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Phylogenetic affiliation of Aeromonas culicicola MTCC 3249(T) based on gyrB gene sequence and PCR-amplicon sequence analysis of cytolytic enterotoxin gene.

We determined the gyrB gene sequences of all 17 hybridizations groups of Aeromonas. Phylogenetic trees showing the evolutionary relatedness of gyrB and 16S rRNA genes in the type strains of Aeromonas were compared. Using this approach, we determined the phylogenetic position of Aeromonas culicicola MTCC 3249(T), isolated from midgut of Culex quinquefasciatus. In the gyrB based-analysis A. culicicola MTCC 3249(T) grouped with A. veronii whereas, it grouped with A. jandaei in the 16S rRNA based tree. The number of nucleotide differences in 16S rRNA sequences was less than found with the gyrB sequence data. Most of the observed nucleotide differences in the gyrB gene were synonymous. The Cophenetic Correlation Coefficient (CCC) for gyrB sequences was 0.87 indicating this gene to be a better molecular chronometer compared to 16S rRNA for delineation of Aeromonas species. This strain was found to be positive for the cytolytic enterotoxin gene. PCR-Amplicon Sequence Analysis (PCR-ASA) of this gene showed that the isolate is affiliated to type I and is potentially pathogenic. These PCR-ASA results agreed in part with the gyrB sequence results.

Aeromonas↗

MHASS: Microbiome HiFi Amplicon Sequencing Simulator.

SUMMARY: Microbiome HiFi Amplicon Sequence Simulator (MHASS) creates realistic synthetic PacBio HiFi amplicon sequencing datasets for microbiome studies, by integrating genome-aware abundance modeling, realistic dual-barcoding strategies, and empirically derived pass-number distributions from actual sequencing runs. MHASS generates datasets tailored for rigorous benchmarking and validation of long-read microbiome analysis workflows, including ASV clustering and taxonomic assignment. AVAILABILITY AND IMPLEMENTATION: Implemented in Python with automated dependency management, the source code for MHASS is freely available at https://github.com/rhowardstone/MHASS along with installation instructions. Our code is also published on Zenodo at https://doi.org/10.5281/zenodo.17486364. The data underlying this article are available on GitHub at https://github.com/rhowardstone/MHASS_evaluation/.

Software↗

Comparison of a long-read amplicon sequencing approach to short-read amplicons for microbiome analysis.

Most microbiome studies to date rely on sequencing short amplicons of the 16S rRNA gene on Illumina's platforms. Because of the short read length, sequences often can be identified reliably only to the family or genus levels. Long read sequencing with whole-length 16S rRNA sequencing can improve taxonomic resolution, but often only to the species level. StrainID is an alternative approach that amplifies a large segment of the ribosomal operon, including the entire 16S rRNA gene, internal transcribed spacer, and a portion of the 23S rRNA gene. This longer amplicon is designed to allow ribotype-level classification. Although studies have demonstrated the utility of StrainID for several sample types, it has not yet been validated for saliva. Here, we compared the performance of StrainID to short read amplicons with saliva samples as well as a synthetic mock DNA community and human and mouse fecal samples. Short reads were amplified with primer pairs appropriate for the corresponding sample type, and were classified with two different taxonomic databases. For both saliva and fecal samples, we found that StrainID performed similarly to short reads overall and demonstrated a key benefit with phylogenetic-based beta diversity tests and taxonomic classification. Our results further build on establishing StrainID as a valid method and specifically validate its use with saliva samples.

Journal Article↗

Molecular epidemiology of enterovirus outbreaks in Canada during 1991-1992: identification of echovirus 30 and coxsackievirus B1 strains by amplicon sequencing.

The relatedness of enteroviral isolates associated with two recent outbreaks in Canada was assessed using direct sequencing of amplicons derived from a large portion of the 5' nontranslated region (NTR) of the viral genome. The amplicons of 60 echovirus 30 isolates originating from seven different provinces in 1991 were found to share 99% or greater sequence identity. Recent coxsackievirus B1 isolates characterised in the same manner were identical to each other. When the 5' NTR sequence of these isolates was compared to prototype strains a difference of 11-15% in nucleotide composition was observed. These results indicate that the variability of nucleotide sequence found in 5' NTRs can be utilized to identify rapidly enteroviral strains associated with particular outbreaks and distinguish them from other strains and serotypes.

Animals↗

Upscaling Genotyping by Amplicon Sequencing With GBAS-GUI.

Genotyping by amplicon sequencing (GBAS) is a relatively low-cost approach for generating genotypic data compared with established genomic methods, making it highly scalable and particularly suitable for large-scale genetic monitoring projects. However, most existing analytical pipelines are either marker-specific, insufficiently scalable, or lacking efficient data management systems for the long-term integration of genotypic information, limiting the full potential of GBAS. Here, we address this gap by introducing GBAS-GUI (https://github.com/sonnenbe-dot/GBAS-GUI), a pipeline capable of generating GBAS-based genotypic data for a wide variety of loci at scale. GBAS-GUI integrates a graphical user interface with multiple checkpoints to improve accessibility and robustness. It implements multiprocessing architecture and a relational database that links genotypic data with associated sample metadata to enhance scalability and data management. The pipeline further enables marker screening through automated calculation of polymorphism information content (PIC) and implements a strategy to recover homologous genotypic information from paralogous loci with non-overlapping amplicon length ranges. Using multiple empirical datasets, we demonstrate substantial improvements in processing speed, database management and handling artefacts related to co-amplification of unspecific regions and duplicates of the same genomic region. We further show that incorporating the full sequence information captured by an amplicon increases marker information content beyond what is achievable with length-based genotyping alone and expands the analytical versatility of GBAS. Overall, GBAS-GUI provides a robust, scalable and versatile framework that unlocks the potential of GBAS for large-scale population genetic and phylogeographic studies.

Genotyping Techniques↗

Determining genotype and antimicrobial resistance of Salmonella Typhi in environmental samples by amplicon sequencing.

BACKGROUND: Estimates of the burden of typhoid fever due to Salmonella enterica serovar Typhi (S. Typhi) rely on data from clinical surveillance, which is rarely done in low income settings and is also limited by the poor sensitivity of the assays used and the reliance on health seeking by patients. Environmental surveillance for S. Typhi shed by symptomatic and asymptomatic individuals in wastewater offers a sensitive surveillance tool that could help to inform burden estimates. Sequencing S. Typhi direct from wastewater concentrates has the potential to identify circulating genotypes and associated antimicrobial resistance (AMR) genes, supporting public health interventions such as vaccination and antimicrobial usage. METHODOLOGY AND PRINCIPAL FINDINGS: We designed a multiplex targeted amplicon sequencing protocol for genotyping and determining AMR in S. Typhi from wastewater samples, targeting SNPs that identify genotypes of interest and both chromosomal and plasmid-borne AMR. PCR products were sequenced using the Oxford Nanopore Technologies (ONT) MinION, and genotypes and AMR identified using the GenoTyphi program. We tested this approach on samples from south India from both hospital outflow and wastewater collected from the community. All samples tested were suspected to be positive for S. Typhi following quantitative PCR for ttr, tviB, and staG gene targets. Out of 110 samples tested we were able to determine a genotype and/or AMR for 8. All samples that gave a genotype call suggested a genotype consistent with those found in clinical cases in India during the same time period and produced consensus sequences that clustered with S. Typhi when included in a phylogenetic tree. CONCLUSIONS: In this study, we provide proof of concept data for amplicon sequencing of S. Typhi in wastewater which with further optimisation could be used to complement clinical surveillance data or provide data on S. Typhi presence in the absence of clinical surveillance. This information can inform public health interventions, and the concept could be applied to other pathogens of interest for genotyping from environmental surveillance samples.

Salmonella typhi↗

Genomic characterization of avian metapneumovirus subtypes A and B in United States poultry by targeted amplicon sequencing.

Avian metapneumovirus (aMPV) subtypes A and B emerged in United States poultry in late 2023 and early 2024, prompting genome-scale surveillance from clinical samples. Here, we developed and optimized targeted amplicon sequencing (TAS) assays for both subtypes and applied them to 104 subtype-positive clinical samples collected from chicken and turkey farms across nine US states between early 2024 and early 2026. TAS recovered 91 genomes suitable for comparative analysis, including 44 aMPV-A and 47 aMPV-B sequences, with successful recovery extending to Ct values of 34.6 for aMPV-A and 31.2 for aMPV-B. Recovered genomes showed near-complete breadth and high mapping efficiency. Phylogenetic analyses of both G-gene and whole-genome datasets showed that US aMPV-A field strains formed a distinct monophyletic lineage within group IV and resolved into three closely related clusters. Cluster 2, first recognized in North Carolina and later detected in Ohio, spread across 30 turkey and chicken farms. Cluster 2 genomes were defined by a concentrated G-protein hotspot within residues 209-275, and most North Carolina Cluster 2 genomes carried 10-11 nonsynonymous substitutions in this region, including multiple proline substitutions suggestive of local structural change. Missouri Cluster 3 remained cohesive but distinct from both Cluster 1 and Cluster 2 in the G-gene and whole-genome trees. In contrast, US aMPV-B field strains remained highly homogeneous across hosts and states, with more than 99% nucleotide identity by both G-gene and WGS analyses. We also identified 12 vaccine-derived genomes on both vaccinated and nonvaccinated farms. These included six genomes related to aMPV-A vaccine and six related to aMPV-B vaccines (VCO3/50 and 1062), all of which retained vaccine-defining markers together with additional substitutions consistent with continued circulation after vaccine use in the field. Selection analyses showed that the G gene had the highest gene-wise dN/dS ratio in both subtypes. Additional elevated signal was observed in SH and M2, and candidate positively or episodically selected codons were concentrated in the subtype A Cluster 2 G-gene hotspot. These findings show that TAS supports direct-from-sample aMPV genomic surveillance and provides genomic context for field clusters, vaccine-derived lineages, and continued adaptive change in aMPV in US poultry.

Animals↗

ALPINE: a scalable pipeline for comprehensive classification of gene-editing outcomes from long-read amplicon sequencing.

SUMMARY: CRISPR genome editing has enabled precise genetic modification for gene and cell therapies, but edits often produce heterogeneous on-target outcomes, including homology-directed repair (HDR) knock-ins, DNA repair template integrations, and structural variants. Existing tools are frequently limited to short reads or lack viral vector-specific integration categories needed for therapeutic development. Here, we present ALPINE (Amplicon Long-read Pipeline for INtegration Evaluation), a scalable and reproducible pipeline for classifying and quantifying gene-editing outcomes from long-read amplicon sequencing supporting both PacBio HiFi and Oxford Nanopore platforms. ALPINE classifies reads into 10+ categories, including DNA repair vector integration subtypes, and performs variant calling near the gene-edited site with batch, multi-sample reporting. Uniquely, ALPINE can distinguish between cells treated with multiple DNA repair vectors and identify distinct molecular features, such as inverted terminal repeats (ITRs), enabling comprehensive characterization of complex gene editing outcomes. Dual-target benchmarking on simulated datasets demonstrated high accuracy for transgene integration events. Independent validation on public crosslinked-HDR dataset confirmed ALPINE's integration detection capabilities, and application to edited T cell samples demonstrated comprehensive gene-editing outcome profiling. AVAILABILITY: ALPINE is available under MIT license at https://github.com/Maggi-Chen/ALPINE and https://doi.org/10.5281/zenodo.20272510. All analysis scripts and visualization code used in this manuscript are available at https://github.com/Maggi-Chen/ALPINE-manuscript-analysis. Simulated datasets are deposited at Zenodo (https://doi.org/10.5281/zenodo.20260865). Public dataset PRJNA913199 is available through NCBI SRA.

Gene Editing↗

Workflow for Long-Read Amplicon Sequencing of Chikungunya Virus Using Oxford Nanopore Technology.

This protocol provides a comprehensive, step-by-step workflow for whole-genome sequencing of Chikungunya virus (CHIKV) using an amplicon-based strategy optimized for Oxford Nanopore Technologies (ONT) platforms. The procedure includes detailed instructions for sample handling, viral RNA extraction, quality control, cDNA synthesis, multiplex PCR amplification, library preparation, sequencing, and primary bioinformatic processing. The protocol is designed to maximize reproducibility across laboratories and is suitable for genomic surveillance applications, including outbreak investigation and molecular epidemiology, even when working with low-to-moderate viral loads.

Chikungunya virus↗

Development and evaluation of an ARTIC-based amplicon sequencing assay for whole-genome characterization of respiratory syncytial virus.

Respiratory syncytial virus (RSV), a ~15.2 kb negative-sense RNA virus, causes acute respiratory infections in infants and older adults. Its two subtypes, RSV-A and RSV-B, evolve rapidly, making ongoing monitoring of circulating strains essential. The Georgia Public Health Laboratory (GPHL) developed and evaluated an amplicon-based whole-genome sequencing (WGS) assay for RSV surveillance. A total of 214 de-identified remnant clinical specimens (102 RSV-A and 112 RSV-B) with RT-PCR Cq values <31 were included. RSV genomes were amplified using ARTIC-style and custom primer sets, with the ARTIC set showing superior performance. Libraries were prepared using a modified Illumina COVIDSeq protocol, sequenced on NextSeq 1000/2000 instruments, and analyzed using the GPHL-RSV-PIPE bioinformatics pipeline. Among genomes meeting validation criteria, sequencing depth was slightly higher for RSV-A (median 53,433&#xd7;; mean 51,076&#xd7;) than RSV-B (median 49,699&#xd7;; mean 46,945&#xd7;), whereas genomic coverage was slightly lower for RSV-A (median 97.5%; mean 96.6%) than RSV-B (median 98.3%; mean 97.6%). Predominant lineages were A.D.3.1 and A.D.5.2 for RSV-A and B.D.E.1 for RSV-B. For RSV-A, the assay showed 92.8% accuracy, 96.2% sensitivity, 87.2% specificity, 92.6% positive predictive value, and 93.2% negative predictive value. Intra- and inter-run precision assessed using 16 and 53-57 genomes, respectively, showed nearly 100% consensus genome identity with 0-5 nucleotide differences. Specificity testing of 31 non-RSV specimens produced no false-positive detections. Limits of detection were 4.4 TCID50/mL for RSV-A and 18.6 TCID50/mL for RSV-B. These results demonstrate that the ARTIC-based RSV WGS assay enables near real-time surveillance and strengthens data-driven public health responses to future outbreaks.IMPORTANCERSV, with two major subtypes, RSV-A and RSV-B, causes acute respiratory infections that can be severe in infants under 6 months and older adults. Current RSV surveillance at the GPHL relies on the Thermo Fisher TaqMan Gene Expression Capillary assay, which detects and subtypes RSV but lacks resolution for lineage classification and identification of emerging variants. To address this critical gap, GPHL developed and evaluated an amplicon-based WGS assay using 214 de-identified RSV clinical specimens. Genomes were amplified using ARTIC-style and custom-primer sets, with ARTIC primers showing superior performance. The assay demonstrated strong sequencing depth, genomic coverage, specificity, repeatability, reproducibility, and low limits of detection. RSV lineages were accurately determined based on genetic variation. These results establish that the ARTIC-based WGS assay enables near real-time genomic surveillance, supporting monitoring of circulating RSV strains and informing data-driven public health responses.

bioinformatics pipeline↗

Nanopore-based, long-range Parvovirus B19 amplicon sequencing for near-whole genome characterization.

BACKGROUND: Whole-Genome Sequencing (WGS) enables monitoring of genomic variation and evaluation of diagnostic PCR assays. However, WGS data for Parvovirus B19 (B19V) remains limited despite its relevance for clinical care and transfusion safety. To increase the availability of high-quality B19V genomic data, a near-WGS protocol was developed and validated. METHOD: The protocol combines long-range PCR to generate a 4.6-kb amplicon, covering &#x223c;82% of the B19V genome, with Oxford Nanopore sequencing. Validation was performed using six reference samples and nineteen B19V-positive donor plasma samples. RESULTS: After quality control, samples achieved a median sequencing depth of 152x. Sequences generated from the six reference samples showed 100% concordance with previously published data. Genomic analysis of donor samples explained atypical amplification profiles observed during routine PCR screening. CONCLUSION: The newly developed protocol provides a scalable method for B19V genome characterization, enabling assessment of oligonucleotide-binding regions for PCR assay monitoring and facilitating the generation of genomic data for future epidemiological investigations.

PCR assay monitoring↗

In situ hybridization detection of short viral amplicon sequences within cultured cells and body fluids after the in situ polymerase chain reaction.

Using single primer pairs, intracellular gene sequences of cytomegalovirus (CMV-Towne's strain) and alpha-tubulin were amplified (in situ PCR) from cells in human body fluids and in suspensions. Visualization of CMV amplificants was carried out by in situ hybridization (ISH), using both a biotinylated double-stranded DNA probe and a radiolabelled oligonucleotide probe. Visualization of alpha-tubulin amplificants was achieved using both radiolabelled single-stranded cRNA and oligonucleotide probes. Liberated amplificants were also identified by bands of expected size by gel electrophoresis. The specificity of the PCR products was confirmed by Southern blot analysis. Intracellular amplification was identified both in unfixed cells and, optimally, after brief alcohol fixation, whilst maintaining relative isotonicity in all working solutions. For CMV, enhanced signal was observed in cells (cultured fibroblasts or urine sediment) undergoing in situ PCR using either biotinylated or radiolabelled probes compared with controls undergoing ISH alone. For alpha-tubulin, radiolabelled riboprobes and oligoprobes only produced signals within cells (human peripheral lymphocytes, ascitic fluid and bladder washings from routine cytological specimens) after in situ PCR, but not after ISH alone. Morphological evaluation was superior with biotinylated probes, and minimal back-diffusion effect was found compared with radiolabelled probes. Up to 80% of cells survived thermal cycling. In situ PCR detected short sequence (100 bp) foreign DNA and low copy number genomic DNA, and was superior to ISH alone. In contrast to radiolabelled probes, very small CMV amplificants could be detected without a significant 'back-diffusion' effect when using the large biotinylated probe in this model system.

Animals↗

Amplicon sequencing and improved detection of human rhinovirus in respiratory samples.

Improved knowledge of the genotypic characteristics of human rhinovirus (HRV) is required, as are nucleic detection assays with the capacity to overcome both the similarities between members of the family Picornaviridae and the wide diversity of different HRV serotypes. The goal of the present study was to investigate the variability and the genotypic diversity of clinical strains circulating in the community. Since most reverse transcription (RT)-PCR assays available cannot differentiate HRV from other members of the family Picornaviridae, we also validated an assay specific for HRV detection. The 5' noncoding regions of 87 different HRV serotypes and clinical isolates were sequenced. On the basis of sequence analysis and phylogenetic determination, we first confirmed that all clinical isolates were HRV. We then validated a real-time RT-PCR assay that was able not only to detect all HRV serotypes and all clinical isolates tested but also to accurately discriminate between rhinovirus and other viruses from the family Picornaviridae. This assay was negative with isolates of coxsackievirus (types A and B), echovirus, enterovirus, parechovirus, and poliovirus, as well as nonpicornaviruses. Among a series of bronchoalveolar lavage specimens, 4% (7 of 161) were positive by culture, whereas 13% (21 of 161) were positive by RT-PCR. In the present study we showed that to specifically identify HRV in clinical specimens, diagnostic assays need to overcome both the diversities and the similarities of picornaviruses. By sequencing the 5' noncoding regions of rhinoviruses recovered from clinical specimens, we designed probes that could specifically detect rhinovirus.

5' Untranslated Regions↗

Survival and safety evaluation of Bifidobacterium longum subsp. longum ZS-8 in healthy adults, determined using PMAxx-qPCR and amplicon sequencing.

UNLABELLED: Species-level quantitative PCR (qPCR) provides in-depth knowledge of oral probiotics in the human gastrointestinal tract (GIT). However, it lacks the capability to differentiate exogenous strains from native microbiota, nor can it distinguish between live and dead bacteria. In this study, we employed improved propidium monoazide (PMAxx)-qPCR to evaluate the survival and colonization of Bifidobacterium longum subsp. longum ZS-8 (designated ZS-8) on the strain level in the GIT and its impact on human gut microbiota. By spiking in live and dead ZS-8, we demonstrated that strain-level PMAxx-qPCR could identify and quantify the viable ZS-8 in fecal samples accurately. Using this method, we found that, in healthy humans, oral administration of ZS-8 can transiently survive in the GIT, and multi-layer seamless capsules (MLSC) significantly improve the gastrointestinal tolerance and survivability of ZS-8 compared to its powder form. Furthermore, through selective cultivation and PMAxx-microbiome sequencing, we investigated the response of gut viable microbiome to ZS-8. Results showed that, while the microbiota diversity and total viable counts of Bifidobacterium and Lactobacillus remained stable, certain indigenous species of Bifidobacterium and Lactobacillus increased in abundance, confirming ZS-8's probiotic potential in healthy individuals. Overall, our study demonstrates the effectiveness of combining strain-specific comparative genomics with PMAxx-qPCR for evaluating probiotic survival and colonization in the human gut and highlights the safety of ZS-8 oral administration in healthy individuals. IMPORTANCE: The survival and colonization of probiotics in the gut are critical for their functional efficacy, yet conventional species-level quantitative PCR (qPCR) fails to distinguish exogenous strains from native microbiota or differentiate live from dead bacteria. By integrating strain-specific comparative genomics with propidium monoazide (PMAxx)-qPCR, we precisely quantified the viability of Bifidobacterium longum ZS-8 at the strain level in the human gut after its oral administration. Our study demonstrated that 1.53-6.90% of cells surviving transit and multi-layer seamless capsules (MLSC) significantly enhanced the gastrointestinal tolerance of ZS-8. While ZS-8 administration did not alter gut microbiota diversity or total viable counts of Bifidobacterium and Lactobacillus, it selectively increased the abundance of specific indigenous beneficial species. This method overcomes the dual limitations of traditional techniques (strain-level specificity and viability discrimination), providing a robust tool for probiotic research. Furthermore, our findings confirm the safety of ZS-8 in healthy individuals and its potential to modulate gut ecology, offering a scientific foundation for personalized probiotic development and clinical translation.

Humans↗

Comparison of amplicon-sequencing, pyrosequencing and real-time PCR for detection of YMDD mutants in patients with chronic hepatitis B.

AIM: To compare the sequencing of PCR products, pyrosequencing, and real-time PCR for detection of Tyrosine-methionine-aspartate-aspartate (YMDD) mutants in patients with chronic hepatitis B. METHODS: Mixtures of plasmids and serum samples from 69 chronic hepatitis B patients treated with lamivudine were tested for YMDD mutations by sequencing of PCR products, pyrosequencing, and real-time PCR, respectively. Time required and reagent costs of the three assays were evaluated. RESULTS: Real-time PCR detected 100%, 50%, 10%, 1% and 0.1% of YVDD plasmid in mixtures with 10(6) copies/mL of YMDD plasmid, whereas sequencing and pyrosequencing only detected 100% and 50% of YVDD plasmid in aliquots of the corresponding mixtures. Completely concordant results were obtained from 60 (87%) out of the 69 clinical serum samples by the three assays. Mutants were detected by real-time PCR in less than 20% of the total virus population, but no mutant was detected by sequencing and pyrosequencing. In addition, real-time PCR required less time and was more cost-effective than the other two assays. However, throughput of pyrosequencing was the highest. CONCLUSION: Among the three assays compared, real-time PCR is the most sensitive, cost-effective, and time saving for monitoring YMDD mutants in patients with chronic hepatitis B on lamivudine therapy.

Drug Resistance, Viral↗

AmpSeqR: an R package for amplicon deep sequencing&#xa0;data&#xa0;analysis.

Amplicon sequencing (AmpSeq) is a methodology that targets specific genomic regions of interest for polymerase chain reaction (PCR) amplification so that they can be sequenced to a high depth of coverage. Amplicons are typically chosen to be highly polymorphic, usually with several highly informative, high frequency single nucleotide polymorphisms (SNPs) segregating in an amplicon of 100-200 base pair (bp). This allows high sensitivity detection and quantification of the frequency of each sequence within each sample making it suitable for applications such as low frequency somatic mosaicism detection or minor clone detection in mixed samples. AmpSeq is being increasingly applied to both biological and medical studies, in applications such as cancer, infectious diseases and brain mosaicism studies. Current bioinformatics pipelines for AmpSeq data processing lack downstream analysis, have difficulty distinguishing between true sequences and PCR sequencing errors and artifacts, and often require bioinformatic expertise. We present a new R package: AmpSeqR, designed for the processing of deep short-read amplicon sequencing data, with a focus on infectious diseases. The pipeline integrates several existing R packages combining them with newly developed functions to perform optimal filtering of reads to remove noise and improve the accuracy of the detected sequences data, permitting detection of very low frequency clones in mixed samples. The package provides useful functions including data pre-processing, amplicon sequence variants (ASVs) estimation, data post-processing, data visualization, and automatically generates a comprehensive Rmarkdown report that contains all essential results facilitating easy inclusion into reports and publications. AmpSeqR is publicly available at https://github.com/bahlolab/AmpSeqR.

High-Throughput Nucleotide Sequencing↗

Molecular cloning and genetic mapping of perennial ryegrass casein protein kinase 2 alpha-subunit genes.

The alpha-subunit of the casein protein kinase CK2 has been implicated in both light-regulated and circadian rhythm-controlled plant gene expression, including control of the flowering time. Two putative CK2alpha genes of perennial ryegrass (Lolium perenne L.) have been obtained from a cDNA library constructed with mRNA isolated from cold-acclimated crown tissue. The genomic organisation of the two genes was determined by Southern hybridisation analysis. Primer designs to the Lpck2a-1 and Lpck2a-2 cDNA sequences permitted the amplification of genomic products containing large intron sequences. Amplicon sequence analysis detected single nucleotide polymorphisms (SNPs) within the p150/112 reference mapping population. Validated SNPs, within diagnostic restriction enzyme sites, were used to design cleaved amplified polymorphic sequence (CAPS) assays. The Lpck2a-1 CAPS marker was assigned to perennial ryegrass linkage group (LG) 4 and the Lpck2a-2 CAPS marker was assigned to LG2. The location of the Lpck2a-1 gene locus supports the previous conclusion of conserved synteny between perennial ryegrass LG4, the Triticeae homoeologous group 5L chromosomes and the corresponding segment of rice chromosome 3. Allelic variation at the Lpck2a-1 and Lpck2a-2 gene loci was correlated with phenotypic variation for heading date and winter survival, respectively. SNP polymorphism may be used for the further study of the role of CK2alpha genes in the initiation of reproductive development and winter hardiness in grasses.

Amino Acid Sequence↗