Primer Sequences Research Articles

MiPRIME: an integrated and intelligent platform for mining primer and probe sequences of microbial species.

Accurately detecting pathogenic microorganisms requires effective primers and probe designs. Literature-derived primers are a valuable resource as they have been tested and proven effective in previous research. However, manually mining primers from published texts is time-consuming and limited in species scop. To address these challenges, we have developed MiPRIME, a real-time Microbial Primer Mining platform for primer/probe sequences extraction of pathogenic microorganisms with three highlights: (i) comprehensive integration. Covering >40 million articles and 548942 organisms, the platform enables high-frequency microbial gene discovery from a global perspective, facilitating user-defined primer design and advancing microbial research. (ii) Using a BioBERT-based text mining model with 98.02% accuracy, greatly reducing information processing time. (iii) Using a primer ranking score, PRscore, for intelligent recommendation of species-specific primers. Overall, MiPRIME is a practical tool for primer mining in the pan-microbial field, saving time and cost of trial-and-error experiments. The web is available at {{https://www.ai-bt.com}}.

Molecular Characterization of Feline Parvovirus from Domestic Cats in Henan Province, China from 2020 to 2022.

Carnivore protoparvovirus-1, feline parvovirus (FPV), and canine parvovirus (CPV) continue to spread in companion animals all over the world. As a result, FPV and CPV underwent host-to-host transfer in carnivorous wild-animal hosts. Here, a total of 82 fecal samples of suspected cat FPV infections were collected from Henan Province from 2020 to 2022. The previously published full-length sequence primers of VP2 and NS1 genes were used to amplify the targeted genes of these samples, and the complete gene sequences of 11 VP2 and 21 NS1 samples were obtained and analyzed. Analysis showed that the amino acid homology of the VP2 and NS1 genes of these isolates was 96.1-100% and 97.6-100%, respectively. The phylogenetic results showed that the VP2 and NS1 genes of the local isolates were mainly concentrated in the G1 subgroup, while the vaccine strains were distributed in the G3 subgroup. Finally, F81 cells were inoculated with the local endemic isolate Luoyang-01 (FPV-LY strain for short) for virus amplification, purification, and titer determination, and the pathogenesis of FPV-LY was detected. After five generations of blind transmission in F81 cells, cells infected with FPV-LY displayed characteristic morphological changes, including a round, threadlike, and wrinkled appearance, indicative of viral infection. The virus titer associated with this cytopathic effect (CPE) was measured at 1.5 × 106 TCID50/mL. Subsequent animal regression tests confirmed that the virus titer of the PFV-LY isolate remained at 1.5 × 106 TCID50/mL, indicating its highly pathogenic nature. Cats exposed to the virus exhibited typical clinical symptoms and pathological changes, ultimately succumbing to the infection. These results suggest that the gene mutation rate of FPV is increasing, resulting in a complex pattern of gene evolution in terms of host preference, geographical selection, and novel genetic variants. The data also indicate that continuous molecular epidemiological surveillance is required to understand the genetic diversity of FPV isolates.

ProtoSpaceJAM: an open-source, customizable and web-accessible design platform for CRISPR/Cas insertional knock-in.

CRISPR/Cas-mediated knock-in of DNA sequences enables precise genome engineering for research and therapeutic applications. However, designing effective guide RNAs (gRNAs) and homology-directed repair (HDR) donors remains a bottleneck. Here, we present protoSpaceJAM, an open-source algorithm to automate and optimize gRNA and HDR donor design for CRISPR/Cas insertional knock-in experiments, currently supporting SpCas9, SpCas9-VQRand enAsCas12a Cas enzymes. protoSpaceJAM utilizes biological rules to rank gRNAs based on specificity, distance to insertion site, and position relative to regulatory regions. protoSpaceJAM can introduce 'recoding' mutations (silent mutations and mutations in non-coding sequences) in HDR donors to prevent re-cutting and increase knock-in efficiency. Users can customize parameters and design double-stranded or single-stranded donors. We validated protoSpaceJAM's design rules by demonstrating increased knock-in efficiency with recoding mutations and optimal strand selection for single-stranded donors. An additional module enables the design of genotyping primers for deep sequencing of edited alleles. Overall, protoSpaceJAM streamlines and optimizes CRISPR knock-in experimental design in a flexible and modular manner to benefit diverse research and therapeutic applications. protoSpaceJAM is available open-source as an interactive web tool at protospacejam.czbiohub.org or as a standalone Python package at github.com/czbiohub-sf/protoSpaceJAM.

Using a DNA mini-barcode within the ITS region to identify toxic Amanita in mushroom poisoning cases

Mushroom poisoning contributes significantly to global foodborne diseases and related fatalities. Amanita mushrooms frequently cause such poisonings; however, identifying these toxic species is challenging due to the unavailability of fresh and intact samples. It is often necessary to analyze residues, vomitus, or stomach extracts to obtain DNA sequences for the identification of species responsible for causing food poisoning. This usually proves challenging to obtain usable DNA sequences that can be analyzed using conventional molecular biology techniques. Therefore, this study aimed to develop a DNA mini-barcoding method for the identification of Amanita species. Following the evaluation and optimization of universal primers for DNA mini-barcoding in Amanita mushrooms, we found that the internal transcribed spacer (ITS) gene sequence primer ITS-a was the most suitable DNA barcode primer for identifying Amanita species. Forty-three Amanita samples were subsequently amplified and sequenced. The sequences obtained were analyzed for intra- and inter-species genetic distances, and a phylogenetic tree was constructed. The findings indicated that the designed primers had strong universality among the Amanita samples and could accurately identify the target gene fragment with a length of 290 bp. Notably, the DNA mini-barcode accurately identified the 43 Amanita samples, demonstrating high consistency with the conventional DNA barcode. Furthermore, it effectively identified DNA from digested samples. In summary, this DNA mini-barcode is a promising tool for detecting accidental ingestion of toxic Amanita mushrooms. It may be used as an optimal barcode for species identification and traceability in events of Amanita-induced mushroom poisoning.Key points• Development of a DNA mini-barcoding method for Amanita species identification without fresh samples.• The ITS-a primer set was optimized for robust universality in Amanita samples.• The mini-barcode is suitable for screening toxic mushroom species in mushroom poisoning cases.Graphical

Identification of Circular RNAs as Biomarker Candidates in Lung Cancer Treatment.

Lung cancer is the most common malignancy and among the leading cause of cancer death worldwide. Therefore, there is an important need for biomarkers that can be used in the early diagnosis of the disease and in the follow-up of treatment. Circular RNAs (circRNAs) have a covalently closed circular structure that lacks 3' and 5' polar ends and is resistant to RNAase enzymes. Due to these properties, they can be stably found in body fluids. Therefore, they can serve as potential biomarkers in the diagnosis, monitoring of therapeutic response and prognosis of cancer. In our study, we aimed to investigate the expression levels of circRNA molecules in the treatment of lung cancer and to determine those that have the potential to be biomarkers. In this in vitro study, expression levels of 163 circRNAs were investigated in A549 cells, a non-small cell lung cancer cell line, before and after treatment with carboplatin and pemetrexed. Total RNA isolation and cDNA synthesis were performed after treatments. Expression levels of circRNA genes were determined by RT-qPCR method with the designed divergent primer sequences. The study revealed the characterisation of differentially expressed circRNAs by treatment in lung cancer cells. Of them, hsa_circ_0001320 is not expressed in cancer cells, is expressed only after treatment, and increased the level of its expression in response to combination therapy. As a result, while carboplatin, pemetrexed, and combined drug applications changed the expression levels of some circRNAs in lung cancer cells, some circRNAs were expressed only after treatment. In treatment follow-up and management, hsa_circ_0001320 has been identified as potential biomarker candidate.

Linear support for the prime number sequence and the first and second Hardy-Littlewood conjectures

Servais and Grün used results about linear support for the prime number sequence to obtain upper bounds on the smallest prime in odd perfect numbers. This was extended by Cohen and Hendy who proved that for every $n \in \mathbb {N}$ there exists an integer $b_n$ such that $p_i \ge p_1 + ni - b_n$ for any sequence $(p_i)$ of odd primes, and found minimal values of $b_n$ for $3 \le n \le 5$, and conjectured minimal values for $6 \le n \le 10$. We give a new proof of the existence of $b_n$ and the values for $3 \le n \le 5$. We also show that if we assume that the second Hardy-Littlewood conjecture, $\pi (a+b) \le \pi (a) + \pi (b)$ for $a, b \ge 2$, is true, then we can in a finite number of steps determine numbers, $T_n$, that give quite close bounds for the values of $b_n$, namely $T_n \le b_n \le T_n + n - 2$, and determine the values of $T_n$ for $6 \le n \le 20$. We also consider the question of whether the values of $b_n$ can be replaced by smaller numbers if we assume that $p_1 > 3$. We will show that if we assume that the first Hardy-Littlewood conjecture is true, then we can determine the minimum such values, $a_n$, for $3 \le n \le 5$. We also determine some lower bounds for $a_n$ for $n \ge 6$. It is well-known that the two Hardy-Littlewood conjectures are mutually exclusive, but we never use both conjectures simultaneously. These results give us the upper bound $p_1<\frac {n}{2^n-1}t+b_n$ on the smallest prime in odd perfect numbers, where $t$ is the number of distinct primes dividing the odd perfect number. This bound was also found by Cohen and Hendy, but we improve the constants $b_n$.

New volvovirus isolate from Thai domesticated house cricket, Acheta domesticus (Orthoptera: Gryllidae)

Abstract This study investigated the genomic characteristics of Acheta domesticus volvovirus (AdVVV) in a commercial cricket farming operation. BLAST analysis of the Acheta domesticus genome assembly identified sequences with high similarity to the AdVVV-Japan genome, suggesting AdVVV presence. PCR confirmed AdVVV infection in the A. domesticus breeding population from Nakhon Ratchasima farm, Thailand. The complete 2,516 nucleotide AdVVV-Thailand genome was reconstructed through targeted primer amplification and sequencing. It contained four open reading frames encoding hypothetical proteins, with a characteristic hairpin structure at the termini, consistent with other AdVVV isolates. Phylogenetic analysis revealed AdVVV-Thailand’s closer genetic affiliation with AdVVV-Japan compared to other isolates. Comparative analysis of coding sequences across five AdVVV isolates showed the highest variability in the hypothetical protein/putative capsid protein ORF1, with 64 variable sites out of 1086 bases, suggesting its significance in genetic diversity. In contrast, ORF2, ORF3, and ORF4 exhibited minimal variability. The majority of variations were singletons, with 85.33% confined to ORF1. This study confirmed AdVVV presence in a commercial cricket farm, reconstructed the AdVVV-Thailand genome, provided insights into its phylogeny and genetic diversity across isolates, highlighting the putative capsid protein’s role in driving variability. These findings enhance understanding of AdVVV genomics and evolutionary dynamics within cricket populations.

A multiplex digital PCR assay for detection and quantitation of porcine circovirus type 2 and type 3.

Porcine circovirus (PCV) has become a major pathogen, causing major economic losses in the global pig industry, and PCV type 2 (PCV2) and 3 (PCV3) are distributed worldwide.We designed specific primer and probe sequences targeting PCV2 Cap and PCV3 Rap anddeveloped a multiplex crystal digital PCR (cdPCR) method after optimizing the primerconcentration, probe concentration, and annealing temperature.The multiplex cdPCR assay permits precise and differential detection of PCV2 and PCV3, with a limit of detection of 1.39 × 101 and 1.27 × 101 copies/reaction, respectively, and no cross-reaction with other porcine viruses was observed. The intra-assay and interassay coefficients of variation (CVs) were less than 8.75%, indicating good repeatability and reproducibility. To evaluate the practical value of this assay, 40 tissue samples and 70 feed samples were tested for both PCV2 and PCV3 by cdPCR and quantitative PCR (qPCR). Using multiplex cdPCR, the rates of PCV2 infection, PCV3 infection, and coinfection were 28.45%, 1.72%, and 12.93%, respectively, and using multiplex qPCR, they were 25.00%, 0.86%, and 4.31%, respectively This highly specific and sensitive multiplex cdPCR thus allows accurate simultaneous detection of PCV2 and PCV3, and it is particularly well suited for applications that require the detection of small amounts of input nucleic acid or samples with intensive processing and complex matrices.

Systematic assessment of the reliability of quantitative PCR assays targeting IS900 for the detection of Mycobacterium avium ssp. paratuberculosis presence in animal and environmental samples

Mycobacterium avium ssp. paratuberculosis (MAP) is the bacterium responsible for causing Johne's disease (JD), which is endemic to dairy cattle and also implicated in the etiology of Crohn's disease. The difficulty in diagnosing asymptomatic cows for JD makes this disease hard to control. Johne's disease is considered a priority under the One Health approach to prevent the spread of the causative agent to humans. Environmental screening is a strategic approach aimed at identifying dairy herds with animals infected with MAP. It serves as the initial step toward implementing more intensive actions to control the disease. Quantitative PCR (qPCR) technology is widely used for diagnosis. Given that genome sequencing is now much more accessible than ever before, it is possible to target regions of the MAP genome that allow for the greatest diagnostic sensitivity and specificity. The aim of this study was to identify among the published qPCR assays targeting IS900 the more cost-effective options to detect MAP and to validate them in the diagnostic context of JD. Mycobacterium avium ssp. paratuberculosis IS900 is a prime target because it is a multicopy genetic element. A total of 136 publications have reported on the use of IS900 qPCR assays over the past 3 decades. Among these records, 29 used the SYBR Green chemistry, and 107 used TaqMan technology. Aside from the 9 reports using commercial assays, 72 TaqMan reports cited previously published work, leaving us with 27 TaqMan qPCR designs. Upon closer examination, 5 TaqMan designs contained mismatches in primer or probe sequences. Additionally, others exhibited high similarity to environmental microorganisms or non-MAP mycobacteria. We assessed the performance of 6 IS900 qPCR designs and their sensitivity when applied to clinical or environmental samples, which varied from 4 to 56 fold overall. Additionally, we provide recommendations for testing clinical and environmental samples, as certain strategies used previously should be avoided due to poor qPCR design (e.g., the presence of mismatches) or a lack of specificity.

A set of nematode rRNA cistron databases and a primer assessment tool to enable more flexible and comprehensive metabarcoding.

The ITS-2-rRNA has been particularly useful for nematode metabarcoding but does not resolve all phylogenetic relationships, and reference sequences are not available for many nematode species. This is a particular issue when metabarcoding complex communities such as wildlife parasites or terrestrial and aquatic free-living nematode communities. We have used markerDB to produce four databases of distinct regions of the rRNA cistron: the 18S rRNA gene, the 28S rRNA gene, the ITS-1 intergenic spacer and the region spanning ITS-1_5.8S_ITS-2. These databases comprise 2645, 254, 13,461 and 10,107 unique full-length sequences representing 1391, 204, 1837 and 1322 nematode species, respectively. The comparative analysis illustrates the complementary value but also reveals a better representation of Clade III, IV and V than Clade I and Clade II nematodes in each case. Although the ITS-1 database includes the largest number of unique full-length sequences, the 18S rRNA database provides the widest taxonomic coverage. We also developed PrimerTC, a tool to assess primer sequence conservation across any reference sequence database, and have applied it to evaluate a large number of previously published rRNA cistron primers. We identified sets of primers that currently provide the broadest taxonomic coverage for each rRNA marker across the nematode phylum. These new resources will facilitate more comprehensive metabarcoding of nematode communities using either short-read or long-read sequencing platforms. Further, PrimerTC is available as a simple WebApp to guide or assess PCR primer design for any genetic marker and/or taxonomic group beyond the nematode phylum.

PCR amplification, sequencing, and in silico analysis of holandric genes TSPYand SRY in Nili Ravi buffalo

The present work has been designed to study the evolutionary perspectives of two important holandric genes, namely, testis-specific protein, Y-encoded (TSPY), and sex determining region, Y-encoded (SRY) in Nili Ravi buffalo. These Y-chromosomal genes are responsible for male sex development. The evolutionary aspects of these genes have not been studied in the Nili Ravi buffaloes from India. A study was carried out on the peripheral blood samples of three adult Nili Ravi bulls belonging to university farm. DNA was extracted using the phenol-chloroform isoamyl alcohol (PCI) technique and reported primer sequences were used to amplify the genes (partially) using a thermocycler. Three biological samples were analyzed using Sanger sequencing and were aligned using Clustal Omega. Separate phylogenetic trees for the genes were constructed using MEGA7 software. The selection pressure analysis and evolutionary divergence were individually studied for each of the genes. The current study reports the partial TSPY and SRY gene sequences of Indian Nili Ravi buffalo. Besides, the molecular evolution analysis indicates that the genes have experienced some purifying selection during the evolutionary process. Molecular characterization of these holandric genes (TSPY and SRY) in Nili Ravi will find applications in sex determination in Nili Ravi and other buffaloes.

First Report of Bacterial Blight of Pennycress Caused by Xanthomonas campestris in Wisconsin.

In May 2023, pennycress (Thlaspi arvense, L.) lines undergoing seed production in the Walnut Street Greenhouse at the University of Wisconsin-Madison displayed symptoms of chlorosis and black necrotic leaf spots (Fig. S1-A). Lesions eventually enlarged to 1-2 cm in diameter, became necrotic, and coalesced to cover a substantial portion of leaves. Symptoms were observed in ~30% of the pennycress lines adversely affecting overall growth and reproduction. Symptomatic leaves were surface sterilized for 30 seconds in 0.75% sodium hypochlorite, rinsed in sterile deionized water, and bacteria were isolated using three-phase streaking of symptomatic tissue onto KB medium (King et al., 1954). Single colonies of three isolates (creamy white to yellow) from this initial isolation were streaked onto KB medium to obtain pure cultures. Individual colonies were transferred for growth overnight in nutrient broth (Difco) and an equal amount of the broth was added to 30% glycerol in deionized (di) water and stored at -80 °C. To validate Koch's Postulates, bacteria were grown from these stocks on Yeast Dextrose Calcium Carbonate medium (Wilson et al., 1967) and were used to inoculate 5-week-old pennycress plants in the greenhouse. The bacteria were grown for 48 hours at 26°C, suspended in 300 ml of 0.05 M PBS buffer (pH=7.2) for inoculum preparation. Plants were inoculated with three bacterial isolates (approx. 108 CFU/ml) by piercing the mid veins or hydathodes with a sterilized toothpick dipped in the suspension. Inoculated plants were then enclosed in clear plastic bags for 24-48 hours and maintained in the greenhouse at a constant temperature of 26°C with a 16-hour photoperiod. After seven days, water-soaked lesions appeared on the inoculated leaves, eventually developing into the characteristic black spots (Fig. S1-B). DNA from the original isolates was extracted, and 16S PCR and sequencing of the positive bands was done. The negative control only produced brown spots at the site of inoculation (Fig. S1-C). The primer sequences were as follows: 27F: AGAGTTTGATCMTGGCTCAG; 1492R: GGTTACCTTGTTACGACTT (Eden et al., 1991; Weisburg et al., 1991). A BLAST analysis showed that the isolates had an E value of 0.0 to the genus Xanthomonas as well as 100% identity. Amplification and sequencing of the bacterium using gyrB amplicons revealed a 99-100% pairwise match with Xc. To enhance taxonomy resolution and confirm the identity of these isolates, the complete genomes of three samples were sequenced using NextSeq2000 Illumina platform (NCBI bioproject ID PRJNA1040293). Average Nucleotide Identity (ANI) analysis was conducted with representative strains from the Xc species (Dubrow et al., 2022), using PanExplorer (Dereeper et al., 2020) featuring integrated FastANI module (Jain et al., 2018). The isolates genomes exhibited over 98% identity and clustered with that of Xc pv. incanae and Xc pv. barbarae (Fig S2). Further work will be required to identify the pathovar of Xc identified in this study through phenotypic host range assay. This marks the first documented case of Xc in pennycress in the Midwestern US. Given the potential use of pennycress as a cover crop in the region, further investigations are warranted to assess its economic impact on production and develop management strategies.

Molecular Identification of Dominant Microbes in Kola nut (Cola nitida)

Kola nut is an important dehiscent fruit but its supply fails to meet the demand due to limitations such as inadequate post-harvest practices leading to spoilage during transportation and storage. Identification of microbial contaminants is a necessary step in reducing the loss. Hence, this work aimed at characterizing the genome of dominant fungus and bacteria associated with kola nut (Cola nitida). Samples of kola nuts were collected from Oje and Oja-oba markets in Ibadan, Nigeria. Isolates were extracted from the lesion region of the samples using the standard method. Macro-morphological and micro-morphological observations of the pure culture of the isolates were conducted. After genomic DNA extraction of fungal and bacterial isolates, Polymerase Chain Reaction (PCR) was carried out using Internal Transcribed Sequence (ITS 1 and ITS 4) and 27F primers for fungal and bacterial genome respectively. Sanger sequencing of the purified DNA fragments was conducted utilizing the Nimagen, BrilliantDye™ Terminator Cycle Sequencing Kit V3.1, BRD3-100/1000. Molecular Evolutionary Genetics Analysis (MEGA version 6) was used for phylogenetic analysis. The result revealed that one fungus and two bacteria were associated with kola nuts. The fungal isolate showed 100% identity with Aspergillus wentii from the National Center for Biotechnology Information data base. The fungus showed a good relationship with A. dimorphicus and A. europaeus. The two bacterial isolates were also identified through the phylogenic analysis as Bacillus cereus and B. subtilis. B. cereus is closely related to B. thuringiensis. This research provides background information on the Kola nut microbial contaminant. Keywords: Bacteria, Contaminant, Fungus, Identification, Primers, Sequencing

NSPlex: an efficient method to analyze non-specific peaks amplified using commercial STR kits.

Commercial short tandem repeat (STR) kits exclusively contain human-specific primers; however, various non-human organisms with high homology to the STR kit's primer sequences can cause cross-reactivity. Owing to the proprietary nature of the primers in STR kits, the origins and sequences of most non-specific peaks (NSPs) remain unclear. Such NSPs can complicate data interpretation between the casework and reference samples; thus, we developed "NSPlex", an efficient method to discover the biological origins of NSPs. We used leftover STR kit amplicons after capillary electrophoresis and performed advanced bioinformatics analyses using next-generation sequencing followed by BLAST nucleotide searches. Using our method, we could successfully identify NSP generated from PCR amplicons of a sample mixture of human DNA and DNA extracted from matcha powder (finely ground powder of green tea leaves and previously known as a potential source of NSP). Our results showed our method is efficient for NSP analysis without the need for the primer information as in commercial STR kits.

Cytokine Genetic Polymorphism of Interleukin-4 and Risk of Asthma in Some Iraqi Patients

Abstract Background: Asthma, a chronic inflammatory respiratory disorder, is influenced by genetic and environmental factors. Allergic asthma is becoming more common because of higher levels of air pollution. Interleukin-4 (IL-4) plays an important role in allergic inflammation and causes the expression of vascular cell adhesion molecule-1. Objective: The present study aims to shed light on the association between cytokine genetic polymorphisms and asthma in Iraqi patients, and to determine their impact on the risk of disease, under the scope of the following: (1) IL-4 cytokines, in terms of their serum level. (2) Assessment of the polymorphisms in the promoter regions of the IL-4, genes in asthma disease patients was carried out, and then their impact on the profile of investigated cytokines was evaluated. Such a collective evaluation may aid in a better understanding of etiopathogenesis in the asthma disease. Materials and Methods: A case-control study was conducted that included 100 participants divided into a patient group (n = 50) with bronchial asthma and a healthy group as a control (n = 50) without asthma. Blood specimens were collected from participants at Marjan Hospital, Babylon Governorate. Serum levels of IL-4 were estimated by an enzyme-linked immunosorbent assay (ELISA) kit. IL4-590 gene polymorphism was detected using amplification refractory mutation system polymerase chain reaction (PCR) with specific primer sequences. Results: The mean concentrations of serum IL-4 were significantly higher in patients having asthma compared to the healthy group (149.84 vs. 53.50, P < 0.0001). In terms of allele and genotype frequencies, the TT genotype was shown to be less common in asthma group compared to controls (4% vs. 22%), whereas the CT genotype was more common in asthma patients (34% vs. 16%). The CC genotype was similar between the two groups. The T allele was more frequent in healthy (39%) compared to asthmatic group (12%), whereas the C allele frequency was higher in asthma patients (61%) compared to controls (88%). Conclusion: This study suggests that gene polymorphism of IL4-590 is associated with risk of developing asthma. Asthma patients have elevated levels of IL-4 and a lower frequency of the TT genotype, indicating an increased likelihood of developing asthma when carrying the T allele and TT genotype. Conversely, the C allele may have a protective influence against asthma development.

BEERS2: RNA-Seq simulation through high fidelity in silico modeling.

Simulation of RNA-seq reads is critical in the assessment, comparison, benchmarking and development of bioinformatics tools. Yet the field of RNA-seq simulators has progressed little in the last decade. To address this need we have developed BEERS2, which combines a flexible and highly configurable design with detailed simulation of the entire library preparation and sequencing pipeline. BEERS2 takes input transcripts (typically fully length messenger RNA transcripts with polyA tails) from either customizable input or from CAMPAREE simulated RNA samples. It produces realistic reads of these transcripts as FASTQ, SAM or BAM formats with the SAM or BAM formats containing the true alignment to the reference genome. It also produces true transcript-level quantification values. BEERS2 combines a flexible and highly configurable design with detailed simulation of the entire library preparation and sequencing pipeline and is designed to include the effects of polyA selection and RiboZero for ribosomal depletion, hexamer priming sequence biases, GC-content biases in polymerase chain reaction (PCR) amplification, barcode read errors and errors during PCR amplification. These characteristics combine to make BEERS2 the most complete simulation of RNA-seq to date. Finally, we demonstrate the use of BEERS2 by measuring the effect of several settings on the popular Salmon pseudoalignment algorithm.

Successful Primer Picking and Pooling for the Design of Multiplex PCR Primers Specific to Pork, Beef, Chicken, and Rat DNA

DNA markers and Multiplex-PCR have emerged as methods for species detection in processed meat products. The primary objective of this study is to design multiplex primer sequences for pork, rat, beef, and chicken, generating distinguishable amplicons through agarose gel electrophoresis for halal detection in processed meat products. Primer design involved utilizing mitochondrial genomic data and the NCBI-Primer BLAST site to obtain specific pork and beef primer sequences. In silico simulations, including single and multiplex-PCR, were conducted using Primer Pooler. In vitro validation encompassed Single-PCR and Multiplex-PCR annealing temperature optimization, using samples of chicken, beef, pork, and rat as well as processed meat products like meatballs, sausages, and nuggets. In vitro validation demonstrated that the halal marker gene's multiplex primer efficiently amplified the target sequence, specifically at the optimal annealing temperature of 58°C. Amplicons from beef (1,217 bp), pork (860 bp), rat (622 bp), and chicken (272 bp) primers could be distinguished on a 1.5% agarose gel. The study's results can aid in cost-effective and rapid halal testing and authentication of processed meat products, offering advantages over PCR with a single primer.

Multilocus sequence-typing scheme for <i>Borrelia miyamotoi</i> — the erythema-free ixodid tick-borne borreliosis pathogens

Introduction. Borrelia miyamotoi is a pathogen of erythema-free ixodid tick-borne borreliosis (ITBB), a disease widespread in Russia. To date, there are no generally accepted methods for B. miyamotoi genotyping. The multilocus sequencing typing (MLST) scheme of Borrelia was originally developed for B. burgdorferi, and does not have the required discrimination power for monitoring the ITBB pathogens.
 The objective of this study is to develop the MLST scheme for B. miyamotoi.
 Materials and Methods. The whole genome sequences of 10 reference strains (GenBank) were analyzed for the selection of the house-keeping loci. The MLST scheme development was based on principles published by the authors of the method. For this experiment, 81 B. miyamotoi strains and positive clinical samples were used to test the MLST scheme.
 Results. After analyzing the genomic data, 8 house-keeping loci were chosen for MLST, for which the PCR and sequencing primers were designed. Each MLST loci was represented by several alleles (from 4 to 7) which form 15 sequence types. The genetic diversity of pathogens isolated from ITBB patients and ticks were characterized.
 Discussion. Based on pairwise distances between allelic profiles, the sequence types can be classified into four groups. The first two groups are clonal complexes; the other two groups are formed by once identified sequence types. The first clonal complex unites 11 sequence types (80 or 88% of the characterized B. miyamotoi), the second consists of 2 sequence types (9 or 9.8%). The genetic differences between B. miyamotoi are associated with the sources of strains and biological isolates. The MLST based classification confirms the previously described genetic heterogeneity of B. miyamotoi populations associated with ecologically unrelated vectors of ITBB pathogens.
 Conclusion. The proposed MLST scheme is an appropriate tool for ITBB pathogen classification and evolutionary change characterization within clonal complexes.

Landscape of IGH germline genes of Chiroptera and the pattern of Rhinolophus affinis bat IGH CDR3 repertoire.

The emergence and re-emergence of abundant viruses from bats that impact human and animal health have resulted in a resurgence of interest in bat immunology. Characterizing the immune receptor repertoire is critical to understanding how bats coexist with viruses in the absence of disease and developing new therapeutics to target viruses in humans and susceptible livestock. In this study, IGH germline genes of Chiroptera including Rhinolophus ferrumequinum, Phyllostomus discolor, and Pipistrellus pipistrellus were annotated, and we profiled the characteristics of Rhinolophus affinis (RA) IGH CDR3 repertoire. The germline genes of Chiroptera are quite different from those of human, mouse, cow, and dog in evolution, but the three bat species have high homology. The CDR3 repertoire of RA is unique in many aspects including CDR3 subclass, V/J genes access and pairing, CDR3 clones, and somatic high-frequency mutation compared with that of human and mouse, which is an important point in understanding the asymptomatic nature of viral infection in bats. This study unveiled a detailed map of bat IGH germline genes on chromosome level and provided the first immune receptor repertoire of bat, which will stimulate new avenues of research that are directly relevant to human health and disease.IMPORTANCEThe intricate relationship between bats and viruses has been a subject of study since the mid-20th century, with more than 100 viruses identified, including those affecting humans. While preliminary investigations have outlined the innate immune responses of bats, the role of adaptive immunity remains unclear. This study presents a pioneering contribution to bat immunology by unveiling, for the first time, a detailed map of bat IGH germline genes at the chromosome level. This breakthrough not only provides a foundation for B cell receptor research in bats but also contributes to primer design and sequencing of the CDR3 repertoire. Additionally, we offer the first comprehensive immune receptor repertoire of bats, serving as a crucial library for future comparative analyses. In summary, this research significantly advances the understanding of bats' immune responses, providing essential resources for further investigations into viral tolerance and potential zoonotic threats.

Effect of target gene sequence evenness and dominance on real-time PCR quantification of artificial sulfate-reducing microbial communities.

Quantitative real-time PCR of phylogenetic and functional marker genes is among the most commonly used techniques to quantify the abundance of microbial taxa in environmental samples. However, in most environmental applications, the approach is a rough assessment of population abundance rather than an exact absolute quantification method because of PCR-based estimation biases caused by multiple factors. Previous studies on these technical issues have focused on primer or template sequence features or PCR reaction conditions. However, how target gene sequence characteristics (e.g., evenness and dominance) in environmental samples affect qPCR quantifications has not been well studied. Here, we compared three primer sets targeting the beta subunit of the dissimilatory sulfite reductase (dsrB) to investigate qPCR quantification performance under different target gene sequence evenness and dominance conditions using artificial gBlock template mixtures designed accordingly. Our results suggested that the qPCR quantification performance of all tested primer sets was determined by the comprehensive effect of the target gene sequence evenness and dominance in environmental samples. Generally, highly degenerate primer sets have equivalent or better qPCR quantification results than a more target-specific primer set. Low template concentration in this study (~105 copies/L) will exaggerate the qPCR quantification results difference among tested primer sets. Improvements to the accuracy and reproducibility of qPCR assays for gene copy number quantification in environmental microbiology and microbial ecology studies should be based on prior knowledge of target gene sequence information acquired by metagenomic analysis or other approaches, careful selection of primer sets, and proper reaction conditions optimization.