scholarly journals Nanopore Sequencing of a Forensic STR Multiplex Reveals Loci Suitable for Single-Contributor STR Profiling

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 381 ◽  
Author(s):  
Olivier Tytgat ◽  
Yannick Gansemans ◽  
Jana Weymaere ◽  
Kaat Rubben ◽  
Dieter Deforce ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Massively Parallel Sequencing ◽  
Flow Cell ◽  
Nanopore Sequencing ◽  
Flow Cells ◽  
Pattern Complexity ◽  
Str Loci ◽  
Oxford Nanopore ◽  
Oxford Nanopore Technologies ◽  
Short Tandem

Nanopore sequencing for forensic short tandem repeats (STR) genotyping comes with the advantages associated with massively parallel sequencing (MPS) without the need for a high up-front device cost, but genotyping is inaccurate, partially due to the occurrence of homopolymers in STR loci. The goal of this study was to apply the latest progress in nanopore sequencing by Oxford Nanopore Technologies in the field of STR genotyping. The experiments were performed using the state of the art R9.4 flow cell and the most recent R10 flow cell, which was specifically designed to improve consensus accuracy of homopolymers. Two single-contributor samples and one mixture sample were genotyped using Illumina sequencing, Nanopore R9.4 sequencing, and Nanopore R10 sequencing. The accuracy of genotyping was comparable for both types of flow cells, although the R10 flow cell provided improved data quality for loci characterized by the presence of homopolymers. We identify locus-dependent characteristics hindering accurate STR genotyping, providing insights for the design of a panel of STR loci suited for nanopore sequencing. Repeat number, the number of different reference alleles for the locus, repeat pattern complexity, flanking region complexity, and the presence of homopolymers are identified as unfavorable locus characteristics. For single-contributor samples and for a limited set of the commonly used STR loci, nanopore sequencing could be applied. However, the technology is not mature enough yet for implementation in routine forensic workflows.

scholarly journals Accurate profiling of forensic autosomal STRs using the Oxford Nanopore Technologies MinION device

2021 ◽  
Author(s):  
Courtney L. Hall ◽  
Rupesh K. Kesharwani ◽  
Nicole R. Phillips ◽  
John V. Planz ◽  
Fritz J. Sedlazeck ◽  
...  
Keyword(s):  
Specific Method ◽  
Nanopore Sequencing ◽  
Autosomal Strs ◽  
Str Typing ◽  
Str Loci ◽  
Oxford Nanopore ◽  
Long Read ◽  
Flanking Region ◽  
Sequencing Platforms ◽  
Oxford Nanopore Technologies

The high variability characteristic of short tandem repeat (STR) markers is harnessed for human identification in forensic genetic analyses. Despite the power and reliability of current typing techniques, sequence-level information both within and around STRs are masked in the length-based profiles generated. Forensic STR typing using next generation sequencing (NGS) has therefore gained attention as an alternative to traditional capillary electrophoresis (CE) approaches. In this proof-of-principle study, we evaluate the forensic applicability of the newest and smallest NGS platform available — the Oxford Nanopore Technologies (ONT) MinION device. Although nanopore sequencing on the handheld MinION offers numerous advantages, including on-site sample processing, the relatively high error rate and lack of forensic-specific analysis software has prevented accurate profiling across STR panels in previous studies. Here we present STRspy, a streamlined method capable of producing length- and sequence-based STR allele designations from noisy, long-read data. To demonstrate the capabilities of STRspy, seven reference samples (female: n = 2; male: n = 5) were amplified at 15 and 30 PCR cycles using the Promega PowerSeq 46GY System and sequenced on the ONT MinION device in triplicate. Basecalled reads were processed with STRspy using a custom database containing alleles reported in the STRSeq BioProject NIST 1036 dataset. Resultant STR allele designations and flanking region single nucleotide polymorphism (SNP) calls were compared to the manufacturer-validated genotypes for each sample. STRspy generated robust and reliable genotypes across all autosomal STR loci amplified with 30 PCR cycles, achieving 100% concordance based on both length and sequence. Furthermore, we were able to identify flanking region SNPs with >90% accuracy. These results demonstrate that nanopore sequencing platforms are capable of revealing additional variation in and around STR loci depending on read coverage. As the first long-read platform-specific method to successfully profile the entire panel of autosomal STRs amplified by a commercially available multiplex, STRspy significantly increases the feasibility of nanopore sequencing in forensic applications.

scholarly journals Genome and transcriptome of a pathogenic yeast, Candida nivariensis

2021 ◽  
Author(s):  
Yunfan Fan ◽  
Andrew N Gale ◽  
Anna Bailey ◽  
Kali Barnes ◽  
Kiersten Colotti ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Glabrata ◽  
Nanopore Sequencing ◽  
Cdna Sequencing ◽  
Pathogenic Yeast ◽  
Mitochondrial Sequence ◽  
Dna And Rna ◽  
Oxford Nanopore ◽  
Candida Nivariensis ◽  
Oxford Nanopore Technologies

Abstract We present a highly contiguous genome and transcriptome of the pathogenic yeast, Candida nivariensis. We sequenced both the DNA and RNA of this species using both the Oxford Nanopore Technologies (ONT) and Illumina platforms. We assembled the genome into an 11.8 Mb draft composed of 16 contigs with an N50 of 886 Kb, including a circular mitochondrial sequence of 28 Kb. Using direct RNA nanopore sequencing and Illumina cDNA sequencing, we constructed an annotation of our new assembly, supplemented by lifting over genes from Saccharomyces cerevisiae and Candida glabrata.

scholarly journals Comprehensive genetic diagnosis of tandem repeat expansion disorders with programmable targeted nanopore sequencing

2021 ◽  
Author(s):  
Igor Stevanovski ◽  
Sanjog R. Chintalaphani ◽  
Hasindu Gamaarachchi ◽  
James M. Ferguson ◽  
Sandy S. Pineda ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Tandem Repeats ◽  
Fragile X ◽  
Genetic Diagnosis ◽  
Neuromuscular Diseases ◽  
Nanopore Sequencing ◽  
Molecular Tests ◽  
Genetic Landscape ◽  
Long Read ◽  
Short Tandem

ABSTRACTShort-tandem repeat (STR) expansions are an important class of pathogenic genetic variants. Over forty neurological and neuromuscular diseases are caused by STR expansions, with 37 different genes implicated to date. Here we describe the use of programmable targeted long-read sequencing with Oxford Nanopore’s ReadUntil function for parallel genotyping of all known neuropathogenic STRs in a single, simple assay. Our approach enables accurate, haplotype-resolved assembly and DNA methylation profiling of expanded and non-expanded STR sites. In doing so, the assay correctly diagnoses all individuals in a cohort of patients (n = 27) with various neurogenetic diseases, including Huntington’s disease, fragile X syndrome and cerebellar ataxia (CANVAS) and others. Targeted long-read sequencing solves large and complex STR expansions that confound established molecular tests and short-read sequencing, and identifies non-canonical STR motif conformations and internal sequence interruptions. Even in our relatively small cohort, we observe a wide diversity of STR alleles of known and unknown pathogenicity, suggesting that long-read sequencing will redefine the genetic landscape of STR expansion disorders. Finally, we show how the flexible inclusion of pharmacogenomics (PGx) genes as secondary ReadUntil targets can identify clinically actionable PGx genotypes to further inform patient care, at no extra cost. Our study addresses the need for improved techniques for genetic diagnosis of STR expansion disorders and illustrates the broad utility of programmable long-read sequencing for clinical genomics.One sentence summaryThis study describes the development and validation of a programmable targeted nanopore sequencing assay for parallel genetic diagnosis of all known pathogenic short-tandem repeats (STRs) in a single, simple test.

scholarly journals Microbial diversity characterization of seawater in a pilot study using Oxford Nanopore Technologies long-read sequencing

2020 ◽  
Author(s):  
Michael Liem ◽  
Tonny Regensburg-Tuïnk ◽  
Christiaan Henkel ◽  
Hans Jansen ◽  
Herman Spaink
Keyword(s):  
Microbial Diversity ◽  
Environmental Samples ◽  
Sea Water ◽  
Flow Cells ◽  
Oxford Nanopore ◽  
Challenging Tasks ◽  
Long Read ◽  
Close Relatives ◽  
Oxford Nanopore Technologies

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.

scholarly journals The Landscape of Human STR Variation

2014 ◽  
Author(s):  
Thomas F. Willems ◽  
Melissa Gymrek ◽  
Gareth Highnam ◽  
The Genomes Project ◽  
David Mittelman ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Phase 1 ◽  
Genetic Diseases ◽  
Point Mutations ◽  
Graphical Interface ◽  
Loss Of Function ◽  
Human Reference Genome ◽  
Str Loci ◽  
Classical Point ◽  
Short Tandem

Short Tandem Repeats are among the most polymorphic loci in the human genome. These loci play a role in the etiology of a range of genetic diseases and have been frequently utilized in forensics, population genetics, and genetic genealogy. Despite this plethora of applications, little is known about the variation of most STRs in the human population. Here, we report the largest-scale analysis of human STR variation to date. We collected information for nearly 700,000 STR loci across over 1,000 individuals in phase 1 of the 1000 Genomes Project. This process nearly saturated common STR variations. After employing a series of quality controls, we utilize this call set to analyze determinants of STR variation, assess the human reference genome?s representation of STR alleles, find STR loci with common loss-of-function alleles, and obtain initial estimates of the linkage disequilibrium between STRs and common SNPs. Overall, these analyses further elucidate the scale of genetic variation beyond classical point mutations. The resource is publicly available at http://strcat.teamerlich.org/ both in raw format and via a graphical interface. 

scholarly journals Microbial diversity characterization of seawater in a pilot study using Oxford Nanopore Technologies long-read sequencing

2020 ◽  
Author(s):  
Michael Liem ◽  
A.J.G. Regensburg-Tuïnk ◽  
C.V. Henkel ◽  
H.P. Spaink
Keyword(s):  
Microbial Diversity ◽  
Environmental Samples ◽  
Sea Water ◽  
Flow Cells ◽  
Oxford Nanopore ◽  
Challenging Tasks ◽  
Long Read ◽  
Close Relatives ◽  
Oxford Nanopore Technologies

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.

scholarly journals SHORT TANDEM REPEATS (STRs) AS A PRIMARY METHOD FOR PERSONAL IDENTIFICATION (A Case Report)

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Johannis Mallo
Keyword(s):  
Police Officers ◽  
Tandem Repeats ◽  
Personal Identification ◽  
Str Loci ◽  
Indonesian Population ◽  
Buccal Swabs ◽  
Paternity Index ◽  
Left And Right ◽  
Dna Pcr ◽  
Short Tandem

Abstrak: Mayat seorang perempuan tak dikenal yang ditemukan di daerah Malalayang dibawa oleh polisi ke Rumah Sakit Umum Pusat Prof.dr.R.D Kandou. Mayat tersebut telah mengalami proses awal pembusukan. Selain itu pihak kepolisian mengalami kesulitan untuk menentukan identitas mayat tersebut serta menemukan keluarganya. Demi pengungkapan kejadian yang menyebabkan kematian perempuan tak dikenal ini, terlebih dahulu polisi harus dapat menentukan identitas mayat. Melalui data medis yang dikumpulkan dari proses autopsi forensik, digabungkan dengan daftar orang hilang yang dibuat oleh kantor kepolisian Sektor Malalayang dan Kepolisian Kota Besar Manado, ditemukan kecocokan data yang merujuk pada seorang perempuan yang dilaporkan hilang oleh keluarganya. Polisi kemudian meminta pemeriksaan identifikasi melalui metode analisis DNA untuk membandingkan DNA mayat dengan DNA individu-individu yang mengaku sebagai keluarga korban. Pada saat autopsi forensik, diambil sampel tulang padat iga kanan dan kiri sepanjang 10 cm dari mayat. Sebagai pembanding diambil apusan mukosa pipi dan 2 cc darah tepi dari individu-individu yang diduga ayah dan adik kandung dari mayat yang ditemukan. Proses ekstraksi, kuantifikasi, PCR, dan proses analisis akan dilakukan di Pusat Laboratorium Forensik Kepolisian Republik Indonesia. Kata kunci: identitas mayat, identifikasi DNA, PCR, STR.     Abstract: Ms X’s corpse was brought to Prof.R.D Kandou general hospital by police officers. Ms X was found in Malalayang without any identity attached to her body. Her body had begun to decompose, and the police had difficulties in finding Ms X’s relatives. In order to uncover the case behind Ms X’s death, the police had to first discover the true identity of Ms X. Medical data was acquired during an autopsy, and from a list that the police made, a match was found in a report of missing persons when two data were compared. The Police requested a paternity DNA examination in order to have a positive identification of Ms X. During the forensic autopsy of Ms X, 10 cm of left and right costal compact bones were obtained. Buccal swabs were made and 2 cc of peripheral blood were taken, each from the suspected father and a suspected sister of Ms X. Extraction, quantification, PCR, and the analysis was made at Pusat Laboratorium Forensik Kepolisian Republik Indonesia the main Police Forensic Laboratory of Indonesia. PCR involves 13 to 15 of nuclear STR loci, and the analyzing process of the samples involves comparing the 13 to 15 nuclear STR loci of the 3 people. If a match is found with 99% accuracy, then identification is verified. The Paternity Index indicates the greatest possibility that the suspected father is the real father of Ms X, compared to other males in the Asian / Indonesian Population.1 Keywords: corpse identity,  DNA identification, PCR, STR.

scholarly journals Methplotlib: analysis of modified nucleotides from nanopore sequencing

2019 ◽  
Author(s):  
Wouter De Coster ◽  
Mojca Strazisar
Keyword(s):  
Gene Expression Regulation ◽  
Command Line ◽  
Nanopore Sequencing ◽  
Modified Nucleotides ◽  
Oxford Nanopore ◽  
Command Line Tool ◽  
Within Subjects ◽  
Allele Specific ◽  
Sequencing Platforms ◽  
Oxford Nanopore Technologies

AbstractSummaryModified nucleotides play a crucial role in gene expression regulation. Here we describe methplotlib, a tool developed for the visualization of modified nucleotides detected from Oxford Nanopore Technologies sequencing platforms, together with additional scripts for statistical analysis of allele specific modification within subjects and differential modification frequency across subjects.Availability and implementationThe methplotlib command-line tool is written in Python3, is compatible with Linux, Mac OS and the MS Windows 10 Subsystem for Linux and released under the MIT license. The source code can be found at https://github.com/wdecoster/methplotlib and can be installed from PyPI and bioconda. Our repository includes test data and the tool is continuously tested at [email protected]

scholarly journals Chasing perfection: validation and polishing strategies for telomere-to-telomere genome assemblies

2021 ◽  
Author(s):  
Arang Rhie ◽  
Ann Mc Cartney ◽  
Kishwar Shafin ◽  
Michael Alonge ◽  
Andrey Bzikadze ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Tandem Repeats ◽  
Hydatidiform Mole ◽  
Segmental Duplications ◽  
Sequencing Technologies ◽  
Oxford Nanopore ◽  
Human Genome Assembly ◽  
Long Read ◽  
Genome Assemblies ◽  
Oxford Nanopore Technologies

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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