243 research outputs found

    A high quality draft consensus sequence of the genome of a heterozygous grapevine variety

    Get PDF
    Background. Worldwide, grapes and their derived products have a large market. The cultivated grape species Vitis vinifera has potential to become a model for fruit trees genetics. Like many plant species, it is highly heterozygous, which is an additional challenge to modern whole genome shotgun sequencing. In this paper a high quality draft genome sequence of a cultivated clone of V. vinifera Pinot Noir is presented. Principal Findings. We estimate the genome size of V. vinifera to be 504.6 Mb. Genomic sequences corresponding to 477.1 Mb were assembled in 2,093 metacontigs and 435.1 Mb were anchored to the 19 linkage groups (LGs). The number of predicted genes is 29,585, of which 96.1% were assigned to LGs. This assembly of the grape genome provides candidate genes implicated in traits relevant to grapevine cultivation, such as those influencing wine quality, via secondary metabolites, and those connected with the extreme susceptibility of grape to pathogens. Single nucleotide polymorphism (SNP) distribution was consistent with a diffuse haplotype structure across the genome. Of around 2,000,000 SNPs, 1,751,176 were mapped to chromosomes and one or more of them were identified in 86.7% of anchored genes. The relative age of grape duplicated genes was estimated and this made possible to reveal a relatively recent Vitisspecific large scale duplication event concerning at least 10 chromosomes (duplication not reported before). Conclusions. Sanger shotgun sequencing and highly efficient sequencing by synthesis (SBS), together with dedicated assembly programs, resolved a complex heterozygous genome. A consensus sequence of the genome and a set of mapped marker loci were generated. Homologous chromosomes of Pinot Noir differ by 11.2% of their DNA (hemizygous DNA plus chromosomal gaps). SNP markers are offered as a tool with the potential of introducing a new era in the molecular breeding of grape

    Spreading good news.

    Get PDF

    Angiosperm polyploids and their road to evolutionary success

    Get PDF
    The abundance of polyploidy among flowering plants has long been recognized, and recent studies have uncovered multiple ancient polyploidization events in the evolutionary history of several angiosperm lineages. Once polyploids are formed they must get locally established and then propagate and survive while adapting to different environments and avoiding extinction. This might ultimately lead to their long-term evolutionary success, where their descendant lineages survive for tens of millions of years. Along this road to evolutionary success, polyploids must overcome several obstacles, to which several genetic and ecological factors are likely to contribute. One recurrent observation, based on present-day polyploids, has been the high frequency of polyploids in harsh environments. Also, recent studies proposed that the success of certain ancient polyploids might be linked to periods of climatic change. Although we are still in the early stages of unraveling the factors that resulted in the long-term evolutionary success of ancient polyploids, the advances in genomic sequencing and molecular dating methods promise to enhance our understanding. It, therefore, seems timely to review our current knowledge of what determines the success of polyploids. Here, we discuss especially how harsh conditions or periods of climatic change might affect the rate of formation, establishment, persistence and long-term evolutionary success of polyploids in angiosperms

    An ancient genome duplication contributed to the abundance of metabolic genes in the moss Physcomitrella patens

    Get PDF
    <p>Abstract</p> <p>Background:</p> <p>Analyses of complete genomes and large collections of gene transcripts have shown that most, if not all seed plants have undergone one or more genome duplications in their evolutionary past.</p> <p>Results:</p> <p>In this study, based on a large collection of EST sequences, we provide evidence that the haploid moss <it>Physcomitrella patens </it>is a paleopolyploid as well. Based on the construction of linearized phylogenetic trees we infer the genome duplication to have occurred between 30 and 60 million years ago. Gene Ontology and pathway association of the duplicated genes in <it>P. patens </it>reveal different biases of gene retention compared with seed plants.</p> <p>Conclusion:</p> <p>Metabolic genes seem to have been retained in excess following the genome duplication in <it>P. patens</it>. This might, at least partly, explain the versatility of metabolism, as described for <it>P. patens </it>and other mosses, in comparison to other land plants.</p

    QTL Map Meets Population Genomics: An Application to Rice

    Get PDF
    Genes involved in the transition from wild to cultivated crop species should be of great agronomic importance. Population genomic approaches utilizing genome resequencing data have been recently applied for this purpose, although it only reports a large list of candidate genes with no biological information. Here, by resequencing more than 30 genomes altogether of wild rice Oryza rufipogon and cultivated rice O. sativa, we identified a number of regions with clear footprints of selection during the domestication process. We then focused on identifying candidate domestication genes in these regions by utilizing the wealth of QTL information in rice. We were able to identify a number of interesting candidates such as transcription factors that should control key domestication traits such as shattering, awn length, and seed dormancy. Other candidates include those that might have been related to the improvement of grain quality and those that might have been involved in the local adaptation to dry conditions and colder environments. Our study shows that population genomic approaches and QTL mapping information can be used together to identify genes that might be of agronomic importance

    Population genomics of the fission yeast Schizosaccharomyces pombe.

    Get PDF
    The fission yeast Schizosaccharomyces pombe has been widely used as a model eukaryote to study a diverse range of biological processes. However, population genetic studies of this species have been limited to date, and we know very little about the evolutionary processes and selective pressures that are shaping its genome. Here, we sequenced the genomes of 32 worldwide S. pombe strains and examined the pattern of polymorphisms across their genomes. In addition to introns and untranslated regions (UTRs), intergenic regions also exhibited lower levels of nucleotide diversity than synonymous sites, suggesting that a considerable amount of noncoding DNA is under selective constraint and thus likely to be functional. A number of genomic regions showed a reduction of nucleotide diversity probably caused by selective sweeps. We also identified a region close to the end of chromosome 3 where an extremely high level of divergence was observed between 5 of the 32 strains and the remain 27, possibly due to introgression, strong positive selection, or that region being responsible for reproductive isolation. Our study should serve as an important starting point in using a population genomics approach to further elucidate the biology of this important model organism

    Characterization of single-nucleotide variation in Indian-origin rhesus macaques (Macaca mulatta)

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Rhesus macaques are the most widely utilized nonhuman primate model in biomedical research. Previous efforts have validated fewer than 900 single nucleotide polymorphisms (SNPs) in this species, which limits opportunities for genetic studies related to health and disease. Extensive information about SNPs and other genetic variation in rhesus macaques would facilitate valuable genetic analyses, as well as provide markers for genome-wide linkage analysis and the genetic management of captive breeding colonies.</p> <p>Results</p> <p>We used the available rhesus macaque draft genome sequence, new sequence data from unrelated individuals and existing published sequence data to create a genome-wide SNP resource for Indian-origin rhesus monkeys. The original reference animal and two additional Indian-origin individuals were resequenced to low coverage using SOLiD™ sequencing. We then used three strategies to validate SNPs: comparison of potential SNPs found in the same individual using two different sequencing chemistries, and comparison of potential SNPs in different individuals identified with either the same or different sequencing chemistries. Our approach validated approximately 3 million SNPs distributed across the genome. Preliminary analysis of SNP annotations suggests that a substantial number of these macaque SNPs may have functional effects. More than 700 non-synonymous SNPs were scored by Polyphen-2 as either possibly or probably damaging to protein function and these variants now constitute potential models for studying functional genetic variation relevant to human physiology and disease.</p> <p>Conclusions</p> <p>Resequencing of a small number of animals identified greater than 3 million SNPs. This provides a significant new information resource for rhesus macaques, an important research animal. The data also suggests that overall genetic variation is high in this species. We identified many potentially damaging non-synonymous coding SNPs, providing new opportunities to identify rhesus models for human disease.</p

    Weight based tacrolimus trough concentrations post liver transplant

    Get PDF
    Tacrolimus is one of the most widely used liver transplant medications. With the increasing number of obese patients requiring liver transplants, knowledge of the effect of body size affecting post-transplant outcomes e.g. drug exposure is increasingly required.1) To investigate whether patient body size (i.e. total body weight) affect trough plasma concentrations of tacrolimus when a standard mg/kg dosing regimen is used; 2) To investigate whether obese patients have different number of plasma concentrations outside the therapeutic range compared to the non-obese patients in the first months after liver transplant.Using a transplant database, data tacrolimus concentrations were available for 69 patients. Tacrolimus was initially dosed at a standard 0.1mg/kg/day after liver transplant, and adjusted to maintain a target trough concentration. Trough blood samples, phenotypic and outcome variables were analysed.Trough concentrations were similar between the obese and non-obese patients (p>0.05) at each sampling day. At day-7 post-transplant, 85.7% and 79.5% of the observed plasma concentrations were outside the recommended therapeutic range for the obese and the non-obese patients respectively; at day-30, 52.9% and 57.4% and at 6 months, 18.7% and 27.5%.In the first week post-transplant, tacrolimus trough concentrations after standard mg/kg dosing post liver transplant appear to be corrected by total body weight. Obese patients have similar number of trough plasma concentrations outside the therapeutic range compared to the non-obese patients. This article is protected by copyright. All rights reserved

    An ecological approach to anomaly detection: the EIA Model.

    Get PDF
    The presented work proposes a new approach for anomaly detection. This approach is based on changes in a population of evolving agents under stress. If conditions are appropriate, changes in the population (modeled by the bioindicators) are representative of the alterations to the environment. This approach, based on an ecological view, improves functionally traditional approaches to the detection of anomalies. To verify this assertion, experiments based on Network Intrussion Detection Systems are presented. The results are compared with the behaviour of other bioinspired approaches and machine learning techniques

    Method for Assigning Priority Levels in Acute Care (MAPLe-AC) predicts outcomes of acute hospital care of older persons - a cross-national validation

    Get PDF
    To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.BACKGROUND: Although numerous risk factors for adverse outcomes for older persons after an acute hospital stay have been : identified, a decision making tool combining all available information in a clinically meaningful way would be helpful for daily hospital practice. The purpose of this study was to evaluate the ability of the Method for Assigning Priority Levels for Acute Care (MAPLe-AC) to predict adverse outcomes in acute care for older people and to assess its usability as a decision making tool for discharge planning. METHODS: Data from a prospective multicenter study in five Nordic acute care hospitals with information from admission to a one year follow-up of older acute care patients were compared with a prospective study of acute care patients from admission to discharge in eight hospitals in Canada. The interRAI Acute Care assessment instrument (v1.1) was used for data collection. Data were collected during the first 24 hours in hospital, including pre-morbid and admission information, and at day 7 or at discharge, whichever came first. Based on this information a crosswalk was developed from the original MAPLe algorithm for home care settings to acute care (MAPLe-AC). The sample included persons 75 years or older who were admitted to acute internal medical services in one hospital in each of the five Nordic countries (n = 763) or to acute hospital care either internal medical or combined medical-surgical services in eight hospitals in Ontario, Canada (n = 393). The outcome measures considered were discharge to home, discharge to institution or death. Outcomes in a 1-year follow-up in the Nordic hospitals were: living at home, living in an institution or death, and survival. Logistic regression with ROC curves and Cox regression analyses were used in the analyses. RESULTS: Low and mild priority levels of MAPLe-AC predicted discharge home and high and very high priority levels predicted adverse outcome at discharge both in the Nordic and Canadian data sets, and one-year outcomes in the Nordic data set. The predictive accuracy (AUC's) of MAPLe-AC's was higher for discharge outcome than one year outcome, and for discharge home in Canadian hospitals but for adverse outcome in Nordic hospitals. High and very high priority levels in MAPLe-AC were also predictive of days to death adjusted for diagnoses in survival models. CONCLUSION: MAPLe-AC is a valid algorithm based on risk factors that predict outcomes of acute hospital care. It could be a helpful tool for early discharge planning although further testing for active use in clinical practice is still needed.Reykjavik Hospital Research Fund St. Joseph's Research Fund, Iceland Norwegian Medical Society 2 Diakonhjemmet Hospital Diakonhjemmet University College Diakonhjemmet Research Fund, Norway Sweden's Lions Fund, Sweden Health Transition Fund Health Canada Canadian Institutes for Health Research (CIHR) Nordic Lions Red Feather Fund Nordic Council of Ministers Roikjer Fund, Denmark Finnish Lions Fund, Finland Icelandic Lions Fund Memorial Fund of Helgu Jensdottur and Sigurliða Kristjanssona
    corecore