scholarly journals A target enrichment high throughput sequencing system for characterization of BLV whole genome sequence, integration sites, clonality and host SNP

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nagaki Ohnuki ◽  
Tomoko Kobayashi ◽  
Misaki Matsuo ◽  
Kohei Nishikaku ◽  
Kazuya Kusama ◽  
...  

AbstractBovine leukemia virus (BLV) is an oncogenic retrovirus which induces malignant lymphoma termed enzootic bovine leukosis (EBL) after a long incubation period. Insertion sites of the BLV proviral genome as well as the associations between disease progression and polymorphisms of the virus and host genome are not fully understood. To characterize the biological coherence between virus and host, we developed a DNA-capture-seq approach, in which DNA probes were used to efficiently enrich target sequence reads from the next-generation sequencing (NGS) library. In addition, enriched reads can also be analyzed for detection of proviral integration sites and clonal expansion of infected cells since the reads include chimeric reads of the host and proviral genomes. To validate this DNA-capture-seq approach, a persistently BLV-infected fetal lamb kidney cell line (FLK-BLV), four EBL tumor samples and four non-EBL blood samples were analyzed to identify BLV integration sites. The results showed efficient enrichment of target sequence reads and oligoclonal integrations of the BLV proviral genome in the FLK-BLV cell line. Moreover, three out of four EBL tumor samples displayed multiple integration sites of the BLV proviral genome, while one sample displayed a single integration site. In this study, we found the evidence for the first time that the integrated provirus defective at the 5′ end was present in the persistent lymphocytosis cattle. The efficient and sensitive identification of BLV variability, integration sites and clonal expansion described in this study provide support for use of this innovative tool for understanding the detailed mechanisms of BLV infection during the course of disease progression.

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
Sean C Patro ◽  
Xiaolin Wu ◽  
Shuang Guo ◽  
Michael J Bale ◽  
Ann Wiegand ◽  
...  

Abstract Accurate definition of the HIV-1 reservoir on antiretroviral therapy (ART) is of paramount importance to the development of curative strategies. Much of this reservoir is derived from clonal expansion of latently infected CD4+ T cells. Methods used to characterize the reservoir include near full-length single-genome sequencing (NFL-SGS) and integration site analysis (ISA). However, current technologies do not link the intact proviruses detected by NFL-SGS to their sites of integration. Therefore, we developed a method to obtain both near full-length single-proviral sequences and their sites of integration. We call our method full-length integrated proviral single-genome sequencing (FLIP-SGS). Genomic DNA from ACH2 and CEM cells mixed at 1:1,000, or patient samples were diluted to a single proviral endpoint. An in-house, optimized whole genome amplification (WGA) method was performed on wells at the endpoint, generating multiple copies of all DNA molecules within each well. The number of proviral copies after WGA was determined by droplet digital PCR targeting the long terminal region (LTR). Forty per cent of each WGA reaction was used to obtain the provirus–host integration sites with ISA (linker ligation, nested PCR, and Illumina sequencing). The remaining fraction was used to amplify the full-length proviruses in four overlapping fragments (LTR-pol, gag-int, int-env, and env-LTR) for Sanger sequencing. WGA performed on the endpoint-diluted ACH2:CEM DNA amplified single-copy HIV-1 proviral templates greater than 500-fold, making it possible to obtain unique integration sites from single proviruses in ACH2 cells, including one that was previously reported (in the NT5C3A gene on chromosome 7) and two that were not previously reported (in the EIF4ENIF1 gene of chromosome 22 and an unknown region of chromosome 6). Near full-length PCR amplification and Sanger sequencing was performed on proviruses integrated in the NT5C3A gene. FLIP-SGS was applied to peripheral blood mononuclear cells from one HIV-1 infected donor with viremia suppressed on ART and yielded integration sites of four genomes that appear to contain large internal deletions. We report a method for near full-length HIV-1 single-genome sequencing combined with host integration site detection that we call FLIP-SGS. This assay will further define clonal expansion of infected CD4+ T cells as a mechanism that maintains the HIV-1 reservoir and as the source of identical sequences observed during therapy and rebound, rather than from ongoing replication.


Author(s):  
Hiroo Katsuya ◽  
Lucy B M Cook ◽  
Aileen G Rowan ◽  
Anat Melamed ◽  
Jocelyn Turpin ◽  
...  

Abstract Background Coinfection with HIV-1 and HTLV-1 diminishes the value of the CD4 + T-cell count in diagnosing AIDS, and increases the rate of HTLV-1-associated myelopathy. It remains elusive how HIV-1/HTLV-1 coinfection is related to such clinical characteristics. Here, we investigated the mutual effect of HIV-1/HTLV-1 coinfection on their integration sites (ISs) and the clonal expansion. Methods We extracted DNA from longitudinal peripheral blood samples from 7 HIV-1/HTLV-1 coinfected individuals, and from 12 HIV-1 and 13 HTLV-1 mono-infected individuals. The proviral loads (PVL) were quantified using real-time PCR. Viral ISs and clonality were quantified by ligation-mediated PCR followed by high-throughput sequencing. Results The PVL of both HIV-1 and HTLV-1 in coinfected individuals was significantly higher than that of the respective virus in mono-infected individuals. The degree of oligoclonality of both HIV-1- and HTLV-1-infected cells in co-infected individuals was also greater than that in mono-infected subjects. The ISs of HIV-1 in cases of coinfection were more frequently located in intergenic regions and transcriptionally silent regions, compared with HIV-1 mono-infected individuals. Conclusion HIV-1/HTLV-1 coinfection makes an impact on the distribution of viral ISs and the clonality of virus-infected cells and thus may alter the risks of both HTLV-1- and HIV-1-associated disease.


2009 ◽  
Vol 83 (17) ◽  
pp. 8396-8408 ◽  
Author(s):  
William S. Mason ◽  
Huey-Chi Low ◽  
Chunxiao Xu ◽  
Carol E. Aldrich ◽  
Catherine A. Scougall ◽  
...  

ABSTRACT During a hepadnavirus infection, viral DNA integrates at a low rate into random sites in the host DNA, producing unique virus-cell junctions detectable by inverse nested PCR (invPCR). These junctions serve as genetic markers of individual hepatocytes, providing a means to detect their subsequent proliferation into clones of two or more hepatocytes. A previous study suggested that the livers of 2.4-year-old woodchucks (Marmota monax) chronically infected with woodchuck hepatitis virus contained at least 100,000 clones of >1,000 hepatocytes (W. S. Mason, A. R. Jilbert, and J. Summers, Proc. Natl. Acad. Sci. USA 102:1139-1144, 2005). However, possible correlations between sites of viral-DNA integration and clonal expansion could not be explored because the woodchuck genome has not yet been sequenced. In order to further investigate this issue, we looked for similar clonal expansion of hepatocytes in the livers of chimpanzees chronically infected with hepatitis B virus (HBV). Liver samples for invPCR were collected from eight chimpanzees chronically infected with HBV for at least 20 years. Fifty clones ranging in size from ∼35 to 10,000 hepatocytes were detected using invPCR in 32 liver biopsy fragments (∼1 mg) containing, in total, ∼3 × 107 liver cells. Based on searching the analogous human genome, integration sites were found on all chromosomes except Y, ∼30% in known or predicted genes. However, no obvious association between the extent of clonal expansion and the integration site was apparent. This suggests that the integration site per se is not responsible for the outgrowth of large clones of hepatocytes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tatsuhiko Hoshino ◽  
Ryohei Nakao ◽  
Hideyuki Doi ◽  
Toshifumi Minamoto

AbstractThe combination of high-throughput sequencing technology and environmental DNA (eDNA) analysis has the potential to be a powerful tool for comprehensive, non-invasive monitoring of species in the environment. To understand the correlation between the abundance of eDNA and that of species in natural environments, we have to obtain quantitative eDNA data, usually via individual assays for each species. The recently developed quantitative sequencing (qSeq) technique enables simultaneous phylogenetic identification and quantification of individual species by counting random tags added to the 5′ end of the target sequence during the first DNA synthesis. Here, we applied qSeq to eDNA analysis to test its effectiveness in biodiversity monitoring. eDNA was extracted from water samples taken over 4 days from aquaria containing five fish species (Hemigrammocypris neglectus, Candidia temminckii, Oryzias latipes, Rhinogobius flumineus, and Misgurnus anguillicaudatus), and quantified by qSeq and microfluidic digital PCR (dPCR) using a TaqMan probe. The eDNA abundance quantified by qSeq was consistent with that quantified by dPCR for each fish species at each sampling time. The correlation coefficients between qSeq and dPCR were 0.643, 0.859, and 0.786 for H. neglectus, O. latipes, and M. anguillicaudatus, respectively, indicating that qSeq accurately quantifies fish eDNA.


Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 22
Author(s):  
Nasim Safaei ◽  
Yvonne Mast ◽  
Michael Steinert ◽  
Katharina Huber ◽  
Boyke Bunk ◽  
...  

Antibiotic producers have mainly been isolated from soil, which often has led to the rediscovery of known compounds. In this study, we identified the freshwater snail Physa acuta as an unexplored source for new antibiotic producers. The bacterial diversity associated with the snail was characterized by a metagenomic approach using cultivation-independent high-throughput sequencing. Although Actinobacteria represented only 2% of the bacterial community, the focus was laid on the isolation of the genus Streptomyces due to its potential to produce antibiotics. Three Streptomyces strains (7NS1, 7NS2 and 7NS3) were isolated from P. acuta, and the antimicrobial activity of the crude extracts were tested against a selection of Gram-positive and Gram-negative bacteria and fungi. 7NS3 showed the strongest activity against Gram-positive bacteria and, thus, was selected for genome sequencing and a phylogenomic analysis. 7NS3 represents a novel Streptomyces species, which was deposited as Streptomyces sp. DSM 110735 at the Leibniz Institute-German Collection of Microorganisms and Cell Cultures (DSMZ). Bioassay-guided high-performance liquid chromatography (HPLC) and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS) analyses of crude extract fractions resulted in the detection of four compounds, one of which matched the compound characteristics of emycin A, an angucycline-like aromatic polyketide. Genome mining studies based on the whole-genome sequence of 7NS3 resulted in the identification of a gene cluster potentially coding for emycin A biosynthesis. Our study demonstrates that freshwater snails like P. acuta can represent promising reservoirs for the isolation of new antibiotic-producing actinobacterial species.


2015 ◽  
Vol 91 (Suppl 2) ◽  
pp. A167.2-A167
Author(s):  
FN Carestiato ◽  
SM Amaro-Filho ◽  
MA Moreira ◽  
RH Barbosa ◽  
YL Furtado ◽  
...  

2021 ◽  
Author(s):  
Zi-Jian Deng ◽  
Dong-Wen Chen ◽  
Xi-Jie Chen ◽  
Jia-Ming Fang ◽  
Liang Xv ◽  
...  

Abstract Background: Gastric cancer is the fourth most common malignant disease. Both CDK10 and long noncoding RNAs (lncRNAs) have been found to exert biological functions in multiple cancers. However, it is still unclear whether CDK10 represses tumor progression in gastric cancer by reducing potential targeting lncRNAs.Methods: The functions of CDK10 and lncRNA-C5ORF42-5 in proliferation, invasion and migration were assessed by MTS assays, colony formation assays, cell cycle and apoptosis assays, Transwell assays, wound healing assays and animal experiments. We used high-throughput sequencing to confirm the existence of lncRNA-C5ORF42-5 and quantitative real-time PCR was used to evaluate lncRNA expression. Then, with RNA-seq sequencing as well as GO function and KEGG enrichment analysis, we identified the signaling pathways in which lncRNA-C5ORF42-5 was involved in gastric cancer. Finally, western blotting was used to identify the genes regulated by lncRNA-C5ORF42-5.Results: Our results showed that CDK10 is expressed at relatively low levels in gastric cancer cell lines and inhibits the progression of gastric cancer cells both in vitro and in vivo. Next, based on high-throughput sequencing, we identified a novel lncRNA, lncRNA-C5ORF42-5, in the stable CDK10-overexpressing cell line compared with the CDK-knockdown cell line and their controls. Additionally, we confirmed that lncRNA-C5ORF42-5 acts as an oncogene to promote metastasis in gastric cancer in vitro and in vivo. We then ascertained that lncRNA-C5ORF42-5 is a major contributor to the function of CDK10 in gastric cancer metastasis by upregulating lncRNA-C5ORF42-5 to reverse the effects of CDK10 overexpression. Finally, we explored the mechanism by which lncRNA-C5ORF42-5 overexpression affects gastric cancer cells to elucidate whether lncRNA-C5ORF42-5 may increase the activity of the SMAD pathway of BMP signaling and promote the expression of EMT-related proteins, such as E-cadherin. Additionally, overexpression of lncRNA-C5ORF42-5 affected the phosphorylation levels of AKT and ERK.Conclusion: Our findings suggest that CDK10 overexpression represses gastric cancer tumor progression by reducing lncRNA-C5ORF42-5 and hindering activation of the related proteins in metastatic signaling pathways, which provides new insight into developing effective therapeutic strategies in the treatment of metastatic gastric cancer.


2021 ◽  
Author(s):  
Yiheng Hu ◽  
Laszlo Irinyi ◽  
Minh Thuy Vi Hoang ◽  
Tavish Eenjes ◽  
Abigail Graetz ◽  
...  

Background: The kingdom fungi is crucial for life on earth and is highly diverse. Yet fungi are challenging to characterize. They can be difficult to culture and may be morphologically indistinct in culture. They can have complex genomes of over 1 Gb in size and are still underrepresented in whole genome sequence databases. Overall their description and analysis lags far behind other microbes such as bacteria. At the same time, classification of species via high throughput sequencing without prior purification is increasingly becoming the norm for pathogen detection, microbiome studies, and environmental monitoring. However, standardized procedures for characterizing unknown fungi from complex sequencing data have not yet been established. Results: We compared different metagenomics sequencing and analysis strategies for the identification of fungal species. Using two fungal mock communities of 44 phylogenetically diverse species, we compared species classification and community composition analysis pipelines using shotgun metagenomics and amplicon sequencing data generated from both short and long read sequencing technologies. We show that regardless of the sequencing methodology used, the highest accuracy of species identification was achieved by sequence alignment against a fungi-specific database. During the assessment of classification algorithms, we found that applying cut-offs to the query coverage of each read or contig significantly improved the classification accuracy and community composition analysis without significant data loss. Conclusion: Overall, our study expands the toolkit for identifying fungi by improving sequence-based fungal classification, and provides a practical guide for the design of metagenomics analyses.


1990 ◽  
Vol 10 (9) ◽  
pp. 4658-4666
Author(s):  
A M Buchberg ◽  
H G Bedigian ◽  
N A Jenkins ◽  
N G Copeland

BXH-2 mice have the highest incidence of spontaneous retrovirally induced myeloid leukemia of any known inbred strain and, as such, represent a valuable model system for identifying cellular proto-oncogenes involved in myeloid disease. Chronic murine leukemia viruses often induce disease by insertional activation or mutation of cellular proto-oncogenes. These loci are identified as common viral integration sites in tumor DNAs. Here we report on the characterization of a novel common viral integration site in BXH-2 myeloid leukemias, designated Evi-2. Within the cluster of viral integration sites that define Evi-2, we identified a gene that has the potential for encoding a novel protein of 223 amino acids. This putative proto-oncogene possesses all of the structural features of a transmembrane protein. Within the transmembrane domain is a "leucine zipper," suggesting that Evi-2 is involved in either homopolymer or heteropolymer formation, which may play an important role in the normal functioning of Evi-2. Interestingly, the human homolog of Evi-2 has recently been shown to be tightly linked to the von Recklinghausen neurofibromatosis locus, suggesting a role for Evi-2 in human disease as well.


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