38 research outputs found
CoolMPS: evaluation of antibody labeling based massively parallel non-coding RNA sequencing
Results of massive parallel sequencing-by-synthesis vary depending on the sequencing approach. CoolMPS™ is a new sequencing chemistry that incorporates bases by labeled antibodies. To evaluate the performance, we sequenced 240 human non-coding RNA samples (dementia patients and controls) with and without CoolMPS. The Q30 value as indicator of the per base sequencing quality increased from 91.8 to 94%. The higher quality was reached across the whole read length. Likewise, the percentage of reads mapping to the human genome increased from 84.9 to 86.2%. For both technologies, we computed similar distributions between different RNA classes (miRNA, piRNA, tRNA, snoRNA and yRNA) and within the classes. While standard sequencing-by-synthesis allowed to recover more annotated miRNAs, CoolMPS yielded more novel miRNAs. The correlation between the two methods was 0.97. Evaluating the diagnostic performance, we observed lower minimal P-values for CoolMPS (adjusted P-value of 0.0006 versus 0.0004) and larger effect sizes (Cohen's d of 0.878 versus 0.9). Validating 19 miRNAs resulted in a correlation of 0.852 between CoolMPS and reverse transcriptase-quantitative polymerase chain reaction. Comparison to data generated with Illumina technology confirmed a known shift in the overall RNA composition. With CoolMPS we evaluated a novel sequencing-by-synthesis technology showing high performance for the analysis of non-coding RNAs
Genome dynamics of the human embryonic kidney 293 lineage in response to cell biology manipulations
The HEK293 human cell lineage is widely used in cell biology and biotechnology. Here we use whole-genome resequencing of six 293 cell lines to study the dynamics of this aneuploid genome in response to the manipulations used to generate common 293 cell derivatives, such as transformation and stable clone generation (293T); suspension growth adaptation (293S); and cytotoxic lectin selection (293SG). Remarkably, we observe that copy number alteration detection could identify the genomic region that enabled cell survival under selective conditions (i.c. ricin selection). Furthermore, we present methods to detect human/vector genome breakpoints and a user-friendly visualization tool for the 293 genome data. We also establish that the genome structure composition is in steady state for most of these cell lines when standard cell culturing conditions are used. This resource enables novel and more informed studies with 293 cells, and we will distribute the sequenced cell lines to this effect
Novel genetic risk variants for pediatric celiac disease
Background: Celiac disease is a complex chronic immune-mediated disorder of the small intestine. Today, the pathobiology of the disease is unclear, perplexing differential diagnosis, patient stratification, and decision-making in the clinic. Methods: Herein, we adopted a next-generation sequencing approach in a celiac disease trio of Greek descent to identify all genomic variants with the potential of celiac disease predisposition. Results: Analysis revealed six genomic variants of prime interest: SLC9A4 c.1919G gt A, KIAA1109 c.2933T gt C and c. 4268_4269delCCinsTA, HoxB6 c.668C gt A, HoxD12 c.418G gt A, and NCK2 c.745_746delAAinsG, from which NCK2 c.745_746delAAinsG is novel. Data validation in pediatric celiac disease patients of Greek (n=109) and Serbian (n=73) descent and their healthy counterparts (n=111 and n=32, respectively) indicated that HoxD12 c.418G gt A is more prevalent in celiac disease patients in the Serbian population (P lt 0.01), while NCK2 c.745_746delAAinsG is less prevalent in celiac disease patients rather than healthy individuals of Greek descent (P = 0. 03). SLC9A4 c.1919G gt A and KIAA1109 c.2933T gt C and c.4268_4269delCCinsTA were more abundant in patients; nevertheless, they failed to show statistical significance. Conclusions: The next-generation sequencing-based family genomics approach described herein may serve as a paradigm towards the identification of novel functional variants with the aim of understanding complex disease pathobiology
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Accurate Whole-Genome Sequencing and Haplotyping from 10 to 20 Human Cells
Recent advances in whole genome sequencing have brought the vision of personal genomics and genomic medicine closer to reality. However, current methods lack clinical accuracy and the ability to describe the context (haplotypes) in which genome variants co-occur in a cost-effective manner. Here we describe a low-cost DNA sequencing and haplotyping process, Long Fragment Read (LFR) technology, similar to sequencing long single DNA molecules without cloning or separation of metaphase chromosomes. In this study, ten LFR libraries were made using only ~100 pg of human DNA per sample. Up to 97% of the heterozygous single nucleotide variants (SNVs) were assembled into long haplotype contigs. Removal of false positive SNVs not phased by multiple LFR haplotypes resulted in a final genome error rate of 1 in 10 Mb. Cost-effective and accurate genome sequencing and haplotyping from 10-20 human cells, as demonstrated here, will enable comprehensive genetic studies and diverse clinical applications
Genomic variants in the FTO gene are associated with sporadic amyotrophic lateral sclerosis in Greek patients
Background: Amyotrophic lateral sclerosis (ALS) is a devastating disease whose complex pathology has been
associated with a strong genetic component in the context of both familial and sporadic disease. Herein, we
adopted a next-generation sequencing approach to Greek patients suffering from sporadic ALS (together with their
healthy counterparts) in order to explore further the genetic basis of sporadic ALS (sALS).
Results: Whole-genome sequencing analysis of Greek sALS patients revealed a positive association between FTO
and TBC1D1 gene variants and sALS. Further, linkage disequilibrium analyses were suggestive of a specific diseaseassociated
haplotype for FTO gene variants. Genotyping for these variants was performed in Greek, Sardinian, and
Turkish sALS patients. A lack of association between FTO and TBC1D1 variants and sALS in patients of Sardinian and
Turkish descent may suggest a founder effect in the Greek population. FTO was found to be highly expressed in
motor neurons, while in silico analyses predicted an impact on FTO and TBC1D1 mRNA splicing for the genomic
variants in question.
Conclusions: To our knowledge, this is the first study to present a possible association between FTO gene variants
and the genetic etiology of sALS. In addition, the next-generation sequencing-based genomics approach coupled
with the two-step validation strategy described herein has the potential to be applied to other types of human
complex genetic disorders in order to identify variants of clinical significance
Selective DNA amplification from complex genomes using universal double-sided adapters
There is a rapidly developing need for new technologies to amplify millions of different targets from genomic DNA for high throughput genotyping and population gene-sequencing from diverse species. Here we describe a novel approach for the specific selection and amplification of genomic DNA fragments of interest that eliminates the need for costly and time consuming synthesis and testing of potentially millions of amplicon-specific primers. This technique relies upon Type IIs restriction enzyme digestion of genomic DNA and ligation of the fragments to double-sided adapters to form closed-circular DNA molecules. The novel use of double-sided adapters, assembled through the combinatorial use of two small universal sets of oligonucleotide building blocks, provides greater selection capacity by utilizing both sides of the adapter in a sequence-specific ligation event. As demonstrated, formation of circular structures results in protection of the desired molecules from nuclease treatment and enables a level of selectivity high enough to isolate single, or multiple, pre-defined fragments from the human genome when digested at over five million sites. Priming sites incorporated into the adapter allows the utilization of a common pair of primers for the amplification of any adapter-captured DNA fragment of interest
Identification of APC gene mutations in colorectal cancer using universal microarray-based combinatorial sequencing-by-hybridization
Familial adenomatous polyposis (FAP) is an autosomal dominant inherited form of colorectal cancer, caused mostly by mutations in the APC gene (OMIM#175100). Due to the wide variety of mutations found and the large size of the APC gene, several methods of mutation detection are used, which can be time consuming and costly. Here we demonstrate a new method of mutation detection in the APC gene using an array-based approach termed combinatorial sequencing by hybridization (cSBH). In cSBH, a universal probe set is attached to a support and a second one is in solution. Two-probe ligation occurs when a DNA strand from the target PCR product consecutively anneals to both unlabeled array-bound and solution-phase, dye-labeled probe, creating all target-complementary long labeled probes attached to the surface. A standard array reader scores fluorescent signals at each array position. Cell lines and patient DNA with known APC gene mutations were analyzed using cSBH based HyChipTM product. Results show this universal 6-mer chip can successfully detect a range of mutations. Results are very robust for a continuous readout of 3.6 kb from a PCR target, with 99.97% accuracy on a single HyChipTM slide. cSBH is a fast, cost-efficient method for first stage mutation screening in the APC or any other gen