Application of Optical Genome Mapping Technology in Detecting Complex Chromosomal Rearrangement / 中山大学学报(医学科学版)

ObjectiveTo investigate the application of optical genome mapping （OGM） technology in detecting complex chromosomal rearrangement. MethodsWe recruited five patients who were diagnosed as complex chromosomal rearrangement at the Reproductive Medicine Center of the Sixth Affiliated Hospital of Sun Yat-sen University from January 2022 to June 2023. They underwent OGM， nanopore sequencing and pre-implantation genetic testing （PGT）. The results were compared with the results of karyotype and chromosomal microarray analysis （CMA）/ copy number variation sequencing （CNV-Seq）. ResultsOGM could detect translocation， invert inversion， and triplet translocation， which were consistent with the results of OGM and CMA/ CNV-Seq. But OGM could not detect Robertsonian translocation. ConclusionBecause of its ultra-long reads， OGM realizes the detection across repetitive regions， and it has great advantages when applied in patients with complex chromosome rearrangement or uncertain karyotype analysis. It can accurately locate breakpoints.

Genetic diagnosis of non-classical 21-hydroxylase deficiency by the new nanopore sequencing detection method / 中华检验医学杂志

Objective:To summarize initial experience of applying nanopore third-generation sequencing detection method (nanopore sequencing) for genetic diagnosis of non-classical 21 hydroxylase deficiency (NC 21-OHD), and to explore its performance and application prospects.Methods:Clinical data of the two NC 21-OHD patients, who were hospitalized at the First Affiliated Hospital of Zhengzhou University in May 2019, were collected. Peripheral venous blood was collected and genome DNA extracted. Genetic variants was detected by nanopore sequencing and underwent bioinformatic analysis. Pathogenetic mutations in CYP21A2 gene were validated with PCR-sanger sequencing in the two patients and their parents.Results:The average reads length and sequence depth in the patient one was 12, 792 bp and 27.19×. The average reads length and sequence depth in the patient two was 13, 123 bp and 21.34×. Compound variants of c.293-13C>G/c.844G>T (p.Val282Leu) and c.332_339delGAGACTAC (p.Gly111Valfs)/c.844G>T (p.Val282Leu) were detected in these two patients, which were consistent with clinical phenotype of NC 21-OHD. Further analysis showed that c.293-13C>G mutation was inherited from her father and c.844G>T (p.Val282Leu) mutation was inherited from her mother for the patient one. The c.844G>T (p.Val282Leu) mutation was inherited from her father and c.332_339delGAGACTAC (p.Gly111Valfs) mutation from her mother.Conclusions:The heterozygous mutations in CYP21A2 gene are the cause of NC 21-OHD in these two patients. Nanopore sequencing technique is a reliable new detection method for patients with NC 21-OHD.

Clinical study on the application of nanopore targeted sequencing technology for rapid and accurate detection of pathogens in patients with complicated urinary tract infections / 中华泌尿外科杂志

Objective:To evaluate the clinical value of nanopore targeted sequencing (NTS) in pathogens detection in urinary tract by comparing the results of different tests performed on the same urine sample.Methods:The results of NTS and urine culture test collected from 326 patients in the Department of Urology of People's Hospital of Wuhan University from July 2020 to June 2021 were retrospectively analyzed. There were 224 males and 102 females. The average age was (56.88 ± 14.58)years old. χ 2 test and Student’s test and Wilcoxon's sign rank test were used to analyze the differences of the pathogen detection rate, pathogen types results and detection time consuming between NTS and urine culture. The clinical value of the NTS in rapid detection of urinary pathogens was evaluated. Results:Among 326 hospitalized patients, the urinary tract microbes’ detecting rate of NTS was significantly higher than that of urine culture[67.80%(221/326)vs. 23.93%(78/326), χ2=130.25, P<0.01]. The uropathogens detecting rate of NTS was significantly higher than that of urine culture[54.29%(177/326)vs. 23.31%(76/326), χ2=38.95, P<0.01]. The number of urinary tract microbes detected by NTS was significantly higher than that of urine culture ( Z=11.49, P<0.01), the number of uropathogens was significantly higher than that of urine culture ( Z=9.67, P<0.01). The detection time of NTS and urine culture positive samples was (24.29±2.65) h and (49.28±11.30) h, the difference was statistically significant ( t =39.48, P<0.01). The results obtained by using NTS and urine culture were consistent in 135 (41.41%) samples. In 150 (46.01%) samples, NTS could detect the urinary tract microbes while urine culture cannot find, of which 112 cases (34.36%) were uropathogenic. In 27 cases (8.28%), more pathogens were detected by NTS except those from urine culture. In 6 cases (1.84%) re-detecting NTS after antibiotic therapy, the number of reads of primary uropathogen decreased gradually with the growth of colonizing bacteria or opportunistic pathogens appeared in the end. Re-examinations of urine culture could verify the results of NTS detection on admission in 5 cases (1.53%). NTS in 2 cases (0.61%) could cover the uropathogens of subsequent several urine cultures. Conclusions:NTS has the advantages of rapid, sensitive and comprehensive detection of urinary tract infection pathogens. When urine culture is not yet reported or even negative, NTS already has a certain clinical reference value and can be used as an effective supplement to urine culture, which is conducive to the comprehensive judgment of the patient's condition.

Application and Prospect of Nanopore Sequencing Technology in Etiological Diagnosis of Blood Stream Infection / 中国医学科学院学报

Blood stream infection (BSI),a blood-borne disease caused by microorganisms such as bacteria,fungi,and viruses,can lead to bacteremia,sepsis,and infectious shock,posing a serious threat to human life and health.Identifying the pathogen is central to the precise treatment of BSI.Traditional blood culture is the gold standard for pathogen identification,while it has limitations in clinical practice due to the long time consumption,production of false negative results,etc.Nanopore sequencing,as a new generation of sequencing technology,can rapidly detect pathogens,drug resistance genes,and virulence genes for the optimization of clinical treatment.This paper reviews the current status of nanopore sequencing technology in the diagnosis of BSI.

DNA sequencing in the classroom: complete genome sequence of two earwig (Dermaptera; Insecta) species

BACKGROUND: Despite representing the largest fraction of animal life, the number of insect species whose genome has been sequenced is barely in the hundreds. The order Dermaptera (the earwigs) suffers from a lack of genomic information despite its unique position as one of the basally derived insect groups and its importance in agroecosystems. As part of a national educational and outreach program in genomics, a plan was formulated to engage the participation of high school students in a genome sequencing project. Students from twelve schools across Chile were instructed to capture earwig specimens in their geographical area, to identify them and to provide material for genome sequencing to be carried out by themselves in their schools. RESULTS: The school students collected specimens from two cosmopolitan earwig species: Euborellia annulipes (Fam. Anisolabididae) and Forficula auricularia (Fam. Forficulidae). Genomic DNA was extracted and, with the help of scientific teams that traveled to the schools, was sequenced using nanopore sequencers. The sequence data obtained for both species was assembled and annotated. We obtained genome sizes of 1.18 Gb (F. auricularia) and 0.94 Gb (E. annulipes) with the number of predicted protein coding genes being 31,800 and 40,000, respectively. Our analysis showed that we were able to capture a high percentage (≥ 93%) of conserved proteins indicating genomes that are useful for comparative and functional analysis. We were also able to characterize structural elements such as repetitive sequences and non-coding RNA genes. Finally, functional categories of genes that are overrepresented in each species suggest important differences in the process underlying the formation of germ cells, and modes of reproduction between them, features that are one of the distinguishing biological properties that characterize these two distant families of Dermaptera. CONCLUSIONS: This work represents an unprecedented instance where the scientific and lay community have come together to collaborate in a genome sequencing project. The versatility and accessibility of nanopore sequencers was key to the success of the initiative. We were able to obtain full genome sequences of two important and widely distributed species of insects which had not been analyzed at this level previously. The data made available by the project should illuminate future studies on the Dermaptera.

Monkeypox virus genome sequence from an imported human case in Colombia / Secuencia genómica del virus de la viruela símica de un caso importado en Colombia

Introduction: Monkeypox virus (MPXV) is an enveloped double-stranded DNA virus with a genome of approximately 197.209 bp. The current classification divides MPXV into three clades: Clade I (Central African or Congo Basin clade) and clades IIa and IIb (West African clades). Objective: To report the complete genome and phylogenetic analysis of a human monkeypox case detected in Colombia. Materials and methods: Exudate from vesicular lesions was obtained from a male patient with recent travel history to Spain. A direct genomic approach was implemented in which total DNA from the sample was purified through a column-based method, followed by sequencing on the Nanopore GridION. Reads were aligned against the MPXV reference genome using minimap2 v.2.24 and phylogenetic inference was performed using maximum likelihood estimation. Results: A total of 11.951 reads mapped directly to a reference genome with 96.8% of coverage (190.898 bp). Conclusion: Phylogenetic analysis of the MPXV circulating in Colombia demonstrated its close relationship to clade IIb responsible for the multi-country outbreak in 2022.

Introducción. El virus de la viruela del mono (MPXV) está compuesto por un genoma de ADN bicatenario, aproximadamente, de 197.209 pb. La clasificación actual agrupa el MPXV en tres clados: clado I (de la cuenca del Congo en África central), y clados IIa y IIb (de África occidental). Objetivo. Reportar el genoma completo y el análisis filogenético de un caso humano de viruela símica detectado en Colombia. Materiales y métodos. Se obtuvo exudado de lesiones vesiculares de un paciente varón con el antecedente de un viaje reciente a España. Se implementó un enfoque directo, en el cual se purificó el ADN total de la muestra mediante un método basado en columnas, seguido de la secuenciación directa en la plataforma Nanopore GridION. Las lecturas se alinearon con el genoma de referencia del MPXV, utilizando minimap2, v.2.24, y la inferencia filogenética fue realizada mediante la estimación por máxima verosimilitud. Resultados. Un total de 11.951 lecturas se alinearon directamente con el genoma de referencia con una cobertura del 96,8 % (190.898 pb). Conclusión. El análisis filogenético del MPXV circulante en Colombia demostró su estrecha relación con el clado de África occidental (clado IIb) responsable del brote en múltiples países en el 2022.

Research progress of nanopore sequencing in the clinic / 中华检验医学杂志

Because of the low throughput of current first-generation sequencing and the shortread length of second-generation sequencing, a new technology that overcomes the above shortcomings has emerged. The third-generation sequencing based on nanopore does not rely on the chain reaction of DNA polymerases and distinguishes bases by identifying electrical signals. It has broad application prospects and also faces more challenges. At present, it has many applications in detection of infectious pathogens, infectious disease prevention and control, genetic variation, and tumor diagnosis.

Unsupervised deep learning for identifying the O 6-carboxymethyl guanine by nanopore sequencing / 生物医学工程学杂志

O 6-carboxymethyl guanine(O 6-CMG) is a highly mutagenic alkylation product of DNA that causes gastrointestinal cancer in organisms. Existing studies used mutant Mycobacterium smegmatis porin A (MspA) nanopore assisted by Phi29 DNA polymerase to localize it. Recently, machine learning technology has been widely used in the analysis of nanopore sequencing data. But the machine learning always need a large number of data labels that have brought extra work burden to researchers, which greatly affects its practicability. Accordingly, this paper proposes a nano-Unsupervised-Deep-Learning method (nano-UDL) based on an unsupervised clustering algorithm to identify methylation events in nanopore data automatically. Specially, nano-UDL first uses the deep AutoEncoder to extract features from the nanopore dataset and then applies the MeanShift clustering algorithm to classify data. Besides, nano-UDL can extract the optimal features for clustering by joint optimizing the clustering loss and reconstruction loss. Experimental results demonstrate that nano-UDL has relatively accurate recognition accuracy on the O 6-CMG dataset and can accurately identify all sequence segments containing O 6-CMG. In order to further verify the robustness of nano-UDL, hyperparameter sensitivity verification and ablation experiments were carried out in this paper. Using machine learning to analyze nanopore data can effectively reduce the additional cost of manual data analysis, which is significant for many biological studies, including genome sequencing.

Application of nanopore sequencing in environmental microbiology research / 生物工程学报

The development of high-throughput sequencing techniques enabled a deeper and more comprehensive understanding of environmental microbiology. Specifically, the third-generation sequencing techniques represented by nanopore sequencing have greatly promoted the development of environmental microbiology research due to its advantages such as long sequencing reads, fast sequencing speed, real-time monitoring of sequencing data, and convenient machine carrying, as well as no GC bias and no PCR amplification requirement. This review briefly summarized the technical principle and characteristics of nanopore sequencing, followed by discussing the application of nanopore sequencing techniques in the amplicon sequencing, metagenome sequencing and whole genome sequencing of environmental microorganisms. The advantages and challenges of nanopore sequencing in the application of environmental microbiology research were also analyzed.

Application of Nanopore Sequencing Technology in the Clinical Diagnosis of Infectious Diseases / 生物医学与环境科学（英文）

Infectious diseases are an enormous public health burden and a growing threat to human health worldwide. Emerging or classic recurrent pathogens, or pathogens with resistant traits, challenge our ability to diagnose and control infectious diseases. Nanopore sequencing technology has the potential to enhance our ability to diagnose, interrogate, and track infectious diseases due to the unrestricted read length and system portability. This review focuses on the application of nanopore sequencing technology in the clinical diagnosis of infectious diseases and includes the following: (i) a brief introduction to nanopore sequencing technology and Oxford Nanopore Technologies (ONT) sequencing platforms; (ii) strategies for nanopore-based sequencing technologies; and (iii) applications of nanopore sequencing technology in monitoring emerging pathogenic microorganisms, molecular detection of clinically relevant drug-resistance genes, and characterization of disease-related microbial communities. Finally, we discuss the current challenges, potential opportunities, and future outlook for applying nanopore sequencing technology in the diagnosis of infectious diseases.

Research progress and application of nanopore sequencing technology / 生物工程学报

Sequencing technology has been greatly improved in terms of throughput and cost. The single-molecule nanopore DNA sequencing, one of the major branches of the third-generation sequencing technology, has made great contributions in the fields of medicine and life sciences due to its advantages of ultra-long reading length, real-time detection and direct detection of base methylation modification, etc. This article briefly describes the principle of nanopore sequencing technology, and discusses its application in clinical, animal, plant, bacterial and virus fields and its future development direction.

Whole-genome sequencing and analysis of the Chinese herbal plant

Background@# () (2n = 2x = 16) is genus of flowering plants belonging to the Gelsemicaeae family.@*Method@#Here, a high-quality genome assembly using the Oxford Nanopore Technologies (ONT) platform and high-throughput chromosome conformation capture techniques (Hi-C) were used.@*Results@#A total of 56.11 Gb of raw GridION X5 platform ONT reads (6.23 Gb per cell) were generated. After filtering, 53.45 Gb of clean reads were obtained, giving 160 × coverage depth. The genome assemblies 335.13 Mb, close to the 338 Mb estimated by k-mer analysis, was generated with contig N50 of 10.23 Mb. The vast majority (99.2%) of the assembled sequence was anchored onto 8 pseudo-chromosomes. The genome completeness was then evaluated and 1338 of the 1440 conserved genes (92.9%) could be found in the assembly. Genome annotation revealed that 43.16% of the genome is composed of repetitive elements and 23.9% is composed of long terminal repeat elements. We predicted 26,768 protein-coding genes, of which 84.56% were functionally annotated.@*Conclusion@#The genomic sequences of could be a valuable source for comparative genomic analysis in the Gelsemicaeae family and will be useful for understanding the phylogenetic relationships of the indole alkaloid metabolism.

Application of nanopore sequencing technology in viral genome research / 中华实验和临床病毒学杂志

MinION is a commercial nanopore sequencer developed by Oxford Nanopore Techno-logies. Compared with the second-generation sequencing platform, MinION is characterized by ultra-long reads, simple and fast sequencing, high portability and real-time data analysis. MinION has been widely applied to the fields of virus identification, whole genome sequencing, new virus discovery, quasispecies and virus evolution. In this article, we review the application of nanopore sequencing technology in the research of the viral genome in recent years, and discuss the existing problems. We also present the prospect for the development trend of nanopore sequencing in the future.

Rapid and Accurate Sequencing of Enterovirus Genomes Using MinION Nanopore Sequencer / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Knowledge of an enterovirus genome sequence is very important in epidemiological investigation to identify transmission patterns and ascertain the extent of an outbreak. The MinION sequencer is increasingly used to sequence various viral pathogens in many clinical situations because of its long reads, portability, real-time accessibility of sequenced data, and very low initial costs. However, information is lacking on MinION sequencing of enterovirus genomes.</p><p><b>METHODS</b>In this proof-of-concept study using Enterovirus 71 (EV71) and Coxsackievirus A16 (CA16) strains as examples, we established an amplicon-based whole genome sequencing method using MinION. We explored the accuracy, minimum sequencing time, discrimination and high-throughput sequencing ability of MinION, and compared its performance with Sanger sequencing.</p><p><b>RESULTS</b>Within the first minute (min) of sequencing, the accuracy of MinION was 98.5% for the single EV71 strain and 94.12%-97.33% for 10 genetically-related CA16 strains. In as little as 14 min, 99% identity was reached for the single EV71 strain, and in 17 min (on average), 99% identity was achieved for 10 CA16 strains in a single run.</p><p><b>CONCLUSION</b>MinION is suitable for whole genome sequencing of enteroviruses with sufficient accuracy and fine discrimination and has the potential as a fast, reliable and convenient method for routine use.</p>