Rapid and Accurate Sequencing of Enterovirus Genomes Using MinION Nanopore Sequencer

Objective 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. Methods 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. Results 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. Conclusion 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.

Biomonitoring for traditional herbal medicinal products using DNA metabarcoding and single molecule, real-time sequencing

Global concerns have been paid to the potential hazard of traditional herbal medicinal products(THMPs). Substandard and counterfeit THMPs, including traditional Chinese patent medicine, health foods, dietary supplements, etc. are potential threats to public health. Recent marketplace studies using DNA barcoding have determined that the current quality control methods are not sufficient for ensuring the presence of authentic herbal ingredients and detection of contaminants/adulterants. An efficient biomonitoring method for THMPs is of great needed. Herein, metabarcoding and single-molecule, realtime(SMRT) sequencing were used to detect the multiple ingredients in Jiuwei Qianghuo Wan(JWQHW), a classical herbal prescription widely used in China for the last 800 years. Reference experimental mixtures and commercial JWQHW products from the marketplace were used to confirm the method. Successful SMRT sequencing results recovered 5416 and 4342 circular-consensus sequencing(CCS) reads belonging to the ITS2 and psb A-trn H regions. The results suggest that with the combination of metabarcoding and SMRT sequencing, it is repeatable, reliable, and sensitive enough to detect species in the THMPs, and the error in SMRT sequencing did not affect the ability to identify multiple prescribed species and several adulterants/contaminants. It has the potential for becoming a valuable tool for the biomonitoring of multi-ingredient THMPs.

Full-length transcripts facilitates Portunus trituberculatus genome structure annotation

Portunus trituberculatus is an ide al model for elucidating crustacean genetic networks.Here we combined single molecule real-time(SMRT)sequencing and Illumina RNA-seq to characterize the coding genes,non-coding RNAs and pseudogenes and further to improve the genome annotation information of P.tritub erculatus.In this study,we assembled 9694 non-redundancy full-length transcripts,and 658737307-bp repetitive sequences were identified in the P.trituberculatus full-length transcriptome.We also predicted the P.tritub erculatus genome structure based on full-length transcripts,including 18602 genes,28686 non-coding RNAs,1407 pseudogenes,740 motif,and 26434 domain.Meanwhile,14460,10211,5412,7314,and 14448 genes had significant matches with sequences in the NR,KOG,GO,KEGG,and TrEMBL database,respectively.Overall,our work firstly provided the long-read transcriptome and we believed that these data are very necessary to improve the annotation information of P.trituberculatus genome structure,and useful information for the future studies on evolution and physiological regulation of P.trituberculatus.

Adaptive nanopores:A bioinspired label-free approach for protein sequencing and identification

Single molecule protein sequencing would tremendously impact in proteomics and human biology and it would promote the development of novel diagnostic and therapeutic approaches.However,its technological realization can only be envisioned,and huge challenges need to be overcome.Major difficulties are inherent to the structure of proteins,which are composed by several different amino-acids.Despite long standing efforts,only few complex techniques,such as Edman degradation,liquid chromatography and mass spectroscopy,make protein sequencing possible.Unfortunately,these techniques present significant limitations in terms of amount of sample required and dynamic range of measurement.It is known that proteins can distinguish closely similar molecules.Moreover,several proteins can work as biological nanopores in order to perform single molecule detection and sequencing.Unfortunately,while DNA sequencing by means of nanopores is demonstrated,very few examples of nanopores able to perform reliable protein-sequencing have been reported sofar.Here,we investigate,by means of molecular dynamics simulations,how a re-engineered protein,acting as biological nanopore,can be used to recognize the sequence of a translocating peptide by sensing the MshapeH of individual amino-acids.In our simulations we demonstrate that it is possible to discriminate with high fidelity,9 different amino-acids in a short peptide translocating through the engineered construct.The method,here shown for fluorescence-based sequencing,does not require any labelling of the peptidic analyte.These results can pave the way for a new and highly sensitive method of sequencing.

Nanopore-based Fourth-generation DNA Sequencing Technology

Nanopore-based sequencers, as the fourth-generation DNA sequencing technology, have the potential to quickly and reliably sequence the entire human genome for less than $1000, and possibly for even less than $100. The single-molecule techniques used by this technology allow us to further study the interaction between DNA and protein, as well as between protein and protein.Nanopore analysis opens a new door to molecular biology investigation at the single-molecule scale.In this article, we have reviewed academic achievements in nanopore technology from the past as well as the latest advances, including both biological and solid-state nanopores, and discussed their recent and potential applications.

Effect of dietary interventions on the intestinal microbiota of Mongolian hosts

The gut microbiota of Mongolian hosts has distinctive characteristics due to their meat- and dairyoriented daily diets and unique genotype.The aim of the present study was to investigate the effect of switching from the typical high protein and fat Mongolian diets to carbohydrate-rich meals composed principally of wheat,rice and naked oats on the host gut microbiota within 3 weeks.Our study took the advantage of the long sequence reads produced by the Pac Bio single molecule real-time sequencing technology to enable the profiling of subjects' gut microbiota communities along the diet intervention to the species precision.We found that the bacterial richness and diversity decreased apparently along the diet intervention.During the diet intervention,the gut microbiota composition displayed no significant difference at phylum level(with major phyla of Firmicutes,Bacteroidetes,Tenericutes and Proteobacteria).The relative abundances of some genera such as Bacteroidetes,Faecalibacterium,Roseburia,Alistipes,Streptococcus,and Oscillospira were significantly altered after the diet switching started.Notably,significant changes were also observed in the proportions of the species Bacteroides dorei,Bacteroides fragilis,Bacteroides thetaiotaomicron,Ruminococcus albus,Ruminococcus faecis,Roseburia faecis and Eubacterium ventriosum.These results have demonstrated that diet and host gut microbiota is closely linked.