piroplasmida lineages. Despite these important advancements, a few studies have been unable to define the taxonomic relationships of some organisms (e.g. C. felis and T. equi) with respect to other Piroplasmida. Additional evidence from mitochondrial genome sequences and synteny should aid in the inference of Piroplasmida phylogeny and resolution of taxonomic uncertainties. In this study, we have amplified, sequenced, and annotated seven previously uncharacterized mitochondrial genomes (Babesia canis, Babesia vogeli, Babesia rossi, Babesia sp. Coco, Babesia conradae, Babesia microti-like sp., and Cytauxzoon felis) and identified additional ribosomal fragments in ten previously characterized mitochondrial genomes. Phylogenetic analysis of concatenated mitochondrial and 18S sequences as well as cox1 amino acid sequence identified five distinct Piroplasmida groups, each of which possesses a unique mitochondrial genome structure. Specifically, our results confirm the existence of four previously identified clades (B. microti group, Babesia sensu stricto, Theileria equi, and a Babesia sensu latu group that includes B. conradae) while supporting the integration of Theileria and Cytauxzoon species into a single fifth taxon. Although known biological characteristics of Piroplasmida corroborate the proposed phylogeny, more investigation into parasite life cycles is warranted to further understand the evolution of the Piroplasmida. Our results provide an evolutionary framework for comparative biology of these important animal and human pathogens and help focus renewed efforts toward understanding the

Mitochondrial Genome Sequences and Structures Aid in the Resolution of Piroplasmida phylogeny.

Directory of Open Access Journals (Sweden)

Megan E Schreeg

Full Text Available The taxonomy of the order Piroplasmida, which includes a number of clinically and economically relevant organisms, is a hotly debated topic amongst parasitologists. Three genera (Babesia, Theileria, and Cytauxzoon are recognized based on parasite life cycle characteristics, but molecular phylogenetic analyses of 18S sequences have suggested the presence of five or more distinct Piroplasmida lineages. Despite these important advancements, a few studies have been unable to define the taxonomic relationships of some organisms (e.g. C. felis and T. equi with respect to other Piroplasmida. Additional evidence from mitochondrial genome sequences and synteny should aid in the inference of Piroplasmida phylogeny and resolution of taxonomic uncertainties. In this study, we have amplified, sequenced, and annotated seven previously uncharacterized mitochondrial genomes (Babesia canis, Babesia vogeli, Babesia rossi, Babesia sp. Coco, Babesia conradae, Babesia microti-like sp., and Cytauxzoon felis and identified additional ribosomal fragments in ten previously characterized mitochondrial genomes. Phylogenetic analysis of concatenated mitochondrial and 18S sequences as well as cox1 amino acid sequence identified five distinct Piroplasmida groups, each of which possesses a unique mitochondrial genome structure. Specifically, our results confirm the existence of four previously identified clades (B. microti group, Babesia sensu stricto, Theileria equi, and a Babesia sensu latu group that includes B. conradae while supporting the integration of Theileria and Cytauxzoon species into a single fifth taxon. Although known biological characteristics of Piroplasmida corroborate the proposed phylogeny, more investigation into parasite life cycles is warranted to further understand the evolution of the Piroplasmida. Our results provide an evolutionary framework for comparative biology of these important animal and human pathogens and help focus renewed efforts toward

A New Approach to Dissect Nuclear Organization: TALE-Mediated Genome Visualization (TGV).

Science.gov (United States)

Miyanari, Yusuke

2016-01-01

Spatiotemporal organization of chromatin within the nucleus has so far remained elusive. Live visualization of nuclear remodeling could be a promising approach to understand its functional relevance in genome functions and mechanisms regulating genome architecture. Recent technological advances in live imaging of chromosomes begun to explore the biological roles of the movement of the chromatin within the nucleus. Here I describe a new technique, called TALE-mediated genome visualization (TGV), which allows us to visualize endogenous repetitive sequence including centromeric, pericentromeric, and telomeric repeats in living cells.

Microbial genome analysis: the COG approach.

Science.gov (United States)

Galperin, Michael Y; Kristensen, David M; Makarova, Kira S; Wolf, Yuri I; Koonin, Eugene V

2017-09-14

For the past 20 years, the Clusters of Orthologous Genes (COG) database had been a popular tool for microbial genome annotation and comparative genomics. Initially created for the purpose of evolutionary classification of protein families, the COG have been used, apart from straightforward functional annotation of sequenced genomes, for such tasks as (i) unification of genome annotation in groups of related organisms; (ii) identification of missing and/or undetected genes in complete microbial genomes; (iii) analysis of genomic neighborhoods, in many cases allowing prediction of novel functional systems; (iv) analysis of metabolic pathways and prediction of alternative forms of enzymes; (v) comparison of organisms by COG functional categories; and (vi) prioritization of targets for structural and functional characterization. Here we review the principles of the COG approach and discuss its key advantages and drawbacks in microbial genome analysis. Published by Oxford University Press 2017. This work is written by US Government employees and is in the public domain in the US.

Genomic structure and evolution of the mating type locus in the green seaweed Ulva partita.

Science.gov (United States)

Yamazaki, Tomokazu; Ichihara, Kensuke; Suzuki, Ryogo; Oshima, Kenshiro; Miyamura, Shinichi; Kuwano, Kazuyoshi; Toyoda, Atsushi; Suzuki, Yutaka; Sugano, Sumio; Hattori, Masahira; Kawano, Shigeyuki

2017-09-15

The evolution of sex chromosomes and mating loci in organisms with UV systems of sex/mating type determination in haploid phases via genes on UV chromosomes is not well understood. We report the structure of the mating type (MT) locus and its evolutionary history in the green seaweed Ulva partita, which is a multicellular organism with an isomorphic haploid-diploid life cycle and mating type determination in the haploid phase. Comprehensive comparison of a total of 12.0 and 16.6 Gb of genomic next-generation sequencing data for mt - and mt + strains identified highly rearranged MT loci of 1.0 and 1.5 Mb in size and containing 46 and 67 genes, respectively, including 23 gametologs. Molecular evolutionary analyses suggested that the MT loci diverged over a prolonged period in the individual mating types after their establishment in an ancestor. A gene encoding an RWP-RK domain-containing protein was found in the mt - MT locus but was not an ortholog of the chlorophycean mating type determination gene MID. Taken together, our results suggest that the genomic structure and its evolutionary history in the U. partita MT locus are similar to those on other UV chromosomes and that the MT locus genes are quite different from those of Chlorophyceae.

Integrating the genomic architecture of human nucleolar organizer regions with the biophysical properties of nucleoli.

Science.gov (United States)

Mangan, Hazel; Gailín, Michael Ó; McStay, Brian

2017-12-01

Nucleoli are the sites of ribosome biogenesis and the largest membraneless subnuclear structures. They are intimately linked with growth and proliferation control and function as sensors of cellular stress. Nucleoli form around arrays of ribosomal gene (rDNA) repeats also called nucleolar organizer regions (NORs). In humans, NORs are located on the short arms of all five human acrocentric chromosomes. Multiple NORs contribute to the formation of large heterochromatin-surrounded nucleoli observed in most human cells. Here we will review recent findings about their genomic architecture. The dynamic nature of nucleoli began to be appreciated with the advent of photodynamic experiments using fluorescent protein fusions. We review more recent data on nucleoli in Xenopus germinal vesicles (GVs) which has revealed a liquid droplet-like behavior that facilitates nucleolar fusion. Further analysis in both XenopusGVs and Drosophila embryos indicates that the internal organization of nucleoli is generated by a combination of liquid-liquid phase separation and active processes involving rDNA. We will attempt to integrate these recent findings with the genomic architecture of human NORs to advance our understanding of how nucleoli form and respond to stress in human cells. © 2017 Federation of European Biochemical Societies.

The Human Genome Initiative of the Department of Energy

Science.gov (United States)

1988-01-01

The structural characterization of genes and elucidation of their encoded functions have become a cornerstone of modern health research, biology and biotechnology. A genome program is an organized effort to locate and identify the functions of all the genes of an organism. Beginning with the DOE-sponsored, 1986 human genome workshop at Santa Fe, the value of broadly organized efforts supporting total genome characterization became a subject of intensive study. There is now national recognition that benefits will rapidly accrue from an effective scientific infrastructure for total genome research. In the US genome research is now receiving dedicated funds. Several other nations are implementing genome programs. Supportive infrastructure is being improved through both national and international cooperation. The Human Genome Initiative of the Department of Energy (DOE) is a focused program of Resource and Technology Development, with objectives of speeding and bringing economies to the national human genome effort. This report relates the origins and progress of the Initiative.

Three-dimensional Structure of a Viral Genome-delivery Portal Vertex

Energy Technology Data Exchange (ETDEWEB)

A Olia; P Prevelige Jr.; J Johnson; G Cingolani

2011-12-31

DNA viruses such as bacteriophages and herpesviruses deliver their genome into and out of the capsid through large proteinaceous assemblies, known as portal proteins. Here, we report two snapshots of the dodecameric portal protein of bacteriophage P22. The 3.25-{angstrom}-resolution structure of the portal-protein core bound to 12 copies of gene product 4 (gp4) reveals a {approx}1.1-MDa assembly formed by 24 proteins. Unexpectedly, a lower-resolution structure of the full-length portal protein unveils the unique topology of the C-terminal domain, which forms a {approx}200-{angstrom}-long {alpha}-helical barrel. This domain inserts deeply into the virion and is highly conserved in the Podoviridae family. We propose that the barrel domain facilitates genome spooling onto the interior surface of the capsid during genome packaging and, in analogy to a rifle barrel, increases the accuracy of genome ejection into the host cell.

The draft genome of a termite illuminates alternative social organization

Science.gov (United States)

Termites have substantial economic and ecological impact worldwide. They are also the oldest organisms living in complex societies, having evolved a caste system independent of that of eusocial Hymenoptera (ants, bees and wasps). Here we provide the first genome sequence for a termite, Zootermopsis ...

Genome-wide comparative analysis of ABC systems in the Bdellovibrio-and-like organisms.

Science.gov (United States)

Li, Nan; Chen, Huan; Williams, Henry N

2015-05-10

Bdellovibrio-and-like organisms (BALOs) are gram-negative, predatory bacteria with wide variations in genome sizes and GC content and ecological habitats. The ATP-binding cassette (ABC) systems have been identified in several prokaryotes, fungi and plants and have a role in transport of materials in and out of cells and in cellular processes. However, knowledge of the ABC systems of BALOs remains obscure. A total of 269 putative ABC proteins were identified in BALOs. The genes encoding these ABC systems occupy nearly 1.3% of the gene content in freshwater Bdellovibrio strains and about 0.7% in their saltwater counterparts. The proteins found belong to 25 ABC system families based on their structural characteristics and functions. Among these, 16 families function as importers, 6 as exporters and 3 are involved in various cellular processes. Eight of these 25 ABC system families were deduced to be the core set of ABC systems conserved in all BALOs. All Bacteriovorax strains have 28 or less ABC systems. On the contrary, the freshwater Bdellovibrio strains have more ABC systems, typically around 51. In the genome of Bdellovibrio exovorus JSS (CP003537.1), 53 putative ABC systems were detected, representing the highest number among all the BALO genomes examined in this study. Unexpected high numbers of ABC systems involved in cellular processes were found in all BALOs. Phylogenetic analysis suggests that the majority of ABC proteins can be assigned into many separate families with high bootstrap supports (>50%). In this study, a general framework of sequence-structure-function connections for the ABC systems in BALOs was revealed providing novel insights for future investigations. Copyright © 2015 Elsevier B.V. All rights reserved.

Fine-structured multi-scaling long-range correlations in completely sequenced genomes - features, origin and classification.

NARCIS (Netherlands)

T.A. Knoch (Tobias); M. Göcker; R. Lohner (Rudolf); A. Abuseiris (Anis); F.G. Grosveld (Frank)

2009-01-01

textabstractThe sequential organization of genomes, i.e. the relations between distant base pairs and regions within sequences, and its connection to the three-dimensional organization of genomes is still a largely unresolved problem. Long-range power-law correlations were found using correlation

Managing mechanistic and organic structure in health care organizations.

Science.gov (United States)

Olden, Peter C

2012-01-01

Managers at all levels in a health care organization must organize work to achieve the organization's mission and goals. This requires managers to decide the organization structure, which involves dividing the work among jobs and departments and then coordinating them all toward the common purpose. Organization structure, which is reflected in an organization chart, may range on a continuum from very mechanistic to very organic. Managers must decide how mechanistic versus how organic to make the entire organization and each of its departments. To do this, managers should carefully consider 5 factors for the organization and for each individual department: external environment, goals, work production, size, and culture. Some factors may push toward more mechanistic structure, whereas others may push in the opposite direction toward more organic structure. Practical advice can help managers at all levels design appropriate structure for their departments and organization.

New families of human regulatory RNA structures identified by comparative analysis of vertebrate genomes

DEFF Research Database (Denmark)

Parker, Brian John; Moltke, Ida; Roth, Adam

2011-01-01

a comparative method, EvoFam, for genome-wide identification of families of regulatory RNA structures, based on primary sequence and secondary structure similarity. We apply EvoFam to a 41-way genomic vertebrate alignment. Genome-wide, we identify 220 human, high-confidence families outside protein...

Chloroplast genomes of Arabidopsis halleri ssp. gemmifera and Arabidopsis lyrata ssp. petraea: Structures and comparative analysis.

Science.gov (United States)

Asaf, Sajjad; Khan, Abdul Latif; Khan, Muhammad Aaqil; Waqas, Muhammad; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

2017-08-08

We investigated the complete chloroplast (cp) genomes of non-model Arabidopsis halleri ssp. gemmifera and Arabidopsis lyrata ssp. petraea using Illumina paired-end sequencing to understand their genetic organization and structure. Detailed bioinformatics analysis revealed genome sizes of both subspecies ranging between 154.4~154.5 kbp, with a large single-copy region (84,197~84,158 bp), a small single-copy region (17,738~17,813 bp) and pair of inverted repeats (IRa/IRb; 26,264~26,259 bp). Both cp genomes encode 130 genes, including 85 protein-coding genes, eight ribosomal RNA genes and 37 transfer RNA genes. Whole cp genome comparison of A. halleri ssp. gemmifera and A. lyrata ssp. petraea, along with ten other Arabidopsis species, showed an overall high degree of sequence similarity, with divergence among some intergenic spacers. The location and distribution of repeat sequences were determined, and sequence divergences of shared genes were calculated among related species. Comparative phylogenetic analysis of the entire genomic data set and 70 shared genes between both cp genomes confirmed the previous phylogeny and generated phylogenetic trees with the same topologies. The sister species of A. halleri ssp. gemmifera is A. umezawana, whereas the closest relative of A. lyrata spp. petraea is A. arenicola.

Sequencing of a Cultivated Diploid Cotton Genome-Gossypium arboreum

Institute of Scientific and Technical Information of China (English)

WILKINS; Thea; A

2008-01-01

Sequencing the genomes of crop species and model systems contributes significantly to our understanding of the organization,structure and function of plant genomes.In a `white paper' published in 2007,the cotton community set forth a strategic plan for sequencing the AD genome of cultivated upland cotton that initially targets less complex diploid genomes.This strategy banks on the high degree

Biology, genome organization and evolution of parvoviruses in marine shrimp

Science.gov (United States)

A number of parvoviruses are now know to infect marine shrimp, and these viruses alone or in combination with other viruses have the potential to cause major losses in shrimp aquaculture globally. This review provides a comprehensive overview of the biology, genome organization, gene expression, and...

Chloroplast Genome Sequence of pigeonpea (Cajanus cajan (L. Millspaugh and Cajanus scarabaeoides: Genome organization and Comparison with other legumes

Directory of Open Access Journals (Sweden)

Tanvi Kaila

2016-12-01

Full Text Available Pigeonpea (Cajanus cajan (L. Millspaugh, a diploid (2n = 22 legume crop with a genome size of 852 Mbp, serves as an important source of human dietary protein especially in South East Asian and African regions. In this study, the draft chloroplast genomes of Cajanus cajan and Cajanus scarabaeoides were sequenced. Cajanus scarabaeoides is an important species of the Cajanus gene pool and has also been used for developing promising CMS system by different groups. A male sterile genotype harbouring the Cajanus scarabaeoides cytoplasm was used for sequencing the plastid genome. The cp genome of Cajanus cajan is 152,242bp long, having a quadripartite structure with LSC of 83,455 bp and SSC of 17,871 bp separated by IRs of 25,398 bp. Similarly, the cp genome of Cajanus scarabaeoides is 152,201bp long, having a quadripartite structure in which IRs of 25,402 bp length separates 83,423 bp of LSC and 17,854 bp of SSC. The pigeonpea cp genome contains 116 unique genes, including 30 tRNA, 4 rRNA, 78 predicted protein coding genes and 5 pseudogenes. A 50kb inversion was observed in the LSC region of pigeonpea cp genome, consistent with other legumes. Comparison of cp genome with other legumes revealed the contraction of IR boundaries due to the absence of rps19 gene in the IR region. Chloroplast SSRs were mined and a total of 280 and 292 cpSSRs were identified in Cajanus scarabaeoides and Cajanus cajan respectively. RNA editing was observed at 37 sites in both Cajanus scarabaeoides and Cajanus cajan, with maximum occurrence in the ndh genes. The pigeonpea cp genome sequence would be beneficial in providing informative molecular markers which can be utilized for genetic diversity analysis and aid in understanding the plant systematics studies among major grain legumes.

Detection of G-Quadruplex Structures Formed by G-Rich Sequences from Rice Genome and Transcriptome Using Combined Probes.

Science.gov (United States)

Chang, Tianjun; Li, Weiguo; Ding, Zhan; Cheng, Shaofei; Liang, Kun; Liu, Xiangjun; Bing, Tao; Shangguan, Dihua

2017-08-01

Putative G-quadruplex (G4) forming sequences (PQS) are highly prevalent in the genome and transcriptome of various organisms and are considered as potential regulation elements in many biological processes by forming G4 structures. The formation of G4 structures highly depends on the sequences and the environment. In most cases, it is difficult to predict G4 formation by PQS, especially PQS containing G2 tracts. Therefore, the experimental identification of G4 formation is essential in the study of G4-related biological functions. Herein, we report a rapid and simple method for the detection of G4 structures by using a pair of complementary reporters, hemin and BMSP. This method was applied to detect G4 structures formed by PQS (DNA and RNA) searched in the genome and transcriptome of Oryza sativa. Unlike most of the reported G4 probes that only recognize part of G4 structures, the proposed method based on combined probes positively responded to almost all G4 conformations, including parallel, antiparallel, and mixed/hybrid G4, but did not respond to non-G4 sequences. This method shows potential for high-throughput identification of G4 structures in genome and transcriptome. Furthermore, BMSP was observed to drive some PQS to form more stable G4 structures or induce the G4 formation of some PQS that cannot form G4 in normal physiological conditions, which may provide a powerful molecular tool for gene regulation.

A novel component of the mitochondrial genome segregation machinery in trypanosomes

Directory of Open Access Journals (Sweden)

Anneliese Hoffmann

2016-07-01

Full Text Available We recently described a new component (TAC102 of the mitochondrial genome segregation machinery (mtGSM in the protozoan parasite Trypanosoma brucei. T. brucei belongs to a group of organisms that contain a single mitochondrial organelle with a single mitochondrial genome (mt-genome per cell. The mt-genome consists of 5000 minicircles (1 kb and 25 maxicircles (23 kb that are catenated into a large network. After replication of the network its segregation is driven by the separating basal bodies, which are homologous structures to the centrioles organizing the spindle apparatus in many eukaryotes. The structure connecting the basal body to the mt-genome was named the Tripartite Attachment Complex (TAC owing its name to the distribution across three areas in the cell including the two mitochondrial membranes.

The genome and transcriptome of Phalaenopsis yield insights into floral organ development and flowering regulation

Directory of Open Access Journals (Sweden)

Jian-Zhi Huang

2016-05-01

Full Text Available The Phalaenopsis orchid is an important potted flower of high economic value around the world. We report the 3.1 Gb draft genome assembly of an important winter flowering Phalaenopsis ‘KHM190’ cultivar. We generated 89.5 Gb RNA-seq and 113 million sRNA-seq reads to use these data to identify 41,153 protein-coding genes and 188 miRNA families. We also generated a draft genome for Phalaenopsis pulcherrima ‘B8802,’ a summer flowering species, via resequencing. Comparison of genome data between the two Phalaenopsis cultivars allowed the identification of 691,532 single-nucleotide polymorphisms. In this study, we reveal that the key role of PhAGL6b in the regulation of labellum organ development involves alternative splicing in the big lip mutant. Petal or sepal overexpressing PhAGL6b leads to the conversion into a lip-like structure. We also discovered that the gibberellin pathway that regulates the expression of flowering time genes during the reproductive phase change is induced by cool temperature. Our work thus depicted a valuable resource for the flowering control, flower architecture development, and breeding of the Phalaenopsis orchids.

Tree decomposition based fast search of RNA structures including pseudoknots in genomes.

Science.gov (United States)

Song, Yinglei; Liu, Chunmei; Malmberg, Russell; Pan, Fangfang; Cai, Liming

2005-01-01

Searching genomes for RNA secondary structure with computational methods has become an important approach to the annotation of non-coding RNAs. However, due to the lack of efficient algorithms for accurate RNA structure-sequence alignment, computer programs capable of fast and effectively searching genomes for RNA secondary structures have not been available. In this paper, a novel RNA structure profiling model is introduced based on the notion of a conformational graph to specify the consensus structure of an RNA family. Tree decomposition yields a small tree width t for such conformation graphs (e.g., t = 2 for stem loops and only a slight increase for pseudo-knots). Within this modelling framework, the optimal alignment of a sequence to the structure model corresponds to finding a maximum valued isomorphic subgraph and consequently can be accomplished through dynamic programming on the tree decomposition of the conformational graph in time O(k(t)N(2)), where k is a small parameter; and N is the size of the projiled RNA structure. Experiments show that the application of the alignment algorithm to search in genomes yields the same search accuracy as methods based on a Covariance model with a significant reduction in computation time. In particular; very accurate searches of tmRNAs in bacteria genomes and of telomerase RNAs in yeast genomes can be accomplished in days, as opposed to months required by other methods. The tree decomposition based searching tool is free upon request and can be downloaded at our site h t t p ://w.uga.edu/RNA-informatics/software/index.php.

Occupancy of chromatin organizers in the Epstein-Barr virus genome.

Science.gov (United States)

Holdorf, Meghan M; Cooper, Samantha B; Yamamoto, Keith R; Miranda, J J L

2011-06-20

The human CCCTC-binding factor, CTCF, regulates transcription of the double-stranded DNA genomes of herpesviruses. The architectural complex cohesin and RNA Polymerase II also contribute to this organization. We profiled the occupancy of CTCF, cohesin, and RNA Polymerase II on the episomal genome of the Epstein-Barr virus in a cell culture model of latent infection. CTCF colocalizes with cohesin but not RNA Polymerase II. CTCF and cohesin bind specific sequences throughout the genome that are found not just proximal to the regulatory elements of latent genes, but also near lytic genes. In addition to tracking with known transcripts, RNA Polymerase II appears at two unannotated positions, one of which lies within the latent origin of replication. The widespread occupancy profile of each protein reveals binding near or at a myriad of regulatory elements and suggests context-dependent functions. Copyright © 2011 Elsevier Inc. All rights reserved.

[Correlation of codon biases and potential secondary structures with mRNA translation efficiency in unicellular organisms].

Science.gov (United States)

Vladimirov, N V; Likhoshvaĭ, V A; Matushkin, Iu G

2007-01-01

Gene expression is known to correlate with degree of codon bias in many unicellular organisms. However, such correlation is absent in some organisms. Recently we demonstrated that inverted complementary repeats within coding DNA sequence must be considered for proper estimation of translation efficiency, since they may form secondary structures that obstruct ribosome movement. We have developed a program for estimation of potential coding DNA sequence expression in defined unicellular organism using its genome sequence. The program computes elongation efficiency index. Computation is based on estimation of coding DNA sequence elongation efficiency, taking into account three key factors: codon bias, average number of inverted complementary repeats, and free energy of potential stem-loop structures formed by the repeats. The influence of these factors on translation is numerically estimated. An optimal proportion of these factors is computed for each organism individually. Quantitative translational characteristics of 384 unicellular organisms (351 bacteria, 28 archaea, 5 eukaryota) have been computed using their annotated genomes from NCBI GenBank. Five potential evolutionary strategies of translational optimization have been determined among studied organisms. A considerable difference of preferred translational strategies between Bacteria and Archaea has been revealed. Significant correlations between elongation efficiency index and gene expression levels have been shown for two organisms (S. cerevisiae and H. pylori) using available microarray data. The proposed method allows to estimate numerically the coding DNA sequence translation efficiency and to optimize nucleotide composition of heterologous genes in unicellular organisms. http://www.mgs.bionet.nsc.ru/mgs/programs/eei-calculator/.

LEMONS - A Tool for the Identification of Splice Junctions in Transcriptomes of Organisms Lacking Reference Genomes.

Directory of Open Access Journals (Sweden)

Liron Levin

Full Text Available RNA-seq is becoming a preferred tool for genomics studies of model and non-model organisms. However, DNA-based analysis of organisms lacking sequenced genomes cannot rely on RNA-seq data alone to isolate most genes of interest, as DNA codes both exons and introns. With this in mind, we designed a novel tool, LEMONS, that exploits the evolutionary conservation of both exon/intron boundary positions and splice junction recognition signals to produce high throughput splice-junction predictions in the absence of a reference genome. When tested on multiple annotated vertebrate mRNA data, LEMONS accurately identified 87% (average of the splice-junctions. LEMONS was then applied to our updated Mediterranean chameleon transcriptome, which lacks a reference genome, and predicted a total of 90,820 exon-exon junctions. We experimentally verified these splice-junction predictions by amplifying and sequencing twenty randomly selected genes from chameleon DNA templates. Exons and introns were detected in 19 of 20 of the positions predicted by LEMONS. To the best of our knowledge, LEMONS is currently the only experimentally verified tool that can accurately predict splice-junctions in organisms that lack a reference genome.

Multiple independent structural dynamic events in the evolution of snake mitochondrial genomes.

Science.gov (United States)

Qian, Lifu; Wang, Hui; Yan, Jie; Pan, Tao; Jiang, Shanqun; Rao, Dingqi; Zhang, Baowei

2018-05-10

Mitochondrial DNA sequences have long been used in phylogenetic studies. However, little attention has been paid to the changes in gene arrangement patterns in the snake's mitogenome. Here, we analyzed the complete mitogenome sequences and structures of 65 snake species from 14 families and examined their structural patterns, organization and evolution. Our purpose was to further investigate the evolutionary implications and possible rearrangement mechanisms of the mitogenome within snakes. In total, eleven types of mitochondrial gene arrangement patterns were detected (Type I, II, III, III-A, III-B, III-B1, III-C, III-D, III-E, III-F, III-G), with mitochondrial genome rearrangements being a major trend in snakes, especially in Alethinophidia. In snake mitogenomes, the rearrangements mainly involved three processes, gene loss, translocation and duplication. Within Scolecophidia, the O L was lost several times in Typhlopidae and Leptotyphlopidae, but persisted as a plesiomorphy in the Alethinophidia. Duplication of the control region and translocation of the tRNA Leu gene are two visible features in Alethinophidian mitochondrial genomes. Independently and stochastically, the duplication of pseudo-Pro (P*) emerged in seven different lineages of unequal size in three families, indicating that the presence of P* was a polytopic event in the mitogenome. The WANCY tRNA gene cluster and the control regions and their adjacent segments were hotspots for mitogenome rearrangement. Maintenance of duplicate control regions may be the source for snake mitogenome structural diversity.

Structured Matrix Completion with Applications to Genomic Data Integration.

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Cai, Tianxi; Cai, T Tony; Zhang, Anru

2016-01-01

Matrix completion has attracted significant recent attention in many fields including statistics, applied mathematics and electrical engineering. Current literature on matrix completion focuses primarily on independent sampling models under which the individual observed entries are sampled independently. Motivated by applications in genomic data integration, we propose a new framework of structured matrix completion (SMC) to treat structured missingness by design. Specifically, our proposed method aims at efficient matrix recovery when a subset of the rows and columns of an approximately low-rank matrix are observed. We provide theoretical justification for the proposed SMC method and derive lower bound for the estimation errors, which together establish the optimal rate of recovery over certain classes of approximately low-rank matrices. Simulation studies show that the method performs well in finite sample under a variety of configurations. The method is applied to integrate several ovarian cancer genomic studies with different extent of genomic measurements, which enables us to construct more accurate prediction rules for ovarian cancer survival.

Origins of the Human Genome Project

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Cook-Deegan, Robert (Affiliation: Institute of Medicine, National Academy of Sciences)

1993-07-01

The human genome project was borne of technology, grew into a science bureaucracy in the United States and throughout the world, and is now being transformed into a hybrid academic and commercial enterprise. The next phase of the project promises to veer more sharply toward commercial application, harnessing both the technical prowess of molecular biology and the rapidly growing body of knowledge about DNA structure to the pursuit of practical benefits. Faith that the systematic analysis of DNA structure will prove to be a powerful research tool underlies the rationale behind the genome project. The notion that most genetic information is embedded in the sequence of CNA base pairs comprising chromosomes is a central tenet. A rough analogy is to liken an organism's genetic code to computer code. The coal of the genome project, in this parlance, is to identify and catalog 75,000 or more files (genes) in the software that directs construction of a self-modifying and self-replicating system -- a living organism.

Origins of the Human Genome Project

Energy Technology Data Exchange (ETDEWEB)

Cook-Deegan, Robert

1993-07-01

The human genome project was borne of technology, grew into a science bureaucracy in the US and throughout the world, and is now being transformed into a hybrid academic and commercial enterprise. The next phase of the project promises to veer more sharply toward commercial application, harnessing both the technical prowess of molecular biology and the rapidly growing body of knowledge about DNA structure to the pursuit of practical benefits. Faith that the systematic analysis of DNA structure will prove to be a powerful research tool underlies the rationale behind the genome project. The notion that most genetic information is embedded in the sequence of CNA base pairs comprising chromosomes is a central tenet. A rough analogy is to liken an organism's genetic code to computer code. The coal of the genome project, in this parlance, is to identify and catalog 75,000 or more files (genes) in the software that directs construction of a self-modifying and self-replicating system -- a living organism.

Organizational heterogeneity of vertebrate genomes.

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Frenkel, Svetlana; Kirzhner, Valery; Korol, Abraham

2012-01-01

Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS) analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers) in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM) allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

Organizational heterogeneity of vertebrate genomes.

Directory of Open Access Journals (Sweden)

Svetlana Frenkel

Full Text Available Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

The Complete Chloroplast and Mitochondrial Genome Sequences of Boea hygrometrica: Insights into the Evolution of Plant Organellar Genomes

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Wang, Xumin; Deng, Xin; Zhang, Xiaowei; Hu, Songnian; Yu, Jun

2012-01-01

The complete nucleotide sequences of the chloroplast (cp) and mitochondrial (mt) genomes of resurrection plant Boea hygrometrica (Bh, Gesneriaceae) have been determined with the lengths of 153,493 bp and 510,519 bp, respectively. The smaller chloroplast genome contains more genes (147) with a 72% coding sequence, and the larger mitochondrial genome have less genes (65) with a coding faction of 12%. Similar to other seed plants, the Bh cp genome has a typical quadripartite organization with a conserved gene in each region. The Bh mt genome has three recombinant sequence repeats of 222 bp, 843 bp, and 1474 bp in length, which divide the genome into a single master circle (MC) and four isomeric molecules. Compared to other angiosperms, one remarkable feature of the Bh mt genome is the frequent transfer of genetic material from the cp genome during recent Bh evolution. We also analyzed organellar genome evolution in general regarding genome features as well as compositional dynamics of sequence and gene structure/organization, providing clues for the understanding of the evolution of organellar genomes in plants. The cp-derived sequences including tRNAs found in angiosperm mt genomes support the conclusion that frequent gene transfer events may have begun early in the land plant lineage. PMID:22291979

Ribosomal DNA sequence heterogeneity reflects intraspecies phylogenies and predicts genome structure in two contrasting yeast species.

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West, Claire; James, Stephen A; Davey, Robert P; Dicks, Jo; Roberts, Ian N

2014-07-01

The ribosomal RNA encapsulates a wealth of evolutionary information, including genetic variation that can be used to discriminate between organisms at a wide range of taxonomic levels. For example, the prokaryotic 16S rDNA sequence is very widely used both in phylogenetic studies and as a marker in metagenomic surveys and the internal transcribed spacer region, frequently used in plant phylogenetics, is now recognized as a fungal DNA barcode. However, this widespread use does not escape criticism, principally due to issues such as difficulties in classification of paralogous versus orthologous rDNA units and intragenomic variation, both of which may be significant barriers to accurate phylogenetic inference. We recently analyzed data sets from the Saccharomyces Genome Resequencing Project, characterizing rDNA sequence variation within multiple strains of the baker's yeast Saccharomyces cerevisiae and its nearest wild relative Saccharomyces paradoxus in unprecedented detail. Notably, both species possess single locus rDNA systems. Here, we use these new variation datasets to assess whether a more detailed characterization of the rDNA locus can alleviate the second of these phylogenetic issues, sequence heterogeneity, while controlling for the first. We demonstrate that a strong phylogenetic signal exists within both datasets and illustrate how they can be used, with existing methodology, to estimate intraspecies phylogenies of yeast strains consistent with those derived from whole-genome approaches. We also describe the use of partial Single Nucleotide Polymorphisms, a type of sequence variation found only in repetitive genomic regions, in identifying key evolutionary features such as genome hybridization events and show their consistency with whole-genome Structure analyses. We conclude that our approach can transform rDNA sequence heterogeneity from a problem to a useful source of evolutionary information, enabling the estimation of highly accurate phylogenies of

Genomic definition of species. Revision 2

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Crkvenjakov, R.; Drmanac, R.

1993-03-01

A genome is the sum total of the DNA sequences in the cells of an individual organism. The common usage that species possess genomes comes naturally to biochemists, who have shown that all protein and nucleic acid molecules are at the same time species- and individual-specific, with minor individual variations being superimposed on a consensus sequence that is constant for a species. By extension, this property is attributed to the common features of DNA in the chromosomes of members of a given species and is called species genome. Our proposal for the definition of a biological species is as follows: A species comprises a group of actual and potential biological organisms built according to a unique genome program that is recorded, and at least in part expressed, in the structures of their genomic nucleic acid molecule(s), having intragroup sequence differences which can be fully interconverted in the process of organismal reproduction.

A Web-Based Comparative Genomics Tutorial for Investigating Microbial Genomes

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Michael Strong

2009-12-01

Full Text Available As the number of completely sequenced microbial genomes continues to rise at an impressive rate, it is important to prepare students with the skills necessary to investigate microorganisms at the genomic level. As a part of the core curriculum for first-year graduate students in the biological sciences, we have implemented a web-based tutorial to introduce students to the fields of comparative and functional genomics. The tutorial focuses on recent computational methods for identifying functionally linked genes and proteins on a genome-wide scale and was used to introduce students to the Rosetta Stone, Phylogenetic Profile, conserved Gene Neighbor, and Operon computational methods. Students learned to use a number of publicly available web servers and databases to identify functionally linked genes in the Escherichia coli genome, with emphasis on genome organization and operon structure. The overall effectiveness of the tutorial was assessed based on student evaluations and homework assignments. The tutorial is available to other educators at http://www.doe-mbi.ucla.edu/~strong/m253.php.

Structured RNAs in the ENCODE selected regions of the human genome

DEFF Research Database (Denmark)

Washietl, Stefan; Pedersen, Jakob Skou; Korbel, Jan O

2007-01-01

Functional RNA structures play an important role both in the context of noncoding RNA transcripts as well as regulatory elements in mRNAs. Here we present a computational study to detect functional RNA structures within the ENCODE regions of the human genome. Since structural RNAs in general lack...... with the GENCODE annotation points to functional RNAs in all genomic contexts, with a slightly increased density in 3'-UTRs. While we estimate a significant false discovery rate of approximately 50%-70% many of the predictions can be further substantiated by additional criteria: 248 loci are predicted by both RNAz...

The Jujube Genome Provides Insights into Genome Evolution and the Domestication of Sweetness/Acidity Taste in Fruit Trees.

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Huang, Jian; Zhang, Chunmei; Zhao, Xing; Fei, Zhangjun; Wan, KangKang; Zhang, Zhong; Pang, Xiaoming; Yin, Xiao; Bai, Yang; Sun, Xiaoqing; Gao, Lizhi; Li, Ruiqiang; Zhang, Jinbo; Li, Xingang

2016-12-01

Jujube (Ziziphus jujuba Mill.) belongs to the Rhamnaceae family and is a popular fruit tree species with immense economic and nutritional value. Here, we report a draft genome of the dry jujube cultivar 'Junzao' and the genome resequencing of 31 geographically diverse accessions of cultivated and wild jujubes (Ziziphus jujuba var. spinosa). Comparative analysis revealed that the genome of 'Dongzao', a fresh jujube, was ~86.5 Mb larger than that of the 'Junzao', partially due to the recent insertions of transposable elements in the 'Dongzao' genome. We constructed eight proto-chromosomes of the common ancestor of Rhamnaceae and Rosaceae, two sister families in the order Rosales, and elucidated the evolutionary processes that have shaped the genome structures of modern jujubes. Population structure analysis revealed the complex genetic background of jujubes resulting from extensive hybridizations between jujube and its wild relatives. Notably, several key genes that control fruit organic acid metabolism and sugar content were identified in the selective sweep regions. We also identified S-locus genes controlling gametophytic self-incompatibility and investigated haplotype patterns of the S locus in the jujube genomes, which would provide a guideline for parent selection for jujube crossbreeding. This study provides valuable genomic resources for jujube improvement, and offers insights into jujube genome evolution and its population structure and domestication.

Functional genomics for food microbiology: Molecular mechanisms of weak organic acid preservative adaptation in yeast

NARCIS (Netherlands)

Brul, S.; Kallemeijn, W.; Smits, G.

2008-01-01

The recent era of genomics has offered tremendous possibilities to biology. This concise review describes the possibilities of applying (functional) genomics studies to the field of microbial food stability. In doing so, the studies on weak-organic-acid stress response in yeast are discussed by way

High throughput platforms for structural genomics of integral membrane proteins.

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Mancia, Filippo; Love, James

2011-08-01

Structural genomics approaches on integral membrane proteins have been postulated for over a decade, yet specific efforts are lagging years behind their soluble counterparts. Indeed, high throughput methodologies for production and characterization of prokaryotic integral membrane proteins are only now emerging, while large-scale efforts for eukaryotic ones are still in their infancy. Presented here is a review of recent literature on actively ongoing structural genomics of membrane protein initiatives, with a focus on those aimed at implementing interesting techniques aimed at increasing our rate of success for this class of macromolecules. Copyright © 2011 Elsevier Ltd. All rights reserved.

G2S: A web-service for annotating genomic variants on 3D protein structures.

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Wang, Juexin; Sheridan, Robert; Sumer, S Onur; Schultz, Nikolaus; Xu, Dong; Gao, Jianjiong

2018-01-27

Accurately mapping and annotating genomic locations on 3D protein structures is a key step in structure-based analysis of genomic variants detected by recent large-scale sequencing efforts. There are several mapping resources currently available, but none of them provides a web API (Application Programming Interface) that support programmatic access. We present G2S, a real-time web API that provides automated mapping of genomic variants on 3D protein structures. G2S can align genomic locations of variants, protein locations, or protein sequences to protein structures and retrieve the mapped residues from structures. G2S API uses REST-inspired design conception and it can be used by various clients such as web browsers, command terminals, programming languages and other bioinformatics tools for bringing 3D structures into genomic variant analysis. The webserver and source codes are freely available at https://g2s.genomenexus.org. g2s@genomenexus.org. Supplementary data are available at Bioinformatics online. © The Author (2018). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Calculation of 3D genome structures for comparison of chromosome conformation capture experiments with microscopy: An evaluation of single-cell Hi-C protocols.

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Lando, David; Stevens, Tim J; Basu, Srinjan; Laue, Ernest D

2018-01-01

Single-cell chromosome conformation capture approaches are revealing the extent of cell-to-cell variability in the organization and packaging of genomes. These single-cell methods, unlike their multi-cell counterparts, allow straightforward computation of realistic chromosome conformations that may be compared and combined with other, independent, techniques to study 3D structure. Here we discuss how single-cell Hi-C and subsequent 3D genome structure determination allows comparison with data from microscopy. We then carry out a systematic evaluation of recently published single-cell Hi-C datasets to establish a computational approach for the evaluation of single-cell Hi-C protocols. We show that the calculation of genome structures provides a useful tool for assessing the quality of single-cell Hi-C data because it requires a self-consistent network of interactions, relating to the underlying 3D conformation, with few errors, as well as sufficient longer-range cis- and trans-chromosomal contacts.

Insights into the Evolution of a Snake Venom Multi-Gene Family from the Genomic Organization of Echis ocellatus SVMP Genes

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Libia Sanz

2016-07-01

Full Text Available The molecular events underlying the evolution of the Snake Venom Metalloproteinase (SVMP family from an A Disintegrin And Metalloproteinase (ADAM ancestor remain poorly understood. Comparative genomics may provide decisive information to reconstruct the evolutionary history of this multi-locus toxin family. Here, we report the genomic organization of Echis ocellatus genes encoding SVMPs from the PII and PI classes. Comparisons between them and between these genes and the genomic structures of Anolis carolinensis ADAM28 and E. ocellatus PIII-SVMP EOC00089 suggest that insertions and deletions of intronic regions played key roles along the evolutionary pathway that shaped the current diversity within the multi-locus SVMP gene family. In particular, our data suggest that emergence of EOC00028-like PI-SVMP from an ancestral PII(e/d-type SVMP involved splicing site mutations that abolished both the 3′ splice AG acceptor site of intron 12* and the 5′ splice GT donor site of intron 13*, and resulted in the intronization of exon 13* and the consequent destruction of the structural integrity of the PII-SVMP characteristic disintegrin domain.

Organization of plastid genomes in the freshwater red algal order Batrachospermales (Rhodophyta).

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Paiano, Monica Orlandi; Del Cortona, Andrea; Costa, Joana F; Liu, Shao-Lun; Verbruggen, Heroen; De Clerck, Olivier; Necchi, Orlando

2018-02-01

Little is known about genome organization in members of the order Batrachospermales, and the infra-ordinal relationship remains unresolved. Plastid (cp) genomes of seven members of the freshwater red algal order Batrachospermales were sequenced, with the following aims: (i) to describe the characteristics of cp genomes and compare these with other red algal groups; (ii) to infer the phylogenetic relationships among these members to better understand the infra-ordinal classification. Cp genomes of Batrachospermales are large, with several cases of gene loss, they are gene-dense (high gene content for the genome size and short intergenic regions) and have highly conserved gene order. Phylogenetic analyses based on concatenated nucleotide genome data roughly supports the current taxonomic system for the order. Comparative analyses confirm data for members of the class Florideophyceae that cp genomes in Batrachospermales is highly conserved, with little variation in gene composition. However, relevant new features were revealed in our study: genome sizes in members of Batrachospermales are close to the lowest values reported for Florideophyceae; differences in cp genome size within the order are large in comparison with other orders (Ceramiales, Gelidiales, Gracilariales, Hildenbrandiales, and Nemaliales); and members of Batrachospermales have the lowest number of protein-coding genes among the Florideophyceae. In terms of gene loss, apcF, which encodes the allophycocyanin beta subunit, is absent in all sequenced taxa of Batrachospermales. We reinforce that the interordinal relationships between the freshwater orders Batrachospermales and Thoreales within the Nemaliophycidae is not well resolved due to limited taxon sampling. © 2017 Phycological Society of America.

Genome Compositional Organization in Gars Shows More Similarities to Mammals than to Other Ray-Finned Fish.

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Symonová, Radka; Majtánová, Zuzana; Arias-Rodriguez, Lenin; Mořkovský, Libor; Kořínková, Tereza; Cavin, Lionel; Pokorná, Martina Johnson; Doležálková, Marie; Flajšhans, Martin; Normandeau, Eric; Ráb, Petr; Meyer, Axel; Bernatchez, Louis

2017-11-01

Genomic GC content can vary locally, and GC-rich regions are usually associated with increased DNA thermostability in thermophilic prokaryotes and warm-blooded eukaryotes. Among vertebrates, fish and amphibians appeared to possess a distinctly less heterogeneous AT/GC organization in their genomes, whereas cytogenetically detectable GC heterogeneity has so far only been documented in mammals and birds. The subject of our study is the gar, an ancient "living fossil" of a basal ray-finned fish lineage, known from the Cretaceous period. We carried out cytogenomic analysis in two gar genera (Atractosteus and Lepisosteus) uncovering a GC chromosomal pattern uncharacteristic for fish. Bioinformatic analysis of the spotted gar (Lepisosteus oculatus) confirmed a GC compartmentalization on GC profiles of linkage groups. This indicates a rather mammalian mode of compositional organization on gar chromosomes. Gars are thus the only analyzed extant ray-finned fishes with a GC compartmentalized genome. Since gars are cold-blooded anamniotes, our results contradict the generally accepted hypothesis that the phylogenomic onset of GC compartmentalization occurred near the origin of amniotes. Ecophysiological findings of other authors indicate a metabolic similarity of gars with mammals. We hypothesize that gars might have undergone convergent evolution with the tetrapod lineages leading to mammals on both metabolic and genomic levels. Their metabolic adaptations might have left footprints in their compositional genome evolution, as proposed by the metabolic rate hypothesis. The genome organization described here in gars sheds new light on the compositional genome evolution in vertebrates generally and contributes to better understanding of the complexities of the mechanisms involved in this process. © 2016 Wiley Periodicals, Inc.

Population Structure Analysis of Bull Genomes of European and Western Ancestry

DEFF Research Database (Denmark)

Chung, Neo Christopher; Szyda, Joanna; Frąszczak, Magdalena

2017-01-01

Since domestication, population bottlenecks, breed formation, and selective breeding have radically shaped the genealogy and genetics of Bos taurus. In turn, characterization of population structure among diverse bull (males of Bos taurus) genomes enables detailed assessment of genetic resources...... and origins. By analyzing 432 unrelated bull genomes from 13 breeds and 16 countries, we demonstrate genetic diversity and structural complexity among the European/Western cattle population. Importantly, we relaxed a strong assumption of discrete or admixed population, by adapting latent variable models...... harboring largest genetic differentiation suggest positive selection underlying population structure. We carried out gene set analysis using SNP annotations to identify enriched functional categories such as energy-related processes and multiple development stages. Our population structure analysis of bull...

A multivalent adsorption apparatus explains the broad host range of phage phi92: a comprehensive genomic and structural analysis.

Science.gov (United States)

Schwarzer, David; Buettner, Falk F R; Browning, Christopher; Nazarov, Sergey; Rabsch, Wolfgang; Bethe, Andrea; Oberbeck, Astrid; Bowman, Valorie D; Stummeyer, Katharina; Mühlenhoff, Martina; Leiman, Petr G; Gerardy-Schahn, Rita

2012-10-01

Bacteriophage phi92 is a large, lytic myovirus isolated in 1983 from pathogenic Escherichia coli strains that carry a polysialic acid capsule. Here we report the genome organization of phi92, the cryoelectron microscopy reconstruction of its virion, and the reinvestigation of its host specificity. The genome consists of a linear, double-stranded 148,612-bp DNA sequence containing 248 potential open reading frames and 11 putative tRNA genes. Orthologs were found for 130 of the predicted proteins. Most of the virion proteins showed significant sequence similarities to proteins of myoviruses rv5 and PVP-SE1, indicating that phi92 is a new member of the novel genus of rv5-like phages. Reinvestigation of phi92 host specificity showed that the host range is not limited to polysialic acid-encapsulated Escherichia coli but includes most laboratory strains of Escherichia coli and many Salmonella strains. Structure analysis of the phi92 virion demonstrated the presence of four different types of tail fibers and/or tailspikes, which enable the phage to use attachment sites on encapsulated and nonencapsulated bacteria. With this report, we provide the first detailed description of a multivalent, multispecies phage armed with a host cell adsorption apparatus resembling a nanosized Swiss army knife. The genome, structure, and, in particular, the organization of the baseplate of phi92 demonstrate how a bacteriophage can evolve into a multi-pathogen-killing agent.

The Past, Present, and Future of Human Centromere Genomics

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Megan E. Aldrup-MacDonald

2014-01-01

Full Text Available The centromere is the chromosomal locus essential for chromosome inheritance and genome stability. Human centromeres are located at repetitive alpha satellite DNA arrays that compose approximately 5% of the genome. Contiguous alpha satellite DNA sequence is absent from the assembled reference genome, limiting current understanding of centromere organization and function. Here, we review the progress in centromere genomics spanning the discovery of the sequence to its molecular characterization and the work done during the Human Genome Project era to elucidate alpha satellite structure and sequence variation. We discuss exciting recent advances in alpha satellite sequence assembly that have provided important insight into the abundance and complex organization of this sequence on human chromosomes. In light of these new findings, we offer perspectives for future studies of human centromere assembly and function.

Entering the Next Dimension: Plant Genomes in 3D.

Science.gov (United States)

Sotelo-Silveira, Mariana; Chávez Montes, Ricardo A; Sotelo-Silveira, Jose R; Marsch-Martínez, Nayelli; de Folter, Stefan

2018-04-24

After linear sequences of genomes and epigenomic landscape data, the 3D organization of chromatin in the nucleus is the next level to be explored. Different organisms present a general hierarchical organization, with chromosome territories at the top. Chromatin interaction maps, obtained by chromosome conformation capture (3C)-based methodologies, for eight plant species reveal commonalities, but also differences, among them and with animals. The smallest structures, found in high-resolution maps of the Arabidopsis genome, are single genes. Epigenetic marks (histone modification and DNA methylation), transcriptional activity, and chromatin interaction appear to be correlated, and whether structure is the cause or consequence of the function of interacting regions is being actively investigated. Copyright © 2018 Elsevier Ltd. All rights reserved.

Genome-wide identification and structure-function studies of proteases and protease inhibitors in Cicer arietinum (chickpea).

Science.gov (United States)

Sharma, Ranu; Suresh, C G

2015-01-01

Proteases are a family of enzymes present in almost all living organisms. In plants they are involved in many biological processes requiring stress response in situations such as water deficiency, pathogen attack, maintaining protein content of the cell, programmed cell death, senescence, reproduction and many more. Similarly, protease inhibitors (PIs) are involved in various important functions like suppression of invasion by pathogenic nematodes, inhibition of spores-germination and mycelium growth of Alternaria alternata and response to wounding and fungal attack. As much as we know, no genome-wide study of proteases together with proteinaceous PIs is reported in any of the sequenced genomes till now. Phylogenetic studies and domain analysis of proteases were carried out to understand the molecular evolution as well as gene and protein features. Structural analysis was carried out to explore the binding mode and affinity of PIs for cognate proteases and prolyl oligopeptidase protease with inhibitor ligand. In the study reported here, a significant number of proteases and PIs were identified in chickpea genome. The gene expression profiles of proteases and PIs in five different plant tissues revealed a differential expression pattern in more than one plant tissue. Molecular dynamics studies revealed the formation of stable complex owing to increased number of protein-ligand and inter and intramolecular protein-protein hydrogen bonds. The genome-wide identification, characterization, evolutionary understanding, gene expression, and structural analysis of proteases and PIs provide a framework for future analysis when defining their roles in stress response and developing a more stress tolerant variety of chickpea. Copyright © 2014 Elsevier Ltd. All rights reserved.

Self-Organization of Genome Expression from Embryo to Terminal Cell Fate: Single-Cell Statistical Mechanics of Biological Regulation

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Alessandro Giuliani

2017-12-01

Full Text Available A statistical mechanical mean-field approach to the temporal development of biological regulation provides a phenomenological, but basic description of the dynamical behavior of genome expression in terms of autonomous self-organization with a critical transition (Self-Organized Criticality: SOC. This approach reveals the basis of self-regulation/organization of genome expression, where the extreme complexity of living matter precludes any strict mechanistic approach. The self-organization in SOC involves two critical behaviors: scaling-divergent behavior (genome avalanche and sandpile-type critical behavior. Genome avalanche patterns—competition between order (scaling and disorder (divergence reflect the opposite sequence of events characterizing the self-organization process in embryo development and helper T17 terminal cell differentiation, respectively. On the other hand, the temporal development of sandpile-type criticality (the degree of SOC control in mouse embryo suggests the existence of an SOC control landscape with a critical transition state (i.e., the erasure of zygote-state criticality. This indicates that a phase transition of the mouse genome before and after reprogramming (immediately after the late 2-cell state occurs through a dynamical change in a control parameter. This result provides a quantitative open-thermodynamic appreciation of the still largely qualitative notion of the epigenetic landscape. Our results suggest: (i the existence of coherent waves of condensation/de-condensation in chromatin, which are transmitted across regions of different gene-expression levels along the genome; and (ii essentially the same critical dynamics we observed for cell-differentiation processes exist in overall RNA expression during embryo development, which is particularly relevant because it gives further proof of SOC control of overall expression as a universal feature.

The Jujube Genome Provides Insights into Genome Evolution and the Domestication of Sweetness/Acidity Taste in Fruit Trees.

Directory of Open Access Journals (Sweden)

Jian Huang

2016-12-01

Full Text Available Jujube (Ziziphus jujuba Mill. belongs to the Rhamnaceae family and is a popular fruit tree species with immense economic and nutritional value. Here, we report a draft genome of the dry jujube cultivar 'Junzao' and the genome resequencing of 31 geographically diverse accessions of cultivated and wild jujubes (Ziziphus jujuba var. spinosa. Comparative analysis revealed that the genome of 'Dongzao', a fresh jujube, was ~86.5 Mb larger than that of the 'Junzao', partially due to the recent insertions of transposable elements in the 'Dongzao' genome. We constructed eight proto-chromosomes of the common ancestor of Rhamnaceae and Rosaceae, two sister families in the order Rosales, and elucidated the evolutionary processes that have shaped the genome structures of modern jujubes. Population structure analysis revealed the complex genetic background of jujubes resulting from extensive hybridizations between jujube and its wild relatives. Notably, several key genes that control fruit organic acid metabolism and sugar content were identified in the selective sweep regions. We also identified S-locus genes controlling gametophytic self-incompatibility and investigated haplotype patterns of the S locus in the jujube genomes, which would provide a guideline for parent selection for jujube crossbreeding. This study provides valuable genomic resources for jujube improvement, and offers insights into jujube genome evolution and its population structure and domestication.

A structural model of the genome packaging process in a membrane-containing double stranded DNA virus.

Directory of Open Access Journals (Sweden)

Chuan Hong

2014-12-01

Full Text Available Two crucial steps in the virus life cycle are genome encapsidation to form an infective virion and genome exit to infect the next host cell. In most icosahedral double-stranded (ds DNA viruses, the viral genome enters and exits the capsid through a unique vertex. Internal membrane-containing viruses possess additional complexity as the genome must be translocated through the viral membrane bilayer. Here, we report the structure of the genome packaging complex with a membrane conduit essential for viral genome encapsidation in the tailless icosahedral membrane-containing bacteriophage PRD1. We utilize single particle electron cryo-microscopy (cryo-EM and symmetry-free image reconstruction to determine structures of PRD1 virion, procapsid, and packaging deficient mutant particles. At the unique vertex of PRD1, the packaging complex replaces the regular 5-fold structure and crosses the lipid bilayer. These structures reveal that the packaging ATPase P9 and the packaging efficiency factor P6 form a dodecameric portal complex external to the membrane moiety, surrounded by ten major capsid protein P3 trimers. The viral transmembrane density at the special vertex is assigned to be a hexamer of heterodimer of proteins P20 and P22. The hexamer functions as a membrane conduit for the DNA and as a nucleating site for the unique vertex assembly. Our structures show a conformational alteration in the lipid membrane after the P9 and P6 are recruited to the virion. The P8-genome complex is then packaged into the procapsid through the unique vertex while the genome terminal protein P8 functions as a valve that closes the channel once the genome is inside. Comparing mature virion, procapsid, and mutant particle structures led us to propose an assembly pathway for the genome packaging apparatus in the PRD1 virion.

A structural model of the genome packaging process in a membrane-containing double stranded DNA virus.

Science.gov (United States)

Hong, Chuan; Oksanen, Hanna M; Liu, Xiangan; Jakana, Joanita; Bamford, Dennis H; Chiu, Wah

2014-12-01

Two crucial steps in the virus life cycle are genome encapsidation to form an infective virion and genome exit to infect the next host cell. In most icosahedral double-stranded (ds) DNA viruses, the viral genome enters and exits the capsid through a unique vertex. Internal membrane-containing viruses possess additional complexity as the genome must be translocated through the viral membrane bilayer. Here, we report the structure of the genome packaging complex with a membrane conduit essential for viral genome encapsidation in the tailless icosahedral membrane-containing bacteriophage PRD1. We utilize single particle electron cryo-microscopy (cryo-EM) and symmetry-free image reconstruction to determine structures of PRD1 virion, procapsid, and packaging deficient mutant particles. At the unique vertex of PRD1, the packaging complex replaces the regular 5-fold structure and crosses the lipid bilayer. These structures reveal that the packaging ATPase P9 and the packaging efficiency factor P6 form a dodecameric portal complex external to the membrane moiety, surrounded by ten major capsid protein P3 trimers. The viral transmembrane density at the special vertex is assigned to be a hexamer of heterodimer of proteins P20 and P22. The hexamer functions as a membrane conduit for the DNA and as a nucleating site for the unique vertex assembly. Our structures show a conformational alteration in the lipid membrane after the P9 and P6 are recruited to the virion. The P8-genome complex is then packaged into the procapsid through the unique vertex while the genome terminal protein P8 functions as a valve that closes the channel once the genome is inside. Comparing mature virion, procapsid, and mutant particle structures led us to propose an assembly pathway for the genome packaging apparatus in the PRD1 virion.

Large-scale trends in the evolution of gene structures within 11 animal genomes.

Directory of Open Access Journals (Sweden)

Mark Yandell

2006-03-01

Full Text Available We have used the annotations of six animal genomes (Homo sapiens, Mus musculus, Ciona intestinalis, Drosophila melanogaster, Anopheles gambiae, and Caenorhabditis elegans together with the sequences of five unannotated Drosophila genomes to survey changes in protein sequence and gene structure over a variety of timescales--from the less than 5 million years since the divergence of D. simulans and D. melanogaster to the more than 500 million years that have elapsed since the Cambrian explosion. To do so, we have developed a new open-source software library called CGL (for "Comparative Genomics Library". Our results demonstrate that change in intron-exon structure is gradual, clock-like, and largely independent of coding-sequence evolution. This means that genome annotations can be used in new ways to inform, corroborate, and test conclusions drawn from comparative genomics analyses that are based upon protein and nucleotide sequence similarities.

Contributions to In Silico Genome Annotation

KAUST Repository

Kalkatawi, Manal M.

2017-11-30

Genome annotation is an important topic since it provides information for the foundation of downstream genomic and biological research. It is considered as a way of summarizing part of existing knowledge about the genomic characteristics of an organism. Annotating different regions of a genome sequence is known as structural annotation, while identifying functions of these regions is considered as a functional annotation. In silico approaches can facilitate both tasks that otherwise would be difficult and timeconsuming. This study contributes to genome annotation by introducing several novel bioinformatics methods, some based on machine learning (ML) approaches. First, we present Dragon PolyA Spotter (DPS), a method for accurate identification of the polyadenylation signals (PAS) within human genomic DNA sequences. For this, we derived a novel feature-set able to characterize properties of the genomic region surrounding the PAS, enabling development of high accuracy optimized ML predictive models. DPS considerably outperformed the state-of-the-art results. The second contribution concerns developing generic models for structural annotation, i.e., the recognition of different genomic signals and regions (GSR) within eukaryotic DNA. We developed DeepGSR, a systematic framework that facilitates generating ML models to predict GSR with high accuracy. To the best of our knowledge, no available generic and automated method exists for such task that could facilitate the studies of newly sequenced organisms. The prediction module of DeepGSR uses deep learning algorithms to derive highly abstract features that depend mainly on proper data representation and hyperparameters calibration. DeepGSR, which was evaluated on recognition of PAS and translation initiation sites (TIS) in different organisms, yields a simpler and more precise representation of the problem under study, compared to some other hand-tailored models, while producing high accuracy prediction results. Finally

Compositional patterns in the genomes of unicellular eukaryotes.

Science.gov (United States)

Costantini, Maria; Alvarez-Valin, Fernando; Costantini, Susan; Cammarano, Rosalia; Bernardi, Giorgio

2013-11-05

The genomes of multicellular eukaryotes are compartmentalized in mosaics of isochores, large and fairly homogeneous stretches of DNA that belong to a small number of families characterized by different average GC levels, by different gene concentration (that increase with GC), different chromatin structures, different replication timing in the cell cycle, and other different properties. A question raised by these basic results concerns how far back in evolution the compartmentalized organization of the eukaryotic genomes arose. In the present work we approached this problem by studying the compositional organization of the genomes from the unicellular eukaryotes for which full sequences are available, the sample used being representative. The average GC levels of the genomes from unicellular eukaryotes cover an extremely wide range (19%-60% GC) and the compositional patterns of individual genomes are extremely different but all genomes tested show a compositional compartmentalization. The average GC range of the genomes of unicellular eukaryotes is very broad (as broad as that of prokaryotes) and individual compositional patterns cover a very broad range from very narrow to very complex. Both features are not surprising for organisms that are very far from each other both in terms of phylogenetic distances and of environmental life conditions. Most importantly, all genomes tested, a representative sample of all supergroups of unicellular eukaryotes, are compositionally compartmentalized, a major difference with prokaryotes.

The complete nucleotide sequence, genome organization, and origin of human adenovirus type 11

International Nuclear Information System (INIS)

Stone, Daniel; Furthmann, Anne; Sandig, Volker; Lieber, Andre

2003-01-01

The complete DNA sequence and transcription map of human adenovirus type 11 are reported here. This is the first published sequence for a subgenera B human adenovirus and demonstrates a genome organization highly similar to those of other human adenoviruses. All of the genes from the early, intermediate, and late regions are present in the expected locations of the genome for a human adenovirus. The genome size is 34,794 bp in length and has a GC content of 48.9%. Sequence alignment with genomes of groups A (Ad12), C (Ad5), D (Ad17), E (Simian adenovirus 25), and F (Ad40) revealed homologies of 64, 54, 68, 75, and 52%, respectively. Detailed genomic analysis demonstrated that Ads 11 and 35 are highly conserved in all areas except the hexon hypervariable regions and fiber. Similarly, comparison of Ad11 with subgroup E SAV25 revealed poor homology between fibers but high homology in proteins encoded by all other areas of the genome. We propose an evolutionary model in which functional viruses can be reconstituted following fiber substitution from one serotype to another. According to this model either the Ad11 genome is a derivative of Ad35, from which the fiber was substituted with Ad7, or the Ad35 genome is the product of a fiber substitution from Ad21 into the Ad11 genome. This model also provides a possible explanation for the origin of group E Ads, which are evolutionarily derived from a group C fiber substitution into a group B genome

Reconstructing spatial organizations of chromosomes through manifold learning.

Science.gov (United States)

Zhu, Guangxiang; Deng, Wenxuan; Hu, Hailin; Ma, Rui; Zhang, Sai; Yang, Jinglin; Peng, Jian; Kaplan, Tommy; Zeng, Jianyang

2018-02-02

Decoding the spatial organizations of chromosomes has crucial implications for studying eukaryotic gene regulation. Recently, chromosomal conformation capture based technologies, such as Hi-C, have been widely used to uncover the interaction frequencies of genomic loci in a high-throughput and genome-wide manner and provide new insights into the folding of three-dimensional (3D) genome structure. In this paper, we develop a novel manifold learning based framework, called GEM (Genomic organization reconstructor based on conformational Energy and Manifold learning), to reconstruct the three-dimensional organizations of chromosomes by integrating Hi-C data with biophysical feasibility. Unlike previous methods, which explicitly assume specific relationships between Hi-C interaction frequencies and spatial distances, our model directly embeds the neighboring affinities from Hi-C space into 3D Euclidean space. Extensive validations demonstrated that GEM not only greatly outperformed other state-of-art modeling methods but also provided a physically and physiologically valid 3D representations of the organizations of chromosomes. Furthermore, we for the first time apply the modeled chromatin structures to recover long-range genomic interactions missing from original Hi-C data. © The Author(s) 2018. Published by Oxford University Press on behalf of Nucleic Acids Research.

PLAZA 3.0: an access point for plant comparative genomics

Science.gov (United States)

Proost, Sebastian; Van Bel, Michiel; Vaneechoutte, Dries; Van de Peer, Yves; Inzé, Dirk; Mueller-Roeber, Bernd; Vandepoele, Klaas

2015-01-01

Comparative sequence analysis has significantly altered our view on the complexity of genome organization and gene functions in different kingdoms. PLAZA 3.0 is designed to make comparative genomics data for plants available through a user-friendly web interface. Structural and functional annotation, gene families, protein domains, phylogenetic trees and detailed information about genome organization can easily be queried and visualized. Compared with the first version released in 2009, which featured nine organisms, the number of integrated genomes is more than four times higher, and now covers 37 plant species. The new species provide a wider phylogenetic range as well as a more in-depth sampling of specific clades, and genomes of additional crop species are present. The functional annotation has been expanded and now comprises data from Gene Ontology, MapMan, UniProtKB/Swiss-Prot, PlnTFDB and PlantTFDB. Furthermore, we improved the algorithms to transfer functional annotation from well-characterized plant genomes to other species. The additional data and new features make PLAZA 3.0 (http://bioinformatics.psb.ugent.be/plaza/) a versatile and comprehensible resource for users wanting to explore genome information to study different aspects of plant biology, both in model and non-model organisms. PMID:25324309

Structural analysis of a set of proteins resulting from a bacterial genomics project.

Science.gov (United States)

Badger, J; Sauder, J M; Adams, J M; Antonysamy, S; Bain, K; Bergseid, M G; Buchanan, S G; Buchanan, M D; Batiyenko, Y; Christopher, J A; Emtage, S; Eroshkina, A; Feil, I; Furlong, E B; Gajiwala, K S; Gao, X; He, D; Hendle, J; Huber, A; Hoda, K; Kearins, P; Kissinger, C; Laubert, B; Lewis, H A; Lin, J; Loomis, K; Lorimer, D; Louie, G; Maletic, M; Marsh, C D; Miller, I; Molinari, J; Muller-Dieckmann, H J; Newman, J M; Noland, B W; Pagarigan, B; Park, F; Peat, T S; Post, K W; Radojicic, S; Ramos, A; Romero, R; Rutter, M E; Sanderson, W E; Schwinn, K D; Tresser, J; Winhoven, J; Wright, T A; Wu, L; Xu, J; Harris, T J R

2005-09-01

The targets of the Structural GenomiX (SGX) bacterial genomics project were proteins conserved in multiple prokaryotic organisms with no obvious sequence homolog in the Protein Data Bank of known structures. The outcome of this work was 80 structures, covering 60 unique sequences and 49 different genes. Experimental phase determination from proteins incorporating Se-Met was carried out for 45 structures with most of the remainder solved by molecular replacement using members of the experimentally phased set as search models. An automated tool was developed to deposit these structures in the Protein Data Bank, along with the associated X-ray diffraction data (including refined experimental phases) and experimentally confirmed sequences. BLAST comparisons of the SGX structures with structures that had appeared in the Protein Data Bank over the intervening 3.5 years since the SGX target list had been compiled identified homologs for 49 of the 60 unique sequences represented by the SGX structures. This result indicates that, for bacterial structures that are relatively easy to express, purify, and crystallize, the structural coverage of gene space is proceeding rapidly. More distant sequence-structure relationships between the SGX and PDB structures were investigated using PDB-BLAST and Combinatorial Extension (CE). Only one structure, SufD, has a truly unique topology compared to all folds in the PDB. Copyright 2005 Wiley-Liss, Inc.

The Impact of Structural Genomics: Expectations and Outcomes

Energy Technology Data Exchange (ETDEWEB)

Chandonia, John-Marc; Brenner, Steven E.

2005-12-21

Structural Genomics (SG) projects aim to expand our structural knowledge of biological macromolecules, while lowering the average costs of structure determination. We quantitatively analyzed the novelty, cost, and impact of structures solved by SG centers, and contrast these results with traditional structural biology. The first structure from a protein family is particularly important to reveal the fold and ancient relationships to other proteins. In the last year, approximately half of such structures were solved at a SG center rather than in a traditional laboratory. Furthermore, the cost of solving a structure at the most efficient U.S. center has now dropped to one-quarter the estimated cost of solving a structure by traditional methods. However, top structural biology laboratories are much more efficient than the average, and comparable to SG centers despite working on very challenging structures. Moreover, traditional structural biology papers are cited significantly more often, suggesting greater current impact.

An Emerging Tick-Borne Disease of Humans Is Caused by a Subset of Strains with Conserved Genome Structure

Science.gov (United States)

Barbet, Anthony F.; Al-Khedery, Basima; Stuen, Snorre; Granquist, Erik G.; Felsheim, Roderick F.; Munderloh, Ulrike G.

2013-01-01

The prevalence of tick-borne diseases is increasing worldwide. One such emerging disease is human anaplasmosis. The causative organism, Anaplasma phagocytophilum, is known to infect multiple animal species and cause human fatalities in the U.S., Europe and Asia. Although long known to infect ruminants, it is unclear why there are increasing numbers of human infections. We analyzed the genome sequences of strains infecting humans, animals and ticks from diverse geographic locations. Despite extensive variability amongst these strains, those infecting humans had conserved genome structure including the pfam01617 superfamily that encodes the major, neutralization-sensitive, surface antigen. These data provide potential targets to identify human-infective strains and have significance for understanding the selective pressures that lead to emergence of disease in new species. PMID:25437207

Exploring the role of genome and structural ions in preventing viral capsid collapse during dehydration

Science.gov (United States)

Martín-González, Natalia; Guérin Darvas, Sofía M.; Durana, Aritz; Marti, Gerardo A.; Guérin, Diego M. A.; de Pablo, Pedro J.

2018-03-01

Even though viruses evolve mainly in liquid milieu, their horizontal transmission routes often include episodes of dry environment. Along their life cycle, some insect viruses, such as viruses from the Dicistroviridae family, withstand dehydrated conditions with presently unknown consequences to their structural stability. Here, we use atomic force microscopy to monitor the structural changes of viral particles of Triatoma virus (TrV) after desiccation. Our results demonstrate that TrV capsids preserve their genome inside, conserving their height after exposure to dehydrating conditions, which is in stark contrast with other viruses that expel their genome when desiccated. Moreover, empty capsids (without genome) resulted in collapsed particles after desiccation. We also explored the role of structural ions in the dehydration process of the virions (capsid containing genome) by chelating the accessible cations from the external solvent milieu. We observed that ion suppression helps to keep the virus height upon desiccation. Our results show that under drying conditions, the genome of TrV prevents the capsid from collapsing during dehydration, while the structural ions are responsible for promoting solvent exchange through the virion wall.

SINEs, evolution and genome structure in the opossum.

Science.gov (United States)

Gu, Wanjun; Ray, David A; Walker, Jerilyn A; Barnes, Erin W; Gentles, Andrew J; Samollow, Paul B; Jurka, Jerzy; Batzer, Mark A; Pollock, David D

2007-07-01

Short INterspersed Elements (SINEs) are non-autonomous retrotransposons, usually between 100 and 500 base pairs (bp) in length, which are ubiquitous components of eukaryotic genomes. Their activity, distribution, and evolution can be highly informative on genomic structure and evolutionary processes. To determine recent activity, we amplified more than one hundred SINE1 loci in a panel of 43 M. domestica individuals derived from five diverse geographic locations. The SINE1 family has expanded recently enough that many loci were polymorphic, and the SINE1 insertion-based genetic distances among populations reflected geographic distance. Genome-wide comparisons of SINE1 densities and GC content revealed that high SINE1 density is associated with high GC content in a few long and many short spans. Young SINE1s, whether fixed or polymorphic, showed an unbiased GC content preference for insertion, indicating that the GC preference accumulates over long time periods, possibly in periodic bursts. SINE1 evolution is thus broadly similar to human Alu evolution, although it has an independent origin. High GC content adjacent to SINE1s is strongly correlated with bias towards higher AT to GC substitutions and lower GC to AT substitutions. This is consistent with biased gene conversion, and also indicates that like chickens, but unlike eutherian mammals, GC content heterogeneity (isochore structure) is reinforced by substitution processes in the M. domestica genome. Nevertheless, both high and low GC content regions are apparently headed towards lower GC content equilibria, possibly due to a relative shift to lower recombination rates in the recent Monodelphis ancestral lineage. Like eutherians, metatherian (marsupial) mammals have evolved high CpG substitution rates, but this is apparently a convergence in process rather than a shared ancestral state.

Are electronic health records ready for genomic medicine?

Science.gov (United States)

Scheuner, Maren T; de Vries, Han; Kim, Benjamin; Meili, Robin C; Olmstead, Sarah H; Teleki, Stephanie

2009-07-01

The goal of this project was to assess genetic/genomic content in electronic health records. Semistructured interviews were conducted with key informants. Questions addressed documentation, organization, display, decision support and security of family history and genetic test information, and challenges and opportunities relating to integrating genetic/genomics content in electronic health records. There were 56 participants: 10 electronic health record specialists, 18 primary care clinicians, 16 medical geneticists, and 12 genetic counselors. Few clinicians felt their electronic record met their current genetic/genomic medicine needs. Barriers to integration were mostly related to problems with family history data collection, documentation, and organization. Lack of demand for genetics content and privacy concerns were also mentioned as challenges. Data elements and functionality requirements that clinicians see include: pedigree drawing; clinical decision support for familial risk assessment and genetic testing indications; a patient portal for patient-entered data; and standards for data elements, terminology, structure, interoperability, and clinical decision support rules. Although most said that there is little impact of genetics/genomics on electronic records today, many stated genetics/genomics would be a driver of content in the next 5-10 years. Electronic health records have the potential to enable clinical integration of genetic/genomic medicine and improve delivery of personalized health care; however, structured and standardized data elements and functionality requirements are needed.

Genomic organization and dynamics of repetitive DNA sequences in representatives of three Fagaceae genera.

Science.gov (United States)

Alves, Sofia; Ribeiro, Teresa; Inácio, Vera; Rocheta, Margarida; Morais-Cecílio, Leonor

2012-05-01

Oaks, chestnuts, and beeches are economically important species of the Fagaceae. To understand the relationship between these members of this family, a deep knowledge of their genome composition and organization is needed. In this work, we have isolated and characterized several AFLP fragments obtained from Quercus rotundifolia Lam. through homology searches in available databases. Genomic polymorphisms involving some of these sequences were evaluated in two species of Quercus, one of Castanea, and one of Fagus with specific primers. Comparative FISH analysis with generated sequences was performed in interphase nuclei of the four species, and the co-immunolocalization of 5-methylcytosine was also studied. Some of the sequences isolated proved to be genus-specific, while others were present in all the genera. Retroelements, either gypsy-like of the Tat/Athila clade or copia-like, are well represented, and most are dispersed in euchromatic regions of these species with no DNA methylation associated, pointing to an interspersed arrangement of these retroelements with potential gene-rich regions. A particular gypsy-sequence is dispersed in oaks and chestnut nuclei, but its confinement to chromocenters in beech evidences genome restructuring events during evolution of Fagaceae. Several sequences generated in this study proved to be good tools to comparatively study Fagaceae genome organization.

Short and long-term genome stability analysis of prokaryotic genomes.

Science.gov (United States)

Brilli, Matteo; Liò, Pietro; Lacroix, Vincent; Sagot, Marie-France

2013-05-08

Gene organization dynamics is actively studied because it provides useful evolutionary information, makes functional annotation easier and often enables to characterize pathogens. There is therefore a strong interest in understanding the variability of this trait and the possible correlations with life-style. Two kinds of events affect genome organization: on one hand translocations and recombinations change the relative position of genes shared by two genomes (i.e. the backbone gene order); on the other, insertions and deletions leave the backbone gene order unchanged but they alter the gene neighborhoods by breaking the syntenic regions. A complete picture about genome organization evolution therefore requires to account for both kinds of events. We developed an approach where we model chromosomes as graphs on which we compute different stability estimators; we consider genome rearrangements as well as the effect of gene insertions and deletions. In a first part of the paper, we fit a measure of backbone gene order conservation (hereinafter called backbone stability) against phylogenetic distance for over 3000 genome comparisons, improving existing models for the divergence in time of backbone stability. Intra- and inter-specific comparisons were treated separately to focus on different time-scales. The use of multiple genomes of a same species allowed to identify genomes with diverging gene order with respect to their conspecific. The inter-species analysis indicates that pathogens are more often unstable with respect to non-pathogens. In a second part of the text, we show that in pathogens, gene content dynamics (insertions and deletions) have a much more dramatic effect on genome organization stability than backbone rearrangements. In this work, we studied genome organization divergence taking into account the contribution of both genome order rearrangements and genome content dynamics. By studying species with multiple sequenced genomes available, we were

Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome.

Science.gov (United States)

Collins, Ryan L; Brand, Harrison; Redin, Claire E; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon-Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A; Lucente, Diane; Levy, Brynn; Sanders, Stephan J; Wapner, Ronald J; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E

2017-03-06

Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. We sequenced 689 participants with autism spectrum disorder (ASD) and other developmental abnormalities to construct a genome-wide map of large SV. Using long-insert jumping libraries at 105X mean physical coverage and linked-read whole-genome sequencing from 10X Genomics, we document seven major SV classes at ~5 kb SV resolution. Our results encompass 11,735 distinct large SV sites, 38.1% of which are novel and 16.8% of which are balanced or complex. We characterize 16 recurrent subclasses of complex SV (cxSV), revealing that: (1) cxSV are larger and rarer than canonical SV; (2) each genome harbors 14 large cxSV on average; (3) 84.4% of large cxSVs involve inversion; and (4) most large cxSV (93.8%) have not been delineated in previous studies. Rare SVs are more likely to disrupt coding and regulatory non-coding loci, particularly when truncating constrained and disease-associated genes. We also identify multiple cases of catastrophic chromosomal rearrangements known as chromoanagenesis, including somatic chromoanasynthesis, and extreme balanced germline chromothripsis events involving up to 65 breakpoints and 60.6 Mb across four chromosomes, further defining rare categories of extreme cxSV. These data provide a foundational map of large SV in the morbid human genome and demonstrate a previously underappreciated abundance and diversity of cxSV that should be considered in genomic studies of human disease.

Genomic sequence and organization of two members of a human lectin gene family

International Nuclear Information System (INIS)

Gitt, M.A.; Barondes, S.H.

1991-01-01

The authors have isolated and sequenced the genomic DNA encoding a human dimeric soluble lactose-binding lectin. The gene has four exons, and its upstream region contains sequences that suggest control by glucocorticoids, heat (environmental) shock, metals, and other factors. They have also isolated and sequenced three exons of the gene encoding another human putative lectin, the existence of which was first indicated by isolation of its cDNA. Comparisons suggest a general pattern of genomic organization of members of this lectin gene family

Mathematical Analysis of Genomic Evolution

Directory of Open Access Journals (Sweden)

Cedric Green

2011-01-01

Full Text Available Changes in nucleotide sequences, or mutations, accumulate from generation to generation in the genomes of all living organisms. The mutations can be advantageous, deleterious, or neutral. The goal of this project is to determine the amount of advantageous mutations it takes to get human (Homo sapiens DNA from the DNA of genetically distinct organisms. We do this by collecting the genomic data of such organisms, and estimating the amount of mutations it takes to transform yeast (Saccharomyces cerevisiae DNA to the DNA of a human. We calculate the typical number of mutations occurring annually through the organism's average life span and the average mutation rate. This allows us to determine the total number of mutations as well as the probability of advantageous mutations. Not surprisingly, this probability proves to be fairly small. A more precise estimate can be determined by accounting for the differences in the chromosomal structure and phenomena like horizontal gene transfer.

Analyses of charophyte chloroplast genomes help characterize the ancestral chloroplast genome of land plants.

Science.gov (United States)

Civaň, Peter; Foster, Peter G; Embley, Martin T; Séneca, Ana; Cox, Cymon J

2014-04-01

Despite the significance of the relationships between embryophytes and their charophyte algal ancestors in deciphering the origin and evolutionary success of land plants, few chloroplast genomes of the charophyte algae have been reconstructed to date. Here, we present new data for three chloroplast genomes of the freshwater charophytes Klebsormidium flaccidum (Klebsormidiophyceae), Mesotaenium endlicherianum (Zygnematophyceae), and Roya anglica (Zygnematophyceae). The chloroplast genome of Klebsormidium has a quadripartite organization with exceptionally large inverted repeat (IR) regions and, uniquely among streptophytes, has lost the rrn5 and rrn4.5 genes from the ribosomal RNA (rRNA) gene cluster operon. The chloroplast genome of Roya differs from other zygnematophycean chloroplasts, including the newly sequenced Mesotaenium, by having a quadripartite structure that is typical of other streptophytes. On the basis of the improbability of the novel gain of IR regions, we infer that the quadripartite structure has likely been lost independently in at least three zygnematophycean lineages, although the absence of the usual rRNA operonic synteny in the IR regions of Roya may indicate their de novo origin. Significantly, all zygnematophycean chloroplast genomes have undergone substantial genomic rearrangement, which may be the result of ancient retroelement activity evidenced by the presence of integrase-like and reverse transcriptase-like elements in the Roya chloroplast genome. Our results corroborate the close phylogenetic relationship between Zygnematophyceae and land plants and identify 89 protein-coding genes and 22 introns present in the chloroplast genome at the time of the evolutionary transition of plants to land, all of which can be found in the chloroplast genomes of extant charophytes.

Multiple Whole Genome Alignments Without a Reference Organism

Energy Technology Data Exchange (ETDEWEB)

Dubchak, Inna; Poliakov, Alexander; Kislyuk, Andrey; Brudno, Michael

2009-01-16

Multiple sequence alignments have become one of the most commonly used resources in genomics research. Most algorithms for multiple alignment of whole genomes rely either on a reference genome, against which all of the other sequences are laid out, or require a one-to-one mapping between the nucleotides of the genomes, preventing the alignment of recently duplicated regions. Both approaches have drawbacks for whole-genome comparisons. In this paper we present a novel symmetric alignment algorithm. The resulting alignments not only represent all of the genomes equally well, but also include all relevant duplications that occurred since the divergence from the last common ancestor. Our algorithm, implemented as a part of the VISTA Genome Pipeline (VGP), was used to align seven vertebrate and sixDrosophila genomes. The resulting whole-genome alignments demonstrate a higher sensitivity and specificity than the pairwise alignments previously available through the VGP and have higher exon alignment accuracy than comparable public whole-genome alignments. Of the multiple alignment methods tested, ours performed the best at aligning genes from multigene families?perhaps the most challenging test for whole-genome alignments. Our whole-genome multiple alignments are available through the VISTA Browser at http://genome.lbl.gov/vista/index.shtml.

Deep ancestry of programmed genome rearrangement in lampreys.

Science.gov (United States)

Timoshevskiy, Vladimir A; Lampman, Ralph T; Hess, Jon E; Porter, Laurie L; Smith, Jeramiah J

2017-09-01

In most multicellular organisms, the structure and content of the genome is rigorously maintained over the course of development. However some species have evolved genome biologies that permit, or require, developmentally regulated changes in the physical structure and content of the genome (programmed genome rearrangement: PGR). Relatively few vertebrates are known to undergo PGR, although all agnathans surveyed to date (several hagfish and one lamprey: Petromyzon marinus) show evidence of large scale PGR. To further resolve the ancestry of PGR within vertebrates, we developed probes that allow simultaneous tracking of nearly all sequences eliminated by PGR in P. marinus and a second lamprey species (Entosphenus tridentatus). These comparative analyses reveal conserved subcellular structures (lagging chromatin and micronuclei) associated with PGR and provide the first comparative embryological evidence in support of the idea that PGR represents an ancient and evolutionarily stable strategy for regulating inherent developmental/genetic conflicts between germline and soma. Copyright © 2017 Elsevier Inc. All rights reserved.

Recognizing genes and other components of genomic structure

Energy Technology Data Exchange (ETDEWEB)

Burks, C. (Los Alamos National Lab., NM (USA)); Myers, E. (Arizona Univ., Tucson, AZ (USA). Dept. of Computer Science); Stormo, G.D. (Colorado Univ., Boulder, CO (USA). Dept. of Molecular, Cellular and Developmental Biology)

1991-01-01

The Aspen Center for Physics (ACP) sponsored a three-week workshop, with 26 scientists participating, from 28 May to 15 June, 1990. The workshop, entitled Recognizing Genes and Other Components of Genomic Structure, focussed on discussion of current needs and future strategies for developing the ability to identify and predict the presence of complex functional units on sequenced, but otherwise uncharacterized, genomic DNA. We addressed the need for computationally-based, automatic tools for synthesizing available data about individual consensus sequences and local compositional patterns into the composite objects (e.g., genes) that are -- as composite entities -- the true object of interest when scanning DNA sequences. The workshop was structured to promote sustained informal contact and exchange of expertise between molecular biologists, computer scientists, and mathematicians. No participant stayed for less than one week, and most attended for two or three weeks. Computers, software, and databases were available for use as electronic blackboards'' and as the basis for collaborative exploration of ideas being discussed and developed at the workshop. 23 refs., 2 tabs.

A decade of human genome project conclusion: Scientific diffusion about our genome knowledge.

Science.gov (United States)

Moraes, Fernanda; Góes, Andréa

2016-05-06

The Human Genome Project (HGP) was initiated in 1990 and completed in 2003. It aimed to sequence the whole human genome. Although it represented an advance in understanding the human genome and its complexity, many questions remained unanswered. Other projects were launched in order to unravel the mysteries of our genome, including the ENCyclopedia of DNA Elements (ENCODE). This review aims to analyze the evolution of scientific knowledge related to both the HGP and ENCODE projects. Data were retrieved from scientific articles published in 1990-2014, a period comprising the development and the 10 years following the HGP completion. The fact that only 20,000 genes are protein and RNA-coding is one of the most striking HGP results. A new concept about the organization of genome arose. The ENCODE project was initiated in 2003 and targeted to map the functional elements of the human genome. This project revealed that the human genome is pervasively transcribed. Therefore, it was determined that a large part of the non-protein coding regions are functional. Finally, a more sophisticated view of chromatin structure emerged. The mechanistic functioning of the genome has been redrafted, revealing a much more complex picture. Besides, a gene-centric conception of the organism has to be reviewed. A number of criticisms have emerged against the ENCODE project approaches, raising the question of whether non-conserved but biochemically active regions are truly functional. Thus, HGP and ENCODE projects accomplished a great map of the human genome, but the data generated still requires further in depth analysis. © 2016 by The International Union of Biochemistry and Molecular Biology, 44:215-223, 2016. © 2016 The International Union of Biochemistry and Molecular Biology.

Spectral entropy criteria for structural segmentation in genomic DNA sequences

International Nuclear Information System (INIS)

Chechetkin, V.R.; Lobzin, V.V.

2004-01-01

The spectral entropy is calculated with Fourier structure factors and characterizes the level of structural ordering in a sequence of symbols. It may efficiently be applied to the assessment and reconstruction of the modular structure in genomic DNA sequences. We present the relevant spectral entropy criteria for the local and non-local structural segmentation in DNA sequences. The results are illustrated with the model examples and analysis of intervening exon-intron segments in the protein-coding regions

16 CFR 0.9 - Organization structure.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Organization structure. 0.9 Section 0.9 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE ORGANIZATION § 0.9 Organization structure. The Federal Trade Commission comprises the following principal units...

PLAZA 3.0: an access point for plant comparative genomics.

Science.gov (United States)

Proost, Sebastian; Van Bel, Michiel; Vaneechoutte, Dries; Van de Peer, Yves; Inzé, Dirk; Mueller-Roeber, Bernd; Vandepoele, Klaas

2015-01-01

Comparative sequence analysis has significantly altered our view on the complexity of genome organization and gene functions in different kingdoms. PLAZA 3.0 is designed to make comparative genomics data for plants available through a user-friendly web interface. Structural and functional annotation, gene families, protein domains, phylogenetic trees and detailed information about genome organization can easily be queried and visualized. Compared with the first version released in 2009, which featured nine organisms, the number of integrated genomes is more than four times higher, and now covers 37 plant species. The new species provide a wider phylogenetic range as well as a more in-depth sampling of specific clades, and genomes of additional crop species are present. The functional annotation has been expanded and now comprises data from Gene Ontology, MapMan, UniProtKB/Swiss-Prot, PlnTFDB and PlantTFDB. Furthermore, we improved the algorithms to transfer functional annotation from well-characterized plant genomes to other species. The additional data and new features make PLAZA 3.0 (http://bioinformatics.psb.ugent.be/plaza/) a versatile and comprehensible resource for users wanting to explore genome information to study different aspects of plant biology, both in model and non-model organisms. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

SINEs as driving forces in genome evolution.

Science.gov (United States)

Schmitz, J

2012-01-01

SINEs are short interspersed elements derived from cellular RNAs that repetitively retropose via RNA intermediates and integrate more or less randomly back into the genome. SINEs propagate almost entirely vertically within their host cells and, once established in the germline, are passed on from generation to generation. As non-autonomous elements, their reverse transcription (from RNA to cDNA) and genomic integration depends on the activity of the enzymatic machinery of autonomous retrotransposons, such as long interspersed elements (LINEs). SINEs are widely distributed in eukaryotes, but are especially effectively propagated in mammalian species. For example, more than a million Alu-SINE copies populate the human genome (approximately 13% of genomic space), and few master copies of them are still active. In the organisms where they occur, SINEs are a challenge to genomic integrity, but in the long term also can serve as beneficial building blocks for evolution, contributing to phenotypic heterogeneity and modifying gene regulatory networks. They substantially expand the genomic space and introduce structural variation to the genome. SINEs have the potential to mutate genes, to alter gene expression, and to generate new parts of genes. A balanced distribution and controlled activity of such properties is crucial to maintaining the organism's dynamic and thriving evolution. Copyright © 2012 S. Karger AG, Basel.

Elevated Rate of Genome Rearrangements in Radiation-Resistant Bacteria.

Science.gov (United States)

Repar, Jelena; Supek, Fran; Klanjscek, Tin; Warnecke, Tobias; Zahradka, Ksenija; Zahradka, Davor

2017-04-01

A number of bacterial, archaeal, and eukaryotic species are known for their resistance to ionizing radiation. One of the challenges these species face is a potent environmental source of DNA double-strand breaks, potential drivers of genome structure evolution. Efficient and accurate DNA double-strand break repair systems have been demonstrated in several unrelated radiation-resistant species and are putative adaptations to the DNA damaging environment. Such adaptations are expected to compensate for the genome-destabilizing effect of environmental DNA damage and may be expected to result in a more conserved gene order in radiation-resistant species. However, here we show that rates of genome rearrangements, measured as loss of gene order conservation with time, are higher in radiation-resistant species in multiple, phylogenetically independent groups of bacteria. Comparison of indicators of selection for genome organization between radiation-resistant and phylogenetically matched, nonresistant species argues against tolerance to disruption of genome structure as a strategy for radiation resistance. Interestingly, an important mechanism affecting genome rearrangements in prokaryotes, the symmetrical inversions around the origin of DNA replication, shapes genome structure of both radiation-resistant and nonresistant species. In conclusion, the opposing effects of environmental DNA damage and DNA repair result in elevated rates of genome rearrangements in radiation-resistant bacteria. Copyright © 2017 Repar et al.

Whole genome PCR scanning reveals the syntenic genome structure of toxigenic Vibrio cholerae strains in the O1/O139 population.

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Bo Pang

Full Text Available Vibrio cholerae is commonly found in estuarine water systems. Toxigenic O1 and O139 V. cholerae strains have caused cholera epidemics and pandemics, whereas the nontoxigenic strains within these serogroups only occasionally lead to disease. To understand the differences in the genome and clonality between the toxigenic and nontoxigenic strains of V. cholerae serogroups O1 and O139, we employed a whole genome PCR scanning (WGPScanning method, an rrn operon-mediated fragment rearrangement analysis and comparative genomic hybridization (CGH to analyze the genome structure of different strains. WGPScanning in conjunction with CGH revealed that the genomic contents of the toxigenic strains were conservative, except for a few indels located mainly in mobile elements. Minor nucleotide variation in orthologous genes appeared to be the major difference between the toxigenic strains. rrn operon-mediated rearrangements were infrequent in El Tor toxigenic strains tested using I-CeuI digested pulsed-field gel electrophoresis (PFGE analysis and PCR analysis based on flanking sequence of rrn operons. Using these methods, we found that the genomic structures of toxigenic El Tor and O139 strains were syntenic. The nontoxigenic strains exhibited more extensive sequence variations, but toxin coregulated pilus positive (TCP+ strains had a similar structure. TCP+ nontoxigenic strains could be subdivided into multiple lineages according to the TCP type, suggesting the existence of complex intermediates in the evolution of toxigenic strains. The data indicate that toxigenic O1 El Tor and O139 strains were derived from a single lineage of intermediates from complex clones in the environment. The nontoxigenic strains with non-El Tor type TCP may yet evolve into new epidemic clones after attaining toxigenic attributes.

Genome-wide identification of structural variants in genes encoding drug targets

DEFF Research Database (Denmark)

Rasmussen, Henrik Berg; Dahmcke, Christina Mackeprang

2012-01-01

The objective of the present study was to identify structural variants of drug target-encoding genes on a genome-wide scale. We also aimed at identifying drugs that are potentially amenable for individualization of treatments based on knowledge about structural variation in the genes encoding...

Structure and Structure-activity Relationship of Functional Organic Molecules

Institute of Scientific and Technical Information of China (English)

2011-01-01

@@ Research theme The group is made up of junior scientists from the State Key Laboratory of Elemento-organic Chemistry, Nankai University.The scientists focus their studis on the structure and structure-activity relationship of functional organic molecules not only because it has been the basis of their research, but also because the functional study of organic compounds is now a major scientific issue for organic chemists around the world.

cDNA structure, genomic organization and expression patterns of ...

African Journals Online (AJOL)

use

2011-11-23

Nov 23, 2011 ... adenine dinucleotide (NAD) intermediate (Rongvaux et al., 2002). Thereupon ... in house mouse, Norway rat and human. It was not difficult to ... species in freshwater regions, and has been a new model organism in aquatic ...

Molecular Cloning, Genomic Organization and Developmental Regulation of a Novel Receptor from Drosophila melanogaster Structurally Related to Gonadotropin-Releasing Hormone Receptors from Vertebrates

DEFF Research Database (Denmark)

Hauser, Frank; Søndergaard, Leif; Grimmelikhuijzen, Cornelis J.P.

1998-01-01

After screening the data base of the BerkeleyDrosophilaGenome Project with a sequence coding for the transmembrane region of a G protein-coupled receptor, we found thatDrosophilamight contain a gene coding for a receptor that is structurally related to the Gonadotropin-Releasing Hormone (GnRH) re...

Mind the gap; seven reasons to close fragmented genome assemblies.

Science.gov (United States)

Thomma, Bart P H J; Seidl, Michael F; Shi-Kunne, Xiaoqian; Cook, David E; Bolton, Melvin D; van Kan, Jan A L; Faino, Luigi

2016-05-01

Like other domains of life, research into the biology of filamentous microbes has greatly benefited from the advent of whole-genome sequencing. Next-generation sequencing (NGS) technologies have revolutionized sequencing, making genomic sciences accessible to many academic laboratories including those that study non-model organisms. Thus, hundreds of fungal genomes have been sequenced and are publically available today, although these initiatives have typically yielded considerably fragmented genome assemblies that often lack large contiguous genomic regions. Many important genomic features are contained in intergenic DNA that is often missing in current genome assemblies, and recent studies underscore the significance of non-coding regions and repetitive elements for the life style, adaptability and evolution of many organisms. The study of particular types of genetic elements, such as telomeres, centromeres, repetitive elements, effectors, and clusters of co-regulated genes, but also of phenomena such as structural rearrangements, genome compartmentalization and epigenetics, greatly benefits from having a contiguous and high-quality, preferably even complete and gapless, genome assembly. Here we discuss a number of important reasons to produce gapless, finished, genome assemblies to help answer important biological questions. Copyright © 2015 Elsevier Inc. All rights reserved.

Partial structure of the phylloxin gene from the giant monkey frog, Phyllomedusa bicolor: parallel cloning of precursor cDNA and genomic DNA from lyophilized skin secretion.

Science.gov (United States)

Chen, Tianbao; Gagliardo, Ron; Walker, Brian; Zhou, Mei; Shaw, Chris

2005-12-01

Phylloxin is a novel prototype antimicrobial peptide from the skin of Phyllomedusa bicolor. Here, we describe parallel identification and sequencing of phylloxin precursor transcript (mRNA) and partial gene structure (genomic DNA) from the same sample of lyophilized skin secretion using our recently-described cloning technique. The open-reading frame of the phylloxin precursor was identical in nucleotide sequence to that previously reported and alignment with the nucleotide sequence derived from genomic DNA indicated the presence of a 175 bp intron located in a near identical position to that found in the dermaseptins. The highly-conserved structural organization of skin secretion peptide genes in P. bicolor can thus be extended to include that encoding phylloxin (plx). These data further reinforce our assertion that application of the described methodology can provide robust genomic/transcriptomic/peptidomic data without the need for specimen sacrifice.

Genome organization of the SARS-CoV

DEFF Research Database (Denmark)

Xu, Jing; Hu, Jianfei; Wang, Jing

2003-01-01

Annotation of the genome sequence of the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) is indispensable to understand its evolution and pathogenesis. We have performed a full annotation of the SARS-CoV genome sequences by using annotation programs publicly available or devel......Annotation of the genome sequence of the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) is indispensable to understand its evolution and pathogenesis. We have performed a full annotation of the SARS-CoV genome sequences by using annotation programs publicly available...

Terminal structures of West Nile virus genomic RNA and their interactions with viral NS5 protein

International Nuclear Information System (INIS)

Dong Hongping; Zhang Bo; Shi Peiyong

2008-01-01

Genome cyclization is essential for flavivirus replication. We used RNases to probe the structures formed by the 5'-terminal 190 nucleotides and the 3'-terminal 111 nucleotides of the West Nile virus (WNV) genomic RNA. When analyzed individually, the two RNAs adopt stem-loop structures as predicted by the thermodynamic-folding program. However, when mixed together, the two RNAs form a duplex that is mediated through base-pairings of two sets of RNA elements (5'CS/3'CSI and 5'UAR/3'UAR). Formation of the RNA duplex facilitates a conformational change that leaves the 3'-terminal nucleotides of the genome (position - 8 to - 16) to be single-stranded. Viral NS5 binds specifically to the 5'-terminal stem-loop (SL1) of the genomic RNA. The 5'SL1 RNA structure is essential for WNV replication. The study has provided further evidence to suggest that flavivirus genome cyclization and NS5/5'SL1 RNA interaction facilitate NS5 binding to the 3' end of the genome for the initiation of viral minus-strand RNA synthesis

The dynamic genome of Hydra

Science.gov (United States)

Chapman, Jarrod A.; Kirkness, Ewen F.; Simakov, Oleg; Hampson, Steven E.; Mitros, Therese; Weinmaier, Therese; Rattei, Thomas; Balasubramanian, Prakash G.; Borman, Jon; Busam, Dana; Disbennett, Kathryn; Pfannkoch, Cynthia; Sumin, Nadezhda; Sutton, Granger G.; Viswanathan, Lakshmi Devi; Walenz, Brian; Goodstein, David M.; Hellsten, Uffe; Kawashima, Takeshi; Prochnik, Simon E.; Putnam, Nicholas H.; Shu, Shengquiang; Blumberg, Bruce; Dana, Catherine E.; Gee, Lydia; Kibler, Dennis F.; Law, Lee; Lindgens, Dirk; Martinez, Daniel E.; Peng, Jisong; Wigge, Philip A.; Bertulat, Bianca; Guder, Corina; Nakamura, Yukio; Ozbek, Suat; Watanabe, Hiroshi; Khalturin, Konstantin; Hemmrich, Georg; Franke, André; Augustin, René; Fraune, Sebastian; Hayakawa, Eisuke; Hayakawa, Shiho; Hirose, Mamiko; Hwang, Jung Shan; Ikeo, Kazuho; Nishimiya-Fujisawa, Chiemi; Ogura, Atshushi; Takahashi, Toshio; Steinmetz, Patrick R. H.; Zhang, Xiaoming; Aufschnaiter, Roland; Eder, Marie-Kristin; Gorny, Anne-Kathrin; Salvenmoser, Willi; Heimberg, Alysha M.; Wheeler, Benjamin M.; Peterson, Kevin J.; Böttger, Angelika; Tischler, Patrick; Wolf, Alexander; Gojobori, Takashi; Remington, Karin A.; Strausberg, Robert L.; Venter, J. Craig; Technau, Ulrich; Hobmayer, Bert; Bosch, Thomas C. G.; Holstein, Thomas W.; Fujisawa, Toshitaka; Bode, Hans R.; David, Charles N.; Rokhsar, Daniel S.; Steele, Robert E.

2015-01-01

The freshwater cnidarian Hydra was first described in 17021 and has been the object of study for 300 years. Experimental studies of Hydra between 1736 and 1744 culminated in the discovery of asexual reproduction of an animal by budding, the first description of regeneration in an animal, and successful transplantation of tissue between animals2. Today, Hydra is an important model for studies of axial patterning3, stem cell biology4 and regeneration5. Here we report the genome of Hydra magnipapillata and compare it to the genomes of the anthozoan Nematostella vectensis6 and other animals. The Hydra genome has been shaped by bursts of transposable element expansion, horizontal gene transfer, trans-splicing, and simplification of gene structure and gene content that parallel simplification of the Hydra life cycle. We also report the sequence of the genome of a novel bacterium stably associated with H. magnipapillata. Comparisons of the Hydra genome to the genomes of other animals shed light on the evolution of epithelia, contractile tissues, developmentally regulated transcription factors, the Spemann–Mangold organizer, pluripotency genes and the neuromuscular junction. PMID:20228792

Complete plastid genomes from Ophioglossum californicum, Psilotum nudum, and Equisetum hyemale reveal an ancestral land plant genome structure and resolve the position of Equisetales among monilophytes

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Grewe Felix

2013-01-01

Full Text Available Abstract Background Plastid genome structure and content is remarkably conserved in land plants. This widespread conservation has facilitated taxon-rich phylogenetic analyses that have resolved organismal relationships among many land plant groups. However, the relationships among major fern lineages, especially the placement of Equisetales, remain enigmatic. Results In order to understand the evolution of plastid genomes and to establish phylogenetic relationships among ferns, we sequenced the plastid genomes from three early diverging species: Equisetum hyemale (Equisetales, Ophioglossum californicum (Ophioglossales, and Psilotum nudum (Psilotales. A comparison of fern plastid genomes showed that some lineages have retained inverted repeat (IR boundaries originating from the common ancestor of land plants, while other lineages have experienced multiple IR changes including expansions and inversions. Genome content has remained stable throughout ferns, except for a few lineage-specific losses of genes and introns. Notably, the losses of the rps16 gene and the rps12i346 intron are shared among Psilotales, Ophioglossales, and Equisetales, while the gain of a mitochondrial atp1 intron is shared between Marattiales and Polypodiopsida. These genomic structural changes support the placement of Equisetales as sister to Ophioglossales + Psilotales and Marattiales as sister to Polypodiopsida. This result is augmented by some molecular phylogenetic analyses that recover the same relationships, whereas others suggest a relationship between Equisetales and Polypodiopsida. Conclusions Although molecular analyses were inconsistent with respect to the position of Marattiales and Equisetales, several genomic structural changes have for the first time provided a clear placement of these lineages within the ferns. These results further demonstrate the power of using rare genomic structural changes in cases where molecular data fail to provide strong phylogenetic

Comparative Annotation of Viral Genomes with Non-Conserved Gene Structure

DEFF Research Database (Denmark)

de Groot, Saskia; Mailund, Thomas; Hein, Jotun

2007-01-01

Motivation: Detecting genes in viral genomes is a complex task. Due to the biological necessity of them being constrained in length, RNA viruses in particular tend to code in overlapping reading frames. Since one amino acid is encoded by a triplet of nucleic acids, up to three genes may be coded...... allows for coding in unidirectional nested and overlapping reading frames, to annotate two homologous aligned viral genomes. Our method does not insist on conserved gene structure between the two sequences, thus making it applicable for the pairwise comparison of more distantly related sequences. Results...... and HIV2, as well as of two different Hepatitis Viruses, attaining results of ~87% sensitivity and ~98.5% specificity. We subsequently incorporate prior knowledge by "knowing" the gene structure of one sequence and annotating the other conditional on it. Boosting accuracy close to perfect we demonstrate...

Flexibility and symmetry of prokaryotic genome rearrangement reveal lineage-associated core-gene-defined genome organizational frameworks.

Science.gov (United States)

Kang, Yu; Gu, Chaohao; Yuan, Lina; Wang, Yue; Zhu, Yanmin; Li, Xinna; Luo, Qibin; Xiao, Jingfa; Jiang, Daquan; Qian, Minping; Ahmed Khan, Aftab; Chen, Fei; Zhang, Zhang; Yu, Jun

2014-11-25

among isolates but also functionally essential for a given species and to further evaluate the stability or flexibility of such genome structures across lineages are of importance. Based on a large number of multi-isolate pangenomic data, our analysis reveals that a subset of core genes is organized into a core-gene-defined genome organizational framework, or cGOF. Furthermore, the lineage-associated cGOFs among Gram-positive and Gram-negative bacteria behave differently: the former, composed of 2 to 4 segments, have their fragments symmetrically rearranged around the origin-terminus axis, whereas the latter show more complex segmentation and are partitioned asymmetrically into chromosomal structures. The definition of cGOFs provides new insights into prokaryotic genome organization and efficient guidance for genome assembly and analysis. Copyright © 2014 Kang et al.

Genomes in Turmoil: Frugality Drives Microbial Community Structure in Extremely Acidic Environments

Science.gov (United States)

Holmes, D. S.

2016-12-01

Extremely acidic environments (To gain insight into these issues, we have conducted deep bioinformatic analyses, including metabolic reconstruction of key assimilatory pathways, phylogenomics and network scrutiny of >160 genomes of acidophiles, including representatives from Archaea, Bacteria and Eukarya and at least ten metagenomes of acidic environments [Cardenas JP, et al. pp 179-197 in Acidophiles, eds R. Quatrini and D. B. Johnson, Caister Academic Press, UK (2016)]. Results yielded valuable insights into cellular processes, including carbon and nitrogen management and energy production, linking biogeochemical processes to organismal physiology. They also provided insight into the evolutionary forces that shape the genomic structure of members of acidophile communities. Niche partitioning can explain diversity patterns in rapidly changing acidic environments such as bioleaching heaps. However, in spatially and temporally homogeneous acidic environments genome flux appears to provide deeper insight into the composition and evolution of acidic consortia. Acidophiles have undergone genome streamlining by gene loss promoting mutual coexistence of species that exploit complementarity use of scarce resources consistent with the Black Queen hypothesis [Morris JJ et al. mBio 3: e00036-12 (2012)]. Acidophiles also have a large pool of accessory genes (the microbial super-genome) that can be accessed by horizontal gene transfer. This further promotes dependency relationships as drivers of community structure and the evolution of keystone species. Acknowledgements: Fondecyt 1130683; Basal CCTE PFB16

Global MLST of Salmonella Typhi Revisited in Post-Genomic Era: Genetic conservation, Population Structure and Comparative genomics of rare sequence types

Directory of Open Access Journals (Sweden)

Kien-Pong eYap

2016-03-01

Full Text Available Typhoid fever, caused by Salmonella enterica serovar Typhi, remains an important public health burden in Southeast Asia and other endemic countries. Various genotyping methods have been applied to study the genetic variations of this human-restricted pathogen. Multilocus Sequence Typing (MLST is one of the widely accepted methods, and recently, there is a growing interest in the re-application of MLST in the post-genomic era. In this study, we provide the global MLST distribution of S. Typhi utilizing both publicly available 1,826 S. Typhi genome sequences in addition to performing conventional MLST on S. Typhi strains isolated from various endemic regions spanning over a century. Our global MLST analysis confirms the predominance of two sequence types (ST1 and ST2 co-existing in the endemic regions. Interestingly, S. Typhi strains with ST8 are currently confined within the African continent. Comparative genomic analyses of ST8 and other rare STs with genomes of ST1/ST2 revealed unique mutations in important virulence genes such as flhB, sipC and tviD that may explain the variations that differentiate between seemingly successful (widespread and unsuccessful (poor dissemination S. Typhi populations. Large scale whole-genome phylogeny demonstrated evidence of phylogeographical structuring and showed that ST8 may have diverged from the earlier ancestral population of ST1 and ST2, which later lost some of its fitness advantages, leading to poor worldwide dissemination. In response to the unprecedented increase in genomic data, this study demonstrates and highlights the utility of large-scale genome-based MLST as a quick and effective approach to narrow the scope of in-depth comparative genomic analysis and consequently provide new insights into the fine scale of pathogen evolution and population structure.

Integrating sequencing technologies in personal genomics: optimal low cost reconstruction of structural variants.

Directory of Open Access Journals (Sweden)

Jiang Du

2009-07-01

Full Text Available The goal of human genome re-sequencing is obtaining an accurate assembly of an individual's genome. Recently, there has been great excitement in the development of many technologies for this (e.g. medium and short read sequencing from companies such as 454 and SOLiD, and high-density oligo-arrays from Affymetrix and NimbelGen, with even more expected to appear. The costs and sensitivities of these technologies differ considerably from each other. As an important goal of personal genomics is to reduce the cost of re-sequencing to an affordable point, it is worthwhile to consider optimally integrating technologies. Here, we build a simulation toolbox that will help us optimally combine different technologies for genome re-sequencing, especially in reconstructing large structural variants (SVs. SV reconstruction is considered the most challenging step in human genome re-sequencing. (It is sometimes even harder than de novo assembly of small genomes because of the duplications and repetitive sequences in the human genome. To this end, we formulate canonical problems that are representative of issues in reconstruction and are of small enough scale to be computationally tractable and simulatable. Using semi-realistic simulations, we show how we can combine different technologies to optimally solve the assembly at low cost. With mapability maps, our simulations efficiently handle the inhomogeneous repeat-containing structure of the human genome and the computational complexity of practical assembly algorithms. They quantitatively show how combining different read lengths is more cost-effective than using one length, how an optimal mixed sequencing strategy for reconstructing large novel SVs usually also gives accurate detection of SNPs/indels, how paired-end reads can improve reconstruction efficiency, and how adding in arrays is more efficient than just sequencing for disentangling some complex SVs. Our strategy should facilitate the sequencing of

Structural and sequence diversity of the transposon Galileo in the Drosophila willistoni genome.

Science.gov (United States)

Gonçalves, Juliana W; Valiati, Victor Hugo; Delprat, Alejandra; Valente, Vera L S; Ruiz, Alfredo

2014-09-13

Galileo is one of three members of the P superfamily of DNA transposons. It was originally discovered in Drosophila buzzatii, in which three segregating chromosomal inversions were shown to have been generated by ectopic recombination between Galileo copies. Subsequently, Galileo was identified in six of 12 sequenced Drosophila genomes, indicating its widespread distribution within this genus. Galileo is strikingly abundant in Drosophila willistoni, a neotropical species that is highly polymorphic for chromosomal inversions, suggesting a role for this transposon in the evolution of its genome. We carried out a detailed characterization of all Galileo copies present in the D. willistoni genome. A total of 191 copies, including 133 with two terminal inverted repeats (TIRs), were classified according to structure in six groups. The TIRs exhibited remarkable variation in their length and structure compared to the most complete copy. Three copies showed extended TIRs due to internal tandem repeats, the insertion of other transposable elements (TEs), or the incorporation of non-TIR sequences into the TIRs. Phylogenetic analyses of the transposase (TPase)-encoding and TIR segments yielded two divergent clades, which we termed Galileo subfamilies V and W. Target-site duplications (TSDs) in D. willistoni Galileo copies were 7- or 8-bp in length, with the consensus sequence GTATTAC. Analysis of the region around the TSDs revealed a target site motif (TSM) with a 15-bp palindrome that may give rise to a stem-loop secondary structure. There is a remarkable abundance and diversity of Galileo copies in the D. willistoni genome, although no functional copies were found. The TIRs in particular have a dynamic structure and extend in different ways, but their ends (required for transposition) are more conserved than the rest of the element. The D. willistoni genome harbors two Galileo subfamilies (V and W) that diverged ~9 million years ago and may have descended from an ancestral

Cop-like operon: Structure and organization in species of the Lactobacillale order

Directory of Open Access Journals (Sweden)

ANGÉLICA REYES

2006-01-01

Full Text Available Copper is an essential and toxic trace metal for bacteria and, therefore, must be tightly regulated in the cell. Enterococcus hirae is a broadly studied model for copper homeostasis. The intracellular copper levels in E. hirae are regulated by the cop operon, which is formed by four genes: copA and copB that encode ATPases for influx and efflux of copper, respectively; copZ that encodes a copper chaperone; and copY, a copper responsive repressor. Since the complete genome sequence for E. hirae is not available, it is possible that other genes may encode proteins involved in copper homeostasis. Here, we identified a cop-like operon in nine species of Lactobacillale order with a known genome sequence. All of them always encoded a CopY-like repressor and a copper ATPase. The alignment of the cop-like operon promoter region revealed two CopY binding sites, one of which was conserved in all strains, and the second was only present in species of Streptococcus genus and L. johnsonii. Additional proteins associated to copper metabolism, CutC and Cupredoxin, also were detected. This study allowed for the description of the structure and organization of the cop operon and discussion of a phylogenetic hypothesis based on the differences observed in this operon's organization and its regulation in Lactobacillale order.

Recurrence time statistics: versatile tools for genomic DNA sequence analysis.

Science.gov (United States)

Cao, Yinhe; Tung, Wen-Wen; Gao, J B

2004-01-01

With the completion of the human and a few model organisms' genomes, and the genomes of many other organisms waiting to be sequenced, it has become increasingly important to develop faster computational tools which are capable of easily identifying the structures and extracting features from DNA sequences. One of the more important structures in a DNA sequence is repeat-related. Often they have to be masked before protein coding regions along a DNA sequence are to be identified or redundant expressed sequence tags (ESTs) are to be sequenced. Here we report a novel recurrence time based method for sequence analysis. The method can conveniently study all kinds of periodicity and exhaustively find all repeat-related features from a genomic DNA sequence. An efficient codon index is also derived from the recurrence time statistics, which has the salient features of being largely species-independent and working well on very short sequences. Efficient codon indices are key elements of successful gene finding algorithms, and are particularly useful for determining whether a suspected EST belongs to a coding or non-coding region. We illustrate the power of the method by studying the genomes of E. coli, the yeast S. cervisivae, the nematode worm C. elegans, and the human, Homo sapiens. Computationally, our method is very efficient. It allows us to carry out analysis of genomes on the whole genomic scale by a PC.

From Genome to Structure and Back Again: A Family Portrait of the Transcarbamylases

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Dashuang Shi

2015-08-01

Full Text Available Enzymes in the transcarbamylase family catalyze the transfer of a carbamyl group from carbamyl phosphate (CP to an amino group of a second substrate. The two best-characterized members, aspartate transcarbamylase (ATCase and ornithine transcarbamylase (OTCase, are present in most organisms from bacteria to humans. Recently, structures of four new transcarbamylase members, N-acetyl-l-ornithine transcarbamylase (AOTCase, N-succinyl-l-ornithine transcarbamylase (SOTCase, ygeW encoded transcarbamylase (YTCase and putrescine transcarbamylase (PTCase have also been determined. Crystal structures of these enzymes have shown that they have a common overall fold with a trimer as their basic biological unit. The monomer structures share a common CP binding site in their N-terminal domain, but have different second substrate binding sites in their C-terminal domain. The discovery of three new transcarbamylases, l-2,3-diaminopropionate transcarbamylase (DPTCase, l-2,4-diaminobutyrate transcarbamylase (DBTCase and ureidoglycine transcarbamylase (UGTCase, demonstrates that our knowledge and understanding of the spectrum of the transcarbamylase family is still incomplete. In this review, we summarize studies on the structures and function of transcarbamylases demonstrating how structural information helps to define biological function and how small structural differences govern enzyme specificity. Such information is important for correctly annotating transcarbamylase sequences in the genome databases and for identifying new members of the transcarbamylase family.

The elevation of radiation load on ecosystems and genome instability of organisms

International Nuclear Information System (INIS)

Gaziyev, A. I.; Bezlepkin, V.Q.

2002-01-01

prophylaxis of human disorders. Thus, it was found that the action of low-dose ionizing radiation on living organisms might induce an adaptive repair response in them aimed at decreasing the genetic consequences of the exposure. However, the potentialities of defense and repair systems of an organism are limited, so an increase in genome lesions may cause inheritable mutations, cancer and other pathologies, and death. DNA lesions caused by ionizing radiation in small and sublethal doses can essentially be repaired, whereas unrepaired lesions and errors of repair, replication, and recombination systems lead to formation of mutational changes in DNA sequences. These changes may be transmitted to daughter cells and induce genome instability in the progeny. Induced genome instability in survived somatic cells is characterized by persistence of a high level of acquired variability in many generations of these cells. Genome instability manifests itself as an increased frequency of karyotypic anomalies, chromosome and gene mutations, clonal heterogeneity, and malignant transformation in the progeny of cells exposed to DNA-damaging agents. Besides, cells with genome instability show increased amplification of genes and changes in their expression, as well as disturbances in their differentiation, delays in reproductive death and other phenotypic characters of abnormal development. Whereas some progress has been made towards knowledge of genome instability in the somatic cells of mammals, the radiation-induced genome instability in germ cells transmitted to individuals of the next generation is still not clearly understood. At the same time, evidence has been obtained which suggests that the transmission of genome instability to the somatic cells of the progeny from the germ cells of gamma - radiation-exposed parents is possible. This conclusion is based on the data on mutation frequency in the progeny of parents exposed to DNA-damaging agents. For instance, a significant increase in

Agricultural genomics and sustainable development: perspectives ...

African Journals Online (AJOL)

Administrator

era is to establish how genes and proteins function to bring about changes in phenotype. Some of ... within the context of sustainable development of African economies. The greatest .... these strategies, the genomes of many organisms have now been ... gene structure and order, e.g. between rice, wheat, corn, millets and ...

New families of human regulatory RNA structures identified by comparative analysis of vertebrate genomes.

Science.gov (United States)

Parker, Brian J; Moltke, Ida; Roth, Adam; Washietl, Stefan; Wen, Jiayu; Kellis, Manolis; Breaker, Ronald; Pedersen, Jakob Skou

2011-11-01

Regulatory RNA structures are often members of families with multiple paralogous instances across the genome. Family members share functional and structural properties, which allow them to be studied as a whole, facilitating both bioinformatic and experimental characterization. We have developed a comparative method, EvoFam, for genome-wide identification of families of regulatory RNA structures, based on primary sequence and secondary structure similarity. We apply EvoFam to a 41-way genomic vertebrate alignment. Genome-wide, we identify 220 human, high-confidence families outside protein-coding regions comprising 725 individual structures, including 48 families with known structural RNA elements. Known families identified include both noncoding RNAs, e.g., miRNAs and the recently identified MALAT1/MEN β lincRNA family; and cis-regulatory structures, e.g., iron-responsive elements. We also identify tens of new families supported by strong evolutionary evidence and other statistical evidence, such as GO term enrichments. For some of these, detailed analysis has led to the formulation of specific functional hypotheses. Examples include two hypothesized auto-regulatory feedback mechanisms: one involving six long hairpins in the 3'-UTR of MAT2A, a key metabolic gene that produces the primary human methyl donor S-adenosylmethionine; the other involving a tRNA-like structure in the intron of the tRNA maturation gene POP1. We experimentally validate the predicted MAT2A structures. Finally, we identify potential new regulatory networks, including large families of short hairpins enriched in immunity-related genes, e.g., TNF, FOS, and CTLA4, which include known transcript destabilizing elements. Our findings exemplify the diversity of post-transcriptional regulation and provide a resource for further characterization of new regulatory mechanisms and families of noncoding RNAs.

Looping and clustering model for the organization of protein-DNA complexes on the bacterial genome

Science.gov (United States)

Walter, Jean-Charles; Walliser, Nils-Ole; David, Gabriel; Dorignac, Jérôme; Geniet, Frédéric; Palmeri, John; Parmeggiani, Andrea; Wingreen, Ned S.; Broedersz, Chase P.

2018-03-01

The bacterial genome is organized by a variety of associated proteins inside a structure called the nucleoid. These proteins can form complexes on DNA that play a central role in various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, which forms an essential component of the segregation machinery in many bacteria. ChIP-Seq experiments show that ParB proteins localize around centromere-like parS sites on the DNA to which ParB binds specifically, and spreads from there over large sections of the chromosome. Recent theoretical and experimental studies suggest that DNA-bound ParB proteins can interact with each other to condense into a coherent 3D complex on the DNA. However, the structural organization of this protein-DNA complex remains unclear, and a predictive quantitative theory for the distribution of ParB proteins on DNA is lacking. Here, we propose the looping and clustering model, which employs a statistical physics approach to describe protein-DNA complexes. The looping and clustering model accounts for the extrusion of DNA loops from a cluster of interacting DNA-bound proteins that is organized around a single high-affinity binding site. Conceptually, the structure of the protein-DNA complex is determined by a competition between attractive protein interactions and loop closure entropy of this protein-DNA cluster on the one hand, and the positional entropy for placing loops within the cluster on the other. Indeed, we show that the protein interaction strength determines the ‘tightness’ of the loopy protein-DNA complex. Thus, our model provides a theoretical framework for quantitatively computing the binding profiles of ParB-like proteins around a cognate (parS) binding site.

Genomic minimalism in the early diverging intestinal parasite Giardia lamblia.

Science.gov (United States)

Morrison, Hilary G; McArthur, Andrew G; Gillin, Frances D; Aley, Stephen B; Adam, Rodney D; Olsen, Gary J; Best, Aaron A; Cande, W Zacheus; Chen, Feng; Cipriano, Michael J; Davids, Barbara J; Dawson, Scott C; Elmendorf, Heidi G; Hehl, Adrian B; Holder, Michael E; Huse, Susan M; Kim, Ulandt U; Lasek-Nesselquist, Erica; Manning, Gerard; Nigam, Anuranjini; Nixon, Julie E J; Palm, Daniel; Passamaneck, Nora E; Prabhu, Anjali; Reich, Claudia I; Reiner, David S; Samuelson, John; Svard, Staffan G; Sogin, Mitchell L

2007-09-28

The genome of the eukaryotic protist Giardia lamblia, an important human intestinal parasite, is compact in structure and content, contains few introns or mitochondrial relics, and has simplified machinery for DNA replication, transcription, RNA processing, and most metabolic pathways. Protein kinases comprise the single largest protein class and reflect Giardia's requirement for a complex signal transduction network for coordinating differentiation. Lateral gene transfer from bacterial and archaeal donors has shaped Giardia's genome, and previously unknown gene families, for example, cysteine-rich structural proteins, have been discovered. Unexpectedly, the genome shows little evidence of heterozygosity, supporting recent speculations that this organism is sexual. This genome sequence will not only be valuable for investigating the evolution of eukaryotes, but will also be applied to the search for new therapeutics for this parasite.

Novel rod-shaped viruses isolated from garlic, Allium sativum, possessing a unique genome organization.

Science.gov (United States)

Sumi, S; Tsuneyoshi, T; Furutani, H

1993-09-01

Rod-shaped flexuous viruses were partially purified from garlic plants (Allium sativum) showing typical mosaic symptoms. The genome was shown to be composed of RNA with a poly(A) tail of an estimated size of 10 kb as shown by denaturing agarose gel electrophoresis. We constructed cDNA libraries and screened four independent clones, which were designated GV-A, GV-B, GV-C and GV-D, using Northern and Southern blot hybridization. Nucleotide sequence determination of the cDNAs, two of which correspond to nearly one-third of the virus genomic RNA, shows that all of these viruses possess an identical genomic structure and that also at least four proteins are encoded in the viral cDNA, their M(r)s being estimated to be 15K, 27K, 40K and 11K. The 15K open reading frame (ORF) encodes the core-like sequence of a zinc finger protein preceded by a cluster of basic amino acid residues. The 27K ORF probably encodes the viral coat protein (CP), based on both the existence of some conserved sequences observed in many other rod-shaped or flexuous virus CPs and an overall amino acid sequence similarity to potexvirus and carlavirus CPs. The 11K ORF shows significant amino acid sequence similarities to the corresponding 12K proteins of the potexviruses and carlaviruses. On the other hand, the 40K ORF product does not resemble any other plant virus gene products reported so far. The genomic organization in the 3' region of the garlic viruses resembles, but clearly differs from, that of carlaviruses. Phylogenetic analysis based upon the amino acid sequence of the viral capsid protein also indicates that the garlic viruses have a unique and distinct domain different from those of the potexvirus and carlavirus groups. The results suggest that the garlic viruses described here belong to an unclassified and new virus group closely related to the carlaviruses.

Considerations in the identification of functional RNA structural elements in genomic alignments

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Blencowe Benjamin J

2007-01-01

Full Text Available Abstract Background Accurate identification of novel, functional noncoding (nc RNA features in genome sequence has proven more difficult than for exons. Current algorithms identify and score potential RNA secondary structures on the basis of thermodynamic stability, conservation, and/or covariance in sequence alignments. Neither the algorithms nor the information gained from the individual inputs have been independently assessed. Furthermore, due to issues in modelling background signal, it has been difficult to gauge the precision of these algorithms on a genomic scale, in which even a seemingly small false-positive rate can result in a vast excess of false discoveries. Results We developed a shuffling algorithm, shuffle-pair.pl, that simultaneously preserves dinucleotide frequency, gaps, and local conservation in pairwise sequence alignments. We used shuffle-pair.pl to assess precision and recall of six ncRNA search tools (MSARI, QRNA, ddbRNA, RNAz, Evofold, and several variants of simple thermodynamic stability on a test set of 3046 alignments of known ncRNAs. Relative to mononucleotide shuffling, preservation of dinucleotide content in shuffling the alignments resulted in a drastic increase in estimated false-positive detection rates for ncRNA elements, precluding evaluation of higher order alignments, which cannot not be adequately shuffled maintaining both dinucleotides and alignment structure. On pairwise alignments, none of the covariance-based tools performed markedly better than thermodynamic scoring alone. Although the high false-positive rates call into question the veracity of any individual predicted secondary structural element in our analysis, we nevertheless identified intriguing global trends in human genome alignments. The distribution of ncRNA prediction scores in 75-base windows overlapping UTRs, introns, and intergenic regions analyzed using both thermodynamic stability and EvoFold (which has no thermodynamic component was

Genomic organization, annotation, and ligand-receptor inferences of chicken chemokines and chemokine receptor genes based on comparative genomics

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Sze Sing-Hoi

2005-03-01

Full Text Available Abstract Background Chemokines and their receptors play important roles in host defense, organogenesis, hematopoiesis, and neuronal communication. Forty-two chemokines and 19 cognate receptors have been found in the human genome. Prior to this report, only 11 chicken chemokines and 7 receptors had been reported. The objectives of this study were to systematically identify chicken chemokines and their cognate receptor genes in the chicken genome and to annotate these genes and ligand-receptor binding by a comparative genomics approach. Results Twenty-three chemokine and 14 chemokine receptor genes were identified in the chicken genome. All of the chicken chemokines contained a conserved CC, CXC, CX3C, or XC motif, whereas all the chemokine receptors had seven conserved transmembrane helices, four extracellular domains with a conserved cysteine, and a conserved DRYLAIV sequence in the second intracellular domain. The number of coding exons in these genes and the syntenies are highly conserved between human, mouse, and chicken although the amino acid sequence homologies are generally low between mammalian and chicken chemokines. Chicken genes were named with the systematic nomenclature used in humans and mice based on phylogeny, synteny, and sequence homology. Conclusion The independent nomenclature of chicken chemokines and chemokine receptors suggests that the chicken may have ligand-receptor pairings similar to mammals. All identified chicken chemokines and their cognate receptors were identified in the chicken genome except CCR9, whose ligand was not identified in this study. The organization of these genes suggests that there were a substantial number of these genes present before divergence between aves and mammals and more gene duplications of CC, CXC, CCR, and CXCR subfamilies in mammals than in aves after the divergence.

Architectural protein subclasses shape 3-D organization of genomes during lineage commitment

Science.gov (United States)

Phillips-Cremins, Jennifer E.; Sauria, Michael E. G.; Sanyal, Amartya; Gerasimova, Tatiana I.; Lajoie, Bryan R.; Bell, Joshua S. K.; Ong, Chin-Tong; Hookway, Tracy A.; Guo, Changying; Sun, Yuhua; Bland, Michael J.; Wagstaff, William; Dalton, Stephen; McDevitt, Todd C.; Sen, Ranjan; Dekker, Job; Taylor, James; Corces, Victor G.

2013-01-01

Summary Understanding the topological configurations of chromatin may reveal valuable insights into how the genome and epigenome act in concert to control cell fate during development. Here we generate high-resolution architecture maps across seven genomic loci in embryonic stem cells and neural progenitor cells. We observe a hierarchy of 3-D interactions that undergo marked reorganization at the sub-Mb scale during differentiation. Distinct combinations of CTCF, Mediator, and cohesin show widespread enrichment in looping interactions at different length scales. CTCF/cohesin anchor long-range constitutive interactions that form the topological basis for invariant sub-domains. Conversely, Mediator/cohesin together with pioneer factors bridge shortrange enhancer-promoter interactions within and between larger sub-domains. Knockdown of Smc1 or Med12 in ES cells results in disruption of spatial architecture and down-regulation of genes found in cohesin-mediated interactions. We conclude that cell type-specific chromatin organization occurs at the sub-Mb scale and that architectural proteins shape the genome in hierarchical length scales. PMID:23706625

Genomic Diversity and Evolution of the Lyssaviruses

Science.gov (United States)

Delmas, Olivier; Holmes, Edward C.; Talbi, Chiraz; Larrous, Florence; Dacheux, Laurent; Bouchier, Christiane; Bourhy, Hervé

2008-01-01

Lyssaviruses are RNA viruses with single-strand, negative-sense genomes responsible for rabies-like diseases in mammals. To date, genomic and evolutionary studies have most often utilized partial genome sequences, particularly of the nucleoprotein and glycoprotein genes, with little consideration of genome-scale evolution. Herein, we report the first genomic and evolutionary analysis using complete genome sequences of all recognised lyssavirus genotypes, including 14 new complete genomes of field isolates from 6 genotypes and one genotype that is completely sequenced for the first time. In doing so we significantly increase the extent of genome sequence data available for these important viruses. Our analysis of these genome sequence data reveals that all lyssaviruses have the same genomic organization. A phylogenetic analysis reveals strong geographical structuring, with the greatest genetic diversity in Africa, and an independent origin for the two known genotypes that infect European bats. We also suggest that multiple genotypes may exist within the diversity of viruses currently classified as ‘Lagos Bat’. In sum, we show that rigorous phylogenetic techniques based on full length genome sequence provide the best discriminatory power for genotype classification within the lyssaviruses. PMID:18446239

Genomic diversity and evolution of the lyssaviruses.

Directory of Open Access Journals (Sweden)

Olivier Delmas

2008-04-01

Full Text Available Lyssaviruses are RNA viruses with single-strand, negative-sense genomes responsible for rabies-like diseases in mammals. To date, genomic and evolutionary studies have most often utilized partial genome sequences, particularly of the nucleoprotein and glycoprotein genes, with little consideration of genome-scale evolution. Herein, we report the first genomic and evolutionary analysis using complete genome sequences of all recognised lyssavirus genotypes, including 14 new complete genomes of field isolates from 6 genotypes and one genotype that is completely sequenced for the first time. In doing so we significantly increase the extent of genome sequence data available for these important viruses. Our analysis of these genome sequence data reveals that all lyssaviruses have the same genomic organization. A phylogenetic analysis reveals strong geographical structuring, with the greatest genetic diversity in Africa, and an independent origin for the two known genotypes that infect European bats. We also suggest that multiple genotypes may exist within the diversity of viruses currently classified as 'Lagos Bat'. In sum, we show that rigorous phylogenetic techniques based on full length genome sequence provide the best discriminatory power for genotype classification within the lyssaviruses.

Extensive gene content variation in the Brachypodium distachyon pan-genome correlates with population structure.

Science.gov (United States)

Gordon, Sean P; Contreras-Moreira, Bruno; Woods, Daniel P; Des Marais, David L; Burgess, Diane; Shu, Shengqiang; Stritt, Christoph; Roulin, Anne C; Schackwitz, Wendy; Tyler, Ludmila; Martin, Joel; Lipzen, Anna; Dochy, Niklas; Phillips, Jeremy; Barry, Kerrie; Geuten, Koen; Budak, Hikmet; Juenger, Thomas E; Amasino, Richard; Caicedo, Ana L; Goodstein, David; Davidson, Patrick; Mur, Luis A J; Figueroa, Melania; Freeling, Michael; Catalan, Pilar; Vogel, John P

2017-12-19

While prokaryotic pan-genomes have been shown to contain many more genes than any individual organism, the prevalence and functional significance of differentially present genes in eukaryotes remains poorly understood. Whole-genome de novo assembly and annotation of 54 lines of the grass Brachypodium distachyon yield a pan-genome containing nearly twice the number of genes found in any individual genome. Genes present in all lines are enriched for essential biological functions, while genes present in only some lines are enriched for conditionally beneficial functions (e.g., defense and development), display faster evolutionary rates, lie closer to transposable elements and are less likely to be syntenic with orthologous genes in other grasses. Our data suggest that differentially present genes contribute substantially to phenotypic variation within a eukaryote species, these genes have a major influence in population genetics, and transposable elements play a key role in pan-genome evolution.

Uncovering the functional constraints underlying the genomic organization of the odorant-binding protein genes.

Science.gov (United States)

Librado, Pablo; Rozas, Julio

2013-01-01

Animal olfactory systems have a critical role for the survival and reproduction of individuals. In insects, the odorant-binding proteins (OBPs) are encoded by a moderately sized gene family, and mediate the first steps of the olfactory processing. Most OBPs are organized in clusters of a few paralogs, which are conserved over time. Currently, the biological mechanism explaining the close physical proximity among OBPs is not yet established. Here, we conducted a comprehensive study aiming to gain insights into the mechanisms underlying the OBP genomic organization. We found that the OBP clusters are embedded within large conserved arrangements. These organizations also include other non-OBP genes, which often encode proteins integral to plasma membrane. Moreover, the conservation degree of such large clusters is related to the following: 1) the promoter architecture of the confined genes, 2) a characteristic transcriptional environment, and 3) the chromatin conformation of the chromosomal region. Our results suggest that chromatin domains may restrict the location of OBP genes to regions having the appropriate transcriptional environment, leading to the OBP cluster structure. However, the appropriate transcriptional environment for OBP and the other neighbor genes is not dominated by reduced levels of expression noise. Indeed, the stochastic fluctuations in the OBP transcript abundance may have a critical role in the combinatorial nature of the olfactory coding process.

Draft Genome Sequence of the Model Naphthalene-Utilizing Organism Pseudomonas putida OUS82

DEFF Research Database (Denmark)

Tay, Martin; Roizman, Dan; Cohen, Yehuda

2014-01-01

Pseudomonas putida OUS82 was isolated from petrol- and oil-contaminated soil in 1992, and ever since, it has been used as a model organism to study the microbial assimilation of naphthalene and phenanthrene. Here, we report the 6.7-Mb draft genome sequence of P. putida OUS82 and analyze its...

Grass genomes

OpenAIRE

Bennetzen, Jeffrey L.; SanMiguel, Phillip; Chen, Mingsheng; Tikhonov, Alexander; Francki, Michael; Avramova, Zoya

1998-01-01

For the most part, studies of grass genome structure have been limited to the generation of whole-genome genetic maps or the fine structure and sequence analysis of single genes or gene clusters. We have investigated large contiguous segments of the genomes of maize, sorghum, and rice, primarily focusing on intergenic spaces. Our data indicate that much (>50%) of the maize genome is composed of interspersed repetitive DNAs, primarily nested retrotransposons that in...

Structuring an Efficient Organic Wheat Breeding Program

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P. Stephen Baenziger

2011-08-01

Full Text Available Our long-term goal is to develop wheat cultivars that will improve the profitability and competitiveness of organic producers in Nebraska and the Northern Great Plains. Our approach is to select in early generations for highly heritable traits that are needed for both organic and conventional production (another breeding goal, followed by a targeted organic breeding effort with testing at two organic locations (each in a different ecological region beginning with the F6 generation. Yield analyses from replicated trials at two organic breeding sites and 7 conventional breeding sites from F6 through F12 nurseries revealed, using analyses of variance, biplots, and comparisons of selected lines that it is inappropriate to use data from conventional testing for making germplasm selections for organic production. Selecting and testing lines under organic production practices in different ecological regions was also needed and cultivar selections for organic production were different than those for conventional production. Modifications to this breeding protocol may include growing early generation bulks in an organic cropping system. In the future, our selection efforts should also focus on using state-of-the-art, non-transgenic breeding technologies (genomic selection, marker-assisted breeding, and high throughput phenotyping to synergistically improve organic and conventional wheat breeding.

Whole-Genome Analysis of a Novel Fish Reovirus (MsReV Discloses Aquareovirus Genomic Structure Relationship with Host in Saline Environments

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Zhong-Yuan Chen

2015-08-01

Full Text Available Aquareoviruses are serious pathogens of aquatic animals. Here, genome characterization and functional gene analysis of a novel aquareovirus, largemouth bass Micropterus salmoides reovirus (MsReV, was described. It comprises 11 dsRNA segments (S1–S11 covering 24,024 bp, and encodes 12 putative proteins including the inclusion forming-related protein NS87 and the fusion-associated small transmembrane (FAST protein NS22. The function of NS22 was confirmed by expression in fish cells. Subsequently, MsReV was compared with two representative aquareoviruses, saltwater fish turbot Scophthalmus maximus reovirus (SMReV and freshwater fish grass carp reovirus strain 109 (GCReV-109. MsReV NS87 and NS22 genes have the same structure and function with those of SMReV, whereas GCReV-109 is either missing the coiled-coil region in NS79 or the gene-encoding NS22. Significant similarities are also revealed among equivalent genome segments between MsReV and SMReV, but a difference is found between MsReV and GCReV-109. Furthermore, phylogenetic analysis showed that 13 aquareoviruses could be divided into freshwater and saline environments subgroups, and MsReV was closely related to SMReV in saline environments. Consequently, these viruses from hosts in saline environments have more genomic structural similarities than the viruses from hosts in freshwater. This is the first study of the relationships between aquareovirus genomic structure and their host environments.

Single-cell Hi-C bridges microscopy and genome-wide sequencing approaches to study 3D chromatin organization.

Science.gov (United States)

Ulianov, Sergey V; Tachibana-Konwalski, Kikue; Razin, Sergey V

2017-10-01

Recent years have witnessed an explosion of the single-cell biochemical toolbox including chromosome conformation capture (3C)-based methods that provide novel insights into chromatin spatial organization in individual cells. The observations made with these techniques revealed that topologically associating domains emerge from cell population averages and do not exist as static structures in individual cells. Stochastic nature of the genome folding is likely to be biologically relevant and may reflect the ability of chromatin fibers to adopt a number of alternative configurations, some of which could be transiently stabilized and serve regulatory purposes. Single-cell Hi-C approaches provide an opportunity to analyze chromatin folding in rare cell types such as stem cells, tumor progenitors, oocytes, and totipotent cells, contributing to a deeper understanding of basic mechanisms in development and disease. Here, we review key findings of single-cell Hi-C and discuss possible biological reasons and consequences of the inferred dynamic chromatin spatial organization. © 2017 WILEY Periodicals, Inc.

Complete Chloroplast Genome of the Wollemi Pine (Wollemia nobilis): Structure and Evolution.

Science.gov (United States)

Yap, Jia-Yee S; Rohner, Thore; Greenfield, Abigail; Van Der Merwe, Marlien; McPherson, Hannah; Glenn, Wendy; Kornfeld, Geoff; Marendy, Elessa; Pan, Annie Y H; Wilton, Alan; Wilkins, Marc R; Rossetto, Maurizio; Delaney, Sven K

2015-01-01

The Wollemi pine (Wollemia nobilis) is a rare Southern conifer with striking morphological similarity to fossil pines. A small population of W. nobilis was discovered in 1994 in a remote canyon system in the Wollemi National Park (near Sydney, Australia). This population contains fewer than 100 individuals and is critically endangered. Previous genetic studies of the Wollemi pine have investigated its evolutionary relationship with other pines in the family Araucariaceae, and have suggested that the Wollemi pine genome contains little or no variation. However, these studies were performed prior to the widespread use of genome sequencing, and their conclusions were based on a limited fraction of the Wollemi pine genome. In this study, we address this problem by determining the entire sequence of the W. nobilis chloroplast genome. A detailed analysis of the structure of the genome is presented, and the evolution of the genome is inferred by comparison with the chloroplast sequences of other members of the Araucariaceae and the related family Podocarpaceae. Pairwise alignments of whole genome sequences, and the presence of unique pseudogenes, gene duplications and insertions in W. nobilis and Araucariaceae, indicate that the W. nobilis chloroplast genome is most similar to that of its sister taxon Agathis. However, the W. nobilis genome contains an unusually high number of repetitive sequences, and these could be used in future studies to investigate and conserve any remnant genetic diversity in the Wollemi pine.

Genomic organization, evolution, and expression of photoprotein and opsin genes in Mnemiopsis leidyi: a new view of ctenophore photocytes

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Schnitzler Christine E

2012-12-01

Full Text Available Abstract Background Calcium-activated photoproteins are luciferase variants found in photocyte cells of bioluminescent jellyfish (Phylum Cnidaria and comb jellies (Phylum Ctenophora. The complete genomic sequence from the ctenophore Mnemiopsis leidyi, a representative of the earliest branch of animals that emit light, provided an opportunity to examine the genome of an organism that uses this class of luciferase for bioluminescence and to look for genes involved in light reception. To determine when photoprotein genes first arose, we examined the genomic sequence from other early-branching taxa. We combined our genomic survey with gene trees, developmental expression patterns, and functional protein assays of photoproteins and opsins to provide a comprehensive view of light production and light reception in Mnemiopsis. Results The Mnemiopsis genome has 10 full-length photoprotein genes situated within two genomic clusters with high sequence conservation that are maintained due to strong purifying selection and concerted evolution. Photoprotein-like genes were also identified in the genomes of the non-luminescent sponge Amphimedon queenslandica and the non-luminescent cnidarian Nematostella vectensis, and phylogenomic analysis demonstrated that photoprotein genes arose at the base of all animals. Photoprotein gene expression in Mnemiopsis embryos begins during gastrulation in migrating precursors to photocytes and persists throughout development in the canals where photocytes reside. We identified three putative opsin genes in the Mnemiopsis genome and show that they do not group with well-known bilaterian opsin subfamilies. Interestingly, photoprotein transcripts are co-expressed with two of the putative opsins in developing photocytes. Opsin expression is also seen in the apical sensory organ. We present evidence that one opsin functions as a photopigment in vitro, absorbing light at wavelengths that overlap with peak photoprotein light

Fungal Genomics Program

Energy Technology Data Exchange (ETDEWEB)

Grigoriev, Igor

2012-03-12

The JGI Fungal Genomics Program aims to scale up sequencing and analysis of fungal genomes to explore the diversity of fungi important for energy and the environment, and to promote functional studies on a system level. Combining new sequencing technologies and comparative genomics tools, JGI is now leading the world in fungal genome sequencing and analysis. Over 120 sequenced fungal genomes with analytical tools are available via MycoCosm (www.jgi.doe.gov/fungi), a web-portal for fungal biologists. Our model of interacting with user communities, unique among other sequencing centers, helps organize these communities, improves genome annotation and analysis work, and facilitates new larger-scale genomic projects. This resulted in 20 high-profile papers published in 2011 alone and contributing to the Genomics Encyclopedia of Fungi, which targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts). Our next grand challenges include larger scale exploration of fungal diversity (1000 fungal genomes), developing molecular tools for DOE-relevant model organisms, and analysis of complex systems and metagenomes.

Complete chloroplast genome sequence of Elodea canadensis and comparative analyses with other monocot plastid genomes.

Science.gov (United States)

Huotari, Tea; Korpelainen, Helena

2012-10-15

Elodea canadensis is an aquatic angiosperm native to North America. It has attracted great attention due to its invasive nature when transported to new areas in its non-native range. We have determined the complete nucleotide sequence of the chloroplast (cp) genome of Elodea. Taxonomically Elodea is a basal monocot, and only few monocot cp genomes representing early lineages of monocots have been sequenced so far. The genome is a circular double-stranded DNA molecule 156,700 bp in length, and has a typical structure with large (LSC 86,194 bp) and small (SSC 17,810 bp) single-copy regions separated by a pair of inverted repeats (IRs 26,348 bp each). The Elodea cp genome contains 113 unique genes and 16 duplicated genes in the IR regions. A comparative analysis showed that the gene order and organization of the Elodea cp genome is almost identical to that of Amborella trichopoda, a basal angiosperm. The structure of IRs in Elodea is unique among monocot species with the whole cp genome sequenced. In Elodea and another monocot Lemna minor the borders between IRs and LSC are located upstream of rps 19 gene and downstream of trnH-GUG gene, while in most monocots, IR has extended to include both trnH and rps 19 genes. A phylogenetic analysis conducted using Bayesian method, based on the DNA sequences of 81 chloroplast genes from 17 monocot taxa provided support for the placement of Elodea together with Lemna as a basal monocot and the next diverging lineage of monocots after Acorales. In comparison with other monocots, the Elodea cp genome has gone through only few rearrangements or gene losses. IR of Elodea has a unique structure among the monocot species studied so far as its structure is similar to that of a basal angiosperm Amborella. This result together with phylogenetic analyses supports the placement of Elodea as a basal monocot to the next diverging lineage of monocots after Acorales. So far, only few cp genomes representing early lineages of monocots have been

Comparative Genome Structure, Secondary Metabolite, and Effector Coding Capacity across Cochliobolus Pathogens

Energy Technology Data Exchange (ETDEWEB)

Condon, Bradford J.; Leng, Yueqiang; Wu, Dongliang; Bushley, Kathryn E.; Ohm, Robin A.; Otillar, Robert; Martin, Joel; Schackwitz, Wendy; Grimwood, Jane; MohdZainudin, NurAinlzzati; Xue, Chunsheng; Wang, Rui; Manning, Viola A.; Dhillon, Braham; Tu, Zheng Jin; Steffenson, Brian J.; Salamov, Asaf; Sun, Hui; Lowry, Steve; LaButti, Kurt; Han, James; Copeland, Alex; Lindquist, Erika; Barry, Kerrie; Schmutz, Jeremy; Baker, Scott E.; Ciuffetti, Lynda M.; Grigoriev, Igor V.; Zhong, Shaobin; Turgeon, B. Gillian

2013-01-24

The genomes of five Cochliobolus heterostrophus strains, two Cochliobolus sativus strains, three additional Cochliobolus species (Cochliobolus victoriae, Cochliobolus carbonum, Cochliobolus miyabeanus), and closely related Setosphaeria turcica were sequenced at the Joint Genome Institute (JGI). The datasets were used to identify SNPs between strains and species, unique genomic regions, core secondary metabolism genes, and small secreted protein (SSP) candidate effector encoding genes with a view towards pinpointing structural elements and gene content associated with specificity of these closely related fungi to different cereal hosts. Whole-genome alignment shows that three to five of each genome differs between strains of the same species, while a quarter of each genome differs between species. On average, SNP counts among field isolates of the same C. heterostrophus species are more than 25 higher than those between inbred lines and 50 lower than SNPs between Cochliobolus species. The suites of nonribosomal peptide synthetase (NRPS), polyketide synthase (PKS), and SSP encoding genes are astoundingly diverse among species but remarkably conserved among isolates of the same species, whether inbred or field strains, except for defining examples that map to unique genomic regions. Functional analysis of several strain-unique PKSs and NRPSs reveal a strong correlation with a role in virulence.

SL1 revisited: functional analysis of the structure and conformation of HIV-1 genome RNA.

Science.gov (United States)

Sakuragi, Sayuri; Yokoyama, Masaru; Shioda, Tatsuo; Sato, Hironori; Sakuragi, Jun-Ichi

2016-11-11

The dimer initiation site/dimer linkage sequence (DIS/DLS) region of HIV is located on the 5' end of the viral genome and suggested to form complex secondary/tertiary structures. Within this structure, stem-loop 1 (SL1) is believed to be most important and an essential key to dimerization, since the sequence and predicted secondary structure of SL1 are highly stable and conserved among various virus subtypes. In particular, a six-base palindromic sequence is always present at the hairpin loop of SL1 and the formation of kissing-loop structure at this position between the two strands of genomic RNA is suggested to trigger dimerization. Although the higher-order structure model of SL1 is well accepted and perhaps even undoubted lately, there could be stillroom for consideration to depict the functional SL1 structure while in vivo (in virion or cell). In this study, we performed several analyses to identify the nucleotides and/or basepairing within SL1 which are necessary for HIV-1 genome dimerization, encapsidation, recombination and infectivity. We unexpectedly found that some nucleotides that are believed to contribute the formation of the stem do not impact dimerization or infectivity. On the other hand, we found that one G-C basepair involved in stem formation may serve as an alternative dimer interactive site. We also report on our further investigation of the roles of the palindromic sequences on viral replication. Collectively, we aim to assemble a more-comprehensive functional map of SL1 on the HIV-1 viral life cycle. We discovered several possibilities for a novel structure of SL1 in HIV-1 DLS. The newly proposed structure model suggested that the hairpin loop of SL1 appeared larger, and genome dimerization process might consist of more complicated mechanism than previously understood. Further investigations would be still required to fully understand the genome packaging and dimerization of HIV.

Genome-wide analysis of the expansin gene superfamily reveals grapevine-specific structural and functional characteristics.

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Silvia Dal Santo

Full Text Available BACKGROUND: Expansins are proteins that loosen plant cell walls in a pH-dependent manner, probably by increasing the relative movement among polymers thus causing irreversible expansion. The expansin superfamily (EXP comprises four distinct families: expansin A (EXPA, expansin B (EXPB, expansin-like A (EXLA and expansin-like B (EXLB. There is experimental evidence that EXPA and EXPB proteins are required for cell expansion and developmental processes involving cell wall modification, whereas the exact functions of EXLA and EXLB remain unclear. The complete grapevine (Vitis vinifera genome sequence has allowed the characterization of many gene families, but an exhaustive genome-wide analysis of expansin gene expression has not been attempted thus far. METHODOLOGY/PRINCIPAL FINDINGS: We identified 29 EXP superfamily genes in the grapevine genome, representing all four EXP families. Members of the same EXP family shared the same exon-intron structure, and phylogenetic analysis confirmed a closer relationship between EXP genes from woody species, i.e. grapevine and poplar (Populus trichocarpa, compared to those from Arabidopsis thaliana and rice (Oryza sativa. We also identified grapevine-specific duplication events involving the EXLB family. Global gene expression analysis confirmed a strong correlation among EXP genes expressed in mature and green/vegetative samples, respectively, as reported for other gene families in the recently-published grapevine gene expression atlas. We also observed the specific co-expression of EXLB genes in woody organs, and the involvement of certain grapevine EXP genes in berry development and post-harvest withering. CONCLUSION: Our comprehensive analysis of the grapevine EXP superfamily confirmed and extended current knowledge about the structural and functional characteristics of this gene family, and also identified properties that are currently unique to grapevine expansin genes. Our data provide a model for the

Genome-wide organization and expression profiling of the R2R3-MYB transcription factor family in pineapple (Ananas comosus).

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Liu, Chaoyang; Xie, Tao; Chen, Chenjie; Luan, Aiping; Long, Jianmei; Li, Chuhao; Ding, Yaqi; He, Yehua

2017-07-01

The MYB proteins comprise one of the largest families of plant transcription factors, which are involved in various plant physiological and biochemical processes. Pineapple (Ananas comosus) is one of three most important tropical fruits worldwide. The completion of pineapple genome sequencing provides a great opportunity to investigate the organization and evolutionary traits of pineapple MYB genes at the genome-wide level. In the present study, a total of 94 pineapple R2R3-MYB genes were identified and further phylogenetically classified into 26 subfamilies, as supported by the conserved gene structures and motif composition. Collinearity analysis indicated that the segmental duplication events played a crucial role in the expansion of pineapple MYB gene family. Further comparative phylogenetic analysis suggested that there have been functional divergences of MYB gene family during plant evolution. RNA-seq data from different tissues and developmental stages revealed distinct temporal and spatial expression profiles of the AcMYB genes. Further quantitative expression analysis showed the specific expression patterns of the selected putative stress-related AcMYB genes in response to distinct abiotic stress and hormonal treatments. The comprehensive expression analysis of the pineapple MYB genes, especially the tissue-preferential and stress-responsive genes, could provide valuable clues for further function characterization. In this work, we systematically identified AcMYB genes by analyzing the pineapple genome sequence using a set of bioinformatics approaches. Our findings provide a global insight into the organization, phylogeny and expression patterns of the pineapple R2R3-MYB genes, and hence contribute to the greater understanding of their biological roles in pineapple.

DNA secondary structures: stability and function of G-quadruplex structures

Science.gov (United States)

Bochman, Matthew L.; Paeschke, Katrin; Zakian, Virginia A.

2013-01-01

In addition to the canonical double helix, DNA can fold into various other inter- and intramolecular secondary structures. Although many such structures were long thought to be in vitro artefacts, bioinformatics demonstrates that DNA sequences capable of forming these structures are conserved throughout evolution, suggesting the existence of non-B-form DNA in vivo. In addition, genes whose products promote formation or resolution of these structures are found in diverse organisms, and a growing body of work suggests that the resolution of DNA secondary structures is critical for genome integrity. This Review focuses on emerging evidence relating to the characteristics of G-quadruplex structures and the possible influence of such structures on genomic stability and cellular processes, such as transcription. PMID:23032257

RNA structural constraints in the evolution of the influenza A virus genome NP segment

NARCIS (Netherlands)

A.P. Gultyaev (Alexander); A. Tsyganov-Bodounov (Anton); M.I. Spronken (Monique); S. Van Der Kooij (Sander); R.A.M. Fouchier (Ron); R.C.L. Olsthoorn (René)

2014-01-01

textabstractConserved RNA secondary structures were predicted in the nucleoprotein (NP) segment of the influenza A virus genome using comparative sequence and structure analysis. A number of structural elements exhibiting nucleotide covariations were identified over the whole segment length,

A Strategic Analysis of Investment Opportunities within British Columbia's Private Healthcare Sector for a Non-Profit Genomics Research Organization

OpenAIRE

Barclay, John W.

2010-01-01

Advances in the genome sciences are leading to the development of new healthcare innovations relevant to the principles of personalized medicine. Genome BC, a non-profit research organization, invests in projects that will help facilitate the integration of these innovations into the delivery of healthcare. This analysis assesses the strategic positioning of private healthcare firms in BC to be early users of such innovations. The analysis assesses the suitability of investment from Genome BC...

GenRGenS: Software for Generating Random Genomic Sequences and Structures

OpenAIRE

Ponty , Yann; Termier , Michel; Denise , Alain

2006-01-01

International audience; GenRGenS is a software tool dedicated to randomly generating genomic sequences and structures. It handles several classes of models useful for sequence analysis, such as Markov chains, hidden Markov models, weighted context-free grammars, regular expressions and PROSITE expressions. GenRGenS is the only program that can handle weighted context-free grammars, thus allowing the user to model and to generate structured objects (such as RNA secondary structures) of any giv...

Comparing genomes: databases and computational tools for comparative analysis of prokaryotic genomes - DOI: 10.3395/reciis.v1i2.Sup.105en

Directory of Open Access Journals (Sweden)

Marcos Catanho

2007-12-01

Full Text Available Since the 1990's, the complete genetic code of more than 600 living organisms has been deciphered, such as bacteria, yeasts, protozoan parasites, invertebrates and vertebrates, including Homo sapiens, and plants. More than 2,000 other genome projects representing medical, commercial, environmental and industrial interests, or comprising model organisms, important for the development of the scientific research, are currently in progress. The achievement of complete genome sequences of numerous species combined with the tremendous progress in computation that occurred in the last few decades allowed the use of new holistic approaches in the study of genome structure, organization and evolution, as well as in the field of gene prediction and functional classification. Numerous public or proprietary databases and computational tools have been created attempting to optimize the access to this information through the web. In this review, we present the main resources available through the web for comparative analysis of prokaryotic genomes. We concentrated on the group of mycobacteria that contains important human and animal pathogens. The birth of Bioinformatics and Computational Biology and the contributions of these disciplines to the scientific development of this field are also discussed.

Using Partial Genomic Fosmid Libraries for Sequencing CompleteOrganellar Genomes

Energy Technology Data Exchange (ETDEWEB)

McNeal, Joel R.; Leebens-Mack, James H.; Arumuganathan, K.; Kuehl, Jennifer V.; Boore, Jeffrey L.; dePamphilis, Claude W.

2005-08-26

Organellar genome sequences provide numerous phylogenetic markers and yield insight into organellar function and molecular evolution. These genomes are much smaller in size than their nuclear counterparts; thus, their complete sequencing is much less expensive than total nuclear genome sequencing, making broader phylogenetic sampling feasible. However, for some organisms it is challenging to isolate plastid DNA for sequencing using standard methods. To overcome these difficulties, we constructed partial genomic libraries from total DNA preparations of two heterotrophic and two autotrophic angiosperm species using fosmid vectors. We then used macroarray screening to isolate clones containing large fragments of plastid DNA. A minimum tiling path of clones comprising the entire genome sequence of each plastid was selected, and these clones were shotgun-sequenced and assembled into complete genomes. Although this method worked well for both heterotrophic and autotrophic plants, nuclear genome size had a dramatic effect on the proportion of screened clones containing plastid DNA and, consequently, the overall number of clones that must be screened to ensure full plastid genome coverage. This technique makes it possible to determine complete plastid genome sequences for organisms that defy other available organellar genome sequencing methods, especially those for which limited amounts of tissue are available.

Leishmania naiffi and Leishmania guyanensis reference genomes highlight genome structure and gene evolution in the Viannia subgenus.

Science.gov (United States)

Coughlan, Simone; Taylor, Ali Shirley; Feane, Eoghan; Sanders, Mandy; Schonian, Gabriele; Cotton, James A; Downing, Tim

2018-04-01

The unicellular protozoan parasite Leishmania causes the neglected tropical disease leishmaniasis, affecting 12 million people in 98 countries. In South America, where the Viannia subgenus predominates, so far only L. ( Viannia ) braziliensis and L. ( V. ) panamensis have been sequenced, assembled and annotated as reference genomes. Addressing this deficit in molecular information can inform species typing, epidemiological monitoring and clinical treatment. Here, L. ( V. ) naiffi and L. ( V. ) guyanensis genomic DNA was sequenced to assemble these two genomes as draft references from short sequence reads. The methods used were tested using short sequence reads for L. braziliensis M2904 against its published reference as a comparison. This assembly and annotation pipeline identified 70 additional genes not annotated on the original M2904 reference. Phylogenetic and evolutionary comparisons of L. guyanensis and L. naiffi with 10 other Viannia genomes revealed four traits common to all Viannia : aneuploidy, 22 orthologous groups of genes absent in other Leishmania subgenera, elevated TATE transposon copies and a high NADH-dependent fumarate reductase gene copy number. Within the Viannia , there were limited structural changes in genome architecture specific to individual species: a 45 Kb amplification on chromosome 34 was present in all bar L. lainsoni , L. naiffi had a higher copy number of the virulence factor leishmanolysin, and laboratory isolate L. shawi M8408 had a possible minichromosome derived from the 3' end of chromosome 34 . This combination of genome assembly, phylogenetics and comparative analysis across an extended panel of diverse Viannia has uncovered new insights into the origin and evolution of this subgenus and can help improve diagnostics for leishmaniasis surveillance.

Discovery of global genomic re-organization based on comparison of two newly sequenced rice mitochondrial genomes with cytoplasmic male sterility-related genes

Directory of Open Access Journals (Sweden)

Yamada Mari

2010-03-01

Full Text Available Abstract Background Plant mitochondrial genomes are known for their complexity, and there is abundant evidence demonstrating that this organelle is important for plant sexual reproduction. Cytoplasmic male sterility (CMS is a phenomenon caused by incompatibility between the nucleus and mitochondria that has been discovered in various plant species. As the exact sequence of steps leading to CMS has not yet been revealed, efforts should be made to elucidate the factors underlying the mechanism of this important trait for crop breeding. Results Two CMS mitochondrial genomes, LD-CMS, derived from Oryza sativa L. ssp. indica (434,735 bp, and CW-CMS, derived from Oryza rufipogon Griff. (559,045 bp, were newly sequenced in this study. Compared to the previously sequenced Nipponbare (Oryza sativa L. ssp. japonica mitochondrial genome, the presence of 54 out of 56 protein-encoding genes (including pseudo-genes, 22 tRNA genes (including pseudo-tRNAs, and three rRNA genes was conserved. Two other genes were not present in the CW-CMS mitochondrial genome, and one of them was present as part of the newly identified chimeric ORF, CW-orf307. At least 12 genomic recombination events were predicted between the LD-CMS mitochondrial genome and Nipponbare, and 15 between the CW-CMS genome and Nipponbare, and novel genetic structures were formed by these genomic rearrangements in the two CMS lines. At least one of the genomic rearrangements was completely unique to each CMS line and not present in 69 rice cultivars or 9 accessions of O. rufipogon. Conclusion Our results demonstrate novel mitochondrial genomic rearrangements that are unique in CMS cytoplasm, and one of the genes that is unique in the CW mitochondrial genome, CW-orf307, appeared to be the candidate most likely responsible for the CW-CMS event. Genomic rearrangements were dynamic in the CMS lines in comparison with those of rice cultivars, suggesting that 'death' and possible 'birth' processes of the

The genome and structural proteome of an ocean siphovirus: a new window into the cyanobacterial 'mobilome'.

Science.gov (United States)

Sullivan, Matthew B; Krastins, Bryan; Hughes, Jennifer L; Kelly, Libusha; Chase, Michael; Sarracino, David; Chisholm, Sallie W

2009-11-01

Prochlorococcus, an abundant phototroph in the oceans, are infected by members of three families of viruses: myo-, podo- and siphoviruses. Genomes of myo- and podoviruses isolated on Prochlorococcus contain DNA replication machinery and virion structural genes homologous to those from coliphages T4 and T7 respectively. They also contain a suite of genes of cyanobacterial origin, most notably photosynthesis genes, which are expressed during infection and appear integral to the evolutionary trajectory of both host and phage. Here we present the first genome of a cyanobacterial siphovirus, P-SS2, which was isolated from Atlantic slope waters using a Prochlorococcus host (MIT9313). The P-SS2 genome is larger than, and considerably divergent from, previously sequenced siphoviruses. It appears most closely related to lambdoid siphoviruses, with which it shares 13 functional homologues. The approximately 108 kb P-SS2 genome encodes 131 predicted proteins and notably lacks photosynthesis genes which have consistently been found in other marine cyanophage, but does contain 14 other cyanobacterial homologues. While only six structural proteins were identified from the genome sequence, 35 proteins were detected experimentally; these mapped onto capsid and tail structural modules in the genome. P-SS2 is potentially capable of integration into its host as inferred from bioinformatically identified genetic machinery int, bet, exo and a 53 bp attachment site. The host attachment site appears to be a genomic island that is tied to insertion sequence (IS) activity that could facilitate mobility of a gene involved in the nitrogen-stress response. The homologous region and a secondary IS-element hot-spot in Synechococcus RS9917 are further evidence of IS-mediated genome evolution coincident with a probable relic prophage integration event. This siphovirus genome provides a glimpse into the biology of a deep-photic zone phage as well as the ocean cyanobacterial prophage and IS element

Visualizing information across multidimensional post-genomic structured and textual databases.

Science.gov (United States)

Tao, Ying; Friedman, Carol; Lussier, Yves A

2005-04-15

Visualizing relationships among biological information to facilitate understanding is crucial to biological research during the post-genomic era. Although different systems have been developed to view gene-phenotype relationships for specific databases, very few have been designed specifically as a general flexible tool for visualizing multidimensional genotypic and phenotypic information together. Our goal is to develop a method for visualizing multidimensional genotypic and phenotypic information and a model that unifies different biological databases in order to present the integrated knowledge using a uniform interface. We developed a novel, flexible and generalizable visualization tool, called PhenoGenesviewer (PGviewer), which in this paper was used to display gene-phenotype relationships from a human-curated database (OMIM) and from an automatic method using a Natural Language Processing tool called BioMedLEE. Data obtained from multiple databases were first integrated into a uniform structure and then organized by PGviewer. PGviewer provides a flexible query interface that allows dynamic selection and ordering of any desired dimension in the databases. Based on users' queries, results can be visualized using hierarchical expandable trees that present views specified by users according to their research interests. We believe that this method, which allows users to dynamically organize and visualize multiple dimensions, is a potentially powerful and promising tool that should substantially facilitate biological research. PhenogenesViewer as well as its support and tutorial are available at http://www.dbmi.columbia.edu/pgviewer/ Lussier@dbmi.columbia.edu.

Genome Organization Drives Chromosome Fragility.

Science.gov (United States)

Canela, Andres; Maman, Yaakov; Jung, Seolkyoung; Wong, Nancy; Callen, Elsa; Day, Amanda; Kieffer-Kwon, Kyong-Rim; Pekowska, Aleksandra; Zhang, Hongliang; Rao, Suhas S P; Huang, Su-Chen; Mckinnon, Peter J; Aplan, Peter D; Pommier, Yves; Aiden, Erez Lieberman; Casellas, Rafael; Nussenzweig, André

2017-07-27

In this study, we show that evolutionarily conserved chromosome loop anchors bound by CCCTC-binding factor (CTCF) and cohesin are vulnerable to DNA double strand breaks (DSBs) mediated by topoisomerase 2B (TOP2B). Polymorphisms in the genome that redistribute CTCF/cohesin occupancy rewire DNA cleavage sites to novel loop anchors. While transcription- and replication-coupled genomic rearrangements have been well documented, we demonstrate that DSBs formed at loop anchors are largely transcription-, replication-, and cell-type-independent. DSBs are continuously formed throughout interphase, are enriched on both sides of strong topological domain borders, and frequently occur at breakpoint clusters commonly translocated in cancer. Thus, loop anchors serve as fragile sites that generate DSBs and chromosomal rearrangements. VIDEO ABSTRACT. Published by Elsevier Inc.

Organizational structure in process-based organizations

NARCIS (Netherlands)

Vanhaverbeke, W.P.M.; Torremans, H.P.M.

1999-01-01

This paper investigates the role of the organization structure in process-based organizations. We argue that companies cannot be designed upon organizational processes only or that process management can be simply imposed as an additional structural dimension on top of the existing functional or

Evidence of pervasive biologically functional secondary structures within the genomes of eukaryotic single-stranded DNA viruses.

Science.gov (United States)

Muhire, Brejnev Muhizi; Golden, Michael; Murrell, Ben; Lefeuvre, Pierre; Lett, Jean-Michel; Gray, Alistair; Poon, Art Y F; Ngandu, Nobubelo Kwanele; Semegni, Yves; Tanov, Emil Pavlov; Monjane, Adérito Luis; Harkins, Gordon William; Varsani, Arvind; Shepherd, Dionne Natalie; Martin, Darren Patrick

2014-02-01

Single-stranded DNA (ssDNA) viruses have genomes that are potentially capable of forming complex secondary structures through Watson-Crick base pairing between their constituent nucleotides. A few of the structural elements formed by such base pairings are, in fact, known to have important functions during the replication of many ssDNA viruses. Unknown, however, are (i) whether numerous additional ssDNA virus genomic structural elements predicted to exist by computational DNA folding methods actually exist and (ii) whether those structures that do exist have any biological relevance. We therefore computationally inferred lists of the most evolutionarily conserved structures within a diverse selection of animal- and plant-infecting ssDNA viruses drawn from the families Circoviridae, Anelloviridae, Parvoviridae, Nanoviridae, and Geminiviridae and analyzed these for evidence of natural selection favoring the maintenance of these structures. While we find evidence that is consistent with purifying selection being stronger at nucleotide sites that are predicted to be base paired than at sites predicted to be unpaired, we also find strong associations between sites that are predicted to pair with one another and site pairs that are apparently coevolving in a complementary fashion. Collectively, these results indicate that natural selection actively preserves much of the pervasive secondary structure that is evident within eukaryote-infecting ssDNA virus genomes and, therefore, that much of this structure is biologically functional. Lastly, we provide examples of various highly conserved but completely uncharacterized structural elements that likely have important functions within some of the ssDNA virus genomes analyzed here.

Building a complete image of genome regulation in the model organism Escherichia coli.

Science.gov (United States)

Ishihama, Akira

2018-01-15

The model organism, Escherichia coli, contains a total of more than 4,500 genes, but the total number of RNA polymerase (RNAP) core enzyme or the transcriptase is only about 2,000 molecules per genome. The regulatory targets of RNAP are, however, modulated by changing its promoter selectivity through two-steps of protein-protein interplay with 7 species of the sigma factor in the first step, and then 300 species of the transcription factor (TF) in the second step. Scientists working in the field of prokaryotic transcription in Japan have made considerable contributions to the elucidation of genetic frameworks and regulatory modes of the genome transcription in E. coli K-12. This review summarizes the findings by this group, first focusing on three sigma factors, the stationary-phase sigma RpoS, the heat-shock sigma RpoH, and the flagellar-chemotaxis sigma RpoF, as examples. It also presents an overview of the current state of the systematic research being carried out to identify the regulatory functions of all TFs from a single and the same bacterium E. coli K-12, using the genomic SELEX and PS-TF screening systems. All these studies have been undertaken with the aim of understanding the genome regulation in E. coli K-12 as a whole.

No boundaries: genomes, organisms, and ecological interactions responsible for divergence and reproductive isolation.

Science.gov (United States)

Etges, William J

2014-01-01

Revealing the genetic basis of traits that cause reproductive isolation, particularly premating or sexual isolation, usually involves the same challenges as most attempts at genotype-phenotype mapping and so requires knowledge of how these traits are expressed in different individuals, populations, and environments, particularly under natural conditions. Genetic dissection of speciation phenotypes thus requires understanding of the internal and external contexts in which underlying genetic elements are expressed. Gene expression is a product of complex interacting factors internal and external to the organism including developmental programs, the genetic background including nuclear-cytotype interactions, epistatic relationships, interactions among individuals or social effects, stochasticity, and prevailing variation in ecological conditions. Understanding of genomic divergence associated with reproductive isolation will be facilitated by functional expression analysis of annotated genomes in organisms with well-studied evolutionary histories, phylogenetic affinities, and known patterns of ecological variation throughout their life cycles. I review progress and prospects for understanding the pervasive role of host plant use on genetic and phenotypic expression of reproductive isolating mechanisms in cactophilic Drosophila mojavensis and suggest how this system can be used as a model for revealing the genetic basis for species formation in organisms where speciation phenotypes are under the joint influences of genetic and environmental factors. © The American Genetic Association. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Unleashing the genome of Brassica rapa

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Haibao eTang

2012-07-01

Full Text Available The completion and release of the Brassica rapa genome is of great benefit to researchers of the Brassicas, Arabidopsis, and genome evolution. While its lineage is closely related to the model organism Arabidopsis thaliana, the Brassicas experienced a whole genome triplication subsequent to their divergence. This event contemporaneously created three copies of its ancestral genome, which had diploidized through the process of homeologous gene loss known as fractionation. By the fractionation of homeologous gene content and genetic regulatory binding sites, Brassica’s genome is well placed to use comparative genomic techniques to identify syntenic regions, homeologous gene duplications, and putative regulatory sequences. Here, we use the comparative genomics platform CoGe to perform several different genomic analyses with which to study structural changes of its genome and dynamics of various genetic elements. Starting with whole genome comparisons, the Brassica paleohexaploidy is characterized, syntenic regions with Arabidopsis thaliana are identified, and the TOC1 gene in the circadian rhythm pathway from Arabidopsis thaliana is used to find duplicated orthologs in Brassica rapa. These TOC1 genes are further analyzed to identify conserved noncoding sequences that contain cis-acting regulatory elements and promoter sequences previously implicated in circadian rhythmicity. Each 'cookbook style' analysis includes a step-by-step walkthrough with links to CoGe to quickly reproduce each step of the analytical process.

The amphioxus genome and the evolution of the chordate karyotype

Energy Technology Data Exchange (ETDEWEB)

Putnam, Nicholas H.; Butts, Thomas; Ferrier, David E.K.; Furlong, Rebecca F.; Hellsten, Uffe; Kawashima, Takeshi; Robinson-Rechavi, Marc; Shoguchi, Eiichi; Terry, Astrid; Yu, Jr-Kai; Benito-Gutierrez, Elia; Dubchak, Inna; Garcia-Fernandez, Jordi; Gibson-Brown, Jeremy J.; Grigoriev, Igor V.; Horton, Amy C.; de Jong, Pieter J.; Jurka, Jerzy; Kapitonov, Vladimir; Kohara, Yuji; Kuroki, Yoko; Lindquist, Erika; Lucas, Susan; Osoegawa, Kazutoyo; Pennacchio, Len A.; Salamov, Asaf A.; Satou, Yutaka; Sauka-Spengler, Tatjana; Schmutz[, Jeremy; Shin-I, Tadasu; Toyoda, Atsushi; Bronner-Fraser, Marianne; Fujiyama, Asao; Holland, Linda Z.; Holland, Peter W. H.; Satoh, Nori; Rokhsar, Daniel S.

2008-04-01

Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage with a fossil record dating back to the Cambrian. We describe the structure and gene content of the highly polymorphic {approx}520 million base pair genome of the Florida lancelet Branchiostoma floridae, and analyze it in the context of chordate evolution. Whole genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets, and vertebrates), and allow reconstruction of not only the gene complement of the last common chordate ancestor, but also a partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution.

The Design of Project Management Structural Organization

OpenAIRE

Dumitru Constantinescu; Cristian Etegan

2007-01-01

The relationships organization-suppliers-customers have recently known major changes in the structure of services and have made the organization develop its managerial and professional competencies in order to do projects. The qualified organization is the most trust-worthy in the process of doing a project. The participation of an organization in doing projects depends on a multitude of factors. Out of these factors, the structural organization comes forth, as it represents the variable with...

Composition and genomic organization of arthropod Hox clusters.

Science.gov (United States)

Pace, Ryan M; Grbić, Miodrag; Nagy, Lisa M

2016-01-01

The ancestral arthropod is believed to have had a clustered arrangement of ten Hox genes. Within arthropods, Hox gene mutations result in transformation of segment identities. Despite the fact that variation in segment number/character was common in the diversification of arthropods, few examples of Hox gene gains/losses have been correlated with morphological evolution. Furthermore, a full appreciation of the variation in the genomic arrangement of Hox genes in extant arthropods has not been recognized, as genome sequences from each major arthropod clade have not been reported until recently. Initial genomic analysis of the chelicerate Tetranychus urticae suggested that loss of Hox genes and Hox gene clustering might be more common than previously assumed. To further characterize the genomic evolution of arthropod Hox genes, we compared the genomic arrangement and general characteristics of Hox genes from representative taxa from each arthropod subphylum. In agreement with others, we find arthropods generally contain ten Hox genes arranged in a common orientation in the genome, with an increasing number of sampled species missing either Hox3 or abdominal-A orthologs. The genomic clustering of Hox genes in species we surveyed varies significantly, ranging from 0.3 to 13.6 Mb. In all species sampled, arthropod Hox genes are dispersed in the genome relative to the vertebrate Mus musculus. Differences in Hox cluster size arise from variation in the number of intervening genes, intergenic spacing, and the size of introns and UTRs. In the arthropods surveyed, Hox gene duplications are rare and four microRNAs are, in general, conserved in similar genomic positions relative to the Hox genes. The tightly clustered Hox complexes found in the vertebrates are not evident within arthropods, and differential patterns of Hox gene dispersion are found throughout the arthropods. The comparative genomic data continue to support an ancestral arthropod Hox cluster of ten genes with

Crystal Structures of DNA-Whirly Complexes and Their Role in Arabidopsis Organelle Genome Repair

Energy Technology Data Exchange (ETDEWEB)

Cappadocia, Laurent; Maréchal, Alexandre; Parent, Jean-Sébastien; Lepage, Étienne; Sygusch, Jurgen; Brisson, Normand (Montreal)

2010-09-07

DNA double-strand breaks are highly detrimental to all organisms and need to be quickly and accurately repaired. Although several proteins are known to maintain plastid and mitochondrial genome stability in plants, little is known about the mechanisms of DNA repair in these organelles and the roles of specific proteins. Here, using ciprofloxacin as a DNA damaging agent specific to the organelles, we show that plastids and mitochondria can repair DNA double-strand breaks through an error-prone pathway similar to the microhomology-mediated break-induced replication observed in humans, yeast, and bacteria. This pathway is negatively regulated by the single-stranded DNA (ssDNA) binding proteins from the Whirly family, thus indicating that these proteins could contribute to the accurate repair of plant organelle genomes. To understand the role of Whirly proteins in this process, we solved the crystal structures of several Whirly-DNA complexes. These reveal a nonsequence-specific ssDNA binding mechanism in which DNA is stabilized between domains of adjacent subunits and rendered unavailable for duplex formation and/or protein interactions. Our results suggest a model in which the binding of Whirly proteins to ssDNA would favor accurate repair of DNA double-strand breaks over an error-prone microhomology-mediated break-induced replication repair pathway.

RNA polymerase III transcription - regulated by chromatin structure and regulator of nuclear chromatin organization.

Science.gov (United States)

Pascali, Chiara; Teichmann, Martin

2013-01-01

RNA polymerase III (Pol III) transcription is regulated by modifications of the chromatin. DNA methylation and post-translational modifications of histones, such as acetylation, phosphorylation and methylation have been linked to Pol III transcriptional activity. In addition to being regulated by modifications of DNA and histones, Pol III genes and its transcription factors have been implicated in the organization of nuclear chromatin in several organisms. In yeast, the ability of the Pol III transcription system to contribute to nuclear organization seems to be dependent on direct interactions of Pol III genes and/or its transcription factors TFIIIC and TFIIIB with the structural maintenance of chromatin (SMC) protein-containing complexes cohesin and condensin. In human cells, Pol III genes and transcription factors have also been shown to colocalize with cohesin and the transcription regulator and genome organizer CCCTC-binding factor (CTCF). Furthermore, chromosomal sites have been identified in yeast and humans that are bound by partial Pol III machineries (extra TFIIIC sites - ETC; chromosome organizing clamps - COC). These ETCs/COC as well as Pol III genes possess the ability to act as boundary elements that restrict spreading of heterochromatin.

Chromatin Structure and Replication Origins: Determinants Of Chromosome Replication And Nuclear Organization

Science.gov (United States)

Smith, Owen K.; Aladjem, Mirit I.

2014-01-01

The DNA replication program is, in part, determined by the epigenetic landscape that governs local chromosome architecture and directs chromosome duplication. Replication must coordinate with other biochemical processes occurring concomitantly on chromatin, such as transcription and remodeling, to insure accurate duplication of both genetic and epigenetic features and to preserve genomic stability. The importance of genome architecture and chromatin looping in coordinating cellular processes on chromatin is illustrated by two recent sets of discoveries. First, chromatin-associated proteins that are not part of the core replication machinery were shown to affect the timing of DNA replication. These chromatin-associated proteins could be working in concert, or perhaps in competition, with the transcriptional machinery and with chromatin modifiers to determine the spatial and temporal organization of replication initiation events. Second, epigenetic interactions are mediated by DNA sequences that determine chromosomal replication. In this review we summarize recent findings and current models linking spatial and temporal regulation of the replication program with epigenetic signaling. We discuss these issues in the context of the genome’s three-dimensional structure with an emphasis on events occurring during the initiation of DNA replication. PMID:24905010

Full-length genomic analysis of korean porcine sapelovirus strains

DEFF Research Database (Denmark)

Son, Kyu-Yeol; Kim, Deok-Song; Kwon, Joseph

2014-01-01

the typical picornavirus genome organization; 5'untranslated region (UTR)-L-VP4-VP2-VP3-VP1-2A-2B-2C-3A-3B-3C-3D-3'UTR. Three distinct cis-active RNA elements, the internal ribosome entry site (IRES) in the 5'UTR, a cis-replication element (CRE) in the 2C coding region and 3'UTR were identified...... and their structures were predicted. Interestingly, the structural features of the CRE and 3'UTR were different between PSV strains. The availability of these first complete genome sequences for PSV strains will facilitate future investigations of the molecular pathogenesis and evolutionary characteristics of PSV....

Structural constraints in the packaging of bluetongue virus genomic segments.

Science.gov (United States)

Burkhardt, Christiane; Sung, Po-Yu; Celma, Cristina C; Roy, Polly

2014-10-01

The mechanism used by bluetongue virus (BTV) to ensure the sorting and packaging of its 10 genomic segments is still poorly understood. In this study, we investigated the packaging constraints for two BTV genomic segments from two different serotypes. Segment 4 (S4) of BTV serotype 9 was mutated sequentially and packaging of mutant ssRNAs was investigated by two newly developed RNA packaging assay systems, one in vivo and the other in vitro. Modelling of the mutated ssRNA followed by biochemical data analysis suggested that a conformational motif formed by interaction of the 5' and 3' ends of the molecule was necessary and sufficient for packaging. A similar structural signal was also identified in S8 of BTV serotype 1. Furthermore, the same conformational analysis of secondary structures for positive-sense ssRNAs was used to generate a chimeric segment that maintained the putative packaging motif but contained unrelated internal sequences. This chimeric segment was packaged successfully, confirming that the motif identified directs the correct packaging of the segment. © 2014 The Authors.

The complete chloroplast genome sequence of an endemic monotypic genus Hagenia (Rosaceae: structural comparative analysis, gene content and microsatellite detection

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Andrew W. Gichira

2017-01-01

Full Text Available Hagenia is an endangered monotypic genus endemic to the topical mountains of Africa. The only species, Hagenia abyssinica (Bruce J.F. Gmel, is an important medicinal plant producing bioactive compounds that have been traditionally used by African communities as a remedy for gastrointestinal ailments in both humans and animals. Complete chloroplast genomes have been applied in resolving phylogenetic relationships within plant families. We employed high-throughput sequencing technologies to determine the complete chloroplast genome sequence of H. abyssinica. The genome is a circular molecule of 154,961 base pairs (bp, with a pair of Inverted Repeats (IR 25,971 bp each, separated by two single copies; a large (LSC, 84,320 bp and a small single copy (SSC, 18,696. H. abyssinica’s chloroplast genome has a 37.1% GC content and encodes 112 unique genes, 78 of which code for proteins, 30 are tRNA genes and four are rRNA genes. A comparative analysis with twenty other species, sequenced to-date from the family Rosaceae, revealed similarities in structural organization, gene content and arrangement. The observed size differences are attributed to the contraction/expansion of the inverted repeats. The translational initiation factor gene (infA which had been previously reported in other chloroplast genomes was conspicuously missing in H. abyssinica. A total of 172 microsatellites and 49 large repeat sequences were detected in the chloroplast genome. A Maximum Likelihood analyses of 71 protein-coding genes placed Hagenia in Rosoideae. The availability of a complete chloroplast genome, the first in the Sanguisorbeae tribe, is beneficial for further molecular studies on taxonomic and phylogenomic resolution within the Rosaceae family.

The complete chloroplast genome sequence of an endemic monotypic genus Hagenia (Rosaceae): structural comparative analysis, gene content and microsatellite detection.

Science.gov (United States)

Gichira, Andrew W; Li, Zhizhong; Saina, Josphat K; Long, Zhicheng; Hu, Guangwan; Gituru, Robert W; Wang, Qingfeng; Chen, Jinming

2017-01-01

Hagenia is an endangered monotypic genus endemic to the topical mountains of Africa. The only species, Hagenia abyssinica (Bruce) J.F. Gmel, is an important medicinal plant producing bioactive compounds that have been traditionally used by African communities as a remedy for gastrointestinal ailments in both humans and animals. Complete chloroplast genomes have been applied in resolving phylogenetic relationships within plant families. We employed high-throughput sequencing technologies to determine the complete chloroplast genome sequence of H. abyssinica. The genome is a circular molecule of 154,961 base pairs (bp), with a pair of Inverted Repeats (IR) 25,971 bp each, separated by two single copies; a large (LSC, 84,320 bp) and a small single copy (SSC, 18,696). H. abyssinica 's chloroplast genome has a 37.1% GC content and encodes 112 unique genes, 78 of which code for proteins, 30 are tRNA genes and four are rRNA genes. A comparative analysis with twenty other species, sequenced to-date from the family Rosaceae, revealed similarities in structural organization, gene content and arrangement. The observed size differences are attributed to the contraction/expansion of the inverted repeats. The translational initiation factor gene ( infA ) which had been previously reported in other chloroplast genomes was conspicuously missing in H. abyssinica . A total of 172 microsatellites and 49 large repeat sequences were detected in the chloroplast genome. A Maximum Likelihood analyses of 71 protein-coding genes placed Hagenia in Rosoideae. The availability of a complete chloroplast genome, the first in the Sanguisorbeae tribe, is beneficial for further molecular studies on taxonomic and phylogenomic resolution within the Rosaceae family.

Analysis of the grape MYB R2R3 subfamily reveals expanded wine quality-related clades and conserved gene structure organization across Vitis and Arabidopsis genomes

Science.gov (United States)

Matus, José Tomás; Aquea, Felipe; Arce-Johnson, Patricio

2008-01-01

Background The MYB superfamily constitutes the most abundant group of transcription factors described in plants. Members control processes such as epidermal cell differentiation, stomatal aperture, flavonoid synthesis, cold and drought tolerance and pathogen resistance. No genome-wide characterization of this family has been conducted in a woody species such as grapevine. In addition, previous analysis of the recently released grape genome sequence suggested expansion events of several gene families involved in wine quality. Results We describe and classify 108 members of the grape R2R3 MYB gene subfamily in terms of their genomic gene structures and similarity to their putative Arabidopsis thaliana orthologues. Seven gene models were derived and analyzed in terms of gene expression and their DNA binding domain structures. Despite low overall sequence homology in the C-terminus of all proteins, even in those with similar functions across Arabidopsis and Vitis, highly conserved motif sequences and exon lengths were found. The grape epidermal cell fate clade is expanded when compared with the Arabidopsis and rice MYB subfamilies. Two anthocyanin MYBA related clusters were identified in chromosomes 2 and 14, one of which includes the previously described grape colour locus. Tannin related loci were also detected with eight candidate homologues in chromosomes 4, 9 and 11. Conclusion This genome wide transcription factor analysis in Vitis suggests that clade-specific grape R2R3 MYB genes are expanded while other MYB genes could be well conserved compared to Arabidopsis. MYB gene abundance, homology and orientation within particular loci also suggests that expanded MYB clades conferring quality attributes of grapes and wines, such as colour and astringency, could possess redundant, overlapping and cooperative functions. PMID:18647406

Exploration of plant genomes in the FLAGdb++ environment

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Leplé Jean-Charles

2011-03-01

Full Text Available Abstract Background In the contexts of genomics, post-genomics and systems biology approaches, data integration presents a major concern. Databases provide crucial solutions: they store, organize and allow information to be queried, they enhance the visibility of newly produced data by comparing them with previously published results, and facilitate the exploration and development of both existing hypotheses and new ideas. Results The FLAGdb++ information system was developed with the aim of using whole plant genomes as physical references in order to gather and merge available genomic data from in silico or experimental approaches. Available through a JAVA application, original interfaces and tools assist the functional study of plant genes by considering them in their specific context: chromosome, gene family, orthology group, co-expression cluster and functional network. FLAGdb++ is mainly dedicated to the exploration of large gene groups in order to decipher functional connections, to highlight shared or specific structural or functional features, and to facilitate translational tasks between plant species (Arabidopsis thaliana, Oryza sativa, Populus trichocarpa and Vitis vinifera. Conclusion Combining original data with the output of experts and graphical displays that differ from classical plant genome browsers, FLAGdb++ presents a powerful complementary tool for exploring plant genomes and exploiting structural and functional resources, without the need for computer programming knowledge. First launched in 2002, a 15th version of FLAGdb++ is now available and comprises four model plant genomes and over eight million genomic features.

Genomes to Proteomes

Energy Technology Data Exchange (ETDEWEB)

Panisko, Ellen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Grigoriev, Igor [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Daly, Don S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Webb-Robertson, Bobbie-Jo [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baker, Scott E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2009-03-01

Biologists are awash with genomic sequence data. In large part, this is due to the rapid acceleration in the generation of DNA sequence that occurred as public and private research institutes raced to sequence the human genome. In parallel with the large human genome effort, mostly smaller genomes of other important model organisms were sequenced. Projects following on these initial efforts have made use of technological advances and the DNA sequencing infrastructure that was built for the human and other organism genome projects. As a result, the genome sequences of many organisms are available in high quality draft form. While in many ways this is good news, there are limitations to the biological insights that can be gleaned from DNA sequences alone; genome sequences offer only a bird's eye view of the biological processes endemic to an organism or community. Fortunately, the genome sequences now being produced at such a high rate can serve as the foundation for other global experimental platforms such as proteomics. Proteomic methods offer a snapshot of the proteins present at a point in time for a given biological sample. Current global proteomics methods combine enzymatic digestion, separations, mass spectrometry and database searching for peptide identification. One key aspect of proteomics is the prediction of peptide sequences from mass spectrometry data. Global proteomic analysis uses computational matching of experimental mass spectra with predicted spectra based on databases of gene models that are often generated computationally. Thus, the quality of gene models predicted from a genome sequence is crucial in the generation of high quality peptide identifications. Once peptides are identified they can be assigned to their parent protein. Proteins identified as expressed in a given experiment are most useful when compared to other expressed proteins in a larger biological context or biochemical pathway. In this chapter we will discuss the automatic

Large-scale chromosome folding versus genomic DNA sequences: A discrete double Fourier transform technique.

Science.gov (United States)

Chechetkin, V R; Lobzin, V V

2017-08-07

Using state-of-the-art techniques combining imaging methods and high-throughput genomic mapping tools leaded to the significant progress in detailing chromosome architecture of various organisms. However, a gap still remains between the rapidly growing structural data on the chromosome folding and the large-scale genome organization. Could a part of information on the chromosome folding be obtained directly from underlying genomic DNA sequences abundantly stored in the databanks? To answer this question, we developed an original discrete double Fourier transform (DDFT). DDFT serves for the detection of large-scale genome regularities associated with domains/units at the different levels of hierarchical chromosome folding. The method is versatile and can be applied to both genomic DNA sequences and corresponding physico-chemical parameters such as base-pairing free energy. The latter characteristic is closely related to the replication and transcription and can also be used for the assessment of temperature or supercoiling effects on the chromosome folding. We tested the method on the genome of E. coli K-12 and found good correspondence with the annotated domains/units established experimentally. As a brief illustration of further abilities of DDFT, the study of large-scale genome organization for bacteriophage PHIX174 and bacterium Caulobacter crescentus was also added. The combined experimental, modeling, and bioinformatic DDFT analysis should yield more complete knowledge on the chromosome architecture and genome organization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gramene 2018: unifying comparative genomics and pathway resources for plant research

OpenAIRE

Tello-Ruiz, Marcela K; Naithani, Sushma; Stein, Joshua C; Gupta, Parul; Campbell, Michael; Olson, Andrew; Wei, Sharon; Preece, Justin; Geniza, Matthew J; Jiao, Yinping; Lee, Young Koung; Wang, Bo; Mulvaney, Joseph; Chougule, Kapeel; Elser, Justin

2017-01-01

Abstract Gramene (http://www.gramene.org) is a knowledgebase for comparative functional analysis in major crops and model plant species. The current release, #54, includes over 1.7 million genes from 44 reference genomes, most of which were organized into 62,367 gene families through orthologous and paralogous gene classification, whole-genome alignments, and synteny. Additional gene annotations include ontology-based protein structure and function; genetic, epigenetic, and phenotypic diversi...

A genome wide survey of SNP variation reveals the genetic structure of sheep breeds.

Directory of Open Access Journals (Sweden)

James W Kijas

Full Text Available The genetic structure of sheep reflects their domestication and subsequent formation into discrete breeds. Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. After identifying the first genome-wide set of SNP for sheep, we report on levels of genetic variability both within and between a diverse sample of ovine populations. Then, using cluster analysis and the partitioning of genetic variation, we demonstrate sheep are characterised by weak phylogeographic structure, overlapping genetic similarity and generally low differentiation which is consistent with their short evolutionary history. The degree of population substructure was, however, sufficient to cluster individuals based on geographic origin and known breed history. Specifically, African and Asian populations clustered separately from breeds of European origin sampled from Australia, New Zealand, Europe and North America. Furthermore, we demonstrate the presence of stratification within some, but not all, ovine breeds. The results emphasize that careful documentation of genetic structure will be an essential prerequisite when mapping the genetic basis of complex traits. Furthermore, the identification of a subset of SNP able to assign individuals into broad groupings demonstrates even a small panel of markers may be suitable for applications such as traceability.

Minerals with metal-organic framework structures.

Science.gov (United States)

Huskić, Igor; Pekov, Igor V; Krivovichev, Sergey V; Friščić, Tomislav

2016-08-01

Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals.

Tree-Structured Digital Organisms Model

Science.gov (United States)

Suzuki, Teruhiko; Nobesawa, Shiho; Tahara, Ikuo

Tierra and Avida are well-known models of digital organisms. They describe a life process as a sequence of computation codes. A linear sequence model may not be the only way to describe a digital organism, though it is very simple for a computer-based model. Thus we propose a new digital organism model based on a tree structure, which is rather similar to the generic programming. With our model, a life process is a combination of various functions, as if life in the real world is. This implies that our model can easily describe the hierarchical structure of life, and it can simulate evolutionary computation through mutual interaction of functions. We verified our model by simulations that our model can be regarded as a digital organism model according to its definitions. Our model even succeeded in creating species such as viruses and parasites.

Combining Functional and Structural Genomics to Sample the Essential Burkholderia Structome

Science.gov (United States)

Baugh, Loren; Gallagher, Larry A.; Patrapuvich, Rapatbhorn; Clifton, Matthew C.; Gardberg, Anna S.; Edwards, Thomas E.; Armour, Brianna; Begley, Darren W.; Dieterich, Shellie H.; Dranow, David M.; Abendroth, Jan; Fairman, James W.; Fox, David; Staker, Bart L.; Phan, Isabelle; Gillespie, Angela; Choi, Ryan; Nakazawa-Hewitt, Steve; Nguyen, Mary Trang; Napuli, Alberto; Barrett, Lynn; Buchko, Garry W.; Stacy, Robin; Myler, Peter J.; Stewart, Lance J.; Manoil, Colin; Van Voorhis, Wesley C.

2013-01-01

Background The genus Burkholderia includes pathogenic gram-negative bacteria that cause melioidosis, glanders, and pulmonary infections of patients with cancer and cystic fibrosis. Drug resistance has made development of new antimicrobials critical. Many approaches to discovering new antimicrobials, such as structure-based drug design and whole cell phenotypic screens followed by lead refinement, require high-resolution structures of proteins essential to the parasite. Methodology/Principal Findings We experimentally identified 406 putative essential genes in B. thailandensis, a low-virulence species phylogenetically similar to B. pseudomallei, the causative agent of melioidosis, using saturation-level transposon mutagenesis and next-generation sequencing (Tn-seq). We selected 315 protein products of these genes based on structure-determination criteria, such as excluding very large and/or integral membrane proteins, and entered them into the Seattle Structural Genomics Center for Infection Disease (SSGCID) structure determination pipeline. To maximize structural coverage of these targets, we applied an “ortholog rescue” strategy for those producing insoluble or difficult to crystallize proteins, resulting in the addition of 387 orthologs (or paralogs) from seven other Burkholderia species into the SSGCID pipeline. This structural genomics approach yielded structures from 31 putative essential targets from B. thailandensis, and 25 orthologs from other Burkholderia species, yielding an overall structural coverage for 49 of the 406 essential gene families, with a total of 88 depositions into the Protein Data Bank. Of these, 25 proteins have properties of a potential antimicrobial drug target i.e., no close human homolog, part of an essential metabolic pathway, and a deep binding pocket. We describe the structures of several potential drug targets in detail. Conclusions/Significance This collection of structures, solubility and experimental essentiality data

Combining functional and structural genomics to sample the essential Burkholderia structome.

Directory of Open Access Journals (Sweden)

Loren Baugh

Full Text Available The genus Burkholderia includes pathogenic gram-negative bacteria that cause melioidosis, glanders, and pulmonary infections of patients with cancer and cystic fibrosis. Drug resistance has made development of new antimicrobials critical. Many approaches to discovering new antimicrobials, such as structure-based drug design and whole cell phenotypic screens followed by lead refinement, require high-resolution structures of proteins essential to the parasite.We experimentally identified 406 putative essential genes in B. thailandensis, a low-virulence species phylogenetically similar to B. pseudomallei, the causative agent of melioidosis, using saturation-level transposon mutagenesis and next-generation sequencing (Tn-seq. We selected 315 protein products of these genes based on structure-determination criteria, such as excluding very large and/or integral membrane proteins, and entered them into the Seattle Structural Genomics Center for Infection Disease (SSGCID structure determination pipeline. To maximize structural coverage of these targets, we applied an "ortholog rescue" strategy for those producing insoluble or difficult to crystallize proteins, resulting in the addition of 387 orthologs (or paralogs from seven other Burkholderia species into the SSGCID pipeline. This structural genomics approach yielded structures from 31 putative essential targets from B. thailandensis, and 25 orthologs from other Burkholderia species, yielding an overall structural coverage for 49 of the 406 essential gene families, with a total of 88 depositions into the Protein Data Bank. Of these, 25 proteins have properties of a potential antimicrobial drug target i.e., no close human homolog, part of an essential metabolic pathway, and a deep binding pocket. We describe the structures of several potential drug targets in detail.This collection of structures, solubility and experimental essentiality data provides a resource for development of drugs against

Combining functional and structural genomics to sample the essential Burkholderia structome.

Science.gov (United States)

Baugh, Loren; Gallagher, Larry A; Patrapuvich, Rapatbhorn; Clifton, Matthew C; Gardberg, Anna S; Edwards, Thomas E; Armour, Brianna; Begley, Darren W; Dieterich, Shellie H; Dranow, David M; Abendroth, Jan; Fairman, James W; Fox, David; Staker, Bart L; Phan, Isabelle; Gillespie, Angela; Choi, Ryan; Nakazawa-Hewitt, Steve; Nguyen, Mary Trang; Napuli, Alberto; Barrett, Lynn; Buchko, Garry W; Stacy, Robin; Myler, Peter J; Stewart, Lance J; Manoil, Colin; Van Voorhis, Wesley C

2013-01-01

The genus Burkholderia includes pathogenic gram-negative bacteria that cause melioidosis, glanders, and pulmonary infections of patients with cancer and cystic fibrosis. Drug resistance has made development of new antimicrobials critical. Many approaches to discovering new antimicrobials, such as structure-based drug design and whole cell phenotypic screens followed by lead refinement, require high-resolution structures of proteins essential to the parasite. We experimentally identified 406 putative essential genes in B. thailandensis, a low-virulence species phylogenetically similar to B. pseudomallei, the causative agent of melioidosis, using saturation-level transposon mutagenesis and next-generation sequencing (Tn-seq). We selected 315 protein products of these genes based on structure-determination criteria, such as excluding very large and/or integral membrane proteins, and entered them into the Seattle Structural Genomics Center for Infection Disease (SSGCID) structure determination pipeline. To maximize structural coverage of these targets, we applied an "ortholog rescue" strategy for those producing insoluble or difficult to crystallize proteins, resulting in the addition of 387 orthologs (or paralogs) from seven other Burkholderia species into the SSGCID pipeline. This structural genomics approach yielded structures from 31 putative essential targets from B. thailandensis, and 25 orthologs from other Burkholderia species, yielding an overall structural coverage for 49 of the 406 essential gene families, with a total of 88 depositions into the Protein Data Bank. Of these, 25 proteins have properties of a potential antimicrobial drug target i.e., no close human homolog, part of an essential metabolic pathway, and a deep binding pocket. We describe the structures of several potential drug targets in detail. This collection of structures, solubility and experimental essentiality data provides a resource for development of drugs against infections and diseases

The Burmese python genome reveals the molecular basis for extreme adaptation in snakes.

Science.gov (United States)

Castoe, Todd A; de Koning, A P Jason; Hall, Kathryn T; Card, Daren C; Schield, Drew R; Fujita, Matthew K; Ruggiero, Robert P; Degner, Jack F; Daza, Juan M; Gu, Wanjun; Reyes-Velasco, Jacobo; Shaney, Kyle J; Castoe, Jill M; Fox, Samuel E; Poole, Alex W; Polanco, Daniel; Dobry, Jason; Vandewege, Michael W; Li, Qing; Schott, Ryan K; Kapusta, Aurélie; Minx, Patrick; Feschotte, Cédric; Uetz, Peter; Ray, David A; Hoffmann, Federico G; Bogden, Robert; Smith, Eric N; Chang, Belinda S W; Vonk, Freek J; Casewell, Nicholas R; Henkel, Christiaan V; Richardson, Michael K; Mackessy, Stephen P; Bronikowski, Anne M; Bronikowsi, Anne M; Yandell, Mark; Warren, Wesley C; Secor, Stephen M; Pollock, David D

2013-12-17

Snakes possess many extreme morphological and physiological adaptations. Identification of the molecular basis of these traits can provide novel understanding for vertebrate biology and medicine. Here, we study snake biology using the genome sequence of the Burmese python (Python molurus bivittatus), a model of extreme physiological and metabolic adaptation. We compare the python and king cobra genomes along with genomic samples from other snakes and perform transcriptome analysis to gain insights into the extreme phenotypes of the python. We discovered rapid and massive transcriptional responses in multiple organ systems that occur on feeding and coordinate major changes in organ size and function. Intriguingly, the homologs of these genes in humans are associated with metabolism, development, and pathology. We also found that many snake metabolic genes have undergone positive selection, which together with the rapid evolution of mitochondrial proteins, provides evidence for extensive adaptive redesign of snake metabolic pathways. Additional evidence for molecular adaptation and gene family expansions and contractions is associated with major physiological and phenotypic adaptations in snakes; genes involved are related to cell cycle, development, lungs, eyes, heart, intestine, and skeletal structure, including GRB2-associated binding protein 1, SSH, WNT16, and bone morphogenetic protein 7. Finally, changes in repetitive DNA content, guanine-cytosine isochore structure, and nucleotide substitution rates indicate major shifts in the structure and evolution of snake genomes compared with other amniotes. Phenotypic and physiological novelty in snakes seems to be driven by system-wide coordination of protein adaptation, gene expression, and changes in the structure of the genome.

The genome and structural proteome of an ocean siphovirus: a new window into the cyanobacterial ‘mobilome’

Science.gov (United States)

Sullivan, Matthew B; Krastins, Bryan; Hughes, Jennifer L; Kelly, Libusha; Chase, Michael; Sarracino, David; Chisholm, Sallie W

2009-01-01

Prochlorococcus, an abundant phototroph in the oceans, are infected by members of three families of viruses: myo-, podo- and siphoviruses. Genomes of myo- and podoviruses isolated on Prochlorococcus contain DNA replication machinery and virion structural genes homologous to those from coliphages T4 and T7 respectively. They also contain a suite of genes of cyanobacterial origin, most notably photosynthesis genes, which are expressed during infection and appear integral to the evolutionary trajectory of both host and phage. Here we present the first genome of a cyanobacterial siphovirus, P-SS2, which was isolated from Atlantic slope waters using a Prochlorococcus host (MIT9313). The P-SS2 genome is larger than, and considerably divergent from, previously sequenced siphoviruses. It appears most closely related to lambdoid siphoviruses, with which it shares 13 functional homologues. The ∼108 kb P-SS2 genome encodes 131 predicted proteins and notably lacks photosynthesis genes which have consistently been found in other marine cyanophage, but does contain 14 other cyanobacterial homologues. While only six structural proteins were identified from the genome sequence, 35 proteins were detected experimentally; these mapped onto capsid and tail structural modules in the genome. P-SS2 is potentially capable of integration into its host as inferred from bioinformatically identified genetic machinery int, bet, exo and a 53 bp attachment site. The host attachment site appears to be a genomic island that is tied to insertion sequence (IS) activity that could facilitate mobility of a gene involved in the nitrogen-stress response. The homologous region and a secondary IS-element hot-spot in Synechococcus RS9917 are further evidence of IS-mediated genome evolution coincident with a probable relic prophage integration event. This siphovirus genome provides a glimpse into the biology of a deep-photic zone phage as well as the ocean cyanobacterial prophage and IS element �

Molecular Epidemiology and Genomics of Group A Streptococcus

Science.gov (United States)

Bessen, Debra E.; McShan, W. Michael; Nguyen, Scott V.; Shetty, Amol; Agrawal, Sonia; Tettelin, Hervé

2014-01-01

Streptococcus pyogenes (group A streptococcus; GAS) is a strict human pathogen with a very high prevalence worldwide. This review highlights the genetic organization of the species and the important ecological considerations that impact its evolution. Recent advances are presented on the topics of molecular epidemiology, population biology, molecular basis for genetic change, genome structure and genetic flux, phylogenomics and closely related streptococcal species, and the long- and short-term evolution of GAS. The application of whole genome sequence data to addressing key biological questions is discussed. PMID:25460818

Genome Microscale Heterogeneity among Wild Potatoes Revealed by Diversity Arrays Technology Marker Sequences

Directory of Open Access Journals (Sweden)

Alessandra Traini

2013-01-01

Full Text Available Tuber-bearing potato species possess several genes that can be exploited to improve the genetic background of the cultivated potato Solanum tuberosum. Among them, S. bulbocastanum and S. commersonii are well known for their strong resistance to environmental stresses. However, scant information is available for these species in terms of genome organization, gene function, and regulatory networks. Consequently, genomic tools to assist breeding are meager, and efficient exploitation of these species has been limited so far. In this paper, we employed the reference genome sequences from cultivated potato and tomato and a collection of sequences of 1,423 potato Diversity Arrays Technology (DArT markers that show polymorphic representation across the genomes of S. bulbocastanum and/or S. commersonii genotypes. Our results highlighted microscale genome sequence heterogeneity that may play a significant role in functional and structural divergence between related species. Our analytical approach provides knowledge of genome structural and sequence variability that could not be detected by transcriptome and proteome approaches.

Genome Microscale Heterogeneity among Wild Potatoes Revealed by Diversity Arrays Technology Marker Sequences.

Science.gov (United States)

Traini, Alessandra; Iorizzo, Massimo; Mann, Harpartap; Bradeen, James M; Carputo, Domenico; Frusciante, Luigi; Chiusano, Maria Luisa

2013-01-01

Tuber-bearing potato species possess several genes that can be exploited to improve the genetic background of the cultivated potato Solanum tuberosum. Among them, S. bulbocastanum and S. commersonii are well known for their strong resistance to environmental stresses. However, scant information is available for these species in terms of genome organization, gene function, and regulatory networks. Consequently, genomic tools to assist breeding are meager, and efficient exploitation of these species has been limited so far. In this paper, we employed the reference genome sequences from cultivated potato and tomato and a collection of sequences of 1,423 potato Diversity Arrays Technology (DArT) markers that show polymorphic representation across the genomes of S. bulbocastanum and/or S. commersonii genotypes. Our results highlighted microscale genome sequence heterogeneity that may play a significant role in functional and structural divergence between related species. Our analytical approach provides knowledge of genome structural and sequence variability that could not be detected by transcriptome and proteome approaches.

Genomic Prospecting for Microbial Biodiesel Production

Energy Technology Data Exchange (ETDEWEB)

Lykidis, Athanasios; Lykidis, Athanasios; Ivanova, Natalia

2008-03-20

Biodiesel is defined as fatty acid mono-alkylesters and is produced from triacylglycerols. In the current article we provide an overview of the structure, diversity and regulation of the metabolic pathways leading to intracellular fatty acid and triacylglycerol accumulation in three types of organisms (bacteria, algae and fungi) of potential biotechnological interest and discuss possible intervention points to increase the cellular lipid content. The key steps that regulate carbon allocation and distribution in lipids include the formation of malonyl-CoA, the synthesis of fatty acids and their attachment onto the glycerol backbone, and the formation of triacylglycerols. The lipid biosynthetic genes and pathways are largely known for select model organisms. Comparative genomics allows the examination of these pathways in organisms of biotechnological interest and reveals the evolution of divergent and yet uncharacterized regulatory mechanisms. Utilization of microbial systems for triacylglycerol and fatty acid production is in its infancy; however, genomic information and technologies combined with synthetic biology concepts provide the opportunity to further exploit microbes for the competitive production of biodiesel.

Evolution and structural organization of the C proteins of paramyxovirinae.

Directory of Open Access Journals (Sweden)

Michael K Lo

Full Text Available The phosphoprotein (P gene of most Paramyxovirinae encodes several proteins in overlapping frames: P and V, which share a common N-terminus (PNT, and C, which overlaps PNT. Overlapping genes are of particular interest because they encode proteins originated de novo, some of which have unknown structural folds, challenging the notion that nature utilizes only a limited, well-mapped area of fold space. The C proteins cluster in three groups, comprising measles, Nipah, and Sendai virus. We predicted that all C proteins have a similar organization: a variable, disordered N-terminus and a conserved, α-helical C-terminus. We confirmed this predicted organization by biophysically characterizing recombinant C proteins from Tupaia paramyxovirus (measles group and human parainfluenza virus 1 (Sendai group. We also found that the C of the measles and Nipah groups have statistically significant sequence similarity, indicating a common origin. Although the C of the Sendai group lack sequence similarity with them, we speculate that they also have a common origin, given their similar genomic location and structural organization. Since C is dispensable for viral replication, unlike PNT, we hypothesize that C may have originated de novo by overprinting PNT in the ancestor of Paramyxovirinae. Intriguingly, in measles virus and Nipah virus, PNT encodes STAT1-binding sites that overlap different regions of the C-terminus of C, indicating they have probably originated independently. This arrangement, in which the same genetic region encodes simultaneously a crucial functional motif (a STAT1-binding site and a highly constrained region (the C-terminus of C, seems paradoxical, since it should severely reduce the ability of the virus to adapt. The fact that it originated twice suggests that it must be balanced by an evolutionary advantage, perhaps from reducing the size of the genetic region vulnerable to mutations.

Gene order data from a model amphibian (Ambystoma: new perspectives on vertebrate genome structure and evolution

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Voss S Randal

2006-08-01

Full Text Available Abstract Background Because amphibians arise from a branch of the vertebrate evolutionary tree that is juxtaposed between fishes and amniotes, they provide important comparative perspective for reconstructing character changes that have occurred during vertebrate evolution. Here, we report the first comparative study of vertebrate genome structure that includes a representative amphibian. We used 491 transcribed sequences from a salamander (Ambystoma genetic map and whole genome assemblies for human, mouse, rat, dog, chicken, zebrafish, and the freshwater pufferfish Tetraodon nigroviridis to compare gene orders and rearrangement rates. Results Ambystoma has experienced a rate of genome rearrangement that is substantially lower than mammalian species but similar to that of chicken and fish. Overall, we found greater conservation of genome structure between Ambystoma and tetrapod vertebrates, nevertheless, 57% of Ambystoma-fish orthologs are found in conserved syntenies of four or more genes. Comparisons between Ambystoma and amniotes reveal extensive conservation of segmental homology for 57% of the presumptive Ambystoma-amniote orthologs. Conclusion Our analyses suggest relatively constant interchromosomal rearrangement rates from the euteleost ancestor to the origin of mammals and illustrate the utility of amphibian mapping data in establishing ancestral amniote and tetrapod gene orders. Comparisons between Ambystoma and amniotes reveal some of the key events that have structured the human genome since diversification of the ancestral amniote lineage.

Large-scale genomic 2D visualization reveals extensive CG-AT skew correlation in bird genomes

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Deng Xuemei

2007-11-01

Full Text Available Abstract Background Bird genomes have very different compositional structure compared with other warm-blooded animals. The variation in the base skew rules in the vertebrate genomes remains puzzling, but it must relate somehow to large-scale genome evolution. Current research is inclined to relate base skew with mutations and their fixation. Here we wish to explore base skew correlations in bird genomes, to develop methods for displaying and quantifying such correlations at different scales, and to discuss possible explanations for the peculiarities of the bird genomes in skew correlation. Results We have developed a method called Base Skew Double Triangle (BSDT for exhibiting the genome-scale change of AT/CG skew as a two-dimensional square picture, showing base skews at many scales simultaneously in a single image. By this method we found that most chicken chromosomes have high AT/CG skew correlation (symmetry in 2D picture, except for some microchromosomes. No other organisms studied (18 species show such high skew correlations. This visualized high correlation was validated by three kinds of quantitative calculations with overlapping and non-overlapping windows, all indicating that chicken and birds in general have a special genome structure. Similar features were also found in some of the mammal genomes, but clearly much weaker than in chickens. We presume that the skew correlation feature evolved near the time that birds separated from other vertebrate lineages. When we eliminated the repeat sequences from the genomes, the AT and CG skews correlation increased for some mammal genomes, but were still clearly lower than in chickens. Conclusion Our results suggest that BSDT is an expressive visualization method for AT and CG skew and enabled the discovery of the very high skew correlation in bird genomes; this peculiarity is worth further study. Computational analysis indicated that this correlation might be a compositional characteristic

Re-Ordering Structural Dimensions for Nigerian Organizations ...

African Journals Online (AJOL)

The organization structure (OS) reflects the interface of the dimensions of the OS, the model in place and the mix of determinants of OS. This paper focuses on the organization structure (OS) to find out, not just the consistency of the structural properties with the OS but also the potentials of OS oriented towards the realization ...

Broad genomic and transcriptional analysis reveals a highly derived genome in dinoflagellate mitochondria

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Keeling Patrick J

2007-09-01

Full Text Available Abstract Background Dinoflagellates comprise an ecologically significant and diverse eukaryotic phylum that is sister to the phylum containing apicomplexan endoparasites. The mitochondrial genome of apicomplexans is uniquely reduced in gene content and size, encoding only three proteins and two ribosomal RNAs (rRNAs within a highly compacted 6 kb DNA. Dinoflagellate mitochondrial genomes have been comparatively poorly studied: limited available data suggest some similarities with apicomplexan mitochondrial genomes but an even more radical type of genomic organization. Here, we investigate structure, content and expression of dinoflagellate mitochondrial genomes. Results From two dinoflagellates, Crypthecodinium cohnii and Karlodinium micrum, we generated over 42 kb of mitochondrial genomic data that indicate a reduced gene content paralleling that of mitochondrial genomes in apicomplexans, i.e., only three protein-encoding genes and at least eight conserved components of the highly fragmented large and small subunit rRNAs. Unlike in apicomplexans, dinoflagellate mitochondrial genes occur in multiple copies, often as gene fragments, and in numerous genomic contexts. Analysis of cDNAs suggests several novel aspects of dinoflagellate mitochondrial gene expression. Polycistronic transcripts were found, standard start codons are absent, and oligoadenylation occurs upstream of stop codons, resulting in the absence of termination codons. Transcripts of at least one gene, cox3, are apparently trans-spliced to generate full-length mRNAs. RNA substitutional editing, a process previously identified for mRNAs in dinoflagellate mitochondria, is also implicated in rRNA expression. Conclusion The dinoflagellate mitochondrial genome shares the same gene complement and fragmentation of rRNA genes with its apicomplexan counterpart. However, it also exhibits several unique characteristics. Most notable are the expansion of gene copy numbers and their arrangements

Analysis of the grape MYB R2R3 subfamily reveals expanded wine quality-related clades and conserved gene structure organization across Vitis and Arabidopsis genomes

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Arce-Johnson Patricio

2008-07-01

Full Text Available Abstract Background The MYB superfamily constitutes the most abundant group of transcription factors described in plants. Members control processes such as epidermal cell differentiation, stomatal aperture, flavonoid synthesis, cold and drought tolerance and pathogen resistance. No genome-wide characterization of this family has been conducted in a woody species such as grapevine. In addition, previous analysis of the recently released grape genome sequence suggested expansion events of several gene families involved in wine quality. Results We describe and classify 108 members of the grape R2R3 MYB gene subfamily in terms of their genomic gene structures and similarity to their putative Arabidopsis thaliana orthologues. Seven gene models were derived and analyzed in terms of gene expression and their DNA binding domain structures. Despite low overall sequence homology in the C-terminus of all proteins, even in those with similar functions across Arabidopsis and Vitis, highly conserved motif sequences and exon lengths were found. The grape epidermal cell fate clade is expanded when compared with the Arabidopsis and rice MYB subfamilies. Two anthocyanin MYBA related clusters were identified in chromosomes 2 and 14, one of which includes the previously described grape colour locus. Tannin related loci were also detected with eight candidate homologues in chromosomes 4, 9 and 11. Conclusion This genome wide transcription factor analysis in Vitis suggests that clade-specific grape R2R3 MYB genes are expanded while other MYB genes could be well conserved compared to Arabidopsis. MYB gene abundance, homology and orientation within particular loci also suggests that expanded MYB clades conferring quality attributes of grapes and wines, such as colour and astringency, could possess redundant, overlapping and cooperative functions.

Integrated genomics and proteomics of the Torpedo californica electric organ: concordance with the mammalian neuromuscular junction

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Mate Suzanne E

2011-05-01

Full Text Available Abstract Background During development, the branchial mesoderm of Torpedo californica transdifferentiates into an electric organ capable of generating high voltage discharges to stun fish. The organ contains a high density of cholinergic synapses and has served as a biochemical model for the membrane specialization of myofibers, the neuromuscular junction (NMJ. We studied the genome and proteome of the electric organ to gain insight into its composition, to determine if there is concordance with skeletal muscle and the NMJ, and to identify novel synaptic proteins. Results Of 435 proteins identified, 300 mapped to Torpedo cDNA sequences with ≥2 peptides. We identified 14 uncharacterized proteins in the electric organ that are known to play a role in acetylcholine receptor clustering or signal transduction. In addition, two human open reading frames, C1orf123 and C6orf130, showed high sequence similarity to electric organ proteins. Our profile lists several proteins that are highly expressed in skeletal muscle or are muscle specific. Synaptic proteins such as acetylcholinesterase, acetylcholine receptor subunits, and rapsyn were present in the electric organ proteome but absent in the skeletal muscle proteome. Conclusions Our integrated genomic and proteomic analysis supports research describing a muscle-like profile of the organ. We show that it is a repository of NMJ proteins but we present limitations on its use as a comprehensive model of the NMJ. Finally, we identified several proteins that may become candidates for signaling proteins not previously characterized as components of the NMJ.

Cephalopod genomics

DEFF Research Database (Denmark)

Albertin, Caroline B.; Bonnaud, Laure; Brown, C. Titus

2012-01-01

The Cephalopod Sequencing Consortium (CephSeq Consortium) was established at a NESCent Catalysis Group Meeting, ``Paths to Cephalopod Genomics-Strategies, Choices, Organization,'' held in Durham, North Carolina, USA on May 24-27, 2012. Twenty-eight participants representing nine countries (Austria......, Australia, China, Denmark, France, Italy, Japan, Spain and the USA) met to address the pressing need for genome sequencing of cephalopod mollusks. This group, drawn from cephalopod biologists, neuroscientists, developmental and evolutionary biologists, materials scientists, bioinformaticians and researchers...... active in sequencing, assembling and annotating genomes, agreed on a set of cephalopod species of particular importance for initial sequencing and developed strategies and an organization (CephSeq Consortium) to promote this sequencing. The conclusions and recommendations of this meeting are described...

Macronuclear genome sequence of the ciliate Tetrahymena thermophila, a model eukaryote.

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Jonathan A Eisen

2006-09-01

Full Text Available The ciliate Tetrahymena thermophila is a model organism for molecular and cellular biology. Like other ciliates, this species has separate germline and soma functions that are embodied by distinct nuclei within a single cell. The germline-like micronucleus (MIC has its genome held in reserve for sexual reproduction. The soma-like macronucleus (MAC, which possesses a genome processed from that of the MIC, is the center of gene expression and does not directly contribute DNA to sexual progeny. We report here the shotgun sequencing, assembly, and analysis of the MAC genome of T. thermophila, which is approximately 104 Mb in length and composed of approximately 225 chromosomes. Overall, the gene set is robust, with more than 27,000 predicted protein-coding genes, 15,000 of which have strong matches to genes in other organisms. The functional diversity encoded by these genes is substantial and reflects the complexity of processes required for a free-living, predatory, single-celled organism. This is highlighted by the abundance of lineage-specific duplications of genes with predicted roles in sensing and responding to environmental conditions (e.g., kinases, using diverse resources (e.g., proteases and transporters, and generating structural complexity (e.g., kinesins and dyneins. In contrast to the other lineages of alveolates (apicomplexans and dinoflagellates, no compelling evidence could be found for plastid-derived genes in the genome. UGA, the only T. thermophila stop codon, is used in some genes to encode selenocysteine, thus making this organism the first known with the potential to translate all 64 codons in nuclear genes into amino acids. We present genomic evidence supporting the hypothesis that the excision of DNA from the MIC to generate the MAC specifically targets foreign DNA as a form of genome self-defense. The combination of the genome sequence, the functional diversity encoded therein, and the presence of some pathways missing from

From the chromatin interaction network to the organization of the human genome into replication N/U-domains

International Nuclear Information System (INIS)

Boulos, Rasha E; Julienne, Hanna; Baker, Antoine; Jensen, Pablo; Arneodo, Alain; Audit, Benjamin; Chen, Chun-Long; D'Aubenton-Carafa, Yves; Thermes, Claude; Petryk, Nataliya; Kahli, Malik; Hyrien, Olivier; Goldar, Arach

2014-01-01

The three-dimensional (3D) architecture of the mammalian nucleus is now being unraveled thanks to the recent development of chromatin conformation capture (3C) technologies. Here we report the results of a combined multiscale analysis of genome-wide mean replication timing and chromatin conformation data that reveal some intimate relationships between chromatin folding and human DNA replication. We previously described megabase replication N/U-domains as mammalian multiorigin replication units, and showed that their borders are ‘master’ replication initiation zones that likely initiate cascades of origin firing responsible for the stereotypic replication of these domains. Here, we demonstrate that replication N/U-domains correspond to the structural domains of self-interacting chromatin, and that their borders act as insulating regions both in high-throughput 3C (Hi-C) data and high-resolution 3C (4C) experiments. Further analyses of Hi-C data using a graph-theoretical approach reveal that N/U-domain borders are long-distance, interconnected hubs of the chromatin interaction network. Overall, these results and the observation that a well-defined ordering of chromatin states exists from N/U-domain borders to centers suggest that ‘master’ replication initiation zones are at the heart of a high-order, epigenetically controlled 3D organization of the human genome. (paper)

Capturing Three-Dimensional Genome Organization in Individual Cells by Single-Cell Hi-C.

Science.gov (United States)

Nagano, Takashi; Wingett, Steven W; Fraser, Peter

2017-01-01

Hi-C is a powerful method to investigate genome-wide, higher-order chromatin and chromosome conformations averaged from a population of cells. To expand the potential of Hi-C for single-cell analysis, we developed single-cell Hi-C. Similar to the existing "ensemble" Hi-C method, single-cell Hi-C detects proximity-dependent ligation events between cross-linked and restriction-digested chromatin fragments in cells. A major difference between the single-cell Hi-C and ensemble Hi-C protocol is that the proximity-dependent ligation is carried out in the nucleus. This allows the isolation of individual cells in which nearly the entire Hi-C procedure has been carried out, enabling the production of a Hi-C library and data from individual cells. With this new method, we studied genome conformations and found evidence for conserved topological domain organization from cell to cell, but highly variable interdomain contacts and chromosome folding genome wide. In addition, we found that the single-cell Hi-C protocol provided cleaner results with less technical noise suggesting it could be used to improve the ensemble Hi-C technique.

Modeling structure of G protein-coupled receptors in huan genome

KAUST Repository

Zhang, Yang

2016-01-26

G protein-coupled receptors (or GPCRs) are integral transmembrane proteins responsible to various cellular signal transductions. Human GPCR proteins are encoded by 5% of human genes but account for the targets of 40% of the FDA approved drugs. Due to difficulties in crystallization, experimental structure determination remains extremely difficult for human GPCRs, which have been a major barrier in modern structure-based drug discovery. We proposed a new hybrid protocol, GPCR-I-TASSER, to construct GPCR structure models by integrating experimental mutagenesis data with ab initio transmembrane-helix assembly simulations, assisted by the predicted transmembrane-helix interaction networks. The method was tested in recent community-wide GPCRDock experiments and constructed models with a root mean square deviation 1.26 Å for Dopamine-3 and 2.08 Å for Chemokine-4 receptors in the transmembrane domain regions, which were significantly closer to the native than the best templates available in the PDB. GPCR-I-TASSER has been applied to model all 1,026 putative GPCRs in the human genome, where 923 are found to have correct folds based on the confidence score analysis and mutagenesis data comparison. The successfully modeled GPCRs contain many pharmaceutically important families that do not have previously solved structures, including Trace amine, Prostanoids, Releasing hormones, Melanocortins, Vasopressin and Neuropeptide Y receptors. All the human GPCR models have been made publicly available through the GPCR-HGmod database at http://zhanglab.ccmb.med.umich.edu/GPCR-HGmod/ The results demonstrate new progress on genome-wide structure modeling of transmembrane proteins which should bring useful impact on the effort of GPCR-targeted drug discovery.

Genomic structural variation contributes to phenotypic change of industrial bioethanol yeast Saccharomyces cerevisiae.

Science.gov (United States)

Zhang, Ke; Zhang, Li-Jie; Fang, Ya-Hong; Jin, Xin-Na; Qi, Lei; Wu, Xue-Chang; Zheng, Dao-Qiong

2016-03-01

Genomic structural variation (GSV) is a ubiquitous phenomenon observed in the genomes of Saccharomyces cerevisiae strains with different genetic backgrounds; however, the physiological and phenotypic effects of GSV are not well understood. Here, we first revealed the genetic characteristics of a widely used industrial S. cerevisiae strain, ZTW1, by whole genome sequencing. ZTW1 was identified as an aneuploidy strain and a large-scale GSV was observed in the ZTW1 genome compared with the genome of a diploid strain YJS329. These GSV events led to copy number variations (CNVs) in many chromosomal segments as well as one whole chromosome in the ZTW1 genome. Changes in the DNA dosage of certain functional genes directly affected their expression levels and the resultant ZTW1 phenotypes. Moreover, CNVs of large chromosomal regions triggered an aneuploidy stress in ZTW1. This stress decreased the proliferation ability and tolerance of ZTW1 to various stresses, while aneuploidy response stress may also provide some benefits to the fermentation performance of the yeast, including increased fermentation rates and decreased byproduct generation. This work reveals genomic characters of the bioethanol S. cerevisiae strain ZTW1 and suggests that GSV is an important kind of mutation that changes the traits of industrial S. cerevisiae strains. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Population Structure and Genomic Breed Composition in an Angus-Brahman Crossbred Cattle Population.

Science.gov (United States)

Gobena, Mesfin; Elzo, Mauricio A; Mateescu, Raluca G

2018-01-01

Crossbreeding is a common strategy used in tropical and subtropical regions to enhance beef production, and having accurate knowledge of breed composition is essential for the success of a crossbreeding program. Although pedigree records have been traditionally used to obtain the breed composition of crossbred cattle, the accuracy of pedigree-based breed composition can be reduced by inaccurate and/or incomplete records and Mendelian sampling. Breed composition estimation from genomic data has multiple advantages including higher accuracy without being affected by missing, incomplete, or inaccurate records and the ability to be used as independent authentication of breed in breed-labeled beef products. The present study was conducted with 676 Angus-Brahman crossbred cattle with genotype and pedigree information to evaluate the feasibility and accuracy of using genomic data to determine breed composition. We used genomic data in parametric and non-parametric methods to detect population structure due to differences in breed composition while accounting for the confounding effect of close familial relationships. By applying principal component analysis (PCA) and the maximum likelihood method of ADMIXTURE to genomic data, it was possible to successfully characterize population structure resulting from heterogeneous breed ancestry, while accounting for close familial relationships. PCA results offered additional insight into the different hierarchies of genetic variation structuring. The first principal component was strongly correlated with Angus-Brahman proportions, and the second represented variation within animals that have a relatively more extended Brangus lineage-indicating the presence of a distinct pattern of genetic variation in these cattle. Although there was strong agreement between breed proportions estimated from pedigree and genetic information, there were significant discrepancies between these two methods for certain animals. This was most likely due

Population Structure and Genomic Breed Composition in an Angus–Brahman Crossbred Cattle Population

Directory of Open Access Journals (Sweden)

Mesfin Gobena

2018-03-01

Full Text Available Crossbreeding is a common strategy used in tropical and subtropical regions to enhance beef production, and having accurate knowledge of breed composition is essential for the success of a crossbreeding program. Although pedigree records have been traditionally used to obtain the breed composition of crossbred cattle, the accuracy of pedigree-based breed composition can be reduced by inaccurate and/or incomplete records and Mendelian sampling. Breed composition estimation from genomic data has multiple advantages including higher accuracy without being affected by missing, incomplete, or inaccurate records and the ability to be used as independent authentication of breed in breed-labeled beef products. The present study was conducted with 676 Angus–Brahman crossbred cattle with genotype and pedigree information to evaluate the feasibility and accuracy of using genomic data to determine breed composition. We used genomic data in parametric and non-parametric methods to detect population structure due to differences in breed composition while accounting for the confounding effect of close familial relationships. By applying principal component analysis (PCA and the maximum likelihood method of ADMIXTURE to genomic data, it was possible to successfully characterize population structure resulting from heterogeneous breed ancestry, while accounting for close familial relationships. PCA results offered additional insight into the different hierarchies of genetic variation structuring. The first principal component was strongly correlated with Angus–Brahman proportions, and the second represented variation within animals that have a relatively more extended Brangus lineage—indicating the presence of a distinct pattern of genetic variation in these cattle. Although there was strong agreement between breed proportions estimated from pedigree and genetic information, there were significant discrepancies between these two methods for certain animals

High-throughput crystal-optimization strategies in the South Paris Yeast Structural Genomics Project: one size fits all?

Science.gov (United States)

Leulliot, Nicolas; Trésaugues, Lionel; Bremang, Michael; Sorel, Isabelle; Ulryck, Nathalie; Graille, Marc; Aboulfath, Ilham; Poupon, Anne; Liger, Dominique; Quevillon-Cheruel, Sophie; Janin, Joël; van Tilbeurgh, Herman

2005-06-01

Crystallization has long been regarded as one of the major bottlenecks in high-throughput structural determination by X-ray crystallography. Structural genomics projects have addressed this issue by using robots to set up automated crystal screens using nanodrop technology. This has moved the bottleneck from obtaining the first crystal hit to obtaining diffraction-quality crystals, as crystal optimization is a notoriously slow process that is difficult to automatize. This article describes the high-throughput optimization strategies used in the Yeast Structural Genomics project, with selected successful examples.

The zebrafish reference genome sequence and its relationship to the human genome.

Science.gov (United States)

Howe, Kerstin; Clark, Matthew D; Torroja, Carlos F; Torrance, James; Berthelot, Camille; Muffato, Matthieu; Collins, John E; Humphray, Sean; McLaren, Karen; Matthews, Lucy; McLaren, Stuart; Sealy, Ian; Caccamo, Mario; Churcher, Carol; Scott, Carol; Barrett, Jeffrey C; Koch, Romke; Rauch, Gerd-Jörg; White, Simon; Chow, William; Kilian, Britt; Quintais, Leonor T; Guerra-Assunção, José A; Zhou, Yi; Gu, Yong; Yen, Jennifer; Vogel, Jan-Hinnerk; Eyre, Tina; Redmond, Seth; Banerjee, Ruby; Chi, Jianxiang; Fu, Beiyuan; Langley, Elizabeth; Maguire, Sean F; Laird, Gavin K; Lloyd, David; Kenyon, Emma; Donaldson, Sarah; Sehra, Harminder; Almeida-King, Jeff; Loveland, Jane; Trevanion, Stephen; Jones, Matt; Quail, Mike; Willey, Dave; Hunt, Adrienne; Burton, John; Sims, Sarah; McLay, Kirsten; Plumb, Bob; Davis, Joy; Clee, Chris; Oliver, Karen; Clark, Richard; Riddle, Clare; Elliot, David; Eliott, David; Threadgold, Glen; Harden, Glenn; Ware, Darren; Begum, Sharmin; Mortimore, Beverley; Mortimer, Beverly; Kerry, Giselle; Heath, Paul; Phillimore, Benjamin; Tracey, Alan; Corby, Nicole; Dunn, Matthew; Johnson, Christopher; Wood, Jonathan; Clark, Susan; Pelan, Sarah; Griffiths, Guy; Smith, Michelle; Glithero, Rebecca; Howden, Philip; Barker, Nicholas; Lloyd, Christine; Stevens, Christopher; Harley, Joanna; Holt, Karen; Panagiotidis, Georgios; Lovell, Jamieson; Beasley, Helen; Henderson, Carl; Gordon, Daria; Auger, Katherine; Wright, Deborah; Collins, Joanna; Raisen, Claire; Dyer, Lauren; Leung, Kenric; Robertson, Lauren; Ambridge, Kirsty; Leongamornlert, Daniel; McGuire, Sarah; Gilderthorp, Ruth; Griffiths, Coline; Manthravadi, Deepa; Nichol, Sarah; Barker, Gary; Whitehead, Siobhan; Kay, Michael; Brown, Jacqueline; Murnane, Clare; Gray, Emma; Humphries, Matthew; Sycamore, Neil; Barker, Darren; Saunders, David; Wallis, Justene; Babbage, Anne; Hammond, Sian; Mashreghi-Mohammadi, Maryam; Barr, Lucy; Martin, Sancha; Wray, Paul; Ellington, Andrew; Matthews, Nicholas; Ellwood, Matthew; Woodmansey, Rebecca; Clark, Graham; Cooper, James D; Cooper, James; Tromans, Anthony; Grafham, Darren; Skuce, Carl; Pandian, Richard; Andrews, Robert; Harrison, Elliot; Kimberley, Andrew; Garnett, Jane; Fosker, Nigel; Hall, Rebekah; Garner, Patrick; Kelly, Daniel; Bird, Christine; Palmer, Sophie; Gehring, Ines; Berger, Andrea; Dooley, Christopher M; Ersan-Ürün, Zübeyde; Eser, Cigdem; Geiger, Horst; Geisler, Maria; Karotki, Lena; Kirn, Anette; Konantz, Judith; Konantz, Martina; Oberländer, Martina; Rudolph-Geiger, Silke; Teucke, Mathias; Lanz, Christa; Raddatz, Günter; Osoegawa, Kazutoyo; Zhu, Baoli; Rapp, Amanda; Widaa, Sara; Langford, Cordelia; Yang, Fengtang; Schuster, Stephan C; Carter, Nigel P; Harrow, Jennifer; Ning, Zemin; Herrero, Javier; Searle, Steve M J; Enright, Anton; Geisler, Robert; Plasterk, Ronald H A; Lee, Charles; Westerfield, Monte; de Jong, Pieter J; Zon, Leonard I; Postlethwait, John H; Nüsslein-Volhard, Christiane; Hubbard, Tim J P; Roest Crollius, Hugues; Rogers, Jane; Stemple, Derek L

2013-04-25

Zebrafish have become a popular organism for the study of vertebrate gene function. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of vertebrate gene function and increasingly, the study of human genetic disease. However, for effective modelling of human genetic disease it is important to understand the extent to which zebrafish genes and gene structures are related to orthologous human genes. To examine this, we generated a high-quality sequence assembly of the zebrafish genome, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map. Detailed automatic and manual annotation provides evidence of more than 26,000 protein-coding genes, the largest gene set of any vertebrate so far sequenced. Comparison to the human reference genome shows that approximately 70% of human genes have at least one obvious zebrafish orthologue. In addition, the high quality of this genome assembly provides a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebrafish-specific genes on chromosome 4 and chromosomal regions that influence sex determination.

A multipartite mitochondrial genome in the potato cyst nematode Globodera pallida.

Science.gov (United States)

Armstrong, M R; Blok, V C; Phillips, M S

2000-01-01

The mitochondrial genome (mtDNA) of the plant parasitic nematode Globodera pallida exists as a population of small, circular DNAs that, taken individually, are of insufficient length to encode the typical metazoan mitochondrial gene complement. As far as we are aware, this unusual structural organization is unique among higher metazoans, although interesting comparisons can be made with the multipartite mitochondrial genome organizations of plants and fungi. The variation in frequency between populations displayed by some components of the mtDNA is likely to have major implications for the way in which mtDNA can be used in population and evolutionary genetic studies of G. pallida.

Genomic mid-range inhomogeneity correlates with an abundance of RNA secondary structures

Directory of Open Access Journals (Sweden)

Song Jun

2008-06-01

Full Text Available Abstract Background Genomes possess different levels of non-randomness, in particular, an inhomogeneity in their nucleotide composition. Inhomogeneity is manifest from the short-range where neighboring nucleotides influence the choice of base at a site, to the long-range, commonly known as isochores, where a particular base composition can span millions of nucleotides. A separate genomic issue that has yet to be thoroughly elucidated is the role that RNA secondary structure (SS plays in gene expression. Results We present novel data and approaches that show that a mid-range inhomogeneity (~30 to 1000 nt not only exists in mammalian genomes but is also significantly associated with strong RNA SS. A whole-genome bioinformatics investigation of local SS in a set of 11,315 non-redundant human pre-mRNA sequences has been carried out. Four distinct components of these molecules (5'-UTRs, exons, introns and 3'-UTRs were considered separately, since they differ in overall nucleotide composition, sequence motifs and periodicities. For each pre-mRNA component, the abundance of strong local SS ( Conclusion We demonstrate that the excess of strong local SS in pre-mRNAs is linked to the little explored phenomenon of genomic mid-range inhomogeneity (MRI. MRI is an interdependence between nucleotide choice and base composition over a distance of 20–1000 nt. Additionally, we have created a public computational resource to support further study of genomic MRI.

Chromatin structure and dynamics in hot environments: architectural proteins and DNA topoisomerases of thermophilic archaea.

Science.gov (United States)

Visone, Valeria; Vettone, Antonella; Serpe, Mario; Valenti, Anna; Perugino, Giuseppe; Rossi, Mosè; Ciaramella, Maria

2014-09-25

In all organisms of the three living domains (Bacteria, Archaea, Eucarya) chromosome-associated proteins play a key role in genome functional organization. They not only compact and shape the genome structure, but also regulate its dynamics, which is essential to allow complex genome functions. Elucidation of chromatin composition and regulation is a critical issue in biology, because of the intimate connection of chromatin with all the essential information processes (transcription, replication, recombination, and repair). Chromatin proteins include architectural proteins and DNA topoisomerases, which regulate genome structure and remodelling at two hierarchical levels. This review is focussed on architectural proteins and topoisomerases from hyperthermophilic Archaea. In these organisms, which live at high environmental temperature (>80 °C <113 °C), chromatin proteins and modulation of the DNA secondary structure are concerned with the problem of DNA stabilization against heat denaturation while maintaining its metabolic activity.

Chromatin Structure and Dynamics in Hot Environments: Architectural Proteins and DNA Topoisomerases of Thermophilic Archaea

Directory of Open Access Journals (Sweden)

Valeria Visone

2014-09-01

Full Text Available In all organisms of the three living domains (Bacteria, Archaea, Eucarya chromosome-associated proteins play a key role in genome functional organization. They not only compact and shape the genome structure, but also regulate its dynamics, which is essential to allow complex genome functions. Elucidation of chromatin composition and regulation is a critical issue in biology, because of the intimate connection of chromatin with all the essential information processes (transcription, replication, recombination, and repair. Chromatin proteins include architectural proteins and DNA topoisomerases, which regulate genome structure and remodelling at two hierarchical levels. This review is focussed on architectural proteins and topoisomerases from hyperthermophilic Archaea. In these organisms, which live at high environmental temperature (>80 °C <113 °C, chromatin proteins and modulation of the DNA secondary structure are concerned with the problem of DNA stabilization against heat denaturation while maintaining its metabolic activity.

Genomic individuality and its biological implications.

Science.gov (United States)

Zhao, J

1996-06-01

It is a widely accepted fundamental concept that all somatic genomes of a human individual are identical to each other. The theoretical basis of this concept is that all of these somatic genomes are the descendants of the genome of a single fertilized cell as well as the simple replicated products of asexual reproduction, thus not forming any new recombined genomes. The question here is whether such a concept might only represent one side of somatic genome biology and, even worse, whether it has perhaps already led to a very prevalent misconception that within the organism body, there exists no variability among individual somatic genomes. A hypothesis, called genomic individuality, is proposed, simply saying that every individual somatic genome, perhaps with rare exceptions, has its own unique or individual 'genetic identity' or 'fingerprint', which is characterized by its distinctive sequences or patterns of deoxyribonucleic acid molecules, or both. Thus, no two somatic genomes can be identical to each other in every or all aspects, and consequently, there must be a great deal of genomic variation present within the body of any multicellular organism. The concept or hypothesis of genomic individuality would not only provide a more complete understanding of genome biology, but also suggest a new insight into the studies of the biology of cells and organisms.

Culture independent genomic comparisons reveal environmental adaptations for Altiarchaeales

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Jordan T Bird

2016-08-01

Full Text Available The recently proposed candidatus order Altiarchaeales remains an uncultured archaeal lineage composed of genetically diverse, globally widespread organisms frequently observed in anoxic subsurface environments. In spite of 15 years of studies on the psychrophilic biofilm-producing Candidatus (Ca. Altiarchaeum hamiconexum and its close relatives, very little is known about the phylogenetic and functional diversity of the widespread free-living marine members of this taxon. From methanogenic sediments in the White Oak River Estuary, NC, we sequenced a single cell amplified genome (SAG, WOR_SCG_SM1, and used it to identify and refine two high-quality genomes from metagenomes, WOR_79 and WOR_86-2, from the same site in a different year. These three genomic reconstructions form a monophyletic group which also includes three previously published genomes from metagenomes from terrestrial springs and a SAG from Sakinaw Lake in a group previously designated as pMC2A384. A synapomorphic mutation in the Altiarchaeales tRNA synthetase β subunit, pheT, causes the protein to be encoded as two subunits at distant loci. Consistent with the terrestrial spring clades, our estuarine genomes contain a near-complete autotrophic metabolism, H2 or CO as potential electron donors, a reductive acetyl-CoA pathway for carbon fixation, and methylotroph-like NADP(H-dependent dehydrogenase. Phylogenies based on 16S rRNA genes and concatenated conserved proteins identify two distinct sub-clades of Altiarchaeales, Alti-1 populated by organisms from actively flowing springs, and Alti-2 which is more widespread, diverse, and not associated with visible mats. The core Alti-1 genome supports Alti-1 as adapted for the stream environment, with lipopolysaccharide production capacity, extracellular hami structures. The core Alti-2 genome members of this clade are free-living, with distinct mechanisms for energy maintenance, motility, osmoregulation, and sulfur redox reactions. These

Exon organization of the mouse entactin gene corresponds to the structural domains of the polypeptide and has regional homology to the low-density lipoprotein receptor gene

DEFF Research Database (Denmark)

Durkin, M E; Wewer, U M; Chung, A E

1995-01-01

of the mouse entactin gene closely corresponds to the organization of the polypeptide into distinct structural and functional domains. The two amino-terminal globular domains are encoded by three exons each. Single exons encode the two protease-sensitive, O-glycosylated linking regions. The six EGF......Entactin is a widespread basement membrane protein of 150 kDa that binds to type IV collagen and laminin. The complete exon-intron structure of the mouse entactin gene has been determined from lambda genomic DNA clones. The gene spans at least 65 kb and contains 20 exons. The exon organization...

Structural genomics in endocrinology

NARCIS (Netherlands)

Smit, J. W.; Romijn, J. A.

2001-01-01

Traditionally, endocrine research evolved from the phenotypical characterisation of endocrine disorders to the identification of underlying molecular pathophysiology. This approach has been, and still is, extremely successful. The introduction of genomics and proteomics has resulted in a reversal of

Cloning, production, and purification of proteins for a medium-scale structural genomics project.

Science.gov (United States)

Quevillon-Cheruel, Sophie; Collinet, Bruno; Trésaugues, Lionel; Minard, Philippe; Henckes, Gilles; Aufrère, Robert; Blondeau, Karine; Zhou, Cong-Zhao; Liger, Dominique; Bettache, Nabila; Poupon, Anne; Aboulfath, Ilham; Leulliot, Nicolas; Janin, Joël; van Tilbeurgh, Herman

2007-01-01

The South-Paris Yeast Structural Genomics Pilot Project (http://www.genomics.eu.org) aims at systematically expressing, purifying, and determining the three-dimensional structures of Saccharomyces cerevisiae proteins. We have already cloned 240 yeast open reading frames in the Escherichia coli pET system. Eighty-two percent of the targets can be expressed in E. coli, and 61% yield soluble protein. We have currently purified 58 proteins. Twelve X-ray structures have been solved, six are in progress, and six other proteins gave crystals. In this chapter, we present the general experimental flowchart applied for this project. One of the main difficulties encountered in this pilot project was the low solubility of a great number of target proteins. We have developed parallel strategies to recover these proteins from inclusion bodies, including refolding, coexpression with chaperones, and an in vitro expression system. A limited proteolysis protocol, developed to localize flexible regions in proteins that could hinder crystallization, is also described.

Morphology, genome sequence, and structural proteome of type phage P335 from Lactococcus lactis

DEFF Research Database (Denmark)

Labrie, Simon J.; Josephsen, Jytte; Neve, Horst

2008-01-01

for a shorter tail and a different collar/whisker structure. Its 33,613-bp double-stranded DNA genome had 50 open reading frames. Putative functions were assigned to 29 of them. Unlike other sequenced genomes from lactococcal phages belonging to this species, P335 did not have a lysogeny module. However, it did...... genome. The genetic diversity of the P335 species indicates that they are exceptional models for studying the modular theory of phage evolution....

Specialized microbial databases for inductive exploration of microbial genome sequences

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Cabau Cédric

2005-02-01

Full Text Available Abstract Background The enormous amount of genome sequence data asks for user-oriented databases to manage sequences and annotations. Queries must include search tools permitting function identification through exploration of related objects. Methods The GenoList package for collecting and mining microbial genome databases has been rewritten using MySQL as the database management system. Functions that were not available in MySQL, such as nested subquery, have been implemented. Results Inductive reasoning in the study of genomes starts from "islands of knowledge", centered around genes with some known background. With this concept of "neighborhood" in mind, a modified version of the GenoList structure has been used for organizing sequence data from prokaryotic genomes of particular interest in China. GenoChore http://bioinfo.hku.hk/genochore.html, a set of 17 specialized end-user-oriented microbial databases (including one instance of Microsporidia, Encephalitozoon cuniculi, a member of Eukarya has been made publicly available. These databases allow the user to browse genome sequence and annotation data using standard queries. In addition they provide a weekly update of searches against the world-wide protein sequences data libraries, allowing one to monitor annotation updates on genes of interest. Finally, they allow users to search for patterns in DNA or protein sequences, taking into account a clustering of genes into formal operons, as well as providing extra facilities to query sequences using predefined sequence patterns. Conclusion This growing set of specialized microbial databases organize data created by the first Chinese bacterial genome programs (ThermaList, Thermoanaerobacter tencongensis, LeptoList, with two different genomes of Leptospira interrogans and SepiList, Staphylococcus epidermidis associated to related organisms for comparison.

Structural genomics: keeping up with expanding knowledge of the protein universe

Science.gov (United States)

Grabowski, Marek; Joachimiak, Andrzej; Otwinowski, Zbyszek; Minor, Wladek

2010-01-01

Structural characterization of the protein universe is the main mission of Structural Genomics (SG) programs. However, progress in gene sequencing technology, set in motion in the 1990s, has resulted in rapid expansion of protein sequence space — a twelvefold increase in the past seven years. For the SG field, this creates new challenges and necessitates a reassessment of its strategies. Nevertheless, despite the growth of sequence space, at present nearly half of the content of the Swiss-Prot database and over 40% of Pfam protein families can be structurally modeled based on structures determined so far, with SG projects making an increasingly significant contribution. The SG contribution of new Pfam structures nearly doubled from 27.2% in 2003 to 51.6% in 2006. PMID:17587562

Structural genomics: keeping up with expanding knowledge of the protein universe.

Science.gov (United States)

Grabowski, Marek; Joachimiak, Andrzej; Otwinowski, Zbyszek; Minor, Wladek

2007-06-01

Structural characterization of the protein universe is the main mission of Structural Genomics (SG) programs. However, progress in gene sequencing technology, set in motion in the 1990s, has resulted in rapid expansion of protein sequence space--a twelvefold increase in the past seven years. For the SG field, this creates new challenges and necessitates a re-assessment of its strategies. Nevertheless, despite the growth of sequence space, at present nearly half of the content of the Swiss-Prot database and over 40% of Pfam protein families can be structurally modeled based on structures determined so far, with SG projects making an increasingly significant contribution. The SG contribution of new Pfam structures nearly doubled from 27.2% in 2003 to 51.6% in 2006.

Evolutionary dynamics of 3D genome architecture following polyploidization in cotton.

Science.gov (United States)

Wang, Maojun; Wang, Pengcheng; Lin, Min; Ye, Zhengxiu; Li, Guoliang; Tu, Lili; Shen, Chao; Li, Jianying; Yang, Qingyong; Zhang, Xianlong

2018-02-01

The formation of polyploids significantly increases the complexity of transcriptional regulation, which is expected to be reflected in sophisticated higher-order chromatin structures. However, knowledge of three-dimensional (3D) genome structure and its dynamics during polyploidization remains poor. Here, we characterize 3D genome architectures for diploid and tetraploid cotton, and find the existence of A/B compartments and topologically associated domains (TADs). By comparing each subgenome in tetraploids with its extant diploid progenitor, we find that genome allopolyploidization has contributed to the switching of A/B compartments and the reorganization of TADs in both subgenomes. We also show that the formation of TAD boundaries during polyploidization preferentially occurs in open chromatin, coinciding with the deposition of active chromatin modification. Furthermore, analysis of inter-subgenomic chromatin interactions has revealed the spatial proximity of homoeologous genes, possibly associated with their coordinated expression. This study advances our understanding of chromatin organization in plants and sheds new light on the relationship between 3D genome evolution and transcriptional regulation.

Three-Dimensional Organization of Chromosome Territories in the Human Interphase Nucleus

NARCIS (Netherlands)

T.A. Knoch (Tobias); J. Langowski (Jörg)

1999-01-01

textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown. The regulation of genes has been shown to be connected closely to the three-dimensional organization of the genome in the cell nucleus. The nucleus of the cell has for a long

Structural-Functional Organization of the Eukaryotic Cell Nucleus and Transcription Regulation: Introduction to This Special Issue of Biochemistry (Moscow).

Science.gov (United States)

Razin, S V

2018-04-01

This issue of Biochemistry (Moscow) is devoted to the cell nucleus and mechanisms of transcription regulation. Over the years, biochemical processes in the cell nucleus have been studied in isolation, outside the context of their spatial organization. Now it is clear that segregation of functional processes within a compartmentalized cell nucleus is very important for the implementation of basic genetic processes. The functional compartmentalization of the cell nucleus is closely related to the spatial organization of the genome, which in turn plays a key role in the operation of epigenetic mechanisms. In this issue of Biochemistry (Moscow), we present a selection of review articles covering the functional architecture of the eukaryotic cell nucleus, the mechanisms of genome folding, the role of stochastic processes in establishing 3D architecture of the genome, and the impact of genome spatial organization on transcription regulation.

STRUCTURE AND COOPTATION IN ORGANIZATION NETWORK

Directory of Open Access Journals (Sweden)

Valéria Riscarolli

2007-10-01

Full Text Available Business executive are rethinking business concept, based on horizontalization principles. As so, most organizational functions are outsourced, leading the enterprise to build business through a network of organizations. Here we study the case of Cia Hering’s network of organizations, a leader in knit apparel segment in Latin America (IEMI, 2004, looking at the network’s structure and levels of cooptation. A theoretical model was used using Quinn et al. (2001 “sun ray” network structure as basis to analyze the case study. Main results indicate higher degree of structural conformity, but incipient degree of coopetation in the network.

From genes to milk: genomic organization and epigenetic regulation of the mammary transcriptome.

Science.gov (United States)

Lemay, Danielle G; Pollard, Katherine S; Martin, William F; Freeman Zadrowski, Courtneay; Hernandez, Joseph; Korf, Ian; German, J Bruce; Rijnkels, Monique

2013-01-01

Even in genomes lacking operons, a gene's position in the genome influences its potential for expression. The mechanisms by which adjacent genes are co-expressed are still not completely understood. Using lactation and the mammary gland as a model system, we explore the hypothesis that chromatin state contributes to the co-regulation of gene neighborhoods. The mammary gland represents a unique evolutionary model, due to its recent appearance, in the context of vertebrate genomes. An understanding of how the mammary gland is regulated to produce milk is also of biomedical and agricultural importance for human lactation and dairying. Here, we integrate epigenomic and transcriptomic data to develop a comprehensive regulatory model. Neighborhoods of mammary-expressed genes were determined using expression data derived from pregnant and lactating mice and a neighborhood scoring tool, G-NEST. Regions of open and closed chromatin were identified by ChIP-Seq of histone modifications H3K36me3, H3K4me2, and H3K27me3 in the mouse mammary gland and liver tissue during lactation. We found that neighborhoods of genes in regions of uniquely active chromatin in the lactating mammary gland, compared with liver tissue, were extremely rare. Rather, genes in most neighborhoods were suppressed during lactation as reflected in their expression levels and their location in regions of silenced chromatin. Chromatin silencing was largely shared between the liver and mammary gland during lactation, and what distinguished the mammary gland was mainly a small tissue-specific repertoire of isolated, expressed genes. These findings suggest that an advantage of the neighborhood organization is in the collective repression of groups of genes via a shared mechanism of chromatin repression. Genes essential to the mammary gland's uniqueness are isolated from neighbors, and likely have less tolerance for variation in expression, properties they share with genes responsible for an organism's survival.

Dynamics of genome rearrangement in bacterial populations.

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Aaron E Darling

2008-07-01

Full Text Available Genome structure variation has profound impacts on phenotype in organisms ranging from microbes to humans, yet little is known about how natural selection acts on genome arrangement. Pathogenic bacteria such as Yersinia pestis, which causes bubonic and pneumonic plague, often exhibit a high degree of genomic rearrangement. The recent availability of several Yersinia genomes offers an unprecedented opportunity to study the evolution of genome structure and arrangement. We introduce a set of statistical methods to study patterns of rearrangement in circular chromosomes and apply them to the Yersinia. We constructed a multiple alignment of eight Yersinia genomes using Mauve software to identify 78 conserved segments that are internally free from genome rearrangement. Based on the alignment, we applied Bayesian statistical methods to infer the phylogenetic inversion history of Yersinia. The sampling of genome arrangement reconstructions contains seven parsimonious tree topologies, each having different histories of 79 inversions. Topologies with a greater number of inversions also exist, but were sampled less frequently. The inversion phylogenies agree with results suggested by SNP patterns. We then analyzed reconstructed inversion histories to identify patterns of rearrangement. We confirm an over-representation of "symmetric inversions"-inversions with endpoints that are equally distant from the origin of chromosomal replication. Ancestral genome arrangements demonstrate moderate preference for replichore balance in Yersinia. We found that all inversions are shorter than expected under a neutral model, whereas inversions acting within a single replichore are much shorter than expected. We also found evidence for a canonical configuration of the origin and terminus of replication. Finally, breakpoint reuse analysis reveals that inversions with endpoints proximal to the origin of DNA replication are nearly three times more frequent. Our findings

MIPS plant genome information resources.

Science.gov (United States)

Spannagl, Manuel; Haberer, Georg; Ernst, Rebecca; Schoof, Heiko; Mayer, Klaus F X

2007-01-01

The Munich Institute for Protein Sequences (MIPS) has been involved in maintaining plant genome databases since the Arabidopsis thaliana genome project. Genome databases and analysis resources have focused on individual genomes and aim to provide flexible and maintainable data sets for model plant genomes as a backbone against which experimental data, for example from high-throughput functional genomics, can be organized and evaluated. In addition, model genomes also form a scaffold for comparative genomics, and much can be learned from genome-wide evolutionary studies.

Protein structure similarity clustering (PSSC) and natural product structure as inspiration sources for drug development and chemical genomics

NARCIS (Netherlands)

Dekker, Frank J; Koch, Marcus A; Waldmann, Herbert; Dekker, Frans

Finding small molecules that modulate protein function is of primary importance in drug development and in the emerging field of chemical genomics. To facilitate the identification of such molecules, we developed a novel strategy making use of structural conservatism found in protein domain

Comparative analysis of prophages in Streptococcus mutans genomes

Science.gov (United States)

Fu, Tiwei; Fan, Xiangyu; Long, Quanxin; Deng, Wanyan; Song, Jinlin

2017-01-01

Prophages have been considered genetic units that have an intimate association with novel phenotypic properties of bacterial hosts, such as pathogenicity and genomic variation. Little is known about the genetic information of prophages in the genome of Streptococcus mutans, a major pathogen of human dental caries. In this study, we identified 35 prophage-like elements in S. mutans genomes and performed a comparative genomic analysis. Comparative genomic and phylogenetic analyses of prophage sequences revealed that the prophages could be classified into three main large clusters: Cluster A, Cluster B, and Cluster C. The S. mutans prophages in each cluster were compared. The genomic sequences of phismuN66-1, phismuNLML9-1, and phismu24-1 all shared similarities with the previously reported S. mutans phages M102, M102AD, and ϕAPCM01. The genomes were organized into seven major gene clusters according to the putative functions of the predicted open reading frames: packaging and structural modules, integrase, host lysis modules, DNA replication/recombination modules, transcriptional regulatory modules, other protein modules, and hypothetical protein modules. Moreover, an integrase gene was only identified in phismuNLML9-1 prophages. PMID:29158986

The family Rhabdoviridae: Mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins

Science.gov (United States)

Dietzgen, Ralf G.; Kondo, Hideki; Goodin, Michael M.; Kurath, Gael; Vasilakis, Nikos

2017-01-01

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- and bipartite genomes.

Structural organization of DNA in chlorella viruses.

Directory of Open Access Journals (Sweden)

Timo Wulfmeyer

Full Text Available Chlorella viruses have icosahedral capsids with an internal membrane enclosing their large dsDNA genomes and associated proteins. Their genomes are packaged in the particles with a predicted DNA density of ca. 0.2 bp nm(-3. Occasionally infection of an algal cell by an individual particle fails and the viral DNA is dynamically ejected from the capsid. This shows that the release of the DNA generates a force, which can aid in the transfer of the genome into the host in a successful infection. Imaging of ejected viral DNA indicates that it is intimately associated with proteins in a periodic fashion. The bulk of the protein particles detected by atomic force microscopy have a size of ∼60 kDa and two proteins (A278L and A282L of about this size are among 6 basic putative DNA binding proteins found in a proteomic analysis of DNA binding proteins packaged in the virion. A combination of fluorescence images of ejected DNA and a bioinformatics analysis of the DNA reveal periodic patterns in the viral DNA. The periodic distribution of GC rich regions in the genome provides potential binding sites for basic proteins. This DNA/protein aggregation could be responsible for the periodic concentration of fluorescently labeled DNA observed in ejected viral DNA. Collectively the data indicate that the large chlorella viruses have a DNA packaging strategy that differs from bacteriophages; it involves proteins and share similarities to that of chromatin structure in eukaryotes.

Visualization of genome signatures of eukaryote genomes by batch-learning self-organizing map with a special emphasis on Drosophila genomes.

Science.gov (United States)

Abe, Takashi; Hamano, Yuta; Ikemura, Toshimichi

2014-01-01

A strategy of evolutionary studies that can compare vast numbers of genome sequences is becoming increasingly important with the remarkable progress of high-throughput DNA sequencing methods. We previously established a sequence alignment-free clustering method "BLSOM" for di-, tri-, and tetranucleotide compositions in genome sequences, which can characterize sequence characteristics (genome signatures) of a wide range of species. In the present study, we generated BLSOMs for tetra- and pentanucleotide compositions in approximately one million sequence fragments derived from 101 eukaryotes, for which almost complete genome sequences were available. BLSOM recognized phylotype-specific characteristics (e.g., key combinations of oligonucleotide frequencies) in the genome sequences, permitting phylotype-specific clustering of the sequences without any information regarding the species. In our detailed examination of 12 Drosophila species, the correlation between their phylogenetic classification and the classification on the BLSOMs was observed to visualize oligonucleotides diagnostic for species-specific clustering.

Rapid detection of structural variation in a human genome using nanochannel-based genome mapping technology

DEFF Research Database (Denmark)

Cao, Hongzhi; Hastie, Alex R.; Cao, Dandan

2014-01-01

mutations; however, none of the current detection methods are comprehensive, and currently available methodologies are incapable of providing sufficient resolution and unambiguous information across complex regions in the human genome. To address these challenges, we applied a high-throughput, cost......-effective genome mapping technology to comprehensively discover genome-wide SVs and characterize complex regions of the YH genome using long single molecules (>150 kb) in a global fashion. RESULTS: Utilizing nanochannel-based genome mapping technology, we obtained 708 insertions/deletions and 17 inversions larger...... fosmid data. Of the remaining 270 SVs, 260 are insertions and 213 overlap known SVs in the Database of Genomic Variants. Overall, 609 out of 666 (90%) variants were supported by experimental orthogonal methods or historical evidence in public databases. At the same time, genome mapping also provides...

Mitotic chromosome structure

International Nuclear Information System (INIS)

Heermann, Dieter W.

2012-01-01

Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

Mitotic chromosome structure

Energy Technology Data Exchange (ETDEWEB)

Heermann, Dieter W., E-mail: heermann@tphys.uni-heidelberg.de

2012-07-15

Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

AGORA : Organellar genome annotation from the amino acid and nucleotide references.

Science.gov (United States)

Jung, Jaehee; Kim, Jong Im; Jeong, Young-Sik; Yi, Gangman

2018-03-29

Next-generation sequencing (NGS) technologies have led to the accumulation of highthroughput sequence data from various organisms in biology. To apply gene annotation of organellar genomes for various organisms, more optimized tools for functional gene annotation are required. Almost all gene annotation tools are mainly focused on the chloroplast genome of land plants or the mitochondrial genome of animals.We have developed a web application AGORA for the fast, user-friendly, and improved annotations of organellar genomes. AGORA annotates genes based on a BLAST-based homology search and clustering with selected reference sequences from the NCBI database or user-defined uploaded data. AGORA can annotate the functional genes in almost all mitochondrion and plastid genomes of eukaryotes. The gene annotation of a genome with an exon-intron structure within a gene or inverted repeat region is also available. It provides information of start and end positions of each gene, BLAST results compared with the reference sequence, and visualization of gene map by OGDRAW. Users can freely use the software, and the accessible URL is https://bigdata.dongguk.edu/gene_project/AGORA/.The main module of the tool is implemented by the python and php, and the web page is built by the HTML and CSS to support all browsers. gangman@dongguk.edu.

GeneViTo: Visualizing gene-product functional and structural features in genomic datasets

Directory of Open Access Journals (Sweden)

Promponas Vasilis J

2003-10-01

Full Text Available Abstract Background The availability of increasing amounts of sequence data from completely sequenced genomes boosts the development of new computational methods for automated genome annotation and comparative genomics. Therefore, there is a need for tools that facilitate the visualization of raw data and results produced by bioinformatics analysis, providing new means for interactive genome exploration. Visual inspection can be used as a basis to assess the quality of various analysis algorithms and to aid in-depth genomic studies. Results GeneViTo is a JAVA-based computer application that serves as a workbench for genome-wide analysis through visual interaction. The application deals with various experimental information concerning both DNA and protein sequences (derived from public sequence databases or proprietary data sources and meta-data obtained by various prediction algorithms, classification schemes or user-defined features. Interaction with a Graphical User Interface (GUI allows easy extraction of genomic and proteomic data referring to the sequence itself, sequence features, or general structural and functional features. Emphasis is laid on the potential comparison between annotation and prediction data in order to offer a supplement to the provided information, especially in cases of "poor" annotation, or an evaluation of available predictions. Moreover, desired information can be output in high quality JPEG image files for further elaboration and scientific use. A compilation of properly formatted GeneViTo input data for demonstration is available to interested readers for two completely sequenced prokaryotes, Chlamydia trachomatis and Methanococcus jannaschii. Conclusions GeneViTo offers an inspectional view of genomic functional elements, concerning data stemming both from database annotation and analysis tools for an overall analysis of existing genomes. The application is compatible with Linux or Windows ME-2000-XP operating

V-GAP: Viral genome assembly pipeline

KAUST Repository

Nakamura, Yoji

2015-10-22

Next-generation sequencing technologies have allowed the rapid determination of the complete genomes of many organisms. Although shotgun sequences from large genome organisms are still difficult to reconstruct perfect contigs each of which represents a full chromosome, those from small genomes have been assembled successfully into a very small number of contigs. In this study, we show that shotgun reads from phage genomes can be reconstructed into a single contig by controlling the number of read sequences used in de novo assembly. We have developed a pipeline to assemble small viral genomes with good reliability using a resampling method from shotgun data. This pipeline, named V-GAP (Viral Genome Assembly Pipeline), will contribute to the rapid genome typing of viruses, which are highly divergent, and thus will meet the increasing need for viral genome comparisons in metagenomic studies.

V-GAP: Viral genome assembly pipeline

KAUST Repository

Nakamura, Yoji; Yasuike, Motoshige; Nishiki, Issei; Iwasaki, Yuki; Fujiwara, Atushi; Kawato, Yasuhiko; Nakai, Toshihiro; Nagai, Satoshi; Kobayashi, Takanori; Gojobori, Takashi; Ototake, Mitsuru

2015-01-01

Next-generation sequencing technologies have allowed the rapid determination of the complete genomes of many organisms. Although shotgun sequences from large genome organisms are still difficult to reconstruct perfect contigs each of which represents a full chromosome, those from small genomes have been assembled successfully into a very small number of contigs. In this study, we show that shotgun reads from phage genomes can be reconstructed into a single contig by controlling the number of read sequences used in de novo assembly. We have developed a pipeline to assemble small viral genomes with good reliability using a resampling method from shotgun data. This pipeline, named V-GAP (Viral Genome Assembly Pipeline), will contribute to the rapid genome typing of viruses, which are highly divergent, and thus will meet the increasing need for viral genome comparisons in metagenomic studies.

Refining the structure and content of clinical genomic reports.

Science.gov (United States)

Dorschner, Michael O; Amendola, Laura M; Shirts, Brian H; Kiedrowski, Lesli; Salama, Joseph; Gordon, Adam S; Fullerton, Stephanie M; Tarczy-Hornoch, Peter; Byers, Peter H; Jarvik, Gail P

2014-03-01

To effectively articulate the results of exome and genome sequencing we refined the structure and content of molecular test reports. To communicate results of a randomized control trial aimed at the evaluation of exome sequencing for clinical medicine, we developed a structured narrative report. With feedback from genetics and non-genetics professionals, we developed separate indication-specific and incidental findings reports. Standard test report elements were supplemented with research study-specific language, which highlighted the limitations of exome sequencing and provided detailed, structured results, and interpretations. The report format we developed to communicate research results can easily be transformed for clinical use by removal of research-specific statements and disclaimers. The development of clinical reports for exome sequencing has shown that accurate and open communication between the clinician and laboratory is ideally an ongoing process to address the increasing complexity of molecular genetic testing. © 2014 Wiley Periodicals, Inc.

Recombination-dependent replication and gene conversion homogenize repeat sequences and diversify plastid genome structure.

Science.gov (United States)

Ruhlman, Tracey A; Zhang, Jin; Blazier, John C; Sabir, Jamal S M; Jansen, Robert K

2017-04-01

There is a misinterpretation in the literature regarding the variable orientation of the small single copy region of plastid genomes (plastomes). The common phenomenon of small and large single copy inversion, hypothesized to occur through intramolecular recombination between inverted repeats (IR) in a circular, single unit-genome, in fact, more likely occurs through recombination-dependent replication (RDR) of linear plastome templates. If RDR can be primed through both intra- and intermolecular recombination, then this mechanism could not only create inversion isomers of so-called single copy regions, but also an array of alternative sequence arrangements. We used Illumina paired-end and PacBio single-molecule real-time (SMRT) sequences to characterize repeat structure in the plastome of Monsonia emarginata (Geraniaceae). We used OrgConv and inspected nucleotide alignments to infer ancestral nucleotides and identify gene conversion among repeats and mapped long (>1 kb) SMRT reads against the unit-genome assembly to identify alternative sequence arrangements. Although M. emarginata lacks the canonical IR, we found that large repeats (>1 kilobase; kb) represent ∼22% of the plastome nucleotide content. Among the largest repeats (>2 kb), we identified GC-biased gene conversion and mapping filtered, long SMRT reads to the M. emarginata unit-genome assembly revealed alternative, substoichiometric sequence arrangements. We offer a model based on RDR and gene conversion between long repeated sequences in the M. emarginata plastome and provide support that both intra-and intermolecular recombination between large repeats, particularly in repeat-rich plastomes, varies unit-genome structure while homogenizing the nucleotide sequence of repeats. © 2017 Botanical Society of America.

Chloroplast Translation: Structural and Functional Organization, Operational Control, and Regulation[OPEN

Science.gov (United States)

2018-01-01

Chloroplast translation is essential for cellular viability and plant development. Its positioning at the intersection of organellar RNA and protein metabolism makes it a unique point for the regulation of gene expression in response to internal and external cues. Recently obtained high-resolution structures of plastid ribosomes, the development of approaches allowing genome-wide analyses of chloroplast translation (i.e., ribosome profiling), and the discovery of RNA binding proteins involved in the control of translational activity have greatly increased our understanding of the chloroplast translation process and its regulation. In this review, we provide an overview of the current knowledge of the chloroplast translation machinery, its structure, organization, and function. In addition, we summarize the techniques that are currently available to study chloroplast translation and describe how translational activity is controlled and which cis-elements and trans-factors are involved. Finally, we discuss how translational control contributes to the regulation of chloroplast gene expression in response to developmental, environmental, and physiological cues. We also illustrate the commonalities and the differences between the chloroplast and bacterial translation machineries and the mechanisms of protein biosynthesis in these two prokaryotic systems. PMID:29610211

Heat Shock Protein Genes Undergo Dynamic Alteration in Their Three-Dimensional Structure and Genome Organization in Response to Thermal Stress.

Science.gov (United States)

Chowdhary, Surabhi; Kainth, Amoldeep S; Gross, David S

2017-12-15

Three-dimensional (3D) chromatin organization is important for proper gene regulation, yet how the genome is remodeled in response to stress is largely unknown. Here, we use a highly sensitive version of chromosome conformation capture in combination with fluorescence microscopy to investigate Heat Shock Protein ( HSP ) gene conformation and 3D nuclear organization in budding yeast. In response to acute thermal stress, HSP genes undergo intense intragenic folding interactions that go well beyond 5'-3' gene looping previously described for RNA polymerase II genes. These interactions include looping between upstream activation sequence (UAS) and promoter elements, promoter and terminator regions, and regulatory and coding regions (gene "crumpling"). They are also dynamic, being prominent within 60 s, peaking within 2.5 min, and attenuating within 30 min, and correlate with HSP gene transcriptional activity. With similarly striking kinetics, activated HSP genes, both chromosomally linked and unlinked, coalesce into discrete intranuclear foci. Constitutively transcribed genes also loop and crumple yet fail to coalesce. Notably, a missense mutation in transcription factor TFIIB suppresses gene looping, yet neither crumpling nor HSP gene coalescence is affected. An inactivating promoter mutation, in contrast, obviates all three. Our results provide evidence for widespread, transcription-associated gene crumpling and demonstrate the de novo assembly and disassembly of HSP gene foci. Copyright © 2017 American Society for Microbiology.

The Amphimedon queenslandica genome and the evolution of animal complexity

Energy Technology Data Exchange (ETDEWEB)

Srivastava, Mansi; Simakov, Oleg; Chapman, Jarrod; Fahey, Bryony; Gauthier, Marie E.A.; Mitros, Therese; Richards, Gemma S.; Conaco, Cecilia; Dacre, Michael; Hellsten, Uffe; Larroux, Claire; Putnam, Nicholas H.; Stanke, Mario; Adamska, Maja; Darling, Aaron; Degnan, Sandie M.; Oakley, Todd H.; Plachetzki, David C.; Zhai, Yufeng; Adamski, Marcin; Calcino, Andrew; Cummins, Scott F.; Goodstein, David M.; Harris, Christina; Jackson, Daniel J.; Leys, Sally P.; Shu, Shengqiang; Woodcroft, Ben J.; Vervoort, Michel; Kosik, Kenneth S.; Manning, Gerard; Degnan, Bernard M.; Rokhsar, Daniel S.

2010-07-01

Sponges are an ancient group of animals that diverged from other metazoans over 600 million years ago. Here we present the draft genome sequence of Amphimedon queenslandica, a demosponge from the Great Barrier Reef, and show that it is remarkably similar to other animal genomes in content, structure and organization. Comparative analysis enabled by the sponge sequence reveals genomic events linked to the origin and early evolution of animals, including the appearance, expansion, and diversification of pan-metazoan transcription factor, signaling pathway, and structural genes. This diverse 'toolkit' of genes correlates with critical aspects of all metazoan body plans, and comprises cell cycle control and growth, development, somatic and germ cell specification, cell adhesion, innate immunity, and allorecognition. Notably, many of the genes associated with the emergence of animals are also implicated in cancer, which arises from defects in basic processes associated with metazoan multicellularity.

Insights into bilaterian evolution from three spiralian genomes

Energy Technology Data Exchange (ETDEWEB)

Simakov, Oleg; Marletaz, Ferdinand; Cho, Sung-Jin; Edsinger-Gonzales, Eric; Havlak, Paul; Hellsten, Uffe; Kuo, Dian-Han; Larsson, Tomas; Lv, Jie; Arendt, Detlev; Savage, Robert; Osoegawa, Kazutoyo; de Jong, Pieter; Grimwood, Jane; Chapman, Jarrod A.; Shapiro, Harris; Otillar, Robert P.; Terry, Astrid Y.; Boore, Jeffrey L.; Grigoriev, Igor V.; Lindberg, David R.; Seaver, Elaine C.; Weisblat, David A.; Putnam, Nicholas H.; Rokhsar, Daniel S.; Aerts, Andrea

2012-01-07

Current genomic perspectives on animal diversity neglect two prominent phyla, the molluscs and annelids, that together account for nearly one-third of known marine species and are important both ecologically and as experimental systems in classical embryology1, 2, 3. Here we describe the draft genomes of the owl limpet (Lottia gigantea), a marine polychaete (Capitella teleta) and a freshwater leech (Helobdella robusta), and compare them with other animal genomes to investigate the origin and diversification of bilaterians from a genomic perspective. We find that the genome organization, gene structure and functional content of these species are more similar to those of some invertebrate deuterostome genomes (for example, amphioxus and sea urchin) than those of other protostomes that have been sequenced to date (flies, nematodes and flatworms). The conservation of these genomic features enables us to expand the inventory of genes present in the last common bilaterian ancestor, establish the tripartite diversification of bilaterians using multiple genomic characteristics and identify ancient conserved long- and short-range genetic linkages across metazoans. Superimposed on this broadly conserved pan-bilaterian background we find examples of lineage-specific genome evolution, including varying rates of rearrangement, intron gain and loss, expansions and contractions of gene families, and the evolution of clade-specific genes that produce the unique content of each genome.

Natural Product Biosynthetic Diversity and Comparative Genomics of the Cyanobacteria.

Science.gov (United States)

Dittmann, Elke; Gugger, Muriel; Sivonen, Kaarina; Fewer, David P

2015-10-01

Cyanobacteria are an ancient lineage of slow-growing photosynthetic bacteria and a prolific source of natural products with intricate chemical structures and potent biological activities. The bulk of these natural products are known from just a handful of genera. Recent efforts have elucidated the mechanisms underpinning the biosynthesis of a diverse array of natural products from cyanobacteria. Many of the biosynthetic mechanisms are unique to cyanobacteria or rarely described from other organisms. Advances in genome sequence technology have precipitated a deluge of genome sequences for cyanobacteria. This makes it possible to link known natural products to biosynthetic gene clusters but also accelerates the discovery of new natural products through genome mining. These studies demonstrate that cyanobacteria encode a huge variety of cryptic gene clusters for the production of natural products, and the known chemical diversity is likely to be just a fraction of the true biosynthetic capabilities of this fascinating and ancient group of organisms. Copyright © 2015. Published by Elsevier Ltd.

Comparison of C. elegans and C. briggsae genome sequences reveals extensive conservation of chromosome organization and synteny.

Directory of Open Access Journals (Sweden)

LaDeana W Hillier

2007-07-01

Full Text Available To determine whether the distinctive features of Caenorhabditis elegans chromosomal organization are shared with the C. briggsae genome, we constructed a single nucleotide polymorphism-based genetic map to order and orient the whole genome shotgun assembly along the six C. briggsae chromosomes. Although these species are of the same genus, their most recent common ancestor existed 80-110 million years ago, and thus they are more evolutionarily distant than, for example, human and mouse. We found that, like C. elegans chromosomes, C. briggsae chromosomes exhibit high levels of recombination on the arms along with higher repeat density, a higher fraction of intronic sequence, and a lower fraction of exonic sequence compared with chromosome centers. Despite extensive intrachromosomal rearrangements, 1:1 orthologs tend to remain in the same region of the chromosome, and colinear blocks of orthologs tend to be longer in chromosome centers compared with arms. More strikingly, the two species show an almost complete conservation of synteny, with 1:1 orthologs present on a single chromosome in one species also found on a single chromosome in the other. The conservation of both chromosomal organization and synteny between these two distantly related species suggests roles for chromosome organization in the fitness of an organism that are only poorly understood presently.

Salmonella strains isolated from Galápagos iguanas show spatial structuring of serovar and genomic diversity.

Science.gov (United States)

Lankau, Emily W; Cruz Bedon, Lenin; Mackie, Roderick I

2012-01-01

It is thought that dispersal limitation primarily structures host-associated bacterial populations because host distributions inherently limit transmission opportunities. However, enteric bacteria may disperse great distances during food-borne outbreaks. It is unclear if such rapid long-distance dispersal events happen regularly in natural systems or if these events represent an anthropogenic exception. We characterized Salmonella enterica isolates from the feces of free-living Galápagos land and marine iguanas from five sites on four islands using serotyping and genomic fingerprinting. Each site hosted unique and nearly exclusive serovar assemblages. Genomic fingerprint analysis offered a more complex model of S. enterica biogeography, with evidence of both unique strain pools and of spatial population structuring along a geographic gradient. These findings suggest that even relatively generalist enteric bacteria may be strongly dispersal limited in a natural system with strong barriers, such as oceanic divides. Yet, these differing results seen on two typing methods also suggests that genomic variation is less dispersal limited, allowing for different ecological processes to shape biogeographical patterns of the core and flexible portions of this bacterial species' genome.

Structural hierarchy in flow-aligned hexagonally self-organized microphases with parallel polyelectrolytic structures

NARCIS (Netherlands)

Ruotsalainen, T; Torkkeli, M; Serimaa, R; Makela, T; Maki-Ontto, R; Ruokolainen, J; ten Brinke, G; Ikkala, O; Mäkelä, Tapio; Mäki-Ontto, Riikka

2003-01-01

We report a novel structural hierarchy where a flow-aligned hexagonal self-organized structure is combined with a polyelectrolytic self-organization on a smaller length scale and where the two structures are mutually parallel. Polystyrene-block-poly(4-vinylpyridine) (PS-block-P4VP) is selected with

Structured-gate organic field-effect transistors

International Nuclear Information System (INIS)

Aljada, Muhsen; Pandey, Ajay K; Velusamy, Marappan; Burn, Paul L; Meredith, Paul; Namdas, Ebinazar B

2012-01-01

We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO 2 ) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends. (paper)

Structured-gate organic field-effect transistors

Science.gov (United States)

Aljada, Muhsen; Pandey, Ajay K.; Velusamy, Marappan; Burn, Paul L.; Meredith, Paul; Namdas, Ebinazar B.

2012-06-01

We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO2) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends.

Organization structure of a basic school of arts

OpenAIRE

Sinkulová, Iveta

2012-01-01

TITLE: Organization Structure of a Basic School of Arts AUTHOR: Iveta Sinkulová ABSTRACT: My bachelor thesis "Organization Structure of a Basic School of Arts" sets a goal to research which organization structures are applied at basic schools of arts, how the jobs of headmaster and heads of departments are incorporated into the Org Chart and which tasks are delegated to them in terms of the management of teaching process. The first thing performed was descriptive research. Then the work of de...

Proteomic strategy for the identification of critical actors in reorganization of the post-meiotic male genome.

Science.gov (United States)

Govin, Jerome; Gaucher, Jonathan; Ferro, Myriam; Debernardi, Alexandra; Garin, Jerome; Khochbin, Saadi; Rousseaux, Sophie

2012-01-01

After meiosis, during the final stages of spermatogenesis, the haploid male genome undergoes major structural changes, resulting in a shift from a nucleosome-based genome organization to the sperm-specific, highly compacted nucleoprotamine structure. Recent data support the idea that region-specific programming of the haploid male genome is of high importance for the post-fertilization events and for successful embryo development. Although these events constitute a unique and essential step in reproduction, the mechanisms by which they occur have remained completely obscure and the factors involved have mostly remained uncharacterized. Here, we sought a strategy to significantly increase our understanding of proteins controlling the haploid male genome reprogramming, based on the identification of proteins in two specific pools: those with the potential to bind nucleic acids (basic proteins) and proteins capable of binding basic proteins (acidic proteins). For the identification of acidic proteins, we developed an approach involving a transition-protein (TP)-based chromatography, which has the advantage of retaining not only acidic proteins due to the charge interactions, but also potential TP-interacting factors. A second strategy, based on an in-depth bioinformatic analysis of the identified proteins, was then applied to pinpoint within the lists obtained, male germ cells expressed factors relevant to the post-meiotic genome organization. This approach reveals a functional network of DNA-packaging proteins and their putative chaperones and sheds a new light on the way the critical transitions in genome organizations could take place. This work also points to a new area of research in male infertility and sperm quality assessments.

The family Rhabdoviridae: mono- and bipartite negative-sense RNA viruses with diverse genome organization and common evolutionary origins.

Science.gov (United States)

Dietzgen, Ralf G; Kondo, Hideki; Goodin, Michael M; Kurath, Gael; Vasilakis, Nikos

2017-01-02

The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- and bipartite genomes. Copyright © 2016 Elsevier B.V. All rights reserved.

Parasite Genome Projects and the Trypanosoma cruzi Genome Initiative

Directory of Open Access Journals (Sweden)

Wim Degrave

1997-11-01

Full Text Available Since the start of the human genome project, a great number of genome projects on other "model" organism have been initiated, some of them already completed. Several initiatives have also been started on parasite genomes, mainly through support from WHO/TDR, involving North-South and South-South collaborations, and great hopes are vested in that these initiatives will lead to new tools for disease control and prevention, as well as to the establishment of genomic research technology in developing countries. The Trypanosoma cruzi genome project, using the clone CL-Brener as starting point, has made considerable progress through the concerted action of more than 20 laboratories, most of them in the South. A brief overview of the current state of the project is given

Shedding genomic light on Aristotle's lantern.

Science.gov (United States)

Sodergren, Erica; Shen, Yufeng; Song, Xingzhi; Zhang, Lan; Gibbs, Richard A; Weinstock, George M

2006-12-01

Sea urchins have proved fascinating to biologists since the time of Aristotle who compared the appearance of their bony mouth structure to a lantern in The History of Animals. Throughout modern times it has been a model system for research in developmental biology. Now, the genome of the sea urchin Strongylocentrotus purpuratus is the first echinoderm genome to be sequenced. A high quality draft sequence assembly was produced using the Atlas assembler to combine whole genome shotgun sequences with sequences from a collection of BACs selected to form a minimal tiling path along the genome. A formidable challenge was presented by the high degree of heterozygosity between the two haplotypes of the selected male representative of this marine organism. This was overcome by use of the BAC tiling path backbone, in which each BAC represents a single haplotype, as well as by improvements in the Atlas software. Another innovation introduced in this project was the sequencing of pools of tiling path BACs rather than individual BAC sequencing. The Clone-Array Pooled Shotgun Strategy greatly reduced the cost and time devoted to preparing shotgun libraries from BAC clones. The genome sequence was analyzed with several gene prediction methods to produce a comprehensive gene list that was then manually refined and annotated by a volunteer team of sea urchin experts. This latter annotation community edited over 9000 gene models and uncovered many unexpected aspects of the sea urchin genetic content impacting transcriptional regulation, immunology, sensory perception, and an organism's development. Analysis of the basic deuterostome genetic complement supports the sea urchin's role as a model system for deuterostome and, by extension, chordate development.

The genome BLASTatlas - a GeneWiz extension for visualization of whole-genome homology

DEFF Research Database (Denmark)

Hallin, Peter Fischer; Binnewies, Tim Terence; Ussery, David

2008-01-01

://www.cbs.dtu.dk/ws/BLASTatlas), where programming examples are available in Perl. By providing an interoperable method to carry out whole genome visualization of homology, this service offers bioinformaticians as well as biologists an easy-to-adopt workflow that can be directly called from the programming language of the user, hence......The development of fast and inexpensive methods for sequencing bacterial genomes has led to a wealth of data, often with many genomes being sequenced of the same species or closely related organisms. Thus, there is a need for visualization methods that will allow easy comparison of many sequenced...... genomes to a defined reference strain. The BLASTatlas is one such tool that is useful for mapping and visualizing whole genome homology of genes and proteins within a reference strain compared to other strains or species of one or more prokaryotic organisms. We provide examples of BLASTatlases, including...

Gene design, cloning and protein-expression methods for high-value targets at the Seattle Structural Genomics Center for Infectious Disease

International Nuclear Information System (INIS)

Raymond, Amy; Haffner, Taryn; Ng, Nathan; Lorimer, Don; Staker, Bart; Stewart, Lance

2011-01-01

An overview of one salvage strategy for high-value SSGCID targets is given. Any structural genomics endeavor, particularly ambitious ones such as the NIAID-funded Seattle Structural Genomics Center for Infectious Disease (SSGCID) and Center for Structural Genomics of Infectious Disease (CSGID), face technical challenges at all points of the production pipeline. One salvage strategy employed by SSGCID is combined gene engineering and structure-guided construct design to overcome challenges at the levels of protein expression and protein crystallization. Multiple constructs of each target are cloned in parallel using Polymerase Incomplete Primer Extension cloning and small-scale expressions of these are rapidly analyzed by capillary electrophoresis. Using the methods reported here, which have proven particularly useful for high-value targets, otherwise intractable targets can be resolved

Pre-genomic, genomic and post-genomic study of microbial communities involved in bioenergy.

Science.gov (United States)

Rittmann, Bruce E; Krajmalnik-Brown, Rosa; Halden, Rolf U

2008-08-01

Microorganisms can produce renewable energy in large quantities and without damaging the environment or disrupting food supply. The microbial communities must be robust and self-stabilizing, and their essential syntrophies must be managed. Pre-genomic, genomic and post-genomic tools can provide crucial information about the structure and function of these microbial communities. Applying these tools will help accelerate the rate at which microbial bioenergy processes move from intriguing science to real-world practice.

in silico Whole Genome Sequencer & Analyzer (iWGS): a computational pipeline to guide the design and analysis of de novo genome sequencing studies

Science.gov (United States)

The availability of genomes across the tree of life is highly biased toward vertebrates, pathogens, human disease models, and organisms with relatively small and simple genomes. Recent progress in genomics has enabled the de novo decoding of the genome of virtually any organism, greatly expanding it...

The zebrafish reference genome sequence and its relationship to the human genome

Science.gov (United States)

Howe, Kerstin; Clark, Matthew D.; Torroja, Carlos F.; Torrance, James; Berthelot, Camille; Muffato, Matthieu; Collins, John E.; Humphray, Sean; McLaren, Karen; Matthews, Lucy; McLaren, Stuart; Sealy, Ian; Caccamo, Mario; Churcher, Carol; Scott, Carol; Barrett, Jeffrey C.; Koch, Romke; Rauch, Gerd-Jörg; White, Simon; Chow, William; Kilian, Britt; Quintais, Leonor T.; Guerra-Assunção, José A.; Zhou, Yi; Gu, Yong; Yen, Jennifer; Vogel, Jan-Hinnerk; Eyre, Tina; Redmond, Seth; Banerjee, Ruby; Chi, Jianxiang; Fu, Beiyuan; Langley, Elizabeth; Maguire, Sean F.; Laird, Gavin K.; Lloyd, David; Kenyon, Emma; Donaldson, Sarah; Sehra, Harminder; Almeida-King, Jeff; Loveland, Jane; Trevanion, Stephen; Jones, Matt; Quail, Mike; Willey, Dave; Hunt, Adrienne; Burton, John; Sims, Sarah; McLay, Kirsten; Plumb, Bob; Davis, Joy; Clee, Chris; Oliver, Karen; Clark, Richard; Riddle, Clare; Eliott, David; Threadgold, Glen; Harden, Glenn; Ware, Darren; Mortimer, Beverly; Kerry, Giselle; Heath, Paul; Phillimore, Benjamin; Tracey, Alan; Corby, Nicole; Dunn, Matthew; Johnson, Christopher; Wood, Jonathan; Clark, Susan; Pelan, Sarah; Griffiths, Guy; Smith, Michelle; Glithero, Rebecca; Howden, Philip; Barker, Nicholas; Stevens, Christopher; Harley, Joanna; Holt, Karen; Panagiotidis, Georgios; Lovell, Jamieson; Beasley, Helen; Henderson, Carl; Gordon, Daria; Auger, Katherine; Wright, Deborah; Collins, Joanna; Raisen, Claire; Dyer, Lauren; Leung, Kenric; Robertson, Lauren; Ambridge, Kirsty; Leongamornlert, Daniel; McGuire, Sarah; Gilderthorp, Ruth; Griffiths, Coline; Manthravadi, Deepa; Nichol, Sarah; Barker, Gary; Whitehead, Siobhan; Kay, Michael; Brown, Jacqueline; Murnane, Clare; Gray, Emma; Humphries, Matthew; Sycamore, Neil; Barker, Darren; Saunders, David; Wallis, Justene; Babbage, Anne; Hammond, Sian; Mashreghi-Mohammadi, Maryam; Barr, Lucy; Martin, Sancha; Wray, Paul; Ellington, Andrew; Matthews, Nicholas; Ellwood, Matthew; Woodmansey, Rebecca; Clark, Graham; Cooper, James; Tromans, Anthony; Grafham, Darren; Skuce, Carl; Pandian, Richard; Andrews, Robert; Harrison, Elliot; Kimberley, Andrew; Garnett, Jane; Fosker, Nigel; Hall, Rebekah; Garner, Patrick; Kelly, Daniel; Bird, Christine; Palmer, Sophie; Gehring, Ines; Berger, Andrea; Dooley, Christopher M.; Ersan-Ürün, Zübeyde; Eser, Cigdem; Geiger, Horst; Geisler, Maria; Karotki, Lena; Kirn, Anette; Konantz, Judith; Konantz, Martina; Oberländer, Martina; Rudolph-Geiger, Silke; Teucke, Mathias; Osoegawa, Kazutoyo; Zhu, Baoli; Rapp, Amanda; Widaa, Sara; Langford, Cordelia; Yang, Fengtang; Carter, Nigel P.; Harrow, Jennifer; Ning, Zemin; Herrero, Javier; Searle, Steve M. J.; Enright, Anton; Geisler, Robert; Plasterk, Ronald H. A.; Lee, Charles; Westerfield, Monte; de Jong, Pieter J.; Zon, Leonard I.; Postlethwait, John H.; Nüsslein-Volhard, Christiane; Hubbard, Tim J. P.; Crollius, Hugues Roest; Rogers, Jane; Stemple, Derek L.

2013-01-01

Zebrafish have become a popular organism for the study of vertebrate gene function1,2. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of vertebrate gene function and increasingly, the study of human genetic disease3–5. However, for effective modelling of human genetic disease it is important to understand the extent to which zebrafish genes and gene structures are related to orthologous human genes. To examine this, we generated a high-quality sequence assembly of the zebrafish genome, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map. Detailed automatic and manual annotation provides evidence of more than 26,000 protein-coding genes6, the largest gene set of any vertebrate so far sequenced. Comparison to the human reference genome shows that approximately 70% of human genes have at least one obvious zebrafish orthologue. In addition, the high quality of this genome assembly provides a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebrafish-specific genes on chromosome 4 and chromosomal regions that influence sex determination. PMID:23594743

Tetrahedral gray code for visualization of genome information.

Directory of Open Access Journals (Sweden)

Natsuhiro Ichinose

Full Text Available We propose a tetrahedral Gray code that facilitates visualization of genome information on the surfaces of a tetrahedron, where the relative abundance of each [Formula: see text]-mer in the genomic sequence is represented by a color of the corresponding cell of a triangular lattice. For biological significance, the code is designed such that the [Formula: see text]-mers corresponding to any adjacent pair of cells differ from each other by only one nucleotide. We present a simple procedure to draw such a pattern on the development surfaces of a tetrahedron. The thus constructed tetrahedral Gray code can demonstrate evolutionary conservation and variation of the genome information of many organisms at a glance. We also apply the tetrahedral Gray code to the honey bee (Apis mellifera genome to analyze its methylation structure. The results indicate that the honey bee genome exhibits CpG overrepresentation in spite of its methylation ability and that two conserved motifs, CTCGAG and CGCGCG, in the unmethylated regions are responsible for the overrepresentation of CpG.

Identification of candidate structured RNAs in the marine organism 'Candidatus Pelagibacter ubique'

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Schwalbach Michael S

2009-06-01

Full Text Available Abstract Background Metagenomic sequence data are proving to be a vast resource for the discovery of biological components. Yet analysis of this data to identify functional RNAs lags behind efforts to characterize protein diversity. The genome of 'Candidatus Pelagibacter ubique' HTCC 1062 is the closest match for approximately 20% of marine metagenomic sequence reads. It is also small, contains little non-coding DNA, and has strikingly low GC content. Results To aid the discovery of RNA motifs within the marine metagenome we exploited the genomic properties of 'Cand. P. ubique' by targeting our search to long intergenic regions (IGRs with relatively high GC content. Analysis of known RNAs (rRNA, tRNA, riboswitches etc. shows that structured RNAs are significantly enriched in such IGRs. To identify additional candidate structured RNAs, we examined other IGRs with similar characteristics from 'Cand. P. ubique' using comparative genomics approaches in conjunction with marine metagenomic data. Employing this strategy, we discovered four candidate structured RNAs including a new riboswitch class as well as three additional likely cis-regulatory elements that precede genes encoding ribosomal proteins S2 and S12, and the cytoplasmic protein component of the signal recognition particle. We also describe four additional potential RNA motifs with few or no examples occurring outside the metagenomic data. Conclusion This work begins the process of identifying functional RNA motifs present in the metagenomic data and illustrates how existing completed genomes may be used to aid in this task.

Archaeal Genome Guardians Give Insights into Eukaryotic DNA Replication and Damage Response Proteins

Directory of Open Access Journals (Sweden)

David S. Shin

2014-01-01

Full Text Available As the third domain of life, archaea, like the eukarya and bacteria, must have robust DNA replication and repair complexes to ensure genome fidelity. Archaea moreover display a breadth of unique habitats and characteristics, and structural biologists increasingly appreciate these features. As archaea include extremophiles that can withstand diverse environmental stresses, they provide fundamental systems for understanding enzymes and pathways critical to genome integrity and stress responses. Such archaeal extremophiles provide critical data on the periodic table for life as well as on the biochemical, geochemical, and physical limitations to adaptive strategies allowing organisms to thrive under environmental stress relevant to determining the boundaries for life as we know it. Specifically, archaeal enzyme structures have informed the architecture and mechanisms of key DNA repair proteins and complexes. With added abilities to temperature-trap flexible complexes and reveal core domains of transient and dynamic complexes, these structures provide insights into mechanisms of maintaining genome integrity despite extreme environmental stress. The DNA damage response protein structures noted in this review therefore inform the basis for genome integrity in the face of environmental stress, with implications for all domains of life as well as for biomanufacturing, astrobiology, and medicine.

Genomics and fish adaptation

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Agostinho Antunes

2015-12-01

Full Text Available The completion of the human genome sequencing in 2003 opened a new perspective into the importance of whole genome sequencing projects, and currently multiple species are having their genomes completed sequenced, from simple organisms, such as bacteria, to more complex taxa, such as mammals. This voluminous sequencing data generated across multiple organisms provides also the framework to better understand the genetic makeup of such species and related ones, allowing to explore the genetic changes underlining the evolution of diverse phenotypic traits. Here, recent results from our group retrieved from comparative evolutionary genomic analyses of varied fish species will be considered to exemplify how gene novelty and gene enhancement by positive selection might have been determinant in the success of adaptive radiations into diverse habitats and lifestyles.

Avian papillomaviruses: the parrot Psittacus erithacus papillomavirus (PePV genome has a unique organization of the early protein region and is phylogenetically related to the chaffinch papillomavirus

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Jenson A Bennett

2002-07-01

Full Text Available Abstract Background An avian papillomavirus genome has been cloned from a cutaneous exophytic papilloma from an African grey parrot (Psittacus erithacus. The nucleotide sequence, genome organization, and phylogenetic position of the Psittacus erithacus papillomavirus (PePV were determined. This PePV sequence represents the first complete avian papillomavirus genome defined. Results The PePV genome (7304 basepairs differs from other papillomaviruses, in that it has a unique organization of the early protein region lacking classical E6 and E7 open reading frames. Phylogenetic comparison of the PePV sequence with partial E1 and L1 sequences of the chaffinch (Fringilla coelebs papillomavirus (FPV reveals that these two avian papillomaviruses form a monophyletic cluster with a common branch that originates near the unresolved center of the papillomavirus evolutionary tree. Conclusions The PePV genome has a unique layout of the early protein region which represents a novel prototypic genomic organization for avian papillomaviruses. The close relationship between PePV and FPV, and between their Psittaciformes and Passeriformes hosts, supports the hypothesis that papillomaviruses have co-evolved and speciated together with their host species throughout evolution.

The perennial ryegrass GenomeZipper: targeted use of genome resources for comparative grass genomics.

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Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F X; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

2013-02-01

Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species.

Molecular Assemblies, Genes and Genomics Integrated Efficiently (MAGGIE)

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Baliga, Nitin S

2011-05-26

Final report on MAGGIE. We set ambitious goals to model the functions of individual organisms and their community from molecular to systems scale. These scientific goals are driving the development of sophisticated algorithms to analyze large amounts of experimental measurements made using high throughput technologies to explain and predict how the environment influences biological function at multiple scales and how the microbial systems in turn modify the environment. By experimentally evaluating predictions made using these models we will test the degree to which our quantitative multiscale understanding wilt help to rationally steer individual microbes and their communities towards specific tasks. Towards this end we have made substantial progress towards understanding evolution of gene families, transcriptional structures, detailed structures of keystone molecular assemblies (proteins and complexes), protein interactions, biological networks, microbial interactions, and community structure. Using comparative analysis we have tracked the evolutionary history of gene functions to understand how novel functions evolve. One level up, we have used proteomics data, high-resolution genome tiling microarrays, and 5' RNA sequencing to revise genome annotations, discover new genes including ncRNAs, and map dynamically changing operon structures of five model organisms: For Desulfovibrio vulgaris Hildenborough, Pyrococcus furiosis, Sulfolobus solfataricus, Methanococcus maripaludis and Haiobacterium salinarum NROL We have developed machine learning algorithms to accurately identify protein interactions at a near-zero false positive rate from noisy data generated using tagfess complex purification, TAP purification, and analysis of membrane complexes. Combining other genome-scale datasets produced by ENIGMA (in particular, microarray data) and available from literature we have been able to achieve a true positive rate as high as 65% at almost zero false positives

Three Infectious Viral Species Lying in Wait in the Banana Genome

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Chabannes, Matthieu; Baurens, Franc-Christophe; Duroy, Pierre-Olivier; Bocs, Stéphanie; Vernerey, Marie-Stéphanie; Rodier-Goud, Marguerite; Barbe, Valérie; Gayral, Philippe

2013-01-01

Plant pararetroviruses integrate serendipitously into their host genomes. The banana genome harbors integrated copies of banana streak virus (BSV) named endogenous BSV (eBSV) that are able to release infectious pararetrovirus. In this investigation, we characterized integrants of three BSV species—Goldfinger (eBSGFV), Imove (eBSImV), and Obino l'Ewai (eBSOLV)—in the seedy Musa balbisiana Pisang klutuk wulung (PKW) by studying their molecular structure, genomic organization, genomic landscape, and infectious capacity. All eBSVs exhibit extensive viral genome duplications and rearrangements. eBSV segregation analysis on an F1 population of PKW combined with fluorescent in situ hybridization analysis showed that eBSImV, eBSOLV, and eBSGFV are each present at a single locus. eBSOLV and eBSGFV contain two distinct alleles, whereas eBSImV has two structurally identical alleles. Genotyping of both eBSV and viral particles expressed in the progeny demonstrated that only one allele for each species is infectious. The infectious allele of eBSImV could not be identified since the two alleles are identical. Finally, we demonstrate that eBSGFV and eBSOLV are located on chromosome 1 and eBSImV is located on chromosome 2 of the reference Musa genome published recently. The structure and evolution of eBSVs suggest sequential integration into the plant genome, and haplotype divergence analysis confirms that the three loci display differential evolution. Based on our data, we propose a model for BSV integration and eBSV evolution in the Musa balbisiana genome. The mutual benefits of this unique host-pathogen association are also discussed. PMID:23720724

Hapsembler: An Assembler for Highly Polymorphic Genomes

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Donmez, Nilgun; Brudno, Michael

As whole genome sequencing has become a routine biological experiment, algorithms for assembly of whole genome shotgun data has become a topic of extensive research, with a plethora of off-the-shelf methods that can reconstruct the genomes of many organisms. Simultaneously, several recently sequenced genomes exhibit very high polymorphism rates. For these organisms genome assembly remains a challenge as most assemblers are unable to handle highly divergent haplotypes in a single individual. In this paper we describe Hapsembler, an assembler for highly polymorphic genomes, which makes use of paired reads. Our experiments show that Hapsembler produces accurate and contiguous assemblies of highly polymorphic genomes, while performing on par with the leading tools on haploid genomes. Hapsembler is available for download at http://compbio.cs.toronto.edu/hapsembler.

Bacillus subtilis genome diversity.

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Earl, Ashlee M; Losick, Richard; Kolter, Roberto

2007-02-01

Microarray-based comparative genomic hybridization (M-CGH) is a powerful method for rapidly identifying regions of genome diversity among closely related organisms. We used M-CGH to examine the genome diversity of 17 strains belonging to the nonpathogenic species Bacillus subtilis. Our M-CGH results indicate that there is considerable genetic heterogeneity among members of this species; nearly one-third of Bsu168-specific genes exhibited variability, as measured by the microarray hybridization intensities. The variable loci include those encoding proteins involved in antibiotic production, cell wall synthesis, sporulation, and germination. The diversity in these genes may reflect this organism's ability to survive in diverse natural settings.

Structural and functional insights of β-glucosidases identified from the genome of Aspergillus fumigatus

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Dodda, Subba Reddy; Aich, Aparajita; Sarkar, Nibedita; Jain, Piyush; Jain, Sneha; Mondal, Sudipa; Aikat, Kaustav; Mukhopadhyay, Sudit S.

2018-03-01

Thermostable glucose tolerant β-glucosidase from Aspergillus species has attracted worldwide interest for their potentiality in industrial applications and bioethanol production. A strain of Aspergillus fumigatus (AfNITDGPKA3) identified by our laboratory from straw retting ground showed higher cellulase activity, specifically the β-glucosidase activity, compared to other contemporary strains. Though A. fumigatus has been known for high cellulase activity, detailed identification and characterization of the cellulase genes from their genome is yet to be done. In this work we have been analyzed the cellulase genes from the genome sequence database of Aspergillus fumigatus (Af293). Genome analysis suggests two cellobiohydrolase, eleven endoglucanase and seventeen β-glucosidase genes present. β-Glucosidase genes belong to either Glycohydro1 (GH1 or Bgl1) or Glycohydro3 (GH3 or Bgl3) family. The sequence similarity suggests that Bgl1 and Bgl3 of A. fumagatus are phylogenetically close to those of A. fisheri and A. oryzae. The modelled structure of the Bgl1 predicts the (β/α)8 barrel type structure with deep and narrow active site, whereas, Bgl3 shows the (α/β)8 barrel and (α/β)6 sandwich structure with shallow and open active site. Docking results suggest that amino acids Glu544, Glu466, Trp408,Trp567,Tyr44,Tyr222,Tyr770,Asp844,Asp537,Asn212,Asn217 of Bgl3 and Asp224,Asn242,Glu440, Glu445, Tyr367, Tyr365,Thr994,Trp435,Trp446 of Bgl1 are involved in the hydrolysis. Binding affinity analyses suggest that Bgl3 and Bgl1 enzymes are more active on the substrates like 4-methylumbelliferyl glycoside (MUG) and p-nitrophenyl-β-D-1, 4-glucopyranoside (pNPG) than on cellobiose. Further docking with glucose suggests that Bgl1 is more glucose tolerant than Bgl3. Analysis of the Aspergillus fumigatus genome may help to identify a β-glucosidase enzyme with better property and the structural information may help to develop an engineered recombinant enzyme.

Extensive structural variations between mitochondrial genomes of CMS and normal peppers (Capsicum annuum L.) revealed by complete nucleotide sequencing.

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Jo, Yeong Deuk; Choi, Yoomi; Kim, Dong-Hwan; Kim, Byung-Dong; Kang, Byoung-Cheorl

2014-07-04

Cytoplasmic male sterility (CMS) is an inability to produce functional pollen that is caused by mutation of the mitochondrial genome. Comparative analyses of mitochondrial genomes of lines with and without CMS in several species have revealed structural differences between genomes, including extensive rearrangements caused by recombination. However, the mitochondrial genome structure and the DNA rearrangements that may be related to CMS have not been characterized in Capsicum spp. We obtained the complete mitochondrial genome sequences of the pepper CMS line FS4401 (507,452 bp) and the fertile line Jeju (511,530 bp). Comparative analysis between mitochondrial genomes of peppers and tobacco that are included in Solanaceae revealed extensive DNA rearrangements and poor conservation in non-coding DNA. In comparison between pepper lines, FS4401 and Jeju mitochondrial DNAs contained the same complement of protein coding genes except for one additional copy of an atp6 gene (ψatp6-2) in FS4401. In terms of genome structure, we found eighteen syntenic blocks in the two mitochondrial genomes, which have been rearranged in each genome. By contrast, sequences between syntenic blocks, which were specific to each line, accounted for 30,380 and 17,847 bp in FS4401 and Jeju, respectively. The previously-reported CMS candidate genes, orf507 and ψatp6-2, were located on the edges of the largest sequence segments that were specific to FS4401. In this region, large number of small sequence segments which were absent or found on different locations in Jeju mitochondrial genome were combined together. The incorporation of repeats and overlapping of connected sequence segments by a few nucleotides implied that extensive rearrangements by homologous recombination might be involved in evolution of this region. Further analysis using mtDNA pairs from other plant species revealed common features of DNA regions around CMS-associated genes. Although large portion of sequence context was