Paired-end Strategy Research Articles

RNAseq Analysis of Brown Adipose Tissue and Thyroid of Newborn Lambs Subjected to Short-Term Cold Exposure Reveals Signs of Early Whitening of Adipose Tissue.

During the early postnatal period, lambs have the ability to thermoregulate body temperature via non-shivering thermogenesis through brown adipose tissue (BAT), which soon after birth begins to transform into white adipose tissue. An RNA seq approach was used to characterize the transcriptome of BAT and thyroid tissue in newborn lambs exposed to cold conditions. Fifteen newborn Romney lambs were selected and divided into three groups: group 1 (n = 3) was a control, and groups 2 and 3 (n = 6 each) were kept indoors for two days at an ambient temperature (20–22 °C) or at a cold temperature (4 °C), respectively. Sequencing was performed using a paired-end strategy through the BGISEQ-500 platform, followed by the identification of differentially expressed genes using DESeq2 and an enrichment analysis by g:Profiler. This study provides an in-depth expression network of the main characters involved in the thermogenesis and fat-whitening mechanisms that take place in the newborn lamb. Data revealed no significant differential expression of key thermogenic factors such as uncoupling protein 1, suggesting that the heat production peak under cold exposure might occur so rapidly and in such an immediate way that it may seem undetectable in BAT by day three of life. Moreover, these changes in expression might indicate the start of the whitening process of the adipose tissue, concluding the non-shivering thermogenesis period.

Integration of metabolomics and transcriptomics data to further characterize Gliricidia sepium (Jacq.) Kunth under high salinity stress

Soil salinity is one abiotic stress that threatens agriculture in more than 100 countries. Gliricidia [Gliricidia sepium (Jacq.) Kunth] is a multipurpose tree known for its ability to adapt to a wide range of soils; however, its tolerance limits and responses to salt stress are not yet well understood. In this study, after characterizing the morphophysiological responses of young gliricidia plants to salinity stress, leaf metabolic and transcription profiles were generated and submitted to single and integrated analyses. RNA from leaf samples were subjected to RNA sequencing using an Illumina HiSeq platform and the paired-end strategy. Polar and lipidic fractions from leaf samples were extracted and analyzed on an ultra-high-performance liquid chromatography (UHPLC) coupled with electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (MS) system. Acquired data were analyzed using the OmicsBox, XCMS Online, MetaboAnalyst, and Omics Fusion platforms. The substrate salinization protocol used allowed the identification of two distinct responses to salt stress: tolerance and adaptation. Single analysis on transcriptome and metabolome data sets led to a group of 5,672 transcripts and 107 metabolites differentially expressed in gliricidia leaves under salt stress. The phenylpropanoid biosynthesis was the most affected pathway, with 15 metabolites and three genes differentially expressed. Results showed that the differentially expressed metabolites and genes from this pathway affect mainly short-term salt stress (STS). The single analysis of the transcriptome identified 12 genes coding for proteins that might play a role in gliricidia response at both STS and long-term salt stress (LTS). Further studies are needed to reveal the mechanisms behind the adaptation response.

Karyosequencing: Integrating Genome-Wide and Targeted Sequencing for Comprehensive Diagnosis of Lymphoproliferative Disorders

Introduction: Molecular diagnostic testing for lymphoproliferative disorders (LPDs) includes detection of clonal immunoglobulin (IG) and/or T cell receptor (TCR) rearrangements, translocations, copy number alterations (CNA) and somatic mutations. To date, laboratories still rely on subjective and labour-intensive technologies, e.g. karyotyping/FISH to detect complex genomic alterations. Whole Genome Sequencing (WGS) can detect all genomic alterations, but factors such as cost, computation/storage, DNA requirements and poor detection of clinically relevant subclonal mutations limits the routine implementation of WGS in clinical diagnostics. We have developed “KaryoSequencing” (KS), a novel approach that combines targeted deep-sequencing, using a targeted hybridisation capture NGS panel, for rare mutation and translocation detection with shallow WGS (sWGS) for genome wide copy number analysis, in a single test.Methods: KS was validated using 138 clinical samples from patients with acute lymphoblastic leukaemia (ALL) (n=46), chronic lymphocytic leukaemia (CLL) (n=46) and plasma cell myeloma (PCM) (n=46) samples from 3 UK laboratories. Samples underwent library preparation and hybridisation using the EuroClonality-NDC assay. A KS library for each sample was prepared by combining the pre-capture and post-capture libraries at an optimised ratio to enable high coverage (>500 x) at regions covered by the targeted panel while providing 0.5-1x coverage genome-wide. Forty-six KS libraries were pooled and sequenced per NovaSeq 6000 run, using a 200-cycle SP flow cell and a 100bp paired-end strategy. For analysis of targeted regions, somatic mutation calling was performed using VarDict and structural variants (rearrangements and translocations) were detected using ARResT/Interrogate. For analysis of large chromosomal copy number variation using sWGS, a modified version of QDNASeq/ACE with a window size of 50kb was performed. For sWGS analysis, bioinformatic exclusion of all target capture regions and panel-specific off-target regions was performed using a panel of 48 DNA samples from healthy individuals ran on the same KS protocol.Results:Analysis of genome-wide copy number by sWGS was concordant in 477 of 503 (95%) evaluable FISH tests, including precise detection of hyper and hypo-diploidy and other complex karyotypes. The performance of the targeted deep-sequencing component of the KS approach was assessed to ensure comparable performance to previously validated results for the EuroClonality-NDC. The EuroClonality-NDC detected a clonal IG rearrangement in 46/46 (100%) CLL cases and in 42/46 (91.3%) PCM cases. Clonality was detected in 43/46 (93.5%) and 44/46 (95.7%) cases at an IG and TCR locus respectively in ALL, a disease entity known to exhibit cross-lineage rearrangements. Overall, 44 translocations were detected in the 138 samples by the EuroClonality-NDC. FISH results were available for 32 of the 44 translocations detected by NGS and were concordant in 29/32 (91%). In two PCM samples NGS and FISH reported a different translocation; in the ALL sample, the FISH pattern showed an additional copy but not a split signal. Across the entire cohort of 138 samples, KaryoSequencing detected 190 mutations with a variant allele frequency ranging from 4.0 - 97.6%. Of the detected mutations, 69/190 (36.3%) had a VAF <20% which can be difficult to detect reliably with typical coverage depths observed with conventional WGS. The most frequently mutated genes were KRAS [30.4%], NRAS [13.0%], KMT2D [10.9%] in ALL; SF3B1 [23.9%], NOTCH1 [19.6%], ATM [15.2%] and TP53[13.0%] in CLL and KRAS [19.6%], NRAS [15.2%] and TP53 [10.9%] in PCM, consistent with expected frequencies in each entity.Conclusions:KaryoSequencing demonstrated >95% sensitivity and specificity for detection of gross genome-wide copy number alterations while retaining the analytical performance for detection of rearrangements, translocations, and mutations for the lymphoid-specific targeted regions of the EuroClonality-NDC assay. KS is a cost-effective and high-throughput integrated alternative to current diagnostic strategies in haematological malignancies and can be implemented in routine clinical practice. DisclosuresJenner: Janssen: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy; Takeda: Consultancy; BMS/Celgene: Consultancy, Honoraria, Speakers Bureau. Gonzalez: Univ8 Genomics Ltd: Current holder of individual stocks in a privately-held company.

Genomic and antimicrobial resistance genes diversity in multidrug-resistant CTX-M-positive isolates of Escherichia coli at a health care facility in Jeddah

BackgroundWhole genome sequencing has revolutionized epidemiological investigations of multidrug-resistant pathogenic bacteria worldwide. Aim of this study was to perform comprehensive characterization of ESBL-positive isolates of Escherichia coli obtained from clinical samples at the King Abdulaziz University Hospital utilizing whole genome sequencing. MethodsIsolates were identified by MALDI-TOF mass spectrometry. Genome sequencing was performed using a paired-end strategy on the MiSeq platform. ResultsNineteen isolates were clustered into different clades in a phylogenetic tree based on single nucleotide polymorphisms in core genomes. Seventeen sequence types were identified in the extended-spectrum β-lactamase (ESBL)-positive isolates, and 11 subtypes were identified based on distinct types of fimH alleles. Forty-one acquired resistance genes were found in the 19 genomes. The blaCTX-M-15 gene, which encodes ESBL, was found in 15 isolates and was the most predominant resistance gene. Other antimicrobial resistance genes (ARGs) found in the isolates were associated with resistance to tetracycline (tetA), aminoglycoside [aph(3″)-Ib, and aph(6)-Id], and sulfonamide (sul1, and sul2). Nonsynonymous chromosomal mutations in the housekeeping genes parC and gyrA were commonly found in several genomes. ConclusionSeveral other ARGs were found in CTX-M-positive E. coli isolates confer resistance to clinically important antibiotics used to treat infections caused by Gram-negative bacteria.

Genomic analysis of multidrug-resistant clinical Enterococcus faecalis isolates for antimicrobial resistance genes and virulence factors from the western region of Saudi Arabia

BackgroundEnterococcus faecalis is a ubiquitous member of the gut microbiota and has emerged as a life- threatening multidrug-resistant (MDR) nosocomial pathogen. The aim of this study was to survey the prevalence of multidrug-resistant and epidemiologically important strains of E. faecalis in the western region of Saudi Arabia using phenotypic and whole genome sequencing approaches.MethodsIn total, 155 patients positive for E. faecalis infection were included in this study. The isolates were identified by MALDI-TOF, and screen for antimicrobial resistance using VITEK-2 system. Genome sequencing was performed with paired-end strategy using MiSeq platform.ResultsSeventeen sequence types (STs) were identified through multilocus sequence typing (MLST) analysis of the E. faecalis genomes, including two novels STs (ST862 and ST863). The most common STs in the Saudi patients were ST179 and ST16 from clonal complex 16 (CC16). Around 96% (n = 149) isolates were MDR. The antibiotics quinupristin/dalfopristin, clindamycin, and erythromycin demonstrated almost no coverage, and high-level streptomycin, gentamycin, and ciprofloxacin demonstrated suboptimal coverage. Low resistance was observed against vancomycin, linezolid, and ampicillin. Moreover, 34 antimicrobial resistance genes and variants, and three families of insertion sequences were found in the E. faecalis genomes, which likely contributed to the observed antimicrobial resistance. Twenty-two virulence factors, which were mainly associated with biofilm formation, endocarditis, cell adherence, and colonization, were detected in the isolates.ConclusionsDiverse STs of E. faecalis, including strains associated with common nosocomial infections are circulating in the healthcare facility of Saudi Arabia and carried multi-drug resistance, which has important implications for infection control.

Muscle transcriptome resource for growth, lipid metabolism and immune system in Hilsa shad, Tenualosa ilisha.

The information on thegenes involved in muscle growth, lipid metabolism and immune systems would help to understand the mechanisms during the spawning migration in Hilsashad, which in turn would be useful in its future domestication process. The primary objective of this study was to generate the transcriptome profile of itsmuscle through RNA seq. The total RNA was isolated and library was prepared from muscle tissue of Tenualosa ilisha, which was collected from Padma River at Farakka, India. The prepared library was then sequenced by Illumina HiSeq platform, HiSeq 2000, using paired-end strategy. A total of 8.68GB of pair-end reads of muscle transcriptome was generated, and43,384,267 pair-end reads were assembled into 3,04,233 contigs, of which 23.99% of assembled contigs has length ≥ 150bp. The total GO terms were categorised into cellular component, molecular function and biological process through PANTHER database. Fifty-three genes related to muscle growth were identified and genes in different pathways were: 75 in PI3/AKT, 46 in mTOR, 76 in MAPK signalling, 24 in Janus kinase-signal transducer and activator of transcription, 45 in AMPK and 27 in cGMP pathways. This study also mined the genes involved in lipid metabolism, in which glycerophospholipid metabolism contained highest number of genes (32) and fourwere found to beinvolved in fatty acid biosynthesis. There were 58 immune related genes found, in which 31 were under innate and 27 under adaptive immunity. The present study included alarge genomic resource of T. ilisha muscle generatedthrough RNAseq, which revealed the essential dataset for our understanding of regulatory processes, specifically during the seasonal spawning migration. As Hilsa is a slow growing fish, the genes identified for muscle growth provided the basic information to study myogenesis. In addition, genes identified for lipid metabolism and immune system would provide resources for lipid synthesis and understanding of Hilsa defense mechanisms, respectively.

New protocol based on massive parallel sequencing for aneuploidy screening of preimplantation human embryos

ABSTRACTNovel next-generation sequencing procedures have rapidly emerged into the preimplantation genetic screening framework. This work presents the design and validation of a new low-coverage whole-genome sequencing assay for aneuploidy detection in single blastomeres and trophectodermal samples from preimplantation embryos. The validation ensures analytical sensitivity, specificity, robustness, precision, limit of detection, resolution, and reproducibility. Specific parameters to measure the performance are defined, and the results are compared with a standardized array-based method to stablish the concordance. From the single cell genomics point of view, the main novelties are the length of reads of the libraries (150 nucleotides) together with a paired-end strategy and the design of an original algorithm and copy number viewer. A total of 129 samples were included in six experimental runs using a MiSeq Illumina platform. Samples included: single amniocytes, single blastomeres (cleavage-stage embryos), trophectoderm samples (blastocyst), and diluted DNA. Sensitivity and specificity were calculated per chromosome yielding 96% and 99%, respectively. The percentage of concordant samples was 98.2% and all of the aneuploid samples were confirmed. In conclusion, the validation yields highly reliable and reproducible results, representing an accurate and cost-effective strategy for the routine detection of aneuploidy in human embryos.

112 UV-signature Notch mutations are subclonal in human UV-exposed skin and clonal in squamous cell carcinoma in situ

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer, and cSCCs typically arise from precancerous lesions termed actinic keratosis (AKs) and squamous cell carcinoma in situ (SCCIS). A better understanding how precancerous lesions develop may lead to new therapeutic insights for cSCCs. Genomic sequencing of cSCC has demonstrated that UV-signature, non-synonymous mutations in the EGF-like repeats of Notch 1 and 2 are prevalent in approximately 50-60% cSCCs. Although UV-signature loss-of-function (LOF) Notch mutations appear to be the most common mutations in cSCC, it is not clear when these mutations are acquired during tumor progression. To determine when UV-signature Notch LOF mutations arise during UV-induced cutaneous neoplasia, we performed laser capture microdissection (LCM) of FFPE human biopsy samples isolated tissue from UV-exposed epidermis and adjacent SCCIS from 5 patients. Genomic DNA was isolated from the dissected tissue and whole exome libraries were constructed for sequencing using a 100bp paired-end strategy. Data analysis demonstrated high quality reads, Q score ≥ 30, with a greater than 20-fold coverage over 80% of the genome. UV- exposed epidermis contained UV-signature Notch 1 LOF mutations in 60% of samples which were subclonal as mutant reads comprised 9.7-20% of the total sequencing reads. Representative mutations include G393D and G471E. UV-signature Notch LOF mutations were found in 60% percent of SCCIS lesions. These mutations involved Notch 1, 2 and 3 and were heterozygous clonal as mutant sequencing reads comprised approximately 50% of the total reads. Representative UV-signature Notch mutations in SCCIS include Notch 2 G543R and Notch 3 R716C. These data show that UV-signature Notch LOF mutations are subclonal in UV-exposed skin and appear to be clonally selected during the early stages of UV-induced carcinogenesis. These data suggest that loss of Notch function may promote the early stages of UV-induced carcinogenesis.

Whole genome sequencing for deciphering the resistome of Chryseobacterium indologenes, an emerging multidrug-resistant bacterium isolated from a cystic fibrosis patient in Marseille, France.

We decipher the resistome of Chryseobacterium indologenes MARS15, an emerging multidrug-resistant clinical strain, using the whole genome sequencing strategy. The bacterium was isolated from the sputum of a hospitalized patient with cystic fibrosis in the Timone Hospital in Marseille, France. Genome sequencing was done with Illumina MiSeq using a paired-end strategy. The in silico analysis was done by RAST, the resistome by the ARG-ANNOT database and detection of polyketide synthase (PKS) by ANTISMAH. The genome size of C. indologenes MARS15 is 4 972 580 bp with 36.4% GC content. This multidrug-resistant bacterium was resistant to all β-lactams, including imipenem, and also to colistin. The resistome of C. indologenes MARS15 includes Ambler class A and B β-lactams encoding blaCIA and blaIND-2 genes and MBL (metallo-β-lactamase) genes, the CAT (chloramphenicol acetyltransferase) gene and the multidrug efflux pump AcrB. Specific features include the presence of an urease operon, an intact prophage and a carotenoid biosynthesis pathway. Interestingly, we report for the first time in C. indologenes a PKS cluster that might be responsible for secondary metabolite biosynthesis, similar to erythromycin. The whole genome sequence analysis provides insight into the resistome and the discovery of new details, such as the PKS cluster.

Enhancing the detection of barcoded reads in high throughput DNA sequencing data by controlling the false discovery rate.

BackgroundDNA barcodes are short unique sequences used to label DNA or RNA-derived samples in multiplexed deep sequencing experiments. During the demultiplexing step, barcodes must be detected and their position identified. In some cases (e.g., with PacBio SMRT), the position of the barcode and DNA context is not well defined. Many reads start inside the genomic insert so that adjacent primers might be missed. The matter is further complicated by coincidental similarities between barcode sequences and reference DNA. Therefore, a robust strategy is required in order to detect barcoded reads and avoid a large number of false positives or negatives.For mass inference problems such as this one, false discovery rate (FDR) methods are powerful and balanced solutions. Since existing FDR methods cannot be applied to this particular problem, we present an adapted FDR method that is suitable for the detection of barcoded reads as well as suggest possible improvements.ResultsIn our analysis, barcode sequences showed high rates of coincidental similarities with the Mus musculus reference DNA. This problem became more acute when the length of the barcode sequence decreased and the number of barcodes in the set increased. The method presented in this paper controls the tail area-based false discovery rate to distinguish between barcoded and unbarcoded reads. This method helps to establish the highest acceptable minimal distance between reads and barcode sequences. In a proof of concept experiment we correctly detected barcodes in 83% of the reads with a precision of 89%. Sensitivity improved to 99% at 99% precision when the adjacent primer sequence was incorporated in the analysis. The analysis was further improved using a paired end strategy. Following an analysis of the data for sequence variants induced in the Atp1a1 gene of C57BL/6 murine melanocytes by ultraviolet light and conferring resistance to ouabain, we found no evidence of cross-contamination of DNA material between samples.ConclusionOur method offers a proper quantitative treatment of the problem of detecting barcoded reads in a noisy sequencing environment. It is based on the false discovery rate statistics that allows a proper trade-off between sensitivity and precision to be chosen.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2105-15-264) contains supplementary material, which is available to authorized users.

Genome study of PDGFRA D842V mutant GIST using next generation sequencing approach.

10540 Background: Mutations of the receptors KIT and PDGFRA in GIST are the oncogenetic events of disease as well as the targets of molecular therapies. Within the PDGFRA mutations, the D842V mutation in exon 18 confers in vitro and in vivo resistance to imatinib. Next generation sequencing techniques may completely dissect all the possible somatic mutations and genomic rearrangements in order to identify novel therapeutic targets in this patients population. Methods: Five patients with gastric GIST were analyased (3 M, 2 F; mean age 65,5 years, range 51-77). The tumor dimension ranged between 3 and 15 cm, MI &lt; 2 and 8 /50 HPF. No metastases were present in all cases. The KIT and PDGFRA anlysis showed a D842V mutation in exon 18 of PDGFRA in all cases. Whole transcriptome sequencing was performed with Illumina HiScanSQ platform with a paired-end strategy (75x2). After performing quality controls, the short reads were mapped with Tophat-Botie pipeline against the human reference genome (HG19). The variations, such as Single nucleotide variants (SNVs) and InDels, were called by SNVMix2 (a software suited for SNVs discovery in tumor samples) implementing an accurate filtering procedures developed in our laboratory. Two predictors of mutations effect at protein level (SNPs&amp;GO and Provean) were employed in order to prioritize the emerging variation. Results: An average of 206 coding non-synonymous variants were highlighted in the five GIST samples, of which ~ 30% were predicted as deleterious with at least one predictor. In addition to PDGFRA D842V mutation, in all five patients were found mutations on different receptor tyrosine kinases, such as FGFR4 and DDR2. Moreover three out of five patients harboured mutations on members of the MDR/TAP subfamily that are involved in multidrug resistance, in particular on ABCB1, ABCB4 and on ABCB6 genes. Other mutations were found on the hedgehog and MAPK signaling pathway and on SNF/SWI chromatin remodeling complex. Conclusions: New molecular events have been identified in PDGFRA D842V mutant GIST. These data should be validated in larger series and the role of these mutations as therapeutic targets should be further investigated.

Identification of SDHA (subunit A of the succinate dehydrogenase) mutations in KIT/PDGFRA WT gastrointestinal stromal tumors (GISTs).

10045 Background: About 10%-15% of GISTs do not harbour KIT/PDGFRA mutations (wild-type, WT). We analyzed the tumor transcriptome of two sporadic young adults WT GISTs patients using massively para...

Identification of single nucleotide variants in gastrointestinal stromal tumor KIT/PDGFRA wild-type (WT GISTs) by massively parallel sequencing.

10046 Background: Recently SDH variations were identified in KIT and PDGFRA wild type GISTs. However the causative genomic alterations of these GISTs still remain unknown. Massively parallel sequencing allows identifying novel putative variants. Methods: Whole transcriptome paired-end RNA sequencing was performed by Illumina GAIIx system using a 75 bases paired-end strategy on tumor samples of two young adults patients (P1 and P2) affected by gastric WT-GIST (age 28 and 30 years). Sequences were aligned with BWA against exon+junction references. SNVmix2 was used for SNP calling, identifying by this 2045 and 1780 coding non-synonymous novel single nucleotide variants (SNVs) in P1 and P2, respectively. After checking misalignments by SAMTools, the variants were filtered to increasing SNPcall confidence: SNVs with quality read score > 30 (error probability of 0.1%), total coverage > 40, and ratio between coverage of alterate base and total coverage >0.3 were labeled high confidence. Single point mutations were translated at the protein level and their likelihood of being disease-associated was computed with SNP&GO and confirmed with Sanger sequencing. Results: In both patients common mutations in SDHA and different private SNV were highlighted. Among the private disease-related SNVs we identified mutations in MYH9 (myosin heavy chain 9) and TPI1 (triosephosphate isomerase 1) in patient P1, and a mutation in OGDHL (oxoglutarate dehydrogenase-like) in P2. MYH9 is involved in cell motility and cytokinesis, while OGDHL is an enzyme of the Krebs cycle, as the SDH complex, and TPI1 is involved in glycolysis. Ongoing validation by Sanger sequencing on DNA from tumor and peripheral blood (PB) already confirmed the presence of heterozygous MYH9 K1775E in P1 and OGDHL V815M in P2, both in tumor and PB, showing that these mutations are germinal. Conclusions: Massively parallel RNA sequencing, followed by data analysis, allows to discover novel single nucleotide variants and to identify new potential target genes in WT-GIST.