Allele-specific Amplification Research Articles

Innovative PNA-LB mediated allele-specific LAMP for KRAS mutation profiling on a compact lab-on-a-disc device

Tailored healthcare, an approach focused on individual patients, requires integrating emerging interdisciplinary technologies to develop accurate and user-friendly diagnostic tools. KRAS mutations, prevalent in various common cancers, are crucial determinants in selecting patients for novel KRAS inhibitor therapies. This study presents a novel state-of-the-art Lab-on-a-Disc system utilizing peptide nucleic acids-loop backward (PNA-LB) mediated allele-specific loop-mediated isothermal amplification (LAMP) for detecting the frequent G12D KRAS mutation, signifying its superiority over alternative mutation detection approaches. The designed Lab-on-a-Disc system demonstrated exceptional preclinical and technical precision, accuracy, and versatility. By applying varying cutoff values to PNA- LB LAMP reactions, the assay's sensitivity and specificity were increased by 80 % and 90 %, respectively. The device's key advantages include a robust microfluidic Lab-on-a-Disc design, precise rotary control, and a cutting-edge induction heating module. These features enable multiplexing of LAMP reactions with high reproducibility and repeatability, with CV% values less than 3.5 % and 5.5 %, respectively. The device offers several methods for accurate endpoint result detection, including naked-eye observation, RGB image analysis using Python code, and time of fluorescence (Tf) values. Preclinical specificity and sensitivity, assessed using different cutoffs for Eva-Green fluorescence Tf values and pH-sensitive dyes, demonstrated comparable performance to the best standard methods. Overall, this study represents a significant step towards tailoring treatment strategies for cancer patients through precise and efficient mutation detection technologies.

A novel method of multiplex SNP genotyping assay through variable fragment length allele-specific polymerase chain reaction: Multiplex VFLASP-ARMS

Variable Fragment Length Allele-Specific Polymerase Chain Reaction (VFLASP) and Amplification Refractory Mutation System (ARMS) are reliable methods for detecting allelic variations resulting from single base changes within the genome. Due to their widespread application, allele variations caused by Single Nucleotide Polymorphisms (SNPs) can be readily detected using allele-specific primers. In the context of the current study, VFLASP was combined with ARMS method as a novel strategy to enhance the efficacy of both techniques. Clinically important base variations within SNP regions used in the study were detected by a fragment analysis method. To validate the accuracy of the developed VFLASP-ARMS method, specifically designed synthetic sequences were tested using a capillary electrophoresis system. Allele-specific primers exhibit differences solely at the 3′ end based on the sequence of the SNP. Additionally, to increase the specificity of the primers, a base was intentionally added for incompatibility. Therefore, allele discrimination on fragment analysis has been made possible through the 3–6 bp differences in the amplicons.With the optimization of the system, designed synthetic sequences provided reliable and reproducible results in wild-type, heterozygous, and homozygous genotypes using the VFLASP-ARMS method. Hence, our results demonstrated that VFLASP-ARMS method, offers a novel design methodology that can be included in the content of SNP genotyping assays.

Development of a rapid detection assay for acetolactate synthase inhibitors resistance in three Amaranthus weed species through loop-mediated isothermal amplification.

The early detection of herbicide resistance in weeds is a key factor to avoid herbicide waste and improve agriculture sustainability. The present study aimed to develop and validate an allele-specific loop-mediated isothermal amplification (AS-LAMP) assay for the quick on-site detection of the resistance-endowing point mutation Trp-574-Leu in the acetolactate synthase (ALS) gene in three widely diffused Amaranthus weed species: Amaranthus retroflexus, Amaranthus hybridus and Amaranthus tuberculatus. The AS-LAMP protocol was developed on wild-type and ALS-mutant plants of the three species and revealed that the amplification approach with only the primer set specific for the mutant allele (574-Leu) was the most promising. The validation and estimation of the AS-LAMP performance evaluated by comparing the results with those of the molecular marker (cleaved amplified polymorphic sequences) indicated that, although the sensitivity and specificity were relatively high in all species (overall 100 and > 65%, respectively), precision was high for A. hybridus L. and A. retroflexus L. (75 and 79%, respectively), but quite low for A. tuberculatus (Moq.) J. D. Sauer (59%). The LAMP assay was also effective on crude genomic DNA extraction, allowing the quick detection of mutant plants in field situation (on site resistance detection). The proposed AS-LAMP method has proven to be a promising technique for rapid detection of resistance as a result of Trp-574-Leu on the two monoecious weedy Amaranthus species but resulted less effective in the genetically variable dioecious species A. tuberculatus. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Global DNA Methylation Levels Viz-a-Viz Genetic and Biochemical Variations in One Carbon Metabolic Pathway: An Exploratory Study from North India.

Despite the importance of one carbon metabolic pathway (OCMP) in modulating the DNA methylation process, only a few population-based studies have explored their relationship among healthy individuals. This study aimed to understand the variations in global DNA methylation levels with respect to selected genetic (CBS 844ins68, MTRR A66G, MTR A2756G, and MTHFR C677T polymorphisms) and biochemical (folate, vitamin B12, and homocysteine) markers associated with OCMP among healthy North Indian adults. The study has been conducted among 1095 individuals of either sex (69.5% females), aged 30-75 years. A sample of 5 mL of blood was collected from each participant. Homocysteine, folate, and vitamin B12 levels were determined using the chemiluminescence technique. Restriction digestion was performed for genotyping MTRR A66G, MTR A2756G, and MTHFR C677T polymorphisms and allele-specific PCR amplification for CBS 844ins68 polymorphism. Global DNA methylation levels were analyzed using ELISA-based colorimetric technique. Of the selected genetic and biochemical markers, the mutant MTRR A66G allele was positively associated with global DNA methylation levels. Further, advanced age was inversely associated with methylation levels. MTRR 66GG genotype group was hypermethylated than other genotypes in folate replete and vitamin B12 deficient group (a condition prevalent among vegetarians), suggesting that the G allele may be more efficient than the wild-type allele in such conditions. Global DNA methylation levels appeared to be more influenced by genetic than biochemical factors. MTRR 66G allele may have a selective advantage in vitamin B12 deficient conditions. Further research should be undertaken to understand how genetics affects epigenetic processes.

Genetic variation of CYP2C9 gene and its correlation with cardiovascular disease risk factors.

The major enzyme that is responsible for Sulfonylureas (SUs) metabolism is hepatic cytochrome P-450 2C9 (CYP2C9). It is encoded by the polymorphic gene CYP2C9, which has many allelic variants, among those the CYP2C9*2 and CYP2C9*3 are the most common and clinically significant allelic variations. People with diabetes mellitus type 2 (T2DM) are more likely to develop cardiovascular disease (CVD), and their risk of dying from it is more than two times higher than that of people without the condition. The purpose of this study was to evaluate the association of genetic variations in the CYP2C9 gene with cardiovascular risk factors by investigating CYP2C9*1, *2, *3, *5, *11, and *13 allelic variants. A total of 226 participants were enrolled in the current case-control study. Allele-specific amplification- PCR (ASA-PCR) was used to determine the allele of different variations and the results were confirmed by sequencing. The findings of this study showed the presence of the CYP2C9*2 allele in the T2DM group does not differ from its percentage in the control group. Also, CYP2C9*3 allele frequencies identified by Hardy-Weinberg equilibrium (HWE) analysis law were not significant, p = 0.6593 and 0.5828 in T2DM and control groups. There is no statistically significant difference between the control and diabetes groups involving the distribution of CYP2C9 alleles and CYP2C9*5, *11, and *13 polymorphisms were absent in the Iraqi population. No carrier for the CYP2C9*3 homozygous state was found in both groups. According to these results T2DM patients with the CYP2C9*2 and *3 variants have an increased risk of developing hypertension.

Establishment of a forward primers-superposed amplification analysis for accurate aspirin pharmacogenomic measurement

Genotyping of gDNA rs12041331 (PEAR1), rs6065 (GP1BA), and rs730012 (LTC4S) can provide systematic guidance on the use of aspirin. However, an accurate, reliable and economical approach to simultaneous detection of the above single nucleotide polymorphisms (SNPs) is not reported. Herein, we designed and substantiated an allele-specific (AS) forward primer-superposed amplification analysis for measurement of the SNPs in PEAR1, GP1BA and LTC4S genes, in which the values of ∆Cq (differences in threshold cycles between the wild-type forward primer-based assay and the mutated-type forward primer-based assay) were employed to decide genotype. Mismatch AS forward primers were screened with the singleplex amplification analysis. Moreover, Cq extension optimized by AS forward primer superposition was observed in the selected forward primer-based triplex analysis. Further, robustness assessment of the triplex analysis showed the amplification efficiency ranging from 0.9 to 1.1. Precision test demonstrated the coefficient of variation of less than 2%. And the detective results of 189 DNA samples was completely concordant with that of commercial Sanger sequencing. In summary, we developed a simple, accurate and economical approach to genotyping of rs12041331 (PEAR1), rs6065 (GP1BA) and rs730012 (LTC4S) to provide a valuable pharmacogenomics tool for guidance of aspirin delivery.

The role of polymorphic cytochrome P450 gene (CYP2B6) in B-chronic lymphocytic leukemia (B-CLL) incidence and outcome among Egyptian patients.

Cytochromes P450 (CYPs) play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75% of the total metabolism of commercially available drugs, including chemotherapeutics. The gene expression and enzyme activity of CYPs are variable between individuals, which subsequently leads to different patterns of susceptibility to carcinogenesis by genotoxic xenobiotics, as well as differences in the efficacy and toxicity of clinically used drugs. This research aimed to examine the presence of the CYP2B6*9 polymorphism and its possible association with the incidence of B-CLL in Egyptian patients, as well as the clinical outcome after receiving cyclophosphamide chemotherapy. DNA was isolated from whole blood samples of 100 de novo B-CLL cases and also from 100 sex- and age-matched healthy individuals. The presence of the CYP2B6*9 (G516T) polymorphism was examined by PCR-based allele specific amplification (ASA). Patients were further indicated for receiving chemotherapy, and then they were followed up. The CYP2B6*9 variant indicated a statistically significant higher risk of B-CLL under different genetic models, comprising allelic (T-allele vs. G-allele, OR = 4.8, p < 0.001) and dominant (GT + TT vs. GG, OR = 5.4, p < 0.001) models. Following cyclophosphamide chemotherapy, we found that the patients with variant genotypes (GT + TT) were less likely to achieve remission compared to those with the wild-type genotype (GG), with a response percentage of (37.5% vs. 83%, respectively). In conclusion, our findings showed that the CYP2B6*9 (G516T) polymorphism is associated with B-CLL susceptibility among Egyptian patients. This variant greatly affected the clinical outcome and can serve as a good therapeutic marker in predicting response to cyclophosphamide treatment.

Analysis of EGFR Gene Mutations in Lung Adenocarcinoma in Karamay, Xinjiang

Abstract Objective To investigate the mutation types and mutation rate of the epidermal growth factor receptor (EGFR) gene in patients with lung adenocarcinoma and the clinical features of lung adenocarcinoma with EGFR gene mutations in Karamay, Xinjiang, China. Methods Paraffin-embedded tissue samples of adenocarcinoma patients were collected in the Karamay Central Hospital from March 2016 to June 2019, and mutations in exon 18–21 of the EGFR gene were detected by the allele-specific amplification polymerase chain reaction (Amplification Refractory Mutation System–PCR) method. The relationships between the mutation types, mutation incidence, and clinical features were analyzed. Results Of the 170 patients with lung adenocarcinoma, 83 had EGFR mutations. The total mutation rate of EGFR in patients with lung adenocarcinoma was 48.8%, which included mutations in exons 18 (1.2% [2/170]), 19 (19.4% [33/170]), 20 (2.4% [4/170]), and 21 (20.6% [35/170]). Intriguingly, there was a case with 9 mutations in exons 20 and 21. The mutations in exon 19 of EGFR resulted in the deletion of codons 746 to 750. The main mutation in exon 21 was L858R (91.4% [32/35]). There was no significant difference in exons 19 and 21 mutation rates (P &gt; 0.05). The mutation rate of EGFR in female patients was significantly higher than that in male patients (P &lt; 0.05) but had no correlation with the age, smoking status, and clinical stage of patients with non–small cell lung cancer (P &gt; 0.05). The EGFR mutation rate may be related to the degree of tumor differentiation. Conclusion Among patients with lung adenocarcinoma in Kelamayi (city in Xinjiang), EGFR mutations were more frequently detected in female patients, and the main sites of mutations were exons 19 and 21.

BRAFV600E, BANCR, miR-203a-3p and miR-204-3p in Risk Stratification of PTC Patients.

In order to enhance the risk stratification of papillary thyroid carcinoma (PTC) patients, we assessed the presence of the most common mutation in PTC (BRAFV600E) with the expression profiles of long non-coding RNA activated by BRAFV600E (BANCR) and microRNAs, which share complementarity with BANCR (miR-203a-3p and miR-204-3p), and thereafter correlated it with several clinicopathological features of PTC. BRAFV600E was detected by mutant allele-specific PCR amplification. BANCR and miRs levels were determined by quantitative RT-PCR. Bioinformatic analysis was applied to determine the miRs' targets. The expression profile of miR-203a-3p/204-3p in PTC was not affected by BRAFV600E. In the BRAFV600E-positive PTC, high expression of miR-203a-3p correlated with extrathyroidal invasion (Ei), but the patients with both high miR-203a-3p and upregulated BANCR were not at risk of Ei. In the BRAFV600E-negative PTC, low expression of miR-204-3p correlated with Ei, intraglandular dissemination and pT status (p < 0.05), and the mutual presence of low miR-204-3p and upregulated BANCR increased the occurrence of Ei. Bioinformatic analysis predicted complementary binding between miR-203a-3p/204-3p and BANCR. The co-occurrence of tested factors might influence the spreading of PTC. These findings partially describe the complicated network of interactions that may occur during the development of PTC aggressiveness, potentially providing a new approach for high-risk PTC patient selection.

Single-Drop Blood Detection of Common G6PD Mutations in Thailand Based on Allele-Specific Recombinase Polymerase Amplification with CRISPR-Cas12a.

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is the most common inherited enzymopathy. Identification of the G6PD deficiency through screening is crucial to preventing adverse effects associated with hemolytic anemia following antimalarial drug exposure. Therefore, a rapid and precise field-based G6PD deficiency diagnosis is required, particularly in rural regions where malaria is prevalent. The phenotypic diagnosis of the G6PD intermediate has also been a challenging issue due to the overlapping of G6PD activity levels between deficient and normal individuals, leading to a misinterpretation. The availability of an accurate point-of-care testing (POCT) for G6PD genotype diagnosis will therefore increase the opportunity for screening heterozygous cases in a low-resource setting. In this study, an allele-specific recombinase polymerase amplification (AS RPA) with clustered regularly interspaced short palindromic repeats-Cas12a (CRISPR-Cas12a) was developed as a POCT for accurate diagnosis of common G6PD mutations in Thailand. The AS primers for the wild type and mutant alleles of G6PD MahidolG487A and G6PD ViangchanG871A were designed and used in RPA reactions. Following application of CRISPR-Cas12a systems containing specific protospacer adjacent motif, the targeted RPA amplicons were visualized with the naked eye. Results demonstrated that the G6PD MahidolG487A and G6PD ViangchanG871A assays reached 93.62 and 98.15% sensitivity, respectively. The specificity was 88.71% in MahidolG487A and 99.02% in G6PD ViangchanG871A. The diagnosis accuracy of the G6PD MahidolG487A and G6PD ViangchanG871A assays was 91.67 and 98.72%, respectively. From DNA extraction to detection, the assay required approximately 52 min. In conclusion, this study demonstrated the high performance of an AS RPA with the CRISPR-Cas12a platform for G6PD MahidolG487A and G6PD ViangchanG871A detection assays and the potential use of G6PD genotyping as POCT.

A point-of-care platform for hair loss-related single nucleotide polymorphism genotyping

Rapid genotyping of single nucleotide polymorphism (SNP) is crucial for prognostics and disease management, enabling more rapid therapy selection and treatment determination. Here, we introduce a point-of-care platform for hair loss-related SNP genotyping based on allele-specific loop-mediated isothermal amplification (AS-LAMP) combined with naked-eye visualization. The specificity of the AS-LAMP assay was significantly enhanced by using mismatched allele-specific primers. AS-LAMP reaction and Schiff's reagent-based colorimetric detection were successfully performed using a thermoplastic genotyping chip. This strategy also showed potential for determining homozygotes and heterozygotes in a target sample. To assess SNP genotyping capacity, the genotyping chip was fabricated to visually detect rs6152 polymorphism of an androgen receptor gene associated with genetically induced hair loss. The genotyping platform rapidly identified the SNP within 40 min, and the detection limit was as low as 1 pg/μL of the target DNA contained in human serum. The introduced strategy showed high specificity and stability in discriminating low-abundance mutations, making it suitable as a portable and affordable point-of-care platform for rapid and accurate SNP discrimination applicable for bedside detection.

Single-Cell Genotyping of Single-Nucleotide Mutations Using In Situ Allele-Specific Loop-Mediated Isothermal Amplification.

Single-nucleotide mutations (SNMs) in the bacterial genome may cause antibiotic resistance. The visualization of SNMs can indicate antibiotic resistance phenotypes at the single-cell level but remains challenging. Herein, we proposed an in situ allele-specific isothermal amplification proceeded inside cells, allowing us to image bacterial genes with single-nucleotide resolution. The primer for loop-mediated isothermal amplification (LAMP) was designed with artificial mismatch bases to serve as an allele-specific probe, endowing LAMP to specifically amplify genes with SNMs. Due to the high amplification efficiency of LAMP, the method termed AlleLAMP can generate high gain for imaging SNMs and precisely quantify mutated quinolone-resistant Salmonella in bacterial mixture. We utilized AlleLAMP to survey the selection of antibiotic resistance under the preservative stress and found that the mutant quinolone-resistant strain owned a survival advantage over the wild-type quinolone-sensitive strain under the stress of preservatives. AlleLAMP can serve as a single-cell tool for analyzing the relationship between bacterial genotype and phenotype.

Discrepancy between recipient and donor rs4364254 heparanase single nucleotide polymorphism impacts graft-versus-host disease after allogeneic stem cell transplant.

The heparanase (HPSE) gene is highly polymorphic, but only a minority of its single nucleotide polymorphisms (SNPs) have been studied. Among these, rs4693608 and rs4364254 SNPs are closely associated with mRNA expression and HPSE protein levels in healthy subjects. Given the association between HPSE and inflammatory response, we aimed to evaluate whether HPSE rs4693608 and rs4364254 SNPs could have an impact on graft-versus-host disease after allogeneic stem cell transplants (HSCT). A total of 228 consecutive patients who underwent HSCT at our center between 2005 and 2018 were included. The rs4693608 SNP was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, while the rs4364254 was detected by allele-specific amplification. The recipient-donor discrepancy for rs4364254 HPSE SNP was significantly associated with grade II-IV aGvHD (HR 1.75, p = 0.03). Patients were stratified into risk groups as follows: low-risk group (LDR) including TT-TT, TT-CT, CT-TT, CC-CC; high-risk group (HDR) including CC-CT, CC-TT, CT-CC, CT-CT, TT-CC. Day 100 cumulative incidence of grade II-IV aGvHD was 23.4% in the LDR group and 41.4% in the HDR group (p = 0.01). One-year cumulative incidence of moderate/severe cGvHD was 42.6% in the LDR group and 58.6% in the HDR group (p = 0.04). Independent variables for moderate/severe cGvHD in patients who received myeloablative conditioning included donor rs4693608 SNP (GA/AA vs. GG: HR 6.86, p = 0.008), rs4693608-rs4364254 SNP combination in recipient (HR/MR vs. LR: HR 3.67, p = 0.01), and previous grade II-IV aGvHD (HR 3.28, p = 0.0005). Finally, donors with rs4364254 SNP CC conferred increased transplant-related mortality (TRM) (39.1% vs. 25%, p = 0.03) and decreased graft-relapse free survival (GRFS) (23.5% vs. 34.4%, p = 0.04) compared with CT or TT genotypes. The differences in incidence of GvHD according to recipient-donor genotype combinations suggests a possible role for rs4364254 HPSE SNP in predicting GvHD. A high level of HPSE, particularly linked to CC genotype of rs4364254 SNP may promote alloreactive T lymphocytes activation and migration toward target organs.

Association of angiotensin-converting enzyme I/D polymorphism and apolipoprotein B with cardiometabolic abnormalities among young adults: a pilot study from Delhi

BackgroundAngiotensin-converting enzyme (ACE) gene polymorphism and elevated apolipoprotein B (apoB) are important risk factors for several cardiometabolic abnormalities. However, much less attention has been given to the relationship between these risk factors and cardiometabolic abnormalities among young adults. Considering this gap, the present study explored the association of ACE I/D polymorphism and apoB with cardiometabolic abnormalities among young adults of Delhi, India.MethodsThis cross-sectional study was conducted among young adults (aged 18–30) of either sex residing in Delhi, India. A total of 330 individuals were invited to participate in the study, and data on the socio-demographic variables were collected using a pre-tested interview schedule. Somatometric and physiological measurements were obtained using standard protocols. However, blood sample collection and biochemical and genetic analyses could successfully be performed for 178 individuals. Fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels were estimated using Erba XL-640 biochemical analyzer. LDL and TG values were used to calculate apoB levels. Genotyping for ACE I/D polymorphism was performed by allele-specific PCR amplification followed by electrophoresis. Statistical analysis was done using SPSS v.20.ResultsACE I/D polymorphism was not found to be associated with hypertension, obesity, and abnormal FBG, TG, and HDL levels. However, DD and ID genotypes and D allele, with II as the reference genotype, significantly reduced the risk for high TC (OR, p value = 0.14, 0.01*; 0.29, 0.04*; 0.22, < 0.01*, respectively) and high LDL (OR, p value = 0.17, 0.03*; 0.20, 0.03*; 0.19, < 0.01*, respectively). Except for abnormal FBG, the prevalence of all the studied cardiometabolic abnormalities was significantly higher in the 4th quartile of apoB when compared to other quartiles. Linear regression model revealed a significant positive association of apoB levels with diastolic blood pressure, studied obesity parameters, TC, TG, and LDL levels.ConclusionThe D allele of ACE I/D polymorphism was not associated with most of the studied cardiometabolic abnormalities in the present study. Further, the association of high apoB with cardiometabolic abnormalities hints toward the importance of apoB in the early diagnosis of CVDs.

Polymorphisms of genes of the renin-angiotensin system: significance in the progression of chronic kidney disease in children

Introduction. A comprehensive analysis of the polymorphisms of the genes of the renin-angiotensin system in children with different nosological forms of nephropathies is a necessary step in determining the clinical and genetic features of the formation of chronic kidney disease (CKD). &#x0D; Aim: to establish the features of ACE (D/I), GT (Thr174Met), AGT (Met235Thr) and AGTR1 (A1166C) gene polymorphisms in CKD children and determine their significance in the progression of the disease. &#x0D; Materials and methods. A retrospective and prospective study included one hundered 1 to 17 years children with nephropathies, examined in the children’s nephrology department of the Samara Regional Hospital over 10 years. In children, the identification of single nucleotide polymorphisms of genes was carried out using an allele-specific polymerase chain amplification reaction using test systems. Evaluation of clinical and paraclinical markers of progression in CKD was carried out twice a year. The results of the study were evaluated with the calculation of the Student–Fisher criteria and correlation analysis.&#x0D; Results. in patients with kidney diseases, there was a trend towards an increase in the occurrence of single nucleotide polymorphisms of genes that affect the renin-angiotensin system (RAS). CKD patients at the stage 3–5 accounted for 35%. They had D/D ACE alleles combined with alleles AGT Thr174Met (27.9 ± 6.83%) and Met235Thr (41.86 ± 7.5%), Thr235Thr (30.2 ± 7.0%) and AGTR1 A1166C (37.2 ± 7.32%) more often than in milder CKD (0 and 7.5 ± 3.37%; 5.2 ± 2.94% and 5.2 ± 2.94%; respectively, p ≤ 0.010). &#x0D; Соnclusion. The study of clinical and genetic features of CKD is relevant for the purpose of timely implementation of preventive measures.

Assessment of health risks caused by overweight in children depending on the FTO gene rs9939609 polymorphism

In this study, we aimed to estimate the association between the rs9939609 FTO (fat mass and obesity associated) polymorphism and a risk of overweight in children living in the Baikal region. We performed a case – control study that included 113 schoolchildren living in industrial centers of the Baikal region (Irkutsk, Angarsk, and Ulan-Ude). Anthropometric parameters were measured and body mass index was calculated with its values being ranked in accordance with the WHO BMI curves depending on a sex and age. Genotyping of the rs9939609 FTO polymorphism was performed by allele-specific amplification with real-time results detection. To assess likelihood of an association between the FTO gene allele and overweight and obesity, relative risk (RR) and 95 % confidence interval (CI) were calculated. The assessment revealed the A allele of the rs9939609 FTO polymorphism to be by 1.29 times more frequent in the examined children with overweight and obesity (48.44 %) than in the children form the reference group (37.65 %). The FTO rs9939609 polymorphism was authentically associated with likelihood of elevated risks of overweight and obesity in children with the homozygous AA genotype (RR = 2.806, 95 % CI: 1.650–4.772; STD = 0.271). Our study confirms that the rs9939609 polymorphism of the FTO gene is a risk factor of overweight and obesity for children from the Baikal region who have the A allele of the homozygous AA genotype. Prevailing frequency of the TT genotype (29.2 %) as compared with the AA genotype (10.62) is likely due to influence of assimilation processes on urbanized territories in the Baikal region.

Оценка риска избыточной массы тела у детей в зависимости от полиморфизма rs9939609 генa FTO

In this study, we aimed to estimate the association between the rs9939609 FTO (fat mass and obesity associated) polymorphism and a risk of overweight in children living in the Baikal region. We performed a case – control study that included 113 schoolchildren living in industrial centers of the Baikal region (Irkutsk, Angarsk, and Ulan-Ude). Anthropometric parameters were measured and body mass index was calculated with its values being ranked in accordance with the WHO BMI curves depending on a sex and age. Genotyping of the rs9939609 FTO polymorphism was performed by allele-specific amplification with real-time results detection. To assess likelihood of an association between the FTO gene allele and overweight and obesity, relative risk (RR) and 95 % confidence interval (CI) were calculated. The assessment revealed the A allele of the rs9939609 FTO polymorphism to be by 1.29 times more frequent in the examined children with overweight and obesity (48.44 %) than in the children form the reference group (37.65 %). The FTO rs9939609 polymorphism was authentically associated with likelihood of elevated risks of overweight and obesity in children with the homozygous AA genotype (RR = 2.806, 95 % CI: 1.650–4.772; STD = 0.271). Our study confirms that the rs9939609 polymorphism of the FTO gene is a risk factor of overweight and obesity for children from the Baikal region who have the A allele of the homozygous AA genotype. Prevailing frequency of the TT genotype (29.2 %) as compared with the AA genotype (10.62) is likely due to influence of assimilation processes on urbanized territories in the Baikal region.

Can allele-specific loop-mediated isothermal amplification be used for rapid detection of target-site herbicide resistance in Lolium spp.?

BackgroundHerbicide resistance is one of the threats to modern agriculture and its early detection is one of the most effective components for sustainable resistance management strategies. Many techniques have been used for target-site-resistance detection. Allele-Specific Loop-Mediated Isothermal Amplification (AS-LAMP) was evaluated as a possible rapid diagnostic method for acetyl-CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibiting herbicides resistance in Lolium spp.ResultsAS-LAMP protocols were set up for the most frequent mutations responsible for herbicide resistance to ALS (positions 197, 376 and 574) and ACCase (positions 1781, 2041 and 2078) inhibitors in previously characterized and genotyped Lolium spp. populations. A validation step on new putative resistant populations gave the overview of a possible use of this tool for herbicide resistance diagnosis in Lolium spp. Regarding the ACCase inhibitor pinoxaden, in more than 65% of the analysed plants, the LAMP assay and genotyping were in keeping, whereas the results were not consistent when ALS inhibitors resistance was considered. Limitations on the use of this technique for herbicide resistance detection in the allogamous Lolium spp. are discussed.ConclusionsThe LAMP method used for the detection of target-site resistance in weed species could be applicable with target genes that do not have high genetic variability, such as ACCase gene in Lolium spp.

Characterization of a pollen-part self-compatible apple (Malus × domestica Borkh.) mutant induced by γ-ray mutagenesis

Self-compatibility (SC) in a naturally self-incompatible fruit tree species is a highly interesting trait for breeding objectives and a valuable tool for investigating the mechanism of the gametophytic self-incompatibility (GSI) system. This study focused on apple (Malus × domestica Borkh.), carried out γ-ray mutagenesis, and succeeded in producing a self-compatible mutant. The reciprocal pollination test showed that a pollen factor is involved in its SC. Results on S-RNase genotyping by allele-specific PCR amplification of the progenies of the mutant revealed that SC in the mutant was not caused by a nonfunctional pollen S factor in either one of the S-haplotypes but presumably by an S-chromosomal alteration (i.e., reciprocal translocation of an S-haplotype or a partial S-chromosomal duplication). Amplicon sequencing of S-haplotypes of progeny individuals suggested that the most probable S-chromosomal alteration in the mutant could be a translocation of an S-haplotype to a nonhomologous chromosome; such S-chromosomal alteration made it possible for the mutant to produce S-heteroallelic pollen grains that overcome self-incompatibility by competitive interaction between the two different S-factors in a pollen grain. These results supported the idea of a “collaborative non-self-recognition system by multiple factors” based on the GSI system in apple, similar to those in Pyrus of Rosaceae and Solanaceae. Implications for breeding self-compatible apple using the mutant induced in this study are briefly discussed.

Bacterial drug-resistance and viability phenotyping upon disinfectant exposure revealed by single-nucleotide resolved-allele specific isothermal RNA amplification

Disinfectant abuse poses a risk of bacterial evolution against stresses, especially during the coronavirus disease 2019 (COVID-19) pandemic. However, bacterial phenotypes, such as drug resistance and viability, are hard to access quickly. Here, we reported an allele specific isothermal RNA amplification (termed AlleRNA) assay, using an isothermal RNA amplification technique, i.e., nucleic acid sequence-based amplification (NASBA), integrated the amplification refractory mutation system (ARMS), involving the use of sequence-specific primers to allow the amplification of the targets with complete complementary sequences. AlleRNA assay enables rapid and simultaneous detection of the single nucleotide polymorphism (SNP) (a detection limit, a LOD of 0.5 % SNP) and the viability (a LOD of 80 CFU) of the quinolone resistant Salmonella enterica. With the use of AlleRNA assay, we found that the quinolone resistant S. enterica exhibited higher survival ability during exposure toquaternary ammonium salt, 75 % ethanol and peracetic acid, which might be attributed to the upregulation of stress response-associated genescompared with the susceptible counterparts. Additionally, the AlleRNA assay indicated the potential risk in a high-frequency occurrence of viable but nonculturable (VBNC) quinolone resistant S. enterica induced by disinfectants due to the depression of ATP biosynthesis. The excessive usage of disinfectants during the COVID-19 pandemic should be carefully evaluated due to the latent threat to ecological and human health.