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Sample records for genome wide dna

  1. Profiling genome-wide DNA methylation.

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    Yong, Wai-Shin; Hsu, Fei-Man; Chen, Pao-Yang

    2016-01-01

    DNA methylation is an epigenetic modification that plays an important role in regulating gene expression and therefore a broad range of biological processes and diseases. DNA methylation is tissue-specific, dynamic, sequence-context-dependent and trans-generationally heritable, and these complex patterns of methylation highlight the significance of profiling DNA methylation to answer biological questions. In this review, we surveyed major methylation assays, along with comparisons and biological examples, to provide an overview of DNA methylation profiling techniques. The advances in microarray and sequencing technologies make genome-wide profiling possible at a single-nucleotide or even a single-cell resolution. These profiling approaches vary in many aspects, such as DNA input, resolution, genomic region coverage, and bioinformatics analysis, and selecting a feasible method requires knowledge of these methods. We first introduce the biological background of DNA methylation and its pattern in plants, animals and fungi. We present an overview of major experimental approaches to profiling genome-wide DNA methylation and hydroxymethylation and then extend to the single-cell methylome. To evaluate these methods, we outline their strengths and weaknesses and perform comparisons across the different platforms. Due to the increasing need to compute high-throughput epigenomic data, we interrogate the computational pipeline for bisulfite sequencing data and also discuss the concept of identifying differentially methylated regions (DMRs). This review summarizes the experimental and computational concepts for profiling genome-wide DNA methylation, followed by biological examples. Overall, this review provides researchers useful guidance for the selection of a profiling method suited to specific research questions.

  2. DNA Break Mapping Reveals Topoisomerase II Activity Genome-Wide

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    Laura Baranello

    2014-07-01

    Full Text Available Genomic DNA is under constant assault by endogenous and exogenous DNA damaging agents. DNA breakage can represent a major threat to genome integrity but can also be necessary for genome function. Here we present approaches to map DNA double-strand breaks (DSBs and single-strand breaks (SSBs at the genome-wide scale by two methods called DSB- and SSB-Seq, respectively. We tested these methods in human colon cancer cells and validated the results using the Topoisomerase II (Top2-poisoning agent etoposide (ETO. Our results show that the combination of ETO treatment with break-mapping techniques is a powerful method to elaborate the pattern of Top2 enzymatic activity across the genome.

  3. Genome-wide mapping of DNA strand breaks.

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    Frédéric Leduc

    Full Text Available Determination of cellular DNA damage has so far been limited to global assessment of genome integrity whereas nucleotide-level mapping has been restricted to specific loci by the use of specific primers. Therefore, only limited DNA sequences can be studied and novel regions of genomic instability can hardly be discovered. Using a well-characterized yeast model, we describe a straightforward strategy to map genome-wide DNA strand breaks without compromising nucleotide-level resolution. This technique, termed "damaged DNA immunoprecipitation" (dDIP, uses immunoprecipitation and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin end-labeling (TUNEL to capture DNA at break sites. When used in combination with microarray or next-generation sequencing technologies, dDIP will allow researchers to map genome-wide DNA strand breaks as well as other types of DNA damage and to establish a clear profiling of altered genes and/or intergenic sequences in various experimental conditions. This mapping technique could find several applications for instance in the study of aging, genotoxic drug screening, cancer, meiosis, radiation and oxidative DNA damage.

  4. Genome-wide mapping of DNA methylation in chicken.

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    Qinghe Li

    Full Text Available Cytosine DNA methylation is an important epigenetic modification termed as the fifth base that functions in diverse processes. Till now, the genome-wide DNA methylation maps of many organisms has been reported, such as human, Arabidopsis, rice and silkworm, but the methylation pattern of bird remains rarely studied. Here we show the genome-wide DNA methylation map of bird, using the chicken as a model organism and an immunocapturing approach followed by high-throughput sequencing. In both of the red jungle fowl and the avian broiler, DNA methylation was described separately for the liver and muscle tissue. Generally, chicken displays analogous methylation pattern with that of animals and plants. DNA methylation is enriched in the gene body regions and the repetitive sequences, and depleted in the transcription start site (TSS and the transcription termination site (TTS. Most of the CpG islands in the chicken genome are kept in unmethylated state. Promoter methylation is negatively correlated with the gene expression level, indicating its suppressive role in regulating gene transcription. This work contributes to our understanding of epigenetics in birds.

  5. Genome-Wide Analysis of DNA Methylation in Human Amnion

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    Jinsil Kim

    2013-01-01

    Full Text Available The amnion is a specialized tissue in contact with the amniotic fluid, which is in a constantly changing state. To investigate the importance of epigenetic events in this tissue in the physiology and pathophysiology of pregnancy, we performed genome-wide DNA methylation profiling of human amnion from term (with and without labor and preterm deliveries. Using the Illumina Infinium HumanMethylation27 BeadChip, we identified genes exhibiting differential methylation associated with normal labor and preterm birth. Functional analysis of the differentially methylated genes revealed biologically relevant enriched gene sets. Bisulfite sequencing analysis of the promoter region of the oxytocin receptor (OXTR gene detected two CpG dinucleotides showing significant methylation differences among the three groups of samples. Hypermethylation of the CpG island of the solute carrier family 30 member 3 (SLC30A3 gene in preterm amnion was confirmed by methylation-specific PCR. This work provides preliminary evidence that DNA methylation changes in the amnion may be at least partially involved in the physiological process of labor and the etiology of preterm birth and suggests that DNA methylation profiles, in combination with other biological data, may provide valuable insight into the mechanisms underlying normal and pathological pregnancies.

  6. Genome-Wide Analysis of DNA Methylation in Human Amnion

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    Kim, Jinsil; Pitlick, Mitchell M.; Christine, Paul J.; Schaefer, Amanda R.; Saleme, Cesar; Comas, Belén; Cosentino, Viviana; Gadow, Enrique; Murray, Jeffrey C.

    2013-01-01

    The amnion is a specialized tissue in contact with the amniotic fluid, which is in a constantly changing state. To investigate the importance of epigenetic events in this tissue in the physiology and pathophysiology of pregnancy, we performed genome-wide DNA methylation profiling of human amnion from term (with and without labor) and preterm deliveries. Using the Illumina Infinium HumanMethylation27 BeadChip, we identified genes exhibiting differential methylation associated with normal labor and preterm birth. Functional analysis of the differentially methylated genes revealed biologically relevant enriched gene sets. Bisulfite sequencing analysis of the promoter region of the oxytocin receptor (OXTR) gene detected two CpG dinucleotides showing significant methylation differences among the three groups of samples. Hypermethylation of the CpG island of the solute carrier family 30 member 3 (SLC30A3) gene in preterm amnion was confirmed by methylation-specific PCR. This work provides preliminary evidence that DNA methylation changes in the amnion may be at least partially involved in the physiological process of labor and the etiology of preterm birth and suggests that DNA methylation profiles, in combination with other biological data, may provide valuable insight into the mechanisms underlying normal and pathological pregnancies. PMID:23533356

  7. Genome-Wide Prediction of DNA Methylation Using DNA Composition and Sequence Complexity in Human

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    Wu, Chengchao; Yao, Shixin; Li, Xinghao; Chen, Chujia; Hu, Xuehai

    2017-01-01

    DNA methylation plays a significant role in transcriptional regulation by repressing activity. Change of the DNA methylation level is an important factor affecting the expression of target genes and downstream phenotypes. Because current experimental technologies can only assay a small proportion of CpG sites in the human genome, it is urgent to develop reliable computational models for predicting genome-wide DNA methylation. Here, we proposed a novel algorithm that accurately extracted sequence complexity features (seven features) and developed a support-vector-machine-based prediction model with integration of the reported DNA composition features (trinucleotide frequency and GC content, 65 features) by utilizing the methylation profiles of embryonic stem cells in human. The prediction results from 22 human chromosomes with size-varied windows showed that the 600-bp window achieved the best average accuracy of 94.7%. Moreover, comparisons with two existing methods further showed the superiority of our model, and cross-species predictions on mouse data also demonstrated that our model has certain generalization ability. Finally, a statistical test of the experimental data and the predicted data on functional regions annotated by ChromHMM found that six out of 10 regions were consistent, which implies reliable prediction of unassayed CpG sites. Accordingly, we believe that our novel model will be useful and reliable in predicting DNA methylation. PMID:28212312

  8. Genome-wide DNA methylation analysis in permanent atrial fibrillation.

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    Zhao, Guochang; Zhou, Jian; Gao, Jie; Liu, Yan; Gu, Song; Zhang, Xitao; Su, Pixiong

    2017-10-01

    Atrial fibrillation (AF) is a highly heterogeneous genetic disease; however, the pathogenesis of AF cannot be explained by genetic variants alone. DNA methylation is a heritable method of gene expression regulation, and may be a potential regulatory mechanism in AF. Therefore, in the present study, the genome‑wide DNA methylation pattern in cells derived from the left atrium of patients with permanent AF (n=7) was compared with that of healthy heart donors (n=4) with a normal sinus rhythm (SR). Enriched biological functions of the differentially methylated genes were assessed. Integrated analysis of genome‑wide methylation and mRNA expression profiles was performed, and reverse transcription quantitative‑polymerase chain reaction (RT‑qPCR) was used to determine the expression levels of four selected genes. A total of 417 differentially methylated CpG sites were identified in the fibrillating atrium (P0.17); the majority of which were located in gene‑body and intergenic regions outside of CpG islands. Aberrantly methylated genes participated in the activation of inflammation, sodium and potassium ion transport, fibrosis and the reduction of lipid metabolism. Hypermethylation in the AF susceptible loci, paired‑like homeodomain transcription factor 2 (chromosome 4q25) and coiled‑coil domain containing 141 (chromosome 2q31), as well as hypomethylation in the calcium voltage‑gated channel subunit α1C (chromosome 12p13) locus, were identified in all patients with AF. Of the 420 upregulated and 567 downregulated genes previously identified in patients with AF relative to those with normal SR (fold‑change >2.0; P≤0.05), 12 genes were hypomethylated and eight genes were hypermethylated in each group, respectively (|β|>0.2: Peffect of DNA methylation on gene expression. These results suggest that DNA methylation‑mediated regulation of gene expression may serve an important role in AF pathogenesis, and several susceptible AF CpG loci were

  9. Robustness of genome-wide scanning using archived dried blood spot samples as a DNA source

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    Børglum Anders D

    2011-07-01

    Full Text Available Abstract Background The search to identify disease-susceptible genes requires access to biological material from numerous well-characterized subjects. Archived residual dried blood spot (DBS samples, also known as Guthrie cards, from national newborn screening programs may provide a DNA source for entire populations. Combined with clinical information from medical registries, DBS samples could provide a rich source for productive research. However, the amounts of DNA which can be extracted from these precious samples are minute and may be prohibitive for numerous genotypings. Previously, we demonstrated that DBS DNA can be whole-genome amplified and used for reliable genetic analysis on different platforms, including genome-wide scanning arrays. However, it remains unclear whether this approach is workable on a large sample scale. We examined the robustness of using DBS samples for whole-genome amplification following genome-wide scanning, using arrays from Illumina and Affymetrix. Results This study is based on 4,641 DBS samples from the Danish Newborn Screening Biobank, extracted for three separate genome-wide association studies. The amount of amplified DNA was significantly (P Conclusion Our study indicates that archived DBS samples from the Danish Newborn Screening Biobank represent a reliable resource of DNA for whole-genome amplification and subsequent genome-wide association studies. With call-rates equivalent to high quality DNA samples, our results point to new opportunities for using the neonatal biobanks available worldwide in the hunt for genetic components of disease.

  10. Single-tube linear DNA amplification for genome-wide studies using a few thousand cells

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    Shankaranarayanan, P.; Mendoza-Parra, M.A.; Gool, van W.; Trindade, L.M.; Gronemeyer, H.

    2012-01-01

    Linear amplification of DNA (LinDA) by T7 polymerase is a versatile and robust method for generating sufficient amounts of DNA for genome-wide studies with minute amounts of cells. LinDA can be coupled to a great number of global profiling technologies. Indeed, chromatin immunoprecipitation coupled

  11. Genome-wide signatures of differential DNA methylation in pediatric acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Nordlund, Jessica; Bäcklin, Christofer L; Wahlberg, Per

    2013-01-01

    BACKGROUND: Although aberrant DNA methylation has been observed previously in acute lymphoblastic leukemia (ALL), the patterns of differential methylation have not been comprehensively determined in all subtypes of ALL on a genome-wide scale. The relationship between DNA methylation, cytogenetic...

  12. Genome-wide analysis of DNA methylation in Arabidopsis using MeDIP-chip.

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    Cortijo, Sandra; Wardenaar, René; Colomé-Tatché, Maria; Johannes, Frank; Colot, Vincent

    2014-01-01

    DNA methylation is an epigenetic mark that is essential for preserving genome integrity and normal development in plants and mammals. Although this modification may serve a variety of purposes, it is best known for its role in stable transcriptional silencing of transposable elements and epigenetic regulation of some genes. In addition, it is increasingly recognized that alterations in DNA methylation patterns can sometimes be inherited across multiple generations and thus are a source of heritable phenotypic variation that is independent of any DNA sequence changes. With the advent of genomics, it is now possible to analyze DNA methylation genome-wide with high precision, which is a prerequisite for understanding fully the various functions and phenotypic impact of this modification. Indeed, several so-called epigenomic mapping methods have been developed for the analysis of DNA methylation. Among these, immunoprecipitation of methylated DNA followed by hybridization to genome tiling arrays (MeDIP-chip) arguably offers a reasonable compromise between cost, ease of implementation, and sensitivity to date. Here we describe the application of this method, from DNA extraction to data analysis, to the study of DNA methylation genome-wide in Arabidopsis.

  13. Genome-Wide Motif Statistics are Shaped by DNA Binding Proteins over Evolutionary Time Scales

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    Qian, Long; Kussell, Edo

    2016-10-01

    The composition of a genome with respect to all possible short DNA motifs impacts the ability of DNA binding proteins to locate and bind their target sites. Since nonfunctional DNA binding can be detrimental to cellular functions and ultimately to organismal fitness, organisms could benefit from reducing the number of nonfunctional DNA binding sites genome wide. Using in vitro measurements of binding affinities for a large collection of DNA binding proteins, in multiple species, we detect a significant global avoidance of weak binding sites in genomes. We demonstrate that the underlying evolutionary process leaves a distinct genomic hallmark in that similar words have correlated frequencies, a signal that we detect in all species across domains of life. We consider the possibility that natural selection against weak binding sites contributes to this process, and using an evolutionary model we show that the strength of selection needed to maintain global word compositions is on the order of point mutation rates. Likewise, we show that evolutionary mechanisms based on interference of protein-DNA binding with replication and mutational repair processes could yield similar results and operate with similar rates. On the basis of these modeling and bioinformatic results, we conclude that genome-wide word compositions have been molded by DNA binding proteins acting through tiny evolutionary steps over time scales spanning millions of generations.

  14. Genome-wide DNA methylation patterns and transcription analysis in sheep muscle.

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    Christine Couldrey

    Full Text Available DNA methylation plays a central role in regulating many aspects of growth and development in mammals through regulating gene expression. The development of next generation sequencing technologies have paved the way for genome-wide, high resolution analysis of DNA methylation landscapes using methodology known as reduced representation bisulfite sequencing (RRBS. While RRBS has proven to be effective in understanding DNA methylation landscapes in humans, mice, and rats, to date, few studies have utilised this powerful method for investigating DNA methylation in agricultural animals. Here we describe the utilisation of RRBS to investigate DNA methylation in sheep Longissimus dorsi muscles. RRBS analysis of ∼1% of the genome from Longissimus dorsi muscles provided data of suitably high precision and accuracy for DNA methylation analysis, at all levels of resolution from genome-wide to individual nucleotides. Combining RRBS data with mRNAseq data allowed the sheep Longissimus dorsi muscle methylome to be compared with methylomes from other species. While some species differences were identified, many similarities were observed between DNA methylation patterns in sheep and other more commonly studied species. The RRBS data presented here highlights the complexity of epigenetic regulation of genes. However, the similarities observed across species are promising, in that knowledge gained from epigenetic studies in human and mice may be applied, with caution, to agricultural species. The ability to accurately measure DNA methylation in agricultural animals will contribute an additional layer of information to the genetic analyses currently being used to maximise production gains in these species.

  15. Genome-wide alterations of the DNA replication program during tumor progression

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    Arneodo, A.; Goldar, A.; Argoul, F.; Hyrien, O.; Audit, B.

    2016-08-01

    Oncogenic stress is a major driving force in the early stages of cancer development. Recent experimental findings reveal that, in precancerous lesions and cancers, activated oncogenes may induce stalling and dissociation of DNA replication forks resulting in DNA damage. Replication timing is emerging as an important epigenetic feature that recapitulates several genomic, epigenetic and functional specificities of even closely related cell types. There is increasing evidence that chromosome rearrangements, the hallmark of many cancer genomes, are intimately associated with the DNA replication program and that epigenetic replication timing changes often precede chromosomic rearrangements. The recent development of a novel methodology to map replication fork polarity using deep sequencing of Okazaki fragments has provided new and complementary genome-wide replication profiling data. We review the results of a wavelet-based multi-scale analysis of genomic and epigenetic data including replication profiles along human chromosomes. These results provide new insight into the spatio-temporal replication program and its dynamics during differentiation. Here our goal is to bring to cancer research, the experimental protocols and computational methodologies for replication program profiling, and also the modeling of the spatio-temporal replication program. To illustrate our purpose, we report very preliminary results obtained for the chronic myelogeneous leukemia, the archetype model of cancer. Finally, we discuss promising perspectives on using genome-wide DNA replication profiling as a novel efficient tool for cancer diagnosis, prognosis and personalized treatment.

  16. Genome-wide association between DNA methylation and alternative splicing in an invertebrate

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    Flores Kevin

    2012-09-01

    Full Text Available Abstract Background Gene bodies are the most evolutionarily conserved targets of DNA methylation in eukaryotes. However, the regulatory functions of gene body DNA methylation remain largely unknown. DNA methylation in insects appears to be primarily confined to exons. Two recent studies in Apis mellifera (honeybee and Nasonia vitripennis (jewel wasp analyzed transcription and DNA methylation data for one gene in each species to demonstrate that exon-specific DNA methylation may be associated with alternative splicing events. In this study we investigated the relationship between DNA methylation, alternative splicing, and cross-species gene conservation on a genome-wide scale using genome-wide transcription and DNA methylation data. Results We generated RNA deep sequencing data (RNA-seq to measure genome-wide mRNA expression at the exon- and gene-level. We produced a de novo transcriptome from this RNA-seq data and computationally predicted splice variants for the honeybee genome. We found that exons that are included in transcription are higher methylated than exons that are skipped during transcription. We detected enrichment for alternative splicing among methylated genes compared to unmethylated genes using fisher’s exact test. We performed a statistical analysis to reveal that the presence of DNA methylation or alternative splicing are both factors associated with a longer gene length and a greater number of exons in genes. In concordance with this observation, a conservation analysis using BLAST revealed that each of these factors is also associated with higher cross-species gene conservation. Conclusions This study constitutes the first genome-wide analysis exhibiting a positive relationship between exon-level DNA methylation and mRNA expression in the honeybee. Our finding that methylated genes are enriched for alternative splicing suggests that, in invertebrates, exon-level DNA methylation may play a role in the construction of splice

  17. Genome-wide DNA methylation profiling of cell-free serum DNA in esophageal adenocarcinoma and Barrett esophagus.

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    Zhai, Rihong; Zhao, Yang; Su, Li; Cassidy, Lauren; Liu, Geoffrey; Christiani, David C

    2012-01-01

    Aberrant DNA methylation (DNAm) is a feature of most types of cancers. Genome-wide DNAm profiling has been performed successfully on tumor tissue DNA samples. However, the invasive procedure limits the utility of tumor tissue for epidemiological studies. While recent data indicate that cell-free circulating DNAm (cfDNAm) profiles reflect DNAm status in corresponding tumor tissues, no studies have examined the association of cfDNAm with cancer or precursors on a genome-wide scale. The objective of this pilot study was to evaluate the putative significance of genome-wide cfDNAm profiles in esophageal adenocarcinoma (EA) and Barrett esophagus (BE, EA precursor). We performed genome-wide DNAm profiling in EA tissue DNA (n = 8) and matched serum DNA (n = 8), in serum DNA of BE (n = 10), and in healthy controls (n = 10) using the Infinium HumanMethylation27 BeadChip that covers 27,578 CpG loci in 14,495 genes. We found that cfDNAm profiles were highly correlated to DNAm profiles in matched tumor tissue DNA (r = 0.92) in patients with EA. We selected the most differentially methylated loci to perform hierarchical clustering analysis. We found that 911 loci can discriminate perfectly between EA and control samples, 554 loci can separate EA from BE samples, and 46 loci can distinguish BE from control samples. These results suggest that genome-wide cfDNAm profiles are highly consistent with DNAm profiles detected in corresponding tumor tissues. Differential cfDNAm profiling may be a useful approach for the noninvasive screening of EA and EA premalignant lesions.

  18. Genome-wide DNA Methylation Profiling of Cell-Free Serum DNA in Esophageal Adenocarcinoma and Barrett Esophagus

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    Rihong Zhai

    2012-01-01

    Full Text Available Aberrant DNA methylation (DNAm is a feature of most types of cancers. Genome-wide DNAm profiling has been performed successfully on tumor tissue DNA samples. However, the invasive procedure limits the utility of tumor tissue for epidemiological studies. While recent data indicate that cell-free circulating DNAm (cfDNAm profiles reflect DNAm status in corresponding tumor tissues, no studies have examined the association of cfDNAm with cancer or precursors on a genome-wide scale. The objective of this pilot study was to evaluate the putative significance of genome-wide cfDNAm profiles in esophageal adenocarcinoma (EA and Barrett esophagus (BE, EA precursor. We performed genome-wide DNAm profiling in EA tissue DNA (n = 8 and matched serum DNA (n = 8, in serum DNA of BE (n = 10, and in healthy controls (n = 10 using the Infinium HumanMethylation27 BeadChip that covers 27,578 CpG loci in 14,495 genes. We found that cfDNAm profiles were highly correlated to DNAm profiles in matched tumor tissue DNA (r = 0.92 in patients with EA. We selected the most differentially methylated loci to perform hierarchical clustering analysis. We found that 911 loci can discriminate perfectly between EA and control samples, 554 loci can separate EA from BE samples, and 46 loci can distinguish BE from control samples. These results suggest that genome-wide cfDNAm profiles are highly consistent with DNAm profiles detected in corresponding tumor tissues. Differential cfDNAm profiling may be a useful approach for the noninvasive screening of EA and EA premalignant lesions.

  19. Epigenetic Variation in Monozygotic Twins: A Genome-Wide Analysis of DNA Methylation in Buccal Cells

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    Jenny van Dongen

    2014-05-01

    Full Text Available DNA methylation is one of the most extensively studied epigenetic marks in humans. Yet, it is largely unknown what causes variation in DNA methylation between individuals. The comparison of DNA methylation profiles of monozygotic (MZ twins offers a unique experimental design to examine the extent to which such variation is related to individual-specific environmental influences and stochastic events or to familial factors (DNA sequence and shared environment. We measured genome-wide DNA methylation in buccal samples from ten MZ pairs (age 8–19 using the Illumina 450k array and examined twin correlations for methylation level at 420,921 CpGs after QC. After selecting CpGs showing the most variation in the methylation level between subjects, the mean genome-wide correlation (rho was 0.54. The correlation was higher, on average, for CpGs within CpG islands (CGIs, compared to CGI shores, shelves and non-CGI regions, particularly at hypomethylated CpGs. This finding suggests that individual-specific environmental and stochastic influences account for more variation in DNA methylation in CpG-poor regions. Our findings also indicate that it is worthwhile to examine heritable and shared environmental influences on buccal DNA methylation in larger studies that also include dizygotic twins.

  20. Evaluating genome-wide DNA methylation changes in mice by Methylation Specific Digital Karyotyping

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    Maruoka Shuichiro

    2008-12-01

    Full Text Available Abstract Background The study of genome-wide DNA methylation changes has become more accessible with the development of various array-based technologies though when studying species other than human the choice of applications are limited and not always within reach. In this study, we adapted and tested the applicability of Methylation Specific Digital Karyotyping (MSDK, a non-array based method, for the prospective analysis of epigenetic changes after perinatal nutritional modifications in a mouse model of allergic airway disease. MSDK is a sequenced based method that allows a comprehensive and unbiased methylation profiling. The method generates 21 base pairs long sequence tags derived from specific locations in the genome. The resulting tag frequencies determine in a quantitative manner the methylation level of the corresponding loci. Results Genomic DNA from whole lung was isolated and subjected to MSDK analysis using the methylation-sensitive enzyme Not I as the mapping enzyme and Nla III as the fragmenting enzyme. In a pair wise comparison of the generated mouse MSDK libraries we identified 158 loci that are significantly differentially methylated (P-value = 0.05 after perinatal dietary changes in our mouse model. Quantitative methylation specific PCR and sequence analysis of bisulfate modified genomic DNA confirmed changes in methylation at specific loci. Differences in genomic MSDK tag counts for a selected set of genes, correlated well with changes in transcription levels as measured by real-time PCR. Furthermore serial analysis of gene expression profiling demonstrated a dramatic difference in expressed transcripts in mice exposed to perinatal nutritional changes. Conclusion The genome-wide methylation survey applied in this study allowed for an unbiased methylation profiling revealing subtle changes in DNA methylation in mice maternally exposed to dietary changes in methyl-donor content. The MSDK method is applicable for mouse models

  1. Profiling the genome-wide DNA methylation pattern of porcine ovaries using reduced representation bisulfite sequencing.

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    Yuan, Xiao-Long; Gao, Ning; Xing, Yan; Zhang, Hai-Bin; Zhang, Ai-Ling; Liu, Jing; He, Jin-Long; Xu, Yuan; Lin, Wen-Mian; Chen, Zan-Mou; Zhang, Hao; Zhang, Zhe; Li, Jia-Qi

    2016-02-25

    Substantial evidence has shown that DNA methylation regulates the initiation of ovarian and sexual maturation. Here, we investigated the genome-wide profile of DNA methylation in porcine ovaries at single-base resolution using reduced representation bisulfite sequencing. The biological variation was minimal among the three ovarian replicates. We found hypermethylation frequently occurred in regions with low gene abundance, while hypomethylation in regions with high gene abundance. The DNA methylation around transcriptional start sites was negatively correlated with their own CpG content. Additionally, the methylation level in the bodies of genes was higher than that in their 5' and 3' flanking regions. The DNA methylation pattern of the low CpG content promoter genes differed obviously from that of the high CpG content promoter genes. The DNA methylation level of the porcine ovary was higher than that of the porcine intestine. Analyses of the genome-wide DNA methylation in porcine ovaries would advance the knowledge and understanding of the porcine ovarian methylome.

  2. Diversity of eukaryotic DNA replication origins revealed by genome-wide analysis of chromatin structure.

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    Nicolas M Berbenetz

    2010-09-01

    Full Text Available Eukaryotic DNA replication origins differ both in their efficiency and in the characteristic time during S phase when they become active. The biological basis for these differences remains unknown, but they could be a consequence of chromatin structure. The availability of genome-wide maps of nucleosome positions has led to an explosion of information about how nucleosomes are assembled at transcription start sites, but no similar maps exist for DNA replication origins. Here we combine high-resolution genome-wide nucleosome maps with comprehensive annotations of DNA replication origins to identify patterns of nucleosome occupancy at eukaryotic replication origins. On average, replication origins contain a nucleosome depleted region centered next to the ACS element, flanked on both sides by arrays of well-positioned nucleosomes. Our analysis identified DNA sequence properties that correlate with nucleosome occupancy at replication origins genome-wide and that are correlated with the nucleosome-depleted region. Clustering analysis of all annotated replication origins revealed a surprising diversity of nucleosome occupancy patterns. We provide evidence that the origin recognition complex, which binds to the origin, acts as a barrier element to position and phase nucleosomes on both sides of the origin. Finally, analysis of chromatin reconstituted in vitro reveals that origins are inherently nucleosome depleted. Together our data provide a comprehensive, genome-wide view of chromatin structure at replication origins and suggest a model of nucleosome positioning at replication origins in which the underlying sequence occludes nucleosomes to permit binding of the origin recognition complex, which then (likely in concert with nucleosome modifiers and remodelers positions nucleosomes adjacent to the origin to promote replication origin function.

  3. Improved reproducibility in genome-wide DNA methylation analysis for PAXgene® fixed samples compared to restored FFPE DNA

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    Andersen, Gitte Brinch; Hager, Henrik; Hansen, Lise Lotte;

    2014-01-01

    , precluding the use of the valuable archives of specimens with long-term follow-up data. Therefore, restoration protocols for DNA from formalin-fixed and paraffin-embedded (FFPE) samples have been developed, although they are cost-intensive and time-consuming. An alternative to FFPE and snap......Chip. Quantitative DNA methylation analysis demonstrated that the methylation profile in PAXgene-fixed tissues showed, in comparison with restored FFPE samples, a higher concordance with the profile detected in frozen samples. We demonstrate, for the first time, that DNA from PAXgene conserved tissue performs better...... compared with restored FFPE DNA in genome-wide DNA methylation analysis. In addition, DNA from PAXgene tissue can be directly used on the array without prior restoration, rendering the analytical process significantly more time- and cost-effective....

  4. Dose dependent impact of recent alcohol use on genome wide DNA methylation signatures

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    Robert ePhilibert

    2012-04-01

    Full Text Available Chronic alcohol intake is associated with a wide variety of adverse health outcomes including depression, diabetes and heart disease. Unfortunately, the molecular mechanisms through which these effects are conveyed are not clearly understood. To examine the potential role of epigenetic factors in this process, we examined the relationship of recent alcohol intake to genome wide methylation patterns using the Illumina 450 Methylation Bead Chip and lymphoblast DNA derived from 165 female subjects participating in the Iowa Adoption Studies. We found that the pattern of alcohol use over the 6 months immediately prior to phlebotomy was associated with stepwise, severity -dependent changes in the degree of genome wide methylation that preferentially hypermethylate the central portion of CpG islands with methylation at cg05600126, a probe in ABR, attaining genome wide significance. Gene pathway analysis of nominally significantly differentiated probes demonstrated that chronic alcohol use has profound effects on a diverse cadre of cellular metabolic pathways. We conclude that recent alcohol use is associated with widespread changes in DNA methylation in women and that further study to confirm these findings and determine their relationship to somatic function are in order.

  5. Recent advances in the genome-wide study of DNA replication origins in yeast

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    Chong ePeng

    2015-02-01

    Full Text Available DNA replication, one of the central events in the cell cycle, is the basis of biological inheritance. In order to be duplicated, a DNA double helix must be opened at defined sites, which are called DNA replication origins (ORIs. Unlike in bacteria, where replication initiates from a single replication origin, multiple origins are utilized in the eukaryotic genome. Among them, the ORIs in budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe have been best characterized. In recent years, advances in DNA microarray and next-generation sequencing technologies have increased the number of yeast species involved in ORIs research dramatically. The ORIs in some nonconventional yeast species such as Kluyveromyces lactis and Pichia pastoris have also been genome-widely identified. Relevant databases of replication origins in yeast were constructed, then the comparative genomic analysis can be carried out. Here, we review several experimental approaches that have been used to map replication origins in yeast and some of the available web resources related to yeast ORIs. We also discuss the sequence characteristics and chromosome structures of ORIs in the four yeast species, which can be utilized to improve the replication origins prediction.

  6. Genome-wide DNA methylation indicates silencing of tumor suppressor genes in uterine leiomyoma.

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    Antonia Navarro

    Full Text Available BACKGROUND: Uterine leiomyomas, or fibroids, represent the most common benign tumor of the female reproductive tract. Fibroids become symptomatic in 30% of all women and up to 70% of African American women of reproductive age. Epigenetic dysregulation of individual genes has been demonstrated in leiomyoma cells; however, the in vivo genome-wide distribution of such epigenetic abnormalities remains unknown. PRINCIPAL FINDINGS: We characterized and compared genome-wide DNA methylation and mRNA expression profiles in uterine leiomyoma and matched adjacent normal myometrial tissues from 18 African American women. We found 55 genes with differential promoter methylation and concominant differences in mRNA expression in uterine leiomyoma versus normal myometrium. Eighty percent of the identified genes showed an inverse relationship between DNA methylation status and mRNA expression in uterine leiomyoma tissues, and the majority of genes (62% displayed hypermethylation associated with gene silencing. We selected three genes, the known tumor suppressors KLF11, DLEC1, and KRT19 and verified promoter hypermethylation, mRNA repression and protein expression using bisulfite sequencing, real-time PCR and western blot. Incubation of primary leiomyoma smooth muscle cells with a DNA methyltransferase inhibitor restored KLF11, DLEC1 and KRT19 mRNA levels. CONCLUSIONS: These results suggest a possible functional role of promoter DNA methylation-mediated gene silencing in the pathogenesis of uterine leiomyoma in African American women.

  7. Genome-Wide DNA Methylation in Mixed Ancestry Individuals with Diabetes and Prediabetes from South Africa

    Directory of Open Access Journals (Sweden)

    Tandi E. Matsha

    2016-01-01

    Full Text Available Aims. To conduct a genome-wide DNA methylation in individuals with type 2 diabetes, individuals with prediabetes, and control mixed ancestry individuals from South Africa. Methods. We used peripheral blood to perform genome-wide DNA methylation analysis in 3 individuals with screen detected diabetes, 3 individuals with prediabetes, and 3 individuals with normoglycaemia from the Bellville South Community, Cape Town, South Africa, who were age-, gender-, body mass index-, and duration of residency-matched. Methylated DNA immunoprecipitation (MeDIP was performed by Arraystar Inc. (Rockville, MD, USA. Results. Hypermethylated DMRs were 1160 (81.97% and 124 (43.20%, respectively, in individuals with diabetes and prediabetes when both were compared to subjects with normoglycaemia. Our data shows that genes related to the immune system, signal transduction, glucose transport, and pancreas development have altered DNA methylation in subjects with prediabetes and diabetes. Pathway analysis based on the functional analysis mapping of genes to KEGG pathways suggested that the linoleic acid metabolism and arachidonic acid metabolism pathways are hypomethylated in prediabetes and diabetes. Conclusions. Our study suggests that epigenetic changes are likely to be an early process that occurs before the onset of overt diabetes. Detailed analysis of DMRs that shows gradual methylation differences from control versus prediabetes to prediabetes versus diabetes in a larger sample size is required to confirm these findings.

  8. Genome-wide DNA methylation modified by soy phytoestrogens: role for epigenetic therapeutics in prostate cancer?

    Science.gov (United States)

    Karsli-Ceppioglu, Seher; Ngollo, Marjolaine; Adjakly, Mawussi; Dagdemir, Aslihan; Judes, Gaëlle; Lebert, André; Boiteux, Jean-Paul; Penault-LLorca, Frédérique; Bignon, Yves-Jean; Guy, Laurent; Bernard-Gallon, Dominique

    2015-04-01

    In prostate cancer, DNA methylation is significantly associated with tumor initiation, progression, and metastasis. Previous studies have suggested that soy phytoestrogens might regulate DNA methylation at individual candidate gene loci and that they play a crucial role as potential therapeutic agents for prostate cancer. The purpose of our study was to examine the modulation effects of phytoestrogens on a genome-wide scale in regards to DNA methylation in prostate cancer. Prostate cancer cell lines DU-145 and LNCaP were treated with 40 μM of genistein and 110 μM of daidzein. DNMT inhibitor 5-azacytidine (2 μM) and the methylating agent budesonide (2 μM) were used to compare their demethylation/methylation effects with phytoestrogens. The regulatory effects of phytoestrogens on DNA methylation were analyzed by using a methyl-DNA immunoprecipitation method coupled with Human DNA Methylation Microarrays (MeDIP-chip). We observed that the methylation profiles of 58 genes were altered by genistein and daidzein treatments in DU-145 and LNCaP prostate cancer cells. In addition, the methylation frequencies of the MAD1L1, TRAF7, KDM4B, and hTERT genes were remarkably modified by genistein treatment. Our results suggest that the modulation effects of phytoestrogens on DNA methylation essentially lead to inhibition of cell growth and induction of apoptosis. Genome-wide methylation profiling reported here suggests that epigenetic regulation mechanisms and, by extension, epigenetics-driven novel therapeutic candidates warrant further consideration in future "omics" studies of prostate cancer.

  9. Genome-wide nucleosome occupancy and DNA methylation profiling of four human cell lines

    Directory of Open Access Journals (Sweden)

    Aaron L. Statham

    2015-03-01

    Full Text Available DNA methylation and nucleosome positioning are two key mechanisms that contribute to the epigenetic control of gene expression. During carcinogenesis, the expression of many genes is altered alongside extensive changes in the epigenome, with repressed genes often being associated with local DNA hypermethylation and gain of nucleosomes at their promoters. However the spectrum of alterations that occur at distal regulatory regions has not been extensively studied. To address this we used Nucleosome Occupancy and Methylation sequencing (NOMe-seq to compare the genome-wide DNA methylation and nucleosome occupancy profiles between normal and cancer cell line models of the breast and prostate. Here we describe the bioinformatic pipeline and methods that we developed for the processing and analysis of the NOMe-seq data published by (Taberlay et al., 2014 [1] and deposited in the Gene Expression Omnibus with accession GSE57498.

  10. Genome-wide DNA methylation profiling with MeDIP-seq using archived dried blood spots

    DEFF Research Database (Denmark)

    Staunstrup, Nicklas H; Starnawska, Anna; Nyegaard, Mette

    2016-01-01

    . The enrichment profile, sequence quality and distribution of reads across genetic regions were comparable between samples archived 16 years, 4 years and a freshly prepared control sample. CONCLUSIONS: In summary, we show that high-quality MeDIP-seq data is achievable from neonatal screening filter cards stored....... RESULTS: Here we demonstrate, as a proof of principle, that genome-wide interrogation of the methylome based on methylated DNA immunoprecipitation coupled with next-generation sequencing (MeDIP-seq) is feasible using a single 3.2 mm DBS punch (60 ng DNA) from filter cards archived for up to 16 years...... at room temperature, thereby providing information on annotated as well as on non-RefSeq genes and repetitive elements. Moreover, the quantity of DNA from one DBS punch proved sufficient allowing for multiple epigenome studies using one single DBS....

  11. Genome-wide screen for differential DNA methylation associated with neural cell differentiation in mouse.

    Directory of Open Access Journals (Sweden)

    Rene Cortese

    Full Text Available Cellular differentiation involves widespread epigenetic reprogramming, including modulation of DNA methylation patterns. Using Differential Methylation Hybridization (DMH in combination with a custom DMH array containing 51,243 features covering more than 16,000 murine genes, we carried out a genome-wide screen for cell- and tissue-specific differentially methylated regions (tDMRs in undifferentiated embryonic stem cells (ESCs, in in-vitro induced neural stem cells (NSCs and 8 differentiated embryonic and adult tissues. Unsupervised clustering of the generated data showed distinct cell- and tissue-specific DNA methylation profiles, revealing 202 significant tDMRs (p1.96 enrichment for genes involved in neural differentiation, including, for example, Jag1 and Tcf4. Our results provide robust evidence for the relevance of DNA methylation in early neural development and identify novel marker candidates for neural cell differentiation.

  12. Genome-wide DNA methylation profiling in cultured eutopic and ectopic endometrial stromal cells.

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    Yoshiaki Yamagata

    Full Text Available The objective of this study was to characterize the genome-wide DNA methylation profiles of isolated endometrial stromal cells obtained from eutopic endometria with (euESCa and without endometriosis (euESCb and ovarian endometrial cysts (choESC. Three samples were analyzed in each group. The infinium methylation array identified more hypermethylated and hypomethylated CpGs in choESC than in euESCa, and only a few genes were methylated differently in euESCa and euESCb. A functional analysis revealed that signal transduction, developmental processes, immunity, etc. were different in choESC and euESCa. A clustering analysis and a principal component analysis performed based on the methylation levels segregated choESC from euESC, while euESCa and euESCb were identical. A transcriptome analysis was then conducted and the results were compared with those of the DNA methylation analysis. Interestingly, the hierarchical clustering and principal component analyses showed that choESC were segregated from euESCa and euESCb in the DNA methylation analysis, while no segregation was recognized in the transcriptome analysis. The mRNA expression levels of the epigenetic modification enzymes, including DNA methyltransferases, obtained from the specimens were not significantly different between the groups. Some of the differentially methylated and/or expressed genes (NR5A1, STAR, STRA6 and HSD17B2, which are related with steroidogenesis, were validated by independent methods in a larger number of samples. Our findings indicate that different DNA methylation profiles exist in ectopic ESC, highlighting the benefits of genome wide DNA methylation analyses over transcriptome analyses in clarifying the development and characterization of endometriosis.

  13. DNA immunoprecipitation semiconductor sequencing (DIP-SC-seq) as a rapid method to generate genome wide epigenetic signatures.

    Science.gov (United States)

    Thomson, John P; Fawkes, Angie; Ottaviano, Raffaele; Hunter, Jennifer M; Shukla, Ruchi; Mjoseng, Heidi K; Clark, Richard; Coutts, Audrey; Murphy, Lee; Meehan, Richard R

    2015-05-14

    Modification of DNA resulting in 5-methylcytosine (5 mC) or 5-hydroxymethylcytosine (5hmC) has been shown to influence the local chromatin environment and affect transcription. Although recent advances in next generation sequencing technology allow researchers to map epigenetic modifications across the genome, such experiments are often time-consuming and cost prohibitive. Here we present a rapid and cost effective method of generating genome wide DNA modification maps utilising commercially available semiconductor based technology (DNA immunoprecipitation semiconductor sequencing; "DIP-SC-seq") on the Ion Proton sequencer. Focussing on the 5hmC mark we demonstrate, by directly comparing with alternative sequencing strategies, that this platform can successfully generate genome wide 5hmC patterns from as little as 500 ng of genomic DNA in less than 4 days. Such a method can therefore facilitate the rapid generation of multiple genome wide epigenetic datasets.

  14. Genome-Wide Expression of MicroRNAs Is Regulated by DNA Methylation in Hepatocarcinogenesis

    Directory of Open Access Journals (Sweden)

    Jing Shen

    2015-01-01

    Full Text Available Background. Previous studies, including ours, have examined the regulation of microRNAs (miRNAs by DNA methylation, but whether this regulation occurs at a genome-wide level in hepatocellular carcinoma (HCC is unclear. Subjects/Methods. Using a two-phase study design, we conducted genome-wide screening for DNA methylation and miRNA expression to explore the potential role of methylation alterations in miRNAs regulation. Results. We found that expressions of 25 miRNAs were statistically significantly different between tumor and nontumor tissues and perfectly differentiated HCC tumor from nontumor. Six miRNAs were overexpressed, and 19 were repressed in tumors. Among 133 miRNAs with inverse correlations between methylation and expression, 8 miRNAs (6% showed statistically significant differences in expression between tumor and nontumor tissues. Six miRNAs were validated in 56 additional paired HCC tissues, and significant inverse correlations were observed for miR-125b and miR-199a, which is consistent with the inactive chromatin pattern found in HepG2 cells. Conclusion. These data suggest that the expressions of miR-125b and miR-199a are dramatically regulated by DNA hypermethylation that plays a key role in hepatocarcinogenesis.

  15. Genome-wide analysis of DNA methylation in five tissues of Zhikong scallop, Chlamys farreri.

    Directory of Open Access Journals (Sweden)

    Yan Sun

    Full Text Available DNA methylation plays a vital role in tissue development and differentiation in eukaryotes. Epigenetic studies have been seldom conducted in the extremely diverse and evolutionarily highly successful bilaterian lineage Mollusca. In the present study, we conducted the genome-wide profiling of DNA methylation for five tissues of a bivalve mollusc, Chlamys farreri using the methylation-sensitive amplification polymorphism (MSAP technique. The methylation levels were quite similar among tissues, ranging from 20.9% to 21.7%. CG methylation was the dominant type (14.9%-16.5% in the C. farreri genome, but CHG methylation also accounted for a substantial fraction of total methylation (5.1%-6.3%. Relatively high methylation diversity was observed within tissues. Methylation differentiation between tissues was evaluated and 460 tissue-specific epiloci were identified. Kidney differs from the other tissues in DNA methylation profiles. Our study presents the first look at the tissue-specific DNA methylation patterns in a bivalve mollusc and represents an initial step towards understanding of epigenetic regulatory mechanism underlying tissue development and differentiation in bivalves.

  16. NSD1 mutations generate a genome-wide DNA methylation signature.

    LENUS (Irish Health Repository)

    Choufani, S

    2015-12-22

    Sotos syndrome (SS) represents an important human model system for the study of epigenetic regulation; it is an overgrowth\\/intellectual disability syndrome caused by mutations in a histone methyltransferase, NSD1. As layered epigenetic modifications are often interdependent, we propose that pathogenic NSD1 mutations have a genome-wide impact on the most stable epigenetic mark, DNA methylation (DNAm). By interrogating DNAm in SS patients, we identify a genome-wide, highly significant NSD1(+\\/-)-specific signature that differentiates pathogenic NSD1 mutations from controls, benign NSD1 variants and the clinically overlapping Weaver syndrome. Validation studies of independent cohorts of SS and controls assigned 100% of these samples correctly. This highly specific and sensitive NSD1(+\\/-) signature encompasses genes that function in cellular morphogenesis and neuronal differentiation, reflecting cardinal features of the SS phenotype. The identification of SS-specific genome-wide DNAm alterations will facilitate both the elucidation of the molecular pathophysiology of SS and the development of improved diagnostic testing.

  17. Genome-wide DNA methylation profiling of non-small cell lung carcinomas

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    Carvalho Rejane

    2012-06-01

    Full Text Available Abstract Background Non-small cell lung carcinoma (NSCLC is a complex malignancy that owing to its heterogeneity and poor prognosis poses many challenges to diagnosis, prognosis and patient treatment. DNA methylation is an important mechanism of epigenetic regulation involved in normal development and cancer. It is a very stable and specific modification and therefore in principle a very suitable marker for epigenetic phenotyping of tumors. Here we present a genome-wide DNA methylation analysis of NSCLC samples and paired lung tissues, where we combine MethylCap and next generation sequencing (MethylCap-seq to provide comprehensive DNA methylation maps of the tumor and paired lung samples. The MethylCap-seq data were validated by bisulfite sequencing and methyl-specific polymerase chain reaction of selected regions. Results Analysis of the MethylCap-seq data revealed a strong positive correlation between replicate experiments and between paired tumor/lung samples. We identified 57 differentially methylated regions (DMRs present in all NSCLC tumors analyzed by MethylCap-seq. While hypomethylated DMRs did not correlate to any particular functional category of genes, the hypermethylated DMRs were strongly associated with genes encoding transcriptional regulators. Furthermore, subtelomeric regions and satellite repeats were hypomethylated in the NSCLC samples. We also identified DMRs that were specific to two of the major subtypes of NSCLC, adenocarcinomas and squamous cell carcinomas. Conclusions Collectively, we provide a resource containing genome-wide DNA methylation maps of NSCLC and their paired lung tissues, and comprehensive lists of known and novel DMRs and associated genes in NSCLC.

  18. DNA evidence for strong genome-wide pleiotropy of cognitive and learning abilities.

    Science.gov (United States)

    Trzaskowski, Maciej; Davis, Oliver S P; DeFries, John C; Yang, Jian; Visscher, Peter M; Plomin, Robert

    2013-07-01

    Very different neurocognitive processes appear to be involved in cognitive abilities such as verbal and non-verbal ability as compared to learning abilities taught in schools such as reading and mathematics. However, twin studies that compare similarity for monozygotic and dizygotic twins suggest that the same genes are largely responsible for genetic influence on these diverse aspects of cognitive function. It is now possible to test this evidence for strong pleiotropy using DNA alone from samples of unrelated individuals. Here we used this new method with 1.7 million DNA markers for a sample of 2,500 unrelated children at age 12 to investigate for the first time the extent of pleiotropy between general cognitive ability (aka intelligence) and learning abilities (reading, mathematics and language skills). We also compared these DNA results to results from twin analyses using the same sample and measures. The DNA-based method revealed strong genome-wide pleiotropy: Genetic correlations were greater than 0.70 between general cognitive ability and language, reading, and mathematics, results that were highly similar to twin study estimates of genetic correlations. These results indicate that genes related to diverse neurocognitive processes have general rather than specific effects.

  19. The genome-wide DNA sequence specificity of the anti-tumour drug bleomycin in human cells.

    Science.gov (United States)

    Murray, Vincent; Chen, Jon K; Tanaka, Mark M

    2016-07-01

    The cancer chemotherapeutic agent, bleomycin, cleaves DNA at specific sites. For the first time, the genome-wide DNA sequence specificity of bleomycin breakage was determined in human cells. Utilising Illumina next-generation DNA sequencing techniques, over 200 million bleomycin cleavage sites were examined to elucidate the bleomycin genome-wide DNA selectivity. The genome-wide bleomycin cleavage data were analysed by four different methods to determine the cellular DNA sequence specificity of bleomycin strand breakage. For the most highly cleaved DNA sequences, the preferred site of bleomycin breakage was at 5'-GT* dinucleotide sequences (where the asterisk indicates the bleomycin cleavage site), with lesser cleavage at 5'-GC* dinucleotides. This investigation also determined longer bleomycin cleavage sequences, with preferred cleavage at 5'-GT*A and 5'- TGT* trinucleotide sequences, and 5'-TGT*A tetranucleotides. For cellular DNA, the hexanucleotide DNA sequence 5'-RTGT*AY (where R is a purine and Y is a pyrimidine) was the most highly cleaved DNA sequence. It was striking that alternating purine-pyrimidine sequences were highly cleaved by bleomycin. The highest intensity cleavage sites in cellular and purified DNA were very similar although there were some minor differences. Statistical nucleotide frequency analysis indicated a G nucleotide was present at the -3 position (relative to the cleavage site) in cellular DNA but was absent in purified DNA.

  20. Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

    DEFF Research Database (Denmark)

    Møller, Henrik D.; Bojsen, Rasmus Kenneth; Tachibana, Chris

    2016-01-01

    for detecting eccDNA are needed to clarify how these elements affect genome stability and how environmental and biological factors induce their formation in eukaryotic cells. This video presents a sensitive eccDNA-purification method called Circle-Seq. The method encompasses column purification of circular DNA...... circularization is conserved between strains at these loci. In sum, the Circle-Seq method has broad applicability for genome-scale screening for eccDNA in eukaryotes as well as for detecting specific eccDNA types....

  1. Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

    DEFF Research Database (Denmark)

    Møller, Henrik D.; Bojsen, Rasmus Kenneth; Tachibana, Chris;

    2016-01-01

    for detecting eccDNA are needed to clarify how these elements affect genome stability and how environmental and biological factors induce their formation in eukaryotic cells. This video presents a sensitive eccDNA-purification method called Circle-Seq. The method encompasses column purification of circular DNA...

  2. Genome-wide DNA methylation levels and altered cortisol stress reactivity following childhood trauma in humans.

    Science.gov (United States)

    Houtepen, Lotte C; Vinkers, Christiaan H; Carrillo-Roa, Tania; Hiemstra, Marieke; van Lier, Pol A; Meeus, Wim; Branje, Susan; Heim, Christine M; Nemeroff, Charles B; Mill, Jonathan; Schalkwyk, Leonard C; Creyghton, Menno P; Kahn, René S; Joëls, Marian; Binder, Elisabeth B; Boks, Marco P M

    2016-03-21

    DNA methylation likely plays a role in the regulation of human stress reactivity. Here we show that in a genome-wide analysis of blood DNA methylation in 85 healthy individuals, a locus in the Kit ligand gene (KITLG; cg27512205) showed the strongest association with cortisol stress reactivity (P=5.8 × 10(-6)). Replication was obtained in two independent samples using either blood (N=45, P=0.001) or buccal cells (N=255, P=0.004). KITLG methylation strongly mediates the relationship between childhood trauma and cortisol stress reactivity in the discovery sample (32% mediation). Its genomic location, a CpG island shore within an H3K27ac enhancer mark, and the correlation between methylation in the blood and prefrontal cortex provide further evidence that KITLG methylation is functionally relevant for the programming of stress reactivity in the human brain. Our results extend preclinical evidence for epigenetic regulation of stress reactivity to humans and provide leads to enhance our understanding of the neurobiological pathways underlying stress vulnerability.

  3. Genome-wide copy number profiling of single cells in S-phase reveals DNA-replication domains.

    Science.gov (United States)

    Van der Aa, Niels; Cheng, Jiqiu; Mateiu, Ligia; Zamani Esteki, Masoud; Kumar, Parveen; Dimitriadou, Eftychia; Vanneste, Evelyne; Moreau, Yves; Vermeesch, Joris Robert; Voet, Thierry

    2013-04-01

    Single-cell genomics is revolutionizing basic genome research and clinical genetic diagnosis. However, none of the current research or clinical methods for single-cell analysis distinguishes between the analysis of a cell in G1-, S- or G2/M-phase of the cell cycle. Here, we demonstrate by means of array comparative genomic hybridization that charting the DNA copy number landscape of a cell in S-phase requires conceptually different approaches to that of a cell in G1- or G2/M-phase. Remarkably, despite single-cell whole-genome amplification artifacts, the log2 intensity ratios of single S-phase cells oscillate according to early and late replication domains, which in turn leads to the detection of significantly more DNA imbalances when compared with a cell in G1- or G2/M-phase. Although these DNA imbalances may, on the one hand, be falsely interpreted as genuine structural aberrations in the S-phase cell's copy number profile and hence lead to misdiagnosis, on the other hand, the ability to detect replication domains genome wide in one cell has important applications in DNA-replication research. Genome-wide cell-type-specific early and late replicating domains have been identified by analyses of DNA from populations of cells, but cell-to-cell differences in DNA replication may be important in genome stability, disease aetiology and various other cellular processes.

  4. Genome-wide divergence of DNA methylation marks in cerebral and cerebellar cortices.

    Directory of Open Access Journals (Sweden)

    Yurong Xin

    Full Text Available BACKGROUND: Emerging evidence suggests that DNA methylation plays an expansive role in the central nervous system (CNS. Large-scale whole genome DNA methylation profiling of the normal human brain offers tremendous potential in understanding the role of DNA methylation in brain development and function. METHODOLOGY/SIGNIFICANT FINDINGS: Using methylation-sensitive SNP chip analysis (MSNP, we performed whole genome DNA methylation profiling of the prefrontal, occipital, and temporal regions of cerebral cortex, as well as cerebellum. These data provide an unbiased representation of CpG sites comprising 377,509 CpG dinucleotides within both the genic and intergenic euchromatic region of the genome. Our large-scale genome DNA methylation profiling reveals that the prefrontal, occipital, and temporal regions of the cerebral cortex compared to cerebellum have markedly different DNA methylation signatures, with the cerebral cortex being hypermethylated and cerebellum being hypomethylated. Such differences were observed in distinct genomic regions, including genes involved in CNS function. The MSNP data were validated for a subset of these genes, by performing bisulfite cloning and sequencing and confirming that prefrontal, occipital, and temporal cortices are significantly more methylated as compared to the cerebellum. CONCLUSIONS: These findings are consistent with known developmental differences in nucleosome repeat lengths in cerebral and cerebellar cortices, with cerebrum exhibiting shorter repeat lengths than cerebellum. Our observed differences in DNA methylation profiles in these regions underscores the potential role of DNA methylation in chromatin structure and organization in CNS, reflecting functional specialization within cortical regions.

  5. Genome-wide peripheral blood leukocyte DNA methylation microarrays identified a single association with inflammatory bowel diseases

    DEFF Research Database (Denmark)

    Harris, R Alan; Nagy-Szakal, Dorottya; Pedersen, Natalia

    2012-01-01

    Crohn's disease (CD) and ulcerative colitis (UC) are common forms of inflammatory bowel disease (IBD). Monozygotic (MZ) twin discordance rates and epidemiologic data implicate that environmental changes and epigenetic factors may play a pathogenic role in IBD. DNA methylation (the methylation...... of cytosines within CpG dinucleotides) is an epigenetic modification, which can respond to environmental influences. We investigated whether DNA methylation might be connected with IBD in peripheral blood leukocyte (PBL) DNA by utilizing genome-wide microarrays....

  6. Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells.

    Science.gov (United States)

    Møller, Henrik D; Bojsen, Rasmus K; Tachibana, Chris; Parsons, Lance; Botstein, David; Regenberg, Birgitte

    2016-04-04

    Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods for detecting eccDNA are needed to clarify how these elements affect genome stability and how environmental and biological factors induce their formation in eukaryotic cells. This video presents a sensitive eccDNA-purification method called Circle-Seq. The method encompasses column purification of circular DNA, removal of remaining linear chromosomal DNA, rolling-circle amplification of eccDNA, deep sequencing, and mapping. Extensive exonuclease treatment was required for sufficient linear chromosomal DNA degradation. The rolling-circle amplification step by φ29 polymerase enriched for circular DNA over linear DNA. Validation of the Circle-Seq method on three S. cerevisiae CEN.PK populations of 10(10) cells detected hundreds of eccDNA profiles in sizes larger than 1 kilobase. Repeated findings of ASP3-1, COS111, CUP1, RSC30, HXT6, HXT7 genes on circular DNA in both S288c and CEN.PK suggests that DNA circularization is conserved between strains at these loci. In sum, the Circle-Seq method has broad applicability for genome-scale screening for eccDNA in eukaryotes as well as for detecting specific eccDNA types.

  7. Genome-wide DNA methylation analysis predicts an epigenetic switch for GATA factor expression in endometriosis.

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    Matthew T Dyson

    2014-03-01

    Full Text Available Endometriosis is a gynecological disease defined by the extrauterine growth of endometrial-like cells that cause chronic pain and infertility. The disease is limited to primates that exhibit spontaneous decidualization, and diseased cells are characterized by significant defects in the steroid-dependent genetic pathways that typify this process. Altered DNA methylation may underlie these defects, but few regions with differential methylation have been implicated in the disease. We mapped genome-wide differences in DNA methylation between healthy human endometrial and endometriotic stromal cells and correlated this with gene expression using an interaction analysis strategy. We identified 42,248 differentially methylated CpGs in endometriosis compared to healthy cells. These extensive differences were not unidirectional, but were focused intragenically and at sites distal to classic CpG islands where methylation status was typically negatively correlated with gene expression. Significant differences in methylation were mapped to 403 genes, which included a disproportionally large number of transcription factors. Furthermore, many of these genes are implicated in the pathology of endometriosis and decidualization. Our results tremendously improve the scope and resolution of differential methylation affecting the HOX gene clusters, nuclear receptor genes, and intriguingly the GATA family of transcription factors. Functional analysis of the GATA family revealed that GATA2 regulates key genes necessary for the hormone-driven differentiation of healthy stromal cells, but is hypermethylated and repressed in endometriotic cells. GATA6, which is hypomethylated and abundant in endometriotic cells, potently blocked hormone sensitivity, repressed GATA2, and induced markers of endometriosis when expressed in healthy endometrial cells. The unique epigenetic fingerprint in endometriosis suggests DNA methylation is an integral component of the disease, and

  8. Genome-wide DNA methylation analysis in obsessive-compulsive disorder patients.

    Science.gov (United States)

    Yue, Weihua; Cheng, Weiqiu; Liu, Zhaorui; Tang, Yi; Lu, Tianlan; Zhang, Dai; Tang, Muni; Huang, Yueqin

    2016-08-16

    Literatures have suggested that not only genetic but also environmental factors, interactively accounted for susceptibility of obsessive-compulsive disorder (OCD). DNA methylation may regulate expression of genes as the heritable epigenetic modification. The examination for genome-wide DNA methylation was performed on blood samples from 65 patients with OCD, as well as 96 healthy control subjects. The DNA methylation was examined at over 485,000 CpG sites using the Illumina Infinium Human Methylation450 BeadChip. As a result, 8,417 probes corresponding to 2,190 unique genes were found to be differentially methylated between OCD and healthy control subjects. Of those genes, 4,013 loci were located in CpG islands and 2,478 were in promoter regions. These included BCYRN1, BCOR, FGF13, HLA-DRB1, ARX, etc., which have previously been reported to be associated with OCD. Pathway analyses indicated that regulation of actin cytoskeleton, cell adhesion molecules (CAMs), actin binding, transcription regulator activity, and other pathways might be further associated with risk of OCD. Unsupervised clustering analysis of the top 3,000 most variable probes revealed two distinct groups with significantly more people with OCD in cluster one compared with controls (67.74% of cases v.s. 27.13% of controls, Chi-square = 26.011, df = 1, P = 3.41E-07). These results strongly suggested that differential DNA methylation might play an important role in etiology of OCD.

  9. Array-based comparative genomic hybridization for genome-wide screening of DNA copy number in bladder tumors.

    NARCIS (Netherlands)

    Veltman, J.A.; Fridlyand, J.; Pejavar, S.; Olshen, A.B.; Korkola, J.E.; Vries, S. de; Carroll, P.; Kuo, W.L.; Pinkel, D.; Albertson, D.; Cordon-Cardo, C.; Jain, A.N.; Waldman, F.M.

    2003-01-01

    Genome-wide copy number profiles were characterized in 41 primary bladder tumors using array-based comparative genomic hybridization (array CGH). In addition to previously identified alterations in large chromosomal regions, alterations were identified in many small genomic regions, some with high-l

  10. Genome-Wide Mapping of in Vivo Protein-DNA Interactions

    OpenAIRE

    Johnson, David S.; Mortazavi, Ali; Myers, Richard M.; Wold, Barbara

    2007-01-01

    In vivo protein-DNA interactions connect each transcription factor with its direct targets to form a gene network scaffold. To map these protein-DNA interactions comprehensively across entire mammalian genomes, we developed a large-scale chromatin immunoprecipitation assay (ChIPSeq) based on direct ultrahigh-throughput DNA sequencing. This sequence census method was then used to map in vivo binding of the neuron-restrictive silencer factor (NRSF; also known as REST, for repressor element–1 si...

  11. DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis.

    Science.gov (United States)

    Joubert, Bonnie R; Felix, Janine F; Yousefi, Paul; Bakulski, Kelly M; Just, Allan C; Breton, Carrie; Reese, Sarah E; Markunas, Christina A; Richmond, Rebecca C; Xu, Cheng-Jian; Küpers, Leanne K; Oh, Sam S; Hoyo, Cathrine; Gruzieva, Olena; Söderhäll, Cilla; Salas, Lucas A; Baïz, Nour; Zhang, Hongmei; Lepeule, Johanna; Ruiz, Carlos; Ligthart, Symen; Wang, Tianyuan; Taylor, Jack A; Duijts, Liesbeth; Sharp, Gemma C; Jankipersadsing, Soesma A; Nilsen, Roy M; Vaez, Ahmad; Fallin, M Daniele; Hu, Donglei; Litonjua, Augusto A; Fuemmeler, Bernard F; Huen, Karen; Kere, Juha; Kull, Inger; Munthe-Kaas, Monica Cheng; Gehring, Ulrike; Bustamante, Mariona; Saurel-Coubizolles, Marie José; Quraishi, Bilal M; Ren, Jie; Tost, Jörg; Gonzalez, Juan R; Peters, Marjolein J; Håberg, Siri E; Xu, Zongli; van Meurs, Joyce B; Gaunt, Tom R; Kerkhof, Marjan; Corpeleijn, Eva; Feinberg, Andrew P; Eng, Celeste; Baccarelli, Andrea A; Benjamin Neelon, Sara E; Bradman, Asa; Merid, Simon Kebede; Bergström, Anna; Herceg, Zdenko; Hernandez-Vargas, Hector; Brunekreef, Bert; Pinart, Mariona; Heude, Barbara; Ewart, Susan; Yao, Jin; Lemonnier, Nathanaël; Franco, Oscar H; Wu, Michael C; Hofman, Albert; McArdle, Wendy; Van der Vlies, Pieter; Falahi, Fahimeh; Gillman, Matthew W; Barcellos, Lisa F; Kumar, Ashish; Wickman, Magnus; Guerra, Stefano; Charles, Marie-Aline; Holloway, John; Auffray, Charles; Tiemeier, Henning W; Smith, George Davey; Postma, Dirkje; Hivert, Marie-France; Eskenazi, Brenda; Vrijheid, Martine; Arshad, Hasan; Antó, Josep M; Dehghan, Abbas; Karmaus, Wilfried; Annesi-Maesano, Isabella; Sunyer, Jordi; Ghantous, Akram; Pershagen, Göran; Holland, Nina; Murphy, Susan K; DeMeo, Dawn L; Burchard, Esteban G; Ladd-Acosta, Christine; Snieder, Harold; Nystad, Wenche; Koppelman, Gerard H; Relton, Caroline L; Jaddoe, Vincent W V; Wilcox, Allen; Melén, Erik; London, Stephanie J

    2016-04-01

    Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The mechanisms are largely unknown, but epigenetics most likely plays a role. We formed the Pregnancy And Childhood Epigenetics (PACE) consortium and meta-analyzed, across 13 cohorts (n = 6,685), the association between maternal smoking in pregnancy and newborn blood DNA methylation at over 450,000 CpG sites (CpGs) by using the Illumina 450K BeadChip. Over 6,000 CpGs were differentially methylated in relation to maternal smoking at genome-wide statistical significance (false discovery rate, 5%), including 2,965 CpGs corresponding to 2,017 genes not previously related to smoking and methylation in either newborns or adults. Several genes are relevant to diseases that can be caused by maternal smoking (e.g., orofacial clefts and asthma) or adult smoking (e.g., certain cancers). A number of differentially methylated CpGs were associated with gene expression. We observed enrichment in pathways and processes critical to development. In older children (5 cohorts, n = 3,187), 100% of CpGs gave at least nominal levels of significance, far more than expected by chance (p value smoking in pregnancy with persistence into later childhood and provide insights into mechanisms underlying effects of this important exposure.

  12. Genome-wide identification of mononuclear cell DNA methylation sites potentially affected by fish oil supplementation in young infants

    DEFF Research Database (Denmark)

    Lind, Mads Vendelbo; Martino, D; Harsløf, Laurine Bente Schram;

    2015-01-01

    Recent evidence suggests that the effects of n-3LCPUFA might be mediated through epigenetic mechanisms, especially DNA-methylation, during pregnancy and early life. A randomized trial was conducted in 133 9-mo-old, infants who received 3.8g/day of fish oil (FO) or sunflower oil (SO) for 9 mo....... In a subset of 12 children, buffy-coat DNA was extracted before and after intervention and analyzed on Illumina-Human-Methylation 450-arrays to explore genome-wide differences between the FO and SO groups. Genome-wide-methylation analysis did not reveal significant differences between groups after adjustment...

  13. Genome-wide age-related changes in DNA methylation and gene expression in human PBMCs.

    Science.gov (United States)

    Steegenga, Wilma T; Boekschoten, Mark V; Lute, Carolien; Hooiveld, Guido J; de Groot, Philip J; Morris, Tiffany J; Teschendorff, Andrew E; Butcher, Lee M; Beck, Stephan; Müller, Michael

    2014-06-01

    Aging is a progressive process that results in the accumulation of intra- and extracellular alterations that in turn contribute to a reduction in health. Age-related changes in DNA methylation have been reported before and may be responsible for aging-induced changes in gene expression, although a causal relationship has yet to be shown. Using genome-wide assays, we analyzed age-induced changes in DNA methylation and their effect on gene expression with and without transient induction with the synthetic transcription modulating agent WY14,643. To demonstrate feasibility of the approach, we isolated peripheral blood mononucleated cells (PBMCs) from five young and five old healthy male volunteers and cultured them with or without WY14,643. Infinium 450K BeadChip and Affymetrix Human Gene 1.1 ST expression array analysis revealed significant differential methylation of at least 5 % (ΔYO > 5 %) at 10,625 CpG sites between young and old subjects, but only a subset of the associated genes were also differentially expressed. Age-related differential methylation of previously reported epigenetic biomarkers of aging including ELOVL2, FHL2, PENK, and KLF14 was confirmed in our study, but these genes did not display an age-related change in gene expression in PBMCs. Bioinformatic analysis revealed that differentially methylated genes that lack an age-related expression change predominantly represent genes involved in carcinogenesis and developmental processes, and expression of most of these genes were silenced in PBMCs. No changes in DNA methylation were found in genes displaying transiently induced changes in gene expression. In conclusion, aging-induced differential methylation often targets developmental genes and occurs mostly without change in gene expression.

  14. Dissection of the inflammatory bowel disease transcriptome using genome-wide cDNA microarrays.

    Directory of Open Access Journals (Sweden)

    Christine M Costello

    2005-08-01

    Full Text Available BACKGROUND: The differential pathophysiologic mechanisms that trigger and maintain the two forms of inflammatory bowel disease (IBD, Crohn disease (CD, and ulcerative colitis (UC are only partially understood. cDNA microarrays can be used to decipher gene regulation events at a genome-wide level and to identify novel unknown genes that might be involved in perpetuating inflammatory disease progression. METHODS AND FINDINGS: High-density cDNA microarrays representing 33,792 UniGene clusters were prepared. Biopsies were taken from the sigmoid colon of normal controls (n = 11, CD patients (n = 10 and UC patients (n = 10. 33P-radiolabeled cDNA from purified poly(A+ RNA extracted from biopsies (unpooled was hybridized to the arrays. We identified 500 and 272 transcripts differentially regulated in CD and UC, respectively. Interesting hits were independently verified by real-time PCR in a second sample of 100 individuals, and immunohistochemistry was used for exemplary localization. The main findings point to novel molecules important in abnormal immune regulation and the highly disturbed cell biology of colonic epithelial cells in IBD pathogenesis, e.g., CYLD (cylindromatosis, turban tumor syndrome and CDH11 (cadherin 11, type 2. By the nature of the array setup, many of the genes identified were to our knowledge previously uncharacterized, and prediction of the putative function of a subsection of these genes indicate that some could be involved in early events in disease pathophysiology. CONCLUSION: A comprehensive set of candidate genes not previously associated with IBD was revealed, which underlines the polygenic and complex nature of the disease. It points out substantial differences in pathophysiology between CD and UC. The multiple unknown genes identified may stimulate new research in the fields of barrier mechanisms and cell signalling in the context of IBD, and ultimately new therapeutic approaches.

  15. Insights into the role of DNA methylation in diatoms by genome-wide profiling in Phaeodactylum tricornutum.

    Science.gov (United States)

    Veluchamy, Alaguraj; Lin, Xin; Maumus, Florian; Rivarola, Maximo; Bhavsar, Jaysheel; Creasy, Todd; O'Brien, Kimberly; Sengamalay, Naomi A; Tallon, Luke J; Smith, Andrew D; Rayko, Edda; Ahmed, Ikhlak; Le Crom, Stéphane; Farrant, Gregory K; Sgro, Jean-Yves; Olson, Sue A; Bondurant, Sandra Splinter; Allen, Andrew E; Allen, Andrew; Rabinowicz, Pablo D; Sussman, Michael R; Bowler, Chris; Tirichine, Leïla

    2013-01-01

    DNA cytosine methylation is a widely conserved epigenetic mark in eukaryotes that appears to have critical roles in the regulation of genome structure and transcription. Genome-wide methylation maps have so far only been established from the supergroups Archaeplastida and Unikont. Here we report the first whole-genome methylome from a stramenopile, the marine model diatom Phaeodactylum tricornutum. Around 6% of the genome is intermittently methylated in a mosaic pattern. We find extensive methylation in transposable elements. We also detect methylation in over 320 genes. Extensive gene methylation correlates strongly with transcriptional silencing and differential expression under specific conditions. By contrast, we find that genes with partial methylation tend to be constitutively expressed. These patterns contrast with those found previously in other eukaryotes. By going beyond plants, animals and fungi, this stramenopile methylome adds significantly to our understanding of the evolution of DNA methylation in eukaryotes.

  16. Molecular verification of the integration of Tripsacum dactyloides DNA into wheat genome through wide hybridization

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    RAPD and RFLP analyses of double haploid lines which derived from hybridization between hexaploid wheat (Triticum aestivum L.2n=42) and eastern gamagrass (Tripsacum dactyloides L.2n=4x=72) are reported.Two of the 340 Operon primers have been screened,which stably amplified Tripsacum dactyloides (male parent) specific bands in the double haploid lines.These results confirm the fact that Tripsacum dactyloides DNA has been integrated into wheat genome by sexual hybridization at molecular level.This idea has been further testified by RFLP analysis.Application and potentials of transferring Tripsacum dactyloides DNA into wheat genome by sexual hybridization in wheat breeding are discussed.

  17. Genome-wide analysis of DNA methylation dynamics during early human development.

    Science.gov (United States)

    Okae, Hiroaki; Chiba, Hatsune; Hiura, Hitoshi; Hamada, Hirotaka; Sato, Akiko; Utsunomiya, Takafumi; Kikuchi, Hiroyuki; Yoshida, Hiroaki; Tanaka, Atsushi; Suyama, Mikita; Arima, Takahiro

    2014-12-01

    DNA methylation is globally reprogrammed during mammalian preimplantation development, which is critical for normal development. Recent reduced representation bisulfite sequencing (RRBS) studies suggest that the methylome dynamics are essentially conserved between human and mouse early embryos. RRBS is known to cover 5-10% of all genomic CpGs, favoring those contained within CpG-rich regions. To obtain an unbiased and more complete representation of the methylome during early human development, we performed whole genome bisulfite sequencing of human gametes and blastocysts that covered>70% of all genomic CpGs. We found that the maternal genome was demethylated to a much lesser extent in human blastocysts than in mouse blastocysts, which could contribute to an increased number of imprinted differentially methylated regions in the human genome. Global demethylation of the paternal genome was confirmed, but SINE-VNTR-Alu elements and some other tandem repeat-containing regions were found to be specifically protected from this global demethylation. Furthermore, centromeric satellite repeats were hypermethylated in human oocytes but not in mouse oocytes, which might be explained by differential expression of de novo DNA methyltransferases. These data highlight both conserved and species-specific regulation of DNA methylation during early mammalian development. Our work provides further information critical for understanding the epigenetic processes underlying differentiation and pluripotency during early human development.

  18. Improved reproducibility in genome-wide DNA methylation analysis for PAXgene-fixed samples compared with restored formalin-fixed and paraffin-embedded DNA.

    Science.gov (United States)

    Andersen, Gitte Brinch; Hager, Henrik; Hansen, Lise Lotte; Tost, Jörg

    2015-01-01

    Formalin fixation has been the standard method for conservation of clinical specimens for decades. However, a major drawback is the high degradation of nucleic acids, which complicates its use in genome-wide analyses. Unbiased identification of biomarkers, however, requires genome-wide studies, precluding the use of the valuable archives of specimens with long-term follow-up data. Therefore, restoration protocols for DNA from formalin-fixed and paraffin-embedded (FFPE) samples have been developed, although they are cost-intensive and time-consuming. An alternative to FFPE and snap-freezing is the PAXgene Tissue System, developed for simultaneous preservation of morphology, proteins, and nucleic acids. In the current study, we compared the performance of DNA from either PAXgene or formalin-fixed tissues to snap-frozen material for genome-wide DNA methylation analysis using the Illumina 450K BeadChip. Quantitative DNA methylation analysis demonstrated that the methylation profile in PAXgene-fixed tissues showed, in comparison with restored FFPE samples, a higher concordance with the profile detected in frozen samples. We demonstrate, for the first time, that DNA from PAXgene conserved tissue performs better compared with restored FFPE DNA in genome-wide DNA methylation analysis. In addition, DNA from PAXgene tissue can be directly used on the array without prior restoration, rendering the analytical process significantly more time- and cost-effective.

  19. Genome-wide DNA promoter methylation and transcriptome analysis in human adipose tissue unravels novel candidate genes for obesity

    OpenAIRE

    Maria Keller; Lydia Hopp; Xuanshi Liu; Tobias Wohland; Kerstin Rohde; Raffaella Cancello; Matthias Klös; Karl Bacos; Matthias Kern; Fabian Eichelmann; Arne Dietrich; Michael R Schön; Daniel Gärtner; Tobias Lohmann; Miriam Dreßler

    2017-01-01

    Objective/methods: DNA methylation plays an important role in obesity and related metabolic complications. We examined genome-wide DNA promoter methylation along with mRNA profiles in paired samples of human subcutaneous adipose tissue (SAT) and omental visceral adipose tissue (OVAT) from non-obese vs. obese individuals. Results: We identified negatively correlated methylation and expression of several obesity-associated genes in our discovery dataset and in silico replicated ETV6 in two i...

  20. Meristem micropropagation of cassava (Manihot esculenta evokes genome-wide changes in DNA methylation

    Directory of Open Access Journals (Sweden)

    Shedrack Reuben Kitimu

    2015-08-01

    Full Text Available There is great interest in the phenotypic, genetic and epigenetic changes associated with plant in vitro culture known as somaclonal variation. In vitro propagation systems that are based on the use of microcuttings or meristem cultures are considered analogous to clonal cuttings and so widely viewed to be largely free from such somaclonal effects. In this study, we surveyed for epigenetic changes during propagation by meristem culture and by field cuttings in five cassava (Manihot esculenta cultivars. Principal Co-ordinate Analysis of profiles generated by Methylation Sensitive Amplified Polymorphism (MSAP revealed clear divergence between samples taken from field-grown cuttings and those recovered from meristem culture. There was also good separation between the tissues of field samples but this effect was less distinct among the meristem culture materials. Application of methylation-sensitive Genotype By Sequencing (msGBS identified 105 candidate epimarks that distinguish between field cutting and meristem culture samples. Cross referencing the sequences of these epimarks to the draft cassava genome revealed 102 sites associated with genes whose homologues have been implicated in a range of fundamental biological processes including cell differentiation, development, sugar metabolism, DNA methylation, stress response, photosynthesis, and transposon activation. We explore the relevance of these findings for the selection of micropropagation systems for use on this and other crops.

  1. Meristem micropropagation of cassava (Manihot esculenta) evokes genome-wide changes in DNA methylation.

    Science.gov (United States)

    Kitimu, Shedrack R; Taylor, Julian; March, Timothy J; Tairo, Fred; Wilkinson, Mike J; Rodríguez López, Carlos M

    2015-01-01

    There is great interest in the phenotypic, genetic and epigenetic changes associated with plant in vitro culture known as somaclonal variation. In vitro propagation systems that are based on the use of microcuttings or meristem cultures are considered analogous to clonal cuttings and so widely viewed to be largely free from such somaclonal effects. In this study, we surveyed for epigenetic changes during propagation by meristem culture and by field cuttings in five cassava (Manihot esculenta) cultivars. Principal Co-ordinate Analysis of profiles generated by methylation-sensitive amplified polymorphism revealed clear divergence between samples taken from field-grown cuttings and those recovered from meristem culture. There was also good separation between the tissues of field samples but this effect was less distinct among the meristem culture materials. Application of methylation-sensitive Genotype by sequencing identified 105 candidate epimarks that distinguish between field cutting and meristem culture samples. Cross referencing the sequences of these epimarks to the draft cassava genome revealed 102 sites associated with genes whose homologs have been implicated in a range of fundamental biological processes including cell differentiation, development, sugar metabolism, DNA methylation, stress response, photosynthesis, and transposon activation. We explore the relevance of these findings for the selection of micropropagation systems for use on this and other crops.

  2. DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis

    Science.gov (United States)

    Joubert, Bonnie R.; Felix, Janine F.; Yousefi, Paul; Bakulski, Kelly M.; Just, Allan C.; Breton, Carrie; Reese, Sarah E.; Markunas, Christina A.; Richmond, Rebecca C.; Xu, Cheng-Jian; Küpers, Leanne K.; Oh, Sam S.; Hoyo, Cathrine; Gruzieva, Olena; Söderhäll, Cilla; Salas, Lucas A.; Baïz, Nour; Zhang, Hongmei; Lepeule, Johanna; Ruiz, Carlos; Ligthart, Symen; Wang, Tianyuan; Taylor, Jack A.; Duijts, Liesbeth; Sharp, Gemma C.; Jankipersadsing, Soesma A.; Nilsen, Roy M.; Vaez, Ahmad; Fallin, M. Daniele; Hu, Donglei; Litonjua, Augusto A.; Fuemmeler, Bernard F.; Huen, Karen; Kere, Juha; Kull, Inger; Munthe-Kaas, Monica Cheng; Gehring, Ulrike; Bustamante, Mariona; Saurel-Coubizolles, Marie José; Quraishi, Bilal M.; Ren, Jie; Tost, Jörg; Gonzalez, Juan R.; Peters, Marjolein J.; Håberg, Siri E.; Xu, Zongli; van Meurs, Joyce B.; Gaunt, Tom R.; Kerkhof, Marjan; Corpeleijn, Eva; Feinberg, Andrew P.; Eng, Celeste; Baccarelli, Andrea A.; Benjamin Neelon, Sara E.; Bradman, Asa; Merid, Simon Kebede; Bergström, Anna; Herceg, Zdenko; Hernandez-Vargas, Hector; Brunekreef, Bert; Pinart, Mariona; Heude, Barbara; Ewart, Susan; Yao, Jin; Lemonnier, Nathanaël; Franco, Oscar H.; Wu, Michael C.; Hofman, Albert; McArdle, Wendy; Van der Vlies, Pieter; Falahi, Fahimeh; Gillman, Matthew W.; Barcellos, Lisa F.; Kumar, Ashish; Wickman, Magnus; Guerra, Stefano; Charles, Marie-Aline; Holloway, John; Auffray, Charles; Tiemeier, Henning W.; Smith, George Davey; Postma, Dirkje; Hivert, Marie-France; Eskenazi, Brenda; Vrijheid, Martine; Arshad, Hasan; Antó, Josep M.; Dehghan, Abbas; Karmaus, Wilfried; Annesi-Maesano, Isabella; Sunyer, Jordi; Ghantous, Akram; Pershagen, Göran; Holland, Nina; Murphy, Susan K.; DeMeo, Dawn L.; Burchard, Esteban G.; Ladd-Acosta, Christine; Snieder, Harold; Nystad, Wenche; Koppelman, Gerard H.; Relton, Caroline L.; Jaddoe, Vincent W.V.; Wilcox, Allen; Melén, Erik; London, Stephanie J.

    2016-01-01

    Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The mechanisms are largely unknown, but epigenetics most likely plays a role. We formed the Pregnancy And Childhood Epigenetics (PACE) consortium and meta-analyzed, across 13 cohorts (n = 6,685), the association between maternal smoking in pregnancy and newborn blood DNA methylation at over 450,000 CpG sites (CpGs) by using the Illumina 450K BeadChip. Over 6,000 CpGs were differentially methylated in relation to maternal smoking at genome-wide statistical significance (false discovery rate, 5%), including 2,965 CpGs corresponding to 2,017 genes not previously related to smoking and methylation in either newborns or adults. Several genes are relevant to diseases that can be caused by maternal smoking (e.g., orofacial clefts and asthma) or adult smoking (e.g., certain cancers). A number of differentially methylated CpGs were associated with gene expression. We observed enrichment in pathways and processes critical to development. In older children (5 cohorts, n = 3,187), 100% of CpGs gave at least nominal levels of significance, far more than expected by chance (p value < 2.2 × 10−16). Results were robust to different normalization methods used across studies and cell type adjustment. In this large scale meta-analysis of methylation data, we identified numerous loci involved in response to maternal smoking in pregnancy with persistence into later childhood and provide insights into mechanisms underlying effects of this important exposure. PMID:27040690

  3. Genome-wide analysis of DNA methylation in Arabidopsis using MeDIP-chip

    NARCIS (Netherlands)

    Cortijo, Sandra; Wardenaar, René; Colomé-Tatché, Maria; Johannes, Frank; Colot, Vincent

    2014-01-01

    DNA methylation is an epigenetic mark that is essential for preserving genome integrity and normal development in plants and mammals. Although this modification may serve a variety of purposes, it is best known for its role in stable transcriptional silencing of transposable elements and epigenetic

  4. A genome-wide association study for late-onset Alzheimer's disease using DNA pooling

    Directory of Open Access Journals (Sweden)

    Hillmer Axel M

    2008-09-01

    Full Text Available Abstract Background Late-onset Alzheimer's disease (LOAD is an age related neurodegenerative disease with a high prevalence that places major demands on healthcare resources in societies with increasingly aged populations. The only extensively replicable genetic risk factor for LOAD is the apolipoprotein E gene. In order to identify additional genetic risk loci we have conducted a genome-wide association (GWA study in a large LOAD case – control sample, reducing costs through the use of DNA pooling. Methods DNA samples were collected from 1,082 individuals with LOAD and 1,239 control subjects. Age at onset ranged from 60 to 95 and Controls were matched for age (mean = 76.53 years, SD = 33, gender and ethnicity. Equimolar amounts of each DNA sample were added to either a case or control pool. The pools were genotyped using Illumina HumanHap300 and Illumina Sentrix HumanHap240S arrays testing 561,494 SNPs. 114 of our best hit SNPs from the pooling data were identified and then individually genotyped in the case – control sample used to construct the pools. Results Highly significant association with LOAD was observed at the APOE locus confirming the validity of the pooled genotyping approach. For 109 SNPs outside the APOE locus, we obtained uncorrected p-values ≤ 0.05 for 74 after individual genotyping. To further test these associations, we added control data from 1400 subjects from the 1958 Birth Cohort with the evidence for association increasing to 3.4 × 10-6 for our strongest finding, rs727153. rs727153 lies 13 kb from the start of transcription of lecithin retinol acyltransferase (phosphatidylcholine – retinol O-acyltransferase, LRAT. Five of seven tag SNPs chosen to cover LRAT showed significant association with LOAD with a SNP in intron 2 of LRAT, showing greatest evidence of association (rs201825, p-value = 6.1 × 10-7. Conclusion We have validated the pooling method for GWA studies by both identifying the APOE locus and by

  5. Genome-wide DNA methylation analysis of neuroblastic tumors reveals clinically relevant epigenetic events and large-scale epigenomic alterations localized to telomeric regions

    NARCIS (Netherlands)

    P.G. Buckley; S. Das; K. Bryan; K.M. Watters; L. Alcock; J. Koster; R. Versteeg; R.L. Stallings

    2011-01-01

    The downregulation of specific genes through DNA hypermethylation is a major hallmark of cancer, although the extent and genomic distribution of hypermethylation occurring within cancer genomes is poorly understood. We report on the first genome-wide analysis of DNA methylation alterations in differ

  6. Young men with low birthweight exhibit decreased plasticity of genome-wide muscle DNA methylation by high-fat overfeeding

    DEFF Research Database (Denmark)

    Jacobsen, Stine C; Gillberg, Linn; Bork-Jensen, Jette

    2014-01-01

    individuals, and we recently showed multiple DNA methylation changes during short-term high-fat overfeeding in muscle of healthy people. In a randomised crossover study, we analysed genome-wide DNA promoter methylation in skeletal muscle of 17 young LBW men and 23 matched normal birthweight (NBW) men after......The association between low birthweight (LBW) and risk of developing type 2 diabetes may involve epigenetic mechanisms, with skeletal muscle being a prime target tissue. Differential DNA methylation patterns have been observed in single genes in muscle tissue from type 2 diabetic and LBW...

  7. A six months exercise intervention influences the genome-wide DNA methylation pattern in human adipose tissue.

    Science.gov (United States)

    Rönn, Tina; Volkov, Petr; Davegårdh, Cajsa; Dayeh, Tasnim; Hall, Elin; Olsson, Anders H; Nilsson, Emma; Tornberg, Asa; Dekker Nitert, Marloes; Eriksson, Karl-Fredrik; Jones, Helena A; Groop, Leif; Ling, Charlotte

    2013-06-01

    Epigenetic mechanisms are implicated in gene regulation and the development of different diseases. The epigenome differs between cell types and has until now only been characterized for a few human tissues. Environmental factors potentially alter the epigenome. Here we describe the genome-wide pattern of DNA methylation in human adipose tissue from 23 healthy men, with a previous low level of physical activity, before and after a six months exercise intervention. We also investigate the differences in adipose tissue DNA methylation between 31 individuals with or without a family history of type 2 diabetes. DNA methylation was analyzed using Infinium HumanMethylation450 BeadChip, an array containing 485,577 probes covering 99% RefSeq genes. Global DNA methylation changed and 17,975 individual CpG sites in 7,663 unique genes showed altered levels of DNA methylation after the exercise intervention (qtype 2 diabetes candidate genes had CpG sites with differences in adipose tissue DNA methylation in response to exercise (qadipose tissue in vivo affect adipocyte metabolism, we silenced Hdac4 and Ncor2 respectively in 3T3-L1 adipocytes, which resulted in increased lipogenesis both in the basal and insulin stimulated state. In conclusion, exercise induces genome-wide changes in DNA methylation in human adipose tissue, potentially affecting adipocyte metabolism.

  8. Comparison of buccal and blood-derived canine DNA, either native or whole genome amplified, for array-based genome-wide association studies

    Directory of Open Access Journals (Sweden)

    Lawley Cynthia

    2011-06-01

    Full Text Available Abstract Background The availability of array-based genotyping platforms for single nucleotide polymorphisms (SNPs for the canine genome has expanded the opportunities to undertake genome-wide association (GWA studies to identify the genetic basis for Mendelian and complex traits. Whole blood as the source of high quality DNA is undisputed but often proves impractical for collection of the large numbers of samples necessary to discover the loci underlying complex traits. Further, many countries prohibit the collection of blood from dogs unless medically necessary thereby restricting access to critical control samples from healthy dogs. Alternate sources of DNA, typically from buccal cytobrush extractions, while convenient, have been suggested to have low yield and perform poorly in GWA. Yet buccal cytobrushes provide a cost-effective means of collecting DNA, are readily accepted by dog owners, and represent a large resource base in many canine genetics laboratories. To increase the DNA quantities, whole genome amplification (WGA can be performed. Thus, the present study assessed the utility of buccal-derived DNA as well as whole genome amplification in comparison to blood samples for use on the most recent iteration of the canine HD SNP array (Illumina. Findings In both buccal and blood samples, whether whole genome amplified or not, 97% of the samples had SNP call rates in excess of 80% indicating that the vast majority of the SNPs would be suitable to perform association studies regardless of the DNA source. Similarly, there were no significant differences in marker intensity measurements between buccal and blood samples for copy number variations (CNV analysis. Conclusions All DNA samples assayed, buccal or blood, native or whole genome amplified, are appropriate for use in array-based genome-wide association studies. The concordance between subsets of dogs for which both buccal and blood samples, or those samples whole genome amplified, was

  9. Genome-wide DNA methylation patterns in CD4+ T cells from Chinese Han patients with rheumatoid arthritis.

    Science.gov (United States)

    Guo, Shicheng; Zhu, Qi; Jiang, Ting; Wang, Rongsheng; Shen, Yi; Zhu, Xiao; Wang, Yan; Bai, Fengmin; Ding, Qin; Zhou, Xiaodong; Chen, Guangjie; He, Dong Yi

    2017-05-01

    Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints. Recent evidence indicated the epigenetic changes may contribute to the pathogenesis of RA. To understand the extent and nature of dysregulated DNA methylation in RA CD4T cells, we performed a genome-wide DNA methylation study in CD4 + T cells in 12 RA patients compared to 12 matched normal healthy controls. Cytosine methylation status was quantified with Illumina methylation 450K microarray. The DNA methylation profiling showed 383 hyper- and 785 hypo-methylated genes in the CD4 + T cells of the RA patients (p ontology analysis indicated transcript alternative splicing and protein modification mediated by DNA methylation might play an important role in the pathogenesis of RA. In addition, the result showed that human leukocyte antigen (HLA) region including HLA-DRB6, HLA-DQA1 and HLA-E was frequently hypomethylated, but HLA-DQB1 hypermethylated in CpG island region and hypomethylated in CpG shelf region in RA patients. Outside the MHC region, HDAC4, NXN, TBCD and TMEM61 were the most hypermethylated genes, while ITIH3, TCN2, PRDM16, SLC1A5 and GALNT9 are the most hypomethylated genes. Genome-wide DNA methylation profile revealed significant DNA methylation change in CD4 + T cells from patients with RA.

  10. Genome-wide mapping of in vivo protein-DNA interactions.

    Science.gov (United States)

    Johnson, David S; Mortazavi, Ali; Myers, Richard M; Wold, Barbara

    2007-06-08

    In vivo protein-DNA interactions connect each transcription factor with its direct targets to form a gene network scaffold. To map these protein-DNA interactions comprehensively across entire mammalian genomes, we developed a large-scale chromatin immunoprecipitation assay (ChIPSeq) based on direct ultrahigh-throughput DNA sequencing. This sequence census method was then used to map in vivo binding of the neuron-restrictive silencer factor (NRSF; also known as REST, for repressor element-1 silencing transcription factor) to 1946 locations in the human genome. The data display sharp resolution of binding position [+/-50 base pairs (bp)], which facilitated our finding motifs and allowed us to identify noncanonical NRSF-binding motifs. These ChIPSeq data also have high sensitivity and specificity [ROC (receiver operator characteristic) area >/= 0.96] and statistical confidence (P <10(-4)), properties that were important for inferring new candidate interactions. These include key transcription factors in the gene network that regulates pancreatic islet cell development.

  11. Genome-wide DNA methylation analysis of transient neonatal diabetes type 1 patients with mutations in ZFP57

    DEFF Research Database (Denmark)

    Bak, Mads; Boonen, Susanne E; Dahl, Christina;

    2016-01-01

    involved in establishment and maintenance of methylation of imprinted loci. Our objective was to investigate whether additional regions are aberrantly methylated in ZFP57 mutation carriers. METHODS: Genome-wide DNA methylation analysis was performed on four individuals with homozygous or compound...... and HYMAI. A subset of patients with maternal hypomethylation at PLAGL1 have hypomethylation at additional imprinted loci throughout the genome, including GRB10, ZIM2 (PEG3), MEST (PEG1), KCNQ1OT1 and NESPAS (GNAS-AS1). About half of the TNDM1 patients carry mutations in ZFP57, a transcription factor...

  12. Genome-wide DNA polymorphisms in Kavuni, a traditional rice cultivar with nutritional and therapeutic properties.

    Science.gov (United States)

    Rathinasabapathi, Pasupathi; Purushothaman, Natarajan; Parani, Madasamy

    2016-05-01

    Although rice genome was sequenced in the year 2002, efforts in resequencing the large number of available accessions, landraces, traditional cultivars, and improved varieties of this important food crop are limited. We have initiated resequencing of the traditional cultivars from India. Kavuni is an important traditional rice cultivar from South India that attracts premium price for its nutritional and therapeutic properties. Whole-genome sequencing of Kavuni using Illumina platform and SNPs analysis using Nipponbare reference genome identified 1 150 711 SNPs of which 377 381 SNPs were located in the genic regions. Non-synonymous SNPs (62 708) were distributed in 19 251 genes, and their number varied between 1 and 115 per gene. Large-effect DNA polymorphisms (7769) were present in 3475 genes. Pathway mapping of these polymorphisms revealed the involvement of genes related to carbohydrate metabolism, translation, protein-folding, and cell death. Analysis of the starch biosynthesis related genes revealed that the granule-bound starch synthase I gene had T/G SNPs at the first intron/exon junction and a two-nucleotide combination, which were reported to favour high amylose content and low glycemic index. The present study provided a valuable genomics resource to study the rice varieties with nutritional and medicinal properties.

  13. Genome-wide Differences in DNA Methylation Changes in Two Contrasting Rice Genotypes in Response to Drought Conditions

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    Wensheng Wang

    2016-11-01

    Full Text Available Differences in drought stress tolerance within diverse rice genotypes have been attributed to genetic diversity and epigenetic alterations. DNA methylation is an important epigenetic modification that influences diverse biological processes, but its effects on rice drought stress tolerance are poorly understood. In this study, methylated DNA immunoprecipitation sequencing and an Affymetrix GeneChip rice genome array were used to profile the DNA methylation patterns and transcriptomes of the drought-tolerant introgression line DK151 and its drought-sensitive recurrent parent IR64 under drought and control conditions. The introgression of donor genomic DNA induced genome-wide DNA methylation changes in DK151 plants. A total of 1190 differentially methylated regions (DMRs were detected between the two genotypes under normal growth conditions, and the DMR-associated genes in DK151 plants were mainly related to stress response, programmed cell death, and nutrient reservoir activity, which are implicated to constitutive drought stress tolerance. A comparison of the DNA methylation changes in the two genotypes under drought conditions indicated that DK151 plants have a more stable methylome, with only 92 drought-induced DMRs, than IR64 plants with 506 DMRs. Gene ontology analyses of the DMR-associated genes in drought-stressed plants revealed that changes to the DNA methylation status of genotype-specific genes are associated with the epigenetic regulation of drought stress responses. Transcriptome analysis further helped to identify a set of 12 and 23 DMR-associated genes that were differentially expressed in DK151 and IR64, respectively, under drought stress compared with respective controls. Correlation analysis indicated that DNA methylation has various effects on gene expression, implying that it affects gene expression directly or indirectly through diverse regulatory pathways. Our results indicate that drought-induced alterations to DNA

  14. Comparison of gene expression and genome-wide DNA methylation profiling between phenotypically normal cloned pigs and conventionally bred controls.

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    Fei Gao

    Full Text Available Animal breeding via Somatic Cell Nuclear Transfer (SCNT has enormous potential in agriculture and biomedicine. However, concerns about whether SCNT animals are as healthy or epigenetically normal as conventionally bred ones are raised as the efficiency of cloning by SCNT is much lower than natural breeding or In-vitro fertilization (IVF. Thus, we have conducted a genome-wide gene expression and DNA methylation profiling between phenotypically normal cloned pigs and control pigs in two tissues (muscle and liver, using Affymetrix Porcine expression array as well as modified methylation-specific digital karyotyping (MMSDK and Solexa sequencing technology. Typical tissue-specific differences with respect to both gene expression and DNA methylation were observed in muscle and liver from cloned as well as control pigs. Gene expression profiles were highly similar between cloned pigs and controls, though a small set of genes showed altered expression. Cloned pigs presented a more different pattern of DNA methylation in unique sequences in both tissues. Especially a small set of genomic sites had different DNA methylation status with a trend towards slightly increased methylation levels in cloned pigs. Molecular network analysis of the genes that contained such differential methylation loci revealed a significant network related to tissue development. In conclusion, our study showed that phenotypically normal cloned pigs were highly similar with normal breeding pigs in their gene expression, but moderate alteration in DNA methylation aspects still exists, especially in certain unique genomic regions.

  15. Genome-wide localization of Rrm3 and Pif1 DNA helicases at stalled active and inactive DNA replication forks of Saccharomyces cerevisiae

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    Silvia Emma Rossi

    2016-03-01

    Full Text Available The genome of the budding yeast Saccharomyces cerevisiae is sequenced and the location and dynamic of activation of DNA replication origins are known. G1 synchronized yeast cells can be released into S-phase in the presence of hydroxyurea (HU (1, which slows down DNA replication and retains replication forks in proximity of DNA replication origins. In this condition, the Chromatin Immuno-Precipitation on chip (ChIP on chip (2–4 of replisome components allows the precise localization of all active DNA replication forks. This analysis can be coupled with the ssDNA-BromodeoxyUridine (ssDNA-BrdU Immuno-Precipitation on chip (ssDNA-BrdU IP on chip technique (5–7, which detects the location of newly synthesized DNA. Comparison of binding and BrdU incorporation profiles allows to locate a factor of interest at DNA replication forks genome wide. We present datasets deposited in the gene expression omnibus (GEO database under accession number GSE68214, which show how the DNA helicases Rrm3 and Pif1 (8 associate to active and inactive DNA replication forks.

  16. PRIMEGENS-v2: genome-wide primer design for analyzing DNA methylation patterns of CpG islands.

    Science.gov (United States)

    Srivastava, Gyan P; Guo, Juyuan; Shi, Huidong; Xu, Dong

    2008-09-01

    DNA methylation plays important roles in biological processes and human diseases, especially cancers. High-throughput bisulfite genomic sequencing based on new generation of sequencers, such as the 454-sequencing system provides an efficient method for analyzing DNA methylation patterns. The successful implementation of this approach depends on the use of primer design software capable of performing genome-wide scan for optimal primers from in silico bisulfite-treated genome sequences. We have developed a method, which fulfills this requirement and conduct primer design for sequences including regions of given promoter CpG islands. The developed method has been implemented using the C and JAVA programming languages. The primer design results were tested in the PCR experiments of 96 selected human DNA sequences containing CpG islands in the promoter regions. The results indicate that this method is efficient and reliable for designing sequence-specific primers. The sequence-specific primer design for DNA meth-ylated sequences including CpG islands has been integrated into the second version of PRIMEGENS as one of the primer design features. The software is freely available for academic use at http://digbio.missouri.edu/primegens/.

  17. Genome-wide copy number analysis using copy number inferring tool (CNIT) and DNA pooling.

    Science.gov (United States)

    Lin, Chien-hsing; Huang, Mei-chu; Li, Ling-hui; Wu, Jer-yuarn; Chen, Yuan-tsong; Fann, Cathy S J

    2008-08-01

    Copy number variation (CNV) has become an important genomic structure element in the human population, and some CNVs are related to specific traits and diseases. Moreover, analysis of human genomes has been potentiated by the use of high-resolution microarrays that assess single nucleotide polymorphisms (SNPs). Although many programs have been designed to analyze data from Affymetrix SNP microarrays, they all have high false-positive rates (FPRs) in copy number (CN) analyses. Copy number analysis tool (CNAT) 4.0 is a recently developed program that offers improved CN estimation, but small amplifications and deletions are lost when using the smoothing procedure. Here, we propose a copy number inferring tool (CNIT) algorithm for the 100K SNP microarray to investigate CNVs at 29.6-kb resolution. CNIT estimated SNP allelic and total CN with reliable P values based on intensity data. In addition, the hidden Markov model (HMM) method was applied to predict regions having altered CN by considering contiguous SNPs. Based on a CN analysis of 23 unrelated Taiwanese and 30 HapMap Centre d'Etude du Polymorphisme Humain (CEPH) trios, CNIT showed higher accuracy and power than other programs. The FPRs and false-negative rates (FNRs) of CNIT were 0.1% and 0.16%, respectively. CNIT also showed better sensitivity for detecting small amplifications and deletions. Furthermore, DNA pooling of 10 and 30 normal unrelated individuals were applied to the 100K SNP microarray, respectively, and 12 common CN-variable regions were identified, suggesting that DNA pooling can be applied to discover common CNVs.

  18. Genome-wide analysis in human colorectal cancer cells reveals ischemia-mediated expression of motility genes via DNA hypomethylation.

    Science.gov (United States)

    Skowronski, Karolina; Skowronki, Karolina; Andrews, Joseph; Rodenhiser, David I; Coomber, Brenda L

    2014-01-01

    DNA hypomethylation is an important epigenetic modification found to occur in many different cancer types, leading to the upregulation of previously silenced genes and loss of genomic stability. We previously demonstrated that hypoxia and hypoglycaemia (ischemia), two common micro-environmental changes in solid tumours, decrease DNA methylation through the downregulation of DNMTs in human colorectal cancer cells. Here, we utilized a genome-wide cross-platform approach to identify genes hypomethylated and upregulated by ischemia. Following exposure to hypoxia or hypoglycaemia, methylated DNA from human colorectal cancer cells (HCT116) was immunoprecipitated and analysed with an Affymetrix promoter array. Additionally, RNA was isolated and analysed in parallel with an Affymetrix expression array. Ingenuity pathway analysis software revealed that a significant proportion of the genes hypomethylated and upregulated were involved in cellular movement, including PLAUR and CYR61. A Matrigel invasion assay revealed that indeed HCT116 cells grown in hypoxic or hypoglycaemic conditions have increased mobility capabilities. Confirmation of upregulated expression of cellular movement genes was performed with qPCR. The correlation between ischemia and metastasis is well established in cancer progression, but the molecular mechanisms responsible for this common observation have not been clearly identified. Our novel data suggests that hypoxia and hypoglycaemia may be driving changes in DNA methylation through downregulation of DNMTs. This is the first report to our knowledge that provides an explanation for the increased metastatic potential seen in ischemic cells; i.e. that ischemia could be driving DNA hypomethylation and increasing expression of cellular movement genes.

  19. Genome-wide DNA methylation maps in follicular lymphoma cells determined by methylation-enriched bisulfite sequencing.

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    Jeong-Hyeon Choi

    Full Text Available BACKGROUND: Follicular lymphoma (FL is a form of non-Hodgkin's lymphoma (NHL that arises from germinal center (GC B-cells. Despite the significant advances in immunotherapy, FL is still not curable. Beyond transcriptional profiling and genomics datasets, there currently is no epigenome-scale dataset or integrative biology approach that can adequately model this disease and therefore identify novel mechanisms and targets for successful prevention and treatment of FL. METHODOLOGY/PRINCIPAL FINDINGS: We performed methylation-enriched genome-wide bisulfite sequencing of FL cells and normal CD19(+ B-cells using 454 sequencing technology. The methylated DNA fragments were enriched with methyl-binding proteins, treated with bisulfite, and sequenced using the Roche-454 GS FLX sequencer. The total number of bases covered in the human genome was 18.2 and 49.3 million including 726,003 and 1.3 million CpGs in FL and CD19(+ B-cells, respectively. 11,971 and 7,882 methylated regions of interest (MRIs were identified respectively. The genome-wide distribution of these MRIs displayed significant differences between FL and normal B-cells. A reverse trend in the distribution of MRIs between the promoter and the gene body was observed in FL and CD19(+ B-cells. The MRIs identified in FL cells also correlated well with transcriptomic data and ChIP-on-Chip analyses of genome-wide histone modifications such as tri-methyl-H3K27, and tri-methyl-H3K4, indicating a concerted epigenetic alteration in FL cells. CONCLUSIONS/SIGNIFICANCE: This study is the first to provide a large scale and comprehensive analysis of the DNA methylation sequence composition and distribution in the FL epigenome. These integrated approaches have led to the discovery of novel and frequent targets of aberrant epigenetic alterations. The genome-wide bisulfite sequencing approach developed here can be a useful tool for profiling DNA methylation in clinical samples.

  20. Plasma DNA tissue mapping by genome-wide methylation sequencing for noninvasive prenatal, cancer, and transplantation assessments

    Science.gov (United States)

    Sun, Kun; Jiang, Peiyong; Chan, K. C. Allen; Wong, John; Cheng, Yvonne K. Y.; Liang, Raymond H. S.; Chan, Wai-kong; Ma, Edmond S. K.; Chan, Stephen L.; Cheng, Suk Hang; Chan, Rebecca W. Y.; Tong, Yu K.; Ng, Simon S. M.; Wong, Raymond S. M.; Hui, David S. C.; Leung, Tse Ngong; Leung, Tak Y.; Lai, Paul B. S.; Chiu, Rossa W. K.; Lo, Yuk Ming Dennis

    2015-01-01

    Plasma consists of DNA released from multiple tissues within the body. Using genome-wide bisulfite sequencing of plasma DNA and deconvolution of the sequencing data with reference to methylation profiles of different tissues, we developed a general approach for studying the major tissue contributors to the circulating DNA pool. We tested this method in pregnant women, patients with hepatocellular carcinoma, and subjects following bone marrow and liver transplantation. In most subjects, white blood cells were the predominant contributors to the circulating DNA pool. The placental contributions in the plasma of pregnant women correlated with the proportional contributions as revealed by fetal-specific genetic markers. The graft-derived contributions to the plasma in the transplant recipients correlated with those determined using donor-specific genetic markers. Patients with hepatocellular carcinoma showed elevated plasma DNA contributions from the liver, which correlated with measurements made using tumor-associated copy number aberrations. In hepatocellular carcinoma patients and in pregnant women exhibiting copy number aberrations in plasma, comparison of methylation deconvolution results using genomic regions with different copy number status pinpointed the tissue type responsible for the aberrations. In a pregnant woman diagnosed as having follicular lymphoma during pregnancy, methylation deconvolution indicated a grossly elevated contribution from B cells into the plasma DNA pool and localized B cells as the origin of the copy number aberrations observed in plasma. This method may serve as a powerful tool for assessing a wide range of physiological and pathological conditions based on the identification of perturbed proportional contributions of different tissues into plasma. PMID:26392541

  1. Genome-wide footprints of pig domestication and selection revealed through massive parallel sequencing of pooled DNA.

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    Andreia J Amaral

    Full Text Available BACKGROUND: Artificial selection has caused rapid evolution in domesticated species. The identification of selection footprints across domesticated genomes can contribute to uncover the genetic basis of phenotypic diversity. METHODOLOGY/MAIN FINDINGS: Genome wide footprints of pig domestication and selection were identified using massive parallel sequencing of pooled reduced representation libraries (RRL representing ∼2% of the genome from wild boar and four domestic pig breeds (Large White, Landrace, Duroc and Pietrain which have been under strong selection for muscle development, growth, behavior and coat color. Using specifically developed statistical methods that account for DNA pooling, low mean sequencing depth, and sequencing errors, we provide genome-wide estimates of nucleotide diversity and genetic differentiation in pig. Widespread signals suggestive of positive and balancing selection were found and the strongest signals were observed in Pietrain, one of the breeds most intensively selected for muscle development. Most signals were population-specific but affected genomic regions which harbored genes for common biological categories including coat color, brain development, muscle development, growth, metabolism, olfaction and immunity. Genetic differentiation in regions harboring genes related to muscle development and growth was higher between breeds than between a given breed and the wild boar. CONCLUSIONS/SIGNIFICANCE: These results, suggest that although domesticated breeds have experienced similar selective pressures, selection has acted upon different genes. This might reflect the multiple domestication events of European breeds or could be the result of subsequent introgression of Asian alleles. Overall, it was estimated that approximately 7% of the porcine genome has been affected by selection events. This study illustrates that the massive parallel sequencing of genomic pools is a cost-effective approach to identify

  2. CNVkit: Genome-Wide Copy Number Detection and Visualization from Targeted DNA Sequencing.

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    Eric Talevich

    2016-04-01

    Full Text Available Germline copy number variants (CNVs and somatic copy number alterations (SCNAs are of significant importance in syndromic conditions and cancer. Massively parallel sequencing is increasingly used to infer copy number information from variations in the read depth in sequencing data. However, this approach has limitations in the case of targeted re-sequencing, which leaves gaps in coverage between the regions chosen for enrichment and introduces biases related to the efficiency of target capture and library preparation. We present a method for copy number detection, implemented in the software package CNVkit, that uses both the targeted reads and the nonspecifically captured off-target reads to infer copy number evenly across the genome. This combination achieves both exon-level resolution in targeted regions and sufficient resolution in the larger intronic and intergenic regions to identify copy number changes. In particular, we successfully inferred copy number at equivalent to 100-kilobase resolution genome-wide from a platform targeting as few as 293 genes. After normalizing read counts to a pooled reference, we evaluated and corrected for three sources of bias that explain most of the extraneous variability in the sequencing read depth: GC content, target footprint size and spacing, and repetitive sequences. We compared the performance of CNVkit to copy number changes identified by array comparative genomic hybridization. We packaged the components of CNVkit so that it is straightforward to use and provides visualizations, detailed reporting of significant features, and export options for integration into existing analysis pipelines. CNVkit is freely available from https://github.com/etal/cnvkit.

  3. Genome-wide association study for ovarian cancer susceptibility using pooled DNA

    DEFF Research Database (Denmark)

    Lu, Yi; Chen, Xiaoqing; Beesley, Jonathan;

    2012-01-01

    Recent Genome-Wide Association Studies (GWAS) have identified four low-penetrance ovarian cancer susceptibility loci. We hypothesized that further moderate- or low-penetrance variants exist among the subset of single-nucleotide polymorphisms (SNPs) not well tagged by the genotyping arrays used...... in a much larger stage 2 set of 4,651 cases and 6,966 controls from the Ovarian Cancer Association Consortium. Given that most of the top 20 SNPs from pooling were validated in the same samples by individual genotyping, the lack of replication is likely to be due to the relatively small sample size in our...... stage 1 GWAS rather than due to problems with the pooling approach. We conclude that there are unlikely to be any moderate or large effects on ovarian cancer risk untagged by less dense arrays. However, our study lacked power to make clear statements on the existence of hitherto untagged small...

  4. Genome-wide stochastic adaptive DNA amplification at direct and inverted DNA repeats in the parasite Leishmania.

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    Jean-Michel Ubeda

    2014-05-01

    Full Text Available Gene amplification of specific loci has been described in all kingdoms of life. In the protozoan parasite Leishmania, the product of amplification is usually part of extrachromosomal circular or linear amplicons that are formed at the level of direct or inverted repeated sequences. A bioinformatics screen revealed that repeated sequences are widely distributed in the Leishmania genome and the repeats are chromosome-specific, conserved among species, and generally present in low copy number. Using sensitive PCR assays, we provide evidence that the Leishmania genome is continuously being rearranged at the level of these repeated sequences, which serve as a functional platform for constitutive and stochastic amplification (and deletion of genomic segments in the population. This process is adaptive as the copy number of advantageous extrachromosomal circular or linear elements increases upon selective pressure and is reversible when selection is removed. We also provide mechanistic insights on the formation of circular and linear amplicons through RAD51 recombinase-dependent and -independent mechanisms, respectively. The whole genome of Leishmania is thus stochastically rearranged at the level of repeated sequences, and the selection of parasite subpopulations with changes in the copy number of specific loci is used as a strategy to respond to a changing environment.

  5. Genome-wide stochastic adaptive DNA amplification at direct and inverted DNA repeats in the parasite Leishmania.

    Science.gov (United States)

    Ubeda, Jean-Michel; Raymond, Frédéric; Mukherjee, Angana; Plourde, Marie; Gingras, Hélène; Roy, Gaétan; Lapointe, Andréanne; Leprohon, Philippe; Papadopoulou, Barbara; Corbeil, Jacques; Ouellette, Marc

    2014-05-01

    Gene amplification of specific loci has been described in all kingdoms of life. In the protozoan parasite Leishmania, the product of amplification is usually part of extrachromosomal circular or linear amplicons that are formed at the level of direct or inverted repeated sequences. A bioinformatics screen revealed that repeated sequences are widely distributed in the Leishmania genome and the repeats are chromosome-specific, conserved among species, and generally present in low copy number. Using sensitive PCR assays, we provide evidence that the Leishmania genome is continuously being rearranged at the level of these repeated sequences, which serve as a functional platform for constitutive and stochastic amplification (and deletion) of genomic segments in the population. This process is adaptive as the copy number of advantageous extrachromosomal circular or linear elements increases upon selective pressure and is reversible when selection is removed. We also provide mechanistic insights on the formation of circular and linear amplicons through RAD51 recombinase-dependent and -independent mechanisms, respectively. The whole genome of Leishmania is thus stochastically rearranged at the level of repeated sequences, and the selection of parasite subpopulations with changes in the copy number of specific loci is used as a strategy to respond to a changing environment.

  6. A six months exercise intervention influences the genome-wide DNA methylation pattern in human adipose tissue.

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    Tina Rönn

    2013-06-01

    Full Text Available Epigenetic mechanisms are implicated in gene regulation and the development of different diseases. The epigenome differs between cell types and has until now only been characterized for a few human tissues. Environmental factors potentially alter the epigenome. Here we describe the genome-wide pattern of DNA methylation in human adipose tissue from 23 healthy men, with a previous low level of physical activity, before and after a six months exercise intervention. We also investigate the differences in adipose tissue DNA methylation between 31 individuals with or without a family history of type 2 diabetes. DNA methylation was analyzed using Infinium HumanMethylation450 BeadChip, an array containing 485,577 probes covering 99% RefSeq genes. Global DNA methylation changed and 17,975 individual CpG sites in 7,663 unique genes showed altered levels of DNA methylation after the exercise intervention (q<0.05. Differential mRNA expression was present in 1/3 of gene regions with altered DNA methylation, including RALBP1, HDAC4 and NCOR2 (q<0.05. Using a luciferase assay, we could show that increased DNA methylation in vitro of the RALBP1 promoter suppressed the transcriptional activity (p = 0.03. Moreover, 18 obesity and 21 type 2 diabetes candidate genes had CpG sites with differences in adipose tissue DNA methylation in response to exercise (q<0.05, including TCF7L2 (6 CpG sites and KCNQ1 (10 CpG sites. A simultaneous change in mRNA expression was seen for 6 of those genes. To understand if genes that exhibit differential DNA methylation and mRNA expression in human adipose tissue in vivo affect adipocyte metabolism, we silenced Hdac4 and Ncor2 respectively in 3T3-L1 adipocytes, which resulted in increased lipogenesis both in the basal and insulin stimulated state. In conclusion, exercise induces genome-wide changes in DNA methylation in human adipose tissue, potentially affecting adipocyte metabolism.

  7. Young men with low birthweight exhibit decreased plasticity of genome-wide muscle DNA methylation by high-fat overfeeding.

    Science.gov (United States)

    Jacobsen, Stine C; Gillberg, Linn; Bork-Jensen, Jette; Ribel-Madsen, Rasmus; Lara, Ester; Calvanese, Vincenzo; Ling, Charlotte; Fernandez, Agustin F; Fraga, Mario F; Poulsen, Pernille; Brøns, Charlotte; Vaag, Allan

    2014-06-01

    The association between low birthweight (LBW) and risk of developing type 2 diabetes may involve epigenetic mechanisms, with skeletal muscle being a prime target tissue. Differential DNA methylation patterns have been observed in single genes in muscle tissue from type 2 diabetic and LBW individuals, and we recently showed multiple DNA methylation changes during short-term high-fat overfeeding in muscle of healthy people. In a randomised crossover study, we analysed genome-wide DNA promoter methylation in skeletal muscle of 17 young LBW men and 23 matched normal birthweight (NBW) men after a control and a 5 day high-fat overfeeding diet. DNA methylation was measured using Illumina's Infinium BeadArray covering 27,578 CpG sites representing 14,475 different genes. After correction for multiple comparisons, DNA methylation levels were found to be similar in the LBW and NBW groups during the control diet. Whereas widespread DNA methylation changes were observed in the NBW group in response to high-fat overfeeding, only a few methylation changes were seen in the LBW group (χ(2), p muscle from LBW vs NBW men, potentially contributing to understanding the link between LBW and increased risk of type 2 diabetes.

  8. Genome-wide mapping of hot spots of DNA double-strand breaks in human cells as a tool for epigenetic studies and cancer genomics

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    N.A. Tchurikov

    2015-09-01

    Full Text Available Hot spots of DNA double-strand breaks (DSBs are associated with coordinated expression of genes in chromosomal domains (Tchurikov et al., 2011 [1]; 2013. These 50–150-kb DNA domains (denoted “forum domains” can be visualized by separation of undigested chromosomal DNA in pulsed-field agarose gels (Tchurikov et al., 1988; 1992 and used for genome-wide mapping of the DSBs that produce them. Recently, we described nine hot spots of DSBs in human rDNA genes and observed that, in rDNA units, the hot spots coincide with CTCF binding sites and H3K4me3 marks (Tchurikov et al., 2014, suggesting a role for DSBs in active transcription. Here we have used Illumina sequencing to map DSBs in chromosomes of human HEK293T cells, and describe in detail the experimental design and bioinformatics analysis of the data deposited in the Gene Expression Omnibus with accession number GSE53811 and associated with the study published in DNA Research (Kravatsky et al., 2015. Our data indicate that H3K4me3 marks often coincide with hot spots of DSBs in HEK293T cells and that the mapping of these hot spots is important for cancer genomic studies.

  9. Comparison of gene expression and genome-wide DNA methylation profiling between phenotypically normal cloned pigs and conventionally bred controls

    DEFF Research Database (Denmark)

    Fei, Gao; Luo, Yonglun; Li, Shengting

    2011-01-01

    Animal breeding via Somatic Cell Nuclear Transfer (SCNT) has enormous potential in agriculture and biomedicine. However, concerns about whether SCNT animals are as healthy or epigenetically normal as conventionally bred ones are raised as the efficiency of cloning by SCNT is much lower than natural...... breeding or In-vitro fertilization (IVF). Thus, we have conducted a genome-wide gene expression and DNA methylation profiling between phenotypically normal cloned pigs and control pigs in two tissues (muscle and liver), using Affymetrix Porcine expression array as well as modified methylation......-specific digital karyotyping (MMSDK) and Solexa sequencing technology. Typical tissue-specific differences with respect to both gene expression and DNA methylation were observed in muscle and liver from cloned as well as control pigs. Gene expression profiles were highly similar between cloned pigs and controls...

  10. Genome-wide analysis of the DNA-binding with one zinc finger (Dof) transcription factor family in bananas.

    Science.gov (United States)

    Dong, Chen; Hu, Huigang; Xie, Jianghui

    2016-12-01

    DNA-binding with one finger (Dof) domain proteins are a multigene family of plant-specific transcription factors involved in numerous aspects of plant growth and development. In this study, we report a genome-wide search for Musa acuminata Dof (MaDof) genes and their expression profiles at different developmental stages and in response to various abiotic stresses. In addition, a complete overview of the Dof gene family in bananas is presented, including the gene structures, chromosomal locations, cis-regulatory elements, conserved protein domains, and phylogenetic inferences. Based on the genome-wide analysis, we identified 74 full-length protein-coding MaDof genes unevenly distributed on 11 chromosomes. Phylogenetic analysis with Dof members from diverse plant species showed that MaDof genes can be classified into four subgroups (StDof I, II, III, and IV). The detailed genomic information of the MaDof gene homologs in the present study provides opportunities for functional analyses to unravel the exact role of the genes in plant growth and development.

  11. Genome-wide analysis in human colorectal cancer cells reveals ischemia-mediated expression of motility genes via DNA hypomethylation.

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    Karolina Skowronski

    Full Text Available DNA hypomethylation is an important epigenetic modification found to occur in many different cancer types, leading to the upregulation of previously silenced genes and loss of genomic stability. We previously demonstrated that hypoxia and hypoglycaemia (ischemia, two common micro-environmental changes in solid tumours, decrease DNA methylation through the downregulation of DNMTs in human colorectal cancer cells. Here, we utilized a genome-wide cross-platform approach to identify genes hypomethylated and upregulated by ischemia. Following exposure to hypoxia or hypoglycaemia, methylated DNA from human colorectal cancer cells (HCT116 was immunoprecipitated and analysed with an Affymetrix promoter array. Additionally, RNA was isolated and analysed in parallel with an Affymetrix expression array. Ingenuity pathway analysis software revealed that a significant proportion of the genes hypomethylated and upregulated were involved in cellular movement, including PLAUR and CYR61. A Matrigel invasion assay revealed that indeed HCT116 cells grown in hypoxic or hypoglycaemic conditions have increased mobility capabilities. Confirmation of upregulated expression of cellular movement genes was performed with qPCR. The correlation between ischemia and metastasis is well established in cancer progression, but the molecular mechanisms responsible for this common observation have not been clearly identified. Our novel data suggests that hypoxia and hypoglycaemia may be driving changes in DNA methylation through downregulation of DNMTs. This is the first report to our knowledge that provides an explanation for the increased metastatic potential seen in ischemic cells; i.e. that ischemia could be driving DNA hypomethylation and increasing expression of cellular movement genes.

  12. Genome-wide analysis of tandem repeats in Tribolium castaneum genome reveals abundant and highly dynamic tandem repeat families with satellite DNA features in euchromatic chromosomal arms.

    Science.gov (United States)

    Pavlek, Martina; Gelfand, Yevgeniy; Plohl, Miroslav; Meštrović, Nevenka

    2015-12-01

    Although satellite DNAs are well-explored components of heterochromatin and centromeres, little is known about emergence, dispersal and possible impact of comparably structured tandem repeats (TRs) on the genome-wide scale. Our bioinformatics analysis of assembled Tribolium castaneum genome disclosed significant contribution of TRs in euchromatic chromosomal arms and clear predominance of satellite DNA-typical 170 bp monomers in arrays of ≥5 repeats. By applying different experimental approaches, we revealed that the nine most prominent TR families Cast1-Cast9 extracted from the assembly comprise ∼4.3% of the entire genome and reside almost exclusively in euchromatic regions. Among them, seven families that build ∼3.9% of the genome are based on ∼170 and ∼340 bp long monomers. Results of phylogenetic analyses of 2500 monomers originating from these families show high-sequence dynamics, evident by extensive exchanges between arrays on non-homologous chromosomes. In addition, our analysis shows that concerted evolution acts more efficiently on longer than on shorter arrays. Efficient genome-wide distribution of nine TR families implies the role of transposition only in expansion of the most dispersed family, and involvement of other mechanisms is anticipated. Despite similarities in sequence features, FISH experiments indicate high-level compartmentalization of centromeric and euchromatic tandem repeats.

  13. Characterisation of QTL-linked and genome-wide restriction site-associated DNA (RAD markers in farmed Atlantic salmon

    Directory of Open Access Journals (Sweden)

    Houston Ross D

    2012-06-01

    Full Text Available Abstract Background Restriction site-associated DNA sequencing (RAD-Seq is a genome complexity reduction technique that facilitates large-scale marker discovery and genotyping by sequencing. Recent applications of RAD-Seq have included linkage and QTL mapping with a particular focus on non-model species. In the current study, we have applied RAD-Seq to two Atlantic salmon families from a commercial breeding program. The offspring from these families were classified into resistant or susceptible based on survival/mortality in an Infectious Pancreatic Necrosis (IPN challenge experiment, and putative homozygous resistant or susceptible genotype at a major IPN-resistance QTL. From each family, the genomic DNA of the two heterozygous parents and seven offspring of each IPN phenotype and genotype was digested with the SbfI enzyme and sequenced in multiplexed pools. Results Sequence was obtained from approximately 70,000 RAD loci in both families and a filtered set of 6,712 segregating SNPs were identified. Analyses of genome-wide RAD marker segregation patterns in the two families suggested SNP discovery on all 29 Atlantic salmon chromosome pairs, and highlighted the dearth of male recombination. The use of pedigreed samples allowed us to distinguish segregating SNPs from putative paralogous sequence variants resulting from the relatively recent genome duplication of salmonid species. Of the segregating SNPs, 50 were linked to the QTL. A subset of these QTL-linked SNPs were converted to a high-throughput assay and genotyped across large commercial populations of IPNV-challenged salmon fry. Several SNPs showed highly significant linkage and association with resistance to IPN, and population linkage-disequilibrium-based SNP tests for resistance were identified. Conclusions We used RAD-Seq to successfully identify and characterise high-density genetic markers in pedigreed aquaculture Atlantic salmon. These results underline the effectiveness of RAD

  14. Chicken spermatogenesis is accompanied by a genomic-wide loss of DNA methylation.

    Science.gov (United States)

    Rocamora, N; Mezquita, C

    1989-04-24

    Renaturation kinetics of DNA obtained from chicken testis cell nuclei separated by sedimentation at unit gravity showed that the undermethylation, previously observed in meiotic and postmeiotic cells, is not a peculiarity of repetitive sequences, but is also a feature of unique sequences. The large proportion of slowly renaturing, intermediately renaturing and rapidly renaturing DNAs contain 27, 32 and 31% less methylcytosines in meiotic and postmeiotic cells than the corresponding fractions of premeiotic cells. DNA methyltransferase activity is lower in meiotic cells containing undermethylated DNA than in immature testis, enriched in spermatogonia, with higher levels of DNA methylation.

  15. Genome-wide DNA methylation analysis identifies hypomethylated genes regulated by FOXP3 in human regulatory T cells.

    Science.gov (United States)

    Zhang, Yuxia; Maksimovic, Jovana; Naselli, Gaetano; Qian, Junyan; Chopin, Michael; Blewitt, Marnie E; Oshlack, Alicia; Harrison, Leonard C

    2013-10-17

    Regulatory T cells (Treg) prevent the emergence of autoimmune disease. Prototypic natural Treg (nTreg) can be reliably identified by demethylation at the Forkhead-box P3 (FOXP3) locus. To explore the methylation landscape of nTreg, we analyzed genome-wide methylation in human naive nTreg (rTreg) and conventional naive CD4(+) T cells (Naive). We detected 2315 differentially methylated cytosine-guanosine dinucleotides (CpGs) between these 2 cell types, many of which clustered into 127 regions of differential methylation (RDMs). Activation changed the methylation status of 466 CpGs and 18 RDMs in Naive but did not alter DNA methylation in rTreg. Gene-set testing of the 127 RDMs showed that promoter methylation and gene expression were reciprocally related. RDMs were enriched for putative FOXP3-binding motifs. Moreover, CpGs within known FOXP3-binding regions in the genome were hypomethylated. In support of the view that methylation limits access of FOXP3 to its DNA targets, we showed that increased expression of the immune suppressive receptor T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), which delineated Treg from activated effector T cells, was associated with hypomethylation and FOXP3 binding at the TIGIT locus. Differential methylation analysis provides insight into previously undefined human Treg signature genes and their mode of regulation.

  16. DNA Methylation in Newborns and Maternal Smoking in Pregnancy : Genome-wide Consortium Meta-analysis

    NARCIS (Netherlands)

    Joubert, Bonnie R; Felix, Janine F; Yousefi, Paul; Bakulski, Kelly M; Just, Allan C; Breton, Carrie; Reese, Sarah E; Markunas, Christina A; Richmond, Rebecca C; Xu, Cheng-Jian; Küpers, Leanne K; Oh, Sam S; Hoyo, Cathrine; Gruzieva, Olena; Söderhäll, Cilla; Salas, Lucas A; Baïz, Nour; Zhang, Hongmei; Lepeule, Johanna; Ruiz, Carlos; Ligthart, Symen; Wang, Tianyuan; Taylor, Jack A; Duijts, Liesbeth; Sharp, Gemma C; Jankipersadsing, Soesma A; Nilsen, Roy M; Vaez, Ahmad; Fallin, M Daniele; Hu, Donglei; Litonjua, Augusto A; Fuemmeler, Bernard F; Huen, Karen; Kere, Juha; Kull, Inger; Munthe-Kaas, Monica Cheng; Gehring, Ulrike|info:eu-repo/dai/nl/304831344; Bustamante, Mariona; Saurel-Coubizolles, Marie José; Quraishi, Bilal M; Ren, Jie; Tost, Jörg; Gonzalez, Juan R; Peters, Marjolein J; Håberg, Siri E; Xu, Zongli; van Meurs, Joyce B; Gaunt, Tom R; Kerkhof, Marjan; Corpeleijn, Eva; Feinberg, Andrew P; Eng, Celeste; Baccarelli, Andrea A; Benjamin Neelon, Sara E; Bradman, Asa; Merid, Simon Kebede; Bergström, Anna; Herceg, Zdenko; Hernandez-Vargas, Hector; Brunekreef, Bert|info:eu-repo/dai/nl/067548180; Pinart, Mariona; Heude, Barbara; Ewart, Susan; Yao, Jin; Lemonnier, Nathanaël; Franco, Oscar H; Wu, Michael C; Hofman, Albert; McArdle, Wendy; Van der Vlies, Pieter; Falahi, Fahimeh; Gillman, Matthew W; Barcellos, Lisa F; Kumar, Ashish; Wickman, Magnus; Guerra, Stefano; Charles, Marie-Aline; Holloway, John; Auffray, Charles; Tiemeier, Henning W; Smith, George Davey; Postma, Dirkje; Hivert, Marie-France; Eskenazi, Brenda; Vrijheid, Martine; Arshad, Hasan; Antó, Josep M; Dehghan, Abbas; Karmaus, Wilfried; Annesi-Maesano, Isabella; Sunyer, Jordi; Ghantous, Akram; Pershagen, Göran; Holland, Nina; Murphy, Susan K; DeMeo, Dawn L; Burchard, Esteban G; Ladd-Acosta, Christine; Snieder, Harold; Nystad, Wenche; Koppelman, Gerard H; Relton, Caroline L; Jaddoe, Vincent W V; Wilcox, Allen; Melén, Erik; London, Stephanie J

    2016-01-01

    Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The

  17. Genome-wide DNA methylation analysis identifies a metabolic memory profile in patient-derived diabetic foot ulcer fibroblasts.

    Science.gov (United States)

    Park, Lara K; Maione, Anna G; Smith, Avi; Gerami-Naini, Behzad; Iyer, Lakshmanan K; Mooney, David J; Veves, Aristidis; Garlick, Jonathan A

    2014-10-01

    Diabetic foot ulcers (DFUs) are a serious complication of diabetes. Previous exposure to hyperglycemic conditions accelerates a decline in cellular function through metabolic memory despite normalization of glycemic control. Persistent, hyperglycemia-induced epigenetic patterns are considered a central mechanism that activates metabolic memory; however, this has not been investigated in patient-derived fibroblasts from DFUs. We generated a cohort of patient-derived lines from DFU fibroblasts (DFUF), and site- and age-matched diabetic foot fibroblasts (DFF) and non-diabetic foot fibroblasts (NFF) to investigate global and genome-wide DNA methylation patterns using liquid chromatography/mass spectrometry and the Illumina Infinium HumanMethylation450K array. DFFs and DFUFs demonstrated significantly lower global DNA methylation compared to NFFs (p = 0.03). Hierarchical clustering of differentially methylated probes (DMPs, p = 0.05) showed that DFFs and DFUFs cluster together and separately from NFFs. Twenty-five percent of the same probes were identified as DMPs when individually comparing DFF and DFUF to NFF. Functional annotation identified enrichment of DMPs associated with genes critical to wound repair, including angiogenesis (p = 0.07) and extracellular matrix assembly (p = 0.035). Identification of sustained DNA methylation patterns in patient-derived fibroblasts after prolonged passage in normoglycemic conditions demonstrates persistent metabolic memory. These findings suggest that epigenetic-related metabolic memory may also underlie differences in wound healing phenotypes and can potentially identify therapeutic targets.

  18. Genetic variations related to maternal whole blood mitochondrial DNA copy number: a genome-wide and candidate gene study.

    Science.gov (United States)

    Workalemahu, Tsegaselassie; Enquobahrie, Daniel A; Tadesse, Mahlet G; Hevner, Karin; Gelaye, Bizu; Sanchez, Sixto E; Williams, Michelle A

    2017-10-01

    We conducted genome-wide (GWAS) and candidate gene association studies of maternal mitochondrial DNA copy number. Maternal peripheral blood was collected during labor and delivery admission from 471 participants of a placental abruption case-control study conducted in Lima, Peru. Single nucleotide polymorphism (SNP) genotyping was performed using the Illumina Cardio-Metabo Chip. Whole blood mitochondrial DNA (mtDNA) copy number was measured using qRT-PCR techniques. We evaluated 119,629 SNPs in the GWAS and 161 SNPs (in 29 mitochondrial biogenesis and oxidative phosphorylation genes) in the candidate association study. Top hits from GWAS and the candidate gene study were selected to compute weighted genetic risk scores (wGRS). Linear regression models were used to calculate effect size estimates and related nominal p values. The top hit in our GWAS was chr19:51063065 in FOXA3 (empirical p values = 2.20e - 6). A total of 134 SNPs had p values copy number (p values copy number was significantly associated with wGRS based on top GWAS hits (β = 0.49, 95% CI:0.38-0.60, p copy number.

  19. Noninvasive detection of cancer-associated genome-wide hypomethylation and copy number aberrations by plasma DNA bisulfite sequencing

    Science.gov (United States)

    Chan, K. C. Allen; Jiang, Peiyong; Chan, Carol W. M.; Sun, Kun; Wong, John; Hui, Edwin P.; Chan, Stephen L.; Chan, Wing Cheong; Hui, David S. C.; Ng, Simon S. M.; Chan, Henry L. Y.; Wong, Cesar S. C.; Ma, Brigette B. Y.; Chan, Anthony T. C.; Lai, Paul B. S.; Sun, Hao; Chiu, Rossa W. K.; Lo, Y. M. Dennis

    2013-01-01

    We explored the detection of genome-wide hypomethylation in plasma using shotgun massively parallel bisulfite sequencing as a marker for cancer. Tumor-associated copy number aberrations (CNAs) could also be observed from the bisulfite DNA sequencing data. Hypomethylation and CNAs were detected in the plasma DNA of patients with hepatocellular carcinoma, breast cancer, lung cancer, nasopharyngeal cancer, smooth muscle sarcoma, and neuroendocrine tumor. For the detection of nonmetastatic cancer cases, plasma hypomethylation gave a sensitivity and specificity of 74% and 94%, respectively, when a mean of 93 million reads per case were obtained. Reducing the sequencing depth to 10 million reads per case was found to have no adverse effect on the sensitivity and specificity for cancer detection, giving respective figures of 68% and 94%. This characteristic thus indicates that analysis of plasma hypomethylation by this sequencing-based method may be a relatively cost-effective approach for cancer detection. We also demonstrated that plasma hypomethylation had utility for monitoring hepatocellular carcinoma patients following tumor resection and for detecting residual disease. Plasma hypomethylation can be combined with plasma CNA analysis for further enhancement of the detection sensitivity or specificity using different diagnostic algorithms. Using the detection of at least one type of aberration to define an abnormality, a sensitivity of 87% could be achieved with a specificity of 88%. These developments have thus expanded the applications of plasma DNA analysis for cancer detection and monitoring. PMID:24191000

  20. Genome-wide DNA methylation analysis reveals a potential mechanism for the pathogenesis and development of uterine leiomyomas.

    Directory of Open Access Journals (Sweden)

    Ryo Maekawa

    Full Text Available BACKGROUND: The pathogenesis of uterine leiomyomas, the most common benign tumor in women, remains unclear. Since acquired factors such as obesity, hypertension and early menarche place women at greater risk for uterine leiomyomas, uterine leiomyomas may be associated with epigenetic abnormalities that are caused by unfavorable environmental exposures. PRINCIPAL FINDINGS: Profiles of genome-wide DNA methylation and mRNA expression were investigated in leiomyomas and in myometrium with and without leiomyomas. Profiles of DNA methylation and mRNA expression in the myometrium with and without leiomyomas were quite similar while those in leiomyomas were distinct. We identified 120 genes whose DNA methylation and mRNA expression patterns differed between leiomyomas and the adjacent myometrium. The biological relevance of the aberrantly methylated and expressed genes was cancer process, including IRS1 that is related to transformation, and collagen-related genes such as COL4A1, COL4A2 and COL6A3. We also detected 22 target genes of estrogen receptor (ER alpha, including apoptosis-related genes, that have aberrant DNA methylation in the promoter, suggesting that the aberrant epigenetic regulation of ER alpha-target genes contributes to the aberrant response to estrogen. CONCLUSIONS: Aberrant DNA methylation and its related transcriptional aberration were associated with cancer processes, which may represent a critical initial mechanism that triggers transformation of a single tumor stem cell that will eventually develop into a monoclonal leiomyoma tumor. The aberrant epigenetic regulation of ER alpha-target genes also may contribute to the aberrant response to estrogen, which is involved in the development of uterine leiomyomas after menarche.

  1. A comparison of genome-wide DNA methylation patterns between different vascular tissues from patients with coronary heart disease.

    Science.gov (United States)

    Nazarenko, Maria S; Markov, Anton V; Lebedev, Igor N; Freidin, Maxim B; Sleptcov, Aleksei A; Koroleva, Iuliya A; Frolov, Aleksei V; Popov, Vadim A; Barbarash, Olga L; Puzyrev, Valery P

    2015-01-01

    Epigenetic mechanisms of gene regulation in context of cardiovascular diseases are of considerable interest. So far, our current knowledge of the DNA methylation profiles for atherosclerosis affected and healthy human vascular tissues is still limited. Using the Illumina Infinium Human Methylation27 BeadChip, we performed a genome-wide analysis of DNA methylation in right coronary artery in the area of advanced atherosclerotic plaques, atherosclerotic-resistant internal mammary arteries, and great saphenous veins obtained from same patients with coronary heart disease. The resulting DNA methylation patterns were markedly different between all the vascular tissues. The genes hypomethylated in athero-prone arteries to compare with atherosclerotic-resistant arteries were predominately involved in regulation of inflammation and immune processes, as well as development. The great saphenous veins exhibited an increase of the DNA methylation age in comparison to the internal mammary arteries. Gene ontology analysis for genes harboring hypermethylated CpG-sites in veins revealed the enrichment for biological processes associated with the development. Four CpG-sites located within the MIR10B gene sequence and about 1 kb upstream of the HOXD4 gene were also confirmed as hypomethylated in the independent dataset of the right coronary arteries in the area of advanced atherosclerotic plaques in comparison with the other vascular tissues. The DNA methylation differences observed in vascular tissues of patients with coronary heart disease can provide new insights into the mechanisms underlying the development of pathology and explanation for the difference in graft patency after coronary artery bypass grafting surgery.

  2. A comparison of genome-wide DNA methylation patterns between different vascular tissues from patients with coronary heart disease.

    Directory of Open Access Journals (Sweden)

    Maria S Nazarenko

    Full Text Available Epigenetic mechanisms of gene regulation in context of cardiovascular diseases are of considerable interest. So far, our current knowledge of the DNA methylation profiles for atherosclerosis affected and healthy human vascular tissues is still limited. Using the Illumina Infinium Human Methylation27 BeadChip, we performed a genome-wide analysis of DNA methylation in right coronary artery in the area of advanced atherosclerotic plaques, atherosclerotic-resistant internal mammary arteries, and great saphenous veins obtained from same patients with coronary heart disease. The resulting DNA methylation patterns were markedly different between all the vascular tissues. The genes hypomethylated in athero-prone arteries to compare with atherosclerotic-resistant arteries were predominately involved in regulation of inflammation and immune processes, as well as development. The great saphenous veins exhibited an increase of the DNA methylation age in comparison to the internal mammary arteries. Gene ontology analysis for genes harboring hypermethylated CpG-sites in veins revealed the enrichment for biological processes associated with the development. Four CpG-sites located within the MIR10B gene sequence and about 1 kb upstream of the HOXD4 gene were also confirmed as hypomethylated in the independent dataset of the right coronary arteries in the area of advanced atherosclerotic plaques in comparison with the other vascular tissues. The DNA methylation differences observed in vascular tissues of patients with coronary heart disease can provide new insights into the mechanisms underlying the development of pathology and explanation for the difference in graft patency after coronary artery bypass grafting surgery.

  3. Genome-Wide Targets Regulated by the OsMADS1 Transcription Factor Reveals Its DNA Recognition Properties1[OPEN

    Science.gov (United States)

    Khanday, Imtiyaz; Das, Sanjukta; Chongloi, Grace L; Vijayraghavan, Usha

    2016-01-01

    OsMADS1 controls rice (Oryza sativa) floral fate and organ development. Yet, its genome-wide targets and the mechanisms underlying its role as a transcription regulator controlling developmental gene expression are unknown. We identify 3112 gene-associated OsMADS1-bound sites in the floret genome. These occur in the vicinity of transcription start sites, within gene bodies, and in intergenic regions. Majority of the bound DNA contained CArG motif variants or, in several cases, only A-tracts. Sequences flanking the binding peak had a higher AT nucleotide content, implying that broader DNA structural features may define in planta binding. Sequences for binding by other transcription factor families like MYC, AP2/ERF, bZIP, etc. are enriched in OsMADS1-bound DNAs. Target genes implicated in transcription, chromatin remodeling, cellular processes, and hormone metabolism were enriched. Combining expression data from OsMADS1 knockdown florets with these DNA binding data, a snapshot of a gene regulatory network was deduced where targets, such as AP2/ERF and bHLH transcription factors and chromatin remodelers form nodes. We show that the expression status of these nodal factors can be altered by inducing the OsMADS1-GR fusion protein and present a model for a regulatory cascade where the direct targets of OsMADS1, OsbHLH108/SPT, OsERF034, and OsHSF24, in turn control genes such as OsMADS32 and OsYABBY5. This cascade, with other similar relationships, cumulatively contributes to floral organ development. Overall, OsMADS1 binds to several regulatory genes and, probably in combination with other factors, controls a gene regulatory network that ensures rice floret development. PMID:27457124

  4. Genome-wide tracking of unmethylated DNA Alu repeats in normal and cancer cells

    DEFF Research Database (Denmark)

    Rodriguez, Jairo; Vives, Laura; Jordà, Mireia

    2008-01-01

    . Demethylation of Alu elements occurs in aging and cancer processes and has been associated with gene reactivation and genomic instability. By targeting the unmethylated SmaI site within the Alu sequence as a surrogate marker, we have quantified and identified unmethylated Alu elements on the genomic scale...... the highest prevalence of the SmaI site (AluY: 42%; AluS: 18%, AluJ: 5%) but the lower rates of unmethylation (AluY: 1.65%; AluS: 3.1%, AluJ: 12%). Data are consistent with a stronger silencing pressure on the youngest repetitive elements, which are closer to genes. Further insights into the functional...

  5. DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis

    NARCIS (Netherlands)

    B.R. Joubert (Bonnie); J.F. Felix (Janine); P. Yousefi (Paul); K.M. Bakulski (Kelly M.); A.C. Just (Allan C.); C. Breton (Carrie); S.E. Reese (Sarah E.); C.A. Markunas (Christina A.); R.C. Richmond (Rebecca C.); C.-J. Xu (Cheng-Jian); L.K. Küpers (Leanne); S.S. Oh (Sam S.); C. Hoyo (Cathrine); O. Gruzieva (Olena); C. Söderhäll (Cilla); L.A. Salas (Lucas A.); N. Baïz (Nour); H. Zhang (Hongmei); J. Lepeule (Johanna); C. Ruiz (Carlos); S. Ligthart (Symen); T. Wang (Tianyuan); J.A. Taylor (Jack A.); L. Duijts (Liesbeth); G.C. Sharp (Gemma C.); S.A. Jankipersadsing (Soesma A.); R.M. Nilsen (Roy M.); A. Vaez (Ahmad); M.D. Fallin (M. Daniele); D. Hu (Donglei); A. Litonjua (Augusto); B.F. Fuemmeler (Bernard F.); K. Huen (Karen); J. Kere (Juha); C.A. Kull (Christian); M.C. Munthe-Kaas (Monica Cheng); U. Gehring (Ulrike); M. Bustamante (Mariona); M.J. Saurel-Coubizolles (Marie José); B.M. Quraishi (Bilal M.); J. Ren (Jie); J. Tost (Jörg); J.R. Gonzalez (Juan R.); M.J. Peters (Marjolein); S.E. Håberg (Siri E); Z. Xu (Zongli); J.B.J. van Meurs (Joyce); T.R. Gaunt (Tom); M. Kerkhof (Marjan); W.E. Corpeleijn (Willemijn); A.P. Feinberg (Andrew P.); C. Eng (Celeste); A.A. Baccarelli (Andrea A.); S.E. Benjamin Neelon (Sara E.); A. Bradman (Asa); S.K. Merid (Simon Kebede); A. Bergström (Anna); Z. Herceg (Zdenko); H. Hernandez-Vargas (Hector); B. Brunekreef (Bert); M. Pinart (Mariona); B. Heude (Barbara); S. Ewart (Susan); J. Yao (Jin); N. Lemonnier (Nathanaël); O.H. Franco (Oscar); M.C. Wu (Michael C.); A. Hofman (Albert); W.L. McArdle (Wendy); P. van der Vlies (P.); F. Falahi (Fahimeh); M.W. Gillman (Matthew W.); L.F. Barcellos (Lisa); A. Kumar (Ashish); M. Wickman (Magnus); S. Guerra (S.); M.-A. Charles (Marie-Aline); J. Holloway (John); C. Auffray (C.); H.W. Tiemeier (Henning); G.D. Smith; D.S. Postma (Dirkje); M.-F. Hivert (Marie-France); B. Eskenazi (Brenda); M. Vrijheid (Martine); H. Arshad (Hasan); J.M. Antó (Josep M.); A. Dehghan (Abbas); W. Karmaus (Wilfried); I. Annesi-Maesano; J. Sunyer (Jordi); A. Ghantous (Akram); G. Pershagen (Göran); N. Holland (Nina); S.K. Murphy (Susan K.); D.L. Demeo (Dawn L.); E.G. Burchard (Esteban); C. Ladd-Acosta (Christine); H. Snieder (Harold); W. Nystad (Wenche); G.H. Koppelman (Gerard); C.L. Relton (Caroline); V.W.V. Jaddoe (Vincent W. V.); A.J. Wilcox (Allen); E. Melén (Erik); S.J. London (Stephanie J.)

    2016-01-01

    textabstractEpigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences.

  6. Genome-wide analysis of ETS-family DNA-binding in vitro and in vivo

    Science.gov (United States)

    Wei, Gong-Hong; Badis, Gwenael; Berger, Michael F; Kivioja, Teemu; Palin, Kimmo; Enge, Martin; Bonke, Martin; Jolma, Arttu; Varjosalo, Markku; Gehrke, Andrew R; Yan, Jian; Talukder, Shaheynoor; Turunen, Mikko; Taipale, Mikko; Stunnenberg, Hendrik G; Ukkonen, Esko; Hughes, Timothy R; Bulyk, Martha L; Taipale, Jussi

    2010-01-01

    Members of the large ETS family of transcription factors (TFs) have highly similar DNA-binding domains (DBDs)—yet they have diverse functions and activities in physiology and oncogenesis. Some differences in DNA-binding preferences within this family have been described, but they have not been analysed systematically, and their contributions to targeting remain largely uncharacterized. We report here the DNA-binding profiles for all human and mouse ETS factors, which we generated using two different methods: a high-throughput microwell-based TF DNA-binding specificity assay, and protein-binding microarrays (PBMs). Both approaches reveal that the ETS-binding profiles cluster into four distinct classes, and that all ETS factors linked to cancer, ERG, ETV1, ETV4 and FLI1, fall into just one of these classes. We identify amino-acid residues that are critical for the differences in specificity between all the classes, and confirm the specificities in vivo using chromatin immunoprecipitation followed by sequencing (ChIP-seq) for a member of each class. The results indicate that even relatively small differences in in vitro binding specificity of a TF contribute to site selectivity in vivo. PMID:20517297

  7. Molecular Profiling of Non-small Cell Lung Carcinomas : A Genome-wide DNA Methylation Analysis

    NARCIS (Netherlands)

    R. Hughes Carvalho (Rejane)

    2012-01-01

    textabstractDNA methylation is a signaling marker used by the cell to control gene expression, to keep genes silenced or active. It is an important part of what is called epigenetic controlling mechanisms (epi- Greek: επί- over, above, outer). We are just beginning to understand the intricate proces

  8. Genome-wide DNA methylation profiling of non-small cell lung carcinomas

    NARCIS (Netherlands)

    R.H. Carvalho (Rejane Hughes); V. Haberle (Vanja); J. Hou (Jun); T. van Gent (Teus); S. Thongjuea (Supat); W.F.J. van IJcken (Wilfred); C. Kockx (Christel); R.W.W. Brouwer (Rutger); E.J. Rijkers; A.M. Sieuwerts (Anieta); J.A. Foekens (John); M. van Vroonhoven (Mirjam); J.G.J.V. Aerts (Joachim); F.G. Grosveld (Frank); B. Lenhard (Boris); J.N.J. Philipsen (Sjaak)

    2012-01-01

    textabstractBackground: Non-small cell lung carcinoma (NSCLC) is a complex malignancy that owing to its heterogeneity and poor prognosis poses many challenges to diagnosis, prognosis and patient treatment. DNA methylation is an important mechanism of epigenetic regulation involved in normal developm

  9. DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis

    NARCIS (Netherlands)

    B.R. Joubert (Bonnie); J.F. Felix (Janine); P. Yousefi (Paul); K.M. Bakulski (Kelly M.); A.C. Just (Allan C.); C. Breton (Carrie); S.E. Reese (Sarah E.); C.A. Markunas (Christina A.); R.C. Richmond (Rebecca C.); C.-J. Xu (Cheng-Jian); L.K. Küpers (Leanne); S.S. Oh (Sam S.); C. Hoyo (Cathrine); O. Gruzieva (Olena); C. Söderhäll (Cilla); L.A. Salas (Lucas A.); N. Baïz (Nour); H. Zhang (Hongmei); J. Lepeule (Johanna); C. Ruiz (Carlos); S. Ligthart (Symen); T. Wang (Tianyuan); J.A. Taylor (Jack A.); L. Duijts (Liesbeth); G.C. Sharp (Gemma C.); S.A. Jankipersadsing (Soesma A.); R.M. Nilsen (Roy M.); A. Vaez (Ahmad); M.D. Fallin (M. Daniele); D. Hu (Donglei); A. Litonjua (Augusto); B.F. Fuemmeler (Bernard F.); K. Huen (Karen); J. Kere (Juha); C.A. Kull (Christian); M.C. Munthe-Kaas (Monica Cheng); U. Gehring (Ulrike); M. Bustamante (Mariona); M.J. Saurel-Coubizolles (Marie José); B.M. Quraishi (Bilal M.); J. Ren (Jie); J. Tost (Jörg); J.R. Gonzalez (Juan R.); M.J. Peters (Marjolein); S.E. Håberg (Siri E); Z. Xu (Zongli); J.B.J. van Meurs (Joyce); T.R. Gaunt (Tom); M. Kerkhof (Marjan); W.E. Corpeleijn (Willemijn); A.P. Feinberg (Andrew P.); C. Eng (Celeste); A.A. Baccarelli (Andrea A.); S.E. Benjamin Neelon (Sara E.); A. Bradman (Asa); S.K. Merid (Simon Kebede); A. Bergström (Anna); Z. Herceg (Zdenko); H. Hernandez-Vargas (Hector); B. Brunekreef (Bert); M. Pinart (Mariona); B. Heude (Barbara); S. Ewart (Susan); J. Yao (Jin); N. Lemonnier (Nathanaël); O.H. Franco (Oscar); M.C. Wu (Michael); A. Hofman (Albert); W.L. McArdle (Wendy); P. van der Vlies (P.); F. Falahi (Fahimeh); M.W. Gillman (Matthew W.); L.F. Barcellos (Lisa); A. Kumar (Ashish); M. Wickman (Magnus); S. Guerra (S.); M.-A. Charles (Marie-Aline); J. Holloway (John); C. Auffray (C.); H.W. Tiemeier (Henning); G.D. Smith; D.S. Postma (Dirkje); M.-F. Hivert (Marie-France); B. Eskenazi (Brenda); M. Vrijheid (Martine); H. Arshad (Hasan); J.M. Antó (Josep M.); A. Dehghan (Abbas); W. Karmaus (Wilfried); I. Annesi-Maesano; J. Sunyer (Jordi); A. Ghantous (Akram); G. Pershagen (Göran); N. Holland (Nina); S.K. Murphy (Susan K.); D.L. Demeo (Dawn L.); E.G. Burchard (Esteban); C. Ladd-Acosta (Christine); H. Snieder (Harold); W. Nystad (Wenche); G.H. Koppelman (Gerard); C.L. Relton (Caroline); V.W.V. Jaddoe (Vincent W. V.); A.J. Wilcox (Allen); E. Melén (Erik); S.J. London (Stephanie J.)

    2016-01-01

    textabstractEpigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences.

  10. DNA Methylation in Newborns and Maternal Smoking in Pregnancy : Genome-wide Consortium Meta-analysis

    NARCIS (Netherlands)

    Joubert, Bonnie R.; Felix, Janine F.; Yousefi, Paul; Bakulski, Kelly M.; Just, Allan C.; Breton, Carrie; Reese, Sarah E.; Markunas, Christina A.; Richmond, Rebecca C.; Xu, Chengjian; Kupers, Leanne K.; Oh, Sam S.; Hoyo, Cathrine; Gruzieva, Olena; Soderhal, Cilla; Salas, Lucas A.; Baiz, Nour; Zhang, Hongmei; Lepeule, Johanna; Ruiz, Carlos; Ligthart, Symen; Wang, Tianyuan; Taylor, Jack A.; Duijts, Liesbeth; Sharp, Gemma C.; Jankipersadsing, Soesma A.; Nilsen, Roy M.; Vaez, Ahmad; Fallin, M. Daniele; Hu, Donglei; Litonjua, Augusto A.; Fuemmeler, Bernard F.; Huen, Karen; Kere, Juha; Kull, Inger; Munthe-Kaas, Monica Cheng; Gehring, Ulrike; Bustamante, Mariona; Saurel-Coubizolles, Marie Jose; Quraishi, Bilal M.; Ren, Jie; Tost, Jorg; Gonzalez, Juan R.; Peters, Marjolein J.; Haberg, Siri E.; Xu, Zongli; van Meurs, Joyce B.; Gaunt, Tom R.; Kerkhof, Marjan; Corpeleijn, Eva; Feinberg, Andrew P.; Eng, Celeste; Baccarelli, Andrea A.; Neelon, Sara E. Benjamin; Bradman, Asa; Merid, Simon Kebede; Bergstrom, Anna; Herceg, Zdenko; Hernandez-Vargas, Hector; Brunekreef, Bert; Pinart, Mariona; Heude, Barbara; Ewart, Susan; Yao, Jin; Lemonnier, Nathanael; Franco, Oscar H.; Wu, Michael C.; Hofman, Albert; McArdle, Wendy; Van der Vlies, Pieter; Falahi, Fahimeh; Gillman, Matthew W.; Barcellos, Lisa F.; Kumar, Ashish; Wickman, Magnus; Guerra, Stefano; Charles, Marie-Aline; Holloway, John; Auffray, Charles; Tiemeier, Henning W.; Smith, George Davey; Postma, Dirkje; Hivert, Marie-France; Eskenazi, Brenda; Vrijheid, Martine; Arshad, Hasan; Anto, Josep M.; Dehghan, Abbas; Karmaus, Wilfried; Annesi-Maesano, Isabella; Sunyer, Jordi; Ghantous, Akram; Pershagen, Goran; Hollands, Nina; Murphy, Susan K.; DeMeo, Dawn L.; Burchard, Esteban G.; Ladd-Acosta, Christine; Snieder, Harold; Nystad, Wenche; Koppelman, Gerard H.; Relton, Caroline L.; Jaddoe, Vincent W. V.; Wilcox, Allen; Melen, Erik; London, Stephanie J.

    2016-01-01

    Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The mechani

  11. Genome-Wide DNA Methylation Profiling Reveals Epigenetic Adaptation of Stickleback to Marine and Freshwater Conditions.

    Science.gov (United States)

    Artemov, Artem V; Mugue, Nikolai S; Rastorguev, Sergey M; Zhenilo, Svetlana; Mazur, Alexander M; Tsygankova, Svetlana V; Boulygina, Eugenia S; Kaplun, Daria; Nedoluzhko, Artem V; Medvedeva, Yulia A; Prokhortchouk, Egor B

    2017-09-01

    The three-spined stickleback (Gasterosteus aculeatus) represents a convenient model to study microevolution-adaptation to a freshwater environment. Although genetic adaptations to freshwater environments are well-studied, epigenetic adaptations have attracted little attention. In this work, we investigated the role of DNA methylation in the adaptation of the marine stickleback population to freshwater conditions. DNA methylation profiling was performed in marine and freshwater populations of sticklebacks, as well as in marine sticklebacks placed into a freshwater environment and freshwater sticklebacks placed into seawater. We showed that the DNA methylation profile after placing a marine stickleback into fresh water partially converged to that of a freshwater stickleback. For six genes including ATP4A ion pump and NELL1, believed to be involved in skeletal ossification, we demonstrated similar changes in DNA methylation in both evolutionary and short-term adaptation. This suggested that an immediate epigenetic response to freshwater conditions can be maintained in freshwater population. Interestingly, we observed enhanced epigenetic plasticity in freshwater sticklebacks that may serve as a compensatory regulatory mechanism for the lack of genetic variation in the freshwater population. For the first time, we demonstrated that genes encoding ion channels KCND3, CACNA1FB, and ATP4A were differentially methylated between the marine and the freshwater populations. Other genes encoding ion channels were previously reported to be under selection in freshwater populations. Nevertheless, the genes that harbor genetic and epigenetic changes were not the same, suggesting that epigenetic adaptation is a complementary mechanism to selection of genetic variants favorable for freshwater environment. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Genome-Wide DNA Copy Number Analysis of Acute Lymphoblastic Leukemia Identifies New Genetic Markers Associated with Clinical Outcome.

    Directory of Open Access Journals (Sweden)

    Maribel Forero-Castro

    Full Text Available Identifying additional genetic alterations associated with poor prognosis in acute lymphoblastic leukemia (ALL is still a challenge.To characterize the presence of additional DNA copy number alterations (CNAs in children and adults with ALL by whole-genome oligonucleotide array (aCGH analysis, and to identify their associations with clinical features and outcome. Array-CGH was carried out in 265 newly diagnosed ALLs (142 children and 123 adults. The NimbleGen CGH 12x135K array (Roche was used to analyze genetic gains and losses. CNAs were analyzed with GISTIC and aCGHweb software. Clinical and biological variables were analyzed. Three of the patients showed chromothripsis (cth6, cth14q and cth15q. CNAs were associated with age, phenotype, genetic subtype and overall survival (OS. In the whole cohort of children, the losses on 14q32.33 (p = 0.019 and 15q13.2 (p = 0.04 were related to shorter OS. In the group of children without good- or poor-risk cytogenetics, the gain on 1p36.11 was a prognostic marker independently associated with shorter OS. In adults, the gains on 19q13.2 (p = 0.001 and Xp21.1 (p = 0.029, and the loss of 17p (p = 0.014 were independent markers of poor prognosis with respect to OS. In summary, CNAs are frequent in ALL and are associated with clinical parameters and survival. Genome-wide DNA copy number analysis allows the identification of genetic markers that predict clinical outcome, suggesting that detection of these genetic lesions will be useful in the management of patients newly diagnosed with ALL.

  13. Estimates of array and pool-construction variance for planning efficient DNA-pooling genome wide association studies

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    Earp Madalene A

    2011-11-01

    Full Text Available Abstract Background Until recently, genome-wide association studies (GWAS have been restricted to research groups with the budget necessary to genotype hundreds, if not thousands, of samples. Replacing individual genotyping with genotyping of DNA pools in Phase I of a GWAS has proven successful, and dramatically altered the financial feasibility of this approach. When conducting a pool-based GWAS, how well SNP allele frequency is estimated from a DNA pool will influence a study's power to detect associations. Here we address how to control the variance in allele frequency estimation when DNAs are pooled, and how to plan and conduct the most efficient well-powered pool-based GWAS. Methods By examining the variation in allele frequency estimation on SNP arrays between and within DNA pools we determine how array variance [var(earray] and pool-construction variance [var(econstruction] contribute to the total variance of allele frequency estimation. This information is useful in deciding whether replicate arrays or replicate pools are most useful in reducing variance. Our analysis is based on 27 DNA pools ranging in size from 74 to 446 individual samples, genotyped on a collective total of 128 Illumina beadarrays: 24 1M-Single, 32 1M-Duo, and 72 660-Quad. Results For all three Illumina SNP array types our estimates of var(earray were similar, between 3-4 × 10-4 for normalized data. Var(econstruction accounted for between 20-40% of pooling variance across 27 pools in normalized data. Conclusions We conclude that relative to var(earray, var(econstruction is of less importance in reducing the variance in allele frequency estimation from DNA pools; however, our data suggests that on average it may be more important than previously thought. We have prepared a simple online tool, PoolingPlanner (available at http://www.kchew.ca/PoolingPlanner/, which calculates the effective sample size (ESS of a DNA pool given a range of replicate array values. ESS can

  14. Genome-wide DNA methylation study in human placenta identifies novel loci associated with maternal smoking during pregnancy.

    Science.gov (United States)

    Morales, Eva; Vilahur, Nadia; Salas, Lucas A; Motta, Valeria; Fernandez, Mariana F; Murcia, Mario; Llop, Sabrina; Tardon, Adonina; Fernandez-Tardon, Guillermo; Santa-Marina, Loreto; Gallastegui, Mara; Bollati, Valentina; Estivill, Xavier; Olea, Nicolas; Sunyer, Jordi; Bustamante, Mariona

    2016-10-01

    We conducted an epigenome-wide association study (EWAS) of DNA methylation in placenta in relation to maternal tobacco smoking during pregnancy and examined whether smoking-induced changes lead to low birthweight. DNA methylation in placenta was measured using the Illumina HumanMethylation450 BeadChip in 179 participants from the INfancia y Medio Ambiente (INMA) birth cohort. Methylation levels across 431 311 CpGs were tested for differential methylation between smokers and non-smokers in pregnancy. We took forward three top-ranking loci for further validation and replication by bisulfite pyrosequencing using data of 248 additional participants of the INMA cohort. We examined the association of methylation at smoking-associated loci with birthweight by applying a mediation analysis and a two-sample Mendelian randomization approach. Fifty CpGs were differentially methylated in placenta between smokers and non-smokers during pregnancy [false discovery rate (FDR) < 0.05]. We validated and replicated differential methylation at three top-ranking loci: cg27402634 located between LINC00086 and LEKR1, a gene previously related to birthweight in genome-wide association studies; cg20340720 (WBP1L); and cg25585967 and cg12294026 (TRIO). Dose-response relationships with maternal urine cotinine concentration during pregnancy were confirmed. Differential methylation at cg27402634 explained up to 36% of the lower birthweight in the offspring of smokers (Sobel P-value < 0.05). A two-sample Mendelian randomization analysis provided evidence that decreases in methylation levels at cg27402634 lead to decreases in birthweight. We identified novel loci differentially methylated in placenta in relation to maternal smoking during pregnancy. Adverse effects of maternal smoking on birthweight of the offspring may be mediated by alterations in the placental methylome. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International

  15. Comparison of the genome-wide DNA methylation profiles between fast-growing and slow-growing broilers.

    Directory of Open Access Journals (Sweden)

    Yongsheng Hu

    Full Text Available INTRODUCTION: Growth traits are important in poultry production, however, little is known for its regulatory mechanism at epigenetic level. Therefore, in this study, we aim to compare DNA methylation profiles between fast- and slow-growing broilers in order to identify candidate genes for chicken growth. Methylated DNA immunoprecipitation-sequencing (MeDIP-seq was used to investigate the genome-wide DNA methylation pattern in high and low tails of Recessive White Rock (WRR(h; WRR(l and that of Xinhua Chickens (XH(h; XH(l at 7 weeks of age. The results showed that the average methylation density was the lowest in CGIs followed by promoters. Within the gene body, the methylation density of introns was higher than that of UTRs and exons. Moreover, different methylation levels were observed in different repeat types with the highest in LINE/CR1. Methylated CGIs were prominently distributed in the intergenic regions and were enriched in the size ranging 200-300 bp. In total 13,294 methylated genes were found in four samples, including 4,085 differentially methylated genes of WRR(h Vs. WRR(l, 5,599 of XH(h Vs. XH(l, 4,204 of WRR(h Vs. XH(h, as well as 7,301 of WRR(l Vs. XH(l. Moreover, 132 differentially methylated genes related to growth and metabolism were observed in both inner contrasts (WRR(h Vs. WRR(l and XH(h Vs. XH(l, whereas 129 differentially methylated genes related to growth and metabolism were found in both across-breed contrasts (WRR(h Vs. XH(h and WRR(l Vs. XH(l. Further analysis showed that overall 75 genes exhibited altered DNA methylation in all four contrasts, which included some well-known growth factors of IGF1R, FGF12, FGF14, FGF18, FGFR2, and FGFR3. In addition, we validate the MeDIP-seq results by bisulfite sequencing in some regions. CONCLUSIONS: This study revealed the global DNA methylation pattern of chicken muscle, and identified candidate genes that potentially regulate muscle development at 7 weeks of age at methylation

  16. Comparison of the Genome-Wide DNA Methylation Profiles between Fast-Growing and Slow-Growing Broilers

    Science.gov (United States)

    Li, Zhenhui; Zheng, Xuejuan; Jia, Xinzheng; Nie, Qinghua; Zhang, Xiquan

    2013-01-01

    Introduction Growth traits are important in poultry production, however, little is known for its regulatory mechanism at epigenetic level. Therefore, in this study, we aim to compare DNA methylation profiles between fast- and slow-growing broilers in order to identify candidate genes for chicken growth. Methylated DNA immunoprecipitation-sequencing (MeDIP-seq) was used to investigate the genome-wide DNA methylation pattern in high and low tails of Recessive White Rock (WRRh; WRRl) and that of Xinhua Chickens (XHh; XHl) at 7 weeks of age. The results showed that the average methylation density was the lowest in CGIs followed by promoters. Within the gene body, the methylation density of introns was higher than that of UTRs and exons. Moreover, different methylation levels were observed in different repeat types with the highest in LINE/CR1. Methylated CGIs were prominently distributed in the intergenic regions and were enriched in the size ranging 200–300 bp. In total 13,294 methylated genes were found in four samples, including 4,085 differentially methylated genes of WRRh Vs. WRRl, 5,599 of XHh Vs. XHl, 4,204 of WRRh Vs. XHh, as well as 7,301 of WRRl Vs. XHl. Moreover, 132 differentially methylated genes related to growth and metabolism were observed in both inner contrasts (WRRh Vs. WRRl and XHh Vs. XHl), whereas 129 differentially methylated genes related to growth and metabolism were found in both across-breed contrasts (WRRh Vs. XHh and WRRl Vs. XHl). Further analysis showed that overall 75 genes exhibited altered DNA methylation in all four contrasts, which included some well-known growth factors of IGF1R, FGF12, FGF14, FGF18, FGFR2, and FGFR3. In addition, we validate the MeDIP-seq results by bisulfite sequencing in some regions. Conclusions This study revealed the global DNA methylation pattern of chicken muscle, and identified candidate genes that potentially regulate muscle development at 7 weeks of age at methylation level. PMID:23441189

  17. Genome-wide analysis of DNA methylation differences in muscle and fat from monozygotic twins discordant for type 2 diabetes.

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    Rasmus Ribel-Madsen

    Full Text Available BACKGROUND: Monozygotic twins discordant for type 2 diabetes constitute an ideal model to study environmental contributions to type 2 diabetic traits. We aimed to examine whether global DNA methylation differences exist in major glucose metabolic tissues from these twins. METHODOLOGY/PRINCIPAL FINDINGS: Skeletal muscle (n = 11 pairs and subcutaneous adipose tissue (n = 5 pairs biopsies were collected from 53-80 year-old monozygotic twin pairs discordant for type 2 diabetes. DNA methylation was measured by microarrays at 26,850 cytosine-guanine dinucleotide (CpG sites in the promoters of 14,279 genes. Bisulfite sequencing was applied to validate array data and to quantify methylation of intergenic repetitive DNA sequences. The overall intra-pair variation in DNA methylation was large in repetitive (LINE1, D4Z4 and NBL2 regions compared to gene promoters (standard deviation of intra-pair differences: 10% points vs. 4% points, P<0.001. Increased variation of LINE1 sequence methylation was associated with more phenotypic dissimilarity measured as body mass index (r = 0.77, P = 0.007 and 2-hour plasma glucose (r = 0.66, P = 0.03 whereas the variation in promoter methylation did not associate with phenotypic differences. Validated methylation changes were identified in the promoters of known type 2 diabetes-related genes, including PPARGC1A in muscle (13.9±6.2% vs. 9.0±4.5%, P = 0.03 and HNF4A in adipose tissue (75.2±3.8% vs. 70.5±3.7%, P<0.001 which had increased methylation in type 2 diabetic individuals. A hypothesis-free genome-wide exploration of differential methylation without correction for multiple testing identified 789 and 1,458 CpG sites in skeletal muscle and adipose tissue, respectively. These methylation changes only reached some percentage points, and few sites passed correction for multiple testing. CONCLUSIONS/SIGNIFICANCE: Our study suggests that likely acquired DNA methylation changes in skeletal muscle or adipose tissue gene

  18. Genome-wide identification and comparative analysis of cytosine-5 DNA methyltransferases and demethylase families in wild and cultivated peanut

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    Pengfei eWang

    2016-02-01

    Full Text Available AbstractDNA methylation plays important roles in genome protection, regulation of gene expression and was associated with plants development. Plant DNA methylation pattern was mediated by cytosine-5 DNA methyltransferases and demethylase. Although the genomes of AA and BB wild peanuts have been fully sequence, these two gene families have not been studied. In this study we report the identification and analysis of putative cytosine-5 DNA methyltransferases (C5-MTases and demethylase in AA and BB wild peanuts. Cytosine-5 DNA methyltransferases in AA and BB wild peanuts could be classified in known MET, CMT and DRM2 groups based on their domain organization. This result was supported by the gene and protein structural characteristics and phylogenetic analysis. We found that some wild peanut DRM2 numbers didn’t contain UBA domain which was different from other plants such as Arabidopsis, maize, soybean. Five DNA demethylase were found in AA genome and five in BB genome. The selective pressure analysis showed that wild peanut C5-MTases gene mainly underwent purifying selection but many positive selection sites can be detected. Conversely, DNA demethylase genes mainly underwent positive selection during evolution. Additionally, the expression dynamic of cytosine-5 DNA methyltransferases and demethylase genes in different cultivated peanut tissues were analyzed. Expression result showed that cold, heat or drought stress could influence the expression level of C5-MTases and DNA demethylase genes in cultivated peanut. These results are useful for better understanding the complexity of these two gene families, and will facilitate epigenetic studies in peanut.

  19. Precise Identification of Genome-Wide Transcription Start Sites in Bacteria by 5'-Rapid Amplification of cDNA Ends (5'-RACE).

    Science.gov (United States)

    Matteau, Dominick; Rodrigue, Sébastien

    2015-01-01

    Transcription start sites are commonly used to locate promoter elements in bacterial genomes. TSS were previously studied one gene at a time, often through 5'-rapid amplification of cDNA ends (5'-RACE). This technique has now been adapted for high-throughput sequencing and can be used to precisely identify TSS in a genome-wide fashion for practically any bacterium, which greatly contributes to our understanding of gene regulatory networks in microorganisms.

  20. Genetic integrity of the Dark European honey bee (Apis mellifera mellifera) from protected populations: a genome-wide assessment using SNPs and mtDNA sequence data

    DEFF Research Database (Denmark)

    Pinto, M Alice; Henriques, Dora; Chávez-Galarza, Julio

    2014-01-01

    to preserve the genetic integrity of A. m. mellifera, protected populations had a measurable component of their gene pool derived from commercial C-lineage honey bees. Here we used both sequence data from the tRNAleu-cox2 intergenic mtDNA region and a genome-wide scan, with over 1183 single nucleotide...

  1. Genetic integrity of the Dark European honey bee (Apis mellifera mellifera) from protected populations: a genome-wide assessment using SNPs and mtDNA sequence data

    DEFF Research Database (Denmark)

    Pinto, M Alice; Henriques, Dora; Chávez-Galarza, Julio

    2014-01-01

    to preserve the genetic integrity of A. m. mellifera, protected populations had a measurable component of their gene pool derived from commercial C-lineage honey bees. Here we used both sequence data from the tRNAleu-cox2 intergenic mtDNA region and a genome-wide scan, with over 1183 single nucleotide...

  2. Genome-wide profiling of DNA methylation provides insights into epigenetic regulation of fungal development in a plant pathogenic fungus, Magnaporthe oryzae.

    Science.gov (United States)

    Jeon, Junhyun; Choi, Jaeyoung; Lee, Gir-Won; Park, Sook-Young; Huh, Aram; Dean, Ralph A; Lee, Yong-Hwan

    2015-02-24

    DNA methylation is an important epigenetic modification that regulates development of plants and mammals. To investigate the roles of DNA methylation in fungal development, we profiled genome-wide methylation patterns at single-nucleotide resolution during vegetative growth, asexual reproduction, and infection-related morphogenesis in a model plant pathogenic fungus, Magnaporthe oryzae. We found that DNA methylation occurs in and around genes as well as transposable elements and undergoes global reprogramming during fungal development. Such reprogramming of DNA methylation suggests that it may have acquired new roles other than controlling the proliferation of TEs. Genetic analysis of DNA methyltransferase deletion mutants also indicated that proper reprogramming in methylomes is required for asexual reproduction in the fungus. Furthermore, RNA-seq analysis showed that DNA methylation is associated with transcriptional silencing of transposable elements and transcript abundance of genes in context-dependent manner, reinforcing the role of DNA methylation as a genome defense mechanism. This comprehensive approach suggests that DNA methylation in fungi can be a dynamic epigenetic entity contributing to fungal development and genome defense. Furthermore, our DNA methylomes provide a foundation for future studies exploring this key epigenetic modification in fungal development and pathogenesis.

  3. Fetal DNA hypermethylation in tight junction pathway is associated with neural tube defects: A genome-wide DNA methylation analysis.

    Science.gov (United States)

    Wang, Linlin; Lin, Shanshan; Zhang, Ji; Tian, Tian; Jin, Lei; Ren, Aiguo

    2017-02-01

    Neural tube defects (NTDs) are a spectrum of severe congenital malformations of fusion failure of the neural tube during early embryogenesis. Evidence on aberrant DNA methylation in NTD development remains scarce, especially when exposure to environmental pollutant is taken into consideration. DNA methylation profiling was quantified using the Infinium HumanMethylation450 array in neural tissues from 10 NTD cases and 8 non-malformed controls (stage 1). Subsequent validation was performed using a Sequenom MassARRAY system in neural tissues from 20 NTD cases and 20 non-malformed controls (stage 2). Correlation analysis of differentially methylated CpG sites in fetal neural tissues and polycyclic aromatic hydrocarbons concentrations in fetal neural tissues and maternal serum was conducted. Differentially methylated CpG sites of neural tissues were further validated in fetal mice with NTDs induced by benzo(a)pyrene given to pregnant mice. Differentially hypermethylated CpG sites in neural tissues from 17 genes and 6 pathways were identified in stage 1. Subsequently, differentially hypermethylated CpG sites in neural tissues from 6 genes (BDKRB2, CTNNA1, CYFIP2, MMP7, MYH2, and TIAM2) were confirmed in stage 2. Correlation analysis showed that methylated CpG sites in CTNNA1 and MYH2 from NTD cases were positively correlated to polycyclic aromatic hydrocarbon level in fetal neural tissues and maternal serum. The correlation was confirmed in NTD-affected fetal mice that were exposed to benzo(a)pyrene in utero. In conclusion, hypermethylation of the CTNNA1 and MYH2 genes in tight junction pathway is associated with the risk for NTDs, and the DNA methylation aberration may be caused by exposure to benzo(a)pyrene.

  4. Cancer immunotherapy using novel tumor-associated antigenic peptides identified by genome-wide cDNA microarray analyses.

    Science.gov (United States)

    Nishimura, Yasuharu; Tomita, Yusuke; Yuno, Akira; Yoshitake, Yoshihiro; Shinohara, Masanori

    2015-05-01

    Recent genome-wide cDNA microarray analysis of gene expression profiles in comprehensive tumor types coupled with isolation of cancer tissues by laser-microbeam microdissection have revealed ideal tumor-associated antigens (TAAs) that are frequently overexpressed in various cancers including head and neck squamous cell cancer (HNSCC) and lung cancer, but not in most normal tissues except for testis, placenta, and fetal organs. Preclinical studies using HLA-transgenic mice and human T cells in vitro showed that TAA-derived CTL-epitope short peptides (SPs) are highly immunogenic and induce HLA-A2 or -A24-restricted CTLs. Based on the accumulated evidence, we carried out a phase II clinical trial of the TAA-SP vaccine in advanced 37 HNSCC patients. This study showed a significant induction of TAA-specific CTLs in the majority of patients without serious adverse effects. Importantly, clinical responses including a complete response were observed in this study. Another phase II clinical trial of therapeutic TAA-SP vaccine, designed to evaluate the ability of prevention of recurrence, is ongoing in HNSCC patients who have received curative operations. Further studies in human preclinical studies and in vivo studies using HLA class I transgenic mice showed TAA-derived long peptides (TAA-LPs) have the capacity to induce not only promiscuous HLA class II-restricted CD4(+) T helper type 1 cells but also tumor-specific CTLs through a cross-presentation mechanism. Moreover, we observed an augmentation of TAA-LP-specific T helper type 1 cell responses and tumor antigen-spreading in HNSCC patients vaccinated with TAA-SPs. This accumulated evidence suggests that therapeutic TAA-SPs and LPs vaccines may provide a promising cancer immunotherapy.

  5. Genome-wide association study of subtype-specific epithelial ovarian cancer risk alleles using pooled DNA

    DEFF Research Database (Denmark)

    Earp, Madalene A; Kelemen, Linda E; Magliocco, Anthony M

    2014-01-01

    Epithelial ovarian cancer (EOC) is a heterogeneous cancer with both genetic and environmental risk factors. Variants influencing the risk of developing the less-common EOC subtypes have not been fully investigated. We performed a genome-wide association study (GWAS) of EOC according to subtype by...

  6. Genome-wide and single-base resolution DNA methylomes of the Pacific oyster Crassostrea gigas provide insight into the evolution of invertebrate CpG methylation.

    Science.gov (United States)

    Wang, Xiaotong; Li, Qiye; Lian, Jinmin; Li, Li; Jin, Lijun; Cai, Huimin; Xu, Fei; Qi, Haigang; Zhang, Linlin; Wu, Fucun; Meng, Jie; Que, Huayong; Fang, Xiaodong; Guo, Ximing; Zhang, Guofan

    2014-12-16

    Studies of DNA methylomes in a wide range of eukaryotes have revealed both conserved and divergent characteristics of DNA methylation among phylogenetic groups. However, data on invertebrates particularly molluscs are limited, which hinders our understanding of the evolution of DNA methylation in metazoa. The sequencing of the Pacific oyster Crassostrea gigas genome provides an opportunity for genome-wide profiling of DNA methylation in this model mollusc. Homologous searches against the C. gigas genome identified functional orthologs for key genes involved in DNA methylation: DNMT1, DNMT2, DNMT3, MBD2/3 and UHRF1. Whole-genome bisulfite sequencing (BS-seq) of the oyster's mantle tissues revealed that more than 99% methylation modification was restricted to cytosines in CpG context and methylated CpGs accumulated in the bodies of genes that were moderately expressed. Young repeat elements were another major targets of CpG methylation in oysters. Comparison with other invertebrate methylomes suggested that the 5'-end bias of gene body methylation and the negative correlation between gene body methylation and gene length were the derived features probably limited to the insect lineage. Interestingly, phylostratigraphic analysis showed that CpG methylation preferentially targeted genes originating in the common ancestor of eukaryotes rather than the oldest genes originating in the common ancestor of cellular organisms. Comparative analysis of the oyster DNA methylomes and that of other animal species revealed that the characteristics of DNA methylation were generally conserved during invertebrate evolution, while some unique features were derived in the insect lineage. The preference of methylation modification on genes originating in the eukaryotic ancestor rather than the oldest genes is unexpected, probably implying that the emergence of methylation regulation in these 'relatively young' genes was critical for the origin and radiation of eukaryotes.

  7. Genome-wide analysis of DNA methylation in the sexual stage of the insect pathogenic fungus Cordyceps militaris.

    Science.gov (United States)

    Wang, Yu-long; Wang, Zhang-xun; Liu, Chun; Wang, Si-bao; Huang, Bo

    2015-12-01

    DNA methylation is a basic epigenetic mechanism found in eukaryotes, but its patterns and roles vary significantly among diverse taxa. In fungi, DNA methylation has various effects on diverse biological processes. However, its function in the sexual development of fungi remains unclear. Cordyceps militaris, readily performs sexual reproduction and thus provides a remarkably rich model for understanding epigenetic processes in sexual development. Here, we surveyed the methylome of C. militaris at single-base resolution to assess DNA methylation patterns during sexual development using genomic bisulfite sequencing (BS-Seq). The results showed that approximately 0.4 % of cytosines are methylated, similar to the DNA methylation level (0.39 %) during asexual development. Importantly, we found that DNA methylation in the fungi undergoes global reprogramming during fungal development. Moreover, RNA-Seq analysis indicated that the differentially methylated regions (DMRs) have no correlation with the genes that have roles during fungal sexual development in C. militaris. These results provide a comprehensive characterization of DNA methylation in the sexual development of C. militaris, which will contribute to future investigations of epigenetics in fungi.

  8. Genome-wide analysis of intraspecific DNA polymorphism in 'Micro-Tom', a model cultivar of tomato (Solanum lycopersicum).

    Science.gov (United States)

    Kobayashi, Masaaki; Nagasaki, Hideki; Garcia, Virginie; Just, Daniel; Bres, Cécile; Mauxion, Jean-Philippe; Le Paslier, Marie-Christine; Brunel, Dominique; Suda, Kunihiro; Minakuchi, Yohei; Toyoda, Atsushi; Fujiyama, Asao; Toyoshima, Hiromi; Suzuki, Takayuki; Igarashi, Kaori; Rothan, Christophe; Kaminuma, Eli; Nakamura, Yasukazu; Yano, Kentaro; Aoki, Koh

    2014-02-01

    Tomato (Solanum lycopersicum) is regarded as a model plant of the Solanaceae family. The genome sequencing of the tomato cultivar 'Heinz 1706' was recently completed. To accelerate the progress of tomato genomics studies, systematic bioresources, such as mutagenized lines and full-length cDNA libraries, have been established for the cultivar 'Micro-Tom'. However, these resources cannot be utilized to their full potential without the completion of the genome sequencing of 'Micro-Tom'. We undertook the genome sequencing of 'Micro-Tom' and here report the identification of single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) between 'Micro-Tom' and 'Heinz 1706'. The analysis demonstrated the presence of 1.23 million SNPs and 0.19 million indels between the two cultivars. The density of SNPs and indels was high in chromosomes 2, 5 and 11, but was low in chromosomes 6, 8 and 10. Three known mutations of 'Micro-Tom' were localized on chromosomal regions where the density of SNPs and indels was low, which was consistent with the fact that these mutations were relatively new and introgressed into 'Micro-Tom' during the breeding of this cultivar. We also report SNP analysis for two 'Micro-Tom' varieties that have been maintained independently in Japan and France, both of which have served as standard lines for 'Micro-Tom' mutant collections. Approximately 28,000 SNPs were identified between these two 'Micro-Tom' lines. These results provide high-resolution DNA polymorphic information on 'Micro-Tom' and represent a valuable contribution to the 'Micro-Tom'-based genomics resources.

  9. p53 shapes genome-wide and cell type-specific changes in microRNA expression during the human DNA damage response.

    Science.gov (United States)

    Hattori, Hiroyoshi; Janky, Rekin's; Nietfeld, Wilfried; Aerts, Stein; Madan Babu, M; Venkitaraman, Ashok R

    2014-01-01

    The human DNA damage response (DDR) triggers profound changes in gene expression, whose nature and regulation remain uncertain. Although certain micro-(mi)RNA species including miR34, miR-18, miR-16 and miR-143 have been implicated in the DDR, there is as yet no comprehensive description of genome-wide changes in the expression of miRNAs triggered by DNA breakage in human cells. We have used next-generation sequencing (NGS), combined with rigorous integrative computational analyses, to describe genome-wide changes in the expression of miRNAs during the human DDR. The changes affect 150 of 1523 miRNAs known in miRBase v18 from 4-24 h after the induction of DNA breakage, in cell-type dependent patterns. The regulatory regions of the most-highly regulated miRNA species are enriched in conserved binding sites for p53. Indeed, genome-wide changes in miRNA expression during the DDR are markedly altered in TP53-/- cells compared to otherwise isogenic controls. The expression levels of certain damage-induced, p53-regulated miRNAs in cancer samples correlate with patient survival. Our work reveals genome-wide and cell type-specific alterations in miRNA expression during the human DDR, which are regulated by the tumor suppressor protein p53. These findings provide a genomic resource to identify new molecules and mechanisms involved in the DDR, and to examine their role in tumor suppression and the clinical outcome of cancer patients.

  10. Genome-wide blood DNA methylation alterations at regulatory elements and heterochromatic regions in monozygotic twins discordant for obesity and liver fat

    OpenAIRE

    Ollikainen, M; Ismail, K.; Gervin, Kristina; Harris, Jennifer; Lyle, Robert

    2015-01-01

    Background: The current epidemic of obesity and associated diseases calls for swift actions to better understand the mechanisms by which genetics and environmental factors affect metabolic health in humans. Monozygotic (MZ) twin pairs showing discordance for obesity suggest that epigenetic influences represent one such mechanism. We studied genome-wide leukocyte DNA methylation variation in 30 clinically healthy young adult MZ twin pairs discordant for body mass index (BMI; average within-pai...

  11. Genome-wide profiling identifies a DNA methylation signature that associates with TET2 mutations in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Asmar, Fazila; Punj, Vasu; Christensen, Jesper Aagaard;

    2013-01-01

    The discovery that the Ten-Eleven Translocation (TET) hydroxylases cause DNA demethylation has fundamentally changed the notion of how DNA methylation is regulated. Clonal analysis of the hematopoetic stem cell compartment suggests that TET2 mutations can be early events in hematologic cancers......% carrying loss-of-function and 5% carrying missense mutations. Genome-wide methylation profiling using 450K Illumina arrays identified 315 differentially methylated genes between TET2 mutated and TET2 wild-type cases. TET2 mutations are primarily associated with hypermethylation within CpG islands (70%; P...

  12. Genome-wide DNA methylation analysis of neuroblastic tumors reveals clinically relevant epigenetic events and large-scale epigenomic alterations localized to telomeric regions.

    Science.gov (United States)

    Buckley, Patrick G; Das, Sudipto; Bryan, Kenneth; Watters, Karen M; Alcock, Leah; Koster, Jan; Versteeg, Rogier; Stallings, Raymond L

    2011-05-15

    The downregulation of specific genes through DNA hypermethylation is a major hallmark of cancer, although the extent and genomic distribution of hypermethylation occurring within cancer genomes is poorly understood. We report on the first genome-wide analysis of DNA methylation alterations in different neuroblastic tumor subtypes and cell lines, revealing higher order organization and clinically relevant alterations of the epigenome. The methylation status of 33,485 discrete loci representing all annotated CpG islands and RefSeq gene promoters was assessed in primary neuroblastic tumors and cell lines. A comparison of genes that were hypermethylated exclusively in the clinically favorable ganglioneuroma/ganglioneuroblastoma tumors revealed that nine genes were associated with poor clinical outcome when overexpressed in the unfavorable neuroblastoma (NB) tumors. Moreover, an integrated DNA methylation and copy number analysis identified 80 genes that were recurrently concomitantly deleted and hypermethylated in NB, with 37 reactivated by 5-aza-deoxycytidine. Lower expression of four of these genes was correlated with poor clinical outcome, further implicating their inactivation in aggressive disease pathogenesis. Analysis of genome-wide hypermethylation patterns revealed 70 recurrent large-scale blocks of contiguously hypermethylated promoters/CpG islands, up to 590 kb in length, with a distribution bias toward telomeric regions. Genome-wide hypermethylation events in neuroblastic tumors are extensive and frequently occur in large-scale blocks with a significant bias toward telomeric regions, indicating that some methylation alterations have occurred in a coordinated manner. Our results indicate that methylation contributes toward the clinicopathological features of neuroblastic tumors, revealing numerous genes associated with poor patient survival in NB.

  13. Buffy coat specimens remain viable as a DNA source for highly multiplexed genome-wide genetic tests after long term storage

    Directory of Open Access Journals (Sweden)

    Bowden Donald W

    2011-06-01

    Full Text Available Abstract Background Blood specimen collection at an early study visit is often included in observational studies or clinical trials for analysis of secondary outcome biomarkers. A common protocol is to store buffy coat specimens for future DNA isolation and these may remain in frozen storage for many years. It is uncertain if the DNA remains suitable for modern genome wide association (GWA genotyping. Methods We isolated DNA from 120 Action to Control Cardiovascular Risk in Diabetes (ACCORD clinical trial buffy coats sampling a range of storage times up to 9 years and other factors that could influence DNA yield. We performed TaqMan SNP and GWA genotyping to test whether the DNA retained integrity for high quality genetic analysis. Results We tested two QIAGEN automated protocols for DNA isolation, preferring the Compromised Blood Protocol despite similar yields. We isolated DNA from all 120 specimens (yield range 1.1-312 ug per 8.5 ml ACD tube of whole blood with only 3/120 samples yielding Conclusions When collected as a long term clinical trial or biobank specimen for DNA, buffy coats can be stored for up to 9 years in a -80degC frozen state and still produce high yields of DNA suitable for GWA analysis and other genetic testing. Trial Registration The Action to Control Cardiovascular Risk in Diabetes (ACCORD trial is registered with ClinicalTrials.gov, number NCT00000620.

  14. Genome-wide survey reveals predisposing diabetes type 2-related DNA methylation variations in human peripheral blood.

    Science.gov (United States)

    Toperoff, Gidon; Aran, Dvir; Kark, Jeremy D; Rosenberg, Michael; Dubnikov, Tatyana; Nissan, Batel; Wainstein, Julio; Friedlander, Yechiel; Levy-Lahad, Ephrat; Glaser, Benjamin; Hellman, Asaf

    2012-01-15

    Inter-individual DNA methylation variations were frequently hypothesized to alter individual susceptibility to Type 2 Diabetes Mellitus (T2DM). Sequence-influenced methylations were described in T2DM-associated genomic regions, but evidence for direct, sequence-independent association with disease risk is missing. Here, we explore disease-contributing DNA methylation through a stepwise study design: first, a pool-based, genome-scale screen among 1169 case and control individuals revealed an excess of differentially methylated sites in genomic regions that were previously associated with T2DM through genetic studies. Next, in-depth analyses were performed at selected top-ranking regions. A CpG site in the first intron of the FTO gene showed small (3.35%) but significant (P = 0.000021) hypomethylation of cases relative to controls. The effect was independent of the sequence polymorphism in the region and persists among individuals carrying the sequence-risk alleles. The odds of belonging to the T2DM group increased by 6.1% for every 1% decrease in methylation (OR = 1.061, 95% CI: 1.032-1.090), the odds ratio for decrease of 1 standard deviation of methylation (adjusted to gender) was 1.5856 (95% CI: 1.2824-1.9606) and the sensitivity (area under the curve = 0.638, 95% CI: 0.586-0.690; males = 0.675, females = 0.609) was better than that of the strongest known sequence variant. Furthermore, a prospective study in an independent population cohort revealed significant hypomethylation of young individuals that later progressed to T2DM, relative to the individuals who stayed healthy. Further genomic analysis revealed co-localization with gene enhancers and with binding sites for methylation-sensitive transcriptional regulators. The data showed that low methylation level at the analyzed sites is an early marker of T2DM and suggests a novel mechanism by which early-onset, inter-individual methylation variation at isolated non-promoter genomic sites predisposes to T2DM.

  15. Genome-wide DNA methylation reprogramming in response to inorganic arsenic links inhibition of CTCF binding, DNMT expression and cellular transformation

    Science.gov (United States)

    Rea, Matthew; Eckstein, Meredith; Eleazer, Rebekah; Smith, Caroline; Fondufe-Mittendorf, Yvonne N.

    2017-02-01

    Chronic low dose inorganic arsenic (iAs) exposure leads to changes in gene expression and epithelial-to-mesenchymal transformation. During this transformation, cells adopt a fibroblast-like phenotype accompanied by profound gene expression changes. While many mechanisms have been implicated in this transformation, studies that focus on the role of epigenetic alterations in this process are just emerging. DNA methylation controls gene expression in physiologic and pathologic states. Several studies show alterations in DNA methylation patterns in iAs-mediated pathogenesis, but these studies focused on single genes. We present a comprehensive genome-wide DNA methylation analysis using methyl-sequencing to measure changes between normal and iAs-transformed cells. Additionally, these differential methylation changes correlated positively with changes in gene expression and alternative splicing. Interestingly, most of these differentially methylated genes function in cell adhesion and communication pathways. To gain insight into how genomic DNA methylation patterns are regulated during iAs-mediated carcinogenesis, we show that iAs probably targets CTCF binding at the promoter of DNA methyltransferases, regulating their expression. These findings reveal how CTCF binding regulates DNA methyltransferase to reprogram the methylome in response to an environmental toxin.

  16. Genome-wide DNA methylation reprogramming in response to inorganic arsenic links inhibition of CTCF binding, DNMT expression and cellular transformation

    Science.gov (United States)

    Rea, Matthew; Eckstein, Meredith; Eleazer, Rebekah; Smith, Caroline; Fondufe-Mittendorf , Yvonne N.

    2017-01-01

    Chronic low dose inorganic arsenic (iAs) exposure leads to changes in gene expression and epithelial-to-mesenchymal transformation. During this transformation, cells adopt a fibroblast-like phenotype accompanied by profound gene expression changes. While many mechanisms have been implicated in this transformation, studies that focus on the role of epigenetic alterations in this process are just emerging. DNA methylation controls gene expression in physiologic and pathologic states. Several studies show alterations in DNA methylation patterns in iAs-mediated pathogenesis, but these studies focused on single genes. We present a comprehensive genome-wide DNA methylation analysis using methyl-sequencing to measure changes between normal and iAs-transformed cells. Additionally, these differential methylation changes correlated positively with changes in gene expression and alternative splicing. Interestingly, most of these differentially methylated genes function in cell adhesion and communication pathways. To gain insight into how genomic DNA methylation patterns are regulated during iAs-mediated carcinogenesis, we show that iAs probably targets CTCF binding at the promoter of DNA methyltransferases, regulating their expression. These findings reveal how CTCF binding regulates DNA methyltransferase to reprogram the methylome in response to an environmental toxin. PMID:28150704

  17. Genome-wide mapping of protein-DNA interaction by chromatin immunoprecipitation and DNA microarray hybridization (ChIP-chip). Part B: ChIP-chip data analysis.

    Science.gov (United States)

    Göbel, Ulrike; Reimer, Julia; Turck, Franziska

    2010-01-01

    Genome-wide targets of chromatin-associated factors can be identified by a combination of chromatin-immunoprecipitation and oligonucleotide microarray hybridization. Genome-wide mircoarray data analysis represents a major challenge for the experimental biologist. This chapter introduces ChIPR, a package written in the R statistical programming language that facilitates the analysis of two-color microarrays from Roche-Nimblegen. The workflow of ChIPR is illustrated with sample data from Arabidopsis thaliana. However, ChIPR supports ChIP-chip data preprocessing, target identification, and cross-annotation of any species for which genome annotation data is available in GFF format. This chapter describes how to use ChIPR as a software tool without the requirement for programming skills in the R language.

  18. Effects of antenatal synthetic glucocorticoid on glucocorticoid receptor binding, DNA methylation, and genome-wide mRNA levels in the fetal male hippocampus.

    Science.gov (United States)

    Crudo, Ariann; Petropoulos, Sophie; Suderman, Matthew; Moisiadis, Vasilis G; Kostaki, Alisa; Hallett, Michael; Szyf, Moshe; Matthews, Stephen G

    2013-11-01

    The endogenous glucocorticoid (GC) surge in late gestation plays a vital role in maturation of several organ systems. For this reason, pregnant women at risk of preterm labor are administered synthetic glucocorticoids (sGCs) to promote fetal lung development. Animal studies have shown that fetal sGC exposure can cause life-long changes in endocrine and metabolic function. We have previously shown that antenatal sGC treatment is associated with alterations in global DNA methylation and modifications to the hippocampal methylome and acetylome. In this study, we hypothesized that: 1) there are changes in the transcriptional landscape of the fetal hippocampus in late gestation, associated with the endogenous cortisol surge; 2) fetal sGC exposure alters genome-wide transcription in the hippocampus; and 3) these changes in transcription are associated with modified glucocorticoid receptor (GR) DNA binding and DNA methylation. sGC was administered as 2 courses on gestational days (GD) 40, 41, 50, and 51, and the hippocampi of fetal guinea pigs were examined before (GD52) and after (GD65) the endogenous cortisol surge (Term ∼GD67). We also analyzed fetal hippocampi 24 hours and 14 days following maternal sGC injections (n = 3-4/group). Genome-wide modification of transcription and GR DNA binding occurred in late gestation, in parallel with the normal GC surge. Further, sGC exposure had a substantial impact on the hippocampal transcriptome, GR-DNA binding, and DNA methylation at 24 hours and 14 days following the final sGC treatment. These data support the hypothesis that GC exposure in late gestation plays a significant role in modifying the transcriptional and epigenetic landscape of the developing fetal hippocampus and that substantial effects are evident for at least 2 weeks after sGC exposure.

  19. Genome-wide analysis of DNA methylation, copy number variation, and gene expression in monozygotic twins discordant for primary biliary cirrhosis

    Directory of Open Access Journals (Sweden)

    Carlo eSelmi

    2014-03-01

    Full Text Available Primary biliary cirrhosis (PBC is an uncommon autoimmune disease with a homogeneous clinical phenotype that reflects incomplete disease concordance in monozygotic (MZ twins. We have taken advantage of a unique collection consisting of genomic DNA and mRNA from peripheral blood cells of female MZ twins (n=3 sets and sisters of similar age (n=8 pairs discordant for disease. We performed a genome-wide study to investigate differences in (i DNA methylation (using a custom tiled 4-plex array containing tiled 50-mers 19,084 randomly chosen methylation sites, (ii copy number variation (CNV (with a chip including markers derived from the 1000 Genomes Project, all three HapMap phases, and recently published studies, and/or (iii gene expression (by whole-genome expression arrays. Based on the results obtained from these three approaches we utilized quantitative PCR to compare the expression of candidate genes. Importantly, our data support consistent differences in discordant twins and siblings for the (i methylation profiles of 60 gene regions, (ii CNV of 10 genes, and (iii the expression of 2 interferon-dependent genes. Quantitative PCR analysis showed that 17 of these genes are differentially expressed in discordant sibling pairs. In conclusion, we report that MZ twins and sisters discordant for PBC manifest particular epigenetic differences and highlight the value of the epigenetic study of twins.

  20. Decoding the Regulatory Landscape of Ageing in Musculoskeletal Engineered Tissues Using Genome-Wide DNA Methylation and RNASeq.

    Science.gov (United States)

    Peffers, Mandy Jayne; Goljanek-Whysall, Katarzyna; Collins, John; Fang, Yongxiang; Rushton, Michael; Loughlin, John; Proctor, Carole; Clegg, Peter David

    2016-01-01

    Mesenchymal stem cells (MSC) are capable of multipotent differentiation into connective tissues and as such are an attractive source for autologous cell-based regenerative medicine and tissue engineering. Epigenetic mechanisms, like DNA methylation, contribute to the changes in gene expression in ageing. However there was a lack of sufficient knowledge of the role that differential methylation plays during chondrogenic, osteogenic and tenogenic differentiation from ageing MSCs. This study undertook genome level determination of the effects of DNA methylation on expression in engineered tissues from chronologically aged MSCs. We compiled unique DNA methylation signatures from chondrogenic, osteogenic, and tenogenic engineered tissues derived from young; n = 4 (21.8 years ± 2.4 SD) and old; n = 4 (65.5 years±8.3SD) human MSCs donors using the Illumina HumanMethylation 450 Beadchip arrays and compared these to gene expression by RNA sequencing. Unique and common signatures of global DNA methylation were identified. There were 201, 67 and 32 chondrogenic, osteogenic and tenogenic age-related DE protein-coding genes respectively. Findings inferred the nature of the transcript networks was predominantly for 'cell death and survival', 'cell morphology', and 'cell growth and proliferation'. Further studies are required to validate if this gene expression effect translates to cell events. Alternative splicing (AS) was dysregulated in ageing with 119, 21 and 9 differential splicing events identified in chondrogenic, osteogenic and tenogenic respectively, and enrichment in genes associated principally with metabolic processes. Gene ontology analysis of differentially methylated loci indicated age-related enrichment for all engineered tissue types in 'skeletal system morphogenesis', 'regulation of cell proliferation' and 'regulation of transcription' suggesting that dynamic epigenetic modifications may occur in genes associated with shared and distinct pathways dependent

  1. A Genome-Wide mQTL Analysis in Human Adipose Tissue Identifies Genetic Variants Associated with DNA Methylation, Gene Expression and Metabolic Traits

    DEFF Research Database (Denmark)

    Volkov, Petr; Olsson, Anders H; Gillberg, Linn

    2016-01-01

    mediate their effects on metabolic traits (e.g. BMI, cholesterol, high-density lipoprotein (HDL), hemoglobin A1c (HbA1c) and homeostatic model assessment of insulin resistance (HOMA-IR)) via altered DNA methylation in human adipose tissue. This study identifies genome-wide interactions between genetic......Little is known about the extent to which interactions between genetics and epigenetics may affect the risk of complex metabolic diseases and/or their intermediary phenotypes. We performed a genome-wide DNA methylation quantitative trait locus (mQTL) analysis in human adipose tissue of 119 men......, where 592,794 single nucleotide polymorphisms (SNPs) were related to DNA methylation of 477,891 CpG sites, covering 99% of RefSeq genes. SNPs in significant mQTLs were further related to gene expression in adipose tissue and obesity related traits. We found 101,911 SNP-CpG pairs (mQTLs) in cis and 5...

  2. Genome-Wide DNA Binding of GBF1 IsModulated by Its Heterodimerizing ProteinPartners, HY5 and HYH

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Dear Editor, In today's post-genomic era where direct targets of manytranscription factors have been identified, it is becomingincreasingly evident that transcriptional networks are verycomplex. Heterodimerization of transcription factors is oneof the several methods by which these complex transcrip-tional networks are formed. By heterodimerization, DNA-binding specificity and affinity, transactivation properties,and ultimately cell physiology might be altered (Naar et al.,2001). The formation of heterodimers has the potential torecognize additional binding sites and increase the rangeof DNA-binding specificity (Foster et al., 1994). Further, het-erodimerization also allows the production of new proteinconfigurations. For example, the protein STF1 from soybeancan dimerize with GBF proteins and this dimerization bringstogether the acidic region from STF1 and the proline-richregion of the GBF proteins into one binding element (Cheonget al., 1998). These results highlight the importance and/orconsequences of heterodimerization of transcription factorsat particular locus. However, to understand the complex tran-scriptional networks, it is important to investigate that howheterodimerization affects the whole-genome-wide bind-ing and transcriptional properties of a transcription factor.Here in this study, we have investigated genome-wide DNAbinding of bZIP transcription factor GBF1, and analyzed theimportance of its heterodimerization with HY5 and HYH forits genome-wide binding. We have found that GBF1 bindingsites are enriched within the 1-kb regions upstream to thetranscription start sites of target genes. Moreover, the bind-ings of GBF1 to most of its targets are largely dependent onHY5, while HYH only affects the binding of GBF1 to somespecific sites.

  3. Construction of genome-wide physical BAC contigs using mapped cDNA as probes: Toward an integrated BAC library resource for genome sequencing and analysis. Annual report, July 1995--January 1997

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, S.C.; Bocskai, D.; Cao, Y. [and others

    1997-12-31

    The goal of human genome project is to characterize and sequence entire genomes of human and several model organisms, thus providing complete sets of information on the entire structure of transcribed, regulatory and other functional regions for these organisms. In the past years, a number of useful genetic and physical markers on human and mouse genomes have been made available along with the advent of BAC library resources for these organisms. The advances in technology and resource development made it feasible to efficiently construct genome-wide physical BAC contigs for human and other genomes. Currently, over 30,000 mapped STSs and 27,000 mapped Unigenes are available for human genome mapping. ESTs and cDNAs are excellent resources for building contig maps for two reasons. Firstly, they exist in two alternative forms--as both sequence information for PCR primer pairs, and cDoreen genomic libraries efficiently for large number of DNA probes by combining over 100 cDNA probes in each hybridization. Second, the linkage and order of genes are rather conserved among human, mouse and other model organisms. Therefore, gene markers have advantages over random anonymous STSs in building maps for comparative genomic studies.

  4. The effects of long-term daily folic acid and vitamin B12 supplementation on genome-wide DNA methylation in elderly subjects.

    Science.gov (United States)

    Kok, Dieuwertje E G; Dhonukshe-Rutten, Rosalie A M; Lute, Carolien; Heil, Sandra G; Uitterlinden, André G; van der Velde, Nathalie; van Meurs, Joyce B J; van Schoor, Natasja M; Hooiveld, Guido J E J; de Groot, Lisette C P G M; Kampman, Ellen; Steegenga, Wilma T

    2015-01-01

    Folate and its synthetic form folic acid function as donor of one-carbon units and have been, together with other B-vitamins, implicated in programming of epigenetic processes such as DNA methylation during early development. To what extent regulation of DNA methylation can be altered via B-vitamins later in life, and how this relates to health and disease, is not exactly known. The aim of this study was to identify effects of long-term supplementation with folic acid and vitamin B12 on genome-wide DNA methylation in elderly subjects. This project was part of a randomized, placebo-controlled trial on effects of supplemental intake of folic acid and vitamin B12 on bone fracture incidence (B-vitamins for the PRevention Of Osteoporotic Fractures (B-PROOF) study). Participants with mildly elevated homocysteine levels, aged 65-75 years, were randomly assigned to take 400 μg folic acid and 500 μg vitamin B12 per day or a placebo during an intervention period of 2 years. DNA was isolated from buffy coats, collected before and after intervention, and genome-wide DNA methylation was determined in 87 participants (n = 44 folic acid/vitamin B12, n = 43 placebo) using the Infinium HumanMethylation450 BeadChip. After intervention with folic acid and vitamin B12, 162 (versus 14 in the placebo group) of the 431,312 positions were differentially methylated as compared to baseline. Comparisons of the DNA methylation changes in the participants receiving folic acid and vitamin B12 versus placebo revealed one single differentially methylated position (cg19380919) with a borderline statistical significance. However, based on the analyses of differentially methylated regions (DMRs) consisting of multiple positions, we identified 6 regions that differed statistically significantly between the intervention and placebo group. Pronounced changes were found for regions in the DIRAS3, ARMC8, and NODAL genes, implicated in carcinogenesis and early embryonic development

  5. Genome-wide DNA markers to support genetic management for domestication and commercial production in a large rodent, the Ghanaian grasscutter (Thryonomys swinderianus).

    Science.gov (United States)

    Adenyo, C; Ogden, R; Kayang, B; Onuma, M; Nakajima, N; Inoue-Murayama, M

    2017-02-01

    Domestication and commercial production of the grasscutter, Thryonomys swinderianus, a large rodent, represents an important opportunity to secure sustainable animal protein for local communities in West Africa. To support production, DNA markers are required for population diversity assessment, pedigree analysis and marker-assisted selection. This study reports the application of double-digest RAD sequencing to simultaneously discover and genotype SNP markers in 24 wild and recently domesticated grasscutters. An initial panel of 1209 SNP loci was characterised from a total of more than 21 000 candidate loci containing single SNPs. This genome-wide resource represents the first application of its type to commercial production of a large rodent for food and advances the use of agricultural genomics in Ghana.

  6. Genome-wide association and genomic selection in animal breeding.

    Science.gov (United States)

    Hayes, Ben; Goddard, Mike

    2010-11-01

    Results from genome-wide association studies in livestock, and humans, has lead to the conclusion that the effect of individual quantitative trait loci (QTL) on complex traits, such as yield, are likely to be small; therefore, a large number of QTL are necessary to explain genetic variation in these traits. Given this genetic architecture, gains from marker-assisted selection (MAS) programs using only a small number of DNA markers to trace a limited number of QTL is likely to be small. This has lead to the development of alternative technology for using the available dense single nucleotide polymorphism (SNP) information, called genomic selection. Genomic selection uses a genome-wide panel of dense markers so that all QTL are likely to be in linkage disequilibrium with at least one SNP. The genomic breeding values are predicted to be the sum of the effect of these SNPs across the entire genome. In dairy cattle breeding, the accuracy of genomic estimated breeding values (GEBV) that can be achieved and the fact that these are available early in life have lead to rapid adoption of the technology. Here, we discuss the design of experiments necessary to achieve accurate prediction of GEBV in future generations in terms of the number of markers necessary and the size of the reference population where marker effects are estimated. We also present a simple method for implementing genomic selection using a genomic relationship matrix. Future challenges discussed include using whole genome sequence data to improve the accuracy of genomic selection and management of inbreeding through genomic relationships.

  7. Dioxidine-induced changes in genome-wide DNA methylation in a culture of peripheral blood lymphocytes.

    Science.gov (United States)

    Smirnikhina, S A; Voronina, E S; Lavrov, A V; Bochkov, N P

    2013-06-01

    We studied the effect of dioxidine on genome-wide methylation in short-term cultures of peripheral blood lymphocytes derived from healthy donors. Methylation was evaluated in lymphocytes before culturing, after 25 h in culture, and 1 h after addition of dioxidine in two concentrations (0.1 and 0.01 mg/ml). The total time in culture was 25 h. The level of methylation was assessed using methyl-sensitive single-cell gel electrophoresis ("comet assay") with additional restriction with HpaII amd MspI. Significant individual differences were found in the levels of methylation in both native cells and in cells treated with dioxidine in both concentrations. Mean group indicators of methylation did not differ before culturing and after 25 h in culture (45.28 and 44.80%, respectively). The mean group rate of methylation increased to 46.14% (p<0.001) after dioxidine treatment in a concentration of 0.01 mg/ml. Dioxidine in 0.1 mg/ml reduced the level of methylation (mean group rate 42.31%; p<0.001).

  8. Genome-wide chromatin accessibility, DNA methylation and gene expression analysis of histone deacetylase inhibition in triple-negative breast cancer.

    Science.gov (United States)

    Bustos, Matias A; Salomon, Matthew P; Nelson, Nellie; Hsu, Sandy C; DiNome, Maggie L; Hoon, Dave S B; Marzese, Diego M

    2017-06-01

    Triple-negative breast cancer (TNBC), especially the subset with a basal phenotype, represents the most aggressive subtype of breast cancer. Unlike other solid tumors, TNBCs harbor a low number of driver mutations. Conversely, we and others have demonstrated a significant impact of epigenetic alterations, including DNA methylation and histone post-translational modifications, affecting TNBCs. Due to the promising results in pre-clinical studies, histone deacetylase inhibitors (HDACi) are currently being tested in several clinical trials for breast cancer and other solid tumors. However, the genome-wide epigenetic and transcriptomic implications of HDAC inhibition are still poorly understood. Here, we provide detailed information about the design of a multi-platform dataset that describes the epigenomic and transcriptomic effects of HDACi. This dataset includes genome-wide chromatin accessibility (assessed by ATAC-Sequencing), DNA methylation (assessed by Illumina HM450K BeadChip) and gene expression (assessed by RNA-Sequencing) analyses before and after HDACi treatment of HCC1806 and MDA-MB-231, two human TNBC cell lines with basal-like phenotype.

  9. MethylRAD: a simple and scalable method for genome-wide DNA methylation profiling using methylation-dependent restriction enzymes.

    Science.gov (United States)

    Wang, Shi; Lv, Jia; Zhang, Lingling; Dou, Jinzhuang; Sun, Yan; Li, Xue; Fu, Xiaoteng; Dou, Huaiqian; Mao, Junxia; Hu, Xiaoli; Bao, Zhenmin

    2015-11-01

    Characterization of dynamic DNA methylomes in diverse phylogenetic groups has attracted growing interest for a better understanding of the evolution of DNA methylation as well as its function and biological significance in eukaryotes. Sequencing-based methods are promising in fulfilling this task. However, none of the currently available methods offers the 'perfect solution', and they have limitations that prevent their application in the less studied phylogenetic groups. The recently discovered Mrr-like enzymes are appealing for new method development, owing to their ability to collect 32-bp methylated DNA fragments from the whole genome for high-throughput sequencing. Here, we have developed a simple and scalable DNA methylation profiling method (called MethylRAD) using Mrr-like enzymes. MethylRAD allows for de novo (reference-free) methylation analysis, extremely low DNA input (e.g. 1 ng) and adjustment of tag density, all of which are still unattainable for most widely used methylation profiling methods such as RRBS and MeDIP. We performed extensive analyses to validate the power and accuracy of our method in both model (plant Arabidopsis thaliana) and non-model (scallop Patinopecten yessoensis) species. We further demonstrated its great utility in identification of a gene (LPCAT1) that is potentially crucial for carotenoid accumulation in scallop adductor muscle. MethylRAD has several advantages over existing tools and fills a void in the current epigenomic toolkit by providing a universal tool that can be used for diverse research applications, e.g. from model to non-model species, from ordinary to precious samples and from small to large genomes, but at an affordable cost.

  10. Genome-Wide DNA Methylation Patterns of Bovine Blastocysts Developed In Vivo from Embryos Completed Different Stages of Development In Vitro.

    Directory of Open Access Journals (Sweden)

    Dessie Salilew-Wondim

    Full Text Available Early embryonic loss and altered gene expression in in vitro produced blastocysts are believed to be partly caused by aberrant DNA methylation. However, specific embryonic stage which is sensitive to in vitro culture conditions to alter the DNA methylation profile of the resulting blastocysts remained unclear. Therefore, the aim of this study was to investigate the stage specific effect of in vitro culture environment on the DNA methylation response of the resulting blastocysts. For this, embryos cultured in vitro until zygote (ZY, 4-cell (4C or 16-cell (16C were transferred to recipients and the blastocysts were recovery at day 7 of the estrous cycle. Another embryo group was cultured in vitro until blastocyst stage (IVP. Genome-wide DNA methylation profiles of ZY, 4C, 16C and IVP blastocyst groups were then determined with reference to blastocysts developed completely under in vivo condition (VO using EmbryoGENE DNA Methylation Array. To assess the contribution of methylation changes on gene expression patterns, the DNA methylation data was superimposed to the transcriptome profile data. The degree of DNA methylation dysregulation in the promoter and/or gene body regions of the resulting blastocysts was correlated with successive stages of development the embryos advanced under in vitro culture before transfer to the in vivo condition. Genomic enrichment analysis revealed that in 4C and 16C blastocyst groups, hypermethylated loci were outpacing the hypomethylated ones in intronic, exonic, promoter and proximal promoter regions, whereas the reverse was observed in ZY blastocyst group. However, in the IVP group, as much hypermethylated as hypomethylated probes were detected in gene body and promoter regions. In addition, gene ontology analysis indicated that differentially methylated regions were found to affected several biological functions including ATP binding in the ZY group, programmed cell death in the 4C, glycolysis in 16C and genetic

  11. Genome-Wide DNA Methylation Patterns of Bovine Blastocysts Developed In Vivo from Embryos Completed Different Stages of Development In Vitro.

    Science.gov (United States)

    Salilew-Wondim, Dessie; Fournier, Eric; Hoelker, Michael; Saeed-Zidane, Mohammed; Tholen, Ernst; Looft, Christian; Neuhoff, Christiane; Besenfelder, Urban; Havlicek, Vita; Rings, Franca; Gagné, Dominic; Sirard, Marc-André; Robert, Claude; Shojaei Saadi, Habib A; Gad, Ahmed; Schellander, Karl; Tesfaye, Dawit

    2015-01-01

    Early embryonic loss and altered gene expression in in vitro produced blastocysts are believed to be partly caused by aberrant DNA methylation. However, specific embryonic stage which is sensitive to in vitro culture conditions to alter the DNA methylation profile of the resulting blastocysts remained unclear. Therefore, the aim of this study was to investigate the stage specific effect of in vitro culture environment on the DNA methylation response of the resulting blastocysts. For this, embryos cultured in vitro until zygote (ZY), 4-cell (4C) or 16-cell (16C) were transferred to recipients and the blastocysts were recovery at day 7 of the estrous cycle. Another embryo group was cultured in vitro until blastocyst stage (IVP). Genome-wide DNA methylation profiles of ZY, 4C, 16C and IVP blastocyst groups were then determined with reference to blastocysts developed completely under in vivo condition (VO) using EmbryoGENE DNA Methylation Array. To assess the contribution of methylation changes on gene expression patterns, the DNA methylation data was superimposed to the transcriptome profile data. The degree of DNA methylation dysregulation in the promoter and/or gene body regions of the resulting blastocysts was correlated with successive stages of development the embryos advanced under in vitro culture before transfer to the in vivo condition. Genomic enrichment analysis revealed that in 4C and 16C blastocyst groups, hypermethylated loci were outpacing the hypomethylated ones in intronic, exonic, promoter and proximal promoter regions, whereas the reverse was observed in ZY blastocyst group. However, in the IVP group, as much hypermethylated as hypomethylated probes were detected in gene body and promoter regions. In addition, gene ontology analysis indicated that differentially methylated regions were found to affected several biological functions including ATP binding in the ZY group, programmed cell death in the 4C, glycolysis in 16C and genetic imprinting and

  12. Genome-wide DNA methylation pattern in visceral adipose tissue differentiates insulin-resistant from insulin-sensitive obese subjects.

    Science.gov (United States)

    Crujeiras, A B; Diaz-Lagares, A; Moreno-Navarrete, J M; Sandoval, J; Hervas, D; Gomez, A; Ricart, W; Casanueva, F F; Esteller, M; Fernandez-Real, J M

    2016-12-01

    Elucidating the potential mechanisms involved in the detrimental effect of excess body weight on insulin action is an important priority in counteracting obesity-associated diseases. The present study aimed to disentangle the epigenetic basis of insulin resistance by performing a genome-wide epigenetic analysis in visceral adipose tissue (VAT) from morbidly obese patients depending on the insulin sensitivity evaluated by the clamp technique. The global human methylome screening performed in VAT from 7 insulin-resistant (IR) and 5 insulin-sensitive (IS) morbidly obese patients (discovery cohort) analyzed using the Infinium HumanMethylation450 BeadChip array identified 982 CpG sites able to perfectly separate the IR and IS samples. The identified sites represented 538 unique genes, 10% of which were diabetes-associated genes. The current work identified novel IR-related genes epigenetically regulated in VAT, such as COL9A1, COL11A2, CD44, MUC4, ADAM2, IGF2BP1, GATA4, TET1, ZNF714, ADCY9, TBX5, and HDACM. The gene with the largest methylation fold-change and mapped by 5 differentially methylated CpG sites located in island/shore and promoter region was ZNF714. This gene presented lower methylation levels in IR than in IS patients in association with increased transcription levels, as further reflected in a validation cohort (n = 24; 11 IR and 13 IS). This study reveals, for the first time, a potential epigenetic regulation involved in the dysregulation of VAT that could predispose patients to insulin resistance and future type 2 diabetes in morbid obesity, providing a potential therapeutic target and biomarkers for counteracting this process. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Genome-wide DNA polymorphism in the indica rice varieties RGD-7S and Taifeng B as revealed by whole genome re-sequencing.

    Science.gov (United States)

    Fu, Chong-Yun; Liu, Wu-Ge; Liu, Di-Lin; Li, Ji-Hua; Zhu, Man-Shan; Liao, Yi-Long; Liu, Zhen-Rong; Zeng, Xue-Qin; Wang, Feng

    2016-03-01

    Next-generation sequencing technologies provide opportunities to further understand genetic variation, even within closely related cultivars. We performed whole genome resequencing of two elite indica rice varieties, RGD-7S and Taifeng B, whose F1 progeny showed hybrid weakness and hybrid vigor when grown in the early- and late-cropping seasons, respectively. Approximately 150 million 100-bp pair-end reads were generated, which covered ∼86% of the rice (Oryza sativa L. japonica 'Nipponbare') reference genome. A total of 2,758,740 polymorphic sites including 2,408,845 SNPs and 349,895 InDels were detected in RGD-7S and Taifeng B, respectively. Applying stringent parameters, we identified 961,791 SNPs and 46,640 InDels between RGD-7S and Taifeng B (RGD-7S/Taifeng B). The density of DNA polymorphisms was 256.8 SNPs and 12.5 InDels per 100 kb for RGD-7S/Taifeng B. Copy number variations (CNVs) were also investigated. In RGD-7S, 1989 of 2727 CNVs were overlapped in 218 genes, and 1231 of 2010 CNVs were annotated in 175 genes in Taifeng B. In addition, we verified a subset of InDels in the interval of hybrid weakness genes, Hw3 and Hw4, and obtained some polymorphic InDel markers, which will provide a sound foundation for cloning hybrid weakness genes. Analysis of genomic variations will also contribute to understanding the genetic basis of hybrid weakness and heterosis.

  14. Early detection of gastric cancer using global, genome-wide and IRF4, ELMO1, CLIP4 and MSC DNA methylation in endoscopic biopsies

    Science.gov (United States)

    Rodriguez-Torres, Sebastian; Friess, Leah; Michailidi, Christina; Cok, Jaime; Combe, Juan; Vargas, Gloria; Prado, William; Soudry, Ethan; Pérez, Jimena; Yudin, Tikki; Mancinelli, Andrea; Unger, Helen; Ili-Gangas, Carmen; Brebi-Mieville, Priscilla; Berg, Douglas E.; Hayashi, Masamichi; Sidransky, David; Gilman, Robert H.; Guerrero-Preston, Rafael

    2017-01-01

    Clinically useful molecular tools to triage gastric cancer patients are not currently available. We aimed to develop a molecular tool to predict gastric cancer risk in endoscopy-driven biopsies obtained from high-risk gastric cancer clinics in low resource settings. We discovered and validated a DNA methylation biomarker panel in endoscopic samples obtained from 362 patients seen between 2004 and 2009 in three high-risk gastric cancer clinics in Lima, Perú, and validated it in 306 samples from the Cancer Genome Atlas project (“TCGA”). Global, epigenome wide and gene-specific DNA methylation analyses were used in a Phase I Biomarker Development Trial to identify a continuous biomarker panel that combines a Global DNA Methylation Index (GDMI) and promoter DNA methylation levels of IRF4, ELMO1, CLIP4 and MSC. We observed an inverse association between the GDMI and histological progression to gastric cancer, when comparing gastritis patients without metaplasia (mean = 5.74, 95% CI, 4.97−6.50), gastritis patients with metaplasia (mean = 4.81, 95% CI, 3.77−5.84), and gastric cancer cases (mean = 3.38, 95% CI, 2.82−3.94), respectively (p 4 are useful molecular tools for gastric cancer risk stratification in endoscopic biopsies. PMID:28418867

  15. DNA pooling base genome-wide association study identifies variants at NRXN3 associated with delayed encephalopathy after acute carbon monoxide poisoning.

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    Wenqiang Li

    Full Text Available Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP is more characteristic of anoxic encephalopathy than of other types of anoxia. Those who have the same poisoning degree and are of similar age and gender have a greater risk of getting DEACMP. This has made it clear that there are obvious personal differences. Genetic factors may play a very important role. The authors performed a genome-wide association study involving pooling of DNA obtained from 175 patients and 244 matched acute carbon monoxide poisoning without delayed encephalopathy controls. The Illumina HumanHap 660 Chip array was used for DNA pools. Allele frequencies of all SNPs were compared between delayed encephalopathy after acute carbon monoxide poisoning and control groups and ranked. A total of 123 SNPs gave an OR >1.4. Of these, 46 mapped in or close to known genes. Forty-eight SNPs located in 19 genes were associated with DEACMP after correction for 5% FDR in the genome-wide association of pooled DNA. Two SNPs (rs11845632 and rs2196447 locate in the Neurexin 3 gene were selected for individual genotyping in all samples and another cohort consisted of 234 and 271 controls. There were significant differences in the genotype and allele frequencies of rs11845632 and rs2196447 between the DEACMP group and controls group (all P-values <0.05. This study describes a positive association between Neurexin 3 and controls in the Han Chinese population, and provides genetic evidence to support the susceptibility of DEACMP, which may be the resulting interaction of environmental and genetic factors.

  16. Genome-wide DNA methylation analyses in the brain reveal four differentially methylated regions between humans and non-human primates

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    Wang Jinkai

    2012-08-01

    Full Text Available Abstract Background The highly improved cognitive function is the most significant change in human evolutionary history. Recently, several large-scale studies reported the evolutionary roles of DNA methylation; however, the role of DNA methylation on brain evolution is largely unknown. Results To test if DNA methylation has contributed to the evolution of human brain, with the use of MeDIP-Chip and SEQUENOM MassARRAY, we conducted a genome-wide analysis to identify differentially methylated regions (DMRs in the brain between humans and rhesus macaques. We first identified a total of 150 candidate DMRs by the MeDIP-Chip method, among which 4 DMRs were confirmed by the MassARRAY analysis. All 4 DMRs are within or close to the CpG islands, and a MIR3 repeat element was identified in one DMR, but no repeat sequence was observed in the other 3 DMRs. For the 4 DMR genes, their proteins tend to be conserved and two genes have neural related functions. Bisulfite sequencing and phylogenetic comparison among human, chimpanzee, rhesus macaque and rat suggested several regions of lineage specific DNA methylation, including a human specific hypomethylated region in the promoter of K6IRS2 gene. Conclusions Our study provides a new angle of studying human brain evolution and understanding the evolutionary role of DNA methylation in the central nervous system. The results suggest that the patterns of DNA methylation in the brain are in general similar between humans and non-human primates, and only a few DMRs were identified.

  17. Distinct genetic loci control plasma HIV-RNA and cellular HIV-DNA levels in HIV-1 infection: the ANRS Genome Wide Association 01 study.

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    Cyril Dalmasso

    Full Text Available Previous studies of the HIV-1 disease have shown that HLA and Chemokine receptor genetic variants influence disease progression and early viral load. We performed a Genome Wide Association study in a cohort of 605 HIV-1-infected seroconverters for detection of novel genetic factors that influence plasma HIV-RNA and cellular HIV-DNA levels. Most of the SNPs strongly associated with HIV-RNA levels were localised in the 6p21 major histocompatibility complex (MHC region and were in the vicinity of class I and III genes. Moreover, protective alleles for four disease-associated SNPs in the MHC locus (rs2395029, rs13199524, rs12198173 and rs3093662 were strikingly over-represented among forty-five Long Term HIV controllers. Furthermore, we show that the HIV-DNA levels (reflecting the HIV reservoir are associated with the same four SNPs, but also with two additional SNPs on chromosome 17 (rs6503919; intergenic region flanked by the DDX40 and YPEL2 genes and chromosome 8 (rs2575735; within the Syndecan 2 gene. Our data provide evidence that the MHC controls both HIV replication and HIV reservoir. They also indicate that two additional genomic loci may influence the HIV reservoir.

  18. DNA replication timing is maintained genome-wide in primary human myoblasts independent of D4Z4 contraction in FSH muscular dystrophy.

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    Benjamin D Pope

    Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is linked to contraction of an array of tandem 3.3-kb repeats (D4Z4 at 4q35.2 from 11-100 copies to 1-10 copies. The extent to which D4Z4 contraction at 4q35.2 affects overall 4q35.2 chromatin organization remains unclear. Because DNA replication timing is highly predictive of long-range chromatin interactions, we generated genome-wide replication-timing profiles for FSHD and control myogenic precursor cells. We compared non-immortalized myoblasts from four FSHD patients and three control individuals to each other and to a variety of other human cell types. This study also represents the first genome-wide comparison of replication timing profiles in non-immortalized human cell cultures. Myoblasts from both control and FSHD individuals all shared a myoblast-specific replication profile. In contrast, male and female individuals were readily distinguished by monoallelic differences in replication timing at DXZ4 and other regions across the X chromosome affected by X inactivation. We conclude that replication timing is a robust cell-type specific feature that is unaffected by FSHD-related D4Z4 contraction.

  19. Genome-wide DNA methylation patterns in naïve CD4+ T cells from patients with primary Sjögren’s syndrome

    Science.gov (United States)

    Altorok, Nezam; Coit, Patrick; Hughes, Travis; Koelsch, Kristi A.; Stone, Donald U.; Rasmussen, Astrid; Radfar, Lida; Scofield, R. Hal; Sivils, Kathy L.; Farris, A. Darise; Sawalha, Amr H.

    2013-01-01

    Objective Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease with incompletely understood etiology. Very little is known about the role of epigenetic dysregulation in the pathogenesis of pSS. Methods We performed a genome-wide DNA methylation study in naïve CD4+ T cells in eleven pSS patients compared to age-, sex-, and ethnicity-matched healthy controls. Cytosine methylation was quantified using the Illumina Infinium HumanMethylation450 BeadChip array and validated using bisulfite sequencing. Results We identified 553 hypomethylated and 200 hypermethylated CpG sites in naïve CD4+ T cells from pSS patients compared to healthy matched controls, representing 311 hypomethylated and 115 hypermethylated gene regions. Hypomethylated genes in pSS include LTA, coding for Lymphotoxin α. Other relevant genes such as CD247, TNFRSF25, PTPRC, GSTM1 and PDCD1 were also hypomethylated. The interferon signature pathway was represented by hypomethylation of STAT1, IFI44L, USP18 and IFITM1. A group of genes encoding for members of the solute carrier proteins were differentially methylated. In addition, the transcription factor RUNX1 was hypermethylated in patients, suggesting a possible connection to lymphoma predisposition. Gene ontology (GO) analysis of hypomethylated genes demonstrated enrichment of genes involved in lymphocyte activation and immune response. GO terms for hypermethylated genes included antigen processing and presentation. Conclusion This is the first epigenome-wide DNA methylation study in pSS. Our data highlight a role for DNA methylation in pSS and identify disease-associated DNA methylation changes in several genes and pathways in naïve CD4+ T cells in pSS that may be involved in the pathogenesis of this disease. PMID:24574234

  20. Genome-wide analysis of DNA methylation differences in muscle and fat from monozygotic twins discordant for type 2 diabetes

    DEFF Research Database (Denmark)

    Ribel-Madsen, Rasmus; Fraga, Mario F; Jacobsen, Stine

    2012-01-01

    Monozygotic twins discordant for type 2 diabetes constitute an ideal model to study environmental contributions to type 2 diabetic traits. We aimed to examine whether global DNA methylation differences exist in major glucose metabolic tissues from these twins.......Monozygotic twins discordant for type 2 diabetes constitute an ideal model to study environmental contributions to type 2 diabetic traits. We aimed to examine whether global DNA methylation differences exist in major glucose metabolic tissues from these twins....

  1. Genome-wide DNA-(de)methylation is associated with Noninfectious Bud-failure exhibition in Almond (Prunus dulcis [Mill.] D.A.Webb)

    Science.gov (United States)

    Fresnedo-Ramírez, Jonathan; Chan, Helen M.; Parfitt, Dan E.; Crisosto, Carlos H.; Gradziel, Thomas M.

    2017-01-01

    Noninfectious bud-failure (BF) remains a major threat to almond production in California, particularly with the recent rapid expansion of acreage and as more intensive cultural practices and modern cultivars are adopted. BF has been shown to be inherited in both vegetative and sexual progeny, with exhibition related to the age and propagation history of scion clonal sources. These characteristics suggest an epigenetic influence, such as the loss of juvenility mediated by DNA-(de)methylation. Various degrees of BF have been reported among cultivars as well as within sources of clonal propagation of the same cultivar. Genome-wide methylation profiles for different clones within almond genotypes were developed to examine their association with BF levels and association with the chronological time from initial propagation. The degree of BF exhibition was found to be associated with DNA-(de)methylation and clonal age, which suggests that epigenetic changes associated with ageing may be involved in the differential exhibition of BF within and among almond clones. Research is needed to investigate the potential of DNA-(de)methylation status as a predictor for BF as well as for effective strategies to improve clonal selection against age related deterioration. This is the first report of an epigenetic-related disorder threatening a major tree crop. PMID:28202904

  2. Genome-wide DNA binding pattern of the homeodomain transcription factor Sine oculis (So in the developing eye of Drosophila melanogaster

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    Barbara Jusiak

    2014-12-01

    Full Text Available The eye of the fruit fly Drosophila melanogaster provides a highly tractable genetic model system for the study of animal development, and many genes that regulate Drosophila eye formation have homologs implicated in human development and disease. Among these is the homeobox gene sine oculis (so, which encodes a homeodomain transcription factor (TF that is both necessary for eye development and sufficient to reprogram a subset of cells outside the normal eye field toward an eye fate. We have performed a genome-wide analysis of So binding to DNA prepared from developing Drosophila eye tissue in order to identify candidate direct targets of So-mediated transcriptional regulation, as described in our recent article [20]. The data are available from NCBI Gene Expression Omnibus (GEO with the accession number GSE52943. Here we describe the methods, data analysis, and quality control of our So ChIP-seq dataset.

  3. Genome-Wide Screening of Genes Showing Altered Expression in Liver Metastases of Human Colorectal Cancers by cDNA Microarray

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    Rempei Yanagawa

    2001-01-01

    Full Text Available In spite of intensive and increasingly successful attempts to determine the multiple steps involved in colorectal carcinogenesis, the mechanisms responsible for metastasis of colorectal tumors to the liver remain to be clarified. To identify genes that are candidates for involvement in the metastatic process, we analyzed genome-wide expression profiles of 10 primary colorectal cancers and their corresponding metastatic lesions by means of a cDNA microarray consisting of 9121 human genes. This analysis identified 40 genes whose expression was commonly upregulated in metastatic lesions, and 7 that were commonly downregulated. The upregulated genes encoded proteins involved in cell adhesion, or remodeling of the actin cytoskeleton. Investigation of the functions of more of the altered genes should improve our understanding of metastasis and may identify diagnostic markers and/or novel molecular targets for prevention or therapy of metastatic lesions.

  4. Genome-wide DNA methylation profiles according to Chlamydophila psittaci infection and the response to doxycycline treatment in ocular adnexal lymphoma.

    Science.gov (United States)

    Lee, Min Joung; Min, Byung-Joo; Choung, Ho-Kyung; Kim, Namju; Kim, Young A; Khwarg, Sang In

    2014-01-01

    To compare genome-wide DNA methylation profiles according to Chlamydophila psittaci (Cp) infection status and the response to doxycycline treatment in Korean patients with ocular adnexal extranodal marginal zone B-cell lymphoma (EMZL). Twelve ocular adnexal EMZL cases were classified into two groups (six Cp-positive cases and six Cp-negative cases). Among the 12 cases, eight were treated with doxycycline as first-line therapy, and they were divided into two groups according to their response to the treatment (four doxy-responders and four doxy-nonresponders). The differences in the DNA methylation states of 27,578 methylation sites in 14,000 genes were evaluated using Illumina bead assay technology. We also validated the top-ranking differentially methylated genes (DMGs) with bisulfite direct sequencing or pyrosequencing. The Infinium methylation chip assay revealed 180 DMGs in the Cp-positive group (74 hypermethylated genes and 106 hypomethylated genes) compared to the Cp-negative group. Among the 180 DMGs, DUSP22, which had two significantly hypomethylated loci, was validated, and the correlation was significant for one CpG site (Spearman coefficient=0.6478, p=0.0262). Regarding the response to doxycycline treatment, a total of 778 DMGs were revealed (389 hypermethylated genes and 336 hypomethylated genes in the doxy-responder group). In a subsequent replication study for representative hypomethylated (IRAK1) and hypermethylated (CXCL6) genes, the correlation between the bead chip analysis and pyrosequencing was significant (Spearman coefficient=0.8961 and 0.7619, respectively, p<0.05). Ocular adnexal EMZL showed distinct methylation patterns according to Cp infection and the response to doxycycline treatment in this genome-wide methylation study. Among the candidate genes, DUSP22 has a methylation status that was likely attributable to Cp infection. Our data also suggest that the methylation statuses of IRAK1 and CXCL6 may reflect the response to doxycycline

  5. A Genome-Wide mQTL Analysis in Human Adipose Tissue Identifies Genetic Variants Associated with DNA Methylation, Gene Expression and Metabolic Traits.

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    Petr Volkov

    Full Text Available Little is known about the extent to which interactions between genetics and epigenetics may affect the risk of complex metabolic diseases and/or their intermediary phenotypes. We performed a genome-wide DNA methylation quantitative trait locus (mQTL analysis in human adipose tissue of 119 men, where 592,794 single nucleotide polymorphisms (SNPs were related to DNA methylation of 477,891 CpG sites, covering 99% of RefSeq genes. SNPs in significant mQTLs were further related to gene expression in adipose tissue and obesity related traits. We found 101,911 SNP-CpG pairs (mQTLs in cis and 5,342 SNP-CpG pairs in trans showing significant associations between genotype and DNA methylation in adipose tissue after correction for multiple testing, where cis is defined as distance less than 500 kb between a SNP and CpG site. These mQTLs include reported obesity, lipid and type 2 diabetes loci, e.g. ADCY3/POMC, APOA5, CETP, FADS2, GCKR, SORT1 and LEPR. Significant mQTLs were overrepresented in intergenic regions meanwhile underrepresented in promoter regions and CpG islands. We further identified 635 SNPs in significant cis-mQTLs associated with expression of 86 genes in adipose tissue including CHRNA5, G6PC2, GPX7, RPL27A, THNSL2 and ZFP57. SNPs in significant mQTLs were also associated with body mass index (BMI, lipid traits and glucose and insulin levels in our study cohort and public available consortia data. Importantly, the Causal Inference Test (CIT demonstrates how genetic variants mediate their effects on metabolic traits (e.g. BMI, cholesterol, high-density lipoprotein (HDL, hemoglobin A1c (HbA1c and homeostatic model assessment of insulin resistance (HOMA-IR via altered DNA methylation in human adipose tissue. This study identifies genome-wide interactions between genetic and epigenetic variation in both cis and trans positions influencing gene expression in adipose tissue and in vivo (dysmetabolic traits associated with the development of

  6. Genome-Wide DNA Methylation Analysis Identifies Novel Hypomethylated Non-Pericentromeric Genes with Potential Clinical Implications in ICF Syndrome.

    Science.gov (United States)

    Simo-Riudalbas, L; Diaz-Lagares, A; Gatto, S; Gagliardi, M; Crujeiras, A B; Matarazzo, M R; Esteller, M; Sandoval, J

    2015-01-01

    Immunodeficiency, centromeric instability and facial anomalies syndrome (ICF) is a rare autosomal recessive disease, characterized by severe hypomethylation in pericentromeric regions of chromosomes (1, 16 and 9), marked immunodeficiency and facial anomalies. The majority of ICF patients present mutations in the DNMT3B gene, affecting the DNA methyltransferase activity of the protein. In the present study, we have used the Infinium 450K DNA methylation array to evaluate the methylation level of 450,000 CpGs in lymphoblastoid cell lines and untrasformed fibroblasts derived from ICF patients and healthy donors. Our results demonstrate that ICF-specific DNMT3B variants A603T/STP807ins and V699G/R54X cause global DNA hypomethylation compared to wild-type protein. We identified 181 novel differentially methylated positions (DMPs) including subtelomeric and intrachromosomic regions, outside the classical ICF-related pericentromeric hypomethylated positions. Interestingly, these sites were mainly located in intergenic regions and inside the CpG islands. Among the identified hypomethylated CpG-island associated genes, we confirmed the overexpression of three selected genes, BOLL, SYCP2 and NCRNA00221, in ICF compared to healthy controls, which are supposed to be expressed in germ line and silenced in somatic tissues. In conclusion, this study contributes in clarifying the direct relationship between DNA methylation defect and gene expression impairment in ICF syndrome, identifying novel direct target genes of DNMT3B. A high percentage of the DMPs are located in the subtelomeric regions, indicating a specific role of DNMT3B in methylating these chromosomal sites. Therefore, we provide further evidence that hypomethylation in specific non-pericentromeric regions of chromosomes might be involved in the molecular pathogenesis of ICF syndrome. The detection of DNA hypomethylation at BOLL, SYCP2 and NCRNA00221 may pave the way for the development of specific clinical biomarkers

  7. Genome-Wide DNA Methylation Analysis Identifies Novel Hypomethylated Non-Pericentromeric Genes with Potential Clinical Implications in ICF Syndrome.

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    L Simo-Riudalbas

    Full Text Available Immunodeficiency, centromeric instability and facial anomalies syndrome (ICF is a rare autosomal recessive disease, characterized by severe hypomethylation in pericentromeric regions of chromosomes (1, 16 and 9, marked immunodeficiency and facial anomalies. The majority of ICF patients present mutations in the DNMT3B gene, affecting the DNA methyltransferase activity of the protein. In the present study, we have used the Infinium 450K DNA methylation array to evaluate the methylation level of 450,000 CpGs in lymphoblastoid cell lines and untrasformed fibroblasts derived from ICF patients and healthy donors. Our results demonstrate that ICF-specific DNMT3B variants A603T/STP807ins and V699G/R54X cause global DNA hypomethylation compared to wild-type protein. We identified 181 novel differentially methylated positions (DMPs including subtelomeric and intrachromosomic regions, outside the classical ICF-related pericentromeric hypomethylated positions. Interestingly, these sites were mainly located in intergenic regions and inside the CpG islands. Among the identified hypomethylated CpG-island associated genes, we confirmed the overexpression of three selected genes, BOLL, SYCP2 and NCRNA00221, in ICF compared to healthy controls, which are supposed to be expressed in germ line and silenced in somatic tissues.In conclusion, this study contributes in clarifying the direct relationship between DNA methylation defect and gene expression impairment in ICF syndrome, identifying novel direct target genes of DNMT3B. A high percentage of the DMPs are located in the subtelomeric regions, indicating a specific role of DNMT3B in methylating these chromosomal sites. Therefore, we provide further evidence that hypomethylation in specific non-pericentromeric regions of chromosomes might be involved in the molecular pathogenesis of ICF syndrome. The detection of DNA hypomethylation at BOLL, SYCP2 and NCRNA00221 may pave the way for the development of specific

  8. Genome-Wide DNA Methylation as an Epigenetic Consequence of Epstein-Barr Virus Infection of Immortalized Keratinocytes

    OpenAIRE

    2014-01-01

    The oral cavity is a persistent reservoir for Epstein-Barr virus (EBV) with lifelong infection of resident epithelial and B cells. Infection of these cell types results in distinct EBV gene expression patterns regulated by epigenetic modifications involving DNA methylation and chromatin structure. Regulation of EBV gene expression relies on viral manipulation of the host epigenetic machinery that may result in long-lasting host epigenetic reprogramming. To identify epigenetic events following...

  9. Kidney Dysfunction in Adult Offspring Exposed In Utero to Type 1 Diabetes Is Associated with Alterations in Genome-Wide DNA Methylation.

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    Jean-François Gautier

    Full Text Available Fetal exposure to hyperglycemia impacts negatively kidney development and function.Our objective was to determine whether fetal exposure to moderate hyperglycemia is associated with epigenetic alterations in DNA methylation in peripheral blood cells and whether those alterations are related to impaired kidney function in adult offspring.Twenty nine adult, non-diabetic offspring of mothers with type 1 diabetes (T1D (case group were matched with 28 offspring of T1D fathers (control group for the study of their leukocyte genome-wide DNA methylation profile (27,578 CpG sites, Human Methylation 27 BeadChip, Illumina Infinium. In a subset of 19 cases and 18 controls, we assessed renal vascular development by measuring Glomerular Filtration Rate (GFR and Effective Renal Plasma Flow (ERPF at baseline and during vasodilatation produced by amino acid infusion.Globally, DNA was under-methylated in cases vs. controls. Among the 87 CpG sites differently methylated, 74 sites were less methylated and 13 sites more methylated in cases vs. controls. None of these CpG sites were located on a gene known to be directly involved in kidney development and/or function. However, the gene encoding DNA methyltransferase 1 (DNMT1--a key enzyme involved in gene expression during early development--was under-methylated in cases. The average methylation of the 74 under-methylated sites differently correlated with GFR in cases and controls.Alterations in methylation profile imprinted by the hyperglycemic milieu of T1D mothers during fetal development may impact kidney function in adult offspring. The involved pathways seem to be a nonspecific imprinting process rather than specific to kidney development or function.

  10. Genome-wide expression profiling of the response to terbinafine in Candida albicans using a cDNA microarray analysis

    Institute of Scientific and Technical Information of China (English)

    ZENG Yue-bin; QIAN Yuan-shu; MA Lian; GU Hong-ni

    2007-01-01

    Background Candida albicans is the most frequently seen opportunistic human fungal pathogen. Terbinafine is an allylamine antifungal agent that has been proven to have high clinical efficacy in the therapy of fungal infections, the mechanism of action of terbinafine involves the specific inhibition of fungal squalene epoxidase, resulting in ergosterol deficiency and accumulation of intracellular squalene. We used cDNA microarray analysis technology to monitor global expression profile changes of Candida albicans genes in response to terbinafine treatment, and we anticipated a panoramic view of the responses of Candida albicans cells to the representatives of allylamine antifungal agents at the molecular level in an effort to identify drug class-specific and mechanism-independent changes in gene expression.Methods Candida albicans strain ATCC 90028 was exposed to either medium alone or terbinafine at a concentration equivalent to the 1/2 minimal inhibitory concentrations (MICs, 4 mg/L) for 90 minutes. RNA was isolated and gene expression profiles were compared to identify the changes in the gene expression profile using a cDNA microarray analysis. Differential expression of 10 select genes detected by cDNA microarray analysis was confirmed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR).Results A total of 222 genes were found to be responsive to terbinafine, including 121 up-regulated genes and 101 down-regulated genes. These included genes encoding membrane transport proteins belonging to the members of the ATP-binding cassette (ABC) or major facilitator superfamily (MFS; CDR1, AGP2, GAP6, PHO84, HOL3, FCY23, VCX1),genes involved in stress response and detoxification (CDR1, AGP2, HOL3), and gene involved in the ergosterol biosynthesis pathway (ERG12). The results of semi-quantitative RT-PCR were consistent with that of the cDNA microarray analysis.Conclusions The up-regulation of the gene encoding the multidrug resistance efflux pump

  11. Genome-wide DNA methylation analysis of transient neonatal diabetes type 1 patients with mutations in ZFP57

    DEFF Research Database (Denmark)

    Bak, Mads; Boonen, Susanne E; Dahl, Christina

    2016-01-01

    of developing diabetes mellitus type 2 later in life. Transient neonatal diabetes mellitus 1 is caused by overexpression of the maternally imprinted genes PLAGL1 and HYMAI on chromosome 6q24. One of the mechanisms leading to overexpression of the locus is hypomethylation of the maternal allele of PLAGL1......BACKGROUND: Transient neonatal diabetes mellitus 1 (TNDM1) is a rare imprinting disorder characterized by intrautering growth retardation and diabetes mellitus usually presenting within the first six weeks of life and resolves by the age of 18 months. However, patients have an increased risk...... and HYMAI. A subset of patients with maternal hypomethylation at PLAGL1 have hypomethylation at additional imprinted loci throughout the genome, including GRB10, ZIM2 (PEG3), MEST (PEG1), KCNQ1OT1 and NESPAS (GNAS-AS1). About half of the TNDM1 patients carry mutations in ZFP57, a transcription factor...

  12. A genome-wide scan reveals important roles of DNA methylation in human longevity by regulating age-related disease genes.

    Directory of Open Access Journals (Sweden)

    Fu-Hui Xiao

    Full Text Available It is recognized that genetic factors contribute to human longevity. Besides the hypothesis of existence of longevity genes, another suggests that a lower frequency of risk alleles decreases the incidence of age-related diseases in the long-lived people. However, the latter finds no support from recent genetic studies. Considering the crucial role of epigenetic modification in gene regulation, we then hypothesize that suppressing disease-related genes in longevity individuals is likely achieved by epigenetic modification, e.g. DNA methylation. To test this hypothesis, we investigated the genome-wide methylation profile in 4 Chinese female centenarians and 4 middle-aged controls using methyl-DNA immunoprecipitation sequencing. 626 differentially methylated regions (DMRs were observed between both groups. Interestingly, genes with these DMRs were enriched in age-related diseases, including type-2 diabetes, cardiovascular disease, stroke and Alzheimer's disease. This pattern remains rather stable after including methylomes of two white individuals. Further analyses suggest that the observed DMRs likely have functional roles in regulating disease-associated gene expressions, with some genes [e.g. caspase 3 (CASP3] being down-regulated whereas the others [i.e. interleukin 1 receptor, type 2 (IL1R2] up-regulated. Therefore, our study suggests that suppressing the disease-related genes via epigenetic modification is an important contributor to human longevity.

  13. Genome-wide mapping of human DNA-replication origins: levels of transcription at ORC1 sites regulate origin selection and replication timing.

    Science.gov (United States)

    Dellino, Gaetano Ivan; Cittaro, Davide; Piccioni, Rossana; Luzi, Lucilla; Banfi, Stefania; Segalla, Simona; Cesaroni, Matteo; Mendoza-Maldonado, Ramiro; Giacca, Mauro; Pelicci, Pier Giuseppe

    2013-01-01

    We report the genome-wide mapping of ORC1 binding sites in mammals, by chromatin immunoprecipitation and parallel sequencing (ChIP-seq). ORC1 binding sites in HeLa cells were validated as active DNA replication origins (ORIs) using Repli-seq, a method that allows identification of ORI-containing regions by parallel sequencing of temporally ordered replicating DNA. ORC1 sites were universally associated with transcription start sites (TSSs) of coding or noncoding RNAs (ncRNAs). Transcription levels at the ORC1 sites directly correlated with replication timing, suggesting the existence of two classes of ORIs: those associated with moderate/high transcription levels (≥1 RNA copy/cell), firing in early S and mapping to the TSSs of coding RNAs; and those associated with low transcription levels (<1 RNA copy/cell), firing throughout the entire S and mapping to TSSs of ncRNAs. These findings are compatible with a scenario whereby TSS expression levels influence the efficiency of ORC1 recruitment at G(1) and the probability of firing during S.

  14. Genome-wide Anaplasma phagocytophilum AnkA-DNA interactions are enriched in intergenic regions and gene promoters and correlate with infection-induced differential gene expression.

    Directory of Open Access Journals (Sweden)

    J Stephen Dumler

    2016-09-01

    Full Text Available Anaplasma phagocytophilum, an obligate intracellular prokaryote, infects neutrophils and alters cardinal functions via reprogrammed transcription. Large contiguous regions of neutrophil chromosomes are differentially expressed during infection. Secreted A. phagocytophilum effector AnkA transits into the neutrophil or granulocyte nucleus to complex with DNA in heterochromatin across all chromosomes. AnkA binds to gene promoters to dampen cis-transcription and also has features of matrix attachment region (MAR-binding proteins that regulate three-dimensional chromatin architecture and coordinate transcriptional programs encoded in topologically-associated chromatin domains. We hypothesize that identification of additional AnkA binding sites will better delineate how A. phagocytophilum infection results in reprogramming of the neutrophil genome. Using AnkA-binding ChIP-seq, we showed that AnkA binds broadly throughout all chromosomes in a reproducible pattern, especially at: i intergenic regions predicted to be matrix attachment regions (MARs; ii within predicted lamina-associated domains; and iii at promoters ≤3,000 bp upstream of transcriptional start sites. These findings provide genome-wide support for AnkA as a regulator of cis-gene transcription. Moreover, the dominant mark of AnkA in distal intergenic regions known to be AT-enriched, coupled with frequent enrichment in the nuclear lamina, provides strong support for its role as a MAR-binding protein and genome re-organizer. AnkA must be considered a prime candidate to promote neutrophil reprogramming and subsequent functional changes that belie improved microbial fitness and pathogenicity.

  15. No DNA damage response and negligible genome-wide transcriptional changes in human embryonic stem cells exposed to terahertz radiation.

    Science.gov (United States)

    Bogomazova, A N; Vassina, E M; Goryachkovskaya, T N; Popik, V M; Sokolov, A S; Kolchanov, N A; Lagarkova, M A; Kiselev, S L; Peltek, S E

    2015-01-13

    Terahertz (THz) radiation was proposed recently for use in various applications, including medical imaging and security scanners. However, there are concerns regarding the possible biological effects of non-ionising electromagnetic radiation in the THz range on cells. Human embryonic stem cells (hESCs) are extremely sensitive to environmental stimuli, and we therefore utilised this cell model to investigate the non-thermal effects of THz irradiation. We studied DNA damage and transcriptome responses in hESCs exposed to narrow-band THz radiation (2.3 THz) under strict temperature control. The transcription of approximately 1% of genes was subtly increased following THz irradiation. Functional annotation enrichment analysis of differentially expressed genes revealed 15 functional classes, which were mostly related to mitochondria. Terahertz irradiation did not induce the formation of γH2AX foci or structural chromosomal aberrations in hESCs. We did not observe any effect on the mitotic index or morphology of the hESCs following THz exposure.

  16. Genome-wide profiles of H2AX and γ-H2AX differentiate endogenous and exogenous DNA damage hotspots in human cells.

    Science.gov (United States)

    Seo, Jungmin; Kim, Sang Cheol; Lee, Heun-Sik; Kim, Jung Kyu; Shon, Hye Jin; Salleh, Nur Lina Mohd; Desai, Kartiki Vasant; Lee, Jae Ho; Kang, Eun-Suk; Kim, Jin Sung; Choi, Jung Kyoon

    2012-07-01

    Phosphorylation of the histone variant H2AX forms γ-H2AX that marks DNA double-strand break (DSB). Here, we generated the sequencing-based maps of H2AX and γ-H2AX positioning in resting and proliferating cells before and after ionizing irradiation. Genome-wide locations of possible endogenous and exogenous DSBs were identified based on γ-H2AX distribution in dividing cancer cells without irradiation and that in resting cells upon irradiation, respectively. γ-H2AX-enriched regions of endogenous origin in replicating cells included sub-telomeres and active transcription start sites, apparently reflecting replication- and transcription-mediated stress during rapid cell division. Surprisingly, H2AX itself, prior to phosphorylation, was specifically located at these endogenous hotspots. This phenomenon was only observed in dividing cancer cells but not in resting cells. Endogenous H2AX was concentrated on the transcription start site of actively transcribed genes but was irrelevant to pausing of RNA polymerase II (pol II), which precisely coincided with γ-H2AX of endogenous origin. γ-H2AX enrichment upon irradiation also coincided with actively transcribed regions, but unlike endogenous γ-H2AX, it extended into the gene body and was not specifically concentrated on the pausing site of pol II. Sub-telomeres were less responsive to external DNA damage than to endogenous stress. Our findings provide insight into DNA repair programs of cancer and may have implications for cancer therapy.

  17. Genome-wide analysis of heteroduplex DNA in mismatch repair-deficient yeast cells reveals novel properties of meiotic recombination pathways.

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    Emmanuelle Martini

    2011-09-01

    Full Text Available Meiotic DNA double-strand breaks (DSBs initiate crossover (CO recombination, which is necessary for accurate chromosome segregation, but DSBs may also repair as non-crossovers (NCOs. Multiple recombination pathways with specific intermediates are expected to lead to COs and NCOs. We revisited the mechanisms of meiotic DSB repair and the regulation of CO formation, by conducting a genome-wide analysis of strand-transfer intermediates associated with recombination events. We performed this analysis in a SK1 × S288C Saccharomyces cerevisiae hybrid lacking the mismatch repair (MMR protein Msh2, to allow efficient detection of heteroduplex DNAs (hDNAs. First, we observed that the anti-recombinogenic activity of MMR is responsible for a 20% drop in CO number, suggesting that in MMR-proficient cells some DSBs are repaired using the sister chromatid as a template when polymorphisms are present. Second, we observed that a large fraction of NCOs were associated with trans-hDNA tracts constrained to a single chromatid. This unexpected finding is compatible with dissolution of double Holliday junctions (dHJs during repair, and it suggests the existence of a novel control point for CO formation at the level of the dHJ intermediate, in addition to the previously described control point before the dHJ formation step. Finally, we observed that COs are associated with complex hDNA patterns, confirming that the canonical double-strand break repair model is not sufficient to explain the formation of most COs. We propose that multiple factors contribute to the complexity of recombination intermediates. These factors include repair of nicks and double-stranded gaps, template switches between non-sister and sister chromatids, and HJ branch migration. Finally, the good correlation between the strand transfer properties observed in the absence of and in the presence of Msh2 suggests that the intermediates detected in the absence of Msh2 reflect normal intermediates.

  18. 7A.03: TRANSGENERATIONAL INHERITANCE OF GENOME-WIDE DNA METHYLATION PROFILES IN PULMONARY VASCULAR ENDOTHELIAL DYSFUNCTION FOLLOWING EXTRAUTERINE GROWTH RESTRICTION.

    Science.gov (United States)

    Zhang, L; Du, L; Tang, L; Lao, L; Hu, Q

    2015-06-01

    Early postnatal life is considered as a critical time window for determination of long-term metabolic states and organ functions. Extrauterine growth restriction (EUGR) causes the development of adult onset chronic diseases, including pulmonary hypertension (PH). However, the mechanisms involved and the possibilities of transgenerational transmission on pulmonary vascular consequences in later life are still unclear. Epigenetic information can be inherited and represents a plausible transgenerational carrier of environmental information. Our study was designed to test whether epigenetics dysregulation mediates the cellular memory of this early postnatal event.(Figure is included in full-text article.) : To test this hypothesis, the EUGR pups were established by undernutritional until weaning. We isolated pulmonary vascular endothelial cells (PVEC) by magnetic-activated cell sorting (MACS) from EUGR and control rats. MeDIP-chip (Methyl-DNA immune precipitation chip), genome-scale mapping studies to search for differentially methylated loci. A postnatal insult, nutritional restriction-induced EUGR caused development of an increased PH at 9-week of age in male rats (First-generation of EUGR, F1-EUGR male). We intercrossed female adult control and F1-EUGR-male rats to obtain the second-generation (F2) offspring in two groups: C male-C female, EUGR-male -C-female. We found that significantly decreased pulmonary artery pressure in F2 female offspring in EUGR-male-C-female group (F2-EUGR-female), compared with controls to some degrees. we carried out genome-wide DNA methylation profiles screen for genes in rats between F1-EUGR-male and F2-EUGR-female. The EUGR and control group comparisons revealed consistently and distinctively methylated loci, with 74.8% F1-EUGR-male group and 84.5% F2-EUGR-female group changes in hyper-methylation loci enriched for highly significant group differences. Gene ontology (GO) analysis on no consistent differentially methylated genes

  19. Genome-wide and phase-specific DNA-binding rhythms of BMAL1 control circadian output functions in mouse liver.

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    Guillaume Rey

    2011-02-01

    Full Text Available The mammalian circadian clock uses interlocked negative feedback loops in which the heterodimeric basic helix-loop-helix transcription factor BMAL1/CLOCK is a master regulator. While there is prominent control of liver functions by the circadian clock, the detailed links between circadian regulators and downstream targets are poorly known. Using chromatin immunoprecipitation combined with deep sequencing we obtained a time-resolved and genome-wide map of BMAL1 binding in mouse liver, which allowed us to identify over 2,000 binding sites, with peak binding narrowly centered around Zeitgeber time 6. Annotation of BMAL1 targets confirms carbohydrate and lipid metabolism as the major output of the circadian clock in mouse liver. Moreover, transcription regulators are largely overrepresented, several of which also exhibit circadian activity. Genes of the core circadian oscillator stand out as strongly bound, often at promoter and distal sites. Genomic sequence analysis of the sites identified E-boxes and tandem E1-E2 consensus elements. Electromobility shift assays showed that E1-E2 sites are bound by a dimer of BMAL1/CLOCK heterodimers with a spacing-dependent cooperative interaction, a finding that was further validated in transactivation assays. BMAL1 target genes showed cyclic mRNA expression profiles with a phase distribution centered at Zeitgeber time 10. Importantly, sites with E1-E2 elements showed tighter phases both in binding and mRNA accumulation. Finally, analyzing the temporal profiles of BMAL1 binding, precursor mRNA and mature mRNA levels showed how transcriptional and post-transcriptional regulation contribute differentially to circadian expression phase. Together, our analysis of a dynamic protein-DNA interactome uncovered how genes of the core circadian oscillator crosstalk and drive phase-specific circadian output programs in a complex tissue.

  20. Analysis of pigmented villonodular synovitis with genome-wide complementary DNA microarray and tissue array technology reveals insight into potential novel therapeutic approaches.

    Science.gov (United States)

    Finis, Katharina; Sültmann, Holger; Ruschhaupt, Markus; Buness, Andreas; Helmchen, Birgit; Kuner, Ruprecht; Gross, Marie-Luise; Fink, Bernd; Schirmacher, Peter; Poustka, Annemarie; Berger, Irina

    2006-03-01

    To characterize the gene expression profile and determine potential diagnostic markers and therapeutic targets in pigmented villonodular synovitis (PVNS). Gene expression patterns in 11 patients with PVNS, 18 patients with rheumatoid arthritis (RA), and 19 patients with osteoarthritis (OA) were investigated using genome-wide complementary DNA microarrays. Validation of differentially expressed genes was performed by real-time quantitative polymerase chain reaction and immunohistochemical analysis on tissue arrays (80 patients with PVNS, 51 patients with RA, and 20 patients with OA). The gene expression profile in PVNS was clearly distinct from those in RA and OA. One hundred forty-one up-regulated genes and 47 down-regulated genes were found in PVNS compared with RA, and 153 up-regulated genes and 89 down-regulated genes were found in PVNS compared with OA (fold change > or = 1.5; Q PVNS were involved in apoptosis regulation, matrix degradation, and inflammation (ALOX5AP, ATP6V1B2, CD53, CHI3L1, CTSL, CXCR4, HSPA8, HSPCA, LAPTM5, MMP9, MOAP1, and SPP1). The gene expression signature in PVNS is similar to that of activated macrophages and is consistent with the local destructive course of the disease. The gene and protein expression patterns suggest that the ongoing proliferation in PVNS is sustained by apoptosis resistance. This result suggests the possibility of a potential novel therapeutic intervention against PVNS.

  1. Epstein-Barr virus nuclear antigen 3A partially coincides with EBNA3C genome-wide and is tethered to DNA through BATF complexes.

    Science.gov (United States)

    Schmidt, Stefanie C S; Jiang, Sizun; Zhou, Hufeng; Willox, Bradford; Holthaus, Amy M; Kharchenko, Peter V; Johannsen, Eric C; Kieff, Elliott; Zhao, Bo

    2015-01-13

    Epstein-Barr Virus (EBV) conversion of B-lymphocytes to Lymphoblastoid Cell Lines (LCLs) requires four EBV nuclear antigen (EBNA) oncoproteins: EBNA2, EBNALP, EBNA3A, and EBNA3C. EBNA2 and EBNALP associate with EBV and cell enhancers, up-regulate the EBNA promoter, MYC, and EBV Latent infection Membrane Proteins (LMPs), which up-regulate BCL2 to protect EBV-infected B-cells from MYC proliferation-induced cell death. LCL proliferation induces p16(INK4A) and p14(ARF)-mediated cell senescence. EBNA3A and EBNA3C jointly suppress p16(INK4A) and p14(ARF), enabling continuous cell proliferation. Analyses of the EBNA3A human genome-wide ChIP-seq landscape revealed 37% of 10,000 EBNA3A sites to be at strong enhancers; 28% to be at weak enhancers; 4.4% to be at active promoters; and 6.9% to be at weak and poised promoters. EBNA3A colocalized with BATF-IRF4, ETS-IRF4, RUNX3, and other B-cell Transcription Factors (TFs). EBNA3A sites clustered into seven unique groups, with differing B-cell TFs and epigenetic marks. EBNA3A coincidence with BATF-IRF4 or RUNX3 was associated with stronger EBNA3A ChIP-Seq signals. EBNA3A was at MYC, CDKN2A/B, CCND2, CXCL9/10, and BCL2, together with RUNX3, BATF, IRF4, and SPI1. ChIP-re-ChIP revealed complexes of EBNA3A on DNA with BATF. These data strongly support a model in which EBNA3A is tethered to DNA through a BATF-containing protein complexes to enable continuous cell proliferation.

  2. Genome-wide DNA methylation patterns in pancreatic ductal adenocarcinoma reveal epigenetic deregulation of SLIT-ROBO, ITGA2 and MET signaling.

    Science.gov (United States)

    Nones, Katia; Waddell, Nic; Song, Sarah; Patch, Ann-Marie; Miller, David; Johns, Amber; Wu, Jianmin; Kassahn, Karin S; Wood, David; Bailey, Peter; Fink, Lynn; Manning, Suzanne; Christ, Angelika N; Nourse, Craig; Kazakoff, Stephen; Taylor, Darrin; Leonard, Conrad; Chang, David K; Jones, Marc D; Thomas, Michelle; Watson, Clare; Pinese, Mark; Cowley, Mark; Rooman, Ilse; Pajic, Marina; Butturini, Giovanni; Malpaga, Anna; Corbo, Vincenzo; Crippa, Stefano; Falconi, Massimo; Zamboni, Giuseppe; Castelli, Paola; Lawlor, Rita T; Gill, Anthony J; Scarpa, Aldo; Pearson, John V; Biankin, Andrew V; Grimmond, Sean M

    2014-09-01

    The importance of epigenetic modifications such as DNA methylation in tumorigenesis is increasingly being appreciated. To define the genome-wide pattern of DNA methylation in pancreatic ductal adenocarcinomas (PDAC), we captured the methylation profiles of 167 untreated resected PDACs and compared them to a panel of 29 adjacent nontransformed pancreata using high-density arrays. A total of 11,634 CpG sites associated with 3,522 genes were significantly differentially methylated (DM) in PDAC and were capable of segregating PDAC from non-malignant pancreas, regardless of tumor cellularity. As expected, PDAC hypermethylation was most prevalent in the 5' region of genes (including the proximal promoter, 5'UTR and CpG islands). Approximately 33% DM genes showed significant inverse correlation with mRNA expression levels. Pathway analysis revealed an enrichment of aberrantly methylated genes involved in key molecular mechanisms important to PDAC: TGF-β, WNT, integrin signaling, cell adhesion, stellate cell activation and axon guidance. Given the recent discovery that SLIT-ROBO mutations play a clinically important role in PDAC, the role of epigenetic perturbation of axon guidance was pursued in more detail. Bisulfite amplicon deep sequencing and qRT-PCR expression analyses confirmed recurrent perturbation of axon guidance pathway genes SLIT2, SLIT3, ROBO1, ROBO3, ITGA2 and MET and suggests epigenetic suppression of SLIT-ROBO signaling and up-regulation of MET and ITGA2 expression. Hypomethylation of MET and ITGA2 correlated with high gene expression, which was associated with poor survival. These data suggest that aberrant methylation plays an important role in pancreatic carcinogenesis affecting core signaling pathways with potential implications for the disease pathophysiology and therapy.

  3. Gene interactions in the DNA damage-response pathway identified by genome-wide RNA-interference analysis of synthetic lethality

    NARCIS (Netherlands)

    van Haaften, Gijs; Vastenhouw, Nadine L; Nollen, Ellen A A; Plasterk, Ronald H A; Tijsterman, Marcel

    2004-01-01

    Here, we describe a systematic search for synthetic gene interactions in a multicellular organism, the nematode Caenorhabditis elegans. We established a high-throughput method to determine synthetic gene interactions by genome-wide RNA interference and identified genes that are required to protect t

  4. Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

    NARCIS (Netherlands)

    Kato, Norihiro; Loh, Marie; Takeuchi, Fumihiko; Verweij, Niek; Wang, Xu; Zhang, Weihua; Kelly, Tanika N.; Saleheen, Danish; Lehne, Benjamin; Leach, Irene Mateo; Drong, Alexander W.; Abbott, James; Wahl, Simone; Tan, Sian-Tsung; Scott, William R.; Campanella, Gianluca; Chadeau-Hyam, Marc; Afzal, Uzma; Ahluwalia, Tarunveer S.; Bonder, Marc Jan; Chen, Peng; Dehghan, Abbas; Edwards, Todd L.; Esko, Tonu; Go, Min Jin; Harris, Sarah E.; Hartiala, Jaana; Kasela, Silva; Kasturiratne, Anuradhani; Khor, Chiea-Chuen; Kleber, Marcus E.; Li, Huaixing; Mok, Zuan Yu; Nakatochi, Masahiro; Sapari, Nur Sabrina; Saxena, Richa; Stewart, Alexandre F. R.; Stolk, Lisette; Tabara, Yasuharu; Teh, Ai Ling; Wu, Ying; Wu, Jer-Yuarn; Zhang, Yi; Aits, Imke; Alves, Alexessander Da Silva Couto; Das, Shikta; Dorajoo, Rajkumar; Hopewell, Jemma C.; Kim, Yun Kyoung; Koivula, Robert W.; Luan, Jian'an; Lyytikainen, Leo-Pekka; Nguyen, Quang N.; Pereira, Mark A.; Postmus, Iris; Raitakari, Olli T.; Bryan, Molly Scannell; Scott, Robert A.; Sorice, Rossella; Tragante, Vinicius; Traglia, Michela; White, Jon; Yamamoto, Ken; Zhang, Yonghong; Adair, Linda S.; Ahmed, Alauddin; Akiyama, Koichi; Asif, Rasheed; Aung, Tin; Barroso, Ines; Bjonnes, Andrew; Braun, Timothy R.; Cai, Hui; Chang, Li-Ching; Chen, Chien-Hsiun; Cheng, Ching-Yu; Chong, Yap-Seng; Collins, Rory; Courtney, Regina; Davies, Gail; Delgado, Graciela; Do, Loi D.; Doevendans, Pieter A.; Gansevoort, Ron T.; Gao, Yu-Tang; Grammer, Tanja B.; Grarup, Niels; Grewal, Jagvir; Gu, Dongfeng; Wander, Gurpreet S.; Hartikainen, Anna-Liisa; Hazen, Stanley L.; He, Jing; Heng, Chew-Kiat; Hixson, James E.; Hofman, Albert; Hsu, Chris; Huang, Wei; Husemoen, Lise L. N.; Hwang, Joo-Yeon; Ichihara, Sahoko; Igase, Michiya; Isono, Masato; Justesen, Johanne M.; Katsuy, Tomohiro; Kibriya, Muhammad G.; Kim, Young Jin; Kishimoto, Miyako; Koh, Woon-Puay; Kohara, Katsuhiko; Kumari, Meena; Kwek, Kenneth; Lee, Nanette R.; Lee, Jeannette; Liao, Jiemin; Lieb, Wolfgang; Liewald, David C. M.; Matsubara, Tatsuaki; Matsushita, Yumi; Meitinger, Thomas; Mihailov, Evelin; Milani, Lili; Mills, Rebecca; Mononen, Nina; Mueller-Nurasyid, Martina; Nabika, Toru; Nakashima, Eitaro; Ng, Hong Kiat; Nikus, Kjell; Nutile, Teresa; Ohkubo, Takayoshi; Ohnaka, Keizo; Parish, Sarah; Paternoster, Lavinia; Peng, Hao; Peters, Annette; Pham, Son T.; Pinidiyapathirage, Mohitha J.; Rahman, Mahfuzar; Rakugi, Hiromi; Rolandsson, Olov; Rozario, Michelle Ann; Ruggiero, Daniela; Sala, Cinzia F.; Sarju, Ralhan; Shimokawa, Kazuro; Snieder, Harold; Sparso, Thomas; Spiering, Wilko; Starr, John M.; Stott, David J.; Stram, Daniel O.; Sugiyama, Takao; Szymczak, Silke; Tang, W. H. Wilson; Tong, Lin; Trompet, Stella; Turjanmaa, Vaino; Ueshima, Hirotsugu; Uitterlinden, Andre G.; Umemura, Satoshi; Vaarasmaki, Marja; van Dam, Rob M.; van Gilst, Wiek H.; van Veldhuisen, Dirk J.; Viikari, Jorma S.; Waldenberger, Melanie; Wang, Yiqin; Wang, Aili; Wilson, Rory; Wong, Tien-Yin; Xiang, Yong-Bing; Yamaguchi, Shuhei; Ye, Xingwang; Young, Robin D.; Young, Terri L.; Yuan, Jian-Min; Zhou, Xueya; Asselbergs, Folkert W.; Ciullo, Marina; Clarke, Robert; Deloukas, Panos; Franke, Andre; Franks, Paul W.; Franks, Steve; Friedlander, Yechiel; Gross, Myron D.; Guo, Zhirong; Hansen, Torben; Jarvelin, Marjo-Riitta; Jorgensen, Torben; Jukema, J. Wouter; Kahonen, Mika; Kajio, Hiroshi; Kivimaki, Mika; Lee, Jong-Young; Lehtimaki, Terho; Linneberg, Allan; Miki, Tetsuro; Pedersen, Oluf; Samani, Nilesh J.; Sorensen, Thorkild I. A.; Takayanagi, Ryoichi; Toniolo, Daniela; Ahsan, Habibul; Allayee, Hooman; Chen, Yuan-Tsong; Danesh, John; Deary, Ian J.; Franco, Oscar H.; Franke, Lude; Heijman, Bastiaan T.; Holbrook, Joanna D.; Isaacs, Aaron; Kim, Bong-Jo; Lin, Xu; Liu, Jianjun; Maerz, Winfried; Metspalu, Andres; Mohlke, Karen L.; Sanghera, Dharambir K.; Shu, Xiao-Ou; van Meurs, Joyce B. J.; Vithana, Eranga; Wickremasinghe, Ananda R.; Wijmenga, Cisca; Wolffenbuttel, Bruce H. W.; Yokota, Mitsuhiro; Zheng, Wei; Zhu, Dingliang; Vineis, Paolo; Kyrtopoulos, Soterios A.; Kleinjans, Jos C. S.; McCarthy, Mark I.; Soong, Richie; Gieger, Christian; Scott, James; Teo, Yik-Ying; He, Jiang; Elliott, Paul; Tai, E. Shyong; van der Harst, Pim; Kooner, Jaspal S.; Chambers, John C.; Doevendans, PAFM

    2015-01-01

    We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 x 10(-11) to 5.0 x 10(-21

  5. Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

    NARCIS (Netherlands)

    N. Kato (Norihiro); M. Loh (Marie); F. Takeuchi (Fumihiko); N. Verweij (Niek); X. Wang (Xu); W. Zhang (Weihua); T. NKelly (Tanika); D. Saleheen; B. Lehne (Benjamin); I.M. Leach (Irene Mateo); A. Drong (Alexander); J. Abbott (James); S. Wahl (Simone); S.-T. Tan (Sian-Tsung); W.R. Scott (William R.); G. Campanella (Gianluca); M. Chadeau-Hyam (Marc); U. Afzal (Uzma); T.S. Ahluwalia (Tarunveer Singh); M.J. Bonder (Marc Jan); P. Chen (Ping); A. Dehghan (Abbas); T.L. Edwards (Todd L.); T. Esko (Tõnu); M.J. Go (Min Jin); S.E. Harris (Sarah); J. Hartiala (Jaana); S. Kasela (Silva); A. Kasturiratne (Anuradhani); C.C. Khor; M.E. Kleber (Marcus); H. Li (Huaixing); Z.Y. Mok (Zuan Yu); M. Nakatochi (Masahiro); N.S. Sapari (Nur Sabrina); R. Saxena (Richa); A.F. Stewart (Alexandre F.); L. Stolk (Lisette); Y. Tabara (Yasuharu); A.L. Teh (Ai Ling); Y. Wu (Ying); J.-Y. Wu (Jer-Yuarn); Y. Zhang (Yi); I. Aits (Imke); A. Da Silva Couto Alves (Alexessander); S. Das; R. Dorajoo (Rajkumar); J. CHopewell (Jemma); Y.K. Kim (Yun Kyoung); R. WKoivula (Robert); J. Luan (Jian'An); L.-P. Lyytikäinen (Leo-Pekka); Q. NNguyen (Quang); M.A. Pereira (Mark A); D. Postmus (Douwe); O. TRaitakari (Olli); M. Scannell Bryan (Molly); R.A. Scott (Robert); R. Sorice; V. Tragante (Vinicius); M. Traglia (Michela); J. White (Jon); K. Yamamoto (Ken); Y. Zhang (Yonghong); L.S. Adair (Linda); A. Ahmed (Alauddin); K. Akiyama (Koichi); R. Asif (Rasheed); T. Aung (Tin); I. Barroso (Inês); A. Bjonnes (Andrew); T.R. Braun (Timothy R.); H. Cai (Hui); L.-C. Chang (Li-Ching); C.-H. Chen; C-Y. Cheng (Ching-Yu); Y.-S. Chong (Yap-Seng); F.S. Collins (Francis); R. Courtney (Regina); G. Davies (Gail); G. Delgado; L.D. Do (Loi D.); P.A. Doevendans (Pieter); R.T. Gansevoort (Ron); Y. Gao; T.B. Grammer (Tanja B); N. Grarup (Niels); J. Grewal (Jagvir); D. Gu (D.); G. SWander (Gurpreet); A.L. Hartikainen; S.L. Hazen (Stanley); J. He (Jing); C.K. Heng (Chew-Kiat); E.J.A. Hixso (E. James Ames); A. Hofman (Albert); C. Hsu (Chris); W. Huang (Wei); L.L.N. Husemoen (Lise Lotte); J.-Y. Hwang (Joo-Yeon); S. Ichihara (Sahoko); M. Igase (Michiya); M. Isono (Masato); J.M. Justesen (Johanne M.); T. Katsuya (Tomohiro); M. GKibriya (Muhammad); Y.J. Kim; M. Kishimoto (Miyako); W.-P. Koh (Woon-Puay); K. Kohara (Katsuhiko); M. Kumari (Meena); K. Kwek (Kenneth); N.R. Lee (Nanette); J. Lee (Jeannette); J. Liao (Jie); W. Lieb (Wolfgang); D.C. Liewald (David C.); T. Matsubara (Tatsuaki); Y. Matsushita (Yumi); T. Meitinger (Thomas); E. Mihailov (Evelin); L. Milani (Lili); R. Mills (Rebecca); K. Mononen (Kari); M. Müller-Nurasyid (Martina); T. Nabika (Toru); E. Nakashima (Eitaro); H.K. Ng (Hong Kiat); K. Nikus (Kjell); T. Nutile; T. Ohkubo (Takayoshi); K. Ohnaka (Keizo); S. Parish (Sarah); L. Paternoster (Lavinia); H. Peng (Hao); A. Peters (Annette); S. TPham (Son); M.J. Pinidiyapathirage (Mohitha J.); M. Rahman (Mahfuzar); H. Rakugi (Hiromi); O. Rolandsson (Olov); M.A. Rozario (Michelle Ann); D. Ruggiero; C. Sala (Cinzia); R. Sarju (Ralhan); K. Shimokawa (Kazuro); H. Snieder (Harold); T. Sparsø (Thomas); W. Spiering (Wilko); J.M. Starr (John); D.J. Stott (David J.); D. OStram (Daniel); T. Sugiyama (Takao); S. Szymczak (Silke); W.H.W. Tang (W.H. Wilson); L. Tong (Lin); S. Trompet (Stella); V. Turjanmaa (Väinö); H. Ueshima (Hirotsugu); A.G. Uitterlinden (André); S. Umemura (Satoshi); M. Vaarasmaki (Marja); R.M. Dam (Rob Mvan); W.H. van Gilst (Wiek); D.J. van Veldhuisen (Dirk); J. Viikari (Jorma); M. Waldenberger (Melanie); Y. Wang (Yiqin); A. Wang (Aili); R. Wilson (Rory); T.-Y. Wong (Tien-Yin); Y.-B. Xiang (Yong-Bing); S. Yamaguchi (Shuhei); X. Ye (Xingwang); R. Young (Robin); T.L. Young (Terri); J.-M. Yuan (Jian-Min); X. Zhou (Xueya); F.W. Asselbergs (Folkert); M. Ciullo; R. Clarke (Robert); P. Deloukas (Panagiotis); A. Franke (Andre); W.F. Paul (W. Frank); S. Franks (Steve); Y. Friedlander (Yechiel); M.D. Gross (Myron D.); Z. Guo (Zhirong); T. Hansen (T.); M.-R. Jarvelin (Marjo-Riitta); T. Jørgensen (Torben); J.W. Jukema (Jan Wouter); M. Kähönen (Mika); H. Kajio (Hiroshi); M. Kivimaki (Mika); J.-Y. Lee (Jong-Young); T. Lehtimäki (Terho); A. Linneberg (Allan); T. Miki (Tetsuro); O. Pedersen (Oluf); N.J. Samani (Nilesh); T.I.A. Sørensen (Thorkild); R. Takayanagi (Ryoichi); D. Toniolo (Daniela); H. Ahsan (Habibul); H. Allayee (Hooman); Y.-T. Chen (Yuan-Tsong); J. Danesh (John); I.J. Deary (Ian J.); O.H. Franco (Oscar); L. Franke (Lude); B. THeijman (Bastiaan); J.D. Holbrook (Joanna D.); A.J. Isaacs (Aaron); B.-J. Kim (Bong-Jo); X. Lin (Xu); J. Liu (Jianjun); W. März (Winfried); A. Metspalu (Andres); K.L. Mohlke (Karen); K. Sangher; D. Harambir (Dharambir); X.-O. Shu (Xiao-Ou); J.B.J. van Meurs (Joyce); E.N. Vithana (Eranga); A.R. Wickremasinghe (Ananda); C. Wijmenga (Cisca); B.H.W. Wolffenbuttel (Bruce H.W.); M. Yokota (Mitsuhiro); W. Zheng (Wei); D. Zhu (Dingliang); P. Vineis (Paolo); S.A. Kyrtopoulos (Soterios A.); J.C.S. Kleinjans (Jos C.S.); M.I. McCarthy (Mark); R. Soong (Richie); C. Gieger (Christian); J. Scott (James); Y.Y. Teo (Yik Ying); J. He (Jiang); P. Elliott (Paul); E.S. Tai (Shyong); P. van der Harst (Pim); J.S. Kooner (Jaspal S.); J.C. Chambers (John)

    2015-01-01

    textabstractWe carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10 -11 to 5

  6. Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

    NARCIS (Netherlands)

    N. Kato (Norihiro); M. Loh (Marie); F. Takeuchi (Fumihiko); N. Verweij (Niek); X. Wang (Xu); W. Zhang (Weihua); T. NKelly (Tanika); D. Saleheen; B. Lehne (Benjamin); I.M. Leach (Irene Mateo); A. Drong (Alexander); J. Abbott (James); S. Wahl (Simone); S.-T. Tan (Sian-Tsung); W.R. Scott (William R.); G. Campanella (Gianluca); M. Chadeau-Hyam (Marc); U. Afzal (Uzma); T.S. Ahluwalia (Tarunveer Singh); M.J. Bonder (Marc); P. Chen (Ping); A. Dehghan (Abbas); T.L. Edwards (Todd L.); T. Esko (Tõnu); M.J. Go (Min Jin); S.E. Harris (Sarah); J. Hartiala (Jaana); S. Kasela (Silva); A. Kasturiratne (Anuradhani); C.C. Khor; M.E. Kleber (Marcus); H. Li (Huaixing); Z.Y. Mok (Zuan Yu); M. Nakatochi (Masahiro); N.S. Sapari (Nur Sabrina); R. Saxena (Richa); A.F. Stewart (Alexandre F.); L. Stolk (Lisette); Y. Tabara (Yasuharu); A.L. Teh (Ai Ling); Y. Wu (Ying); J.-Y. Wu (Jer-Yuarn); Y. Zhang (Yi); I. Aits (Imke); A. Da Silva Couto Alves (Alexessander); S. Das (Shikta); R. Dorajoo (Rajkumar); J. CHopewell (Jemma); Y.K. Kim (Yun Kyoung); R. WKoivula (Robert); J. Luan (Jian'An); L.-P. Lyytikäinen (Leo-Pekka); Q. NNguyen (Quang); M.A. Pereira (Mark A); D. Postmus (Douwe); O. TRaitakari (Olli); M. Scannell Bryan (Molly); R.A. Scott (Robert); R. Sorice; V. Tragante (Vinicius); M. Traglia (Michela); J. White (Jon); K. Yamamoto (Ken); Y. Zhang (Yonghong); L.S. Adair (Linda); A. Ahmed (Alauddin); K. Akiyama (Koichi); R. Asif (Rasheed); T. Aung (Tin); I. Barroso (Inês); A. Bjonnes (Andrew); T.R. Braun (Timothy R.); H. Cai (Hui); L.-C. Chang (Li-Ching); C.-H. Chen; C-Y. Cheng (Ching-Yu); Y.-S. Chong (Yap-Seng); F.S. Collins (Francis); R. Courtney (Regina); G. Davies (Gail); G. Delgado; L.D. Do (Loi D.); P.A. Doevendans (Pieter); R.T. Gansevoort (Ron); Y. Gao; T.B. Grammer (Tanja B); N. Grarup (Niels); J. Grewal (Jagvir); D. Gu (D.); G. SWander (Gurpreet); A.L. Hartikainen; S.L. Hazen (Stanley); J. He (Jing); C.K. Heng (Chew-Kiat); E.J.A. Hixso (E. James Ames); A. Hofman (Albert); C. Hsu (Chris); W. Huang (Wei); L.L.N. Husemoen (Lise Lotte); J.-Y. Hwang (Joo-Yeon); S. Ichihara (Sahoko); M. Igase (Michiya); M. Isono (Masato); J.M. Justesen (Johanne M.); T. Katsuya (Tomohiro); M. GKibriya (Muhammad); Y.J. Kim; M. Kishimoto (Miyako); W.-P. Koh (Woon-Puay); K. Kohara (Katsuhiko); M. Kumari (Meena); K. Kwek (Kenneth); N.R. Lee (Nanette); J. Lee (Jeannette); J. Liao (Jie); W. Lieb (Wolfgang); D.C. Liewald (David C.); T. Matsubara (Tatsuaki); Y. Matsushita (Yumi); T. Meitinger (Thomas); E. Mihailov (Evelin); L. Milani (Lili); R. Mills (Rebecca); K. Mononen (Kari); M. Müller-Nurasyid (Martina); T. Nabika (Toru); E. Nakashima (Eitaro); H.K. Ng (Hong Kiat); K. Nikus (Kjell); T. Nutile; T. Ohkubo (Takayoshi); K. Ohnaka (Keizo); S. Parish (Sarah); L. Paternoster (Lavinia); H. Peng (Hao); A. Peters (Annette); S. TPham (Son); M.J. Pinidiyapathirage (Mohitha J.); M. Rahman (Mahfuzar); H. Rakugi (Hiromi); O. Rolandsson (Olov); M.A. Rozario (Michelle Ann); D. Ruggiero; C. Sala (Cinzia); R. Sarju (Ralhan); K. Shimokawa (Kazuro); H. Snieder (Harold); T. Sparsø (Thomas); W. Spiering (Wilko); J.M. Starr (John); D.J. Stott (David J.); D. OStram (Daniel); T. Sugiyama (Takao); S. Szymczak (Silke); W.H.W. Tang (W.H. Wilson); L. Tong (Lin); S. Trompet (Stella); V. Turjanmaa (Väinö); H. Ueshima (Hirotsugu); A.G. Uitterlinden (André); S. Umemura (Satoshi); M. Vaarasmaki (Marja); R.M. Dam (Rob Mvan); W.H. van Gilst (Wiek); D.J. van Veldhuisen (Dirk); J. Viikari (Jorma); M. Waldenberger (Melanie); Y. Wang (Yiqin); A. Wang (Aili); R. Wilson (Rory); T.-Y. Wong (Tien-Yin); Y.-B. Xiang (Yong-Bing); S. Yamaguchi (Shuhei); X. Ye (Xingwang); R. Young (Robin); T.L. Young (Terri); J.-M. Yuan (Jian-Min); X. Zhou (Xueya); F.W. Asselbergs (Folkert); M. Ciullo; R. Clarke (Robert); P. Deloukas (Panagiotis); A. Franke (Andre); W.F. Paul (W. Frank); S. Franks (Steve); Y. Friedlander (Yechiel); M.D. Gross (Myron D.); Z. Guo (Zhirong); T. Hansen (T.); M.-R. Jarvelin (Marjo-Riitta); T. Jørgensen (Torben); J.W. Jukema (Jan Wouter); M. Kähönen (Mika); H. Kajio (Hiroshi); M. Kivimaki (Mika); J.-Y. Lee (Jong-Young); T. Lehtimäki (Terho); A. Linneberg (Allan); T. Miki (Tetsuro); O. Pedersen (Oluf); N.J. Samani (Nilesh); T.I.A. Sørensen (Thorkild); R. Takayanagi (Ryoichi); D. Toniolo (Daniela); H. Ahsan (Habibul); H. Allayee (Hooman); Y.-T. Chen (Yuan-Tsong); J. Danesh (John); I.J. Deary (Ian J.); O.H. Franco (Oscar); L. Franke (Lude); B. THeijman (Bastiaan); J.D. Holbrook (Joanna D.); A.J. Isaacs (Aaron)

    2015-01-01

    textabstractWe carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10 -11 to

  7. Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

    DEFF Research Database (Denmark)

    Kato, Norihiro; Loh, Marie; Takeuchi, Fumihiko

    2015-01-01

    We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.0 × 10(...

  8. Rapid 96-well plates DNA extraction and sequencing procedures to identify genome-wide transposon insertion sites in a difficult to lyse bacterium: Lactobacillus casei.

    Science.gov (United States)

    Scornec, Hélène; Tichit, Magali; Bouchier, Christiane; Pédron, Thierry; Cavin, Jean-François; Sansonetti, Philippe J; Licandro-Seraut, Hélène

    2014-11-01

    Random transposon mutagenesis followed by adequate screening methods is an unavoidable procedure to characterize genetics of bacterial adaptation to environmental changes. We have recently constructed a mutant library of Lactobacillus casei and we aimed to fully annotate it. However, we have observed that, for L. casei which is a difficult to lyse bacterium, methods used to identify the transposon insertion site in a few mutants (transposon rescue by restriction and recircularization or PCR-based methods) were not transposable for a larger number because they are too time-consuming and sometimes not reliable. Here, we describe a method for large-scale and reliable identification of transposon insertion sites in a L. casei mutant library of 9250 mutants. DNA extraction procedure based on silica membranes in 96-column format was optimized to obtain genomic DNA from a large number of mutants. Then reliable direct genomic sequencing was improved to fit the obtained genomic DNA extracts. Using this procedure, readable and identifiable sequences were obtained for 87% of the L. casei mutants. This method extends the applications of a library of this type, reduces the number of insertions needed to be screened, and allows selection of specific mutants from an arrayed and stored mutant library. This method is applicable to any already existing mutant library (obtained by transposon or insertional mutagenesis) and could be useful for other bacterial species, especially for highly lysis-resistant bacteria species such as lactic acid bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Genome-wide nucleosome map and cytosine methylation levels of an ancient human genome

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Valen, Eivind; Velazquez, Amhed M Vargas

    2014-01-01

    Epigenetic information is available from contemporary organisms, but is difficult to track back in evolutionary time. Here, we show that genome-wide epigenetic information can be gathered directly from next-generation sequence reads of DNA isolated from ancient remains. Using the genome sequence ...

  10. Genome wide copy number analysis of single cells

    Science.gov (United States)

    Baslan, Timour; Kendall, Jude; Rodgers, Linda; Cox, Hilary; Riggs, Mike; Stepansky, Asya; Troge, Jennifer; Ravi, Kandasamy; Esposito, Diane; Lakshmi, B.; Wigler, Michael; Navin, Nicholas; Hicks, James

    2016-01-01

    Summary Copy number variation (CNV) is increasingly recognized as an important contributor to phenotypic variation in health and disease. Most methods for determining CNV rely on admixtures of cells, where information regarding genetic heterogeneity is lost. Here, we present a protocol that allows for the genome wide copy number analysis of single nuclei isolated from mixed populations of cells. Single nucleus sequencing (SNS), combines flow sorting of single nuclei based on DNA content, whole genome amplification (WGA), followed by next generation sequencing to quantize genomic intervals in a genome wide manner. Multiplexing of single cells is discussed. Additionally, we outline informatic approaches that correct for biases inherent in the WGA procedure and allow for accurate determination of copy number profiles. All together, the protocol takes ~3 days from flow cytometry to sequence-ready DNA libraries. PMID:22555242

  11. Brief Guide to Genomics: DNA, Genes and Genomes

    Science.gov (United States)

    ... Breve guía de genómica A Brief Guide to Genomics DNA, Genes and Genomes Deoxyribonucleic acid (DNA) is ... genetic basis for health and disease. Implications of Genomics for Medical Science Virtually every human ailment has ...

  12. Genome-wide identification of direct HBx genomic targets

    KAUST Repository

    Guerrieri, Francesca

    2017-02-17

    Background The Hepatitis B Virus (HBV) HBx regulatory protein is required for HBV replication and involved in HBV-related carcinogenesis. HBx interacts with chromatin modifying enzymes and transcription factors to modulate histone post-translational modifications and to regulate viral cccDNA transcription and cellular gene expression. Aiming to identify genes and non-coding RNAs (ncRNAs) directly targeted by HBx, we performed a chromatin immunoprecipitation sequencing (ChIP-Seq) to analyse HBV recruitment on host cell chromatin in cells replicating HBV. Results ChIP-Seq high throughput sequencing of HBx-bound fragments was used to obtain a high-resolution, unbiased, mapping of HBx binding sites across the genome in HBV replicating cells. Protein-coding genes and ncRNAs involved in cell metabolism, chromatin dynamics and cancer were enriched among HBx targets together with genes/ncRNAs known to modulate HBV replication. The direct transcriptional activation of genes/miRNAs that potentiate endocytosis (Ras-related in brain (RAB) GTPase family) and autophagy (autophagy related (ATG) genes, beclin-1, miR-33a) and the transcriptional repression of microRNAs (miR-138, miR-224, miR-576, miR-596) that directly target the HBV pgRNA and would inhibit HBV replication, contribute to HBx-mediated increase of HBV replication. Conclusions Our ChIP-Seq analysis of HBx genome wide chromatin recruitment defined the repertoire of genes and ncRNAs directly targeted by HBx and led to the identification of new mechanisms by which HBx positively regulates cccDNA transcription and HBV replication.

  13. 25-Hydroxyvitamin D in pregnancy and genome wide cord blood DNA methylation in two pregnancy cohorts (MoBa and ALSPAC).

    Science.gov (United States)

    Suderman, M; Stene, L C; Bohlin, J; Page, C M; Holvik, K; Parr, C L; Magnus, M C; Håberg, S E; Joubert, B R; Wu, M C; London, S J; Relton, C; Nystad, W

    2016-05-01

    The aim of the study was to investigate whether maternal mid-pregnancy 25-hydroxyvitamin D concentrations are associated with cord blood DNA methylation. DNA methylation was assessed using the Illumina HumanMethylation450 BeadChip, and maternal plasma 25-hydroxyvitamin D was measured in 819 mothers/newborn pairs participating in the Norwegian Mother and Child Cohort (MoBa) and 597 mothers/newborn pairs participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Across 473,731CpG DNA methylation sites in cord blood DNA, none were strongly associated with maternal 25-hydroxyvitamin D after adjusting for multiple tests (false discovery rate (FDR)>0.5; 473,731 tests). A meta-analysis of the results from both cohorts, using the Fisher method for combining p-values, also did not strengthen findings (FDR>0.2). Further exploration of a set of CpG sites in the proximity of four a priori defined candidate genes (CYP24A1, CYP27B1, CYP27A1 and CYP2R1) did not result in any associations with FDRDNA methylation, we did not find any convincing associations in 1416 newborns. If true associations do exist, their identification might require much larger consortium studies, expanded genomic coverage, investigation of alternative cell types or measurements of 25-hydroxyvitamin D at different gestational time points.

  14. Arabidopsis transcription factors: genome-wide comparative analysis among eukaryotes.

    Science.gov (United States)

    Riechmann, J L; Heard, J; Martin, G; Reuber, L; Jiang, C; Keddie, J; Adam, L; Pineda, O; Ratcliffe, O J; Samaha, R R; Creelman, R; Pilgrim, M; Broun, P; Zhang, J Z; Ghandehari, D; Sherman, B K; Yu, G

    2000-12-15

    The completion of the Arabidopsis thaliana genome sequence allows a comparative analysis of transcriptional regulators across the three eukaryotic kingdoms. Arabidopsis dedicates over 5% of its genome to code for more than 1500 transcription factors, about 45% of which are from families specific to plants. Arabidopsis transcription factors that belong to families common to all eukaryotes do not share significant similarity with those of the other kingdoms beyond the conserved DNA binding domains, many of which have been arranged in combinations specific to each lineage. The genome-wide comparison reveals the evolutionary generation of diversity in the regulation of transcription.

  15. Preparation of genomic DNA from bacteria.

    Science.gov (United States)

    Andreou, Lefkothea-Vasiliki

    2013-01-01

    The purpose of this protocol is the isolation of bulk cellular DNA from bacteria (alternatively see Preparation of genomic DNA from Saccharomyces cerevisiae or Isolation of Genomic DNA from Mammalian Cells protocols). Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Genome-wide patterns of selection in 230 ancient Eurasians

    Science.gov (United States)

    Mathieson, Iain; Lazaridis, Iosif; Rohland, Nadin; Mallick, Swapan; Patterson, Nick; Roodenberg, Songül Alpaslan; Harney, Eadaoin; Stewardson, Kristin; Fernandes, Daniel; Novak, Mario; Sirak, Kendra; Gamba, Cristina; Jones, Eppie R.; Llamas, Bastien; Dryomov, Stanislav; Pickrel, Joseph; Arsuaga, Juan Luís; de Castro, José María Bermúdez; Carbonell, Eudald; Gerritsen, Fokke; Khokhlov, Aleksandr; Kuznetsov, Pavel; Lozano, Marina; Meller, Harald; Mochalov, Oleg; Moiseyev, Vayacheslav; Rojo Guerra, Manuel A.; Roodenberg, Jacob; Vergès, Josep Maria; Krause, Johannes; Cooper, Alan; Alt, Kurt W.; Brown, Dorcas; Anthony, David; Lalueza-Fox, Carles; Haak, Wolfgang; Pinhasi, Ron; Reich, David

    2016-01-01

    Ancient DNA makes it possible to directly witness natural selection by analyzing samples from populations before, during and after adaptation events. Here we report the first scan for selection using ancient DNA, capitalizing on the largest genome-wide dataset yet assembled: 230 West Eurasians dating to between 6500 and 1000 BCE, including 163 with newly reported data. The new samples include the first genome-wide data from the Anatolian Neolithic culture whose genetic material we extracted from the DNA-rich petrous bone and who we show were members of the population that was the source of Europe’s first farmers. We also report a complete transect of the steppe region in Samara between 5500 and 1200 BCE that allows us to recognize admixture from at least two external sources into steppe populations during this period. We detect selection at loci associated with diet, pigmentation and immunity, and two independent episodes of selection on height. PMID:26595274

  17. Genome-wide non-CpG methylation of the host genome during M. tuberculosis infection

    Science.gov (United States)

    Sharma, Garima; Sowpati, Divya Tej; Singh, Prakruti; Khan, Mehak Zahoor; Ganji, Rakesh; Upadhyay, Sandeep; Banerjee, Sharmistha; Nandicoori, Vinay Kumar; Khosla, Sanjeev

    2016-01-01

    A mammalian cell utilizes DNA methylation to modulate gene expression in response to environmental changes during development and differentiation. Aberrant DNA methylation changes as a correlate to diseased states like cancer, neurodegenerative conditions and cardiovascular diseases have been documented. Here we show genome-wide DNA methylation changes in macrophages infected with the pathogen M. tuberculosis. Majority of the affected genomic loci were hypermethylated in M. tuberculosis infected THP1 macrophages. Hotspots of differential DNA methylation were enriched in genes involved in immune response and chromatin reorganization. Importantly, DNA methylation changes were observed predominantly for cytosines present in non-CpG dinucleotide context. This observation was consistent with our previous finding that the mycobacterial DNA methyltransferase, Rv2966c, targets non-CpG dinucleotides in the host DNA during M. tuberculosis infection and reiterates the hypothesis that pathogenic bacteria use non-canonical epigenetic strategies during infection. PMID:27112593

  18. Identification of networks of co-occurring, tumor-related DNA copy number changes using a genome-wide scoring approach.

    Directory of Open Access Journals (Sweden)

    Christiaan Klijn

    2010-01-01

    Full Text Available Tumorigenesis is a multi-step process in which normal cells transform into malignant tumors following the accumulation of genetic mutations that enable them to evade the growth control checkpoints that would normally suppress their growth or result in apoptosis. It is therefore important to identify those combinations of mutations that collaborate in cancer development and progression. DNA copy number alterations (CNAs are one of the ways in which cancer genes are deregulated in tumor cells. We hypothesized that synergistic interactions between cancer genes might be identified by looking for regions of co-occurring gain and/or loss. To this end we developed a scoring framework to separate truly co-occurring aberrations from passenger mutations and dominant single signals present in the data. The resulting regions of high co-occurrence can be investigated for between-region functional interactions. Analysis of high-resolution DNA copy number data from a panel of 95 hematological tumor cell lines correctly identified co-occurring recombinations at the T-cell receptor and immunoglobulin loci in T- and B-cell malignancies, respectively, showing that we can recover truly co-occurring genomic alterations. In addition, our analysis revealed networks of co-occurring genomic losses and gains that are enriched for cancer genes. These networks are also highly enriched for functional relationships between genes. We further examine sub-networks of these networks, core networks, which contain many known cancer genes. The core network for co-occurring DNA losses we find seems to be independent of the canonical cancer genes within the network. Our findings suggest that large-scale, low-intensity copy number alterations may be an important feature of cancer development or maintenance by affecting gene dosage of a large interconnected network of functionally related genes.

  19. Inbreeding in genome-wide selection

    NARCIS (Netherlands)

    Daetwyler, H.D.; Villanueva, B.; Bijma, P.; Woolliams, J.A.

    2007-01-01

    Traditional selection methods, such as sib and best linear unbiased prediction (BLUP) selection, which increased genetic gain by increasing accuracy of evaluation have also led to an increased rate of inbreeding per generation (¿FG). This is not necessarily the case with genome-wide selection, which

  20. Diagnosis and Prognostication of Ductal Adenocarcinomas of the Pancreas Based on Genome-Wide DNA Methylation Profiling by Bacterial Artificial Chromosome Array-Based Methylated CpG Island Amplification

    Directory of Open Access Journals (Sweden)

    Masahiro Gotoh

    2011-01-01

    Full Text Available To establish diagnostic criteria for ductal adenocarcinomas of the pancreas (PCs, bacterial artificial chromosome (BAC array-based methylated CpG island amplification was performed using 139 tissue samples. Twelve BAC clones, for which DNA methylation status was able to discriminate cancerous tissue (T from noncancerous pancreatic tissue in the learning cohort with a specificity of 100%, were identified. Using criteria that combined the 12 BAC clones, T-samples were diagnosed as cancers with 100% sensitivity and specificity in both the learning and validation cohorts. DNA methylation status on 11 of the BAC clones, which was able to discriminate patients showing early relapse from those with no relapse in the learning cohort with 100% specificity, was correlated with the recurrence-free and overall survival rates in the validation cohort and was an independent prognostic factor by multivariate analysis. Genome-wide DNA methylation profiling may provide optimal diagnostic markers and prognostic indicators for patients with PCs.

  1. Unraveling the rat blood genome-wide transcriptome after oral administration of lavender oil by a two-color dye-swap DNA microarray approach

    Directory of Open Access Journals (Sweden)

    Motohide Hori

    2016-06-01

    Full Text Available Lavender oil (LO is a commonly used essential oil in aromatherapy as non-traditional medicine. With an aim to demonstrate LO effects on the body, we have recently established an animal model investigating the influence of orally administered LO in rat tissues, genome-wide. In this brief, we investigate the effect of LO ingestion in the blood of rat. Rats were administered LO at usual therapeutic dose (5 mg/kg in humans, and following collection of the venous blood from the heart and extraction of total RNA, the differentially expressed genes were screened using a 4 × 44-K whole-genome rat chip (Agilent microarray platform; Agilent Technologies, Palo Alto, CA, USA in conjunction with a two-color dye-swap approach. A total of 834 differentially expressed genes in the blood were identified: 362 up-regulated and 472 down-regulated. These genes were functionally categorized using bioinformatics tools. The gene expression inventory of rat blood transcriptome under LO, a first report, has been deposited into the Gene Expression Omnibus (GEO: GSE67499. The data will be a valuable resource in examining the effects of natural products, and which could also serve as a human model for further functional analysis and investigation.

  2. A genome-wide 20 K citrus microarray for gene expression analysis

    OpenAIRE

    Martinez-Godoy, M Angeles; Mauri, Nuria; Juarez, Jose; Marques, M Carmen; Santiago, Julia; Forment, Javier; Gadea, Jose

    2008-01-01

    Background Understanding of genetic elements that contribute to key aspects of citrus biology will impact future improvements in this economically important crop. Global gene expression analysis demands microarray platforms with a high genome coverage. In the last years, genome-wide EST collections have been generated in citrus, opening the possibility to create new tools for functional genomics in this crop plant. Results We have designed and constructed a publicly available genome-wide cDNA...

  3. Genome-Wide Scan for Methylation Profiles in Keloids

    Directory of Open Access Journals (Sweden)

    Lamont R. Jones

    2015-01-01

    Full Text Available Keloids are benign fibroproliferative tumors of the skin which commonly occur after injury mainly in darker skinned patients. Medical treatment is fraught with high recurrence rates mainly because of an incomplete understanding of the biological mechanisms that lead to keloids. The purpose of this project was to examine keloid pathogenesis from the epigenome perspective of DNA methylation. Genome-wide profiling used the Infinium HumanMethylation450 BeadChip to interrogate DNA from 6 fresh keloid and 6 normal skin samples from 12 anonymous donors. A 3-tiered approach was used to call out genes most differentially methylated between keloid and normal. When compared to normal, of the 685 differentially methylated CpGs at Tier 3, 510 were hypomethylated and 175 were hypermethylated with 190 CpGs in promoter and 495 in nonpromoter regions. The 190 promoter region CpGs corresponded to 152 genes: 96 (63% were hypomethylated and 56 (37% hypermethylated. This exploratory genome-wide scan of the keloid methylome highlights a predominance of hypomethylated genomic landscapes, favoring nonpromoter regions. DNA methylation, as an additional mechanism for gene regulation in keloid pathogenesis, holds potential for novel treatments that reverse deleterious epigenetic changes. As an alternative mechanism for regulating genes, epigenetics may explain why gene mutations alone do not provide definitive mechanisms for keloid formation.

  4. Comparative analysis of methods for genome-wide nucleosome cartography.

    Science.gov (United States)

    Quintales, Luis; Vázquez, Enrique; Antequera, Francisco

    2015-07-01

    Nucleosomes contribute to compacting the genome into the nucleus and regulate the physical access of regulatory proteins to DNA either directly or through the epigenetic modifications of the histone tails. Precise mapping of nucleosome positioning across the genome is, therefore, essential to understanding the genome regulation. In recent years, several experimental protocols have been developed for this purpose that include the enzymatic digestion, chemical cleavage or immunoprecipitation of chromatin followed by next-generation sequencing of the resulting DNA fragments. Here, we compare the performance and resolution of these methods from the initial biochemical steps through the alignment of the millions of short-sequence reads to a reference genome to the final computational analysis to generate genome-wide maps of nucleosome occupancy. Because of the lack of a unified protocol to process data sets obtained through the different approaches, we have developed a new computational tool (NUCwave), which facilitates their analysis, comparison and assessment and will enable researchers to choose the most suitable method for any particular purpose. NUCwave is freely available at http://nucleosome.usal.es/nucwave along with a step-by-step protocol for its use. © The Author 2014. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  5. Expression profile analysis of the oxygen response in the nitrogen-fixing Pseudomonas stutzeri A1501 by genome-wide DNA microarray

    Institute of Scientific and Technical Information of China (English)

    DOU YueTan; YAN YongLiang; PING ShuZhen; LU Wei; CHEN Ming; ZHANG Wei; WANG YiPing; JIN Qi; LIN Min

    2008-01-01

    Pseudomonas stutzeri A1501, an associative nitrogen-fixing bacterium, was isolated from the rice paddy rhizosphere. This bacterium fixes nitrogen under microaerobic conditions. In this study, ge-nome-wide DNA microarrays were used to analyze the global transcription profile of A1501 under aerobic and microaerobic conditions. The expression of 135 genes was significantly altered by more than 2-fold in response to oxygen stress. Among these genes, 68 were down-regulated under aerobic conditions; these genes included those responsible for nitrogen fixation and denitrification. Sixty-seven genes were up-regulated under aerobic conditions; these genes included sodC, encoding a copper-zinc superoxide dismutase, PST2179, encoding an NAD(P)-dependent oxidoreductase, PST3584, encoding a 2OG-Fe(Ⅱ) oxygenase, and PST3602, encoding an NAD(P)H-flavin oxidoreductase. Addi-tionally, seven genes involved in capsular polysaccharide and antigen oligosaccharide biosynthesis together with 17 genes encoding proteins of unknown function were up-regulated under aerobic con-ditions. The overall analysis suggests that the genes we identified are involved in the protection of the bacterium from oxygen, but the mechanisms of their action remain to be elucidated.

  6. High-resolution genome-wide mapping of histone modifications.

    Science.gov (United States)

    Roh, Tae-young; Ngau, Wing Chi; Cui, Kairong; Landsman, David; Zhao, Keji

    2004-08-01

    The expression patterns of eukaryotic genomes are controlled by their chromatin structure, consisting of nucleosome subunits in which DNA of approximately 146 bp is wrapped around a core of 8 histone molecules. Post-translational histone modifications play an essential role in modifying chromatin structure. Here we apply a combination of SAGE and chromatin immunoprecipitation (ChIP) protocols to determine the distribution of hyperacetylated histones H3 and H4 in the Saccharomyces cerevisiae genome. We call this approach genome-wide mapping technique (GMAT). Using GMAT, we find that the highest acetylation levels are detected in the 5' end of a gene's coding region, but not in the promoter. Furthermore, we show that the histone acetyltransferase, GCN5p, regulates H3 acetylation in the promoter and 5' end of the coding regions. These findings indicate that GMAT should find valuable applications in mapping target sites of chromatin-modifying enzymes.

  7. A conserved BDNF, glutamate- and GABA-enriched gene module related to human depression identified by coexpression meta-analysis and DNA variant genome-wide association studies.

    Directory of Open Access Journals (Sweden)

    Lun-Ching Chang

    Full Text Available Large scale gene expression (transcriptome analysis and genome-wide association studies (GWAS for single nucleotide polymorphisms have generated a considerable amount of gene- and disease-related information, but heterogeneity and various sources of noise have limited the discovery of disease mechanisms. As systematic dataset integration is becoming essential, we developed methods and performed meta-clustering of gene coexpression links in 11 transcriptome studies from postmortem brains of human subjects with major depressive disorder (MDD and non-psychiatric control subjects. We next sought enrichment in the top 50 meta-analyzed coexpression modules for genes otherwise identified by GWAS for various sets of disorders. One coexpression module of 88 genes was consistently and significantly associated with GWAS for MDD, other neuropsychiatric disorders and brain functions, and for medical illnesses with elevated clinical risk of depression, but not for other diseases. In support of the superior discriminative power of this novel approach, we observed no significant enrichment for GWAS-related genes in coexpression modules extracted from single studies or in meta-modules using gene expression data from non-psychiatric control subjects. Genes in the identified module encode proteins implicated in neuronal signaling and structure, including glutamate metabotropic receptors (GRM1, GRM7, GABA receptors (GABRA2, GABRA4, and neurotrophic and development-related proteins [BDNF, reelin (RELN, Ephrin receptors (EPHA3, EPHA5]. These results are consistent with the current understanding of molecular mechanisms of MDD and provide a set of putative interacting molecular partners, potentially reflecting components of a functional module across cells and biological pathways that are synchronously recruited in MDD, other brain disorders and MDD-related illnesses. Collectively, this study demonstrates the importance of integrating transcriptome data, gene

  8. A conserved BDNF, glutamate- and GABA-enriched gene module related to human depression identified by coexpression meta-analysis and DNA variant genome-wide association studies.

    Science.gov (United States)

    Chang, Lun-Ching; Jamain, Stephane; Lin, Chien-Wei; Rujescu, Dan; Tseng, George C; Sibille, Etienne

    2014-01-01

    Large scale gene expression (transcriptome) analysis and genome-wide association studies (GWAS) for single nucleotide polymorphisms have generated a considerable amount of gene- and disease-related information, but heterogeneity and various sources of noise have limited the discovery of disease mechanisms. As systematic dataset integration is becoming essential, we developed methods and performed meta-clustering of gene coexpression links in 11 transcriptome studies from postmortem brains of human subjects with major depressive disorder (MDD) and non-psychiatric control subjects. We next sought enrichment in the top 50 meta-analyzed coexpression modules for genes otherwise identified by GWAS for various sets of disorders. One coexpression module of 88 genes was consistently and significantly associated with GWAS for MDD, other neuropsychiatric disorders and brain functions, and for medical illnesses with elevated clinical risk of depression, but not for other diseases. In support of the superior discriminative power of this novel approach, we observed no significant enrichment for GWAS-related genes in coexpression modules extracted from single studies or in meta-modules using gene expression data from non-psychiatric control subjects. Genes in the identified module encode proteins implicated in neuronal signaling and structure, including glutamate metabotropic receptors (GRM1, GRM7), GABA receptors (GABRA2, GABRA4), and neurotrophic and development-related proteins [BDNF, reelin (RELN), Ephrin receptors (EPHA3, EPHA5)]. These results are consistent with the current understanding of molecular mechanisms of MDD and provide a set of putative interacting molecular partners, potentially reflecting components of a functional module across cells and biological pathways that are synchronously recruited in MDD, other brain disorders and MDD-related illnesses. Collectively, this study demonstrates the importance of integrating transcriptome data, gene coexpression modules

  9. Genome-wide patterns of nucleotide polymorphism in domesticated rice

    DEFF Research Database (Denmark)

    Caicedo, Ana L; Williamson, Scott H; Hernandez, Ryan D

    2007-01-01

    Domesticated Asian rice (Oryza sativa) is one of the oldest domesticated crop species in the world, having fed more people than any other plant in human history. We report the patterns of DNA sequence variation in rice and its wild ancestor, O. rufipogon, across 111 randomly chosen gene fragments......, and use these to infer the evolutionary dynamics that led to the origins of rice. There is a genome-wide excess of high-frequency derived single nucleotide polymorphisms (SNPs) in O. sativa varieties, a pattern that has not been reported for other crop species. We developed several alternative models...... explanations for patterns of variation in domesticated rice varieties. If selective sweeps are indeed the explanation for the observed nucleotide data of domesticated rice, it suggests that strong selection can leave its imprint on genome-wide polymorphism patterns, contrary to expectations that selection...

  10. Genome-wide analysis reveals coating of the mitochondrial genome by TFAM.

    Directory of Open Access Journals (Sweden)

    Yun E Wang

    Full Text Available Mitochondria contain a 16.6 kb circular genome encoding 13 proteins as well as mitochondrial tRNAs and rRNAs. Copies of the genome are organized into nucleoids containing both DNA and proteins, including the machinery required for mtDNA replication and transcription. The transcription factor TFAM is critical for initiation of transcription and replication of the genome, and is also thought to perform a packaging function. Although specific binding sites required for initiation of transcription have been identified in the D-loop, little is known about the characteristics of TFAM binding in its nonspecific packaging state. In addition, it is unclear whether TFAM also plays a role in the regulation of nuclear gene expression. Here we investigate these questions by using ChIP-seq to directly localize TFAM binding to DNA in human cells. Our results demonstrate that TFAM uniformly coats the whole mitochondrial genome, with no evidence of robust TFAM binding to the nuclear genome. Our study represents the first high-resolution assessment of TFAM binding on a genome-wide scale in human cells.

  11. Genome-wide identification of enhancer elements.

    Science.gov (United States)

    Tulin, Sarah; Barsi, Julius C; Bocconcelli, Carlo; Smith, Joel

    2016-01-01

    We present a prospective genome-wide regulatory element database for the sea urchin embryo and the modified chromosome capture-related methodology used to create it. The method we developed is termed GRIP-seq for genome-wide regulatory element immunoprecipitation and combines features of chromosome conformation capture, chromatin immunoprecipitation, and paired-end next-generation sequencing with molecular steps that enrich for active cis-regulatory elements associated with basal transcriptional machinery. The first GRIP-seq database, available to the community, comes from S. purpuratus 24 hpf embryos and takes advantage of the extremely well-characterized cis-regulatory elements in this system for validation. In addition, using the GRIP-seq database, we identify and experimentally validate a novel, intronic cis-regulatory element at the onecut locus. We find GRIP-seq signal sensitively identifies active cis-regulatory elements with a high signal-to-noise ratio for both distal and intronic elements. This promising GRIP-seq protocol has the potential to address a rate-limiting step in resolving comprehensive, predictive network models in all systems.

  12. Impact of age, BMI and HbA1c levels on the genome-wide DNA methylation and mRNA expression patterns in human adipose tissue and identification of epigenetic biomarkers in blood.

    Science.gov (United States)

    Rönn, Tina; Volkov, Petr; Gillberg, Linn; Kokosar, Milana; Perfilyev, Alexander; Jacobsen, Anna Louisa; Jørgensen, Sine W; Brøns, Charlotte; Jansson, Per-Anders; Eriksson, Karl-Fredrik; Pedersen, Oluf; Hansen, Torben; Groop, Leif; Stener-Victorin, Elisabet; Vaag, Allan; Nilsson, Emma; Ling, Charlotte

    2015-07-01

    Increased age, BMI and HbA1c levels are risk factors for several non-communicable diseases. However, the impact of these factors on the genome-wide DNA methylation pattern in human adipose tissue remains unknown. We analyzed the DNA methylation of ∼480 000 sites in human adipose tissue from 96 males and 94 females and related methylation to age, BMI and HbA1c. We also compared epigenetic signatures in adipose tissue and blood. Age was significantly associated with both altered DNA methylation and expression of 1050 genes (e.g. FHL2, NOX4 and PLG). Interestingly, many reported epigenetic biomarkers of aging in blood, including ELOVL2, FHL2, KLF14 and GLRA1, also showed significant correlations between adipose tissue DNA methylation and age in our study. The most significant association between age and adipose tissue DNA methylation was found upstream of ELOVL2. We identified 2825 genes (e.g. FTO, ITIH5, CCL18, MTCH2, IRS1 and SPP1) where both DNA methylation and expression correlated with BMI. Methylation at previously reported HIF3A sites correlated significantly with BMI in females only. HbA1c (range 28-46 mmol/mol) correlated significantly with the methylation of 711 sites, annotated to, for example, RAB37, TICAM1 and HLA-DPB1. Pathway analyses demonstrated that methylation levels associated with age and BMI are overrepresented among genes involved in cancer, type 2 diabetes and cardiovascular disease. Our results highlight the impact of age, BMI and HbA1c on epigenetic variation of candidate genes for obesity, type 2 diabetes and cancer in human adipose tissue. Importantly, we demonstrate that epigenetic biomarkers in blood can mirror age-related epigenetic signatures in target tissues for metabolic diseases such as adipose tissue.

  13. The effects of long-term daily folic acid and vitamin B12 supplementation on genome-wide DNA methylation in elderly subjects

    NARCIS (Netherlands)

    D.E.G. Kok (Dieuwertje); R.A.M. Dhonukshe-Rutten (Rosalie); C. Lute (Carolien); S.G. Heil (Sandra); A.G. Uitterlinden (André); N. van der Velde (Nathalie); J.B.J. van Meurs (Joyce); N.M. van Schoor (Natasja); G.J.E.J. Hooiveld; L.C.P.G.M. de Groot (Lisette); E. Kampman (Ellen); W.T. Steegenga (Wilma T.)

    2015-01-01

    textabstractBackground: Folate and its synthetic form folic acid function as donor of one-carbon units and have been, together with other B-vitamins, implicated in programming of epigenetic processes such as DNA methylation during early development. To what extent regulation of DNA methylation can b

  14. A genome wide dosage suppressor network reveals genomic robustness

    Science.gov (United States)

    Patra, Biranchi; Kon, Yoshiko; Yadav, Gitanjali; Sevold, Anthony W.; Frumkin, Jesse P.; Vallabhajosyula, Ravishankar R.; Hintze, Arend; Østman, Bjørn; Schossau, Jory; Bhan, Ashish; Marzolf, Bruz; Tamashiro, Jenna K.; Kaur, Amardeep; Baliga, Nitin S.; Grayhack, Elizabeth J.; Adami, Christoph; Galas, David J.; Raval, Alpan; Phizicky, Eric M.; Ray, Animesh

    2017-01-01

    Genomic robustness is the extent to which an organism has evolved to withstand the effects of deleterious mutations. We explored the extent of genomic robustness in budding yeast by genome wide dosage suppressor analysis of 53 conditional lethal mutations in cell division cycle and RNA synthesis related genes, revealing 660 suppressor interactions of which 642 are novel. This collection has several distinctive features, including high co-occurrence of mutant-suppressor pairs within protein modules, highly correlated functions between the pairs and higher diversity of functions among the co-suppressors than previously observed. Dosage suppression of essential genes encoding RNA polymerase subunits and chromosome cohesion complex suggests a surprising degree of functional plasticity of macromolecular complexes, and the existence of numerous degenerate pathways for circumventing the effects of potentially lethal mutations. These results imply that organisms and cancer are likely able to exploit the genomic robustness properties, due the persistence of cryptic gene and pathway functions, to generate variation and adapt to selective pressures. PMID:27899637

  15. Plant DNA barcoding: from gene to genome.

    Science.gov (United States)

    Li, Xiwen; Yang, Yang; Henry, Robert J; Rossetto, Maurizio; Wang, Yitao; Chen, Shilin

    2015-02-01

    DNA barcoding is currently a widely used and effective tool that enables rapid and accurate identification of plant species; however, none of the available loci work across all species. Because single-locus DNA barcodes lack adequate variations in closely related taxa, recent barcoding studies have placed high emphasis on the use of whole-chloroplast genome sequences which are now more readily available as a consequence of improving sequencing technologies. While chloroplast genome sequencing can already deliver a reliable barcode for accurate plant identification it is not yet resource-effective and does not yet offer the speed of analysis provided by single-locus barcodes to unspecialized laboratory facilities. Here, we review the development of candidate barcodes and discuss the feasibility of using the chloroplast genome as a super-barcode. We advocate a new approach for DNA barcoding that, for selected groups of taxa, combines the best use of single-locus barcodes and super-barcodes for efficient plant identification. Specific barcodes might enhance our ability to distinguish closely related plants at the species and population levels.

  16. Genome-wide association study of relative telomere length.

    Science.gov (United States)

    Prescott, Jennifer; Kraft, Peter; Chasman, Daniel I; Savage, Sharon A; Mirabello, Lisa; Berndt, Sonja I; Weissfeld, Joel L; Han, Jiali; Hayes, Richard B; Chanock, Stephen J; Hunter, David J; De Vivo, Immaculata

    2011-05-10

    Telomere function is essential to maintaining the physical integrity of linear chromosomes and healthy human aging. The probability of forming proper telomere structures depends on the length of the telomeric DNA tract. We attempted to identify common genetic variants associated with log relative telomere length using genome-wide genotyping data on 3,554 individuals from the Nurses' Health Study and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial that took part in the National Cancer Institute Cancer Genetic Markers of Susceptibility initiative for breast and prostate cancer. After genotyping 64 independent SNPs selected for replication in additional Nurses' Health Study and Women's Genome Health Study participants, we did not identify genome-wide significant loci; however, we replicated the inverse association of log relative telomere length with the minor allele variant [C] of rs16847897 at the TERC locus (per allele β = -0.03, P = 0.003) identified by a previous genome-wide association study. We did not find evidence for an association with variants at the OBFC1 locus or other loci reported to be associated with telomere length. With this sample size we had >80% power to detect β estimates as small as ±0.10 for SNPs with minor allele frequencies of ≥0.15 at genome-wide significance. However, power is greatly reduced for β estimates smaller than ±0.10, such as those for variants at the TERC locus. In general, common genetic variants associated with telomere length homeostasis have been difficult to detect. Potential biological and technical issues are discussed.

  17. Genome-wide association study of relative telomere length.

    Directory of Open Access Journals (Sweden)

    Jennifer Prescott

    Full Text Available Telomere function is essential to maintaining the physical integrity of linear chromosomes and healthy human aging. The probability of forming proper telomere structures depends on the length of the telomeric DNA tract. We attempted to identify common genetic variants associated with log relative telomere length using genome-wide genotyping data on 3,554 individuals from the Nurses' Health Study and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial that took part in the National Cancer Institute Cancer Genetic Markers of Susceptibility initiative for breast and prostate cancer. After genotyping 64 independent SNPs selected for replication in additional Nurses' Health Study and Women's Genome Health Study participants, we did not identify genome-wide significant loci; however, we replicated the inverse association of log relative telomere length with the minor allele variant [C] of rs16847897 at the TERC locus (per allele β = -0.03, P = 0.003 identified by a previous genome-wide association study. We did not find evidence for an association with variants at the OBFC1 locus or other loci reported to be associated with telomere length. With this sample size we had >80% power to detect β estimates as small as ±0.10 for SNPs with minor allele frequencies of ≥0.15 at genome-wide significance. However, power is greatly reduced for β estimates smaller than ±0.10, such as those for variants at the TERC locus. In general, common genetic variants associated with telomere length homeostasis have been difficult to detect. Potential biological and technical issues are discussed.

  18. DNA methylation profiling using bisulfite-based epityping of pooled genomic DNA.

    Science.gov (United States)

    Docherty, Sophia J; Davis, Oliver S P; Haworth, Claire M A; Plomin, Robert; Mill, Jonathan

    2010-11-01

    DNA methylation plays a vital role in normal cellular function, with aberrant methylation signatures being implicated in a growing number of human pathologies and complex human traits. Methods based on the modification of genomic DNA with sodium bisulfite are considered the 'gold-standard' for DNA methylation profiling on genomic DNA; however they require large amounts of DNA and may be prohibitively expensive when used on the large sample sizes necessary to detect small effects. DNA pooling approaches are already widely used in large-scale studies of DNA sequence and gene expression. In this paper, we describe the application of this economical DNA pooling technique to the study of DNA methylation profiles. This method generates accurate quantitative assessments of group DNA methylation averages, reducing the time, cost and amount of DNA starting material required for large-scale epigenetic investigation of disease phenotypes.

  19. Genome-wide and caste-specific DNA methylomes of the ants Camponotus floridanus and Harpegnathos saltator

    DEFF Research Database (Denmark)

    Bonasio, Roberto; Li, Qiye; Lian, Jinmin

    2012-01-01

    Ant societies comprise individuals belonging to different castes characterized by specialized morphologies and behaviors. Because ant embryos can follow different developmental trajectories, epigenetic mechanisms must play a role in caste determination. Ants have a full set of DNA methyltransfera...

  20. Impact of age, BMI and HbA1c levels on the genome-wide DNA methylation and mRNA expression patterns in human adipose tissue and identification of epigenetic biomarkers in blood

    DEFF Research Database (Denmark)

    Rönn, Tina; Volkov, Petr; Gillberg, Linn

    2015-01-01

    Increased age, BMI and HbA1c levels are risk factors for several non-communicable diseases. However, the impact of these factors on the genome-wide DNA methylation pattern in human adipose tissue remains unknown. We analyzed the DNA methylation of ∼480 000 sites in human adipose tissue from 96 ma...... of candidate genes for obesity, type 2 diabetes and cancer in human adipose tissue. Importantly, we demonstrate that epigenetic biomarkers in blood can mirror age-related epigenetic signatures in target tissues for metabolic diseases such as adipose tissue....... males and 94 females and related methylation to age, BMI and HbA1c. We also compared epigenetic signatures in adipose tissue and blood. Age was significantly associated with both altered DNA methylation and expression of 1050 genes (e.g. FHL2, NOX4 and PLG). Interestingly, many reported epigenetic...... to, for example, RAB37, TICAM1 and HLA-DPB1. Pathway analyses demonstrated that methylation levels associated with age and BMI are overrepresented among genes involved in cancer, type 2 diabetes and cardiovascular disease. Our results highlight the impact of age, BMI and HbA1c on epigenetic variation...

  1. Genome-wide analysis correlates Ayurveda Prakriti.

    Science.gov (United States)

    Govindaraj, Periyasamy; Nizamuddin, Sheikh; Sharath, Anugula; Jyothi, Vuskamalla; Rotti, Harish; Raval, Ritu; Nayak, Jayakrishna; Bhat, Balakrishna K; Prasanna, B V; Shintre, Pooja; Sule, Mayura; Joshi, Kalpana S; Dedge, Amrish P; Bharadwaj, Ramachandra; Gangadharan, G G; Nair, Sreekumaran; Gopinath, Puthiya M; Patwardhan, Bhushan; Kondaiah, Paturu; Satyamoorthy, Kapaettu; Valiathan, Marthanda Varma Sankaran; Thangaraj, Kumarasamy

    2015-10-29

    The practice of Ayurveda, the traditional medicine of India, is based on the concept of three major constitutional types (Vata, Pitta and Kapha) defined as "Prakriti". To the best of our knowledge, no study has convincingly correlated genomic variations with the classification of Prakriti. In the present study, we performed genome-wide SNP (single nucleotide polymorphism) analysis (Affymetrix, 6.0) of 262 well-classified male individuals (after screening 3416 subjects) belonging to three Prakritis. We found 52 SNPs (p ≤ 1 × 10(-5)) were significantly different between Prakritis, without any confounding effect of stratification, after 10(6) permutations. Principal component analysis (PCA) of these SNPs classified 262 individuals into their respective groups (Vata, Pitta and Kapha) irrespective of their ancestry, which represent its power in categorization. We further validated our finding with 297 Indian population samples with known ancestry. Subsequently, we found that PGM1 correlates with phenotype of Pitta as described in the ancient text of Caraka Samhita, suggesting that the phenotypic classification of India's traditional medicine has a genetic basis; and its Prakriti-based practice in vogue for many centuries resonates with personalized medicine.

  2. Genome-wide Analysis of Gene Regulation

    DEFF Research Database (Denmark)

    Chen, Yun

    cells are capable of regulating their gene expression, so that each cell can only express a particular set of genes yielding limited numbers of proteins with specialized functions. Therefore a rigid control of differential gene expression is necessary for cellular diversity. On the other hand, aberrant...... gene regulation will disrupt the cell’s fundamental processes, which in turn can cause disease. Hence, understanding gene regulation is essential for deciphering the code of life. Along with the development of high throughput sequencing (HTS) technology and the subsequent large-scale data analysis......, genome-wide assays have increased our understanding of gene regulation significantly. This thesis describes the integration and analysis of HTS data across different important aspects of gene regulation. Gene expression can be regulated at different stages when the genetic information is passed from gene...

  3. Integrative genome-wide approaches in embryonic stem cell research.

    Science.gov (United States)

    Zhang, Xinyue; Huang, Jing

    2010-10-01

    Embryonic stem (ES) cells are derived from blastocysts. They can differentiate into the three embryonic germ layers and essentially any type of somatic cells. They therefore hold great potential in tissue regeneration therapy. The ethical issues associated with the use of human embryonic stem cells are resolved by the technical break-through of generating induced pluripotent stem (iPS) cells from various types of somatic cells. However, how ES and iPS cells self-renew and maintain their pluripotency is still largely unknown in spite of the great progress that has been made in the last two decades. Integrative genome-wide approaches, such as the gene expression microarray, chromatin immunoprecipitation based microarray (ChIP-chip) and chromatin immunoprecipitation followed by massive parallel sequencing (ChIP-seq) offer unprecedented opportunities to elucidate the mechanism of the pluripotency, reprogramming and DNA damage response of ES and iPS cells. This frontier article summarizes the fundamental biological questions about ES and iPS cells and reviews the recent advances in ES and iPS cell research using genome-wide technologies. To this end, we offer our perspectives on the future of genome-wide studies on stem cells.

  4. Isolation of genomic DNA from mammalian cells.

    Science.gov (United States)

    Koh, Cheryl M

    2013-01-01

    The isolation of genomic DNA from mammalian cells is a routine molecular biology laboratory technique with numerous downstream applications. The isolated DNA can be used as a template for PCR, cloning, and genotyping and to generate genomic DNA libraries. It can also be used for sequencing to detect mutations and other alterations, and for DNA methylation analyses. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Effects of short-term high-fat overfeeding on genome-wide DNA methylation in the skeletal muscle of healthy young men

    DEFF Research Database (Denmark)

    Jacobsen, Stine; Brøns, Cecilie; Bork-Jensen, Jette;

    2012-01-01

    Energy-dense diets that are high in fat are associated with a risk of metabolic diseases. The underlying molecular mechanisms could involve epigenetics, as recent data show altered DNA methylation of putative type 2 diabetes candidate genes in response to high-fat diets. We examined the effect of...

  6. Genome-wide DNA methylation profiles and their replationship with mRNA and the microRNA transcriptome in bovine muscle tissue (Bos Taurine)

    Science.gov (United States)

    DNA methylation is a key epigenetic modification in mammals, having essential and important roles in muscle development. We sample longissimus thoracis tissues from a well-known elite native breed of Chinese Qinchuan cattle living within comparable environments at fetal and adult stages, using methy...

  7. Genome-wide scans using archived neonatal dried blood spot samples

    Directory of Open Access Journals (Sweden)

    Wiuf Carsten

    2009-07-01

    Full Text Available Abstract Background Identification of disease susceptible genes requires access to DNA from numerous well-characterised subjects. Archived residual dried blood spot samples from national newborn screening programs may provide DNA from entire populations and medical registries the corresponding clinical information. The amount of DNA available in these samples is however rarely sufficient for reliable genome-wide scans, and whole-genome amplification may thus be necessary. This study assess the quality of DNA obtained from different amplification protocols by evaluating fidelity and robustness of the genotyping of 610,000 single nucleotide polymorphisms, using the Illumina Infinium HD Human610-Quad BeadChip. Whole-genome amplified DNA from 24 neonatal dried blood spot samples stored between 15 to 25 years was tested, and high-quality genomic DNA from 8 of the same individuals was used as reference. Results Using 3.2 mm disks from dried blood spot samples the optimal DNA-extraction and amplification protocol resulted in call-rates between 99.15% – 99.73% (mean 99.56%, N = 16, and conflicts with reference DNA in only three per 10,000 genotype calls. Conclusion Whole-genome amplified DNA from archived neonatal dried blood spot samples can be used for reliable genome-wide scans and is a cost-efficient alternative to collecting new samples.

  8. Slow DNA loss in the gigantic genomes of salamanders.

    Science.gov (United States)

    Sun, Cheng; López Arriaza, José R; Mueller, Rachel Lockridge

    2012-01-01

    Evolutionary changes in genome size result from the combined effects of mutation, natural selection, and genetic drift. Insertion and deletion mutations (indels) directly impact genome size by adding or removing sequences. Most species lose more DNA through small indels (i.e., ~1-30 bp) than they gain, which can result in genome reduction over time. Because this rate of DNA loss varies across species, small indel dynamics have been suggested to contribute to genome size evolution. Species with extremely large genomes provide interesting test cases for exploring the link between small indels and genome size; however, most large genomes remain relatively unexplored. Here, we examine rates of DNA loss in the tetrapods with the largest genomes-the salamanders. We used low-coverage genomic shotgun sequence data from four salamander species to examine patterns of insertion, deletion, and substitution in neutrally evolving non-long terminal repeat (LTR) retrotransposon sequences. For comparison, we estimated genome-wide DNA loss rates in non-LTR retrotransposon sequences from five other vertebrate genomes: Anolis carolinensis, Danio rerio, Gallus gallus, Homo sapiens, and Xenopus tropicalis. Our results show that salamanders have significantly lower rates of DNA loss than do other vertebrates. More specifically, salamanders experience lower numbers of deletions relative to insertions, and both deletions and insertions are skewed toward smaller sizes. On the basis of these patterns, we conclude that slow DNA loss contributes to genomic gigantism in salamanders. We also identify candidate molecular mechanisms underlying these differences and suggest that natural variation in indel dynamics provides a unique opportunity to study the basis of genome stability.

  9. DNA methylation map in circulating leukocytes mirrors subcutaneous adipose tissue methylation pattern: a genome-wide analysis from non-obese and obese patients

    Science.gov (United States)

    Crujeiras, A. B.; Diaz-Lagares, A.; Sandoval, J.; Milagro, F. I.; Navas-Carretero, S.; Carreira, M. C.; Gomez, A.; Hervas, D.; Monteiro, M. P.; Casanueva, F. F.; Esteller, M.; Martinez, J. A.

    2017-01-01

    The characterization of the epigenetic changes within the obesity-related adipose tissue will provide new insights to understand this metabolic disorder, but adipose tissue is not easy to sample in population-based studies. We aimed to evaluate the capacity of circulating leukocytes to reflect the adipose tissue-specific DNA methylation status of obesity susceptibility. DNA samples isolated from subcutaneous adipose tissue and circulating leukocytes were hybridized in the Infinium HumanMethylation 450 BeadChip. Data were compared between samples from obese (n = 45) and non-obese (n = 8–10) patients by Wilcoxon-rank test, unadjusted for cell type distributions. A global hypomethylation of the differentially methylated CpG sites (DMCpGs) was observed in the obese subcutaneous adipose tissue and leukocytes. The overlap analysis yielded a number of genes mapped by the common DMCpGs that were identified to reflect the obesity state in the leukocytes. Specifically, the methylation levels of FGFRL1, NCAPH2, PNKD and SMAD3 exhibited excellent and statistically significant efficiencies in the discrimination of obesity from non-obesity status (AUC > 0.80; p < 0.05) and a great correlation between both tissues. Therefore, the current study provided new and valuable DNA methylation biomarkers of obesity-related adipose tissue pathogenesis through peripheral blood analysis, an easily accessible and minimally invasive biological material instead of adipose tissue. PMID:28211912

  10. Genome wide selection in Citrus breeding.

    Science.gov (United States)

    Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

    2016-10-17

    Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq(TM) (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

  11. A Pooled Genome-Wide Association Study of Asperger Syndrome.

    Directory of Open Access Journals (Sweden)

    Varun Warrier

    Full Text Available Asperger Syndrome (AS is a neurodevelopmental condition characterized by impairments in social interaction and communication, alongside the presence of unusually repetitive, restricted interests and stereotyped behaviour. Individuals with AS have no delay in cognitive and language development. It is a subset of Autism Spectrum Conditions (ASC, which are highly heritable and has a population prevalence of approximately 1%. Few studies have investigated the genetic basis of AS. To address this gap in the literature, we performed a genome-wide pooled DNA association study to identify candidate loci in 612 individuals (294 cases and 318 controls of Caucasian ancestry, using the Affymetrix GeneChip Human Mapping version 6.0 array. We identified 11 SNPs that had a p-value below 1x10-5. These SNPs were independently genotyped in the same sample. Three of the SNPs (rs1268055, rs7785891 and rs2782448 were nominally significant, though none remained significant after Bonferroni correction. Two of our top three SNPs (rs7785891 and rs2782448 lie in loci previously implicated in ASC. However, investigation of the three SNPs in the ASC genome-wide association dataset from the Psychiatric Genomics Consortium indicated that these three SNPs were not significantly associated with ASC. The effect sizes of the variants were modest, indicating that our study was not sufficiently powered to identify causal variants with precision.

  12. A Pooled Genome-Wide Association Study of Asperger Syndrome.

    Science.gov (United States)

    Warrier, Varun; Chakrabarti, Bhismadev; Murphy, Laura; Chan, Allen; Craig, Ian; Mallya, Uma; Lakatošová, Silvia; Rehnstrom, Karola; Peltonen, Leena; Wheelwright, Sally; Allison, Carrie; Fisher, Simon E; Baron-Cohen, Simon

    2015-01-01

    Asperger Syndrome (AS) is a neurodevelopmental condition characterized by impairments in social interaction and communication, alongside the presence of unusually repetitive, restricted interests and stereotyped behaviour. Individuals with AS have no delay in cognitive and language development. It is a subset of Autism Spectrum Conditions (ASC), which are highly heritable and has a population prevalence of approximately 1%. Few studies have investigated the genetic basis of AS. To address this gap in the literature, we performed a genome-wide pooled DNA association study to identify candidate loci in 612 individuals (294 cases and 318 controls) of Caucasian ancestry, using the Affymetrix GeneChip Human Mapping version 6.0 array. We identified 11 SNPs that had a p-value below 1x10-5. These SNPs were independently genotyped in the same sample. Three of the SNPs (rs1268055, rs7785891 and rs2782448) were nominally significant, though none remained significant after Bonferroni correction. Two of our top three SNPs (rs7785891 and rs2782448) lie in loci previously implicated in ASC. However, investigation of the three SNPs in the ASC genome-wide association dataset from the Psychiatric Genomics Consortium indicated that these three SNPs were not significantly associated with ASC. The effect sizes of the variants were modest, indicating that our study was not sufficiently powered to identify causal variants with precision.

  13. Genome-wide inference of regulatory networks in Streptomyces coelicolor

    Directory of Open Access Journals (Sweden)

    Takano Eriko

    2010-10-01

    Full Text Available Abstract Background The onset of antibiotics production in Streptomyces species is co-ordinated with differentiation events. An understanding of the genetic circuits that regulate these coupled biological phenomena is essential to discover and engineer the pharmacologically important natural products made by these species. The availability of genomic tools and access to a large warehouse of transcriptome data for the model organism, Streptomyces coelicolor, provides incentive to decipher the intricacies of the regulatory cascades and develop biologically meaningful hypotheses. Results In this study, more than 500 samples of genome-wide temporal transcriptome data, comprising wild-type and more than 25 regulatory gene mutants of Streptomyces coelicolor probed across multiple stress and medium conditions, were investigated. Information based on transcript and functional similarity was used to update a previously-predicted whole-genome operon map and further applied to predict transcriptional networks constituting modules enriched in diverse functions such as secondary metabolism, and sigma factor. The predicted network displays a scale-free architecture with a small-world property observed in many biological networks. The networks were further investigated to identify functionally-relevant modules that exhibit functional coherence and a consensus motif in the promoter elements indicative of DNA-binding elements. Conclusions Despite the enormous experimental as well as computational challenges, a systems approach for integrating diverse genome-scale datasets to elucidate complex regulatory networks is beginning to emerge. We present an integrated analysis of transcriptome data and genomic features to refine a whole-genome operon map and to construct regulatory networks at the cistron level in Streptomyces coelicolor. The functionally-relevant modules identified in this study pose as potential targets for further studies and verification.

  14. Genome-wide identification of significant aberrations in cancer genome

    Directory of Open Access Journals (Sweden)

    Yuan Xiguo

    2012-07-01

    Full Text Available Abstract Background Somatic Copy Number Alterations (CNAs in human genomes are present in almost all human cancers. Systematic efforts to characterize such structural variants must effectively distinguish significant consensus events from random background aberrations. Here we introduce Significant Aberration in Cancer (SAIC, a new method for characterizing and assessing the statistical significance of recurrent CNA units. Three main features of SAIC include: (1 exploiting the intrinsic correlation among consecutive probes to assign a score to each CNA unit instead of single probes; (2 performing permutations on CNA units that preserve correlations inherent in the copy number data; and (3 iteratively detecting Significant Copy Number Aberrations (SCAs and estimating an unbiased null distribution by applying an SCA-exclusive permutation scheme. Results We test and compare the performance of SAIC against four peer methods (GISTIC, STAC, KC-SMART, CMDS on a large number of simulation datasets. Experimental results show that SAIC outperforms peer methods in terms of larger area under the Receiver Operating Characteristics curve and increased detection power. We then apply SAIC to analyze structural genomic aberrations acquired in four real cancer genome-wide copy number data sets (ovarian cancer, metastatic prostate cancer, lung adenocarcinoma, glioblastoma. When compared with previously reported results, SAIC successfully identifies most SCAs known to be of biological significance and associated with oncogenes (e.g., KRAS, CCNE1, and MYC or tumor suppressor genes (e.g., CDKN2A/B. Furthermore, SAIC identifies a number of novel SCAs in these copy number data that encompass tumor related genes and may warrant further studies. Conclusions Supported by a well-grounded theoretical framework, SAIC has been developed and used to identify SCAs in various cancer copy number data sets, providing useful information to study the landscape of cancer genomes

  15. Genome-wide screening identifies Plasmodium chabaudi-induced modifications of DNA methylation status of Tlr1 and Tlr6 gene promoters in liver, but not spleen, of female C57BL/6 mice.

    Science.gov (United States)

    Al-Quraishy, Saleh; Dkhil, Mohamed A; Abdel-Baki, Abdel Azeem S; Delic, Denis; Santourlidis, Simeon; Wunderlich, Frank

    2013-11-01

    Epigenetic reprogramming of host genes via DNA methylation is increasingly recognized as critical for the outcome of diverse infectious diseases, but information for malaria is not yet available. Here, we investigate the effect of blood-stage malaria of Plasmodium chabaudi on the DNA methylation status of host gene promoters on a genome-wide scale using methylated DNA immunoprecipitation and Nimblegen microarrays containing 2,000 bp oligonucleotide features that were split into -1,500 to -500 bp Ups promoters and -500 to +500 bp Cor promoters, relative to the transcription site, for evaluation of differential DNA methylation. Gene expression was analyzed by Agilent and Affymetrix microarray technology. Challenging of female C57BL/6 mice with 10(6) P. chabaudi-infected erythrocytes resulted in a self-healing outcome of infections with peak parasitemia on day 8 p.i. These infections induced organ-specific modifications of DNA methylation of gene promoters. Among the 17,354 features on Nimblegen arrays, only seven gene promoters were identified to be hypermethylated in the spleen, whereas the liver exhibited 109 hyper- and 67 hypomethylated promoters at peak parasitemia in comparison with non-infected mice. Among the identified genes with differentially methylated Cor-promoters, only the 7 genes Pigr, Ncf1, Klkb1, Emr1, Ndufb11, and Tlr6 in the liver and Apol6 in the spleen were detected to have significantly changed their expression. Remarkably, the Cor promoter of the toll-like receptor Tlr6 became hypomethylated and Tlr6 expression increased by 3.4-fold during infection. Concomitantly, the Ups promoter of the Tlr1 was hypermethylated, but Tlr1 expression also increased by 11.3-fold. TLR6 and TLR1 are known as auxillary receptors to form heterodimers with TLR2 in plasma membranes of macrophages, which recognize different pathogen-associated molecular patterns (PAMPs), as, e.g., intact 3-acyl and sn-2-lyso-acyl glycosylphosphatidylinositols of P. falciparum

  16. Genome-wide SNP scan of pooled DNA reveals nonsense mutation in FGF20 in the scaleless line of featherless chickens

    Directory of Open Access Journals (Sweden)

    Wells Kirsty L

    2012-06-01

    Full Text Available Abstract Background Scaleless (sc/sc chickens carry a single recessive mutation that causes a lack of almost all body feathers, as well as foot scales and spurs, due to a failure of skin patterning during embryogenesis. This spontaneous mutant line, first described in the 1950s, has been used extensively to explore the tissue interactions involved in ectodermal appendage formation in embryonic skin. Moreover, the trait is potentially useful in tropical agriculture due to the ability of featherless chickens to tolerate heat, which is at present a major constraint to efficient poultry meat production in hot climates. In the interests of enhancing our understanding of feather placode development, and to provide the poultry industry with a strategy to breed heat-tolerant meat-type chickens (broilers, we mapped and identified the sc mutation. Results Through a cost-effective and labour-efficient SNP array mapping approach using DNA from sc/sc and sc/+ blood sample pools, we map the sc trait to chromosome 4 and show that a nonsense mutation in FGF20 is completely associated with the sc/sc phenotype. This mutation, common to all sc/sc individuals and absent from wild type, is predicted to lead to loss of a highly conserved region of the FGF20 protein important for FGF signalling. In situ hybridisation and quantitative RT-PCR studies reveal that FGF20 is epidermally expressed during the early stages of feather placode patterning. In addition, we describe a dCAPS genotyping assay based on the mutation, developed to facilitate discrimination between wild type and sc alleles. Conclusions This work represents the first loss of function genetic evidence supporting a role for FGF ligand signalling in feather development, and suggests FGF20 as a novel central player in the development of vertebrate skin appendages, including hair follicles and exocrine glands. In addition, this is to our knowledge the first report describing the use of the chicken SNP array to

  17. DNA secondary structures and epigenetic determinants of cancer genome evolution

    OpenAIRE

    2010-01-01

    An unstable genome is a hallmark of many cancers. It is unclear, however, whether some mutagenic features driving somatic alterations in cancer are encoded in the genome sequence and whether they can operate in a tissue-specific manner. We performed a genome-wide analysis of 663,446 DNA breakpoints associated with somatic copy-number alterations (SCNAs) from 2,792 cancer samples classified into 26 cancer types. Many SCNA breakpoints are spatially clustered in cancer genomes. We observed a sig...

  18. Sequencing intractable DNA to close microbial genomes.

    Science.gov (United States)

    Hurt, Richard A; Brown, Steven D; Podar, Mircea; Palumbo, Anthony V; Elias, Dwayne A

    2012-01-01

    Advancement in high throughput DNA sequencing technologies has supported a rapid proliferation of microbial genome sequencing projects, providing the genetic blueprint for in-depth studies. Oftentimes, difficult to sequence regions in microbial genomes are ruled "intractable" resulting in a growing number of genomes with sequence gaps deposited in databases. A procedure was developed to sequence such problematic regions in the "non-contiguous finished" Desulfovibrio desulfuricans ND132 genome (6 intractable gaps) and the Desulfovibrio africanus genome (1 intractable gap). The polynucleotides surrounding each gap formed GC rich secondary structures making the regions refractory to amplification and sequencing. Strand-displacing DNA polymerases used in concert with a novel ramped PCR extension cycle supported amplification and closure of all gap regions in both genomes. The developed procedures support accurate gene annotation, and provide a step-wise method that reduces the effort required for genome finishing.

  19. Sequencing intractable DNA to close microbial genomes.

    Directory of Open Access Journals (Sweden)

    Richard A Hurt

    Full Text Available Advancement in high throughput DNA sequencing technologies has supported a rapid proliferation of microbial genome sequencing projects, providing the genetic blueprint for in-depth studies. Oftentimes, difficult to sequence regions in microbial genomes are ruled "intractable" resulting in a growing number of genomes with sequence gaps deposited in databases. A procedure was developed to sequence such problematic regions in the "non-contiguous finished" Desulfovibrio desulfuricans ND132 genome (6 intractable gaps and the Desulfovibrio africanus genome (1 intractable gap. The polynucleotides surrounding each gap formed GC rich secondary structures making the regions refractory to amplification and sequencing. Strand-displacing DNA polymerases used in concert with a novel ramped PCR extension cycle supported amplification and closure of all gap regions in both genomes. The developed procedures support accurate gene annotation, and provide a step-wise method that reduces the effort required for genome finishing.

  20. Simple & Safe Genomic DNA Isolation.

    Science.gov (United States)

    Moss, Robert; Solomon, Sondra

    1991-01-01

    A procedure for purifying DNA using either bacteria or rat liver is presented. Directions for doing a qualitative DNA assay using diphenylamine and a quantitative DNA assay using spectroscopy are included. (KR)

  1. Planning and executing a genome wide association study (GWAS).

    Science.gov (United States)

    Sale, Michèle M; Mychaleckyj, Josyf C; Chen, Wei-Min

    2009-01-01

    In recent years, genome-wide association approaches have proven a powerful and successful strategy to identify genetic contributors to complex traits, including a number of endocrine disorders. Their success has meant that genome wide association studies (GWAS) are fast becoming the default study design for discovery of new genetic variants that influence a clinical trait or phenotype. This chapter focuses on a number of key elements that require consideration for the successful conduct of a GWAS. Although many of the considerations are common to any genetic study, the greater cost, extreme multiple testing, and greater openness to data sharing require specific awareness and planning by investigators. In the section on designing a GWAS, we reflect on ethical considerations, study design, selection of phenotype/s, power considerations, sample tracking and storage issues, and genotyping product selection. During execution, important considerations include DNA quantity and preparation, genotyping methods, quality control checks of genotype data, in silico genotyping (imputation), tests of association, and replication of association signals. Although the field of human genetics is rapidly evolving, recent experiences can help guide an investigator in making practical and methodological choices that will eventually determine the overall quality of GWAS results. Given the investment to recruit patient populations or cohorts that are powered for a GWAS, and the still substantial costs associated with genotyping, it is helpful to be aware of these aspects to maximize the likelihood of success, especially where there is an opportunity for implementing them prospectively.

  2. Genome-wide patterns of nucleotide polymorphism in domesticated rice.

    Directory of Open Access Journals (Sweden)

    Ana L Caicedo

    2007-09-01

    Full Text Available Domesticated Asian rice (Oryza sativa is one of the oldest domesticated crop species in the world, having fed more people than any other plant in human history. We report the patterns of DNA sequence variation in rice and its wild ancestor, O. rufipogon, across 111 randomly chosen gene fragments, and use these to infer the evolutionary dynamics that led to the origins of rice. There is a genome-wide excess of high-frequency derived single nucleotide polymorphisms (SNPs in O. sativa varieties, a pattern that has not been reported for other crop species. We developed several alternative models to explain contemporary patterns of polymorphisms in rice, including a (i selectively neutral population bottleneck model, (ii bottleneck plus migration model, (iii multiple selective sweeps model, and (iv bottleneck plus selective sweeps model. We find that a simple bottleneck model, which has been the dominant demographic model for domesticated species, cannot explain the derived nucleotide polymorphism site frequency spectrum in rice. Instead, a bottleneck model that incorporates selective sweeps, or a more complex demographic model that includes subdivision and gene flow, are more plausible explanations for patterns of variation in domesticated rice varieties. If selective sweeps are indeed the explanation for the observed nucleotide data of domesticated rice, it suggests that strong selection can leave its imprint on genome-wide polymorphism patterns, contrary to expectations that selection results only in a local signature of variation.

  3. Genome-wide studies of telomere biology in budding yeast

    Directory of Open Access Journals (Sweden)

    Yaniv Harari

    2014-03-01

    Full Text Available Telomeres are specialized DNA-protein structures at the ends of eukaryotic chromosomes. Telomeres are essential for chromosomal stability and integrity, as they prevent chromosome ends from being recognized as double strand breaks. In rapidly proliferating cells, telomeric DNA is synthesized by the enzyme telomerase, which copies a short template sequence within its own RNA moiety, thus helping to solve the “end-replication problem”, in which information is lost at the ends of chromosomes with each DNA replication cycle. The basic mechanisms of telomere length, structure and function maintenance are conserved among eukaryotes. Studies in the yeast Saccharomyces cerevisiae have been instrumental in deciphering the basic aspects of telomere biology. In the last decade, technical advances, such as the availability of mutant collections, have allowed carrying out systematic genome-wide screens for mutants affecting various aspects of telomere biology. In this review we summarize these efforts, and the insights that this Systems Biology approach has produced so far.

  4. Genome-wide profiling of p63 DNA-binding sites identifies an element that regulates gene expression during limb development in the 7q21 SHFM1 locus.

    Directory of Open Access Journals (Sweden)

    Evelyn N Kouwenhoven

    2010-08-01

    Full Text Available Heterozygous mutations in p63 are associated with split hand/foot malformations (SHFM, orofacial clefting, and ectodermal abnormalities. Elucidation of the p63 gene network that includes target genes and regulatory elements may reveal new genes for other malformation disorders. We performed genome-wide DNA-binding profiling by chromatin immunoprecipitation (ChIP, followed by deep sequencing (ChIP-seq in primary human keratinocytes, and identified potential target genes and regulatory elements controlled by p63. We show that p63 binds to an enhancer element in the SHFM1 locus on chromosome 7q and that this element controls expression of DLX6 and possibly DLX5, both of which are important for limb development. A unique micro-deletion including this enhancer element, but not the DLX5/DLX6 genes, was identified in a patient with SHFM. Our study strongly indicates disruption of a non-coding cis-regulatory element located more than 250 kb from the DLX5/DLX6 genes as a novel disease mechanism in SHFM1. These data provide a proof-of-concept that the catalogue of p63 binding sites identified in this study may be of relevance to the studies of SHFM and other congenital malformations that resemble the p63-associated phenotypes.

  5. A genome-wide association study of social and non-social autistic-like traits in the general population using pooled DNA, 500 K SNP microarrays and both community and diagnosed autism replication samples.

    Science.gov (United States)

    Ronald, Angelica; Butcher, Lee M; Docherty, Sophia; Davis, Oliver S P; Schalkwyk, Leonard C; Craig, Ian W; Plomin, Robert

    2010-01-01

    Two separate genome-wide association studies were conducted to identify single nucleotide polymorphisms (SNPs) associated with social and nonsocial autistic-like traits. We predicted that we would find SNPs associated with social and non-social autistic-like traits and that different SNPs would be associated with social and nonsocial. In Stage 1, each study screened for allele frequency differences in approximately 430,000 autosomal SNPs using pooled DNA on microarrays in high-scoring versus low-scoring boys from a general population sample (N = approximately 400/group). In Stage 2, 22 and 20 SNPs in the social and non-social studies, respectively, were tested for QTL association by individually genotyping an independent community sample of 1,400 boys. One SNP (rs11894053) was nominally associated (P < .05, uncorrected for multiple testing) with social autistic-like traits. When the sample was increased by adding females, 2 additional SNPs were nominally significant (P < .05). These 3 SNPs, however, showed no significant association in transmission disequilibrium analyses of diagnosed ASD families.

  6. Genome-wide nucleosome map and cytosine methylation levels of an ancient human genome

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Valen, Eivind; Velazquez, Amhed Missael Vargas;

    2014-01-01

    data generated from hair shafts of a 4000-yr-old Paleo-Eskimo belonging to the Saqqaq culture, we generate the first ancient nucleosome map coupled with a genome-wide survey of cytosine methylation levels. The validity of both nucleosome map and methylation levels were confirmed by the recovery...... of the expected signals at promoter regions, exon/intron boundaries, and CTCF sites. The top-scoring nucleosome calls revealed distinct DNA positioning biases, attesting to nucleotide-level accuracy. The ancient methylation levels exhibited high conservation over time, clustering closely with modern hair tissues...

  7. Genome-wide polymorphisms show unexpected targets of natural selection

    OpenAIRE

    Pespeni, Melissa H.; Garfield, David A.; Manier, Mollie K; Palumbi, Stephen R.

    2011-01-01

    Natural selection can act on all the expressed genes of an individual, leaving signatures of genetic differentiation or diversity at many loci across the genome. New power to assay these genome-wide effects of selection comes from associating multi-locus patterns of polymorphism with gene expression and function. Here, we performed one of the first genome-wide surveys in a marine species, comparing purple sea urchins, Strongylocentrotus purpuratus, from two distant locations along the species...

  8. DNA Microarrays in Comparative Genomics and Transcriptomics

    DEFF Research Database (Denmark)

    Willenbrock, Hanni

    2007-01-01

    of each method’s ability to analyze DNA copy number data. Moreover, our study shows that analysis methods developed for cancer research may also successfully be applied to DNA copy number profiles from bacterial genomes. However, here the purpose is to characterize variations in the gene content...... to verify predictions of highly expressed genes. Moreover, the codon bias of microbial genomes was found to constitute an environmental signature. For example, soil bacteria have very similar codon bias....

  9. A Genome-Wide Perspective on Metabolism

    DEFF Research Database (Denmark)

    Rauch, Alexander; Mandrup, Susanne

    2015-01-01

    Mammals have at least 210 histologically diverse cell types (Alberts, Molecular biology of the cell. Garland Science, New York, 2008) and the number would be even higher if functional differences are taken into account. The genome in each of these cell types is differentially programmed to expres...

  10. Genome-wide comparison of medieval and modern Mycobacterium leprae

    DEFF Research Database (Denmark)

    Schuenemann, Verena J; Singh, Pushpendra; Mendum, Thomas A;

    2013-01-01

    Leprosy was endemic in Europe until the Middle Ages. Using DNA array capture, we have obtained genome sequences of Mycobacterium leprae from skeletons of five medieval leprosy cases from the United Kingdom, Sweden, and Denmark. In one case, the DNA was so well preserved that full de novo assembly...... of the ancient bacterial genome could be achieved through shotgun sequencing alone. The ancient M. leprae sequences were compared with those of 11 modern strains, representing diverse genotypes and geographic origins. The comparisons revealed remarkable genomic conservation during the past 1000 years, a European...

  11. Genome-wide search for strabismus susceptibility loci.

    Directory of Open Access Journals (Sweden)

    Fujiwara H

    2003-06-01

    Full Text Available The purpose of this study was to search for chromosomal susceptibility loci for comitant strabismus. Genomic DNA was isolated from 10mL blood taken from each member of 30 nuclear families in which 2 or more siblings are affected by either esotropia or exotropia. A genome-wide search was performed with amplification by polymerase chain reaction of 400 markers in microsatellite regions with approximately 10 cM resolution. For each locus, non-parametric affected sib-pair analysis and non-parametric linkage analysis for multiple pedigrees (Genehunter software, http://linkage.rockefeller.edu/soft/ were used to calculate multipoint lod scores and non-parametric linkage (NPL scores, respectively. In sib-pair analysis, lod scores showed basically flat lines with several peaks of 0.25 on all chromosomes. In non-parametric linkage analysis for multiple pedigrees, NPL scores showed one peak as high as 1.34 on chromosomes 1, 2, 4, 7, 10, 15, and 16, while 2 such peaks were found on chromosomes 3, 9, 11, 12, 18, and 20. Non-parametric linkage analysis for multiple pedigrees of 30 families with comitant strabismus suggested a number of chromosomal susceptibility loci. Our ongoing study involving a larger number of families will refine the accuracy of statistical analysis to pinpoint susceptibility loci for comitant strabismus.

  12. Differential DNA Methylation Analysis without a Reference Genome

    Directory of Open Access Journals (Sweden)

    Johanna Klughammer

    2015-12-01

    Full Text Available Genome-wide DNA methylation mapping uncovers epigenetic changes associated with animal development, environmental adaptation, and species evolution. To address the lack of high-throughput methods for DNA methylation analysis in non-model organisms, we developed an integrated approach for studying DNA methylation differences independent of a reference genome. Experimentally, our method relies on an optimized 96-well protocol for reduced representation bisulfite sequencing (RRBS, which we have validated in nine species (human, mouse, rat, cow, dog, chicken, carp, sea bass, and zebrafish. Bioinformatically, we developed the RefFreeDMA software to deduce ad hoc genomes directly from RRBS reads and to pinpoint differentially methylated regions between samples or groups of individuals (http://RefFreeDMA.computational-epigenetics.org. The identified regions are interpreted using motif enrichment analysis and/or cross-mapping to annotated genomes. We validated our method by reference-free analysis of cell-type-specific DNA methylation in the blood of human, cow, and carp. In summary, we present a cost-effective method for epigenome analysis in ecology and evolution, which enables epigenome-wide association studies in natural populations and species without a reference genome.

  13. Differential DNA Methylation Analysis without a Reference Genome.

    Science.gov (United States)

    Klughammer, Johanna; Datlinger, Paul; Printz, Dieter; Sheffield, Nathan C; Farlik, Matthias; Hadler, Johanna; Fritsch, Gerhard; Bock, Christoph

    2015-12-22

    Genome-wide DNA methylation mapping uncovers epigenetic changes associated with animal development, environmental adaptation, and species evolution. To address the lack of high-throughput methods for DNA methylation analysis in non-model organisms, we developed an integrated approach for studying DNA methylation differences independent of a reference genome. Experimentally, our method relies on an optimized 96-well protocol for reduced representation bisulfite sequencing (RRBS), which we have validated in nine species (human, mouse, rat, cow, dog, chicken, carp, sea bass, and zebrafish). Bioinformatically, we developed the RefFreeDMA software to deduce ad hoc genomes directly from RRBS reads and to pinpoint differentially methylated regions between samples or groups of individuals (http://RefFreeDMA.computational-epigenetics.org). The identified regions are interpreted using motif enrichment analysis and/or cross-mapping to annotated genomes. We validated our method by reference-free analysis of cell-type-specific DNA methylation in the blood of human, cow, and carp. In summary, we present a cost-effective method for epigenome analysis in ecology and evolution, which enables epigenome-wide association studies in natural populations and species without a reference genome.

  14. Defining functional DNA elements in the human genome.

    Science.gov (United States)

    Kellis, Manolis; Wold, Barbara; Snyder, Michael P; Bernstein, Bradley E; Kundaje, Anshul; Marinov, Georgi K; Ward, Lucas D; Birney, Ewan; Crawford, Gregory E; Dekker, Job; Dunham, Ian; Elnitski, Laura L; Farnham, Peggy J; Feingold, Elise A; Gerstein, Mark; Giddings, Morgan C; Gilbert, David M; Gingeras, Thomas R; Green, Eric D; Guigo, Roderic; Hubbard, Tim; Kent, Jim; Lieb, Jason D; Myers, Richard M; Pazin, Michael J; Ren, Bing; Stamatoyannopoulos, John A; Weng, Zhiping; White, Kevin P; Hardison, Ross C

    2014-04-29

    With the completion of the human genome sequence, attention turned to identifying and annotating its functional DNA elements. As a complement to genetic and comparative genomics approaches, the Encyclopedia of DNA Elements Project was launched to contribute maps of RNA transcripts, transcriptional regulator binding sites, and chromatin states in many cell types. The resulting genome-wide data reveal sites of biochemical activity with high positional resolution and cell type specificity that facilitate studies of gene regulation and interpretation of noncoding variants associated with human disease. However, the biochemically active regions cover a much larger fraction of the genome than do evolutionarily conserved regions, raising the question of whether nonconserved but biochemically active regions are truly functional. Here, we review the strengths and limitations of biochemical, evolutionary, and genetic approaches for defining functional DNA segments, potential sources for the observed differences in estimated genomic coverage, and the biological implications of these discrepancies. We also analyze the relationship between signal intensity, genomic coverage, and evolutionary conservation. Our results reinforce the principle that each approach provides complementary information and that we need to use combinations of all three to elucidate genome function in human biology and disease.

  15. A genome-wide methylation study on obesity

    Science.gov (United States)

    Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A.; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Huidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling

    2013-01-01

    Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common complex disease. We analyzed genome-wide methylation profiles of over 470,000 CpGs in peripheral blood samples from 48 obese and 48 lean African-American youth aged 14–20 y old. A substantial number of differentially variable CpG sites (DVCs), using statistics based on variances, as well as a substantial number of differentially methylated CpG sites (DMCs), using statistics based on means, were identified. Similar to the findings in cancers, DVCs generally exhibited an outlier structure and were more variable in cases than in controls. By randomly splitting the current sample into a discovery and validation set, we observed that both the DVCs and DMCs identified from the first set could independently predict obesity status in the second set. Furthermore, both the genes harboring DMCs and the genes harboring DVCs showed significant enrichment of genes identified by genome-wide association studies on obesity and related diseases, such as hypertension, dyslipidemia, type 2 diabetes and certain types of cancers, supporting their roles in the etiology and pathogenesis of obesity. We generalized the recent finding on methylation variability in cancer research to obesity and demonstrated that differential variability is also an important feature of obesity-related methylation changes. Future studies on the epigenetics of obesity will benefit from both statistics based on means and statistics based on variances. PMID:23644594

  16. Transcriptome profiling and genome-wide DNA binding define the differential role of fenretinide and all-trans RA in regulating the death and survival of human hepatocellular carcinoma Huh7 cells.

    Science.gov (United States)

    Hu, Ying; Liu, Hui-Xin; He, Yuqi; Fang, Yaping; Fang, Jianwen; Wan, Yu-Jui Yvonne

    2013-04-01

    Fenretinide is significantly more effective in inducing apoptosis in cancer cells than all-trans retinoic acid (ATRA). The current study uses a genome-wide approach to understand the differential role fenretinide and ATRA have in inducing apoptosis in Huh7 cells. Fenretinide and ATRA-induced gene expressions and DNA bindings were profiled using microarray and chromatin immunoprecipitation with anti-RXRα antibody. The data showed that fenretinide was not a strong transcription regulator. Fenretinide only changed the expressions of 1 093 genes, approximately three times less than the number of genes regulated by ATRA (2 811). Biological function annotation demonstrated that both fenretinide and ATRA participated in pathways that determine cell fate and metabolic processes. However, fenretinide specifically induced Fas/TNFα-mediated apoptosis by increasing the expression of pro-apoptotic genes i.e., DEDD2, CASP8, CASP4, and HSPA1A/B; whereas, ATRA induced the expression of BIRC3 and TNFAIP3, which inhibit apoptosis by interacting with TRAF2. In addition, fenretinide inhibited the expression of the genes involved in RAS/RAF/ERK-mediated survival pathway. In contrast, ATRA increased the expression of SOSC2, BRAF, MEK, and ERK genes. Most genes regulated by fenretinide and ATRA were bound by RXRα, suggesting a direct effect. This study revealed that by regulating fewer genes, the effects of fenretinide become more specific and thus has fewer side effects than ATRA. The data also suggested that fenretinide induces apoptosis via death receptor effector and by inhibiting the RAS/RAF/ERK pathway. It provides insight on how retinoid efficacy can be improved and how side effects in cancer therapy can be reduced.

  17. Genome-Wide Analysis Reveals Coating of the Mitochondrial Genome by TFAM

    OpenAIRE

    Wang, Yun E.; Marinov, Georgi K.; Wold, Barbara J.; Chan, David C.

    2013-01-01

    Mitochondria contain a 16.6 kb circular genome encoding 13 proteins as well as mitochondrial tRNAs and rRNAs. Copies of the genome are organized into nucleoids containing both DNA and proteins, including the machinery required for mtDNA replication and transcription. The transcription factor TFAM is critical for initiation of transcription and replication of the genome, and is also thought to perform a packaging function. Although specific binding sites required for initiation of transcriptio...

  18. A genome-wide scan for preeclampsia in the Netherlands

    NARCIS (Netherlands)

    Lachmeijer, AMA; Arngrimsson, R; Bastiaans, EJ; Frigge, ML; Pals, G; Sigurdardottir, S; Stefansson, H; Palsson, B; Nicolae, D; Kong, A; Aarnoudse, JG; Gulcher, [No Value; Dekker, GA; ten Kate, LP; Stefansson, K

    2001-01-01

    Preeclampsia, hallmarked by de novo hypertension and proteinuria in pregnancy, has a familial tendency. Recently, a large Icelandic genome-wide scan provided evidence for a maternal susceptibility locus for preeclampsia on chromosome 2p13 which was confirmed by a genome scan from Australia and New

  19. Genome-wide association study of clinical dimensions of schizophrenia

    DEFF Research Database (Denmark)

    Fanous, Ayman H; Zhou, Baiyu; Aggen, Steven H;

    2012-01-01

    Multiple sources of evidence suggest that genetic factors influence variation in clinical features of schizophrenia. The authors present the first genome-wide association study (GWAS) of dimensional symptom scores among individuals with schizophrenia....

  20. Genome-Wide Analysis Reveals Selective Modulation of microRNAs and mRNAs by Histone Deacetylase Inhibitor in B Cells Induced to Undergo Class-Switch DNA Recombination and Plasma Cell Differentiation.

    Science.gov (United States)

    Shen, Tian; Sanchez, Helia N; Zan, Hong; Casali, Paolo

    2015-01-01

    As we have suggested, epigenetic factors, such as microRNAs (miRNAs), can interact with genetic programs to regulate B cell functions, thereby informing antibody and autoantibody responses. We have shown that histone deacetylase (HDAC) inhibitors (HDI) inhibit the differentiation events critical to the maturation of the antibody response: class-switch DNA recombination (CSR), somatic hypermutation (SHM), and plasma cell differentiation, by modulating intrinsic B cell mechanisms. HDI repress the expression of AID and Blimp-1, which are critical for CSR/SHM and plasma cell differentiation, respectively, in mouse and human B cells by upregulating selected miRNAs that silenced AICDA/Aicda and PRDM1/Prdm1 mRNAs, as demonstrated by multiple qRT-PCRs (J Immunol 193:5933-5950, 2014). To further define the selectivity of HDI-mediated modulation of miRNA and gene expression, we performed genome-wide miRNA-Seq and mRNA-Seq analysis in B cells stimulated by LPS plus IL-4 and treated with HDI or nil. Consistent with what we have shown using qRT-PCR, these HDI-treated B cells displayed reduced expression of Aicda and Prdm1, and increased expression of miR-155, miR-181b, and miR-361, which target Aicda, and miR-23b, miR-30a, and miR-125b, which target Prdm1. In B cells induced to undergo CSR and plasma cell differentiation, about 23% of over 22,000 mRNAs analyzed were expressed at a significantly high copy number (more than 20 copies/cell). Only 18 (0.36%) of these highly expressed mRNAs, including Aicda, Prdm1, and Xbp1, were downregulated by HDI by 50% or more. Further, only 16 (0.30%) of the highly expressed mRNAs were upregulated (more than twofold) by HDI. The selectivity of HDI-mediated modulation of gene expression was emphasized by unchanged expression of the genes that are involved in regulation, targeting, or DNA repair processes of CSR, as well as unchanged expression of the genes encoding epigenetic regulators and factors that are important for cell signaling or

  1. Genome-wide analysis reveals selective modulation of microRNAs and mRNAs by histone deacetylase inhibitor in B cells induced to undergo class switch DNA recombination and plasma cell differentiation

    Directory of Open Access Journals (Sweden)

    Tian eShen

    2015-12-01

    Full Text Available As we have suggested, epigenetic factors, such as microRNAs (miRNAs, can interact with genetic programs to regulate B cell functions, thereby informing antibody and autoantibody responses. We have shown that histone deacetylase inhibitors (HDI inhibit the differentiation events critical to the maturation of the antibody response: class-switch DNA recombination (CSR, somatic hypermutation (SHM and plasma cell differentiation, by modulating intrinsic B cell mechanisms. HDI repress the expression of AID and Blimp-1, which are critical for CSR/SHM and plasma cell differentiation, respectively, in mouse and human B cells by upregulating selected miRNAs that silenced AICDA/Aicda and PRDM1/Prdm1 mRNAs, as demonstrated by multiple qRT-PCRs (J. Immunol. 193:5933-5950, 2014. To further define the selectivity of HDI-mediated modulation of miRNA and gene expression, we performed genome-wide miRNA-Seq and mRNA-Seq analysis in B cells stimulated by LPS plus IL-4 and treated with HDI or nil. Consistent with what we have shown using qRT-PCR, these HDI-treated B cells displayed reduced expression of Aicda and Prdm1, and increased expression of miR-155, miR-181b and miR-361, which target Aicda, and miR-23b, miR-30a and miR-125b, which target Prdm1. In B cells induced to undergo CSR and plasma cell differentiation, about 23% of over 22,000 mRNAs analyzed were expressed at a significantly high copy number (more than 20 copies/cell. Only 18 (0.36% of these highly expressed mRNAs, including Aicda, Prdm1 and Xbp1, were downregulated by HDI by 50% or more. Further, only 16 (0.30% of the highly expressed mRNAs were upregulated (more than twofold by HDI. The selectivity of HDI-mediated modulation of gene expression was emphasized by unchanged expression of the genes that are involved in regulation, targeting or DNA repair processes of CSR, as well as unchanged expression of the genes encoding epigenetic regulators and factors that are important for cell signaling or

  2. No genome barriers to promiscuous DNA

    Science.gov (United States)

    Lewin, R.

    1984-06-01

    Farrelly and Butow (1983) used the term 'promiscuous DNA' in their report of the apparent natural transfer of yeast mitochondrial DNA sequences into the nuclear genome. Ellis (1982) applied the same term in an editorial comment. It is pointed out since that time the subject of DNA's promiscuity has exploded with a series of reports. According to a report by Stern (1984), movement of DNA sequences between chloroplasts and mitochondria is not just a rare event but is a rampant process. It was recently concluded that 'the widespread presence of ctDNA sequences in plant mtDNA is best regarded as a dramatic demonstration of the dynamo nature of interactions between the chloroplast and the mitochondrion, similar to the ongoing process of interorganellar DNA transfer already documented between mitochondrion and nucleus and between chloroplast and nucleus'.

  3. Detection of Non-Amplified Genomic DNA

    CERN Document Server

    Corradini, Roberto

    2012-01-01

    This book offers a state-of-the-art overview on non amplified DNA detection methods and provides chemists, biochemists, biotechnologists and material scientists with an introduction to these methods. In fact all these fields have dedicated resources to the problem of nucleic acid detection, each contributing with their own specific methods and concepts. This book will explain the basic principles of the different non amplified DNA detection methods available, highlighting their respective advantages and limitations. The importance of non-amplified DNA sequencing technologies will be also discussed. Non-amplified DNA detection can be achieved by adopting different techniques. Such techniques have allowed the commercialization of innovative platforms for DNA detection that are expected to break into the DNA diagnostics market. The enhanced sensitivity required for the detection of non amplified genomic DNA has prompted new strategies that can achieve ultrasensitivity by combining specific materials with specifi...

  4. Cancer genetic association studies in the genome-wide age

    OpenAIRE

    Savage, Sharon A

    2008-01-01

    Genome-wide association studies of hundreds of thousands of SNPs have led to a deluge of studies of genetic variation in cancer and other common diseases. Large case–control and cohort studies have identified novel SNPs as markers of cancer risk. Genome-wide association study SNP data have also advanced understanding of population-specific genetic variation. While studies of risk profiles, combinations of SNPs that may increase cancer risk, are not yet clinically applicable, future, large-sca...

  5. Genome-wide association study of multiplex schizophrenia pedigrees

    DEFF Research Database (Denmark)

    Levinson, Douglas F; Shi, Jianxin; Wang, Kai

    2012-01-01

    The authors used a genome-wide association study (GWAS) of multiply affected families to investigate the association of schizophrenia to common single-nucleotide polymorphisms (SNPs) and rare copy number variants (CNVs).......The authors used a genome-wide association study (GWAS) of multiply affected families to investigate the association of schizophrenia to common single-nucleotide polymorphisms (SNPs) and rare copy number variants (CNVs)....

  6. Genome-wide Analysis of Gene Regulation

    DEFF Research Database (Denmark)

    Chen, Yun

    IP-seq and small RNA-seq, we delineated the landscape of the promoters with bidirectional transcriptions that yield steady-state RNA in only one directions (Paper III). A subsequent motif analysis enabled us to uncover specific DNA signals – early polyA sites – that make RNA on the reverse strand sensitive...... they regulated or if the sites had global elevated usage rates by multiple TFs. Using RNA-seq, 5’end-seq in combination with depletion of 5’exonuclease as well as nonsensemediated decay (NMD) factors, we systematically analyzed NMD substrates as well as their degradation intermediates in human cells (Paper V......). Gene enrichment analysis on the detected NMD substrates revealed an unappreciated NMD-based regulatory mechanism of the genes hosting multiple intronic snoRNAs, which can facilitate differential expression of individual snoRNAs from a single host gene locus. Finally, supported by RNA-seq and small RNA-seq...

  7. Genome-wide comparison of medieval and modern Mycobacterium leprae

    DEFF Research Database (Denmark)

    Schuenemann, Verena J; Singh, Pushpendra; Mendum, Thomas A

    2013-01-01

    Leprosy was endemic in Europe until the Middle Ages. Using DNA array capture, we have obtained genome sequences of Mycobacterium leprae from skeletons of five medieval leprosy cases from the United Kingdom, Sweden, and Denmark. In one case, the DNA was so well preserved that full de novo assembly...... of the ancient bacterial genome could be achieved through shotgun sequencing alone. The ancient M. leprae sequences were compared with those of 11 modern strains, representing diverse genotypes and geographic origins. The comparisons revealed remarkable genomic conservation during the past 1000 years, a European...... origin for leprosy in the Americas, and the presence of an M. leprae genotype in medieval Europe now commonly associated with the Middle East. The exceptional preservation of M. leprae biomarkers, both DNA and mycolic acids, in ancient skeletons has major implications for palaeomicrobiology and human...

  8. Genome-wide comparison of medieval and modern Mycobacterium leprae.

    Science.gov (United States)

    Schuenemann, Verena J; Singh, Pushpendra; Mendum, Thomas A; Krause-Kyora, Ben; Jäger, Günter; Bos, Kirsten I; Herbig, Alexander; Economou, Christos; Benjak, Andrej; Busso, Philippe; Nebel, Almut; Boldsen, Jesper L; Kjellström, Anna; Wu, Huihai; Stewart, Graham R; Taylor, G Michael; Bauer, Peter; Lee, Oona Y-C; Wu, Houdini H T; Minnikin, David E; Besra, Gurdyal S; Tucker, Katie; Roffey, Simon; Sow, Samba O; Cole, Stewart T; Nieselt, Kay; Krause, Johannes

    2013-07-12

    Leprosy was endemic in Europe until the Middle Ages. Using DNA array capture, we have obtained genome sequences of Mycobacterium leprae from skeletons of five medieval leprosy cases from the United Kingdom, Sweden, and Denmark. In one case, the DNA was so well preserved that full de novo assembly of the ancient bacterial genome could be achieved through shotgun sequencing alone. The ancient M. leprae sequences were compared with those of 11 modern strains, representing diverse genotypes and geographic origins. The comparisons revealed remarkable genomic conservation during the past 1000 years, a European origin for leprosy in the Americas, and the presence of an M. leprae genotype in medieval Europe now commonly associated with the Middle East. The exceptional preservation of M. leprae biomarkers, both DNA and mycolic acids, in ancient skeletons has major implications for palaeomicrobiology and human pathogen evolution.

  9. Genome-wide ancestry of 17th-century enslaved Africans from the Caribbean

    DEFF Research Database (Denmark)

    Schroeder, Hannes; Avila-Arcos, Maria C.; Malaspinas, Anna-Sapfo

    2015-01-01

    Between 1500 and 1850, more than 12 million enslaved Africans were transported to the New World. The vast majority were shipped from West and West-Central Africa, but their precise origins are largely unknown. We used genome-wide ancient DNA analyses to investigate the genetic origins of three...

  10. AluScan: a method for genome-wide scanning of sequence and structure variations in the human genome

    Directory of Open Access Journals (Sweden)

    Mei Lingling

    2011-11-01

    Full Text Available Abstract Background To complement next-generation sequencing technologies, there is a pressing need for efficient pre-sequencing capture methods with reduced costs and DNA requirement. The Alu family of short interspersed nucleotide elements is the most abundant type of transposable elements in the human genome and a recognized source of genome instability. With over one million Alu elements distributed throughout the genome, they are well positioned to facilitate genome-wide sequence amplification and capture of regions likely to harbor genetic variation hotspots of biological relevance. Results Here we report on the use of inter-Alu PCR with an enhanced range of amplicons in conjunction with next-generation sequencing to generate an Alu-anchored scan, or 'AluScan', of DNA sequences between Alu transposons, where Alu consensus sequence-based 'H-type' PCR primers that elongate outward from the head of an Alu element are combined with 'T-type' primers elongating from the poly-A containing tail to achieve huge amplicon range. To illustrate the method, glioma DNA was compared with white blood cell control DNA of the same patient by means of AluScan. The over 10 Mb sequences obtained, derived from more than 8,000 genes spread over all the chromosomes, revealed a highly reproducible capture of genomic sequences enriched in genic sequences and cancer candidate gene regions. Requiring only sub-micrograms of sample DNA, the power of AluScan as a discovery tool for genetic variations was demonstrated by the identification of 357 instances of loss of heterozygosity, 341 somatic indels, 274 somatic SNVs, and seven potential somatic SNV hotspots between control and glioma DNA. Conclusions AluScan, implemented with just a small number of H-type and T-type inter-Alu PCR primers, provides an effective capture of a diversity of genome-wide sequences for analysis. The method, by enabling an examination of gene-enriched regions containing exons, introns, and

  11. A novel statistic for genome-wide interaction analysis.

    Science.gov (United States)

    Wu, Xuesen; Dong, Hua; Luo, Li; Zhu, Yun; Peng, Gang; Reveille, John D; Xiong, Momiao

    2010-09-23

    Although great progress in genome-wide association studies (GWAS) has been made, the significant SNP associations identified by GWAS account for only a few percent of the genetic variance, leading many to question where and how we can find the missing heritability. There is increasing interest in genome-wide interaction analysis as a possible source of finding heritability unexplained by current GWAS. However, the existing statistics for testing interaction have low power for genome-wide interaction analysis. To meet challenges raised by genome-wide interactional analysis, we have developed a novel statistic for testing interaction between two loci (either linked or unlinked). The null distribution and the type I error rates of the new statistic for testing interaction are validated using simulations. Extensive power studies show that the developed statistic has much higher power to detect interaction than classical logistic regression. The results identified 44 and 211 pairs of SNPs showing significant evidence of interactions with FDRanalysis is a valuable tool for finding remaining missing heritability unexplained by the current GWAS, and the developed novel statistic is able to search significant interaction between SNPs across the genome. Real data analysis showed that the results of genome-wide interaction analysis can be replicated in two independent studies.

  12. Tracking replication enzymology in vivo by genome-wide mapping of ribonucleotide incorporation.

    Science.gov (United States)

    Clausen, Anders R; Lujan, Scott A; Burkholder, Adam B; Orebaugh, Clinton D; Williams, Jessica S; Clausen, Maryam F; Malc, Ewa P; Mieczkowski, Piotr A; Fargo, David C; Smith, Duncan J; Kunkel, Thomas A

    2015-03-01

    Ribonucleotides are frequently incorporated into DNA during replication in eukaryotes. Here we map genome-wide distribution of these ribonucleotides as markers of replication enzymology in budding yeast, using a new 5' DNA end-mapping method, hydrolytic end sequencing (HydEn-seq). HydEn-seq of DNA from ribonucleotide excision repair-deficient strains reveals replicase- and strand-specific patterns of ribonucleotides in the nuclear genome. These patterns support the roles of DNA polymerases α and δ in lagging-strand replication and of DNA polymerase ɛ in leading-strand replication. They identify replication origins, termination zones and variations in ribonucleotide incorporation frequency across the genome that exceed three orders of magnitude. HydEn-seq also reveals strand-specific 5' DNA ends at mitochondrial replication origins, thus suggesting unidirectional replication of a circular genome. Given the conservation of enzymes that incorporate and process ribonucleotides in DNA, HydEn-seq can be used to track replication enzymology in other organisms.

  13. Whole genome amplification of DNA for genotyping pharmacogenetics candidate genes.

    Directory of Open Access Journals (Sweden)

    Santosh ePhilips

    2012-03-01

    Full Text Available Whole genome amplification (WGA technologies can be used to amplify genomic DNA when only small amounts of DNA are available. The Multiple Displacement Amplification Phi polymerase based amplification has been shown to accurately amplify DNA for a variety of genotyping assays; however, it has not been tested for genotyping many of the clinically relevant genes important for pharmacogenetic studies, such as the cytochrome P450 genes, that are typically difficult to genotype due to multiple pseudogenes, copy number variations, and high similarity to other related genes. We evaluated whole genome amplified samples for Taqman™ genotyping of SNPs in a variety of pharmacogenetic genes. In 24 DNA samples from the Coriell human diversity panel, the call rates and concordance between amplified (~200-fold amplification and unamplified samples was 100% for two SNPs in CYP2D6 and one in ESR1. In samples from a breast cancer clinical trial (Trial 1, we compared the genotyping results in samples before and after WGA for four SNPs in CYP2D6, one SNP in CYP2C19, one SNP in CYP19A1, two SNPs in ESR1, and two SNPs in ESR2. The concordance rates were all >97%. Finally, we compared the allele frequencies of 143 SNPs determined in Trial 1 (whole genome amplified DNA to the allele frequencies determined in unamplified DNA samples from a separate trial (Trial 2 that enrolled a similar population. The call rates and allele frequencies between the two trials were 98% and 99.7%, respectively. We conclude that the whole genome amplified DNA is suitable for Taqman™ genotyping for a wide variety of pharmacogenetically relevant SNPs.

  14. Reconstructing Roma history from genome-wide data.

    Directory of Open Access Journals (Sweden)

    Priya Moorjani

    Full Text Available The Roma people, living throughout Europe and West Asia, are a diverse population linked by the Romani language and culture. Previous linguistic and genetic studies have suggested that the Roma migrated into Europe from South Asia about 1,000-1,500 years ago. Genetic inferences about Roma history have mostly focused on the Y chromosome and mitochondrial DNA. To explore what additional information can be learned from genome-wide data, we analyzed data from six Roma groups that we genotyped at hundreds of thousands of single nucleotide polymorphisms (SNPs. We estimate that the Roma harbor about 80% West Eurasian ancestry-derived from a combination of European and South Asian sources-and that the date of admixture of South Asian and European ancestry was about 850 years before present. We provide evidence for Eastern Europe being a major source of European ancestry, and North-west India being a major source of the South Asian ancestry in the Roma. By computing allele sharing as a measure of linkage disequilibrium, we estimate that the migration of Roma out of the Indian subcontinent was accompanied by a severe founder event, which appears to have been followed by a major demographic expansion after the arrival in Europe.

  15. Genome-wide identification of KANADI1 target genes.

    Directory of Open Access Journals (Sweden)

    Paz Merelo

    Full Text Available Plant organ development and polarity establishment is mediated by the action of several transcription factors. Among these, the KANADI (KAN subclade of the GARP protein family plays important roles in polarity-associated processes during embryo, shoot and root patterning. In this study, we have identified a set of potential direct target genes of KAN1 through a combination of chromatin immunoprecipitation/DNA sequencing (ChIP-Seq and genome-wide transcriptional profiling using tiling arrays. Target genes are over-represented for genes involved in the regulation of organ development as well as in the response to auxin. KAN1 affects directly the expression of several genes previously shown to be important in the establishment of polarity during lateral organ and vascular tissue development. We also show that KAN1 controls through its target genes auxin effects on organ development at different levels: transport and its regulation, and signaling. In addition, KAN1 regulates genes involved in the response to abscisic acid, jasmonic acid, brassinosteroids, ethylene, cytokinins and gibberellins. The role of KAN1 in organ polarity is antagonized by HD-ZIPIII transcription factors, including REVOLUTA (REV. A comparison of their target genes reveals that the REV/KAN1 module acts in organ patterning through opposite regulation of shared targets. Evidence of mutual repression between closely related family members is also shown.

  16. Reconstructing Roma History from Genome-Wide Data

    Science.gov (United States)

    Moorjani, Priya; Patterson, Nick; Loh, Po-Ru; Lipson, Mark; Kisfali, Péter; Melegh, Bela I.; Bonin, Michael; Kádaši, Ľudevít; Rieß, Olaf; Berger, Bonnie; Reich, David; Melegh, Béla

    2013-01-01

    The Roma people, living throughout Europe and West Asia, are a diverse population linked by the Romani language and culture. Previous linguistic and genetic studies have suggested that the Roma migrated into Europe from South Asia about 1,000–1,500 years ago. Genetic inferences about Roma history have mostly focused on the Y chromosome and mitochondrial DNA. To explore what additional information can be learned from genome-wide data, we analyzed data from six Roma groups that we genotyped at hundreds of thousands of single nucleotide polymorphisms (SNPs). We estimate that the Roma harbor about 80% West Eurasian ancestry–derived from a combination of European and South Asian sources–and that the date of admixture of South Asian and European ancestry was about 850 years before present. We provide evidence for Eastern Europe being a major source of European ancestry, and North-west India being a major source of the South Asian ancestry in the Roma. By computing allele sharing as a measure of linkage disequilibrium, we estimate that the migration of Roma out of the Indian subcontinent was accompanied by a severe founder event, which appears to have been followed by a major demographic expansion after the arrival in Europe. PMID:23516520

  17. TALENs: a widely applicable technology for targeted genome editing

    OpenAIRE

    Joung, J. Keith; Sander, Jeffry D.

    2012-01-01

    Engineered nucleases enable the targeted alteration of any DNA sequence in a wide range of cell types and organisms. The newly-developed transcription activator-like effector nucleases (TALENs) comprise a non-specific DNA-cleaving nuclease fused to a DNA-binding domain that can be easily engineered so that TALENs can target essentially any sequence. The capability to quickly and efficiently alter any gene sequence using TALENs promises to have profound impacts on biological research and to yi...

  18. Genome-wide profiling of genetic variation in Agrobacterium-transformed rice plants*#

    Science.gov (United States)

    Li, Wen-xu; Wu, San-ling; Liu, Yan-hua; Jin, Gu-lei; Zhao, Hai-jun; Fan, Long-jiang; Shu, Qing-yao

    2016-01-01

    Agrobacterium-mediated transformation has been widely used in producing transgenic plants, and was recently used to generate “transgene-clean” targeted genomic modifications coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas9) system. Although tremendous variation in morphological and agronomic traits, such as plant height, seed fertility, and grain size, was observed in transgenic plants, the underlying mechanisms are not yet well understood, and the types and frequency of genetic variation in transformed plants have not been fully disclosed. To reveal the genome-wide variation in transformed plants, we sequenced the genomes of five independent T0 rice plants using next-generation sequencing (NGS) techniques. Bioinformatics analyses followed by experimental validation revealed the following: (1) in addition to transfer-DNA (T-DNA) insertions, three transformed plants carried heritable plasmid backbone DNA of variable sizes (855–5216 bp) and in different configurations with the T-DNA insertions (linked or apart); (2) each transgenic plant contained an estimated 338–1774 independent genetic variations (single nucleotide variations (SNVs) or small insertion/deletions); and (3) 2–6 new Tos17 insertions were detected in each transformed plant, but no other transposable elements or bacterial genomic DNA. PMID:27921404

  19. Annotation-based genome-wide SNP discovery in the large and complex Aegilops tauschii genome using next-generation sequencing without a reference genome sequence

    Directory of Open Access Journals (Sweden)

    Luo Ming-Cheng

    2011-01-01

    Full Text Available Abstract Background Many plants have large and complex genomes with an abundance of repeated sequences. Many plants are also polyploid. Both of these attributes typify the genome architecture in the tribe Triticeae, whose members include economically important wheat, rye and barley. Large genome sizes, an abundance of repeated sequences, and polyploidy present challenges to genome-wide SNP discovery using next-generation sequencing (NGS of total genomic DNA by making alignment and clustering of short reads generated by the NGS platforms difficult, particularly in the absence of a reference genome sequence. Results An annotation-based, genome-wide SNP discovery pipeline is reported using NGS data for large and complex genomes without a reference genome sequence. Roche 454 shotgun reads with low genome coverage of one genotype are annotated in order to distinguish single-copy sequences and repeat junctions from repetitive sequences and sequences shared by paralogous genes. Multiple genome equivalents of shotgun reads of another genotype generated with SOLiD or Solexa are then mapped to the annotated Roche 454 reads to identify putative SNPs. A pipeline program package, AGSNP, was developed and used for genome-wide SNP discovery in Aegilops tauschii-the diploid source of the wheat D genome, and with a genome size of 4.02 Gb, of which 90% is repetitive sequences. Genomic DNA of Ae. tauschii accession AL8/78 was sequenced with the Roche 454 NGS platform. Genomic DNA and cDNA of Ae. tauschii accession AS75 was sequenced primarily with SOLiD, although some Solexa and Roche 454 genomic sequences were also generated. A total of 195,631 putative SNPs were discovered in gene sequences, 155,580 putative SNPs were discovered in uncharacterized single-copy regions, and another 145,907 putative SNPs were discovered in repeat junctions. These SNPs were dispersed across the entire Ae. tauschii genome. To assess the false positive SNP discovery rate, DNA

  20. A novel statistic for genome-wide interaction analysis.

    Directory of Open Access Journals (Sweden)

    Xuesen Wu

    2010-09-01

    Full Text Available Although great progress in genome-wide association studies (GWAS has been made, the significant SNP associations identified by GWAS account for only a few percent of the genetic variance, leading many to question where and how we can find the missing heritability. There is increasing interest in genome-wide interaction analysis as a possible source of finding heritability unexplained by current GWAS. However, the existing statistics for testing interaction have low power for genome-wide interaction analysis. To meet challenges raised by genome-wide interactional analysis, we have developed a novel statistic for testing interaction between two loci (either linked or unlinked. The null distribution and the type I error rates of the new statistic for testing interaction are validated using simulations. Extensive power studies show that the developed statistic has much higher power to detect interaction than classical logistic regression. The results identified 44 and 211 pairs of SNPs showing significant evidence of interactions with FDR<0.001 and 0.001genome-wide interaction analysis is a valuable tool for finding remaining missing heritability unexplained by the current GWAS, and the developed novel statistic is able to search significant interaction between SNPs across the genome. Real data analysis showed that the results of genome-wide interaction analysis can be replicated in two independent studies.

  1. Genome-wide association study for hereditary ataxia in the Parson Russell Terrier and DNA-testing for ataxia-associated mutations in the Parson and Jack Russell Terrier.

    Science.gov (United States)

    Gast, Alana Christina; Metzger, Julia; Tipold, Andrea; Distl, Ottmar

    2016-10-10

    Spinocerebellar ataxia also referred to as hereditary ataxia comprises different forms of progressive neurodegenerative diseases. A complex mode of inheritance was most likely in Parson Russell Terriers (PRT) and in Jack Russell Terriers (JRT). Recently, the missense mutation KCNJ10:c.627C > G was shown to be associated with the spinocerebellar ataxia (SCA) in JRT and related Russell group of terriers, whereas the missense mutation CAPN1:c.344G > A was associated with late onset ataxia (LOA) in PRT. We performed a genome-wide association study (GWAS) in PRT including 15 cases and 29 controls and found a statistically strong signal in the genomic region on dog chromosome 38 (CFA38) where KCNJ10 is located. We tested the CAPN1:c.344G > A and KCNJ10:c.627C > G (Transcript XM_545752.4) mutations in a sample of 77 PRT and 9 JRT from Germany as well as further 179 controls from 20 different dog breeds. All cases and controls genotyped carried the wild-type for the CAPN1:c.344G > A mutation. Among the PRT, 17/77 (22.1 %) dogs were homozygous for the mutant KCNJ10 allele and 22/77 (28.6 %) dogs were heterozygous. Three cases of PRT had the homozygous KCNJ10 wild-type. In JRT, 1/3 cases did show the mutant KCNJ10 allele homozygous. Thus, we sequenced the KCNJ10 exons with their adjacent regions from 10 PRT and 3 JRT including the animals with imperfect co-segregation of the c.627C > G mutation. We identified a total of 45 genetic variants within KCNJ10. The most likely variant explaining the cases appeared a 1-bp-insertion in a C-stretch within exon 3 (KCNJ10:g.22141027insC). In silico analysis showed that this indel may influence the regulation of gene expression. In the present study, 16/21 cases of hereditary ataxia perfectly co-segregated with the KCNJ10:c.627C > G mutation. The CAPN1:c.344G > A mutation could not be validated and seems to be a rare variant in the samples screened. Screening KCNJ10 for further mutations did result in a

  2. Genome-wide conserved consensus transcription factor binding motifs are hyper-methylated

    Directory of Open Access Journals (Sweden)

    Down Thomas A

    2010-09-01

    Full Text Available Abstract Background DNA methylation can regulate gene expression by modulating the interaction between DNA and proteins or protein complexes. Conserved consensus motifs exist across the human genome ("predicted transcription factor binding sites": "predicted TFBS" but the large majority of these are proven by chromatin immunoprecipitation and high throughput sequencing (ChIP-seq not to be biological transcription factor binding sites ("empirical TFBS". We hypothesize that DNA methylation at conserved consensus motifs prevents promiscuous or disorderly transcription factor binding. Results Using genome-wide methylation maps of the human heart and sperm, we found that all conserved consensus motifs as well as the subset of those that reside outside CpG islands have an aggregate profile of hyper-methylation. In contrast, empirical TFBS with conserved consensus motifs have a profile of hypo-methylation. 40% of empirical TFBS with conserved consensus motifs resided in CpG islands whereas only 7% of all conserved consensus motifs were in CpG islands. Finally we further identified a minority subset of TF whose profiles are either hypo-methylated or neutral at their respective conserved consensus motifs implicating that these TF may be responsible for establishing or maintaining an un-methylated DNA state, or whose binding is not regulated by DNA methylation. Conclusions Our analysis supports the hypothesis that at least for a subset of TF, empirical binding to conserved consensus motifs genome-wide may be controlled by DNA methylation.

  3. Genome-Wide Prediction of C. elegans Genetic Interactions

    OpenAIRE

    Zhong, Weiwei; Sternberg, Paul W.

    2006-01-01

    To obtain a global view of functional interactions among genes in a metazoan genome, we computationally integrated interactome data, gene expression data, phenotype data, and functional annotation data from three model organisms—Saccharomyces cerevisiae, Caenorhabditis elegans, and Drosophila melanogaster—and predicted genome-wide genetic interactions in C. elegans. The resulting genetic interaction network (consisting of 18,183 interactions) provides a framework for system-level understandin...

  4. Mosaicism for genome-wide paternal uniparental disomy with features of multiple imprinting disorders: diagnostic and management issues.

    Science.gov (United States)

    Inbar-Feigenberg, Michal; Choufani, Sanaa; Cytrynbaum, Cheryl; Chen, Yi-An; Steele, Leslie; Shuman, Cheryl; Ray, Peter N; Weksberg, Rosanna

    2013-01-01

    Mosaicism for genome-wide paternal uniparental disomy (UPD) has been reported in only seven live born individuals to date. Clinical presentation includes manifestations of multiple paternal UPD syndromes with high variability, likely due to the variable levels of mosaicism in different somatic tissues. We report an eighth case in a female patient with mosaicism for genome-wide paternal UPD which highlights the complex clinical presentation. Our patient had features of Beckwith-Wiedemann syndrome (BWS), Angelman syndrome, and congenital hyperinsulinism. The clinical findings included prematurity, organomegaly, hemihyperplasia, developmental delay, benign tumors, and cystic lesions. The diagnosis in our patient was established utilizing microarray-based genome-wide DNA methylation analysis performed on leukocyte DNA. Targeted multiplex ligation-dependent probe amplification (MLPA) analysis of chromosome regions 11p15 and 15q13 confirmed mosaicism for paternal UPD at these genomic regions. This case represents the first report of microarray-based genome-wide DNA methylation analysis in the diagnosis of genome-wide paternal UPD. The application of microarray-based genome-wide DNA methylation analysis on selected individuals with complex clinical presentations could be a valuable diagnostic tool to improve the detection rate of mosaic genome-wide paternal UPD. This approach, which screens many loci simultaneously, is more cost-effective and less labor-intensive than performing multiple targeted DNA methylation-based assays. Identification of individuals with mosaicism for genome-wide paternal UPD is an important goal as it confers a low recurrence risk for the family and identifies individuals who require surveillance due to increased tumor risk.

  5. Power analysis for genome-wide association studies

    Directory of Open Access Journals (Sweden)

    Klein Robert J

    2007-08-01

    Full Text Available Abstract Background Genome-wide association studies are a promising new tool for deciphering the genetics of complex diseases. To choose the proper sample size and genotyping platform for such studies, power calculations that take into account genetic model, tag SNP selection, and the population of interest are required. Results The power of genome-wide association studies can be computed using a set of tag SNPs and a large number of genotyped SNPs in a representative population, such as available through the HapMap project. As expected, power increases with increasing sample size and effect size. Power also depends on the tag SNPs selected. In some cases, more power is obtained by genotyping more individuals at fewer SNPs than fewer individuals at more SNPs. Conclusion Genome-wide association studies should be designed thoughtfully, with the choice of genotyping platform and sample size being determined from careful power calculations.

  6. Genome-wide approaches to understanding behaviour in Drosophila melanogaster.

    Science.gov (United States)

    Neville, Megan; Goodwin, Stephen F

    2012-09-01

    Understanding how an organism exhibits specific behaviours remains a major and important biological question. Studying behaviour in a simple model organism like the fruit fly Drosophila melanogaster has the advantages of advanced molecular genetics approaches along with well-defined anatomy and physiology. With advancements in functional genomic technologies, researchers are now attempting to uncover genes and pathways involved in complex behaviours on a genome-wide scale. A systems-level network approach, which will include genomic approaches, to study behaviour will be key to understanding the regulation and modulation of behaviours and the importance of context in regulating them.

  7. High-resolution, genome-wide mapping of chromatin modifications by GMAT.

    Science.gov (United States)

    Roh, Tae-Young; Zhao, Keji

    2008-01-01

    One major postgenomic challenge is to characterize the epigenomes that control genome functions. The epigenomes are mainly defined by the specific association of nonhistone proteins with chromatin and the covalent modifications of chromatin, including DNA methylation and posttranslational histone modifications. The in vivo protein-binding and chromatin-modification patterns can be revealed by the chromatin immunoprecipitation assay (ChIP). By combining the ChIP assays and the serial analysis of gene expression (SAGE) protocols, we have developed an unbiased and high-resolution genome-wide mapping technique (GMAT) to determine the genome-wide protein-targeting and chromatin-modification patterns. GMAT has been successfully applied to mapping the target sites of the histone acetyltransferase, Gcn5p, in yeast and to the discovery of the histone acetylation islands as an epigenetic mark for functional regulatory elements in the human genome.

  8. Genome-Wide Chromatin Immunoprecipitation in Candida albicans and Other Yeasts

    Science.gov (United States)

    Lohse, Matthew B.; Kongsomboonvech, Pisiwat; Madrigal, Maria; Hernday, Aaron D.; Nobile, Clarissa J.

    2016-01-01

    Chromatin immunoprecipitation experiments are critical to investigating the interactions between DNA and a wide range of nuclear proteins within a cell or biological sample. In this chapter we outline an optimized protocol for genome-wide chromatin immunoprecipitation that has been used successfully for several distinct morphological forms of numerous yeast species, and include an optimized method for amplification of chromatin immunoprecipitated DNA samples and hybridization to a high-density oligonucleotide tiling microarray. We also provide detailed suggestions on how to analyze the complex data obtained from these experiments. PMID:26483022

  9. Maintenance of Genome Integrity: How Mammalian Cells Orchestrate Genome Duplication by Coordinating Replicative and Specialized DNA Polymerases

    Directory of Open Access Journals (Sweden)

    Ryan Barnes

    2017-01-01

    Full Text Available Precise duplication of the human genome is challenging due to both its size and sequence complexity. DNA polymerase errors made during replication, repair or recombination are central to creating mutations that drive cancer and aging. Here, we address the regulation of human DNA polymerases, specifically how human cells orchestrate DNA polymerases in the face of stress to complete replication and maintain genome stability. DNA polymerases of the B-family are uniquely adept at accurate genome replication, but there are numerous situations in which one or more additional DNA polymerases are required to complete genome replication. Polymerases of the Y-family have been extensively studied in the bypass of DNA lesions; however, recent research has revealed that these polymerases play important roles in normal human physiology. Replication stress is widely cited as contributing to genome instability, and is caused by conditions leading to slowed or stalled DNA replication. Common Fragile Sites epitomize “difficult to replicate” genome regions that are particularly vulnerable to replication stress, and are associated with DNA breakage and structural variation. In this review, we summarize the roles of both the replicative and Y-family polymerases in human cells, and focus on how these activities are regulated during normal and perturbed genome replication.

  10. Maintenance of Genome Integrity: How Mammalian Cells Orchestrate Genome Duplication by Coordinating Replicative and Specialized DNA Polymerases.

    Science.gov (United States)

    Barnes, Ryan; Eckert, Kristin

    2017-01-06

    Precise duplication of the human genome is challenging due to both its size and sequence complexity. DNA polymerase errors made during replication, repair or recombination are central to creating mutations that drive cancer and aging. Here, we address the regulation of human DNA polymerases, specifically how human cells orchestrate DNA polymerases in the face of stress to complete replication and maintain genome stability. DNA polymerases of the B-family are uniquely adept at accurate genome replication, but there are numerous situations in which one or more additional DNA polymerases are required to complete genome replication. Polymerases of the Y-family have been extensively studied in the bypass of DNA lesions; however, recent research has revealed that these polymerases play important roles in normal human physiology. Replication stress is widely cited as contributing to genome instability, and is caused by conditions leading to slowed or stalled DNA replication. Common Fragile Sites epitomize "difficult to replicate" genome regions that are particularly vulnerable to replication stress, and are associated with DNA breakage and structural variation. In this review, we summarize the roles of both the replicative and Y-family polymerases in human cells, and focus on how these activities are regulated during normal and perturbed genome replication.

  11. Statistical Approaches in Genome-Wide Association Studies

    OpenAIRE

    Yazdani, Akram

    2014-01-01

    Genome-wide association studies, GWAS, typically contain hundreds of thousands single nucleotide polymorphisms, SNPs, genotyped for few numbers of samples. The aim of these studies is to identify regions harboring SNPs or to predict the outcomes of interest. Since the number of predictors in the GWAS far exceeds the number of samples, it is impossible to analyze the data with classical statistical methods. In the current GWAS, the widely applied methods are based on single marker analysis th...

  12. An improved chloroplast DNA extraction procedure for whole plastid genome sequencing.

    Science.gov (United States)

    Shi, Chao; Hu, Na; Huang, Hui; Gao, Ju; Zhao, You-Jie; Gao, Li-Zhi

    2012-01-01

    Chloroplast genomes supply valuable genetic information for evolutionary and functional studies in plants. The past five years have witnessed a dramatic increase in the number of completely sequenced chloroplast genomes with the application of second-generation sequencing technology in plastid genome sequencing projects. However, cost-effective high-throughput chloroplast DNA (cpDNA) extraction becomes a major bottleneck restricting the application, as conventional methods are difficult to make a balance between the quality and yield of cpDNAs. We first tested two traditional methods to isolate cpDNA from the three species, Oryza brachyantha, Leersia japonica and Prinsepia utihis. Both of them failed to obtain properly defined cpDNA bands. However, we developed a simple but efficient method based on sucrose gradients and found that the modified protocol worked efficiently to isolate the cpDNA from the same three plant species. We sequenced the isolated DNA samples with Illumina (Solexa) sequencing technology to test cpDNA purity according to aligning sequence reads to the reference chloroplast genomes, showing that the reference genome was properly covered. We show that 40-50% cpDNA purity is achieved with our method. Here we provide an improved method used to isolate cpDNA from angiosperms. The Illumina sequencing results suggest that the isolated cpDNA has reached enough yield and sufficient purity to perform subsequent genome assembly. The cpDNA isolation protocol thus will be widely applicable to the plant chloroplast genome sequencing projects.

  13. Genome-wide association studies and resting heart rate

    DEFF Research Database (Denmark)

    Oskari Kilpeläinen, Tuomas

    2016-01-01

    Genome-wide association studies (GWASs) have revolutionized the search for genetic variants regulating resting heart rate. In the last 10 years, GWASs have led to the identification of at least 21 novel heart rate loci. These discoveries have provided valuable insights into the mechanisms...... and pathways that regulate heart rate and link heart rate to cardiovascular morbidity and mortality. GWASs capture majority of genetic variation in a population sample by utilizing high-throughput genotyping chips measuring genotypes for up to several millions of SNPs across the genome in thousands...... of individuals. This allows the identification of the strongest heart rate associated signals at genome-wide level. While GWASs provide robust statistical evidence of the association of a given genetic locus with heart rate, they are only the starting point for detailed follow-up studies to locate the causal...

  14. Genome accessibility is widely preserved and locally modulated during mitosis.

    Science.gov (United States)

    Hsiung, Chris C-S; Morrissey, Christapher S; Udugama, Maheshi; Frank, Christopher L; Keller, Cheryl A; Baek, Songjoon; Giardine, Belinda; Crawford, Gregory E; Sung, Myong-Hee; Hardison, Ross C; Blobel, Gerd A

    2015-02-01

    Mitosis entails global alterations to chromosome structure and nuclear architecture, concomitant with transient silencing of transcription. How cells transmit transcriptional states through mitosis remains incompletely understood. While many nuclear factors dissociate from mitotic chromosomes, the observation that certain nuclear factors and chromatin features remain associated with individual loci during mitosis originated the hypothesis that such mitotically retained molecular signatures could provide transcriptional memory through mitosis. To understand the role of chromatin structure in mitotic memory, we performed the first genome-wide comparison of DNase I sensitivity of chromatin in mitosis and interphase, using a murine erythroblast model. Despite chromosome condensation during mitosis visible by microscopy, the landscape of chromatin accessibility at the macromolecular level is largely unaltered. However, mitotic chromatin accessibility is locally dynamic, with individual loci maintaining none, some, or all of their interphase accessibility. Mitotic reduction in accessibility occurs primarily within narrow, highly DNase hypersensitive sites that frequently coincide with transcription factor binding sites, whereas broader domains of moderate accessibility tend to be more stable. In mitosis, proximal promoters generally maintain their accessibility more strongly, whereas distal regulatory elements tend to lose accessibility. Large domains of DNA hypomethylation mark a subset of promoters that retain accessibility during mitosis and across many cell types in interphase. Erythroid transcription factor GATA1 exerts site-specific changes in interphase accessibility that are most pronounced at distal regulatory elements, but has little influence on mitotic accessibility. We conclude that features of open chromatin are remarkably stable through mitosis, but are modulated at the level of individual genes and regulatory elements.

  15. Genome-wide gene expression analysis of anguillid herpesvirus 1

    NARCIS (Netherlands)

    Beurden, van S.J.; Peeters, B.P.H.; Rottier, P.J.M.; Davison, A.A.; Engelsma, M.Y.

    2013-01-01

    Background Whereas temporal gene expression in mammalian herpesviruses has been studied extensively, little is known about gene expression in fish herpesviruses. Here we report a genome-wide transcription analysis of a fish herpesvirus, anguillid herpesvirus 1, in cell culture, studied during the

  16. Genome-Wide Scan Reveals Mutation Associated with Melanoma

    Science.gov (United States)

    ... Q R S T U V W X Y Z We want to hear from you You are here: News & Events 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 Spotlight on Research 2012 July 2012 (historical) Genome-Wide Scan Reveals Mutation Associated with Melanoma A team of ...

  17. Genome-wide RNA Tomography in the Zebrafish Embryo

    NARCIS (Netherlands)

    Junker, Jan Philipp; Noël, Emily S; Guryev, Victor; Peterson, Kevin A; Shah, Gopi; Huisken, Jan; McMahon, Andrew P; Berezikov, Eugene; Bakkers, Jeroen; van Oudenaarden, Alexander

    2014-01-01

    Advancing our understanding of embryonic development is heavily dependent on identification of novel pathways or regulators. Although genome-wide techniques such as RNA sequencing are ideally suited for discovering novel candidate genes, they are unable to yield spatially resolved information in

  18. Genome-wide RNA Tomography in the zebrafish embryo

    NARCIS (Netherlands)

    Junker, Jan Philipp; Noël, Emily S; Guryev, Victor; Peterson, Kevin A; Shah, Gopi; Huisken, Jan; McMahon, Andrew P; Berezikov, Eugene; Bakkers, Jeroen; van Oudenaarden, Alexander

    2014-01-01

    Advancing our understanding of embryonic development is heavily dependent on identification of novel pathways or regulators. Although genome-wide techniques such as RNA sequencing are ideally suited for discovering novel candidate genes, they are unable to yield spatially resolved information in

  19. Genome-wide association study identifies five new schizophrenia loci

    NARCIS (Netherlands)

    Ripke, Stephan; Sanders, Alan R.; Kendler, Kenneth S.; Levinson, Douglas F.; Sklar, Pamela; Holmans, Peter A.; Lin, Dan-Yu; Duan, Jubao; Ophoff, Roel A.; Andreassen, Ole A.; Scolnick, Edward; Cichon, Sven; Clair, David St.; Corvin, Aiden; Gurling, Hugh; Werge, Thomas; Rujescu, Dan; Blackwood, Douglas H. R.; Pato, Carlos N.; Malhotra, Anil K.; Purcell, Shaun; Dudbridge, Frank; Neale, Benjamin M.; Rossin, Lizzy; Visscher, Peter M.; Posthuma, Danielle; Ruderfer, Douglas M.; Fanous, Ayman; Stefansson, Hreinn; Steinberg, Stacy; Mowry, Bryan J.; Golimbet, Vera; De Hert, Marc; Jonsson, Erik G.; Bitter, Istvan; Pietilainen, Olli P. H.; Collier, David A.; Tosato, Sarah; Agartz, Ingrid; Albus, Margot; Alexander, Madeline; Amdur, Richard L.; Amin, Farooq; Bass, Nicholas; Bergen, Sarah E.; Black, Donald W.; Borglum, Anders D.; Brown, Matthew A.; Bruggeman, Richard; Buccola, Nancy G.; Byerley, William F.; Cahn, Wiepke; Cantor, Rita M.; Carr, Vaughan J.; Catts, Stanley V.; Choudhury, Khalid; Cloninger, C. Robert; Cormican, Paul; Craddock, Nicholas; Danoy, Patrick A.; Datta, Susmita; De Haan, Lieuwe; Demontis, Ditte; Dikeos, Dimitris; Djurovic, Srdjan; Donnelly, Peter; Donohoe, Gary; Duong, Linh; Dwyer, Sarah; Fink-Jensen, Anders; Freedman, Robert; Freimer, Nelson B.; Friedl, Marion; Georgieva, Lyudmila; Giegling, Ina; Gill, Michael; Glenthoj, Birte; Godard, Stephanie; Hamshere, Marian; Hansen, Mark; Hansen, Thomas; Hartmann, Annette M.; Henskens, Frans A.; Hougaard, David M.; Hultman, Christina M.; Ingason, Andres; Jablensky, Assen V.; Jakobsen, Klaus D.; Jay, Maurice; Juergens, Gesche; Kahn, Renes; Keller, Matthew C.; Kenis, Gunter; Kenny, Elaine; Kim, Yunjung; Kirov, George K.; Konnerth, Heike; Konte, Bettina; Krabbendam, Lydia; Krasucki, Robert; Lasseter, Virginia K.; Laurent, Claudine; Lawrence, Jacob; Lencz, Todd; Lerer, F. Bernard; Liang, Kung-Yee; Lichtenstein, Paul; Lieberman, Jeffrey A.; Linszen, Don H.; Lonnqvist, Jouko; Loughland, Carmel M.; Maclean, Alan W.; Maher, Brion S.; Maier, Wolfgang; Mallet, Jacques; Malloy, Pat; Mattheisen, Manuel; Mattingsdal, Morten; McGhee, Kevin A.; McGrath, John J.; McIntosh, Andrew; McLean, Duncan E.; McQuillin, Andrew; Melle, Ingrid; Michie, Patricia T.; Milanova, Vihra; Morris, Derek W.; Mors, Ole; Mortensen, Preben B.; Moskvina, Valentina; Muglia, Pierandrea; Myin-Germeys, Inez; Nertney, Deborah A.; Nestadt, Gerald; Nielsen, Jimmi; Nikolov, Ivan; Nordentoft, Merete; Norton, Nadine; Noethen, Markus M.; O'Dushlaine, Colm T.; Olincy, Ann; Olsen, Line; O'Neill, F. Anthony; Orntoft, Torben F.; Owen, Michael J.; Pantelis, Christos; Papadimitriou, George; Pato, Michele T.; Peltonen, Leena; Petursson, Hannes; Pickard, Ben; Pimm, Jonathan; Pulver, Ann E.; Puri, Vinay; Quested, Digby; Quinn, Emma M.; Rasmussen, Henrik B.; Rethelyi, Janos M.; Ribble, Robert; Rietschel, Marcella; Riley, Brien P.; Ruggeri, Mirella; Schall, Ulrich; Schulze, Thomas G.; Schwab, Sibylle G.; Scott, Rodney J.; Shi, Jianxin; Sigurdsson, Engilbert; Silverman, Jeremy M.; Spencer, Chris C. A.; Stefansson, Kari; Strange, Amy; Strengman, Eric; Stroup, T. Scott; Suvisaari, Jaana; Terenius, Lars; Thirumalai, Srinivasa; Thygesen, Johan H.; Timm, Sally; Toncheva, Draga; van den Oord, Edwin; van Os, Jim; van Winkel, Ruud; Veldink, Jan; Walsh, Dermot; Wang, August G.; Wiersma, Durk; Wildenauer, Dieter B.; Williams, Hywel J.; Williams, Nigel M.; Wormley, Brandon; Zammit, Stan; Sullivan, Patrick F.; O'Donovan, Michael C.; Daly, Mark J.; Gejman, Pablo V.

    2011-01-01

    We examined the role of common genetic variation in schizophrenia in a genome-wide association study of substantial size: a stage 1 discovery sample of 21,856 individuals of European ancestry and a stage 2 replication sample of 29,839 independent subjects. The combined stage 1 and 2 analysis yielded

  20. A genome-wide association study of anorexia nervosa

    NARCIS (Netherlands)

    Boraska, V; Franklin, C S; Floyd, J A B; Thornton, L M; Huckins, L M; Southam, L; Rayner, N W; Tachmazidou, I; Klump, K L; Treasure, J; Lewis, C M; Schmidt, U; Tozzi, F; Kiezebrink, K; Hebebrand, J; Gorwood, P; Adan, R A H; Kas, M J H; Favaro, A; Santonastaso, P; Fernández-Aranda, F; Gratacos, M; Rybakowski, F; Dmitrzak-Weglarz, M; Kaprio, J; Keski-Rahkonen, A; Raevuori, A; Van Furth, E F; Slof-Op 't Landt, M C T; Hudson, J I; Reichborn-Kjennerud, T; Knudsen, G P S; Monteleone, P; Kaplan, A S; Karwautz, A; Hakonarson, H; Berrettini, W H; Guo, Y; Li, D; Schork, N J; Komaki, G; Ando, T; Inoko, H; Esko, T; Fischer, K; Männik, K; Metspalu, A; Baker, J H; Cone, R D; Dackor, J; DeSocio, J E; Hilliard, C E; O'Toole, J K; Pantel, J; Szatkiewicz, J P; Taico, C; Zerwas, S; Trace, S E; Davis, O S P; Helder, S; Bühren, K; Burghardt, R; de Zwaan, M; Egberts, K; Ehrlich, S; Herpertz-Dahlmann, B; Herzog, W; Imgart, H; Scherag, A; Scherag, S; Zipfel, S; Boni, C; Ramoz, N; Versini, A; Brandys, M K; Danner, U N; de Kovel, C; Hendriks, J; Koeleman, B P C; Ophoff, R A; Strengman, E; van Elburg, Annemarie; Bruson, A; Clementi, M; Degortes, D; Forzan, M; Tenconi, E; Docampo, E; Escaramís, G; Jiménez-Murcia, S; Lissowska, J; Rajewski, A; Szeszenia-Dabrowska, N; Slopien, A; Hauser, J; Karhunen, L; Meulenbelt, I; Slagboom, P E; Tortorella, A; Maj, M; Dedoussis, G; Dikeos, D; Gonidakis, F; Tziouvas, K; Tsitsika, A; Papezova, H; Slachtova, L; Martaskova, D; Kennedy, J L; Levitan, R D; Yilmaz, Z; Huemer, J; Koubek, D; Merl, E; Wagner, G; Lichtenstein, P; Breen, G; Cohen-Woods, S; Farmer, A; McGuffin, P; Cichon, S; Giegling, I; Herms, S; Rujescu, D; Schreiber, S; Wichmann, H-E; Dina, C; Sladek, R; Gambaro, G; Soranzo, N; Julia, A; Marsal, S; Rabionet, R; Gaborieau, V; Dick, D M; Palotie, A; Ripatti, S; Widén, E; Andreassen, O A; Espeseth, T; Lundervold, A; Reinvang, I; Steen, V M; Le Hellard, S; Mattingsdal, M; Ntalla, I; Bencko, V; Foretova, L; Janout, V; Navratilova, M; Gallinger, S; Pinto, D; Scherer, S W; Aschauer, H; Carlberg, L; Schosser, A; Alfredsson, L; Ding, B; Klareskog, L; Padyukov, L; Courtet, P; Guillaume, S; Jaussent, I; Finan, C; Kalsi, G; Roberts, M; Logan, D W; Peltonen, L; Ritchie, G R S; Barrett, J C; Estivill, X; Hinney, A; Sullivan, P F; Collier, D A; Zeggini, E; Bulik, C M

    2014-01-01

    Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countri

  1. Genome-Wide Association Analysis in Primary Sclerosing Cholangitis

    NARCIS (Netherlands)

    T.H. Karlsen; A. Franke; E. Melum; A.. Kaser; J.R. Hov; T. Balschun; B.A. Lie; A. Bergquist; C. Schramm; T.J. Weismüller; D. Gotthardt; C. Rust; E.E.R. Philipp; T. Fritz; L. Henckaerts; R. Weersma; P. Stokkers; C.Y. Ponsioen; C. Wijmenga; M. Sterneck; M. Nothnagel; J. Hampe; A. Teufel; H. Runz; P. Rosenstiel; A. Stiehl; S. Vermeire; U. Beuers; M. Manns; E. Schrumpf; K.M. Boberg; S. Schreiber

    2010-01-01

    BACKGROUND & AIMS: We aimed to characterize the genetic susceptibility to primary sclerosing cholangitis (PSC) by means of a genome-wide association analysis of single nucleotide polymorphism (SNP) markers. METHODS: A total of 443,816 SNPs on the Affymetrix SNP Array 5.0 (Affymetrix, Santa Clara, CA

  2. Genome-wide association study of Tourette's syndrome

    NARCIS (Netherlands)

    Scharf, J. M.; Yu, D.; Mathews, C. A.; Neale, B. M.; Stewart, S. E.; Fagerness, J. A.; Evans, P.; Gamazon, E.; Edlund, C. K.; Service, S. K.; Tikhomirov, A.; Osiecki, L.; Illmann, C.; Pluzhnikov, A.; Konkashbaev, A.; Davis, L. K.; Han, B.; Crane, J.; Moorjani, P.; Crenshaw, A. T.; Parkin, M. A.; Reus, V. I.; Lowe, T. L.; Rangel-Lugo, M.; Chouinard, S.; Dion, Y.; Girard, S.; Cath, D. C.; Smit, J. H.; King, R. A.; Fernandez, T. V.; Leckman, J. F.; Kidd, K. K.; Kidd, J. R.; Pakstis, A. J.; State, M. W.; Herrera, L. D.; Romero, R.; Fournier, E.; Sandor, P.; Barr, C. L.; Phan, N.; Gross-Tsur, V.; Benarroch, F.; Pollak, Y.; Budman, C. L.; Bruun, R. D.; Erenberg, G.; Naarden, A. L.; Lee, P. C.; Weiss, N.; Kremeyer, B.; Berrio, G. B.; Campbell, D. D.; Cardona Silgado, J. C.; Ochoa, W. C.; Mesa Restrepo, S. C.; Muller, H.; Valencia Duarte, A. V.; Lyon, G. J.; Leppert, M.; Morgan, J.; Weiss, R.; Grados, M. A.; Anderson, K.; Davarya, S.; Singer, H.; Walkup, J.; Jankovic, J.; Tischfield, J. A.; Heiman, G. A.; Gilbert, D. L.; Hoekstra, P. J.; Robertson, M. M.; Kurlan, R.; Liu, C.; Gibbs, J. R.; Singleton, A.; Hardy, J.; Strengman, E.; Ophoff, R. A.; Wagner, M.; Moessner, R.; Mirel, D. B.; Posthuma, D.; Sabatti, C.; Eskin, E.; Conti, D. V.; Knowles, J. A.; Ruiz-Linares, A.; Rouleau, G. A.; Purcell, S.; Heutink, P.; Oostra, B. A.; McMahon, W. M.; Freimer, N. B.; Cox, N. J.; Pauls, D. L.

    2013-01-01

    Tourette's syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association

  3. Genome-wide association study identifies five new schizophrenia loci

    NARCIS (Netherlands)

    Ripke, Stephan; Sanders, Alan R.; Kendler, Kenneth S.; Levinson, Douglas F.; Sklar, Pamela; Holmans, Peter A.; Lin, Dan-Yu; Duan, Jubao; Ophoff, Roel A.; Andreassen, Ole A.; Scolnick, Edward; Cichon, Sven; Clair, David St.; Corvin, Aiden; Gurling, Hugh; Werge, Thomas; Rujescu, Dan; Blackwood, Douglas H. R.; Pato, Carlos N.; Malhotra, Anil K.; Purcell, Shaun; Dudbridge, Frank; Neale, Benjamin M.; Rossin, Lizzy; Visscher, Peter M.; Posthuma, Danielle; Ruderfer, Douglas M.; Fanous, Ayman; Stefansson, Hreinn; Steinberg, Stacy; Mowry, Bryan J.; Golimbet, Vera; De Hert, Marc; Jonsson, Erik G.; Bitter, Istvan; Pietilainen, Olli P. H.; Collier, David A.; Tosato, Sarah; Agartz, Ingrid; Albus, Margot; Alexander, Madeline; Amdur, Richard L.; Amin, Farooq; Bass, Nicholas; Bergen, Sarah E.; Black, Donald W.; Borglum, Anders D.; Brown, Matthew A.; Bruggeman, Richard; Buccola, Nancy G.; Byerley, William F.; Cahn, Wiepke; Cantor, Rita M.; Carr, Vaughan J.; Catts, Stanley V.; Choudhury, Khalid; Cloninger, C. Robert; Cormican, Paul; Craddock, Nicholas; Danoy, Patrick A.; Datta, Susmita; De Haan, Lieuwe; Demontis, Ditte; Dikeos, Dimitris; Djurovic, Srdjan; Donnelly, Peter; Donohoe, Gary; Duong, Linh; Dwyer, Sarah; Fink-Jensen, Anders; Freedman, Robert; Freimer, Nelson B.; Friedl, Marion; Georgieva, Lyudmila; Giegling, Ina; Gill, Michael; Glenthoj, Birte; Godard, Stephanie; Hamshere, Marian; Hansen, Mark; Hansen, Thomas; Hartmann, Annette M.; Henskens, Frans A.; Hougaard, David M.; Hultman, Christina M.; Ingason, Andres; Jablensky, Assen V.; Jakobsen, Klaus D.; Jay, Maurice; Juergens, Gesche; Kahn, Renes; Keller, Matthew C.; Kenis, Gunter; Kenny, Elaine; Kim, Yunjung; Kirov, George K.; Konnerth, Heike; Konte, Bettina; Krabbendam, Lydia; Krasucki, Robert; Lasseter, Virginia K.; Laurent, Claudine; Lawrence, Jacob; Lencz, Todd; Lerer, F. Bernard; Liang, Kung-Yee; Lichtenstein, Paul; Lieberman, Jeffrey A.; Linszen, Don H.; Lonnqvist, Jouko; Loughland, Carmel M.; Maclean, Alan W.; Maher, Brion S.; Maier, Wolfgang; Mallet, Jacques; Malloy, Pat; Mattheisen, Manuel; Mattingsdal, Morten; McGhee, Kevin A.; McGrath, John J.; McIntosh, Andrew; McLean, Duncan E.; McQuillin, Andrew; Melle, Ingrid; Michie, Patricia T.; Milanova, Vihra; Morris, Derek W.; Mors, Ole; Mortensen, Preben B.; Moskvina, Valentina; Muglia, Pierandrea; Myin-Germeys, Inez; Nertney, Deborah A.; Nestadt, Gerald; Nielsen, Jimmi; Nikolov, Ivan; Nordentoft, Merete; Norton, Nadine; Noethen, Markus M.; O'Dushlaine, Colm T.; Olincy, Ann; Olsen, Line; O'Neill, F. Anthony; Orntoft, Torben F.; Owen, Michael J.; Pantelis, Christos; Papadimitriou, George; Pato, Michele T.; Peltonen, Leena; Petursson, Hannes; Pickard, Ben; Pimm, Jonathan; Pulver, Ann E.; Puri, Vinay; Quested, Digby; Quinn, Emma M.; Rasmussen, Henrik B.; Rethelyi, Janos M.; Ribble, Robert; Rietschel, Marcella; Riley, Brien P.; Ruggeri, Mirella; Schall, Ulrich; Schulze, Thomas G.; Schwab, Sibylle G.; Scott, Rodney J.; Shi, Jianxin; Sigurdsson, Engilbert; Silverman, Jeremy M.; Spencer, Chris C. A.; Stefansson, Kari; Strange, Amy; Strengman, Eric; Stroup, T. Scott; Suvisaari, Jaana; Terenius, Lars; Thirumalai, Srinivasa; Thygesen, Johan H.; Timm, Sally; Toncheva, Draga; van den Oord, Edwin; van Os, Jim; van Winkel, Ruud; Veldink, Jan; Walsh, Dermot; Wang, August G.; Wiersma, Durk; Wildenauer, Dieter B.; Williams, Hywel J.; Williams, Nigel M.; Wormley, Brandon; Zammit, Stan; Sullivan, Patrick F.; O'Donovan, Michael C.; Daly, Mark J.; Gejman, Pablo V.

    2011-01-01

    We examined the role of common genetic variation in schizophrenia in a genome-wide association study of substantial size: a stage 1 discovery sample of 21,856 individuals of European ancestry and a stage 2 replication sample of 29,839 independent subjects. The combined stage 1 and 2 analysis yielded

  4. Genome-wide association study identifies five new schizophrenia loci.

    LENUS (Irish Health Repository)

    Ripke, Stephan

    2011-10-01

    We examined the role of common genetic variation in schizophrenia in a genome-wide association study of substantial size: a stage 1 discovery sample of 21,856 individuals of European ancestry and a stage 2 replication sample of 29,839 independent subjects. The combined stage 1 and 2 analysis yielded genome-wide significant associations with schizophrenia for seven loci, five of which are new (1p21.3, 2q32.3, 8p23.2, 8q21.3 and 10q24.32-q24.33) and two of which have been previously implicated (6p21.32-p22.1 and 18q21.2). The strongest new finding (P = 1.6 × 10(-11)) was with rs1625579 within an intron of a putative primary transcript for MIR137 (microRNA 137), a known regulator of neuronal development. Four other schizophrenia loci achieving genome-wide significance contain predicted targets of MIR137, suggesting MIR137-mediated dysregulation as a previously unknown etiologic mechanism in schizophrenia. In a joint analysis with a bipolar disorder sample (16,374 affected individuals and 14,044 controls), three loci reached genome-wide significance: CACNA1C (rs4765905, P = 7.0 × 10(-9)), ANK3 (rs10994359, P = 2.5 × 10(-8)) and the ITIH3-ITIH4 region (rs2239547, P = 7.8 × 10(-9)).

  5. Genome-wide association study identifies five new schizophrenia loci

    DEFF Research Database (Denmark)

    Ripke, Stephan; Sanders, Alan R; Kendler, Kenneth S

    2011-01-01

    We examined the role of common genetic variation in schizophrenia in a genome-wide association study of substantial size: a stage 1 discovery sample of 21,856 individuals of European ancestry and a stage 2 replication sample of 29,839 independent subjects. The combined stage 1 and 2 analysis yiel...

  6. Genome-wide significant risk associations for mucinous ovarian carcinoma

    DEFF Research Database (Denmark)

    Kelemen, Linda E; Lawrenson, Kate; Tyrer, Jonathan;

    2015-01-01

    Genome-wide association studies have identified several risk associations for ovarian carcinomas but not for mucinous ovarian carcinomas (MOCs). Our analysis of 1,644 MOC cases and 21,693 controls with imputation identified 3 new risk associations: rs752590 at 2q13 (P = 3.3 × 10(-8)), rs711830 at...

  7. Genome-Wide Approaches to Drosophila Heart Development

    Directory of Open Access Journals (Sweden)

    Manfred Frasch

    2016-05-01

    Full Text Available The development of the dorsal vessel in Drosophila is one of the first systems in which key mechanisms regulating cardiogenesis have been defined in great detail at the genetic and molecular level. Due to evolutionary conservation, these findings have also provided major inputs into studies of cardiogenesis in vertebrates. Many of the major components that control Drosophila cardiogenesis were discovered based on candidate gene approaches and their functions were defined by employing the outstanding genetic tools and molecular techniques available in this system. More recently, approaches have been taken that aim to interrogate the entire genome in order to identify novel components and describe genomic features that are pertinent to the regulation of heart development. Apart from classical forward genetic screens, the availability of the thoroughly annotated Drosophila genome sequence made new genome-wide approaches possible, which include the generation of massive numbers of RNA interference (RNAi reagents that were used in forward genetic screens, as well as studies of the transcriptomes and proteomes of the developing heart under normal and experimentally manipulated conditions. Moreover, genome-wide chromatin immunoprecipitation experiments have been performed with the aim to define the full set of genomic binding sites of the major cardiogenic transcription factors, their relevant target genes, and a more complete picture of the regulatory network that drives cardiogenesis. This review will give an overview on these genome-wide approaches to Drosophila heart development and on computational analyses of the obtained information that ultimately aim to provide a description of this process at the systems level.

  8. Genome-wide analysis of alternative splicing in Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Thomas Julie

    2010-02-01

    Full Text Available Abstract Background Genome-wide computational analysis of alternative splicing (AS in several flowering plants has revealed that pre-mRNAs from about 30% of genes undergo AS. Chlamydomonas, a simple unicellular green alga, is part of the lineage that includes land plants. However, it diverged from land plants about one billion years ago. Hence, it serves as a good model system to study alternative splicing in early photosynthetic eukaryotes, to obtain insights into the evolution of this process in plants, and to compare splicing in simple unicellular photosynthetic and non-photosynthetic eukaryotes. We performed a global analysis of alternative splicing in Chlamydomonas reinhardtii using its recently completed genome sequence and all available ESTs and cDNAs. Results Our analysis of AS using BLAT and a modified version of the Sircah tool revealed AS of 498 transcriptional units with 611 events, representing about 3% of the total number of genes. As in land plants, intron retention is the most prevalent form of AS. Retained introns and skipped exons tend to be shorter than their counterparts in constitutively spliced genes. The splice site signals in all types of AS events are weaker than those in constitutively spliced genes. Furthermore, in alternatively spliced genes, the prevalent splice form has a stronger splice site signal than the non-prevalent form. Analysis of constitutively spliced introns revealed an over-abundance of motifs with simple repetitive elements in comparison to introns involved in intron retention. In almost all cases, AS results in a truncated ORF, leading to a coding sequence that is around 50% shorter than the prevalent splice form. Using RT-PCR we verified AS of two genes and show that they produce more isoforms than indicated by EST data. All cDNA/EST alignments and splice graphs are provided in a website at http://combi.cs.colostate.edu/as/chlamy. Conclusions The extent of AS in Chlamydomonas that we observed is much

  9. Genome-wide BAC-end sequencing of Cucumis melo using two BAC libraries

    Directory of Open Access Journals (Sweden)

    Puigdomènech Pere

    2010-11-01

    Full Text Available Abstract Background Although melon (Cucumis melo L. is an economically important fruit crop, no genome-wide sequence information is openly available at the current time. We therefore sequenced BAC-ends representing a total of 33,024 clones, half of them from a previously described melon BAC library generated with restriction endonucleases and the remainder from a new random-shear BAC library. Results We generated a total of 47,140 high-quality BAC-end sequences (BES, 91.7% of which were paired-BES. Both libraries were assembled independently and then cross-assembled to obtain a final set of 33,372 non-redundant, high-quality sequences. These were grouped into 6,411 contigs (4.5 Mb and 26,961 non-assembled BES (14.4 Mb, representing ~4.2% of the melon genome. The sequences were used to screen genomic databases, identifying 7,198 simple sequence repeats (corresponding to one microsatellite every 2.6 kb and 2,484 additional repeats of which 95.9% represented transposable elements. The sequences were also used to screen expressed sequence tag (EST databases, revealing 11,372 BES that were homologous to ESTs. This suggests that ~30% of the melon genome consists of coding DNA. We observed regions of microsynteny between melon paired-BES and six other dicotyledonous plant genomes. Conclusion The analysis of nearly 50,000 BES from two complementary genomic libraries covered ~4.2% of the melon genome, providing insight into properties such as microsatellite and transposable element distribution, and the percentage of coding DNA. The observed synteny between melon paired-BES and six other plant genomes showed that useful comparative genomic data can be derived through large scale BAC-end sequencing by anchoring a small proportion of the melon genome to other sequenced genomes.

  10. Global genome nucleotide excision repair is organized into domains that promote efficient DNA repair in chromatin

    Science.gov (United States)

    Yu, Shirong; Evans, Katie; Bennett, Mark; Webster, Richard M.; Leadbitter, Matthew; Teng, Yumin; Waters, Raymond

    2016-01-01

    The rates at which lesions are removed by DNA repair can vary widely throughout the genome, with important implications for genomic stability. To study this, we measured the distribution of nucleotide excision repair (NER) rates for UV-induced lesions throughout the budding yeast genome. By plotting these repair rates in relation to genes and their associated flanking sequences, we reveal that, in normal cells, genomic repair rates display a distinctive pattern, suggesting that DNA repair is highly organized within the genome. Furthermore, by comparing genome-wide DNA repair rates in wild-type cells and cells defective in the global genome–NER (GG-NER) subpathway, we establish how this alters the distribution of NER rates throughout the genome. We also examined the genomic locations of GG-NER factor binding to chromatin before and after UV irradiation, revealing that GG-NER is organized and initiated from specific genomic locations. At these sites, chromatin occupancy of the histone acetyl-transferase Gcn5 is controlled by the GG-NER complex, which regulates histone H3 acetylation and chromatin structure, thereby promoting efficient DNA repair of UV-induced lesions. Chromatin remodeling during the GG-NER process is therefore organized into these genomic domains. Importantly, loss of Gcn5 significantly alters the genomic distribution of NER rates; this has implications for the effects of chromatin modifiers on the distribution of mutations that arise throughout the genome. PMID:27470111

  11. Chromatin Dynamics in Genome Stability: Roles in Suppressing Endogenous DNA Damage and Facilitating DNA Repair

    Directory of Open Access Journals (Sweden)

    Nidhi Nair

    2017-07-01

    Full Text Available Genomic DNA is compacted into chromatin through packaging with histone and non-histone proteins. Importantly, DNA accessibility is dynamically regulated to ensure genome stability. This is exemplified in the response to DNA damage where chromatin relaxation near genomic lesions serves to promote access of relevant enzymes to specific DNA regions for signaling and repair. Furthermore, recent data highlight genome maintenance roles of chromatin through the regulation of endogenous DNA-templated processes including transcription and replication. Here, we review research that shows the importance of chromatin structure regulation in maintaining genome integrity by multiple mechanisms including facilitating DNA repair and directly suppressing endogenous DNA damage.

  12. Potential assessment of genome-wide association study and genomic selection in Japanese pear Pyrus pyrifolia

    OpenAIRE

    Iwata, Hiroyoshi; Hayashi, Takeshi; Terakami, Shingo; Takada, Norio; Sawamura, Yutaka; Yamamoto, Toshiya

    2013-01-01

    Although the potential of marker-assisted selection (MAS) in fruit tree breeding has been reported, bi-parental QTL mapping before MAS has hindered the introduction of MAS to fruit tree breeding programs. Genome-wide association studies (GWAS) are an alternative to bi-parental QTL mapping in long-lived perennials. Selection based on genomic predictions of breeding values (genomic selection: GS) is another alternative for MAS. This study examined the potential of GWAS and GS in pear breeding w...

  13. High quality and quantity Genome-wide germline genotypes from FFPE normal tissue

    Directory of Open Access Journals (Sweden)

    Georgelas Ann

    2011-05-01

    Full Text Available Abstract Background Although collections of formalin fixed paraffin embedded (FFPE samples exist, sometimes representing decades of stored samples, they have not typically been utilized to their full potential. Normal tissue from such samples would be extremely valuable for generation of genotype data for individuals who cannot otherwise provide a DNA sample. Findings We extracted DNA from normal tissue identified in FFPE tissue blocks from prostate surgery and obtained complete genome wide genotype data for over 500,000 SNP markers for these samples, and for DNA extracted from whole blood for 2 of the cases, for comparison. Four of the five FFPE samples of varying age and amount of tissue had identifiable normal tissue. We obtained good quality genotype data for between 89 and 99% of all SNP markers for the 4 samples from FFPE. Concordance rates of over 99% were observed for the 2 samples with DNA from both FFPE and from whole blood. Conclusions DNA extracted from normal FFPE tissue provides excellent quality and quantity genome-wide genotyping data representing germline DNA, sufficient for both linkage and association analyses. This allows genetic analysis of informative individuals who are no longer available for sampling in genetic studies.

  14. Genome-Wide Detection and Analysis of Multifunctional Genes

    Science.gov (United States)

    Pritykin, Yuri; Ghersi, Dario; Singh, Mona

    2015-01-01

    Many genes can play a role in multiple biological processes or molecular functions. Identifying multifunctional genes at the genome-wide level and studying their properties can shed light upon the complexity of molecular events that underpin cellular functioning, thereby leading to a better understanding of the functional landscape of the cell. However, to date, genome-wide analysis of multifunctional genes (and the proteins they encode) has been limited. Here we introduce a computational approach that uses known functional annotations to extract genes playing a role in at least two distinct biological processes. We leverage functional genomics data sets for three organisms—H. sapiens, D. melanogaster, and S. cerevisiae—and show that, as compared to other annotated genes, genes involved in multiple biological processes possess distinct physicochemical properties, are more broadly expressed, tend to be more central in protein interaction networks, tend to be more evolutionarily conserved, and are more likely to be essential. We also find that multifunctional genes are significantly more likely to be involved in human disorders. These same features also hold when multifunctionality is defined with respect to molecular functions instead of biological processes. Our analysis uncovers key features about multifunctional genes, and is a step towards a better genome-wide understanding of gene multifunctionality. PMID:26436655

  15. A genome-wide 20 K citrus microarray for gene expression analysis.

    Science.gov (United States)

    Martinez-Godoy, M Angeles; Mauri, Nuria; Juarez, Jose; Marques, M Carmen; Santiago, Julia; Forment, Javier; Gadea, Jose

    2008-07-03

    Understanding of genetic elements that contribute to key aspects of citrus biology will impact future improvements in this economically important crop. Global gene expression analysis demands microarray platforms with a high genome coverage. In the last years, genome-wide EST collections have been generated in citrus, opening the possibility to create new tools for functional genomics in this crop plant. We have designed and constructed a publicly available genome-wide cDNA microarray that include 21,081 putative unigenes of citrus. As a functional companion to the microarray, a web-browsable database 1 was created and populated with information about the unigenes represented in the microarray, including cDNA libraries, isolated clones, raw and processed nucleotide and protein sequences, and results of all the structural and functional annotation of the unigenes, like general description, BLAST hits, putative Arabidopsis orthologs, microsatellites, putative SNPs, GO classification and PFAM domains. We have performed a Gene Ontology comparison with the full set of Arabidopsis proteins to estimate the genome coverage of the microarray. We have also performed microarray hybridizations to check its usability. This new cDNA microarray replaces the first 7K microarray generated two years ago and allows gene expression analysis at a more global scale. We have followed a rational design to minimize cross-hybridization while maintaining its utility for different citrus species. Furthermore, we also provide access to a website with full structural and functional annotation of the unigenes represented in the microarray, along with the ability to use this site to directly perform gene expression analysis using standard tools at different publicly available servers. Furthermore, we show how this microarray offers a good representation of the citrus genome and present the usefulness of this genomic tool for global studies in citrus by using it to catalogue genes expressed in

  16. A genome-wide 20 K citrus microarray for gene expression analysis

    Directory of Open Access Journals (Sweden)

    Gadea Jose

    2008-07-01

    Full Text Available Abstract Background Understanding of genetic elements that contribute to key aspects of citrus biology will impact future improvements in this economically important crop. Global gene expression analysis demands microarray platforms with a high genome coverage. In the last years, genome-wide EST collections have been generated in citrus, opening the possibility to create new tools for functional genomics in this crop plant. Results We have designed and constructed a publicly available genome-wide cDNA microarray that include 21,081 putative unigenes of citrus. As a functional companion to the microarray, a web-browsable database 1 was created and populated with information about the unigenes represented in the microarray, including cDNA libraries, isolated clones, raw and processed nucleotide and protein sequences, and results of all the structural and functional annotation of the unigenes, like general description, BLAST hits, putative Arabidopsis orthologs, microsatellites, putative SNPs, GO classification and PFAM domains. We have performed a Gene Ontology comparison with the full set of Arabidopsis proteins to estimate the genome coverage of the microarray. We have also performed microarray hybridizations to check its usability. Conclusion This new cDNA microarray replaces the first 7K microarray generated two years ago and allows gene expression analysis at a more global scale. We have followed a rational design to minimize cross-hybridization while maintaining its utility for different citrus species. Furthermore, we also provide access to a website with full structural and functional annotation of the unigenes represented in the microarray, along with the ability to use this site to directly perform gene expression analysis using standard tools at different publicly available servers. Furthermore, we show how this microarray offers a good representation of the citrus genome and present the usefulness of this genomic tool for global

  17. A Genome-Wide Association Study for Regulators of Micronucleus Formation in Mice

    Directory of Open Access Journals (Sweden)

    Rebecca E. McIntyre

    2016-08-01

    Full Text Available In mammals the regulation of genomic instability plays a key role in tumor suppression and also controls genome plasticity, which is important for recombination during the processes of immunity and meiosis. Most studies to identify regulators of genomic instability have been performed in cells in culture or in systems that report on gross rearrangements of the genome, yet subtle differences in the level of genomic instability can contribute to whole organism phenotypes such as tumor predisposition. Here we performed a genome-wide association study in a population of 1379 outbred Crl:CFW(SW-US_P08 mice to dissect the genetic landscape of micronucleus formation, a biomarker of chromosomal breaks, whole chromosome loss, and extranuclear DNA. Variation in micronucleus levels is a complex trait with a genome-wide heritability of 53.1%. We identify seven loci influencing micronucleus formation (false discovery rate <5%, and define candidate genes at each locus. Intriguingly at several loci we find evidence for sexual dimorphism in micronucleus formation, with a locus on chromosome 11 being specific to males.

  18. Genome-wide prediction of C. elegans genetic interactions.

    Science.gov (United States)

    Zhong, Weiwei; Sternberg, Paul W

    2006-03-10

    To obtain a global view of functional interactions among genes in a metazoan genome, we computationally integrated interactome data, gene expression data, phenotype data, and functional annotation data from three model organisms-Saccharomyces cerevisiae, Caenorhabditis elegans, and Drosophila melanogaster-and predicted genome-wide genetic interactions in C. elegans. The resulting genetic interaction network (consisting of 18,183 interactions) provides a framework for system-level understanding of gene functions. We experimentally tested the predicted interactions for two human disease-related genes and identified 14 new modifiers.

  19. Genome-wide approaches to understanding human ageing

    Directory of Open Access Journals (Sweden)

    Kaeberlein Matt

    2006-06-01

    Full Text Available Abstract The use of genomic technologies in biogerontology has the potential to greatly enhance our understanding of human ageing. High-throughput screens for alleles correlated with survival in long-lived people have uncovered novel genes involved in age-associated disease. Genome-wide longevity studies in simple eukaryotes are identifying evolutionarily conserved pathways that determine longevity. It is hoped that validation of these 'public' aspects of ageing in mice, along with analyses of variation in candidate human ageing genes, will provide targets for future interventions to slow the ageing process and retard the onset of age-associated pathologies.

  20. Genome-wide association studies for Agronomical Traits in a world wide Spring Barley Collection

    NARCIS (Netherlands)

    Pasam, R.K.; Sharma, R.; Malosetti, M.; Eeuwijk, van F.A.; Haseneyer, G.; Kilian, B.; Graner, A.

    2012-01-01

    Background Genome-wide association studies (GWAS) based on linkage disequilibrium (LD) provide a promising tool for the detection and fine mapping of quantitative trait loci (QTL) underlying complex agronomic traits. In this study we explored the genetic basis of variation for the traits heading dat

  1. cDNA-AFLP-based genetical genomics in cotton fibers.

    Science.gov (United States)

    Claverie, Michel; Souquet, Marlène; Jean, Janine; Forestier-Chiron, Nelly; Lepitre, Vincent; Pré, Martial; Jacobs, John; Llewellyn, Danny; Lacape, Jean-Marc

    2012-03-01

    Genetical genomics, or genetic analysis applied to gene expression data, has not been widely used in plants. We used quantitative cDNA-AFLP to monitor the variation in the expression level of cotton fiber transcripts among a population of inter-specific Gossypium hirsutum × G. barbadense recombinant inbred lines (RILs). Two key fiber developmental stages, elongation (10 days post anthesis, dpa), and secondary cell wall thickening (22 dpa), were studied. Normalized intensity ratios of 3,263 and 1,201 transcript-derived fragments (TDFs) segregating over 88 RILs were analyzed for quantitative trait loci (QTL) mapping for the 10 and 22 dpa fibers, respectively. Two-thirds of all TDFs mapped between 1 and 6 eQTLs (LOD > 3.5). Chromosome 21 had a higher density of eQTLs than other chromosomes in both data sets and, within chromosomes, hotspots of presumably trans-acting eQTLs were identified. The eQTL hotspots were compared to the location of phenotypic QTLs for fiber characteristics among the RILs, and several cases of co-localization were detected. Quantitative RT-PCR for 15 sequenced TDFs showed that 3 TDFs had at least one eQTL at a similar location to those identified by cDNA-AFLP, while 3 other TDFs mapped an eQTL at a similar location but with opposite additive effect. In conclusion, cDNA-AFLP proved to be a cost-effective and highly transferable platform for genome-wide and population-wide gene expression profiling. Because TDFs are anonymous, further validation and interpretation (in silico analysis, qPCR gene profiling) of the eQTL and eQTL hotspots will be facilitated by the increasing availability of cDNA and genomic sequence resources in cotton.

  2. Genomic selective constraints in murid noncoding DNA.

    Directory of Open Access Journals (Sweden)

    Daniel J Gaffney

    2006-11-01

    Full Text Available Recent work has suggested that there are many more selectively constrained, functional noncoding than coding sites in mammalian genomes. However, little is known about how selective constraint varies amongst different classes of noncoding DNA. We estimated the magnitude of selective constraint on a large dataset of mouse-rat gene orthologs and their surrounding noncoding DNA. Our analysis indicates that there are more than three times as many selectively constrained, nonrepetitive sites within noncoding DNA as in coding DNA in murids. The majority of these constrained noncoding sites appear to be located within intergenic regions, at distances greater than 5 kilobases from known genes. Our study also shows that in murids, intron length and mean intronic selective constraint are negatively correlated with intron ordinal number. Our results therefore suggest that functional intronic sites tend to accumulate toward the 5' end of murid genes. Our analysis also reveals that mean number of selectively constrained noncoding sites varies substantially with the function of the adjacent gene. We find that, among others, developmental and neuronal genes are associated with the greatest numbers of putatively functional noncoding sites compared with genes involved in electron transport and a variety of metabolic processes. Combining our estimates of the total number of constrained coding and noncoding bases we calculate that over twice as many deleterious mutations have occurred in intergenic regions as in known genic sequence and that the total genomic deleterious point mutation rate is 0.91 per diploid genome, per generation. This estimated rate is over twice as large as a previous estimate in murids.

  3. A genome-wide analysis of gene-caffeine consumption interaction on basal cell carcinoma.

    Science.gov (United States)

    Li, Xin; Cornelis, Marilyn C; Liang, Liming; Song, Fengju; De Vivo, Immaculata; Giovannucci, Edward; Tang, Jean Y; Han, Jiali

    2016-12-01

    Animal models have suggested that oral or topical administration of caffeine could inhibit ultraviolet-induced carcinogenesis via the ataxia telangiectasia and rad3 (ATR)-related apoptosis. Previous epidemiological studies have demonstrated that increased caffeine consumption is associated with reduced risk of basal cell carcinoma (BCC). To identify common genetic markers that may modify this association, we tested gene-caffeine intake interaction on BCC risk in a genome-wide analysis. We included 3383 BCC cases and 8528 controls of European ancestry from the Nurses' Health Study and Health Professionals Follow-up Study. Single nucleotide polymorphism (SNP) rs142310826 near the NEIL3 gene showed a genome-wide significant interaction with caffeine consumption (P = 1.78 × 10(-8) for interaction) on BCC risk. There was no gender difference for this interaction (P = 0.64 for heterogeneity). NEIL3, a gene belonging to the base excision DNA repair pathway, encodes a DNA glycosylase that recognizes and removes lesions produced by oxidative stress. In addition, we identified several loci with P value for interaction caffeine consumption-related SNPs reported by previous genome-wide association studies and risk of BCC, both individually and jointly, but found no significant association. In sum, we identified a DNA repair gene that could be involved in caffeine-mediated skin tumor inhibition. Further studies are warranted to confirm these findings. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. AID/APOBEC cytosine deaminase induces genome-wide kataegis

    Directory of Open Access Journals (Sweden)

    Lada Artem G

    2012-12-01

    Full Text Available Abstract Clusters of localized hypermutation in human breast cancer genomes, named “kataegis” (from the Greek for thunderstorm, are hypothesized to result from multiple cytosine deaminations catalyzed by AID/APOBEC proteins. However, a direct link between APOBECs and kataegis is still lacking. We have sequenced the genomes of yeast mutants induced in diploids by expression of the gene for PmCDA1, a hypermutagenic deaminase from sea lamprey. Analysis of the distribution of 5,138 induced mutations revealed localized clusters very similar to those found in tumors. Our data provide evidence that unleashed cytosine deaminase activity is an evolutionary conserved, prominent source of genome-wide kataegis events. Reviewers This article was reviewed by: Professor Sandor Pongor, Professor Shamil R. Sunyaev, and Dr Vladimir Kuznetsov.

  5. Brewing yeast genomes and genome-wide expression and proteome profiling during fermentation.

    Science.gov (United States)

    Smart, Katherine A

    2007-11-01

    The genome structure, ancestry and instability of the brewing yeast strains have received considerable attention. The hybrid nature of brewing lager yeast strains provides adaptive potential but yields genome instability which can adversely affect fermentation performance. The requirement to differentiate between production strains and assess master cultures for genomic instability has led to significant adoption of specialized molecular tool kits by the industry. Furthermore, the development of genome-wide transcriptional and protein expression technologies has generated significant interest from brewers. The opportunity presented to explore, and the concurrent requirement to understand both, the constraints and potential of their strains to generate existing and new products during fermentation is discussed.

  6. Imputation and quality control steps for combining multiple genome-wide datasets

    Directory of Open Access Journals (Sweden)

    Shefali S Verma

    2014-12-01

    Full Text Available The electronic MEdical Records and GEnomics (eMERGE network brings together DNA biobanks linked to electronic health records (EHRs from multiple institutions. Approximately 52,000 DNA samples from distinct individuals have been genotyped using genome-wide SNP arrays across the nine sites of the network. The eMERGE Coordinating Center and the Genomics Workgroup developed a pipeline to impute and merge genomic data across the different SNP arrays to maximize sample size and power to detect associations with a variety of clinical endpoints. The 1000 Genomes cosmopolitan reference panel was used for imputation. Imputation results were evaluated using the following metrics: accuracy of imputation, allelic R2 (estimated correlation between the imputed and true genotypes, and the relationship between allelic R2 and minor allele frequency. Computation time and memory resources required by two different software packages (BEAGLE and IMPUTE2 were also evaluated. A number of challenges were encountered due to the complexity of using two different imputation software packages, multiple ancestral populations, and many different genotyping platforms. We present lessons learned and describe the pipeline implemented here to impute and merge genomic data sets. The eMERGE imputed dataset will serve as a valuable resource for discovery, leveraging the clinical data that can be mined from the EHR.

  7. Defining and improving the genome-wide specificities of CRISPR-Cas9 nucleases.

    Science.gov (United States)

    Tsai, Shengdar Q; Joung, J Keith

    2016-05-01

    CRISPR-Cas9 RNA-guided nucleases are a transformative technology for biology, genetics and medicine owing to the simplicity with which they can be programmed to cleave specific DNA target sites in living cells and organisms. However, to translate these powerful molecular tools into safe, effective clinical applications, it is of crucial importance to carefully define and improve their genome-wide specificities. Here, we outline our state-of-the-art understanding of target DNA recognition and cleavage by CRISPR-Cas9 nucleases, methods to determine and improve their specificities, and key considerations for how to evaluate and reduce off-target effects for research and therapeutic applications.

  8. Genome-Wide Association Study of Polymorphisms Predisposing to Bronchiolitis

    Science.gov (United States)

    Pasanen, Anu; Karjalainen, Minna K.; Bont, Louis; Piippo-Savolainen, Eija; Ruotsalainen, Marja; Goksör, Emma; Kumawat, Kuldeep; Hodemaekers, Hennie; Nuolivirta, Kirsi; Jartti, Tuomas; Wennergren, Göran; Hallman, Mikko; Rämet, Mika; Korppi, Matti

    2017-01-01

    Bronchiolitis is a major cause of hospitalization among infants. Severe bronchiolitis is associated with later asthma, suggesting a common genetic predisposition. Genetic background of bronchiolitis is not well characterized. To identify polymorphisms associated with bronchiolitis, we conducted a genome-wide association study (GWAS) in which 5,300,000 single nucleotide polymorphisms (SNPs) were tested for association in a Finnish–Swedish population of 217 children hospitalized for bronchiolitis and 778 controls. The most promising SNPs (n = 77) were genotyped in a Dutch replication population of 416 cases and 432 controls. Finally, we used a set of 202 Finnish bronchiolitis cases to further investigate candidate SNPs. We did not detect genome-wide significant associations, but several suggestive association signals (p bronchiolitis. These preliminary findings require further validation in a larger sample size. PMID:28139761

  9. Genome-wide association studies in pediatric endocrinology.

    Science.gov (United States)

    Dauber, Andrew; Hirschhorn, Joel N

    2011-01-01

    Genome-wide association (GWA) studies are a powerful tool for understanding the genetic underpinnings of human disease. In this article, we briefly review the role and findings of GWA studies in type 1 diabetes, stature, pubertal timing, obesity, and vitamin D deficiency. We then discuss the present and future implications of these findings with regards to disease prediction, uncovering basic biology, and the development of novel therapeutic agents.

  10. Impact of chromatin structures on DNA processing for genomic analyses.

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    Leonid Teytelman

    Full Text Available Chromatin has an impact on recombination, repair, replication, and evolution of DNA. Here we report that chromatin structure also affects laboratory DNA manipulation in ways that distort the results of chromatin immunoprecipitation (ChIP experiments. We initially discovered this effect at the Saccharomyces cerevisiae HMR locus, where we found that silenced chromatin was refractory to shearing, relative to euchromatin. Using input samples from ChIP-Seq studies, we detected a similar bias throughout the heterochromatic portions of the yeast genome. We also observed significant chromatin-related effects at telomeres, protein binding sites, and genes, reflected in the variation of input-Seq coverage. Experimental tests of candidate regions showed that chromatin influenced shearing at some loci, and that chromatin could also lead to enriched or depleted DNA levels in prepared samples, independently of shearing effects. Our results suggested that assays relying on immunoprecipitation of chromatin will be biased by intrinsic differences between regions packaged into different chromatin structures - biases which have been largely ignored to date. These results established the pervasiveness of this bias genome-wide, and suggested that this bias can be used to detect differences in chromatin structures across the genome.

  11. Universal seeds for cDNA-to-genome comparison

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    Florea Liliana

    2008-01-01

    Full Text Available Abstract Background To meet the needs of gene annotation for newly sequenced organisms, optimized spaced seeds can be implemented into cross-species sequence alignment programs to accurately align gene sequences to the genome of a related species. So far, seed performance has been tested for comparisons between closely related species, such as human and mouse, or on simulated data. As the number and variety of genomes increases, it becomes desirable to identify a small set of universal seeds that perform optimally or near-optimally on a large range of comparisons. Results Using statistical regression methods, we investigate the sensitivity of seeds, in particular good seeds, between four cDNA-to-genome comparisons at different evolutionary distances (human-dog, human-mouse, human-chicken and human-zebrafish, and identify classes of comparisons that show similar seed behavior and therefore can employ the same seed. In addition, we find that with high confidence good seeds for more distant comparisons perform well on closer comparisons, within 98–99% of the optimal seeds, and thus represent universal good seeds. Conclusion We show for the first time that optimal and near-optimal seeds for distant species-to-species comparisons are more generally applicable to a wide range of comparisons. This finding will be instrumental in developing practical and user-friendly cDNA-to-genome alignment applications, to aid in the annotation of new model organisms.

  12. Comparative genomics and molecular dynamics of DNA repeats in eukaryotes.

    Science.gov (United States)

    Richard, Guy-Franck; Kerrest, Alix; Dujon, Bernard

    2008-12-01

    Repeated elements can be widely abundant in eukaryotic genomes, composing more than 50% of the human genome, for example. It is possible to classify repeated sequences into two large families, "tandem repeats" and "dispersed repeats." Each of these two families can be itself divided into subfamilies. Dispersed repeats contain transposons, tRNA genes, and gene paralogues, whereas tandem repeats contain gene tandems, ribosomal DNA repeat arrays, and satellite DNA, itself subdivided into satellites, minisatellites, and microsatellites. Remarkably, the molecular mechanisms that create and propagate dispersed and tandem repeats are specific to each class and usually do not overlap. In the present review, we have chosen in the first section to describe the nature and distribution of dispersed and tandem repeats in eukaryotic genomes in the light of complete (or nearly complete) available genome sequences. In the second part, we focus on the molecular mechanisms responsible for the fast evolution of two specific classes of tandem repeats: minisatellites and microsatellites. Given that a growing number of human neurological disorders involve the expansion of a particular class of microsatellites, called trinucleotide repeats, a large part of the recent experimental work on microsatellites has focused on these particular repeats, and thus we also review the current knowledge in this area. Finally, we propose a unified definition for mini- and microsatellites that takes into account their biological properties and try to point out new directions that should be explored in a near future on our road to understanding the genetics of repeated sequences.

  13. TALENs: a widely applicable technology for targeted genome editing.

    Science.gov (United States)

    Joung, J Keith; Sander, Jeffry D

    2013-01-01

    Engineered nucleases enable the targeted alteration of nearly any gene in a wide range of cell types and organisms. The newly-developed transcription activator-like effector nucleases (TALENs) comprise a nonspecific DNA-cleaving nuclease fused to a DNA-binding domain that can be easily engineered so that TALENs can target essentially any sequence. The capability to quickly and efficiently alter genes using TALENs promises to have profound impacts on biological research and to yield potential therapeutic strategies for genetic diseases.

  14. Genome-wide prediction and validation of sigma70 promoters in Lactobacillus plantarum WCFS1.

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    Tilman J Todt

    Full Text Available BACKGROUND: In prokaryotes, sigma factors are essential for directing the transcription machinery towards promoters. Various sigma factors have been described that recognize, and bind to specific DNA sequence motifs in promoter sequences. The canonical sigma factor σ(70 is commonly involved in transcription of the cell's housekeeping genes, which is mediated by the conserved σ(70 promoter sequence motifs. In this study the σ(70-promoter sequences in Lactobacillus plantarum WCFS1 were predicted using a genome-wide analysis. The accuracy of the transcriptionally-active part of this promoter prediction was subsequently evaluated by correlating locations of predicted promoters with transcription start sites inferred from the 5'-ends of transcripts detected by high-resolution tiling array transcriptome datasets. RESULTS: To identify σ(70-related promoter sequences, we performed a genome-wide sequence motif scan of the L. plantarum WCFS1 genome focussing on the regions upstream of protein-encoding genes. We obtained several highly conserved motifs including those resembling the conserved σ(70-promoter consensus. Position weight matrices-based models of the recovered σ(70-promoter sequence motif were employed to identify 3874 motifs with significant similarity (p-value<10(-4 to the model-motif in the L. plantarum genome. Genome-wide transcript information deduced from whole genome tiling-array transcriptome datasets, was used to infer transcription start sites (TSSs from the 5'-end of transcripts. By this procedure, 1167 putative TSSs were identified that were used to corroborate the transcriptionally active fraction of these predicted promoters. In total, 568 predicted promoters were found in proximity (≤ 40 nucleotides of the putative TSSs, showing a highly significant co-occurrence of predicted promoter and TSS (p-value<10(-263. CONCLUSIONS: High-resolution tiling arrays provide a suitable source to infer TSSs at a genome-wide level, and

  15. The development of a genome wide SNP set for the Barnacle goose Branta leucopsis.

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    Rudy M Jonker

    Full Text Available Migratory birds are of particular interest for population genetics because of the high connectivity between habitats and populations. A high degree of connectivity requires using many genetic markers to achieve the required statistical power, and a genome wide SNP set can fit this purpose. Here we present the development of a genome wide SNP set for the Barnacle Goose Branta leucopsis, a model species for the study of bird migration. We used the genome of a different waterfowl species, Mallard Anas platyrhynchos, as a reference to align Barnacle Goose second generation sequence reads from an RRL library and detected 2188 SNPs genome wide. Furthermore, we used chimeric flanking sequences, merged from both Mallard and Barnacle Goose DNA sequence information, to create primers for validation by genotyping. Validation with a 384 SNP genotyping set resulted in 374 (97% successfully typed SNPs in the assay, of which 358 (96% were polymorphic. Additionally, we validated our SNPs on relatively old (30 years museum samples, which resulted in a success rate of at least 80%. This shows that museum samples could be used in standard SNP genotyping assays. Our study also shows that the genome of a related species can be used as reference to detect genome wide SNPs in birds, because genomes of birds are highly conserved. This is illustrated by the use of chimeric flanking sequences, which showed that the incorporation of flanking nucleotides from Mallard into Barnacle Goose sequences lead to equal genotyping performance when compared to flanking sequences solely composed of Barnacle Goose sequence.

  16. Genome-wide landscapes of human local adaptation in Asia.

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    Wei Qian

    Full Text Available Genetic studies of human local adaptation have been facilitated greatly by recent advances in high-throughput genotyping and sequencing technologies. However, few studies have investigated local adaptation in Asian populations on a genome-wide scale and with a high geographic resolution. In this study, taking advantage of the dense population coverage in Southeast Asia, which is the part of the world least studied in term of natural selection, we depicted genome-wide landscapes of local adaptations in 63 Asian populations representing the majority of linguistic and ethnic groups in Asia. Using genome-wide data analysis, we discovered many genes showing signs of local adaptation or natural selection. Notable examples, such as FOXQ1, MAST2, and CDH4, were found to play a role in hair follicle development and human cancer, signal transduction, and tumor repression, respectively. These showed strong indications of natural selection in Philippine Negritos, a group of aboriginal hunter-gatherers living in the Philippines. MTTP, which has associations with metabolic syndrome, body mass index, and insulin regulation, showed a strong signature of selection in Southeast Asians, including Indonesians. Functional annotation analysis revealed that genes and genetic variants underlying natural selections were generally enriched in the functional category of alternative splicing. Specifically, many genes showing significant difference with respect to allele frequency between northern and southern Asian populations were found to be associated with human height and growth and various immune pathways. In summary, this study contributes to the overall understanding of human local adaptation in Asia and has identified both known and novel signatures of natural selection in the human genome.

  17. Delineation of Methyl-DNA Binding Protein Interactions in the Prostate Cancer Genome (PC110091)

    Science.gov (United States)

    2014-03-01

    DNA Binding Protein Interactions in the Prostate Cancer Genome (PC110091) PRINCIPAL INVESTIGATOR: Roderick T Hori, PhD...13. SUPPLEMENTARY NOTES Prostate Cancer, Methylated DNA, Methyl- CpG Binding Domain, Chromatin Immunoprecipitation 14. ABSTRACT The purpose...of this study is to generate a genome-wide association profile of Methyl- CpG Domain-containing (MBD) proteins, such as MeCP2, MBD1, MBD2 and MBD4, in

  18. ReplicationDomain: a visualization tool and comparative database for genome-wide replication timing data

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    Yokochi Tomoki

    2008-12-01

    Full Text Available Abstract Background Eukaryotic DNA replication is regulated at the level of large chromosomal domains (0.5–5 megabases in mammals within which replicons are activated relatively synchronously. These domains replicate in a specific temporal order during S-phase and our genome-wide analyses of replication timing have demonstrated that this temporal order of domain replication is a stable property of specific cell types. Results We have developed ReplicationDomain http://www.replicationdomain.org as a web-based database for analysis of genome-wide replication timing maps (replication profiles from various cell lines and species. This database also provides comparative information of transcriptional expression and is configured to display any genome-wide property (for instance, ChIP-Chip or ChIP-Seq data via an interactive web interface. Our published microarray data sets are publicly available. Users may graphically display these data sets for a selected genomic region and download the data displayed as text files, or alternatively, download complete genome-wide data sets. Furthermore, we have implemented a user registration system that allows registered users to upload their own data sets. Upon uploading, registered users may choose to: (1 view their data sets privately without sharing; (2 share with other registered users; or (3 make their published or "in press" data sets publicly available, which can fulfill journal and funding agencies' requirements for data sharing. Conclusion ReplicationDomain is a novel and powerful tool to facilitate the comparative visualization of replication timing in various cell types as well as other genome-wide chromatin features and is considerably faster and more convenient than existing browsers when viewing multi-megabase segments of chromosomes. Furthermore, the data upload function with the option of private viewing or sharing of data sets between registered users should be a valuable resource for the

  19. Elg1 forms an alternative RFC complex important for DNA replication and genome integrity

    NARCIS (Netherlands)

    Bellaoui, Mohammed; Chang, Michael; Ou, Jiongwen; Xu, Hong; Boone, Charles; Brown, Grant W

    2003-01-01

    Genome-wide synthetic genetic interaction screens with mutants in the mus81 and mms4 replication fork-processing genes identified a novel replication factor C (RFC) homolog, Elg1, which forms an alternative RFC complex with Rfc2-5. This complex is distinct from the DNA replication RFC, the DNA

  20. Elg1 forms an alternative RFC complex important for DNA replication and genome integrity

    NARCIS (Netherlands)

    Bellaoui, Mohammed; Chang, Michael; Ou, Jiongwen; Xu, Hong; Boone, Charles; Brown, Grant W

    2003-01-01

    Genome-wide synthetic genetic interaction screens with mutants in the mus81 and mms4 replication fork-processing genes identified a novel replication factor C (RFC) homolog, Elg1, which forms an alternative RFC complex with Rfc2-5. This complex is distinct from the DNA replication RFC, the DNA damag

  1. Whole-genome DNA methylation profiling using MethylCap-seq.

    Science.gov (United States)

    Brinkman, Arie B; Simmer, Femke; Ma, Kelong; Kaan, Anita; Zhu, Jingde; Stunnenberg, Hendrik G

    2010-11-01

    MethylCap-seq is a robust procedure for genome-wide profiling of DNA methylation. The approach consists of the capture of methylated DNA using the MBD domain of MeCP2, and subsequent next-generation sequencing of eluted DNA. Elution of the captured methylated DNA is done in steps using a salt gradient, which stratifies the genome into fractions with different CpG density. The enrichment reached within the individual eluates allows for cost-effective deep sequence coverage. The profiles together yield a detailed genome-wide map of methylated regions and readily allows detection of DNA methylation in known and novel regions. Here, we describe principles and details of the MethylCap-seq procedure using different sources of starting material. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Chapter 10: Mining genome-wide genetic markers.

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    Xiang Zhang

    Full Text Available Genome-wide association study (GWAS aims to discover genetic factors underlying phenotypic traits. The large number of genetic factors poses both computational and statistical challenges. Various computational approaches have been developed for large scale GWAS. In this chapter, we will discuss several widely used computational approaches in GWAS. The following topics will be covered: (1 An introduction to the background of GWAS. (2 The existing computational approaches that are widely used in GWAS. This will cover single-locus, epistasis detection, and machine learning methods that have been recently developed in biology, statistic, and computer science communities. This part will be the main focus of this chapter. (3 The limitations of current approaches and future directions.

  3. An analysis of the use of genomic DNA as a universal reference in two channel DNA microarrays

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    Kapur Vivek

    2005-05-01

    Full Text Available Abstract Background DNA microarray is an invaluable tool for gene expression explorations. In the two-dye microarray, fluorescence intensities of two samples, each labeled with a different dye, are compared after hybridization. To compare a large number of samples, the 'reference design' is widely used, in which all RNA samples are hybridized to a common reference. Genomic DNA is an attractive candidate for use as a universal reference, especially for bacterial systems with a low percentage of non-coding sequences. However, genomic DNA, comprising of both the sense and anti-sense strands, is unlike the single stranded cDNA usually used in microarray hybridizations. The presence of the antisense strand in the 'reference' leads to reactions between complementary labeled strands in solution and may cause the assay result to deviate from true values. Results We have developed a mathematical model to predict the validity of using genomic DNA as a reference in the microarray assay. The model predicts that the assay can accurately estimate relative concentrations for a wide range of initial cDNA concentrations. Experimental results of DNA microarray assay using genomic DNA as a reference correlated well to those obtained by a direct hybridization between two cDNA samples. The model predicts that the initial concentrations of labeled genomic DNA strands and immobilized strands, and the hybridization time do not significantly affect the assay performance. At low values of the rate constant for hybridization between immobilized and mobile strands, the assay performance varies with the hybridization time and initial cDNA concentrations. For the case where a microarray with immobilized single strands is used, results from hybridizations using genomic DNA as a reference will correspond to true ratios under all conditions. Conclusion Simulation using the mathematical model, and the experimental study presented here show the potential utility of microarray

  4. A genome-wide association study of aging.

    Science.gov (United States)

    Walter, Stefan; Atzmon, Gil; Demerath, Ellen W; Garcia, Melissa E; Kaplan, Robert C; Kumari, Meena; Lunetta, Kathryn L; Milaneschi, Yuri; Tanaka, Toshiko; Tranah, Gregory J; Völker, Uwe; Yu, Lei; Arnold, Alice; Benjamin, Emelia J; Biffar, Reiner; Buchman, Aron S; Boerwinkle, Eric; Couper, David; De Jager, Philip L; Evans, Denis A; Harris, Tamara B; Hoffmann, Wolfgang; Hofman, Albert; Karasik, David; Kiel, Douglas P; Kocher, Thomas; Kuningas, Maris; Launer, Lenore J; Lohman, Kurt K; Lutsey, Pamela L; Mackenbach, Johan; Marciante, Kristin; Psaty, Bruce M; Reiman, Eric M; Rotter, Jerome I; Seshadri, Sudha; Shardell, Michelle D; Smith, Albert V; van Duijn, Cornelia; Walston, Jeremy; Zillikens, M Carola; Bandinelli, Stefania; Baumeister, Sebastian E; Bennett, David A; Ferrucci, Luigi; Gudnason, Vilmundur; Kivimaki, Mika; Liu, Yongmei; Murabito, Joanne M; Newman, Anne B; Tiemeier, Henning; Franceschini, Nora

    2011-11-01

    Human longevity and healthy aging show moderate heritability (20%-50%). We conducted a meta-analysis of genome-wide association studies from 9 studies from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium for 2 outcomes: (1) all-cause mortality, and (2) survival free of major disease or death. No single nucleotide polymorphism (SNP) was a genome-wide significant predictor of either outcome (p < 5 × 10(-8)). We found 14 independent SNPs that predicted risk of death, and 8 SNPs that predicted event-free survival (p < 10(-5)). These SNPs are in or near genes that are highly expressed in the brain (HECW2, HIP1, BIN2, GRIA1), genes involved in neural development and function (KCNQ4, LMO4, GRIA1, NETO1) and autophagy (ATG4C), and genes that are associated with risk of various diseases including cancer and Alzheimer's disease. In addition to considerable overlap between the traits, pathway and network analysis corroborated these findings. These findings indicate that variation in genes involved in neurological processes may be an important factor in regulating aging free of major disease and achieving longevity.

  5. Natural selection on functional modules, a genome-wide analysis.

    Science.gov (United States)

    Serra, François; Arbiza, Leonardo; Dopazo, Joaquín; Dopazo, Hernán

    2011-03-01

    Classically, the functional consequences of natural selection over genomes have been analyzed as the compound effects of individual genes. The current paradigm for large-scale analysis of adaptation is based on the observed significant deviations of rates of individual genes from neutral evolutionary expectation. This approach, which assumed independence among genes, has not been able to identify biological functions significantly enriched in positively selected genes in individual species. Alternatively, pooling related species has enhanced the search for signatures of selection. However, grouping signatures does not allow testing for adaptive differences between species. Here we introduce the Gene-Set Selection Analysis (GSSA), a new genome-wide approach to test for evidences of natural selection on functional modules. GSSA is able to detect lineage specific evolutionary rate changes in a notable number of functional modules. For example, in nine mammal and Drosophilae genomes GSSA identifies hundreds of functional modules with significant associations to high and low rates of evolution. Many of the detected functional modules with high evolutionary rates have been previously identified as biological functions under positive selection. Notably, GSSA identifies conserved functional modules with many positively selected genes, which questions whether they are exclusively selected for fitting genomes to environmental changes. Our results agree with previous studies suggesting that adaptation requires positive selection, but not every mutation under positive selection contributes to the adaptive dynamical process of the evolution of species.

  6. Natural selection on functional modules, a genome-wide analysis.

    Directory of Open Access Journals (Sweden)

    François Serra

    2011-03-01

    Full Text Available Classically, the functional consequences of natural selection over genomes have been analyzed as the compound effects of individual genes. The current paradigm for large-scale analysis of adaptation is based on the observed significant deviations of rates of individual genes from neutral evolutionary expectation. This approach, which assumed independence among genes, has not been able to identify biological functions significantly enriched in positively selected genes in individual species. Alternatively, pooling related species has enhanced the search for signatures of selection. However, grouping signatures does not allow testing for adaptive differences between species. Here we introduce the Gene-Set Selection Analysis (GSSA, a new genome-wide approach to test for evidences of natural selection on functional modules. GSSA is able to detect lineage specific evolutionary rate changes in a notable number of functional modules. For example, in nine mammal and Drosophilae genomes GSSA identifies hundreds of functional modules with significant associations to high and low rates of evolution. Many of the detected functional modules with high evolutionary rates have been previously identified as biological functions under positive selection. Notably, GSSA identifies conserved functional modules with many positively selected genes, which questions whether they are exclusively selected for fitting genomes to environmental changes. Our results agree with previous studies suggesting that adaptation requires positive selection, but not every mutation under positive selection contributes to the adaptive dynamical process of the evolution of species.

  7. Stimulation of the Drosophila immune system alters genome-wide nucleosome occupancy

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    Yingxue Ren

    2015-03-01

    Full Text Available In eukaryotes, nucleosomes participate in all DNA-templated events by regulating access to the underlying DNA sequence. However, nucleosome dynamics during a genome response have not been well characterized [1,2]. We stimulated Drosophila S2 cells with heat-killed Gram-negative bacteria Salmonella typhimurium, and mapped genome-wide nucleosome occupancy at high temporal resolution by MNase-seq using Illumina HiSeq 2500. We show widespread nucleosome occupancy change in S2 cells during the immune response, with the significant nucleosomal loss occurring at 4 h after stimulation. Data have been deposited to the Gene Expression Omnibus (GEO database repository with the dataset identifier GSE64507.

  8. Genome-wide analysis of potential cross-reactive endogenous allergens in rice (Oryza sativa L.

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    Fang Chao Zhu

    2015-01-01

    Full Text Available The proteins in the food are the source of common allergic components to certain patients. Current lists of plant endogenous allergens were based on the medical/clinical reports as well as laboratory results. Plant genome sequences made it possible to predict and characterize the genome-wide of putative endogenous allergens in rice (Oryza sativa L.. In this work, we identified and characterized 122 candidate rice allergens including the 22 allergens in present databases. Conserved domain analysis also revealed 37 domains among rice allergens including one novel domain (histidine kinase-, DNA gyrase B-, and HSP90-like ATPase, PF13589 adding to the allergen protein database. Phylogenetic analysis of the allergens revealed the diversity among the Prolamin superfamily and DnaK protein family, respectively. Additionally, some allergens proteins clustered on the rice chromosome might suggest the molecular function during the evolution.

  9. Comparative analysis of genome-wide divergence, domestication footprints and genome-wide association study of root traits for Gossypium hirsutum and Gossypium barbadense

    Science.gov (United States)

    Use of 10,129 singleton SNPs of known genomic location in tetraploid cotton provided unique opportunities to characterize genome-wide diversity among 440 Gossypium hirsutum and 219 G. barbadense cultivars and landrace accessions of widespread origin. Using genome-wide distributed SNPs, we examined ...

  10. GenoGAM: genome-wide generalized additive models for ChIP-Seq analysis.

    Science.gov (United States)

    Stricker, Georg; Engelhardt, Alexander; Schulz, Daniel; Schmid, Matthias; Tresch, Achim; Gagneur, Julien

    2017-08-01

    Chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) is a widely used approach to study protein-DNA interactions. Often, the quantities of interest are the differential occupancies relative to controls, between genetic backgrounds, treatments, or combinations thereof. Current methods for differential occupancy of ChIP-Seq data rely however on binning or sliding window techniques, for which the choice of the window and bin sizes are subjective. Here, we present GenoGAM (Genome-wide Generalized Additive Model), which brings the well-established and flexible generalized additive models framework to genomic applications using a data parallelism strategy. We model ChIP-Seq read count frequencies as products of smooth functions along chromosomes. Smoothing parameters are objectively estimated from the data by cross-validation, eliminating ad hoc binning and windowing needed by current approaches. GenoGAM provides base-level and region-level significance testing for full factorial designs. Application to a ChIP-Seq dataset in yeast showed increased sensitivity over existing differential occupancy methods while controlling for type I error rate. By analyzing a set of DNA methylation data and illustrating an extension to a peak caller, we further demonstrate the potential of GenoGAM as a generic statistical modeling tool for genome-wide assays. Software is available from Bioconductor: https://www.bioconductor.org/packages/release/bioc/html/GenoGAM.html . gagneur@in.tum.de. Supplementary information is available at Bioinformatics online.

  11. Genome-wide genetic changes during modern breeding of maize.

    Science.gov (United States)

    Jiao, Yinping; Zhao, Hainan; Ren, Longhui; Song, Weibin; Zeng, Biao; Guo, Jinjie; Wang, Baobao; Liu, Zhipeng; Chen, Jing; Li, Wei; Zhang, Mei; Xie, Shaojun; Lai, Jinsheng

    2012-06-03

    The success of modern maize breeding has been demonstrated by remarkable increases in productivity over the last four decades. However, the underlying genetic changes correlated with these gains remain largely unknown. We report here the sequencing of 278 temperate maize inbred lines from different stages of breeding history, including deep resequencing of 4 lines with known pedigree information. The results show that modern breeding has introduced highly dynamic genetic changes into the maize genome. Artificial selection has affected thousands of targets, including genes and non-genic regions, leading to a reduction in nucleotide diversity and an increase in the proportion of rare alleles. Genetic changes during breeding happen rapidly, with extensive variation (SNPs, indels and copy-number variants (CNVs)) occurring, even within identity-by-descent regions. Our genome-wide assessment of genetic changes during modern maize breeding provides new strategies as well as practical targets for future crop breeding and biotechnology.

  12. Genome-wide significant loci for addiction and anxiety

    Science.gov (United States)

    Hodgson, K.; Almasy, L.; Knowles, E.E.M.; Kent, J.W.; Curran, J.E.; Dyer, T.D.; Göring, H.H.H.; Olvera, R.L.; Fox, P.T.; Pearlson, G.D.; Krystal, J.H.; Duggirala, R.; Blangero, J.; Glahn, D.C.

    2017-01-01

    Background Psychiatric comorbidity is common among individuals with addictive disorders, with patients frequently suffering from anxiety disorders. While the genetic architecture of comorbid addictive and anxiety disorders remains unclear, elucidating the genes involved could provide important insights into the underlying etiology. Methods Here we examine a sample of 1284 Mexican-Americans from randomly selected extended pedigrees. Variance decomposition methods were used to examine the role of genetics in addiction phenotypes (lifetime history of alcohol dependence, drug dependence or chronic smoking) and various forms of clinically relevant anxiety. Genome-wide univariate and bivariate linkage scans were conducted to localize the chromosomal regions influencing these traits. Results Addiction phenotypes and anxiety were shown to be heritable and univariate genome-wide linkage scans revealed significant quantitative trait loci for drug dependence (14q13.2–q21.2, LOD = 3.322) and a broad anxiety phenotype (12q24.32–q24.33, LOD = 2.918). Significant positive genetic correlations were observed between anxiety and each of the addiction subtypes (ρg = 0.550–0.655) and further investigation with bivariate linkage analyses identified significant pleiotropic signals for alcohol dependence-anxiety (9q33.1–q33.2, LOD = 3.054) and drug dependence-anxiety (18p11.23–p11.22, LOD = 3.425). Conclusions This study confirms the shared genetic underpinnings of addiction and anxiety and identifies genomic loci involved in the etiology of these comorbid disorders. The linkage signal for anxiety on 12q24 spans the location of TMEM132D, an emerging gene of interest from previous GWAS of anxiety traits, whilst the bivariate linkage signal identified for anxiety-alcohol on 9q33 peak coincides with a region where rare CNVs have been associated with psychiatric disorders. Other signals identified implicate novel regions of the genome in addiction genetics. PMID:27318301

  13. Identification of neural outgrowth genes using genome-wide RNAi.

    Directory of Open Access Journals (Sweden)

    Katharine J Sepp

    2008-07-01

    Full Text Available While genetic screens have identified many genes essential for neurite outgrowth, they have been limited in their ability to identify neural genes that also have earlier critical roles in the gastrula, or neural genes for which maternally contributed RNA compensates for gene mutations in the zygote. To address this, we developed methods to screen the Drosophila genome using RNA-interference (RNAi on primary neural cells and present the results of the first full-genome RNAi screen in neurons. We used live-cell imaging and quantitative image analysis to characterize the morphological phenotypes of fluorescently labelled primary neurons and glia in response to RNAi-mediated gene knockdown. From the full genome screen, we focused our analysis on 104 evolutionarily conserved genes that when downregulated by RNAi, have morphological defects such as reduced axon extension, excessive branching, loss of fasciculation, and blebbing. To assist in the phenotypic analysis of the large data sets, we generated image analysis algorithms that could assess the statistical significance of the mutant phenotypes. The algorithms were essential for the analysis of the thousands of images generated by the screening process and will become a valuable tool for future genome-wide screens in primary neurons. Our analysis revealed unexpected, essential roles in neurite outgrowth for genes representing a wide range of functional categories including signalling molecules, enzymes, channels, receptors, and cytoskeletal proteins. We also found that genes known to be involved in protein and vesicle trafficking showed similar RNAi phenotypes. We confirmed phenotypes of the protein trafficking genes Sec61alpha and Ran GTPase using Drosophila embryo and mouse embryonic cerebral cortical neurons, respectively. Collectively, our results showed that RNAi phenotypes in primary neural culture can parallel in vivo phenotypes, and the screening technique can be used to identify many new

  14. DNA Repair and Genome Maintenance in Bacillus subtilis

    OpenAIRE

    2012-01-01

    Summary: From microbes to multicellular eukaryotic organisms, all cells contain pathways responsible for genome maintenance. DNA replication allows for the faithful duplication of the genome, whereas DNA repair pathways preserve DNA integrity in response to damage originating from endogenous and exogenous sources. The basic pathways important for DNA replication and repair are often conserved throughout biology. In bacteria, high-fidelity repair is balanced with low-fidelity repair and mutage...

  15. Genephony: a knowledge management tool for genome-wide research

    Science.gov (United States)

    Nuzzo, Angelo; Riva, Alberto

    2009-01-01

    Background One of the consequences of the rapid and widespread adoption of high-throughput experimental technologies is an exponential increase of the amount of data produced by genome-wide experiments. Researchers increasingly need to handle very large volumes of heterogeneous data, including both the data generated by their own experiments and the data retrieved from publicly available repositories of genomic knowledge. Integration, exploration, manipulation and interpretation of data and information therefore need to become as automated as possible, since their scale and breadth are, in general, beyond the limits of what individual researchers and the basic data management tools in normal use can handle. This paper describes Genephony, a tool we are developing to address these challenges. Results We describe how Genephony can be used to manage large datesets of genomic information, integrating them with existing knowledge repositories. We illustrate its functionalities with an example of a complex annotation task, in which a set of SNPs coming from a genotyping experiment is annotated with genes known to be associated to a phenotype of interest. We show how, thanks to the modular architecture of Genephony and its user-friendly interface, this task can be performed in a few simple steps. Conclusion Genephony is an online tool for the manipulation of large datasets of genomic information. It can be used as a browser for genomic data, as a high-throughput annotation tool, and as a knowledge discovery tool. It is designed to be easy to use, flexible and extensible. Its knowledge management engine provides fine-grained control over individual data elements, as well as efficient operations on large datasets. PMID:19728881

  16. Genome-Wide Associations of Gene Expression Variation in Humans.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available The exploration of quantitative variation in human populations has become one of the major priorities for medical genetics. The successful identification of variants that contribute to complex traits is highly dependent on reliable assays and genetic maps. We have performed a genome-wide quantitative trait analysis of 630 genes in 60 unrelated Utah residents with ancestry from Northern and Western Europe using the publicly available phase I data of the International HapMap project. The genes are located in regions of the human genome with elevated functional annotation and disease interest including the ENCODE regions spanning 1% of the genome, Chromosome 21 and Chromosome 20q12-13.2. We apply three different methods of multiple test correction, including Bonferroni, false discovery rate, and permutations. For the 374 expressed genes, we find many regions with statistically significant association of single nucleotide polymorphisms (SNPs with expression variation in lymphoblastoid cell lines after correcting for multiple tests. Based on our analyses, the signal proximal (cis- to the genes of interest is more abundant and more stable than distal and trans across statistical methodologies. Our results suggest that regulatory polymorphism is widespread in the human genome and show that the 5-kb (phase I HapMap has sufficient density to enable linkage disequilibrium mapping in humans. Such studies will significantly enhance our ability to annotate the non-coding part of the genome and interpret functional variation. In addition, we demonstrate that the HapMap cell lines themselves may serve as a useful resource for quantitative measurements at the cellular level.

  17. Genome-wide associations of gene expression variation in humans.

    Directory of Open Access Journals (Sweden)

    Barbara E Stranger

    2005-12-01

    Full Text Available The exploration of quantitative variation in human populations has become one of the major priorities for medical genetics. The successful identification of variants that contribute to complex traits is highly dependent on reliable assays and genetic maps. We have performed a genome-wide quantitative trait analysis of 630 genes in 60 unrelated Utah residents with ancestry from Northern and Western Europe using the publicly available phase I data of the International HapMap project. The genes are located in regions of the human genome with elevated functional annotation and disease interest including the ENCODE regions spanning 1% of the genome, Chromosome 21 and Chromosome 20q12-13.2. We apply three different methods of multiple test correction, including Bonferroni, false discovery rate, and permutations. For the 374 expressed genes, we find many regions with statistically significant association of single nucleotide polymorphisms (SNPs with expression variation in lymphoblastoid cell lines after correcting for multiple tests. Based on our analyses, the signal proximal (cis- to the genes of interest is more abundant and more stable than distal and trans across statistical methodologies. Our results suggest that regulatory polymorphism is widespread in the human genome and show that the 5-kb (phase I HapMap has sufficient density to enable linkage disequilibrium mapping in humans. Such studies will significantly enhance our ability to annotate the non-coding part of the genome and interpret functional variation. In addition, we demonstrate that the HapMap cell lines themselves may serve as a useful resource for quantitative measurements at the cellular level.

  18. Genome-wide Association Study of Obsessive-Compulsive Disorder

    Science.gov (United States)

    Stewart, S Evelyn; Yu, Dongmei; Scharf, Jeremiah M; Neale, Benjamin M; Fagerness, Jesen A; Mathews, Carol A; Arnold, Paul D; Evans, Patrick D; Gamazon, Eric R; Osiecki, Lisa; McGrath, Lauren; Haddad, Stephen; Crane, Jacquelyn; Hezel, Dianne; Illman, Cornelia; Mayerfeld, Catherine; Konkashbaev, Anuar; Liu, Chunyu; Pluzhnikov, Anna; Tikhomirov, Anna; Edlund, Christopher K; Rauch, Scott L; Moessner, Rainald; Falkai, Peter; Maier, Wolfgang; Ruhrmann, Stephan; Grabe, Hans-Jörgen; Lennertz, Leonard; Wagner, Michael; Bellodi, Laura; Cavallini, Maria Cristina; Richter, Margaret A; Cook, Edwin H; Kennedy, James L; Rosenberg, David; Stein, Dan J; Hemmings, Sian MJ; Lochner, Christine; Azzam, Amin; Chavira, Denise A; Fournier, Eduardo; Garrido, Helena; Sheppard, Brooke; Umaña, Paul; Murphy, Dennis L; Wendland, Jens R; Veenstra-VanderWeele, Jeremy; Denys, Damiaan; Blom, Rianne; Deforce, Dieter; Van Nieuwerburgh, Filip; Westenberg, Herman GM; Walitza, Susanne; Egberts, Karin; Renner, Tobias; Miguel, Euripedes Constantino; Cappi, Carolina; Hounie, Ana G; Conceição do Rosário, Maria; Sampaio, Aline S; Vallada, Homero; Nicolini, Humberto; Lanzagorta, Nuria; Camarena, Beatriz; Delorme, Richard; Leboyer, Marion; Pato, Carlos N; Pato, Michele T; Voyiaziakis, Emanuel; Heutink, Peter; Cath, Danielle C; Posthuma, Danielle; Smit, Jan H; Samuels, Jack; Bienvenu, O Joseph; Cullen, Bernadette; Fyer, Abby J; Grados, Marco A; Greenberg, Benjamin D; McCracken, James T; Riddle, Mark A; Wang, Ying; Coric, Vladimir; Leckman, James F; Bloch, Michael; Pittenger, Christopher; Eapen, Valsamma; Black, Donald W; Ophoff, Roel A; Strengman, Eric; Cusi, Daniele; Turiel, Maurizio; Frau, Francesca; Macciardi, Fabio; Gibbs, J Raphael; Cookson, Mark R; Singleton, Andrew; Hardy, John; Crenshaw, Andrew T; Parkin, Melissa A; Mirel, Daniel B; Conti, David V; Purcell, Shaun; Nestadt, Gerald; Hanna, Gregory L; Jenike, Michael A; Knowles, James A; Cox, Nancy; Pauls, David L

    2014-01-01

    Obsessive-compulsive disorder (OCD) is a common, debilitating neuropsychiatric illness with complex genetic etiology. The International OCD Foundation Genetics Collaborative (IOCDF-GC) is a multi-national collaboration established to discover the genetic variation predisposing to OCD. A set of individuals affected with DSM-IV OCD, a subset of their parents, and unselected controls, were genotyped with several different Illumina SNP microarrays. After extensive data cleaning, 1,465 cases, 5,557 ancestry-matched controls and 400 complete trios remained, with a common set of 469,410 autosomal and 9,657 X-chromosome SNPs. Ancestry-stratified case-control association analyses were conducted for three genetically-defined subpopulations and combined in two meta-analyses, with and without the trio-based analysis. In the case-control analysis, the lowest two p-values were located within DLGAP1 (p=2.49×10-6 and p=3.44×10-6), a member of the neuronal postsynaptic density complex. In the trio analysis, rs6131295, near BTBD3, exceeded the genome-wide significance threshold with a p-value=3.84 × 10-8. However, when trios were meta-analyzed with the combined case-control samples, the p-value for this variant was 3.62×10-5, losing genome-wide significance. Although no SNPs were identified to be associated with OCD at a genome-wide significant level in the combined trio-case-control sample, a significant enrichment of methylation-QTLs (p<0.001) and frontal lobe eQTLs (p=0.001) was observed within the top-ranked SNPs (p<0.01) from the trio-case-control analysis, suggesting these top signals may have a broad role in gene expression in the brain, and possibly in the etiology of OCD. PMID:22889921

  19. Isolation of "Caenorhabditis elegans" Genomic DNA and Detection of Deletions in the "unc-93" Gene Using PCR

    Science.gov (United States)

    Lissemore, James L.; Lackner, Laura L.; Fedoriw, George D.; De Stasio, Elizabeth A.

    2005-01-01

    PCR, genomic DNA isolation, and agarose gel electrophoresis are common molecular biology techniques with a wide range of applications. Therefore, we have developed a series of exercises employing these techniques for an intermediate level undergraduate molecular biology laboratory course. In these exercises, students isolate genomic DNA from the…

  20. Dry and wet approaches for genome-wide functional annotation of conventional and unconventional transcriptional activators

    Directory of Open Access Journals (Sweden)

    Elisabetta Levati

    2016-01-01

    Full Text Available Transcription factors (TFs are master gene products that regulate gene expression in response to a variety of stimuli. They interact with DNA in a sequence-specific manner using a variety of DNA-binding domain (DBD modules. This allows to properly position their second domain, called “effector domain”, to directly or indirectly recruit positively or negatively acting co-regulators including chromatin modifiers, thus modulating preinitiation complex formation as well as transcription elongation. At variance with the DBDs, which are comprised of well-defined and easily recognizable DNA binding motifs, effector domains are usually much less conserved and thus considerably more difficult to predict. Also not so easy to identify are the DNA-binding sites of TFs, especially on a genome-wide basis and in the case of overlapping binding regions. Another emerging issue, with many potential regulatory implications, is that of so-called “moonlighting” transcription factors, i.e., proteins with an annotated function unrelated to transcription and lacking any recognizable DBD or effector domain, that play a role in gene regulation as their second job. Starting from bioinformatic and experimental high-throughput tools for an unbiased, genome-wide identification and functional characterization of TFs (especially transcriptional activators, we describe both established (and usually well affordable as well as newly developed platforms for DNA-binding site identification. Selected combinations of these search tools, some of which rely on next-generation sequencing approaches, allow delineating the entire repertoire of TFs and unconventional regulators encoded by the any sequenced genome.

  1. Genome-wide association studies and contribution to cardiovascular physiology.

    Science.gov (United States)

    Munroe, Patricia B; Tinker, Andrew

    2015-09-01

    The study of family pedigrees with rare monogenic cardiovascular disorders has revealed new molecular players in physiological processes. Genome-wide association studies of complex traits with a heritable component may afford a similar and potentially intellectually richer opportunity. In this review we focus on the interpretation of genetic associations and the issue of causality in relation to known and potentially new physiology. We mainly discuss cardiometabolic traits as it reflects our personal interests, but the issues pertain broadly in many other disciplines. We also describe some of the resources that are now available that may expedite follow up of genetic association signals into observations on causal mechanisms and pathophysiology.

  2. [Genome-wide association study for adolescent idiopathic scoliosis].

    Science.gov (United States)

    Ogura, Yoji; Kou, Ikuyo; Scoliosis, Japan; Matsumoto, Morio; Watanabe, Kota; Ikegawa, Shiro

    2016-04-01

    Adolescent idiopathic scoliosis(AIS)is a polygenic disease. Genome-wide association studies(GWASs)have been performed for a lot of polygenic diseases. For AIS, we conducted GWAS and identified the first AIS locus near LBX1. After the discovery, we have extended our study by increasing the numbers of subjects and SNPs. In total, our Japanese GWAS has identified four susceptibility genes. GWASs for AIS have also been performed in the USA and China, which identified one and three susceptibility genes, respectively. Here we review GWASs in Japan and abroad and functional analysis to clarify the pathomechanism of AIS.

  3. From human monocytes to genome-wide binding sites--a protocol for small amounts of blood: monocyte isolation/ChIP-protocol/library amplification/genome wide computational data analysis.

    Directory of Open Access Journals (Sweden)

    Sebastian Weiterer

    Full Text Available Chromatin immunoprecipitation in combination with a genome-wide analysis via high-throughput sequencing is the state of the art method to gain genome-wide representation of histone modification or transcription factor binding profiles. However, chromatin immunoprecipitation analysis in the context of human experimental samples is limited, especially in the case of blood cells. The typically extremely low yields of precipitated DNA are usually not compatible with library amplification for next generation sequencing. We developed a highly reproducible protocol to present a guideline from the first step of isolating monocytes from a blood sample to analyse the distribution of histone modifications in a genome-wide manner.The protocol describes the whole work flow from isolating monocytes from human blood samples followed by a high-sensitivity and small-scale chromatin immunoprecipitation assay with guidance for generating libraries compatible with next generation sequencing from small amounts of immunoprecipitated DNA.

  4. Layers of epistasis: genome-wide regulatory networks and network approaches to genome-wide association studies

    Science.gov (United States)

    Cowper-Sal·lari, Richard; Cole, Michael D.; Karagas, Margaret R.; Lupien, Mathieu; Moore, Jason H.

    2010-01-01

    The conceptual foundation of the genome-wide association study (GWAS) has advanced unchecked since its conception. A revision might seem premature as the potential of GWAS has not been fully realized. Multiple technical and practical limitations need to be overcome before GWAS can be fairly criticized. But with the completion of hundreds of studies and a deeper understanding of the genetic architecture of disease, warnings are being raised. The results compiled to date indicate that risk-associated variants lie predominantly in non-coding regions of the genome. Additionally, alternative methodologies are uncovering large and heterogeneous sets of rare variants underlying disease. The fear is that, even in its fulfilment, the current GWAS paradigm might be incapable of dissecting all kinds of phenotypes. In the following text we review several initiatives that aim to overcome these limitations. The overarching theme of these studies is the inclusion of biological knowledge to both the analysis and interpretation of genotyping data. GWAS is uninformed of biology by design and although there is some virtue in its simplicity it is also its most conspicuous deficiency. We propose a framework in which to integrate these novel approaches, both empirical and theoretical, in the form of a genome-wide regulatory network (GWRN). By processing experimental data into networks, emerging data types based on chromatin-immunoprecipitation are made computationally tractable. This will give GWAS re-analysis efforts the most current and relevant substrates, and root them firmly on our knowledge of human disease. PMID:21197657

  5. A genome-wide screen for Schizosaccharomyces pombe deletion mutants that affect telomere length

    Institute of Scientific and Technical Information of China (English)

    Ning-Ning Liu; Tian Xu Han; Li-Lin Du; Jin-Qiu Zhou

    2010-01-01

    @@ Dear Editor, Both the fission yeast Schizosaccharomyces pombe and the budding yeast Saccharomyces cerevisiae are popular model organisms, and studies using these models have provided many informative clues for solving fundamental biological questions [1], such as DNA replication,cell cycle regulation and gene transcription. Since the completion of genome sequencing of these fungi [2, 3],systematic genetic modification, e.g. gene deletion, has become possible, and genome-wide phenotypic screening for gene function has been widely carried out. For example, Askree et al. and Gatbonton et al. examined the telomere-length change in about 4 800 non-essential gene deletion mutants of S. cerevisiae, and found that about 250 genes are involved in telomere-length regulation.

  6. Genome-wide translocation sequencing reveals mechanisms of chromosome breaks and rearrangements in B cells.

    Science.gov (United States)

    Chiarle, Roberto; Zhang, Yu; Frock, Richard L; Lewis, Susanna M; Molinie, Benoit; Ho, Yu-Jui; Myers, Darienne R; Choi, Vivian W; Compagno, Mara; Malkin, Daniel J; Neuberg, Donna; Monti, Stefano; Giallourakis, Cosmas C; Gostissa, Monica; Alt, Frederick W

    2011-09-30

    Whereas chromosomal translocations are common pathogenetic events in cancer, mechanisms that promote them are poorly understood. To elucidate translocation mechanisms in mammalian cells, we developed high-throughput, genome-wide translocation sequencing (HTGTS). We employed HTGTS to identify tens of thousands of independent translocation junctions involving fixed I-SceI meganuclease-generated DNA double-strand breaks (DSBs) within the c-myc oncogene or IgH locus of B lymphocytes induced for activation-induced cytidine deaminase (AID)-dependent IgH class switching. DSBs translocated widely across the genome but were preferentially targeted to transcribed chromosomal regions. Additionally, numerous AID-dependent and AID-independent hot spots were targeted, with the latter comprising mainly cryptic I-SceI targets. Comparison of translocation junctions with genome-wide nuclear run-ons revealed a marked association between transcription start sites and translocation targeting. The majority of translocation junctions were formed via end-joining with short microhomologies. Our findings have implications for diverse fields, including gene therapy and cancer genomics.

  7. Unraveling the Rat Intestine, Spleen and Liver Genome-Wide Transcriptome after the Oral Administration of Lavender Oil by a Two-Color Dye-Swap DNA Microarray Approach.

    Directory of Open Access Journals (Sweden)

    Hiroko Kubo

    Full Text Available The use of lavender oil (LO--a commonly, used oil in aromatherapy, with well-defined volatile components linalool and linalyl acetate--in non-traditional medicine is increasing globally. To understand and demonstrate the potential positive effects of LO on the body, we have established an animal model in this current study, investigating the orally administered LO effects genome wide in the rat small intestine, spleen, and liver. The rats were administered LO at 5 mg/kg (usual therapeutic dose in humans followed by the screening of differentially expressed genes in the tissues, using a 4×44-K whole-genome rat chip (Agilent microarray platform; Agilent Technologies, Palo Alto, CA, USA in conjunction with a dye-swap approach, a novelty of this study. Fourteen days after LO treatment and compared with a control group (sham, a total of 156 and 154 up (≧ 1.5-fold- and down (≦ 0.75-fold-regulated genes, 174 and 66 up- (≧ 1.5-fold- and down (≦ 0.75-fold-regulated genes, and 222 and 322 up- (≧ 1.5-fold- and down (≦ 0.75-fold-regulated genes showed differential expression at the mRNA level in the small intestine, spleen and liver, respectively. The reverse transcription-polymerase chain reaction (RT-PCR validation of highly up- and down-regulated genes confirmed the regulation of the Papd4, Lrp1b, Alb, Cyr61, Cyp2c, and Cxcl1 genes by LO as examples in these tissues. Using bioinformatics, including Ingenuity Pathway Analysis (IPA, differentially expressed genes were functionally categorized by their Gene Ontology (GO and biological function and network analysis, revealing their diverse functions and potential roles in LO-mediated effects in rat. Further IPA analysis in particular unraveled the presence of novel genes, such as Papd4, Or8k5, Gprc5b, Taar5, Trpc6, Pld2 and Onecut3 (up-regulated top molecules and Tnf, Slc45a4, Slc25a23 and Samt4 (down-regulated top molecules, to be influenced by LO treatment in the small intestine, spleen and

  8. Unraveling the Rat Intestine, Spleen and Liver Genome-Wide Transcriptome after the Oral Administration of Lavender Oil by a Two-Color Dye-Swap DNA Microarray Approach.

    Science.gov (United States)

    Kubo, Hiroko; Shibato, Junko; Saito, Tomomi; Ogawa, Tetsuo; Rakwal, Randeep; Shioda, Seiji

    2015-01-01

    The use of lavender oil (LO)--a commonly, used oil in aromatherapy, with well-defined volatile components linalool and linalyl acetate--in non-traditional medicine is increasing globally. To understand and demonstrate the potential positive effects of LO on the body, we have established an animal model in this current study, investigating the orally administered LO effects genome wide in the rat small intestine, spleen, and liver. The rats were administered LO at 5 mg/kg (usual therapeutic dose in humans) followed by the screening of differentially expressed genes in the tissues, using a 4×44-K whole-genome rat chip (Agilent microarray platform; Agilent Technologies, Palo Alto, CA, USA) in conjunction with a dye-swap approach, a novelty of this study. Fourteen days after LO treatment and compared with a control group (sham), a total of 156 and 154 up (≧ 1.5-fold)- and down (≦ 0.75-fold)-regulated genes, 174 and 66 up- (≧ 1.5-fold)- and down (≦ 0.75-fold)-regulated genes, and 222 and 322 up- (≧ 1.5-fold)- and down (≦ 0.75-fold)-regulated genes showed differential expression at the mRNA level in the small intestine, spleen and liver, respectively. The reverse transcription-polymerase chain reaction (RT-PCR) validation of highly up- and down-regulated genes confirmed the regulation of the Papd4, Lrp1b, Alb, Cyr61, Cyp2c, and Cxcl1 genes by LO as examples in these tissues. Using bioinformatics, including Ingenuity Pathway Analysis (IPA), differentially expressed genes were functionally categorized by their Gene Ontology (GO) and biological function and network analysis, revealing their diverse functions and potential roles in LO-mediated effects in rat. Further IPA analysis in particular unraveled the presence of novel genes, such as Papd4, Or8k5, Gprc5b, Taar5, Trpc6, Pld2 and Onecut3 (up-regulated top molecules) and Tnf, Slc45a4, Slc25a23 and Samt4 (down-regulated top molecules), to be influenced by LO treatment in the small intestine, spleen and liver

  9. Genome-wide association study of serum selenium concentrations

    DEFF Research Database (Denmark)

    Gong, Jian; Hsu, Li; Harrison, Tabitha

    2013-01-01

    Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated...... this hypothesis. Therefore, we conducted a two-stage genome-wide association study to identify genetic variants associated with serum selenium concentrations in 1203 European descents from two cohorts: the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening and the Women’s Health Initiative (WHI). We...... tested association between 2,474,333 single nucleotide polymorphisms (SNPs) and serum selenium concentrations using linear regression models. In the first stage (PLCO) 41 SNPs clustered in 15 regions had p

  10. High quality genomic DNA extraction from postmortem fetal tissue.

    Science.gov (United States)

    Addison, S; Sebire, N J; Taylor, A M; Abrams, D; Peebles, D; Mein, C; Munroe, P B; Thayyil, S

    2012-11-01

    We examined the yield and quality of genomic deoxyribonucleic acid (DNA) extracted from various postmortem fetal tissues. Fetal tissues were collected at the time of autopsy, and DNA was subsequently extracted. The yield and DNA quality was assessed using ultraviolet spectrometry and agarose gel electrophoresis. We used polymerase chain reaction (PCR) to assess the DNA extracted for genomic testing. The median (range) gestation of the fetuses was 22 (16-41) weeks and the postmortem interval was 5.5 (2-10) days. Non-degraded genomic DNA was successfully extracted from all fetal tissues. Liver tissue had the lowest quality and muscle the highest quality. DNA yield or purity was not influenced by the postmortem interval. High quality genomic DNA can be extracted from fetal muscle, despite postmortem intervals of several days.

  11. Genome-wide computational prediction and analysis of core promoter elements across plant monocots and dicots.

    Directory of Open Access Journals (Sweden)

    Sunita Kumari

    Full Text Available Transcription initiation, essential to gene expression regulation, involves recruitment of basal transcription factors to the core promoter elements (CPEs. The distribution of currently known CPEs across plant genomes is largely unknown. This is the first large scale genome-wide report on the computational prediction of CPEs across eight plant genomes to help better understand the transcription initiation complex assembly. The distribution of thirteen known CPEs across four monocots (Brachypodium distachyon, Oryza sativa ssp. japonica, Sorghum bicolor, Zea mays and four dicots (Arabidopsis thaliana, Populus trichocarpa, Vitis vinifera, Glycine max reveals the structural organization of the core promoter in relation to the TATA-box as well as with respect to other CPEs. The distribution of known CPE motifs with respect to transcription start site (TSS exhibited positional conservation within monocots and dicots with slight differences across all eight genomes. Further, a more refined subset of annotated genes based on orthologs of the model monocot (O. sativa ssp. japonica and dicot (A. thaliana genomes supported the positional distribution of these thirteen known CPEs. DNA free energy profiles provided evidence that the structural properties of promoter regions are distinctly different from that of the non-regulatory genome sequence. It also showed that monocot core promoters have lower DNA free energy than dicot core promoters. The comparison of monocot and dicot promoter sequences highlights both the similarities and differences in the core promoter architecture irrespective of the species-specific nucleotide bias. This study will be useful for future work related to genome annotation projects and can inspire research efforts aimed to better understand regulatory mechanisms of transcription.

  12. Evolutionary history of mammalian transposons determined by genome-wide defragmentation.

    Directory of Open Access Journals (Sweden)

    Joti Giordano

    2007-07-01

    Full Text Available The constant bombardment of mammalian genomes by transposable elements (TEs has resulted in TEs comprising at least 45% of the human genome. Because of their great age and abundance, TEs are important in comparative phylogenomics. However, estimates of TE age were previously based on divergence from derived consensus sequences or phylogenetic analysis, which can be unreliable, especially for older more diverged elements. Therefore, a novel genome-wide analysis of TE organization and fragmentation was performed to estimate TE age independently of sequence composition and divergence or the assumption of a constant molecular clock. Analysis of TEs in the human genome revealed approximately 600,000 examples where TEs have transposed into and fragmented other TEs, covering >40% of all TEs or approximately 542 Mbp of genomic sequence. The relative age of these TEs over evolutionary time is implicit in their organization, because newer TEs have necessarily transposed into older TEs that were already present. A matrix of the number of times that each TE has transposed into every other TE was constructed, and a novel objective function was developed that derived the chronological order and relative ages of human TEs spanning >100 million years. This method has been used to infer the relative ages across all four major TE classes, including the oldest, most diverged elements. Analysis of DNA transposons over the history of the human genome has revealed the early activity of some MER2 transposons, and the relatively recent activity of MER1 transposons during primate lineages. The TEs from six additional mammalian genomes were defragmented and analyzed. Pairwise comparison of the independent chronological orders of TEs in these mammalian genomes revealed species phylogeny, the fact that transposons shared between genomes are older than species-specific transposons, and a subset of TEs that were potentially active during periods of speciation.

  13. Insights into kidney diseases from genome-wide association studies.

    Science.gov (United States)

    Wuttke, Matthias; Köttgen, Anna

    2016-09-01

    Over the past decade, genome-wide association studies (GWAS) have considerably improved our understanding of the genetic basis of kidney function and disease. Population-based studies, used to investigate traits that define chronic kidney disease (CKD), have identified >50 genomic regions in which common genetic variants associate with estimated glomerular filtration rate or urinary albumin-to-creatinine ratio. Case-control studies, used to study specific CKD aetiologies, have yielded risk loci for specific kidney diseases such as IgA nephropathy and membranous nephropathy. In this Review, we summarize important findings from GWAS and clinical and experimental follow-up studies. We also compare risk allele frequency, effect sizes, and specificity in GWAS of CKD-defining traits and GWAS of specific CKD aetiologies and the implications for study design. Genomic regions identified in GWAS of CKD-defining traits can contain causal genes for monogenic kidney diseases. Population-based research on kidney function traits can therefore generate insights into more severe forms of kidney diseases. Experimental follow-up studies have begun to identify causal genes and variants, which are potential therapeutic targets, and suggest mechanisms underlying the high allele frequency of causal variants. GWAS are thus a useful approach to advance knowledge in nephrology.

  14. Sequence-based prediction of single nucleosome positioning and genome-wide nucleosome occupancy.

    Science.gov (United States)

    van der Heijden, Thijn; van Vugt, Joke J F A; Logie, Colin; van Noort, John

    2012-09-18

    Nucleosome positioning dictates eukaryotic DNA compaction and access. To predict nucleosome positions in a statistical mechanics model, we exploited the knowledge that nucleosomes favor DNA sequences with specific periodically occurring dinucleotides. Our model is the first to capture both dyad position within a few base pairs, and free binding energy within 2 k(B)T, for all the known nucleosome positioning sequences. By applying Percus's equation to the derived energy landscape, we isolate sequence effects on genome-wide nucleosome occupancy from other factors that may influence nucleosome positioning. For both in vitro and in vivo systems, three parameters suffice to predict nucleosome occupancy with correlation coefficients of respectively 0.74 and 0.66. As predicted, we find the largest deviations in vivo around transcription start sites. This relatively simple algorithm can be used to guide future studies on the influence of DNA sequence on chromatin organization.

  15. A genome-wide SNP scan accelerates trait-regulatory genomic loci identification in chickpea

    Science.gov (United States)

    Kujur, Alice; Bajaj, Deepak; Upadhyaya, Hari D.; Das, Shouvik; Ranjan, Rajeev; Shree, Tanima; Saxena, Maneesha S.; Badoni, Saurabh; Kumar, Vinod; Tripathi, Shailesh; Gowda, C.L.L.; Sharma, Shivali; Singh, Sube; Tyagi, Akhilesh K.; Parida, Swarup K.

    2015-01-01

    We identified 44844 high-quality SNPs by sequencing 92 diverse chickpea accessions belonging to a seed and pod trait-specific association panel using reference genome- and de novo-based GBS (genotyping-by-sequencing) assays. A GWAS (genome-wide association study) in an association panel of 211, including the 92 sequenced accessions, identified 22 major genomic loci showing significant association (explaining 23–47% phenotypic variation) with pod and seed number/plant and 100-seed weight. Eighteen trait-regulatory major genomic loci underlying 13 robust QTLs were validated and mapped on an intra-specific genetic linkage map by QTL mapping. A combinatorial approach of GWAS, QTL mapping and gene haplotype-specific LD mapping and transcript profiling uncovered one superior haplotype and favourable natural allelic variants in the upstream regulatory region of a CesA-type cellulose synthase (Ca_Kabuli_CesA3) gene regulating high pod and seed number/plant (explaining 47% phenotypic variation) in chickpea. The up-regulation of this superior gene haplotype correlated with increased transcript expression of Ca_Kabuli_CesA3 gene in the pollen and pod of high pod/seed number accession, resulting in higher cellulose accumulation for normal pollen and pollen tube growth. A rapid combinatorial genome-wide SNP genotyping-based approach has potential to dissect complex quantitative agronomic traits and delineate trait-regulatory genomic loci (candidate genes) for genetic enhancement in crop plants, including chickpea. PMID:26058368

  16. A genome-wide association study of female sexual dysfunction.

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    Andrea Burri

    Full Text Available BACKGROUND: Female sexual dysfunction (FSD is an important but controversial problem with serious negative impact on women's quality of life. Data from twin studies have shown a genetic contribution to the development and maintenance of FSD. METHODOLOGY/PRINCIPAL FINDINGS: We performed a genome-wide association study (GWAS on 2.5 million single-nucleotide polymorphisms (SNPs in 1,104 female twins (25-81 years of age in a population-based register and phenotypic data on lifelong sexual functioning. Although none reached conventional genome-wide level of significance (10 × -8, we found strongly suggestive associations with the phenotypic dimension of arousal (rs13202860, P = 1.2 × 10(-7; rs1876525, P = 1.2 × 10(-7; and rs13209281 P = 8.3 × 10(-7 on chromosome 6, around 500 kb upstream of the locus HTR1E (5-hydroxytryptamine receptor 1E locus, related to the serotonin brain pathways. We could not replicate previously reported candidate SNPs associated with FSD in the DRD4, 5HT2A and IL-1B loci. CONCLUSIONS/SIGNIFICANCE: We report the first GWAS of FSD symptoms in humans. This has pointed to several "risk alleles" and the implication of the serotonin and GABA pathways. Ultimately, understanding key mechanisms via this research may lead to new FSD treatments and inform clinical practice and developments in psychiatric nosology.

  17. Genome-wide analyses of small noncoding RNAs in streptococci

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    Nadja ePatenge

    2015-05-01

    Full Text Available Streptococci represent a diverse group of Gram-positive bacteria, which colonize a wide range of hosts among animals and humans. Streptococcal species occur as commensal as well as pathogenic organisms. Many of the pathogenic species can cause severe, invasive infections in their hosts leading to a high morbidity and mortality. The consequence is a tremendous suffering on the part of men and livestock besides the significant financial burden in the agricultural and healthcare sectors. An environmentally stimulated and tightly controlled expression of virulence factor genes is of fundamental importance for streptococcal pathogenicity. Bacterial small noncoding RNAs (sRNAs modulate the expression of genes involved in stress response, sugar metabolism, surface composition, and other properties that are related to bacterial virulence. Even though the regulatory character is shared by this class of RNAs, variation on the molecular level results in a high diversity of functional mechanisms. The knowledge about the role of sRNAs in streptococci is still limited, but in recent years, genome-wide screens for sRNAs have been conducted in an increasing number of species. Bioinformatics prediction approaches have been employed as well as expression analyses by classical array techniques or next generation sequencing. This review will give an overview of whole genome screens for sRNAs in streptococci with a focus on describing the different methods and comparing their outcome considering sRNA conservation among species, functional similarities, and relevance for streptococcal infection.

  18. Genome-wide association studies of obesity and metabolic syndrome.

    Science.gov (United States)

    Fall, Tove; Ingelsson, Erik

    2014-01-25

    Until just a few years ago, the genetic determinants of obesity and metabolic syndrome were largely unknown, with the exception of a few forms of monogenic extreme obesity. Since genome-wide association studies (GWAS) became available, large advances have been made. The first single nucleotide polymorphism robustly associated with increased body mass index (BMI) was in 2007 mapped to a gene with for the time unknown function. This gene, now known as fat mass and obesity associated (FTO) has been repeatedly replicated in several ethnicities and is affecting obesity by regulating appetite. Since the first report from a GWAS of obesity, an increasing number of markers have been shown to be associated with BMI, other measures of obesity or fat distribution and metabolic syndrome. This systematic review of obesity GWAS will summarize genome-wide significant findings for obesity and metabolic syndrome and briefly give a few suggestions of what is to be expected in the next few years. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Genome-wide patterns of Arabidopsis gene expression in nature.

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    Christina L Richards

    Full Text Available Organisms in the wild are subject to multiple, fluctuating environmental factors, and it is in complex natural environments that genetic regulatory networks actually function and evolve. We assessed genome-wide gene expression patterns in the wild in two natural accessions of the model plant Arabidopsis thaliana and examined the nature of transcriptional variation throughout its life cycle and gene expression correlations with natural environmental fluctuations. We grew plants in a natural field environment and measured genome-wide time-series gene expression from the plant shoot every three days, spanning the seedling to reproductive stages. We find that 15,352 genes were expressed in the A. thaliana shoot in the field, and accession and flowering status (vegetative versus flowering were strong components of transcriptional variation in this plant. We identified between ∼110 and 190 time-varying gene expression clusters in the field, many of which were significantly overrepresented by genes regulated by abiotic and biotic environmental stresses. The two main principal components of vegetative shoot gene expression (PC(veg correlate to temperature and precipitation occurrence in the field. The largest PC(veg axes included thermoregulatory genes while the second major PC(veg was associated with precipitation and contained drought-responsive genes. By exposing A. thaliana to natural environments in an open field, we provide a framework for further understanding the genetic networks that are deployed in natural environments, and we connect plant molecular genetics in the laboratory to plant organismal ecology in the wild.

  20. Genome-wide association studies in asthma: progress and pitfalls

    Directory of Open Access Journals (Sweden)

    March ME

    2015-01-01

    Full Text Available Michael E March,1 Patrick MA Sleiman,1,2 Hakon Hakonarson1,2 1Center for Applied Genomics, Children's Hospital of Philadelphia Research Institute, 2Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Abstract: Genetic studies of asthma have revealed that there is considerable heritability to the phenotype. An extensive history of candidate-gene studies has identified a long list of genes associated with immune function that are potentially involved in asthma pathogenesis. However, many of the results of candidate-gene studies have failed to be replicated, leaving in question the true impact of the implicated biological pathways on asthma. With the advent of genome-wide association studies, geneticists are able to examine the association of hundreds of thousands of genetic markers with a phenotype, allowing the hypothesis-free identification of variants associated with disease. Many such studies examining asthma or related phenotypes have been published, and several themes have begun to emerge regarding the biological pathways underpinning asthma. The results of many genome-wide association studies have currently not been replicated, and the large sample sizes required for this experimental strategy invoke difficulties with sample stratification and phenotypic heterogeneity. Recently, large collaborative groups of researchers have formed consortia focused on asthma, with the goals of sharing material and data and standardizing diagnosis and experimental methods. Additionally, research has begun to focus on genetic variants that affect the response to asthma medications and on the biology that generates the heterogeneity in the asthma phenotype. As this work progresses, it will move asthma patients closer to more specific, personalized medicine. Keywords: asthma, genetics, GWAS, pharmacogenetics, biomarkers

  1. Genome-wide signatures of convergent evolution in echolocating mammals.

    Science.gov (United States)

    Parker, Joe; Tsagkogeorga, Georgia; Cotton, James A; Liu, Yuan; Provero, Paolo; Stupka, Elia; Rossiter, Stephen J

    2013-10-10

    Evolution is typically thought to proceed through divergence of genes, proteins and ultimately phenotypes. However, similar traits might also evolve convergently in unrelated taxa owing to similar selection pressures. Adaptive phenotypic convergence is widespread in nature, and recent results from several genes have suggested that this phenomenon is powerful enough to also drive recurrent evolution at the sequence level. Where homoplasious substitutions do occur these have long been considered the result of neutral processes. However, recent studies have demonstrated that adaptive convergent sequence evolution can be detected in vertebrates using statistical methods that model parallel evolution, although the extent to which sequence convergence between genera occurs across genomes is unknown. Here we analyse genomic sequence data in mammals that have independently evolved echolocation and show that convergence is not a rare process restricted to several loci but is instead widespread, continuously distributed and commonly driven by natural selection acting on a small number of sites per locus. Systematic analyses of convergent sequence evolution in 805,053 amino acids within 2,326 orthologous coding gene sequences compared across 22 mammals (including four newly sequenced bat genomes) revealed signatures consistent with convergence in nearly 200 loci. Strong and significant support for convergence among bats and the bottlenose dolphin was seen in numerous genes linked to hearing or deafness, consistent with an involvement in echolocation. Unexpectedly, we also found convergence in many genes linked to vision: the convergent signal of many sensory genes was robustly correlated with the strength of natural selection. This first attempt to detect genome-wide convergent sequence evolution across divergent taxa reveals the phenomenon to be much more pervasive than previously recognized.

  2. Enhancing genomic prediction with genome-wide association studies in multiparental maize populations

    Science.gov (United States)

    Genome-wide association mapping using dense marker sets has identified some nucleotide variants affecting complex traits which have been validated with fine-mapping and functional analysis. Many sequence variants associated with complex traits in maize have small effects and low repeatability, howev...

  3. Meta-analysis of genome-wide association from genomic prediction models

    Science.gov (United States)

    A limitation of many genome-wide association studies (GWA) in animal breeding is that there are many loci with small effect sizes; thus, larger sample sizes (N) are required to guarantee suitable power of detection. To increase sample size, results from different GWA can be combined in a meta-analys...

  4. Genome-wide association study of sepsis in extremely premature infants.

    Science.gov (United States)

    Srinivasan, Lakshmi; Page, Grier; Kirpalani, Haresh; Murray, Jeffrey C; Das, Abhik; Higgins, Rosemary D; Carlo, Waldemar A; Bell, Edward F; Goldberg, Ronald N; Schibler, Kurt; Sood, Beena G; Stevenson, David K; Stoll, Barbara J; Van Meurs, Krisa P; Johnson, Karen J; Levy, Joshua; McDonald, Scott A; Zaterka-Baxter, Kristin M; Kennedy, Kathleen A; Sánchez, Pablo J; Duara, Shahnaz; Walsh, Michele C; Shankaran, Seetha; Wynn, James L; Cotten, C Michael

    2017-09-01

    To identify genetic variants associated with sepsis (early-onset and late-onset) using a genome-wide association (GWA) analysis in a cohort of extremely premature infants. Previously generated GWA data from the Neonatal Research Network's anonymised genomic database biorepository of extremely premature infants were used for this study. Sepsis was defined as culture-positive early-onset or late-onset sepsis or culture-proven meningitis. Genomic and whole-genome-amplified DNA was genotyped for 1.2 million single-nucleotide polymorphisms (SNPs); 91% of SNPs were successfully genotyped. We imputed 7.2 million additional SNPs. p Values and false discovery rates (FDRs) were calculated from multivariate logistic regression analysis adjusting for gender, gestational age and ancestry. Target statistical value was p<10(-5). Secondary analyses assessed associations of SNPs with pathogen type. Pathway analyses were also run on primary and secondary end points. Data from 757 extremely premature infants were included: 351 infants with sepsis and 406 infants without sepsis. No SNPs reached genome-wide significance levels (5×10(-8)); two SNPs in proximity to FOXC2 and FOXL1 genes achieved target levels of significance. In secondary analyses, SNPs for ELMO1, IRAK2 (Gram-positive sepsis), RALA, IMMP2L (Gram-negative sepsis) and PIEZO2 (fungal sepsis) met target significance levels. Pathways associated with sepsis and Gram-negative sepsis included gap junctions, fibroblast growth factor receptors, regulators of cell division and interleukin-1-associated receptor kinase 2 (p values<0.001 and FDR<20%). No SNPs met genome-wide significance in this cohort of extremely low birthweight infants; however, areas of potential association and pathways meriting further study were identified. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. The CHR site: definition and genome-wide identification of a cell cycle transcriptional element.

    Science.gov (United States)

    Müller, Gerd A; Wintsche, Axel; Stangner, Konstanze; Prohaska, Sonja J; Stadler, Peter F; Engeland, Kurt

    2014-01-01

    The cell cycle genes homology region (CHR) has been identified as a DNA element with an important role in transcriptional regulation of late cell cycle genes. It has been shown that such genes are controlled by DREAM, MMB and FOXM1-MuvB and that these protein complexes can contact DNA via CHR sites. However, it has not been elucidated which sequence variations of the canonical CHR are functional and how frequent CHR-based regulation is utilized in mammalian genomes. Here, we define the spectrum of functional CHR elements. As the basis for a computational meta-analysis, we identify new CHR sequences and compile phylogenetic motif conservation as well as genome-wide protein-DNA binding and gene expression data. We identify CHR elements in most late cell cycle genes binding DREAM, MMB, or FOXM1-MuvB. In contrast, Myb- and forkhead-binding sites are underrepresented in both early and late cell cycle genes. Our findings support a general mechanism: sequential binding of DREAM, MMB and FOXM1-MuvB complexes to late cell cycle genes requires CHR elements. Taken together, we define the group of CHR-regulated genes in mammalian genomes and provide evidence that the CHR is the central promoter element in transcriptional regulation of late cell cycle genes by DREAM, MMB and FOXM1-MuvB. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Genome-wide Studies of Mycolic Acid Bacteria: Computational Identification and Analysis of a Minimal Genome

    KAUST Repository

    Kamanu, Frederick Kinyua

    2012-12-01

    The mycolic acid bacteria are a distinct suprageneric group of asporogenous Grampositive, high GC-content bacteria, distinguished by the presence of mycolic acids in their cell envelope. They exhibit great diversity in their cell and morphology; although primarily non-pathogens, this group contains three major pathogens Mycobacterium leprae, Mycobacterium tuberculosis complex, and Corynebacterium diphtheria. Although the mycolic acid bacteria are a clearly defined group of bacteria, the taxonomic relationships between its constituent genera and species are less well defined. Two approaches were tested for their suitability in describing the taxonomy of the group. First, a Multilocus Sequence Typing (MLST) experiment was assessed and found to be superior to monophyletic (16S small ribosomal subunit) in delineating a total of 52 mycolic acid bacterial species. Phylogenetic inference was performed using the neighbor-joining method. To further refine phylogenetic analysis and to take advantage of the widespread availability of bacterial genome data, a computational framework that simulates DNA-DNA hybridisation was developed and validated using multiscale bootstrap resampling. The tool classifies microbial genomes based on whole genome DNA, and was deployed as a web-application using PHP and Javascript. It is accessible online at http://cbrc.kaust.edu.sa/dna_hybridization/ A third study was a computational and statistical methods in the identification and analysis of a putative minimal mycolic acid bacterial genome so as to better understand (1) the genomic requirements to encode a mycolic acid bacterial cell and (2) the role and type of genes and genetic elements that lead to the massive increase in genome size in environmental mycolic acid bacteria. Using a reciprocal comparison approach, a total of 690 orthologous gene clusters forming a putative minimal genome were identified across 24 mycolic acid bacterial species. In order to identify new potential drug

  7. A genome-wide association study identifies CDHR3 as a susceptibility locus for early childhood asthma with severe exacerbations

    DEFF Research Database (Denmark)

    Bønnelykke, Klaus; Sleiman, Patrick; Nielsen, Kasper

    2014-01-01

    years of age in a total of 1,173 cases and 2,522 controls. Cases were identified from national health registries of hospitalization, and DNA was obtained from the Danish Neonatal Screening Biobank. We identified five loci with genome-wide significant association. Four of these, GSDMB, IL33, RAD50 and IL...

  8. A method to evaluate genome-wide methylation in archival formalin-fixed, paraffin-embedded ovarian epithelial cells.

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    Qiling Li

    Full Text Available BACKGROUND: The use of DNA from archival formalin and paraffin embedded (FFPE tissue for genetic and epigenetic analyses may be problematic, since the DNA is often degraded and only limited amounts may be available. Thus, it is currently not known whether genome-wide methylation can be reliably assessed in DNA from archival FFPE tissue. METHODOLOGY/PRINCIPAL FINDINGS: Ovarian tissues, which were obtained and formalin-fixed and paraffin-embedded in either 1999 or 2011, were sectioned and stained with hematoxylin-eosin (H&E.Epithelial cells were captured by laser micro dissection, and their DNA subjected to whole genomic bisulfite conversion, whole genomic polymerase chain reaction (PCR amplification, and purification. Sequencing and software analyses were performed to identify the extent of genomic methylation. We observed that 31.7% of sequence reads from the DNA in the 1999 archival FFPE tissue, and 70.6% of the reads from the 2011 sample, could be matched with the genome. Methylation rates of CpG on the Watson and Crick strands were 32.2% and 45.5%, respectively, in the 1999 sample, and 65.1% and 42.7% in the 2011 sample. CONCLUSIONS/SIGNIFICANCE: We have developed an efficient method that allows DNA methylation to be assessed in archival FFPE tissue samples.

  9. DNA Oncogenic Virus-Induced Oxidative Stress, Genomic Damage, and Aberrant Epigenetic Alterations

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    Mankgopo Magdeline Kgatle

    2017-01-01

    Full Text Available Approximately 20% of human cancers is attributable to DNA oncogenic viruses such as human papillomavirus (HPV, hepatitis B virus (HBV, and Epstein-Barr virus (EBV. Unrepaired DNA damage is the most common and overlapping feature of these DNA oncogenic viruses and a source of genomic instability and tumour development. Sustained DNA damage results from unceasing production of reactive oxygen species and activation of inflammasome cascades that trigger genomic changes and increased propensity of epigenetic alterations. Accumulation of epigenetic alterations may interfere with genome-wide cellular signalling machineries and promote malignant transformation leading to cancer development. Untangling and understanding the underlying mechanisms that promote these detrimental effects remain the major objectives for ongoing research and hope for effective virus-induced cancer therapy. Here, we review current literature with an emphasis on how DNA damage influences HPV, HVB, and EBV replication and epigenetic alterations that are associated with carcinogenesis.

  10. An improved chloroplast DNA extraction procedure for whole plastid genome sequencing.

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    Chao Shi

    Full Text Available BACKGROUND: Chloroplast genomes supply valuable genetic information for evolutionary and functional studies in plants. The past five years have witnessed a dramatic increase in the number of completely sequenced chloroplast genomes with the application of second-generation sequencing technology in plastid genome sequencing projects. However, cost-effective high-throughput chloroplast DNA (cpDNA extraction becomes a major bottleneck restricting the application, as conventional methods are difficult to make a balance between the quality and yield of cpDNAs. METHODOLOGY/PRINCIPAL FINDINGS: We first tested two traditional methods to isolate cpDNA from the three species, Oryza brachyantha, Leersia japonica and Prinsepia utihis. Both of them failed to obtain properly defined cpDNA bands. However, we developed a simple but efficient method based on sucrose gradients and found that the modified protocol worked efficiently to isolate the cpDNA from the same three plant species. We sequenced the isolated DNA samples with Illumina (Solexa sequencing technology to test cpDNA purity according to aligning sequence reads to the reference chloroplast genomes, showing that the reference genome was properly covered. We show that 40-50% cpDNA purity is achieved with our method. CONCLUSION: Here we provide an improved method used to isolate cpDNA from angiosperms. The Illumina sequencing results suggest that the isolated cpDNA has reached enough yield and sufficient purity to perform subsequent genome assembly. The cpDNA isolation protocol thus will be widely applicable to the plant chloroplast genome sequencing projects.

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

    Science.gov (United States)

    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

  12. Strong genome-wide selection early in the evolution of Prochlorococcus resulted in a reduced genome through the loss of a large number of small effect genes.

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    Zhiyi Sun

    Full Text Available The smallest genomes of any photosynthetic organisms are found in a group of free-living marine cyanobacteria, Prochlorococcus. To determine the underlying evolutionary mechanisms, we developed a new method to reconstruct the steps leading to the Prochlorococcus genome reduction using 12 Prochlorococcus and 6 marine Synechococcus genomes. Our results reveal that small genome sizes within Prochlorococcus were largely determined shortly after the split of Prochlorococcus and Synechococcus (an early big shrink and thus for the first time decouple the genome reduction from Prochlorococcus diversification. A maximum likelihood approach was then used to estimate changes of nucleotide substitution rate and selection strength along Prochlorococcus evolution in a phylogenetic framework. Strong genome wide purifying selection was associated with the loss of many genes in the early evolutionary stage. The deleted genes were distributed around the genome, participated in many different functional categories and in general had been under relaxed selection pressure. We propose that shortly after Prochlorococcus diverged from its common ancestor with marine Synechococcus, its population size increased quickly thus increasing efficacy of selection. Due to limited nutrients and a relatively constant environment, selection favored a streamlined genome for maximum economy. Strong genome wide selection subsequently caused the loss of genes with small functional effect including the loss of some DNA repair genes. In summary, genome reduction in Prochlorococcus resulted in genome features that are similar to symbiotic bacteria and pathogens, however, the small genome sizes resulted from an increase in genome wide selection rather than a consequence of a reduced ecological niche or relaxed selection due to genetic drift.

  13. Genome Calligrapher: A Web Tool for Refactoring Bacterial Genome Sequences for de Novo DNA Synthesis.

    Science.gov (United States)

    Christen, Matthias; Deutsch, Samuel; Christen, Beat

    2015-08-21

    Recent advances in synthetic biology have resulted in an increasing demand for the de novo synthesis of large-scale DNA constructs. Any process improvement that enables fast and cost-effective streamlining of digitized genetic information into fabricable DNA sequences holds great promise to study, mine, and engineer genomes. Here, we present Genome Calligrapher, a computer-aided design web tool intended for whole genome refactoring of bacterial chromosomes for de novo DNA synthesis. By applying a neutral recoding algorithm, Genome Calligrapher optimizes GC content and removes obstructive DNA features known to interfere with the synthesis of double-stranded DNA and the higher order assembly into large DNA constructs. Subsequent bioinformatics analysis revealed that synthesis constraints are prevalent among bacterial genomes. However, a low level of codon replacement is sufficient for refactoring bacterial genomes into easy-to-synthesize DNA sequences. To test the algorithm, 168 kb of synthetic DNA comprising approximately 20 percent of the synthetic essential genome of the cell-cycle bacterium Caulobacter crescentus was streamlined and then ordered from a commercial supplier of low-cost de novo DNA synthesis. The successful assembly into eight 20 kb segments indicates that Genome Calligrapher algorithm can be efficiently used to refactor difficult-to-synthesize DNA. Genome Calligrapher is broadly applicable to recode biosynthetic pathways, DNA sequences, and whole bacterial genomes, thus offering new opportunities to use synthetic biology tools to explore the functionality of microbial diversity. The Genome Calligrapher web tool can be accessed at https://christenlab.ethz.ch/GenomeCalligrapher  .

  14. A genome-wide association study of optic disc parameters.

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    Wishal D Ramdas

    2010-06-01

    Full Text Available The optic nerve head is involved in many ophthalmic disorders, including common diseases such as myopia and open-angle glaucoma. Two of the most important parameters are the size of the optic disc area and the vertical cup-disc ratio (VCDR. Both are highly heritable but genetically largely undetermined. We performed a meta-analysis of genome-wide association (GWA data to identify genetic variants associated with optic disc area and VCDR. The gene discovery included 7,360 unrelated individuals from the population-based Rotterdam Study I and Rotterdam Study II cohorts. These cohorts revealed two genome-wide significant loci for optic disc area, rs1192415 on chromosome 1p22 (p = 6.72x10(-19 within 117 kb of the CDC7 gene and rs1900004 on chromosome 10q21.3-q22.1 (p = 2.67x10(-33 within 10 kb of the ATOH7 gene. They revealed two genome-wide significant loci for VCDR, rs1063192 on chromosome 9p21 (p = 6.15x10(-11 in the CDKN2B gene and rs10483727 on chromosome 14q22.3-q23 (p = 2.93x10(-10 within 40 kbp of the SIX1 gene. Findings were replicated in two independent Dutch cohorts (Rotterdam Study III and Erasmus Rucphen Family study; N = 3,612, and the TwinsUK cohort (N = 843. Meta-analysis with the replication cohorts confirmed the four loci and revealed a third locus at 16q12.1 associated with optic disc area, and four other loci at 11q13, 13q13, 17q23 (borderline significant, and 22q12.1 for VCDR. ATOH7 was also associated with VCDR independent of optic disc area. Three of the loci were marginally associated with open-angle glaucoma. The protein pathways in which the loci of optic disc area are involved overlap with those identified for VCDR, suggesting a common genetic origin.

  15. Genome-wide Pleiotropy Between Parkinson Disease and Autoimmune Diseases.

    Science.gov (United States)

    Witoelar, Aree; Jansen, Iris E; Wang, Yunpeng; Desikan, Rahul S; Gibbs, J Raphael; Blauwendraat, Cornelis; Thompson, Wesley K; Hernandez, Dena G; Djurovic, Srdjan; Schork, Andrew J; Bettella, Francesco; Ellinghaus, David; Franke, Andre; Lie, Benedicte A; McEvoy, Linda K; Karlsen, Tom H; Lesage, Suzanne; Morris, Huw R; Brice, Alexis; Wood, Nicholas W; Heutink, Peter; Hardy, John; Singleton, Andrew B; Dale, Anders M; Gasser, Thomas; Andreassen, Ole A; Sharma, Manu

    2017-07-01

    Recent genome-wide association studies (GWAS) and pathway analyses supported long-standing observations of an association between immune-mediated diseases and Parkinson disease (PD). The post-GWAS era provides an opportunity for cross-phenotype analyses between different complex phenotypes. To test the hypothesis that there are common genetic risk variants conveying risk of both PD and autoimmune diseases (ie, pleiotropy) and to identify new shared genetic variants and their pathways by applying a novel statistical framework in a genome-wide approach. Using the conjunction false discovery rate method, this study analyzed GWAS data from a selection of archetypal autoimmune diseases among 138 511 individuals of European ancestry and systemically investigated pleiotropy between PD and type 1 diabetes, Crohn disease, ulcerative colitis, rheumatoid arthritis, celiac disease, psoriasis, and multiple sclerosis. NeuroX data (6927 PD cases and 6108 controls) were used for replication. The study investigated the biological correlation between the top loci through protein-protein interaction and changes in the gene expression and methylation levels. The dates of the analysis were June 10, 2015, to March 4, 2017. The primary outcome was a list of novel loci and their pathways involved in PD and autoimmune diseases. Genome-wide conjunctional analysis identified 17 novel loci at false discovery rate less than 0.05 with overlap between PD and autoimmune diseases, including known PD loci adjacent to GAK, HLA-DRB5, LRRK2, and MAPT for rheumatoid arthritis, ulcerative colitis and Crohn disease. Replication confirmed the involvement of HLA, LRRK2, MAPT, TRIM10, and SETD1A in PD. Among the novel genes discovered, WNT3, KANSL1, CRHR1, BOLA2, and GUCY1A3 are within a protein-protein interaction network with known PD genes. A subset of novel loci was significantly associated with changes in methylation or expression levels of adjacent genes. The study findings provide novel mechanistic

  16. Genome-wide association study of antisocial personality disorder

    Science.gov (United States)

    Rautiainen, M-R; Paunio, T; Repo-Tiihonen, E; Virkkunen, M; Ollila, H M; Sulkava, S; Jolanki, O; Palotie, A; Tiihonen, J

    2016-01-01

    The pathophysiology of antisocial personality disorder (ASPD) remains unclear. Although the most consistent biological finding is reduced grey matter volume in the frontal cortex, about 50% of the total liability to developing ASPD has been attributed to genetic factors. The contributing genes remain largely unknown. Therefore, we sought to study the genetic background of ASPD. We conducted a genome-wide association study (GWAS) and a replication analysis of Finnish criminal offenders fulfilling DSM-IV criteria for ASPD (N=370, N=5850 for controls, GWAS; N=173, N=3766 for controls and replication sample). The GWAS resulted in suggestive associations of two clusters of single-nucleotide polymorphisms at 6p21.2 and at 6p21.32 at the human leukocyte antigen (HLA) region. Imputation of HLA alleles revealed an independent association with DRB1*01:01 (odds ratio (OR)=2.19 (1.53–3.14), P=1.9 × 10-5). Two polymorphisms at 6p21.2 LINC00951–LRFN2 gene region were replicated in a separate data set, and rs4714329 reached genome-wide significance (OR=1.59 (1.37–1.85), P=1.6 × 10−9) in the meta-analysis. The risk allele also associated with antisocial features in the general population conditioned for severe problems in childhood family (β=0.68, P=0.012). Functional analysis in brain tissue in open access GTEx and Braineac databases revealed eQTL associations of rs4714329 with LINC00951 and LRFN2 in cerebellum. In humans, LINC00951 and LRFN2 are both expressed in the brain, especially in the frontal cortex, which is intriguing considering the role of the frontal cortex in behavior and the neuroanatomical findings of reduced gray matter volume in ASPD. To our knowledge, this is the first study showing genome-wide significant and replicable findings on genetic variants associated with any personality disorder. PMID:27598967

  17. A powerful test of independent assortment that determines genome-wide significance quickly and accurately.

    Science.gov (United States)

    Stewart, W C L; Hager, V R

    2016-08-01

    In the analysis of DNA sequences on related individuals, most methods strive to incorporate as much information as possible, with little or no attention paid to the issue of statistical significance. For example, a modern workstation can easily handle the computations needed to perform a large-scale genome-wide inheritance-by-descent (IBD) scan, but accurate assessment of the significance of that scan is often hindered by inaccurate approximations and computationally intensive simulation. To address these issues, we developed gLOD-a test of co-segregation that, for large samples, models chromosome-specific IBD statistics as a collection of stationary Gaussian processes. With this simple model, the parametric bootstrap yields an accurate and rapid assessment of significance-the genome-wide corrected P-value. Furthermore, we show that (i) under the null hypothesis, the limiting distribution of the gLOD is the standard Gumbel distribution; (ii) our parametric bootstrap simulator is approximately 40 000 times faster than gene-dropping methods, and it is more powerful than methods that approximate the adjusted P-value; and, (iii) the gLOD has the same statistical power as the widely used maximum Kong and Cox LOD. Thus, our approach gives researchers the ability to determine quickly and accurately the significance of most large-scale IBD scans, which may contain multiple traits, thousands of families and tens of thousands of DNA sequences.

  18. Exploring the utility of human DNA methylation arrays for profiling mouse genomic DNA.

    Science.gov (United States)

    Wong, Nicholas C; Ng, Jane; Hall, Nathan E; Lunke, Sebastian; Salmanidis, Marika; Brumatti, Gabriela; Ekert, Paul G; Craig, Jeffrey M; Saffery, Richard

    2013-07-01

    Illumina Infinium Human Methylation (HM) BeadChips are widely used for measuring genome-scale DNA methylation, particularly in relation to epigenome-wide association studies (EWAS) studies. The methylation profile of human samples can be assessed accurately and reproducibly using the HM27 BeadChip (27,578 CpG sites) or its successor, the HM450 BeadChip (482,421 CpG sites). To date no mouse equivalent has been developed, greatly hindering the application of this methodology to the wide range of valuable murine models of disease and development currently in existence. We found 1308 and 13,715 probes from HM27 and HM450 BeadChip respectively, uniquely matched the bisulfite converted reference mouse genome (mm9). We demonstrate reproducible measurements of DNA methylation at these probes in a range of mouse tissue samples and in a murine cell line model of acute myeloid leukaemia. In the absence of a mouse counterpart, the Infinium Human Methylation BeadChip arrays have utility for methylation profiling in non-human species.

  19. Effects of in ovo electroporation on endogenous gene expression: genome-wide analysis

    Directory of Open Access Journals (Sweden)

    Chambers David

    2011-04-01

    Full Text Available Abstract Background In ovo electroporation is a widely used technique to study gene function in developmental biology. Despite the widespread acceptance of this technique, no genome-wide analysis of the effects of in ovo electroporation, principally the current applied across the tissue and exogenous vector DNA introduced, on endogenous gene expression has been undertaken. Here, the effects of electric current and expression of a GFP-containing construct, via electroporation into the midbrain of Hamburger-Hamilton stage 10 chicken embryos, are analysed by microarray. Results Both current alone and in combination with exogenous DNA expression have a small but reproducible effect on endogenous gene expression, changing the expression of the genes represented on the array by less than 0.1% (current and less than 0.5% (current + DNA, respectively. The subset of genes regulated by electric current and exogenous DNA span a disparate set of cellular functions. However, no genes involved in the regional identity were affected. In sharp contrast to this, electroporation of a known transcription factor, Dmrt5, caused a much greater change in gene expression. Conclusions These findings represent the first systematic genome-wide analysis of the effects of in ovo electroporation on gene expression during embryonic development. The analysis reveals that this process has minimal impact on the genetic basis of cell fate specification. Thus, the study demonstrates the validity of the in ovo electroporation technique to study gene function and expression during development. Furthermore, the data presented here can be used as a resource to refine the set of transcriptional responders in future in ovo electroporation studies of specific gene function.

  20. Two-dimensional DNA displays for comparisons of bacterial genomes

    Directory of Open Access Journals (Sweden)

    Malloff Chad

    2003-01-01

    Full Text Available We have developed two whole genome-scanning techniques to aid in the discovery of polymorphisms as well as horizontally acquired genes in prokaryotic organisms. First, two-dimensional bacterial genomic display (2DBGD was developed using restriction enzyme fragmentation to separate genomic DNA based on size, and then employing denaturing gradient gel electrophoresis (DGGE in the second dimension to exploit differences in sequence composition. This technique was used to generate high-resolution displays that enable the direct comparison of > 800 genomic fragments simultaneously and can be adapted for the high-throughput comparison of bacterial genomes. 2DBGDs are capable of detecting acquired and altered DNA, however, only in very closely related strains. If used to compare more distantly related strains (e.g. different species within a genus numerous small changes (i.e. small deletions and point mutations unrelated to the interesting phenotype, would encumber the comparison of 2DBGDs. For this reason a second method, bacterial comparative genomic hybridization (BCGH, was developed to directly compare bacterial genomes to identify gain or loss of genomic DNA. BCGH relies on performing 2DBGD on a pooled sample of genomic DNA from 2 strains to be compared and subsequently hybridizing the resulting 2DBGD blot separately with DNA from each individual strain. Unique spots (hybridization signals represent foreign DNA. The identification of novel DNA is easily achieved by excising the DNA from a dried gel followed by subsequent cloning and sequencing. 2DBGD and BCGH thus represent novel high resolution genome scanning techniques for directly identifying altered and/or acquired DNA.

  1. Amplification of Whole Tumor Genomes and Gene-by-Gene Mapping of Genomic Aberrations from Limited Sources of Fresh-Frozen and Paraffin-Embedded DNA

    Science.gov (United States)

    Bredel, Markus; Bredel, Claudia; Juric, Dejan; Kim, Young; Vogel, Hannes; Harsh, Griffith R.; Recht, Lawrence D.; Pollack, Jonathan R.; Sikic, Branimir I.

    2005-01-01

    Sufficient quantity of genomic DNA can be a bottleneck in genome-wide analysis of clinical tissue samples. DNA polymerase Phi29 can be used for the random-primed amplification of whole genomes, although the amplification may introduce bias in gene dosage. We have performed a detailed investigation of this technique in archival fresh-frozen and formalin-fixed/paraffin-embedded tumor DNA by using cDNA microarray-based comparative genomic hybridization. Phi29 amplified DNA from matched pairs of fresh-frozen and formalin-fixed/paraffin-embedded tumor samples with similar efficiency. The distortion in gene dosage representation in the amplified DNA was nonrandom and reproducibly involved distinct genomic loci. Regional amplification efficiency was significantly linked to regional GC content of the template genome. The biased gene representation in amplified tumor DNA could be effectively normalized by using amplified reference DNA. Our data suggest that genome-wide gene dosage alterations in clinical tumor samples can be reliably assessed from a few hundred tumor cells. Therefore, this amplification method should lend itself to high-throughput genetic analyses of limited sources of tumor, such as fine-needle biopsies, laser-microdissected tissue, and small paraffin-embedded specimens. PMID:15858140

  2. Genome-wide significant risk associations for mucinous ovarian carcinoma

    Science.gov (United States)

    Kelemen, Linda E.; Lawrenson, Kate; Tyrer, Jonathan; Li, Qiyuan; M. Lee, Janet; Seo, Ji-Heui; Phelan, Catherine M.; Beesley, Jonathan; Chen, Xiaoqin; Spindler, Tassja J.; Aben, Katja K.H.; Anton-Culver, Hoda; Antonenkova, Natalia; Baker, Helen; Bandera, Elisa V.; Bean, Yukie; Beckmann, Matthias W.; Bisogna, Maria; Bjorge, Line; Bogdanova, Natalia; Brinton, Louise A.; Brooks-Wilson, Angela; Bruinsma, Fiona; Butzow, Ralf; Campbell, Ian G.; Carty, Karen; Chang-Claude, Jenny; Chen, Y. Ann; Chen, Zhihua; Cook, Linda S.; Cramer, Daniel W.; Cunningham, Julie M.; Cybulski, Cezary; Dansonka-Mieszkowska, Agnieszka; Dennis, Joe; Dicks, Ed; Doherty, Jennifer A.; Dörk, Thilo; du Bois, Andreas; Dürst, Matthias; Eccles, Diana; Easton, Douglas T.; Edwards, Robert P.; Eilber, Ursula; Ekici, Arif B.; Engelholm, Svend Aage; Fasching, Peter A.; Fridley, Brooke L.; Gao, Yu-Tang; Gentry-Maharaj, Aleksandra; Giles, Graham G.; Glasspool, Rosalind; Goode, Ellen L.; Goodman, Marc T.; Grownwald, Jacek; Harrington, Patricia; Harter, Philipp; Hasmad, Hanis Nazihah; Hein, Alexander; Heitz, Florian; Hildebrandt, Michelle A.T.; Hillemanns, Peter; Hogdall, Estrid; Hogdall, Claus; Hosono, Satoyo; Iversen, Edwin S.; Jakubowska, Anna; Jensen, Allan; Ji, Bu-Tian; Karlan, Beth Y; Kellar, Melissa; Kelley, Joseph L.; Kiemeney, Lambertus A.; Krakstad, Camilla; Kjaer, Susanne K.; Kupryjanczyk, Jolanta; Lambrechts, Diether; Lambrechts, Sandrina; Le, Nhu D.; Lee, Alice W.; Lele, Shashi; Leminen, Arto; Lester, Jenny; Levine, Douglas A.; Liang, Dong; Lissowska, Jolanta; Lu, Karen; Lubinski, Jan; Lundvall, Lene; Massuger, Leon F.A.G.; Matsuo, Keitaro; McGuire, Valerie; McLaughlin, John R.; McNeish, Iain; Menon, Usha; Modugno, Francesmary; Moes-Sosnowska, Joanna; Moysich, Kirsten B.; Narod, Steven A.; Nedergaard, Lotte; Ness, Roberta B.; Nevanlinna, Heli; Azmi, Mat Adenan Noor; Odunsi, Kunle; Olson, Sara H.; Orlow, Irene; Orsulic, Sandra; Weber, Rachel Palmieri; Paul, James; Pearce, Celeste Leigh; Pejovic, Tanja; Pelttari, Liisa M.; Permuth-Wey, Jennifer; Pike, Malcolm C.; Poole, Elizabeth M.; Ramus, Susan J.; Risch, Harvey A.; Rosen, Barry; Rossing, Mary Anne; Rothstein, Joseph H.; Rudolph, Anja; Runnebaum, Ingo B.; Rzepecka, Iwona K.; Salvesen, Helga B.; Schildkraut, Joellen M.; Schwaab, Ira; Shu, Xiao-Ou; Shvetsov, Yurii B; Siddiqui, Nadeem; Sieh, Weiva; Song, Honglin; Southey, Melissa C.; Sucheston, Lara; Tangen, Ingvild L.; Teo, Soo-Hwang; Terry, Kathryn L.; Thompson, Pamela J; Tworoger, Shelley S.; van Altena, Anne M.; Van Nieuwenhuysen, Els; Vergote, Ignace; Vierkant, Robert A.; Wang-Gohrke, Shan; Walsh, Christine; Wentzensen, Nicolas; Whittemore, Alice S.; Wicklund, Kristine G.; Wilkens, Lynne R.; Wlodzimierz, Sawicki; Woo, Yin-Ling; Wu, Xifeng; Wu, Anna H.; Yang, Hannah; Zheng, Wei; Ziogas, Argyrios; Sellers, Thomas A.; Freedman, Matthew L.; Chenevix-Trench, Georgia; Pharoah, Paul D.; Gayther, Simon A.; Berchuck, Andrew

    2015-01-01

    Genome-wide association studies have identified several risk associations for ovarian carcinomas (OC) but not for mucinous ovarian carcinomas (MOC). Genotypes from OC cases and controls were imputed into the 1000 Genomes Project reference panel. Analysis of 1,644 MOC cases and 21,693 controls identified three novel risk associations: rs752590 at 2q13 (P = 3.3 × 10−8), rs711830 at 2q31.1 (P = 7.5 × 10−12) and rs688187 at 19q13.2 (P = 6.8 × 10−13). Expression Quantitative Trait Locus (eQTL) analysis in ovarian and colorectal tumors (which are histologically similar to MOC) identified significant eQTL associations for HOXD9 at 2q31.1 in ovarian (P = 4.95 × 10−4, FDR = 0.003) and colorectal (P = 0.01, FDR = 0.09) tumors, and for PAX8 at 2q13 in colorectal tumors (P = 0.03, FDR = 0.09). Chromosome conformation capture analysis identified interactions between the HOXD9 promoter and risk SNPs at 2q31.1. Overexpressing HOXD9 in MOC cells augmented the neoplastic phenotype. These findings provide the first evidence for MOC susceptibility variants and insights into the underlying biology of the disease. PMID:26075790

  3. Genome-wide association study and premature ovarian failure.

    Science.gov (United States)

    Christin-Maitre, S; Tachdjian, G

    2010-05-01

    Premature ovarian failure (POF) is defined as an amenorrhea for more than 4months, associated with elevated gonadotropins, usually higher than 20mIU/ml, occurring in a woman before the age of 40. Some candidate genes have been identified in the past 15years, such as FOXL2, FSHR, BMP15, GDF9, Xfra premutation. However, POF etiology remains unknown in more than 90% of cases. The first strategy to identify candidate gene, apart from studying genes involved in ovarian failure in animal models, relies on the study of X chromosome deletions and X;autosome translocations in patients. The second strategy is based on linkage analysis, the third one on Comparative Genomic Hybridization (CGH) array. The latest strategy relies on Genome-Wide Association Studies (GWAS). This technique consists in screening single nucleotide polymorphisms (SNPs) in patients and controls. So far, three studies have been performed and have identified different loci potentially linked to POF, such as PTHB1 and ADAMTS19. However, replications in independent cohorts need to be performed. GWAS studies on large cohorts of women with POF should find new candidate genes in the near future.

  4. Genome-Wide Association Studies of the Human Gut Microbiota.

    Directory of Open Access Journals (Sweden)

    Emily R Davenport

    Full Text Available The bacterial composition of the human fecal microbiome is influenced by many lifestyle factors, notably diet. It is less clear, however, what role host genetics plays in dictating the composition of bacteria living in the gut. In this study, we examined the association of ~200K host genotypes with the relative abundance of fecal bacterial taxa in a founder population, the Hutterites, during two seasons (n = 91 summer, n = 93 winter, n = 57 individuals collected in both. These individuals live and eat communally, minimizing variation due to environmental exposures, including diet, which could potentially mask small genetic effects. Using a GWAS approach that takes into account the relatedness between subjects, we identified at least 8 bacterial taxa whose abundances were associated with single nucleotide polymorphisms in the host genome in each season (at genome-wide FDR of 20%. For example, we identified an association between a taxon known to affect obesity (genus Akkermansia and a variant near PLD1, a gene previously associated with body mass index. Moreover, we replicate a previously reported association from a quantitative trait locus (QTL mapping study of fecal microbiome abundance in mice (genus Lactococcus, rs3747113, P = 3.13 x 10-7. Finally, based on the significance distribution of the associated microbiome QTLs in our study with respect to chromatin accessibility profiles, we identified tissues in which host genetic variation may be acting to influence bacterial abundance in the gut.

  5. Development and characterization of genomic and expressed SSRs in citrus by genome-wide analysis.

    Directory of Open Access Journals (Sweden)

    Sheng-Rui Liu

    Full Text Available Microsatellites or simple sequence repeats (SSRs are one of the most popular sources of genetic markers and play a significant role in plant genetics and breeding. In this study, we identified citrus SSRs in the genome of Clementine mandarin and analyzed their frequency and distribution in different genomic regions. A total of 80,708 SSRs were detected in the genome with an overall density of 268 SSRs/Mb. While di-nucleotide repeats were the most frequent microsatellites in genomic DNA sequence, tetra-nucleotides, which had more repeat units than any other SSR types, had the highest cumulative sequence length. We identified 6,834 transcripts as containing 8,989 SSRs in 33,929 Clementine mandarin transcripts, among which, tri-nucleotide motifs (36.0% were the most common, followed by di-nucleotide (26.9% and hexa-nucleotide motifs (15.1%. The motif AG (16.7% was most abundant among these SSRs, while motifs AAG (6.6%, AAT (5.0%, and TAG (2.2% were most common among tri-nucleotides. Functional categorization of transcripts containing SSRs revealed that 5,879 (86.0% of such transcripts had homology with known proteins, GO and KEGG annotation revealed that transcripts containing SSRs were those implicated in diverse biological processes in plants, including binding, development, transcription, and protein degradation. When 27 genomic and 78 randomly selected SSRs were tested on Clementine mandarin, 95 SSRs revealed polymorphism. These 95 SSRs were further deployed on 18 genotypes of the three generas of Rutaceae for the genetic diversity assessment, genomic SSRs generally show low transferability in comparison to SSRs developed from expressed sequences. These transcript-markers identified in our study may provide a valuable genetic and genomic tool for further genetic research and varietal development in citrus, such as diversity study, QTL mapping, molecular breeding, comparative mapping and other genetic analyses.

  6. Development and characterization of genomic and expressed SSRs in citrus by genome-wide analysis.

    Science.gov (United States)

    Liu, Sheng-Rui; Li, Wen-Yang; Long, Dang; Hu, Chun-Gen; Zhang, Jin-Zhi

    2013-01-01

    Microsatellites or simple sequence repeats (SSRs) are one of the most popular sources of genetic markers and play a significant role in plant genetics and breeding. In this study, we identified citrus SSRs in the genome of Clementine mandarin and analyzed their frequency and distribution in different genomic regions. A total of 80,708 SSRs were detected in the genome with an overall density of 268 SSRs/Mb. While di-nucleotide repeats were the most frequent microsatellites in genomic DNA sequence, tetra-nucleotides, which had more repeat units than any other SSR types, had the highest cumulative sequence length. We identified 6,834 transcripts as containing 8,989 SSRs in 33,929 Clementine mandarin transcripts, among which, tri-nucleotide motifs (36.0%) were the most common, followed by di-nucleotide (26.9%) and hexa-nucleotide motifs (15.1%). The motif AG (16.7%) was most abundant among these SSRs, while motifs AAG (6.6%), AAT (5.0%), and TAG (2.2%) were most common among tri-nucleotides. Functional categorization of transcripts containing SSRs revealed that 5,879 (86.0%) of such transcripts had homology with known proteins, GO and KEGG annotation revealed that transcripts containing SSRs were those implicated in diverse biological processes in plants, including binding, development, transcription, and protein degradation. When 27 genomic and 78 randomly selected SSRs were tested on Clementine mandarin, 95 SSRs revealed polymorphism. These 95 SSRs were further deployed on 18 genotypes of the three generas of Rutaceae for the genetic diversity assessment, genomic SSRs generally show low transferability in comparison to SSRs developed from expressed sequences. These transcript-markers identified in our study may provide a valuable genetic and genomic tool for further genetic research and varietal development in citrus, such as diversity study, QTL mapping, molecular breeding, comparative mapping and other genetic analyses.

  7. Genome-wide profiling of structural genomic variations in Korean HapMap individuals.

    Directory of Open Access Journals (Sweden)

    Joon Seol Bae

    Full Text Available BACKGROUND: Structural genomic variation study, along with microarray technology development has provided many genomic resources related with architecture of human genome, and led to the fact that human genome structure is a lot more complicated than previously thought. METHODOLOGY/PRINCIPAL FINDINGS: In the case of International HapMap Project, Epstein-Barr various immortalized cell lines were preferably used over blood in order to get a larger number of genomic DNA. However, genomic aberration stemming from immortalization process, biased representation of the donor tissue, and culture process may influence the accuracy of SNP genotypes. In order to identify chromosome aberrations including loss of heterozygosity (LOH, large-scale and small-scale copy number variations, we used Illumina HumanHap500 BeadChip (555,352 markers on Korean HapMap individuals (n = 90 to obtain Log R ratio and B allele frequency information, and then utilized the data with various programs including Illumina ChromoZone, cnvParition and PennCNV. As a result, we identified 28 LOHs (>3 mb and 35 large-scale CNVs (>1 mb, with 4 samples having completely duplicated chromosome. In addition, after checking the sample quality (standard deviation of log R ratio <0.30, we selected 79 samples and used both signal intensity and B allele frequency simultaneously for identification of small-scale CNVs (<1 mb to discover 4,989 small-scale CNVs. Identified CNVs in this study were successfully validated using visual examination of the genoplot images, overlapping analysis with previously reported CNVs in DGV, and quantitative PCR. CONCLUSION/SIGNIFICANCE: In this study, we describe the result of the identified chromosome aberrations in Korean HapMap individuals, and expect that these findings will provide more meaningful information on the human genome.

  8. Genome-wide association studies in pharmacogenomics of antidepressants.

    Science.gov (United States)

    Lin, Eugene; Lane, Hsien-Yuan

    2015-01-01

    Major depressive disorder (MDD) is one of the most common psychiatric disorders worldwide. Doctors must prescribe antidepressants based on educated guesses due to the fact that it is unmanageable to predict the effectiveness of any particular antidepressant in an individual patient. With the recent advent of scientific research, the genome-wide association study (GWAS) is extensively employed to analyze hundreds of thousands of single nucleotide polymorphisms by high-throughput genotyping technologies. In addition to the candidate-gene approach, the GWAS approach has recently been utilized to investigate the determinants of antidepressant response to therapy. In this study, we reviewed GWAS studies, their limitations and future directions with respect to the pharmacogenomics of antidepressants in MDD.

  9. Genome-wide association studies in pediatric chronic kidney disease.

    Science.gov (United States)

    Gupta, Jayanta; Kanetsky, Peter A; Wuttke, Matthias; Köttgen, Anna; Schaefer, Franz; Wong, Craig S

    2016-08-01

    The genome-wide association study (GWAS) has become an established scientific method that provides an unbiased screen for genetic loci potentially associated with phenotypes of clinical interest, such as chronic kidney disease (CKD). Thus, GWAS provides opportunities to gain new perspectives regarding the genetic architecture of CKD progression by identifying new candidate genes and targets for intervention. As such, it has become an important arm of translational science providing a complementary line of investigation to identify novel therapeutics to treat CKD. In this review, we describe the method and the challenges of performing GWAS in the pediatric CKD population. We also provide an overview of successful GWAS for kidney disease, and we discuss the established pediatric CKD cohorts in North America and Europe that are poised to identify genetic risk variants associated with CKD progression.

  10. Genome-wide measurement of RNA folding energies.

    Science.gov (United States)

    Wan, Yue; Qu, Kun; Ouyang, Zhengqing; Kertesz, Michael; Li, Jun; Tibshirani, Robert; Makino, Debora L; Nutter, Robert C; Segal, Eran; Chang, Howard Y

    2012-10-26

    RNA structural transitions are important in the function and regulation of RNAs. Here, we reveal a layer of transcriptome organization in the form of RNA folding energies. By probing yeast RNA structures at different temperatures, we obtained relative melting temperatures (Tm) for RNA structures in over 4000 transcripts. Specific signatures of RNA Tm demarcated the polarity of mRNA open reading frames and highlighted numerous candidate regulatory RNA motifs in 3' untranslated regions. RNA Tm distinguished noncoding versus coding RNAs and identified mRNAs with distinct cellular functions. We identified thousands of putative RNA thermometers, and their presence is predictive of the pattern of RNA decay in vivo during heat shock. The exosome complex recognizes unpaired bases during heat shock to degrade these RNAs, coupling intrinsic structural stabilities to gene regulation. Thus, genome-wide structural dynamics of RNA can parse functional elements of the transcriptome and reveal diverse biological insights.

  11. Genome-wide transcriptional reprogramming under drought stress

    KAUST Repository

    Chen, Hao

    2012-01-01

    Soil water deficit is one of the major factors limiting plant productivity. Plants cope with this adverse environmental condition by coordinating the up- or downregulation of an array of stress responsive genes. Reprogramming the expression of these genes leads to rebalanced development and growth that are in concert with the reduced water availability and that ultimately confer enhanced stress tolerance. Currently, several techniques have been employed to monitor genome-wide transcriptional reprogramming under drought stress. The results from these high throughput studies indicate that drought stress-induced transcriptional reprogramming is dynamic, has temporal and spatial specificity, and is coupled with the circadian clock and phytohormone signaling pathways. © 2012 Springer-Verlag Berlin Heidelberg. All rights are reserved.

  12. Genome-Wide Association Study of Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Naomi Ogawa

    2010-01-01

    Full Text Available Coronary artery disease (CAD is a multifactorial disease with environmental and genetic determinants. The genetic determinants of CAD have previously been explored by the candidate gene approach. Recently, the data from the International HapMap Project and the development of dense genotyping chips have enabled us to perform genome-wide association studies (GWAS on a large number of subjects without bias towards any particular candidate genes. In 2007, three chip-based GWAS simultaneously revealed the significant association between common variants on chromosome 9p21 and CAD. This association was replicated among other ethnic groups and also in a meta-analysis. Further investigations have detected several other candidate loci associated with CAD. The chip-based GWAS approach has identified novel and unbiased genetic determinants of CAD and these insights provide the important direction to better understand the pathogenesis of CAD and to develop new and improved preventive measures and treatments for CAD.

  13. A comparison of multivariate genome-wide association methods

    DEFF Research Database (Denmark)

    Galesloot, Tessel E; Van Steen, Kristel; Kiemeney, Lambertus A L M

    2014-01-01

    Joint association analysis of multiple traits in a genome-wide association study (GWAS), i.e. a multivariate GWAS, offers several advantages over analyzing each trait in a separate GWAS. In this study we directly compared a number of multivariate GWAS methods using simulated data. We focused on six...... methods that are implemented in the software packages PLINK, SNPTEST, MultiPhen, BIMBAM, PCHAT and TATES, and also compared them to standard univariate GWAS, analysis of the first principal component of the traits, and meta-analysis of univariate results. We simulated data (N = 1000) for three...... correlation. We compared the power of the methods using empirically fixed significance thresholds (α = 0.05). Our results showed that the multivariate methods implemented in PLINK, SNPTEST, MultiPhen and BIMBAM performed best for the majority of the tested scenarios, with a notable increase in power...

  14. Combing genomic DNA for structural and functional studies.

    Science.gov (United States)

    Schurra, Catherine; Bensimon, Aaron

    2009-01-01

    Molecular combing is a process whereby single DNA molecules bind by their extremities to a silanised surface and are then uniformly stretched and aligned by a receding air/water interface (1). This method, with a high resolution ranging from a few kilobases to megabases, has many applications in the field of molecular cytogenetics, allowing structural and functional analysis at the genome level. Here we describe protocols for preparing DNA for combing and for the use of fluorescent hybridisation (FH) applied to combed DNA to conduct physical mapping or genomic structural analysis. We also present the methodology for visualising and studying DNA replication using combed DNA.

  15. Genome-Wide Association Study of Meiotic Recombination Phenotypes

    Science.gov (United States)

    Begum, Ferdouse; Chowdhury, Reshmi; Cheung, Vivian G.; Sherman, Stephanie L.; Feingold, Eleanor

    2016-01-01

    Meiotic recombination is an essential step in gametogenesis, and is one that also generates genetic diversity. Genome-wide association studies (GWAS) and molecular studies have identified genes that influence of human meiotic recombination. RNF212 is associated with total or average number of recombination events, and PRDM9 is associated with the locations of hotspots, or sequences where crossing over appears to cluster. In addition, a common inversion on chromosome 17 is strongly associated with recombination. Other genes have been identified by GWAS, but those results have not been replicated. In this study, using new datasets, we characterized additional recombination phenotypes to uncover novel candidates and further dissect the role of already known loci. We used three datasets totaling 1562 two-generation families, including 3108 parents with 4304 children. We estimated five different recombination phenotypes including two novel phenotypes (average recombination counts within recombination hotspots and outside of hotspots) using dense SNP array genotype data. We then performed gender-specific and combined-sex genome-wide association studies (GWAS) meta-analyses. We replicated associations for several previously reported recombination genes, including RNF212 and PRDM9. By looking specifically at recombination events outside of hotspots, we showed for the first time that PRDM9 has different effects in males and females. We identified several new candidate loci, particularly for recombination events outside of hotspots. These include regions near the genes SPINK6, EVC2, ARHGAP25, and DLGAP2. This study expands our understanding of human meiotic recombination by characterizing additional features that vary across individuals, and identifying regulatory variants influencing the numbers and locations of recombination events. PMID:27733454

  16. A genome-wide association study of anorexia nervosa

    Science.gov (United States)

    Boraska, Vesna; Franklin, Christopher S; Floyd, James AB; Thornton, Laura M; Huckins, Laura M; Southam, Lorraine; Rayner, N William; Tachmazidou, Ioanna; Klump, Kelly L; Treasure, Janet; Lewis, Cathryn M; Schmidt, Ulrike; Tozzi, Federica; Kiezebrink, Kirsty; Hebebrand, Johannes; Gorwood, Philip; Adan, Roger AH; Kas, Martien JH; Favaro, Angela; Santonastaso, Paolo; Fernández-Aranda, Fernando; Gratacos, Monica; Rybakowski, Filip; Dmitrzak-Weglarz, Monika; Kaprio, Jaakko; Keski-Rahkonen, Anna; Raevuori, Anu; Van Furth, Eric F; Landt, Margarita CT Slof-Op t; Hudson, James I; Reichborn-Kjennerud, Ted; Knudsen, Gun Peggy S; Monteleone, Palmiero; Kaplan, Allan S; Karwautz, Andreas; Hakonarson, Hakon; Berrettini, Wade H; Guo, Yiran; Li, Dong; Schork, Nicholas J.; Komaki, Gen; Ando, Tetsuya; Inoko, Hidetoshi; Esko, Tõnu; Fischer, Krista; Männik, Katrin; Metspalu, Andres; Baker, Jessica H; Cone, Roger D; Dackor, Jennifer; DeSocio, Janiece E; Hilliard, Christopher E; O'Toole, Julie K; Pantel, Jacques; Szatkiewicz, Jin P; Taico, Chrysecolla; Zerwas, Stephanie; Trace, Sara E; Davis, Oliver SP; Helder, Sietske; Bühren, Katharina; Burghardt, Roland; de Zwaan, Martina; Egberts, Karin; Ehrlich, Stefan; Herpertz-Dahlmann, Beate; Herzog, Wolfgang; Imgart, Hartmut; Scherag, André; Scherag, Susann; Zipfel, Stephan; Boni, Claudette; Ramoz, Nicolas; Versini, Audrey; Brandys, Marek K; Danner, Unna N; de Kovel, Carolien; Hendriks, Judith; Koeleman, Bobby PC; Ophoff, Roel A; Strengman, Eric; van Elburg, Annemarie A; Bruson, Alice; Clementi, Maurizio; Degortes, Daniela; Forzan, Monica; Tenconi, Elena; Docampo, Elisa; Escaramís, Geòrgia; Jiménez-Murcia, Susana; Lissowska, Jolanta; Rajewski, Andrzej; Szeszenia-Dabrowska, Neonila; Slopien, Agnieszka; Hauser, Joanna; Karhunen, Leila; Meulenbelt, Ingrid; Slagboom, P Eline; Tortorella, Alfonso; Maj, Mario; Dedoussis, George; Dikeos, Dimitris; Gonidakis, Fragiskos; Tziouvas, Konstantinos; Tsitsika, Artemis; Papezova, Hana; Slachtova, Lenka; Martaskova, Debora; Kennedy, James L.; Levitan, Robert D.; Yilmaz, Zeynep; Huemer, Julia; Koubek, Doris; Merl, Elisabeth; Wagner, Gudrun; Lichtenstein, Paul; Breen, Gerome; Cohen-Woods, Sarah; Farmer, Anne; McGuffin, Peter; Cichon, Sven; Giegling, Ina; Herms, Stefan; Rujescu, Dan; Schreiber, Stefan; Wichmann, H-Erich; Dina, Christian; Sladek, Rob; Gambaro, Giovanni; Soranzo, Nicole; Julia, Antonio; Marsal, Sara; Rabionet, Raquel; Gaborieau, Valerie; Dick, Danielle M; Palotie, Aarno; Ripatti, Samuli; Widén, Elisabeth; Andreassen, Ole A; Espeseth, Thomas; Lundervold, Astri; Reinvang, Ivar; Steen, Vidar M; Le Hellard, Stephanie; Mattingsdal, Morten; Ntalla, Ioanna; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Navratilova, Marie; Gallinger, Steven; Pinto, Dalila; Scherer, Stephen; Aschauer, Harald; Carlberg, Laura; Schosser, Alexandra; Alfredsson, Lars; Ding, Bo; Klareskog, Lars; Padyukov, Leonid; Finan, Chris; Kalsi, Gursharan; Roberts, Marion; Logan, Darren W; Peltonen, Leena; Ritchie, Graham RS; Barrett, Jeffrey C; Estivill, Xavier; Hinney, Anke; Sullivan, Patrick F; Collier, David A; Zeggini, Eleftheria; Bulik, Cynthia M

    2015-01-01

    Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2,907 cases with AN from 14 countries (15 sites) and 14,860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery datasets. Seventy-six (72 independent) SNPs were taken forward for in silico (two datasets) or de novo (13 datasets) replication genotyping in 2,677 independent AN cases and 8,629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication datasets comprised 5,551 AN cases and 21,080 controls. AN subtype analyses (1,606 AN restricting; 1,445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01×10-7) in SOX2OT and rs17030795 (P=5.84×10-6) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76×10-6) between CUL3 and FAM124B and rs1886797 (P=8.05×10-6) near SPATA13. Comparing discovery to replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4×10-6), strongly suggesting that true findings exist but that our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field. PMID:24514567

  17. A genome-wide association study of anorexia nervosa.

    Science.gov (United States)

    Boraska, V; Franklin, C S; Floyd, J A B; Thornton, L M; Huckins, L M; Southam, L; Rayner, N W; Tachmazidou, I; Klump, K L; Treasure, J; Lewis, C M; Schmidt, U; Tozzi, F; Kiezebrink, K; Hebebrand, J; Gorwood, P; Adan, R A H; Kas, M J H; Favaro, A; Santonastaso, P; Fernández-Aranda, F; Gratacos, M; Rybakowski, F; Dmitrzak-Weglarz, M; Kaprio, J; Keski-Rahkonen, A; Raevuori, A; Van Furth, E F; Slof-Op 't Landt, M C T; Hudson, J I; Reichborn-Kjennerud, T; Knudsen, G P S; Monteleone, P; Kaplan, A S; Karwautz, A; Hakonarson, H; Berrettini, W H; Guo, Y; Li, D; Schork, N J; Komaki, G; Ando, T; Inoko, H; Esko, T; Fischer, K; Männik, K; Metspalu, A; Baker, J H; Cone, R D; Dackor, J; DeSocio, J E; Hilliard, C E; O'Toole, J K; Pantel, J; Szatkiewicz, J P; Taico, C; Zerwas, S; Trace, S E; Davis, O S P; Helder, S; Bühren, K; Burghardt, R; de Zwaan, M; Egberts, K; Ehrlich, S; Herpertz-Dahlmann, B; Herzog, W; Imgart, H; Scherag, A; Scherag, S; Zipfel, S; Boni, C; Ramoz, N; Versini, A; Brandys, M K; Danner, U N; de Kovel, C; Hendriks, J; Koeleman, B P C; Ophoff, R A; Strengman, E; van Elburg, A A; Bruson, A; Clementi, M; Degortes, D; Forzan, M; Tenconi, E; Docampo, E; Escaramís, G; Jiménez-Murcia, S; Lissowska, J; Rajewski, A; Szeszenia-Dabrowska, N; Slopien, A; Hauser, J; Karhunen, L; Meulenbelt, I; Slagboom, P E; Tortorella, A; Maj, M; Dedoussis, G; Dikeos, D; Gonidakis, F; Tziouvas, K; Tsitsika, A; Papezova, H; Slachtova, L; Martaskova, D; Kennedy, J L; Levitan, R D; Yilmaz, Z; Huemer, J; Koubek, D; Merl, E; Wagner, G; Lichtenstein, P; Breen, G; Cohen-Woods, S; Farmer, A; McGuffin, P; Cichon, S; Giegling, I; Herms, S; Rujescu, D; Schreiber, S; Wichmann, H-E; Dina, C; Sladek, R; Gambaro, G; Soranzo, N; Julia, A; Marsal, S; Rabionet, R; Gaborieau, V; Dick, D M; Palotie, A; Ripatti, S; Widén, E; Andreassen, O A; Espeseth, T; Lundervold, A; Reinvang, I; Steen, V M; Le Hellard, S; Mattingsdal, M; Ntalla, I; Bencko, V; Foretova, L; Janout, V; Navratilova, M; Gallinger, S; Pinto, D; Scherer, S W; Aschauer, H; Carlberg, L; Schosser, A; Alfredsson, L; Ding, B; Klareskog, L; Padyukov, L; Courtet, P; Guillaume, S; Jaussent, I; Finan, C; Kalsi, G; Roberts, M; Logan, D W; Peltonen, L; Ritchie, G R S; Barrett, J C; Estivill, X; Hinney, A; Sullivan, P F; Collier, D A; Zeggini, E; Bulik, C M

    2014-10-01

    Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery data sets. Seventy-six (72 independent) single nucleotide polymorphisms were taken forward for in silico (two data sets) or de novo (13 data sets) replication genotyping in 2677 independent AN cases and 8629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication data sets comprised 5551 AN cases and 21 080 controls. AN subtype analyses (1606 AN restricting; 1445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01 × 10(-7)) in SOX2OT and rs17030795 (P=5.84 × 10(-6)) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76 × 10(-)(6)) between CUL3 and FAM124B and rs1886797 (P=8.05 × 10(-)(6)) near SPATA13. Comparing discovery with replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4 × 10(-6)), strongly suggesting that true findings exist but our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.

  18. Genome-wide expression profiling of complex regional pain syndrome.

    Directory of Open Access Journals (Sweden)

    Eun-Heui Jin

    Full Text Available Complex regional pain syndrome (CRPS is a chronic, progressive, and devastating pain syndrome characterized by spontaneous pain, hyperalgesia, allodynia, altered skin temperature, and motor dysfunction. Although previous gene expression profiling studies have been conducted in animal pain models, there genome-wide expression profiling in the whole blood of CRPS patients has not been reported yet. Here, we successfully identified certain pain-related genes through genome-wide expression profiling in the blood from CRPS patients. We found that 80 genes were differentially expressed between 4 CRPS patients (2 CRPS I and 2 CRPS II and 5 controls (cut-off value: 1.5-fold change and p<0.05. Most of those genes were associated with signal transduction, developmental processes, cell structure and motility, and immunity and defense. The expression levels of major histocompatibility complex class I A subtype (HLA-A29.1, matrix metalloproteinase 9 (MMP9, alanine aminopeptidase N (ANPEP, l-histidine decarboxylase (HDC, granulocyte colony-stimulating factor 3 receptor (G-CSF3R, and signal transducer and activator of transcription 3 (STAT3 genes selected from the microarray were confirmed in 24 CRPS patients and 18 controls by quantitative reverse transcription-polymerase chain reaction (qRT-PCR. We focused on the MMP9 gene that, by qRT-PCR, showed a statistically significant difference in expression in CRPS patients compared to controls with the highest relative fold change (4.0±1.23 times and p = 1.4×10(-4. The up-regulation of MMP9 gene in the blood may be related to the pain progression in CRPS patients. Our findings, which offer a valuable contribution to the understanding of the differential gene expression in CRPS may help in the understanding of the pathophysiology of CRPS pain progression.

  19. Nonconsensus Protein Binding to Repetitive DNA Sequence Elements Significantly Affects Eukaryotic Genomes.

    Science.gov (United States)

    Afek, Ariel; Cohen, Hila; Barber-Zucker, Shiran; Gordân, Raluca; Lukatsky, David B

    2015-08-01

    Recent genome-wide experiments in different eukaryotic genomes provide an unprecedented view of transcription factor (TF) binding locations and of nucleosome occupancy. These experiments revealed that a large fraction of TF binding events occur in regions where only a small number of specific TF binding sites (TFBSs) have been detected. Furthermore, in vitro protein-DNA binding measurements performed for hundreds of TFs indicate that TFs are bound with wide range of affinities to different DNA sequences that lack known consensus motifs. These observations have thus challenged the classical picture of specific protein-DNA binding and strongly suggest the existence of additional recognition mechanisms that affect protein-DNA binding preferences. We have previously demonstrated that repetitive DNA sequence elements characterized by certain symmetries statistically affect protein-DNA binding preferences. We call this binding mechanism nonconsensus protein-DNA binding in order to emphasize the point that specific consensus TFBSs do not contribute to this effect. In this paper, using the simple statistical mechanics model developed previously, we calculate the nonconsensus protein-DNA binding free energy for the entire C. elegans and D. melanogaster genomes. Using the available chromatin immunoprecipitation followed by sequencing (ChIP-seq) results on TF-DNA binding preferences for ~100 TFs, we show that DNA sequences characterized by low predicted free energy of nonconsensus binding have statistically higher experimental TF occupancy and lower nucleosome occupancy than sequences characterized by high free energy of nonconsensus binding. This is in agreement with our previous analysis performed for the yeast genome. We suggest therefore that nonconsensus protein-DNA binding assists the formation of nucleosome-free regions, as TFs outcompete nucleosomes at genomic locations with enhanced nonconsensus binding. In addition, here we perform a new, large-scale analysis using

  20. Nonconsensus Protein Binding to Repetitive DNA Sequence Elements Significantly Affects Eukaryotic Genomes.

    Directory of Open Access Journals (Sweden)

    Ariel Afek

    2015-08-01

    Full Text Available Recent genome-wide experiments in different eukaryotic genomes provide an unprecedented view of transcription factor (TF binding locations and of nucleosome occupancy. These experiments revealed that a large fraction of TF binding events occur in regions where only a small number of specific TF binding sites (TFBSs have been detected. Furthermore, in vitro protein-DNA binding measurements performed for hundreds of TFs indicate that TFs are bound with wide range of affinities to different DNA sequences that lack known consensus motifs. These observations have thus challenged the classical picture of specific protein-DNA binding and strongly suggest the existence of additional recognition mechanisms that affect protein-DNA binding preferences. We have previously demonstrated that repetitive DNA sequence elements characterized by certain symmetries statistically affect protein-DNA binding preferences. We call this binding mechanism nonconsensus protein-DNA binding in order to emphasize the point that specific consensus TFBSs do not contribute to this effect. In this paper, using the simple statistical mechanics model developed previously, we calculate the nonconsensus protein-DNA binding free energy for the entire C. elegans and D. melanogaster genomes. Using the available chromatin immunoprecipitation followed by sequencing (ChIP-seq results on TF-DNA binding preferences for ~100 TFs, we show that DNA sequences characterized by low predicted free energy of nonconsensus binding have statistically higher experimental TF occupancy and lower nucleosome occupancy than sequences characterized by high free energy of nonconsensus binding. This is in agreement with our previous analysis performed for the yeast genome. We suggest therefore that nonconsensus protein-DNA binding assists the formation of nucleosome-free regions, as TFs outcompete nucleosomes at genomic locations with enhanced nonconsensus binding. In addition, here we perform a new, large

  1. Genome wide nucleosome mapping for HSV-1 shows nucleosomes are deposited at preferred positions during lytic infection.

    Science.gov (United States)

    Oh, Jaewook; Sanders, Iryna F; Chen, Eric Z; Li, Hongzhe; Tobias, John W; Isett, R Benjamin; Penubarthi, Sindura; Sun, Hao; Baldwin, Don A; Fraser, Nigel W

    2015-01-01

    HSV is a large double stranded DNA virus, capable of causing a variety of diseases from the common cold sore to devastating encephalitis. Although DNA within the HSV virion does not contain any histone protein, within 1 h of infecting a cell and entering its nucleus the viral genome acquires some histone protein (nucleosomes). During lytic infection, partial micrococcal nuclease (MNase) digestion does not give the classic ladder band pattern, seen on digestion of cell DNA or latent viral DNA. However, complete digestion does give a mono-nucleosome band, strongly suggesting that there are some nucleosomes present on the viral genome during the lytic infection, but that they are not evenly positioned, with a 200 bp repeat pattern, like cell DNA. Where then are the nucleosomes positioned? Here we perform HSV-1 genome wide nucleosome mapping, at a time when viral replication is in full swing (6 hr PI), using a microarray consisting of 50mer oligonucleotides, covering the whole viral genome (152 kb). Arrays were probed with MNase-protected fragments of DNA from infected cells. Cells were not treated with crosslinking agents, thus we are only mapping tightly bound nucleosomes. The data show that nucleosome deposition is not random. The distribution of signal on the arrays suggest that nucleosomes are located at preferred positions on the genome, and that there are some positions that are not occupied (nucleosome free regions -NFR or Nucleosome depleted regions -NDR), or occupied at frequency below our limit of detection in the population of genomes. Occupancy of only a fraction of the possible sites may explain the lack of a typical MNase partial digestion band ladder pattern for HSV DNA during lytic infection. On average, DNA encoding Immediate Early (IE), Early (E) and Late (L) genes appear to have a similar density of nucleosomes.

  2. Assaying genome-wide recombination and centromere functions with Arabidopsis tetrads

    Science.gov (United States)

    Copenhaver, Gregory P.; Browne, William E.; Preuss, Daphne

    1998-01-01

    During meiosis, crossover events generate new allelic combinations, yet the abundance of these genetic exchanges in individual cells has not been measured previously on a genomic level. To perform a genome-wide analysis of recombination, we monitored the assortment of genetic markers in meiotic tetrads from Arabidopsis. By determining the number and distribution of crossovers in individual meiotic cells, we demonstrated (i) surprisingly precise regulation of crossover number in each meiosis, (ii) considerably reduced recombination along chromosomes carrying ribosomal DNA arrays, and (iii) an inversely proportional relationship between recombination frequencies and chromosome size. This use of tetrad analysis also achieved precise mapping of all five Arabidopsis centromeres, localizing centromere functions in the intact chromosomes of a higher eukaryote. PMID:9419361

  3. Genome-wide differential gene expression in children exposed to air pollution in the Czech Republic

    DEFF Research Database (Denmark)

    van Leeuwen, D M; van Herwijnen, M H M; Pedersen, Marie

    2006-01-01

    The Teplice area in the Czech Republic is a mining district where elevated levels of air pollution including airborne carcinogens, have been demonstrated, especially during winter time. This environmental exposure can impact human health; in particular children may be more vulnerable. To study....... This suggests an effect of air pollution on the primary structural unit of the condensed DNA. In addition, several other pathways were modulated. Based on the results of this study, we suggest that transcriptomic analysis represents a promising biomarker for environmental carcinogenesis....... the impact of air pollution in children at the transcriptional level, peripheral blood cells were subjected to whole genome response analysis, in order to identify significantly modulated biological pathways and processes as a result of exposure. Using genome-wide oligonucleotide microarrays, we investigated...

  4. Genome-wide analyses for dissecting gene regulatory networks in the shoot apical meristem.

    Science.gov (United States)

    Bustamante, Mariana; Matus, José Tomás; Riechmann, José Luis

    2016-03-01

    Shoot apical meristem activity is controlled by complex regulatory networks in which components such as transcription factors, miRNAs, small peptides, hormones, enzymes and epigenetic marks all participate. Many key genes that determine the inherent characteristics of the shoot apical meristem have been identified through genetic approaches. Recent advances in genome-wide studies generating extensive transcriptomic and DNA-binding datasets have increased our understanding of the interactions within the regulatory networks that control the activity of the meristem, identifying new regulators and uncovering connections between previously unlinked network components. In this review, we focus on recent studies that illustrate the contribution of whole genome analyses to understand meristem function. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Multi-platform genome-wide analysis of melanoma progression to brain metastasis

    Directory of Open Access Journals (Sweden)

    Diego M. Marzese

    2014-12-01

    Full Text Available Melanoma has a high tendency to metastasize to brain tissue. The understanding about the molecular alterations of early-stage melanoma progression to brain metastasis (MBM is very limited. Identifying MBM-specific genomic and epigenomic alterations is a key initial step in understanding its aggressive nature and identifying specific novel druggable targets. Here, we describe a multi-platform dataset generated with different stages of melanoma progression to MBM. This data includes genome-wide DNA methylation (Illumina HM450K BeadChip, gene expression (Affymetrix HuEx 1.0 ST array, single nucleotide polymorphisms (SNPs and copy number variation (CNV; Affymetrix SNP 6.0 array analyses of melanocyte cells (MNCs, primary melanoma tumors (PRMs, lymph node metastases (LNMs and MBMs. The analysis of this data has been reported in our recently published study (Marzese et al., 2014.

  6. Genome-Wide Association Study of Serum Selenium Concentrations

    Directory of Open Access Journals (Sweden)

    Ulrike Peters

    2013-05-01

    Full Text Available Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated this hypothesis. Therefore, we conducted a two-stage genome-wide association study to identify genetic variants associated with serum selenium concentrations in 1203 European descents from two cohorts: the Prostate, Lung, Colorectal, and Ovarian (PLCO Cancer Screening and the Women’s Health Initiative (WHI. We tested association between 2,474,333 single nucleotide polymorphisms (SNPs and serum selenium concentrations using linear regression models. In the first stage (PLCO 41 SNPs clustered in 15 regions had p < 1 × 10−5. None of these 41 SNPs reached the significant threshold (p = 0.05/15 regions = 0.003 in the second stage (WHI. Three SNPs had p < 0.05 in the second stage (rs1395479 and rs1506807 in 4q34.3/AGA-NEIL3; and rs891684 in 17q24.3/SLC39A11 and had p between 2.62 × 10−7 and 4.04 × 10−7 in the combined analysis (PLCO + WHI. Additional studies are needed to replicate these findings. Identification of genetic variation that impacts selenium concentrations may contribute to a better understanding of which genes regulate circulating selenium concentrations.

  7. Genomic Research and Wide Data Sharing: Views of Prospective Participants

    Science.gov (United States)

    Trinidad, Susan Brown; Fullerton, Stephanie M.; Bares, Julie M.; Jarvik, Gail P.; Larson, Eric B.; Burke, Wylie

    2011-01-01

    Purpose Sharing study data within the research community generates tension between two important goods: promoting scientific goals and protecting the privacy interests of study participants. The present study was designed to explore the perceptions, beliefs, and attitudes of research participants and possible future participants regarding genome-wide association studies (GWAS) and repository-based research. Methods Focus group sessions with (1) current research participants, (2) surrogate decision-makers, and (3) three age-defined cohorts (18–34 years, 35–50, >50). Results Participants expressed a variety of opinions about the acceptability of wide sharing of genetic and phenotypic information for research purposes through large, publicly accessible data repositories. Most believed that making de-identified study data available to the research community is a social good that should be pursued. Privacy and confidentiality concerns were common, though they would not necessarily preclude participation. Many participants voiced reservations about sharing data with for-profit organizations. Conclusions Trust is central in participants’ views regarding GWAS data sharing. Further research is needed to develop governance models that enact the values of stewardship. PMID:20535021

  8. Genome-wide association study of circulating retinol levels.

    Science.gov (United States)

    Mondul, Alison M; Yu, Kai; Wheeler, William; Zhang, Hong; Weinstein, Stephanie J; Major, Jacqueline M; Cornelis, Marilyn C; Männistö, Satu; Hazra, Aditi; Hsing, Ann W; Jacobs, Kevin B; Eliassen, Heather; Tanaka, Toshiko; Reding, Douglas J; Hendrickson, Sara; Ferrucci, Luigi; Virtamo, Jarmo; Hunter, David J; Chanock, Stephen J; Kraft, Peter; Albanes, Demetrius

    2011-12-01

    Retinol is one of the most biologically active forms of vitamin A and is hypothesized to influence a wide range of human diseases including asthma, cardiovascular disease, infectious diseases and cancer. We conducted a genome-wide association study of 5006 Caucasian individuals drawn from two cohorts of men: the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study and the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. We identified two independent single-nucleotide polymorphisms associated with circulating retinol levels, which are located near the transthyretin (TTR) and retinol binding protein 4 (RBP4) genes which encode major carrier proteins of retinol: rs1667255 (P =2.30× 10(-17)) and rs10882272 (P =6.04× 10(-12)). We replicated the association with rs10882272 in RBP4 in independent samples from the Nurses' Health Study and the Invecchiare in Chianti Study (InCHIANTI) that included 3792 women and 504 men (P =9.49× 10(-5)), but found no association for retinol with rs1667255 in TTR among women, thus suggesting evidence for gender dimorphism (P-interaction=1.31× 10(-5)). Discovery of common genetic variants associated with serum retinol levels may provide further insight into the contribution of retinol and other vitamin A compounds to the development of cancer and other complex diseases.

  9. Potential assessment of genome-wide association study and genomic selection in Japanese pear Pyrus pyrifolia.

    Science.gov (United States)

    Iwata, Hiroyoshi; Hayashi, Takeshi; Terakami, Shingo; Takada, Norio; Sawamura, Yutaka; Yamamoto, Toshiya

    2013-03-01

    Although the potential of marker-assisted selection (MAS) in fruit tree breeding has been reported, bi-parental QTL mapping before MAS has hindered the introduction of MAS to fruit tree breeding programs. Genome-wide association studies (GWAS) are an alternative to bi-parental QTL mapping in long-lived perennials. Selection based on genomic predictions of breeding values (genomic selection: GS) is another alternative for MAS. This study examined the potential of GWAS and GS in pear breeding with 76 Japanese pear cultivars to detect significant associations of 162 markers with nine agronomic traits. We applied multilocus Bayesian models accounting for ordinal categorical phenotypes for GWAS and GS model training. Significant associations were detected at harvest time, black spot resistance and the number of spurs and two of the associations were closely linked to known loci. Genome-wide predictions for GS were accurate at the highest level (0.75) in harvest time, at medium levels (0.38-0.61) in resistance to black spot, firmness of flesh, fruit shape in longitudinal section, fruit size, acid content and number of spurs and at low levels (pear.

  10. Methylome-wide Sequencing Detects DNA Hypermethylation Distinguishing Indolent from Aggressive Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Bhasin

    2015-12-01

    Full Text Available A critical need in understanding the biology of prostate cancer is characterizing the molecular differences between indolent and aggressive cases. Because DNA methylation can capture the regulatory state of tumors, we analyzed differential methylation patterns genome-wide among benign prostatic tissue and low-grade and high-grade prostate cancer and found extensive, focal hypermethylation regions unique to high-grade disease. These hypermethylation regions occurred not only in the promoters of genes but also in gene bodies and at intergenic regions that are enriched for DNA-protein binding sites. Integration with existing RNA-sequencing (RNA-seq and survival data revealed regions where DNA methylation correlates with reduced gene expression associated with poor outcome. Regions specific to aggressive disease are proximal to genes with distinct functions from regions shared by indolent and aggressive disease. Our compendium of methylation changes reveals crucial molecular distinctions between indolent and aggressive prostate cancer.

  11. Semantically enabling a genome-wide association study database

    Directory of Open Access Journals (Sweden)

    Beck Tim

    2012-12-01

    Full Text Available Abstract Background The amount of data generated from genome-wide association studies (GWAS has grown rapidly, but considerations for GWAS phenotype data reuse and interchange have not kept pace. This impacts on the work of GWAS Central – a free and open access resource for the advanced querying and comparison of summary-level genetic association data. The benefits of employing ontologies for standardising and structuring data are widely accepted. The complex spectrum of observed human phenotypes (and traits, and the requirement for cross-species phenotype comparisons, calls for reflection on the most appropriate solution for the organisation of human phenotype data. The Semantic Web provides standards for the possibility of further integration of GWAS data and the ability to contribute to the web of Linked Data. Results A pragmatic consideration when applying phenotype ontologies to GWAS data is the ability to retrieve all data, at the most granular level possible, from querying a single ontology graph. We found the Medical Subject Headings (MeSH terminology suitable for describing all traits (diseases and medical signs and symptoms at various levels of granularity and the Human Phenotype Ontology (HPO most suitable for describing phenotypic abnormalities (medical signs and symptoms at the most granular level. Diseases within MeSH are mapped to HPO to infer the phenotypic abnormalities associated with diseases. Building on the rich semantic phenotype annotation layer, we are able to make cross-species phenotype comparisons and publish a core subset of GWAS data as RDF nanopublications. Conclusions We present a methodology for applying phenotype annotations to a comprehensive genome-wide association dataset and for ensuring compatibility with the Semantic Web. The annotations are used to assist with cross-species genotype and phenotype comparisons. However, further processing and deconstructions of terms may be required to facilitate automatic

  12. Gene tree discordance of wild and cultivated Asian rice deciphered by genome-wide sequence comparison.

    Science.gov (United States)

    Yang, Ching-chia; Sakai, Hiroaki; Numa, Hisataka; Itoh, Takeshi

    2011-05-15

    Although a large number of genes are expected to correctly solve a phylogenetic relationship, inconsistent gene tree topologies have been observed. This conflicting evidence in gene tree topologies, known as gene tree discordance, becomes increasingly important as advanced sequencing technologies produce an enormous amount of sequence information for phylogenomic studies among closely related species. Here, we aim to characterize the gene tree discordance of the Asian cultivated rice Oryza sativa and its progenitor, O. rufipogon, which will be an ideal case study of gene tree discordance. Using genome and cDNA sequences of O. sativa and O. rufipogon, we have conducted the first in-depth analyses of gene tree discordance in Asian rice. Our comparison of full-length cDNA sequences of O. rufipogon with the genome sequences of the japonica and indica cultivars of O. sativa revealed that 60% of the gene trees showed a topology consistent with the expected one, whereas the remaining genes supported significantly different topologies. Moreover, the proportions of the topologies deviated significantly from expectation, suggesting at least one hybridization event between the two subgroups of O. sativa, japonica and indica. In fact, a genome-wide alignment between japonica and indica indicated that significant portions of the indica genome are derived from japonica. In addition, literature concerning the pedigree of the indica cultivar strongly supported the hybridization hypothesis. Our molecular evolutionary analyses deciphered complicated evolutionary processes in closely related species. They also demonstrated the importance of gene tree discordance in the era of high-speed DNA sequencing.

  13. Genome-wide profiling of p63 DNA-binding sites identifies an element that regulates gene expression during limb development in the 7q21 SHFM1 locus.

    NARCIS (Netherlands)

    Kouwenhoven, E.N.; Heeringen, S.J. van; Tena, J.J.; Oti, M.O.; Dutilh, B.E.; Alonso, M.E.; Calle-Mustienes, E. de la; Smeenk, L.; Rinne, T.K.; Parsaulian, L.; Bolat, E.; Jurgelenaite, R.; Huynen, M.A.; Hoischen, A.; Veltman, J.A.; Brunner, H.G.; Roscioli, T.; Oates, E.; Wilson, M.; Manzanares, M.; Gomez-Skarmeta, J.L.; Stunnenberg, H.G.; Lohrum, M.A.E.; Bokhoven, J.H.L.M. van; Zhou, H.

    2010-01-01

    Heterozygous mutations in p63 are associated with split hand/foot malformations (SHFM), orofacial clefting, and ectodermal abnormalities. Elucidation of the p63 gene network that includes target genes and regulatory elements may reveal new genes for other malformation disorders. We performed genome-

  14. Greater than X kb: a quantitative assessment of preservation conditions on genomic DNA quality, and a proposed standard for genome-quality DNA.

    Science.gov (United States)

    Mulcahy, Daniel G; Macdonald, Kenneth S; Brady, Seán G; Meyer, Christopher; Barker, Katharine B; Coddington, Jonathan

    2016-01-01

    Advances in biodiversity genomic sequencing will increasingly depend on the availability of DNA samples-and their quantifiable metadata-preserved in large institutional biorepositories that are discoverable to the scientific community. Improvements in sequencing technology constantly provide longer reads, such that longer fragment length, higher molecular weight, and overall "genome-quality" DNA (gDNA) will be desirable. Ideally, biorepositories should publish numerical scale measurements of DNA quality useful to the user community. However, the most widely used technique to evaluate DNA quality, the classic agarose gel, has yet to be quantified. Here we propose a simple and economical method using open source image analysis software to make gDNA gel images quantifiable, and propose percentage of gDNA "greater than X kb" as a standard of comparison, where X is a band from any widely used DNA ladder with desirably large band sizes. We employ two metadata standards ("DNA Threshold" and "Percent above Threshold") introduced as part of the Global Genome Biodiversity Network (GGBN) Darwin Core extension. We illustrate the method using the traditionally used HindIII ladder and the 9,416 base-pair (bp) band as a standard. We also present data, for two taxa, a vertebrate (fish) and an invertebrate (crab), on how gDNA quality varies with seven tissue preservation methods, time since death, preservation method (i.e. buffers vs. cold temperatures), and storage temperature of various buffers over time. Our results suggest that putting tissue into a buffer prior to freezing may be better than directly into ultra-cold conditions.

  15. Greater than X kb: a quantitative assessment of preservation conditions on genomic DNA quality, and a proposed standard for genome-quality DNA

    Science.gov (United States)

    Macdonald, Kenneth S.; Meyer, Christopher; Barker, Katharine B.; Coddington, Jonathan

    2016-01-01

    Advances in biodiversity genomic sequencing will increasingly depend on the availability of DNA samples—and their quantifiable metadata—preserved in large institutional biorepositories that are discoverable to the scientific community. Improvements in sequencing technology constantly provide longer reads, such that longer fragment length, higher molecular weight, and overall “genome-quality” DNA (gDNA) will be desirable. Ideally, biorepositories should publish numerical scale measurements of DNA quality useful to the user community. However, the most widely used technique to evaluate DNA quality, the classic agarose gel, has yet to be quantified. Here we propose a simple and economical method using open source image analysis software to make gDNA gel images quantifiable, and propose percentage of gDNA “greater than X kb” as a standard of comparison, where X is a band from any widely used DNA ladder with desirably large band sizes. We employ two metadata standards (“DNA Threshold” and “Percent above Threshold”) introduced as part of the Global Genome Biodiversity Network (GGBN) Darwin Core extension. We illustrate the method using the traditionally used HindIII ladder and the 9,416 base-pair (bp) band as a standard. We also present data, for two taxa, a vertebrate (fish) and an invertebrate (crab), on how gDNA quality varies with seven tissue preservation methods, time since death, preservation method (i.e. buffers vs. cold temperatures), and storage temperature of various buffers over time. Our results suggest that putting tissue into a buffer prior to freezing may be better than directly into ultra-cold conditions. PMID:27761327

  16. ATM signaling and genomic stability in response to DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Lavin, Martin F. [Queensland Cancer Fund Research Unit, Queensland Institute of Medical Research, PO Box Royal Brisbane Hospital, Herston, Brisbane 4029 (Australia) and Central Clinical Division, University of Queensland, Brisbane (Australia)]. E-mail: martinl@qimr.edu.au; Birrell, Geoff [Queensland Cancer Fund Research Unit, Queensland Institute of Medical Research, PO Box Royal Brisbane Hospital, Herston, Brisbane 4029 (Australia); Chen, Philip [Queensland Cancer Fund Research Unit, Queensland Institute of Medical Research, PO Box Royal Brisbane Hospital, Herston, Brisbane 4029 (Australia); Kozlov, Sergei [Queensland Cancer Fund Research Unit, Queensland Institute of Medical Research, PO Box Royal Brisbane Hospital, Herston, Brisbane 4029 (Australia); Scott, Shaun [Queensland Cancer Fund Research Unit, Queensland Institute of Medical Research, PO Box Royal Brisbane Hospital, Herston, Brisbane 4029 (Australia); Gueven, Nuri [Queensland Cancer Fund Research Unit, Queensland Institute of Medical Research, PO Box Royal Brisbane Hospital, Herston, Brisbane 4029 (Australia)

    2005-01-06

    DNA double strand breaks represent the most threatening lesion to the integrity of the genome in cells exposed to ionizing radiation and radiomimetic chemicals. Those breaks are recognized, signaled to cell cycle checkpoints and repaired by protein complexes. The product of the gene (ATM) mutated in the human genetic disorder ataxia-telangiectasia (A-T) plays a central role in the recognition and signaling of DNA damage. ATM is one of an ever growing number of proteins which when mutated compromise the stability of the genome and predispose to tumour development. Mechanisms for recognising double strand breaks in DNA, maintaining genome stability and minimizing risk of cancer are discussed.

  17. DNA-free genome editing methods for targeted crop improvement.

    Science.gov (United States)

    Kanchiswamy, Chidananda Nagamangala

    2016-07-01

    Evolution of the next-generation clustered, regularly interspaced, short palindromic repeat/Cas9 (CRISPR/Cas9) genome editing tools, ribonucleoprotein (RNA)-guided endonuclease (RGEN) RNPs, is paving the way for developing DNA-free genetically edited crop plants. In this review, I discuss the various methods of RGEN RNPs tool delivery into plant cells and their limitations to adopt this technology to numerous crop plants. Furthermore, focus is given on the importance of developing DNA-free genome edited crop plants, including perennial crop plants. The possible regulation on the DNA-free, next-generation genome-edited crop plants is also highlighted.

  18. Inverted Low-Copy Repeats and Genome Instability—A Genome-Wide Analysis

    Science.gov (United States)

    Dittwald, Piotr; Gambin, Tomasz; Gonzaga-Jauregui, Claudia; Carvalho, Claudia M.B.; Lupski, James R.; Stankiewicz, Paweł; Gambin, Anna

    2013-01-01

    Inverse paralogous low-copy repeats (IP-LCRs) can cause genome instability by nonallelic homologous recombination (NAHR)-mediated balanced inversions. When disrupting a dosage-sensitive gene(s), balanced inversions can lead to abnormal phenotypes. We delineated the genome-wide distribution of IP-LCRs >1 kB in size with >95% sequence identity and mapped the genes, potentially intersected by an inversion, that overlap at least one of the IP-LCRs. Remarkably, our results show that 12.0% of the human genome is potentially susceptible to such inversions and 942 genes, 99 of which are on the X chromosome, are predicted to be disrupted secondary to such an inversion! In addition, IP-LCRs larger than 800 bp with at least 98% sequence identity (duplication/triplication facilitating IP-LCRs, DTIP-LCRs) were recently implicated in the formation of complex genomic rearrangements with a duplication-inverted triplication–duplication (DUP-TRP/INV-DUP) structure by a replication-based mechanism involving a template switch between such inverted repeats. We identified 1,551 DTIP-LCRs that could facilitate DUP-TRP/INV-DUP formation. Remarkably, 1,445 disease-associated genes are at risk of undergoing copy-number gain as they map to genomic intervals susceptible to the formation of DUP-TRP/INV-DUP complex rearrangements. We implicate inverted LCRs as a human genome architectural feature that could potentially be responsible for genomic instability associated with many human disease traits. PMID:22965494

  19. Genomic DNA extraction protocols from ovine hair

    Directory of Open Access Journals (Sweden)

    Jennifer Nonato da Silva Prate

    2013-12-01

    Full Text Available Genomic DNA extracted from animal cells can be used for several purposes, for example, to know genetic variability and genetic relationships between individuals, breeds and/or species, paternity tests, to describe the genetic profile for registration of the animal at association of breeders, detect genetic polymorphisms (SNP related to characteristics of commercial interest, disease diagnose, assess resistance or susceptibility to pathogens, etc. For such evaluations, in general, DNA is amplified by PCR (polymerase chain reaction, and then subjected to various techniques as RFLP (restriction fragments length polymorphism, SSCP (single strand conformation polymorphism, and sequencing. The DNA may be obtained from blood, buccal swabs, meat, cartilage or hair bulb. Among all, the last biological material has been preferred by farmers for its ease acquisition. Several methods for extracting DNA from hair bulb were reported without any consensus for its implementation. This study aimed to optimize a protocol for efficient DNA extraction for use in PCR-RFLP analysis of the Prion gene. For this study, were collected hair samples containing hair bulb from 131 Santa Inês sheep belonging to the Institute of Zootechny, Nova Odessa - SP. Two DNA extraction protocols were evaluated. The first, called phenol-chloroform-isoamyl alcohol (PCIA has long been used by Animal Genetic Laboratories, whose procedures are described below: in each microtube (1.5 mL containing 500 µL of TE-Tween solution (Tris-HCl 50 mM, EDTA 1 mM and 0.5% Tween 20 were added to approximately 30 hair bulb per animal which was incubated at 65°C with shaking at 170 rpm for 2 hours. Then was added 15 µL of proteinase K [10 mg mL-1] and incubated at 55°C at 170 rpm for 6-12 hours. At the end of digestion was added 1 volume of solution phenol-chloroform-isoamyl alcohol (25:24:1 followed by vigorous shaking for 10 seconds and centrifuged at 8000 rpm and 4°C for 10 minutes. The upper phase

  20. Population stratification in the context of diverse epidemiologic surveys sans genome-wide data

    Directory of Open Access Journals (Sweden)

    Matthew T. Oetjens

    2016-05-01

    Full Text Available Population stratification or confounding by genetic ancestry is a potential cause of false associations in genetic association studies. Estimation of and adjustment for genetic ancestry has become common practice thanks in part to the availability of ancestry informative markers on genome-wide association study (GWAS arrays. While array data is now widespread, these data are not ubiquitous as several large epidemiologic and clinic-based studies lack genome-wide data. One such large epidemiologic-based study lacking genome-wide data accessible to investigators is the National Health and Nutrition Examination Surveys (NHANES, population-based cross-sectional surveys of Americans linked to demographic, health, and lifestyle data conducted by the Centers for Disease Control and Prevention. DNA samples (n=14,998 were extracted from biospecimens from consented NHANES participants between 1991-1994 (NHANES III, phase 2 and 1999-2002 and represent three major self-identified racial/ethnic groups: non-Hispanic whites (n=6,634, non-Hispanic blacks (n=3,458, and Mexican Americans (n=3,950. We as the Epidemiologic Architecture for Genes Linked to Environment (EAGLE study genotyped candidate gene and GWAS-identified index variants in NHANES as part of the larger Population Architecture using Genomics and Epidemiology (PAGE I study for collaborative genetic association studies. To enable basic quality control such as estimation of genetic ancestry to control for population stratification in NHANES san genome-wide data, we outline here strategies that use limited genetic data to identify the markers optimal for characterizing genetic ancestry. From among 411 and 295 autosomal SNPs available in NHANES III and NHANES 1999-2002, we demonstrate that markers with ancestry information can be identified to estimate global ancestry. Despite limited resolution, global genetic ancestry is highly correlated with self-identified race for the majority of participants

  1. MECP2 as genome wide modulator: the renewal of an old story

    Directory of Open Access Journals (Sweden)

    Floriana eDella Ragione

    2012-09-01

    Full Text Available Since the discovery of MECP2, its functions have attracted the interest of generations of molecular biologists. Its function as a transducer of DNA methylation, the major post-biosynthetic modification found throughout genomes, and its association with the neurodevelopmental disease Rett syndrome highlight its central role as a transcriptional regulator, and, at the same time, poses puzzling questions concerning its roles in physiology and pathology.The classical model of the MECP2 function predicts its role in gene specific repression through the binding of methylated DNA, via its interaction with the histone deacetylases and co-repressor complexes. This view has been questioned and, intriguingly, new roles for MECP2 as a splicing modulator and as a transcriptional activator have been proposed. Recent data have demonstrated that MECP2 is extremely abundant in the neurons, where it reaches the level of histone H1; it is widely distributed, tracking the methylated CpGs and regulates repetitive elements expression. The role of MECP2 in maintaining the global chromatin structure is further sustained by its involvement in other biologically relevant phenomena, such as the L1 repetitive sequences retrotransposition and the pericentromeric heterochromatin clustering during cellular differentiation.These new concepts renew the old view suggesting a role for DNA methylation in transcriptional noise reduction, pointing to a key role for MECP2 in the modulation of the genome architecture.

  2. The anti-CMS technique for genome-wide mapping of 5-hydroxymethylcytosine.

    Science.gov (United States)

    Huang, Yun; Pastor, William A; Zepeda-Martínez, Jorge A; Rao, Anjana

    2012-10-01

    5-Hydroxymethylcytosine (5hmC) is a recently discovered base in the mammalian genome, produced upon oxidation of 5-methylcytosine (5mC) in a process catalyzed by TET proteins. The biological functions of 5hmC and further oxidation products of 5mC are under intense investigation, as they are likely intermediates in DNA demethylation pathways. Here we describe a novel protocol to profile 5hmC at a genome-wide scale. This approach is based on sodium bisulfite-mediated conversion of 5hmC to cytosine-5-methylenesulfonate (CMS); CMS-containing DNA fragments are then immunoprecipitated using a CMS-specific antiserum. The anti-CMS technique is highly specific with a low background, and is much less dependent on 5hmC density than anti-5hmC immunoprecipitation (IP). Moreover, it does not enrich for CA and CT repeats, as noted for 5hmC DNA IP using antibodies to 5hmC. The anti-CMS protocol takes 3 d to complete.

  3. Efficient Genome-Wide Sequencing and Low-Coverage Pedigree Analysis from Noninvasively Collected Samples.

    Science.gov (United States)

    Snyder-Mackler, Noah; Majoros, William H; Yuan, Michael L; Shaver, Amanda O; Gordon, Jacob B; Kopp, Gisela H; Schlebusch, Stephen A; Wall, Jeffrey D; Alberts, Susan C; Mukherjee, Sayan; Zhou, Xiang; Tung, Jenny

    2016-06-01

    Research on the genetics of natural populations was revolutionized in the 1990s by methods for genotyping noninvasively collected samples. However, these methods have remained largely unchanged for the past 20 years and lag far behind the genomics era. To close this gap, here we report an optimized laboratory protocol for genome-wide capture of endogenous DNA from noninvasively collected samples, coupled with a novel computational approach to reconstruct pedigree links from the resulting low-coverage data. We validated both methods using fecal samples from 62 wild baboons, including 48 from an independently constructed extended pedigree. We enriched fecal-derived DNA samples up to 40-fold for endogenous baboon DNA and reconstructed near-perfect pedigree relationships even with extremely low-coverage sequencing. We anticipate that these methods will be broadly applicable to the many research systems for which only noninvasive samples are available. The lab protocol and software ("WHODAD") are freely available at www.tung-lab.org/protocols-and-software.html and www.xzlab.org/software.html, respectively. Copyright © 2016 by the Genetics Society of America.

  4. Mosaic paternal genome-wide uniparental isodisomy with down syndrome.

    Science.gov (United States)

    Darcy, Diana; Atwal, Paldeep Singh; Angell, Cathy; Gadi, Inder; Wallerstein, Robert

    2015-10-01

    We report on a 6-month-old girl with two apparent cell lines; one with trisomy 21, and the other with paternal genome-wide uniparental isodisomy (GWUPiD), identified using single nucleotide polymorphism (SNP) based microarray and microsatellite analysis of polymorphic loci. The patient has Beckwith-Wiedemann syndrome (BWS) due to paternal uniparental disomy (UPD) at chromosome location 11p15 (UPD 11p15), which was confirmed through methylation analysis. Hyperinsulinemic hypoglycemia is present, which is associated with paternal UPD 11p15.5; and she likely has medullary nephrocalcinosis, which is associated with paternal UPD 20, although this was not biochemically confirmed. Angelman syndrome (AS) analysis was negative but this testing is not completely informative; she has no specific features of AS. Clinical features of this patient include: dysmorphic features consistent with trisomy 21, tetralogy of Fallot, hemihypertrophy, swirled skin hyperpigmentation, hepatoblastoma, and Wilms tumor. Her karyotype is 47,XX,+21[19]/46,XX[4], and microarray results suggest that the cell line with trisomy 21 is biparentally inherited and represents 40-50% of the genomic material in the tested specimen. The difference in the level of cytogenetically detected mosaicism versus the level of mosaicism observed via microarray analysis is likely caused by differences in the test methodologies. While a handful of cases of mosaic paternal GWUPiD have been reported, this patient is the only reported case that also involves trisomy 21. Other GWUPiD patients have presented with features associated with multiple imprinted regions, as does our patient. © 2015 Wiley Periodicals, Inc.

  5. Genome-Wide Architecture of Disease Resistance Genes in Lettuce.

    Science.gov (United States)

    Christopoulou, Marilena; Wo, Sebastian Reyes-Chin; Kozik, Alex; McHale, Leah K; Truco, Maria-Jose; Wroblewski, Tadeusz; Michelmore, Richard W

    2015-10-08

    Genome-wide motif searches identified 1134 genes in the lettuce reference genome of cv. Salinas that are potentially involved in pathogen recognition, of which 385 were predicted to encode nucleotide binding-leucine rich repeat receptor (NLR) proteins. Using a maximum-likelihood approach, we grouped the NLRs into 25 multigene families and 17 singletons. Forty-one percent of these NLR-encoding genes belong to three families, the largest being RGC16 with 62 genes in cv. Salinas. The majority of NLR-encoding genes are located in five major resistance clusters (MRCs) on chromosomes 1, 2, 3, 4, and 8 and cosegregate with multiple disease resistance phenotypes. Most MRCs contain primarily members of a single NLR gene family but a few are more complex. MRC2 spans 73 Mb and contains 61 NLRs of six different gene families that cosegregate with nine disease resistance phenotypes. MRC3, which is 25 Mb, contains 22 RGC21 genes and colocates with Dm13. A library of 33 transgenic RNA interference tester stocks was generated for functional analysis of NLR-encoding genes that cosegregated with disease resistance phenotypes in each of the MRCs. Members of four NLR-encoding families, RGC1, RGC2, RGC21, and RGC12 were shown to be required for 16 disease resistance phenotypes in lettuce. The general composition of MRCs is conserved across different genotypes; however, the specific repertoire of NLR-encoding genes varied particularly of the rapidly evolving Type I genes. These tester stocks are valuable resources for future analyses of additional resistance phenotypes. Copyright © 2015 Christopoulou et al.

  6. Genome-wide survey for biologically functional pseudogenes.

    Directory of Open Access Journals (Sweden)

    Orjan Svensson

    2006-05-01

    Full Text Available According to current estimates there exist about 20,000 pseudogenes in a mammalian genome. The vast majority of these are disabled and nonfunctional copies of protein-coding genes which, therefore, evolve neutrally. Recent findings that a Makorin1 pseudogene, residing on mouse Chromosome 5, is, indeed, in vivo vital and also evolutionarily preserved, encouraged us to conduct a genome-wide survey for other functional pseudogenes in human, mouse, and chimpanzee. We identify to our knowledge the first examples of conserved pseudogenes common to human and mouse, originating from one duplication predating the human-mouse species split and having evolved as pseudogenes since the species split. Functionality is one possible way to explain the apparently contradictory properties of such pseudogene pairs, i.e., high conservation and ancient origin. The hypothesis of functionality is tested by comparing expression evidence and synteny of the candidates with proper test sets. The tests suggest potential biological function. Our candidate set includes a small set of long-lived pseudogenes whose unknown potential function is retained since before the human-mouse species split, and also a larger group of primate-specific ones found from human-chimpanzee searches. Two processed sequences are notable, their conservation since the human-mouse split being as high as most protein-coding genes; one is derived from the protein Ataxin 7-like 3 (ATX7NL3, and one from the Spinocerebellar ataxia type 1 protein (ATX1. Our approach is comparative and can be applied to any pair of species. It is implemented by a semi-automated pipeline based on cross-species BLAST comparisons and maximum-likelihood phylogeny estimations. To separate pseudogenes from protein-coding genes, we use standard methods, utilizing in-frame disablements, as well as a probabilistic filter based on Ka/Ks ratios.

  7. Genome-wide methylation analyses in glioblastoma multiforme.

    Directory of Open Access Journals (Sweden)

    Rose K Lai

    Full Text Available Few studies had investigated genome-wide methylation in glioblastoma multiforme (GBM. Our goals were to study differential methylation across the genome in gene promoters using an array-based method, as well as repetitive elements using surrogate global methylation markers. The discovery sample set for this study consisted of 54 GBM from Columbia University and Case Western Reserve University, and 24 brain controls from the New York Brain Bank. We assembled a validation dataset using methylation data of 162 TCGA GBM and 140 brain controls from dbGAP. HumanMethylation27 Analysis Bead-Chips (Illumina were used to interrogate 26,486 informative CpG sites in both the discovery and validation datasets. Global methylation levels were assessed by analysis of L1 retrotransposon (LINE1, 5 methyl-deoxycytidine (5m-dC and 5 hydroxylmethyl-deoxycytidine (5hm-dC in the discovery dataset. We validated a total of 1548 CpG sites (1307 genes that were differentially methylated in GBM compared to controls. There were more than twice as many hypomethylated genes as hypermethylated ones. Both the discovery and validation datasets found 5 tumor methylation classes. Pathway analyses showed that the top ten pathways in hypomethylated genes were all related to functions of innate and acquired immunities. Among hypermethylated pathways, transcriptional regulatory network in embryonic stem cells was the most significant. In the study of global methylation markers, 5m-dC level was the best discriminant among methylation classes, whereas in survival analyses, high level of LINE1 methylation was an independent, favorable prognostic factor in the discovery dataset. Based on a pathway approach, hypermethylation in genes that control stem cell differentiation were significant, poor prognostic factors of overall survival in both the discovery and validation datasets. Approaches that targeted these methylated genes may be a future therapeutic goal.

  8. Dating the age of admixture via wavelet transform analysis of genome-wide data

    NARCIS (Netherlands)

    I. Pugach (Irina); R. Matveyev (Rostislav); A. Wollstein (Andreas); M.H. Kayser (Manfred); M. Stoneking (Mark)

    2011-01-01

    textabstractWe describe a PCA-based genome scan approach to analyze genome-wide admixture structure, and introduce wavelet transform analysis as a method for estimating the time of admixture. We test the wavelet transform method with simulations and apply it to genome-wide SNP data from eight admixe