To Analyze the Sensitivity of RT-PCR Assays Employing S Gene Target Failure with Whole Genome Sequencing Data during Third Wave by SARS-CoV-2 Omicron Variant

Introduction: Omicron is a highly divergent variant of concern (VOCs) of a severe acute respiratory syndrome SARS-CoV-2. It carries a high number of mutations in its spike protein hence;it is more transmissible in the community by immune evasion mechanisms. Due to mutation within S gene, most Omicron variants have reported S gene target failure (SGTF) with some commercially available PCR kits. Such diagnostic features can be used as markers to screen Omicron. However, Whole Genome Sequencing (WGS) is the only gold standard approach to confirm novel microorganisms at genetically level as similar mutations can also be found in other variants that are circulating at low frequencies worldwide. This Retrospective study is aimed to assess RT-PCR sensitivity in the detection of S gene target failure in comparison with whole genome sequencing to detect variants of Omicron. Methods: We have analysed retrospective data of SARS-CoV-2 positive RT-PCR samples for S gene target failure (SGTF) with TaqPath COVID-19 RT-PCR Combo Kit (ThermoFisher) and combined with sequencing technologies to study the emerged pattern of SARS-CoV-2 variants during third wave at the tertiary care centre, Surat. Results: From the first day of December 2021 till the end of February 2022, a total of 321,803 diagnostic RT-PCR tests for SARS-CoV-2 were performed, of which 20,566 positive cases were reported at our tertiary care centre with an average cumulative positivity of 6.39% over a period of three months. In the month of December 21 samples characterized by the SGTF (70/129) were suggestive of being infected by the Omicron variant and identified as Omicron (B.1.1.529 lineage) when sequence. In the month of January, we analysed a subset of samples (n = 618) with SGTF (24%) and without SGTF (76%) with Ct values Conclusions: During the COVID-19 pandemic, it took almost more than 15 days to diagnose infection and identify pathogen by sequencing technology. In contrast to that molecular assay provided quick identification with the help of SGTF phenomenon within 5 hours of duration. This strategy helps scientists and health policymakers for the quick isolation and identification of clusters. That ultimately results in a decreased transmission of pathogen among the community.

Surveillance of emerging SARS-CoV-2 variants by nanopore technology-based genome sequencing

Objective:To surveill emerging variants by nanopore technology-based genome sequencing in different COVID-19 waves in Sri Lanka and to examine the association with the sample characteristics,and vaccination status.Methods:The study analyzed 207 RNA positive swab samples received to sequence laboratory during different waves.The N gene cut-off threshold of less than 30 was considered as the major inclusion criteria.Viral RNA was extracted,and elutes were subjected to nanopore sequencing.All the sequencing data were uploaded in the publicly accessible database,GISAID.Results:The Omicron,Delta and Alpha variants accounted for 58%,22%and 4%of the variants throughout the period.Less than 1%were Kappa variant and 16%of the study samples remained unassigned.Omicron variant was circulated among all age groups and in all the provinces.Ct value and variants assigned percentage was 100%in Ct values of 10-15 while only 45%assigned Ct value over 25.Conclusions:The present study examined the emergence,prevalence,and distribution of SARS-CoV-2 variants locally and has shown that nanopore technology-based genome sequencing enables whole genome sequencing in a low resource setting country.

Safety evaluation and whole genome sequencing for revealing the ability of Penicillium oxalicum WX-209 to safely and effectively degrade citrus segments

The microbial potential of Penicillium has received critical attention.The present research aimed to elucidate the efficacy of crude enzyme secreted from Penicillium oxalicum WX-209 in degrading citrus segments and evaluate the safety of the process.Results showed that citrus segment membranes gradually dissolved after treatment with the crude enzyme solution,indicating good degradation capability.No significant differences in body weight,food ingestion rate,hematology,blood biochemistry,and weight changes of different organs were found between the enzyme intake and control groups.Serial experiments showed that the crude enzyme had high biological safety.Moreover,the whole genome of P.oxalicum WX-209 was sequenced by PacBio and Illumina platforms.Twenty-five scaffolds were assembled to generate 36 Mbp size of genome sequence comprising 11369 predicted genes modeled with a GC content of 48.33%.A total of 592 genes were annotated to encode enzymes related to carbohydrates,and some degradation enzyme genes were identified in strain P.oxalicum WX-209.

Evaluation of A Single-reaction Method for Whole Genome Sequencing of Influenza A Virus using Next Generation Sequencing

Objective To evaluate a single-reaction genome amplification method, the multisegment reverse transcription-PCR （M-RTPCR）, for its sensitivity to full genome sequencing of influenza A virus, and the ability to differentiate mix-subtype virus, using the next generation sequencing （NGS） platform. Methods Virus genome copy was quantified and seria（iy diluted to different titers, followed by amplification with the M-RTPCR method and sequencing on the NGS platform. Furthermore, we manually mixed two subtype viruses to different titer rate and amplified the mixed virus with the M-RTPCR protocol, followed by whole genome sequencing on the NGS platform. We also used clinical samples to test the method performance. Results The M-RTPCR method obtained complete genome of testing virus at 125 copies/reaction and determined the virus subtype at titer of 25 copies/reaction. Moreover, the two subtypes in the mixed virus could be discriminated, even though these two virus copies differed by 200-fold using this amplification protocol. The sensitivity of this protocol we detected using virus RNA was also confirmed with clinical samples containing Iow-titer virus. Conclusion The M-RTPCR is a robust and sensitive amplification method for whole genome sequencing of influenza A virus using NGS platform.

Genome sequencing provides potential strategies for drug discovery and synthesis

Medicinal plants are renowned for their abundant production of secondary metabolites,which exhibit notable pharmacological activities and great potential for drug development.The biosynthesis of secondary metabolites is highly intricate and influenced by various intrinsic and extrinsic factors,resulting in substantial species diversity and content variation.Consequently,precise regulation of secondary metabolite synthesis is of utmost importance.In recent years,genome sequencing has emerged as a valuable tool for investigating the synthesis and regulation of secondary metabolites in medicinal plants,facilitated by the widespread use of high-throughput sequencing technologies.This review highlights the latest advancements in genome sequencing within this field and presents several strategies for studying secondary metabolites.Specifically,the article elucidates how genome sequencing can unravel the pathways for secondary metabolite synthesis in medicinal plants,offering insights into the functions and regulatory mechanisms of participating enzymes.Comparative analyses of plant genomes allow identification of shared pathways of metabolite synthesis among species,thereby providing novel avenues for obtaining cost-effective biosynthetic intermediates.By examining individual genomic variations,genes or gene clusters associated with the synthesis of specific compounds can be discovered,indicating potential targets and directions for drug development and the exploration of alternative compound sources.Moreover,the advent of gene-editing technology has enabled the precise modifications of medicinal plant genomes.Optimization of specific secondary metabolite synthesis pathways becomes thus feasible,enabling the precise editing of target genes to regulate secondary metabolite production within cells.These findings serve as valuable references and lessons for future drug development endeavors,conservation of rare resources,and the exploration of new resources.

Genome Sequencing Reveals the Role of MADS-box Gene Families in the Floral Morphology Evolution of Orchids

Orchid origin and evolution are common topics in evolutionary biology. Orchidaceae have approximately 30 000 orchid species distributed in diverse habitats and account for approximately 10% of the flowering plant species worldwide. Orchids provide us with materials to explore coevolution and organic evolution. In this review, we highlighted the genome study progress of orchids. In addition, we revealed the role of MADS-box gene families in the floral morphology and evolution of orchids. Genomics studies confirmed that all five subfamilies of existing orchids evolved from a common ancestor. Loss of Mβ MADS-box genes resulted in the endosperm from the seed of all existing orchids being absent. Perianth reversion to the ancestral state occurred because Apostasia and Apostasioideae lost B-AP3 and E class paralogous genes. Loss of P-subclade members of MIKC*-Type in Phalaenopsis equestris, Dendrobium catenatum, and Epidendroideae caused the formation of pollinium.In addition, the combined loss of AGL12 and contraction of ANR1 gave orchids the ability to be successfully epiphytic on trees or rocks and to develop a unique root system. Both pollinium and epiphytic production on trees are beneficial for orchid adaptations, and Epidendroideae evolved more species(~ 20 000) than Apostasioideae(16 species). Genome studies shed new light on determining the evolutionary history of orchids and understanding the genetic mechanisms of orchid morphological evolution.

Construction of random sheared fosmid library from Chinese cabbage and its use for Brassica rapa genome sequencing project

As a part of the Multinational Genome Sequencing Project of Brassica rapa, linkage group R9 and R3 were sequenced using a bacterial artificial chromosome （BAC） by BAC strategy. The current physical contigs are expected to cover approximately 90% euchromatins of both chromosomes. As the project progresses, BAC selection for sequence extension becomes more limited because BAC libraries are restriction enzyme-specific. To support the project, a random sheared fosmid library was constructed. The library consists of 97536 clones with average insert size of approximately 40 kb corresponding to seven genome equivalents, assuming a Chinese cabbage genome size of 550 Mb. The library was screened with primers designed at the end of sequences of nine points of scaffold gaps where BAC clones cannot be selected to extend the physical contigs. The selected positive clones were end-sequenced to check the overlap between the fosmid clones and the adjacent BAC clones. Nine fosmid clones were selected and fully sequenced. The sequences revealed two completed gap filling and seven sequence extensions, which can be used for further selection of BAC clones confirming that the fosmid library will facilitate the sequence completion of B. rapa.

Investigation of the genetic etiology in male infertility with apparently balanced chromosomal structural rearrangements by genome sequencing

Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and etiologies are still largely unknown.Herein,we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants.In addition,high read-depth genome sequencing(GS)(30-fold)was performed to investigate point mutations causative of male infertility.Mate-pair GS(4-fold)revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements.Overall,the breakpoints caused truncations of 30 RefSeq genes,five of which were associated with spermatogenesis.Furthermore,the breakpoints disrupted 43 topological-associated domains.Direct disruptions or potential dysregulations of genes,which play potential roles in male germ cell development,apoptosis,and spermatogenesis,were found in all cases(n=6).In addition,high read-depth GS detected dual molecular findings in case MI6,involving a complex rearrangement and two point mutations in the gene DNAH1.Overall,our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility.We demonstrated the complexity of chromosomal structural rearrangements,potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.

Genome sequencing of the bacterial blight pathogen DY89031 reveals its diverse virulence and origins of Xanthomonas oryzae pv.oryzae strains

The bacterial pathogen Xanthomonas oryzae pv.oryzae(Xoo),belonging to Xanthomonas sp.,causes one of the most destructive vascular diseases in rice worldwide,particularly in Asia and Africa.To better understand Xoo pathogenesis,we performed genome sequencing of the Korea race 1 strain DY89031(J18)and analyzed the phylogenetic tree of 63 Xoo strains.We found that the rich diversity of evolutionary features is likely associated with the rice cultivation regions.Further,virulence effector proteins secreted by the type III secretion system(T3SS)of Xoo showed pathogenesis divergence.The genome of DY89031 shows a remarkable difference from that of the widely prevailed Philippines race 6 strain PXO99A,which is avirulent to rice Xa21,a well-known disease resistance(R)gene that can be broken down by DY89031.Interestingly,plant inoculation experiments with the PXO99A transformants expressing the DY89031 genes enabled us to identify additional TAL(transcription activator-like)and non-TAL effectors that may support DY89031-specific virulence.Characterization of DY89031 genome and identification of new effectors will facilitate the investigation of the rice-Xoo interaction and new mechanisms involved.

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.

Validation of the diagnostic potential of mtDNA copy number derived from whole genome sequencing

Diagnosis of mitochondrial DNA（mt DNA）disorders has traditionally been focused on the presence of point mutations and large deletions.However,deviations in mitochondrial abundance or mt DNA copy number can also be associated with many physiological and pathological conditions（Bai and Wong,2005）.

Whole genome sequencing and its applications in medical genetics

Fundamental improvement was made for genome sequencing since the next-generation sequencing （NGS） came out in the 2000s. The newer technologies make use of the power of massively-parallel short-read DNA sequencing, genome alignment and assembly methods to digitally and rapidly search the genomes on a revolutionary scale, which enable large-scale whole genome sequencing （WGS） accessible and practical for researchers. Nowadays, whole genome sequencing is more and more prevalent in detecting the genetics of diseases, studying causative relations with cancers, making genome-level comparative analysis, reconstruction of human population history, and giving clinical implications and instructions. In this review, we first give a typical pipeline of whole genome sequencing, including the lab template preparation, sequencing, genome assembling and quality control, variants calling and annotations. We compare the difference between whole genome and whole exome sequencing （WES）, and explore a wide range of applications of whole genome sequencing for both mendelian diseases and complex diseases in medical genetics. We highlight the impact of whole genome sequencing in cancer studies, regulatory variant analysis, predictive medicine and precision medicine, as well as discuss the challenges of the whole genome sequencing.

Genome sequencing brought Gossypium biology research into a new era

The first sequenced diploid cotton genome was published in2012 by the group led by the Institute of Cotton Research,Chinese Academy of Agricultural Sciences.Cotton genomics research subsequently entered a period of rapid development.

Genome-wide mining, characterization, and development of microsatellite markers in Marsupenaeus japonicus by genome survey sequencing

The kuruma prawn, Marsupenaeus japonicus, is one of the most cultivated and consumed species of shrimp. However, very few molecular genetic/genomic resources are publically available for it. Thus, the characterization and distribution of simple sequence repeats(SSRs) remains ambiguous and the use of SSR markers in genomic studies and marker-assisted selection is limited. The goal of this study is to characterize and develop genome-wide SSR markers in M. japonicus by genome survey sequencing for application in comparative genomics and breeding. A total of 326 945 perfect SSRs were identified, among which dinucleotide repeats were the most frequent class(44.08%), followed by mononucleotides(29.67%), trinucleotides(18.96%), tetranucleotides(5.66%), hexanucleotides(1.07%), and pentanucleotides(0.56%). In total, 151 541 SSR loci primers were successfully designed. A subset of 30 SSR primer pairs were synthesized and tested in 42 individuals from a wild population, of which 27 loci(90.0%) were successfully amplified with specific products and 24(80.0%) were polymorphic. For the amplified polymorphic loci, the alleles ranged from 5 to 17(with an average of 9.63), and the average PIC value was 0.796. A total of 58 256 SSR-containing sequences had significant Gene Ontology annotation; these are good functional molecular marker candidates for association studies and comparative genomic analysis. The newly identified SSRs significantly contribute to the M. japonicus genomic resources and will facilitate a number of genetic and genomic studies, including high density linkage mapping, genome-wide association analysis, marker-aided selection, comparative genomics analysis, population genetics, and evolution.

Sequencing of the Cultivated Tetraploid Cotton Genome-Gossypium hirsutum

Cotton is an important cash crop in the world,and it plays an irreplaceable role in China's national economy.Cultivated upland cotton(Gossypium hirsutum L.) represents 95% of the world's cotton production,but it has a complex allotetraploid genome that contains at least 30000 genes in 2500

Complete Sequence and Gene Organization of the Mitochondrial Genome of Tokay (Gekko gecko)

Long-PCR amplification, clone and primer-walking sequencing methods were employed in determine the complete sequence of mitochondrial genome of tokay (Gekko gecko). The genome is 16 435 bp in size, contains 13 protein-coding, 2 ribosomal and 22 transfer RNA genes. The mt genome of Gekko is similar to most of the vertebrates in gene components, order, orientation, tRNA structures, low percentage of guanine and high percentage of thymine, and skews of base GC and AT. Base A was preferred at third codon positions for protein genes is similar to amphibians and fishes rather than amnion vertebrates. The standard stop codes (TAA) present only in three protein genes, less than those of most vertebrates. Transfer RNA genes range in length from 63 to 76 nt, their planar structure present characteristic clover leaf, except for tRNA-Cys and tRNA-Ser (AGY) because of lacking the D arm.

QTL mapping of drought tolerance traits in soybean with SLAF sequencing

Drought stress is an important factor affecting soybean yield.Improving drought tolerance of soybean varieties can increase yield and yield stability when the stress occurs.Identifying QTL related to drought tolerance using molecular marker-assisted selection is able to facilitate the development of drought-tolerant soybean varieties.In this study,we used a high-yielding and drought-sensitive cultivar‘Zhonghuang 35’and a drought-tolerant cultivar‘Jindou 21’to establish F6:9 recombinant inbred lines.We constructed a highdensity genetic map using specific locus amplified fragment sequencing(SLAF-Seq)technology.The genetic map contained 8078 SLAF markers distributing across 20 soybean chromosomes with a total genetic distance of 3780.98 c M and an average genetic distance of0.59 c M between adjacent markers.Two treatments(irrigation and drought)were used in the field tests,the Additive-Inclusive Composite Interval Mapping(ICIM-ADD)was used to call QTL,and plant height and seed weight per plant were used as the indicators of drought tolerance.We identified a total of 23 QTL related to drought tolerance.Among them,seven QTL(q PH2,q PH6,q PH7,q PH17,q PH19-1,q PH19-2,and q PH19-3)on chromosomes 2,6,7,17,and 19 were related to plant height,and five QTL(q SWPP2,q SWPP6,q SWPP13,q SWPP17,and q SWPP19)on chromosomes 2,6,13,17,and 19 were related to seed weight and could be considered as the major QTL.In addition,three common QTL(q PH6/q SWPP6,q PH17/q SWPP17,and q PH19-3/q SWPP19)for both plant height and seed weight per plant were located in the same genomic regions on the same chromosomes.Three(q PH2,q PH17,and q PH19-2)and four novel QTL(q SWPP2,q SWPP13,q SWPP17,and q SWPP19)were identified for plant height and seed weight per plant,respectively.Two pairs of QTL(q PH2/q SWPP2 and q PH17/q SWPP17)were also common for both plant height and seed weight per plant.These QTL and closely linked SLAF markers could be used to accelerate breeding for drought tolerant cultivars via MAS.

The role of bone marrow-derived cells in the origin of liver cancer revealed by single-cell sequencing

Objective:Epithelial cancers often originate from progenitor cells,while the origin of hepatocellular carcinoma(HCC)is still controversial.HCC,one of the deadliest cancers,is closely linked with liver injuries and chronic inflammation,which trigger massive infiltration of bone marrow-derived cells(BMDCs)during liver repair.Methods:To address the possible roles of BMDCs in HCC origination,we established a diethylnitrosamine(DEN)-induced HCC model in bone marrow transplanted mice.Immunohistochemistry and frozen tissue immunofluorescence were used to verify DENinduced HCC in the pathology of the disease.The cellular origin of DEN-induced HCC was further studied by single cell sequencing,single-cell nested PCR,and immunofluorescence-fluorescence in situ hybridization.Results:Studies by using single cell sequencing and biochemical analysis revealed that HCC cells in these mice were coming from donor mice BMDCs,and not from recipient mice.Furthermore,the copy numbers of mouse orthologs of several HCC-related genes previously reported in human HCC were also altered in our mouse model.DEN-induced HCCs exhibited a similar histological phenotype and genomic profile as human HCCs.Conclusions:These results suggested that BMDCs are an important origin of HCC,which provide important clues to HCC prevention,detection,and treatments.

From Markers to Genome Based Breeding in Horticultural Crops: An Overview

Molecular markers,genome sequencing and genome editing are considered as efficient tools to accomplish demands of plant breeders for crop improvement programs.Morphological and biochemical markers have not been extensively used as these are greatly influenced by environmental factors.Different molecular markers and sequencing techniques are routinely used in evaluation of genetic diversity and evolutionary relationship,accurate classification or taxonomy,characterization of germplasm,identification of hybrids and phylogenetic studies.Desired and undesired traits controlled by genes can be identified through different molecular markers technology all over the globe.These molecular markers are well established and have successfully been used for genetic analysis of different plants during last two decades.Recently,advanced techniques of molecular markers have been developed,which provide advance genotypic platform and tends to merge valuable properties of many basic systems.New class of markers also includes little modifications in basic methods to enhance the sensitivity and resolution.Biotechnologists,plant breeders and strong investment are strongly linked for crop improvement purposes.Current review provides detailed description of different markers,genome sequencing and genome editing that have been utilized for different genetic analyses of horticultural crops.Genome editing technologies based on CRISPR/Cas are now successfully applied in horticultural crops.Moreover,current review encourages the use of molecular marker technology for DNA fingerprinting,bar coding,sequencing,re-sequencing QTL mapping,genome association mapping and genome editing.It is need of time that diverse germplasm should be identified with different molecular techniques and further utilized in breeding purposes to achieve higher yielding and resistant cultivars against biotic and abiotic stresses.

A Roadmap for Whitefly Genomics Research:Lessons from Previous Insect Genome Projects

Due to evolving molecular and informatics technologies,modern genome sequencing projects have more different characteristics than what most biologists have become accustomed to during the capillary-based sequencing era.In this paper,we explore the characteristics that made past insect genome projects successful and place them in the context of next-generation sequencing.By taking into account the intricacies of whitefly biology and the community,we present a roadmap for whitefly-omics,which focuses on the formation of an international consortium,deployment of informatic platforms and realistic generation of reference sequence data.