WorldWideScience

Sample records for genome-wide snp markers

  1. Genome-wide association of 10 horticultural traits with expressed sequence tag-derived SNP markers in a collection of lettuce lines

    Science.gov (United States)

    Genetic diversity, population structure, and genome-wide marker-trait association analyses were conducted on a special collection of 298 homozygous lettuce (Lactuca sativa L.) lines. Each of these lines was derived from a single plant that had been genotyped with 384 SNP makers using LSGermOPA. They...

  2. Genetic Diversity, Population Structure, and Linkage Disequilibrium of an Association-Mapping Panel Revealed by Genome-Wide SNP Markers in Sesame

    Science.gov (United States)

    Cui, Chengqi; Mei, Hongxian; Liu, Yanyang; Zhang, Haiyang; Zheng, Yongzhan

    2017-01-01

    The characterization of genetic diversity and population structure can be used in tandem to detect reliable phenotype–genotype associations. In the present study, we genotyped a set of 366 sesame germplasm accessions by using 89,924 single-nucleotide polymorphisms (SNPs). The number of SNPs on each chromosome was consistent with the physical length of the respective chromosome, and the average marker density was approximately 2.67 kb/SNP. The genetic diversity analysis showed that the average nucleotide diversity of the panel was 1.1 × 10-3, with averages of 1.0 × 10-4, 2.7 × 10-4, and 3.6 × 10-4 obtained, respectively for three identified subgroups of the panel: Pop 1, Pop 2, and the Mixed. The genetic structure analysis revealed that these sesame germplasm accessions were structured primarily along the basis of their geographic collection, and that an extensive admixture occurred in the panel. The genome-wide linkage disequilibrium (LD) analysis showed that an average LD extended up to ∼99 kb. The genetic diversity and population structure revealed in this study should provide guidance to the future design of association studies and the systematic utilization of the genetic variation characterizing the sesame panel. PMID:28729877

  3. Genome-wide associations for water-soluble carbohydrate concentration and relative maturity in wheat using SNP and DArT marker arrays

    Science.gov (United States)

    Improving water-use efficiency by incorporating drought avoidance traits into new wheat varieties is an important objective for wheat breeding in water-limited environments. This study uses genome wide association studies (GWAS) to identify candidate loci for water-soluble carbohydrate accumulation,...

  4. Psoriasis prediction from genome-wide SNP profiles

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    Fang Xiangzhong

    2011-01-01

    Full Text Available Abstract Background With the availability of large-scale genome-wide association study (GWAS data, choosing an optimal set of SNPs for disease susceptibility prediction is a challenging task. This study aimed to use single nucleotide polymorphisms (SNPs to predict psoriasis from searching GWAS data. Methods Totally we had 2,798 samples and 451,724 SNPs. Process for searching a set of SNPs to predict susceptibility for psoriasis consisted of two steps. The first one was to search top 1,000 SNPs with high accuracy for prediction of psoriasis from GWAS dataset. The second one was to search for an optimal SNP subset for predicting psoriasis. The sequential information bottleneck (sIB method was compared with classical linear discriminant analysis(LDA for classification performance. Results The best test harmonic mean of sensitivity and specificity for predicting psoriasis by sIB was 0.674(95% CI: 0.650-0.698, while only 0.520(95% CI: 0.472-0.524 was reported for predicting disease by LDA. Our results indicate that the new classifier sIB performs better than LDA in the study. Conclusions The fact that a small set of SNPs can predict disease status with average accuracy of 68% makes it possible to use SNP data for psoriasis prediction.

  5. 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.

  6. Exhaustive Genome-Wide Search for SNP-SNP Interactions Across 10 Human Diseases

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    William Murk

    2016-07-01

    Full Text Available The identification of statistical SNP-SNP interactions may help explain the genetic etiology of many human diseases, but exhaustive genome-wide searches for these interactions have been difficult, due to a lack of power in most datasets. We aimed to use data from the Resource for Genetic Epidemiology Research on Adult Health and Aging (GERA study to search for SNP-SNP interactions associated with 10 common diseases. FastEpistasis and BOOST were used to evaluate all pairwise interactions among approximately N = 300,000 single nucleotide polymorphisms (SNPs with minor allele frequency (MAF ≥ 0.15, for the dichotomous outcomes of allergic rhinitis, asthma, cardiac disease, depression, dermatophytosis, type 2 diabetes, dyslipidemia, hemorrhoids, hypertensive disease, and osteoarthritis. A total of N = 45,171 subjects were included after quality control steps were applied. These data were divided into discovery and replication subsets; the discovery subset had > 80% power, under selected models, to detect genome-wide significant interactions (P < 10−12. Interactions were also evaluated for enrichment in particular SNP features, including functionality, prior disease relevancy, and marginal effects. No interaction in any disease was significant in both the discovery and replication subsets. Enrichment analysis suggested that, for some outcomes, interactions involving SNPs with marginal effects were more likely to be nominally replicated, compared to interactions without marginal effects. If SNP-SNP interactions play a role in the etiology of the studied conditions, they likely have weak effect sizes, involve lower-frequency variants, and/or involve complex models of interaction that are not captured well by the methods that were utilized.

  7. A novel algorithm for simultaneous SNP selection in high-dimensional genome-wide association studies

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    Zuber Verena

    2012-10-01

    Full Text Available Abstract Background Identification of causal SNPs in most genome wide association studies relies on approaches that consider each SNP individually. However, there is a strong correlation structure among SNPs that needs to be taken into account. Hence, increasingly modern computationally expensive regression methods are employed for SNP selection that consider all markers simultaneously and thus incorporate dependencies among SNPs. Results We develop a novel multivariate algorithm for large scale SNP selection using CAR score regression, a promising new approach for prioritizing biomarkers. Specifically, we propose a computationally efficient procedure for shrinkage estimation of CAR scores from high-dimensional data. Subsequently, we conduct a comprehensive comparison study including five advanced regression approaches (boosting, lasso, NEG, MCP, and CAR score and a univariate approach (marginal correlation to determine the effectiveness in finding true causal SNPs. Conclusions Simultaneous SNP selection is a challenging task. We demonstrate that our CAR score-based algorithm consistently outperforms all competing approaches, both uni- and multivariate, in terms of correctly recovered causal SNPs and SNP ranking. An R package implementing the approach as well as R code to reproduce the complete study presented here is available from http://strimmerlab.org/software/care/.

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

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    James W Kijas

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

  9. Genome-wide SNP identification in multiple morphotypes of allohexaploid tall fescue (Festuca arundinacea Schreb

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    Hand Melanie L

    2012-06-01

    GoldenGate™ assay is capable of high-throughput co-dominant SNP allele detection, and minimises the problems associated with SNP genotyping in a polyploid by effectively reducing the complexity to a diploid system. This SNP collection may now be refined and used in applications such as cultivar identification, genetic linkage map construction, genome-wide association studies and genomic selection in tall fescue. The bioinformatic pipeline described here represents an effective general method for SNP discovery within outbreeding allopolyploid species.

  10. Polygenic analysis of genome-wide SNP data identifies common variants on allergic rhinitis

    DEFF Research Database (Denmark)

    Mohammadnejad, Afsaneh; Brasch-Andersen, Charlotte; Haagerup, Annette

    Background: Allergic Rhinitis (AR) is a complex disorder that affects many people around the world. There is a high genetic contribution to the development of the AR, as twins and family studies have estimated heritability of more than 33%. Due to the complex nature of the disease, single SNP...... analysis has limited power in identifying the genetic variations for AR. We combined genome-wide association analysis (GWAS) with polygenic risk score (PRS) in exploring the genetic basis underlying the disease. Methods: We collected clinical data on 631 Danish subjects with AR cases consisting of 434...... sibling pairs and unrelated individuals and control subjects of 197 unrelated individuals. SNP genotyping was done by Affymetrix Genome-Wide Human SNP Array 5.0. SNP imputation was performed using "IMPUTE2". Using additive effect model, GWAS was conducted in discovery sample, the genotypes...

  11. SNPpy--database management for SNP data from genome wide association studies.

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    Faheem Mitha

    Full Text Available BACKGROUND: We describe SNPpy, a hybrid script database system using the Python SQLAlchemy library coupled with the PostgreSQL database to manage genotype data from Genome-Wide Association Studies (GWAS. This system makes it possible to merge study data with HapMap data and merge across studies for meta-analyses, including data filtering based on the values of phenotype and Single-Nucleotide Polymorphism (SNP data. SNPpy and its dependencies are open source software. RESULTS: The current version of SNPpy offers utility functions to import genotype and annotation data from two commercial platforms. We use these to import data from two GWAS studies and the HapMap Project. We then export these individual datasets to standard data format files that can be imported into statistical software for downstream analyses. CONCLUSIONS: By leveraging the power of relational databases, SNPpy offers integrated management and manipulation of genotype and phenotype data from GWAS studies. The analysis of these studies requires merging across GWAS datasets as well as patient and marker selection. To this end, SNPpy enables the user to filter the data and output the results as standardized GWAS file formats. It does low level and flexible data validation, including validation of patient data. SNPpy is a practical and extensible solution for investigators who seek to deploy central management of their GWAS data.

  12. Genome-wide SNP discovery in mungbean by Illumina HiSeq.

    Science.gov (United States)

    Van, Kyujung; Kang, Yang Jae; Han, Kwang-Soo; Lee, Yeong-Ho; Gwag, Jae-Gyun; Moon, Jung-Kyung; Lee, Suk-Ha

    2013-08-01

    Mungbean [Vigna radiata (L.) Wilczek], a self-pollinated diploid plant with 2n = 22 chromosomes, is an important legume crop with a high-quality amino acid profile. Sequence variation at the whole-genome level was examined by comparing two mungbean cultivars, Sunhwanokdu and Gyeonggijaerae 5, using Illumina HiSeq sequencing data. More than 40 billion bp from both mungbean cultivars were sequenced to a depth of 72×. After de novo assembly of Sunhwanokdu contigs by ABySS 1.3.2 (N50 = 9,958 bp), those longer than 10 kb were aligned with Gyeonggijaerae 5 reads using the Burrows-Wheeler Aligner. SAMTools was used for retrieving single nucleotide polymorphisms (SNPs) between Sunhwanokdu and Gyeonggijaerae 5, defining the lowest and highest depths as 5 and 100, respectively, and the sequence quality as 100. Of the 305,504 single-base changes identified, 40,503 SNPs were considered heterozygous in Gyeonggijaerae 5. Among the remaining 265,001 SNPs, 65.9 % (174,579 cases) were transitions and 34.1 % (90,422 cases) were transversions. For SNP validation, a total of 42 SNPs were chosen among Sunhwanokdu contigs longer than 10 kb and sharing at least 80 % sequence identity with common bean expressed sequence tags as determined with est2genome. Using seven mungbean cultivars from various origins in addition to Sunhwanokdu and Gyeonggijaerae 5, most of the SNPs identified by bioinformatics tools were confirmed by Sanger sequencing. These genome-wide SNP markers could enrich the current molecular resources and might be of value for the construction of a mungbean genetic map and the investigation of genetic diversity.

  13. Genome wide SNP discovery in flax through next generation sequencing of reduced representation libraries

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    Kumar Santosh

    2012-12-01

    Full Text Available Abstract Background Flax (Linum usitatissimum L. is a significant fibre and oilseed crop. Current flax molecular markers, including isozymes, RAPDs, AFLPs and SSRs are of limited use in the construction of high density linkage maps and for association mapping applications due to factors such as low reproducibility, intense labour requirements and/or limited numbers. We report here on the use of a reduced representation library strategy combined with next generation Illumina sequencing for rapid and large scale discovery of SNPs in eight flax genotypes. SNP discovery was performed through in silico analysis of the sequencing data against the whole genome shotgun sequence assembly of flax genotype CDC Bethune. Genotyping-by-sequencing of an F6-derived recombinant inbred line population provided validation of the SNPs. Results Reduced representation libraries of eight flax genotypes were sequenced on the Illumina sequencing platform resulting in sequence coverage ranging from 4.33 to 15.64X (genome equivalents. Depending on the relatedness of the genotypes and the number and length of the reads, between 78% and 93% of the reads mapped onto the CDC Bethune whole genome shotgun sequence assembly. A total of 55,465 SNPs were discovered with the largest number of SNPs belonging to the genotypes with the highest mapping coverage percentage. Approximately 84% of the SNPs discovered were identified in a single genotype, 13% were shared between any two genotypes and the remaining 3% in three or more. Nearly a quarter of the SNPs were found in genic regions. A total of 4,706 out of 4,863 SNPs discovered in Macbeth were validated using genotyping-by-sequencing of 96 F6 individuals from a recombinant inbred line population derived from a cross between CDC Bethune and Macbeth, corresponding to a validation rate of 96.8%. Conclusions Next generation sequencing of reduced representation libraries was successfully implemented for genome-wide SNP discovery from

  14. Supervised Learning-Based tagSNP Selection for Genome-Wide Disease Classifications

    OpenAIRE

    Yang Mary Qu; Chen Zhongxue; Yang Jack; Liu Qingzhong; Sung Andrew H; Huang Xudong

    2008-01-01

    Abstract Background Comprehensive evaluation of common genetic variations through association of single nucleotide polymorphisms (SNPs) with complex human diseases on the genome-wide scale is an active area in human genome research. One of the fundamental questions in a SNP-disease association study is to find an optimal subset of SNPs with predicting power for disease status. To find that subset while reducing study burden in terms of time and costs, one can potentially reconcile information...

  15. BlueSNP: R package for highly scalable genome-wide association studies using Hadoop clusters.

    Science.gov (United States)

    Huang, Hailiang; Tata, Sandeep; Prill, Robert J

    2013-01-01

    Computational workloads for genome-wide association studies (GWAS) are growing in scale and complexity outpacing the capabilities of single-threaded software designed for personal computers. The BlueSNP R package implements GWAS statistical tests in the R programming language and executes the calculations across computer clusters configured with Apache Hadoop, a de facto standard framework for distributed data processing using the MapReduce formalism. BlueSNP makes computationally intensive analyses, such as estimating empirical p-values via data permutation, and searching for expression quantitative trait loci over thousands of genes, feasible for large genotype-phenotype datasets. http://github.com/ibm-bioinformatics/bluesnp

  16. Genome-wide association study of swine farrowing traits. Part II: Bayesian analysis of marker data.

    Science.gov (United States)

    Schneider, J F; Rempel, L A; Snelling, W M; Wiedmann, R T; Nonneman, D J; Rohrer, G A

    2012-10-01

    Reproductive efficiency has a great impact on the economic success of pork (sus scrofa) production. Number born alive (NBA) and average piglet birth weight (ABW) contribute greatly to reproductive efficiency. To better understand the underlying genetics of birth traits, a genome-wide association study (GWAS) was undertaken. Samples of DNA were collected and tested using the Illumina PorcineSNP60 BeadChip from 1,152 first parity gilts. Traits included total number born (TNB), NBA, number born dead (NBD), number stillborn (NSB), number of mummies (MUM), total litter birth weight (LBW), and ABW. A total of 41,151 SNP were tested using a Bayesian approach. Beginning with the first 5 SNP on SSC1 and ending with the last 5 SNP on the SSCX, SNP were assigned to groups of 5 consecutive SNP by chromosome-position order and analyzed again using a Bayesian approach. From that analysis, 5-SNP groups were selected having no overlap with another 5-SNP groups and no overlap across chromosomes. These selected 5-SNP non-overlapping groups were defined as QTL. Of the available 8,814 QTL, 124 were found to be statistically significant (P ABW, 9 on SSC1, 3 on SSC2, 9 on SSC5, 5 on SSC6, 1 on SSC7, 2 on SSC8, 2 on SSC9, 3 on SSC10, 1 on SSC11, 3 on SSC12, 2 on SSC13, 8 on SSC14, 8 on SSC15, 1 on SSC17, and 8 on SSC18. Several candidate genes have been identified that overlap QTL locations among TNB, NBA, NBD, and ABW. These QTL when combined with information on genes found in the same regions should provide useful information that could be used for marker assisted selection, marker assisted management, or genomic selection applications in commercial pig populations.

  17. Genome-Wide Association Mapping for Intelligence in Military Working Dogs: Development of Advanced Classification Algorithm for Genome-Wide Single Nucleotide Polymorphism (SNP) Data Analysis

    Science.gov (United States)

    2011-04-01

    al. (2007) “Efficient mapping of mendelian traits in dogs through genome-wide association.” Nat Genet 39:1321-1328. 12 Distribution A...collected data to genetically map superior intelligence in the military working dog. A behavioral testing regimen was developed by canine cognitive expert Dr...TERMS Military working dog genome-wide association study genetic marker intelligence 16

  18. A genome-wide SNP panel for mapping and association studies in the rat

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    Guryev Victor

    2008-02-01

    Full Text Available Abstract Background The laboratory rat (Rattus norvegicus is an important model for human disease, and is extensively used for studying complex traits for example in the physiological and pharmacological fields. To facilitate genetic studies like QTL mapping, genetic makers that can be easily typed, like SNPs, are essential. Results A genome-wide set of 820 SNP assays was designed for the KASPar genotyping platform, which uses a technique based on allele specific oligo extension and energy transfer-based detection. SNPs were chosen to be equally spread along all chromosomes except Y and to be polymorphic between Brown Norway and SS or Wistar rat strains based on data from the rat HapMap EU project. This panel was tested on 38 rats of 34 different strains and 3 wild rats to determine the level of polymorphism and to generate a phylogenetic network to show their genetic relationships. As a proof of principle we used this panel to map an obesity trait in Zucker rats and confirmed significant linkage (LOD 122 to chromosome 5: 119–129 Mb, where the leptin receptor gene (Lepr is located (chr5: 122 Mb. Conclusion We provide a fast and cost-effective platform for genome-wide SNP typing, which can be used for first-pass genetic mapping and association studies in a wide variety of rat strains.

  19. GStream: improving SNP and CNV coverage on genome-wide association studies.

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    Arnald Alonso

    Full Text Available We present GStream, a method that combines genome-wide SNP and CNV genotyping in the Illumina microarray platform with unprecedented accuracy. This new method outperforms previous well-established SNP genotyping software. More importantly, the CNV calling algorithm of GStream dramatically improves the results obtained by previous state-of-the-art methods and yields an accuracy that is close to that obtained by purely CNV-oriented technologies like Comparative Genomic Hybridization (CGH. We demonstrate the superior performance of GStream using microarray data generated from HapMap samples. Using the reference CNV calls generated by the 1000 Genomes Project (1KGP and well-known studies on whole genome CNV characterization based either on CGH or genotyping microarray technologies, we show that GStream can increase the number of reliably detected variants up to 25% compared to previously developed methods. Furthermore, the increased genome coverage provided by GStream allows the discovery of CNVs in close linkage disequilibrium with SNPs, previously associated with disease risk in published Genome-Wide Association Studies (GWAS. These results could provide important insights into the biological mechanism underlying the detected disease risk association. With GStream, large-scale GWAS will not only benefit from the combined genotyping of SNPs and CNVs at an unprecedented accuracy, but will also take advantage of the computational efficiency of the method.

  20. Genomic selection and complex trait prediction using a fast EM algorithm applied to genome-wide markers.

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    Shepherd, Ross K; Meuwissen, Theo H E; Woolliams, John A

    2010-10-22

    The information provided by dense genome-wide markers using high throughput technology is of considerable potential in human disease studies and livestock breeding programs. Genome-wide association studies relate individual single nucleotide polymorphisms (SNP) from dense SNP panels to individual measurements of complex traits, with the underlying assumption being that any association is caused by linkage disequilibrium (LD) between SNP and quantitative trait loci (QTL) affecting the trait. Often SNP are in genomic regions of no trait variation. Whole genome Bayesian models are an effective way of incorporating this and other important prior information into modelling. However a full Bayesian analysis is often not feasible due to the large computational time involved. This article proposes an expectation-maximization (EM) algorithm called emBayesB which allows only a proportion of SNP to be in LD with QTL and incorporates prior information about the distribution of SNP effects. The posterior probability of being in LD with at least one QTL is calculated for each SNP along with estimates of the hyperparameters for the mixture prior. A simulated example of genomic selection from an international workshop is used to demonstrate the features of the EM algorithm. The accuracy of prediction is comparable to a full Bayesian analysis but the EM algorithm is considerably faster. The EM algorithm was accurate in locating QTL which explained more than 1% of the total genetic variation. A computational algorithm for very large SNP panels is described. emBayesB is a fast and accurate EM algorithm for implementing genomic selection and predicting complex traits by mapping QTL in genome-wide dense SNP marker data. Its accuracy is similar to Bayesian methods but it takes only a fraction of the time.

  1. Development and application of a novel genome-wide SNP array reveals domestication history in soybean.

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    Wang, Jiao; Chu, Shanshan; Zhang, Huairen; Zhu, Ying; Cheng, Hao; Yu, Deyue

    2016-02-09

    Domestication of soybeans occurred under the intense human-directed selections aimed at developing high-yielding lines. Tracing the domestication history and identifying the genes underlying soybean domestication require further exploration. Here, we developed a high-throughput NJAU 355 K SoySNP array and used this array to study the genetic variation patterns in 367 soybean accessions, including 105 wild soybeans and 262 cultivated soybeans. The population genetic analysis suggests that cultivated soybeans have tended to originate from northern and central China, from where they spread to other regions, accompanied with a gradual increase in seed weight. Genome-wide scanning for evidence of artificial selection revealed signs of selective sweeps involving genes controlling domestication-related agronomic traits including seed weight. To further identify genomic regions related to seed weight, a genome-wide association study (GWAS) was conducted across multiple environments in wild and cultivated soybeans. As a result, a strong linkage disequilibrium region on chromosome 20 was found to be significantly correlated with seed weight in cultivated soybeans. Collectively, these findings should provide an important basis for genomic-enabled breeding and advance the study of functional genomics in soybean.

  2. 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

  3. Genome-wide SNP discovery in walnut with an AGSNP pipeline updated for SNP discovery in allogamous organisms

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    You Frank M

    2012-07-01

    Full Text Available Abstract Background A genome-wide set of single nucleotide polymorphisms (SNPs is a valuable resource in genetic research and breeding and is usually developed by re-sequencing a genome. If a genome sequence is not available, an alternative strategy must be used. We previously reported the development of a pipeline (AGSNP for genome-wide SNP discovery in coding sequences and other single-copy DNA without a complete genome sequence in self-pollinating (autogamous plants. Here we updated this pipeline for SNP discovery in outcrossing (allogamous species and demonstrated its efficacy in SNP discovery in walnut (Juglans regia L.. Results The first step in the original implementation of the AGSNP pipeline was the construction of a reference sequence and the identification of single-copy sequences in it. To identify single-copy sequences, multiple genome equivalents of short SOLiD reads of another individual were mapped to shallow genome coverage of long Sanger or Roche 454 reads making up the reference sequence. The relative depth of SOLiD reads was used to filter out repeated sequences from single-copy sequences in the reference sequence. The second step was a search for SNPs between SOLiD reads and the reference sequence. Polymorphism within the mapped SOLiD reads would have precluded SNP discovery; hence both individuals had to be homozygous. The AGSNP pipeline was updated here for using SOLiD or other type of short reads of a heterozygous individual for these two principal steps. A total of 32.6X walnut genome equivalents of SOLiD reads of vegetatively propagated walnut scion cultivar ‘Chandler’ were mapped to 48,661 ‘Chandler’ bacterial artificial chromosome (BAC end sequences (BESs produced by Sanger sequencing during the construction of a walnut physical map. A total of 22,799 putative SNPs were initially identified. A total of 6,000 Infinium II type SNPs evenly distributed along the walnut physical map were selected for the

  4. Genome-wide copy number profiling using high-density SNP array in chickens.

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    Yi, G; Qu, L; Chen, S; Xu, G; Yang, N

    2015-04-01

    Phenotypic diversity is a direct consequence resulting mainly from the impact of underlying genetic variation, and recent studies have shown that copy number variation (CNV) is emerging as an important contributor to both phenotypic variability and disease susceptibility. Herein, we performed a genome-wide CNV scan in 96 chickens from 12 diversified breeds, benefiting from the high-density Affymetrix 600 K SNP arrays. We identified a total of 231 autosomal CNV regions (CNVRs) encompassing 5.41 Mb of the chicken genome and corresponding to 0.59% of the autosomal sequence. The length of these CNVRs ranged from 2.6 to 586.2 kb with an average of 23.4 kb, including 130 gain, 93 loss and eight both gain and loss events. These CNVRs, especially deletions, had lower GC content and were located particularly in gene deserts. In particular, 102 CNVRs harbored 128 chicken genes, most of which were enriched in immune responses. We obtained 221 autosomal CNVRs after converting probe coordinates to Galgal3, and comparative analysis with previous studies illustrated that 153 of these CNVRs were regarded as novel events. Furthermore, qPCR assays were designed for 11 novel CNVRs, and eight (72.73%) were validated successfully. In this study, we demonstrated that the high-density 600 K SNP array can capture CNVs with higher efficiency and accuracy and highlighted the necessity of integrating multiple technologies and algorithms. Our findings provide a pioneering exploration of chicken CNVs based on a high-density SNP array, which contributes to a more comprehensive understanding of genetic variation in the chicken genome and is beneficial to unearthing potential CNVs underlying important traits of chickens. © 2015 Stichting International Foundation for Animal Genetics.

  5. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago.

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    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-12-10

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history.

  6. Single- and Bayesian Multi-Marker Genome-Wide Association for Haematological Parameters in Pigs.

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    Siriluck Ponsuksili

    Full Text Available Haematological traits are important traits that show associations with immune and metabolic status, as well as diseases in humans and animals. Mapping genome regions that affect the blood cell traits can contribute to the identification of genomic features useable as biomarkers for immune, disease and metabolic status. A genome-wide association study (GWAS was conducted using PorcineSNP60 BeadChips. Single-marker and Bayesian multi-marker approaches were integrated to identify genomic regions and corresponding genes overlapping for both methods. GWAS was performed for haematological traits of 591 German Landrace pig. Heritability estimates for haematological traits were medium to high. In total 252 single SNPs associated with 12 haematological traits were identified (NegLog10 of p-value > 5. The Bayesian multi-marker approach revealed 102 QTL regions across the genome, indicated by 1-Mb windows with contribution to additive genetic variance above 0.5%. The integration of both methods resulted in 24 overlapping QTL regions. This study identified overlapping QTL regions from single- and multi-marker approaches for haematological traits. Identifying candidate genes that affect blood cell traits provides the first step towards the understanding of the molecular basis of haematological phenotypes.

  7. Chapter 10: Mining genome-wide genetic markers.

    Directory of Open Access Journals (Sweden)

    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.

  8. SNP-based pathway enrichment analysis for genome-wide association studies

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    Potkin Steven G

    2011-04-01

    Full Text Available Abstract Background Recently we have witnessed a surge of interest in using genome-wide association studies (GWAS to discover the genetic basis of complex diseases. Many genetic variations, mostly in the form of single nucleotide polymorphisms (SNPs, have been identified in a wide spectrum of diseases, including diabetes, cancer, and psychiatric diseases. A common theme arising from these studies is that the genetic variations discovered by GWAS can only explain a small fraction of the genetic risks associated with the complex diseases. New strategies and statistical approaches are needed to address this lack of explanation. One such approach is the pathway analysis, which considers the genetic variations underlying a biological pathway, rather than separately as in the traditional GWAS studies. A critical challenge in the pathway analysis is how to combine evidences of association over multiple SNPs within a gene and multiple genes within a pathway. Most current methods choose the most significant SNP from each gene as a representative, ignoring the joint action of multiple SNPs within a gene. This approach leads to preferential identification of genes with a greater number of SNPs. Results We describe a SNP-based pathway enrichment method for GWAS studies. The method consists of the following two main steps: 1 for a given pathway, using an adaptive truncated product statistic to identify all representative (potentially more than one SNPs of each gene, calculating the average number of representative SNPs for the genes, then re-selecting the representative SNPs of genes in the pathway based on this number; and 2 ranking all selected SNPs by the significance of their statistical association with a trait of interest, and testing if the set of SNPs from a particular pathway is significantly enriched with high ranks using a weighted Kolmogorov-Smirnov test. We applied our method to two large genetically distinct GWAS data sets of schizophrenia, one

  9. Genetic diversity and structure of elite cotton germplasm (Gossypium hirsutum L.) using genome-wide SNP data.

    Science.gov (United States)

    Ai, XianTao; Liang, YaJun; Wang, JunDuo; Zheng, JuYun; Gong, ZhaoLong; Guo, JiangPing; Li, XueYuan; Qu, YanYing

    2017-07-28

    Cotton (Gossypium spp.) is the most important natural textile fiber crop, and Gossypium hirsutum L. is responsible for 90% of the annual cotton crop in the world. Information on cotton genetic diversity and population structure is essential for new breeding lines. In this study, we analyzed population structure and genetic diversity of 288 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China, using genome-wide single nucleotide polymorphisms (SNP) markers. The average polymorphsim information content (PIC) was 0.25, indicating a relatively low degree of genetic diversity. Population structure analysis revealed extensive admixture and identified three subgroups. Phylogenetic analysis supported the subgroups identified by STRUCTURE. The results from both population structure and phylogenetic analysis were, for the most part, in agreement with pedigree information. Analysis of molecular variance revealed a larger amount of variation was due to diversity within the groups. Establishment of genetic diversity and population structure from this study could be useful for genetic and genomic analysis and systematic utilization of the standing genetic variation in upland cotton.

  10. Identification of genome-wide copy number variations among diverse pig breeds using SNP genotyping arrays.

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    Jiying Wang

    Full Text Available Copy number variations (CNVs are important forms of genetic variation complementary to SNPs, and can be considered as promising markers for some phenotypic and economically important traits or diseases susceptibility in domestic animals. In the present study, we performed a genome-wide CNV identification in 14 individuals selected from diverse populations, including six types of Chinese indigenous breeds, one Asian wild boar population, as well as three modern commercial foreign breeds. We identified 63 CNVRs in total, which covered 9.98 Mb of polymorphic sequence and corresponded to 0.36% of the genome sequence. The length of these CNVRs ranged from 3.20 to 827.21 kb, with an average of 158.37 kb and a median of 97.85 kb. Functional annotation revealed these identified CNVR have important molecular function, and may play an important role in exploring the genetic basis of phenotypic variability and disease susceptibility among pigs. Additionally, to confirm these potential CNVRs, we performed qPCR for 12 randomly selected CNVRs and 8 of them (66.67% were confirmed successfully. CNVs detected in diverse populations herein are essential complementary to the CNV map in the pig genome, which provide an important resource for studies of genomic variation and the association between various economically important traits and CNVs.

  11. Exploiting SNP correlations within random forest for genome-wide association studies.

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    Vincent Botta

    Full Text Available The primary goal of genome-wide association studies (GWAS is to discover variants that could lead, in isolation or in combination, to a particular trait or disease. Standard approaches to GWAS, however, are usually based on univariate hypothesis tests and therefore can account neither for correlations due to linkage disequilibrium nor for combinations of several markers. To discover and leverage such potential multivariate interactions, we propose in this work an extension of the Random Forest algorithm tailored for structured GWAS data. In terms of risk prediction, we show empirically on several GWAS datasets that the proposed T-Trees method significantly outperforms both the original Random Forest algorithm and standard linear models, thereby suggesting the actual existence of multivariate non-linear effects due to the combinations of several SNPs. We also demonstrate that variable importances as derived from our method can help identify relevant loci. Finally, we highlight the strong impact that quality control procedures may have, both in terms of predictive power and loci identification. Variable importance results and T-Trees source code are all available at www.montefiore.ulg.ac.be/~botta/ttrees/ and github.com/0asa/TTree-source respectively.

  12. Development and evaluation of a genome-wide 6K SNP array for diploid sweet cherry and tetraploid sour cherry.

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    Cameron Peace

    Full Text Available High-throughput genome scans are important tools for genetic studies and breeding applications. Here, a 6K SNP array for use with the Illumina Infinium® system was developed for diploid sweet cherry (Prunus avium and allotetraploid sour cherry (P. cerasus. This effort was led by RosBREED, a community initiative to enable marker-assisted breeding for rosaceous crops. Next-generation sequencing in diverse breeding germplasm provided 25 billion basepairs (Gb of cherry DNA sequence from which were identified genome-wide SNPs for sweet cherry and for the two sour cherry subgenomes derived from sweet cherry (avium subgenome and P. fruticosa (fruticosa subgenome. Anchoring to the peach genome sequence, recently released by the International Peach Genome Initiative, predicted relative physical locations of the 1.9 million putative SNPs detected, preliminarily filtered to 368,943 SNPs. Further filtering was guided by results of a 144-SNP subset examined with the Illumina GoldenGate® assay on 160 accessions. A 6K Infinium® II array was designed with SNPs evenly spaced genetically across the sweet and sour cherry genomes. SNPs were developed for each sour cherry subgenome by using minor allele frequency in the sour cherry detection panel to enrich for subgenome-specific SNPs followed by targeting to either subgenome according to alleles observed in sweet cherry. The array was evaluated using panels of sweet (n = 269 and sour (n = 330 cherry breeding germplasm. Approximately one third of array SNPs were informative for each crop. A total of 1825 polymorphic SNPs were verified in sweet cherry, 13% of these originally developed for sour cherry. Allele dosage was resolved for 2058 polymorphic SNPs in sour cherry, one third of these being originally developed for sweet cherry. This publicly available genomics resource represents a significant advance in cherry genome-scanning capability that will accelerate marker-locus-trait association discovery

  13. OpenADAM: an open source genome-wide association data management system for Affymetrix SNP arrays

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    Sham P C

    2008-12-01

    Full Text Available Abstract Background Large scale genome-wide association studies have become popular since the introduction of high throughput genotyping platforms. Efficient management of the vast array of data generated poses many challenges. Description We have developed an open source web-based data management system for the large amount of genotype data generated from the Affymetrix GeneChip® Mapping Array and Affymetrix Genome-Wide Human SNP Array platforms. The database supports genotype calling using DM, BRLMM, BRLMM-P or Birdseed algorithms provided by the Affymetrix Power Tools. The genotype and corresponding pedigree data are stored in a relational database for efficient downstream data manipulation and analysis, such as calculation of allele and genotype frequencies, sample identity checking, and export of genotype data in various file formats for analysis using commonly-available software. A novel method for genotyping error estimation is implemented using linkage disequilibrium information from the HapMap project. All functionalities are accessible via a web-based user interface. Conclusion OpenADAM provides an open source database system for management of Affymetrix genome-wide association SNP data.

  14. Genome-wide SNP discovery in tetraploid alfalfa using 454 sequencing and high resolution melting analysis

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    Zhao Patrick X

    2011-07-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are the most common type of sequence variation among plants and are often functionally important. We describe the use of 454 technology and high resolution melting analysis (HRM for high throughput SNP discovery in tetraploid alfalfa (Medicago sativa L., a species with high economic value but limited genomic resources. Results The alfalfa genotypes selected from M. sativa subsp. sativa var. 'Chilean' and M. sativa subsp. falcata var. 'Wisfal', which differ in water stress sensitivity, were used to prepare cDNA from tissue of clonally-propagated plants grown under either well-watered or water-stressed conditions, and then pooled for 454 sequencing. Based on 125.2 Mb of raw sequence, a total of 54,216 unique sequences were obtained including 24,144 tentative consensus (TCs sequences and 30,072 singletons, ranging from 100 bp to 6,662 bp in length, with an average length of 541 bp. We identified 40,661 candidate SNPs distributed throughout the genome. A sample of candidate SNPs were evaluated and validated using high resolution melting (HRM analysis. A total of 3,491 TCs harboring 20,270 candidate SNPs were located on the M. truncatula (MT 3.5.1 chromosomes. Gene Ontology assignments indicate that sequences obtained cover a broad range of GO categories. Conclusions We describe an efficient method to identify thousands of SNPs distributed throughout the alfalfa genome covering a broad range of GO categories. Validated SNPs represent valuable molecular marker resources that can be used to enhance marker density in linkage maps, identify potential factors involved in heterosis and genetic variation, and as tools for association mapping and genomic selection in alfalfa.

  15. A genome wide association study for milk production traits in Danish Jersey cattle using a 50K SNP chip

    DEFF Research Database (Denmark)

    Mai, M D; Sahana, G; Christiansen, F B;

    2010-01-01

    index and 18 for protein index. The evidence presents 33 genome-wide QTL on 14 BTA. Of these, seven had effects on milk index, 21 on fat index and five on protein index. Among the genome-wide QTL, 26 have been previously reported, two on BTA4 and -5 were new for milk index, and five on BTA4, -5, -13......QTL for milk production traits in Danish Jersey cattle were mapped by a genome-wide association analysis using a mixed model. The analysis incorporated 1,039 bulls and 33,090 SNP, and resulted in 98 detected combinations of QTL and traits on 27 BTA. These QTL comprised 30 for milk index, 50 for fat......, -20, and -29 were new QTL for fat index. We found seven pleiotropic or very closely linked QTL. Most of the QTL were associated with polymorphisms within narrow regions and several may represent the effects of polymorphisms of genes: DGAT1, Casein, ARFGAP3, CYP11B1, and CDC-like kinase 4...

  16. Genome-wide joint meta-analysis of SNP and SNP-by-smoking interaction identifies novel loci for pulmonary function.

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    Dana B Hancock

    Full Text Available Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV(1, and its ratio to forced vital capacity (FEV(1/FVC. Given that cigarette smoking adversely affects pulmonary function, we conducted genome-wide joint meta-analyses (JMA of single nucleotide polymorphism (SNP and SNP-by-smoking (ever-smoking or pack-years associations on FEV(1 and FEV(1/FVC across 19 studies (total N = 50,047. We identified three novel loci not previously associated with pulmonary function. SNPs in or near DNER (smallest P(JMA = 5.00×10(-11, HLA-DQB1 and HLA-DQA2 (smallest P(JMA = 4.35×10(-9, and KCNJ2 and SOX9 (smallest P(JMA = 1.28×10(-8 were associated with FEV(1/FVC or FEV(1 in meta-analysis models including SNP main effects, smoking main effects, and SNP-by-smoking (ever-smoking or pack-years interaction. The HLA region has been widely implicated for autoimmune and lung phenotypes, unlike the other novel loci, which have not been widely implicated. We evaluated DNER, KCNJ2, and SOX9 and found them to be expressed in human lung tissue. DNER and SOX9 further showed evidence of differential expression in human airway epithelium in smokers compared to non-smokers. Our findings demonstrated that joint testing of SNP and SNP-by-environment interaction identified novel loci associated with complex traits that are missed when considering only the genetic main effects.

  17. Genetic diversity in the modern horse illustrated from genome-wide SNP data.

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    Jessica L Petersen

    Full Text Available Horses were domesticated from the Eurasian steppes 5,000-6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds. This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. F(ST calculations, parsimony, and distance analysis demonstrated relationships among the breeds that largely reflect geographic origins and known breed histories. Low levels of population divergence were observed between breeds that are relatively early on in the process of breed development, and between those with high levels of within-breed diversity, whether due to large population size, ongoing outcrossing, or large within-breed phenotypic diversity. Populations with low within-breed diversity included those which have experienced population bottlenecks, have been under intense selective pressure, or are closed populations with long breed histories. These results provide new insights into the relationships among and the diversity within breeds of horses. In addition these results will facilitate future genome-wide association studies and investigations into genomic targets of selection.

  18. Genetic Diversity in the Modern Horse Illustrated from Genome-Wide SNP Data

    Science.gov (United States)

    Petersen, Jessica L.; Mickelson, James R.; Cothran, E. Gus; Andersson, Lisa S.; Axelsson, Jeanette; Bailey, Ernie; Bannasch, Danika; Binns, Matthew M.; Borges, Alexandre S.; Brama, Pieter; da Câmara Machado, Artur; Distl, Ottmar; Felicetti, Michela; Fox-Clipsham, Laura; Graves, Kathryn T.; Guérin, Gérard; Haase, Bianca; Hasegawa, Telhisa; Hemmann, Karin; Hill, Emmeline W.; Leeb, Tosso; Lindgren, Gabriella; Lohi, Hannes; Lopes, Maria Susana; McGivney, Beatrice A.; Mikko, Sofia; Orr, Nicholas; Penedo, M. Cecilia T; Piercy, Richard J.; Raekallio, Marja; Rieder, Stefan; Røed, Knut H.; Silvestrelli, Maurizio; Swinburne, June; Tozaki, Teruaki; Vaudin, Mark; M. Wade, Claire; McCue, Molly E.

    2013-01-01

    Horses were domesticated from the Eurasian steppes 5,000–6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. FST calculations, parsimony, and distance analysis demonstrated relationships among the breeds that largely reflect geographic origins and known breed histories. Low levels of population divergence were observed between breeds that are relatively early on in the process of breed development, and between those with high levels of within-breed diversity, whether due to large population size, ongoing outcrossing, or large within-breed phenotypic diversity. Populations with low within-breed diversity included those which have experienced population bottlenecks, have been under intense selective pressure, or are closed populations with long breed histories. These results provide new insights into the relationships among and the diversity within breeds of horses. In addition these results will facilitate future genome-wide association studies and investigations into genomic targets of selection. PMID:23383025

  19. ChIP on SNP-chip for genome-wide analysis of human histone H4 hyperacetylation

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    Porter Christopher J

    2007-09-01

    Full Text Available Abstract Background SNP microarrays are designed to genotype Single Nucleotide Polymorphisms (SNPs. These microarrays report hybridization of DNA fragments and therefore can be used for the purpose of detecting genomic fragments. Results Here, we demonstrate that a SNP microarray can be effectively used in this way to perform chromatin immunoprecipitation (ChIP on chip as an alternative to tiling microarrays. We illustrate this novel application by mapping whole genome histone H4 hyperacetylation in human myoblasts and myotubes. We detect clusters of hyperacetylated histone H4, often spanning across up to 300 kilobases of genomic sequence. Using complementary genome-wide analyses of gene expression by DNA microarray we demonstrate that these clusters of hyperacetylated histone H4 tend to be associated with expressed genes. Conclusion The use of a SNP array for a ChIP-on-chip application (ChIP on SNP-chip will be of great value to laboratories whose interest is the determination of general rules regarding the relationship of specific chromatin modifications to transcriptional status throughout the genome and to examine the asymmetric modification of chromatin at heterozygous loci.

  20. Genome-wide SNP association-based localization of a dwarfism gene in Friesian dwarf horses

    NARCIS (Netherlands)

    Orr, J.L.; Back, W.; Gu, J.; Leegwater, P.H.; Govindarajan, P.; Conroy, J.; Ducro, B.J.; Arendonk, van J.A.M.

    2010-01-01

    The recent completion of the horse genome and commercial availability of an equine SNP genotyping array has facilitated the mapping of disease genes. We report putative localization of the gene responsible for dwarfism, a trait in Friesian horses that is thought to have a recessive mode of

  1. Power to detect risk alleles using genome-wide tag SNP panels.

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    Michael A Eberle

    2007-10-01

    Full Text Available Advances in high-throughput genotyping and the International HapMap Project have enabled association studies at the whole-genome level. We have constructed whole-genome genotyping panels of over 550,000 (HumanHap550 and 650,000 (HumanHap650Y SNP loci by choosing tag SNPs from all populations genotyped by the International HapMap Project. These panels also contain additional SNP content in regions that have historically been overrepresented in diseases, such as nonsynonymous sites, the MHC region, copy number variant regions and mitochondrial DNA. We estimate that the tag SNP loci in these panels cover the majority of all common variation in the genome as measured by coverage of both all common HapMap SNPs and an independent set of SNPs derived from complete resequencing of genes obtained from SeattleSNPs. We also estimate that, given a sample size of 1,000 cases and 1,000 controls, these panels have the power to detect single disease loci of moderate risk (lambda approximately 1.8-2.0. Relative risks as low as lambda approximately 1.1-1.3 can be detected using 10,000 cases and 10,000 controls depending on the sample population and disease model. If multiple loci are involved, the power increases significantly to detect at least one locus such that relative risks 20%-35% lower can be detected with 80% power if between two and four independent loci are involved. Although our SNP selection was based on HapMap data, which is a subset of all common SNPs, these panels effectively capture the majority of all common variation and provide high power to detect risk alleles that are not represented in the HapMap data.

  2. Novel approach for deriving genome wide SNP analysis data from archived blood spots

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    Fowler Katie E

    2012-09-01

    Full Text Available Abstract Background The ability to transport and store DNA at room temperature in low volumes has the advantage of optimising cost, time and storage space. Blood spots on adapted filter papers are popular for this, with FTA (Flinders Technology Associates Whatman™TM technology being one of the most recent. Plant material, plasmids, viral particles, bacteria and animal blood have been stored and transported successfully using this technology, however the method of porcine DNA extraction from FTA Whatman™TM cards is a relatively new approach, allowing nucleic acids to be ready for downstream applications such as PCR, whole genome amplification, sequencing and subsequent application to single nucleotide polymorphism microarrays has hitherto been under-explored. Findings DNA was extracted from FTA Whatman™TM cards (following adaptations of the manufacturer’s instructions, whole genome amplified and subsequently analysed to validate the integrity of the DNA for downstream SNP analysis. DNA was successfully extracted from 288/288 samples and amplified by WGA. Allele dropout post WGA, was observed in less than 2% of samples and there was no clear evidence of amplification bias nor contamination. Acceptable call rates on porcine SNP chips were also achieved using DNA extracted and amplified in this way. Conclusions DNA extracted from FTA Whatman cards is of a high enough quality and quantity following whole genomic amplification to perform meaningful SNP chip studies.

  3. Genome-wide microsatellite characterization and marker development in the sequenced Brassica crop species.

    Science.gov (United States)

    Shi, Jiaqin; Huang, Shunmou; Zhan, Jiepeng; Yu, Jingyin; Wang, Xinfa; Hua, Wei; Liu, Shengyi; Liu, Guihua; Wang, Hanzhong

    2014-02-01

    Although much research has been conducted, the pattern of microsatellite distribution has remained ambiguous, and the development/utilization of microsatellite markers has still been limited/inefficient in Brassica, due to the lack of genome sequences. In view of this, we conducted genome-wide microsatellite characterization and marker development in three recently sequenced Brassica crops: Brassica rapa, Brassica oleracea and Brassica napus. The analysed microsatellite characteristics of these Brassica species were highly similar or almost identical, which suggests that the pattern of microsatellite distribution is likely conservative in Brassica. The genomic distribution of microsatellites was highly non-uniform and positively or negatively correlated with genes or transposable elements, respectively. Of the total of 115 869, 185 662 and 356 522 simple sequence repeat (SSR) markers developed with high frequencies (408.2, 343.8 and 356.2 per Mb or one every 2.45, 2.91 and 2.81 kb, respectively), most represented new SSR markers, the majority had determined physical positions, and a large number were genic or putative single-locus SSR markers. We also constructed a comprehensive database for the newly developed SSR markers, which was integrated with public Brassica SSR markers and annotated genome components. The genome-wide SSR markers developed in this study provide a useful tool to extend the annotated genome resources of sequenced Brassica species to genetic study/breeding in different Brassica species.

  4. Genome-wide SNP association-based localization of a dwarfism gene in Friesian dwarf horses.

    Science.gov (United States)

    Orr, N; Back, W; Gu, J; Leegwater, P; Govindarajan, P; Conroy, J; Ducro, B; Van Arendonk, J A M; MacHugh, D E; Ennis, S; Hill, E W; Brama, P A J

    2010-12-01

    The recent completion of the horse genome and commercial availability of an equine SNP genotyping array has facilitated the mapping of disease genes. We report putative localization of the gene responsible for dwarfism, a trait in Friesian horses that is thought to have a recessive mode of inheritance, to a 2-MB region of chromosome 14 using just 10 affected animals and 10 controls. We successfully genotyped 34,429 SNPs that were tested for association with dwarfism using chi-square tests. The most significant SNP in our study, BIEC2-239376 (P(2df)=4.54 × 10(-5), P(rec)=7.74 × 10(-6)), is located close to a gene implicated in human dwarfism. Fine-mapping and resequencing analyses did not aid in further localization of the causative variant, and replication of our findings in independent sample sets will be necessary to confirm these results. © 2010 The Authors, Journal compilation © 2010 Stichting International Foundation for Animal Genetics.

  5. Identification of Risk Pathways and Functional Modules for Coronary Artery Disease Based on Genome-wide SNP Data

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    Xiang Zhao

    2016-12-01

    Full Text Available Coronary artery disease (CAD is a complex human disease, involving multiple genes and their nonlinear interactions, which often act in a modular fashion. Genome-wide single nucleotide polymorphism (SNP profiling provides an effective technique to unravel these underlying genetic interplays or their functional involvements for CAD. This study aimed to identify the susceptible pathways and modules for CAD based on SNP omics. First, the Wellcome Trust Case Control Consortium (WTCCC SNP datasets of CAD and control samples were used to assess the joint effect of multiple genetic variants at the pathway level, using logistic kernel machine regression model. Then, an expanded genetic network was constructed by integrating statistical gene–gene interactions involved in these susceptible pathways with their protein–protein interaction (PPI knowledge. Finally, risk functional modules were identified by decomposition of the network. Of 276 KEGG pathways analyzed, 6 pathways were found to have a significant effect on CAD. Other than glycerolipid metabolism, glycosaminoglycan biosynthesis, and cardiac muscle contraction pathways, three pathways related to other diseases were also revealed, including Alzheimer’s disease, non-alcoholic fatty liver disease, and Huntington’s disease. A genetic epistatic network of 95 genes was further constructed using the abovementioned integrative approach. Of 10 functional modules derived from the network, 6 have been annotated to phospholipase C activity and cell adhesion molecule binding, which also have known functional involvement in Alzheimer’s disease. These findings indicate an overlap of the underlying molecular mechanisms between CAD and Alzheimer’s disease, thus providing new insights into the molecular basis for CAD and its molecular relationships with other diseases.

  6. Genome-wide association study identifies candidate markers for bull fertility in Holstein dairy cattle.

    Science.gov (United States)

    Peñagaricano, F; Weigel, K A; Khatib, H

    2012-07-01

    The decline in the reproductive efficiency of dairy cattle has become a challenging problem worldwide. Female fertility is now taken into account in breeding goals while generally less attention is given to male fertility. The objective of this study was to perform a genome-wide association study in Holstein bulls to identify genetic variants significantly related to sire conception rate (SCR), a new phenotypic evaluation of bull fertility. The analysis included 1755 sires with SCR data and 38,650 single nucleotide polymorphisms (SNPs) spanning the entire bovine genome. Associations between SNPs and SCR were analyzed using a mixed linear model that included a random polygenic effect and SNP genotype either as a linear covariate or as a categorical variable. A multiple testing correction approach was used to account for the correlation between SNPs because of linkage disequilibrium. After genome-wide correction, eight SNPs showed significant association with SCR. Some of these SNPs are located close to or in the middle of genes with functions related to male fertility, such as the sperm acrosome reaction, chromatin remodeling during the spermatogenesis, and the meiotic process during male germ cell maturation. Some SNPs showed marked dominance effects, which provide more evidence for the relevance of non-additive effects in traits closely related to fitness such as fertility. The results could contribute to the identification of genes and pathways associated with male fertility in dairy cattle.

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

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    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

  8. Estimating Additive and Non-Additive Genetic Variances and Predicting Genetic Merits Using Genome-Wide Dense Single Nucleotide Polymorphism Markers

    DEFF Research Database (Denmark)

    Su, Guosheng; Christensen, Ole Fredslund; Ostersen, Tage;

    2012-01-01

    Non-additive genetic variation is usually ignored when genome-wide markers are used to study the genetic architecture and genomic prediction of complex traits in human, wild life, model organisms or farm animals. However, non-additive genetic effects may have an important contribution to total...... genetic variation of complex traits. This study presented a genomic BLUP model including additive and non-additive genetic effects, in which additive and non-additive genetic relation matrices were constructed from information of genome-wide dense single nucleotide polymorphism (SNP) markers. In addition...... of genomic predictions for daily gain in pigs. In the analysis of daily gain, four linear models were used: 1) a simple additive genetic model (MA), 2) a model including both additive and additive by additive epistatic genetic effects (MAE), 3) a model including both additive and dominance genetic effects...

  9. Genome-wide linkage analysis of QTL for growth and body composition employing the PorcineSNP60 BeadChip

    Directory of Open Access Journals (Sweden)

    Fernández Ana I

    2012-05-01

    Full Text Available Abstract Background The traditional strategy to map QTL is to use linkage analysis employing a limited number of markers. These analyses report wide QTL confidence intervals, making very difficult to identify the gene and polymorphisms underlying the QTL effects. The arrival of genome-wide panels of SNPs makes available thousands of markers increasing the information content and therefore the likelihood of detecting and fine mapping QTL regions. The aims of the current study are to confirm previous QTL regions for growth and body composition traits in different generations of an Iberian x Landrace intercross (IBMAP and especially identify new ones with narrow confidence intervals by employing the PorcineSNP60 BeadChip in linkage analyses. Results Three generations (F3, Backcross 1 and Backcross 2 of the IBMAP and their related animals were genotyped with PorcineSNP60 BeadChip. A total of 8,417 SNPs equidistantly distributed across autosomes were selected after filtering by quality, position and frequency to perform the QTL scan. The joint and separate analyses of the different IBMAP generations allowed confirming QTL regions previously identified in chromosomes 4 and 6 as well as new ones mainly for backfat thickness in chromosomes 4, 5, 11, 14 and 17 and shoulder weight in chromosomes 1, 2, 9 and 13; and many other to the chromosome-wide signification level. In addition, most of the detected QTLs displayed narrow confidence intervals, making easier the selection of positional candidate genes. Conclusions The use of higher density of markers has allowed to confirm results obtained in previous QTL scans carried out with microsatellites. Moreover several new QTL regions have been now identified in regions probably not covered by markers in previous scans, most of these QTLs displayed narrow confidence intervals. Finally, prominent putative biological and positional candidate genes underlying those QTL effects are listed based on recent porcine

  10. Genome-Wide Association Mapping for Intelligence in Military Working Dogs: Canine Cohort, Canine Intelligence Assessment Regimen, Genome-Wide Single Nucleotide Polymorphism (SNP) Typing, and Unsupervised Classification Algorithm for Genome-Wide Association Data Analysis

    Science.gov (United States)

    2011-09-01

    Almasy, L, Blangero, J. (2009) Human QTL linkage mapping. Genetica 136:333-340. Amos, CI. (2007) Successful design and conduct of genome-wide...quantitative trait loci. Genetica 136:237-243. Skol AD, Scott LJ, Abecasis GR, Boehnke M. (2006) Joint analysis is more efficient than replication

  11. Analysis of East Asia genetic substructure using genome-wide SNP arrays.

    Directory of Open Access Journals (Sweden)

    Chao Tian

    Full Text Available Accounting for population genetic substructure is important in reducing type 1 errors in genetic studies of complex disease. As efforts to understand complex genetic disease are expanded to different continental populations the understanding of genetic substructure within these continents will be useful in design and execution of association tests. In this study, population differentiation (Fst and Principal Components Analyses (PCA are examined using >200 K genotypes from multiple populations of East Asian ancestry. The population groups included those from the Human Genome Diversity Panel [Cambodian, Yi, Daur, Mongolian, Lahu, Dai, Hezhen, Miaozu, Naxi, Oroqen, She, Tu, Tujia, Naxi, Xibo, and Yakut], HapMap [ Han Chinese (CHB and Japanese (JPT], and East Asian or East Asian American subjects of Vietnamese, Korean, Filipino and Chinese ancestry. Paired Fst (Wei and Cockerham showed close relationships between CHB and several large East Asian population groups (CHB/Korean, 0.0019; CHB/JPT, 00651; CHB/Vietnamese, 0.0065 with larger separation with Filipino (CHB/Filipino, 0.014. Low levels of differentiation were also observed between Dai and Vietnamese (0.0045 and between Vietnamese and Cambodian (0.0062. Similarly, small Fst's were observed among different presumed Han Chinese populations originating in different regions of mainland of China and Taiwan (Fst's <0.0025 with CHB. For PCA, the first two PC's showed a pattern of relationships that closely followed the geographic distribution of the different East Asian populations. PCA showed substructure both between different East Asian groups and within the Han Chinese population. These studies have also identified a subset of East Asian substructure ancestry informative markers (EASTASAIMS that may be useful for future complex genetic disease association studies in reducing type 1 errors and in identifying homogeneous groups that may increase the power of such studies.

  12. RAD-seq derived genome-wide nuclear markers resolve the phylogeny of tunas

    KAUST Repository

    Díaz-Arce, Natalia

    2016-06-07

    Although species from the genus Thunnus include some of the most commercially important and most severely overexploited fishes, the phylogeny of this genus is still unresolved, hampering evolutionary and traceability studies that could help improve conservation and management strategies for these species. Previous attempts based on mitochondrial and nuclear markers were unsuccessful in inferring a congruent and reliable phylogeny, probably due to mitochondrial introgression events and lack of enough phylogenetically informative markers. Here we infer the first genome-wide nuclear marker-based phylogeny of tunas using restriction site associated DNA sequencing (RAD-seq) data. Our results, derived from phylogenomic inferences obtained from 128 nucleotide matrices constructed using alternative data assembly procedures, support a single Thunnus evolutionary history that challenges previous assumptions based on morphological and molecular data.

  13. 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.

  14. Allelic association studies of genome wide association data can reveal errors in marker position assignments

    Directory of Open Access Journals (Sweden)

    Curtis David

    2007-06-01

    Full Text Available Abstract Background Genome wide association (GWA studies provide the opportunity to develop new kinds of analysis. Analysing pairs of markers from separate regions might lead to the detection of allelic association which might indicate an interaction between nearby genes. Methods 396,591 markers typed in 541 subjects were studied. 7.8*1010 pairs of markers were screened and those showing initial evidence for allelic association were subjected to more thorough investigation along with 10 flanking markers on either side. Results No evidence was detected for interaction. However 6 markers appeared to have an incorrect map position according to NCBI Build 35. One of these was corrected in Build 36 and 2 were dropped. The remaining 3 were left with map positions inconsistent with their allelic association relationships. Discussion Although no interaction effects were detected the method was successful in identifying markers with probably incorrect map positions. Conclusion The study of allelic association can supplement other methods for assigning markers to particular map positions. Analyses of this type may usefully be applied to data from future GWA studies.

  15. Genome-wide SNP-based linkage scan identifies a locus on 8q24 for an age-related hearing impairment trait

    DEFF Research Database (Denmark)

    Huyghe, J.R.; Laer, L. Van; Hendrickx, J.J.

    2008-01-01

    the results of a cross-sectional family-based genetic study employing audiometric data. By using principal component analysis, we were able to reduce the dimensionality of this multivariate phenotype while capturing most of the variation and retaining biologically important features of the audiograms. We...... conducted a genome-wide association as well as a linkage scan with high-density SNP microarrays. Because of the presence of genetic population substructure, association testing was stratified after which evidence was combined by meta-analysis. No association signals reaching genome-wide significance were...

  16. Rapid Diagnosis of Imprinting Disorders Involving Copy Number Variation and Uniparental Disomy Using Genome-Wide SNP Microarrays.

    Science.gov (United States)

    Liu, Weiqiang; Zhang, Rui; Wei, Jun; Zhang, Huimin; Yu, Guojiu; Li, Zhihua; Chen, Min; Sun, Xiaofang

    2015-01-01

    Imprinting disorders, such as Beckwith-Wiedemann syndrome (BWS), Prader-Willi syndrome (PWS) and Angelman syndrome (AS), can be detected via methylation analysis, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), or other methods. In this study, we applied single nucleotide polymorphism (SNP)-based chromosomal microarray analysis to detect copy number variations (CNVs) and uniparental disomy (UPD) events in patients with suspected imprinting disorders. Of 4 patients, 2 had a 5.25-Mb microdeletion in the 15q11.2q13.2 region, 1 had a 38.4-Mb mosaic UPD in the 11p15.4 region, and 1 had a 60-Mb detectable UPD between regions 14q13.2 and 14q32.13. Although the 14q32.2 region was classified as normal by SNP array for the 14q13 UPD patient, it turned out to be a heterodisomic UPD by short tandem repeat marker analysis. MS-MLPA analysis was performed to validate the variations. In conclusion, SNP-based microarray is an efficient alternative method for quickly and precisely diagnosing PWS, AS, BWS, and other imprinted gene-associated disorders when considering aberrations due to CNVs and most types of UPD.

  17. A Genome-Wide SNP Linkage Analysis Suggests a Susceptibility Locus on 6p21 for Ankylosing Spondylitis and Inflammatory Back Pain Trait

    Science.gov (United States)

    Zhang, Yanli; Liao, Zetao; Wei, Qiujing; Pan, Yunfeng; Wang, Xinwei; Cao, Shuangyan; Guo, Zishi; Wu, Yuqiong; Rong, Ju; Jin, Ou; Xu, Manlong; Gu, Jieruo

    2016-01-01

    Objectives To screen susceptibility loci for ankylosing spondylitis (AS) using an affected-only linkage analysis based on high-density single nucleotide polymorphisms (SNPs) in a genome-wide manner. Patients and Methods AS patients from ten families with Cantonese origin of China were enrolled in the study. Blood samples were genotyped using genomic DNA derived from peripheral blood leukocytes by Illumina HumanHap 610-Quad SNP Chip. Genotype data were generated using the Illumina BeadStudio 3.2 software. PLINK package was used to remove non-autosomal SNPs and to further eliminate markers of typing errors. An affected-only linkage analysis was carried out using both non-parametric and parametric linkage analyses, as implemented in MERLIN. Result Seventy-eight AS patients (48 males and 30 females, mean age: 39±16 years) were enrolled in the study. The mean age of onset was 23±10 years and mean duration of disease was 16.7±12.2 years. Iritis (2/76, 2.86%), dactylitis (5/78, 6.41%), hip joint involvement (9/78, 11.54%), peripheral arthritis (22/78, 28.21%), inflammatory back pain (IBP) (69/78, 88.46%) and HLA-B27 positivity (70/78, 89.74%) were observed in these patients. Using non-parameter linkage analysis, we found one susceptibility locus for AS, IBP and HLA-B27 in 6p21 respectively, spanning about 13.5Mb, 20.9Mb and 21.2Mb, respectively No significant results were found in the other clinical trait groups including dactylitis, hip involved and arthritis. The identical susceptibility locus region spanning above 9.44Mb was detected in AS IBP and HLA-B27 by the parametric linkage analysis. Conclusion Our genome-wide SNP linkage analysis in ten families with ankylosing spondylitis suggests a susceptibility locus on 6p21 in AS, which is a risk locus for IBP in AS patients. PMID:27973620

  18. Comparative genome-wide polymorphic microsatellite markers in Antarctic penguins through next generation sequencing.

    Science.gov (United States)

    Vianna, Juliana A; Noll, Daly; Mura-Jornet, Isidora; Valenzuela-Guerra, Paulina; González-Acuña, Daniel; Navarro, Cristell; Loyola, David E; Dantas, Gisele P M

    Microsatellites are valuable molecular markers for evolutionary and ecological studies. Next generation sequencing is responsible for the increasing number of microsatellites for non-model species. Penguins of the Pygoscelis genus are comprised of three species: Adélie (P. adeliae), Chinstrap (P. antarcticus) and Gentoo penguin (P. papua), all distributed around Antarctica and the sub-Antarctic. The species have been affected differently by climate change, and the use of microsatellite markers will be crucial to monitor population dynamics. We characterized a large set of genome-wide microsatellites and evaluated polymorphisms in all three species. SOLiD reads were generated from the libraries of each species, identifying a large amount of microsatellite loci: 33,677, 35,265 and 42,057 for P. adeliae, P. antarcticus and P. papua, respectively. A large number of dinucleotide (66,139), trinucleotide (29,490) and tetranucleotide (11,849) microsatellites are described. Microsatellite abundance, diversity and orthology were characterized in penguin genomes. We evaluated polymorphisms in 170 tetranucleotide loci, obtaining 34 polymorphic loci in at least one species and 15 polymorphic loci in all three species, which allow to perform comparative studies. Polymorphic markers presented here enable a number of ecological, population, individual identification, parentage and evolutionary studies of Pygoscelis, with potential use in other penguin species.

  19. 利用高密度SNP对猪血糖和糖基化血清蛋白性状的全基因组关联分析%Genome-Wide Association Study on Porcine Serum Glucose (GLU) and Glycosylated Serum Proteins (GSP) with High Density SNP Markers

    Institute of Scientific and Technical Information of China (English)

    曾治君; 刘晨龙; 杨慧; 杨斌; 杨竹青; 陈从英

    2014-01-01

    [Objective] Serum glucose (GLU) and glycosylated serum protein (GSP) contents in a Sutai population and a large-scale White Duroc×Erhualian F2 intercross at the age of 240 days were measured. A genome-wide association study was carried out to identify the SNPs or chromosomal regions associated with GLU and GSP. The aim of the study is to establish a foundation for identification of causative genes influencing the serum GLU and GSP, and provide the clues for genetic analysis of human hypoglycemia and diabetes.[Method]The experimental pigs used in this study included 435 Sutai pigs that were bought from Sutai Pig Breeding Center in Suzhou city and 760 F2 individuals from White Duroc × Erhualian intercross that was constructed by Key Laboratory for Animal Biotechnology of Jiangxi Agricultural University. All experimental pigs were fed under the same farm conditions and slaughtered at the age of 240 days at Guohong abattoir. The collected blood samples were kept at room temperature for 5 hours, then centrifuged at 4℃, 3 000 r/min for 20 min. The serum GLU and GSP were determined with commercial kits. Genomic DNA was extracted from ear tissues using a standard phenol/chloroform method, the concentration and quality were determined by NANODROP 1000 analyzer. All DNA samples were diluted to 20ng·μL-1, and then stored at -20℃until used. All experimental animals were genotyped with Illumina porcine 60K SNP chip. Quality control of genotyping results was carried out using PLINK software. The genome-wide association studies were performed with the mixed linear model with the SNPs passed the quality control by using GenABEL software in the R packages to identify the significant SNPs associated with GLU and GSP at 240 days in the Sutai and White Duroc × Erhualian F2 intercross. The possible candidate genes were chosen for each of significant region according to gene annotations in Ensembl or NCBI websites. [Result]A total of 5 SNPs that significantly associated with

  20. Accuracy of genome-wide imputation of untyped markers and impacts on statistical power for association studies

    Directory of Open Access Journals (Sweden)

    McElwee Joshua

    2009-06-01

    Full Text Available Abstract Background Although high-throughput genotyping arrays have made whole-genome association studies (WGAS feasible, only a small proportion of SNPs in the human genome are actually surveyed in such studies. In addition, various SNP arrays assay different sets of SNPs, which leads to challenges in comparing results and merging data for meta-analyses. Genome-wide imputation of untyped markers allows us to address these issues in a direct fashion. Methods 384 Caucasian American liver donors were genotyped using Illumina 650Y (Ilmn650Y arrays, from which we also derived genotypes from the Ilmn317K array. On these data, we compared two imputation methods: MACH and BEAGLE. We imputed 2.5 million HapMap Release22 SNPs, and conducted GWAS on ~40,000 liver mRNA expression traits (eQTL analysis. In addition, 200 Caucasian American and 200 African American subjects were genotyped using the Affymetrix 500 K array plus a custom 164 K fill-in chip. We then imputed the HapMap SNPs and quantified the accuracy by randomly masking observed SNPs. Results MACH and BEAGLE perform similarly with respect to imputation accuracy. The Ilmn650Y results in excellent imputation performance, and it outperforms Affx500K or Ilmn317K sets. For Caucasian Americans, 90% of the HapMap SNPs were imputed at 98% accuracy. As expected, imputation of poorly tagged SNPs (untyped SNPs in weak LD with typed markers was not as successful. It was more challenging to impute genotypes in the African American population, given (1 shorter LD blocks and (2 admixture with Caucasian populations in this population. To address issue (2, we pooled HapMap CEU and YRI data as an imputation reference set, which greatly improved overall performance. The approximate 40,000 phenotypes scored in these populations provide a path to determine empirically how the power to detect associations is affected by the imputation procedures. That is, at a fixed false discovery rate, the number of cis

  1. Meta-analysis of Genome Wide Association Studies Identifies Genetic Markers of Late Toxicity Following Radiotherapy for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Sarah L. Kerns

    2016-08-01

    Full Text Available Nearly 50% of cancer patients undergo radiotherapy. Late radiotherapy toxicity affects quality-of-life in long-term cancer survivors and risk of side-effects in a minority limits doses prescribed to the majority of patients. Development of a test predicting risk of toxicity could benefit many cancer patients. We aimed to meta-analyze individual level data from four genome-wide association studies from prostate cancer radiotherapy cohorts including 1564 men to identify genetic markers of toxicity. Prospectively assessed two-year toxicity endpoints (urinary frequency, decreased urine stream, rectal bleeding, overall toxicity and single nucleotide polymorphism (SNP associations were tested using multivariable regression, adjusting for clinical and patient-related risk factors. A fixed-effects meta-analysis identified two SNPs: rs17599026 on 5q31.2 with urinary frequency (odds ratio [OR] 3.12, 95% confidence interval [CI] 2.08–4.69, p-value 4.16 × 10−8 and rs7720298 on 5p15.2 with decreased urine stream (OR 2.71, 95% CI 1.90–3.86, p-value = 3.21 × 10−8. These SNPs lie within genes that are expressed in tissues adversely affected by pelvic radiotherapy including bladder, kidney, rectum and small intestine. The results show that heterogeneous radiotherapy cohorts can be combined to identify new moderate-penetrance genetic variants associated with radiotherapy toxicity. The work provides a basis for larger collaborative efforts to identify enough variants for a future test involving polygenic risk profiling.

  2. Meta-analysis of Genome Wide Association Studies Identifies Genetic Markers of Late Toxicity Following Radiotherapy for Prostate Cancer.

    Science.gov (United States)

    Kerns, Sarah L; Dorling, Leila; Fachal, Laura; Bentzen, Søren; Pharoah, Paul D P; Barnes, Daniel R; Gómez-Caamaño, Antonio; Carballo, Ana M; Dearnaley, David P; Peleteiro, Paula; Gulliford, Sarah L; Hall, Emma; Michailidou, Kyriaki; Carracedo, Ángel; Sia, Michael; Stock, Richard; Stone, Nelson N; Sydes, Matthew R; Tyrer, Jonathan P; Ahmed, Shahana; Parliament, Matthew; Ostrer, Harry; Rosenstein, Barry S; Vega, Ana; Burnet, Neil G; Dunning, Alison M; Barnett, Gillian C; West, Catharine M L

    2016-08-01

    Nearly 50% of cancer patients undergo radiotherapy. Late radiotherapy toxicity affects quality-of-life in long-term cancer survivors and risk of side-effects in a minority limits doses prescribed to the majority of patients. Development of a test predicting risk of toxicity could benefit many cancer patients. We aimed to meta-analyze individual level data from four genome-wide association studies from prostate cancer radiotherapy cohorts including 1564 men to identify genetic markers of toxicity. Prospectively assessed two-year toxicity endpoints (urinary frequency, decreased urine stream, rectal bleeding, overall toxicity) and single nucleotide polymorphism (SNP) associations were tested using multivariable regression, adjusting for clinical and patient-related risk factors. A fixed-effects meta-analysis identified two SNPs: rs17599026 on 5q31.2 with urinary frequency (odds ratio [OR] 3.12, 95% confidence interval [CI] 2.08-4.69, p-value 4.16×10(-8)) and rs7720298 on 5p15.2 with decreased urine stream (OR 2.71, 95% CI 1.90-3.86, p-value=3.21×10(-8)). These SNPs lie within genes that are expressed in tissues adversely affected by pelvic radiotherapy including bladder, kidney, rectum and small intestine. The results show that heterogeneous radiotherapy cohorts can be combined to identify new moderate-penetrance genetic variants associated with radiotherapy toxicity. The work provides a basis for larger collaborative efforts to identify enough variants for a future test involving polygenic risk profiling.

  3. Southeast Asian origins of five Hill Tribe populations and correlation of genetic to linguistic relationships inferred with genome-wide SNP data.

    Science.gov (United States)

    Listman, J B; Malison, R T; Sanichwankul, K; Ittiwut, C; Mutirangura, A; Gelernter, J

    2011-02-01

    In Thailand, the term Hill Tribe is used to describe populations whose members traditionally practice slash and burn agriculture and reside in the mountains. These tribes are thought to have migrated throughout Asia for up to 5,000 years, including migrations through Southern China and/or Southeast Asia. There have been continuous migrations southward from China into Thailand for approximately the past thousand years and the present geographic range of any given tribe straddles multiple political borders. As none of these populations have autochthonous scripts, written histories have until recently, been externally produced. Northern Asian, Tibetan, and Siberian origins of Hill Tribes have been proposed. All purport endogamy and have nonmutually intelligible languages. To test hypotheses regarding the geographic origins of these populations, relatedness and migrations among them and neighboring populations, and whether their genetic relationships correspond with their linguistic relationships, we analyzed 2,445 genome-wide SNP markers in 118 individuals from five Thai Hill Tribe populations (Akha, Hmong, Karen, Lahu, and Lisu), 90 individuals from majority Thai populations, and 826 individuals from Asian and Oceanean HGDP and HapMap populations using a Bayesian clustering method. Considering these results within the context of results ofrecent large-scale studies of Asian geographic genetic variation allows us to infer a shared Southeast Asian origin of these five Hill Tribe populations as well ancestry components that distinguish among them seen in successive levels of clustering. In addition, the inferred level of shared ancestry among the Hill Tribes corresponds well to relationships among their languages.

  4. Genome-Wide Gene Expression Profile Analyses Identify CTTN as a Potential Prognostic Marker in Esophageal Cancer

    OpenAIRE

    2014-01-01

    Aim Esophageal squamous cell carcinoma (ESCC) is one of the most common fatal malignances of the digestive tract. Its prognosis is poor mainly due to the lack of reliable markers for early detection and prognostic prediction. Here we aim to identify the molecules involved in ESCC carcinogenesis and those as potential markers for prognosis and as new molecular therapeutic targets. Methods We performed genome-wide gene expression profile analyses of 10 primary ESCCs and their adjacent normal ti...

  5. 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

  6. ChIP on SNP-chip for genome-wide analysis of human histone H4 hyperacetylation

    OpenAIRE

    Porter Christopher J; Palidwor Gareth; Palmer Claire; Muro Enrique M; McCann Jennifer A; Andrade-Navarro Miguel A; Rudnicki Michael A

    2007-01-01

    Abstract Background SNP microarrays are designed to genotype Single Nucleotide Polymorphisms (SNPs). These microarrays report hybridization of DNA fragments and therefore can be used for the purpose of detecting genomic fragments. Results Here, we demonstrate that a SNP microarray can be effectively used in this way to perform chromatin immunoprecipitation (ChIP) on chip as an alternative to tiling microarrays. We illustrate this novel application by mapping whole genome histone H4 hyperacety...

  7. Mosaic maternal uniparental disomy of chromosome 15 in Prader-Willi syndrome: utility of genome-wide SNP array.

    Science.gov (United States)

    Izumi, Kosuke; Santani, Avni B; Deardorff, Matthew A; Feret, Holly A; Tischler, Tanya; Thiel, Brian D; Mulchandani, Surabhi; Stolle, Catherine A; Spinner, Nancy B; Zackai, Elaine H; Conlin, Laura K

    2013-01-01

    Prader-Willi syndrome is caused by the loss of paternal gene expression on 15q11.2-q13.2, and one of the mechanisms resulting in Prader-Willi syndrome phenotype is maternal uniparental disomy of chromosome 15. Various mechanisms including trisomy rescue, monosomy rescue, and post fertilization errors can lead to uniparental disomy, and its mechanism can be inferred from the pattern of uniparental hetero and isodisomy. Detection of a mosaic cell line provides a unique opportunity to understand the mechanism of uniparental disomy; however, mosaic uniparental disomy is a rare finding in patients with Prader-Willi syndrome. We report on two infants with Prader-Willi syndrome caused by mosaic maternal uniparental disomy 15. Patient 1 has mosaic uniparental isodisomy of the entire chromosome 15, and Patient 2 has mosaic uniparental mixed iso/heterodisomy 15. Genome-wide single-nucleotide polymorphism array was able to demonstrate the presence of chromosomally normal cell line in the Patient 1 and trisomic cell line in Patient 2, and provide the evidence that post-fertilization error and trisomy rescue as a mechanism of uniparental disomy in each case, respectively. Given its ability of detecting small percent mosaicism as well as its capability of identifying the loss of heterozygosity of chromosomal regions, genome-wide single-nucleotide polymorphism array should be utilized as an adjunct to the standard methylation analysis in the evaluation of Prader-Willi syndrome.

  8. Genome-wide joint meta-analysis of SNP and SNP-by-smoking interaction identifies novel loci for pulmonary function

    NARCIS (Netherlands)

    Hancock, Dana B; Artigas, María Soler; Gharib, Sina A; Henry, Amanda; Manichaikul, Ani; Ramasamy, Adaikalavan; Loth, Daan W; Imboden, Medea; Koch, Beate; McArdle, Wendy L; Smith, Albert V; Smolonska, Joanna; Sood, Akshay; Tang, Wenbo; Wilk, Jemma B; Zhai, Guangju; Zhao, Jing Hua; Aschard, Hugues; Burkart, Kristin M; Curjuric, Ivan; Eijgelsheim, Mark; Elliott, Paul; Gu, Xiangjun; Harris, Tamara B; Janson, Christer; Homuth, Georg; Hysi, Pirro G; Liu, Jason Z; Loehr, Laura R; Lohman, Kurt; Loos, Ruth J F; Manning, Alisa K; Marciante, Kristin D; Obeidat, Ma'en; Postma, Dirkje S; Aldrich, Melinda C; Brusselle, Guy G; Chen, Ting-hsu; Eiriksdottir, Gudny; Franceschini, Nora; Heinrich, Joachim; Rotter, Jerome I; Wijmenga, Cisca; Williams, O Dale; Bentley, Amy R; Hofman, Albert; Laurie, Cathy C; Lumley, Thomas; Morrison, Alanna C; Joubert, Bonnie R; Rivadeneira, Fernando; Couper, David J; Kritchevsky, Stephen B; Liu, Yongmei; Wjst, Matthias; Wain, Louise V; Vonk, Judith M; Uitterlinden, André G; Rochat, Thierry; Rich, Stephen S; Psaty, Bruce M; O'Connor, George T; North, Kari E; Mirel, Daniel B; Meibohm, Bernd; Launer, Lenore J; Khaw, Kay-Tee; Hartikainen, Anna-Liisa; Hammond, Christopher J; Gläser, Sven; Marchini, Jonathan; Kraft, Peter; Wareham, Nicholas J; Völzke, Henry; Stricker, Bruno H C; Spector, Timothy D; Probst-Hensch, Nicole M; Jarvis, Deborah; Jarvelin, Marjo-Riitta; Heckbert, Susan R; Gudnason, Vilmundur; Boezen, Hendrika; Barr, R Graham; Cassano, Patricia A; Strachan, David P; Fornage, Myriam; Hall, Ian P; Dupuis, Josée; Tobin, Martin D; London, Stephanie J

    2012-01-01

    Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV(1)), and its ratio to forced vital capacity (FEV(1)/FVC). Given that cigarette smoking adversely affects pulmonary function, we conducted g

  9. SHEsisEpi, a GPU-enhanced genome-wide SNP-SNP interaction scanning algorithm, efficiently reveals the risk genetic epistasis in bipolar disorder

    Institute of Scientific and Technical Information of China (English)

    Xiaohan Hu; Qiang Liu; Zhao Zhang; Zhiqiang Li; Shilin Wang; Lin He; Yongyong Shi

    2010-01-01

    @@ Dear Editor, We developed a GPU-based analytical method, named as SHEsisEpi, which purely focuses on risk epistasis in a genome-wide association study (GWAS) of complex traits, excluding the contamination of marginal effects caused by single-locus association. We analyzed the Wellcome Trust Case Control Consortium's (WTCCC)GWAS data of bipolar disorder (BPD) with 500K SNPs.

  10. Genome-wide joint meta-analysis of SNP and SNP-by-smoking interaction identifies novel loci for pulmonary function

    NARCIS (Netherlands)

    Hancock, Dana B; Artigas, María Soler; Gharib, Sina A; Henry, Amanda; Manichaikul, Ani; Ramasamy, Adaikalavan; Loth, Daan W; Imboden, Medea; Koch, Beate; McArdle, Wendy L; Smith, Albert V; Smolonska, Joanna; Sood, Akshay; Tang, Wenbo; Wilk, Jemma B; Zhai, Guangju; Zhao, Jing Hua; Aschard, Hugues; Burkart, Kristin M; Curjuric, Ivan; Eijgelsheim, Mark; Elliott, Paul; Gu, Xiangjun; Harris, Tamara B; Janson, Christer; Homuth, Georg; Hysi, Pirro G; Liu, Jason Z; Loehr, Laura R; Lohman, Kurt; Loos, Ruth J F; Manning, Alisa K; Marciante, Kristin D; Obeidat, Ma'en; Postma, Dirkje S; Aldrich, Melinda C; Brusselle, Guy G; Chen, Ting-hsu; Eiriksdottir, Gudny; Franceschini, Nora; Heinrich, Joachim; Rotter, Jerome I; Wijmenga, Cisca; Williams, O Dale; Bentley, Amy R; Hofman, Albert; Laurie, Cathy C; Lumley, Thomas; Morrison, Alanna C; Joubert, Bonnie R; Rivadeneira, Fernando; Couper, David J; Kritchevsky, Stephen B; Liu, Yongmei; Wjst, Matthias; Wain, Louise V; Vonk, Judith M; Uitterlinden, André G; Rochat, Thierry; Rich, Stephen S; Psaty, Bruce M; O'Connor, George T; North, Kari E; Mirel, Daniel B; Meibohm, Bernd; Launer, Lenore J; Khaw, Kay-Tee; Hartikainen, Anna-Liisa; Hammond, Christopher J; Gläser, Sven; Marchini, Jonathan; Kraft, Peter; Wareham, Nicholas J; Völzke, Henry; Stricker, Bruno H C; Spector, Timothy D; Probst-Hensch, Nicole M; Jarvis, Deborah; Jarvelin, Marjo-Riitta; Heckbert, Susan R; Gudnason, Vilmundur; Boezen, Hendrika; Barr, R Graham; Cassano, Patricia A; Strachan, David P; Fornage, Myriam; Hall, Ian P; Dupuis, Josée; Tobin, Martin D; London, Stephanie J

    2012-01-01

    Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV(1)), and its ratio to forced vital capacity (FEV(1)/FVC). Given that cigarette smoking adversely affects pulmonary function, we conducted

  11. A genome-wide SNP-association study confirms a sequence variant (g.66493737C>T) in the equine myostatin (MSTN) gene as the most powerful predictor of optimum racing distance for Thoroughbred racehorses.

    Science.gov (United States)

    Hill, Emmeline W; McGivney, Beatrice A; Gu, Jingjing; Whiston, Ronan; Machugh, David E

    2010-10-11

    Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important. A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of n = 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated genotypic variation at 40,977 SNPs between horses suited to short distance (≤ 8 f) and middle-long distance (> 8 f) races. The most significant SNP was located on chromosome 18: BIEC2-417495 ~690 kb from the gene encoding myostatin (MSTN) [P(unadj.) = 6.96 x 10⁻⁶]. Considering best race distance as a quantitative phenotype, a peak of association on chromosome 18 (chr18:65809482-67545806) comprising eight SNPs encompassing a 1.7 Mb region was observed. Again, similar to the cohort-based analysis, the most significant SNP was BIEC2-417495 (P(unadj.) = 1.61 x 10⁻⁹; P(Bonf.) = 6.58 x 10⁻⁵). In a candidate gene study we have previously reported a SNP (g.66493737C>T) in MSTN associated with best race distance in Thoroughbreds; however, its functional and genome-wide relevance were uncertain. Additional re-sequencing in the flanking regions of the MSTN gene revealed four novel 3' UTR SNPs and a 227 bp SINE insertion polymorphism in the 5' UTR promoter sequence. Linkage disequilibrium was highest between g.66493737C>T and BIEC2-417495 (r² = 0.86). Comparative association tests consistently demonstrated the g.66493737C>T SNP as the superior variant in the prediction of distance aptitude in racehorses (g.66493737C>T, P = 1.02 x 10⁻¹⁰; BIEC2-417495, P(unadj.) = 1.61 x 10⁻⁹). Functional investigations will be required to determine whether this polymorphism affects putative

  12. Development and evaluation of a genome-wide 6K SNP array for diploid sweet cherry and tetraploid sour cherry

    Science.gov (United States)

    High-throughput genome scans are important tools for genetic studies and breeding applications. Here, a 6K SNP array for use with the Illumina Infinium® system was developed for diploid sweet cherry (Prunus avium) and allotetraploid sour cherry (P. cerasus). This effort was led by RosBREED, a commun...

  13. 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

  14. Dominant Genetic Variation and Missing Heritability for Human Complex Traits: Insights from Twin versus Genome-wide Common SNP Models.

    Science.gov (United States)

    Chen, Xu; Kuja-Halkola, Ralf; Rahman, Iffat; Arpegård, Johannes; Viktorin, Alexander; Karlsson, Robert; Hägg, Sara; Svensson, Per; Pedersen, Nancy L; Magnusson, Patrik K E

    2015-11-05

    In order to further illuminate the potential role of dominant genetic variation in the "missing heritability" debate, we investigated the additive (narrow-sense heritability, h(2)) and dominant (δ(2)) genetic variance for 18 human complex traits. Within the same study base (10,682 Swedish twins), we calculated and compared the estimates from classic twin-based structural equation model with SNP-based genomic-relatedness-matrix restricted maximum likelihood [GREML(d)] method. Contributions of δ(2) were evident for 14 traits in twin models (average δ(2)twin = 0.25, range 0.14-0.49), two of which also displayed significant δ(2) in the GREMLd analyses (triglycerides δ(2)SNP = 0.28 and waist circumference δ(2)SNP = 0.19). On average, the proportion of h(2)SNP/h(2)twin was 70% for ADE-fitted traits (for which the best-fitting model included additive and dominant genetic and unique environmental components) and 31% for AE-fitted traits (for which the best-fitting model included additive genetic and unique environmental components). Independent evidence for contribution from shared environment, also in ADE-fitted traits, was obtained from self-reported within-pair contact frequency and age at separation. We conclude that despite the fact that additive genetics appear to constitute the bulk of genetic influences for most complex traits, dominant genetic variation might often be masked by shared environment in twin and family studies and might therefore have a more prominent role than what family-based estimates often suggest. The risk of erroneously attributing all inherited genetic influences (additive and dominant) to the h(2) in too-small twin studies might also lead to exaggerated "missing heritability" (the proportion of h(2) that remains unexplained by SNPs). Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  15. Genome-wide distribution and organization of microsatellites in plants: an insight into marker development in Brachypodium.

    Science.gov (United States)

    Sonah, Humira; Deshmukh, Rupesh K; Sharma, Anshul; Singh, Vinay P; Gupta, Deepak K; Gacche, Raju N; Rana, Jai C; Singh, Nagendra K; Sharma, Tilak R

    2011-01-01

    Plant genomes are complex and contain large amounts of repetitive DNA including microsatellites that are distributed across entire genomes. Whole genome sequences of several monocot and dicot plants that are available in the public domain provide an opportunity to study the origin, distribution and evolution of microsatellites, and also facilitate the development of new molecular markers. In the present investigation, a genome-wide analysis of microsatellite distribution in monocots (Brachypodium, sorghum and rice) and dicots (Arabidopsis, Medicago and Populus) was performed. A total of 797,863 simple sequence repeats (SSRs) were identified in the whole genome sequences of six plant species. Characterization of these SSRs revealed that mono-nucleotide repeats were the most abundant repeats, and that the frequency of repeats decreased with increase in motif length both in monocots and dicots. However, the frequency of SSRs was higher in dicots than in monocots both for nuclear and chloroplast genomes. Interestingly, GC-rich repeats were the dominant repeats only in monocots, with the majority of them being present in the coding region. These coding GC-rich repeats were found to be involved in different biological processes, predominantly binding activities. In addition, a set of 22,879 SSR markers that were validated by e-PCR were developed and mapped on different chromosomes in Brachypodium for the first time, with a frequency of 101 SSR markers per Mb. Experimental validation of 55 markers showed successful amplification of 80% SSR markers in 16 Brachypodium accessions. An online database 'BraMi' (Brachypodium microsatellite markers) of these genome-wide SSR markers was developed and made available in the public domain. The observed differential patterns of SSR marker distribution would be useful for studying microsatellite evolution in a monocot-dicot system. SSR markers developed in this study would be helpful for genomic studies in Brachypodium and related

  16. Genome-wide distribution and organization of microsatellites in plants: an insight into marker development in Brachypodium.

    Directory of Open Access Journals (Sweden)

    Humira Sonah

    Full Text Available Plant genomes are complex and contain large amounts of repetitive DNA including microsatellites that are distributed across entire genomes. Whole genome sequences of several monocot and dicot plants that are available in the public domain provide an opportunity to study the origin, distribution and evolution of microsatellites, and also facilitate the development of new molecular markers. In the present investigation, a genome-wide analysis of microsatellite distribution in monocots (Brachypodium, sorghum and rice and dicots (Arabidopsis, Medicago and Populus was performed. A total of 797,863 simple sequence repeats (SSRs were identified in the whole genome sequences of six plant species. Characterization of these SSRs revealed that mono-nucleotide repeats were the most abundant repeats, and that the frequency of repeats decreased with increase in motif length both in monocots and dicots. However, the frequency of SSRs was higher in dicots than in monocots both for nuclear and chloroplast genomes. Interestingly, GC-rich repeats were the dominant repeats only in monocots, with the majority of them being present in the coding region. These coding GC-rich repeats were found to be involved in different biological processes, predominantly binding activities. In addition, a set of 22,879 SSR markers that were validated by e-PCR were developed and mapped on different chromosomes in Brachypodium for the first time, with a frequency of 101 SSR markers per Mb. Experimental validation of 55 markers showed successful amplification of 80% SSR markers in 16 Brachypodium accessions. An online database 'BraMi' (Brachypodium microsatellite markers of these genome-wide SSR markers was developed and made available in the public domain. The observed differential patterns of SSR marker distribution would be useful for studying microsatellite evolution in a monocot-dicot system. SSR markers developed in this study would be helpful for genomic studies in Brachypodium

  17. 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...

  18. An evaluation of the genetic-matched pair study design using genome-wide SNP data from the European population

    DEFF Research Database (Denmark)

    Lu, Timothy Tehua; Lao, Oscar; Nothnagel, Michael;

    2009-01-01

    of cases (76.0%), the BOM of a given individual, based on the complete marker set, came from a different recruitment site than the individual itself. A second marker set, specifically selected for ancestry sensitivity using singular value decomposition, performed even more poorly and was no more capable......Chip Human Mapping 500K Array) from 2457 individuals, sampled at 23 different recruitment sites across Europe. Using pair-wise identity-by-state (IBS) as a matching criterion, we tried to derive a subset of markers that would allow identification of the best overall matching (BOM) partner for a given...... individual, based on the IBS status for the subset alone. However, our results suggest that, by following this approach, the prediction accuracy is only notably improved by the first 20 markers selected, and increases proportionally to the marker number thereafter. Furthermore, in a considerable proportion...

  19. High-throughput development of genome-wide locus-specific informative SSR markers in wheat

    Science.gov (United States)

    Although simple sequence repeat (SSR) markers are not new, they are still useful and often used markers in molecular mapping and marker-assisted breeding, particularly in developing countries. However, locus-specific SSR markers could be more useful and informative in wheat breeding and genetic stud...

  20. A genome-wide study of cytogenetic changes in colorectal cancer using SNP microarrays: opportunities for future personalized treatment.

    Directory of Open Access Journals (Sweden)

    Farzana Jasmine

    Full Text Available In colorectal cancer (CRC, chromosomal instability (CIN is typically studied using comparative-genomic hybridization (CGH arrays. We studied paired (tumor and surrounding healthy fresh frozen tissue from 86 CRC patients using Illumina's Infinium-based SNP array. This method allowed us to study CIN in CRC, with simultaneous analysis of copy number (CN and B-allele frequency (BAF--a representation of allelic composition. These data helped us to detect mono-allelic and bi-allelic amplifications/deletion, copy neutral loss of heterozygosity, and levels of mosaicism for mixed cell populations, some of which can not be assessed with other methods that do not measure BAF. We identified associations between CN abnormalities and different CRC phenotypes (histological diagnosis, location, tumor grade, stage, MSI and presence of lymph node metastasis. We showed commonalities between regions of CN change observed in CRC and the regions reported in previous studies of other solid cancers (e.g. amplifications of 20q, 13q, 8q, 5p and deletions of 18q, 17p and 8p. From Therapeutic Target Database, we identified relevant drugs, targeted to the genes located in these regions with CN changes, approved or in trials for other cancers and common diseases. These drugs may be considered for future therapeutic trials in CRC, based on personalized cytogenetic diagnosis. We also found many regions, harboring genes, which are not currently targeted by any relevant drugs that may be considered for future drug discovery studies. Our study shows the application of high density SNP arrays for cytogenetic study in CRC and its potential utility for personalized treatment.

  1. Multi-marker-LD based genetic algorithm for tag SNP selection.

    Science.gov (United States)

    Mouawad, Amer E; Mansour, Nashat

    2014-12-01

    Despite the advances in genotyping technologies which have led to large reduction in genotyping cost, the Tag SNP Selection problem remains an important problem for computational biologists and geneticists. Selecting the smallest subset of tag SNPs that can predict the other SNPs would considerably minimize the complexity of genome-wide or block-based SNP-disease association studies. These studies would lead to better diagnosis and treatment of diseases. In this work, we propose three variations of a genetic algorithm based on two-marker linkage disequilibrium, multi-marker linkage disequilibrium, and a third measure that we denote by prediction power. The performance of the three algorithms are compared with those of a recognized tag SNP selection algorithm using three different real data sets from the HapMap project. The results indicate that the multi-marker linkage disequilibrium based genetic algorithm yields better prediction accuracy.

  2. DOMINO: development of informative molecular markers for phylogenetic and genome-wide population genetic studies in non-model organisms.

    Science.gov (United States)

    Frías-López, Cristina; Sánchez-Herrero, José F; Guirao-Rico, Sara; Mora, Elisa; Arnedo, Miquel A; Sánchez-Gracia, Alejandro; Rozas, Julio

    2016-12-15

    The development of molecular markers is one of the most important challenges in phylogenetic and genome wide population genetics studies, especially in studies with non-model organisms. A highly promising approach for obtaining suitable markers is the utilization of genomic partitioning strategies for the simultaneous discovery and genotyping of a large number of markers. Unfortunately, not all markers obtained from these strategies provide enough information for solving multiple evolutionary questions at a reasonable taxonomic resolution. We have developed Development Of Molecular markers In Non-model Organisms (DOMINO), a bioinformatics tool for informative marker development from both next generation sequencing (NGS) data and pre-computed sequence alignments. The application implements popular NGS tools with new utilities in a highly versatile pipeline specifically designed to discover or select personalized markers at different levels of taxonomic resolution. These markers can be directly used to study the taxa surveyed for their design, utilized for further downstream PCR amplification in a broader set taxonomic scope, or exploited as suitable templates to bait design for target DNA enrichment techniques. We conducted an exhaustive evaluation of the performance of DOMINO via computer simulations and illustrate its utility to find informative markers in an empirical dataset. DOMINO is freely available from www.ub.edu/softevol/domino CONTACT: elsanchez@ub.edu or jrozas@ub.eduSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Genome-wide association study identifies three novel genetic markers associated with elite endurance performance

    DEFF Research Database (Denmark)

    Ahmetov, Ii; Kulemin, Na; Popov, Dv

    2015-01-01

    in elite endurance athletes (95.5%) in comparison with non-elite endurance athletes (89.8%, P = 0.0257), Russian (88.8%, P = 0.007) and European (90.6%, P = 0.0197) controls and power athletes (86.2%, P = 0.0005). The rs1572312 SNP is located on the nuclear factor I A antisense RNA 2 (NFIA-AS2) gene which...

  4. Prediction of total genetic value using genome-wide dense marker maps

    NARCIS (Netherlands)

    Meuwissen, T.H.; Hayes, B.J.; Goddard, M.E.

    2001-01-01

    Recent advances in molecular genetic techniques will make dense marker maps available and genotyping many individuals for these markers feasible. Here we attempted to estimate the effects of ∼50,000 marker haplotypes simultaneously from a limited number of phenotypic records. A genome of 1000 cM was

  5. Significance of genome-wide analysis of copy number alterations and UPD in myelodysplastic syndromes using combined CGH - SNP arrays.

    Science.gov (United States)

    Ahmad, Ausaf; Iqbal, M Anwar

    2012-01-01

    Genetic information is an extremely valuable data source in characterizing the personal nature of cancer. Chromosome instability is a hallmark of most cancer cells. Chromosomal abnormalities are correlated with poor prognosis, disease classification, risk stratification, and treatment selection. Copy number alterations (CNAs) are an important molecular signature in cancer initiation, development, and progression. Recent application of whole-genome tools to characterize normal and cancer genomes provides the powerful molecular cytogenetic means to enumerate the multiple somatic, genetic and epigenetic alterations that occur in cancer. Combined array comparative genomic hybridization (aCGH) with single nucleotide polymorphism (SNP) array is a useful technique allowing detection of CNAs and loss of heterozygosity (LOH) or uni-parental disomy (UPD) together in a single experiment. It also provides allelic information on deletions, duplications, and amplifications. UPD can result in an abnormal phenotype when the chromosomes involved are imprinted. Myelodysplastic syndromes (MDS) are the most common clonal stem cell hematologic malignancy characterized by ineffective hematopoiesis, which leads to rapid progression into acute myeloid leukemia. UPD that occurs without concurrent changes in the gene copy number is a common chromosomal defect in hematologic malignancies, especially in MDS. Approximately 40-50% of MDS patients do not have karyotypic abnormalities that are detectable using classical metaphase cytogenetic techniques (MC) because of inherent limitations of MC, low resolution and the requirement of having dividing cells. In this review, we highlight advances in the clinical application of microarray technology in MDS and discuss the clinical potential of microarray.

  6. Genome-wide SNP analysis reveals no gain in power for association studies of common variants in the Finnish Saami.

    Science.gov (United States)

    Huyghe, Jeroen R; Fransen, Erik; Hannula, Samuli; Van Laer, Lut; Van Eyken, Els; Mäki-Torkko, Elina; Lysholm-Bernacchi, Alana; Aikio, Pekka; Stephan, Dietrich A; Sorri, Martti; Huentelman, Matthew J; Van Camp, Guy

    2010-05-01

    The Saami from Fennoscandia are believed to represent an ancient, genetically isolated population with no evidence of population expansion. Theoretical work has indicated that under this demographic scenario, extensive linkage disequilibrium (LD) is generated by genetic drift. Therefore, it has been suggested that the Saami would be particularly suited for genetic association studies, offering a substantial power advantage and allowing more economic study designs. However, no study has yet assessed this claim. As part of a GWAS for a complex trait, we evaluated the relative power for association studies of common variants in the Finnish Saami. LD patterns in the Saami were very similar to those in the non-African HapMap reference panels. Haplotype diversity was reduced and, on average, levels of LD were higher in the Saami as compared with those in the HapMap panels. However, using a 'hidden' SNP approach we show that this does not translate into a power gain in association studies. Contrary to earlier claims, we show that for a given set of common SNPs, genomic coverage attained in the Saami is similar to that in the non-African HapMap panels. Nevertheless, the reduced haplotype diversity could potentially facilitate gene identification, especially if multiple rare variants play a role in disease etiology. Our results further indicate that the HapMap is a useful resource for genetic studies in the Saami.

  7. Rapid fixation of non-native alleles revealed by genome-wide SNP analysis of hybrid tiger salamanders

    Directory of Open Access Journals (Sweden)

    Shaffer H Bradley

    2009-07-01

    Full Text Available Abstract Background Hybrid zones represent valuable opportunities to observe evolution in systems that are unusually dynamic and where the potential for the origin of novelty and rapid adaptation co-occur with the potential for dysfunction. Recently initiated hybrid zones are particularly exciting evolutionary experiments because ongoing natural selection on novel genetic combinations can be studied in ecological time. Moreover, when hybrid zones involve native and introduced species, complex genetic patterns present important challenges for conservation policy. To assess variation of admixture dynamics, we scored a large panel of markers in five wild hybrid populations formed when Barred Tiger Salamanders were introduced into the range of California Tiger Salamanders. Results At three of 64 markers, introduced alleles have largely displaced native alleles within the hybrid populations. Another marker (GNAT1 showed consistent heterozygote deficits in the wild, and this marker was associated with embryonic mortality in laboratory F2's. Other deviations from equilibrium expectations were idiosyncratic among breeding ponds, consistent with highly stochastic demographic effects. Conclusion While most markers retain native and introduced alleles in expected proportions, strong selection appears to be eliminating native alleles at a smaller set of loci. Such rapid fixation of alleles is detectable only in recently formed hybrid zones, though it might be representative of dynamics that frequently occur in nature. These results underscore the variable and mosaic nature of hybrid genomes and illustrate the potency of recombination and selection in promoting variable, and often unpredictable genetic outcomes. Introgression of a few, strongly selected introduced alleles should not necessarily affect the conservation status of California Tiger Salamanders, but suggests that genetically pure populations of this endangered species will be difficult to

  8. Hierarchical modeling of genome-wide Short Tandem Repeat (STR) markers infers native American prehistory.

    Science.gov (United States)

    Lewis, Cecil M

    2010-02-01

    This study examines a genome-wide dataset of 678 Short Tandem Repeat loci characterized in 444 individuals representing 29 Native American populations as well as the Tundra Netsi and Yakut populations from Siberia. Using these data, the study tests four current hypotheses regarding the hierarchical distribution of neutral genetic variation in native South American populations: (1) the western region of South America harbors more variation than the eastern region of South America, (2) Central American and western South American populations cluster exclusively, (3) populations speaking the Chibchan-Paezan and Equatorial-Tucanoan language stock emerge as a group within an otherwise South American clade, (4) Chibchan-Paezan populations in Central America emerge together at the tips of the Chibchan-Paezan cluster. This study finds that hierarchical models with the best fit place Central American populations, and populations speaking the Chibchan-Paezan language stock, at a basal position or separated from the South American group, which is more consistent with a serial founder effect into South America than that previously described. Western (Andean) South America is found to harbor similar levels of variation as eastern (Equatorial-Tucanoan and Ge-Pano-Carib) South America, which is inconsistent with an initial west coast migration into South America. Moreover, in all relevant models, the estimates of genetic diversity within geographic regions suggest a major bottleneck or founder effect occurring within the North American subcontinent, before the peopling of Central and South America. 2009 Wiley-Liss, Inc.

  9. Genome-wide characteristics of copy number variation in Polish Holstein and Polish Red cattle using SNP genotyping assay.

    Science.gov (United States)

    Gurgul, A; Jasielczuk, I; Szmatoła, T; Pawlina, K; Ząbek, T; Żukowski, K; Bugno-Poniewierska, M

    2015-04-01

    Copy number variation (CNV), which results from deletions or amplifications of large fragments of genomic DNA, is widespread in mammalian genomes and apart from its potential pathogenic effect it is considered as a source of natural genetic diversity. In cattle populations, this kind of genetic variability remains still insufficiently elucidated and studies focusing on the detection of new structural genomic variants in different cattle populations may contribute to a better understanding of cattle breeds' diversity and genetic basis of production traits. In this study, by using BovineSNP50 assay and cnvPartition algorithm we identified CNVs in two different cattle breeds: Holstein (859 animals) and Polish Red (301). In Holstein cattle we found 648 CNVs which could be reduced to 91 non-redundant variable genomic regions (CNVRs) covering in total 168.6 Mb of the genomic sequence. In Polish Red cattle we detected 62 CNVs, localized in 37 variable regions encompassing 22.3 Mb of the sequence, corresponding to 0.89 % of the autosomal genome. Within the regions we identified 1,192 unique RefSeq genes which are engaged in a variety of biological processes. High concordance of the regions' distribution was found between the studied breeds, however copy number variants seemed to be more common in Holstein cattle. About 26 % of the regions described in this study could be classified as newly identified. The results of this study will broaden the knowledge of CNVs in genomes of cattle of different breeds and will provide foundations for further research aiming to identify a relationship between this type of genetic variation and phenotypic traits.

  10. Genome-wide mining, characterization, and development of microsatellite markers in Marsupenaeus japonicus by genome survey sequencing

    Science.gov (United States)

    Lu, Xia; Luan, Sheng; Kong, Jie; Hu, Longyang; Mao, Yong; Zhong, Shengping

    2017-01-01

    The kuruma prawn, Marsupenaeus japonicus, is one of the most cultivated and consumed species of shrimp. However, very few molecular genetic/genomic resources are publically available for it. Thus, the characterization and distribution of simple sequence repeats (SSRs) remains ambiguous and the use of SSR markers in genomic studies and marker-assisted selection is limited. The goal of this study is to characterize and develop genome-wide SSR markers in M. japonicus by genome survey sequencing for application in comparative genomics and breeding. A total of 326 945 perfect SSRs were identified, among which dinucleotide repeats were the most frequent class (44.08%), followed by mononucleotides (29.67%), trinucleotides (18.96%), tetranucleotides (5.66%), hexanucleotides (1.07%), and pentanucleotides (0.56%). In total, 151 541 SSR loci primers were successfully designed. A subset of 30 SSR primer pairs were synthesized and tested in 42 individuals from a wild population, of which 27 loci (90.0%) were successfully amplified with specific products and 24 (80.0%) were polymorphic. For the amplified polymorphic loci, the alleles ranged from 5 to 17 (with an average of 9.63), and the average PIC value was 0.796. A total of 58 256 SSR-containing sequences had significant Gene Ontology annotation; these are good functional molecular marker candidates for association studies and comparative genomic analysis. The newly identified SSRs significantly contribute to the M. japonicus genomic resources and will facilitate a number of genetic and genomic studies, including high density linkage mapping, genome-wide association analysis, marker-aided selection, comparative genomics analysis, population genetics, and evolution.

  11. How to link call rate and p-values for Hardy-Weinberg equilibrium as measures of genome-wide SNP data quality.

    Science.gov (United States)

    Finner, Helmut; Strassburger, Klaus; Heid, Iris M; Herder, Christian; Rathmann, Wolfgang; Giani, Guido; Dickhaus, Thorsten; Lichtner, Peter; Meitinger, Thomas; Wichmann, H-Erich; Illig, Thomas; Gieger, Christian

    2010-09-30

    We study the link between two quality measures of SNP (single nucleotide polymorphism) data in genome-wide association (GWA) studies, that is, per SNP call rates (CR) and p-values for testing Hardy-Weinberg equilibrium (HWE). The aim is to improve these measures by applying methods based on realized randomized p-values, the false discovery rate and estimates for the proportion of false hypotheses. While exact non-randomized conditional p-values for testing HWE cannot be recommended for estimating the proportion of false hypotheses, their realized randomized counterparts should be used. P-values corresponding to the asymptotic unconditional chi-square test lead to reasonable estimates only if SNPs with low minor allele frequency are excluded. We provide an algorithm to compute the probability that SNPs violate HWE given the observed CR, which yields an improved measure of data quality. The proposed methods are applied to SNP data from the KORA (Cooperative Health Research in the Region of Augsburg, Southern Germany) 500 K project, a GWA study in a population-based sample genotyped by Affymetrix GeneChip 500 K arrays using the calling algorithm BRLMM 1.4.0. We show that all SNPs with CR = 100 per cent are nearly in perfect HWE which militates in favor of the population to meet the conditions required for HWE at least for these SNPs. Moreover, we show that the proportion of SNPs not being in HWE increases with decreasing CR. We conclude that using a single threshold for judging HWE p-values without taking the CR into account is problematic. Instead we recommend a stratified analysis with respect to CR.

  12. Two non-synonymous markers in PTPN21, identified by genome-wide association study data-mining and replication, are associated with schizophrenia.

    LENUS (Irish Health Repository)

    Chen, Jingchun

    2011-09-01

    We conducted data-mining analyses of genome wide association (GWA) studies of the CATIE and MGS-GAIN datasets, and found 13 markers in the two physically linked genes, PTPN21 and EML5, showing nominally significant association with schizophrenia. Linkage disequilibrium (LD) analysis indicated that all 7 markers from PTPN21 shared high LD (r(2)>0.8), including rs2274736 and rs2401751, the two non-synonymous markers with the most significant association signals (rs2401751, P=1.10 × 10(-3) and rs2274736, P=1.21 × 10(-3)). In a meta-analysis of all 13 replication datasets with a total of 13,940 subjects, we found that the two non-synonymous markers are significantly associated with schizophrenia (rs2274736, OR=0.92, 95% CI: 0.86-0.97, P=5.45 × 10(-3) and rs2401751, OR=0.92, 95% CI: 0.86-0.97, P=5.29 × 10(-3)). One SNP (rs7147796) in EML5 is also significantly associated with the disease (OR=1.08, 95% CI: 1.02-1.14, P=6.43 × 10(-3)). These 3 markers remain significant after Bonferroni correction. Furthermore, haplotype conditioned analyses indicated that the association signals observed between rs2274736\\/rs2401751 and rs7147796 are statistically independent. Given the results that 2 non-synonymous markers in PTPN21 are associated with schizophrenia, further investigation of this locus is warranted.

  13. Genome-wide association study identifies three novel genetic markers associated with elite endurance performance

    Science.gov (United States)

    Kulemin, NA; Popov, DV; Naumov, VA; Akimov, EB; Bravy, YR; Egorova, ES; Galeeva, AA; Generozov, EV; Kostryukova, ES; Larin, AK; Mustafina, LJ; Ospanova, EA; Pavlenko, AV; Starnes, LM; Żmijewski, P; Alexeev, DG; Vinogradova, OL; Govorun, VM

    2014-01-01

    To investigate the association between multiple single-nucleotide polymorphisms (SNPs), aerobic performance and elite endurance athlete status in Russians. By using GWAS approach, we examined the association between 1,140,419 SNPs and relative maximal oxygen consumption rate (V.O2max) in 80 international-level Russian endurance athletes (46 males and 34 females). To validate obtained results, we further performed case-control studies by comparing the frequencies of the most significant SNPs (with P < 10−5-10−8) between 218 endurance athletes and opposite cohorts (192 Russian controls, 1367 European controls, and 230 Russian power athletes). Initially, six ‘endurance alleles’ were identified showing discrete associations with V.O2max both in males and females. Next, case-control studies resulted in remaining three SNPs (NFIA-AS2 rs1572312, TSHR rs7144481, RBFOX1 rs7191721) associated with endurance athlete status. The C allele of the most significant SNP, rs1572312, was associated with high values of V.O2max (males: P = 0.0051; females: P = 0.0005). Furthermore, the frequency of the rs1572312 C allele was significantly higher in elite endurance athletes (95.5%) in comparison with non-elite endurance athletes (89.8%, P = 0.0257), Russian (88.8%, P = 0.007) and European (90.6%, P = 0.0197) controls and power athletes (86.2%, P = 0.0005). The rs1572312 SNP is located on the nuclear factor I A antisense RNA 2 (NFIA-AS2) gene which is supposed to regulate the expression of the NFIA gene (encodes transcription factor involved in activation of erythropoiesis and repression of the granulopoiesis). Our data show that the NFIA-AS2 rs1572312, TSHR rs7144481 and RBFOX1 rs7191721 polymorphisms are associated with aerobic performance and elite endurance athlete status. PMID:25729143

  14. Genome wide characterization of short tandem repeat markers in sweet orange (Citrus sinensis.

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    Manosh Kumar Biswas

    Full Text Available Sweet orange (Citrus sinensis is one of the major cultivated and most-consumed citrus species. With the goal of enhancing the genomic resources in citrus, we surveyed, developed and characterized microsatellite markers in the ≈347 Mb sequence assembly of the sweet orange genome. A total of 50,846 SSRs were identified with a frequency of 146.4 SSRs/Mbp. Dinucleotide repeats are the most frequent repeat class and the highest density of SSRs was found in chromosome 4. SSRs are non-randomly distributed in the genome and most of the SSRs (62.02% are located in the intergenic regions. We found that AT-rich SSRs are more frequent than GC-rich SSRs. A total number of 21,248 SSR primers were successfully developed, which represents 89 SSR markers per Mb of the genome. A subset of 950 developed SSR primer pairs were synthesized and tested by wet lab experiments on a set of 16 citrus accessions. In total we identified 534 (56.21% polymorphic SSR markers that will be useful in citrus improvement. The number of amplified alleles ranges from 2 to 12 with an average of 4 alleles per marker and an average PIC value of 0.75. The newly developed sweet orange primer sequences, their in silico PCR products, exact position in the genome assembly and putative function are made publicly available. We present the largest number of SSR markers ever developed for a citrus species. Almost two thirds of the markers are transferable to 16 citrus relatives and may be used for constructing a high density linkage map. In addition, they are valuable for marker-assisted selection studies, population structure analyses and comparative genomic studies of C. sinensis with other citrus related species. Altogether, these markers provide a significant contribution to the citrus research community.

  15. Genome wide characterization of short tandem repeat markers in sweet orange (Citrus sinensis).

    Science.gov (United States)

    Biswas, Manosh Kumar; Xu, Qiang; Mayer, Christoph; Deng, Xiuxin

    2014-01-01

    Sweet orange (Citrus sinensis) is one of the major cultivated and most-consumed citrus species. With the goal of enhancing the genomic resources in citrus, we surveyed, developed and characterized microsatellite markers in the ≈347 Mb sequence assembly of the sweet orange genome. A total of 50,846 SSRs were identified with a frequency of 146.4 SSRs/Mbp. Dinucleotide repeats are the most frequent repeat class and the highest density of SSRs was found in chromosome 4. SSRs are non-randomly distributed in the genome and most of the SSRs (62.02%) are located in the intergenic regions. We found that AT-rich SSRs are more frequent than GC-rich SSRs. A total number of 21,248 SSR primers were successfully developed, which represents 89 SSR markers per Mb of the genome. A subset of 950 developed SSR primer pairs were synthesized and tested by wet lab experiments on a set of 16 citrus accessions. In total we identified 534 (56.21%) polymorphic SSR markers that will be useful in citrus improvement. The number of amplified alleles ranges from 2 to 12 with an average of 4 alleles per marker and an average PIC value of 0.75. The newly developed sweet orange primer sequences, their in silico PCR products, exact position in the genome assembly and putative function are made publicly available. We present the largest number of SSR markers ever developed for a citrus species. Almost two thirds of the markers are transferable to 16 citrus relatives and may be used for constructing a high density linkage map. In addition, they are valuable for marker-assisted selection studies, population structure analyses and comparative genomic studies of C. sinensis with other citrus related species. Altogether, these markers provide a significant contribution to the citrus research community.

  16. Genome-wide copy number profiling using a 100K SNP array reveals novel disease-related genes BORIS and TSHZ1 in juvenile angiofibroma.

    Science.gov (United States)

    Schick, Bernhard; Wemmert, Silke; Willnecker, Vivienne; Dlugaiczyk, Julia; Nicolai, Piero; Siwiec, Henryk; Thiel, Christian T; Rauch, Anita; Wendler, Olaf

    2011-11-01

    Juvenile angiofibroma (JA) is a unique fibrovascular tumor, which is almost exclusively found in the posterior nasal cavity of adolescent males. Although histologically classified as benign, the tumor often shows an aggressive growth pattern and has been associated with chromosomal imbalances, amplification of oncogenes and epigenetic dysregulation. We present the first genome-wide profiling of JAs (n=14) with a 100K single nucleotide polymorphism (SNP) microarray. Among the 30 novel JA-specific amplifications detected on autosomal chromosomes with this technique, the genes encoding the cancer-testis antigen BORIS (brother of the regulator of imprinted sites) and the developmental regulator protein TSHZ1 (teashirt zinc finger homeobox 1) were selected for further analysis. Gains for both BORIS (20q13.3) and TSHZ1 (18q22.3) were confirmed by quantitative genomic PCR. Furthermore, quantitative RT-PCR revealed a significant up-regulation of BORIS (ptool for identifying novel disease-related genes in JAs and newly implicates BORIS and TSHZ1 overexpression in the pathogenesis of JAs. Detection of BORIS in JAs is described with special regard to tumor proliferation and epigenetic dysregulation, and the finding of TSHZ1 amplifications is discussed with special respect to the hypothesis of JAs as malformations of the first branchial arch artery.

  17. Genome-wide ENU mutagenesis in combination with high density SNP analysis and exome sequencing provides rapid identification of novel mouse models of developmental disease.

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    Georgina Caruana

    Full Text Available BACKGROUND: Mice harbouring gene mutations that cause phenotypic abnormalities during organogenesis are invaluable tools for linking gene function to normal development and human disorders. To generate mouse models harbouring novel alleles that are involved in organogenesis we conducted a phenotype-driven, genome-wide mutagenesis screen in mice using the mutagen N-ethyl-N-nitrosourea (ENU. METHODOLOGY/PRINCIPAL FINDINGS: ENU was injected into male C57BL/6 mice and the mutations transmitted through the germ-line. ENU-induced mutations were bred to homozygosity and G3 embryos screened at embryonic day (E 13.5 and E18.5 for abnormalities in limb and craniofacial structures, skin, blood, vasculature, lungs, gut, kidneys, ureters and gonads. From 52 pedigrees screened 15 were detected with anomalies in one or more of the structures/organs screened. Using single nucleotide polymorphism (SNP-based linkage analysis in conjunction with candidate gene or next-generation sequencing (NGS we identified novel recessive alleles for Fras1, Ift140 and Lig1. CONCLUSIONS/SIGNIFICANCE: In this study we have generated mouse models in which the anomalies closely mimic those seen in human disorders. The association between novel mutant alleles and phenotypes will lead to a better understanding of gene function in normal development and establish how their dysfunction causes human anomalies and disease.

  18. Development of a Panel of Genome-Wide Ancestry Informative Markers to Study Admixture Throughout the Americas

    Science.gov (United States)

    Galanter, Joshua Mark; Fernandez-Lopez, Juan Carlos; Gignoux, Christopher R.; Barnholtz-Sloan, Jill; Fernandez-Rozadilla, Ceres; Via, Marc; Hidalgo-Miranda, Alfredo; Contreras, Alejandra V.; Figueroa, Laura Uribe; Raska, Paola; Jimenez-Sanchez, Gerardo; Silva Zolezzi, Irma; Torres, Maria; Ponte, Clara Ruiz; Ruiz, Yarimar; Salas, Antonio; Nguyen, Elizabeth; Eng, Celeste; Borjas, Lisbeth; Zabala, William; Barreto, Guillermo; Rondón González, Fernando; Ibarra, Adriana; Taboada, Patricia; Porras, Liliana; Moreno, Fabián; Bigham, Abigail; Gutierrez, Gerardo; Brutsaert, Tom; León-Velarde, Fabiola; Moore, Lorna G.; Vargas, Enrique; Cruz, Miguel; Escobedo, Jorge; Rodriguez-Santana, José; Rodriguez-Cintrón, William; Chapela, Rocio; Ford, Jean G.; Bustamante, Carlos; Seminara, Daniela; Shriver, Mark; Ziv, Elad; Gonzalez Burchard, Esteban; Haile, Robert

    2012-01-01

    Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region. PMID:22412386

  19. Development of a panel of genome-wide ancestry informative markers to study admixture throughout the Americas.

    Directory of Open Access Journals (Sweden)

    Joshua Mark Galanter

    Full Text Available Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R² > 0.9 for ancestral components with significant between-subject variance. Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.

  20. Genome Wide Characterization of Short Tandem Repeat Markers in Sweet Orange (Citrus sinensis)

    OpenAIRE

    BISWAS, Manosh Kumar; XU, Qiang; Mayer, Christoph; Deng, Xiuxin

    2014-01-01

    Sweet orange (Citrus sinensis) is one of the major cultivated and most-consumed citrus species. With the goal of enhancing the genomic resources in citrus, we surveyed, developed and characterized microsatellite markers in the ≈347 Mb sequence assembly of the sweet orange genome. A total of 50,846 SSRs were identified with a frequency of 146.4 SSRs/Mbp. Dinucleotide repeats are the most frequent repeat class and the highest density of SSRs was found in chromosome 4. SSRs are non-randomly dist...

  1. Genome Wide Characterization of Short Tandem Repeat Markers in Sweet Orange (Citrus sinensis)

    OpenAIRE

    Biswas, Manosh Kumar; Xu, Qiang; Mayer, Christoph; Deng, Xiuxin

    2014-01-01

    Sweet orange (Citrus sinensis) is one of the major cultivated and most-consumed citrus species. With the goal of enhancing the genomic resources in citrus, we surveyed, developed and characterized microsatellite markers in the ≈347 Mb sequence assembly of the sweet orange genome. A total of 50,846 SSRs were identified with a frequency of 146.4 SSRs/Mbp. Dinucleotide repeats are the most frequent repeat class and the highest density of SSRs was found in chromosome 4. SSRs are non-randomly dist...

  2. Genome-wide identification of R genes and exploitation of candidate RGA markers in rice

    Institute of Scientific and Technical Information of China (English)

    WANG Xusheng; WU Weiren; JIN Gulei; ZHU Jun

    2005-01-01

    By scanning the whole genomic sequence of japonica rice using 45 known plant disease resistance (R) genes, we identified 2119 resistance gene homologs or analogs (RGAs) and verified that RGAs are not randomly distributed but tend to cluster in the rice genome. The RGAs were classified into 21 families according to their functional domain based on Hidden Markov model (HMM). By comparing the RGAs of japonica rice with the whole genomic sequence of indica rice, we found 702 RGAs allelic between the two subspecies and revealed that 671 (95.6%) of them have length difference (InDels) in their genomic sequences (including coding and non-coding regions) between the two subspecies, suggesting that RGAs are highly polymorphic between the two subspecies in rice. We also exploited 402 PCR-based and co-dominant candidate RGA markers by designing primer pairs on the regions flanking the InDels and validating them via e-PCR. The length differences of the candidate RGA markers between the two subspecies are from 1 to 742 bp, with an average of 10.26 bp. All related information of the RGAs is available from our web site (http://ibi.zju.edu.cn/RGAs/index.html).

  3. Using Genome-Wide SNP Discovery and Genotyping to Reveal the Main Source of Population Differentiation in Nothofagus dombeyi (Mirb.) Oerst. in Chile

    Science.gov (United States)

    González, Jorge; Fuentes, Glenda; Alarcón, Diego; Ruiz, Eduardo

    2016-01-01

    Within a woody plant species, environmental heterogeneity has the potential to influence the distribution of genetic variation among populations through several evolutionary processes. In some species, a relationship between environmental characteristics and the distribution of genotypes can be detected, showing the importance of natural selection as the main source of differentiation. Nothofagus dombeyi (Mirb.) Oerst. (Nothofagaceae) is an endemic tree species occurring both in Chile and in Argentina temperate forests. Postglacial history has been studied with chloroplast DNA and evolutionary forces shaping genetic variation patterns have been analysed with isozymes but fine-scale genetic diversity studies are needed. The study of demographic and selection histories in Nothofagus dombeyi requires more informative markers such as single nucleotide polymorphisms (SNP). Genotyping-by-Sequencing tools now allow studying thousands of SNP markers at reasonable prices in nonmodel species. We investigated more than 10 K SNP loci for signatures of local adaptation and showed that interrogation of genomic resources can identify shifts in genetic diversity and putative adaptive signals in this nonmodel woody species. PMID:27446942

  4. Genome-wide analysis reveals DNA methylation markers that vary with both age and obesity.

    Science.gov (United States)

    Almén, Markus Sällman; Nilsson, Emil K; Jacobsson, Josefin A; Kalnina, Ineta; Klovins, Janis; Fredriksson, Robert; Schiöth, Helgi B

    2014-09-10

    The combination of the obesity epidemic and an aging population presents growing challenges for the healthcare system. Obesity and aging are major risk factors for a diverse number of diseases and it is of importance to understand their interaction and the underlying molecular mechanisms. Herein the authors examined the methylation levels of 27578 CpG sites in 46 samples from adult peripheral blood. The effect of obesity and aging was ascertained with general linear models. More than one hundred probes were correlated to aging, nine of which belonged to the KEGG group map04080. Additionally, 10 CpG sites had diverse methylation profiles in obese and lean individuals, one of which was the telomerase catalytic subunit (TERT). In eight of ten cases the methylation change was reverted between obese and lean individuals. One region proved to be differentially methylated with obesity (LINC00304) independent of age. This study provides evidence that obesity influences age driven epigenetic changes, which provides a molecular link between aging and obesity. This link and the identified markers may prove to be valuable biomarkers for the understanding of the molecular basis of aging, obesity and associated diseases. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Genome wide linkage study, using a 250K SNP map, of Plasmodium falciparum infection and mild malaria attack in a Senegalese population.

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    Jacqueline Milet

    Full Text Available Multiple factors are involved in the variability of host's response to P. falciparum infection, like the intensity and seasonality of malaria transmission, the virulence of parasite and host characteristics like age or genetic make-up. Although admitted nowadays, the involvement of host genetic factors remains unclear. Discordant results exist, even concerning the best-known malaria resistance genes that determine the structure or function of red blood cells. Here we report on a genome-wide linkage and association study for P. falciparum infection intensity and mild malaria attack among a Senegalese population of children and young adults from 2 to 18 years old. A high density single nucleotide polymorphisms (SNP genome scan (Affimetrix GeneChip Human Mapping 250K-nsp was performed for 626 individuals: i.e. 249 parents and 377 children out of the 504 ones included in the follow-up. The population belongs to a unique ethnic group and was closely followed-up during 3 years. Genome-wide linkage analyses were performed on four clinical and parasitological phenotypes and association analyses using the family based association tests (FBAT method were carried out in regions previously linked to malaria phenotypes in literature and in the regions for which we identified a linkage peak. Analyses revealed three strongly suggestive evidences for linkage: between mild malaria attack and both the 6p25.1 and the 12q22 regions (empirical p-value=5x10(-5 and 9x10(-5 respectively, and between the 20p11q11 region and the prevalence of parasite density in asymptomatic children (empirical p-value=1.5x10(-4. Family based association analysis pointed out one significant association between the intensity of plasmodial infection and a polymorphism located in ARHGAP26 gene in the 5q31-q33 region (p-value=3.7x10(-5. This study identified three candidate regions, two of them containing genes that could point out new pathways implicated in the response to malaria infection

  6. Physical mapping of QTL for tuber yield, starch content and starch yield in tetraploid potato (Solanum tuberosum L.) by means of genome wide genotyping by sequencing and the 8.3 K SolCAP SNP array.

    Science.gov (United States)

    Schönhals, Elske Maria; Ding, Jia; Ritter, Enrique; Paulo, Maria João; Cara, Nicolás; Tacke, Ekhard; Hofferbert, Hans-Reinhard; Lübeck, Jens; Strahwald, Josef; Gebhardt, Christiane

    2017-08-22

    Tuber yield and starch content of the cultivated potato are complex traits of decisive importance for breeding improved varieties. Natural variation of tuber yield and starch content depends on the environment and on multiple, mostly unknown genetic factors. Dissection and molecular identification of the genes and their natural allelic variants controlling these complex traits will lead to the development of diagnostic DNA-based markers, by which precision and efficiency of selection can be increased (precision breeding). Three case-control populations were assembled from tetraploid potato cultivars based on maximizing the differences between high and low tuber yield (TY), starch content (TSC) and starch yield (TSY, arithmetic product of TY and TSC). The case-control populations were genotyped by restriction-site associated DNA sequencing (RADseq) and the 8.3 k SolCAP SNP genotyping array. The allele frequencies of single nucleotide polymorphisms (SNPs) were compared between cases and controls. RADseq identified, depending on data filtering criteria, between 6664 and 450 genes with one or more differential SNPs for one, two or all three traits. Differential SNPs in 275 genes were detected using the SolCAP array. A genome wide association study using the SolCAP array on an independent, unselected population identified SNPs associated with tuber starch content in 117 genes. Physical mapping of the genes containing differential or associated SNPs, and comparisons between the two genome wide genotyping methods and two different populations identified genome segments on all twelve potato chromosomes harboring one or more quantitative trait loci (QTL) for TY, TSC and TSY. Several hundred genes control tuber yield and starch content in potato. They are unequally distributed on all potato chromosomes, forming clusters between 0.5-4 Mbp width. The largest fraction of these genes had unknown function, followed by genes with putative signalling and regulatory functions. The

  7. Genome-Wide Single-Nucleotide Polymorphisms in CMS and Restorer Lines Discovered by Genotyping Using Sequencing and Association with Marker-Combining Ability for 12 Yield-Related Traits in Oryza sativa L. subsp. Japonica

    Science.gov (United States)

    Zaid, Imdad U.; Tang, Weijie; Liu, Erbao; Khan, Sana U.; Wang, Hui; Mawuli, Edzesi W.; Hong, Delin

    2017-01-01

    Heterosis or hybrid vigor is closely related with general combing ability (GCA) of parents and special combining ability (SCA) of combinations. The evaluation of GCA and SCA facilitate selection of parents and combinations in heterosis breeding. In order to improve combining ability (CA) by molecular marker assist selection, it is necessary to identify marker loci associated with the CA. To identify the single nucleotide polymorphisms (SNP) loci associated with CA in the parental genomes of japonica rice, genome-wide discovered SNP loci were tested for association with the CA of 18 parents for 12 yield-related traits. In this study, 81 hybrids were created and evaluated to calculate the CA of 18 parents. The parents were sequenced by genotyping by sequencing (GBS) method for identification of genome-wide SNPs. The analysis of GBS indicated that the successful mapping of 9.86 × 106 short reads in the Nipponbare reference genome consists of 39,001 SNPs in parental genomes at 11,085 chromosomal positions. The discovered SNPs were non-randomly distributed within and among the 12 chromosomes of rice. Overall, 20.4% (8026) of the discovered SNPs were coding types, and 8.6% (3344) and 9.9% (3951) of the SNPs revealed synonymous and non-synonymous changes, which provide valuable knowledge about the underlying performance of the parents. Furthermore, the associations between SNPs and CA indicated that 362 SNP loci were significantly related to the CA of 12 parental traits. The identified SNP loci of CA in our study were distributed genome wide and caused a positive or negative effect on the CA of traits. For the yield-related traits, such as grain thickness, days to heading, panicle length, grain length and 1000-grain weight, a maximum number of positive SNP loci of CA were found in CMS A171 and in the restorers LC64 and LR27. On an individual basis, some of associated loci that resided on chromosomes 2, 5, 7, 9, and 11 recorded maximum positive values for the CA of traits

  8. Genome-wide methylation profiling and a multiplex construction for the identification of body fluids using epigenetic markers.

    Science.gov (United States)

    Lee, Hwan Young; An, Ja Hyun; Jung, Sang-Eun; Oh, Yu Na; Lee, Eun Young; Choi, Ajin; Yang, Woo Ick; Shin, Kyoung-Jin

    2015-07-01

    The identification of body fluids found at crime scenes can contribute to solving crimes by providing important insights into crime scene reconstruction. In the present study, body fluid-specific epigenetic marker candidates were identified from genome-wide DNA methylation profiling of 42 body fluid samples including blood, saliva, semen, vaginal fluid and menstrual blood using the Illumina Infinium HumanMethylation450 BeadChip array. A total of 64 CpG sites were selected as body fluid-specific marker candidates by having more than 20% discrepancy in DNA methylation status between a certain type of body fluid and other types of body fluids and to have methylation or unmethylation pattern only in a particular type of body fluid. From further locus-specific methylation analysis in additional samples, 1 to 3 CpG sites were selected for each body fluid. Then, a multiplex methylation SNaPshot reaction was constructed to analyze methylation status of 8 body fluid-specific CpG sites. The developed multiplex reaction positively identifies blood, saliva, semen and the body fluid which originates from female reproductive organ in one reaction, and produces successful DNA methylation profiles in aged or mixed samples. Although it remains to be investigated whether this approach is more sensitive, more practical than RNA- or peptide-based assays and whether it can be successfully applied to forensic casework, the results of the present study will be useful for the forensic investigators dealing with body fluid samples.

  9. Integration of Genome-Wide SNP Data and Gene-Expression Profiles Reveals Six Novel Loci and Regulatory Mechanisms for Amino Acids and Acylcarnitines in Whole Blood.

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    Ralph Burkhardt

    2015-09-01

    Full Text Available Profiling amino acids and acylcarnitines in whole blood spots is a powerful tool in the laboratory diagnosis of several inborn errors of metabolism. Emerging data suggests that altered blood levels of amino acids and acylcarnitines are also associated with common metabolic diseases in adults. Thus, the identification of common genetic determinants for blood metabolites might shed light on pathways contributing to human physiology and common diseases. We applied a targeted mass-spectrometry-based method to analyze whole blood concentrations of 96 amino acids, acylcarnitines and pathway associated metabolite ratios in a Central European cohort of 2,107 adults and performed genome-wide association (GWA to identify genetic modifiers of metabolite concentrations. We discovered and replicated six novel loci associated with blood levels of total acylcarnitine, arginine (both on chromosome 6; rs12210538, rs17657775, propionylcarnitine (chromosome 10; rs12779637, 2-hydroxyisovalerylcarnitine (chromosome 21; rs1571700, stearoylcarnitine (chromosome 1; rs3811444, and aspartic acid traits (chromosome 8; rs750472. Based on an integrative analysis of expression quantitative trait loci in blood mononuclear cells and correlations between gene expressions and metabolite levels, we provide evidence for putative causative genes: SLC22A16 for total acylcarnitines, ARG1 for arginine, HLCS for 2-hydroxyisovalerylcarnitine, JAM3 for stearoylcarnitine via a trans-effect at chromosome 1, and PPP1R16A for aspartic acid traits. Further, we report replication and provide additional functional evidence for ten loci that have previously been published for metabolites measured in plasma, serum or urine. In conclusion, our integrative analysis of SNP, gene-expression and metabolite data points to novel genetic factors that may be involved in the regulation of human metabolism. At several loci, we provide evidence for metabolite regulation via gene-expression and observed

  10. Determination of Genetic Structure and Signatures of Selection in Three Strains of Tanzania Shorthorn Zebu, Boran and Friesian Cattle by Genome-Wide SNP Analyses

    Science.gov (United States)

    Msalya, George; Kim, Eui-Soo; Laisser, Emmanuel L. K.; Kipanyula, Maulilio J.; Karimuribo, Esron D.; Kusiluka, Lughano J. M.; Chenyambuga, Sebastian W.; Rothschild, Max F.

    2017-01-01

    Background More than 90 percent of cattle in Tanzania belong to the indigenous Tanzania Short Horn Zebu (TSZ) population which has been classified into 12 strains based on historical evidence, morphological characteristics, and geographic distribution. However, specific genetic information of each TSZ population has been lacking and has caused difficulties in designing programs such as selection, crossbreeding, breed improvement or conservation. This study was designed to evaluate the genetic structure, assess genetic relationships, and to identify signatures of selection among cattle of Tanzania with the main goal of understanding genetic relationship, variation and uniqueness among them. Methodology/Principal findings The Illumina Bos indicus SNP 80K BeadChip was used to genotype genome wide SNPs in 168 DNA samples obtained from three strains of TSZ cattle namely Maasai, Tarime and Sukuma as well as two comparative breeds; Boran and Friesian. Population structure and signatures of selection were examined using principal component analysis (PCA), admixture analysis, pairwise distances (FST), integrated haplotype score (iHS), identical by state (IBS) and runs of homozygosity (ROH). There was a low level of inbreeding (F~0.01) in the TSZ population compared to the Boran and Friesian breeds. The analyses of FST, IBS and admixture identified no considerable differentiation between TSZ trains. Importantly, common ancestry in Boran and TSZ were revealed based on admixture and IBD, implying gene flow between two populations. In addition, Friesian ancestry was found in Boran. A few common significant iHS were detected, which may reflect influence of recent selection in each breed or strain. Conclusions Population admixture and selection signatures could be applied to develop conservation plan of TSZ cattle as well as future breeding programs in East African cattle. PMID:28129396

  11. The genetic aetiology of cannabis use initiation: A meta-analysis of genome-wide association studies and a SNP-based heritability estimation

    NARCIS (Netherlands)

    Verweij, C.J.H.; Vinkhuyzen, A.A.E.; Benyamin, B.; Lynskey, M.T.; Quaye, L.; Agrawal, A.; Gordon, S.D.; Montgomery, G.W.; Madden, P.A.F.; Heath, A.C.; Spector, T.D.; Martin, N.G.; Medland, S.E.

    2013-01-01

    While initiation of cannabis use is around 40% heritable, not much is known about the underlying genetic aetiology. Here, we meta-analysed two genome-wide association studies of initiation of cannabis use with >10000 individuals. None of the genetic variants reached genome-wide significance. We a

  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. Genome-wide identification of novel genetic markers from RNA sequencing assembly of diverse Aegilops tauschii accessions.

    Science.gov (United States)

    Nishijima, Ryo; Yoshida, Kentaro; Motoi, Yuka; Sato, Kazuhiro; Takumi, Shigeo

    2016-08-01

    The wild species in the Triticeae tribe are tremendous resources for crop breeding due to their abundant natural variation. However, their huge and highly repetitive genomes have hindered the establishment of physical maps and the completeness of their genome sequences. To develop molecular markers for the efficient utilization of their valuable traits while avoiding their genome complexity, we assembled RNA sequences of ten representative accessions of Aegilops tauschii, the progenitor of the wheat D genome, and estimated single nucleotide polymorphisms (SNPs) and insertions/deletions (indels). The deduced unigenes were anchored to the chromosomes of Ae. tauschii and barley. The SNPs and indels in the anchored unigenes, covering entire chromosomes, were sufficient for linkage map construction, even in combinations between the genetically closest accessions. Interestingly, the resolution of SNP and indel distribution on barley chromosomes was slightly higher than on Ae. tauschii chromosomes. Since barley chromosomes are regarded as virtual chromosomes of Triticeae species, our strategy allows capture of genetic markers arranged on the chromosomes in order based on the conserved synteny. The resolution of these genetic markers will be comparable to that of the Ae. tauschii whose draft genome sequence is available. Our procedure should be applicable to marker development for Triticeae species, which have no draft sequences available.

  14. Genome-wide gene expression profile analyses identify CTTN as a potential prognostic marker in esophageal cancer.

    Directory of Open Access Journals (Sweden)

    Pei Lu

    Full Text Available AIM: Esophageal squamous cell carcinoma (ESCC is one of the most common fatal malignances of the digestive tract. Its prognosis is poor mainly due to the lack of reliable markers for early detection and prognostic prediction. Here we aim to identify the molecules involved in ESCC carcinogenesis and those as potential markers for prognosis and as new molecular therapeutic targets. METHODS: We performed genome-wide gene expression profile analyses of 10 primary ESCCs and their adjacent normal tissues by cDNA microarrays representing 47,000 transcripts and variants. Candidate genes were then validated by semi quantitative reverse transcription-PCR (RT-PCR, tissue microarrays (TMAs and immunohistochemistry (IHC staining. RESULTS: Using an arbitrary cutoff line of signal log ratio of ≥1.5 or ≤-1.5, we observed 549 up-regulated genes and 766 down-regulated genes in ESCCs compared with normal esophageal tissues. The functions of 302 differentially expressed genes were associated with cell metabolism, cell adhesion and immune response. Several candidate deregulated genes including four overexpressed (CTTN, DMRT2, MCM10 and SCYA26 and two underexpressed (HMGCS2 and SORBS2 were subsequently verified, which can be served as biomarkers for ESCC. Moreover, overexpression of cortactin (CTTN was observed in 126/198 (63.6% of ESCC cases and was significantly associated with lymph node metastasis (P = 0.000, pathologic stage (P = 0.000 and poor survival (P<0.001 of ESCC patients. Furthermore, a significant correlation between CTTN overexpression and shorter disease-specific survival rate was found in different subgroups of ESCC patient stratified by the pathologic stage (P<0.05. CONCLUSION: Our data provide valuable information for establishing molecules as candidates for prognostic and/or as therapeutic targets.

  15. Genome-wide Association Studies from the Cancer Genetic Markers of Susceptibility (CGEMS) Initiative | Office of Cancer Genomics

    Science.gov (United States)

    CGEMS identifies common inherited genetic variations associated with a number of cancers, including breast and prostate. Data from these genome-wide association studies (GWAS) are available through the Division of Cancer Epidemiology & Genetics website.

  16. Extent of genome-wide linkage disequilibrium in Australian Holstein-Friesian cattle based on a high-density SNP panel

    Directory of Open Access Journals (Sweden)

    Cavanagh Julie AL

    2008-04-01

    Full Text Available Abstract Background The extent of linkage disequilibrium (LD within a population determines the number of markers that will be required for successful association mapping and marker-assisted selection. Most studies on LD in cattle reported to date are based on microsatellite markers or small numbers of single nucleotide polymorphisms (SNPs covering one or only a few chromosomes. This is the first comprehensive study on the extent of LD in cattle by analyzing data on 1,546 Holstein-Friesian bulls genotyped for 15,036 SNP markers covering all regions of all autosomes. Furthermore, most studies in cattle have used relatively small sample sizes and, consequently, may have had biased estimates of measures commonly used to describe LD. We examine minimum sample sizes required to estimate LD without bias and loss in accuracy. Finally, relatively little information is available on comparative LD structures including other mammalian species such as human and mouse, and we compare LD structure in cattle with public-domain data from both human and mouse. Results We computed three LD estimates, D', Dvol and r2, for 1,566,890 syntenic SNP pairs and a sample of 365,400 non-syntenic pairs. Mean D' is 0.189 among syntenic SNPs, and 0.105 among non-syntenic SNPs; mean r2 is 0.024 among syntenic SNPs and 0.0032 among non-syntenic SNPs. All three measures of LD for syntenic pairs decline with distance; the decline is much steeper for r2 than for D' and Dvol. The value of D' and Dvol are quite similar. Significant LD in cattle extends to 40 kb (when estimated as r2 and 8.2 Mb (when estimated as D'. The mean values for LD at large physical distances are close to those for non-syntenic SNPs. Minor allelic frequency threshold affects the distribution and extent of LD. For unbiased and accurate estimates of LD across marker intervals spanning 50 Mb, minimum sample sizes of 400 (for D' and 75 (for r2 are required. The bias due to small samples sizes increases with inter-marker

  17. Developing genome-wide microsatellite markers of bamboo and their applications on molecular marker assisted taxonomy for accessions in the genus Phyllostachys.

    Science.gov (United States)

    Zhao, Hansheng; Yang, Li; Peng, Zhenhua; Sun, Huayu; Yue, Xianghua; Lou, Yongfeng; Dong, Lili; Wang, Lili; Gao, Zhimin

    2015-01-26

    Morphology-based taxonomy via exiguously reproductive organ has severely limitation on bamboo taxonomy, mainly owing to infrequent and unpredictable flowering events of bamboo. Here, we present the first genome-wide analysis and application of microsatellites based on the genome of moso bamboo (Phyllostachys edulis) to assist bamboo taxonomy. Of identified 127,593 microsatellite repeat-motifs, the primers of 1,451 microsatellites were designed and 1,098 markers were physically mapped on the genome of moso bamboo. A total of 917 markers were successfully validated in 9 accessions with ~39.8% polymorphic potential. Retrieved from validated microsatellite markers, 23 markers were selected for polymorphic analysis among 78 accessions and 64 alleles were detected with an average of 2.78 alleles per primers. The cluster result indicated the majority of the accessions were consistent with their current taxonomic classification, confirming the suitability and effectiveness of the developed microsatellite markers. The variations of microsatellite marker in different species were confirmed by sequencing and in silico comparative genome mapping were investigated. Lastly, a bamboo microsatellites database (http://www.bamboogdb.org/ssr) was implemented to browse and search large information of bamboo microsatellites. Consequently, our results of microsatellite marker development are valuable for assisting bamboo taxonomy and investigating genomic studies in bamboo and related grass species.

  18. SNP2CAPS: a SNP and INDEL analysis tool for CAPS marker development

    OpenAIRE

    Thiel, Thomas; Kota, Raja; Grosse, Ivo; Stein, Nils; Graner, Andreas

    2004-01-01

    With the influx of various SNP genotyping assays in recent years, there has been a need for an assay that is robust, yet cost effective, and could be performed using standard gel-based procedures. In this context, CAPS markers have been shown to meet these criteria. However, converting SNPs to CAPS markers can be a difficult process if done manually. In order to address this problem, we describe a computer program, SNP2CAPS, that facilitates the computational conversion of SNP markers into CA...

  19. A comparison in association and linkage genome-wide scans for alcoholism susceptibility genes using single-nucleotide polymorphisms.

    Science.gov (United States)

    Chiu, Yen-Feng; Liu, Su-Yun; Tsai, Ya-Yu

    2005-12-30

    We conducted genome-wide linkage scans using both microsatellite and single-nucleotide polymorphism (SNP) markers. Regions showing the strongest evidence of linkage to alcoholism susceptibility genes were identified. Haplotype analyses using a sliding-window approach for SNPs in these regions were performed. In addition, we performed a genome-wide association scan using SNP data. SNPs in these regions with evidence of association (P alcoholism (the most significant SNP had a p-value of 0.030) as those identified from association genomic screening (the most significant SNP had a p-value of 2.0 x 10(-8)).

  20. Genome-wide study of percent emphysema on computed tomography in the general population. The Multi-Ethnic Study of Atherosclerosis Lung/SNP Health Association Resource Study

    NARCIS (Netherlands)

    Manichaikul, Ani; Hoffman, Eric A.; Smolonska, Joanna; Gao, Wei; Cho, Michael H.; Baumhauer, Heather; Budoff, Matthew; Austin, John H. M.; Washko, George R.; Carr, J. Jeffrey; Kaufman, Joel D.; Pottinger, Tess; Powell, Charles A.; Wijmenga, Cisca; Zanen, Pieter; Groen, Harry J.M.; Postma, Dirkje S.; Wanner, Adam; Rouhani, Farshid N.; Brantly, Mark L.; Powell, Rhea; Smith, Benjamin M.; Rabinowitz, Dan; Raffel, Leslie J.; Stukovsky, Karen D. Hinckley; Crapo, James D.; Beaty, Terri H.; Hokanson, John E.; Silverman, Edwin K.; Dupuis, Josee; O'Connor, George T.; Boezen, Hendrika; Rich, Stephen S.; Barr, R. Graham

    2014-01-01

    Rationale: Pulmonary emphysema overlaps partially with spirometrically defined chronic obstructive pulmonary disease and is heritable, with moderately high familial clustering. Objectives: To complete a genome-wide association study (GWAS) for the percentage of emphysema-like lung on computed tomogr

  1. Development of genome-wide informative simple sequence repeat markers for molecular diversity analysis in chickpea and development of web resource

    Directory of Open Access Journals (Sweden)

    SWARUP KUMAR PARIDA

    2015-08-01

    Full Text Available Development of informative polymorphic simple sequence repeat (SSR markers at a genome-wide scale is essential for efficient large-scale genotyping applications. We identified genome-wide 1835 SSRs showing polymorphism between desi and kabuli chickpea. A total of 1470 polymorphic SSR markers from diverse coding and non-coding regions of the chickpea genome were developed. These physically-mapped SSR markers exhibited robust amplification efficiency (73.9% and high intra- and inter-specific polymorphic potential (63.5%, thereby suggesting their immense use in various genomics-assisted breeding applications. The SSR markers particularly derived from intergenic and intronic sequences revealed high polymorphic potential. Using the mapped SSR markers, a wider functional molecular diversity (16-94%, mean: 68%, and parentage- and cultivar-specific admixed domestication pattern and phylogenetic relationships in a structured population of desi and kabuli chickpea genotypes was evident. The intra-specific polymorphism (47.6% and functional molecular diversity (65% potential of polymorphic SSR markers developed in our study is much higher than that of previous documentations. Finally, we have developed a user-friendly web resource, Chickpea Microsatellite Database (CMsDB; http://www.nipgr.res.in/CMsDB.html, which provides public access to the data and results reported in this study. The developed informative SSR markers can serve as a resource for various genotyping applications, including genetic enhancement studies in chickpea.

  2. Genome-wide high-throughput SNP discovery and genotyping for understanding natural (functional) allelic diversity and domestication patterns in wild chickpea

    Science.gov (United States)

    Bajaj, Deepak; Das, Shouvik; Badoni, Saurabh; Kumar, Vinod; Singh, Mohar; Bansal, Kailash C.; Tyagi, Akhilesh K.; Parida, Swarup K.

    2015-01-01

    We identified 82489 high-quality genome-wide SNPs from 93 wild and cultivated Cicer accessions through integrated reference genome- and de novo-based GBS assays. High intra- and inter-specific polymorphic potential (66–85%) and broader natural allelic diversity (6–64%) detected by genome-wide SNPs among accessions signify their efficacy for monitoring introgression and transferring target trait-regulating genomic (gene) regions/allelic variants from wild to cultivated Cicer gene pools for genetic improvement. The population-specific assignment of wild Cicer accessions pertaining to the primary gene pool are more influenced by geographical origin/phenotypic characteristics than species/gene-pools of origination. The functional significance of allelic variants (non-synonymous and regulatory SNPs) scanned from transcription factors and stress-responsive genes in differentiating wild accessions (with potential known sources of yield-contributing and stress tolerance traits) from cultivated desi and kabuli accessions, fine-mapping/map-based cloning of QTLs and determination of LD patterns across wild and cultivated gene-pools are suitably elucidated. The correlation between phenotypic (agromorphological traits) and molecular diversity-based admixed domestication patterns within six structured populations of wild and cultivated accessions via genome-wide SNPs was apparent. This suggests utility of whole genome SNPs as a potential resource for identifying naturally selected trait-regulating genomic targets/functional allelic variants adaptive to diverse agroclimatic regions for genetic enhancement of cultivated gene-pools. PMID:26208313

  3. Genome-wide association analysis of bacterial cold water disease resistance in rainbow trout reveals the potential of a hybrid approach between genomic selection and marker assisted selection

    Science.gov (United States)

    Genomic selection (GS) simultaneously incorporates dense SNP marker genotypes with phenotypic data from related animals to predict animal-specific genomic breeding value (GEBV), which circumvents the need to measure the disease phenotype in potential breeders. Marker assisted selection (MAS) involv...

  4. Genome-wide insertion–deletion (InDel) marker discovery and genotyping for genomics-assisted breeding applications in chickpea

    Science.gov (United States)

    Das, Shouvik; Upadhyaya, Hari D.; Srivastava, Rishi; Bajaj, Deepak; Gowda, C.L.L.; Sharma, Shivali; Singh, Sube; Tyagi, Akhilesh K.; Parida, Swarup K.

    2015-01-01

    We developed 21,499 genome-wide insertion–deletion (InDel) markers (2- to 54-bp in silico fragment length polymorphism) by comparing the genomic sequences of four (desi, kabuli and wild C. reticulatum) chickpea [Cicer arietinum (L.)] accessions. InDel markers showing 2- to 6-bp fragment length polymorphism among accessions were abundant (76.8%) in the chickpea genome. The physically mapped 7,643 and 13,856 markers on eight chromosomes and unanchored scaffolds, respectively, were structurally and functionally annotated. The 4,506 coding (23% large-effect frameshift mutations) and regulatory InDel markers were identified from 3,228 genes (representing 11.7% of total 27,571 desi genes), suggesting their functional relevance for trait association/genetic mapping. High amplification (97%) and intra-specific polymorphic (60–83%) potential and wider genetic diversity (15–89%) were detected by genome-wide 6,254 InDel markers among desi, kabuli and wild accessions using even a simpler cost-effective agarose gel-based assay. This signifies added advantages of this user-friendly genetic marker system for manifold large-scale genotyping applications in laboratories with limited infrastructure and resources. Utilizing 6,254 InDel markers-based high-density (inter-marker distance: 0.212 cM) inter-specific genetic linkage map (ICC 4958 × ICC 17160) of chickpea as a reference, three major genomic regions harboring six flowering and maturity time robust QTLs (16.4–27.5% phenotypic variation explained, 8.1–11.5 logarithm of odds) were identified. Integration of genetic and physical maps at these target QTL intervals mapped on three chromosomes delineated five InDel markers-containing candidate genes tightly linked to the QTLs governing flowering and maturity time in chickpea. Taken together, our study demonstrated the practical utility of developing and high-throughput genotyping of such beneficial InDel markers at a genome-wide scale to expedite genomics

  5. A custom correlation coefficient (CCC) approach for fast identification of multi-SNP association patterns in genome-wide SNPs data.

    Science.gov (United States)

    Climer, Sharlee; Yang, Wei; de las Fuentes, Lisa; Dávila-Román, Victor G; Gu, C Charles

    2014-11-01

    Complex diseases are often associated with sets of multiple interacting genetic factors and possibly with unique sets of the genetic factors in different groups of individuals (genetic heterogeneity). We introduce a novel concept of custom correlation coefficient (CCC) between single nucleotide polymorphisms (SNPs) that address genetic heterogeneity by measuring subset correlations autonomously. It is used to develop a 3-step process to identify candidate multi-SNP patterns: (1) pairwise (SNP-SNP) correlations are computed using CCC; (2) clusters of so-correlated SNPs identified; and (3) frequencies of these clusters in disease cases and controls compared to identify disease-associated multi-SNP patterns. This method identified 42 candidate multi-SNP associations with hypertensive heart disease (HHD), among which one cluster of 22 SNPs (six genes) included 13 in SLC8A1 (aka NCX1, an essential component of cardiac excitation-contraction coupling) and another of 32 SNPs had 29 from a different segment of SLC8A1. While allele frequencies show little difference between cases and controls, the cluster of 22 associated alleles were found in 20% of controls but no cases and the other in 3% of controls but 20% of cases. These suggest that both protective and risk effects on HHD could be exerted by combinations of variants in different regions of SLC8A1, modified by variants from other genes. The results demonstrate that this new correlation metric identifies disease-associated multi-SNP patterns overlooked by commonly used correlation measures. Furthermore, computation time using CCC is a small fraction of that required by other methods, thereby enabling the analyses of large GWAS datasets.

  6. Genome-wide association mapping for female fertility traits in Danish and Swedish Holstein cattle

    DEFF Research Database (Denmark)

    Sahana, G; Guldbrandtsen, B; Bendixen, C;

    2010-01-01

    A genome-wide association study was conducted using a mixed model analysis for QTL for fertility traits in Danish and Swedish Holstein cattle. The analysis incorporated 2,531 progeny tested bulls, and a total of 36 387 SNP markers on 29 bovine autosomes were used. Eleven fertility traits were...

  7. Genome-wide CNV analysis replicates the association between GSTM1 deletion and bladder cancer: a support for using continuous measurement from SNP-array data

    Directory of Open Access Journals (Sweden)

    Marenne Gaëlle

    2012-07-01

    Full Text Available Abstract Background Structural variations such as copy number variants (CNV influence the expression of different phenotypic traits. Algorithms to identify CNVs through SNP-array platforms are available. The ability to evaluate well-characterized CNVs such as GSTM1 (1p13.3 deletion provides an important opportunity to assess their performance. Results 773 cases and 759 controls from the SBC/EPICURO Study were genotyped in the GSTM1 region using TaqMan, Multiplex Ligation-dependent Probe Amplification (MLPA, and Illumina Infinium 1 M SNP-array platforms. CNV callings provided by TaqMan and MLPA were highly concordant and replicated the association between GSTM1 and bladder cancer. This was not the case when CNVs were called using Illumina 1 M data through available algorithms since no deletion was detected across the study samples. In contrast, when the Log R Ratio (LRR was used as a continuous measure for the 5 probes contained in this locus, we were able to detect their association with bladder cancer using simple regression models or more sophisticated methods such as the ones implemented in the CNVtools package. Conclusions This study highlights an important limitation in the CNV calling from SNP-array data in regions of common aberrations and suggests that there may be added advantage for using LRR as a continuous measure in association tests rather than relying on calling algorithms.

  8. Population-genetic comparison of the Sorbian isolate population in Germany with the German KORA population using genome-wide SNP arrays

    Directory of Open Access Journals (Sweden)

    Gieger Christian

    2011-07-01

    Full Text Available Abstract Background The Sorbs are an ethnic minority in Germany with putative genetic isolation, making the population interesting for disease mapping. A sample of N = 977 Sorbs is currently analysed in several genome-wide meta-analyses. Since genetic differences between populations are a major confounding factor in genetic meta-analyses, we compare the Sorbs with the German outbred population of the KORA F3 study (N = 1644 and other publically available European HapMap populations by population genetic means. We also aim to separate effects of over-sampling of families in the Sorbs sample from effects of genetic isolation and compare the power of genetic association studies between the samples. Results The degree of relatedness was significantly higher in the Sorbs. Principal components analysis revealed a west to east clustering of KORA individuals born in Germany, KORA individuals born in Poland or Czech Republic, Half-Sorbs (less than four Sorbian grandparents and Full-Sorbs. The Sorbs cluster is nearest to the cluster of KORA individuals born in Poland. The number of rare SNPs is significantly higher in the Sorbs sample. FST between KORA and Sorbs is an order of magnitude higher than between different regions in Germany. Compared to the other populations, Sorbs show a higher proportion of individuals with runs of homozygosity between 2.5 Mb and 5 Mb. Linkage disequilibrium (LD at longer range is also slightly increased but this has no effect on the power of association studies. Oversampling of families in the Sorbs sample causes detectable bias regarding higher FST values and higher LD but the effect is an order of magnitude smaller than the observed differences between KORA and Sorbs. Relatedness in the Sorbs also influenced the power of uncorrected association analyses. Conclusions Sorbs show signs of genetic isolation which cannot be explained by over-sampling of relatives, but the effects are moderate in size. The Slavonic origin of the

  9. Population-genetic comparison of the Sorbian isolate population in Germany with the German KORA population using genome-wide SNP arrays.

    Science.gov (United States)

    Gross, Arnd; Tönjes, Anke; Kovacs, Peter; Veeramah, Krishna R; Ahnert, Peter; Roshyara, Nab R; Gieger, Christian; Rueckert, Ina-Maria; Loeffler, Markus; Stoneking, Mark; Wichmann, Heinz-Erich; Novembre, John; Stumvoll, Michael; Scholz, Markus

    2011-07-28

    The Sorbs are an ethnic minority in Germany with putative genetic isolation, making the population interesting for disease mapping. A sample of N = 977 Sorbs is currently analysed in several genome-wide meta-analyses. Since genetic differences between populations are a major confounding factor in genetic meta-analyses, we compare the Sorbs with the German outbred population of the KORA F3 study (N = 1644) and other publically available European HapMap populations by population genetic means. We also aim to separate effects of over-sampling of families in the Sorbs sample from effects of genetic isolation and compare the power of genetic association studies between the samples. The degree of relatedness was significantly higher in the Sorbs. Principal components analysis revealed a west to east clustering of KORA individuals born in Germany, KORA individuals born in Poland or Czech Republic, Half-Sorbs (less than four Sorbian grandparents) and Full-Sorbs. The Sorbs cluster is nearest to the cluster of KORA individuals born in Poland. The number of rare SNPs is significantly higher in the Sorbs sample. FST between KORA and Sorbs is an order of magnitude higher than between different regions in Germany. Compared to the other populations, Sorbs show a higher proportion of individuals with runs of homozygosity between 2.5 Mb and 5 Mb. Linkage disequilibrium (LD) at longer range is also slightly increased but this has no effect on the power of association studies. Oversampling of families in the Sorbs sample causes detectable bias regarding higher FST values and higher LD but the effect is an order of magnitude smaller than the observed differences between KORA and Sorbs. Relatedness in the Sorbs also influenced the power of uncorrected association analyses. Sorbs show signs of genetic isolation which cannot be explained by over-sampling of relatives, but the effects are moderate in size. The Slavonic origin of the Sorbs is still genetically detectable. Regarding LD

  10. Follow-up of potential novel Graves' disease susceptibility loci, identified in the UK WTCCC genome-wide nonsynonymous SNP study.

    Science.gov (United States)

    Newby, Paul R; Pickles, Oliver J; Mazumdar, Samaresh; Brand, Oliver J; Carr-Smith, Jaqueline D; Pearce, Simon H S; Franklyn, Jayne A; Evans, David M; Simmonds, Matthew J; Gough, Stephen C L

    2010-09-01

    A recent association scan using a genome-wide set of nonsynonymous coding single-nucleotide polymorphisms (nsSNPs) conducted in four diseases including Graves' disease (GD), identified nine novel possible regions of association with GD. We used a case-control approach in an attempt to replicate association of these nine regions in an independent collection of 1578 British GD patients and 1946 matched Caucasian controls. Although none of these loci showed evidence of association with GD in the independent data set, when combined with the original Wellcome Trust Case-Control Consortium study group, minor differences in allele frequencies (P>or=10(-3)) remained in the combined collection of 5924 subjects for four of the nsSNPs, present within HDLBP, TEKT1, JSRP1 and UTX. An additional 29 Tag SNPs were screened within these four gene regions to determine if further associations could be detected. Similarly, minor differences only (P=0.042-0.002) were detected in two HDLBP and two TEKT1 Tag SNPs in the combined UK GD collection. In conclusion, it is unlikely that the SNPs selected in this replication study have a significant effect on the risk of GD in the United Kingdom. Our study confirms the need for large data sets and stringent analysis criteria when searching for susceptibility loci in common diseases.

  11. Unraveling biocomplexity of Northeast Atlantic herring stocks using SNP markers

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Limborg, Morten; Helyar, Sarah;

    2012-01-01

    complicating stock assessment and management. It is therefore of management interest to trace individual population migration patterns and contributions to fisheries. To underpin management and to develop a validated tool for traceability of individuals from mixed‐stock samples we applied single nucleotide......Atlantic herring (Clupea harengus) exhibit biocomplexity, with widespread, geographically explicit populations that perform long‐range migration to common feeding and wintering areas, where they are exploited by fisheries. This means that exploited stocks do not describe discrete units, thereby...... polymorphism (SNP) markers in Northeast Atlantic herring population samples. Marker panels were targeted to include gene‐associated loci to maximize statistical resolution. Application of 281 SNP markers to samples representing different levels of stock complexity showed that the regional origin of individual...

  12. SNP marker discovery in koala TLR genes.

    Directory of Open Access Journals (Sweden)

    Jian Cui

    Full Text Available Toll-like receptors (TLRs play a crucial role in the early defence against invading pathogens, yet our understanding of TLRs in marsupial immunity is limited. Here, we describe the characterisation of nine TLRs from a koala immune tissue transcriptome and one TLR from a draft sequence of the koala genome and the subsequent development of an assay to study genetic diversity in these genes. We surveyed genetic diversity in 20 koalas from New South Wales, Australia and showed that one gene, TLR10 is monomorphic, while the other nine TLR genes have between two and 12 alleles. 40 SNPs (16 non-synonymous were identified across the ten TLR genes. These markers provide a springboard to future studies on innate immunity in the koala, a species under threat from two major infectious diseases.

  13. Identification of Novel Genetic Markers Associated with Clinical Phenotypes of Systemic Sclerosis through a Genome-Wide Association Strategy

    Science.gov (United States)

    Ying, Jun; Teruel, Maria; Diaz-Gallo, Lina-Marcela; Broen, Jasper C.; Vonk, Madelon C.; Simeon, Carmen P.; Alizadeh, Behrooz Z.; Coenen, Marieke J. H.; Voskuyl, Alexandre E.; Schuerwegh, Annemie J.; van Riel, Piet L. C. M.; Vanthuyne, Marie; van 't Slot, Ruben; Italiaander, Annet; Ophoff, Roel A.; Hunzelmann, Nicolas; Fonollosa, Vicente; Ortego-Centeno, Norberto; González-Gay, Miguel A.; García-Hernández, Francisco J.; González-Escribano, María F.; Airo, Paolo; van Laar, Jacob; Worthington, Jane; Hesselstrand, Roger; Smith, Vanessa; de Keyser, Filip; Houssiau, Fredric; Chee, Meng May; Madhok, Rajan; Shiels, Paul G.; Westhovens, Rene; Kreuter, Alexander; de Baere, Elfride; Witte, Torsten; Padyukov, Leonid; Nordin, Annika; Scorza, Raffaella; Lunardi, Claudio; Lie, Benedicte A.; Hoffmann-Vold, Anna-Maria; Palm, Øyvind; García de la Peña, Paloma; Carreira, Patricia; Varga, John; Hinchcliff, Monique; Lee, Annette T.; Gourh, Pravitt; Amos, Christopher I.; Wigley, Frederick M.; Hummers, Laura K.; Hummers, J.; Nelson, J. Lee; Riemekasten, Gabriella; Herrick, Ariane; Beretta, Lorenzo; Fonseca, Carmen; Denton, Christopher P.; Gregersen, Peter K.; Agarwal, Sandeep; Assassi, Shervin; Tan, Filemon K.; Arnett, Frank C.; Radstake, Timothy R. D. J.; Mayes, Maureen D.; Martin, Javier

    2011-01-01

    The aim of this study was to determine, through a genome-wide association study (GWAS), the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc). We considered limited (lcSSc) and diffuse (dcSSc) cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA), and anti-topoisomerase I (ATA). Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10−12, OR = 0.75). Also, rs12540874 in GRB10 gene (P = 1.27 × 10−6, OR = 1.15) and rs11047102 in SOX5 gene (P = 1.39×10−7, OR = 1.36) showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10−61, OR = 2.48), in the HLA-DPA1/B1 loci with ATA (P = 4.57×10−76, OR = 8.84), and in NOTCH4 with ACA P = 8.84×10−21, OR = 0.55) and ATA (P = 1.14×10−8, OR = 0.54). We have identified three new non-HLA genes (IRF8, GRB10, and SOX5) associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc. PMID:21779181

  14. Identification of novel genetic markers associated with clinical phenotypes of systemic sclerosis through a genome-wide association strategy.

    Directory of Open Access Journals (Sweden)

    Olga Gorlova

    2011-07-01

    Full Text Available The aim of this study was to determine, through a genome-wide association study (GWAS, the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc. We considered limited (lcSSc and diffuse (dcSSc cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA, and anti-topoisomerase I (ATA. Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10(-12, OR = 0.75. Also, rs12540874 in GRB10 gene (P = 1.27 × 10(-6, OR = 1.15 and rs11047102 in SOX5 gene (P = 1.39×10(-7, OR = 1.36 showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10(-61, OR = 2.48, in the HLA-DPA1/B1 loci with ATA (P = 4.57×10(-76, OR = 8.84, and in NOTCH4 with ACA P = 8.84×10(-21, OR = 0.55 and ATA (P = 1.14×10(-8, OR = 0.54. We have identified three new non-HLA genes (IRF8, GRB10, and SOX5 associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc.

  15. Identification of novel genetic markers associated with clinical phenotypes of systemic sclerosis through a genome-wide association strategy.

    Directory of Open Access Journals (Sweden)

    Olga Gorlova

    2011-07-01

    Full Text Available The aim of this study was to determine, through a genome-wide association study (GWAS, the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc. We considered limited (lcSSc and diffuse (dcSSc cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA, and anti-topoisomerase I (ATA. Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10(-12, OR = 0.75. Also, rs12540874 in GRB10 gene (P = 1.27 × 10(-6, OR = 1.15 and rs11047102 in SOX5 gene (P = 1.39×10(-7, OR = 1.36 showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10(-61, OR = 2.48, in the HLA-DPA1/B1 loci with ATA (P = 4.57×10(-76, OR = 8.84, and in NOTCH4 with ACA P = 8.84×10(-21, OR = 0.55 and ATA (P = 1.14×10(-8, OR = 0.54. We have identified three new non-HLA genes (IRF8, GRB10, and SOX5 associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc.

  16. Comparison of different methods for imputing genome-wide marker genotypes in Swedish and Finnish Red Cattle

    DEFF Research Database (Denmark)

    Ma, Peipei; Brøndum, Rasmus Froberg; Qin, Zahng

    2013-01-01

    This study investigated the imputation accuracy of different methods, considering both the minor allele frequency and relatedness between individuals in the reference and test data sets. Two data sets from the combined population of Swedish and Finnish Red Cattle were used to test the influence...... of these factors on the accuracy of imputation. Data set 1 consisted of 2,931 reference bulls and 971 test bulls, and was used for validation of imputation from 3,000 markers (3K) to 54,000 markers (54K). Data set 2 contained 341 bulls in the reference set and 117 in the test set, and was used for validation...... of imputation from 54K to high density [777,000 markers (777K)]. Both test sets were divided into 4 groups according to their relationship to the reference population. Five imputation methods (Beagle, IMPUTE2, findhap, AlphaImpute, and FImpute) were used in this study. Imputation accuracy was measured...

  17. Development and Characterization of Simple Sequence Repeat Markers Providing Genome-Wide Coverage and High Resolution in Maize

    Science.gov (United States)

    Xu, Jie; Liu, Ling; Xu, Yunbi; Chen, Churun; Rong, Tingzhao; Ali, Farhan; Zhou, Shufeng; Wu, Fengkai; Liu, Yaxi; Wang, Jing; Cao, Moju; Lu, Yanli

    2013-01-01

    Simple sequence repeats (SSRs) have been widely used in maize genetics and breeding, because they are co-dominant, easy to score, and highly abundant. In this study, we used whole-genome sequences from 16 maize inbreds and 1 wild relative to determine SSR abundance and to develop a set of high-density polymorphic SSR markers. A total of 264 658 SSRs were identified across the 17 genomes, with an average of 135 693 SSRs per genome. Marker density was one SSR every of 15.48 kb. (C/G)n, (AT)n, (CAG/CTG)n, and (AAAT/ATTT)n were the most frequent motifs for mono, di-, tri-, and tetra-nucleotide SSRs, respectively. SSRs were most abundant in intergenic region and least frequent in untranslated regions, as revealed by comparing SSR distributions of three representative resequenced genomes. Comparing SSR sequences and e-polymerase chain reaction analysis among the 17 tested genomes created a new database, including 111 887 SSRs, that could be develop as polymorphic markers in silico. Among these markers, 58.00, 26.09, 7.20, 3.00, 3.93, and 1.78% of them had mono, di-, tri-, tetra-, penta-, and hexa-nucleotide motifs, respectively. Polymorphic information content for 35 573 polymorphic SSRs out of 111 887 loci varied from 0.05 to 0.83, with an average of 0.31 in the 17 tested genomes. Experimental validation of polymorphic SSR markers showed that over 70% of the primer pairs could generate the target bands with length polymorphism, and these markers would be very powerful when they are used for genetic populations derived from various types of maize germplasms that were sampled for this study. PMID:23804557

  18. Genome-Wide Analysis of Microsatellite Markers Based on Sequenced Database in Chinese Spring Wheat (Triticum aestivum L..

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    Bin Han

    Full Text Available Microsatellites or simple sequence repeats (SSRs are distributed across both prokaryotic and eukaryotic genomes and have been widely used for genetic studies and molecular marker-assisted breeding in crops. Though an ordered draft sequence of hexaploid bread wheat have been announced, the researches about systemic analysis of SSRs for wheat still have not been reported so far. In the present study, we identified 364,347 SSRs from among 10,603,760 sequences of the Chinese spring wheat (CSW genome, which were present at a density of 36.68 SSR/Mb. In total, we detected 488 types of motifs ranging from di- to hexanucleotides, among which dinucleotide repeats dominated, accounting for approximately 42.52% of the genome. The density of tri- to hexanucleotide repeats was 24.97%, 4.62%, 3.25% and 24.65%, respectively. AG/CT, AAG/CTT, AGAT/ATCT, AAAAG/CTTTT and AAAATT/AATTTT were the most frequent repeats among di- to hexanucleotide repeats. Among the 21 chromosomes of CSW, the density of repeats was highest on chromosome 2D and lowest on chromosome 3A. The proportions of di-, tri-, tetra-, penta- and hexanucleotide repeats on each chromosome, and even on the whole genome, were almost identical. In addition, 295,267 SSR markers were successfully developed from the 21 chromosomes of CSW, which cover the entire genome at a density of 29.73 per Mb. All of the SSR markers were validated by reverse electronic-Polymerase Chain Reaction (re-PCR; 70,564 (23.9% were found to be monomorphic and 224,703 (76.1% were found to be polymorphic. A total of 45 monomorphic markers were selected randomly for validation purposes; 24 (53.3% amplified one locus, 8 (17.8% amplified multiple identical loci, and 13 (28.9% did not amplify any fragments from the genomic DNA of CSW. Then a dendrogram was generated based on the 24 monomorphic SSR markers among 20 wheat cultivars and three species of its diploid ancestors showing that monomorphic SSR markers represented a promising

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

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    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

  20. Genome-Wide Survey of Nuclear Protein-Coding Markers for Beetle Phylogenetics and Their Application in Resolving both Deep and Shallow-Level Divergences.

    Science.gov (United States)

    Che, Li-Heng; Zhang, Shao-Qian; Li, Yun; Liang, Dan; Pang, Hong; Ślipiński, Adam; Zhang, Peng

    2017-03-03

    Beetles (Coleoptera) are the most diverse and species-rich insect group, representing an impressive explosive radiation in the evolutionary history of insects, and their evolutionary relationships are often difficult to resolve. The amount of "traditional markers" (e.g., mitochondrial genes and nuclear rDNAs) for beetle phylogenetics is small and these markers often lack sufficient signals in resolving relationships for such a rapidly radiating lineage. Here, based on the available genome data of beetles and other related insect species, we performed a genome-wide survey to search nuclear protein-coding (NPC) genes suitable for research on beetle phylogenetics. As a result, we identified 1470 candidate loci, which provided a valuable data resource to the beetle evolutionary research community for NPC marker development. We randomly chose 180 candidate loci from the database to design primers and successfully developed 95 NPC markers which can be PCR amplified from standard genomic DNA extracts. These new nuclear markers are universally applicable across Coleoptera, with an average amplification success rate of 90%. To test the phylogenetic utility, we used them to investigate the backbone phylogeny of Coleoptera (18 families sampled) and the family Coccinellidae (39 species sampled). Both phylogenies are well resolved (average bootstrap support > 95%), showing that our markers can be used to address phylogenetic questions of various evolutionary depth (from species level to family level). In general, the newly developed nuclear markers are much easier to use and more phylogenetically informative than the "traditional markers", and show great potential to expedite resolution of many parts in the Beetle Tree of Life. This article is protected by copyright. All rights reserved.

  1. Development and Integration of Genome-Wide Polymorphic Microsatellite Markers onto a Reference Linkage Map for Constructing a High-Density Genetic Map of Chickpea.

    Science.gov (United States)

    Khajuria, Yash Paul; Saxena, Maneesha S; Gaur, Rashmi; Chattopadhyay, Debasis; Jain, Mukesh; Parida, Swarup K; Bhatia, Sabhyata

    2015-01-01

    The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777) of an inter-specific reference mapping population. High amplification efficiency (87%), experimental validation success rate (81%) and polymorphic potential (55%) of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48%) detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than inter-specific polymorphic potential (59%). An advanced, high-density, integrated and inter-specific chickpea genetic map (ICC4958 x PI489777) having 1697 map positions spanning 1061.16 cM with an average inter-marker distance of 0.625 cM was constructed by assigning 634 novel informative transcript-derived and genomic microsatellite markers on eight linkage groups (LGs) of our prior documented, 1063 marker-based genetic map. The constructed genome map identified 88, including four major (7-23 cM) longest high-resolution genomic regions on LGs 3, 5 and 8, where the maximum number of novel genomic and genic microsatellite markers were specifically clustered within 1 cM genetic distance. It was for the first time in chickpea that in silico FLP analysis at genome-wide level was carried out and such a large number of microsatellite markers were identified, experimentally validated and further used in genetic mapping. To best of our knowledge, in the presently constructed genetic map, we mapped highest

  2. Development and Integration of Genome-Wide Polymorphic Microsatellite Markers onto a Reference Linkage Map for Constructing a High-Density Genetic Map of Chickpea.

    Directory of Open Access Journals (Sweden)

    Yash Paul Khajuria

    Full Text Available The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777 of an inter-specific reference mapping population. High amplification efficiency (87%, experimental validation success rate (81% and polymorphic potential (55% of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48% detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than inter-specific polymorphic potential (59%. An advanced, high-density, integrated and inter-specific chickpea genetic map (ICC4958 x PI489777 having 1697 map positions spanning 1061.16 cM with an average inter-marker distance of 0.625 cM was constructed by assigning 634 novel informative transcript-derived and genomic microsatellite markers on eight linkage groups (LGs of our prior documented, 1063 marker-based genetic map. The constructed genome map identified 88, including four major (7-23 cM longest high-resolution genomic regions on LGs 3, 5 and 8, where the maximum number of novel genomic and genic microsatellite markers were specifically clustered within 1 cM genetic distance. It was for the first time in chickpea that in silico FLP analysis at genome-wide level was carried out and such a large number of microsatellite markers were identified, experimentally validated and further used in genetic mapping. To best of our knowledge, in the presently constructed genetic map, we mapped

  3. Development and Integration of Genome-Wide Polymorphic Microsatellite Markers onto a Reference Linkage Map for Constructing a High-Density Genetic Map of Chickpea

    Science.gov (United States)

    Gaur, Rashmi; Chattopadhyay, Debasis; Jain, Mukesh; Parida, Swarup K.; Bhatia, Sabhyata

    2015-01-01

    The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777) of an inter-specific reference mapping population. High amplification efficiency (87%), experimental validation success rate (81%) and polymorphic potential (55%) of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48%) detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than inter-specific polymorphic potential (59%). An advanced, high-density, integrated and inter-specific chickpea genetic map (ICC4958 x PI489777) having 1697 map positions spanning 1061.16 cM with an average inter-marker distance of 0.625 cM was constructed by assigning 634 novel informative transcript-derived and genomic microsatellite markers on eight linkage groups (LGs) of our prior documented, 1063 marker-based genetic map. The constructed genome map identified 88, including four major (7–23 cM) longest high-resolution genomic regions on LGs 3, 5 and 8, where the maximum number of novel genomic and genic microsatellite markers were specifically clustered within 1 cM genetic distance. It was for the first time in chickpea that in silico FLP analysis at genome-wide level was carried out and such a large number of microsatellite markers were identified, experimentally validated and further used in genetic mapping. To best of our knowledge, in the presently constructed genetic map, we mapped highest

  4. Genome-wide conserved non-coding microsatellite (CNMS) marker-based integrative genetical genomics for quantitative dissection of seed weight in chickpea

    Science.gov (United States)

    Bajaj, Deepak; Saxena, Maneesha S.; Kujur, Alice; Das, Shouvik; Badoni, Saurabh; Tripathi, Shailesh; Upadhyaya, Hari D.; Gowda, C. L. L.; Sharma, Shivali; Singh, Sube; Tyagi, Akhilesh K.; Parida, Swarup K.

    2015-01-01

    Phylogenetic footprinting identified 666 genome-wide paralogous and orthologous CNMS (conserved non-coding microsatellite) markers from 5′-untranslated and regulatory regions (URRs) of 603 protein-coding chickpea genes. The (CT)n and (GA)n CNMS carrying CTRMCAMV35S and GAGA8BKN3 regulatory elements, respectively, are abundant in the chickpea genome. The mapped genic CNMS markers with robust amplification efficiencies (94.7%) detected higher intraspecific polymorphic potential (37.6%) among genotypes, implying their immense utility in chickpea breeding and genetic analyses. Seventeen differentially expressed CNMS marker-associated genes showing strong preferential and seed tissue/developmental stage-specific expression in contrasting genotypes were selected to narrow down the gene targets underlying seed weight quantitative trait loci (QTLs)/eQTLs (expression QTLs) through integrative genetical genomics. The integration of transcript profiling with seed weight QTL/eQTL mapping, molecular haplotyping, and association analyses identified potential molecular tags (GAGA8BKN3 and RAV1AAT regulatory elements and alleles/haplotypes) in the LOB-domain-containing protein- and KANADI protein-encoding transcription factor genes controlling the cis-regulated expression for seed weight in the chickpea. This emphasizes the potential of CNMS marker-based integrative genetical genomics for the quantitative genetic dissection of complex seed weight in chickpea. PMID:25504138

  5. Rapid SNP discovery and genetic mapping using sequenced RAD markers.

    Directory of Open Access Journals (Sweden)

    Nathan A Baird

    Full Text Available Single nucleotide polymorphism (SNP discovery and genotyping are essential to genetic mapping. There remains a need for a simple, inexpensive platform that allows high-density SNP discovery and genotyping in large populations. Here we describe the sequencing of restriction-site associated DNA (RAD tags, which identified more than 13,000 SNPs, and mapped three traits in two model organisms, using less than half the capacity of one Illumina sequencing run. We demonstrated that different marker densities can be attained by choice of restriction enzyme. Furthermore, we developed a barcoding system for sample multiplexing and fine mapped the genetic basis of lateral plate armor loss in threespine stickleback by identifying recombinant breakpoints in F(2 individuals. Barcoding also facilitated mapping of a second trait, a reduction of pelvic structure, by in silico re-sorting of individuals. To further demonstrate the ease of the RAD sequencing approach we identified polymorphic markers and mapped an induced mutation in Neurospora crassa. Sequencing of RAD markers is an integrated platform for SNP discovery and genotyping. This approach should be widely applicable to genetic mapping in a variety of organisms.

  6. A genome-wide screen for promoter methylation in lung cancer identifies novel methylation markers for multiple malignancies.

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    David S Shames

    2006-12-01

    Full Text Available BACKGROUND: Promoter hypermethylation coupled with loss of heterozygosity at the same locus results in loss of gene function in many tumor cells. The "rules" governing which genes are methylated during the pathogenesis of individual cancers, how specific methylation profiles are initially established, or what determines tumor type-specific methylation are unknown. However, DNA methylation markers that are highly specific and sensitive for common tumors would be useful for the early detection of cancer, and those required for the malignant phenotype would identify pathways important as therapeutic targets. METHODS AND FINDINGS: In an effort to identify new cancer-specific methylation markers, we employed a high-throughput global expression profiling approach in lung cancer cells. We identified 132 genes that have 5' CpG islands, are induced from undetectable levels by 5-aza-2'-deoxycytidine in multiple non-small cell lung cancer cell lines, and are expressed in immortalized human bronchial epithelial cells. As expected, these genes were also expressed in normal lung, but often not in companion primary lung cancers. Methylation analysis of a subset (45/132 of these promoter regions in primary lung cancer (n = 20 and adjacent nonmalignant tissue (n = 20 showed that 31 genes had acquired methylation in the tumors, but did not show methylation in normal lung or peripheral blood cells. We studied the eight most frequently and specifically methylated genes from our lung cancer dataset in breast cancer (n = 37, colon cancer (n = 24, and prostate cancer (n = 24 along with counterpart nonmalignant tissues. We found that seven loci were frequently methylated in both breast and lung cancers, with four showing extensive methylation in all four epithelial tumors. CONCLUSIONS: By using a systematic biological screen we identified multiple genes that are methylated with high penetrance in primary lung, breast, colon, and prostate cancers. The cross

  7. Whole-genome single-nucleotide polymorphism (SNP marker discovery and association analysis with the eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA content in Larimichthys crocea

    Directory of Open Access Journals (Sweden)

    Shijun Xiao

    2016-12-01

    Full Text Available Whole-genome single-nucleotide polymorphism (SNP markers are valuable genetic resources for the association and conservation studies. Genome-wide SNP development in many teleost species are still challenging because of the genome complexity and the cost of re-sequencing. Genotyping-By-Sequencing (GBS provided an efficient reduced representative method to squeeze cost for SNP detection; however, most of recent GBS applications were reported on plant organisms. In this work, we used an EcoRI-NlaIII based GBS protocol to teleost large yellow croaker, an important commercial fish in China and East-Asia, and reported the first whole-genome SNP development for the species. 69,845 high quality SNP markers that evenly distributed along genome were detected in at least 80% of 500 individuals. Nearly 95% randomly selected genotypes were successfully validated by Sequenom MassARRAY assay. The association studies with the muscle eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA content discovered 39 significant SNP markers, contributing as high up to ∼63% genetic variance that explained by all markers. Functional genes that involved in fat digestion and absorption pathway were identified, such as APOB, CRAT and OSBPL10. Notably, PPT2 Gene, previously identified in the association study of the plasma n-3 and n-6 polyunsaturated fatty acid level in human, was re-discovered in large yellow croaker. Our study verified that EcoRI-NlaIII based GBS could produce quality SNP markers in a cost-efficient manner in teleost genome. The developed SNP markers and the EPA and DHA associated SNP loci provided invaluable resources for the population structure, conservation genetics and genomic selection of large yellow croaker and other fish organisms.

  8. A Genome Wide Comparison to Identify Markers to Differentiate the Sex of Larval Stages of Schistosoma haematobium, Schistosoma bovis and their Respective Hybrids.

    Directory of Open Access Journals (Sweden)

    Julien Kincaid-Smith

    2016-11-01

    Full Text Available For scientists working on gonochoric organisms, determining sex can be crucial for many biological questions and experimental studies, such as crossbreeding, but it can also be a challenging task, particularly when no sexual dimorphism is visible or cannot be directly observed. In metazoan parasites of the genus Schistosoma responsible for schistosomiasis, sex is genetically determined in the zygote with a female heterogametic ZW/ZZ system. Adult flukes have a pronounced sexual dimorphism, whereas the sexes of the larval stages are morphologically indistinguishable but can be distinguished uniquely by using molecular methods. Therefore, reliable methods are needed to identify the sex of larvae individuals. Here, we present an endpoint PCR-based assay using female-specific sequences identified using a genome-wide comparative analysis between males and females. This work allowed us to identify sex-markers for Schistosoma haematobium and Schistosoma bovis but also the hybrid between both species that has recently emerged in Corsica (France. Five molecular sex-markers were identified and are female-specific in S. haematobium and the hybrid parasite, whereas three of them are also female-specific in S. bovis. These molecular markers will be useful to conduct studies, such as experimental crosses on these disease-causing blood flukes, which are still largely neglected but no longer restricted to tropical areas.

  9. Development of Highly Informative Genome-Wide Single Sequence Repeat Markers for Breeding Applications in Sesame and Construction of a Web Resource: SisatBase

    Science.gov (United States)

    Dossa, Komivi; Yu, Jingyin; Liao, Boshou; Cisse, Ndiaga; Zhang, Xiurong

    2017-01-01

    The sequencing of the full nuclear genome of sesame (Sesamum indicum L.) provides the platform for functional analyses of genome components and their application in breeding programs. Although the importance of microsatellites markers or simple sequence repeats (SSR) in crop genotyping, genetics, and breeding applications is well established, only a little information exist concerning SSRs at the whole genome level in sesame. In addition, SSRs represent a suitable marker type for sesame molecular breeding in developing countries where it is mainly grown. In this study, we identified 138,194 genome-wide SSRs of which 76.5% were physically mapped onto the 13 pseudo-chromosomes. Among these SSRs, up to three primers pairs were supplied for 101,930 SSRs and used to in silico amplify the reference genome together with two newly sequenced sesame accessions. A total of 79,957 SSRs (78%) were polymorphic between the three genomes thereby suggesting their promising use in different genomics-assisted breeding applications. From these polymorphic SSRs, 23 were selected and validated to have high polymorphic potential in 48 sesame accessions from different growing areas of Africa. Furthermore, we have developed an online user-friendly database, SisatBase (http://www.sesame-bioinfo.org/SisatBase/), which provides free access to SSRs data as well as an integrated platform for functional analyses. Altogether, the reference SSR and SisatBase would serve as useful resources for genetic assessment, genomic studies, and breeding advancement in sesame, especially in developing countries. PMID:28878802

  10. Development of Highly Informative Genome-Wide Single Sequence Repeat Markers for Breeding Applications in Sesame and Construction of a Web Resource: SisatBase

    Directory of Open Access Journals (Sweden)

    Komivi Dossa

    2017-08-01

    Full Text Available The sequencing of the full nuclear genome of sesame (Sesamum indicum L. provides the platform for functional analyses of genome components and their application in breeding programs. Although the importance of microsatellites markers or simple sequence repeats (SSR in crop genotyping, genetics, and breeding applications is well established, only a little information exist concerning SSRs at the whole genome level in sesame. In addition, SSRs represent a suitable marker type for sesame molecular breeding in developing countries where it is mainly grown. In this study, we identified 138,194 genome-wide SSRs of which 76.5% were physically mapped onto the 13 pseudo-chromosomes. Among these SSRs, up to three primers pairs were supplied for 101,930 SSRs and used to in silico amplify the reference genome together with two newly sequenced sesame accessions. A total of 79,957 SSRs (78% were polymorphic between the three genomes thereby suggesting their promising use in different genomics-assisted breeding applications. From these polymorphic SSRs, 23 were selected and validated to have high polymorphic potential in 48 sesame accessions from different growing areas of Africa. Furthermore, we have developed an online user-friendly database, SisatBase (http://www.sesame-bioinfo.org/SisatBase/, which provides free access to SSRs data as well as an integrated platform for functional analyses. Altogether, the reference SSR and SisatBase would serve as useful resources for genetic assessment, genomic studies, and breeding advancement in sesame, especially in developing countries.

  11. The Use of Targeted Marker Subsets to Account for Population Structure and Relatedness in Genome-Wide Association Studies of Maize (Zea mays L.

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    Angela H. Chen

    2016-08-01

    Full Text Available A typical plant genome-wide association study (GWAS uses a mixed linear model (MLM that includes a trait as the response variable, a marker as an explanatory variable, and fixed and random effect covariates accounting for population structure and relatedness. Although effective in controlling for false positive signals, this model typically fails to detect signals that are correlated with population structure or are located in high linkage disequilibrium (LD genomic regions. This result likely arises from each tested marker being used to estimate population structure and relatedness. Previous work has demonstrated that it is possible to increase the power of the MLM by estimating relatedness (i.e., kinship with markers that are not located on the chromosome where the tested marker resides. To quantify the amount of additional significant signals one can expect using this so-called K_chr model, we reanalyzed Mendelian, polygenic, and complex traits in two maize (Zea mays L. diversity panels that have been previously assessed using the traditional MLM. We demonstrated that the K_chr model could find more significant associations, especially in high LD regions. This finding is underscored by our identification of novel genomic signals proximal to the tocochromanol biosynthetic pathway gene ZmVTE1 that are associated with a ratio of tocotrienols. We conclude that the K_chr model can detect more intricate sources of allelic variation underlying agronomically important traits, and should therefore become more widely used for GWAS. To facilitate the implementation of the K_chr model, we provide code written in the R programming language.

  12. 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.

  13. Genome-wide association mapping and biochemical markers reveal that seed ageing and longevity are intricately affected by genetic background and developmental and environmental conditions in barley.

    Science.gov (United States)

    Nagel, Manuela; Kranner, Ilse; Neumann, Kerstin; Rolletschek, Hardy; Seal, Charlotte E; Colville, Louise; Fernández-Marín, Beatriz; Börner, Andreas

    2015-06-01

    Globally, over 7.4 million accessions of crop seeds are stored in gene banks, and conservation of genotypic variation is pivotal for breeding. We combined genetic and biochemical approaches to obtain a broad overview of factors that influence seed storability and ageing in barley (Hordeum vulgare). Seeds from a germplasm collection of 175 genotypes from four continents grown in field plots with different nutrient supply were subjected to two artificial ageing regimes. Genome-wide association mapping revealed 107 marker trait associations, and hence, genotypic effects on seed ageing. Abiotic and biotic stresses were found to affect seed longevity. To address aspects of abiotic, including oxidative, stress, two major antioxidant groups were analysed. No correlation was found between seed deterioration and the lipid-soluble tocochromanols, nor with oil, starch and protein contents. Conversely, the water-soluble glutathione and related thiols were converted to disulphides, indicating a strong shift towards more oxidizing intracellular conditions, in seeds subjected to long-term dry storage at two temperatures or to two artificial ageing treatments. The data suggest that intracellular pH and (bio)chemical processes leading to seed deterioration were influenced by the type of ageing or storage. Moreover, seed response to ageing or storage treatment appears to be significantly influenced by both maternal environment and genetic background. © 2014 John Wiley & Sons Ltd.

  14. 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.

  15. Using the Pareto principle in genome-wide breeding value estimation

    Directory of Open Access Journals (Sweden)

    Yu Xijiang

    2011-11-01

    Full Text Available Abstract Genome-wide breeding value (GWEBV estimation methods can be classified based on the prior distribution assumptions of marker effects. Genome-wide BLUP methods assume a normal prior distribution for all markers with a constant variance, and are computationally fast. In Bayesian methods, more flexible prior distributions of SNP effects are applied that allow for very large SNP effects although most are small or even zero, but these prior distributions are often also computationally demanding as they rely on Monte Carlo Markov chain sampling. In this study, we adopted the Pareto principle to weight available marker loci, i.e., we consider that x% of the loci explain (100 - x% of the total genetic variance. Assuming this principle, it is also possible to define the variances of the prior distribution of the 'big' and 'small' SNP. The relatively few large SNP explain a large proportion of the genetic variance and the majority of the SNP show small effects and explain a minor proportion of the genetic variance. We name this method MixP, where the prior distribution is a mixture of two normal distributions, i.e. one with a big variance and one with a small variance. Simulation results, using a real Norwegian Red cattle pedigree, show that MixP is at least as accurate as the other methods in all studied cases. This method also reduces the hyper-parameters of the prior distribution from 2 (proportion and variance of SNP with big effects to 1 (proportion of SNP with big effects, assuming the overall genetic variance is known. The mixture of normal distribution prior made it possible to solve the equations iteratively, which greatly reduced computation loads by two orders of magnitude. In the era of marker density reaching million(s and whole-genome sequence data, MixP provides a computationally feasible Bayesian method of analysis.

  16. Development and application of a 20K SNP array in potato

    NARCIS (Netherlands)

    Vos, Peter

    2016-01-01

    In this thesis the results are described of investigations of various application of genome wide SNP (single nucleotide polymorphism) markers. The set of SNP markers was identified by GBS (genotyping by sequencing) strategy. The resulting dataset of 129,156 SNPs across 83 tetraploid varieties was us

  17. Genome-wide distribution of genetic diversity and linkage disequilibrium in elite sugar beet germplasm

    Directory of Open Access Journals (Sweden)

    Weißleder Knuth

    2011-10-01

    Full Text Available Abstract Background Characterization of population structure and genetic diversity of germplasm is essential for the efficient organization and utilization of breeding material. The objectives of this study were to (i explore the patterns of population structure in the pollen parent heterotic pool using different methods, (ii investigate the genome-wide distribution of genetic diversity, and (iii assess the extent and genome-wide distribution of linkage disequilibrium (LD in elite sugar beet germplasm. Results A total of 264 and 238 inbred lines from the yield type and sugar type inbreds of the pollen parent heterotic gene pools, respectively, which had been genotyped with 328 SNP markers, were used in this study. Two distinct subgroups were detected based on different statistical methods within the elite sugar beet germplasm set, which was in accordance with its breeding history. MCLUST based on principal components, principal coordinates, or lapvectors had high correspondence with the germplasm type information as well as the assignment by STRUCTURE, which indicated that these methods might be alternatives to STRUCTURE for population structure analysis. Gene diversity and modified Roger's distance between the examined germplasm types varied considerably across the genome, which might be due to artificial selection. This observation indicates that population genetic approaches could be used to identify candidate genes for the traits under selection. Due to the fact that r2 >0.8 is required to detect marker-phenotype association explaining less than 1% of the phenotypic variance, our observation of a low proportion of SNP loci pairs showing such levels of LD suggests that the number of markers has to be dramatically increased for powerful genome-wide association mapping. Conclusions We provided a genome-wide distribution map of genetic diversity and linkage disequilibrium for the elite sugar beet germplasm, which is useful for the application of

  18. Genome-wide scan for visceral leishmaniasis in mixed-breed dogs identifies candidate genes involved in T helper cells and macrophage signaling

    Science.gov (United States)

    We conducted a genome-wide scan for visceral leishmaniasis in mixed-breed dogs from a highly endemic area in Brazil using 149,648 single nucleotide polymorphism (SNP) markers genotyped in 20 cases and 28 controls. Using a mixed model approach, we found two candidate loci on canine autosomes 1 and 2....

  19. Genome-wide copy number variant analysis in Holstein cattle reveals variants associated with 10 production traits including residual feed intake and dry matter intake

    Science.gov (United States)

    Copy number variation (CNV) is an important type of genetic variation contributing to phenotypic differences among mammals and may serve as an alternative molecular marker to single nucleotide polymorphism (SNP) for genome-wide association study (GWAS). Recently, GWAS analysis using CNV has been app...

  20. Outlier SNP markers reveal fine-scale genetic structuring across European hake populations (Merluccius merluccius).

    Science.gov (United States)

    Milano, Ilaria; Babbucci, Massimiliano; Cariani, Alessia; Atanassova, Miroslava; Bekkevold, Dorte; Carvalho, Gary R; Espiñeira, Montserrat; Fiorentino, Fabio; Garofalo, Germana; Geffen, Audrey J; Hansen, Jakob H; Helyar, Sarah J; Nielsen, Einar E; Ogden, Rob; Patarnello, Tomaso; Stagioni, Marco; Tinti, Fausto; Bargelloni, Luca

    2014-01-01

    Shallow population structure is generally reported for most marine fish and explained as a consequence of high dispersal, connectivity and large population size. Targeted gene analyses and more recently genome-wide studies have challenged such view, suggesting that adaptive divergence might occur even when neutral markers provide genetic homogeneity across populations. Here, 381 SNPs located in transcribed regions were used to assess large- and fine-scale population structure in the European hake (Merluccius merluccius), a widely distributed demersal species of high priority for the European fishery. Analysis of 850 individuals from 19 locations across the entire distribution range showed evidence for several outlier loci, with significantly higher resolving power. While 299 putatively neutral SNPs confirmed the genetic break between basins (F(CT) = 0.016) and weak differentiation within basins, outlier loci revealed a dramatic divergence between Atlantic and Mediterranean populations (F(CT) range 0.275-0.705) and fine-scale significant population structure. Outlier loci separated North Sea and Northern Portugal populations from all other Atlantic samples and revealed a strong differentiation among Western, Central and Eastern Mediterranean geographical samples. Significant correlation of allele frequencies at outlier loci with seawater surface temperature and salinity supported the hypothesis that populations might be adapted to local conditions. Such evidence highlights the importance of integrating information from neutral and adaptive evolutionary patterns towards a better assessment of genetic diversity. Accordingly, the generated outlier SNP data could be used for tackling illegal practices in hake fishing and commercialization as well as to develop explicit spatial models for defining management units and stock boundaries.

  1. Evaluation of approaches for identifying population informative markers from high density SNP Chips

    Directory of Open Access Journals (Sweden)

    McKay Stephanie D

    2011-05-01

    Full Text Available Abstract Background Genetic markers can be used to identify and verify the origin of individuals. Motivation for the inference of ancestry ranges from conservation genetics to forensic analysis. High density assays featuring Single Nucleotide Polymorphism (SNP markers can be exploited to create a reduced panel containing the most informative markers for these purposes. The objectives of this study were to evaluate methods of marker selection and determine the minimum number of markers from the BovineSNP50 BeadChip required to verify the origin of individuals in European cattle breeds. Delta, Wright's FST, Weir & Cockerham's FST and PCA methods for population differentiation were compared. The level of informativeness of each SNP was estimated from the breed specific allele frequencies. Individual assignment analysis was performed using the ranked informative markers. Stringency levels were applied by log-likelihood ratio to assess the confidence of the assignment test. Results A 95% assignment success rate for the 384 individually genotyped animals was achieved with ST (60 to 140 SNPs depending on the chosen degree of confidence. Certain breeds required fewer markers ( 95% assignment success. The power of assignment success, and therefore the number of SNP markers required, is dependent on the levels of genetic heterogeneity and pool of samples considered. Conclusions While all SNP selection methods produced marker panels capable of breed identification, the power of assignment varied markedly among analysis methods. Thus, with effective exploration of available high density genetic markers, a diagnostic panel of highly informative markers can be produced.

  2. A resource of genome-wide single-nucleotide polymorphisms generated by RAD tag sequencing in the critically endangered European eel

    DEFF Research Database (Denmark)

    Pujolar, J.M.; Jacobsen, M.W.; Frydenberg, J.

    2013-01-01

    Reduced representation genome sequencing such as restriction-site-associated DNA (RAD) sequencing is finding increased use to identify and genotype large numbers of single-nucleotide polymorphisms (SNPs) in model and nonmodel species. We generated a unique resource of novel SNP markers for the Eu......Reduced representation genome sequencing such as restriction-site-associated DNA (RAD) sequencing is finding increased use to identify and genotype large numbers of single-nucleotide polymorphisms (SNPs) in model and nonmodel species. We generated a unique resource of novel SNP markers...... for the European eel using the RAD sequencing approach that was simultaneously identified and scored in a genome-wide scan of 30 individuals. Whereas genomic resources are increasingly becoming available for this species, including the recent release of a draft genome, no genome-wide set of SNP markers...

  3. Outlier SNP markers reveal fine-scale genetic structuring across European hake populations (Merluccius merluccius)

    DEFF Research Database (Denmark)

    Milano, I.; Babbucci, M.; Cariani, A.;

    2014-01-01

    of integrating information from neutral and adaptive evolutionary patterns towards a better assessment of genetic diversity. Accordingly, the generated outlier SNP data could be used for tackling illegal practices in hake fishing and commercialization as well as to develop explicit spatial models for defining......Shallow population structure is generally reported for most marine fish and explained as a consequence of high dispersal, connectivity and large population size. Targeted gene analyses and more recently genome-wide studies have challenged such view, suggesting that adaptive divergence might occur...

  4. SNP and SSR marker analysis and mapping of a maize population

    Directory of Open Access Journals (Sweden)

    Šimić Domagoj

    2009-01-01

    Full Text Available Although highly polymorphic SSRs are currently the marker of choice worldwide in maize breeding, single nucleotide polymorphisms (SNPs as a newer marker system are recently used more extensively. The objective of this study was investigate the utility of SSR and SNP markers for mapping of a maize population adapted to conditions of Southeast Europe. Total of 294 F2:3 lines derived from a biparental mapping population were genotyped using 121 polymorphic SNP and SSR markers. The SNP markers were analyzed using the SNPlex technology. 56 of the 142 tested SNPs (39% were polymorphic between the parents of the mapping population and were successfully mapped. The remaining markers were either not functional (5 = 3.5% or not polymorphic (81 = 57%. No mapped SNP marker showed more than 10% missing data. On average, the level of missing data for SNPs (1.5% was considerably lower than that for SSRs (3.4%. For the mapping procedure, the SNP data were combined SSR data. A comparison of the mapping data with the publicly available mapping data on SSR markers and the proprietary mapping data indicates that the map is of good quality and that the map position of almost all markers agrees with their published map position. Thus, information obtained from both marker systems is utilizable for further QTL analysis.

  5. Genome-wide association study for wool production traits in a Chinese Merino sheep population.

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    Zhipeng Wang

    Full Text Available Genome-wide association studies (GWAS provide a powerful approach for identifying quantitative trait loci without prior knowledge of location or function. To identify loci associated with wool production traits, we performed a genome-wide association study on a total of 765 Chinese Merino sheep (JunKen type genotyped with 50 K single nucleotide polymorphisms (SNPs. In the present study, five wool production traits were examined: fiber diameter, fiber diameter coefficient of variation, fineness dispersion, staple length and crimp. We detected 28 genome-wide significant SNPs for fiber diameter, fiber diameter coefficient of variation, fineness dispersion, and crimp trait in the Chinese Merino sheep. About 43% of the significant SNP markers were located within known or predicted genes, including YWHAZ, KRTCAP3, TSPEAR, PIK3R4, KIF16B, PTPN3, GPRC5A, DDX47, TCF9, TPTE2, EPHA5 and NBEA genes. Our results not only confirm the results of previous reports, but also provide a suite of novel SNP markers and candidate genes associated with wool traits. Our findings will be useful for exploring the genetic control of wool traits in sheep.

  6. Genome-wide association study for wool production traits in a Chinese Merino sheep population.

    Science.gov (United States)

    Wang, Zhipeng; Zhang, Hui; Yang, Hua; Wang, Shouzhi; Rong, Enguang; Pei, Wenyu; Li, Hui; Wang, Ning

    2014-01-01

    Genome-wide association studies (GWAS) provide a powerful approach for identifying quantitative trait loci without prior knowledge of location or function. To identify loci associated with wool production traits, we performed a genome-wide association study on a total of 765 Chinese Merino sheep (JunKen type) genotyped with 50 K single nucleotide polymorphisms (SNPs). In the present study, five wool production traits were examined: fiber diameter, fiber diameter coefficient of variation, fineness dispersion, staple length and crimp. We detected 28 genome-wide significant SNPs for fiber diameter, fiber diameter coefficient of variation, fineness dispersion, and crimp trait in the Chinese Merino sheep. About 43% of the significant SNP markers were located within known or predicted genes, including YWHAZ, KRTCAP3, TSPEAR, PIK3R4, KIF16B, PTPN3, GPRC5A, DDX47, TCF9, TPTE2, EPHA5 and NBEA genes. Our results not only confirm the results of previous reports, but also provide a suite of novel SNP markers and candidate genes associated with wool traits. Our findings will be useful for exploring the genetic control of wool traits in sheep.

  7. RAD tag sequencing as a source of SNP markers in Cynara cardunculus L.

    OpenAIRE

    Scaglione Davide; Acquadro Alberto; Portis Ezio; Tirone Matteo; Knapp Steven J; Lanteri Sergio

    2012-01-01

    Abstract Background The globe artichoke (Cynara cardunculus L. var. scolymus) genome is relatively poorly explored, especially compared to those of the other major Asteraceae crops sunflower and lettuce. No SNP markers are in the public domain. We have combined the recently developed restriction-site associated DNA (RAD) approach with the Illumina DNA sequencing platform to effect the rapid and mass discovery of SNP markers for C. cardunculus. Results RAD tags were sequenced from the genomic ...

  8. Identification of a glutamic acid repeat polymorphism of ALMS1 as a novel genetic risk marker for early-onset myocardial infarction by genome-wide linkage analysis.

    Science.gov (United States)

    Ichihara, Sahoko; Yamamoto, Ken; Asano, Hiroyuki; Nakatochi, Masahiro; Sukegawa, Mayo; Ichihara, Gaku; Izawa, Hideo; Hirashiki, Akihiro; Takatsu, Fumimaro; Umeda, Hisashi; Iwase, Mitsunori; Inagaki, Haruo; Hirayama, Haruo; Sone, Takahito; Nishigaki, Kazuhiko; Minatoguchi, Shinya; Cho, Myeong-Chan; Jang, Yangsoo; Kim, Hyo-Soo; Park, Jeong E; Tada-Oikawa, Saeko; Kitajima, Hidetoshi; Matsubara, Tatsuaki; Sunagawa, Kenji; Shimokawa, Hiroaki; Kimura, Akinori; Lee, Jong-Young; Murohara, Toyoaki; Inoue, Ituro; Yokota, Mitsuhiro

    2013-12-01

    Myocardial infarction (MI) is a leading cause of death worldwide. Given that a family history is an independent risk factor for coronary artery disease, genetic variants are thought to contribute directly to the development of this condition. The identification of susceptibility genes for coronary artery disease or MI may thus help to identify high-risk individuals and offer the opportunity for disease prevention. We designed a 5-step protocol, consisting of a genome-wide linkage study followed by association analysis, to identify novel genetic variants that confer susceptibility to coronary artery disease or MI. A genome-wide affected sib-pair linkage study with 221 Japanese families with coronary artery disease yielded a statistically significant logarithm of the odds score of 3.44 for chromosome 2p13 and MI. Further association analysis implicated Alström syndrome 1 gene (ALMS1) as a candidate gene within the linkage region. Validation association analysis revealed that representative single-nucleotide polymorphisms of the ALMS1 promoter region were significantly associated with early-onset MI in both Japanese and Korean populations. Moreover, direct sequencing of the ALMS1 coding region identified a glutamic acid repeat polymorphism in exon 1, which was subsequently found to be associated with early-onset MI. The glutamic acid repeat polymorphism of ALMS1 identified in the present study may provide insight into the pathogenesis of early-onset MI.

  9. GLIDERS - A web-based search engine for genome-wide linkage disequilibrium between HapMap SNPs

    Directory of Open Access Journals (Sweden)

    Broxholme John

    2009-10-01

    Full Text Available Abstract Background A number of tools for the examination of linkage disequilibrium (LD patterns between nearby alleles exist, but none are available for quickly and easily investigating LD at longer ranges (>500 kb. We have developed a web-based query tool (GLIDERS: Genome-wide LInkage DisEquilibrium Repository and Search engine that enables the retrieval of pairwise associations with r2 ≥ 0.3 across the human genome for any SNP genotyped within HapMap phase 2 and 3, regardless of distance between the markers. Description GLIDERS is an easy to use web tool that only requires the user to enter rs numbers of SNPs they want to retrieve genome-wide LD for (both nearby and long-range. The intuitive web interface handles both manual entry of SNP IDs as well as allowing users to upload files of SNP IDs. The user can limit the resulting inter SNP associations with easy to use menu options. These include MAF limit (5-45%, distance limits between SNPs (minimum and maximum, r2 (0.3 to 1, HapMap population sample (CEU, YRI and JPT+CHB combined and HapMap build/release. All resulting genome-wide inter-SNP associations are displayed on a single output page, which has a link to a downloadable tab delimited text file. Conclusion GLIDERS is a quick and easy way to retrieve genome-wide inter-SNP associations and to explore LD patterns for any number of SNPs of interest. GLIDERS can be useful in identifying SNPs with long-range LD. This can highlight mis-mapping or other potential association signal localisation problems.

  10. CAGI4 Crohn's exome challenge: Marker SNP versus exome variant models for assigning risk of Crohn disease.

    Science.gov (United States)

    Pal, Lipika R; Kundu, Kunal; Yin, Yizhou; Moult, John

    2017-09-01

    Understanding the basis of complex trait disease is a fundamental problem in human genetics. The CAGI Crohn's Exome challenges are providing insight into the adequacy of current disease models by requiring participants to identify which of a set of individuals has been diagnosed with the disease, given exome data. For the CAGI4 round, we developed a method that used the genotypes from exome sequencing data only to impute the status of genome wide association studies marker SNPs. We then used the imputed genotypes as input to several machine learning methods that had been trained to predict disease status from marker SNP information. We achieved the best performance using Naïve Bayes and with a consensus machine learning method, obtaining an area under the curve of 0.72, larger than other methods used in CAGI4. We also developed a model that incorporated the contribution from rare missense variants in the exome data, but this performed less well. Future progress is expected to come from the use of whole genome data rather than exomes. © 2017 Wiley Periodicals, Inc.

  11. European American stratification in ovarian cancer case control data: the utility of genome-wide data for inferring ancestry.

    Directory of Open Access Journals (Sweden)

    Paola Raska

    Full Text Available We investigated the ability of several principal components analysis (PCA-based strategies to detect and control for population stratification using data from a multi-center study of epithelial ovarian cancer among women of European-American ethnicity. These include a correction based on an ancestry informative markers (AIMs panel designed to capture European ancestral variation and corrections utilizing un-thinned genome-wide SNP data; case-control samples were drawn from four geographically distinct North-American sites. The AIMs-only and genome-wide first principal components (PC1 both corresponded to the previously described North or Northwest-Southeast axis of European variation. We found that the genome-wide PCA captured this primary dimension of variation more precisely and identified additional axes of genome-wide variation of relevance to epithelial ovarian cancer. Associations evident between the genome-wide PCs and study site corroborate North American immigration history and suggest that undiscovered dimensions of variation lie within Northern Europe. The structure captured by the genome-wide PCA was also found within control individuals and did not reflect the case-control variation present in the data. The genome-wide PCA highlighted three regions of local LD, corresponding to the lactase (LCT gene on chromosome 2, the human leukocyte antigen system (HLA on chromosome 6 and to a common inversion polymorphism on chromosome 8. These features did not compromise the efficacy of PCs from this analysis for ancestry control. This study concludes that although AIMs panels are a cost-effective way of capturing population structure, genome-wide data should preferably be used when available.

  12. Genome wide association study (GWAS) for grain yield in rice cultivated under water deficit.

    Science.gov (United States)

    Pantalião, Gabriel Feresin; Narciso, Marcelo; Guimarães, Cléber; Castro, Adriano; Colombari, José Manoel; Breseghello, Flavio; Rodrigues, Luana; Vianello, Rosana Pereira; Borba, Tereza Oliveira; Brondani, Claudio

    2016-12-01

    The identification of rice drought tolerant materials is crucial for the development of best performing cultivars for the upland cultivation system. This study aimed to identify markers and candidate genes associated with drought tolerance by Genome Wide Association Study analysis, in order to develop tools for use in rice breeding programs. This analysis was made with 175 upland rice accessions (Oryza sativa), evaluated in experiments with and without water restriction, and 150,325 SNPs. Thirteen SNP markers associated with yield under drought conditions were identified. Through stepwise regression analysis, eight SNP markers were selected and validated in silico, and when tested by PCR, two out of the eight SNP markers were able to identify a group of rice genotypes with higher productivity under drought. These results are encouraging for deriving markers for the routine analysis of marker assisted selection. From the drought experiment, including the genes inherited in linkage blocks, 50 genes were identified, from which 30 were annotated, and 10 were previously related to drought and/or abiotic stress tolerance, such as the transcription factors WRKY and Apetala2, and protein kinases.

  13. Genome-Wide Discovery of Microsatellite Markers from Diploid Progenitor Species, Arachis duranensis and A. ipaensis, and Their Application in Cultivated Peanut (A. hypogaea

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    Chuanzhi Zhao

    2017-07-01

    Full Text Available Despite several efforts in the last decade toward development of simple sequence repeat (SSR markers in peanut, there is still a need for more markers for conducting different genetic and breeding studies. With the effort of the International Peanut Genome Initiative, the availability of reference genome for both the diploid progenitors of cultivated peanut allowed us to identify 135,529 and 199,957 SSRs from the A (Arachis duranensis and B genomes (Arachis ipaensis, respectively. Genome sequence analysis showed uneven distribution of the SSR motifs across genomes with variation in parameters such as SSR type, repeat number, and SSR length. Using the flanking sequences of identified SSRs, primers were designed for 51,354 and 60,893 SSRs with densities of 49 and 45 SSRs per Mb in A. duranensis and A. ipaensis, respectively. In silico PCR analysis of these SSR markers showed high transferability between wild and cultivated Arachis species. Two physical maps were developed for the A genome and the B genome using these SSR markers, and two reported disease resistance quantitative trait loci (QTLs, qF2TSWV5 for tomato spotted wilt virus (TSWV and qF2LS6 for leaf spot (LS, were mapped in the 8.135 Mb region of chromosome A04 of A. duranensis. From this genomic region, 719 novel SSR markers were developed, which provide the possibility for fine mapping of these QTLs. In addition, this region also harbors 652 genes and 49 of these are defense related genes, including two NB-ARC genes, three LRR receptor-like genes and three WRKY transcription factors. These disease resistance related genes could contribute to resistance to viral (such as TSWV and fungal (such as LS diseases in peanut. In summary, this study not only provides a large number of molecular markers for potential use in peanut genetic map development and QTL mapping but also for map-based gene cloning and molecular breeding.

  14. Phenotypes, genome wide markers and structured genetic populations; a means to understand economically important traits in beta vulgaris and to inform the process of germplasm enhancement

    Science.gov (United States)

    Although hybrid seed systems in beet have been widely adopted due to profitability and productivity, the population remains the operational unit of beet improvement and thus characterizing populations in terms of markers and phenotypes is critical for novel trait discovery and eventual deployment of...

  15. Development of discrimination SNP markers for Hanwoo (Korean native cattle).

    Science.gov (United States)

    Cheong, H S; Kim, L H; Namgoong, S; Shin, H D

    2013-07-01

    In the Korean meat market, the native cattle, Hanwoo beef, are preferred over imported beef and domestic Holstein beef despite its relatively high price. In order to hold the beef industry accountable and support consumers' right to know, correct beef-origin labeling is required. For this purpose, we developed 90 single-nucleotide polymorphism markers to discriminate between Hanwoo and other breeds including Holstein using 1602 cattle DNAs. The probability of discrimination was found to be 100% in a subsequent validation set consisting of 632 DNAs. Our study suggests that improved beef-origin discrimination can be achieved by using a combined genetic model that takes into account small genetic differences among a large number of markers. These markers could be useful for discriminating between Hanwoo and imported breeds including domestic Holsteins, and would contribute to the prevention of falsified beef origin.

  16. Methodological Considerations in Estimation of Phenotype Heritability Using Genome-Wide SNP Data, Illustrated by an Analysis of the Heritability of Height in a Large Sample of African Ancestry Adults

    Science.gov (United States)

    Chen, Fang; He, Jing; Zhang, Jianqi; Chen, Gary K.; Thomas, Venetta; Ambrosone, Christine B.; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Cai, Qiuyin; Carpten, John; Casey, Graham; Chanock, Stephen J.; Cheng, Iona; Chu, Lisa; Deming, Sandra L.; Driver, W. Ryan; Goodman, Phyllis; Hayes, Richard B.; Hennis, Anselm J. M.; Hsing, Ann W.; Hu, Jennifer J.; Ingles, Sue A.; John, Esther M.; Kittles, Rick A.; Kolb, Suzanne; Leske, M. Cristina; Monroe, Kristine R.; Murphy, Adam; Nemesure, Barbara; Neslund-Dudas, Christine; Nyante, Sarah; Ostrander, Elaine A; Press, Michael F.; Rodriguez-Gil, Jorge L.; Rybicki, Ben A.; Schumacher, Fredrick; Stanford, Janet L.; Signorello, Lisa B.; Strom, Sara S.; Stevens, Victoria; Van Den Berg, David; Wang, Zhaoming; Witte, John S.; Wu, Suh-Yuh; Yamamura, Yuko; Zheng, Wei; Ziegler, Regina G.; Stram, Alexander H.; Kolonel, Laurence N.; Marchand, Loïc Le; Henderson, Brian E.; Haiman, Christopher A.; Stram, Daniel O.

    2015-01-01

    Height has an extremely polygenic pattern of inheritance. Genome-wide association studies (GWAS) have revealed hundreds of common variants that are associated with human height at genome-wide levels of significance. However, only a small fraction of phenotypic variation can be explained by the aggregate of these common variants. In a large study of African-American men and women (n = 14,419), we genotyped and analyzed 966,578 autosomal SNPs across the entire genome using a linear mixed model variance components approach implemented in the program GCTA (Yang et al Nat Genet 2010), and estimated an additive heritability of 44.7% (se: 3.7%) for this phenotype in a sample of evidently unrelated individuals. While this estimated value is similar to that given by Yang et al in their analyses, we remain concerned about two related issues: (1) whether in the complete absence of hidden relatedness, variance components methods have adequate power to estimate heritability when a very large number of SNPs are used in the analysis; and (2) whether estimation of heritability may be biased, in real studies, by low levels of residual hidden relatedness. We addressed the first question in a semi-analytic fashion by directly simulating the distribution of the score statistic for a test of zero heritability with and without low levels of relatedness. The second question was addressed by a very careful comparison of the behavior of estimated heritability for both observed (self-reported) height and simulated phenotypes compared to imputation R2 as a function of the number of SNPs used in the analysis. These simulations help to address the important question about whether today's GWAS SNPs will remain useful for imputing causal variants that are discovered using very large sample sizes in future studies of height, or whether the causal variants themselves will need to be genotyped de novo in order to build a prediction model that ultimately captures a large fraction of the variability

  17. Methodological Considerations in Estimation of Phenotype Heritability Using Genome-Wide SNP Data, Illustrated by an Analysis of the Heritability of Height in a Large Sample of African Ancestry Adults.

    Directory of Open Access Journals (Sweden)

    Fang Chen

    Full Text Available Height has an extremely polygenic pattern of inheritance. Genome-wide association studies (GWAS have revealed hundreds of common variants that are associated with human height at genome-wide levels of significance. However, only a small fraction of phenotypic variation can be explained by the aggregate of these common variants. In a large study of African-American men and women (n = 14,419, we genotyped and analyzed 966,578 autosomal SNPs across the entire genome using a linear mixed model variance components approach implemented in the program GCTA (Yang et al Nat Genet 2010, and estimated an additive heritability of 44.7% (se: 3.7% for this phenotype in a sample of evidently unrelated individuals. While this estimated value is similar to that given by Yang et al in their analyses, we remain concerned about two related issues: (1 whether in the complete absence of hidden relatedness, variance components methods have adequate power to estimate heritability when a very large number of SNPs are used in the analysis; and (2 whether estimation of heritability may be biased, in real studies, by low levels of residual hidden relatedness. We addressed the first question in a semi-analytic fashion by directly simulating the distribution of the score statistic for a test of zero heritability with and without low levels of relatedness. The second question was addressed by a very careful comparison of the behavior of estimated heritability for both observed (self-reported height and simulated phenotypes compared to imputation R2 as a function of the number of SNPs used in the analysis. These simulations help to address the important question about whether today's GWAS SNPs will remain useful for imputing causal variants that are discovered using very large sample sizes in future studies of height, or whether the causal variants themselves will need to be genotyped de novo in order to build a prediction model that ultimately captures a large fraction of the

  18. Genome-wide significant association between alcohol dependence and a variant in the ADH gene cluster.

    Science.gov (United States)

    Frank, Josef; Cichon, Sven; Treutlein, Jens; Ridinger, Monika; Mattheisen, Manuel; Hoffmann, Per; Herms, Stefan; Wodarz, Norbert; Soyka, Michael; Zill, Peter; Maier, Wolfgang; Mössner, Rainald; Gaebel, Wolfgang; Dahmen, Norbert; Scherbaum, Norbert; Schmäl, Christine; Steffens, Michael; Lucae, Susanne; Ising, Marcus; Müller-Myhsok, Bertram; Nöthen, Markus M; Mann, Karl; Kiefer, Falk; Rietschel, Marcella

    2012-01-01

    Alcohol dependence (AD) is an important contributory factor to the global burden of disease. The etiology of AD involves both environmental and genetic factors, and the disorder has a heritability of around 50%. The aim of the present study was to identify susceptibility genes for AD by performing a genome-wide association study (GWAS). The sample comprised 1333 male in-patients with severe AD according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and 2168 controls. These included 487 patients and 1358 controls from a previous GWAS study by our group. All individuals were of German descent. Single-marker tests and a polygenic score-based analysis to assess the combined contribution of multiple markers with small effects were performed. The single nucleotide polymorphism (SNP) rs1789891, which is located between the ADH1B and ADH1C genes, achieved genome-wide significance [P = 1.27E-8, odds ratio (OR) = 1.46]. Other markers from this region were also associated with AD, and conditional analyses indicated that these made a partially independent contribution. The SNP rs1789891 is in complete linkage disequilibrium with the functional Arg272Gln variant (P = 1.24E-7, OR = 1.31) of the ADH1C gene, which has been reported to modify the rate of ethanol oxidation to acetaldehyde in vitro. A polygenic score-based approach produced a significant result (P = 9.66E-9). This is the first GWAS of AD to provide genome-wide significant support for the role of the ADH gene cluster and to suggest a polygenic component to the etiology of AD. The latter result may indicate that many more AD susceptibility genes still await identification.

  19. Applying SNP marker technology in the cacao breeding program at the Cocoa Research Institute of Ghana

    Science.gov (United States)

    In this investigation 45 parental cacao plants and five progeny derived from the parental stock studied were genotyped using six SNP markers to determine off-types or mislabeled clones and to authenticate crosses made in the Cocoa Research Institute of Ghana (CRIG) breeding program. Investigation wa...

  20. SNP-markers in Allium species to facilitate introgression breeding in onion

    NARCIS (Netherlands)

    Scholten, Olga E.; Kaauwen, van Martijn P.W.; Shahin, Arwa; Hendrickx, Patrick M.; Keizer, Paul; Burger-Meijer, Karin; Heusden, van Sjaak; Linden, van der Gerard; Vosman, Ben

    2016-01-01

    Background: Within onion, Allium cepa L., the availability of disease resistance is limited. The identification of sources of resistance in related species, such as Allium roylei and Allium fistulosum, was a first step towards the improvement of onion cultivars by breeding. SNP markers linked to

  1. 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.

  2. Genome-Wide Analysis of Evolutionary Markers of Human Influenza A(H1N1)pdm09 and A(H3N2) Viruses May Guide Selection of Vaccine Strain Candidates.

    Science.gov (United States)

    Belanov, Sergei S; Bychkov, Dmitrii; Benner, Christian; Ripatti, Samuli; Ojala, Teija; Kankainen, Matti; Kai Lee, Hong; Wei-Tze Tang, Julian; Kainov, Denis E

    2015-11-27

    Here we analyzed whole-genome sequences of 3,969 influenza A(H1N1)pdm09 and 4,774 A(H3N2) strains that circulated during 2009-2015 in the world. The analysis revealed changes at 481 and 533 amino acid sites in proteins of influenza A(H1N1)pdm09 and A(H3N2) strains, respectively. Many of these changes were introduced as a result of random drift. However, there were 61 and 68 changes that were present in relatively large number of A(H1N1)pdm09 and A(H3N2) strains, respectively, that circulated during relatively long time. We named these amino acid substitutions evolutionary markers, as they seemed to contain valuable information regarding the viral evolution. Interestingly, influenza A(H1N1)pdm09 and A(H3N2) viruses acquired non-overlapping sets of evolutionary markers. We next analyzed these characteristic markers in vaccine strains recommended by the World Health Organization for the past five years. Our analysis revealed that vaccine strains carried only few evolutionary markers at antigenic sites of viral hemagglutinin (HA) and neuraminidase (NA). The absence of these markers at antigenic sites could affect the recognition of HA and NA by human antibodies generated in response to vaccinations. This could, in part, explain moderate efficacy of influenza vaccines during 2009-2014. Finally, we identified influenza A(H1N1)pdm09 and A(H3N2) strains, which contain all the evolutionary markers of influenza A strains circulated in 2015, and which could be used as vaccine candidates for the 2015/2016 season. Thus, genome-wide analysis of evolutionary markers of influenza A(H1N1)pdm09 and A(H3N2) viruses may guide selection of vaccine strain candidates.

  3. Correlation Analysis Between Heterosis and Genetic Distance Evaluated by Genome-Wide SNP Chip inBrassica napus%利用全基因组SNP芯片分析油菜遗传距离与杂种优势的关系

    Institute of Scientific and Technical Information of China (English)

    桑世飞; 王会; 梅德圣; 刘佳; 付丽; 王军; 汪文祥; 胡琼

    2015-01-01

    , R6, R9 and R10 in a second group, three restorer lines R1, R3 and R11 in the third group, and the remaining one restorer OR1 in the fourth group. This cluster results indicate that the genetic variation in the restorers is greater than that in the maintainers, which is in accordance with their pedigree relationships. The average mid-parent heterosis of the 10 traits ranged from -0.07%-38.78%, and the average high-parent heterosis ranged from -7.74%-20.78%. Except for NEPB, all other nine yield-related traits showed significant heterosis in F1 hybrids. Especially for PH, SPS, BH and YPP, the average mid-parent heterosis was 6.83%, 15.31%, 16.13% and 38.78%, respectively, with the number of F1s having positive mid-parent heterosis was 45, 41, 46 and 46; and the average high-parent heterosis reached 3.18%, 5.19%, 7.85% and 20.78%, respectively, with the number of F1s having positive high-parent heterosis was 41, 31, 42 and 44. A significant positive correlation between heterosis and SNP estimated GD was detected for PH, BH and YPP, with the correlation coefficients between SNP estimated GD and mid-parent heterosis were 0.3884, 0.4051 and 0.4038, respectively. The correlation between heterosis and SNP estimated GD for other traits was not significant.[Conclusion]The genome-wide 60K SNP chip ofBrassicas has significant advantages for genotyping, genetic distance estimation and cluster analysis. The GD estimated by genome-wide SNP makers has a very significantly positive correlation with heterosis for traits with high and universal heterosis, including plant yield. Thus, the genome-wide 60K SNP chip ofBrassicas can be used to well predict heterosis in rapeseed.%【目的】利用单核苷酸多态性(single nucleotide polymorphism,简称SNP)标记估算油菜优异亲本间的遗传距离,分析其与杂种优势间的关系,探讨利用SNP标记预测油菜杂种优势的可行性,为油菜杂种优势利用育种提供指导。【方法】将油菜波里马

  4. Agronomic and seed quality traits dissected by genome-wide association mapping in Brassica napus

    Directory of Open Access Journals (Sweden)

    Niklas eKörber

    2016-03-01

    Full Text Available In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. % as well as require high experimental effort due to their quantitative inheritance and the importance of genotype*environment interaction. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i genome regions associated with the examined agronomic and seed quality traits, (ii the interrelationship of population structure and the detected associations, and (iii candidate genes for the revealed associations. The diversity set used in this study consisted of 405 Brassica napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P-value 100 and a sequence identity of > 70 % to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations.

  5. The challenges of genome-wide interaction studies: Lessons to learn from the analysis of HDL blood levels

    NARCIS (Netherlands)

    E.M. van Leeuwen (Elisa); F.A.S. Smouter (Françoise A.S.); T. Kam-Thong (Tony); N. Karbalai (Nazanin); G.D. Smith; T.B. Harris (Tamara); L.J. Launer (Lenore); C.M. Sitlani (Colleen); G. Li (Guo); J. Brody (Jennifer); J.C. Bis (Joshua); C.C. White (Charles); A. Jaiswal (Alok); B.A. Oostra (Ben); A. Hofman (Albert); F. Rivadeneira Ramirez (Fernando); A.G. Uitterlinden (André); E.A. Boerwinkle (Eric); C. Ballantyne (Christie); V. Gudnason (Vilmundur); B.M. Psaty (Bruce); L.A. Cupples (Adrienne); M.-R. Jarvelin (Marjo-Riitta); S. Ripatti (Samuli); A.J. Isaacs (Aaron); B. Müller-Myhsok (B.); L.C. Karssen (Lennart); C.M. van Duijn (Cock)

    2014-01-01

    textabstractGenome-wide association studies (GWAS) have revealed 74 single nucleotide polymorphisms (SNPs) associated with high-density lipoprotein cholesterol (HDL) blood levels. This study is, to our knowledge, the first genome-wide interaction study (GWIS) to identify SNP6SNP interactions associa

  6. 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

  7. Genome-wide association studies of female reproduction in tropically adapted beef cattle

    National Research Council Canada - National Science Library

    Hawken, R J; Zhang, Y D; Fortes, M R S; Collis, E; Barris, W C; Corbet, N J; Williams, P J; Fordyce, G; Holroyd, R G; Walkley, J R W; Barendse, W; Johnston, D J; Prayaga, K C; Tier, B; Reverter, A; Lehnert, S A

    2012-01-01

    .... To elucidate the genetics underlying reproduction in beef cattle, we performed a genome-wide association study using the bovine SNP50 chip in 2 tropically adapted beef cattle breeds, Brahman and Tropical Composite...

  8. RAD tag sequencing as a source of SNP markers in Cynara cardunculus L

    Directory of Open Access Journals (Sweden)

    Scaglione Davide

    2012-01-01

    Full Text Available Abstract Background The globe artichoke (Cynara cardunculus L. var. scolymus genome is relatively poorly explored, especially compared to those of the other major Asteraceae crops sunflower and lettuce. No SNP markers are in the public domain. We have combined the recently developed restriction-site associated DNA (RAD approach with the Illumina DNA sequencing platform to effect the rapid and mass discovery of SNP markers for C. cardunculus. Results RAD tags were sequenced from the genomic DNA of three C. cardunculus mapping population parents, generating 9.7 million reads, corresponding to ~1 Gbp of sequence. An assembly based on paired ends produced ~6.0 Mbp of genomic sequence, separated into ~19,000 contigs (mean length 312 bp, of which ~21% were fragments of putative coding sequence. The shared sequences allowed for the discovery of ~34,000 SNPs and nearly 800 indels, equivalent to a SNP frequency of 5.6 per 1,000 nt, and an indel frequency of 0.2 per 1,000 nt. A sample of heterozygous SNP loci was mapped by CAPS assays and this exercise provided validation of our mining criteria. The repetitive fraction of the genome had a high representation of retrotransposon sequence, followed by simple repeats, AT-low complexity regions and mobile DNA elements. The genomic k-mers distribution and CpG rate of C. cardunculus, compared with data derived from three whole genome-sequenced dicots species, provided a further evidence of the random representation of the C. cardunculus genome generated by RAD sampling. Conclusion The RAD tag sequencing approach is a cost-effective and rapid method to develop SNP markers in a highly heterozygous species. Our approach permitted to generate a large and robust SNP datasets by the adoption of optimized filtering criteria.

  9. The Impact of Genotyping-by-Sequencing Pipelines on SNP Discovery and Identification of Markers Associated with Verticillium Wilt Resistance in Autotetraploid Alfalfa (Medicago sativa L.)

    Science.gov (United States)

    Yu, Long-Xi; Zheng, Ping; Bhamidimarri, Suresh; Liu, Xiang-Ping; Main, Dorie

    2017-01-01

    Verticillium wilt (VW) of alfalfa is a soilborne disease causing severe yield loss in alfalfa. To identify molecular markers associated with VW resistance, we used an integrated framework of genome-wide association study (GWAS) with high-throughput genotyping by sequencing (GBS) to identify loci associated with VW resistance in an F1 full-sib alfalfa population. Phenotyping was performed using manual inoculation of the pathogen to cloned plants of each individual and disease severity was scored using a standard scale. Genotyping was done by GBS, followed by genotype calling using three bioinformatics pipelines including the TASSEL-GBS pipeline (TASSEL), the Universal Network Enabled Analysis Kit (UNEAK), and the haplotype-based FreeBayes pipeline (FreeBayes). The resulting numbers of SNPs, marker density, minor allele frequency (MAF) and heterozygosity were compared among the pipelines. The TASSEL pipeline generated more markers with the highest density and MAF, whereas the highest heterozygosity was obtained by the UNEAK pipeline. The FreeBayes pipeline generated tetraploid genotypes, with the least number of markers. SNP markers generated from each pipeline were used independently for marker-trait association. Markers significantly associated with VW resistance identified by each pipeline were compared. Similar marker loci were found on chromosomes 5, 6, and 7, whereas different loci on chromosome 1, 2, 3, and 4 were identified by different pipelines. Most significant markers were located on chromosome 6 and they were identified by all three pipelines. Of those identified, several loci were linked to known genes whose functions are involved in the plants’ resistance to pathogens. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms of VW resistance in alfalfa. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance

  10. The use of SNP markers for linkage mapping in diploid and tetraploid peanuts.

    Science.gov (United States)

    Bertioli, David J; Ozias-Akins, Peggy; Chu, Ye; Dantas, Karinne M; Santos, Silvio P; Gouvea, Ediene; Guimarães, Patricia M; Leal-Bertioli, Soraya C M; Knapp, Steven J; Moretzsohn, Marcio C

    2014-01-10

    Single nucleotide polymorphic markers (SNPs) are attractive for use in genetic mapping and marker-assisted breeding because they can be scored in parallel assays at favorable costs. However, scoring SNP markers in polyploid plants like the peanut is problematic because of interfering signal generated from the DNA bases that are homeologous to those being assayed. The present study used a previously constructed 1536 GoldenGate SNP assay developed using SNPs identified between two A. duranensis accessions. In this study, the performance of this assay was tested on two RIL mapping populations, one diploid (A. duranensis × A. stenosperma) and one tetraploid [A. hypogaea cv. Runner IAC 886 × synthetic tetraploid (A. ipaënsis × A. duranensis)(4×)]. The scoring was performed using the software GenomeStudio version 2011.1. For the diploid, polymorphic markers provided excellent genotyping scores with default software parameters. In the tetraploid, as expected, most of the polymorphic markers provided signal intensity plots that were distorted compared to diploid patterns and that were incorrectly scored using default parameters. However, these scorings were easily corrected using the GenomeStudio software. The degree of distortion was highly variable. Of the polymorphic markers, approximately 10% showed no distortion at all behaving as expected for single-dose markers, and another 30% showed low distortion and could be considered high-quality. The genotyped markers were incorporated into diploid and tetraploid genetic maps of Arachis and, in the latter case, were located almost entirely on A genome linkage groups.

  11. 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.

  12. 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.

  13. Genome-wide association study of hepatitis C virus- and cryoglobulin-related vasculitis.

    Science.gov (United States)

    Zignego, A L; Wojcik, G L; Cacoub, P; Visentini, M; Casato, M; Mangia, A; Latanich, R; Charles, E D; Gragnani, L; Terrier, B; Piazzola, V; Dustin, L B; Khakoo, S I; Busch, M P; Lauer, G M; Kim, A Y; Alric, L; Thomas, D L; Duggal, P

    2014-10-01

    The host genetic basis of mixed cryoglobulin vasculitis is not well understood and has not been studied in large cohorts. A genome-wide association study was conducted among 356 hepatitis C virus (HCV) RNA-positive individuals with cryoglobulin-related vasculitis and 447 ethnically matched, HCV RNA-positive controls. All cases had both serum cryoglobulins and a vasculitis syndrome. A total of 899 641 markers from the Illumina HumanOmni1-Quad chip were analyzed using logistic regression adjusted for sex, as well as genetically determined ancestry. Replication of select single-nucleotide polymorphisms (SNPs) was conducted using 91 cases and 180 controls, adjusting for sex and country of origin. The most significant associations were identified on chromosome 6 near the NOTCH4 and MHC class II genes. A genome-wide significant association was detected on chromosome 6 at SNP rs9461776 (odds ratio=2.16, P=1.16E-07) between HLA-DRB1 and DQA1: this association was further replicated in additional independent samples (meta-analysis P=7.1 × 10(-9)). A genome-wide significant association with cryoglobulin-related vasculitis was identified with SNPs near NOTCH4 and MHC Class II genes. The two regions are correlated and it is difficult to disentangle which gene is responsible for the association with mixed cryoglobulinemia vasculitis in this extended major histocompatibility complex region.

  14. Diverse Genome-wide Association Studies Associate the IL12/IL23 Pathway with Crohn Disease

    Science.gov (United States)

    Wang, Kai; Zhang, Haitao; Kugathasan, Subra; Annese, Vito; Bradfield, Jonathan P.; Russell, Richard K.; Sleiman, Patrick M.A.; Imielinski, Marcin; Glessner, Joseph; Hou, Cuiping; Wilson, David C.; Walters, Thomas; Kim, Cecilia; Frackelton, Edward C.; Lionetti, Paolo; Barabino, Arrigo; Van Limbergen, Johan; Guthery, Stephen; Denson, Lee; Piccoli, David; Li, Mingyao; Dubinsky, Marla; Silverberg, Mark; Griffiths, Anne; Grant, Struan F.A.; Satsangi, Jack; Baldassano, Robert; Hakonarson, Hakon

    2009-01-01

    Previous genome-wide association (GWA) studies typically focus on single-locus analysis, which may not have the power to detect the majority of genuinely associated loci. Here, we applied pathway analysis using Affymetrix SNP genotype data from the Wellcome Trust Case Control Consortium (WTCCC) and uncovered significant association between Crohn Disease (CD) and the IL12/IL23 pathway, harboring 20 genes (p = 8 × 10−5). Interestingly, the pathway contains multiple genes (IL12B and JAK2) or homologs of genes (STAT3 and CCR6) that were recently identified as genuine susceptibility genes only through meta-analysis of several GWA studies. In addition, the pathway contains other susceptibility genes for CD, including IL18R1, JUN, IL12RB1, and TYK2, which do not reach genome-wide significance by single-marker association tests. The observed pathway-specific association signal was subsequently replicated in three additional GWA studies of European and African American ancestry generated on the Illumina HumanHap550 platform. Our study suggests that examination beyond individual SNP hits, by focusing on genetic networks and pathways, is important to unleashing the true power of GWA studies. PMID:19249008

  15. Genome-wide association scan suggests basis for microtia in Awassi sheep.

    Science.gov (United States)

    Jawasreh, K; Boettcher, P J; Stella, A

    2016-08-01

    Hereditary underdevelopment of the ear, a condition also known as microtia, has been observed in several sheep breeds as well as in humans and other species. Its genetic basis in sheep is unknown. The Awassi sheep, a breed native to southwest Asia, carries this phenotype and was targeted for molecular characterization via a genome-wide association study. DNA samples were collected from sheep in Jordan. Eight affected and 12 normal individuals were genotyped with the Illumina OvineSNP50(®) chip. Multilocus analyses failed to identify any genotypic association. In contrast, a single-locus analysis revealed a statistically significant association (P = 0.012, genome-wide) with a SNP at basepair 34 647 499 on OAR23. This marker is adjacent to the gene encoding transcription factor GATA-6, which has been shown to play a role in many developmental processes, including chondrogenesis. The lack of extended homozygosity in this region suggests a fairly ancient mutation, and the time of occurrence was estimated to be approximately 3000 years ago. Many of the earless sheep breeds may thus share the causative mutation, especially within the subgroup of fat-tailed, wool sheep.

  16. 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.

  17. SNP Marker Discovery in Pima Cotton (Gossypium barbadense L.) Leaf Transcriptomes

    Science.gov (United States)

    Kottapalli, Pratibha; Ulloa, Mauricio; Kottapalli, Kameswara Rao; Payton, Paxton; Burke, John

    2016-01-01

    The objective of this study was to explore the known narrow genetic diversity and discover single-nucleotide polymorphic (SNP) markers for marker-assisted breeding within Pima cotton (Gossypium barbadense L.) leaf transcriptomes. cDNA from 25-day plants of three diverse cotton genotypes [Pima S6 (PS6), Pima S7 (PS7), and Pima 3-79 (P3-79)] was sequenced on Illumina sequencing platform. A total of 28.9 million reads (average read length of 138 bp) were generated by sequencing cDNA libraries of these three genotypes. The de novo assembly of reads generated transcriptome sets of 26,369 contigs for PS6, 25,870 contigs for PS7, and 24,796 contigs for P3-79. A Pima leaf reference transcriptome was generated consisting of 42,695 contigs. More than 10,000 single-nucleotide polymorphisms (SNPs) were identified between the genotypes, with 100% SNP frequency and a minimum of eight sequencing reads. The most prevalent SNP substitutions were C—T and A—G in these cotton genotypes. The putative SNPs identified can be utilized for characterizing genetic diversity, genotyping, and eventually in Pima cotton breeding through marker-assisted selection.

  18. High-resolution genetic map for understanding the effect of genome-wide recombination rate on nucleotide diversity in watermelon.

    Science.gov (United States)

    Reddy, Umesh K; Nimmakayala, Padma; Levi, Amnon; Abburi, Venkata Lakshmi; Saminathan, Thangasamy; Tomason, Yan R; Vajja, Gopinath; Reddy, Rishi; Abburi, Lavanya; Wehner, Todd C; Ronin, Yefim; Karol, Abraham

    2014-09-15

    We used genotyping by sequencing to identify a set of 10,480 single nucleotide polymorphism (SNP) markers for constructing a high-resolution genetic map of 1096 cM for watermelon. We assessed the genome-wide variation in recombination rate (GWRR) across the map and found an association between GWRR and genome-wide nucleotide diversity. Collinearity between the map and the genome-wide reference sequence for watermelon was studied to identify inconsistency and chromosome rearrangements. We assessed genome-wide nucleotide diversity, linkage disequilibrium (LD), and selective sweep for wild, semi-wild, and domesticated accessions of Citrullus lanatus var. lanatus to track signals of domestication. Principal component analysis combined with chromosome-wide phylogenetic study based on 1563 SNPs obtained after LD pruning with minor allele frequency of 0.05 resolved the differences between semi-wild and wild accessions as well as relationships among worldwide sweet watermelon. Population structure analysis revealed predominant ancestries for wild, semi-wild, and domesticated watermelons as well as admixture of various ancestries that were important for domestication. Sliding window analysis of Tajima's D across various chromosomes was used to resolve selective sweep. LD decay was estimated for various chromosomes. We identified a strong selective sweep on chromosome 3 consisting of important genes that might have had a role in sweet watermelon domestication. Copyright © 2014 Reddy et al.

  19. Genome-Wide Pharmacogenomic Study on Methadone Maintenance Treatment Identifies SNP rs17180299 and Multiple Haplotypes on CYP2B6, SPON1, and GSG1L Associated with Plasma Concentrations of Methadone R- and S-enantiomers in Heroin-Dependent Patients.

    Science.gov (United States)

    Yang, Hsin-Chou; Chu, Shih-Kai; Huang, Chieh-Liang; Kuo, Hsiang-Wei; Wang, Sheng-Chang; Liu, Sheng-Wen; Ho, Ing-Kang; Liu, Yu-Li

    2016-03-01

    Methadone maintenance treatment (MMT) is commonly used for controlling opioid dependence, preventing withdrawal symptoms, and improving the quality of life of heroin-dependent patients. A steady-state plasma concentration of methadone enantiomers, a measure of methadone metabolism, is an index of treatment response and efficacy of MMT. Although the methadone metabolism pathway has been partially revealed, no genome-wide pharmacogenomic study has been performed to identify genetic determinants and characterize genetic mechanisms for the plasma concentrations of methadone R- and S-enantiomers. This study was the first genome-wide pharmacogenomic study to identify genes associated with the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites in a methadone maintenance cohort. After data quality control was ensured, a dataset of 344 heroin-dependent patients in the Han Chinese population of Taiwan who underwent MMT was analyzed. Genome-wide single-locus and haplotype-based association tests were performed to analyze four quantitative traits: the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites. A significant single nucleotide polymorphism (SNP), rs17180299 (raw p = 2.24 × 10(-8)), was identified, accounting for 9.541% of the variation in the plasma concentration of the methadone R-enantiomer. In addition, 17 haplotypes were identified on SPON1, GSG1L, and CYP450 genes associated with the plasma concentration of methadone S-enantiomer. These haplotypes accounted for approximately one-fourth of the variation of the overall S-methadone plasma concentration. The association between the S-methadone plasma concentration and CYP2B6, SPON1, and GSG1L were replicated in another independent study. A gene expression experiment revealed that CYP2B6, SPON1, and GSG1L can be activated concomitantly through a constitutive androstane receptor (CAR) activation pathway. In conclusion, this study revealed new

  20. The application and performance of single nucleotide polymorphism (SNP markers for population genetic analyses of Lepidoptera

    Directory of Open Access Journals (Sweden)

    Brad S. Coates

    2011-06-01

    Full Text Available Microsatellite markers are difficult to apply within lepidopteran studies due to the lack of locus-specific PCR amplification and the high proportion of null alleles, such that erroneous estimations of population genetic parameters often result. Herein single nucleotide polymorphism (SNP markers are developed from Ostrinia nubilalis (Lepidoptera: Crambidae using next-generation expressed sequence tag (EST data. A total of 2742 SNPs were predicted within a reference assembly of 7414 EST contigs, and a subset of 763 were incorporated into 24 multiplex PCR reactions. To validate this pipeline, 5 European and North American sample sites were genotyped at 178 SNP loci, which indicated 84 (47.2% were in Hardy-Weinberg equilibrium. Locus-by-locus FST, analysis of molecular variance (AMOVA, and STRUCTURE analyses indicate significant genetic differentiation may exist between European and North American O. nubilalis. The observed genetic diversity was significantly lower among European sites, which may be the result from genetic drift, natural selection, a genetic bottleneck, or ascertainment bias due to North American origin of EST sequence data. SNPs are an abundant mutation data molecular genetic marker development in non-model species with shared ancestral SNPs showing application within closely related species. These markers offer advantages over microsatellite markers for genetic and genomic analyses of Lepidoptera, but the source of mutation data may affect the estimation of population parameters and likely need be considered in the interpretation of empirical data.

  1. Molecular Characterization and SNP Markers of the β-purothionin Gene in Einkorn Wheats

    Institute of Scientific and Technical Information of China (English)

    LI Jing-qiong; ZHENG You-liang; WEI Yu-ming

    2009-01-01

    Forty-three gene sequences encoding purothionin were characterized from the three species or subspecies of einkorn wheats.These sequences contained 887 bp,among which 92 SNPs including 29 indel loci were detected,giving an average SNP frequency of one SNP per 9.64 bases.According to these sequences,5 SNP markers were successfully designed,which were used to mine the variations of purothionin genes of 102 einkorn wheat accessions.Based on the 5 detected SNP loci,102 einkorn wheat accessions could be divided into 21 haplotypes,among which 11 hapiotypes contained a single sample.Phylogenetic analysis indicated that the purothionin genes from einkorn wheats were more closely related to those from D genome than B genome.Seven out of the 43 gene sequences were assumed to be pseudogenes by the definition of containing in-frame stop codons and small insertions/deletions leading to frameshifi.In the remaining 36 amino acid sequences,the 8 Cys and Tyr-13 loci in the mature thionin domain which played important roles in the biological activities were all conserved,whereas there were some varieties occurred in some other important amino acid residues such as Lys and Arg.

  2. Genome-wide SNP identification for the construction of a high-resolution genetic map of Japanese flounder (Paralichthys olivaceus): applications to QTL mapping of Vibrio anguillarum disease resistance and comparative genomic analysis.

    Science.gov (United States)

    Shao, Changwei; Niu, Yongchao; Rastas, Pasi; Liu, Yang; Xie, Zhiyuan; Li, Hengde; Wang, Lei; Jiang, Yong; Tai, Shuaishuai; Tian, Yongsheng; Sakamoto, Takashi; Chen, Songlin

    2015-04-01

    High-resolution genetic maps are essential for fine mapping of complex traits, genome assembly, and comparative genomic analysis. Single-nucleotide polymorphisms (SNPs) are the primary molecular markers used for genetic map construction. In this study, we identified 13,362 SNPs evenly distributed across the Japanese flounder (Paralichthys olivaceus) genome. Of these SNPs, 12,712 high-confidence SNPs were subjected to high-throughput genotyping and assigned to 24 consensus linkage groups (LGs). The total length of the genetic linkage map was 3,497.29 cM with an average distance of 0.47 cM between loci, thereby representing the densest genetic map currently reported for Japanese flounder. Nine positive quantitative trait loci (QTLs) forming two main clusters for Vibrio anguillarum disease resistance were detected. All QTLs could explain 5.1-8.38% of the total phenotypic variation. Synteny analysis of the QTL regions on the genome assembly revealed 12 immune-related genes, among them 4 genes strongly associated with V. anguillarum disease resistance. In addition, 246 genome assembly scaffolds with an average size of 21.79 Mb were anchored onto the LGs; these scaffolds, comprising 522.99 Mb, represented 95.78% of assembled genomic sequences. The mapped assembly scaffolds in Japanese flounder were used for genome synteny analyses against zebrafish (Danio rerio) and medaka (Oryzias latipes). Flounder and medaka were found to possess almost one-to-one synteny, whereas flounder and zebrafish exhibited a multi-syntenic correspondence. The newly developed high-resolution genetic map, which will facilitate QTL mapping, scaffold assembly, and genome synteny analysis of Japanese flounder, marks a milestone in the ongoing genome project for this species.

  3. 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.

  4. Using SNP markers to estimate additive, dominance and imprinting genetic variance

    DEFF Research Database (Denmark)

    Lopes, M S; Bastiaansen, J W M; Janss, Luc

    The contributions of additive, dominance and imprinting effects to the variance of number of teats (NT) were evaluated in two purebred pig populations using SNP markers. Three different random regression models were evaluated, accounting for the mean and: 1) additive effects (MA), 2) additive...... and dominance effects (MAD) and 3) additive, dominance and imprinting effects (MADI). Additive heritability estimates were 0.30, 0.28 and 0.27-0.28 in both lines using MA, MAD and MADI, respectively. Dominance heritability ranged from 0.06 to 0.08 using MAD and MADI. Imprinting heritability ranged from 0.......01 to 0.02. Dominance effects make an important contribution to the genetic variation of NT in the two lines evaluated. Imprinting effects appeared less important for NT than additive and dominance effects. The SNP random regression model presented and evaluated in this study is a feasible approach...

  5. 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.

  6. Genome-wide association study of drought-related resistance traits in Aegilops tauschii

    Science.gov (United States)

    Qin, Peng; Lin, Yu; Hu, Yaodong; Liu, Kun; Mao, Shuangshuang; Li, Zhanyi; Wang, Jirui; Liu, Yaxi; Wei, Yuming; Zheng, Youliang

    2016-01-01

    Abstract The D-genome progenitor of wheat (Triticum aestivum), Aegilops tauschii, possesses numerous genes for resistance to abiotic stresses, including drought. Therefore, information on the genetic architecture of A. tauschii can aid the development of drought-resistant wheat varieties. Here, we evaluated 13 traits in 373 A. tauschii accessions grown under normal and polyethylene glycol-simulated drought stress conditions and performed a genome-wide association study using 7,185 single nucleotide polymorphism (SNP) markers. We identified 208 and 28 SNPs associated with all traits using the general linear model and mixed linear model, respectively, while both models detected 25 significant SNPs with genome-wide distribution. Public database searches revealed several candidate/flanking genes related to drought resistance that were grouped into three categories according to the type of encoded protein (enzyme, storage protein, and drought-induced protein). This study provided essential information for SNPs and genes related to drought resistance in A. tauschii and wheat, and represents a foundation for breeding drought-resistant wheat cultivars using marker-assisted selection. PMID:27560650

  7. Identification of a novel susceptibility locus for juvenile idiopathic arthritis by genome-wide association analysis

    Science.gov (United States)

    Hinks, Anne; Barton, Anne; Shephard, Neil; Eyre, Steve; Bowes, John; Cargill, Michele; Wang, Eric; Ke, Xiayi; Kennedy, Giulia C; John, Sally; Worthington, Jane; Thomson, Wendy

    2009-01-01

    Objective Juvenile idiopathic arthritis (JIA) is a chronic rheumatic disease of childhood. Two well-established genetic factors known to contribute to JIA susceptibility, HLA and PTPN22, account for less than half of the genetic susceptibility to disease; therefore, additional genetic factors have yet to be identified. The purpose of this study was to perform a systematic search of the genome to identify novel susceptibility loci for JIA. Methods A genome-wide association study using Affymetrix GeneChip 100K arrays was performed in a discovery cohort (279 cases and 184 controls). Single-nucleotide polymorphisms (SNPs) showing the most significant differences between cases and controls were then genotyped in a validation sample of cases (n = 321) and controls, combined with control data from the 1958 UK birth cohort (n = 2,024). In one region in which association was confirmed, fine-mapping was performed (654 cases and 1,847 controls). Results Of the 112 SNPs that were significantly associated with JIA in the discovery cohort, 6 SNPs were associated with JIA in the independent validation cohort. The most strongly associated SNP mapped to the HLA region, while the second strongest association was with a SNP within the VTCN1 gene. Fine-mapping of that gene was performed, and 10 SNPs were found to be associated with JIA. Conclusion This study is the first to successfully apply a SNP-based genome-wide association approach to the investigation of JIA. The replicated association with markers in the VTCN1 gene defined an additional susceptibility locus for JIA and implicates a novel pathway in the pathogenesis of this chronic disease of childhood. PMID:19116933

  8. Identification of Promising Mutants Associated with Egg Production Traits Revealed by Genome-Wide Association Study.

    Directory of Open Access Journals (Sweden)

    Jingwei Yuan

    Full Text Available Egg number (EN, egg laying rate (LR and age at first egg (AFE are important production traits related to egg production in poultry industry. To better understand the knowledge of genetic architecture of dynamic EN during the whole laying cycle and provide the precise positions of associated variants for EN, LR and AFE, laying records from 21 to 72 weeks of age were collected individually for 1,534 F2 hens produced by reciprocal crosses between White Leghorn and Dongxiang Blue-shelled chicken, and their genotypes were assayed by chicken 600 K Affymetrix high density genotyping arrays. Subsequently, pedigree and SNP-based genetic parameters were estimated and a genome-wide association study (GWAS was conducted on EN, LR and AFE. The heritability estimates were similar between pedigree and SNP-based estimates varying from 0.17 to 0.36. In the GWA analysis, we identified nine genome-wide significant loci associated with EN of the laying periods from 21 to 26 weeks, 27 to 36 weeks and 37 to 72 weeks. Analysis of GTF2A1 and CLSPN suggested that they influenced the function of ovary and uterus, and may be considered as relevant candidates. The identified SNP rs314448799 for accumulative EN from 21 to 40 weeks on chromosome 5 created phenotypic differences of 6.86 eggs between two homozygous genotypes, which could be potentially applied to the molecular breeding for EN selection. Moreover, our finding showed that LR was a moderate polygenic trait. The suggestive significant region on chromosome 16 for AFE suggested the relationship between sex maturity and immune in the current population. The present study comprehensively evaluates the role of genetic variants in the development of egg laying. The findings will be helpful to investigation of causative genes function and future marker-assisted selection and genomic selection in chickens.

  9. Characterizing associations and SNP-environment interactions for GWAS-identified prostate cancer risk markers--results from BPC3.

    Directory of Open Access Journals (Sweden)

    Sara Lindstrom

    Full Text Available Genome-wide association studies (GWAS have identified multiple single nucleotide polymorphisms (SNPs associated with prostate cancer risk. However, whether these associations can be consistently replicated, vary with disease aggressiveness (tumor stage and grade and/or interact with non-genetic potential risk factors or other SNPs is unknown. We therefore genotyped 39 SNPs from regions identified by several prostate cancer GWAS in 10,501 prostate cancer cases and 10,831 controls from the NCI Breast and Prostate Cancer Cohort Consortium (BPC3. We replicated 36 out of 39 SNPs (P-values ranging from 0.01 to 10⁻²⁸. Two SNPs located near KLK3 associated with PSA levels showed differential association with Gleason grade (rs2735839, P = 0.0001 and rs266849, P = 0.0004; case-only test, where the alleles associated with decreasing PSA levels were inversely associated with low-grade (as defined by Gleason grade < 8 tumors but positively associated with high-grade tumors. No other SNP showed differential associations according to disease stage or grade. We observed no effect modification by SNP for association with age at diagnosis, family history of prostate cancer, diabetes, BMI, height, smoking or alcohol intake. Moreover, we found no evidence of pair-wise SNP-SNP interactions. While these SNPs represent new independent risk factors for prostate cancer, we saw little evidence for effect modification by other SNPs or by the environmental factors examined.

  10. Diversity in 113 cowpea [Vigna unguiculata (L) Walp] accessions assessed with 458 SNP markers.

    Science.gov (United States)

    Egbadzor, Kenneth F; Ofori, Kwadwo; Yeboah, Martin; Aboagye, Lawrence M; Opoku-Agyeman, Michael O; Danquah, Eric Y; Offei, Samuel K

    2014-01-01

    Single Nucleotide Polymorphism (SNP) markers were used in characterization of 113 cowpea accessions comprising of 108 from Ghana and 5 from abroad. Leaf tissues from plants cultivated at the University of Ghana were genotyped at KBioscience in the United Kingdom. Data was generated for 477 SNPs, out of which 458 revealed polymorphism. The results were used to analyze genetic dissimilarity among the accessions using Darwin 5 software. The markers discriminated among all of the cowpea accessions and the dissimilarity values which ranged from 0.006 to 0.63 were used for factorial plot. Unexpected high levels of heterozygosity were observed on some of the accessions. Accessions known to be closely related clustered together in a dendrogram drawn with WPGMA method. A maximum length sub-tree which comprised of 48 core accessions was constructed. The software package structure was used to separate accessions into three groups, and the programme correctly identified varieties that were known hybrids. The hybrids were those accessions with numerous heterozygous loci. The structure plot showed closely related accessions with similar genome patterns. The SNP markers were more efficient in discriminating among the cowpea germplasm than morphological, seed protein polymorphism and simple sequence repeat studies reported earlier on the same collection.

  11. Genome-wide Association Study Identifies New Loci for Resistance to Leptosphaeria maculans in Canola

    Directory of Open Access Journals (Sweden)

    Harsh Raman

    2016-10-01

    Full Text Available Blackleg, caused by Leptosphaeria maculans, is a significant disease which affects the sustainable production of canola. This study reports a genome-wide association study based on 18,804 polymorphic SNPs to identify loci associated with qualitative and quantitative resistance to L. maculans. Genomic regions delimited with 503 significant SNP markers, that are associated with resistance evaluated using 12 single spore isolates and pathotypes from four canola stubble were identified. Several significant associations were detected at known disease resistance loci including in the vicinity of recently cloned Rlm2/LepR3 genes, and at new loci on chromosomes A01/C01, A02/C02, A03/C03, A05/C05, A06, A08, and A09. In addition, we validated statistically significant associations on A01, A07 and A10 in four genetic mapping populations, demonstrating that GWAS marker loci are indeed associated with resistance to L. maculans. One of the novel loci identified for the first time, Rlm12, conveys adult plant resistance and mapped within 13.2 kb from Arabidopsis R gene of TIR-NBS class. We showed that resistance loci are located in the vicinity of R genes of A. thaliana and B. napus on the sequenced genome of B. napus cv. Darmor-bzh. Significantly associated SNP markers provide a valuable tool to enrich germplasm for favorable alleles in order to improve the level of resistance to L. maculans in canola.

  12. Fine Mapping of a Clubroot Resistance Gene in Chinese Cabbage Using SNP Markers Identified from Bulked Segregant RNA Sequencing

    Science.gov (United States)

    Huang, Zhen; Peng, Gary; Liu, Xunjia; Deora, Abhinandan; Falk, Kevin C.; Gossen, Bruce D.; McDonald, Mary R.; Yu, Fengqun

    2017-01-01

    Clubroot, caused by Plasmodiophora brassicae, is an important disease of canola (Brassica napus) in western Canada and worldwide. In this study, a clubroot resistance gene (Rcr2) was identified and fine mapped in Chinese cabbage cv. “Jazz” using single-nucleotide polymorphisms (SNP) markers identified from bulked segregant RNA sequencing (BSR-Seq) and molecular markers were developed for use in marker assisted selection. In total, 203.9 million raw reads were generated from one pooled resistant (R) and one pooled susceptible (S) sample, and >173,000 polymorphic SNP sites were identified between the R and S samples. One significant peak was observed between 22 and 26 Mb of chromosome A03, which had been predicted by BSR-Seq to contain the causal gene Rcr2. There were 490 polymorphic SNP sites identified in the region. A segregating population consisting of 675 plants was analyzed with 15 SNP sites in the region using the Kompetitive Allele Specific PCR method, and Rcr2 was fine mapped between two SNP markers, SNP_A03_32 and SNP_A03_67 with 0.1 and 0.3 cM from Rcr2, respectively. Five SNP markers co-segregated with Rcr2 in this region. Variants were identified in 14 of 36 genes annotated in the Rcr2 target region. The numbers of poly variants differed among the genes. Four genes encode TIR-NBS-LRR proteins and two of them Bra019410 and Bra019413, had high numbers of polymorphic variants and so are the most likely candidates of Rcr2. PMID:28894454

  13. Misclassification in binary responses and effect on genome-wide association studies.

    Science.gov (United States)

    Rekaya, Romdhane; Smith, Shannon; Hay, El Hamidi; Aggrey, Samuel E

    2013-09-01

    Misclassification of dependent variables is a major issue in many areas of science that can arise when indirect markers are used to classify subjects or continuous traits are treated as categorical. In human medicine, this can have significant impacts on diagnostic accuracy. In animal science applications, misclassification can negatively affect both the accuracy of selection and the ability to ascertain the biological mechanisms for traits of interest. When dealing with traits influenced by genetic factors, genomic markers, such as SNP, can provide direct measurements of the underlying mechanisms controlling phenotypic responses. Unfortunately, in the presence of misclassification in the discrete dependent variables, the robustness of the analysis and the validity of the results could be severely compromised. To quantify the impact of misclassification on genome-wide association studies for binary responses, a real databased simulation was carried out. The simulated data consisted of 2,400 animals genotyped for 50K SNP. A binary trait with heritability equal to 0.10 and prevalence of 20% was generated. A rate of 1, 5, and 10% misclassification was artificially introduced to the true binary responses. Using a latent-threshold model, 3 analyses were carried out for each misclassification rate using 1) the true data (M1), 2) the contaminated data and ignoring misclassification (M2), and 3) the contaminated data and accounting for misclassification (M3). The results indicate that ignoring misclassification, when it exists in the data such as in M2, will lead to major deterioration in the performance of the model. When misclassification was contemplated in the model (M2), the results indicated a strong capacity of the procedure in dealing with potential misclassification in the training set. In fact, a large portion of miscoded samples in the training set was identified and corrected. The results of this study suggest that the proposed method is adequate and effective

  14. 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.

  15. Multigenic control of pod shattering resistance in Chinese rapeseed germplasm revealed by genome-wide association and linkage analyses

    Directory of Open Access Journals (Sweden)

    Jia Liu

    2016-07-01

    Full Text Available Majority of rapeseed cultivars shatter seeds upon maturity especially under hot-dry and windy conditions, reducing yield and gross margin return to growers. Here, we identified quantitative trait loci (QTL for resistance to pod shatter in unstructured diverse panel of 143 rapeseed accessions, and two structured populations derived from bi-parental doubled haploid (DH and inter-mated (IF2 crosses derived from R1 (resistant to pod shattering and R2 (prone to pod shattering accessions. Genome-wide association analysis identified six significant QTL for resistance to pod shatter located on chromosomes A01, A06, A07, A09, C02 and C05. Two of the QTL, qSRI.A09 delimited with the SNP marker Bn-A09-p30171993 (A09 and qSRI.A06 delimited with the SNP marker Bn-A06-p115948 (A06 could be repeatedly detected across environments in diversity panel, DH and IF2 populations, suggesting that at least two loci on chromosomes A06 and A09 were the main contributors to pod shatter resistance in Chinese germplasm. Significant SNP markers identified in this study especially those appeared repeatedly across environments provide a cost-effective and an efficient method for introgression and pyramiding of favorable alleles for pod shatter resistance via marker-assisted selection in rapeseed improvement programs.

  16. Genotyping-by-sequencing-based genome-wide association studies on Verticillium wilt resistance in autotetraploid alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Yu, Long-Xi; Zheng, Ping; Zhang, Tiejun; Rodringuez, Jonas; Main, Dorrie

    2017-02-01

    Verticillium wilt (VW) is a fungal disease that causes severe yield losses in alfalfa. The most effective method to control the disease is through the development and use of resistant varieties. The identification of marker loci linked to VW resistance can facilitate breeding for disease-resistant alfalfa. In the present investigation, we applied an integrated framework of genome-wide association with genotyping-by-sequencing (GBS) to identify VW resistance loci in a panel of elite alfalfa breeding lines. Phenotyping was performed by manual inoculation of the pathogen to healthy seedlings, and scoring for disease resistance was carried out according to the standard test of the North America Alfalfa Improvement Conference (NAAIC). Marker-trait association by linkage disequilibrium identified 10 single nucleotide polymorphism (SNP) markers significantly associated with VW resistance. Alignment of the SNP marker sequences to the M. truncatula genome revealed multiple quantitative trait loci (QTLs). Three, two, one and five markers were located on chromosomes 5, 6, 7 and 8, respectively. Resistance loci found on chromosomes 7 and 8 in the present study co-localized with the QTLs reported previously. A pairwise alignment (blastn) using the flanking sequences of the resistance loci against the M. truncatula genome identified potential candidate genes with putative disease resistance function. With further investigation, these markers may be implemented into breeding programmes using marker-assisted selection, ultimately leading to improved VW resistance in alfalfa. PUBLISHED 2016. THIS ARTICLE IS A U.S. GOVERNMENT WORK AND IS IN THE PUBLIC DOMAIN IN THE USA.

  17. Analysis of main effect QTL for thousand grain weight in European winter wheat (Triticum aestivum L. by genome-wide association mapping

    Directory of Open Access Journals (Sweden)

    Christine Désirée Zanke

    2015-09-01

    Full Text Available Grain weight, an essential yield component, is under strong genetic control and at the same time markedly influenced by the environment. Genetic analysis of the thousand grain weight (TGW by genome-wide association study (GWAS was performed with a panel of 358 European winter wheat (Triticum aestivum L. varieties and 14 spring wheat varieties using phenotypic data of field tests in eight environments. Wide phenotypic variations were indicated for the TGW with BLUEs (best linear unbiased estimations values ranging from 35.9 g to 58.2 g with a mean value of 45.4 g and a heritability of H2=0.89. A total of 12 candidate genes for plant height, photoperiodism and grain weight were genotyped on all varieties. Only three candidates, the photoperiodism gene Ppd-D1, dwarfing gene Rht-B1and the TaGW-6A gene were significant explaining up to 14.4%, 2.3% and 3.4% of phenotypic variation, respectively. For a comprehensive genome-wide analysis of TGW-QTL genotyping data from 732 microsatellite markers and a set of 7769 mapped SNP markers genotyped with the 90k iSELECT array were analyzed. In total, 342 significant (-log10 (P-value > 3.0 marker trait associations (MTAs were detected for SSR markers and 1195 MTAs (-log10P-value > 3.0 for SNP markers in all single environments plus the BLUEs. After Bonferroni correction, 28 MTAs remained significant for SSR markers (-log10 (P-value > 4.82 and 58 MTAs for SNP markers (-log10 (P value > 5.89. Apart from chromosomes 4B and 6B for SSR markers and chromosomes 4D and 5D for SNP markers, MTAs were detected on all chromosomes. The highest number of significant SNP markers was found on chromosomes 3B and 1B, while for the SSRs most markers were significant on chromosomes 6D and 3D. Overall, TGW was determined by many markers with small effects. Only three SNP-markers had R2 values above 6%.

  18. Identification and characterisation of novel SNP markers in Atlantic cod: Evidence for directional selection

    Directory of Open Access Journals (Sweden)

    Fjalestad Kjersti T

    2008-02-01

    Full Text Available Abstract Background The Atlantic cod (Gadus morhua is a groundfish of great economic value in fisheries and an emerging species in aquaculture. Genetic markers are needed to identify wild stocks in order to ensure sustainable management, and for marker-assisted selection and pedigree determination in aquaculture. Here, we report on the development and evaluation of a large number of Single Nucleotide Polymorphism (SNP markers from the alignment of Expressed Sequence Tag (EST sequences in Atlantic cod. We also present basic population parameters of the SNPs in samples of North-East Arctic cod and Norwegian coastal cod obtained from three different localities, and test for SNPs that may have been targeted by natural selection. Results A total of 17,056 EST sequences were used to find 724 putative SNPs, from which 318 segregating SNPs were isolated. The SNPs were tested on Atlantic cod from four different sites, comprising both North-East Arctic cod (NEAC and Norwegian coastal cod (NCC. The average heterozygosity of the SNPs was 0.25 and the average minor allele frequency was 0.18. FST values were highly variable, with the majority of SNPs displaying very little differentiation while others had FST values as high as 0.83. The FST values of 29 SNPs were found to be larger than expected under a strictly neutral model, suggesting that these loci are, or have been, influenced by natural selection. For the majority of these outlier SNPs, allele frequencies in a northern sample of NCC were intermediate between allele frequencies in a southern sample of NCC and a sample of NEAC, indicating a cline in allele frequencies similar to that found at the Pantophysin I locus. Conclusion The SNP markers presented here are powerful tools for future genetics work related to management and aquaculture. In particular, some SNPs exhibiting high levels of population divergence have potential to significantly enhance studies on the population structure of Atlantic cod.

  19. RAD SNP markers as a tool for conservation of dolphinfish Coryphaena hippurus in the Mediterranean Sea: Identification of subtle genetic structure and assessment of populations sex-ratios.

    Science.gov (United States)

    Maroso, Francesco; Franch, Rafaella; Dalla Rovere, Giulia; Arculeo, Marco; Bargelloni, Luca

    2016-08-01

    Dolphinfish is an important fish species for both commercial and sport fishing, but so far limited information is available on genetic variability and pattern of differentiation of dolphinfish populations in the Mediterranean basin. Recently developed techniques allow genome-wide identification of genetic markers for better understanding of population structure in species with limited genome information. Using restriction-site associated DNA analysis we successfully genotyped 140 individuals of dolphinfish from eight locations in the Mediterranean Sea at 3324 SNP loci. We identified 311 sex-related loci that were used to assess sex-ratio in dolphinfish populations. In addition, we identified a weak signature of genetic differentiation of the population closer to Gibraltar Strait in comparison to other Mediterranean populations, which might be related to introgression of individuals from Atlantic. No further genetic differentiation could be detected in the other populations sampled, as expected considering the known highly mobility of the species. The results obtained improve our knowledge of the species and can help managing dolphinfish stock in the future.

  20. Development of a core set of SNP markers for the identiifcation of upland cotton cultivars in China

    Institute of Scientific and Technical Information of China (English)

    KUANG Meng; WEI Shou-jun; WANG Yan-qin; ZHOU Da-yun; MA Lei; FANG Dan; YANG Wei-hua; MA Zhi-ying

    2016-01-01

    Considering the advantages of single nucleotide polymorphisms (SNP) in genotyping and variety identiifcation, the ifrst set public SNP markers at Cotton Marker Database (http://www.cottonmarker.org/) were validated and screened across standard varieties of cotton distinctness, uniformity and stability (DUS) test, aiming to obtain an appropriate set of core SNP markers suitable for upland cotton cultivars in China. A total of 399 out of 1005 SNPs from 270 loci including 170 insertions-dele-tions (InDels) were evaluated for their polymorphisms among 30 standard varieties using Sanger sequencing. As a result, 147 loci were sequenced successfuly, 377 SNPs and 49 InDels markers were obtained. Among the 377 SNP markers, 333 markers (88.3%) were polymorphic betweenGossypium hirsutum andG. barbadense, while 164 markers (43.5%) were polymorphic within upland cotton. As for InDel markers, the polymorphic rate is relatively lower than that of SNP both between species and within species. The homozygous DNA locus ratio of 121 SNPs was higher than 86.2% while that of other 43 SNPs was less than 70%. Only 64 SNPs displayed completely homozygous genotypes among al of the detected upland cotton varieties with 100% homozygous DNA locus ratio. At last, a set of 23 pairs of core SNPs were achieved in view of avoidance of linkage, with polymorphism information content (PIC) values varying from 0.21 to 0.38 with an average of 0.28. Genotype characteristics and genetic diversity were analyzed based on the set of core markers, while 40 pairs of core simple-sequence repeats (SSR) primers comprised of 10 sets of four multiplex PCR combinations were also used for analysis based on lfuorescence detection system. Comparison results indicated that the genetic diversity level was almost equal, while various varieties were signiifcantly different from each other. Genetic relationship revealed by SSR markers is related to geographic source to a certain extent. Meanwhile clustering results analyzed

  1. A method for detecting epistasis in genome-wide studies using case-control multi-locus association analysis

    Directory of Open Access Journals (Sweden)

    Galan Jose

    2008-07-01

    Full Text Available Abstract Background The difficulty in elucidating the genetic basis of complex diseases roots in the many factors that can affect the development of a disease. Some of these genetic effects may interact in complex ways, proving undetectable by current single-locus methodology. Results We have developed an analysis tool called Hypothesis Free Clinical Cloning (HFCC to search for genome-wide epistasis in a case-control design. HFCC combines a relatively fast computing algorithm for genome-wide epistasis detection, with the flexibility to test a variety of different epistatic models in multi-locus combinations. HFCC has good power to detect multi-locus interactions simulated under a variety of genetic models and noise conditions. Most importantly, HFCC can accomplish exhaustive genome-wide epistasis search with large datasets as demonstrated with a 400,000 SNP set typed on a cohort of Parkinson's disease patients and controls. Conclusion With the current availability of genetic studies with large numbers of individuals and genetic markers, HFCC can have a great impact in the identification of epistatic effects that escape the standard single-locus association analyses.

  2. Genome-wide association study of tick resistance in South African Nguni cattle.

    Science.gov (United States)

    Mapholi, N O; Maiwashe, A; Matika, O; Riggio, V; Bishop, S C; MacNeil, M D; Banga, C; Taylor, J F; Dzama, K

    2016-04-01

    Ticks and tick-borne diseases are among the main causes of economic loss in the South African cattle industry through high morbidity and mortality rates. Concerns of the general public regarding chemical residues may tarnish their perceptions of food safety and environmental health when the husbandry of cattle includes frequent use of acaricides to manage ticks. The primary objective of this study was to identify single nucleotide polymorphism (SNP) markers associated with host resistance to ticks in South African Nguni cattle. Tick count data were collected monthly from 586 Nguni cattle reared in four herds under natural grazing conditions over a period of two years. The counts were recorded for six species of ticks attached in eight anatomical locations on the animals and were summed by species and anatomical location. This gave rise to 63 measured phenotypes or traits, with results for 12 of these traits being reported here. Tick count (x) data were transformed using log10(x+1) and the resulting values were examined for normality. DNA was extracted from hair and blood samples and was genotyped using the Illumina BovineSNP50 assay. After quality control (call rate >90%, minor allele frequency >0.02), 40,436 SNPs were retained for analysis. Genetic parameters were estimated and association analysis for tick resistance was carried out using two approaches: a genome-wide association (GWA) analysis using the GenABEL package and a regional heritability mapping (RHM) analysis. The Bonferroni genome-wide (PAmblyomma hebraeum (the vector for Heartwater disease) being the dominant species. Heritability estimates (h(2)) from the fitted animal and sire models ranged from 0.02±0.00 to 0.17±0.04 for the transformed tick count data. Several genomic regions harbouring quantitative trait loci (QTL) were identified for different tick count traits by both the GWA and RHM approaches. Three genome-wide significant regions on chromosomes 7, 10 and 19 were identified for total tick

  3. A genome-wide association study of COPD identifies a susceptibility locus on chromosome 19q13.

    Science.gov (United States)

    Cho, Michael H; Castaldi, Peter J; Wan, Emily S; Siedlinski, Mateusz; Hersh, Craig P; Demeo, Dawn L; Himes, Blanca E; Sylvia, Jody S; Klanderman, Barbara J; Ziniti, John P; Lange, Christoph; Litonjua, Augusto A; Sparrow, David; Regan, Elizabeth A; Make, Barry J; Hokanson, John E; Murray, Tanda; Hetmanski, Jacqueline B; Pillai, Sreekumar G; Kong, Xiangyang; Anderson, Wayne H; Tal-Singer, Ruth; Lomas, David A; Coxson, Harvey O; Edwards, Lisa D; MacNee, William; Vestbo, Jørgen; Yates, Julie C; Agusti, Alvar; Calverley, Peter M A; Celli, Bartolome; Crim, Courtney; Rennard, Stephen; Wouters, Emiel; Bakke, Per; Gulsvik, Amund; Crapo, James D; Beaty, Terri H; Silverman, Edwin K

    2012-02-15

    The genetic risk factors for chronic obstructive pulmonary disease (COPD) are still largely unknown. To date, genome-wide association studies (GWASs) of limited size have identified several novel risk loci for COPD at CHRNA3/CHRNA5/IREB2, HHIP and FAM13A; additional loci may be identified through larger studies. We performed a GWAS using a total of 3499 cases and 1922 control subjects from four cohorts: the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE); the Normative Aging Study (NAS) and National Emphysema Treatment Trial (NETT); Bergen, Norway (GenKOLS); and the COPDGene study. Genotyping was performed on Illumina platforms with additional markers imputed using 1000 Genomes data; results were summarized using fixed-effect meta-analysis. We identified a new genome-wide significant locus on chromosome 19q13 (rs7937, OR = 0.74, P = 2.9 × 10(-9)). Genotyping this single nucleotide polymorphism (SNP) and another nearby SNP in linkage disequilibrium (rs2604894) in 2859 subjects from the family-based International COPD Genetics Network study (ICGN) demonstrated supportive evidence for association for COPD (P = 0.28 and 0.11 for rs7937 and rs2604894), pre-bronchodilator FEV(1) (P = 0.08 and 0.04) and severe (GOLD 3&4) COPD (P = 0.09 and 0.017). This region includes RAB4B, EGLN2, MIA and CYP2A6, and has previously been identified in association with cigarette smoking behavior.

  4. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.)

    Science.gov (United States)

    Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  5. Genetic Diversity in Jatropha curcas L. Assessed with SSR and SNP Markers

    Directory of Open Access Journals (Sweden)

    Juan M. Montes

    2014-08-01

    Full Text Available Jatropha curcas L. (jatropha is an undomesticated plant that has recently received great attention for its utilization in biofuel production, rehabilitation of wasteland, and rural development. Knowledge of genetic diversity and marker-trait associations is urgently needed for the design of breeding strategies. The main goal of this study was to assess the genetic structure and diversity in jatropha germplasm with co-dominant markers (Simple Sequence Repeats (SSR and Single Nucleotide Polymorphism (SNP in a diverse, worldwide, germplasm panel of 70 accessions. We found a high level of homozygosis in the germplasm that does not correspond to the purely outcrossing mating system assumed to be present in jatropha. We hypothesize that the prevalent mating system of jatropha comprise a high level of self-fertilization and that the outcrossing rate is low. Genetic diversity in accessions from Central America and Mexico was higher than in accession from Africa, Asia, and South America. We identified makers associated with the presence of phorbol esters. We think that the utilization of molecular markers in breeding of jatropha will significantly accelerate the development of improved cultivars.

  6. SNP typing for germplasm identification of Amomum villosum Lour. Based on DNA barcoding markers.

    Directory of Open Access Journals (Sweden)

    Qionglin Huang

    Full Text Available Amomum villosum Lour., produced from Yangchun, Guangdong Province, China, is a Daodi medicinal material of Amomi Fructus in traditional Chinese medicine. This herb germplasm should be accurately identified and collected to ensure its quality and safety in medication. In the present study, single nucleotide polymorphism typing method was evaluated on the basis of DNA barcoding markers to identify the germplasm of Amomi Fructus. Genomic DNA was extracted from the leaves of 29 landraces representing three Amomum species (A. villosum Lour., A. xanthioides Wall. ex Baker and A. longiligulare T. L. Wu by using the CTAB method. Six barcoding markers (ITS, ITS2, LSU D1-D3, matK, rbcL and trnH-psbA were PCR amplified and sequenced; SNP typing and phylogenetic analysis were performed to differentiate the landraces. Results showed that high-quality bidirectional sequences were acquired for five candidate regions (ITS, ITS2, LSU D1-D3, matK, and rbcL except trnH-psbA. Three ribosomal regions, namely, ITS, ITS2, and LSU D1-D3, contained more SNP genotypes (STs than the plastid genes rbcL and matK. In the 29 specimens, 19 STs were detected from the combination of four regions (ITS, LSU D1-D3, rbcL, and matK. Phylogenetic analysis results further revealed two clades. Minimum-spanning tree demonstrated the existence of two main groups: group I was consisting of 9 STs (ST1-8 and ST11 of A. villosum Lour., and group II was composed of 3 STs (ST16-18 of A. longiligulare T.L. Wu. Our results suggested that ITS and LSU D1-D3 should be incorporated with the core barcodes rbcL and matK. The four combined regions could be used as a multiregional DNA barcode to precisely differentiate the Amomi Fructus landraces in different producing areas.

  7. Radial basis function regression methods for predicting quantitative traits using SNP markers.

    Science.gov (United States)

    Long, Nanye; Gianola, Daniel; Rosa, Guilherme J M; Weigel, Kent A; Kranis, Andreas; González-Recio, Oscar

    2010-06-01

    A challenge when predicting total genetic values for complex quantitative traits is that an unknown number of quantitative trait loci may affect phenotypes via cryptic interactions. If markers are available, assuming that their effects on phenotypes are additive may lead to poor predictive ability. Non-parametric radial basis function (RBF) regression, which does not assume a particular form of the genotype-phenotype relationship, was investigated here by simulation and analysis of body weight and food conversion rate data in broilers. The simulation included a toy example in which an arbitrary non-linear genotype-phenotype relationship was assumed, and five different scenarios representing different broad sense heritability levels (0.1, 0.25, 0.5, 0.75 and 0.9) were created. In addition, a whole genome simulation was carried out, in which three different gene action modes (pure additive, additive+dominance and pure epistasis) were considered. In all analyses, a training set was used to fit the model and a testing set was used to evaluate predictive performance. The latter was measured by correlation and predictive mean-squared error (PMSE) on the testing data. For comparison, a linear additive model known as Bayes A was used as benchmark. Two RBF models with single nucleotide polymorphism (SNP)-specific (RBF I) and common (RBF II) weights were examined. Results indicated that, in the presence of complex genotype-phenotype relationships (i.e. non-linearity and non-additivity), RBF outperformed Bayes A in predicting total genetic values using SNP markers. Extension of Bayes A to include all additive, dominance and epistatic effects could improve its prediction accuracy. RBF I was generally better than RBF II, and was able to identify relevant SNPs in the toy example.

  8. Genome-Wide Association Study for Autism Spectrum Disorder in Taiwanese Han Population.

    Directory of Open Access Journals (Sweden)

    Po-Hsiu Kuo

    Full Text Available Autism spectrum disorder (ASD is a neurodevelopmental disorder with strong genetic components. Several recent genome-wide association (GWA studies in Caucasian samples have reported a number of gene regions and loci correlated with the risk of ASD--albeit with very little consensus across studies.A two-stage GWA study was employed to identify common genetic variants for ASD in the Taiwanese Han population. The discovery stage included 315 patients with ASD and 1,115 healthy controls, using the Affymetrix SNP array 6.0 platform for genotyping. Several gene regions were then selected for fine-mapping and top markers were examined in extended samples. Single marker, haplotype, gene-based, and pathway analyses were conducted for associations.Seven SNPs had p-values ranging from 3.4~9.9*10-6, but none reached the genome-wide significant level. Five of them were mapped to three known genes (OR2M4, STYK1, and MNT with significant empirical gene-based p-values in OR2M4 (p = 3.4*10(-5 and MNT (p = 0.0008. Results of the fine-mapping study showed single-marker associations in the GLIS1 (rs12082358 and rs12080993 and NAALADL2 (rs3914502 and rs2222447 genes, and gene-based associations for the OR2M3-OR2T5 (olfactory receptor genes, p = 0.02, and GLIPR1/KRR1 gene regions (p = 0.015. Pathway analyses revealed important pathways for ASD, such as olfactory and G protein-coupled receptors signaling pathways.We reported Taiwanese Han specific susceptibility genes and variants for ASD. However, further replication in other Asian populations is warranted to validate our findings. Investigation in the biological functions of our reported genetic variants might also allow for better understanding on the underlying pathogenesis of autism.

  9. The association of genome-wide significant spirometric loci with chronic obstructive pulmonary disease susceptibility.

    Science.gov (United States)

    Castaldi, Peter J; Cho, Michael H; Litonjua, Augusto A; Bakke, Per; Gulsvik, Amund; Lomas, David A; Anderson, Wayne; Beaty, Terri H; Hokanson, John E; Crapo, James D; Laird, Nan; Silverman, Edwin K

    2011-12-01

    Two recent metaanalyses of genome-wide association studies conducted by the CHARGE and SpiroMeta consortia identified novel loci yielding evidence of association at or near genome-wide significance (GWS) with FEV(1) and FEV(1)/FVC. We hypothesized that a subset of these markers would also be associated with chronic obstructive pulmonary disease (COPD) susceptibility. Thirty-two single-nucleotide polymorphisms (SNPs) in or near 17 genes in 11 previously identified GWS spirometric genomic regions were tested for association with COPD status in four COPD case-control study samples (NETT/NAS, the Norway case-control study, ECLIPSE, and the first 1,000 subjects in COPDGene; total sample size, 3,456 cases and 1,906 controls). In addition to testing the 32 spirometric GWS SNPs, we tested a dense panel of imputed HapMap2 SNP markers from the 17 genes located near the 32 GWS SNPs and in a set of 21 well studied COPD candidate genes. Of the previously identified GWS spirometric genomic regions, three loci harbored SNPs associated with COPD susceptibility at a 5% false discovery rate: the 4q24 locus including FLJ20184/INTS12/GSTCD/NPNT, the 6p21 locus including AGER and PPT2, and the 5q33 locus including ADAM19. In conclusion, markers previously associated at or near GWS with spirometric measures were tested for association with COPD status in data from four COPD case-control studies, and three loci showed evidence of association with COPD susceptibility at a 5% false discovery rate.

  10. Genome-Wide Association Analysis of the Anthocyanin and Carotenoid Contents of Rose Petals

    Science.gov (United States)

    Schulz, Dietmar F.; Schott, Rena T.; Voorrips, Roeland E.; Smulders, Marinus J. M.; Linde, Marcus; Debener, Thomas

    2016-01-01

    Petal color is one of the key characteristics determining the attractiveness and therefore the commercial value of an ornamental crop. Here, we present the first genome-wide association study for the important ornamental crop rose, focusing on the anthocyanin and carotenoid contents in petals of 96 diverse tetraploid garden rose genotypes. Cultivated roses display a vast phenotypic and genetic diversity and are therefore ideal targets for association genetics. For marker analysis, we used a recently designed Axiom SNP chip comprising 68,000 SNPs with additionally 281 SSRs, 400 AFLPs and 246 markers from candidate genes. An analysis of the structure of the rose population revealed three subpopulations with most of the genetic variation between individual genotypes rather than between clusters and with a high average proportion of heterozygous loci. The mapping of markers significantly associated with anthocyanin and carotenoid content to the related Fragaria and Prunus genomes revealed clusters of associated markers indicating five genomic regions associated with the total anthocyanin content and two large clusters associated with the carotenoid content. Among the marker clusters associated with the phenotypes, we found several candidate genes with known functions in either the anthocyanin or the carotenoid biosynthesis pathways. Among others, we identified a glutathione-S-transferase, 4CL, an auxin response factor and F3'H as candidate genes affecting anthocyanin concentration, and CCD4 and Zeaxanthine epoxidase as candidates affecting the concentration of carotenoids. These markers are starting points for future validation experiments in independent populations as well as for functional genomic studies to identify the causal factors for the observed color phenotypes. Furthermore, validated markers may be interesting tools for marker-assisted selection in commercial breeding programmes in that they provide the tools to identify superior parental combinations that

  11. Targeted SNP discovery in Atlantic salmon (Salmo salar genes using a 3'UTR-primed SNP detection approach

    Directory of Open Access Journals (Sweden)

    Høyheim Bjørn

    2010-12-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs represent the most widespread type of DNA variation in vertebrates and may be used as genetic markers for a range of applications. This has led to an increased interest in identification of SNP markers in non-model species and farmed animals. The in silico SNP mining method used for discovery of most known SNPs in Atlantic salmon (Salmo salar has applied a global (genome-wide approach. In this study we present a targeted 3'UTR-primed SNP discovery strategy that utilizes sequence data from Salmo salar full length sequenced cDNAs (FLIcs. We compare the efficiency of this new strategy to the in silico SNP mining method when using both methods for targeted SNP discovery. Results The SNP discovery efficiency of the two methods was tested in a set of FLIc target genes. The 3'UTR-primed SNP discovery method detected novel SNPs in 35% of the target genes while the in silico SNP mining method detected novel SNPs in 15% of the target genes. Furthermore, the 3'UTR-primed SNP discovery strategy was the less labor intensive one and revealed a higher success rate than the in silico SNP mining method in the initial amplification step. When testing the methods we discovered 112 novel bi-allelic polymorphisms (type I markers in 88 salmon genes [dbSNP: ss179319972-179320081, ss250608647-250608648], and three of the SNPs discovered were missense substitutions. Conclusions Full length insert cDNAs (FLIcs are important genomic resources that have been developed in many farmed animals. The 3'UTR-primed SNP discovery strategy successfully utilized FLIc data to detect novel SNPs in the partially tetraploid Atlantic salmon. This strategy may therefore be useful for targeted SNP discovery in several species, and particularly useful in species that, like salmonids, have duplicated genomes.

  12. Genome-wide association studies of female reproduction in tropically adapted beef cattle.

    Science.gov (United States)

    Hawken, R J; Zhang, Y D; Fortes, M R S; Collis, E; Barris, W C; Corbet, N J; Williams, P J; Fordyce, G; Holroyd, R G; Walkley, J R W; Barendse, W; Johnston, D J; Prayaga, K C; Tier, B; Reverter, A; Lehnert, S A

    2012-05-01

    The genetics of reproduction is poorly understood because the heritabilities of traits currently recorded are low. To elucidate the genetics underlying reproduction in beef cattle, we performed a genome-wide association study using the bovine SNP50 chip in 2 tropically adapted beef cattle breeds, Brahman and Tropical Composite. Here we present the results for 3 female reproduction traits: 1) age at puberty, defined as age in days at first observed corpus luteum (CL) after frequent ovarian ultrasound scans (AGECL); 2) the postpartum anestrous interval, measured as the number of days from calving to first ovulation postpartum (first rebreeding interval, PPAI); and 3) the occurrence of the first postpartum ovulation before weaning in the first rebreeding period (PW), defined from PPAI. In addition, correlated traits such as BW, height, serum IGF1 concentration, condition score, and fatness were also examined. In the Brahman and Tropical Composite cattle, 169 [false positive rate (FPR) = 0.262] and 84 (FPR = 0.581) SNP, respectively, were significant (P cattle, the largest concentration of markers for postpartum anestrus was located on BTA3 (14% for PPAI and PW) and BTA14 (17% PPAI). Very few of the significant markers for female reproduction traits for the Brahman and Tropical Composite breeds were located in the same chromosomal regions. However, fatness and BW traits as well as serum IGF1 concentration were found to be associated with similar genome regions within and between breeds. Clusters of SNP associated with multiple traits were located on BTA14 in Brahman and BTA5 in Tropical Composites.

  13. 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...

  14. Additive and epistatic genome-wide association for growth and ultrasound scan measures of carcass-related traits in Brahman cattle.

    Science.gov (United States)

    Ali, A A; Khatkar, M S; Kadarmideen, H N; Thomson, P C

    2015-04-01

    Genome-wide association studies are routinely used to identify genomic regions associated with traits of interest. However, this ignores an important class of genomic associations, that of epistatic interactions. A genome-wide interaction analysis between single nucleotide polymorphisms (SNPs) using highly dense markers can detect epistatic interactions, but is a difficult task due to multiple testing and computational demand. However, It is important for revealing complex trait heredity. This study considers analytical methods that detect statistical interactions between pairs of loci. We investigated a three-stage modelling procedure: (i) a model without the SNP to estimate the variance components; (ii) a model with the SNP using variance component estimates from (i), thus avoiding iteration; and (iii) using the significant SNPs from (ii) for genome-wide epistasis analysis. We fitted these three-stage models to field data for growth and ultrasound measures for subcutaneous fat thickness in Brahman cattle. The study demonstrated the usefulness of modelling epistasis in the analysis of complex traits as it revealed extra sources of genetic variation and identified potential candidate genes affecting the concentration of insulin-like growth factor-1 and ultrasound scan measure of fat depth traits. Information about epistasis can add to our understanding of the complex genetic networks that form the fundamental basis of biological systems. © 2015 Blackwell Verlag GmbH.

  15. Development of EST-based SNP and InDel markers and their utilization in tetraploid cotton genetic mapping

    Science.gov (United States)

    Expressed sequence tags (ESTs) were analyzed in silico in order to identify single nucleotide polymorphisms (SNPs) and insertion-deletion polymorphisms (InDels) in cotton. A total of 1349 EST-based SNP and InDel markers were developed by comparing ESTs between Gossypium hirsutum and G. barbadense, m...

  16. Evaluation of genome-wide power of genetic association studies based on empirical data from the HapMap project.

    Science.gov (United States)

    Nannya, Yasuhito; Taura, Kenjiro; Kurokawa, Mineo; Chiba, Shigeru; Ogawa, Seishi

    2007-10-15

    With recent advances in high-throughput single nucleotide polymorphism (SNP) typing technologies, genome-wide association studies have become a realistic approach to identify the causative genes that are responsible for common diseases of complex genetic traits. In this strategy, a trade-off between the increased genome coverage and a chance of finding SNPs incidentally showing a large statistics becomes serious due to extreme multiple-hypothesis testing. We investigated the extent to which this trade-off limits the genome-wide power with this approach by simulating a large number of case-control panels based on the empirical data from the HapMap Project. In our simulations, statistical costs of multiple hypothesis testing were evaluated by empirically calculating distributions of the maximum value of the chi(2) statistics for a series of marker sets having increasing numbers of SNPs, which were used to determine a genome-wide threshold in the following power simulations. With a practical study size, the cost of multiple testing largely offsets the potential benefits from increased genome coverage given modest genetic effects and/or low frequencies of causal alleles. In most realistic scenarios, increasing genome coverage becomes less influential on the power, while sample size is the predominant determinant of the feasibility of genome-wide association tests. Increasing genome coverage without corresponding increase in sample size will only consume resources without little gain in power. For common causal alleles with relatively large effect sizes [genotype relative risk > or =1.7], we can expect satisfactory power with currently available large-scale genotyping platforms using realistic sample size ( approximately 1000 per arm).

  17. Genetic diversity and relatedness of sweet cherry (Prunus avium L. cultivars based on single nucleotide polymorphic (SNP markers

    Directory of Open Access Journals (Sweden)

    Angel eFernandez i Marti

    2012-06-01

    Full Text Available Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD and SSR markers. This study was carried out to assess the utility of SNP markers generated from 3’UTRs for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars and old cultivars imported from different parts of the world were screened with 7 SSR markers developed from other Prunus species and with 40 SNPs obtained from 3’UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity and polymorphic information content (PIC values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, ‘Stella’ was separated from ‘Compact Stella’. This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3’ UTR SNPs for genetic fingerprinting, parentage verification, gene mapping and study of genetic diversity in sweet cherry.

  18. Genome wide association analysis for residual feed intake in Danish Duroc boars

    DEFF Research Database (Denmark)

    Do, Duy Ngoc; Ostersen, Tage; Strathe, Anders Bjerring;

    2013-01-01

    gain (30-100 kg). RFI2 was the same as RFI1 except that it was also regressed on backfat (BF). A total of 868 boars had phenotypic and genotype (i.e. Illumina Porcine SNP60 BeadChip) records. A total of 33945 SNPs were available for genome wide association studies (GWAS) after quality control...

  19. Fine Mapping QTLs Affecting Milk Production Traits on BTA6 in Chinese Holstein with SNP Markers

    Institute of Scientific and Technical Information of China (English)

    LIU Rui; SUN Dong-xiao; WANG Ya-chun; YU Ying; ZHANG Yi; CHEN Hui-yong; ZHANG Qin; ZHANG Sheng-li; ZHANG Yuan

    2013-01-01

    Our previous studies demonstrated that the region around markers BMS470 and BMS1242 on BTA6 showed a linkage to 305-d milk yield and composition traits in the Chinese Holstein population. We herein focused on such narrow region to fine map milk production QTLs with 15 SNPs across 25 Mb with each SNP in 1 Mb within most regions in a Chinese Holstein population with daughter design. 1 449 Holstein cows and 11 sires were genotyped for such SNPs by using TaqMan probe and RFLP assays. Multipoint linkage analysis across family revealed a QTL affecting milk yield between PPARGC1A C4075T and SLC34A2 T1713C. Meanwhile, within family analysis found three milk yield QTLs (two in CR T60984131G-CEP135 C501T and one in PDLIM5 A106C-OPN T3907, a fat yield QTL in UGDH T1670C-CR T60984131G region, and two protein yield QTLs in TBC1D1 G501C-UGDH T1670C and PPARGC1A C4075T-SLC34A2 T1713C, respectively. Associations between aforementioned significant SNP markers and milk production traits were further implemented. We found significant associations of PPARGC1A C4075T, SLC34A2 T1713C with milk yield (P<0.05, P<0.01, P<0.01), UGDH T1670C, and CR T60984131G with fat yield (P<0.01, P<0.01), and PPARGC1A C4075T, SLC34A2 T1713C, UGDH T1670C and OPN T3907 with protein yield (P<0.01, P<0.01, P<0.01, P<0.01). Our findings implied that QTLs affecting milk production traits on BTA6 were pleictropism or multigenic effect and PPARGC1A and OPN may be the causal mutations behind milk production QTLs on BTA6 in the Chinese Holstein population.

  20. SNP Typing for Germplasm Identification of Amomum villosum Lour. Based on DNA Barcoding Markers

    Science.gov (United States)

    Yang, Jinfen; Ma, Xinye; Zhan, Ruoting; Xu, Hui; Chen, Weiwen

    2014-01-01

    Amomum villosum Lour., produced from Yangchun, Guangdong Province, China, is a Daodi medicinal material of Amomi Fructus in traditional Chinese medicine. This herb germplasm should be accurately identified and collected to ensure its quality and safety in medication. In the present study, single nucleotide polymorphism typing method was evaluated on the basis of DNA barcoding markers to identify the germplasm of Amomi Fructus. Genomic DNA was extracted from the leaves of 29 landraces representing three Amomum species (A. villosum Lour., A. xanthioides Wall. ex Baker and A. longiligulare T. L. Wu) by using the CTAB method. Six barcoding markers (ITS, ITS2, LSU D1–D3, matK, rbcL and trnH-psbA) were PCR amplified and sequenced; SNP typing and phylogenetic analysis were performed to differentiate the landraces. Results showed that high-quality bidirectional sequences were acquired for five candidate regions (ITS, ITS2, LSU D1–D3, matK, and rbcL) except trnH-psbA. Three ribosomal regions, namely, ITS, ITS2, and LSU D1–D3, contained more SNP genotypes (STs) than the plastid genes rbcL and matK. In the 29 specimens, 19 STs were detected from the combination of four regions (ITS, LSU D1–D3, rbcL, and matK). Phylogenetic analysis results further revealed two clades. Minimum-spanning tree demonstrated the existence of two main groups: group I was consisting of 9 STs (ST1–8 and ST11) of A. villosum Lour., and group II was composed of 3 STs (ST16–18) of A. longiligulare T.L. Wu. Our results suggested that ITS and LSU D1–D3 should be incorporated with the core barcodes rbcL and matK. The four combined regions could be used as a multiregional DNA barcode to precisely differentiate the Amomi Fructus landraces in different producing areas. PMID:25531885

  1. A high-throughput SNP marker system for parental polymorphism screening, and diversity analysis in common bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Blair, Matthew W; Cortés, Andrés J; Penmetsa, R Varma; Farmer, Andrew; Carrasquilla-Garcia, Noelia; Cook, Doug R

    2013-02-01

    Single nucleotide polymorphism (SNP) detection has become a marker system of choice, because of the high abundance of source polymorphisms and the ease with which allele calls are automated. Various technologies exist for the evaluation of SNP loci and previously we validated two medium throughput technologies. In this study, our goal was to utilize a 768 feature, Illumina GoldenGate assay for common bean (Phaseolus vulgaris L.) developed from conserved legume gene sequences and to use the new technology for (1) the evaluation of parental polymorphisms in a mini-core set of common bean accessions and (2) the analysis of genetic diversity in the crop. A total of 736 SNPs were scored on 236 diverse common bean genotypes with the GoldenGate array. Missing data and heterozygosity levels were low and 94 % of the SNPs were scorable. With the evaluation of the parental polymorphism genotypes, we estimated the utility of the SNP markers in mapping for inter-genepool and intra-genepool populations, the latter being of lower polymorphism than the former. When we performed the diversity analysis with the diverse genotypes, we found Illumina GoldenGate SNPs to provide equivalent evaluations as previous gene-based SNP markers, but less fine-distinctions than with previous microsatellite marker analysis. We did find, however, that the gene-based SNPs in the GoldenGate array had some utility in race structure analysis despite the low polymorphism. Furthermore the SNPs detected high heterozygosity in wild accessions which was probably a reflection of ascertainment bias. The Illumina SNPs were shown to be effective in distinguishing between the genepools, and therefore were most useful in saturation of inter-genepool genetic maps. The implications of these results for breeding in common bean are discussed as well as the advantages and disadvantages of the GoldenGate system for SNP detection.

  2. Identification of a sex-linked SNP marker in the salmon louse (Lepeophtheirus salmonis using RAD sequencing.

    Directory of Open Access Journals (Sweden)

    Stephen N Carmichael

    Full Text Available The salmon louse (Lepeophtheirus salmonis (Krøyer, 1837 is a parasitic copepod that can, if untreated, cause considerable damage to Atlantic salmon (Salmo salar Linnaeus, 1758 and incurs significant costs to the Atlantic salmon mariculture industry. Salmon lice are gonochoristic and normally show sex ratios close to 1:1. While this observation suggests that sex determination in salmon lice is genetic, with only minor environmental influences, the mechanism of sex determination in the salmon louse is unknown. This paper describes the identification of a sex-linked Single Nucleotide Polymorphism (SNP marker, providing the first evidence for a genetic mechanism of sex determination in the salmon louse. Restriction site-associated DNA sequencing (RAD-seq was used to isolate SNP markers in a laboratory-maintained salmon louse strain. A total of 85 million raw Illumina 100 base paired-end reads produced 281,838 unique RAD-tags across 24 unrelated individuals. RAD marker Lsa101901 showed complete association with phenotypic sex for all individuals analysed, being heterozygous in females and homozygous in males. Using an allele-specific PCR assay for genotyping, this SNP association pattern was further confirmed for three unrelated salmon louse strains, displaying complete association with phenotypic sex in a total of 96 genotyped individuals. The marker Lsa101901 was located in the coding region of the prohibitin-2 gene, which showed a sex-dependent differential expression, with mRNA levels determined by RT-qPCR about 1.8-fold higher in adult female than adult male salmon lice. This study's observations of a novel sex-linked SNP marker are consistent with sex determination in the salmon louse being genetic and following a female heterozygous system. Marker Lsa101901 provides a tool to determine the genetic sex of salmon lice, and could be useful in the development of control strategies.

  3. The impact of genotyping-by-sequencing pipelines on SNP discovery and identification of markers associated verticillium wilt resistance in autotetraploid alfalfa (sedicago sativa l.)

    Science.gov (United States)

    Verticillium wilt (VW) of alfalfa is a soilborne disease that causes severe yield loss in alfalfa. To identify molecular markers associated with VW resistance, an integrated framework of genome-wide association study (GWAS) with high-throughput genotyping by sequencing (GBS) was used for mapping lo...

  4. Genome-Wide Association Study between Single Nucleotide Polymorphisms and Flight Speed in Nellore Cattle

    Science.gov (United States)

    Valente, Tiago Silva; Baldi, Fernando; Sant’Anna, Aline Cristina; Albuquerque, Lucia Galvão; Paranhos da Costa, Mateus José Rodrigues

    2016-01-01

    Introduction Cattle temperament is an important factor that affects the profitability of beef cattle enterprises, due to its relationship with productivity traits, animal welfare and labor safety. Temperament is a complex phenotype often assessed by measuring a series of behavioral traits, which result from the effects of multiple environmental and genetic factors, and their interactions. The aims of this study were to perform a genome-wide association study and detect genomic regions, potential candidate genes and their biological mechanisms underlying temperament, measured by flight speed (FS) test in Nellore cattle. Materials and Methods The genome-wide association study (GWAS) was performed using a single-step procedure (ssGBLUP) which combined simultaneously all 16,600 phenotypes from genotyped and non-genotyped animals, full pedigree information of 162,645 animals and 1,384 genotyped animals in one step. The animals were genotyped with High Density Bovine SNP BeadChip which contains 777,962 SNP markers. After quality control (QC) a total of 455,374 SNPs remained. Results Heritability estimated for FS was 0.21 ± 0.02. Consecutive SNPs explaining 1% or more of the total additive genetic variance were considered as windows associated with FS. Nine candidate regions located on eight different Bos taurus chromosomes (BTA) (1 at 73 Mb, 2 at 65 Mb, 5 at 22 Mb and 119 Mb, 9 at 98 Mb, 11 at 67 Mb, 15 at 16 Mb, 17 at 63 Kb, and 26 at 47 Mb) were identified. The candidate genes identified in these regions were NCKAP5 (BTA2), PARK2 (BTA9), ANTXR1 (BTA11), GUCY1A2 (BTA15), CPE (BTA17) and DOCK1 (BTA26). Among these genes PARK2, GUCY1A2, CPE and DOCK1 are related to dopaminergic system, memory formation, biosynthesis of peptide hormone and neurotransmitter and brain development, respectively. Conclusions Our findings allowed us to identify nine genomic regions (SNP windows) associated with beef cattle temperament, measured by FS test. Within these windows, six promising

  5. Genome-Wide Association Study between Single Nucleotide Polymorphisms and Flight Speed in Nellore Cattle.

    Directory of Open Access Journals (Sweden)

    Tiago Silva Valente

    Full Text Available Cattle temperament is an important factor that affects the profitability of beef cattle enterprises, due to its relationship with productivity traits, animal welfare and labor safety. Temperament is a complex phenotype often assessed by measuring a series of behavioral traits, which result from the effects of multiple environmental and genetic factors, and their interactions. The aims of this study were to perform a genome-wide association study and detect genomic regions, potential candidate genes and their biological mechanisms underlying temperament, measured by flight speed (FS test in Nellore cattle.The genome-wide association study (GWAS was performed using a single-step procedure (ssGBLUP which combined simultaneously all 16,600 phenotypes from genotyped and non-genotyped animals, full pedigree information of 162,645 animals and 1,384 genotyped animals in one step. The animals were genotyped with High Density Bovine SNP BeadChip which contains 777,962 SNP markers. After quality control (QC a total of 455,374 SNPs remained.Heritability estimated for FS was 0.21 ± 0.02. Consecutive SNPs explaining 1% or more of the total additive genetic variance were considered as windows associated with FS. Nine candidate regions located on eight different Bos taurus chromosomes (BTA (1 at 73 Mb, 2 at 65 Mb, 5 at 22 Mb and 119 Mb, 9 at 98 Mb, 11 at 67 Mb, 15 at 16 Mb, 17 at 63 Kb, and 26 at 47 Mb were identified. The candidate genes identified in these regions were NCKAP5 (BTA2, PARK2 (BTA9, ANTXR1 (BTA11, GUCY1A2 (BTA15, CPE (BTA17 and DOCK1 (BTA26. Among these genes PARK2, GUCY1A2, CPE and DOCK1 are related to dopaminergic system, memory formation, biosynthesis of peptide hormone and neurotransmitter and brain development, respectively.Our findings allowed us to identify nine genomic regions (SNP windows associated with beef cattle temperament, measured by FS test. Within these windows, six promising candidate genes and their biological functions were

  6. Epigenomic model of cardiac enhancers with application to genome wide association studies.

    Science.gov (United States)

    Sahu, Avinash Das; Aniba, Radhouane; Chang, Yen-Pei Christy; Hannenhalli, Sridhar

    2013-01-01

    Mammalian gene regulation is often mediated by distal enhancer elements, in particular, for tissue specific and developmental genes. Computational identification of enhancers is difficult because they do not exhibit clear location preference relative to their target gene and also because they lack clearly distinguishing genomic features. This represents a major challenge in deciphering transcriptional regulation. Recent ChIP-seq based genome-wide investigation of epigenomic modifications have revealed that enhancers are often enriched for certain epigenomic marks. Here we utilize the epigenomic data in human heart tissue along with validated human heart enhancers to develop a Support Vector Machine (SVM) model of cardiac enhancers. Cross-validation classification accuracy of our model was 84% and 92% on positive and negative sets respectively with ROC AUC = 0.92. More importantly, while P300 binding has been used as gold standard for enhancers, our model can distinguish P300-bound validated enhancers from other P300-bound regions that failed to exhibit enhancer activity in transgenic mouse. While GWAS studies reveal polymorphic regions associated with certain phenotypes, they do not immediately provide causality. Next, we hypothesized that genomic regions containing a GWAS SNP associated with a cardiac phenotype might contain another SNP in a cardiac enhancer, which presumably mediates the phenotype. Starting with a comprehensive set of SNPs associated with cardiac phenotypes in GWAS studies, we scored other SNPs in LD with the GWAS SNP according to its probability of being an enhancer and choose one with best score in the LD as enhancer. We found that our predicted enhancers are enriched for known cardiac transcriptional regulator motifs and are likely to regulate the nearby gene. Importantly, these tendencies are more favorable for the predicted enhancers compared with an approach that uses P300 binding as a marker of enhancer activity.

  7. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Perseguini, Juliana Morini Küpper Cardoso; Oblessuc, Paula Rodrigues; Rosa, João Ricardo Bachega Feijó; Gomes, Kleber Alves; Chiorato, Alisson Fernando; Carbonell, Sérgio Augusto Morais; Garcia, Antonio Augusto Franco; Vianello, Rosana Pereira; Benchimol-Reis, Luciana Lasry

    2016-01-01

    The common bean (Phaseolus vulgaris L.) is the world's most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum) and angular leaf spot (ALS; Pseudocercospora griseola) are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL) controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will contribute to more

  8. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L..

    Directory of Open Access Journals (Sweden)

    Juliana Morini Küpper Cardoso Perseguini

    Full Text Available The common bean (Phaseolus vulgaris L. is the world's most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum and angular leaf spot (ALS; Pseudocercospora griseola are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will

  9. Genome Wide Examination of Allelic Loss in Lobular and Ductal Breast Cancer

    Science.gov (United States)

    2004-07-01

    assay with data from array comparative genomic hybridization (CGH) on the same tumors. We find almost complete concordance with LOH as defined by the...Facility for assis- HuSNP assay on PEP material may be an acceptable tance in the hybridization and analysis of the HuSNP arrays, approach to genome-wide...Levine D, it is still a low-density map, with an average of one SNP Rabinovitch P, Reid B: 17p (p53) allelic losses, 4N (G2/ tetraploid ) site per 8.5 Mb in

  10. VIGoR: Variational Bayesian Inference for Genome-Wide Regression

    Directory of Open Access Journals (Sweden)

    Akio Onogi

    2016-04-01

    Full Text Available Genome-wide regression using a number of genome-wide markers as predictors is now widely used for genome-wide association mapping and genomic prediction. We developed novel software for genome-wide regression which we named VIGoR (variational Bayesian inference for genome-wide regression. Variational Bayesian inference is computationally much faster than widely used Markov chain Monte Carlo algorithms. VIGoR implements seven regression methods, and is provided as a command line program package for Linux/Mac, and as a cross-platform R package. In addition to model fitting, cross-validation and hyperparameter tuning using cross-validation can be automatically performed by modifying a single argument. VIGoR is available at https://github.com/Onogi/VIGoR. The R package is also available at https://cran.r-project.org/web/packages/VIGoR/index.html.

  11. SNP markers identify widely distributed clonal lineages of Phytophthora colocasiae in Vietnam, Hawaii and Hainan Island, China.

    Science.gov (United States)

    Shrestha, Sandesh; Hu, Jian; Fryxell, Rebecca Trout; Mudge, Joann; Lamour, Kurt

    2014-01-01

    Taro (Colocasia esculenta) is an important food crop, and taro leaf blight caused by Phytophthora colocasiae can significantly affect production. Our objectives were to develop single nucleotide polymorphism (SNP) markers for P. colocasiae and characterize populations in Hawaii (HI), Vietnam (VN) and Hainan Island, China (HIC). In total, 379 isolates were analyzed for mating type and multilocus SNP profiles including 214 from HI, 97 from VN and 68 from HIC. A total of 1152 single nucleotide variant (SNV) sites were identified via restriction site-associated DNA (RAD) sequencing of two field isolates. Genotyping with 27 SNPs revealed 41 multilocus SNP genotypes grouped into seven clonal lineages containing 2-232 members. Three clonal lineages were shared among countries. In addition, five SNP markers had a low incidence of loss of heterozygosity (LOH) during asexual laboratory growth. For HI and VN, >95% of isolates were the A2 mating type. On HIC, isolates within single clonal lineages had A1, A2 and A0 (neuter) isolates. The implications for the wide dispersal of clonal lineages are discussed.

  12. 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

  13. Genome-wide association study of grain polyphenol concentrations in global sorghum [Sorghum bicolor (L.) Moench] germplasm.

    Science.gov (United States)

    Rhodes, Davina H; Hoffmann, Leo; Rooney, William L; Ramu, Punna; Morris, Geoffrey P; Kresovich, Stephen

    2014-11-12

    Identifying natural variation of health-promoting compounds in staple crops and characterizing its genetic basis can help improve human nutrition through crop biofortification. Some varieties of sorghum, a staple cereal crop grown worldwide, have high concentrations of proanthocyanidins and 3-deoxyanthocyanidins, polyphenols with antioxidant and anti-inflammatory properties. We quantified total phenols, proanthocyanidins, and 3-deoxyanthocyanidins in a global sorghum diversity panel (n = 381) using near-infrared spectroscopy (NIRS), and characterized the patterns of variation with respect to geographic origin and botanical race. A genome-wide association study (GWAS) with 404,628 SNP markers identified novel quantitative trait loci for sorghum polyphenols, some of which colocalized with homologues of flavonoid pathway genes from other plants, including an orthologue of maize (Zea mays) Pr1 and a homologue of Arabidopsis (Arabidopsis thaliana) TT16. This survey of grain polyphenol variation in sorghum germplasm and catalog of flavonoid pathway loci may be useful to guide future enhancement of cereal polyphenols.

  14. Genome-Wide Association of Stem Water Soluble Carbohydrates in Bread Wheat

    Science.gov (United States)

    Dong, Yan; Liu, Jindong; Zhang, Yan; Geng, Hongwei; Rasheed, Awais; Xiao, Yonggui; Cao, Shuanghe; Fu, Luping; Yan, Jun; Wen, Weie; Zhang, Yong; Jing, Ruilian; Xia, Xianchun; He, Zhonghu

    2016-01-01

    Water soluble carbohydrates (WSC) in stems play an important role in buffering grain yield in wheat against biotic and abiotic stresses; however, knowledge of genes controlling WSC is very limited. We conducted a genome-wide association study (GWAS) using a high-density 90K SNP array to better understand the genetic basis underlying WSC, and to explore marker-based breeding approaches. WSC was evaluated in an association panel comprising 166 Chinese bread wheat cultivars planted in four environments. Fifty two marker-trait associations (MTAs) distributed across 23 loci were identified for phenotypic best linear unbiased estimates (BLUEs), and 11 MTAs were identified in two or more environments. Liner regression showed a clear dependence of WSC BLUE scores on numbers of favorable (increasing WSC content) and unfavorable alleles (decreasing WSC), indicating that genotypes with higher numbers of favorable or lower numbers of unfavorable alleles had higher WSC content. In silico analysis of flanking sequences of trait-associated SNPs revealed eight candidate genes related to WSC content grouped into two categories based on the type of encoding proteins, namely, defense response proteins and proteins triggered by environmental stresses. The identified SNPs and candidate genes related to WSC provide opportunities for breeding higher WSC wheat cultivars. PMID:27802269

  15. 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

  16. Simultaneous analysis of all SNPs in genome-wide and re-sequencing association studies.

    Directory of Open Access Journals (Sweden)

    Clive J Hoggart

    2008-07-01

    Full Text Available Testing one SNP at a time does not fully realise the potential of genome-wide association studies to identify multiple causal variants, which is a plausible scenario for many complex diseases. We show that simultaneous analysis of the entire set of SNPs from a genome-wide study to identify the subset that best predicts disease outcome is now feasible, thanks to developments in stochastic search methods. We used a Bayesian-inspired penalised maximum likelihood approach in which every SNP can be considered for additive, dominant, and recessive contributions to disease risk. Posterior mode estimates were obtained for regression coefficients that were each assigned a prior with a sharp mode at zero. A non-zero coefficient estimate was interpreted as corresponding to a significant SNP. We investigated two prior distributions and show that the normal-exponential-gamma prior leads to improved SNP selection in comparison with single-SNP tests. We also derived an explicit approximation for type-I error that avoids the need to use permutation procedures. As well as genome-wide analyses, our method is well-suited to fine mapping with very dense SNP sets obtained from re-sequencing and/or imputation. It can accommodate quantitative as well as case-control phenotypes, covariate adjustment, and can be extended to search for interactions. Here, we demonstrate the power and empirical type-I error of our approach using simulated case-control data sets of up to 500 K SNPs, a real genome-wide data set of 300 K SNPs, and a sequence-based dataset, each of which can be analysed in a few hours on a desktop workstation.

  17. 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.

  18. Large-scale development of gene-associated SNP markers for linkage mapping in perennial ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Studer, Bruno; Nielsen, Rasmus Ory; Panitz, Frank;

    2011-01-01

    a clear cluster separation. An additional 83 (12%) were monomorphic. A total of 513 gene-associated SNPs were available for linkage mapping, out of which 495 (64% of the total 768 SNPs on the array) were successfully mapped in the VrnA population. The current VrnA map contains a total of 837 DNA markers......-assisted breeding strategies, a surprisingly low number of validated SNPs are currently available in perennial ryegrass. The advent of next generation sequencing opened up the opportunity for efficient and high throughput in silico SNP discovery in absence of a reference genome sequence. However, the percentages...... of 768 SNP markers were selected for GoldenGate genotyping on 181 individuals of the perennial ryegrass mapping population VrnA, which has been previously evaluated for important agronomic traits. A total of 692 (90%) of the 768 SNPs tested were successfully called. Of these, 96 (14%) did not reveal...

  19. Genome-Wide Differentiation of Various Melon Horticultural Groups for Use in GWAS for Fruit Firmness and Construction of a High Resolution Genetic Map

    Science.gov (United States)

    Nimmakayala, Padma; Tomason, Yan R.; Abburi, Venkata L.; Alvarado, Alejandra; Saminathan, Thangasamy; Vajja, Venkata G.; Salazar, Germania; Panicker, Girish K.; Levi, Amnon; Wechter, William P.; McCreight, James D.; Korol, Abraham B.; Ronin, Yefim; Garcia-Mas, Jordi; Reddy, Umesh K.

    2016-01-01

    Melon (Cucumis melo L.) is a phenotypically diverse eudicot diploid (2n = 2x = 24) has climacteric and non-climacteric morphotypes and show wide variation for fruit firmness, an important trait for transportation and shelf life. We generated 13,789 SNP markers using genotyping-by-sequencing (GBS) and anchored them to chromosomes to understand genome-wide fixation indices (Fst) between various melon morphotypes and genomewide linkage disequilibrium (LD) decay. The FST between accessions of cantalupensis and inodorus was 0.23. The FST between cantalupensis and various agrestis accessions was in a range of 0.19–0.53 and between inodorus and agrestis accessions was in a range of 0.21–0.59 indicating sporadic to wide ranging introgression. The EM (Expectation Maximization) algorithm was used for estimation of 1436 haplotypes. Average genome-wide LD decay for the melon genome was noted to be 9.27 Kb. In the current research, we focused on the genome-wide divergence underlying diverse melon horticultural groups. A high-resolution genetic map with 7153 loci was constructed. Genome-wide segregation distortion and recombination rate across various chromosomes were characterized. Melon has climacteric and non-climacteric morphotypes and wide variation for fruit firmness, a very important trait for transportation and shelf life. Various levels of QTLs were identified with high to moderate stringency and linked to fruit firmness using both genome-wide association study (GWAS) and biparental mapping. Gene annotation revealed some of the SNPs are located in β-D-xylosidase, glyoxysomal malate synthase, chloroplastic anthranilate phosphoribosyltransferase, and histidine kinase, the genes that were previously characterized for fruit ripening and softening in other crops. PMID:27713759

  20. SNP genotyping technologies

    DEFF Research Database (Denmark)

    Studer, Bruno; Kölliker, Roland

    2013-01-01

    for this is the availability of high-throughput platforms for multiplexed SNP genotyping. Advancements in these technologies have enabled increased flexibility and throughput, allowing for the generation of adequate SNP marker data at very competitive cost per data point.......In the recent years, single nucleotide polymorphism (SNP) markers have emerged as the marker technology of choice for plant genetics and breeding applications. Besides the efficient technologies available for SNP discovery even in complex genomes, one of the main reasons...

  1. SNP genotyping technologies

    DEFF Research Database (Denmark)

    Studer, Bruno; Kölliker, Roland

    2013-01-01

    In the recent years, single nucleotide polymorphism (SNP) markers have emerged as the marker technology of choice for plant genetics and breeding applications. Besides the efficient technologies available for SNP discovery even in complex genomes, one of the main reasons...... for this is the availability of high-throughput platforms for multiplexed SNP genotyping. Advancements in these technologies have enabled increased flexibility and throughput, allowing for the generation of adequate SNP marker data at very competitive cost per data point....

  2. Genome-wide association study of metabolic traits reveals novel gene-metabolite-disease links.

    Directory of Open Access Journals (Sweden)

    Rico Rueedi

    2014-02-01

    Full Text Available Metabolic traits are molecular phenotypes that can drive clinical phenotypes and may predict disease progression. Here, we report results from a metabolome- and genome-wide association study on (1H-NMR urine metabolic profiles. The study was conducted within an untargeted approach, employing a novel method for compound identification. From our discovery cohort of 835 Caucasian individuals who participated in the CoLaus study, we identified 139 suggestively significant (P<5×10(-8 and independent associations between single nucleotide polymorphisms (SNP and metabolome features. Fifty-six of these associations replicated in the TasteSensomics cohort, comprising 601 individuals from São Paulo of vastly diverse ethnic background. They correspond to eleven gene-metabolite associations, six of which had been previously identified in the urine metabolome and three in the serum metabolome. Our key novel findings are the associations of two SNPs with NMR spectral signatures pointing to fucose (rs492602, P = 6.9×10(-44 and lysine (rs8101881, P = 1.2×10(-33, respectively. Fine-mapping of the first locus pinpointed the FUT2 gene, which encodes a fucosyltransferase enzyme and has previously been associated with Crohn's disease. This implicates fucose as a potential prognostic disease marker, for which there is already published evidence from a mouse model. The second SNP lies within the SLC7A9 gene, rare mutations of which have been linked to severe kidney damage. The replication of previous associations and our new discoveries demonstrate the potential of untargeted metabolomics GWAS to robustly identify molecular disease markers.

  3. Genome-Wide Association Study of Metabolic Traits Reveals Novel Gene-Metabolite-Disease Links

    Science.gov (United States)

    Nicholls, Andrew W.; Salek, Reza M.; Marques-Vidal, Pedro; Morya, Edgard; Sameshima, Koichi; Montoliu, Ivan; Da Silva, Laeticia; Collino, Sebastiano; Martin, François-Pierre; Rezzi, Serge; Steinbeck, Christoph; Waterworth, Dawn M.; Waeber, Gérard; Vollenweider, Peter; Beckmann, Jacques S.; Le Coutre, Johannes; Mooser, Vincent; Bergmann, Sven; Genick, Ulrich K.; Kutalik, Zoltán

    2014-01-01

    Metabolic traits are molecular phenotypes that can drive clinical phenotypes and may predict disease progression. Here, we report results from a metabolome- and genome-wide association study on 1H-NMR urine metabolic profiles. The study was conducted within an untargeted approach, employing a novel method for compound identification. From our discovery cohort of 835 Caucasian individuals who participated in the CoLaus study, we identified 139 suggestively significant (P<5×10−8) and independent associations between single nucleotide polymorphisms (SNP) and metabolome features. Fifty-six of these associations replicated in the TasteSensomics cohort, comprising 601 individuals from São Paulo of vastly diverse ethnic background. They correspond to eleven gene-metabolite associations, six of which had been previously identified in the urine metabolome and three in the serum metabolome. Our key novel findings are the associations of two SNPs with NMR spectral signatures pointing to fucose (rs492602, P = 6.9×10−44) and lysine (rs8101881, P = 1.2×10−33), respectively. Fine-mapping of the first locus pinpointed the FUT2 gene, which encodes a fucosyltransferase enzyme and has previously been associated with Crohn's disease. This implicates fucose as a potential prognostic disease marker, for which there is already published evidence from a mouse model. The second SNP lies within the SLC7A9 gene, rare mutations of which have been linked to severe kidney damage. The replication of previous associations and our new discoveries demonstrate the potential of untargeted metabolomics GWAS to robustly identify molecular disease markers. PMID:24586186

  4. A Genome-Wide Association Study of Vertical Cup-Disc Ratio in a Latino Population

    Science.gov (United States)

    Nannini, Drew R.; Torres, Mina; Chen, Yii-Der I.; Taylor, Kent D.; Rotter, Jerome I.; Varma, Rohit; Gao, Xiaoyi

    2017-01-01

    Purpose Vertical cup-disc ratio (VCDR) is used as a clinical assessment measure to identify and monitor glaucomatous damage to the optic nerve. Previous genetic studies conducted in European and Asian populations have identified many loci associated with VCDR. The genetic factors in other ethnic populations, such as Latino, influencing VCDR remain to be determined. Here, we describe the first genome-wide association study (GWAS) on VCDR in Latino individuals. Methods We conducted this GWAS on VCDR using 4537 Latino individuals who were genotyped by using either the Illumina OmniExpress BeadChip (∼730K markers) or the Illumina Hispanic/SOL BeadChip (∼2.5 million markers). Study subjects were 40 years of age and older. Linear regression, adjusting for age, sex, and principal components of genetic ancestry, was conducted to assess the associations between single nucleotide polymorphisms (SNPs) and VCDR. We imputed SNPs from the 1000 Genomes Project to integrate additional SNPs not directly genotyped. Results We replicated two previously reported SNPs that reached GWAS significance, rs1900005 and rs7916697, in the ATOH7-PBLD region, as well as identified two suggestive associations in the CDC7-TGFBR3 region on chromosome 1p22.1 and in the ZNF770-DPH6 region on chromosome 15q14. We discovered a novel SNP, rs56238729 (P = 1.22 × 10−13), in the ATOH7-PBLD region that is significantly associated with VCDR in Latino individuals. We replicated eight previously reported regions, including COL8A1, CDKN2B-CDKN2BAS, BMP2, and CHEK2 (P < 2.17 × 10−3). Conclusions Our results discovered a novel SNP that is significantly associated with VCDR in Latino individuals and confirmed previously reported loci, providing further insight into the genetic architecture of VCDR. PMID:28061514

  5. Genome-wide association for heifer reproduction and calf performance traits in beef cattle.

    Science.gov (United States)

    Akanno, Everestus C; Plastow, Graham; Fitzsimmons, Carolyn; Miller, Stephen P; Baron, Vern; Ominski, Kimberly; Basarab, John A

    2015-12-01

    The aim of this study was to identify SNP markers that associate with variation in beef heifer reproduction and performance of their calves. A genome-wide association study was performed by means of the generalized quasi-likelihood score (GQLS) method using heifer genotypes from the BovineSNP50 BeadChip and estimated breeding values for pre-breeding body weight (PBW), pregnancy rate (PR), calving difficulty (CD), age at first calving (AFC), calf birth weight (BWT), calf weaning weight (WWT), and calf pre-weaning average daily gain (ADG). Data consisted of 785 replacement heifers from three Canadian research herds, namely Brandon Research Centre, Brandon, Manitoba, University of Alberta Roy Berg Kinsella Ranch, Kinsella, Alberta, and Lacombe Research Centre, Lacombe, Alberta. After applying a false discovery rate correction at a 5% significance level, a total of 4, 3, 3, 9, 6, 2, and 1 SNPs were significantly associated with PBW, PR, CD, AFC, BWT, WWT, and ADG, respectively. These SNPs were located on chromosomes 1, 5-7, 9, 13-16, 19-21, 24, 25, and 27-29. Chromosomes 1, 5, and 24 had SNPs with pleiotropic effects. New significant SNPs that impact functional traits were detected, many of which have not been previously reported. The results of this study support quantitative genetic studies related to the inheritance of these traits, and provides new knowledge regarding beef cattle quantitative trait loci effects. The identification of these SNPs provides a starting point to identify genes affecting heifer reproduction traits and performance of their calves (BWT, WWT, and ADG). They also contribute to a better understanding of the biology underlying these traits and will be potentially useful in marker- and genome-assisted selection and management.

  6. 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.

  7. 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.

  8. The Challenges of Genome-Wide Interaction Studies: Lessons to Learn from the Analysis of HDL Blood Levels

    OpenAIRE

    van Leeuwen, Elisabeth M.; Smouter, Françoise A. S.; Tony Kam-Thong; Nazanin Karbalai; Smith, Albert V.; Harris, Tamara B.; Launer, Lenore J.; Sitlani, Colleen M.; Guo Li; Brody, Jennifer A; Bis, Joshua C.; White, Charles C.; Alok Jaiswal; Oostra, Ben A.; Albert Hofman

    2014-01-01

    Genome-wide association studies (GWAS) have revealed 74 single nucleotide polymorphisms (SNPs) associated with high-density lipoprotein cholesterol (HDL) blood levels. This study is, to our knowledge, the first genome-wide interaction study (GWIS) to identify SNPxSNP interactions associated with HDL levels. We performed a GWIS in the Rotterdam Study (RS) cohort I (RS-I) using the GLIDE tool which leverages the massively parallel computing power of Graphics Processing Units (GPUs) to perform l...

  9. Development of EST Intron-Targeting SNP Markers for Panax ginseng and Their Application to Cultivar Authentication.

    Science.gov (United States)

    Wang, Hongtao; Li, Guisheng; Kwon, Woo-Saeng; Yang, Deok-Chun

    2016-06-04

    Panax ginseng is one of the most valuable medicinal plants in the Orient. The low level of genetic variation has limited the application of molecular markers for cultivar authentication and marker-assisted selection in cultivated ginseng. To exploit DNA polymorphism within ginseng cultivars, ginseng expressed sequence tags (ESTs) were searched against the potential intron polymorphism (PIP) database to predict the positions of introns. Intron-flanking primers were then designed in conserved exon regions and used to amplify across the more variable introns. Sequencing results showed that single nucleotide polymorphisms (SNPs), as well as indels, were detected in four EST-derived introns, and SNP markers specific to "Gopoong" and "K-1" were first reported in this study. Based on cultivar-specific SNP sites, allele-specific polymerase chain reaction (PCR) was conducted and proved to be effective for the authentication of ginseng cultivars. Additionally, the combination of a simple NaOH-Tris DNA isolation method and real-time allele-specific PCR assay enabled the high throughput selection of cultivars from ginseng fields. The established real-time allele-specific PCR assay should be applied to molecular authentication and marker assisted selection of P. ginseng cultivars, and the EST intron-targeting strategy will provide a potential approach for marker development in species without whole genomic DNA sequence information.

  10. Genome-wide association study for cheese yield and curd nutrient recovery in dairy cows.

    Science.gov (United States)

    Dadousis, C; Biffani, S; Cipolat-Gotet, C; Nicolazzi, E L; Rosa, G J M; Gianola, D; Rossoni, A; Santus, E; Bittante, G; Cecchinato, A

    2017-02-01

    Cheese production and consumption are increasing in many countries worldwide. As a result, interest has increased in strategies for genetic selection of individuals for technological traits of milk related to cheese yield (CY) in dairy cattle breeding. However, little is known about the genetic background of a cow's ability to produce cheese. Recently, a relatively large panel (1,264 cows) of different measures of individual cow CY and milk nutrient and energy recoveries in the cheese (REC) became available. Genetic analyses showed considerable variation for CY and for aptitude to retain high proportions of fat, protein, and water in the coagulum. For the dairy industry, these characteristics are of major economic importance. Nevertheless, use of this knowledge in dairy breeding is hampered by high costs, intense labor requirement, and lack of appropriate technology. However, in the era of genomics, new possibilities are available for animal breeding and genetic improvement. For example, identification of genomic regions involved in cow CY might provide potential for marker-assisted selection. The objective of this study was to perform genome-wide association studies on different CY and REC measures. Milk and DNA samples from 1,152 Italian Brown Swiss cows were used. Three CY traits expressing the weight (wt) of fresh curd (%CYCURD), curd solids (%CYSOLIDS), and curd moisture (%CYWATER) as a percentage of weight of milk processed, and 4 REC (RECFAT, RECPROTEIN, RECSOLIDS, and RECENERGY, calculated as the % ratio between the nutrient in curd and the corresponding nutrient in processed milk) were analyzed. Animals were genotyped with the Illumina BovineSNP50 Bead Chip v.2. Single marker regressions were fitted using the GenABEL R package (genome-wide association using mixed model and regression-genomic control). In total, 103 significant associations (88 single nucleotide polymorphisms) were identified in 10 chromosomes (2, 6, 9, 11, 12, 14, 18, 19, 27, 28). For

  11. Gene expression levels as endophenotypes in genome-wide association studies of Alzheimer disease

    Science.gov (United States)

    Zou, F.; Carrasquillo, M. M.; Pankratz, V. S.; Belbin, O.; Morgan, K.; Allen, M.; Wilcox, S. L.; Ma, L.; Walker, L. P.; Kouri, N.; Burgess, J. D.; Younkin, L. H.; Younkin, Samuel G.; Younkin, C. S.; Bisceglio, G. D.; Crook, J. E.; Dickson, D. W.; Petersen, R. C.; Graff-Radford, N.; Younkin, Steven G.; Ertekin-Taner, N.

    2010-01-01

    Background: Late-onset Alzheimer disease (LOAD) is a common disorder with a substantial genetic component. We postulate that many disease susceptibility variants act by altering gene expression levels. Methods: We measured messenger RNA (mRNA) expression levels of 12 LOAD candidate genes in the cerebella of 200 subjects with LOAD. Using the genotypes from our LOAD genome-wide association study for the cis-single nucleotide polymorphisms (SNPs) (n = 619) of these 12 LOAD candidate genes, we tested for associations with expression levels as endophenotypes. The strongest expression cis-SNP was tested for AD association in 7 independent case-control series (2,280 AD and 2,396 controls). Results: We identified 3 SNPs that associated significantly with IDE (insulin degrading enzyme) expression levels. A single copy of the minor allele for each significant SNP was associated with ∼twofold higher IDE expression levels. The most significant SNP, rs7910977, is 4.2 kb beyond the 3′ end of IDE. The association observed with this SNP was significant even at the genome-wide level (p = 2.7 × 10−8). Furthermore, the minor allele of rs7910977 associated significantly (p = 0.0046) with reduced LOAD risk (OR = 0.81 with a 95% CI of 0.70-0.94), as expected biologically from its association with elevated IDE expression. Conclusions: These results provide strong evidence that IDE is a late-onset Alzheimer disease (LOAD) gene with variants that modify risk of LOAD by influencing IDE expression. They also suggest that the use of expression levels as endophenotypes in genome-wide association studies may provide a powerful approach for the identification of disease susceptibility alleles. GLOSSARY AD = Alzheimer disease; CI = confidence interval; GWAS = genome-wide association study; LOAD = late-onset Alzheimer disease; mRNA = messenger RNA; OR = odds ratio; SNP = single nucleotide polymorphism. PMID:20142614

  12. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS).

    Science.gov (United States)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc; Weider, Lawrence J

    2016-06-27

    The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon.

  13. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS)

    Science.gov (United States)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc; Weider, Lawrence J.

    2016-01-01

    The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon. PMID:27346179

  14. Evaluating the performance of Affymetrix SNP Array 6.0 platform with 400 Japanese individuals

    Directory of Open Access Journals (Sweden)

    Uehara Yasuka

    2008-09-01

    Full Text Available Abstract Background With improvements in genotyping technologies, genome-wide association studies with hundreds of thousands of SNPs allow the identification of candidate genetic loci for multifactorial diseases in different populations. However, genotyping errors caused by genotyping platforms or genotype calling algorithms may lead to inflation of false associations between markers and phenotypes. In addition, the number of SNPs available for genome-wide association studies in the Japanese population has been investigated using only 45 samples in the HapMap project, which could lead to an inaccurate estimation of the number of SNPs with low minor allele frequencies. We genotyped 400 Japanese samples in order to estimate the number of SNPs available for genome-wide association studies in the Japanese population and to examine the performance of the current SNP Array 6.0 platform and the genotype calling algorithm "Birdseed". Results About 20% of the 909,622 SNP markers on the array were revealed to be monomorphic in the Japanese population. Consequently, 661,599 SNPs were available for genome-wide association studies in the Japanese population, after excluding the poorly behaving SNPs. The Birdseed algorithm accurately determined the genotype calls of each sample with a high overall call rate of over 99.5% and a high concordance rate of over 99.8% using more than 48 samples after removing low-quality samples by adjusting QC criteria. Conclusion Our results confirmed that the SNP Array 6.0 platform reached the level reported by the manufacturer, and thus genome-wide association studies using the SNP Array 6.0 platform have considerable potential to identify candidate susceptibility or resistance genetic factors for multifactorial diseases in the Japanese population, as well as in other populations.

  15. Genome-wide association study for semen volume and total number of sperm in Holstein-Friesian bulls.

    Science.gov (United States)

    Hering, D M; Oleński, K; Ruść, A; Kaminski, S

    2014-12-30

    In artificial insemination industry bulls producing high volume of semen with relatively high concentration of sperm are very desirable since they ensure stable production of commercial straws especially in case of top bulls. The aim of the study was to screen the entire bull genome to identify markers and candidate genes underlying semen volume (SV) and total number of sperm (TNS) in ejaculate produced by Holstein-Friesian bulls. Data on semen production were retrieved from records of AI center and included a population of 877 Holstein-Friesian bulls. Each bull was genotyped using the Illumina BovineSNP50 BeadChip. Genome-wide association analysis was performed with the use of GoldenHelix SVS7 software. An additive model for Linear Regression Analysis was used to estimate the effect of SNP marker for SV and TNS. After Bonferroni correction, 3 markers located on chromosome 22 reached the highest significance (rs41625599, rs41584616, rs42012507) for both traits. In the vicinity of these significant markers 3 genes are located (DCP1A, SFMBT1, TMEM110). Moreover, marker rs110109069 located on chromosome 25 was significantly associated with TNS and marker rs42438348 located on chromosome 10 has been found to be associated with SV. Some additional candidate genes were suggested to be potentially involved in analyzed traits (GALC, PRKCD, PHF7, TLR9, SPATA7). Identifying SNPs associated with the lower total number of sperm may be very useful for early recognition of a young sire as less suitable for effective semen production in artificial insemination centers.

  16. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits.

    Science.gov (United States)

    Biazzi, Elisa; Nazzicari, Nelson; Pecetti, Luciano; Brummer, E Charles; Palmonari, Alberto; Tava, Aldo; Annicchiarico, Paolo

    2017-01-01

    Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3-0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits

  17. Genome-Wide Analysis of Simple Sequence Repeats and Efficient Development of Polymorphic SSR Markers Based on Whole Genome Re-Sequencing of Multiple Isolates of the Wheat Stripe Rust Fungus.

    Directory of Open Access Journals (Sweden)

    Huaiyong Luo

    Full Text Available The biotrophic parasitic fungus Puccinia striiformis f. sp. tritici (Pst causes stripe rust, a devastating disease of wheat, endangering global food security. Because the Pst population is highly dynamic, it is difficult to develop wheat cultivars with durable and highly effective resistance. Simple sequence repeats (SSRs are widely used as molecular markers in genetic studies to determine population structure in many organisms. However, only a small number of SSR markers have been developed for Pst. In this study, a total of 4,792 SSR loci were identified using the whole genome sequences of six isolates from different regions of the world, with a marker density of one SSR per 22.95 kb. The majority of the SSRs were di- and tri-nucleotide repeats. A database containing 1,113 SSR markers were established. Through in silico comparison, the previously reported SSR markers were found mainly in exons, whereas the SSR markers in the database were mostly in intergenic regions. Furthermore, 105 polymorphic SSR markers were confirmed in silico by their identical positions and nucleotide variations with INDELs identified among the six isolates. When 104 in silico polymorphic SSR markers were used to genotype 21 Pst isolates, 84 produced the target bands, and 82 of them were polymorphic and revealed the genetic relationships among the isolates. The results show that whole genome re-sequencing of multiple isolates provides an ideal resource for developing SSR markers, and the newly developed SSR markers are useful for genetic and population studies of the wheat stripe rust fungus.

  18. Exploring germplasm diversity to understand the domestication process in Cicer spp. using SNP and DArT markers.

    Directory of Open Access Journals (Sweden)

    Manish Roorkiwal

    Full Text Available To estimate genetic diversity within and between 10 interfertile Cicer species (94 genotypes from the primary, secondary and tertiary gene pool, we analysed 5,257 DArT markers and 651 KASPar SNP markers. Based on successful allele calling in the tertiary gene pool, 2,763 DArT and 624 SNP markers that are polymorphic between genotypes from the gene pools were analyzed further. STRUCTURE analyses were consistent with 3 cultivated populations, representing kabuli, desi and pea-shaped seed types, with substantial admixture among these groups, while two wild populations were observed using DArT markers. AMOVA was used to partition variance among hierarchical sets of landraces and wild species at both the geographical and species level, with 61% of the variation found between species, and 39% within species. Molecular variance among the wild species was high (39% compared to the variation present in cultivated material (10%. Observed heterozygosity was higher in wild species than the cultivated species for each linkage group. Our results support the Fertile Crescent both as the center of domestication and diversification of chickpea. The collection used in the present study covers all the three regions of historical chickpea cultivation, with the highest diversity in the Fertile Crescent region. Shared alleles between different gene pools suggest the possibility of gene flow among these species or incomplete lineage sorting and could indicate complicated patterns of divergence and fusion of wild chickpea taxa in the past.

  19. Genome wide association studies for body conformation traits in the Chinese Holstein cattle population

    DEFF Research Database (Denmark)

    Wu, Xiaoping; Fang, Ming; Liu, Lin;

    2013-01-01

    Background: Genome-wide association study (GWAS) is a powerful tool for revealing the genetic basis of quantitative traits. However, studies using GWAS for conformation traits of cattle is comparatively less. This study aims to use GWAS to find the candidates genes for body conformation traits.......Results: The Illumina BovineSNP50 BeadChip was used to identify single nucleotide polymorphisms (SNPs) that are associated with body conformation traits. A least absolute shrinkage and selection operator (LASSO) was applied to detect multiple SNPs simultaneously for 29 body conformation traits with 1,314 Chinese...... Holstein cattle and 52,166 SNPs. Totally, 59 genome-wide significant SNPs associated with 26 conformation traits were detected by genome-wide association analysis; five SNPs were within previously reported QTL regions (Animal Quantitative Trait Loci (QTL) database) and 11 were very close to the reported...

  20. [New SNP markers of the honeybee vitellogenin gene (Vg) used for identification of subspecies Apis mellifera mellifera L].

    Science.gov (United States)

    Ilyasov, R A; Poskryakov, A V; Nikolenko, A G

    2015-02-01

    Preservation of the gene pool of honeybee subspecies Apis mellifera mellifera is of vital importance for successful beekeeping development in the northern regions of Eurasia. An effective method of genotyping honeybee colonies used in modern science is the mapping of sites of single nucleotide polymorphism (SNP). The honeybee vitellogenin gene (Vg) encodes a protein that affects reproductive function, behavior, immunity, longevity, and social organization in the honeybee Apis mellifera and is therefore a topical research subject. The results of comparative analysis of honeybee Vg sequences show that there are 26 SNP sites that differentiate M and C evolutionary branches and can be used as markers in selective breeding, DNA-barcoding, and the creation of genetic passports for A. m. mellifera colonies.

  1. Nuclear species-diagnostic SNP markers mined from 454 amplicon sequencing reveal admixture genomic structure of modern citrus varieties.

    Science.gov (United States)

    Curk, Franck; Ancillo, Gema; Ollitrault, Frédérique; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Garcia-Lor, Andres; Navarro, Luis; Ollitrault, Patrick

    2015-01-01

    Most cultivated Citrus species originated from interspecific hybridisation between four ancestral taxa (C. reticulata, C. maxima, C. medica, and C. micrantha) with limited further interspecific recombination due to vegetative propagation. This evolution resulted in admixture genomes with frequent interspecific heterozygosity. Moreover, a major part of the phenotypic diversity of edible citrus results from the initial differentiation between these taxa. Deciphering the phylogenomic structure of citrus germplasm is therefore essential for an efficient utilization of citrus biodiversity in breeding schemes. The objective of this work was to develop a set of species-diagnostic single nucleotide polymorphism (SNP) markers for the four Citrus ancestral taxa covering the nine chromosomes, and to use these markers to infer the phylogenomic structure of secondary species and modern cultivars. Species-diagnostic SNPs were mined from 454 amplicon sequencing of 57 gene fragments from 26 genotypes of the four basic taxa. Of the 1,053 SNPs mined from 28,507 kb sequence, 273 were found to be highly diagnostic for a single basic taxon. Species-diagnostic SNP markers (105) were used to analyse the admixture structure of varieties and rootstocks. This revealed C. maxima introgressions in most of the old and in all recent selections of mandarins, and suggested that C. reticulata × C. maxima reticulation and introgression processes were important in edible mandarin domestication. The large range of phylogenomic constitutions between C. reticulata and C. maxima revealed in mandarins, tangelos, tangors, sweet oranges, sour oranges, grapefruits, and orangelos is favourable for genetic association studies based on phylogenomic structures of the germplasm. Inferred admixture structures were in agreement with previous hypotheses regarding the origin of several secondary species and also revealed the probable origin of several acid citrus varieties. The developed species-diagnostic SNP

  2. A genome-wide scan for common alleles affecting risk for autism

    Science.gov (United States)

    Anney, Richard; Klei, Lambertus; Pinto, Dalila; Regan, Regina; Conroy, Judith; Magalhaes, Tiago R.; Correia, Catarina; Abrahams, Brett S.; Sykes, Nuala; Pagnamenta, Alistair T.; Almeida, Joana; Bacchelli, Elena; Bailey, Anthony J.; Baird, Gillian; Battaglia, Agatino; Berney, Tom; Bolshakova, Nadia; Bölte, Sven; Bolton, Patrick F.; Bourgeron, Thomas; Brennan, Sean; Brian, Jessica; Carson, Andrew R.; Casallo, Guillermo; Casey, Jillian; Chu, Su H.; Cochrane, Lynne; Corsello, Christina; Crawford, Emily L.; Crossett, Andrew; Dawson, Geraldine; de Jonge, Maretha; Delorme, Richard; Drmic, Irene; Duketis, Eftichia; Duque, Frederico; Estes, Annette; Farrar, Penny; Fernandez, Bridget A.; Folstein, Susan E.; Fombonne, Eric; Freitag, Christine M.; Gilbert, John; Gillberg, Christopher; Glessner, Joseph T.; Goldberg, Jeremy; Green, Jonathan; Guter, Stephen J.; Hakonarson, Hakon; Heron, Elizabeth A.; Hill, Matthew; Holt, Richard; Howe, Jennifer L.; Hughes, Gillian; Hus, Vanessa; Igliozzi, Roberta; Kim, Cecilia; Klauck, Sabine M.; Kolevzon, Alexander; Korvatska, Olena; Kustanovich, Vlad; Lajonchere, Clara M.; Lamb, Janine A.; Laskawiec, Magdalena; Leboyer, Marion; Le Couteur, Ann; Leventhal, Bennett L.; Lionel, Anath C.; Liu, Xiao-Qing; Lord, Catherine; Lotspeich, Linda; Lund, Sabata C.; Maestrini, Elena; Mahoney, William; Mantoulan, Carine; Marshall, Christian R.; McConachie, Helen; McDougle, Christopher J.; McGrath, Jane; McMahon, William M.; Melhem, Nadine M.; Merikangas, Alison; Migita, Ohsuke; Minshew, Nancy J.; Mirza, Ghazala K.; Munson, Jeff; Nelson, Stanley F.; Noakes, Carolyn; Noor, Abdul; Nygren, Gudrun; Oliveira, Guiomar; Papanikolaou, Katerina; Parr, Jeremy R.; Parrini, Barbara; Paton, Tara; Pickles, Andrew; Piven, Joseph; Posey, David J; Poustka, Annemarie; Poustka, Fritz; Prasad, Aparna; Ragoussis, Jiannis; Renshaw, Katy; Rickaby, Jessica; Roberts, Wendy; Roeder, Kathryn; Roge, Bernadette; Rutter, Michael L.; Bierut, Laura J.; Rice, John P.; Salt, Jeff; Sansom, Katherine; Sato, Daisuke; Segurado, Ricardo; Senman, Lili; Shah, Naisha; Sheffield, Val C.; Soorya, Latha; Sousa, Inês; Stoppioni, Vera; Strawbridge, Christina; Tancredi, Raffaella; Tansey, Katherine; Thiruvahindrapduram, Bhooma; Thompson, Ann P.; Thomson, Susanne; Tryfon, Ana; Tsiantis, John; Van Engeland, Herman; Vincent, John B.; Volkmar, Fred; Wallace, Simon; Wang, Kai; Wang, Zhouzhi; Wassink, Thomas H.; Wing, Kirsty; Wittemeyer, Kerstin; Wood, Shawn; Yaspan, Brian L.; Zurawiecki, Danielle; Zwaigenbaum, Lonnie; Betancur, Catalina; Buxbaum, Joseph D.; Cantor, Rita M.; Cook, Edwin H.; Coon, Hilary; Cuccaro, Michael L.; Gallagher, Louise; Geschwind, Daniel H.; Gill, Michael; Haines, Jonathan L.; Miller, Judith; Monaco, Anthony P.; Nurnberger, John I.; Paterson, Andrew D.; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Scherer, Stephen W.; Sutcliffe, James S.; Szatmari, Peter; Vicente, Astrid M.; Vieland, Veronica J.; Wijsman, Ellen M.; Devlin, Bernie; Ennis, Sean; Hallmayer, Joachim

    2010-01-01

    Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10−8. When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10−8 threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C. PMID:20663923

  3. A genome wide association study of pulmonary tuberculosis susceptibility in Indonesians

    Directory of Open Access Journals (Sweden)

    Png Eileen

    2012-01-01

    Full Text Available Abstract Background There is reason to expect strong genetic influences on the risk of developing active pulmonary tuberculosis (TB among latently infected individuals. Many of the genome wide linkage and association studies (GWAS to date have been conducted on African populations. In order to identify additional targets in genetically dissimilar populations, and to enhance our understanding of this disease, we performed a multi-stage GWAS in a Southeast Asian cohort from Indonesia. Methods In stage 1, we used the Affymetrix 100 K SNP GeneChip marker set to genotype 259 Indonesian samples. After quality control filtering, 108 cases and 115 controls were analyzed for association of 95,207 SNPs. In stage 2, we attempted validation of 2,453 SNPs with promising associations from the first stage, in 1,189 individuals from the same Indonesian cohort, and finally in stage 3 we selected 251 SNPs from this stage to test TB association in an independent Caucasian cohort (n = 3,760 from Russia. Results Our study suggests evidence of association (P = 0.0004-0.0067 for 8 independent loci (nominal significance P JAG1, DYNLRB2, EBF1, TMEFF2, CCL17, HAUS6, PENK and TXNDC4. Conclusions Mechanisms of immune defense suggested by some of the identified genes exhibit biological plausibility and may suggest novel pathways involved in the host containment of infection with TB.

  4. A genome-wide scan for common alleles affecting risk for autism.

    Science.gov (United States)

    Anney, Richard; Klei, Lambertus; Pinto, Dalila; Regan, Regina; Conroy, Judith; Magalhaes, Tiago R; Correia, Catarina; Abrahams, Brett S; Sykes, Nuala; Pagnamenta, Alistair T; Almeida, Joana; Bacchelli, Elena; Bailey, Anthony J; Baird, Gillian; Battaglia, Agatino; Berney, Tom; Bolshakova, Nadia; Bölte, Sven; Bolton, Patrick F; Bourgeron, Thomas; Brennan, Sean; Brian, Jessica; Carson, Andrew R; Casallo, Guillermo; Casey, Jillian; Chu, Su H; Cochrane, Lynne; Corsello, Christina; Crawford, Emily L; Crossett, Andrew; Dawson, Geraldine; de Jonge, Maretha; Delorme, Richard; Drmic, Irene; Duketis, Eftichia; Duque, Frederico; Estes, Annette; Farrar, Penny; Fernandez, Bridget A; Folstein, Susan E; Fombonne, Eric; Freitag, Christine M; Gilbert, John; Gillberg, Christopher; Glessner, Joseph T; Goldberg, Jeremy; Green, Jonathan; Guter, Stephen J; Hakonarson, Hakon; Heron, Elizabeth A; Hill, Matthew; Holt, Richard; Howe, Jennifer L; Hughes, Gillian; Hus, Vanessa; Igliozzi, Roberta; Kim, Cecilia; Klauck, Sabine M; Kolevzon, Alexander; Korvatska, Olena; Kustanovich, Vlad; Lajonchere, Clara M; Lamb, Janine A; Laskawiec, Magdalena; Leboyer, Marion; Le Couteur, Ann; Leventhal, Bennett L; Lionel, Anath C; Liu, Xiao-Qing; Lord, Catherine; Lotspeich, Linda; Lund, Sabata C; Maestrini, Elena; Mahoney, William; Mantoulan, Carine; Marshall, Christian R; McConachie, Helen; McDougle, Christopher J; McGrath, Jane; McMahon, William M; Melhem, Nadine M; Merikangas, Alison; Migita, Ohsuke; Minshew, Nancy J; Mirza, Ghazala K; Munson, Jeff; Nelson, Stanley F; Noakes, Carolyn; Noor, Abdul; Nygren, Gudrun; Oliveira, Guiomar; Papanikolaou, Katerina; Parr, Jeremy R; Parrini, Barbara; Paton, Tara; Pickles, Andrew; Piven, Joseph; Posey, David J; Poustka, Annemarie; Poustka, Fritz; Prasad, Aparna; Ragoussis, Jiannis; Renshaw, Katy; Rickaby, Jessica; Roberts, Wendy; Roeder, Kathryn; Roge, Bernadette; Rutter, Michael L; Bierut, Laura J; Rice, John P; Salt, Jeff; Sansom, Katherine; Sato, Daisuke; Segurado, Ricardo; Senman, Lili; Shah, Naisha; Sheffield, Val C; Soorya, Latha; Sousa, Inês; Stoppioni, Vera; Strawbridge, Christina; Tancredi, Raffaella; Tansey, Katherine; Thiruvahindrapduram, Bhooma; Thompson, Ann P; Thomson, Susanne; Tryfon, Ana; Tsiantis, John; Van Engeland, Herman; Vincent, John B; Volkmar, Fred; Wallace, Simon; Wang, Kai; Wang, Zhouzhi; Wassink, Thomas H; Wing, Kirsty; Wittemeyer, Kerstin; Wood, Shawn; Yaspan, Brian L; Zurawiecki, Danielle; Zwaigenbaum, Lonnie; Betancur, Catalina; Buxbaum, Joseph D; Cantor, Rita M; Cook, Edwin H; Coon, Hilary; Cuccaro, Michael L; Gallagher, Louise; Geschwind, Daniel H; Gill, Michael; Haines, Jonathan L; Miller, Judith; Monaco, Anthony P; Nurnberger, John I; Paterson, Andrew D; Pericak-Vance, Margaret A; Schellenberg, Gerard D; Scherer, Stephen W; Sutcliffe, James S; Szatmari, Peter; Vicente, Astrid M; Vieland, Veronica J; Wijsman, Ellen M; Devlin, Bernie; Ennis, Sean; Hallmayer, Joachim

    2010-10-15

    Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10(-8). When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10(-8) threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C.

  5. A genome-wide scan for common alleles affecting risk for autism.

    LENUS (Irish Health Repository)

    Anney, Richard

    2010-10-15

    Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10(-8). When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner\\'s curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10(-8) threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C.

  6. Genome-wide association study identifies SESTD1 as a novel risk gene for lithium-responsive bipolar disorder.

    Science.gov (United States)

    Song, J; Bergen, S E; Di Florio, A; Karlsson, R; Charney, A; Ruderfer, D M; Stahl, E A; Chambert, K D; Moran, J L; Gordon-Smith, K; Forty, L; Green, E K; Jones, I; Jones, L; Scolnick, E M; Sklar, P; Smoller, J W; Lichtenstein, P; Hultman, C; Craddock, N; Landén, M; Smoller, Jordan W; Perlis, Roy H; Lee, Phil Hyoun; Castro, Victor M; Hoffnagle, Alison G; Sklar, Pamela; Stahl, Eli A; Purcell, Shaun M; Ruderfer, Douglas M; Charney, Alexander W; Roussos, Panos; Michele Pato, Carlos Pato; Medeiros, Helen; Sobel, Janet; Craddock, Nick; Jones, Ian; Forty, Liz; Florio, Arianna Di; Green, Elaine; Jones, Lisa; Gordon-Smith, Katherine; Landen, Mikael; Hultman, Christina; Jureus, Anders; Bergen, Sarah; McCarroll, Steven; Moran, Jennifer; Smoller, Jordan W; Chambert, Kimberly; Belliveau, Richard A

    2016-09-01

    Lithium is the mainstay prophylactic treatment for bipolar disorder (BD), but treatment response varies considerably across individuals. Patients who respond well to lithium treatment might represent a relatively homogeneous subtype of this genetically and phenotypically diverse disorder. Here, we performed genome-wide association studies (GWAS) to identify (i) specific genetic variations influencing lithium response and (ii) genetic variants associated with risk for lithium-responsive BD. Patients with BD and controls were recruited from Sweden and the United Kingdom. GWAS were performed on 2698 patients with subjectively defined (self-reported) lithium response and 1176 patients with objectively defined (clinically documented) lithium response. We next conducted GWAS comparing lithium responders with healthy controls (1639 subjective responders and 8899 controls; 323 objective responders and 6684 controls). Meta-analyses of Swedish and UK results revealed no significant associations with lithium response within the bipolar subjects. However, when comparing lithium-responsive patients with controls, two imputed markers attained genome-wide significant associations, among which one was validated in confirmatory genotyping (rs116323614, P=2.74 × 10(-8)). It is an intronic single-nucleotide polymorphism (SNP) on chromosome 2q31.2 in the gene SEC14 and spectrin domains 1 (SESTD1), which encodes a protein involved in regulation of phospholipids. Phospholipids have been strongly implicated as lithium treatment targets. Furthermore, we estimated the proportion of variance for lithium-responsive BD explained by common variants ('SNP heritability') as 0.25 and 0.29 using two definitions of lithium response. Our results revealed a genetic variant in SESTD1 associated with risk for lithium-responsive BD, suggesting that the understanding of BD etiology could be furthered by focusing on this subtype of BD.

  7. Genome-wide association study (GWAS for growth rate and age at sexual maturation in Atlantic salmon (Salmo salar.

    Directory of Open Access Journals (Sweden)

    Alejandro P Gutierrez

    Full Text Available Early sexual maturation is considered a serious drawback for Atlantic salmon aquaculture as it retards growth, increases production times and affects flesh quality. Although both growth and sexual maturation are thought to be complex processes controlled by several genetic and environmental factors, selection for these traits has been continuously accomplished since the beginning of Atlantic salmon selective breeding programs. In this genome-wide association study (GWAS we used a 6.5K single-nucleotide polymorphism (SNP array to genotype ∼ 480 individuals from the Cermaq Canada broodstock program and search for SNPs associated with growth and age at sexual maturation. Using a mixed model approach we identified markers showing a significant association with growth, grilsing (early sexual maturation and late sexual maturation. The most significant associations were found for grilsing, with markers located in Ssa10, Ssa02, Ssa13, Ssa25 and Ssa12, and for late maturation with markers located in Ssa28, Ssa01 and Ssa21. A lower level of association was detected with growth on Ssa13. Candidate genes, which were linked to these genetic markers, were identified and some of them show a direct relationship with developmental processes, especially for those in association with sexual maturation. However, the relatively low power to detect genetic markers associated with growth (days to 5 kg in this GWAS indicates the need to use a higher density SNP array in order to overcome the low levels of linkage disequilibrium observed in Atlantic salmon before the information can be incorporated into a selective breeding program.

  8. Profiling genome-wide DNA methylation.

    Science.gov (United States)

    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.

  9. A genome-wide association scan in pig identifies novel regions associated with feed efficiency trait

    DEFF Research Database (Denmark)

    Sahana, Goutam; Kadlecová, Veronika; Hornshøj, Henrik;

    2013-01-01

    Feed conversion ratio (FCR) is an economically important trait in pigs and feed accounts for a significant proportion of the costs involved in pig production. In this study we used a high density SNP chip panel, Porcine SNP60 BeadChip, to identify association between FCR and SNP markers and to st...

  10. Assessment of microsatellite and SNP markers for parentage assignment in ex situ African Penguin (Spheniscus demersus) populations.

    Science.gov (United States)

    Labuschagne, Christiaan; Nupen, Lisa; Kotzé, Antoinette; Grobler, Paul J; Dalton, Desiré L

    2015-10-01

    Captive management of ex situ populations of endangered species is traditionally based on pedigree information derived from studbook data. However, molecular methods could provide a powerful set of complementary tools to verify studbook records and also contribute to improving the understanding of the genetic status of captive populations. Here, we compare the utility of single nucleotide polymorphisms (SNPs) and microsatellites (MS) and two analytical methods for assigning parentage in ten families of captive African penguins held in South African facilities. We found that SNPs performed better than microsatellites under both analytical frameworks, but a combination of all markers was most informative. A subset of combined SNP (n = 14) and MS loci (n = 10) provided robust assessments of parentage. Captive or supportive breeding programs will play an important role in future African penguin conservation efforts as a source of individuals for reintroduction. Cooperation among these captive facilities is essential to facilitate this process and improve management. This study provided us with a useful set of SNP and MS markers for parentage and relatedness testing among these captive populations. Further assessment of the utility of these markers over multiple (>3) generations and the incorporation of a larger variety of relationships among individuals (e.g., half-siblings or cousins) is strongly suggested.

  11. Meta-analysis of genome-wide association studies identifies ten loci influencing allergic sensitization

    DEFF Research Database (Denmark)

    Bønnelykke, Klaus; Matheson, Melanie C; Pers, Tune Hannes

    2013-01-01

    the top SNP at each of 26 loci in 6,114 affected individuals and 9,920 controls. We increased the number of susceptibility loci with genome-wide significant association with allergic sensitization from three to ten, including SNPs in or near TLR6, C11orf30, STAT6, SLC25A46, HLA-DQB1, IL1RL1, LPP, MYC, IL2...

  12. Cloud computing for detecting high-order genome-wide epistatic interaction via dynamic clustering

    OpenAIRE

    Guo, Xuan; Meng, Yu; Yu, Ning; Pan, Yi

    2014-01-01

    Backgroud Taking the advan tage of high-throughput single nucleotide polymorphism (SNP) genotyping technology, large genome-wide association studies (GWASs) have been considered to hold promise for unravelling complex relationships between genotype and phenotype. At present, traditional single-locus-based methods are insufficient to detect interactions consisting of multiple-locus, which are broadly existing in complex traits. In addition, statistic tests for high order epistatic interactions...

  13. SNP Markers Discovery in Soybean with Use of Degenerate Oligolucleotide Primed PCR

    Institute of Scientific and Technical Information of China (English)

    A. Janiak; M.Y. Kim; S.H. Lee

    2007-01-01

    @@ There are several strategies that can be applied in SNP discovery, as for example the locus-specific amplification of target genome regions (Primmer et al., 2002; Van et al., 2004) or simultaneous assembly of anonymous sequences which are the product of whole genome shotgun sequencing (Webber and Myers, 1997) or reduced representation shotgun sequencing (Altshuler et al., 2000).

  14. 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

  15. 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.

  16. Genome-wide Association Study to Identify Quantitative Trait Loci for Meat and Carcass Quality Traits in Berkshire

    Directory of Open Access Journals (Sweden)

    Asif Iqbal

    2015-11-01

    Full Text Available Meat and carcass quality attributes are of crucial importance influencing consumer preference and profitability in the pork industry. A set of 400 Berkshire pigs were collected from Dasan breeding farm, Namwon, Chonbuk province, Korea that were born between 2012 and 2013. To perform genome wide association studies (GWAS, eleven meat and carcass quality traits were considered, including carcass weight, backfat thickness, pH value after 24 hours (pH24, Commission Internationale de l’Eclairage lightness in meat color (CIE L, redness in meat color (CIE a, yellowness in meat color (CIE b, filtering, drip loss, heat loss, shear force and marbling score. All of the 400 animals were genotyped with the Porcine 62K SNP BeadChips (Illumina Inc., USA. A SAS general linear model procedure (SAS version 9.2 was used to pre-adjust the animal phenotypes before GWAS with sire and sex effects as fixed effects and slaughter age as a covariate. After fitting the fixed and covariate factors in the model, the residuals of the phenotype regressed on additive effects of each single nucleotide polymorphism (SNP under a linear regression model (PLINK version 1.07. The significant SNPs after permutation testing at a chromosome-wise level were subjected to stepwise regression analysis to determine the best set of SNP markers. A total of 55 significant (p<0.05 SNPs or quantitative trait loci (QTL were detected on various chromosomes. The QTLs explained from 5.06% to 8.28% of the total phenotypic variation of the traits. Some QTLs with pleiotropic effect were also identified. A pair of significant QTL for pH24 was also found to affect both CIE L and drip loss percentage. The significant QTL after characterization of the functional candidate genes on the QTL or around the QTL region may be effectively and efficiently used in marker assisted selection to achieve enhanced genetic improvement of the trait considered.

  17. A genome-wide association analysis implicates SOX6 as a candidate gene for wrist bone mass

    Institute of Scientific and Technical Information of China (English)

    Shawn; LEVY

    2010-01-01

    Osteoporosis is a highly heritable common bone disease leading to fractures that severely impair the life quality of patients.Wrist fractures caused by osteoporosis are largely due to the scarcity of wrist bone mass.Here we report the results of a genome-wide association study (GWAS) of wrist bone mineral density (BMD).We examined ~500000 SNP markers in 1000 unrelated homogeneous Caucasian subjects and found a novel allelic association with wrist BMD at rs11023787 in the SOX6 (SRY (sex determining region Y)-box 6) gene (P=9.00×10-5).Subjects carrying the C allele of rs11023787 in SOX6 had significantly higher mean wrist BMD values than those with the T allele (0.485:0.462 g cm-2 for C allele vs.T allele carriers).For validation,we performed SOX6 association for BMD in an independent Chinese sample and found that SNP rs11023787 was significantly associated with wrist BMD in the Chinese sample (P=6.41×10-3).Meta-analyses of the GWAS scan and the replication studies yielded P-values of 5.20×10-6 for rs11023787.Results of this study,together with the functional relevance of SOX6 in cartilage formation,support the SOX6 gene as an important gene for BMD variation.

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

    Directory of Open Access Journals (Sweden)

    Koepke Tyson

    2012-01-01

    Full Text Available Abstract Background Sweet cherry (Prunus avium L., a non-model crop with narrow genetic diversity, is an important member of sub-family Amygdoloideae within Rosaceae. Compared to other important members like peach and apple, sweet cherry lacks in genetic and genomic information, impeding understanding of important biological processes and development of efficient breeding approaches. Availability of single nucleotide polymorphism (SNP-based molecular markers can greatly benefit breeding efforts in such non-model species. RNA-seq approaches employing second generation sequencing platforms offer a unique avenue to rapidly identify gene-based SNPs. Additionally, haplotype markers can be rapidly generated from transcript-based SNPs since they have been found to be extremely utile in identification of genetic variants related to health, disease and response to environment as highlighted by the human HapMap project. Results RNA-seq was performed on two sweet cherry cultivars, Bing and Rainier using a 3' untranslated region (UTR sequencing method yielding 43,396 assembled contigs. In order to test our approach of rapid identification of SNPs without any reference genome information, over 25% (10,100 of the contigs were screened for the SNPs. A total of 207 contigs from this set were identified to contain high quality SNPs. A set of 223 primer pairs were designed to amplify SNP containing regions from these contigs and high resolution melting (HRM analysis was performed with eight important parental sweet cherry cultivars. Six of the parent cultivars were distantly related to Bing and Rainier, the cultivars used for initial SNP discovery. Further, HRM analysis was also performed on 13 seedlings derived from a cross between two of the parents. Our analysis resulted in the identification of 84 (38.7% primer sets that demonstrated variation among the tested germplasm. Reassembly of the raw 3'UTR sequences using upgraded transcriptome assembly software

  19. 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.

  20. De novo assembly and transcriptome analysis of the rubber tree (Hevea brasiliensis and SNP markers development for rubber biosynthesis pathways.

    Directory of Open Access Journals (Sweden)

    Camila Campos Mantello

    Full Text Available Hevea brasiliensis (Willd. Ex Adr. Juss. Muell.-Arg. is the primary source of natural rubber that is native to the Amazon rainforest. The singular properties of natural rubber make it superior to and competitive with synthetic rubber for use in several applications. Here, we performed RNA sequencing (RNA-seq of H. brasiliensis bark on the Illumina GAIIx platform, which generated 179,326,804 raw reads on the Illumina GAIIx platform. A total of 50,384 contigs that were over 400 bp in size were obtained and subjected to further analyses. A similarity search against the non-redundant (nr protein database returned 32,018 (63% positive BLASTx hits. The transcriptome analysis was annotated using the clusters of orthologous groups (COG, gene ontology (GO, Kyoto Encyclopedia of Genes and Genomes (KEGG, and Pfam databases. A search for putative molecular marker was performed to identify simple sequence repeats (SSRs and single nucleotide polymorphisms (SNPs. In total, 17,927 SSRs and 404,114 SNPs were detected. Finally, we selected sequences that were identified as belonging to the mevalonate (MVA and 2-C-methyl-D-erythritol 4-phosphate (MEP pathways, which are involved in rubber biosynthesis, to validate the SNP markers. A total of 78 SNPs were validated in 36 genotypes of H. brasiliensis. This new dataset represents a powerful information source for rubber tree bark genes and will be an important tool for the development of microsatellites and SNP markers for use in future genetic analyses such as genetic linkage mapping, quantitative trait loci identification, investigations of linkage disequilibrium and marker-assisted selection.

  1. De novo assembly and transcriptome analysis of the rubber tree (Hevea brasiliensis) and SNP markers development for rubber biosynthesis pathways.

    Science.gov (United States)

    Mantello, Camila Campos; Cardoso-Silva, Claudio Benicio; da Silva, Carla Cristina; de Souza, Livia Moura; Scaloppi Junior, Erivaldo José; de Souza Gonçalves, Paulo; Vicentini, Renato; de Souza, Anete Pereira

    2014-01-01

    Hevea brasiliensis (Willd. Ex Adr. Juss.) Muell.-Arg. is the primary source of natural rubber that is native to the Amazon rainforest. The singular properties of natural rubber make it superior to and competitive with synthetic rubber for use in several applications. Here, we performed RNA sequencing (RNA-seq) of H. brasiliensis bark on the Illumina GAIIx platform, which generated 179,326,804 raw reads on the Illumina GAIIx platform. A total of 50,384 contigs that were over 400 bp in size were obtained and subjected to further analyses. A similarity search against the non-redundant (nr) protein database returned 32,018 (63%) positive BLASTx hits. The transcriptome analysis was annotated using the clusters of orthologous groups (COG), gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Pfam databases. A search for putative molecular marker was performed to identify simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). In total, 17,927 SSRs and 404,114 SNPs were detected. Finally, we selected sequences that were identified as belonging to the mevalonate (MVA) and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathways, which are involved in rubber biosynthesis, to validate the SNP markers. A total of 78 SNPs were validated in 36 genotypes of H. brasiliensis. This new dataset represents a powerful information source for rubber tree bark genes and will be an important tool for the development of microsatellites and SNP markers for use in future genetic analyses such as genetic linkage mapping, quantitative trait loci identification, investigations of linkage disequilibrium and marker-assisted selection.

  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. Genome-wide association study identifies a common variant in RAD51B associated with male breast cancer risk

    DEFF Research Database (Denmark)

    Orr, Nick; Lemnrau, Alina; Cooke, Rosie

    2012-01-01

    We conducted a genome-wide association study of male breast cancer comprising 823 cases and 2,795 controls of European ancestry, with validation in independent sample sets totaling 438 cases and 474 controls. A SNP in RAD51B at 14q24.1 was significantly associated with male breast cancer risk (P...

  4. Genome-wide meta-analyses of smoking behaviors in African Americans.

    Science.gov (United States)

    David, S P; Hamidovic, A; Chen, G K; Bergen, A W; Wessel, J; Kasberger, J L; Brown, W M; Petruzella, S; Thacker, E L; Kim, Y; Nalls, M A; Tranah, G J; Sung, Y J; Ambrosone, C B; Arnett, D; Bandera, E V; Becker, D M; Becker, L; Berndt, S I; Bernstein, L; Blot, W J; Broeckel, U; Buxbaum, S G; Caporaso, N; Casey, G; Chanock, S J; Deming, S L; Diver, W R; Eaton, C B; Evans, D S; Evans, M K; Fornage, M; Franceschini, N; Harris, T B; Henderson, B E; Hernandez, D G; Hitsman, B; Hu, J J; Hunt, S C; Ingles, S A; John, E M; Kittles, R; Kolb, S; Kolonel, L N; Le Marchand, L; Liu, Y; Lohman, K K; McKnight, B; Millikan, R C; Murphy, A; Neslund-Dudas, C; Nyante, S; Press, M; Psaty, B M; Rao, D C; Redline, S; Rodriguez-Gil, J L; Rybicki, B A; Signorello, L B; Singleton, A B; Smoller, J; Snively, B; Spring, B; Stanford, J L; Strom, S S; Swan, G E; Taylor, K D; Thun, M J; Wilson, A F; Witte, J S; Yamamura, Y; Yanek, L R; Yu, K; Zheng, W; Ziegler, R G; Zonderman, A B; Jorgenson, E; Haiman, C A; Furberg, H

    2012-05-22

    The identification and exploration of genetic loci that influence smoking behaviors have been conducted primarily in populations of the European ancestry. Here we report results of the first genome-wide association study meta-analysis of smoking behavior in African Americans in the Study of Tobacco in Minority Populations Genetics Consortium (n = 32,389). We identified one non-coding single-nucleotide polymorphism (SNP; rs2036527[A]) on chromosome 15q25.1 associated with smoking quantity (cigarettes per day), which exceeded genome-wide significance (β = 0.040, s.e. = 0.007, P = 1.84 × 10(-8)). This variant is present in the 5'-distal enhancer region of the CHRNA5 gene and defines the primary index signal reported in studies of the European ancestry. No other SNP reached genome-wide significance for smoking initiation (SI, ever vs never smoking), age of SI, or smoking cessation (SC, former vs current smoking). Informative associations that approached genome-wide significance included three modestly correlated variants, at 15q25.1 within PSMA4, CHRNA5 and CHRNA3 for smoking quantity, which are associated with a second signal previously reported in studies in European ancestry populations, and a signal represented by three SNPs in the SPOCK2 gene on chr10q22.1. The association at 15q25.1 confirms this region as an important susceptibility locus for smoking quantity in men and women of African ancestry. Larger studies will be needed to validate the suggestive loci that did not reach genome-wide significance and further elucidate the contribution of genetic variation to disparities in cigarette consumption, SC and smoking-attributable disease between African Americans and European Americans.

  5. Susceptibility to Chronic Mucus Hypersecretion, a Genome Wide Association Study

    Science.gov (United States)

    Dijkstra, Akkelies E.; Smolonska, Joanna; van den Berge, Maarten; Wijmenga, Ciska; Zanen, Pieter; Luinge, Marjan A.; Platteel, Mathieu; Lammers, Jan-Willem; Dahlback, Magnus; Tosh, Kerrie; Hiemstra, Pieter S.; Sterk, Peter J.; Spira, Avi; Vestbo, Jorgen; Nordestgaard, Borge G.; Benn, Marianne; Nielsen, Sune F.; Dahl, Morten; Verschuren, W. Monique; Picavet, H. Susan J.; Smit, Henriette A.; Owsijewitsch, Michael; Kauczor, Hans U.; de Koning, Harry J.; Nizankowska-Mogilnicka, Eva; Mejza, Filip; Nastalek, Pawel; van Diemen, Cleo C.; Cho, Michael H.; Silverman, Edwin K.; Crapo, James D.; Beaty, Terri H.; Lomas, David A.; Bakke, Per; Gulsvik, Amund; Bossé, Yohan; Obeidat, M. A.; Loth, Daan W.; Lahousse, Lies; Rivadeneira, Fernando; Uitterlinden, Andre G.; Hofman, Andre; Stricker, Bruno H.; Brusselle, Guy G.; van Duijn, Cornelia M.; Brouwer, Uilke; Koppelman, Gerard H.; Vonk, Judith M.; Nawijn, Martijn C.; Groen, Harry J. M.; Timens, Wim; Boezen, H. Marike; Postma, Dirkje S.

    2014-01-01

    Background Chronic mucus hypersecretion (CMH) is associated with an increased frequency of respiratory infections, excess lung function decline, and increased hospitalisation and mortality rates in the general population. It is associated with smoking, but it is unknown why only a minority of smokers develops CMH. A plausible explanation for this phenomenon is a predisposing genetic constitution. Therefore, we performed a genome wide association (GWA) study of CMH in Caucasian populations. Methods GWA analysis was performed in the NELSON-study using the Illumina 610 array, followed by replication and meta-analysis in 11 additional cohorts. In total 2,704 subjects with, and 7,624 subjects without CMH were included, all current or former heavy smokers (≥20 pack-years). Additional studies were performed to test the functional relevance of the most significant single nucleotide polymorphism (SNP). Results A strong association with CMH, consistent across all cohorts, was observed with rs6577641 (p = 4.25×10−6, OR = 1.17), located in intron 9 of the special AT-rich sequence-binding protein 1 locus (SATB1) on chromosome 3. The risk allele (G) was associated with higher mRNA expression of SATB1 (4.3×10−9) in lung tissue. Presence of CMH was associated with increased SATB1 mRNA expression in bronchial biopsies from COPD patients. SATB1 expression was induced during differentiation of primary human bronchial epithelial cells in culture. Conclusions Our findings, that SNP rs6577641 is associated with CMH in multiple cohorts and is a cis-eQTL for SATB1, together with our additional observation that SATB1 expression increases during epithelial differentiation provide suggestive evidence that SATB1 is a gene that affects CMH. PMID:24714607

  6. Susceptibility to chronic mucus hypersecretion, a genome wide association study.

    Directory of Open Access Journals (Sweden)

    Akkelies E Dijkstra

    Full Text Available BACKGROUND: Chronic mucus hypersecretion (CMH is associated with an increased frequency of respiratory infections, excess lung function decline, and increased hospitalisation and mortality rates in the general population. It is associated with smoking, but it is unknown why only a minority of smokers develops CMH. A plausible explanation for this phenomenon is a predisposing genetic constitution. Therefore, we performed a genome wide association (GWA study of CMH in Caucasian populations. METHODS: GWA analysis was performed in the NELSON-study using the Illumina 610 array, followed by replication and meta-analysis in 11 additional cohorts. In total 2,704 subjects with, and 7,624 subjects without CMH were included, all current or former heavy smokers (≥20 pack-years. Additional studies were performed to test the functional relevance of the most significant single nucleotide polymorphism (SNP. RESULTS: A strong association with CMH, consistent across all cohorts, was observed with rs6577641 (p = 4.25×10(-6, OR = 1.17, located in intron 9 of the special AT-rich sequence-binding protein 1 locus (SATB1 on chromosome 3. The risk allele (G was associated with higher mRNA expression of SATB1 (4.3×10(-9 in lung tissue. Presence of CMH was associated with increased SATB1 mRNA expression in bronchial biopsies from COPD patients. SATB1 expression was induced during differentiation of primary human bronchial epithelial cells in culture. CONCLUSIONS: Our findings, that SNP rs6577641 is associated with CMH in multiple cohorts and is a cis-eQTL for SATB1, together with our additional observation that SATB1 expression increases during epithelial differentiation provide suggestive evidence that SATB1 is a gene that affects CMH.

  7. Genome-Wide Association Study of Schizophrenia in Japanese Population

    Science.gov (United States)

    Yamada, Kazuo; Iwayama, Yoshimi; Hattori, Eiji; Iwamoto, Kazuya; Toyota, Tomoko; Ohnishi, Tetsuo; Ohba, Hisako; Maekawa, Motoko; Kato, Tadafumi; Yoshikawa, Takeo

    2011-01-01

    Schizophrenia is a devastating neuropsychiatric disorder with genetically complex traits. Genetic variants should explain a considerable portion of the risk for schizophrenia, and genome-wide association study (GWAS) is a potentially powerful tool for identifying the risk variants that underlie the disease. Here, we report the results of a three-stage analysis of three independent cohorts consisting of a total of 2,535 samples from Japanese and Chinese populations for searching schizophrenia susceptibility genes using a GWAS approach. Firstly, we examined 115,770 single nucleotide polymorphisms (SNPs) in 120 patient-parents trio samples from Japanese schizophrenia pedigrees. In stage II, we evaluated 1,632 SNPs (1,159 SNPs of p<0.01 and 473 SNPs of p<0.05 that located in previously reported linkage regions). The second sample consisted of 1,012 case-control samples of Japanese origin. The most significant p value was obtained for the SNP in the ELAVL2 [(embryonic lethal, abnormal vision, Drosophila)-like 2] gene located on 9p21.3 (p = 0.00087). In stage III, we scrutinized the ELAVL2 gene by genotyping gene-centric tagSNPs in the third sample set of 293 family samples (1,163 individuals) of Chinese descent and the SNP in the gene showed a nominal association with schizophrenia in Chinese population (p = 0.026). The current data in Asian population would be helpful for deciphering ethnic diversity of schizophrenia etiology. PMID:21674006

  8. Genome-wide association study of schizophrenia in Japanese population.

    Directory of Open Access Journals (Sweden)

    Kazuo Yamada

    Full Text Available Schizophrenia is a devastating neuropsychiatric disorder with genetically complex traits. Genetic variants should explain a considerable portion of the risk for schizophrenia, and genome-wide association study (GWAS is a potentially powerful tool for identifying the risk variants that underlie the disease. Here, we report the results of a three-stage analysis of three independent cohorts consisting of a total of 2,535 samples from Japanese and Chinese populations for searching schizophrenia susceptibility genes using a GWAS approach. Firstly, we examined 115,770 single nucleotide polymorphisms (SNPs in 120 patient-parents trio samples from Japanese schizophrenia pedigrees. In stage II, we evaluated 1,632 SNPs (1,159 SNPs of p<0.01 and 473 SNPs of p<0.05 that located in previously reported linkage regions. The second sample consisted of 1,012 case-control samples of Japanese origin. The most significant p value was obtained for the SNP in the ELAVL2 [(embryonic lethal, abnormal vision, Drosophila-like 2] gene located on 9p21.3 (p = 0.00087. In stage III, we scrutinized the ELAVL2 gene by genotyping gene-centric tagSNPs in the third sample set of 293 family samples (1,163 individuals of Chinese descent and the SNP in the gene showed a nominal association with schizophrenia in Chinese population (p = 0.026. The current data in Asian population would be helpful for deciphering ethnic diversity of schizophrenia etiology.

  9. Evaluation of probabilistic and logical inference for a SNP annotation system.

    Science.gov (United States)

    Shen, Terry H; Tarczy-Hornoch, Peter; Detwiler, Landon T; Cadag, Eithon; Carlson, Christopher S

    2010-06-01

    Genome wide association studies (GWAS) are an important approach to understanding the genetic mechanisms behind human diseases. Single nucleotide polymorphisms (SNPs) are the predominant markers used in genome wide association studies, and the ability to predict which SNPs are likely to be functional is important for both a priori and a posteriori analyses of GWA studies. This article describes the design, implementation and evaluation of a family of systems for the purpose of identifying SNPs that may cause a change in phenotypic outcomes. The methods described in this article characterize the feasibility of combinations of logical and probabilistic inference with federated data integration for both point and regional SNP annotation and analysis. Evaluations of the methods demonstrate the overall strong predictive value of logical, and logical with probabilistic, inference applied to the domain of SNP annotation.

  10. A genome-wide association meta-analysis on apolipoprotein A-IV concentrations.

    Science.gov (United States)

    Lamina, Claudia; Friedel, Salome; Coassin, Stefan; Rueedi, Rico; Yousri, Noha A; Seppälä, Ilkka; Gieger, Christian; Schönherr, Sebastian; Forer, Lukas; Erhart, Gertraud; Kollerits, Barbara; Marques-Vidal, Pedro; Ried, Janina; Waeber, Gerard; Bergmann, Sven; Dähnhardt, Doreen; Stöckl, Andrea; Kiechl, Stefan; Raitakari, Olli T; Kähönen, Mika; Willeit, Johann; Kedenko, Ludmilla; Paulweber, Bernhard; Peters, Annette; Meitinger, Thomas; Strauch, Konstantin; Study Group, Kora; Lehtimäki, Terho; Hunt, Steven C; Vollenweider, Peter; Kronenberg, Florian

    2016-08-15

    Apolipoprotein A-IV (apoA-IV) is a major component of HDL and chylomicron particles and is involved in reverse cholesterol transport. It is an early marker of impaired renal function. We aimed to identify genetic loci associated with apoA-IV concentrations and to investigate relationships with known susceptibility loci for kidney function and lipids. A genome-wide association meta-analysis on apoA-IV concentrations was conducted in five population-based cohorts (n = 13,813) followed by two additional replication studies (n = 2,267) including approximately 10 M SNPs. Three independent SNPs from two genomic regions were significantly associated with apoA-IV concentrations: rs1729407 near APOA4 (P = 6.77 × 10 (-)  (44)), rs5104 in APOA4 (P = 1.79 × 10(-)(24)) and rs4241819 in KLKB1 (P = 5.6 × 10(-)(14)). Additionally, a look-up of the replicated SNPs in downloadable GWAS meta-analysis results was performed on kidney function (defined by eGFR), HDL-cholesterol and triglycerides. From these three SNPs mentioned above, only rs1729407 showed an association with HDL-cholesterol (P = 7.1 × 10 (-)  (07)). Moreover, weighted SNP-scores were built involving known susceptibility loci for the aforementioned traits (53, 70 and 38 SNPs, respectively) and were associated with apoA-IV concentrations. This analysis revealed a significant and an inverse association for kidney function with apoA-IV concentrations (P = 5.5 × 10(-)(05)). Furthermore, an increase of triglyceride-increasing alleles was found to decrease apoA-IV concentrations (P = 0.0078). In summary, we identified two independent SNPs located in or next the APOA4 gene and one SNP in KLKB1 The association of KLKB1 with apoA-IV suggests an involvement of apoA-IV in renal metabolism and/or an interaction within HDL particles. Analyses of SNP-scores indicate potential causal effects of kidney function and by lesser extent triglycerides on apoA-IV concentrations.

  11. Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMahon, Katherine D.; Malmstrom, Rex R.

    2014-06-18

    Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ‘ecotype model’ of diversification, but not previously observed in natural populations.

  12. Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMcahon, Katherine D.; Mamlstrom, Rex R.

    2014-05-12

    Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ecotype model? of diversification, but not previously observed in natural populations.

  13. Reducing dimensionality for prediction of genome-wide breeding values

    Directory of Open Access Journals (Sweden)

    Woolliams John A

    2009-03-01

    Full Text Available Abstract Partial least square regression (PLSR and principal component regression (PCR are methods designed for situations where the number of predictors is larger than the number of records. The aim was to compare the accuracy of genome-wide breeding values (EBV produced using PLSR and PCR with a Bayesian method, 'BayesB'. Marker densities of 1, 2, 4 and 8 Ne markers/Morgan were evaluated when the effective population size (Ne was 100. The correlation between true breeding value and estimated breeding value increased with density from 0.611 to 0.681 and 0.604 to 0.658 using PLSR and PCR respectively, with an overall advantage to PLSR of 0.016 (s.e = 0.008. Both methods gave a lower accuracy compared to the 'BayesB', for which accuracy increased from 0.690 to 0.860. PLSR and PCR appeared less responsive to increased marker density with the advantage of 'BayesB' increasing by 17% from a marker density of 1 to 8Ne/M. PCR and PLSR showed greater bias than 'BayesB' in predicting breeding values at all densities. Although, the PLSR and PCR were computationally faster and simpler, these advantages do not outweigh the reduction in accuracy, and there is a benefit in obtaining relevant prior information from the distribution of gene effects.

  14. Fine Mapping for Identification of Citrus Alternaria Brown Spot Candidate Resistance Genes and Development of New SNP Markers for Marker-Assisted Selection

    Science.gov (United States)

    Cuenca, Jose; Aleza, Pablo; Garcia-Lor, Andres; Ollitrault, Patrick; Navarro, Luis

    2016-01-01

    Alternaria brown spot (ABS) is a serious disease affecting susceptible citrus genotypes, which is a strong concern regarding citrus breeding programs. Resistance is conferred by a recessive locus (ABSr) previously located by our group within a 3.3 Mb genome region near the centromere in chromosome III. This work addresses fine-linkage mapping of this region for identifying candidate resistance genes and develops new molecular markers for ABS-resistance effective marker-assisted selection (MAS). Markers closely linked to ABSr locus were used for fine mapping using a 268-segregating diploid progeny derived from a heterozygous susceptible × resistant cross. Fine mapping limited the genomic region containing the ABSr resistance gene to 366 kb, flanked by markers at 0.4 and 0.7 cM. This region contains nine genes related to pathogen resistance. Among them, eight are resistance (R) gene homologs, with two of them harboring a serine/threonine protein kinase domain. These two genes along with a gene encoding a S-adenosyl-L-methionine-dependent-methyltransferase protein, should be considered as strong candidates for ABS-resistance. Moreover, the closest SNP was genotyped in 40 citrus varieties, revealing very high association with the resistant/susceptible phenotype. This new marker is currently used in our citrus breeding program for ABS-resistant parent and cultivar selection, at diploid, triploid and tetraploid level. PMID:28066498

  15. Candidate SNP Markers of Chronopathologies Are Predicted by a Significant Change in the Affinity of TATA-Binding Protein for Human Gene Promoters

    Directory of Open Access Journals (Sweden)

    Petr Ponomarenko

    2016-01-01

    Full Text Available Variations in human genome (e.g., single nucleotide polymorphisms, SNPs may be associated with hereditary diseases, their complications, comorbidities, and drug responses. Using Web service SNP_TATA_Comparator presented in our previous paper, here we analyzed immediate surroundings of known SNP markers of diseases and identified several candidate SNP markers that can significantly change the affinity of TATA-binding protein for human gene promoters, with circadian consequences. For example, rs572527200 may be related to asthma, where symptoms are circadian (worse at night, and rs367732974 may be associated with heart attacks that are characterized by a circadian preference (early morning. By the same method, we analyzed the 90 bp proximal promoter region of each protein-coding transcript of each human gene of the circadian clock core. This analysis yielded 53 candidate SNP markers, such as rs181985043 (susceptibility to acute Q fever in male patients, rs192518038 (higher risk of a heart attack in patients with diabetes, and rs374778785 (emphysema and lung cancer in smokers. If they are properly validated according to clinical standards, these candidate SNP markers may turn out to be useful for physicians (to select optimal treatment for each patient and for the general population (to choose a lifestyle preventing possible circadian complications of diseases.

  16. Interim report on updated microarray probes for the LLNL Burkholderia pseudomallei SNP array

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, S; Jaing, C

    2012-03-27

    The overall goal of this project is to forensically characterize 100 unknown Burkholderia isolates in the US-Australia collaboration. We will identify genome-wide single nucleotide polymorphisms (SNPs) from B. pseudomallei and near neighbor species including B. mallei, B. thailandensis and B. oklahomensis. We will design microarray probes to detect these SNP markers and analyze 100 Burkholderia genomic DNAs extracted from environmental, clinical and near neighbor isolates from Australian collaborators on the Burkholderia SNP microarray. We will analyze the microarray genotyping results to characterize the genetic diversity of these new isolates and triage the samples for whole genome sequencing. In this interim report, we described the SNP analysis and the microarray probe design for the Burkholderia SNP microarray.

  17. Integrating genome-wide genetic variations and monocyte expression data reveals trans-regulated gene modules in humans.

    Directory of Open Access Journals (Sweden)

    Maxime Rotival

    2011-12-01

    Full Text Available One major expectation from the transcriptome in humans is to characterize the biological basis of associations identified by genome-wide association studies. So far, few cis expression quantitative trait loci (eQTLs have been reliably related to disease susceptibility. Trans-regulating mechanisms may play a more prominent role in disease susceptibility. We analyzed 12,808 genes detected in at least 5% of circulating monocyte samples from a population-based sample of 1,490 European unrelated subjects. We applied a method of extraction of expression patterns-independent component analysis-to identify sets of co-regulated genes. These patterns were then related to 675,350 SNPs to identify major trans-acting regulators. We detected three genomic regions significantly associated with co-regulated gene modules. Association of these loci with multiple expression traits was replicated in Cardiogenics, an independent study in which expression profiles of monocytes were available in 758 subjects. The locus 12q13 (lead SNP rs11171739, previously identified as a type 1 diabetes locus, was associated with a pattern including two cis eQTLs, RPS26 and SUOX, and 5 trans eQTLs, one of which (MADCAM1 is a potential candidate for mediating T1D susceptibility. The locus 12q24 (lead SNP rs653178, which has demonstrated extensive disease pleiotropy, including type 1 diabetes, hypertension, and celiac disease, was associated to a pattern strongly correlating to blood pressure level. The strongest trans eQTL in this pattern was CRIP1, a known marker of cellular proliferation in cancer. The locus 12q15 (lead SNP rs11177644 was associated with a pattern driven by two cis eQTLs, LYZ and YEATS4, and including 34 trans eQTLs, several of them tumor-related genes. This study shows that a method exploiting the structure of co-expressions among genes can help identify genomic regions involved in trans regulation of sets of genes and can provide clues for understanding the

  18. Phylogeography and adaptation genetics of stickleback from the Haida Gwaii archipelago revealed using genome-wide single nucleotide polymorphism genotyping.

    Science.gov (United States)

    Deagle, Bruce E; Jones, Felicity C; Absher, Devin M; Kingsley, David M; Reimchen, Thomas E

    2013-04-01

    Threespine stickleback populations are model systems for studying adaptive evolution and the underlying genetics. In lakes on the Haida Gwaii archipelago (off western Canada), stickleback have undergone a remarkable local radiation and show phenotypic diversity matching that seen throughout the species distribution. To provide a historical context for this radiation, we surveyed genetic variation at >1000 single nucleotide polymorphism (SNP) loci in stickleback from over 100 populations. SNPs included markers evenly distributed throughout genome and candidate SNPs tagging adaptive genomic regions. Based on evenly distributed SNPs, the phylogeographic pattern differs substantially from the disjunct pattern previously observed between two highly divergent mtDNA lineages. The SNP tree instead shows extensive within watershed population clustering and different watersheds separated by short branches deep in the tree. These data are consistent with separate colonizations of most watersheds, despite underlying genetic connections between some independent drainages. This supports previous suppositions that morphological diversity observed between watersheds has been shaped independently, with populations exhibiting complete loss of lateral plates and giant size each occurring in several distinct clades. Throughout the archipelago, we see repeated selection of SNPs tagging candidate freshwater adaptive variants at several genomic regions differentiated between marine-freshwater populations on a global scale (e.g. EDA, Na/K ATPase). In estuarine sites, both marine and freshwater allelic variants were commonly detected. We also found typically marine alleles present in a few freshwater lakes, especially those with completely plated morphology. These results provide a general model for postglacial colonization of freshwater habitat by sticklebacks and illustrate the tremendous potential of genome-wide SNP data sets hold for resolving patterns and processes underlying recent

  19. Detection of genome-wide polymorphisms in the AT-rich Plasmodium falciparum genome using a high-density microarray

    Directory of Open Access Journals (Sweden)

    Huyen Yentram

    2008-08-01

    Full Text Available Abstract Background Genetic mapping is a powerful method to identify mutations that cause drug resistance and other phenotypic changes in the human malaria parasite Plasmodium falciparum. For efficient mapping of a target gene, it is often necessary to genotype a large number of polymorphic markers. Currently, a community effort is underway to collect single nucleotide polymorphisms (SNP from the parasite genome. Here we evaluate polymorphism detection accuracy of a high-density 'tiling' microarray with 2.56 million probes by comparing single feature polymorphisms (SFP calls from the microarray with known SNP among parasite isolates. Results We found that probe GC content, SNP position in a probe, probe coverage, and signal ratio cutoff values were important factors for accurate detection of SFP in the parasite genome. We established a set of SFP calling parameters that could predict mSFP (SFP called by multiple overlapping probes with high accuracy (≥ 94% and identified 121,087 mSFP genome-wide from five parasite isolates including 40,354 unique mSFP (excluding those from multi-gene families and ~18,000 new mSFP, producing a genetic map with an average of one unique mSFP per 570 bp. Genomic copy number variation (CNV among the parasites was also cataloged and compared. Conclusion A large number of mSFP were discovered from the P. falciparum genome using a high-density microarray, most of which were in clusters of highly polymorphic genes at chromosome ends. Our method for accurate mSFP detection and the mSFP identified will greatly facilitate large-scale studies of genome variation in the P. falciparum parasite and provide useful resources for mapping important parasite traits.

  20. Application of genome-wide single nucleotide polymorphism typing: simple association and beyond.

    Directory of Open Access Journals (Sweden)

    J Raphael Gibbs

    2006-10-01

    Full Text Available The International HapMap Project and the arrival of technologies that type more than 100,000 SNPs in a single experiment have made genome-wide single nucleotide polymorphism (GW-SNP assay a realistic endeavor. This has sparked considerable debate regarding the promise of GW-SNP typing to identify genetic association in disease. As has already been shown, this approach has the potential to localize common genetic variation underlying disease risk. The data provided from this technology also lends itself to several other lines of investigation; autozygosity mapping in consanguineous families and outbred populations, direct detection of structural variation, admixture analysis, and other population genetic approaches. In this review we will discuss the potential uses and practical application of GW-SNP typing including those above and beyond simple association testing.

  1. A Genome-Wide Scan for Breast Cancer Risk Haplotypes among African American Women

    Science.gov (United States)

    Song, Chi; Chen, Gary K.; Millikan, Robert C.; Ambrosone, Christine B.; John, Esther M.; Bernstein, Leslie; Zheng, Wei; Hu, Jennifer J.; Ziegler, Regina G.; Nyante, Sarah; Bandera, Elisa V.; Ingles, Sue A.; Press, Michael F.; Deming, Sandra L.; Rodriguez-Gil, Jorge L.; Chanock, Stephen J.; Wan, Peggy; Sheng, Xin; Pooler, Loreall C.; Van Den Berg, David J.; Le Marchand, Loic; Kolonel, Laurence N.; Henderson, Brian E.; Haiman, Chris A.; Stram, Daniel O.

    2013-01-01

    Genome-wide association studies (GWAS) simultaneously investigating hundreds of thousands of single nucleotide polymorphisms (SNP) have become a powerful tool in the investigation of new disease susceptibility loci. Haplotypes are sometimes thought to be superior to SNPs and are promising in genetic association analyses. The application of genome-wide haplotype analysis, however, is hindered by the complexity of haplotypes themselves and sophistication in computation. We systematically analyzed the haplotype effects for breast cancer risk among 5,761 African American women (3,016 cases and 2,745 controls) using a sliding window approach on the genome-wide scale. Three regions on chromosomes 1, 4 and 18 exhibited moderate haplotype effects. Furthermore, among 21 breast cancer susceptibility loci previously established in European populations, 10p15 and 14q24 are likely to harbor novel haplotype effects. We also proposed a heuristic of determining the significance level and the effective number of independent tests by the permutation analysis on chromosome 22 data. It suggests that the effective number was approximately half of the total (7,794 out of 15,645), thus the half number could serve as a quick reference to evaluating genome-wide significance if a similar sliding window approach of haplotype analysis is adopted in similar populations using similar genotype density. PMID:23468962

  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. Identification of Candidate Genes for Reactivity in Guzerat (Bos indicus) Cattle: A Genome-Wide Association Study

    Science.gov (United States)

    Fonseca, Pablo Augusto de Souza; Pires, Maria de Fátima Ávila; Ventura, Ricardo Vieira; Rosse, Izinara da Cruz.; Bruneli, Frank Angelo Tomita; Machado, Marco Antonio; Carvalho, Maria Raquel Santos

    2017-01-01

    Temperament is fundamental to animal production due to its direct influence on the animal-herdsman relationship. When compared to calm animals, the aggressive, anxious or fearful ones exhibit less weight gain, lower reproductive efficiency, decreased milk production and higher herd maintenance costs, all of which contribute to reduced profits. However, temperament is a trait that is complex and difficult to assess. Recently, a new quantitative system, REATEST®, for assessing reactivity, a phenotype of temperament, was developed. Herein, we describe the results of a Genome-wide association study for reactivity, assessed using REATEST® with a sample of 754 females from five dual-purpose (milk and meat production) Guzerat (Bos indicus) herds. Genotyping was performed using a 50k SNP chip and a two-step mixed model approach (Grammar-Gamma) with a one-by-one marker regression was used to identify QTLs. QTLs for reactivity were identified on chromosomes BTA1, BTA5, BTA14, and BTA25. Five intronic and two intergenic markers were significantly associated with reactivity. POU1F1, DRD3, VWA3A, ZBTB20, EPHA6, SNRPF and NTN4 were identified as candidate genes. Previous QTL reports for temperament traits, covering areas surrounding the SNPs/genes identified here, further corroborate these associations. The seven genes identified in the present study explain 20.5% of reactivity variance and give a better understanding of temperament biology. PMID:28125592

  4. Genetic Map of Triticale Integrating Microsatellite, DArT and SNP Markers.

    Science.gov (United States)

    Tyrka, Mirosław; Tyrka, Dorota; Wędzony, Maria

    2015-01-01

    Triticale (×Triticosecale Wittm) is an economically important crop for fodder and biomass production. To facilitate the identification of markers for agronomically important traits and for genetic and genomic characteristics of this species, a new high-density genetic linkage map of triticale was constructed using doubled haploid (DH) population derived from a cross between cultivars 'Hewo' and 'Magnat'. The map consists of 1615 bin markers, that represent 50 simple sequence repeat (SSR), 842 diversity array technology (DArT), and 16888 DArTseq markers mapped onto 20 linkage groups assigned to the A, B, and R genomes of triticale. No markers specific to chromosome 7R were found, instead mosaic linkage group composed of 1880 highly distorted markers (116 bins) from 10 wheat chromosomes was identified. The genetic map covers 4907 cM with a mean distance between two bins of 3.0 cM. Comparative analysis in respect to published maps of wheat, rye and triticale revealed possible deletions in chromosomes 4B, 5A, and 6A, as well as inversion in chromosome 7B. The number of bin markers in each chromosome varied from 24 in chromosome 3R to 147 in chromosome 6R. The length of individual chromosomes ranged between 50.7 cM for chromosome 2R and 386.2 cM for chromosome 7B. A total of 512 (31.7%) bin markers showed significant (P triticale will facilitate fine mapping of quantitative trait loci, the identification of candidate genes and map-based cloning.

  5. Genome-wide SNPs resolve a key conflict between sequence and allozyme data to confirm another threatened candidate species of river blackfishes (Teleostei: Percichthyidae: Gadopsis).

    Science.gov (United States)

    Unmack, Peter J; Sandoval-Castillo, Jonathan; Hammer, Michael P; Adams, Mark; Raadik, Tarmo A; Beheregaray, Luciano B

    2017-02-22

    Conflicting results from different molecular datasets have long confounded our ability to characterise species boundaries. Here we use genome-wide SNP data and an expanded allozyme dataset to resolve conflicting systematic hypotheses on an enigmatic group of fishes (Gadopsis, river blackfishes, Percichthyidae) restricted to southeastern Australia. Previous work based on three sets of molecular markers: mtDNA, nuclear intron DNA and 51 allozyme loci was unable to clearly resolve the status of a putative fifth candidate species (SWV) within Gadopsis marmoratus. Resolving the taxonomic status of candidate species SWV is particularly critical as based on IUCN criteria this taxon would be considered Critically Endangered. After all filtering steps we retained a subset of 10,862 putatively unlinked SNP loci for population genetic and phylogenomic analyses. Analyses of SNP loci based on maximum likelihood, fastSTRUCTURE and DAPC were all consistent with the previous and updated allozyme results supporting the validity of the candidate Gadopsis species SWV. Immediate conservation actions should focus on preventing take by anglers, protection of water resources to sustain perennial reaches and drought refuge pools, and aquatic and riparian habitat protection and improvement. In addition, a formal morphological taxonomic review of the genus Gadopsis is urgently required.

  6. 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

  7. Analysis of genome-wide structure, diversity and fine mapping of Mendelian traits in traditional and village chickens

    Science.gov (United States)

    Wragg, D; Mwacharo, J M; Alcalde, J A; Hocking, P M; Hanotte, O

    2012-01-01

    Extensive phenotypic variation is a common feature among village chickens found throughout much of the developing world, and in traditional chicken breeds that have been artificially selected for traits such as plumage variety. We present here an assessment of traditional and village chicken populations, for fine mapping of Mendelian traits using genome-wide single-nucleotide polymorphism (SNP) genotyping while providing information on their genetic structure and diversity. Bayesian clustering analysis reveals two main genetic backgrounds in traditional breeds, Kenyan, Ethiopian and Chilean village chickens. Analysis of linkage disequilibrium (LD) reveals useful LD (r2⩾0.3) in both traditional and village chickens at pairwise marker distances of ∼10 Kb; while haplotype block analysis indicates a median block size of 11–12 Kb. Association mapping yielded refined mapping intervals for duplex comb (Gga 2:38.55–38.89 Mb) and rose comb (Gga 7:18.41–22.09 Mb) phenotypes in traditional breeds. Combined mapping information from traditional breeds and Chilean village chicken allows the oocyan phenotype to be fine mapped to two small regions (Gga 1:67.25–67.28 Mb, Gga 1:67.28–67.32 Mb) totalling ∼75 Kb. Mapping the unmapped earlobe pigmentation phenotype supports previous findings that the trait is sex-linked and polygenic. A critical assessment of the number of SNPs required to map simple traits indicate that between 90 and 110K SNPs are required for full genome-wide analysis of haplotype block structure/ancestry, and for association mapping in both traditional and village chickens. Our results demonstrate the importance and uniqueness of phenotypic diversity and genetic structure of traditional chicken breeds for fine-scale mapping of Mendelian traits in the species, with village chicken populations providing further opportunities to enhance mapping resolutions. PMID:22395157

  8. Three novel quantitative trait loci for skin thickness in swine identified by linkage and genome-wide association studies.

    Science.gov (United States)

    Ai, Huashui; Xiao, Shijun; Zhang, Zhiyan; Yang, Bin; Li, Lin; Guo, Yuanmei; Lin, Guoshan; Ren, Jun; Huang, Lusheng

    2014-08-01

    Skin is the largest organ in the pig body and plays a key role in protecting the body against pathogens and excessive water loss. Deciphering the genetic basis of swine skin thickness would enrich our knowledge about the skin. To identify the loci for porcine skin thickness, we first performed a genome scan with 194 microsatellite markers in a White Duroc × Erhualian F2 intercross. We identified three genome-wide significant QTL on pig chromosomes (SSC) 4, 7 and 15 using linkage analysis. The most significant QTL was found on SSC7 with a small confidence interval of ~5 cM, explaining 23.9 percent of phenotypic variance. Further, we conducted a genome-wide association study (GWAS) using Illumina PorcineSNP60 Beadchips for the F2 pedigree and a population of Chinese Sutai pigs. We confirmed significant QTL in the F2 pedigree and replicated QTL on SSC15 in Chinese Sutai pigs. A meta-analysis of GWASs on both populations detected a genomic region associated with skin thickness on SSC4. GWAS results were generally consistent with QTL mapping. Identical-by-descent analysis defined QTL on SSC7 in a 683-kb region harboring an interesting candidate gene: HMGA1. On SSC15, the linkage disequilibrium analysis showed a haplotype block of 2.20 Mb that likely harbors the gene responsible for skin thickness. Our findings provide novel insights into the genetic basis of swine skin thickness, which would benefit further understanding of porcine skin function.

  9. Genome-wide association study identifies candidate genes for starch content regulation in maize kernels

    Directory of Open Access Journals (Sweden)

    Na Liu

    2016-07-01

    Full Text Available Kernel starch content is an important trait in maize (Zea mays L. as it accounts for 65% to 75% of the dry kernel weight and positively correlates with seed yield. A number of starch synthesis-related genes have been identified in maize in recent years. However, many loci underlying variation in starch content among maize inbred lines still remain to be identified. The current study is a genome-wide association study that used a set of 263 maize inbred lines. In this panel, the average kernel starch content was 66.99%, ranging from 60.60% to 71.58% over the three study years. These inbred lines were genotyped with the SNP50 BeadChip maize array, which is comprised of 56,110 evenly spaced, random SNPs. Population structure was controlled by a mixed linear model (MLM as implemented in the software package TASSEL. After the statistical analyses, four SNPs were identified as significantly associated with starch content (P ≤ 0.0001, among which one each are located on chromosomes 1 and 5 and two are on chromosome 2. Furthermore, 77 candidate genes associated with starch synthesis were found within the 100-kb intervals containing these four QTLs, and four highly associated genes were within 20-kb intervals of the associated SNPs. Among the four genes, Glucose-1-phosphate adenylyltransferase (APS1; Gene ID GRMZM2G163437 is known as an important regulator of kernel starch content. The identified SNPs, QTLs, and candidate genes may not only be readily used for germplasm improvement by marker-assisted selection in breeding, but can also elucidate the genetic basis of starch content. Further studies on these identified candidate genes may help determine the molecular mechanisms regulating kernel starch content in maize and other important cereal crops.

  10. An across-breed genome wide association analysis of susceptibility to paratuberculosis in dairy cattle.

    Science.gov (United States)

    Sallam, Ahmed M; Zare, Yalda; Alpay, Fazli; Shook, George E; Collins, Michael T; Alsheikh, Samir; Sharaby, Mahmoud; Kirkpatrick, Brian W

    2017-02-01

    Paratuberculosis is a chronic disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). It occurs worldwide and causes a significant loss in the animal production industry. There is no cure for MAP infection and vaccination is problematic. Identification of genetics of susceptibility could be a useful adjunct for programs that focus on management, testing and culling of diseased animals. A case-control, genome-wide association study (GWAS) was conducted using Holstein and Jersey cattle in a combined analysis in order to identify markers and chromosomal regions associated with susceptibility to MAP infection across-breed. A mixed-model method (GRAMMAR-GC) implemented in the GenABEL R package and a Bayes C analysis implemented in GenSel software were used as alternative approaches to conduct GWAS analysis focused on single SNPs and chromosomal segments, respectively. After conducting quality control, 22 406 SNPs from 2157 individuals were available for the GRAMMAR-GC (Bayes C) analysis and 45 640 SNPs from 2199 individuals were available for the Bayes C analysis. One SNP located on BTA27 (8·6 Mb) was identified as moderately associated (P < 5 × 10-5, FDR = 0·44) in the GRAMMAR-GC analysis of the combined breed data. Nine 1 Mb windows located on BTA 2, 3 (3 windows), 6, 8, 25, 27 and 29 each explained ≥1% of the total proportion of genetic variance in the Bayes C analysis. In an analysis ignoring differences in linkage phase, two moderately significantly associated SNPs were identified; ARS-BFGL-NGS-19381 on BTA23 (32 Mb) and Hapmap40994-BTA-46361 on BTA19 (61 Mb). New common genomic regions and candidate genes have been identified from the across-breed analysis that might be involved in the immune response and susceptibility to MAP infection.

  11. Genome-Wide Association Study for Nine Plant Architecture Traits in Sorghum

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2016-07-01

    Full Text Available Sorghum [ (L Moench], an important grain and forage crop, is receiving significant attention as a lignocellulosic feedstock because of its water-use efficiency and high biomass yield potential. Because of the advancement of genotyping and sequencing technologies, genome-wide association study (GWAS has become a routinely used method to investigate the genetic mechanisms underlying natural phenotypic variation. In this study, we performed a GWAS for nine grain and biomass-related plant architecture traits to determine their overall genetic architecture and the specific association of allelic variants in gibberellin (GA biosynthesis and signaling genes with these phenotypes. A total of 101 single-nucleotide polymorphism (SNP representative regions were associated with at least one of the nine traits, and two of the significant markers correspond to GA candidate genes, ( and (, affecting plant height and seed number, respectively. The resolution of a previously reported quantitative trait loci (QTL for leaf angle on chromosome 7 was increased to a 1.67 Mb region containing seven candidate genes with good prospects for further investigation. This study provides new knowledge of the association of GA genes with plant architecture traits and the genomic regions controlling variation in leaf angle, stem circumference, internode number, tiller number, seed number, panicle exsertion, and panicle length. The GA gene affecting seed number variation ( and the genomic region on chromosome 7 associated with variation in leaf angle are also important outcomes of this study and represent the foundation of future validation studies needed to apply this knowledge in breeding programs.

  12. The first genetic linkage map of Primulina eburnea (Gesneriaceae) based on EST-derived SNP marker

    Indian Academy of Sciences (India)

    CHEN FENG; CHAO FENG; MING KANG

    2016-06-01

    Primulina eburneais a promising candidate for domestication and floriculture, since it is easy to culture and has beautiful flow-ers. An F2population of 189 individuals was established for the construction of first-generation linkage maps based onexpressed sequence tags-derived single-nucleotide polymorphism markers using the massARRAY genotyping platform. Ofthe 232 screened markers, 215 were assigned to 18 LG according to the haploid number of chromosomes in the species. Thelinkage map spanned a total of 3774.7 cM with an average distance of 17.6 cM between adjacent markers. This linkage mapprovides a framework for identification of important genes in breeding programm

  13. The first genetic linkage map of Primulina eburnea (Gesneriaceae) based on EST-derived SNP markers.

    Science.gov (United States)

    Feng, Chen; Feng, Chao; Kang, Ming

    2016-06-01

    Primulina eburnea is a promising candidate for domestication and floriculture, since it is easy to culture and has beautiful flowers. An F₂ population of 189 individuals was established for the construction of first-generation linkage maps based on expressed sequence tags-derived single-nucleotide polymorphism markers using the massARRAY genotyping platform. Of the 232 screened markers, 215 were assigned to 18 LG according to the haploid number of chromosomes in the species. The linkage map spanned a total of 3774.7 cM with an average distance of 17.6 cM between adjacent markers. This linkage map provides a framework for identification of important genes in breeding programmes.

  14. Novel R tools for analysis of genome-wide population genetic data with emphasis on clonality

    Directory of Open Access Journals (Sweden)

    Zhian N Kamvar

    2015-06-01

    Full Text Available To gain a detailed understanding of how plant microbes evolve and adapt to hosts, pesticides, and other factors, knowledge of the population dynamics and evolutionary history of populations is crucial. Plant pathogen populations are often clonal or partially clonal which requires different analytical tools. With the advent of high throughput sequencing technologies, obtaining genome-wide population genetic data has become easier than ever before. We previously contributed the R package poppr specifically addressing issues with analysis of clonal populations. In this paper we provide several significant extensions to poppr with a focus on large, genome-wide SNP data. Specifically, we provide several new functionalities including the new function mlg.filter to define clone boundaries allowing for inspection and definition of what is a clonal lineage, minimum spanning networks with reticulation, a sliding-window analysis of the index of association, modular bootstrapping of any genetic distance, and analyses across any level of hierarchies.

  15. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits

    Science.gov (United States)

    Pecetti, Luciano; Brummer, E. Charles; Palmonari, Alberto; Tava, Aldo

    2017-01-01

    Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3–0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits

  16. Genetic diversity and population structure assessed by SSR and SNP markers in a large germplasm collection of grape

    Science.gov (United States)

    2013-01-01

    Background The economic importance of grapevine has driven significant efforts in genomics to accelerate the exploitation of Vitis resources for development of new cultivars. However, although a large number of clonally propagated accessions are maintained in grape germplasm collections worldwide, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome-wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of such core samples. Results We investigated patterns of molecular diversity at 22 common microsatellite loci and 384 single nucleotide polymorphisms (SNPs) in 2273 accessions of domesticated grapevine V. vinifera ssp. sativa, its wild relative V. vinifera ssp. sylvestris, interspecific hybrid cultivars and rootstocks. Despite the large number of putative duplicates and extensive clonal relationships among the accessions, we observed high level of genetic variation. In the total germplasm collection the average genetic diversity, as quantified by the expected heterozygosity, was higher for SSR loci (0.81) than for SNPs (0.34). The analysis of the genetic structure in the grape germplasm collection revealed several levels of stratification. The primary division was between accessions of V. vinifera and non-vinifera, followed by the distinction between wild and domesticated grapevine. Intra-specific subgroups were detected within cultivated grapevine representing different eco-geographic groups. The comparison of a phenological core collection and genetic core collections showed that the latter retained more genetic diversity, while maintaining a similar phenotypic variability. Conclusions The comprehensive molecular characterization of our grape

  17. Pedigree reconstruction with genome-wide markers in potato

    Science.gov (United States)

    Reliable pedigree information facilitates a scientific approach to breeding, but errors can be introduced in many stages of a breeding program. Our objective was to use single nucleotide polymorphisms (SNPs) to check the pedigree records of elite North American potato germplasm. A population of 635 ...

  18. Fine QTL mapping of mandarin (Citrus reticulata) fruit characters using high-throughput SNP markers

    Science.gov (United States)

    Seedlessness, flavor, and color are top priorities for mandarin (Citrus reticulata Blanco) cultivar improvement. Given long juvenility, large tree size, and high breeding cost, marker-assisted selection (MAS) may be an expeditious and economical approach to these challenges. The objectives of this s...

  19. A genome-wide association study of hypertension and blood pressure in African Americans.

    Directory of Open Access Journals (Sweden)

    Adebowale Adeyemo

    2009-07-01

    Full Text Available The evidence for the existence of genetic susceptibility variants for the common form of hypertension ("essential hypertension" remains weak and inconsistent. We sought genetic variants underlying blood pressure (BP by conducting a genome-wide association study (GWAS among African Americans, a population group in the United States that is disproportionately affected by hypertension and associated complications, including stroke and kidney diseases. Using a dense panel of over 800,000 SNPs in a discovery sample of 1,017 African Americans from the Washington, D.C., metropolitan region, we identified multiple SNPs reaching genome-wide significance for systolic BP in or near the genes: PMS1, SLC24A4, YWHA7, IPO7, and CACANA1H. Two of these genes, SLC24A4 (a sodium/potassium/calcium exchanger and CACNA1H (a voltage-dependent calcium channel, are potential candidate genes for BP regulation and the latter is a drug target for a class of calcium channel blockers. No variant reached genome wide significance for association with diastolic BP (top scoring SNP rs1867226, p = 5.8 x 10(-7 or with hypertension as a binary trait (top scoring SNP rs9791170, p = 5.1 x 10(-7. We replicated some of the significant SNPs in a sample of West Africans. Pathway analysis revealed that genes harboring top-scoring variants cluster in pathways and networks of biologic relevance to hypertension and BP regulation. This is the first GWAS for hypertension and BP in an African American population. The findings suggests that, in addition to or in lieu of relying solely on replicated variants of moderate-to-large effect reaching genome-wide significance, pathway and network approaches may be useful in identifying and prioritizing candidate genes/loci for further experiments.

  20. An integrated genetic linkage map of watermelon and genetic diversity based on single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers

    Science.gov (United States)

    Watermelon (Citrullus lanatus var. lanatus) is an important vegetable fruit throughout the world. A high number of single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers should provide large coverage of the watermelon genome and high phylogenetic resolution of germplasm acces...

  1. Genome-wide association study of the backfat thickness trait in two pig populations

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    Dandan ZHU,Xiaolei LIU,Rothschild MAX,Zhiwu ZHANG,Shuhong ZHAO,Bin FAN

    2014-06-01

    Full Text Available Backfat thickness is a good predictor of carcass lean content, an economically important trait, and a main breeding target in pig improvement. In this study, the candidate genes and genomic regions associated with the tenth rib backfat thickness trait were identified in two independent pig populations, using a genome-wide association study of porcine 60K SNP genotype data applying the compressed mixed linear model (CMLM statistical method. For each population, 30 most significant single-nucleotide polymorphisms (SNPs were selected and SNP annotation implemented using Sus scrofa Build 10.2. In the first population, 25 significant SNPs were distributed on seven chromosomes, and SNPs on SSC1 and SSC7 showed great significance for fat deposition. The most significant SNP (ALGA0006623 was located on SSC1, upstream of the MC4R gene. In the second population, 27 significant SNPs were recognized by annotation, and 12 SNPs on SSC12 were related to fat deposition. Two haplotype blocks, M1GA0016251-MARC0075799 and ALGA0065251-MARC0014203-M1GA0016298-ALGA0065308, were detected in significant regions where the PIPNC1 and GH1 genes were identified as contributing to fat metabolism. The results indicated that genetic mechanism regulating backfat thickness is complex, and that genome-wide associations can be affected by populations with different genetic backgrounds.

  2. 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.

  3. SNP Typing for Germplasm Identification of Amomum villosum Lour. Based on DNA Barcoding Markers

    OpenAIRE

    Qionglin Huang; Zhonggang Duan; Jinfen Yang; Xinye Ma; Ruoting Zhan; Hui Xu; Weiwen Chen

    2014-01-01

    Amomum villosum Lour., produced from Yangchun, Guangdong Province, China, is a Daodi medicinal material of Amomi Fructus in traditional Chinese medicine. This herb germplasm should be accurately identified and collected to ensure its quality and safety in medication. In the present study, single nucleotide polymorphism typing method was evaluated on the basis of DNA barcoding markers to identify the germplasm of Amomi Fructus. Genomic DNA was extracted from the leaves of 29 landraces represen...

  4. A new panel of SNP markers for the individual identification of North American pumas

    Science.gov (United States)

    Fitak, Robert R.; Naidu, Ashwin; Thompson, Ron W.; Culver, Melanie

    2016-01-01

    Pumas Puma concolor are one of the most studied terrestrial carnivores because of their widespread distribution, substantial ecological impacts, and conflicts with humans. Over the past decade, managing pumas has involved extensive efforts including the use of genetic methods. Microsatellites have been the most commonly used genetic markers; however, technical artifacts and little overlap of frequently used loci render large-scale comparison of puma genetic data across studies challenging. Therefore, a panel of genetic markers that can produce consistent genotypes across studies without the need for extensive calibrations is essential for range-wide genetic management of puma populations. Here, we describe the development of PumaPlex, a high-throughput assay to genotype 25 single nucleotide polymorphisms in pumas. We validated PumaPlex in 748 North American pumas Puma concolor couguar, and demonstrated its ability to generate reproducible genotypes and accurately identify individuals. Furthermore, in a test using fecal deoxyribonucleic acid (DNA) samples, we found that PumaPlex produced significantly more genotypes with fewer errors than 12 microsatellite loci, 8 of which are commonly used. Our results demonstrate that PumaPlex is a valuable tool for the genetic monitoring and management of North American puma populations. Given the analytical simplicity, reproducibility, and high-throughput capability of single nucleotide polymorphisms, PumaPlex provides a standard panel of markers that promotes the comparison of genotypes across studies and independent of the genotyping technology used.

  5. Genome-wide association of coagulation properties, curd firmness modeling, protein percentage, and acidity in milk from Brown Swiss cows.

    Science.gov (United States)

    Dadousis, C; Biffani, S; Cipolat-Gotet, C; Nicolazzi, E L; Rossoni, A; Santus, E; Bittante, G; Cecchinato, A

    2016-05-01

    Cheese production is increasing in many countries, and a desire toward genetic selection for milk coagulation properties in dairy cattle breeding exists. However, measurements of individual cheesemaking properties are hampered by high costs and labor, whereas traditional single-point milk coagulation properties (MCP) are sometimes criticized. Nevertheless, new modeling of the entire curd firmness and syneresis process (CFt equation) offers new insight into the cheesemaking process. Moreover, identification of genomic regions regulating milk cheesemaking properties might enhance direct selection of individuals in breeding programs based on cheese ability rather than related milk components. Therefore, the objective of this study was to perform genome-wide association studies to identify genomic regions linked to traditional MCP and new CFt parameters, milk acidity (pH), and milk protein percentage. Milk and DNA samples from 1,043 Italian Brown Swiss cows were used. Milk pH and 3 MCP traits were grouped together to represent the MCP set. Four CFt equation parameters, 2 derived traits, and protein percentage were considered as the second group of traits (CFt set). Animals were genotyped with the Illumina SNP50 BeadChip v.2 (Illumina Inc., San Diego, CA). Multitrait animal models were used to estimate variance components. For genome-wide association studies, the genome-wide association using mixed model and regression-genomic control approach was used. In total, 106 significant marker traits associations and 66 single nucleotide polymorphisms were identified on 12 chromosomes (1, 6, 9, 11, 13, 15, 16, 19, 20, 23, 26, and 28). Sharp peaks were detected at 84 to 88 Mbp on Bos taurus autosome (BTA) 6, with a peak at 87.4 Mbp in the region harboring the casein genes. Evidence of quantitative trait loci at 82.6 and 88.4 Mbp on the same chromosome was found. All chromosomes but BTA6, BTA11, and BTA28 were associated with only one trait. Only BTA6 was in common between MCP

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

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    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

  7. Genome-wide association study identifies Loci and candidate genes for body composition and meat quality traits in Beijing-You chickens.

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    Ranran Liu

    Full Text Available Body composition and meat quality traits are important economic traits of chickens. The development of high-throughput genotyping platforms and relevant statistical methods have enabled genome-wide association studies in chickens. In order to identify molecular markers and candidate genes associated with body composition and meat quality traits, genome-wide association studies were conducted using the Illumina 60 K SNP Beadchip to genotype 724 Beijing-You chickens. For each bird, a total of 16 traits were measured, including carcass weight (CW, eviscerated weight (EW, dressing percentage, breast muscle weight (BrW and percentage (BrP, thigh muscle weight and percentage, abdominal fat weight and percentage, dry matter and intramuscular fat contents of breast and thigh muscle, ultimate pH, and shear force of the pectoralis major muscle at 100 d of age. The SNPs that were significantly associated with the phenotypic traits were identified using both simple (GLM and compressed mixed linear (MLM models. For nine of ten body composition traits studied, SNPs showing genome wide significance (P<2.59E-6 have been identified. A consistent region on chicken (Gallus gallus chromosome 4 (GGA4, including seven significant SNPs and four candidate genes (LCORL, LAP3, LDB2, TAPT1, were found to be associated with CW and EW. Another 0.65 Mb region on GGA3 for BrW and BrP was identified. After measuring the mRNA content in beast muscle for five genes located in this region, the changes in GJA1 expression were found to be consistent with that of breast muscle weight across development. It is highly possible that GJA1 is a functional gene for breast muscle development in chickens. For meat quality traits, several SNPs reaching suggestive association were identified and possible candidate genes with their functions were discussed.

  8. Identification of Korean-specific SNP markers from whole-exome sequencing data.

    Science.gov (United States)

    Kim, Sung Min; Yoo, Seong Yeon; Nam, Soo Hyun; Lee, Jae Moon; Chung, Ki Wha

    2016-05-01

    Analysis of large numbers of single-nucleotide polymorphisms (SNPs) can increase individual discrimination power, and, particularly, it can supply important evidence for kinship or ethnic identification. We identified 300 Korean-specific SNPs from 306 Korean whole-exome sequencing (WES) data. Functionally significant SNPs (variants in splicing site, missense, nonsense, and exonic indels) were filtered out from the variant pool, and SNPs with minor allele frequencies (MAFs) of 0.3 in the Korean population were selected. Genotypes obtained from WES were confirmed by the Sanger sequencing method. The identified markers were evenly distributed throughout the autosomal chromosomes. All the SNPs were in the Hardy-Weinberg equilibrium with a mean MAF of 0.415 (0.161 in 1000G). The mean heterozygosities were 0.476 (observed) and 0.470 (experimental). The combined power of discrimination was very high. Korean MAFs in most SNPs were similar to those for the Chinese and Japanese populations, but were significantly higher than those for several other ethnic populations. These selected SNPs will be used to develop forensic markers and are expected to be widely used for additional individual identification, ethnic discrimination, and linkage analysis for kinship tests.

  9. Development of admixture mapping panels for African Americans from commercial high-density SNP arrays

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    Dunston Georgia M

    2010-07-01

    Full Text Available Abstract Background Admixture mapping is a powerful approach for identifying genetic variants involved in human disease that exploits the unique genomic structure in recently admixed populations. To use existing published panels of ancestry-informative markers (AIMs for admixture mapping, markers have to be genotyped de novo for each admixed study sample and samples representing the ancestral parental populations. The increased availability of dense marker data on commercial chips has made it feasible to develop panels wherein the markers need not be predetermined. Results We developed two panels of AIMs (~2,000 markers each based on the Affymetrix Genome-Wide Human SNP Array 6.0 for admixture mapping with African American samples. These two AIM panels had good map power that was higher than that of a denser panel of ~20,000 random markers as well as other published panels of AIMs. As a test case, we applied the panels in an admixture mapping study of hypertension in African Americans in the Washington, D.C. metropolitan area. Conclusions Developing marker panels for admixture mapping from existing genome-wide genotype data offers two major advantages: (1 no de novo genotyping needs to be done, thereby saving costs, and (2 markers can be filtered for various quality measures and replacement markers (to minimize gaps can be selected at no additional cost. Panels of carefully selected AIMs have two major advantages over panels of random markers: (1 the map power from sparser panels of AIMs is higher than that of ~10-fold denser panels of random markers, and (2 clusters can be labeled based on information from the parental populations. With current technology, chip-based genome-wide genotyping is less expensive than genotyping ~20,000 random markers. The major advantage of using random markers is the absence of ascertainment effects resulting from the process of selecting markers. The ability to develop marker panels informative for ancestry from

  10. Genome-wide association study of type 2 diabetes in a sample from Mexico City and a meta-analysis of a Mexican-American sample from Starr County, Texas.

    Science.gov (United States)

    Parra, E J; Below, J E; Krithika, S; Valladares, A; Barta, J L; Cox, N J; Hanis, C L; Wacher, N; Garcia-Mena, J; Hu, P; Shriver, M D; Kumate, J; McKeigue, P M; Escobedo, J; Cruz, M

    2011-08-01

    We report a genome-wide association study of type 2 diabetes in an admixed sample from Mexico City and describe the results of a meta-analysis of this study and another genome-wide scan in a Mexican-American sample from Starr County, TX, USA. The top signals observed in this meta-analysis were followed up in the Diabetes Genetics Replication and Meta-analysis Consortium (DIAGRAM) and DIAGRAM+ datasets. We analysed 967 cases and 343 normoglycaemic controls. The samples were genotyped with the Affymetrix Genome-wide Human SNP array 5.0. Associations of genotyped and imputed markers with type 2 diabetes were tested using a missing data likelihood score test. A fixed-effects meta-analysis including 1,804 cases and 780 normoglycaemic controls was carried out by weighting the effect estimates by their inverse variances. In the meta-analysis of the two Hispanic studies, markers showing suggestive associations (p < 10(-5)) were identified in two known diabetes genes, HNF1A and KCNQ1, as well as in several additional regions. Meta-analysis of the two Hispanic studies and the recent DIAGRAM+ dataset identified genome-wide significant signals (p < 5 × 10(-8)) within or near the genes HNF1A and CDKN2A/CDKN2B, as well as suggestive associations in three additional regions, IGF2BP2, KCNQ1 and the previously unreported C14orf70. We observed numerous regions with suggestive associations with type 2 diabetes. Some of these signals correspond to regions described in previous studies. However, many of these regions could not be replicated in the DIAGRAM datasets. It is critical to carry out additional studies in Hispanic and American Indian populations, which have a high prevalence of type 2 diabetes.

  11. Effect of marker-data editing on the accuracy of genomic prediction

    DEFF Research Database (Denmark)

    Edriss, Vahid; Guldbrandtsen, Bernt; Lund, Mogens Sandø

    2013-01-01

    Genomic selection is a method to predict breeding values using genome-wide single-nucleotide polymorphism (SNP) markers. High-quality marker data are necessary for genomic selection. The aim of this study was to investigate the effect of marker-editing criteria on the accuracy of genomic predicti......Genomic selection is a method to predict breeding values using genome-wide single-nucleotide polymorphism (SNP) markers. High-quality marker data are necessary for genomic selection. The aim of this study was to investigate the effect of marker-editing criteria on the accuracy of genomic...... predictions in the Nordic Holstein and Jersey populations. Data included 4429 Holstein and 1071 Jersey bulls. In total, 48 222 SNP for Holstein and 44 305 SNP for Jersey were polymorphic. The SNP data were edited based on (i) minor allele frequencies (MAF) with thresholds of no limit, 0.001, 0.01, 0.02, 0.......05 and 0.10, (ii) deviations from Hardy–Weinberg proportions (HWP) with thresholds of no limit, chi-squared p-values of 0.001, 0.02, 0.05 and 0.10, and (iii) GenCall (GC) scores with thresholds of 0.15, 0.55, 0.60, 0.65 and 0.70. The marker data sets edited with different criteria were used for genomic...

  12. Genome-wide scan identifies TNIP1, PSORS1C1, and RHOB as novel risk loci for systemic sclerosis.

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    Yannick Allanore

    2011-07-01

    Full Text Available Systemic sclerosis (SSc is an orphan, complex, inflammatory disease affecting the immune system and connective tissue. SSc stands out as a severely incapacitating and life-threatening inflammatory rheumatic disease, with a largely unknown pathogenesis. We have designed a two-stage genome-wide association study of SSc using case-control samples from France, Italy, Germany, and Northern Europe. The initial genome-wide scan was conducted in a French post quality-control sample of 564 cases and 1,776 controls, using almost 500 K SNPs. Two SNPs from the MHC region, together with the 6 loci outside MHC having at least one SNP with a P<10(-5 were selected for follow-up analysis. These markers were genotyped in a post-QC replication sample of 1,682 SSc cases and 3,926 controls. The three top SNPs are in strong linkage disequilibrium and located on 6p21, in the HLA-DQB1 gene: rs9275224, P = 9.18×10(-8, OR = 0.69, 95% CI [0.60-0.79]; rs6457617, P = 1.14×10(-7 and rs9275245, P = 1.39×10(-7. Within the MHC region, the next most associated SNP (rs3130573, P = 1.86×10(-5, OR = 1.36 [1.18-1.56] is located in the PSORS1C1 gene. Outside the MHC region, our GWAS analysis revealed 7 top SNPs (P<10(-5 that spanned 6 independent genomic regions. Follow-up of the 17 top SNPs in an independent sample of 1,682 SSc and 3,926 controls showed associations at PSORS1C1 (overall P = 5.70×10(-10, OR:1.25, TNIP1 (P = 4.68×10(-9, OR:1.31, and RHOB loci (P = 3.17×10(-6, OR:1.21. Because of its biological relevance, and previous reports of genetic association at this locus with connective tissue disorders, we investigated TNIP1 expression. A markedly reduced expression of the TNIP1 gene and also its protein product were observed both in lesional skin tissue and in cultured dermal fibroblasts from SSc patients. Furthermore, TNIP1 showed in vitro inhibitory effects on inflammatory cytokine-induced collagen production. The genetic signal of

  13. Genetic dissection of drought and heat tolerance in chickpea through genome-wide and candidate gene-based association mapping approaches.

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    Mahendar Thudi

    Full Text Available To understand the genetic basis of tolerance to drought and heat stresses in chickpea, a comprehensive association mapping approach has been undertaken. Phenotypic data were generated on the reference set (300 accessions, including 211 mini-core collection accessions for drought tolerance related root traits, heat tolerance, yield and yield component traits from 1-7 seasons and 1-3 locations in India (Patancheru, Kanpur, Bangalore and three locations in Africa (Nairobi, Egerton in Kenya and Debre Zeit in Ethiopia. Diversity Array Technology (DArT markers equally distributed across chickpea genome were used to determine population structure and three sub-populations were identified using admixture model in STRUCTURE. The pairwise linkage disequilibrium (LD estimated using the squared-allele frequency correlations (r2; when r2<0.20 was found to decay rapidly with the genetic distance of 5 cM. For establishing marker-trait associations (MTAs, both genome-wide and candidate gene-sequencing based association mapping approaches were conducted using 1,872 markers (1,072 DArTs, 651 single nucleotide polymorphisms [SNPs], 113 gene-based SNPs and 36 simple sequence repeats [SSRs] and phenotyping data mentioned above employing mixed linear model (MLM analysis with optimum compression with P3D method and kinship matrix. As a result, 312 significant MTAs were identified and a maximum number of MTAs (70 was identified for 100-seed weight. A total of 18 SNPs from 5 genes (ERECTA, 11 SNPs; ASR, 4 SNPs; DREB, 1 SNP; CAP2 promoter, 1 SNP and AMDH, 1SNP were significantly associated with different traits. This study provides significant MTAs for drought and heat tolerance in chickpea that can be used, after validation, in molecular breeding for developing superior varieties with enhanced drought and heat tolerance.

  14. Genome-wide Association Study for Warner-Bratzler Shear Force and Sensory Traits in Hanwoo (Korean Cattle

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    C. G. Dang

    2014-09-01

    Full Text Available Significant SNPs associated with Warner-Bratzler (WB shear force and sensory traits were confirmed for Hanwoo beef (Korean cattle. A Bonferroni-corrected genome-wide significant association (p<1.3×10−6 was detected with only one single nucleotide polymorphism (SNP on chromosome 5 for WB shear force. A slightly higher number of SNPs was significantly (p<0.001 associated with WB shear force than with other sensory traits. Further, 50, 25, 29, and 34 SNPs were significantly associated with WB shear force, tenderness, juiciness, and flavor likeness, respectively. The SNPs between p = 0.001 and p = 0.0001 thresholds explained 3% to 9% of the phenotypic variance, while the most significant SNPs accounted for 7% to 12% of the phenotypic variance. In conclusion, because WB shear force and sensory evaluation were moderately affected by a few loci and minimally affected by other loci, further studies are required by using a large sample size and high marker density.

  15. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces.

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    Albert Kertho

    Full Text Available Leaf rust, caused by Puccinia triticina (Pt, and stripe rust, caused by P. striiformis f. sp. tritici (Pst, are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance. Here we report a genome-wide association analysis of 567 winter wheat (Triticum aestivum landrace accessions using the Infinium iSelect 9K wheat SNP array to identify loci associated with seedling resistance to five races of Pt (MDCL, MFPS, THBL, TDBG, and TBDJ and one race of Pst (PSTv-37 frequently found in the Northern Great Plains of the United States. Mixed linear models identified 65 and eight significant markers associated with leaf rust and stripe rust, respectively. Further, we identified 31 and three QTL associated with resistance to Pt and Pst, respectively. Eleven QTL, identified on chromosomes 3A, 4A, 5A, and 6D, are previously unknown for leaf rust resistance in T. aestivum.

  16. A genome-wide association study in large white and landrace pig populations for number piglets born alive.

    Science.gov (United States)

    Bergfelder-Drüing, Sarah; Grosse-Brinkhaus, Christine; Lind, Bianca; Erbe, Malena; Schellander, Karl; Simianer, Henner; Tholen, Ernst

    2015-01-01

    The number of piglets born alive (NBA) per litter is one of the most important traits in pig breeding due to its influence on production efficiency. It is difficult to improve NBA because the heritability of the trait is low and it is governed by a high number of loci with low to moderate effects. To clarify the biological and genetic background of NBA, genome-wide association studies (GWAS) were performed using 4,012 Large White and Landrace pigs from herdbook and commercial breeding companies in Germany (3), Austria (1) and Switzerland (1). The animals were genotyped with the Illumina PorcineSNP60 BeadChip. Because of population stratifications within and between breeds, clusters were formed using the genetic distances between the populations. Five clusters for each breed were formed and analysed by GWAS approaches. In total, 17 different significant markers affecting NBA were found in regions with known effects on female reproduction. No overlapping significant chromosome areas or QTL between Large White and Landrace breed were detected.

  17. A genome-wide association study in large white and landrace pig populations for number piglets born alive.

    Directory of Open Access Journals (Sweden)

    Sarah Bergfelder-Drüing

    Full Text Available The number of piglets born alive (NBA per litter is one of the most important traits in pig breeding due to its influence on production efficiency. It is difficult to improve NBA because the heritability of the trait is low and it is governed by a high number of loci with low to moderate effects. To clarify the biological and genetic background of NBA, genome-wide association studies (GWAS were performed using 4,012 Large White and Landrace pigs from herdbook and commercial breeding companies in Germany (3, Austria (1 and Switzerland (1. The animals were genotyped with the Illumina PorcineSNP60 BeadChip. Because of population stratifications within and between breeds, clusters were formed using the genetic distances between the populations. Five clusters for each breed were formed and analysed by GWAS approaches. In total, 17 different significant markers affecting NBA were found in regions with known effects on female reproduction. No overlapping significant chromosome areas or QTL between Large White and Landrace breed were detected.

  18. Genome-wide association implicates numerous genes underlying ecological trait variation in natural populations of Populus trichocarpa.

    Science.gov (United States)

    McKown, Athena D; Klápště, Jaroslav; Guy, Robert D; Geraldes, Armando; Porth, Ilga; Hannemann, Jan; Friedmann, Michael; Muchero, Wellington; Tuskan, Gerald A; Ehlting, Jürgen; Cronk, Quentin C B; El-Kassaby, Yousry A; Mansfield, Shawn D; Douglas, Carl J

    2014-07-01

    In order to uncover the genetic basis of phenotypic trait variation, we used 448 unrelated wild accessions of black cottonwood (Populus trichocarpa) from much of its range in western North America. Extensive data from large-scale trait phenotyping (with spatial and temporal replications within a common garden) and genotyping (with a 34 K Populus single nucleotide polymorphism (SNP) array) of all accessions were used for gene discovery in a genome-wide association study (GWAS). We performed GWAS with 40 biomass, ecophysiology and phenology traits and 29,355 filtered SNPs representing 3518 genes. The association analyses were carried out using a Unified Mixed Model accounting for population structure effects among accessions. We uncovered 410 significant SNPs using a Bonferroni-corrected threshold (P<1.7×10(-6)). Markers were found across 19 chromosomes, explained 1-13% of trait variation, and implicated 275 unique genes in trait associations. Phenology had the largest number of associated genes (240 genes), followed by biomass (53 genes) and ecophysiology traits (25 genes). The GWAS results propose numerous loci for further investigation. Many traits had significant associations with multiple genes, underscoring their genetic complexity. Genes were also identified with multiple trait associations within and/or across trait categories. In some cases, traits were genetically correlated while in others they were not.

  19. A combined genome-wide linkage and association approach to find susceptibility loci for platelet function phenotypes in European American and African American families with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Wilson Alexander F

    2010-06-01

    Full Text Available Abstract Background The inability of aspirin (ASA to adequately suppress platelet aggregation is associated with future risk of coronary artery disease (CAD. Heritability studies of agonist-induced platelet function phenotypes suggest that genetic variation may be responsible for ASA responsiveness. In this study, we leverage independent information from genome-wide linkage and association data to determine loci controlling platelet phenotypes before and after treatment with ASA. Methods Clinical data on 37 agonist-induced platelet function phenotypes were evaluated before and after a 2-week trial of ASA (81 mg/day in 1231 European American and 846 African American healthy subjects with a family history of premature CAD. Principal component analysis was performed to minimize the number of independent factors underlying the covariance of these various phenotypes. Multi-point sib-pair based linkage analysis was performed using a microsatellite marker set, and single-SNP association tests were performed using markers from the Illumina 1 M genotyping chip from deCODE Genetics, Inc. All analyses were performed separately within each ethnic group. Results Several genomic regions appear to be linked to ASA response factors: a 10 cM region in African Americans on chromosome 5q11.2 had several STRs with suggestive (p-value -4 and significant (p-value -5 linkage to post aspirin platelet response to ADP, and ten additional factors had suggestive evidence for linkage (p-value -4 to thirteen genomic regions. All but one of these factors were aspirin response variables. While the strength of genome-wide SNP association signals for factors showing evidence for linkage is limited, especially at the strict thresholds of genome-wide criteria (N = 9 SNPs for 11 factors, more signals were considered significant when the association signal was weighted by evidence for linkage (N = 30 SNPs. Conclusions Our study supports the hypothesis that platelet phenotypes in

  20. A 2cM genome-wide scan of European Holstein cattle affected by classical BSE

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    Prasad Aparna

    2010-03-01

    Full Text Available Abstract Background Classical bovine spongiform encephalopathy (BSE is an acquired prion disease that is invariably fatal in cattle and has been implicated as a significant human health risk. Polymorphisms that alter the prion protein of sheep or humans have been associated with variations in transmissible spongiform encephalopathy susceptibility or resistance. In contrast, there is no strong evidence that non-synonymous mutations in the bovine prion gene (PRNP are associated with classical BSE disease susceptibility. However, two bovine PRNP insertion/deletion polymorphisms, one within the promoter region and the other in intron 1, have been associated with susceptibility to classical BSE. These associations do not explain the full extent of BSE susceptibility, and loci outside of PRNP appear to be associated with disease incidence in some cattle populations. To test for associations with BSE susceptibility, we conducted a genome wide scan using a panel of 3,072 single nucleotide polymorphism (SNP markers on 814 animals representing cases and control Holstein cattle from the United Kingdom BSE epidemic. Results Two sets of BSE affected Holstein cattle were analyzed in this study, one set with known family relationships and the second set of paired cases with controls. The family set comprises half-sibling progeny from six sires. The progeny from four of these sires had previously been scanned with microsatellite markers. The results obtained from the current analysis of the family set yielded both some supporting and new results compared with those obtained in the earlier study. The results revealed 27 SNPs representing 18 chromosomes associated with incidence of BSE disease. These results confirm a region previously reported on chromosome 20, and identify additional regions on chromosomes 2, 14, 16, 21 and 28. This study did not identify a significant association near the PRNP in the family sample set. The only association found in the PRNP

  1. The Minnesota Center for Twin and Family Research Genome-Wide Association Study

    DEFF Research Database (Denmark)

    Miller, M. B.; Basu, S.; Cunningham, J.

    2012-01-01

    on 527,829 single nucleotide polymorphism (SNP) markers using Illumina's Human660W-Quad array. Quality control screening of samples and markers as well as SNP imputation procedures are described. We also describe methods for ancestry control and how the familial clustering of the MCTFR sample can...... be accounted for in the analysis using a Rapid Feasible Generalized Least Squares algorithm. The rich longitudinal MCTFR assessments provide numerous opportunities for collaboration....

  2. Use of modern tomato breeding germplasm for deciphering the genetic control of agronomical traits by Genome Wide Association study.

    Science.gov (United States)

    Bauchet, Guillaume; Grenier, Stéphane; Samson, Nicolas; Bonnet, Julien; Grivet, Laurent; Causse, Mathilde

    2017-05-01

    A panel of 300 tomato accessions including breeding materials was built and characterized with >11,000 SNP. A population structure in six subgroups was identified. Strong heterogeneity in linkage disequilibrium and recombination landscape among groups and chromosomes was shown. GWAS identified several associations for fruit weight, earliness and plant growth. Genome-wide association studies (GWAS) have become a method of choice in quantitative trait dissection. First limited to highly polymorphic and outcrossing species, it is now applied in horticultural crops, notably in tomato. Until now GWAS in tomato has been performed on panels of heirloom and wild accessions. Using modern breeding materials would be of direct interest for breeding purpose. To implement GWAS on a large panel of 300 tomato accessions including 168 breeding lines, this study assessed the genetic diversity and linkage disequilibrium decay and revealed the population structure and performed GWA experiment. Genetic diversity and population structure analyses were based on molecular markers (>11,000 SNP) covering the whole genome. Six genetic subgroups were revealed and associated to traits of agronomical interest, such as fruit weight and disease resistance. Estimates of linkage disequilibrium highlighted the heterogeneity of its decay among genetic subgroups. Haplotype definition allowed a fine characterization of the groups and their recombination landscape revealing the patterns of admixture along the genome. Selection footprints showed results in congruence with introgressions. Taken together, all these elements refined our knowledge of the genetic material included in this panel and allowed the identification of several associations for fruit weight, plant growth and earliness, deciphering the genetic architecture of these complex traits and identifying several new loci useful for tomato breeding.

  3. Genome-wide study of association and interaction with maternal cytomegalovirus infection suggests new schizophrenia loci

    DEFF Research Database (Denmark)

    Børglum, A D; Demontis, D; Grove, J;

    2014-01-01

    in ARNTL (P=3.78 × 10(-6)) and rs8057927 in CDH13 (P=1.39 × 10(-5)). Both genes have previously been linked to schizophrenia or other psychiatric disorders. The strongest associated SNP in the combined analysis, including Danish and German-Dutch samples, was rs12922317 in RUNDC2A (P=9.04 × 10...... was found for rs7902091 (P(SNP × CMV)=7.3 × 10(-7)) in CTNNA3, a gene not previously implicated in schizophrenia, stressing the importance of including environmental factors in genetic studies.......Genetic and environmental components as well as their interaction contribute to the risk of schizophrenia, making it highly relevant to include environmental factors in genetic studies of schizophrenia. This study comprises genome-wide association (GWA) and follow-up analyses of all individuals...

  4. Identification of SNP markers for inferring phylogeny in temperate bamboos (Poaceae: Bambusoideae) using RAD sequencing.

    Science.gov (United States)

    Wang, X Q; Zhao, L; Eaton, D A R; Li, D Z; Guo, Z H

    2013-09-01

    Phylogenetic relationships among temperate species of bamboo are difficult to resolve, owing to both the challenge of detecting sufficiently variable markers and their polyploid history. Here, we use restriction site-associated DNA sequencing to identify candidate loci with fixed allelic differences segregating between and within two temperate species of bamboos: Arundinaria faberi and Yushania brevipaniculata. Approximately 27 million paired-end sequencing reads were generated across four samples. From pooled data, we assembled 67 685 and 70 668 de novo contigs from partial overlap among paired-end reads, with an average length of 240 and 241 bp for the two species, respectively, which were used to investigate functional classification of RAD tags in a blastx search. Analysed separately by population, we recovered 29 443 putatively orthologous RAD tags shared across the four sampled populations, containing 28 023 sequence variants, of which c. 13 000 are segregating between species, and c. 3000 segregating between populations within each species. Analyses based on these RAD tags yielded robust phylogenetic inferences, even with data set constructed from surprisingly few loci. This study illustrates the potential for reduced-representation genome data to resolve difficult phylogenetic relationships in temperate bamboos. © 2013 John Wiley & Sons Ltd.

  5. 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.

  6. Genome-wide association mapping of resistance to eyespot disease (Pseudocercosporella herpotrichoides) in European winter wheat (Triticum aestivum L.) and fine-mapping of Pch1.

    Science.gov (United States)

    Zanke, Christine D; Rodemann, Bernd; Ling, Jie; Muqaddasi, Quddoos H; Plieske, Jörg; Polley, Andreas; Kollers, Sonja; Ebmeyer, Erhard; Korzun, Viktor; Argillier, Odile; Stiewe, Gunther; Zschäckel, Thomas; Ganal, Martin W; Röder, Marion S

    2017-03-01

    Genotypes with recombination events in the Triticum ventricosum introgression on chromosome 7D allowed to fine-map resistance gene Pch1, the main source of eyespot resistance in European winter wheat cultivars. Eyespot (also called Strawbreaker) is a common and serious fungal disease of winter wheat caused by the necrotrophic fungi Oculimacula yallundae and Oculimacula acuformis (former name Pseudocercosporella herpotrichoides). A genome-wide association study (GWAS) for eyespot was performed with 732 microsatellite markers (SSR) and 7761 mapped SNP markers derived from the 90 K iSELECT wheat array using a panel of 168 European winter wheat varieties as well as three spring wheat varieties and phenotypic evaluation of eyespot in field tests in three environments. Best linear unbiased estimations (BLUEs) were calculated across all trials and ranged from 1.20 (most resistant) to 5.73 (most susceptible) with an average value of 4.24 and a heritability of H (2) = 0.91. A total of 108 SSR and 235 SNP marker-trait associations (MTAs) were identified by considering associations with a -log10 (P value) ≥3.0. Significant MTAs for eyespot-score BLUEs were found on chromosomes 1D, 2A, 2D, 3D, 5A, 5D, 6A, 7A and 7D for the SSR markers and chromosomes 1B, 2A, 2B, 2D, 3B and 7D for the SNP markers. For 18 varieties (10.5%), a highly resistant phenotype was detected that was linked to the presence of the resistance gene Pch1 on chromosome 7D. The identification of genotypes with recombination events in the introgressed genomic segment from Triticum ventricosum harboring the Pch1 resistance gene on chromosome 7DL allowed the fine-mapping of this gene using additional SNP markers and a potential candidate gene Traes_7DL_973A33763 coding for a CC-NBS-LRR class protein was identified.

  7. Exploring genome-wide - dietary heme iron intake interactions and the risk of type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Louis Robert Pasquale

    2013-01-01

    Full Text Available Aims/hypothesis: Genome-wide association studies have identified over 50 new genetic loci for type 2 diabetes (T2D. Several studies conclude that higher dietary heme iron intake increases the risk of T2D. Therefore we assessed whether the relation between genetic loci and type 2 diabetes is modified by dietary heme iron intake. Methods: We used Affymetrix Genome-Wide Human 6.0 array data (681,770 single nucleotide polymorphisms (SNPs and dietary information collected in the Health Professionals Follow-up Study (n=725 cases; n=1,273 controls and the Nurses’ Health Study (n=1,081 cases; n=1,692 controls. We assessed whether genome-wide SNPs or iron metabolism SNPs interacted with dietary heme iron intake in relation to T2D, testing for associations in each cohort separately and then meta-analyzing to pool the results. Finally, we created 1,000 synthetic pathways matched to an iron metabolism pathway on number of genes, and number of SNPs in each gene. We compared the iron metabolic pathway SNPs with these synthetic SNP assemblies in their relation to T2D to assess if the pathway as a whole interacts with dietary heme iron intake.Results: Using a genomic approach, we found no significant gene-environment interactions with dietary heme iron intake in relation to T2D (top SNP in pooled analysis: intergenic rs10980508; p=1.03E-06 > Bonferroni corrected p=7.33E-08. Furthermore, no SNP in the iron metabolic pathway significantly interacted with dietary heme iron intake (top SNP in pooled analysis: rs1805313; p=1.14E-03 > Bonferroni corrected p=2.10E-04. Finally, neither the main genetic effects (pooled empirical p by SNP=0.41, nor gene – dietary heme-iron interactions (pooled empirical p value for the interactions=0.72 were significant for the iron metabolic pathway as a whole. Conclusions: We found no significant interactions between dietary heme iron intake and common SNPs in relation to T2D.

  8. SAQC: SNP Array Quality Control

    Directory of Open Access Journals (Sweden)

    Li Ling-Hui

    2011-04-01

    Full Text Available Abstract Background Genome-wide single-nucleotide polymorphism (SNP arrays containing hundreds of thousands of SNPs from the human genome have proven useful for studying important human genome questions. Data quality of SNP arrays plays a key role in the accuracy and precision of downstream data analyses. However, good indices for assessing data quality of SNP arrays have not yet been developed. Results We developed new quality indices to measure the quality of SNP arrays and/or DNA samples and investigated their statistical properties. The indices quantify a departure of estimated individual-level allele frequencies (AFs from expected frequencies via standardized distances. The proposed quality indices followed lognormal distributions in several large genomic studies that we empirically evaluated. AF reference data and quality index reference data for different SNP array platforms were established based on samples from various reference populations. Furthermore, a confidence interval method based on the underlying empirical distributions of quality indices was developed to identify poor-quality SNP arrays and/or DNA samples. Analyses of authentic biological data and simulated data show that this new method is sensitive and specific for the detection of poor-quality SNP arrays and/or DNA samples. Conclusions This study introduces new quality indices, establishes references for AFs and quality indices, and develops a detection method for poor-quality SNP arrays and/or DNA samples. We have developed a new computer program that utilizes these methods called SNP Array Quality Control (SAQC. SAQC software is written in R and R-GUI and was developed as a user-friendly tool for the visualization and evaluation of data quality of genome-wide SNP arrays. The program is available online (http://www.stat.sinica.edu.tw/hsinchou/genetics/quality/SAQC.htm.

  9. 1 + 1 = 3: Development and validation of a SNP-based algorithm to identify genetic contributions from three distinct inbred mouse strains.

    Science.gov (United States)

    Gorham, James D; Ranson, Matthew S; Smith, Janebeth C; Gorham, Beverly J; Muirhead, Kristen-Ashley

    2012-12-01

    State-of-the-art, genome-wide assessment of mouse genetic background uses single nucleotide polymorphism (SNP) PCR. As SNP analysis can use multiplex testing, it is amenable to high-throughput analysis and is the preferred method for shared resource facilities that offer genetic background assessment of mouse genomes. However, a typical individual SNP query yields only two alleles (A vs. B), limiting the application of this methodology to distinguishing contributions from no more than two inbred mouse strains. By contrast, simple sequence length polymorphism (SSLP) analysis yields multiple alleles but is not amenable to high-throughput testing. We sought to devise a SNP-based technique to identify donor strain origins when three distinct mouse strains potentially contribute to the genetic makeup of an individual mouse. A computational approach was used to devise a three-strain analysis (3SA) algorithm that would permit identification of three genetic backgrounds while still using a binary-output SNP platform. A panel of 15 mosaic mice with contributions from BALB/c, C57Bl/6, and DBA/2 genetic backgrounds was bred and analyzed using a genome-wide SNP panel using 1449 markers. The 3SA algorithm was applied and then validated using SSLP. The 3SA algorithm assigned 85% of 1449 SNPs as informative for the C57Bl/6, BALB/c, or DBA/2 backgrounds, respectively. Testing the panel of 15 F2 mice, the 3SA algorithm predicted donor strain origins genome-wide. Donor strain origins predicted by the 3SA algorithm correlated perfectly with results from individual SSLP markers located on five different chromosomes (n=70 tests). We have established and validated an analysis algorithm based on binary SNP data that can successfully identify the donor strain origins of chromosomal regions in mice that are bred from three distinct inbred mouse strains.

  10. Development of SNP markers and their application for genetic diversity analysis in the oil palm (Elaeis guineensis).

    Science.gov (United States)

    Ong, P W; Maizura, I; Abdullah, N A P; Rafii, M Y; Ooi, L C L; Low, E T L; Singh, R

    2015-10-09

    The genetic evaluation of oil palm germplasm collections is required for insight into the variability among populations. The information obtained is also useful for incorporating new genetic materials into current breeding programs. Single nucleotide polymorphisms (SNPs) have been widely used in many plant genetic studies due to the availability of large numbers of genomic sequences and expressed sequence tags. The present study examined 219 oil palms collected from two natural Angolan populations, a few hundred kilometers apart. A total of 62 SNPs were designed from oil palm genomic sequences and converted to cleaved amplified polymorphic sequence (CAPS). Of these, nine were found to be informative across the two populations. The nine informative SNPs revealed mean major allele frequency of 0.693. The average expected and observed heterozygosities were 0.398 and 0.400, respectively. The mean polymorphism information content was 0.315 (ranging between 0.223 and 0.375). None of the loci deviated from Hardy-Weinberg equilibrium and no rare alleles were detected. In cluster analysis using unweighted pair group method with arithmetic, the 219 oil palms fell into two clusters. This was further supported by the population structure analysis result (K = 2), suggesting that the samples were divided into two main genetic groups. However, the two groups did not coincide with the geographic populations. Analysis of molecular variance indicated that within-population variation contributed 93% of the total genetic variation. This study showed that SNP-based CAPS markers are useful for studying the genetic diversity of oil palm and have potential application for marker-trait association studies.

  11. Common genes underlying asthma and COPD? Genome-wide analysis on the Dutch hypothesis

    Science.gov (United States)

    Smolonska, Joanna; Koppelman, Gerard H.; Wijmenga, Cisca; Vonk, Judith M.; Zanen, Pieter; Bruinenberg, Marcel; Curjuric, Ivan; Imboden, Medea; Thun, Gian-Andri; Franke, Lude; Probst-Hensch, Nicole M.; Nürnberg, Peter; Riemersma, Roland A.; van Schayck, Onno; Loth, Daan W.; Bruselle, Guy G.; Stricker, Bruno H; Hofman, Albert; Uitterlinden, André G.; Lahousse, Lies; London, Stephanie J.; Loehr, Laura R.; Manichaikul, Ani; Barr, R. Graham; Donohue, Kathleen M.; Rich, Stephen S.; Pare, Peter; Bossé, Yohan; Hao, Ke; van den Berge, Maarten; Groen, Harry J.M.; Lammers, Jan-Willem J.; Mali, Willem; Boezen, H. Marike; Postma, Dirkje S.

    2014-01-01

    Asthma and chronic obstructive pulmonary disease (COPD) are thought to share a genetic background (“Dutch hypothesis”). We investigated whether asthma and COPD have common underlying genetic factors, performing genome-wide association studies for both asthma and COPD and combining the results in meta-analyses. Three loci showed potential involvement in both diseases: chr2p24.3, chr5q23.1 and chr13q14.2, containing DDX1, COMMD10 (both participating in the NFκβ pathway) and GNG5P5, respectively. SNP rs9534578 in GNG5P5 reached genome-wide significance after first stage replication (p=9.96·*10−9). The second stage replication in seven independent cohorts provided no significant replication. eQTL analysis in blood and lung on the top 20 associated SNPs identified two SNPs in COMMD10 influencing gene expression. Inflammatory processes differ in asthma and COPD and are mediated by NFκβ, which could be driven by the same underlying genes, COMMD10 and DDX1. None of the SNPs reached genome-wide significance. Our eQTL studies support a functional role of two COMMD10 SNPs, since they influence gene expression in both blood cells and lung tissue. Our findings either suggest that there is no common genetic component in asthma and COPD or, alternatively, different environmental factors, like lifestyle and occupation in different countries and continents may have obscured the genetic common contribution. PMID:24993907

  12. Gene set analyses of genome-wide association studies on 49 quantitative traits measured in a single genetic epidemiology dataset.

    Science.gov (United States)

    Kim, Jihye; Kwon, Ji-Sun; Kim, Sangsoo

    2013-09-01

    Gene set analysis is a powerful tool for interpreting a genome-wide association study result and is gaining popularity these days. Comparison of the gene sets obtained for a variety of traits measured from a single genetic epidemiology dataset may give insights into the biological mechanisms underlying these traits. Based on the previously published single nucleotide polymorphism (SNP) genotype data on 8,842 individuals enrolled in the Korea Association Resource project, we performed a series of systematic genome-wide association analyses for 49 quantitative traits of basic epidemiological, anthropometric, or blood chemistry parameters. Each analysis result was subjected to subsequent gene set analyses based on Gene Ontology (GO) terms using gene set analysis software, GSA-SNP, identifying a set of GO terms significantly associated to each trait (pcorr neuronal or nerve systems.

  13. Genome-wide meta-analyses identify multiple loci associated with smoking behavior.

    LENUS (Irish Health Repository)

    2010-05-01

    Consistent but indirect evidence has implicated genetic factors in smoking behavior. We report meta-analyses of several smoking phenotypes within cohorts of the Tobacco and Genetics Consortium (n = 74,053). We also partnered with the European Network of Genetic and Genomic Epidemiology (ENGAGE) and Oxford-GlaxoSmithKline (Ox-GSK) consortia to follow up the 15 most significant regions (n > 140,000). We identified three loci associated with number of cigarettes smoked per day. The strongest association was a synonymous 15q25 SNP in the nicotinic receptor gene CHRNA3 (rs1051730[A], beta = 1.03, standard error (s.e.) = 0.053, P = 2.8 x 10(-73)). Two 10q25 SNPs (rs1329650[G], beta = 0.367, s.e. = 0.059, P = 5.7 x 10(-10); and rs1028936[A], beta = 0.446, s.e. = 0.074, P = 1.3 x 10(-9)) and one 9q13 SNP in EGLN2 (rs3733829[G], beta = 0.333, s.e. = 0.058, P = 1.0 x 10(-8)) also exceeded genome-wide significance for cigarettes per day. For smoking initiation, eight SNPs exceeded genome-wide significance, with the strongest association at a nonsynonymous SNP in BDNF on chromosome 11 (rs6265[C], odds ratio (OR) = 1.06, 95% confidence interval (Cl) 1.04-1.08, P = 1.8 x 10(-8)). One SNP located near DBH on chromosome 9 (rs3025343[G], OR = 1.12, 95% Cl 1.08-1.18, P = 3.6 x 10(-8)) was significantly associated with smoking cessation.

  14. Genome Wide Association Mapping for Arabinoxylan Content in a Collection of Tetraploid Wheats.

    Directory of Open Access Journals (Sweden)

    Ilaria Marcotuli

    Full Text Available Arabinoxylans (AXs are major components of plant cell walls in bread wheat and are important in bread-making and starch extraction. Furthermore, arabinoxylans are components of soluble dietary fibre that has potential health-promoting effects in human nutrition. Despite their high value for human health, few studies have been carried out on the genetics of AX content in durum wheat.The genetic variability of AX content was investigated in a set of 104 tetraploid wheat genotypes and regions attributable to AX content were identified through a genome wide association study (GWAS. The amount of arabinoxylan, expressed as percentage (w/w of the dry weight of the kernel, ranged from 1.8% to 5.5% with a mean value of 4.0%. The GWAS revealed a total of 37 significant marker-trait associations (MTA, identifying 19 quantitative trait loci (QTL associated with AX content. The highest number of MTAs was identified on chromosome 5A (seven, where three QTL regions were associated with AX content, while the lowest number of MTAs was detected on chromosomes 2B and 4B, where only one MTA identified a single locus. Conservation of synteny between SNP marker sequences and the annotated genes and proteins in Brachypodium distachyon, Oryza sativa and Sorghum bicolor allowed the identification of nine QTL coincident with candidate genes. These included a glycosyl hydrolase GH35, which encodes Gal7 and a glucosyltransferase GT31 on chromosome 1A; a cluster of GT1 genes on chromosome 2B that includes TaUGT1 and cisZog1; a glycosyl hydrolase that encodes a CelC gene on chromosome 3A; Ugt12887 and TaUGT1genes on chromosome 5A; a (1,3-β-D-glucan synthase (Gsl12 gene and a glucosyl hydrolase (Cel8 gene on chromosome 7A.This study identifies significant MTAs for the AX content in the grain of tetraploid wheat genotypes. We propose that these may be used for molecular breeding of durum wheat varieties with higher soluble fibre content.

  15. The identification of loci for immune traits in chickens using a genome-wide association study.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available The genetic improvement of disease resistance in poultry continues to be a challenge. To identify candidate genes and loci responsible for these traits, genome-wide association studies using the chicken 60k high density single nucleotide polymorphism (SNP array for six immune traits, total serum immunoglobulin Y (IgY level, numbers of, and the ratio of heterophils and lymphocytes, and antibody responses against Avian Influenza Virus (AIV and Sheep Red Blood Cell (SRBC, were performed. RT-qPCR was used to quantify the relative expression of the identified candidate genes. Nine significantly associated SNPs (P < 2.81E-06 and 30 SNPs reaching the suggestively significant level (P < 5.62E-05 were identified. Five of the 10 SNPs that were suggestively associated with the antibody response to SRBC were located within or close to previously reported QTL regions. Fifteen SNPs reached a suggestive significance level for AIV antibody titer and seven were found on the sex chromosome Z. Seven suggestive markers involving five different SNPs were identified for the numbers of heterophils and lymphocytes, and the heterophil/lymphocyte ratio. Nine significant SNPs, all on chromosome 16, were significantly associated with serum total IgY concentration, and the five most significant were located within a narrow region spanning 6.4kb to 253.4kb (P = 1.20E-14 to 5.33E-08. After testing expression of five candidate genes (IL4I1, CD1b, GNB2L1, TRIM27 and ZNF692 located in this region, changes in IL4I1, CD1b transcripts were consistent with the concentrations of IgY, while abundances of TRIM27 and ZNF692 showed reciprocal changes to those of IgY concentrations. This study has revealed 39 SNPs associated with six immune traits (total serum IgY level, numbers of, and the ratio of heterophils and lymphocytes, and antibody responses against AIV and SRBC in Beijing-You chickens. The narrow region spanning 247kb on chromosome 16 is an important QTL for serum total Ig

  16. From disease association to risk assessment: an optimistic view from genome-wide association studies on type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Zhi Wei

    2009-10-01

    Full Text Available Genome-wide association studies (GWAS have been fruitful in identifying disease susceptibility loci for common and complex diseases. A remaining question is whether we can quantify individual disease risk based on genotype data, in order to facilitate personalized prevention and treatment for complex diseases. Previous studies have typically failed to achieve satisfactory performance, primarily due to the use of only a limited number of confirmed susceptibility loci. Here we propose that sophisticated machine-learning approaches with a large ensemble of markers may improve the performance of disease risk assessment. We applied a Support Vector Machine (SVM algorithm on a GWAS dataset generated on the Affymetrix genotyping platform for type 1 diabetes (T1D and optimized a risk assessment model with hundreds of markers. We subsequently tested this model on an independent Illumina-genotyped dataset with imputed genotypes (1,008 cases and 1,000 controls, as well as a separate Affymetrix-genotyped dataset (1,529 cases and 1,458 controls, resulting in area under ROC curve (AUC of approximately 0.84 in both datasets. In contrast, poor performance was achieved when limited to dozens of known susceptibility loci in the SVM model or logistic regression model. Our study suggests that improved disease risk assessment can be achieved by using algorithms that take into account interactions between a large ensemble of markers. We are optimistic that genotype-based disease risk assessment may be feasible for diseases where a notable proportion of the risk has already been captured by SNP arrays.

  17. A sequential Monte Carlo framework for haplotype inference in CNV/SNP genotype data.

    Science.gov (United States)

    Iliadis, Alexandros; Anastassiou, Dimitris; Wang, Xiaodong

    2014-01-01

    Copy number variations (CNVs) are abundant in the human genome. They have been associated with complex traits in genome-wide association studies (GWAS) and expected to continue playing an important role in identifying the etiology of disease phenotypes. As a result of current high throughput whole-genome single-nucleotide polymorphism (SNP) arrays, we currently have datasets that simultaneously have integer copy numbers in CNV regions as well as SNP genotypes. At the same time, haplotypes that have been shown to offer advantages over genotypes in identifying disease traits even though available for SNP genotypes are largely not available for CNV/SNP data due to insufficient computational tools. We introduce a new framework for inferring haplotypes in CNV/SNP data using a sequential Monte Carlo sampling scheme 'Tree-Based Deterministic Sampling CNV' (TDSCNV). We compare our method with polyHap(v2.0), the only currently available software able to perform inference in CNV/SNP genotypes, on datasets of varying number of markers. We have found that both algorithms show similar accuracy but TDSCNV is an order of magnitude faster while scaling linearly with the number of markers and number of individuals and thus could be the method of choice for haplotype inference in such datasets. Our method is implemented in the TDSCNV package which is available for download at http://www.ee.columbia.edu/~anastas/tdscnv.

  18. Genome-wide association implicates numerous genes and pleiotropy underlying ecological trait variation in natural populations of Populus trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    McKown, Athena [University of British Columbia, Vancouver; Klapste, Jaroslav [University of British Columbia, Vancouver; Guy, Robert [University of British Columbia, Vancouver; Geraldes, Armando [University of British Columbia, Vancouver; Porth, Ilga [University of British Columbia, Vancouver; Hannemann, Jan [University of Victoria, Canada; Friedmann, Michael [University of British Columbia, Vancouver; Muchero, Wellington [ORNL; Tuskan, Gerald A [ORNL; Ehlting, Juergen [University of Victoria, Canada; Cronk, Quentin [University of British Columbia, Vancouver; El-Kassaby, Yousry [University of British Columbia, Vancouver; Mansfield, Shawn [University of British Columbia, Vancouver; Douglas, Carl [University of British Columbia, Vancouver

    2014-01-01

    To uncover the genetic basis of phenotypic trait variation, we used 448 unrelated wild accessions of black cottonwood (Populus trichocarpa Torr. & Gray) from natural populations throughout western North America. Extensive information from large-scale trait phenotyping (with spatial and temporal replications within a common garden) and genotyping (with a 34K Populus SNP array) of all accessions were used for gene discovery in a genome-wide association study (GWAS).

  19. Genome-Wide Association Study Identifies Loci for Salt Tolerance during Germination in Autotetraploid Alfalfa (Medicago sativa L.) Using Genotyping-by-Sequencing.

    Science.gov (United States)

    Yu, Long-Xi; Liu, Xinchun; Boge, William; Liu, Xiang-Ping

    2016-01-01

    Salinity is one of major abiotic stresses limiting alfalfa (Medicago sativa L.) production in the arid and semi-arid regions in US and other counties. In this study, we used a diverse panel of alfalfa accessions previously described by Zhang et al. (2015) to identify molecular markers associated with salt tolerance during germination using genome-wide association study (GWAS) and genotyping-by-sequencing (GBS). Phenotyping was done by germinating alfalfa seeds under different levels of salt stress. Phenotypic data of adjusted germination rates and SNP markers generated by GBS were used for marker-trait association. Thirty six markers were significantly associated with salt tolerance in at least one level of salt treatments. Alignment of sequence tags to the Medicago truncatula genome revealed genetic locations of the markers on all chromosomes except chromosome 3. Most significant markers were found on chromosomes 1, 2, and 4. BLAST search using the flanking sequences of significant markers identified 14 putative candidate genes linked to 23 significant markers. Most of them were repeatedly identified in two or three salt treatments. Several loci identified in the present study had similar genetic locations to the reported QTL associated with salt tolerance in M. truncatula. A locus identified on chromosome 6 by this study overlapped with that by drought in our previous study. To our knowledge, this is the first report on mapping loci associated with salt tolerance during germination in autotetraploid alfalfa. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms by which salt and drought stresses affect alfalfa growth. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance to drought and salt stresses.

  20. 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.

  1. Genome-Wide Association Study Identifies Novel Loci Associated With Diisocyanate-Induced Occupational Asthma

    Science.gov (United States)

    Yucesoy, Berran; Kaufman, Kenneth M.; Lummus, Zana L.; Weirauch, Matthew T.; Zhang, Ge; Cartier, André; Boulet, Louis-Philippe; Sastre, Joaquin; Quirce, Santiago; Tarlo, Susan M.; Cruz, Maria-Jesus; Munoz, Xavier; Harley, John B.; Bernstein, David I.

    2015-01-01

    Diisocyanates, reactive chemicals used to produce polyurethane products, are the most common causes of occupational asthma. The aim of this study is to identify susceptibility gene variants that could contribute to the pathogenesis of diisocyanate asthma (DA) using a Genome-Wide Association Study (GWAS) approach. Genome-wide single nucleotide polymorphism (SNP) genotyping was performed in 74 diisocyanate-exposed workers with DA and 824 healthy controls using Omni-2.5 and Omni-5 SNP microarrays. We identified 11 SNPs that exceeded genome-wide significance; the strongest association was for the rs12913832 SNP located on chromosome 15, which has been mapped to the HERC2 gene (p = 6.94 × 10−14). Strong associations were also found for SNPs near the ODZ3 and CDH17 genes on chromosomes 4 and 8 (rs908084, p = 8.59 × 10−9 and rs2514805, p = 1.22 × 10−8, respectively). We also prioritized 38 SNPs with suggestive genome-wide significance (p < 1 × 10−6). Among them, 17 SNPs map to the PITPNC1, ACMSD, ZBTB16, ODZ3, and CDH17 gene loci. Functional genomics data indicate that 2 of the suggestive SNPs (rs2446823 and rs2446824) are located within putative binding sites for the CCAAT/Enhancer Binding Protein (CEBP) and Hepatocyte Nuclear Factor 4, Alpha transcription factors (TFs), respectively. This study identified SNPs mapping to the HERC2, CDH17, and ODZ3 genes as potential susceptibility loci for DA. Pathway analysis indicated that these genes are associated with antigen processing and presentation, and other immune pathways. Overlap of 2 suggestive SNPs with likely TF binding sites suggests possible roles in disruption of gene regulation. These results provide new insights into the genetic architecture of DA and serve as a basis for future functional and mechanistic studies. PMID:25918132

  2. Genome-wide association and biological pathway analysis for milk-fat composition in Danish Holstein and Danish Jersey cattle

    DEFF Research Database (Denmark)

    Buitenhuis, Bart; Janss, Luc L G; Poulsen, Nina Aagaard;

    2014-01-01

    The milk fat profile of the Danish Holstein (DH) and Danish Jersey (DJ) show clear differences. Identification of the genomic regions, genes and biological pathways underlying the milk fat biosynthesis will improve the understanding of the biology underlying bovine milk fat production and may...... provide new possibilities to change the milk fat composition by selective breeding. In this study a genome wide association scan (GWAS) in the DH and DJ was performed for a detailed milk fatty acid (FA) profile using the HD bovine SNP array and subsequently a biological pathway analysis based on the SNP...

  3. 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....

  4. Genome-wide Association Study of Personality Traits in the Long Life Family Study

    Directory of Open Access Journals (Sweden)

    Harold T Bae

    2013-05-01

    Full Text Available Personality traits have been shown to be associated with longevity and healthy aging. In order to discover novel genetic modifiers associated with personality traits as related with longevity, we performed a genome-wide association study (GWAS on personality factors assessed by NEO-FFI in individuals enrolled in the Long Life Family Study (LLFS, a study of 583 families (N up to 4595 with clustering for longevity in the United States and Denmark. Three SNPs, in almost perfect LD, associated with agreeableness reached genome-wide significance (p<10-8 and replicated in an additional sample of 1279 LLFS subjects, although one (rs9650241 failed to replicate and the other two were not available in two independent replication cohorts, the Baltimore Longitudinal Study of Aging and the New England Centenarian Study. Based on 10,000,000 permutations, the empirical p-value of 2X10-7 was observed for the genome-wide significant SNPs. Seventeen SNPs that reached marginal statistical significance in the two previous GWASs (p-value < 10-4 and 10-5, were also marginally significantly associated in this study (p-value < 0.05, although none of the associations passed the Bonferroni correction. In addition, we tested age-by-SNP interactions and found some significant associations. Since scores of personality traits in LLFS subjects change in the oldest ages, and genetic factors outweigh environmental factors to achieve extreme ages, these age-by-SNP interactions could be a proxy for complex gene-gene interactions affecting personality traits and longevity.

  5. Genome-wide mapping of copy number variation in humans: comparative analysis of high resolution array platforms.

    Directory of Open Access Journals (Sweden)

    Rajini R Haraksingh

    Full Text Available Accurate and efficient genome-wide detection of copy number variants (CNVs is essential for understanding human genomic variation, genome-wide CNV association type studies, cytogenetics research and diagnostics, and independent validation of CNVs identified from sequencing based technologies. Numerous, array-based platforms for CNV detection exist utilizing array Comparative Genome Hybridization (aCGH, Single Nucleotide Polymorphism (SNP genotyping or both. We have quantitatively assessed the abilities of twelve leading genome-wide CNV detection platforms to accurately detect Gold Standard sets of CNVs in the genome of HapMap CEU sample NA12878, and found significant differences in performance. The technologies analyzed were the NimbleGen 4.2 M, 2.1 M and 3×720 K Whole Genome and CNV focused arrays, the Agilent 1×1 M CGH and High Resolution and 2×400 K CNV and SNP+CGH arrays, the Illumina Human Omni1Quad array and the Affymetrix SNP 6.0 array. The Gold Standards used were a 1000 Genomes Project sequencing-based set of 3997 validated CNVs and an ultra high-resolution aCGH-based set of 756 validated CNVs. We found that sensitivity, total number, size range and breakpoint resolution of CNV calls were highest for CNV focused arrays. Our results are important for cost effective CNV detection and validation for both basic and clinical applications.

  6. Cooperative genome-wide analysis shows increased homozygosity in early onset Parkinson's disease.

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    Javier Simón-Sánchez

    Full Text Available Parkinson's disease (PD occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD is particularly associated with autosomal recessive (AR mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity.We carried out genome wide SNP genotyping to look for extended runs of homozygosity (ROHs in 1,445 EOPD cases and 6,987 controls. Logistic regression analyses showed an increased level of genomic homozygosity in EOPD cases compared to controls. These differences are larger for ROH of 9 Mb and above, where there is a more than three-fold increase in the proportion of cases carrying a ROH. These differences are not explained by occult recessive mutations at existing loci. Controlling for genome wide homozygosity in logistic regression analyses increased the differences between cases and controls, indicating that in EOPD cases ROHs do not simply relate to genome wide measures of inbreeding. Homozygosity at a locus on chromosome19p13.3 was identified as being more common in EOPD cases as compared to controls. Sequencing analysis of genes and predicted transcripts within this locus failed to identify a novel mutation causing EOPD in our cohort.There is an increased rate of genome wide homozygosity in EOPD, as measured by an increase in ROHs. These ROHs are a signature of inbreeding and do not necessarily harbour disease-causing genetic variants. Although there might be other regions of interest apart from chromosome 19p13.3, we lack the power to detect them with this analysis.

  7. Genome-wide search for gene-gene interactions in colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Shuo Jiao

    Full Text Available Genome-wide association studies (GWAS have successfully identified a number of single-nucleotide polymorphisms (SNPs associated with colorectal cancer (CRC risk. However, these susceptibility loci known today explain only a small fraction of the genetic risk. Gene-gene interaction (GxG is considered to be one source of the missing heritability. To address this, we performed a genome-wide search for pair-wise GxG associated with CRC risk using 8,380 cases and 10,558 controls in the discovery phase and 2,527 cases and 2,658 controls in the replication phase. We developed a simple, but powerful method for testing interaction, which we term the Average Risk Due to Interaction (ARDI. With this method, we conducted a genome-wide search to identify SNPs showing evidence for GxG with previously identified CRC susceptibility loci from 14 independent regions. We also conducted a genome-wide search for GxG using the marginal association screening and examining interaction among SNPs that pass the screening threshold (p<10(-4. For the known locus rs10795668 (10p14, we found an interacting SNP rs367615 (5q21 with replication p = 0.01 and combined p = 4.19×10(-8. Among the top marginal SNPs after LD pruning (n = 163, we identified an interaction between rs1571218 (20p12.3 and rs10879357 (12q21.1 (nominal combined p = 2.51×10(-6; Bonferroni adjusted p = 0.03. Our study represents the first comprehensive search for GxG in CRC, and our results may provide new insight into the genetic etiology of CRC.

  8. 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...

  9. 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)....

  10. Genome-wide association mapping including phenotypes from relatives without genotypes in a single-step (ssGWAS for 6-week body weight in broiler chickens

    Directory of Open Access Journals (Sweden)

    Huiyu eWang

    2014-05-01

    Full Text Available The purpose of this study was to compare results obtained from various methodologies for genome-wide association studies, when applied to real data, in terms of number and commonality of regions identified and their genetic variance explained, computational speed, and possible pitfalls in interpretations of results. Methodologies include: two iteratively reweighted single-step genomic BLUP procedures (ssGWAS1 and ssGWAS2, a single-marker model (CGWAS, and BayesB. The ssGWAS methods utilize genomic breeding values (GEBVs based on combined pedigree, genomic and phenotypic information, while CGWAS and BayesB only utilize phenotypes from genotyped animals or pseudo-phenotypes. In this study, ssGWAS was performed by converting GEBVs to SNP marker effects. Unequal variances for markers were incorporated for calculating weights into a new genomic relationship matrix. SNP weights were refined iteratively. The data was body weight at 6 weeks on 274,776 broiler chickens, of which 4553 were genotyped using a 60k SNP chip. Comparison of genomic regions was based on genetic variances explained by local SNP regions (20 SNPs. After 3 iterations, the noise was greatly reduced of ssGWAS1 and results are similar to that of CGWAS, with 4 out of the top 10 regions in common. In contrast, for BayesB, the plot was dominated by a single region explaining 23.1% of the genetic variance. This same region was found by ssGWAS1 with the same rank, but the amount of genetic variation attributed to the region was only 3%. These finding emphasize the need for caution when comparing and interpreting results from various methods, and highlight that detected associations, and strength of association, strongly depends on methodologies and details of implementations. BayesB appears to overly shrink regions to zero, while overestimating the amount of genetic variation attributed to the remaining SNP effects. The real world is most likely a compromise between methods and remains to

  11. 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...

  12. Combining Genome-Wide Information with a Functional Structural Plant Model to Simulate 1-Year-Old Apple Tree Architecture

    Science.gov (United States)

    Migault, Vincent; Pallas, Benoît; Costes, Evelyne

    2017-01-01

    In crops, optimizing target traits in breeding programs can be fostered by selecting appropriate combinations of architectural traits which determine light interception and carbon acquisition. In apple tree, architectural traits were observed to be under genetic control. However, architectural traits also result from many organogenetic and morphological processes interacting with the environment. The present study aimed at combining a FSPM built for apple tree, MAppleT, with genetic determinisms of architectural traits, previously described in a bi-parental population. We focused on parameters related to organogenesis (phyllochron and immediate branching) and morphogenesis processes (internode length and leaf area) during the first year of tree growth. Two independent datasets collected in 2004 and 2007 on 116 genotypes, issued from a ‘Starkrimson’ × ‘Granny Smith’ cross, were used. The phyllochron was estimated as a function of thermal time and sylleptic branching was modeled subsequently depending on phyllochron. From a genetic map built with SNPs, marker effects were estimated on four MAppleT parameters with rrBLUP, using 2007 data. These effects were then considered in MAppleT to simulate tree development in the two climatic conditions. The genome wide prediction model gave consistent estimations of parameter values with correlation coefficients between observed values and estimated values from SNP markers ranging from 0.79 to 0.96. However, the accuracy of the prediction model following cross validation schemas was lower. Three integrative traits (the number of leaves, trunk length, and number of sylleptic laterals) were considered for validating MAppleT simulations. In 2007 climatic conditions, simulated values were close to observations, highlighting the correct simulation of genetic variability. However, in 2004 conditions which were not used for model calibration, the simulations differed from observations. This study demonstrates the possibility

  13. Genome-wide effects of long-term divergent selection.

    Directory of Open Access Journals (Sweden)

    Anna M Johansson

    2010-11-01

    Full Text Available To understand the genetic mechanisms leading to phenotypic differentiation, it is important to identify genomic regions under selection. We scanned the genome of two chicken lines from a single trait selection experiment, where 50 generations of selection have resulted in a 9-fold difference in body weight. Analyses of nearly 60,000 SNP markers showed that the effects of selection on the genome are dramatic. The lines were fixed for alternative alleles in more than 50 regions as a result of selection. Another 10 regions displayed strong evidence for ongoing differentiation during the last 10 generations. Many more regions across the genome showed large differences in allele frequency between the lines, indicating that the phenotypic evolution in the lines in 50 generations is the result of an exploitation of standing genetic variation at 100s of loci across the genome.

  14. Genetic diversity, population structure and relationships in indigenous cattle populations of Ethiopia and Korean Hanwoo breeds using SNP markers.

    Science.gov (United States)

    Edea, Zewdu; Dadi, Hailu; Kim, Sang-Wook; Dessie, Tadelle; Lee, Taeheon; Kim, Heebal; Kim, Jong-Joo; Kim, Kwan-Suk

    2013-01-01

    In total, 166 individuals from five indigenous Ethiopian cattle populations - Ambo (n = 27), Borana (n = 35), Arsi (n = 30), Horro (n = 36), and Danakil (n = 38) - were genotyped for 8773 single nucleotide polymorphism (SNP) markers to assess genetic diversity, population structure, and relationships. As a representative of taurine breeds, Hanwoo cattle (n = 40) were also included in the study for reference. Among Ethiopian cattle populations, the proportion of SNPs with minor allele frequencies (MAFs) ≥0.05 ranged from 81.63% in Borana to 85.30% in Ambo, with a mean of 83.96% across all populations. The Hanwoo breed showed the highest proportion of polymorphism, with MAFs ≥0.05, accounting for 95.21% of total SNPs. The mean expected heterozygosity varied from 0.370 in Danakil to 0.410 in Hanwoo. The mean genetic differentiation (F ST; 1%) in Ethiopian cattle revealed that within individual variation accounted for approximately 99% of the total genetic variation. As expected, F ST and Reynold genetic distance were greatest between Hanwoo and Ethiopian cattle populations, with average values of 17.62 and 18.50, respectively. The first and second principal components explained approximately 78.33% of the total variation and supported the clustering of the populations according to their historical origins. At K = 2 and 3, a considerable source of variation among cattle is the clustering of the populations into Hanwoo (taurine) and Ethiopian cattle populations. The low estimate of genetic differentiation (F ST) among Ethiopian cattle populations indicated that differentiation among these populations is low, possibly owing to a common historical origin and high gene flow. Genetic distance, phylogenic tree, principal component analysis, and population structure analyses clearly differentiated the cattle population according to their historical origins, and confirmed that Ethiopian cattle populations are genetically distinct from the Hanwoo breed.

  15. Genetic diversity, population structure and relationships in indigenous cattle populations of Ethiopia and Hanwoo breeds using SNP markers

    Directory of Open Access Journals (Sweden)

    Zewdu eEdea

    2013-03-01

    Full Text Available In total, 166 individuals from 5 indigenous Ethiopian cattle populations—Ambo (n = 27, Borana (n = 35, Arsi (n = 30, Horro (n = 36, and Danakil (n = 38—were genotyped for 8773 single nucleotide polymorphism (SNP markers to assess genetic diversity, population structure, and relationships. As a representative of taurine breeds, Hanwoo cattle (n = 40 were also included in the study for reference. Among Ethiopian cattle populations, the proportion of SNPs with minor allele frequencies (MAFs ≥ 0.05 ranged from 81.63% in Borana to 85.30% in Ambo, with a mean of 83.96% across all populations. The Hanwoo breed showed the highest proportion of polymorphism, with MAFs ≥ 0.05, accounting for 95.21% of total SNPs. The mean expected heterozygosity varied from 0.370 in Danakil to 0.410 in Hanwoo. The mean genetic differentiation (FST (1% in Ethiopian cattle revealed that within-individual variation accounted for approximately 99% of the total genetic variation. As expected, FST and Reynold genetic distance were greatest between Hanwoo and Ethiopian cattle populations, with average values of 17.62 and 18.50, respectively. The first and second principal components explained approximately 78.33% of the total variation and supported the clustering of the populations according to their historical origins. At K = 2 and 3, a considerable source of variation among cattle is the clustering of the populations into Hanwoo (taurine and Ethiopian cattle populations. The low estimate of genetic differentiation (FST among Ethiopian cattle populations indicated that differentiation among these populations is low, possibly owing to a common historical origin and high gene flow. Genetic distance, phylogenic tree, PCA, and population structure analyses clearly differentiated the cattle population according to their historical origins, and confirmed that Ethiopian cattle populations are genetically distinct from the Hanwoo breed

  16. SNP detection from de novo transcriptome sequencing in the bivalve Macoma balthica: marker development for evolutionary studies.

    Directory of Open Access Journals (Sweden)

    Eric Pante

    Full Text Available Hybrid zones are noteworthy systems for the study of environmental adaptation to fast-changing environments, as they constitute reservoirs of polymorphism and are key to the maintenance of biodiversity. They can move in relation to climate fluctuations, as temperature can affect both selection and migration, or remain trapped by environmental and physical barriers. There is therefore a very strong incentive to study the dynamics of hybrid zones subjected to climate variations. The infaunal bivalve Macoma balthica emerges as a noteworthy model species, as divergent lineages hybridize, and its native NE Atlantic range is currently contracting to the North. To investigate the dynamics and functioning of hybrid zones in M. balthica, we developed new molecular markers by sequencing the collective transcriptome of 30 individuals. Ten individuals were pooled for each of the three populations sampled at the margins of two hybrid zones. A single 454 run generated 277 Mb from which 17K SNPs were detected. SNP density averaged 1 polymorphic site every 14 to 19 bases, for mitochondrial and nuclear loci, respectively. An [Formula: see text] scan detected high genetic divergence among several hundred SNPs, some of them involved in energetic metabolism, cellular respiration and physiological stress. The high population differentiation, recorded for nuclear-encoded ATP synthase and NADH dehydrogenase as well as most mitochondrial loci, suggests cytonuclear genetic incompatibilities. Results from this study will help pave the way to a high-resolution study of hybrid zone dynamics in M. balthica, and the relative importance of endogenous and exogenous barriers to gene flow in this system.

  17. Genome-wide gene-environment study identifies glutamate receptor gene GRIN2A as a Parkinson's disease modifier gene via interaction with coffee.

    Science.gov (United States)

    Hamza, Taye H; Chen, Honglei; Hill-Burns, Erin M; Rhodes, Shannon L; Montimurro, Jennifer; Kay, Denise M; Tenesa, Albert; Kusel, Victoria I; Sheehan, Patricia; Eaaswarkhanth, Muthukrishnan; Yearout, Dora; Samii, Ali; Roberts, John W; Agarwal, Pinky; Bordelon, Yvette; Park, Yikyung; Wang, Liyong; Gao, Jianjun; Vance, Jeffery M; Kendler, Kenneth S; Bacanu, Silviu-Alin; Scott, William K; Ritz, Beate; Nutt, John; Factor, Stewart A; Zabetian, Cyrus P; Payami, Haydeh

    2011-08-01

    Our aim was to identify genes that influence the inverse association of coffee with the risk of developing Parkinson's disease (PD). We used genome-wide genotype data and lifetime caffeinated-coffee-consumption data on 1,458 persons with PD and 931 without PD from the NeuroGenetics Research Consortium (NGRC), and we performed a genome-wide association and interaction study (GWAIS), testing each SNP's main-effect plus its interaction with coffee, adjusting for sex, age, and two principal components. We then stratified subjects as heavy or light coffee-drinkers and performed genome-wide association study (GWAS) in each group. We replicated the most significant SNP. Finally, we imputed the NGRC dataset, increasing genomic coverage to examine the region of interest in detail. The primary analyses (GWAIS, GWAS, Replication) were performed using genotyped data. In GWAIS, the most significant signal came from rs4998386 and the neighboring SNPs in GRIN2A. GRIN2A encodes an NMDA-glutamate-receptor subunit and regulates excitatory neurotransmission in the brain. Achieving P(2df) = 10(-6), GRIN2A surpassed all known PD susceptibility genes in significance in the GWAIS. In stratified GWAS, the GRIN2A signal was present in heavy coffee-drinkers (OR = 0.43; P = 6×10(-7)) but not in light coffee-drinkers. The a priori Replication hypothesis that "Among heavy coffee-drinkers, rs4998386_T carriers have lower PD risk than rs4998386_CC carriers" was confirmed: OR(Replication) = 0.59, P(Replication) = 10(-3); OR(Pooled) = 0.51, P(Pooled) = 7×10(-8). Compared to light coffee-drinkers with rs4998386_CC genotype, heavy coffee-drinkers with rs4998386_CC genotype had 18% lower risk (P = 3×10(-3)), whereas heavy coffee-drinkers with rs4998386_TC genotype had 59% lower risk (P = 6×10(-13)). Imputation revealed a block of SNPs that achieved P(2df)coffee-drinkers. This study is proof of concept that inclusion of environmental factors can help identify

  18. Genome-Wide Gene-Environment Study Identifies Glutamate Receptor Gene GRIN2A as a Parkinson's Disease Modifier Gene via Interaction with Coffee

    Science.gov (United States)

    Hamza, Taye H.; Chen, Honglei; Hill-Burns, Erin M.; Rhodes, Shannon L.; Montimurro, Jennifer; Kay, Denise M.; Tenesa, Albert; Kusel, Victoria I.; Sheehan, Patricia; Eaaswarkhanth, Muthukrishnan; Yearout, Dora; Samii, Ali; Roberts, John W.; Agarwal, Pinky; Bordelon, Yvette; Park, Yikyung; Wang, Liyong; Gao, Jianjun; Vance, Jeffery M.; Kendler, Kenneth S.; Bacanu, Silviu-Alin; Scott, William K.; Ritz, Beate; Nutt, John; Factor, Stewart A.; Zabetian, Cyrus P.; Payami, Haydeh

    2011-01-01

    Our aim was to identify genes that influence the inverse association of coffee with the risk of developing Parkinson's disease (PD). We used genome-wide genotype data and lifetime caffeinated-coffee-consumption data on 1,458 persons with PD and 931 without PD from the NeuroGenetics Research Consortium (NGRC), and we performed a genome-wide association and interaction study (GWAIS), testing each SNP's main-effect plus its interaction with coffee, adjusting for sex, age, and two principal components. We then stratified subjects as heavy or light coffee-drinkers and performed genome-wide association study (GWAS) in each group. We replicated the most significant SNP. Finally, we imputed the NGRC dataset, increasing genomic coverage to examine the region of interest in detail. The primary analyses (GWAIS, GWAS, Replication) were performed using genotyped data. In GWAIS, the most significant signal came from rs4998386 and the neighboring SNPs in GRIN2A. GRIN2A encodes an NMDA-glutamate-receptor subunit and regulates excitatory neurotransmission in the brain. Achieving P2df = 10−6, GRIN2A surpassed all known PD susceptibility genes in significance in the GWAIS. In stratified GWAS, the GRIN2A signal was present in heavy coffee-drinkers (OR = 0.43; P = 6×10−7) but not in light coffee-drinkers. The a priori Replication hypothesis that “Among heavy coffee-drinkers, rs4998386_T carriers have lower PD risk than rs4998386_CC carriers” was confirmed: ORReplication = 0.59, PReplication = 10−3; ORPooled = 0.51, PPooled = 7×10−8. Compared to light coffee-drinkers with rs4998386_CC genotype, heavy coffee-drinkers with rs4998386_CC genotype had 18% lower risk (P = 3×10−3), whereas heavy coffee-drinkers with rs4998386_TC genotype had 59% lower risk (P = 6×10−13). Imputation revealed a block of SNPs that achieved P2dfcoffee-drinkers. This study is proof of concept that inclusion of environmental factors can help identify genes that

  19. Report on ISFG SNP Panel Discussion

    DEFF Research Database (Denmark)

    Butler, John M.; Budowle, B.; Gill, P.;

    2008-01-01

    Six scientists presented their views and experience with single nucleotide polymorphism (SNP) markers, multiplexes, and methods regarding their potential application in forensic identity and relationship testing. Benefits and limitations of SNPs were reviewed, as were different SNP marker categor...

  20. A genome-wide meta-analysis identifies novel loci associated with schizophrenia and bipolar disorder.

    Science.gov (United States)

    Wang, Ke-Sheng; Liu, Xue-Feng; Aragam, Nagesh

    2010-12-01

    Schizophrenia and bipolar disorder both have strong inherited components. Recent studies have indicated that schizophrenia and bipolar disorder may share more than half of their genetic determinants. In this study, we performed a meta-analysis (combined analysis) for genome-wide association data of the Affymetrix Genome-Wide Human SNP array 6.0 to detect genetic variants influencing both schizophrenia and bipolar disorder using European-American samples (653 bipolar cases and 1034 controls, 1172 schizophrenia cases and 1379 controls). The best associated SNP rs11789399 was located at 9q33.1 (p=2.38 × 10(-6), 5.74 × 10(-4), and 5.56 × 10(-9), for schizophrenia, bipolar disorder and meta-analysis of schizophrenia and bipolar disorder, respectively), where one flanking gene, ASTN2 (220kb away) has been associated with attention deficit/hyperactivity disorder and schizophrenia. The next best SNP was rs12201676 located at 6q15 (p=2.67 × 10(-4), 2.12 × 10(-5), 3.88 × 10(-8) for schizophrenia, bipolar disorder and meta-analysis, respectively), near two flanking genes, GABRR1 and GABRR2 (15 and 17kb away, respectively). The third interesting SNP rs802568 was at 7q35 within CNTNAP2 (p=8.92 × 10(-4), 1.38 × 10(-5), and 1.62 × 10(-7) for schizophrenia, bipolar disorder and meta-analysis, respectively). Through meta-analysis, we found two additional associated genes NALCN (the top SNP is rs2044117, p=4.57 × 10(-7)) and NAP5 (the top SNP is rs10496702, p=7.15 × 10(-7)). Haplotype analyses of above five loci further supported the associations with schizophrenia and bipolar disorder. These results provide evidence of common genetic variants influencing schizophrenia and bipolar disorder. These findings will serve as a resource for replication in other populations to elucidate the potential role of these genetic variants in schizophrenia and bipolar disorder.

  1. Generation and analysis of ESTs from the eastern oyster, Crassostrea virginica Gmelin and identification of microsatellite and SNP markers

    Directory of Open Access Journals (Sweden)

    Wallace Richard

    2007-06-01

    Full Text Available Abstract Background The eastern oyster, Crassostrea virginica (Gmelin 1791, is an economically important species cultured in many areas in North America. It is also ecologically important because of the impact of its filter feeding behaviour on water quality. Populations of C. virginica have been threatened by overfishing, habitat degradation, and diseases. Through genome research, strategies are being developed to reverse its population decline. However, large-scale expressed sequence tag (EST resources have been lacking for this species. Efficient generation of EST resources from this species has been hindered by a high redundancy of transcripts. The objectives of this study were to construct a normalized cDNA library for efficient EST analysis, to generate thousands of ESTs, and to analyze the ESTs for microsatellites and potential single nucleotide polymorphisms (SNPs. Results A normalized and subtracted C. virginica cDNA library was constructed from pooled RNA isolated from hemocytes, mantle, gill, gonad and digestive tract, muscle, and a whole juvenile oyster. A total of 6,528 clones were sequenced from this library generating 5,542 high-quality EST sequences. Cluster analysis indicated the presence of 635 contigs and 4,053 singletons, generating a total of 4,688 unique sequences. About 46% (2,174 of the unique ESTs had significant hits (E-value ≤ 1e-05 to the non-redundant protein database; 1,104 of which were annotated using Gene Ontology (GO terms. A total of 35 microsatellites were identified from the ESTs, with 18 having sufficient flanking sequences for primer design. A total of 6,533 putative SNPs were also identified using all existing and the newly generated EST resources of the eastern oysters. Conclusion A high quality normalized cDNA library was constructed. A total of 5,542 ESTs were generated representing 4,688 unique sequences. Putative microsatellite and SNP markers were identified. These genome resources provide the

  2. Genome-wide association study of toxic metals and trace elements reveals novel associations.

    Science.gov (United States)

    Ng, Esther; Lind, P Monica; Lindgren, Cecilia; Ingelsson, Erik; Mahajan, Anubha; Morris, Andrew; Lind, Lars

    2015-08-15

    The accumulation of toxic metals in the human body is influenced by exposure and mechanisms involved in metabolism, some of which may be under genetic control. This is the first genome-wide association study to investigate variants associated with whole blood levels of a range of toxic metals. Eleven toxic metals and trace elements (aluminium, cadmium, cobalt, copper, chromium, mercury, manganese, molybdenum, nickel, lead and zinc) were assayed in a cohort of 949 individuals using mass spectrometry. DNA samples were genotyped on the Infinium Omni Express bead microarray and imputed up to reference panels from the 1000 Genomes Project. Analyses revealed two regions associated with manganese level at genome-wide significance, mapping to 4q24 and 1q41. The lead single nucleotide polymorphism (SNP) in the 4q24 locus was rs13107325 (P-value = 5.1 × 10(-11), β = -0.77), located in an exon of SLC39A8, which encodes a protein involved in manganese and zinc transport. The lead SNP in the 1q41 locus is rs1776029 (P-value = 2.2 × 10(-14), β = -0.46). The SNP lies within the intronic region of SLC30A10, another transporter protein. Among other metals, the loci 6q14.1 and 3q26.32 were associated with cadmium and mercury levels (P = 1.4 × 10(-10), β = -1.2 and P = 1.8 × 10(-9), β = -1.8, respectively). Whole blood measurements of toxic metals are associated with genetic variants in metal transporter genes and others. This is relevant in inferring metabolic pathways of metals and identifying subsets of individuals who may be more susceptible to metal toxicity. © The Author 2015. Published by Oxford University Press.

  3. Discovering Genome-Wide Tag SNPs Based on the Mutual Information of the Variants

    Science.gov (United States)

    Elmas, Abdulkadir; Ou Yang, Tai-Hsien; Wang, Xiaodong

    2016-01-01

    Exploring linkage disequilibrium (LD) patterns among the single nucleotide polymorphism (SNP) sites can improve the accuracy and cost-effectiveness of genomic association studies, whereby representative (tag) SNPs are identified to sufficiently represent the genomic diversity in populations. There has been considerable amount of effort in developing efficient algorithms to select tag SNPs from the growing large-scale data sets. Methods using the classical pairwise-LD and multi-locus LD measures have been proposed that aim to reduce the computational complexity and to increase the accuracy, respectively. The present work solves the tag SNP selection problem by efficiently balancing the computational complexity and accuracy, and improves the coverage in genomic diversity in a cost-effective manner. The employed algorithm makes use of mutual information to explore the multi-locus association between SNPs and can handle different data types and conditions. Experiments with benchmark HapMap data sets show comparable or better performance against the state-of-the-art algorithms. In particular, as a novel application, the genome-wide SNP tagging is performed in the 1000 Genomes Project data sets, and produced a well-annotated database of tagging variants that capture the common genotype diversity in 2,504 samples from 26 human populations. Compared to conventional methods, the algorithm requires as input only the genotype (or haplotype) sequences, can scale up to genome-wide analyses, and produces accurate solutions with more information-rich output, providing an improved platform for researchers towards the subsequent association studies. PMID:27992465

  4. Comparison of 6q25 Breast Cancer Hits from Asian and European Genome Wide Association Studies in the Breast Cancer Association Consortium (BCAC)

    NARCIS (Netherlands)

    Hein, Rebecca; Maranian, Melanie; Hopper, John L.; Kapuscinski, Miroslaw K.; Southey, Melissa C.; Park, Daniel J.; Schmidt, Marjanka K.; Broeks, Annegien; Hogervorst, Frans B. L.; Bueno-de-Mesquit, H. Bas; Muir, Kenneth R.; Lophatananon, Artitaya; Rattanamongkongul, Suthee; Puttawibul, Puttisak; Fasching, Peter A.; Hein, Alexander; Ekici, Arif B.; Beckmann, Matthias W.; Fletcher, Olivia; Johnson, Nichola; Silva, Isabel dos Santos; Peto, Julian; Sawyer, Elinor; Tomlinson, Ian; Kerin, Michael; Miller, Nicola; Marmee, Frederick; Schneeweiss, Andreas; Sohn, Christof; Burwinkel, Barbara; Guenel, Pascal; Cordina-Duverger, Emilie; Menegaux, Florence; Truong, Therese; Bojesen, Stig E.; Nordestgaard, Borge G.; Flyger, Henrik; Milne, Roger L.; Arias Perez, Jose Ignacio; Pilar Zamora, M.; Benitez, Javier; Anton-Culver, Hoda; Ziogas, Argyrios; Bernstein, Leslie; Clarke, Christina A.; Brenner, Hermann; Mueller, Heiko; Arndt, Volker; Stegmaier, Christa; Rahman, Nazneen; Seal, Sheila; Turnbull, Clare; Renwick, Anthony; Meindl, Alfons; Schott, Sarah; Bartram, Claus R.; Schmutzler, Rita K.; Brauch, Hiltrud; Hamann, Ute; Ko, Yon-Dschun; Wang-Gohrke, Shan; Doerk, Thilo; Schuermann, Peter; Karstens, Johann H.; Hillemanns, Peter; Nevanlinna, Heli; Heikkinen, Tuomas; Aittomaki, Kristiina; Blomqvist, Carl; Bogdanova, Natalia V.; Zalutsky, Iosif V.; Antonenkova, Natalia N.; Bermisheva, Marina; Prokovieva, Darya; Farahtdinova, Albina; Khusnutdinova, Elza; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana; Chen, Xiaoqing; Beesley, Jonathan; Lambrechts, Diether; Zhao, Hui; Neven, Patrick; Wildiers, Hans; Nickels, Stefan; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Manoukian, Siranoush; Barile, Monica; Couch, Fergus J.; Olson, Janet E.; Wang, Xianshu; Fredericksen, Zachary; Giles, Graham G.; Baglietto, Laura; McLean, Catriona A.; Severi, Gianluca; Offit, Kenneth; Robson, Mark; Gaudet, Mia M.; Vijai, Joseph; Alnaes, Grethe Grenaker; Kristensen, Vessela; Borresen-Dale, Anne-Lise; John, Esther M.; Miron, Alexander; Winqvist, Robert; Pylkas, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Andrulis, Irene L.; Knight, Julia A.; Glendon, Gord; Mulligan, Anna Marie; Figueroa, Jonine D.; Garcia-Closas, Montserrat; Lissowska, Jolanta; Sherman, Mark E.; Hooning, Maartje; Martens, John W. M.; Seynaeve, Caroline; Collee, Margriet; Hall, Per; Humpreys, Keith; Czene, Kamila; Liu, Jianjun; Cox, Angela; Brock, Ian W.; Cross, Simon S.; Reed, Malcolm W. R.; Ahmed, Shahana; Ghoussaini, Maya; Pharoah, Paul D. P.; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Jakubowska, Anna; Jaworska, Katarzyna; Durda, Katarzyna; Zlowocka, Elzbieta; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; McKay, James; Shen, Chen-Yang; Yu, Jyh-Cherng; Hsu, Huan-Ming; Hou, Ming-Feng; Orr, Nick; Schoemaker, Minouk; Ashworth, Alan; Swerdlow, Anthony; Trentham-Dietz, Amy; Newcomb, Polly A.; Titus, Linda; Egan, Kathleen M.; Chenevix-Trench, Georgia; Antoniou, Antonis C.; Humphreys, Manjeet K.; Morrison, Jonathan; Chang-Claude, Jenny; Easton, Douglas F.; Dunning, Alison M.

    2012-01-01

    The 6q25.1 locus was first identified via a genome-wide association study (GWAS) in Chinese women and marked by single nucleotide polymorphism (SNP) rs2046210, approximately 180 Kb upstream of ESR1. There have been conflicting reports about the association of this locus with breast cancer in Europea

  5. A genome-wide association study of cleft lip with and without cleft palate identifies risk variants near MAFB and ABCA4

    DEFF Research Database (Denmark)

    Beaty, Terri H; Murray, Jeffrey C; Marazita, Mary L

    2010-01-01

    Case-parent trios were used in a genome-wide association study of cleft lip with and without cleft palate. SNPs near two genes not previously associated with cleft lip with and without cleft palate (MAFB, most significant SNP rs13041247, with odds ratio (OR) per minor allele = 0.704, 95% CI 0...

  6. Population structure of Atlantic Mackerel inferred from RAD-seq derived SNP markers: effects of sequence clustering parameters and hierarchical SNP selection

    KAUST Repository

    Rodríguez-Ezpeleta, Naiara

    2016-03-03

    Restriction-site associated DNA sequencing (RAD-seq) and related methods are revolutionizing the field of population genomics in non-model organisms as they allow generating an unprecedented number of single nucleotide polymorphisms (SNPs) even when no genomic information is available. Yet, RAD-seq data analyses rely on assumptions on nature and number of nucleotide variants present in a single locus, the choice of which may lead to an under- or overestimated number of SNPs and/or to incorrectly called genotypes. Using the Atlantic mackerel (Scomber scombrus L.) and a close relative, the Atlantic chub mackerel (Scomber colias), as case study, here we explore the sensitivity of population structure inferences to two crucial aspects in RAD-seq data analysis: the maximum number of mismatches allowed to merge reads into a locus and the relatedness of the individuals used for genotype calling and SNP selection. Our study resolves the population structure of the Atlantic mackerel, but, most importantly, provides insights into the effects of alternative RAD-seq data analysis strategies on population structure inferences that are directly applicable to other species.

  7. Analysis of binary responses with outcome-specific misclassification probability in genome-wide association studies

    Directory of Open Access Journals (Sweden)

    Rekaya R

    2016-11-01

    Full Text Available Romdhane Rekaya,1–3 Shannon Smith,4 El Hamidi Hay,5 Nourhene Farhat,6 Samuel E Aggrey3,7 1Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, 2Department of Statistics, Franklin College of Arts and Sciences, 3Institute of Bioinformatics, The University of Georgia, Athens, GA, 4Zoetis, Kalamazoo, MI, 5United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, 6Carolinas HealthCare System Blue Ridge, Morganton, NC, 7Department of Poultry Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA Abstract: Errors in the binary status of some response traits are frequent in human, animal, and plant applications. These error rates tend to differ between cases and controls because diagnostic and screening tests have different sensitivity and specificity. This increases the inaccuracies of classifying individuals into correct groups, giving rise to both false-positive and false-negative cases. The analysis of these noisy binary responses due to misclassification will undoubtedly reduce the statistical power of genome-wide association studies (GWAS. A threshold model that accommodates varying diagnostic errors between cases and controls was investigated. A simulation study was carried out where several binary data sets (case–control were generated with varying effects for the most influential single nucleotide polymorphisms (SNPs and different diagnostic error rate for cases and controls. Each simulated data set consisted of 2000 individuals. Ignoring misclassification resulted in biased estimates of true influential SNP effects and inflated estimates for true noninfluential markers. A substantial reduction in bias and increase in accuracy ranging from 12% to 32% was observed when the misclassification procedure was invoked. In fact, the majority of influential SNPs that were not identified using the noisy data were captured using the

  8. Design and characterization of a 52K SNP chip for goats.

    Directory of Open Access Journals (Sweden)

    Gwenola Tosser-Klopp

    Full Text Available The success of Genome Wide Association Studies in the discovery of sequence variation linked to complex traits in humans has increased interest in high throughput SNP genotyping assays in livestock species. Primary goals are QTL detection and genomic selection. The purpose here was design of a 50-60,000 SNP chip for goats. The success of a moderate density SNP assay depends on reliable bioinformatic SNP detection procedures, the technological success rate of the SNP design, even spacing of SNPs on the genome and selection of Minor Allele Frequencies (MAF suitable to use in diverse breeds. Through the federation of three SNP discovery projects consolidated as the International Goat Genome Consortium, we have identified approximately twelve million high quality SNP variants in the goat genome stored in a database together with their biological and technical characteristics. These SNPs were identified within and between six breeds (meat, milk and mixed: Alpine, Boer, Creole, Katjang, Saanen and Savanna, comprising a total of 97 animals. Whole genome and Reduced Representation Library sequences were aligned on >10 kb scaffolds of the de novo goat genome assembly. The 60,000 selected SNPs, evenly spaced on the goat genome, were submitted for oligo manufacturing (Illumina, Inc and published in dbSNP along with flanking sequences and map position on goat assemblies (i.e. scaffolds and pseudo-chromosomes, sheep genome V2 and cattle UMD3.1 assembly. Ten breeds were then used to validate the SNP content and 52,295 loci could be successfully genotyped and used to generate a final cluster file. The combined strategy of using mainly whole genome Next Generation Sequencing and mapping on a contig genome assembly, complemented with Illumina design tools proved to be efficient in producing this GoatSNP50 chip. Advances in use of molecular markers are expected to accelerate goat genomic studies in coming years.

  9. Highly effective SNP-based association mapping and management of recessive defects in livestock

    DEFF Research Database (Denmark)

    Charlier, Carole; Coppieters, Wouter; Rollin, Frédéric;

    2008-01-01

    The widespread use of elite sires by means of artificial insemination in livestock breeding leads to the frequent emergence of recessive genetic defects, which cause significant economic and animal welfare concerns. Here we show that the availability of genome-wide, high-density SNP panels, combi...... (CMD) types 1 and 2 in Belgian Blue cattle and ichthyosis fetalis in Italian Chianina cattle. Identification of these causative mutations has an immediate translation into breeding practive, allowing marker assisted selection against the defects through avoidance of at-risk matings....

  10. Integration of novel SSR and gene-based SNP marker loci in the chickpea genetic map and establishment of new anchor points with Medicago truncatula genome

    Science.gov (United States)

    Nayak, Spurthi N.; Zhu, Hongyan; Varghese, Nicy; Datta, Subhojit; Choi, Hong-Kyu; Horres, Ralf; Jüngling, Ruth; Singh, Jagbir; Kavi Kishor, P. B.; Sivaramakrishnan, S.; Hoisington, Dave A.; Kahl, Günter; Winter, Peter; Cook, Douglas R.

    2010-01-01

    This study presents the development and mapping of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers in chickpea. The mapping population is based on an inter-specific cross between domesticated and non-domesticated genotypes of chickpea (Cicer arietinum ICC 4958 × C. reticulatum PI 489777). This same population has been the focus of previous studies, permitting integration of new and legacy genetic markers into a single genetic map. We report a set of 311 novel SSR markers (designated ICCM—ICRISAT chickpea microsatellite), obtained from an SSR-enriched genomic library of ICC 4958. Screening of these SSR markers on a diverse panel of 48 chickpea accessions provided 147 polymorphic markers with 2–21 alleles and polymorphic information content value 0.04–0.92. Fifty-two of these markers were polymorphic between parental genotypes of the inter-specific population. We also analyzed 233 previously published (H-series) SSR markers that provided another set of 52 polymorphic markers. An additional 71 gene-based SNP markers were developed from transcript sequences that are highly conserved between chickpea and its near relative Medicago truncatula. By using these three approaches, 175 new marker loci along with 407 previously reported marker loci were integrated to yield an improved genetic map of chickpea. The integrated map contains 521 loci organized into eight linkage groups that span 2,602 cM, with an average inter-marker distance of 4.99 cM. Gene-based markers provide anchor points for comparing the genomes of Medicago and chickpea, and reveal extended synteny between these two species. The combined set of genetic markers and their integration into an improved genetic map should facilitate chickpea genetics and breeding, as well as translational studies between chickpea and Medicago. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1265-1) contains supplementary material, which is

  11. Accuracy of Assignment of Atlantic Salmon (Salmo salar L.) to Rivers and Regions in Scotland and Northeast England Based on Single Nucleotide Polymorphism (SNP) Markers

    Science.gov (United States)

    Gilbey, John; Cauwelier, Eef; Coulson, Mark W.; Stradmeyer, Lee; Sampayo, James N.; Armstrong, Anja; Verspoor, Eric; Corrigan, Laura; Shelley, Jonathan; Middlemas, Stuart

    2016-01-01

    Understanding the habitat use patterns of migratory fish, such as Atlantic salmon (Salmo salar L.), and the natural and anthropogenic impacts on them, is aided by the ability to identify individuals to their stock of origin. Presented here are the results of an analysis of informative single nucleotide polymorphic (SNP) markers for detecting genetic structuring in Atlantic salmon in Scotland and NE England and their ability to allow accurate genetic stock identification. 3,787 fish from 147 sites covering 27 rivers were screened at 5,568 SNP markers. In order to identify a cost-effective subset of SNPs, they were ranked according to their ability to differentiate between fish from different rivers. A panel of 288 SNPs was used to examine both individual assignments and mixed stock fisheries and eighteen assignment units were defined. The results improved greatly on previously available methods and, for the first time, fish caught in the marine environment can be confidently assigned to geographically coherent units within Scotland and NE England, including individual rivers. As such, this SNP panel has the potential to aid understanding of the various influences acting upon Atlantic salmon on their marine migrations, be they natural environmental variations and/or anthropogenic impacts, such as mixed stock fisheries and interactions with marine power generation installations. PMID:27723810

  12. A genome-wide association study identifies risk loci to equine recurrent uveitis in German warmblood horses.

    Science.gov (United States)

    Kulbrock, Maike; Lehner, Stefanie; Metzger, Julia; Ohnesorge, Bernhard; Distl, Ottmar

    2013-01-01

    Equine recurrent uveitis (ERU) is a common eye disease affecting up to 3-15% of the horse population. A genome-wide association study (GWAS) using the Illumina equine SNP50 bead chip was performed to identify loci conferring risk to ERU. The sample included a total of 144 German warmblood horses. A GWAS showed a significant single nucleotide polymorphism (SNP) on horse chromosome (ECA) 20 at 49.3 Mb, with IL-17A and IL-17F being the closest genes. This locus explained a fraction of 23% of the phenotypic variance for ERU. A GWAS taking into account the severity of ERU, revealed a SNP on ECA18 nearby to the crystalline gene cluster CRYGA-CRYGF. For both genomic regions on ECA18 and 20, significantly associated haplotypes containing the genome-wide significant SNPs could be demonstrated. In conclusion, our results are indicative for a genetic component regulating the possible critical role of IL-17A and IL-17F in the pathogenesis of ERU. The associated SNP on ECA18 may be indicative for cataract formation in the course of ERU.

  13. A genome-wide association study identifies risk loci to equine recurrent uveitis in German warmblood horses.

    Directory of Open Access Journals (Sweden)

    Maike Kulbrock

    Full Text Available Equine recurrent uveitis (ERU is a common eye disease affecting up to 3-15% of the horse population. A genome-wide association study (GWAS using the Illumina equine SNP50 bead chip was performed to identify loci conferring risk to ERU. The sample included a total of 144 German warmblood horses. A GWAS showed a significant single nucleotide polymorphism (SNP on horse chromosome (ECA 20 at 49.3 Mb, with IL-17A and IL-17F being the closest genes. This locus explained a fraction of 23% of the phenotypic variance for ERU. A GWAS taking into account the severity of ERU, revealed a SNP on ECA18 nearby to the crystalline gene cluster CRYGA-CRYGF. For both genomic regions on ECA18 and 20, significantly associated haplotypes containing the genome-wide significant SNPs could be demonstrated. In conclusion, our results are indicative for a genetic component regulating the possible critical role of IL-17A and IL-17F in the pathogenesis of ERU. The associated SNP on ECA18 may be indicative for cataract formation in the course of ERU.

  14. MegaSNPHunter: a learning approach to detect disease predisposition SNPs and high level interactions in genome wide association study

    Directory of Open Access Journals (Sweden)

    Xue Hong

    2009-01-01

    Full Text Available Abstract Background The interactions of multiple single nucleotide polymorphisms (SNPs are highly hypothesized to affect an individual's susceptibility to complex diseases. Although many works have been done to identify and quantify the importance of multi-SNP interactions, few of them could handle the genome wide data due to the combinatorial explosive search space and the difficulty to statistically evaluate the high-order interactions given limited samples. Results Three comparative experiments are designed to evaluate the performance of MegaSNPHunter. The first experiment uses synthetic data generated on the basis of epistasis models. The second one uses a genome wide study on Parkinson disease (data acquired by using Illumina HumanHap300 SNP chips. The third one chooses the rheumatoid arthritis study from Wellcome Trust Case Control Consortium (WTCCC using Affymetrix GeneChip 500K Mapping Array Set. MegaSNPHunter outperforms the best solution in this area and reports many potential interactions for the two real studies. Conclusion The experimental results on both synthetic data and two real data sets demonstrate that our proposed approach outperforms the best solution that is currently available in handling large-scale SNP data both in terms of speed and in terms of detection of potential interactions that were not identified before. To our knowledge, MegaSNPHunter is the first approach that is capable of identifying the disease-associated SNP interactions from WTCCC studies and is promising for practical disease prognosis.

  15. Principal components analysis corrects for stratification in genome-wide association studies.

    Science.gov (United States)

    Price, Alkes L; Patterson, Nick J; Plenge, Robert M; Weinblatt, Michael E; Shadick, Nancy A; Reich, David

    2006-08-01

    Population stratification--allele frequency differences between cases and controls due to systematic ancestry differences-can cause spurious associations in disease studies. We describe a method that enables explicit detection and correction of population stratification on a genome-wide scale. Our method uses principal components analysis to explicitly model ancestry differences between cases and controls. The resulting correction is specific to a candidate marker's variation in frequency across ancestral populations, minimizing spurious associations while maximizing power to detect true associations. Our simple, efficient approach can easily be applied to disease studies with hundreds of thousands of markers.

  16. Genome-Wide Association Study in Dachshund: Identification of a Major Locus Affecting Intervertebral Disc Calcification

    DEFF Research Database (Denmark)

    Mogensen, Mette Sloth; Karlskov-Mortensen, Peter; Proschowsky, Helle Friis;

    2011-01-01

    Intervertebral disc calcification and herniation commonly affects Dachshund where the predisposition is caused by an early onset degenerative process resulting in disc calcification. A continuous spectrum of disc degeneration is seen within and among clog breeds, suggesting a multifactorial...... with intervertebral disc calcification in Dachshund through a genome-wide association (GWA) study. Based on thorough radiographic examinations, 48 cases with >= 6 disc calcifications or surgically treated for disc herniation and 46 controls with 0-1 disc calcifications were identified. GWA using the Illumina Canine......HD BeadChip identified a locus on chromosome 12 from 36.8 to 38.6 Mb with 36 markers reaching genome-wide significance (P-genome = 0.00001-0.026). This study suggests that a major locus on chromosome 12 harbors genetic variations affecting the development of intervertebral disc calcification in Dachshund....

  17. Genome-wide association study identified a narrow chromosome 1 region associated with chicken growth traits.

    Directory of Open Access Journals (Sweden)

    Liang Xie

    Full Text Available Chicken growth traits are important economic traits in broilers. A large number of studies are available on finding genetic factors affecting chicken growth. However, most of these studies identified chromosome regions containing putative quantitative trait loci and finding causal mutations is still a challenge. In this genome-wide association study (GWAS, we identified a narrow 1.5 Mb region (173.5-175 Mb of chicken (Gallus gallus chromosome (GGA 1 to be strongly associated with chicken growth using 47,678 SNPs and 489 F2 chickens. The growth traits included aggregate body weight (BW at 0-90 d of age measured weekly, biweekly average daily gains (ADG derived from weekly body weight, and breast muscle weight (BMW, leg muscle weight (LMW and wing weight (WW at 90 d of age. Five SNPs in the 1.5 Mb KPNA3-FOXO1A region at GGA1 had the highest significant effects for all growth traits in this study, including a SNP at 8.9 Kb upstream of FOXO1A for BW at 22-48 d and 70 d, a SNP at 1.9 Kb downstream of FOXO1A for WW, a SNP at 20.9 Kb downstream of ENSGALG00000022732 for ADG at 29-42 d, a SNP in INTS6 for BW at 90 d, and a SNP in KPNA3 for BMW and LMW. The 1.5 Mb KPNA3-FOXO1A region contained two microRNA genes that could bind to messenger ribonucleic acid (mRNA of IGF1, FOXO1A and KPNA3. It was further indicated that the 1.5 Mb GGA1 region had the strongest effects on chicken growth during 22-42 d.

  18. Genome-wide association studies for agronomical traits in a world wide spring barley collection

    Directory of Open Access Journals (Sweden)

    Pasam Raj K

    2012-01-01

    Full Text Available Abstract 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 date, plant height, thousand grain weight, starch content and crude protein content in a diverse collection of 224 spring barleys of worldwide origin. The whole panel was genotyped with a customized oligonucleotide pool assay containing 1536 SNPs using Illumina's GoldenGate technology resulting in 957 successful SNPs covering all chromosomes. The morphological trait "row type" (two-rowed spike vs. six-rowed spike was used to confirm the high level of selectivity and sensitivity of the approach. This study describes the detection of QTL for the above mentioned agronomic traits by GWAS. Results Population structure in the panel was investigated by various methods and six subgroups that are mainly based on their spike morphology and region of origin. We explored the patterns of linkage disequilibrium (LD among the whole panel for all seven barley chromosomes. Average LD was observed to decay below a critical level (r2-value 0.2 within a map distance of 5-10 cM. Phenotypic variation within the panel was reasonably large for all the traits. The heritabilities calculated for each trait over multi-environment experiments ranged between 0.90-0.95. Different statistical models were tested to control spurious LD caused by population structure and to calculate the P-value of marker-trait associations. Using a mixed linear model with kinship for controlling spurious LD effects, we found a total of 171 significant marker trait associations, which delineate into 107 QTL regions. Across all traits these can be grouped into 57 novel QTL and 50 QTL that are congruent with previously mapped QTL positions. Conclusions Our results demonstrate that the described

  19. SUSCEPTIBILITY LOCI FOR UMBILICAL HERNIA IN SWINE DETECTED BY GENOME-WIDE ASSOCIATION.

    Science.gov (United States)

    Liao, X J; Lia, L; Zhang, Z Y; Long, Y; Yang, B; Ruan, G R; Su, Y; Ai, H S; Zhang, W C; Deng, W Y; Xiao, S J; Ren, J; Ding, N S; Huang, L S

    2015-10-01

    Umbilical hernia (UH) is a complex disorder caused by both genetic and environmental factors. UH brings animal welfare problems and severe economic loss to the pig industry. Until now, the genetic basis of UH is poorly understood. The high-density 60K porcine SNP array enables the rapid application of genome-wide association study (GWAS) to identify genetic loci for phenotypic traits at genome wide scale in pigs. The objective of this research was to identify susceptibility loci for swine umbilical hernia using the GWAS approach. We genotyped 478 piglets from 142 families representing three Western commercial breeds with the Illumina PorcineSNP60 BeadChip. Then significant SNPs were detected by GWAS using ROADTRIPS (Robust Association-Detection Test for Related Individuals with Population Substructure) software base on a Bonferroni corrected threshold (P = 1.67E-06) or suggestive threshold (P = 3.34E-05) and false discovery rate (FDR = 0.05). After quality control, 29,924 qualified SNPs and 472 piglets were used for GWAS. Two suggestive loci predisposing to pig UH were identified at 44.25MB on SSC2 (rs81358018, P = 3.34E-06, FDR = 0.049933) and at 45.90MB on SSC17 (rs81479278, P = 3.30E-06, FDR = 0.049933) in Duroc population, respectively. And no SNP was detected to be associated with pig UH at significant level in neither Landrace nor Large White population. Furthermore, we carried out a meta-analysis in the combined pure-breed population containing all the 472 piglets. rs81479278 (P = 1.16E-06, FDR = 0.022475) was identified to associate with pig UH at genome-wide significant level. SRC was characterized as plausible candidate gene for susceptibility to pig UH according to its genomic position and biological functions. To our knowledge, this study gives the first description of GWAS identifying susceptibility loci for umbilical hernia in pigs. Our findings provide deeper insights to the genetic architecture of umbilical hernia in pigs.

  20. Genome-wide association of lipid-lowering response to statins in combined study populations.

    Directory of Open Access Journals (Sweden)

    Mathew J Barber

    Full Text Available BACKGROUND: Statins effectively lower total and plasma LDL-cholesterol, but the magnitude of decrease varies among individuals. To identify single nucleotide polymorphisms (SNPs contributing to this variation, we performed a combined analysis of genome-wide association (GWA results from three trials of statin efficacy. METHODS AND PRINCIPAL FINDINGS: Bayesian and standard frequentist association analyses were performed on untreated and statin-mediated changes in LDL-cholesterol, total cholesterol, HDL-cholesterol, and triglyceride on a total of 3932 subjects using data from three studies: Cholesterol and Pharmacogenetics (40 mg/day simvastatin, 6 weeks, Pravastatin/Inflammation CRP Evaluation (40 mg/day pravastatin, 24 weeks, and Treating to New Targets (10 mg/day atorvastatin, 8 weeks. Genotype imputation was used to maximize genomic coverage and to combine information across studies. Phenotypes were normalized within each study to account for systematic differences among studies, and fixed-effects combined analysis of the combined sample were performed to detect consistent effects across studies. Two SNP associations were assessed as having posterior probability greater than 50%, indicating that they were more likely than not to be genuinely associated with statin-mediated lipid response. SNP rs8014194, located within the CLMN gene on chromosome 14, was strongly associated with statin-mediated change in total cholesterol with an 84% probability by Bayesian analysis, and a p-value exceeding conventional levels of genome-wide significance by frequentist analysis (P = 1.8 x 10(-8. This SNP was less significantly associated with change in LDL-cholesterol (posterior probability = 0.16, P = 4.0 x 10(-6. Bayesian analysis also assigned a 51% probability that rs4420638, located in APOC1 and near APOE, was associated with change in LDL-cholesterol. CONCLUSIONS AND SIGNIFICANCE: Using combined GWA analysis from three clinical trials involving nearly 4

  1. A Genome-Wide Association Study Suggests Novel Loci Associated with a Schizophrenia-Related Brain-Based Phenotype.

    Directory of Open Access Journals (Sweden)

    Johanna Hass

    Full Text Available Patients with schizophrenia and their siblings typically show subtle changes of brain structures, such as a reduction of hippocampal volume. Hippocampal volume is heritable, may explain a variety of cognitive symptoms of schizophrenia and is thus considered an intermediate phenotype for this mental illness. The aim of our analyses was to identify single-nucleotide polymorphisms (SNP related to hippocampal volume without making prior assumptions about possible candidate genes. In this study, we combined genetics, imaging and neuropsychological data obtained from the Mind Clinical Imaging Consortium study of schizophrenia (n = 328. A total of 743,591 SNPs were tested for association with hippocampal volume in a genome-wide association study. Gene expression profiles of human hippocampal tissue were investigated for gene regions of significantly associated SNPs. None of the genetic markers reached genome-wide significance. However, six highly correlated SNPs (rs4808611, rs35686037, rs12982178, rs1042178, rs10406920, rs8170 on chromosome 19p13.11, located within or in close proximity to the genes NR2F6, USHBP1, and BABAM1, as well as four SNPs in three other genomic regions (chromosome 1, 2 and 10 had p-values between 6.75×10(-6 and 8.3×10(-7. Using existing data of a very recently published GWAS of hippocampal volume and additional data of a multicentre study in a large cohort of adolescents of European ancestry, we found supporting evidence for our results. Furthermore, allelic differences in rs4808611 and rs8170 were highly associated with differential mRNA expression in the cis-acting region. Associations with memory functioning indicate a possible functional importance of the identified risk variants. Our findings provide new insights into the genetic architecture of a brain structure closely linked to schizophrenia. In silico replication, mRNA expression and cognitive data provide additional support for the relevance of our findings

  2. Multi-locus Test and Correction for Confounding Effects in Genome-Wide Association Studies.

    Science.gov (United States)

    Chen, Donglai; Liu, Chuanhai; Xie, Jun

    2016-11-01

    Genome-wide association studies (GWAS) examine a large number of genetic variants, e. g., single nucleotide polymorphisms (SNP), and associate them with a disease of interest. Traditional statistical methods for GWASs can produce spurious associations, due to limited information from individual SNPs and confounding effects. This paper develops two statistical methods to enhance data analysis of GWASs. The first is a multiple-SNP association test, which is a weighted chi-square test derived for big contingency tables. The test assesses combinatorial effects of multiple SNPs and improves conventional methods of single SNP analysis. The second is a method that corrects for confounding effects, which may come from population stratification as well as other ambiguous (unknown) factors. The proposed method identifies a latent confounding factor, using a profile of whole genome SNPs, and eliminates confounding effects through matching or stratified statistical analysis. Simulations and a GWAS of rheumatoid arthritis demonstrate that the proposed methods dramatically remove the number of significant tests, or false positives, and outperforms other available methods.

  3. Genome-wide characterization of microsatellites in Triticeae species: abundance, distribution and evolution

    Science.gov (United States)

    Deng, Pingchuan; Wang, Meng; Feng, Kewei; Cui, Licao; Tong, Wei; Song, Weining; Nie, Xiaojun

    2016-01-01

    Microsatellites are an important constituent of plant genome and distributed across entire genome. In this study, genome-wide analysis of microsatellites in 8 Triticeae species and 9 model plants revealed that microsatellite characteristics were similar among the Triticeae species. Furthermore, genome-wide microsatellite markers were designed in wheat and then used to analyze the evolutionary relationship of wheat and other Triticeae species. Results displayed that Aegilops tauschii was found to be the closest species to Triticum aestivum, followed by Triticum urartu, Triticum turgidum and Aegilops speltoides, while Triticum monococcum, Aegilops sharonensis and Hordeum vulgare showed a relatively lower PCR amplification effectivity. Additionally, a significantly higher PCR amplification effectivity was found in chromosomes at the same subgenome than its homoeologous when these markers were subjected to search against different chromosomes in wheat. After a rigorous screening process, a total of 20,666 markers showed high amplification and polymorphic potential in wheat and its relatives, which were integrated with the public available wheat markers and then anchored to the genome of wheat (CS). This study not only provided the useful resource for SSR markers development in Triticeae species, but also shed light on the evolution of polyploid wheat from the perspective of microsatellites. PMID:27561724

  4. The challenges of genome-wide interaction studies: lessons to learn from the analysis of HDL blood levels.

    Science.gov (United States)

    van Leeuwen, Elisabeth M; Smouter, Françoise A S; Kam-Thong, Tony; Karbalai, Nazanin; Smith, Albert V; Harris, Tamara B; Launer, Lenore J; Sitlani, Colleen M; Li, Guo; Brody, Jennifer A; Bis, Joshua C; White, Charles C; Jaiswal, Alok; Oostra, Ben A; Hofman, Albert; Rivadeneira, Fernando; Uitterlinden, Andre G; Boerwinkle, Eric; Ballantyne, Christie M; Gudnason, Vilmundur; Psaty, Bruce M; Cupples, L Adrienne; Järvelin, Marjo-Riitta; Ripatti, Samuli; Isaacs, Aaron; Müller-Myhsok, Bertram; Karssen, Lennart C; van Duijn, Cornelia M

    2014-01-01

    Genome-wide association studies (GWAS) have revealed 74 single nucleotide polymorphisms (SNPs) associated with high-density lipoprotein cholesterol (HDL) blood levels. This study is, to our knowledge, the first genome-wide interaction study (GWIS) to identify SNP×SNP interactions associated with HDL levels. We performed a GWIS in the Rotterdam Study (RS) cohort I (RS-I) using the GLIDE tool which leverages the massively parallel computing power of Graphics Processing Units (GPUs) to perform linear regression on all genome-wide pairs of SNPs. By performing a meta-analysis together with Rotterdam Study cohorts II and III (RS-II and RS-III), we were able to filter 181 interaction terms with a p-valueSPATA8 (ENSG00000185594) being associated with HDL levels. However, p-values do not reach the preset Bonferroni correction of the p-values. Our study suggest that even for highly genetically determined traits such as HDL the sample sizes needed to detect SNP×SNP interactions are large and the 2-step filtering approaches do not yield a solution. Here we present our analysis plan and our reservations concerning GWIS.

  5. Concept and design of a genome-wide association genotyping array tailored for transplantation-specific studies

    DEFF Research Database (Denmark)

    Li, Yun R.; van Setten, Jessica; Verma, Shefali S.;

    2015-01-01

    genome-wide genotyping array, the 'TxArray', comprising approximately 782,000 markers with tailored content for deeper capture of variants across HLA, KIR, pharmacogenomic, and metabolic loci important in transplantation. To test concordance and genotyping quality, we genotyped 85 HapMap samples...

  6. 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

  7. Demography-adjusted tests of neutrality based on genome-wide SNP data

    KAUST Repository

    Rafajlović, Marina

    2014-08-01

    Tests of the neutral evolution hypothesis are usually built on the standard model which assumes that mutations are neutral and the population size remains constant over time. However, it is unclear how such tests are affected if the last assumption is dropped. Here, we extend the unifying framework for tests based on the site frequency spectrum, introduced by Achaz and Ferretti, to populations of varying size. Key ingredients are the first two moments of the site frequency spectrum. We show how these moments can be computed analytically if a population has experienced two instantaneous size changes in the past. We apply our method to data from ten human populations gathered in the 1000 genomes project, estimate their demographies and define demography-adjusted versions of Tajima\\'s D, Fay & Wu\\'s H, and Zeng\\'s E. Our results show that demography-adjusted test statistics facilitate the direct comparison between populations and that most of the differences among populations seen in the original unadjusted tests can be explained by their underlying demographies. Upon carrying out whole-genome screens for deviations from neutrality, we identify candidate regions of recent positive selection. We provide track files with values of the adjusted and unadjusted tests for upload to the UCSC genome browser. © 2014 Elsevier Inc.

  8. A genome-wide SNP panel for mapping and association studies in the rat

    NARCIS (Netherlands)

    Nijman, Isaäc J; Kuipers, Sylvia; Verheul, Mark; Guryev, Victor; Cuppen, Edwin

    2008-01-01

    BACKGROUND: The laboratory rat (Rattus norvegicus) is an important model for human disease, and is extensively used for studying complex traits for example in the physiological and pharmacological fields. To facilitate genetic studies like QTL mapping, genetic makers that can be easily typed, like S

  9. A genome-wide SNP panel for mapping and association studies in the rat.

    NARCIS (Netherlands)

    Nijman, I.J.; Kuipers, S.; Verheul, M.; Guryev, V.; Cuppen, E.

    2008-01-01

    BACKGROUND: The laboratory rat (Rattus norvegicus) is an important model for human disease, and is extensively used for studying complex traits for example in the physiological and pharmacological fields. To facilitate genetic studies like QTL mapping, genetic makers that can be easily typed, like S

  10. Genome-wide SNP detection in the great tit Parus major using high throughput sequencing

    NARCIS (Netherlands)

    Van Bers, Nikkie E. M.; Van Oers, Kees; Kerstens, Hindrik H. D.; Dibbits, Bert W.; Crooijmans, Richard P. M. A.; Visser, Marcel E.; Groenen, Martien A. M.

    2010-01-01

    Identifying genes that underlie ecological traits will open exiting possibilities to study gene-environment interactions in shaping phenotypes and in measuring natural selection on genes. Evolutionary ecology has been pursuing these objectives for decades, but they come into reach now that next gene

  11. Genome-wide SNP detection in the great tit Parus major using high throughput sequencing

    NARCIS (Netherlands)

    van Bers, N.E.M.; Van Oers, K.; Kerstens, H.H.D.; Dibbits, B.W.; Crooijmans, R.P.M.A.; Visser, M.E.; Groenen, M.A.M.

    2010-01-01

    Identifying genes that underlie ecological traits will open exiting possibilities to study gene–environment interactions in shaping phenotypes and in measuring natural selection on genes. Evolutionary ecology has been pursuing these objectives for decades, but they come into reach now that next gene

  12. Genome-wide association study in German patients with attention deficit/hyperactivity disorder.

    Science.gov (United States)

    Hinney, Anke; Scherag, André; Jarick, Ivonne; Albayrak, Özgür; Pütter, Carolin; Pechlivanis, Sonali; Dauvermann, Maria R; Beck, Sebastian; Weber, Heike; Scherag, Susann; Nguyen, Trang T; Volckmar, Anna-Lena; Knoll, Nadja; Faraone, Stephen V; Neale, Benjamin M; Franke, Barbara; Cichon, Sven; Hoffmann, Per; Nöthen, Markus M; Schreiber, Stefan; Jöckel, Karl-Heinz; Wichmann, H-Erich; Freitag, Christine; Lempp, Thomas; Meyer, Jobst; Gilsbach, Susanne; Herpertz-Dahlmann, Beate; Sinzig, Judith; Lehmkuhl, Gerd; Renner, Tobias J; Warnke, Andreas; Romanos, Marcel; Lesch, Klaus-Peter; Reif, Andreas; Schimmelmann, Benno G; Hebebrand, Johannes

    2011-12-01

    The heritability of attention deficit hyperactivity disorder (ADHD) is approximately 0.8. Despite several larger scale attempts, genome-wide association studies (GWAS) have not led to the identification of significant results. We performed a GWAS based on 495 German young patients with ADHD (according to DSM-IV criteria; Human660W-Quadv1; Illumina, San Diego, CA) and on 1,300 population-based adult controls (HumanHap550v3; Illumina). Some genes neighboring the single nucleotide polymorphisms (SNPs) with the lowest P-values (best P-value: 8.38 × 10(-7)) have potential relevance for ADHD (e.g., glutamate receptor, metabotropic 5 gene, GRM5). After quality control, the 30 independent SNPs with the lowest P-values (P-values ≤ 7.57 × 10(-5) ) were chosen for confirmation. Genotyping of these SNPs in up to 320 independent German families comprising at least one child with ADHD revealed directionally consistent effect-size point estimates for 19 (10 not consistent) of the SNPs. In silico analyses of the 30 SNPs in the largest meta-analysis so far (2,064 trios, 896 cases, and 2,455 controls) revealed directionally consistent effect-size point estimates for 16 SNPs (11 not consistent). None of the combined analyses revealed a genome-wide significant result. SNPs in previously described autosomal candidate genes did not show significantly lower P-values compared to SNPs within random sets of genes of the same size. We did not find genome-wide significant results in a GWAS of German children with ADHD compared to controls. The second best SNP is located in an intron of GRM5, a gene located within a recently described region with an infrequent copy number variation in patients with ADHD.

  13. Genome-wide association study identified CNP12587 region underlying height variation in Chinese females.

    Directory of Open Access Journals (Sweden)

    Yin-Ping Zhang

    Full Text Available INTRODUCTION: Human height is a highly heritable trait considered as an important factor for health. There has been limited success in identifying the genetic factors underlying height variation. We aim to identify sequence variants associated with adult height by a genome-wide association study of copy number variants (CNVs in Chinese. METHODS: Genome-wide CNV association analyses were conducted in 1,625 unrelated Chinese adults and sex specific subgroup for height variation, respectively. Height was measured with a stadiometer. Affymetrix SNP6.0 genotyping platform was used to identify copy number polymorphisms (CNPs. We constructed a genomic map containing 1,009 CNPs in Chinese individuals and performed a genome-wide association study of CNPs with height. RESULTS: We detected 10 significant association signals for height (p<0.05 in the whole population, 9 and 11 association signals for Chinese female and male population, respectively. A copy number polymorphism (CNP12587, chr18:54081842-54086942, p = 2.41 × 10(-4 was found to be significantly associated with height variation in Chinese females even after strict Bonferroni correction (p = 0.048. Confirmatory real time PCR experiments lent further support for CNV validation. Compared to female subjects with two copies of the CNP, carriers of three copies had an average of 8.1% decrease in height. An important candidate gene, ubiquitin-protein ligase NEDD4-like (NEDD4L, was detected at this region, which plays important roles in bone metabolism by binding to bone formation regulators. CONCLUSIONS: Our findings suggest the important genetic variants underlying height variation in Chinese.

  14. 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

  15. 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 ...

  16. 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

  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