scholarly journals A draft genome of grass pea (Lathyrus sativus), a resilient diploid legume

2020 ◽  
Author(s):  
Peter M. F. Emmrich ◽  
Abhimanyu Sarkar ◽  
Isaac Njaci ◽  
Gemy George Kaithakottil ◽  
Noel Ellis ◽  
...  

AbstractWe have sequenced the genome of grass pea (Lathyrus sativus), a resilient diploid (2n=14) legume closely related to pea (Pisum sativum). We determined the genome size of the sequenced European accession (LS007) as 6.3 Gbp. We generated two assemblies of this genome, i) EIv1 using Illumina PCR-free paired-end sequencing and assembly followed by long-mate-pair scaffolding and ii) Rbp using Oxford Nanopore Technologies long-read sequencing and assembly followed by polishing with Illumina paired-end data. EIv1 has a total length of 8.12 Gbp (including 1.9 billion Ns) and scaffold N50 59,7 kbp. Annotation has identified 33,819 high confidence genes in the assembly. Rbp has a total length of 6.2 Gbp (with no Ns) and a contig N50 of 155.7 kbp. Gene space assessment using the eukaryote BUSCO database showed completeness scores of 82.8 % and 89.8%, respectively.

2021 ◽  
Vol 10 (22) ◽  
Author(s):  
Chanakya Pachi Pulusu ◽  
Balaram Khamari ◽  
Manmath Lama ◽  
Arun Sai Kumar Peketi ◽  
Prakash Kumar ◽  
...  

The draft genome of pandrug-resistant Pseudomonas aeruginosa strain SPA03, which belongs to global high-risk sequence type 357 (ST357) and was isolated from a patient with benign prostatic hyperplasia, is presented in this report. The genome assembly was generated by combining short-read Illumina HiSeq-X Ten and long-read Oxford Nanopore Technologies MinION sequence data using the Unicycler assembler.


2021 ◽  
Author(s):  
Gábor Torma ◽  
Dóra Tombácz ◽  
Norbert Moldován ◽  
Ádám Fülöp ◽  
István Prazsák ◽  
...  

Abstract In this study, we used two long-read sequencing (LRS) techniques, Sequel from the Pacific Biosciences and MinION from Oxford Nanopore Technologies, for the transcriptional characterization of a prototype baculovirus, Autographacalifornica multiple nucleopolyhedrovirus. LRS is able to read full-length RNA molecules, and thereby to distinguish between transcript isoforms, mono- and polycistronic RNAs, and overlapping transcripts. Altogether, we detected 875 transcripts, of which 759 are novel and 116 have been annotated previously. These RNA molecules include 41 novel putative protein coding transcript (each containing 5’-truncated in-frame ORFs), 14 monocistronic transcripts, 99 multicistronic RNAs, 101 non-coding RNA, and 504 length isoforms. We also detected RNA methylation in 12 viral genes and RNA hyper-editing in the longer 5’-UTR transcript isoform of ORF 19 gene.


2020 ◽  
Author(s):  
Michael Liem ◽  
Tonny Regensburg-Tuïnk ◽  
Christiaan Henkel ◽  
Hans Jansen ◽  
Herman Spaink

Abstract Objective: Currently the majority of non-culturable microbes in sea water are yet to be discovered, Nanopore offers a solution to overcome the challenging tasks to identify the genomes and complex composition of oceanic microbiomes. In this study we evaluate the utility of Oxford Nanopore Technologies (ONT) sequencing to characterize microbial diversity in seawater from multiple locations. We compared the microbial species diversity of retrieved environmental samples from two different locations and time points.Results: With only three ONT flow cells we were able to identify thousands of organisms, including bacteriophages, from which a large part at species level. It was possible to assemble genomes from environmental samples with Flye. In several cases this resulted in >1 Mbp contigs and in the particular case of a Thioglobus singularis species it even produced a near complete genome. k-mer analysis reveals that a large part of the data represents species of which close relatives have not yet been deposited to the database. These results show that our approach is suitable for scalable genomic investigations such as monitoring oceanic biodiversity and provides a new platform for education in biodiversity.


2021 ◽  
Author(s):  
Chi yang ◽  
Lu Ma ◽  
Donglai Xiao ◽  
Xiaoyu Liu ◽  
Xiaoling Jiang ◽  
...  

Sparassis latifolia is a valuable edible mushroom cultivated in China. In 2018, our research group reported an incomplete and low quality genome of S. latifolia was obtained by Illumina HiSeq 2500 sequencing. These limitations in the available genome have constrained genetic and genomic studies in this mushroom resource. Herein, an updated draft genome sequence of S. latifolia was generated by Oxford Nanopore sequencing and the Hi-C technique. A total of 8.24 Gb of Oxford Nanopore long reads representing ~198.08X coverage of the S. latifolia genome were generated. Subsequently, a high-quality genome of 41.41 Mb, with scaffold and contig N50 sizes of 3.31 Mb and 1.51 Mb, respectively, was assembled. Hi-C scaffolding of the genome resulted in 12 pseudochromosomes containing 93.56% of the bases in the assembled genome. Genome annotation further revealed that 17.47% of the genome was composed of repetitive sequences. In addition, 13,103 protein-coding genes were predicted, among which 98.72% were functionally annotated. BUSCO assay results further revealed that there were 92.07% complete BUSCOs. The improved chromosome-scale assembly and genome features described here will aid further molecular elucidation of various traits, breeding of S. latifolia, and evolutionary studies with related taxa.


2020 ◽  
Vol 8 (6) ◽  
pp. 895 ◽  
Author(s):  
Saïd Oulghazi ◽  
Mohieddine Moumni ◽  
Slimane Khayi ◽  
Kévin Robic ◽  
Sohaib Sarfraz ◽  
...  

Dickeya and Pectobacterium pathogens are causative agents of several diseases that affect many crops worldwide. This work investigated the species diversity of these pathogens in Morocco, where Dickeya pathogens have only been isolated from potato fields recently. To this end, samplings were conducted in three major potato growing areas over a three-year period (2015–2017). Pathogens were characterized by sequence determination of both the gapA gene marker and genomes using Illumina and Oxford Nanopore technologies. We isolated 119 pathogens belonging to P. versatile (19%), P. carotovorum (3%), P. polaris (5%), P. brasiliense (56%) and D. dianthicola (17%). Their taxonomic assignation was confirmed by draft genome analyses of 10 representative strains of the collected species. D. dianthicola were isolated from a unique area where a wide species diversity of pectinolytic pathogens was observed. In tuber rotting assays, D. dianthicola isolates were more aggressive than Pectobacterium isolates. The complete genome sequence of D. dianthicola LAR.16.03.LID was obtained and compared with other D. dianthicola genomes from public databases. Overall, this study highlighted the ecological context from which some Dickeya and Pectobacterium species emerged in Morocco, and reported the first complete genome of a D. dianthicola strain isolated in Morocco that will be suitable for further epidemiological studies.


2020 ◽  
Author(s):  
Aki Hirabayashi ◽  
Koji Yahara ◽  
Satomi Mitsuhashi ◽  
So Nakagawa ◽  
Tadashi Imanishi ◽  
...  

Carbapenem-resistant Enterobacteriaceae (CRE) represent a serious threat to public health due to limited management of severe infections and high mortality. The rate of resistance of Enterobacteriaceae isolates to major antimicrobials, including carbapenems, is much higher in Vietnam than in Western countries, but the reasons remain unknown due to the lack of genomic epidemiology research. A previous study suggested that carbapenem resistance genes, such as the carbapenemase gene bla NDM-1 , spread via plasmids among Enterobacteriaceae in Vietnam. In this study, we performed detection and molecular characterization of bla NDM-1 -carrying plasmids in CRE isolated in Vietnam, and identified several possible cases of horizontal transfer of plasmids both within and among species of bacteria. Twenty-five carbapenem-resistant isolates from Enterobacteriaceae clinically isolated in a reference medical institution in Hanoi were sequenced on Illumina short-read sequencers, and 12 isolates harboring bla NDM-1 were sequenced on an Oxford Nanopore Technologies long-read sequencer to obtain complete plasmid sequences. Most of the plasmids co-carried genes conferring resistance to clinically relevant antimicrobials, including third-generation cephalosporins, aminoglycosides, and fluoroquinolones, in addition to bla NDM-1 , leading to multidrug resistance of their bacterial hosts. These results provide insight into the genetic basis of CRE in Vietnam, and could help control nosocomial infections.


2020 ◽  
Author(s):  
Michael Liem ◽  
A.J.G. Regensburg-Tuïnk ◽  
C.V. Henkel ◽  
H.P. Spaink

Abstract Objective Currently the majority of non-culturable microbes in sea water are yet to be discovered, Nanopore offers a solution to overcome the challenging tasks to identify the genomes and complex composition of oceanic microbiomes. In this study we evaluate the utility of Oxford Nanopore Technologies (ONT) sequencing to characterize microbial diversity in seawater from multiple locations. We compared the microbial species diversity of retrieved environmental samples from two different locations and time points. Results With only three ONT flow cells we were able to identify thousands of organisms, including bacteriophages, from which a large part at species level. It was possible to assemble genomes from environmental samples with Flye. In several cases this resulted in >1 Mbp contigs and in the particular case of a Thioglobus singularis species it even produced a near complete genome. k-mer analysis reveals that a large part of the data represents species of which close relatives have not yet been deposited to the database. These results show that our approach is suitable for scalable genomic investigations such as monitoring oceanic biodiversity and provides a new platform for education in biodiversity.


2021 ◽  
Vol 10 (27) ◽  
Author(s):  
Kristian Jensen ◽  
Kosai Al-Nakeeb ◽  
Anna Koza ◽  
Ahmad A. Zeidan

The genome of Bifidobacterium animalis subsp. lactis BB-12 was sequenced using Oxford Nanopore Technologies long-read and Illumina short-read sequencing platforms. A hybrid genome assembly approach was used to construct an updated complete genome sequence for BB-12 containing 1,944,152 bp, with a G+C content of 60.5% and 1,615 genes.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 227 ◽  
Author(s):  
Scott Gigante

Oxford Nanopore Technologies' (ONT's) MinION and PromethION long-read sequencing technologies are emerging as genuine alternatives to established Next-Generation Sequencing technologies. A combination of the highly redundant file format and a rapid increase in data generation have created a significant problem both for immediate data storage on MinION-capable laptops, and for long-term storage on lab data servers. We developed Picopore, a software suite offering three methods of compression. Picopore's lossless and deep lossless methods provide a 25% and 44% average reduction in size, respectively, without removing any data from the files. Picopore's raw method provides an 88% average reduction in size, while retaining biologically relevant data for the end-user. All methods have the capacity to run in real-time in parallel to a sequencing run, reducing demand for both immediate and long-term storage space.


2021 ◽  
Author(s):  
Arang Rhie ◽  
Ann Mc Cartney ◽  
Kishwar Shafin ◽  
Michael Alonge ◽  
Andrey Bzikadze ◽  
...  

Abstract Advances in long-read sequencing technologies and genome assembly methods have enabled the recent completion of the first Telomere-to-Telomere (T2T) human genome assembly, which resolves complex segmental duplications and large tandem repeats, including centromeric satellite arrays in a complete hydatidiform mole (CHM13). Though derived from highly accurate sequencing, evaluation revealed that the initial T2T draft assembly had evidence of small errors and structural misassemblies. To correct these errors, we designed a novel repeat-aware polishing strategy that made accurate assembly corrections in large repeats without overcorrection, ultimately fixing 51% of the existing errors and improving the assembly QV to 73.9. By comparing our results to standard automated polishing tools, we outline common polishing errors and offer practical suggestions for genome projects with limited resources. We also show how sequencing biases in both PacBio HiFi and Oxford Nanopore Technologies reads cause signature assembly errors that can be corrected with a diverse panel of sequencing technologies


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