Comparative genomic hybridization to investigate copy number variation in the human Hapmap sample NA15510
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Armand Valsesia
PROVIDER: E-TABM-203 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:There is growing evidence for the prevalence of DNA copy number variation (CNV) and its role in phenotypic variation in recent years. Comparative genomic hybridization (CGH) was used to explore the extent of this type of structural variation in the barley genome. In a panel of 14 genotypes including domesticated cultivars and wild barleys, we found that 14.9% of all the sequences on the array are affected by CNV. Higher levels of CNV diversity are present in the wild accessions relative to cultivated barley. A substantial portion (37%) of the CNV events are present in both wild and domesticated barley. CNVs are enriched in telomeric regions for all chromosomes except 4H, which is also the barley chromosome with the lowest proportion of CNVs. CNV affected 9.5% of the coding sequences represented on the array. The genes affected by CNV are enriched for sequences annotated as disease-resistance proteins and protein kinases, suggesting the potential for CNV to influence variation for responses to biotic and abiotic stress. The analysis of CNV breakpoints indicated that DNA repair mechanisms of double-strand breaks (DSBs) via single-stranded annealing (SSA) and synthesis-dependent strand annealing (SDSA) play an important role in the origin of many structural changes in barley. Here we present the first catalog of CNVs in a diploid Triticeae species, which opens the door for future genome diversity research in a tribe that comprises the economically important cereal species wheat, barley and rye. Our findings constitute a valuable resource for the identification of CNV affecting genes of agronomic importance. 1-2 replications of 8 barley cultivars and 6 wild barley accessions were hybridized to an array designed from 115,003 whole genome shotgun (WGS) contigs of the ‘reference’ genome of cv. Morex
2013-05-09 | E-GEOD-44293 | biostudies-arrayexpress
Project description:The ideal genome sequence for medical interpretation is complete and diploid, capturing the full spectrum of genetic variation. Toward this end, there has been progress in discovery of single nucleotide polymorphism (SNP) and small (<10bp) insertion/deletions (indels), but annotation of larger structural variation (SV) including copy number variation (CNV) has been less comprehensive, even with available diploid sequence assemblies. We applied a multi-step sequence and microarray-based analysis to identify numerous previously unknown SVs within the first genome sequence reported from an individual. The HuRef genomic DNA (from lymphoblastoid cell line) was co-hybridized with the female sample NA15510 (from lymphoblastoid cell line) from the Polymorphism Discovery Resources. The NimbleGen platform consists of 20 NimbleGen HD2 chips, each containing 2.1M probes, and each chip is further subdivided into 3 equal-sized subarrays containing about 726K probes. The probes target the NCBI Build 36 genome, with the exception that no homology filter was applied, allowing coverage of segmentally duplicated regions.
2013-02-12 | E-GEOD-20289 | biostudies-arrayexpress
Project description:Genetic variation amongst individual humans occurs on many different scales, ranging from gross alterations in the human karyotype to single-nucleotide changes. In this manuscript we explore variation on an intermediate scale-particularly insertions, deletions, and inversions affecting from a few thousand to a few million base pairs. We employed a clone-based method to interrogate this intermediate structural variation in eight individuals of diverse geographic ancestry. Our analysis provides a comprehensive overview of the normal pattern of structural variation present in these genomes, refining the location of 1695 structural variants. We find that 50% were seen in more than one individual and that nearly half lay outside regions of the genome previously described as structurally variant. We discover 525 new insertion sequences that are not present in the human reference genome and show that many of these are variable in copy number among individuals. Sequencing of a subset of structural variants reveals considerable locus complexity and provides insights into the different mutational processes that have shaped the human genome. These data provide the first high-resolution sequence-map of human structural variation-an important standard for genotyping platforms and a prelude to future individual genome sequencing projects. Keywords: comparitive genomic hybridization, copy number variation, structural variation, fosmid end sequencing CGH analysis targeted against sites identified by fosmid end sequencing. 8 HapMap samples (sources of libraries ABC7-ABC14) are hybed against NA15510 (source of fosmid library G248).
2008-05-01 | E-GEOD-10037 | biostudies-arrayexpress
Project description:H. jecorina undergoes a heterothallic reproductive cycle, and the mating yields asci with 16 linearly arranged ascospores. The sixteen ascospores are generated via two rounds of postmeiotic mitosis following the two meiotic divisions. We have discovered that viable aneuploid ascosporesare are frequently (~90%) generated due to a net gain of a conserved ~500 kbp genomic segment. Here we have compared whole genome gene copy number changes in the aneuploid F1 progeny, euploid F1 progeny, parental strains and the F1 progeny of RTU strain backcross with CBS999.97 . We determined genome-wide gene copy number in the genomes of ascospores generated from haploid wild-type strain. We also determined genome-wide gene copy number in the genomes of the F1 progeny of CBS999.97 wild type.
2015-01-07 | E-GEOD-41965 | biostudies-arrayexpress
Project description:DNA methylation is a chromatin modification that is frequently associated with epigenetic regulation in plants and mammals. However, other genetic changes such as transposon insertions also can lead to changes in DNA methylation levels. Genome-wide profiles of DNA methylation levels for 20 maize inbreds were used to discover differentially methylated regions (DMRs). The methylation level for each of these DMRs was also assayed in 31 additional maize genotypes resulting in the discovery of 1,966 common DMRs and 1,754 rare DMRs. Analysis of recombinant inbred lines provides evidence that the majority of DMRs are heritable. A local association scan found that nearly half of the DMRs with common variation are significantly associated with SNPs found within or near the DMR. Many of the DMRs that are significantly associated with local genetic variation are found near transposable elements that may contribute to the DNA methylation variation. The analysis of gene expression in the same samples used for DNA methylation profiling identifies over 300 genes with expression patterns that are significantly associated with the DNA methylation variation among genotypes. Collectively, our results suggest that DNA methylation variation is influenced by genetic and epigenetic variation is often stably inherited and can influence expression level of genes in the population. Methylation profiles in seedling tissue of a panel of 51 maize inbred lines using a custom 2.1M or 1.4M feature NimbleGen array. Methylation profiles in seedling tissue of maize inbred lines, teosinte and recombinant inbred lines (RILs) derived from B73 and Mo17 using a custom 12x270K NimbleGen array. Inbred lines B73 and Mo17 each had 3 biological replicates, the other sample had 1 replicate.
2013-08-12 | E-GEOD-46949 | biostudies-arrayexpress
Project description:Despite considerable excitement over the potential functional significance of copy number variants (CNVs), we still lack knowledge of the fine-scale architecture of the large majority of CNV regions in the human genome. In this study, we used a high-resolution array-based comparative genomic hybridization (aCGH) platform that targeted known CNV regions of the human genome at ~1 kb resolution to interrogate the genomic DNAs of 30 individuals from four HapMap populations. Our results revealed that 1,020 of 1,153 CNV loci (88%) were actually smaller in size than what is recorded in the Database of Genomic Variants based on previously published studies. A reduction in size of more than 50% was observed for 876 CNV regions (76%). We conclude that the total genomic content of common human CNVs may be smaller than previously thought. In addition, approximately 8% of the CNV regions observed in multiple individuals exhibited genomic architectural complexity in the form of smaller CNVs within larger ones and CNVs with inter-individual variation in breakpoints. Future association studies that aim to capture the potential influences of CNVs on disease phenotypes will need to consider how to best ascertain this previously underappreciated complexity. The DNA samples are a panel of 30 Hapmap samples, and a female sample NA15510 of undetermined geographic origin, which has been well characterized by fosmid-end sequencing (Tuzun et al. 2005, Nature Genetics 10, p1038). The DNA for this set of 16 female and 15 male samples are all supplied by the Coriell Cell Repository, and is comprised of samples from four populations: 10 unrelated Yoruban, 10 unrelated European-American individuals from Utah (CEPH), 5 unrelated Chinese, and 5 unrelated Japanese. The reference sample, NA10851 is also a male CEPH also from the HapMap Sample set (Corriel Cell Repository). Each of these samples was hybridized in pairs with the reversed labeling polarities. Additionally, 3 self-self control hybridizations were carried out for the reference sample, NA10851, one on each hybridization date. In the Title for each of the samples, each hybridization session is indicated by the letters A, B or C.
2008-01-23 | E-GEOD-9831 | biostudies-arrayexpress
Project description:Array-based comparative genome hybridization. The aneuploid progeny could return to euploid state. We determined genome-wide gene copy number in the genomes of aneuploid progeny after 14, 24 and 34 days vegetative propagation in dextrose-containing rich medim.
2015-01-07 | E-GEOD-42359 | biostudies-arrayexpress
Project description:DNA methylation is a chromatin modification that contributes to epigenetic regulation of gene expression. The inheritance patterns and trans-generational stability of 962 differentially methylated regions (DMRs) were assessed in a panel of 71 near-isogenic lines (NILs) derived from maize (Zea mays) inbred lines B73 and Mo17. The majority of DMRs exhibit inheritance patterns that would be expected for local (cis) inheritance of DNA methylation variation such that DNA methylation level was coupled to local genotype. There are few examples of DNA methylation that exhibit trans-acting control or paramutation-like patterns. The cis-controlled DMRs provided an opportunity to study the stability of inheritance for DNA methylation variation. There was very little evidence for alterations of DNA methylation levels at the cis-controlled DMRs during NIL population development. DNA methylation level was associated with local genotypes in all of the >30,000 examined cases except one. Additionally, the majority of the DMRs were not associated with small RNA. Together, our results suggest that a significant portion of DNA methylation variation in maize exhibits cis-controlled inheritance patterns, is highly stable and does not require active programming by small RNAs for maintenance. Methylation profiles in seedling tissue of maize near-isogenic lines (NILs) derived from B73 and Mo17 using a custom 12x270K NimbleGen array.
2014-04-01 | E-GEOD-51567 | biostudies-arrayexpress
Project description:Goal: To identify copy number variation in normal individuals using high density, non-polymorphic oligonucleotide probes Background DNA sequence diversity within the human genome may be more greatly affected by copy number variations (CNVs) than single nucleotide polymorphisms (SNPs). Although the importance of CNVs in genome wide association studies (GWAS) is becoming widely accepted, the optimal methods for identifying these variants are still under evaluation. We have previously reported a comprehensive view of CNVs in the HapMap DNA collection using high density 500K EA (Early Access) SNP genotyping arrays which revealed greater than 1,000 CNVs ranging in size from 1kb to over 3Mb. Although the arrays used most commonly for GWAS predominantly interrogate SNPs, CNV identification and detection does not necessarily require the use of DNA probes centered on polymorphic nucleotides and may even be hindered by the dependence on a successful SNP genotyping assay. Results In this study, we have designed and evaluated a high density array predicated on the use of non-polymorphic oligonucleotide probes for CNV detection. This approach effectively uncouples copy number detection from SNP genotyping and thus has the potential to significantly improve probe coverage for genome-wide CNV identification. This array, in conjunction with PCR-based, complexity-reduced DNA target, queries over 1.3M independent NspI restriction enzyme fragments in the 200bp to 1100bp size range, which is a several fold increase in marker density as compared to the 500K EA array. In addition, a novel algorithm was developed and validated to extract CNV regions and boundaries. Conclusions Using a well-characterized pair of DNA samples, close to 200 CNVs were identified, of which nearly 50% appear novel yet were independently validated using quantitative PCR. The results indicate that non-polymorphic probes provide a robust approach for CNV identification, and the increasing precision of CNV boundary delineation should allow a more complete analysis of their genomic organization. A set of five genomic DNA samples containing different numbers of X chromosomes (1X to 5X sample set, including NA15510 and NA10851) were hybridized to Nsp copy number (CN) arrays in triplicate to evaluate detection of copy number variation using high density, non-polymorphic oligonucleotide probes. 6 Hapmap samples were hybridized to Nsp CN arrays to evaluate Mendelian inheritance of CNVs.
2008-04-24 | E-GEOD-9053 | biostudies-arrayexpress
Project description:Genome instability is a characteristic of malignant cells, however, evidence for its contribution to tumorigenesis has been enigmatic. In this study we demonstrate that a complex containing the retinoblastoma protein, E2F1, and Condensin II localizes to major satellite repeats at pericentromeres. In the absence of this complex, this genomic region fails to properly replicate and H2AX phosphorylation at pericentromeric repeats is increased. Our data indicates that these lesions contribute to defective chromosome segregation in the ensuing mitosis. Surprisingly, loss of even one copy of the retinoblastoma gene was sufficient to reduce recruitment of Condensin II to pericentromeres and cause this phenotype. Furthermore, we determined that human RB1 mutation status in cancers of mesenchymal origin correlated with copy number variation, chromosomal gains and losses, as well as chromothriptic rearrangements. Importantly, the magnitude of these chromosomal abnormalities was indistinguishable between RB1+/- and RB1-/- genotypes. Lastly, using gene-targeted mice we determined that mutation of just one copy of the murine Rb1 gene causes sarcomas and lymphomas with increased chromosome copy number variation. Our study connects replication stress with a number of common chromosomal abnormalities in cancer through a dosage sensitive complex present at pericentromeric repeats. Copy number data of thymic lymphomas from 12 different RB1 Δ/+; Trp53-/- mice were analyzed. Tumor DNA was hybridized against same sex control samples (pooled DNA from 5 normal male or female mice). NimbleGen performed a control male vs control female hybridization. All hybridizations were done on a mouse whole genome array (design 2006-07-26-MM8-WG-CGH). Conclusions were drawn from 10X window avereaged, CGH-segMNT analysed data files.
2014-06-19 | E-GEOD-51876 | biostudies-arrayexpress