scholarly journals High-throughput sequencing of the chloroplast and mitochondrion of Chlamydomonas reinhardtii to generate improved de novo assemblies, analyze expression patterns and transcript speciation, and evaluate diversity among laboratory strains and wild isolates

2018 ◽  
Vol 93 (3) ◽  
pp. 545-565 ◽  
Author(s):  
Sean D. Gallaher ◽  
Sorel T. Fitz-Gibbon ◽  
Daniela Strenkert ◽  
Samuel O. Purvine ◽  
Matteo Pellegrini ◽  
...  
Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 753
Author(s):  
Miroslav Glasa ◽  
Richard Hančinský ◽  
Katarína Šoltys ◽  
Lukáš Predajňa ◽  
Jana Tomašechová ◽  
...  

In recent years, high throughput sequencing (HTS) has brought new possibilities to the study of the diversity and complexity of plant viromes. Mixed infection of a single plant with several viruses is frequently observed in such studies. We analyzed the virome of 10 tomato and sweet pepper samples from Slovakia, all showing the presence of potato virus Y (PVY) infection. Most datasets allow the determination of the nearly complete sequence of a single-variant PVY genome, belonging to one of the PVY recombinant strains (N-Wi, NTNa, or NTNb). However, in three to-mato samples (T1, T40, and T62) the presence of N-type and O-type sequences spanning the same genome region was documented, indicative of mixed infections involving different PVY strains variants, hampering the automated assembly of PVY genomes present in the sample. The N- and O-type in silico data were further confirmed by specific RT-PCR assays targeting UTR-P1 and NIa genomic parts. Although full genomes could not be de novo assembled directly in this situation, their deep coverage by relatively long paired reads allowed their manual re-assembly using very stringent mapping parameters. These results highlight the complexity of PVY infection of some host plants and the challenges that can be met when trying to precisely identify the PVY isolates involved in mixed infection.


Author(s):  
Yuansheng Liu ◽  
Xiaocai Zhang ◽  
Quan Zou ◽  
Xiangxiang Zeng

Abstract Summary Removing duplicate and near-duplicate reads, generated by high-throughput sequencing technologies, is able to reduce computational resources in downstream applications. Here we develop minirmd, a de novo tool to remove duplicate reads via multiple rounds of clustering using different length of minimizer. Experiments demonstrate that minirmd removes more near-duplicate reads than existing clustering approaches and is faster than existing multi-core tools. To the best of our knowledge, minirmd is the first tool to remove near-duplicates on reverse-complementary strand. Availability and implementation https://github.com/yuansliu/minirmd. Supplementary information Supplementary data are available at Bioinformatics online.


Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 633 ◽  
Author(s):  
Maria Paola Pisano ◽  
Nicole Grandi ◽  
Enzo Tramontano

Human Endogenous retroviruses (HERVs) are remnants of ancient retroviral infections that represent a large fraction of our genome. Their transcriptional activity is finely regulated in early developmental stages and their expression is modulated in different cell types and tissues. Such activity has an impact on human physiology and pathology that is only partially understood up to date. Novel high-throughput sequencing tools have recently allowed for a great advancement in elucidating the various HERV expression patterns in different tissues as well as the mechanisms controlling their transcription, and overall, have helped in gaining better insights in an all-inclusive understanding of the impact of HERVs in biology of the host.


Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1367
Author(s):  
Edgar Baldemar Sepúlveda-García ◽  
José Francisco Pulido-Barajas ◽  
Ariana Arlene Huerta-Heredia ◽  
Julián Mario Peña-Castro ◽  
Renyi Liu ◽  
...  

Submergence and drought stresses are the main constraints to crop production worldwide. MicroRNAs (miRNAs) are known to play a major role in plant response to various stresses. In this study, we analyzed the expression of maize and teosinte miRNAs by high-throughput sequencing of small RNA libraries in maize and its ancestor teosinte (Zea mays ssp. parviglumis), under submergence, drought, and alternated stress. We found that the expression patterns of 67 miRNA sequences representing 23 miRNA families in maize and other plants were regulated by submergence or drought. miR159a, miR166b, miR167c, and miR169c were downregulated by submergence in both plants but more severely in maize. miR156k and miR164e were upregulated by drought in teosinte but downregulated in maize. Small RNA profiling of teosinte subject to alternate treatments with drought and submergence revealed that submergence as the first stress attenuated the response to drought, while drought being the first stress did not alter the response to submergence. The miRNAs identified herein, and their potential targets, indicate that control of development, growth, and response to oxidative stress could be crucial for adaptation and that there exists evolutionary divergence between these two subspecies in miRNA response to abiotic stresses.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1383-1383
Author(s):  
Kezhi Huang ◽  
Min Yang ◽  
Zengkai Pan ◽  
Florian H. Heidel ◽  
Michaela Scherr ◽  
...  

Abstract Using high-throughput sequencing, an increased number of gene mutations has been identified in cancer. Among the up to hundreds of acquired mutations in cancer clones, only a few cooperating mutations are believed to be needed for initiation of the malignant disease. Recently, we reported a single amino acid substitution at position 676 (N676K) within the FLT3 kinase domain as the sole cause of resistance to PKC412 in one patient with FLT3-ITD associated acute myeloid leukemia (AML). The FLT3-N676K mutation was more recently identified independently in up to 6% of de novo AML patients with inv(16) by other groups. As FLT3-TKD mutations are strongly associated with inv(16) in AML and particularly FLT3-N676K was found almost exclusively in AML patients with inv(16), this prompted us to investigate the transforming activity of FLT3-N676K and to test whether FLT3-N676K would cooperate with inv(16) to promote AML. First, we analyzed in vivo leukemogenesis mediated by FLT3-N676K. Retroviral expression of FLT3-N676K in myeloid 32D cells induced AML in syngeneic C3H/HeJ mice (n=11/13, latency ~8 weeks), with a transforming activity similar to FLT3-ITD (n=8/8), FLT3-TKD D835Y (n=8/9), and FLT3-ITD-N676K (n=9/9) mutations. Three out of 14 C57BL/6J mice transplanted with FLT3-N676K-transduced primary lineage negative (Lin-) bone marrow cells died of acute leukemia (latency of 68, 77, and 273 days), while none of 16 animals in the control groups including FLT3-ITD and CBFß-SMMHC developed any hematological malignancy. Secondly, co-expression of FLT3-N676K and CBFß-SMMHC did not promote acute leukemia in 3 independent experiments using C3H/HeJ and C57BL/6J mice (n=16). So far only 1 out of 11 C57BL/6J mice co-expressing FLT3-N676K and CBFß-SMMHC developed acute leukemia (AML with latency of 166 days). In comparison with FLT3-ITD, FLT3-N676K tended to result in stronger phosphorylation of FLT3, MAPK and AKT, and diseased animals carrying FLT3-N676K demonstrated much lower frequency of leukemic stem cells in the majority of analyzed cases. Importantly, leukemic cells co-expressing FLT3-N676K and CBFß-SMMHC were still highly sensitive to the FLT3 inhibitor AC220. Taken together, we show that FLT3-N676K mutant is potent to transform murine hematopoietic stem/progenitor cells in vivo independently of the inv(16) chimeric gene CBFB-MYH11. This is the first report of acute leukemia induced by an activating FLT3 mutation in C57BL/6J mice. Moreover, our data suggest that targeting FLT3-N676K mutation may be an attractive treatment option for FLT3-N676K-positive patients without concurrent ITD. Our data emphasize more careful analysis of the cooperating network of mutations identified in AML by high-throughput sequencing. This work was supported by DJCLS (grant: 13/22) and the Deutsche Forschungsgemeinschaft (grant: Li 1608/2-1). KH and ZP were supported by the China Scholarship Council (2011638024 and 201406100008). Disclosures Heidel: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1867
Author(s):  
Ziyi Wang ◽  
Achal Neupane ◽  
Jiuhuan Feng ◽  
Connor Pedersen ◽  
Shin-Yi Lee Marzano

Sunflowers (Helianthus annuus L.) are susceptible to multiple diseases in field production. In this study, we collected diseased sunflower leaves in fields located in South Dakota, USA, for virome investigation. The leaves showed visible symptoms on the foliage, indicating phomopsis and rust infections. To identify the viruses potentially associated with the disease diagnosed, symptomatic leaves were obtained from diseased plants. Total RNA was extracted corresponding to each disease diagnosed to generate libraries for paired-end high throughput sequencing. Short sequencing reads were assembled de novo and the contigs with similarities to viruses were identified by aligning against a custom protein database. We report the discovery of two novel mitoviruses, four novel partitiviruses, one novel victorivirus, and nine novel totiviruses based on similarities to RNA-dependent RNA polymerases and capsid proteins. Contigs similar to bean yellow mosaic virus and Sclerotinia sclerotiorum hypovirulence-associated DNA virus were also detected. To the best of our knowledge, this is the first report of direct metatranscriptomics discovery of viruses associated with fungal infections of sunflowers bypassing culturing. These newly discovered viruses represent a natural genetic resource from which we can further develop potential biopesticide to control sunflower diseases.


2022 ◽  
Vol 23 (2) ◽  
pp. 900
Author(s):  
Taja Jeseničnik ◽  
Nataša Štajner ◽  
Sebastjan Radišek ◽  
Ajay Kumar Mishra ◽  
Katarina Košmelj ◽  
...  

Verticillium nonalfalfae (V. nonalfalfae) is one of the most problematic hop (Humulus lupulus L.) pathogens, as the highly virulent fungal pathotypes cause severe annual yield losses due to infections of entire hop fields. In recent years, the RNA interference (RNAi) mechanism has become one of the main areas of focus in plant—fungal pathogen interaction studies and has been implicated as one of the major contributors to fungal pathogenicity. MicroRNA-like RNAs (milRNAs) have been identified in several important plant pathogenic fungi; however, to date, no milRNA has been reported in the V. nonalfalfae species. In the present study, using a high-throughput sequencing approach and extensive bioinformatics analysis, a total of 156 milRNA precursors were identified in the annotated V. nonalfalfae genome, and 27 of these milRNA precursors were selected as true milRNA candidates, with appropriate microRNA hairpin secondary structures. The stem-loop RT-qPCR assay was used for milRNA validation; a total of nine V. nonalfalfae milRNAs were detected, and their expression was confirmed. The milRNA expression patterns, determined by the absolute quantification approach, imply that milRNAs play an important role in the pathogenicity of highly virulent V. nonalfalfae pathotypes. Computational analysis predicted milRNA targets in the V. nonalfalfae genome and in the host hop transcriptome, and the activity of milRNA-mediated RNAi target cleavage was subsequently confirmed for two selected endogenous fungal target gene models using the 5′ RLM-RACE approach.


2019 ◽  
Vol 63 (4) ◽  
pp. 471-479
Author(s):  
Anna Orłowska ◽  
Ewelina Iwan ◽  
Marcin Smreczak ◽  
Jerzy Rola

AbstractIntroductionHigh-throughput sequencing (HTS) identifies random viral fragments in environmental samples metagenomically. High reliability gains it broad application in virus evolution, host-virus interaction, and pathogenicity studies. Deep sequencing of field samples with content of host genetic material and bacteria often produces insufficient data for metagenomics and must be preceded by target enrichment. The main goal of the study was the evaluation of HTS for complete genome sequencing of field-case rabies viruses (RABVs).Material and MethodsThe material was 23 RABVs isolated mainly from red foxes and one European bat lyssavirus-1 isolate propagated in neuroblastoma cells. Three methods of RNA isolation were tested for the direct metagenomics and RABV-enriched approaches. Deep sequencing was performed with a MiSeq sequencer (Illumina) and reagent v3 kit. Bioinformatics data were evaluated by Kraken and Centrifuge software and de novo assembly was done with metaSPAdes.ResultsTesting RNA extraction procedures revealed the deep sequencing scope superiority of the combined TRIzol/column method. This HTS methodology made it possible to obtain complete genomes of all the RABV isolates collected in the field. Significantly greater rates of RABV genome coverages (over 5,900) were obtained with RABV enrichment. Direct metagenomic studies sequenced the full length of 6 out of 16 RABV isolates with a medium coverage between 1 and 71.ConclusionDirect metagenomics gives the most realistic illustration of the field sample microbiome, but with low coverage. For deep characterisation of viruses, e.g. for spatial and temporal phylogeography during outbreaks, target enrichment is recommended as it covers sequences much more completely.


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