Guidelines for the tetra-primer ARMS-PCR technique development

Association of Alzheimer's-Related Gene Variants with Autism Spectrum Disorder: A Case-Control Study in an Iraqi Cohort

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that manifests as difficulties in social communication and the presence of restricted and repetitive behaviors. The etiology remains obscure, although there is increasing evidence of shared neurodevelopmental and neurodegenerative disorder pathways. This study aimed to determine whether gene variants previously linked to Alzheimer's disease (AD) have a role in ASD susceptibility. Within a case-control framework, we studied a sample of 270 Iraqi children, 135 with ASD and 135 age-matched controls aged 6-12 years. T-ARMS PCR was used to determine the genotypes of five selected polymorphisms NECTIN2 (rs6859), CR1 (rs670173), CLU (rs7982), ABCA7 (rs3764650), and BIN1 (rs744373) that have been associated with AD. The polymorphism genotype and allele frequencies were analyzed using the chi-square test, and odds ratio analysis with 95% confidence intervals was conducted. Age and sex-stratified analyses in addition to biochemical profiling were also conducted. Significant associations with ASD were found for three polymorphisms: CR1 rs670173 (p = 0.007), CLU rs7982 (p = 0.010), and BIN1 rs744373 (p = 0.013). The male-to-female effect ratio was stronger than the female-to-male. Interestingly, younger boys aged 6 to 9 years demonstrated the most pronounced effect of CLU rs7982 (OR = 1.92, 95% CI: 1.25-2.94, p = 0.003). NECTIN2 rs6859 (p = 0.543) and ABCA7 rs3764650 (p = 0.102) did not yield significant associations. Biochemical parameters showed no significant differences among the groups. Our results imply that some AD-associated gene variants, especially those related to neuroinflammation and synaptic activity, could elevate the risk for ASD. This reinforces the notion of shared genetic risk factors between neurodevelopmental and neurodegenerative disorders, likely involving common mechanisms for the formation and maintenance of neural circuits.

Potential Impact of SOD2 (rs4880; p.Val16Ala) Variant with the Susceptibility for Childhood Bronchial Asthma

Oxidative stress is a sophisticated situation that orignates from the accumulation of reactive free radicals within cellular compartments. The antioxidant mechanism of the MnSOD enzyme facilitates the removal of these lethal oxygen species from cellular components. The main goal of this pertained work is to study the contribution of the SOD2 (rs4880; p.Val16Ala) variant to the development of bronchial asthma among children. The study's design was carried out based on a total of 254 participants including 127 asthmatic children (91 atopic and 36 non-atopic) along with 127 unrelated healthy controls. Allelic discrimination analysis was executed using the T-ARMS-PCR protocol. This potential variant conferred a significant association with decreased risk of bronchial asthmatic children under allelic (OR = 0.56, P-value = 0.002), recessive (OR = 0.32, P-value = 0.011), and dominant (OR = 0.51, P-value = 0.040) models. Additionally, atopic and non-atopic asthmatic children indicated a protection against bronchial asthma development under allelic, and dominant models (p-value < 0.05). Our findings suggested that the SOD2*rs4880 variant was correlated with decreased risk of childhood bronchial asthma.

Fluorescent primers amplification refractory mutation system qPCR (FP ARMS-qPCR) for MTHFR C677T SNP genotyping

BACKGROUND

The currently used methods for the detection of methylene tetrahydrofolic acid reductase (MTHFR) C677T single nucleotide polymorphism (SNP) are either time-consuming or expensive. In this study, we devised an accurate, rapid and easy-to-use SNP detection system based on fluorescent primers amplification refractory mutation system qPCR, known as FP ARMS-qPCR.

METHODS

Fluorescent primers (FPs) modified by fluorescent dye or quencher near the 3' terminal thymine were designed. The reaction conditions were optimized and the performance was evaluated. Using commercial kits as controls, 242 samples were tested in parallel to verify the feasibility of the FP ARMS-qPCR assay.

RESULTS

We demonstrated the good sensitivity and specificity of the FP ARMS-qPCR with optimized conditions. The assay was able to accurately distinguish between different SNP sites of MTHFR C677T in less than 2 h using as low as 50 pg of template genomic DNA. Completely consistent genotyping results reveal that FP ARMS-qPCR is concordant with commercial kits.

CONCLUSION

We established a specific, sensitive, and rapid FP ARMS-qPCR method for the detection of MTHFR C677T genotype. This could also serve as a potential diagnostic tool for a variety of diseases.

Association of MnSOD, CAT, and GPx1 Gene Polymorphism with Risk of Diabetic Nephropathy in South Indian Patients: A Case-Control Study

Diabetic nephropathy (DN) is one of the common complications of type 2 diabetes mellitus (T2DM), and oxidative stress plays a key role in the pathogenesis of DN. Studies have demonstrated that antioxidants (MnSOD, CAT, and GPx1) may reduce the complications associated with T2DM. The purpose of the study is to correlate the role of antioxidant gene polymorphisms in the pathogenesis of DN among T2DM individuals in the South Indian population. It clarifies the importance of early manifestation and reliable genetic indicators modulating the oxidative stress mechanism in DN. The study participants were divided and grouped as Group 1: Control, Group 2: T2DM without DN, and Group 3: T2DM with DN (n = 100 in each group). The levels of plasma glucose, HbA1c, renal profile, SOD, CAT, GPx1, MDA, and TAS were assessed. MnSOD (rs4880), CAT (rs1049982), and GPx1 (rs1050450) polymorphisms were genotyped via Tetra-arms PCR. The genotypes of GPx1 depict a significant role in the progression of DN in T2DM patients (co-dominant [OR: 2.134; 95% CI (1.202-3.788), p < 0.01], dominant [OR: 2.015; 95% CI (1.117-3.634), p = 0.02], and recessive model [OR: 2.215; 95% CI (1.235-3.972), p = 0.008]); whereas rs4880 and rs1049982 polymorphisms are not associated with DN progression. As a result, GPx1 (rs1050450) polymorphism could be a diagnostic risk factor for developing DN in T2DM patients. Moreover, the genotypes of rs4880 and rs1049982 polymorphism show significant difference in the antioxidant parameters compared to the genotypes of rs1050450. In contradiction to earlier studies, the current study demonstrates that the genotypes of rs1050450 (GPx1) can be considered as an influential component for higher susceptibility and risk of developing DN in T2DM patients among the South Indian population.

DNAMarkMaker: streamlining ARMS and CAPS marker development from resequencing data with NGS short reads

DNA markers serve as essential tools in breeding selection and genetic analysis. However, developing DNA markers can be time-consuming and labor-intensive due to the need to identify polymorphisms between cultivars/lines and to design suitable primers. To address these challenges, we have developed DNAMarkMaker, a tool designed to automate the process of primer design for Amplification Refractory Mutation System (ARMS) and Cleaved Amplified Polymorphic Sequences (CAPS) markers, utilizing resequencing data. One key feature of DNAMarkMaker is its user-friendly graphical user interface (GUI), ensuring its accessibility and ease of use, even for researchers not well-versed in bioinformatics. We confirmed DNAMarkMaker's applicability by developing DNA markers for rice, potato, and turnip-each representing distinct genome structures: homozygous diploid, heterozygous autotetraploid, and heterozygous diploid, respectively. DNAMarkMaker will contribute to the rapid and efficient development of DNA markers, accelerating breeding and genetic analysis in various crops.

Potential Association of The Pathogenic Kruppel-like Factor 14 (KLF14) and Adiponectin (ADIPOQ) SNVs with Susceptibility to T2DM

AIM

To evaluate the associations of the pathogenic variants in Kruppel-like Factor 14 (KLF 14) and Adiponectin (ADIPOQ) with susceptibility to type 2 diabetes mellitus (T2DM).

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a pandemic metabolic disease characterized by increased blood sugar and caused by resistance to insulin in peripheral tissues and damage to pancreatic beta cells. Kruppel-like Factor 14 (KLF-14) is proposed to be a regulator of metabolic diseases, such as diabetes mellitus (DM) and obesity. Adiponectin (ADIPOQ) is an adipocytokine produced by the adipocytes and other tissues and was reported to be involved in T2DM.

OBJECTIVES

To study the possible association of the KLF-14 rs972283 and ADIPOQ-rs266729 with the risk of T2DM in the Saudi population.

METHODS

We have evaluated the association of KLF-14 rs972283 C>T and ADIPOQ-rs266729 C>G SNV with the risk to T2D in the Saudi population using the Amplification Refractory Mutation System PCR (ARMS-PCR), and blood biochemistry analysis. For the KLF-14 rs972283 C>T SNV we included 115 cases and 116 healthy controls, and ADIPOQ-rs266729 C>G SNV, 103 cases and 104 healthy controls were included.

RESULTS

Results indicated that the KLF-14 rs972283 GA genotype and A allele were associated with T2D risk with OR=2.14, p-value= 0.014 and OR=1.99, p-value=0.0003, respectively. Results also ADIPOQ-rs266729 CG genotype and C allele were associated with an elevated T2D risk with an OR=2.53, p=0.003 and OR=1.66, p-value =0.012, respectively.

CONCLUSION

We conclude that SNVs in KLF-14 and ADIPOQ are potential loci for T2D risk. Future large-scale studies to verify these findings are recommended. These results need further verifications in protein functional and large-scale case control studies before being introduced for genetic testing.

Identification and development of Tetra-ARMS PCR-based screening test for a genetic variant of OLA1 (Tyr254Cys) in the human failing heart

Obg-like ATPase 1 (OLA1) protein has GTP and ATP hydrolyzing activities and is important for cellular growth and survival. The human OLA1 gene maps on chromosome 2, at the locus 1q31, close to the Titin (TTN) gene, which is associated with familial dilated cardiomyopathy (DCM). In this study, we found that expression of OLA1 was significantly downregulated in human failing heart tissue (HF) as compared to in non-failing heart tissues (NF). Moreover, using the Sanger sequencing method, we characterized the human OLA1 gene and screened genetic mutations in patients with heart-failing and non-failing. Among failing and non-failing heart patients, we found a total of 15 mutations, including two transversions, one substitution, one indel, and eleven transition mutations in the OLA1 gene. All the mutations were intronic except for a non-synonymous mutation, 5144A>G, resulting in 254Tyr>Cys in exon 8 of the OLA1 gene. Furthermore, haplotype analysis of these mutations revealed that these single nucleotide polymorphisms (SNPs) are linked to each other, resulting in disease-specific haplotypes. Additionally, to screen for the 254Tyr>Cys point mutation, we developed a cost-effective, rapid genetic screening PCR test that can differentiate between homozygous (AA and GG) and heterozygous (A/G) genotypes. Our results show that this test can be used as a genetic screening tool for human cardiomyopathy. These findings have important implications for the diagnosis and treatment of cardiomyopathy.

S14-Phosphorylated RPN6 Mediates Proteasome Activation by PKA and Alleviates Proteinopathy

BACKGROUND

A better understanding of the regulation of proteasome activities can facilitate the search for new therapeutic strategies. A cell culture study shows that PKA (cAMP-dependent protein kinase or protein kinase A) activates the 26S proteasome by pS14-Rpn6 (serine14-phosphorylated Rpn6), but this discovery and its physiological significance remain to be established in vivo.

METHODS

Male and female mice with Ser14 of Rpn6 (regulatory particle non-ATPase 6) mutated to Ala (S14A [Rpn6/Psmd11S14A]) or Asp (S14D) to respectively block or mimic pS14-Rpn6 were created and used along with cells derived from them. cAMP/PKA were manipulated pharmacologically. Ubiquitin-proteasome system functioning was evaluated with the GFPdgn (green fluorescence protein with carboxyl fusion of the CL1 degron) reporter mouse and proteasomal activity assays. Impact of S14A and S14D on proteotoxicity was tested in mice and cardiomyocytes overexpressing the misfolded protein R120G-CryAB (R120G [arginine120 to glycine missense mutant alpha B-crystallin]).

RESULTS

PKA activation increased pS14-Rpn6 and 26S proteasome activities in wild-type but not S14A embryonic fibroblasts (mouse embryonic fibroblasts), adult cardiomyocytes, and mouse hearts. Basal 26S proteasome activities were significantly greater in S14D myocardium and adult mouse cardiomyocytes than in wild-type counterparts. S14D::GFPdgn mice displayed significantly lower myocardial GFPdgn protein but not mRNA levels than GFPdgn mice. In R120G mice, a classic model of cardiac proteotoxicity, basal myocardial pS14-Rpn6 was significantly lower compared with nontransgenic littermates, which was not always associated with reduction of other phosphorylated PKA substrates. Cultured S14D neonatal cardiomyocytes displayed significantly faster proteasomal degradation of R120G than wild-type neonatal cardiomyocytes. Compared with R120G mice, S14D/S14D::R120G mice showed significantly greater myocardial proteasome activities, lower levels of total and K48-linked ubiquitin conjugates, and of aberrant CryAB (alpha B-crystallin) protein aggregates, less fetal gene reactivation, and cardiac hypertrophy, and delays in cardiac malfunction.

CONCLUSIONS

This study establishes in animals that pS14-Rpn6 mediates the activation of 26S proteasomes by PKA and that the reduced pS14-Rpn6 is a key pathogenic factor in cardiac proteinopathy, thereby identifying a new therapeutic target to reduce cardiac proteotoxicity.

Fine mapping of two recessive powdery mildew resistance genes from Aegilops tauschii accession CIae8

KEY MESSAGE

Two recessive powdery mildew resistance loci pmAeCIae8_2DS and pmAeCIae8_7DS from Aegilops tauschii were mapped and two synthesized hexaploid wheat lines were developed by distant hybridization. Wheat powdery mildew (Pm), one of the worldwide destructive fungal diseases, causes significant yield loss up to 30%. The identification of new Pm resistance genes will enrich the genetic diversity of wheat breeding for Pm resistance. Aegilops tauschii is the ancestor donor of sub-genome D of hexaploid wheat. It provides beneficial genes that can be easily transferred into wheat by producing synthetic hexaploid wheat followed by genetic recombination. We assessed the Pm resistance level of 35 Ae. tauschii accessions from different origins. Accession CIae8 exhibited high Pm resistance. Inheritance analysis and gene mapping were performed using F2 and F2:3 populations derived from the cross between CIae8 and a Pm susceptible accession PI574467. The Pm resistance of CIae8 was controlled by two independent recessive genes. Bulked segregate analysis using a 55 K SNP array revealed the SNPs were mainly enriched into genome regions, i.e. 2DS (13.5-20 Mb) and 7DS (4.0-15.5 Mb). The Pm resistance loci were named as pmAeCIae8_2DS and pmAeCIae8_7DS, respectively. By recombinant screening, we narrowed the pmAeCIae8_2DS into a 370-kb interval flanked by markers CINAU-AE7800 (14.89 Mb) and CINAU-AE20 (15.26 Mb), and narrowed the pmAeCIae8_7DS into a 260-kb interval flanked by markers CINAU-AE58 (4.72 Mb) and CINAU-AE25 (4.98 Mb). The molecular markers closely linked with the resistance loci were developed, and two synthesized hexaploid wheat (SHW) lines were produced. These laid the foundation for cloning of the two resistance loci and for transferring the resistance into common wheat.

Detecting fa leptin receptor mutation in Zucker rats with tetra-primer amplification-refractory mutation system (ARMS)-PCR

Due to the genetic mutation (fa) in the gene encoding for leptin receptor, homozygous Zucker rats (fa-/-) develop excessive adiposity and become an experimental animal model in obesity and metabolic-related diseases research. Based on tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR), we developed a method to quickly genotype Zucker rats with a mutated fa allele from their wildtype littermates. The three genotypes are clearly discriminated on 2.0% agarose gel. Our method can be used as a reliable tool to set up and maintain the breeding colony in animal facilities as well as assign animals to control and treatment groups based on their genotypes for animal studies.

Ser14-RPN6 Phosphorylation Mediates the Activation of 26S Proteasomes by cAMP and Protects against Cardiac Proteotoxic Stress in Mice

Background

A better understanding of the regulation of proteasome activities can facilitate the search for new therapeutic strategies. A cell culture study shows that cAMP-dependent protein kinase (PKA) activates the 26S proteasome by phosphorylating Ser14 of RPN6 (pS14-RPN6), but this discovery and its physiological significance remain to be established in vivo .

Methods

Male and female mice with Ser14 of Rpn6 mutated to Ala (S14A) or Asp (S14D) to respectively block or mimic pS14-Rpn6 were created and used along with cells derived from them. cAMP/PKA were manipulated pharmacologically. Ubiquitin-proteasome system (UPS) functioning was evaluated with the GFPdgn reporter mouse and proteasomal activity assays. Impact of S14A and S14D on proteotoxicity was tested in mice and cardiomyocytes overexpressing the misfolded protein R120G-CryAB (R120G).

Results

PKA activation increased pS14-Rpn6 and 26S proteasome activities in wild-type (WT) but not S14A embryonic fibroblasts (MEFs), adult cardiomyocytes (AMCMs), and mouse hearts. Basal 26S proteasome activities were significantly greater in S14D myocardium and AMCMs than in WT counterparts. S14D::GFPdgn mice displayed significantly lower myocardial GFPdgn protein but not mRNA levels than GFPdgn mice. In R120G mice, a classic model of cardiac proteotoxicity, basal myocardial pS14-Rpn6 was significantly lower compared with non- transgenic littermates, which was not always associated with reduction of other phosphorylated PKA substrates. Cultured S14D neonatal cardiomyocytes displayed significantly faster proteasomal degradation of R120G than WT neonatal cardiomyocytes. Compared with R120G mice, S14D/S14D::R120G mice showed significantly greater myocardial proteasome activities, lower levels of total and K48-linked ubiquitin conjugates and of aberrant CryAB protein aggregates, less reactivation of fetal genes and cardiac hypertrophy, and delays in cardiac malfunction.

Conclusions

This study establishes in animals that pS14-Rpn6 mediates the activation of 26S proteasomes by PKA and that the reduced pS14-Rpn6 is a key pathogenic factor in cardiac proteinopathy, thereby identifies a new therapeutic target to reduce cardiac proteotoxicity.

Electrochemical biosensors for analysis of DNA point mutations in cancer research

Cancer is a genetic disease induced by mutations in DNA, in particular point mutations in important driver genes that lead to protein malfunctioning and ultimately to tumorigenesis. Screening for the most common DNA point mutations, especially in such genes as TP53, BRCA1 and BRCA2, EGFR, KRAS, or BRAF, is crucial to determine predisposition risk for cancer or to predict response to therapy. In this review, we briefly depict how these genes are involved in cancer, followed by a description of the most common techniques routinely applied for their analysis, including high-throughput next-generation sequencing technology and less expensive low-throughput options, such as real-time PCR, restriction fragment length polymorphism, or high resolution melting analysis. We then introduce benefits of electrochemical biosensors as interesting alternatives to the standard methods in terms of cost, speed, and simplicity. We describe most common strategies involved in electrochemical biosensing of point mutations, relying mostly on PCR or isothermal amplification techniques, and critically discuss major challenges and obstacles that, until now, prevented their more widespread application in clinical settings.

Tetra-ARMS-PCR assay development for genotyping of AGT rs699 T/C polymorphism, its comparison with PCR-RFLP and application in a case-control association study of cardiovascular disease patients

Genetic variations in the AGT gene play a significant role in controlling the plasma concentration of angiotensinogen (precursor protein of bioactive octapeptide angiotensin II) and the efficacy of antihypertensive drugs. In the current study, Tetra-Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS-PCR) was developed for genotyping of AGT rs699 T/C polymorphism and validated through Sanger DNA sequencing. Its efficiency was also tested using 474 human DNA samples [control, n = 181; cardiovascular disease (CVD) patients, n = 293]. Results showed that T-ARMS-PCR is superior to the commonly used PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). Statistical analysis revealed that the AGT rs699 CC genotype is more prevalent in the CVD patient group (37% vs. 28%) and AGT rs699 C allele and CC genotype increased the risk of CVD by 1.4 and 1.9 fold, respectively. In summary, T-ARMS-PCR is the most suitable approach for quick and efficient genotyping of AGT rs699 T/C polymorphism in a large population in resource-limited countries, Furthermore, AGT rs699 T/C polymorphism is associated with the risk of CVD in the Punjabi Pakistani population.

Tetra-Primer Amplification Refractory Mutation System (T-ARMS)

Single-nucleotide polymorphisms (SNPs), the most abundant genetic variation in the population, have become the molecular marker of choice. Generally, the efficient detection of SNPs requires specialized costly equipment. Although there are a few strategies for detecting SNPs through polymerase chain reaction, followed by restriction enzyme digestion and agarose gel electrophoresis, these methods are time-consuming and might be less diagnostic. Interestingly, the tetra primer amplification refractory mutation system (T-ARMS) strategy utilizes a pair of allele-specific primers in a single PCR for the diagnostic detection of SNPs in a codominant manner through standard agarose gel electrophoresis. The simplicity and robustness of the strategy have inspired the researchers to adopt this low-cost method of SNP detection in different crop plants. Here, we have described the principle, methods, and conditions for the T-ARMS strategy. The described methodology starts from the isolation of genomic DNA and ends with the post-PCR analysis of refractory amplicons in standard agarose gel electrophoresis. The limitations and future perspectives are also discussed. Taken together, T-ARMS evolves as a method of choice for low-cost SNP detection in plants.

ASSOCIATION OF SOLUTE CARRIER ORGANIC ANION TRANSPORTER 1B1 GENE POLYMORPHISM WITH RESPONSE TO ATORVASTATIN AND ASSOCIATED MYOPATHY IN IRAQI DYSLIPIDEMIA PATIENTS

OBJECTIVE

Aim: The study aims to investigate the effect of solute carriers organic anions transporters 1B1 (SLCO1B1) gene polymorphisms rs4149056, rs2306283, rs55901008, and rs729559745 in a sample of patients with dyslipidemia, and relate it to atorvastatin response and associated myopathy.

PATIENTS AND METHODS

Materials and Methods: A cross sectional enrolled 200 patients both males and females of Arabic race, Iraqi nationality aged between 30-65 years. The patients were divided into two groups: Group 1 (Atorvastatin responders and tolerant), Group 2 (Atorvastatin non responder and intolerant). Blood samples collected from the patients for biochemical studies and analyzed statistically by Student T-test and Chi-square, and DNA extracted for polymerase chains reactions (PCR).

RESULTS

Results: The results showed insignificant association P≥0.05 between the demographic characteristics of the study population with different genotypes, and significant difference P<0.05 in the biochemical parameters regarding (T-cholesterol, triglycerides, low density lipoproteins, and Creatine kinase-MM) when comparing the two groups. Odds ratio (OR) with confidence intervals CI (95%) used to evaluate the risk association to develop myopathy and poor response to atorvastatin therapy show relevant association for CC and CT genotype of rs4149056, while rs2306283 GG genotype show low association, also rs55901008 show low association for CC genotype, and moderate association for rs72559745 genotypes GG, AG.

CONCLUSION

Conclusions: The mutant allele's genotypes of rs4149056, rs55901008, and rs72559745, and the wild allele genotype of rs2306283 show significant association with the development of poor response to atorvastatin and elevated the level of CK-MM plasma concentration.

Tetra-Primer Amplification-Refractory Mutation System (ARMS)-PCR for Genotyping Mouse Leptin Gene Mutation

Due to spontaneous deficiency in leptin, ob/ob mice are one of the most commonly used experimental animal models in diabetes research. In this study, we reported a quick and easy-to-conduct genotyping method using tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) to differentiate mice with a mutated allele from the wild-type genotype. The amplicon patterns of different genotypes are clearly visible and distinguishable on 1.5% agarose gel. This method can serve as a valuable tool to differentiate genotypes for breeding purposes, to maintain animal colonies, control the available space in the animal facility, and identify appropriate individuals for animal experiments.

Genetic Polymorphisms in miR-137 and Its Target Genes, TCF4 and CACNA1C, Contribute to the Risk of Bipolar Disorder: A Preliminary Case-Control Study and Bioinformatics Analysis

Accumulating evidence has suggested that miR-137 and its target genes, CACNA1C, and TCF4, are amongst the most robustly implicated genes in psychiatric disorders. This preliminary study is aimed at investigating the effects of genetic variations in miR-137 (rs1625579A/C), TCF4 (rs1261084C/T), and CACNA1C (rs10774053A/G and rs10466907G/T) on BD susceptibility. We recruited 252 BD patients and 213 healthy subjects as the control group. Genotyping was performed using PCR-RFLP and ARMS-PCR methods. Enhanced risk of BD was found under the codominant homozygous, dominant, and allelic models of TCF4 rs1261084C/T, codominant homozygous and allelic models of CACNA1C rs10466907G/T polymorphisms, as well as codominant homozygous, dominant, recessive, and allelic models of the CACNA1C rs10774053A/G. Moreover, both TT/AG/GT/AA and TT/GG/GT/AC genotype combinations strongly increased the risk of BD in the participants. The bioinformatics analyses revealed that rs1261084C/T and rs10466907G/T created and disrupted binding sites of some miRNAs in the 3'-untranslated region of TCF4 and CACNA1C genes. In contrast, the rs10774053A/G created a new binding site for a major splicing factor and might have an effective role in the function of the CACNA1C protein. We have found that all the studied SNPs are positively associated with BD susceptibility. Replicated studies on different ethnicities are required to confirm these findings.

Oxidative stress monitoring in iPSC-derived motor neurons using genetically encoded biosensors of H2O2

Oxidative stress plays an important role in the development of neurodegenerative diseases, being either the initiator or part of a pathological cascade that leads to the neuron’s death. Genetically encoded biosensors of oxidative stress demonstrated their general functionality and overall safety in various systems. However, there is still insufficient data regarding their use in the research of disease-related phenotypes in relevant model systems, such as human cells. Here, we establish an approach for monitoring the redox state of live motor neurons with SOD1 mutations associated with amyotrophic lateral sclerosis. Using CRISPR/Cas9, we insert genetically encoded biosensors of cytoplasmic and mitochondrial H₂O₂ in the genome of induced pluripotent stem cell (iPSC) lines. We demonstrate that the biosensors remain functional in motor neurons derived from these iPSCs and reflect the differences in the stationary redox state of the neurons with different genotypes. Moreover, we show that the biosensors respond to alterations in motor neuron oxidation caused by either environmental changes or cellular stress. Thus, the obtained platform is suitable for cell-based research of neurodegenerative mechanisms.

Association of Polymorphisms in miR146a, an Inflammation-Associated MicroRNA, with the Risk of Idiopathic Recurrent Spontaneous Miscarriage: A Case-Control Study

It has been established that microRNAs (miRNAs) are involved in the regulation of immune responses and serve as biomarkers of inflammatory diseases as well as recurrent spontaneous miscarriage (RSM). Herein, we aimed to study the relationship between three functional miR146a gene polymorphisms with idiopathic RSM (IRSM) susceptibility. We recruited 161 patients with IRSM and 177 healthy women with at least one live birth and without a history of abortion. Genotyping was performed using RFLP-PCR and ARMS-PCR methods. We found that the rs6864584 T/C decreased the risk of IRSM under dominant TT+TC vs. CC (OR = 0.029) and allelic C vs. T (OR = 0.028) contrast models. Regarding rs2961920 A/C and rs57095329 A/G polymorphisms, the enhanced risk of IRSM was observed under different genetic contrasted models, including the codominant CC vs. AA (OR = 2.81 for rs2961920) and codominant GG vs. AA (OR = 2.36 for rs57095329). After applying a Bonferroni correction, haplotype analysis revealed a 51% decreased risk of IRSM regarding the ACA genotype combination. This is the first study reporting that miR146a rs57095329 A/G, rs2961920A/C, and rs6864584 T/C polymorphisms are associated with the risk of IRSM in a southern Iranian population. Performing replicated case-control studies on other ethnicities is warranted to outline the precise effects of the studied variants on the risk of gestational trophoblastic disorders.

Design and implementation of a novel pharmacogenetic assay for the identification of the CYP2D6*10 genetic variant

Objectives

Tamoxifen is considered to be the most widely used adjuvant therapy for hormone receptor positive breast cancer in premenopausal women. However, it is reported that nearly 30% of patients receiving tamoxifen therapy have shown reduced or no benefits. This may be due to the high inter-individual variations in the CYP2D6 gene that is involved in tamoxifen metabolism. The CYP2D6*10 gene variant (rs1065852C>T) is reported to be commonly found in Asian and South Asian populations. The present study was undertaken to design a novel pharmacogenetic assay (Single step-Tetra Arms Polymerase Chain Reaction) for the identification of the CYP2D6*10 variant and implement the designed assay by genotyping a cohort of breast cancer patients.

Results

The novel assay was successfully designed, optimized and validated using Sanger sequencing. Blood samples from 70 patients were genotyped. The following bands were observed in the gel image: Control band at 454 bp; band for C allele at 195 bp; band for T allele at 300 bp. The genotype frequencies for the CYP2D6*10 (rs1065852C>T) variant were: CC-24.28% (17/70), CT-75.71% (53/70), TT-0% (0/70). The allele frequencies were: T-allele-37.86% and C-allele-62.14%.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05993-6.

Adaptation to an amoeba host drives selection of virulence-associated traits in Vibrio cholerae

Predation by heterotrophic protists drives the emergence of adaptive traits in bacteria, and often these traits lead to altered interactions with hosts and persistence in the environment. Here we studied adaptation of the cholera pathogen, Vibrio cholerae during long-term co-incubation with the protist host, Acanthamoeba castellanii. We determined phenotypic and genotypic changes associated with long-term intra-amoebal host adaptation and how this impacts pathogen survival and fitness. We showed that adaptation to the amoeba host leads to temporal changes in multiple phenotypic traits in V. cholerae that facilitate increased survival and competitive fitness in amoeba. Genome sequencing and mutational analysis revealed that these altered lifestyles were linked to non-synonymous mutations in conserved regions of the flagellar transcriptional regulator, flrA. Additionally, the mutations resulted in enhanced colonisation in zebrafish, establishing a link between adaptation of V. cholerae to amoeba predation and enhanced environmental persistence. Our results show that pressure imposed by amoeba on V. cholerae selects for flrA mutations that serves as a key driver for adaptation. Importantly, this study provides evidence that adaptive traits that evolve in pathogens in response to environmental predatory pressure impact the colonisation of eukaryotic organisms by these pathogens.

Allele Frequency of APAF1 Mutation in Holstein Cattle in Brazil

APAF1 is an autosomal recessive inherited mutation, associated with Holstein haplotype 1 (HH1) and characterized by a substitution of cytosine for a thymine (c.1741C>T) in chromosome 5. The mutation causes fetal and embryonic loss, between 60 and 200 days of gestation, and reduced conception rate. The ARMS-PCR is considered a simple and low-cost method to determine single nucleotide polymorphism (SNP) with no need for genetic sequencing of the animal genome. This study aimed to verify the allelic frequency of APAF1 mutation in Brazilian Holstein cattle. A total of 248 Holstein DNA samples (210 cows and 38 bulls) were analyzed, and synthetic genes were manufactured to validate the primers developed by the authors. All animals assessed in this study were classified as wild-type for APAF1 mutation. The primers and protocol developed for the ARMS-PCR technique work with 100% specificity and efficiency since the amplicon formations are as expected according to the genotypes. In conclusion, the mutation responsible for APAF1 was not detected in the Brazilian Holstein cattle population assessed in this prevalence study, although it is not possible to affirm that APAF1 does not occur in Brazilian Holstein animals. The tetra-primer ARMS-PCR protocol for APAF1 mutation that has been validated here may be a relatively simple and economical method to determine the animals' genotype.

Universally Stable and Precise CRISPR-LAMP Detection Platform for Precise Multiple Respiratory Tract Virus Diagnosis Including Mutant SARS-CoV-2 Spike N501Y

Nowadays, rapid and accurate diagnosis of respiratory tract viruses is an urgent need to prevent another epidemic outbreak. To overcome this problem, we have developed a clustered, regularly interspaced short palindromic repeats (CRISPR) loop mediated amplification (LAMP) technology to detect influenza A virus, influenza B virus, respiratory syncytial A virus, respiratory syncytial B virus, and severe acute respiratory syndrome coronavirus 2, including variants of concern (B.1.1.7), which utilized CRISPR-associated protein 12a (Cas12a) to advance LAMP technology with the sensitivity increased 10 times. To reduce aerosol contamination in CRISPR-LAMP technology, an uracil-DNA-glycosylase-reverse transcription-LAMP system was also developed which can effectively remove dUTP-incorporated LAMP amplicons. In vitro Cas12a cleavage reaction with 28 crRNAs showed that there were no position constraints for Cas12a/CRISPR RNA (crRNA) recognition and cleavage in LAMP amplicons, and even the looped position of LAMP amplicons could be effectively recognized and cleaved. Wild-type or spike N501Y can be detected with a limit of detection of 10 copies/μL (wild-type) even at a 1% ratio level on the background (spike N501Y). Combining UDG-RT-LAMP technology, CRISPR-LAMP design, and mutation detection design, we developed a CRISPR-LAMP detection platform that can precisely diagnose pathogens with better stability and significantly improved point mutation detection efficiency.

Designing PCR Primers for the Amplification-Refractory Mutation System

The recent development in genetic research indicates that there exists intraspecific genetic variability in many organism groups. These variations, which result in a variety of genotypes and phenotypes within a population, are called polymorphism. Mutations in different ways can alter the organism's phenotype and affect its fitness, for example, by altering disease susceptibility or resistance. Therefore, the detection of point mutations in different genes of a population is of particular importance. The amplification-refractory mutation system technique is a PCR-based method to detect single nucleotide polymorphisms in the genome. The high repeatability, low cost, high accessibility, and no need for sophisticated technology are the main advantages of the ARMS-PCR technique, compared with other available methods such as PCR-RFLP. This chapter describes the design and analysis method of primers for the ARMS-PCR technique.

Clinical Implications of MiR128, Angiotensin I Converting Enzyme and Vascular Endothelial Growth Factor Gene Abnormalities and Their Association with T2D

Type 2 DM (T2D) results from the interaction of the genetic and environmental risk factors. Vascular endothelial growth factor (VEGF), angiotensin I-converting enzyme (ACE), and MicroRNAs (MiRNAs) are involved in important physiological processes. Gene variations in VEGF, ACE and MiRNA genes are associated with diseases. In this study we investigated the associations of the VEGF-2578 C/A (rs699947), VEGF-2549 insertion/deletion (I/D), and ACE I/D rs4646994 and Mir128a (rs11888095) gene variations with T2D using the amplification refractory mutation system PCR (ARMS-PCR) and mutation specific PCR (MSP). We screened 122 T2D cases and 126 healthy controls (HCs) for the rs699947, and 133 T2D cases and 133 HCs for the VEGF I/D polymorphism. For the ACE I/D we screened 152 cases and 150 HCs, and we screened 129 cases and 112 HCs for the Mir128a (rs11888095). The results showed that the CA genotype of the VEGF rs699947 and D allele of the VEGF I/D polymorphisms were associated with T2D with OR =2.01, p-value = 0.011, and OR = 2.42, p-value = 0.010, respectively. The result indicated the D allele of the ACE ID was protective against T2D with OR = 0.10, p-value = 0.0001, whereas the TC genotype and the T allele of the Mir128a (rs11888095) were associated with increased risk to T2D with OR = 3.16, p-value = 0.0001, and OR = 1.68, p-value = 0.01, respectively. We conclude that the VEGF (rs699947), VEGF I/D and Mir128a (rs11888095) are potential risk loci for T2D, and that the D allele of the ACE ID polymorphism may be protective against T2D. These results help in identification and stratification for the individuals that at risk for T2D. However, future well-designed studies in different populations and with larger sample sizes are required. Moreover, studies to examine the effects of these polymorphisms on VEGF and ACE proteins are recommended.

Association of NOS3 (rs 2070744) and SOD2Val16Ala (rs4880) gene polymorphisms with increased risk of ESRD among Egyptian patients

BACKGROUND

Chronic kidney Failure (CKD), particularly End-Stage Renal Disease (ESRD), may be serious ill-health related to a high death rate. Uremic syndrome leads to increased oxidative stress, inflammation, and dyslipidemia. Our study aimed at identifying the association of NOS3 (rs 2070744) and SOD2 Val16Ala (rs4880) gene polymorphisms within ESRD Egyptian patients.

METHODS

This work was conducted on 100 ESRD and 16 CKD Egyptian patients who were compared to 100 healthy controls. DNA was genotyped for these variants using the (T-ARMS-PCR) technique.

RESULTS

ESRD patients showed a significant association of the genotype of NOS3 gene polymorphism compared with healthy controls (P = 0.032). In the contrast, the present study revealed that no statistically significant differences were found among the CKD, ESRD, and control groups as regards the SOD2 genotypes (P = 0.064).

CONCLUSIONS

Our findings indicated a significant association between NOS3 (rs 2070744) gene polymorphism and increased risk of ESRD and CKD among Egyptian patients.

Inclusion of double helix structural oligonucleotide (STexS) results in an enhance of SNP specificity in PCR

Genetic mutations such as single nucleotide polymorphisms (SNP) are known as one of the most common forms which related to various genetic disorders and cancers. Among of the methods developed for efficient detection of such SNP, polymerase chain reaction (PCR) methods are widely used worldwide for its cost and viable advantages. However, the technique to discriminate small amounts of SNP mixed in abundant normal DNA is incomplete due to intrinsic technical problems of PCR such as amplification occurring even in 3’mismatched cases because of high enzyme activity of DNA polymerases. To overcome the issue, specifically designed PCR platform, STexS (SNP typing with excellent specificity) using double stranded oligonucleotides was implemented as a means to emphasize the amplification of SNP templates by decreasing unwanted amplification of 3’mismatched DNA copies. In this study, the results indicate several EGFR mutations were easily detected specifically utilizing the STexS platform. Further trials show the novel method works effectively to discriminate mutations in not only general allele specific (AS)-PCRs, but also amplification refractory mutation system (ARMS)-PCR. The STexS platform will give aid in PCRs targeting potential SNPs or genetically mutated biomarkers in human clinical samples.

Investigation of FADS Gene Cluster Single Nucleotide Polymorphisms in End-Stage Renal Disease Compared With Normal Controls

End-stage renal disease (ESRD) is a public health problem with a high burden. The condition is associated with abnormalities in lipid metabolism. The fatty acid desaturase (FADS) gene cluster includes three genes that are significantly correlated with a number of pathologic conditions related to abnormal lipid levels. In the current study, we genotyped rs174556, rs99780, and rs7115739 single nucleotide polymorphisms within the FADS cluster in a population of ESRD patients and healthy controls. The rs174556 of the FADS1 gene and rs99780 of the FADS2 gene were not associated with the risk of ESRD in any inheritance model. However, the rs7115739 of FADS3 was associated with the risk of ESRD in all models except for the recessive model. The T allele of this SNP was significantly less prevalent among cases compared with controls [odds ratio (OR) (95% CI) = 0.44 (0.25-0.77), P value = 0.004]. GT and TT genotypes has been shown to decrease the risk of ESRD in a codominant model [OR (95% CI) = 0.49 (0.26-0.92) and OR (95% CI) = 0.18 (0.02-1.6), respectively; P value = 0.019]. In the dominant model, GT + TT status was associated with lower risk of ESRD [OR (95% CI) = 0.45 (0.24-0.82), P value = 0.0078]. Assessment of association between this SNP and risk of ESRD in an overdominant model revealed that GT genotype decreases the risk of this condition [OR (95% CI) = 0.5 (0.27-0.94), P value = 0.029]. Taken together, the rs7115739 of FADS3 is suggested as a putative modulator of the risk of ESRD in the Iranian population.

Enzymatically Active DNA-Protein Nanogels with Tunable Cross-Linking Density

Hybrid DNA-protein nanogels represent potential protein vectors and enzymatic nanoreactors for modern biotechnology. Here, we describe a new, easy, and robust method for preparation of tunable DNA-protein nanogels with controllable size and density. For this purpose, polymerase chain reaction is used to prepare highly biotinylated DNA as a soft biopolymeric backbone, which can be efficiently cross-linked via streptavidin-biotin binding. This approach enables us to control both the density and size of the resulting nanogels not only by adjusting the amount of the cross-linking streptavidin but also by using different rates of DNA biotinylation. This gives DNA-streptavidin nanogels with the size ranging from 80 nm, for the most compact state, to up to 200 nm. Furthermore, using streptavidin-enzyme conjugates allows the straightforward one-pot incorporation of enzymes during the preparation of the nanogels. Monoenzymatic and multienzymatic nanogels have been obtained in this manner, and their catalytic activities have been characterized. All tested enzymes (alkaline phosphatase (AP), horseradish peroxidase (HRP), and β-galactosidase (βGal)), incorporated individually or in a coupled manner (glucose oxidase (GOx)-HRP cascade), were shown to remain functional. The activities of AP and βGal were unchanged while that of HRP was slightly improved inside the nanogels. We demonstrate that, for HRP, it is not the DNA-to-enzyme ratio but the physical density of the functionalized DNA nanogels that is responsible for the improvement of its enzymatic activity.

Linkage mapping and QTL analysis of flowering time in faba bean

Flowering time marks the transition from vegetative to reproductive growth and is key for optimal yield in any crop. The molecular mechanisms controlling this trait have been extensively studied in model plants such as Arabidopsis thaliana and rice. While knowledge on the molecular regulation of this trait is rapidly increasing in sequenced galegoid legume crops, understanding in faba bean remains limited. Here we exploited translational genomics from model legume crops to identify and fine map QTLs linked to flowering time in faba bean. Among the 31 candidate genes relevant for flowering control in A. thaliana and Cicer arietinum assayed, 25 could be mapped in a segregating faba bean RIL population. While most of the genes showed conserved synteny among related legume species, none of them co-localized with the 9 significant QTL regions identified. The FT gene, previously implicated in the control of flowering time in numerous members of the temperate legume clade, mapped close to the most relevant stable and conserved QTL in chromosome V. Interestingly, QTL analysis suggests an important role of epigenetic modifications in faba bean flowering control. The new QTLs and candidate genes assayed here provide a robust framework for further genetic studies and will contribute to the elucidation of the molecular mechanisms controlling this trait.

Designing, optimization, and validation of whole blood direct T-ARMS PCR for precise and rapid genotyping of complex vertebral malformation in cattle

Background

DNA testing in the cattle industry undergoes multiple hurdles. Successful genotyping involves the transportation of samples from the field to the laboratory in a chilled environment followed by DNA extraction, and finally, a specific genotyping protocol is followed. Various researches are focused on overcoming these issues. Microcards offer blood transportation at ambient temperature. Direct PCR methods can save the time of DNA extraction but available only for simplex PCR. Tetra Primer-Amplification Refractory Mutation System based Polymerase Chain Reaction (T-ARMS PCR) can make DNA testing faster in a low-cost setting. The present study was aimed to design, optimize, and validate a T-ARMS PCR for faster DNA testing of SNP responsible for Complex Vertebral Malformation (CVM)-an important genetic disease of the cattle industry. Further, a direct T-ARMS PCR from whole blood was developed to avoid the DNA extraction steps. Lastly, using the optimized protocol, genotyping of blood spotted on Microcard eliminates the need for cold chain maintenance in the transportation of samples.

Results

The present study demonstrated a novel T-ARMS PCR-based genotyping of the SNP rs438228855, which is responsible for CVM. Here, wild genotypes were recognized by 389 bp and 199 bp bands in agarose gel, while the carrier genotype showed an additional 241 bp band. The developed protocol was validated using PCR-Primer Introduced Restriction Analysis (PCR-PIRA) and sequencing. The present study further established a direct T-ARMS PCR for this SNP from whole blood. Different conditions such as heparin and EDTA treated blood, the need for pre-treatment, and two different DNA Polymerases for the direct PCR were optimized. Finally, our optimized protocol successfully genotyped the whole blood samples dried on Insta™DNA cards.

Conclusions

The present study reported the usefulness of primer modified T-ARMS PCR for detecting CVM for the first time. To the best of our knowledge, direct PCR in T-ARMS PCR has never been reported. Lastly, the use of microcards in the developed protocol can make the assay useful in the DNA testing of field samples.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12896-021-00696-5.

Sorghum Brown Midrib19 (Bmr19) Gene Links Lignin Biosynthesis to Folate Metabolism

Genetic analysis of brown midrib sorghum (Sorghum bicolor) mutant lines assembled in our program has previously shown that the mutations fall into four allelic groups, bmr2, bmr6, bmr12 or bmr19. Causal genes for allelic groups bmr2, bmr6 and bmr12, have since been identified. In this report, we provide evidence for the nature of the bmr19 mutation. This was accomplished by introgressing each of the four bmr alleles into nine different genetic backgrounds. Polymorphisms from four resequenced bulks of sorghum introgression lines containing either mutation, relative to those of a resequenced bulk of the nine normal midrib recurrent parent lines, were used to locate their respective causal mutations. The analysis confirmed the previously reported causal mutations for bmr2 and bmr6 but failed in the case of bmr12-bulk due to a mixture of mutant alleles at the locus among members of that mutant bulk. In the bmr19-bulk, a common G → A mutation was found among all members in Sobic.001G535500. This gene encodes a putative folylpolyglutamate synthase with high homology to maize Bm4. The brown midrib phenotype co-segregated with this point mutation in two separate F₂ populations. Furthermore, an additional variant allele at this locus obtained from a TILLING population also showed a brown midrib phenotype, confirming this locus as Bmr19.

CRISPR-edit point mutant allele detection (CEPAD)-PCR method for rapid screening of CRISPR edited point mutations

CRISPR-Cas9 mediated genome editing is widely used for generating genetic lesions in C. elegans. Detection of single-site mutations in F1 progeny after CRISPR-Cas9 injections is currently labor intensive due to lack of a single step PCR-based detection method. Here we present CEPAD-PCR, an allele-specific PCR detection method based on generating silent mutations around the site of the desired genetic lesion during the CRISPR-Cas9 genome editing process. Detection of the desired allele is then performed by taking advantage of the tetra primer PCR method, based on the principle described in the ARMS-PCR. In the CEPAD-PCR, however, unlike ARMS-PCR, presence of additional silent mutations near the desired site-specific mutation in the genome results in PCR priming with high specificity resulting in a low false positive rate. As proof of concept, the method was successfully tested on point mutations in two different genes, daf-15 and raga-1.

Polymorphic variants INSIG2 rs6726538, HLA-DRB1 rs9272143, and GCNT1P5 rs7780883 contribute to the susceptibility of cervical cancer in the Bangladeshi women

Objective

Cervical cancer is a gynecological health problem, affecting nearly 500,000 women each year worldwide. Genome‐wide association studies have revealed multiple susceptible genes and their polymorphisms for cervical carcinoma risk. We have carried out this case‐control study to investigate the association of INSIG2 rs6726538 (A; T), HLA‐DRB1 rs9272143 (T; C), and GCNT1P5 rs7780883 (G; A) with cervical cancer.

Methods

The present study recruited 234 cervical cancer patients as cases and 212 healthy females as controls. We have applied the tetra‐primer amplification refractory mutation system polymerase chain reaction (T‐ARMS‐PCR) method for genotyping.

Results

The SNP rs6726538 was significantly associated with increased risk of cervical cancer in all genetic models (AT vs. AA: OR = 3.30, 95% CI = 2.19–4.97, p < 0.0001; TT vs. AA: OR = 8.72, 95% CI = 3.87–19.7, p < 0.0001; AT+TT vs. AA: OR = 3.87, 95% CI = 2.61–5.73, p < 0.0001; T vs. A: OR = 2.97, 95% CI = 2.20–4.01, p < 0.0001) except the recessive model which showed a significantly reduced risk (TT vs. AA+AT: OR = 0.20, 95% CI = 0.09–0.44, p = 0.0001). rs9272143 showed significantly reduced risk for the additive model 1, dominant model, and allelic model (TC vs. TT: OR = 0.46, 95% CI = 0.31–0.70, p = 0.0004; TC+CC vs. TT: OR = 0.47 95% CI = 0.32–0.70, p = 0.0002; C vs. T: OR = 0.56, 95% CI = 0.40–0.78, p = 0.0006, respectively). The third variant, rs7780883, was significantly associated with increased risk in additive model 2, dominant, and allelic models (AA vs. GG: OR = 5.08, 95% CI = 2.45–10.5, p < 0.0001; GA+AA vs. GG: OR = 1.54, 95% CI = 1.06–2.24, p = 0.0237; A vs. G: OR = 1.88, 95% CI = 1.34–2.52, p < 0.0001, consecutively), whereas recessive model reduced the risk of cervical cancer (AA vs. GG+GA: OR = 0.20, 95% CI = 0.09–0.41, p < 0.0001). Other models of these SNPs were not associated with cervical cancer. All significant associations for three SNPs withstand after Bonferroni correction except the additive model 2 of rs7780883.

Conclusion

Our study concludes that INSIG2 rs6726538, HLA‐DRB1 rs9272143, and GCNT1P5 rs7780883 polymorphisms may contribute to the development of cervical cancer in the Bangladeshi population.

Simple Nested Allele-Specific approach with penultimate mismatch for precise species and sex identification of tiger and leopard

Accurate species and sex identification of non-invasive and forensic samples of the tiger and leopard is still confusing when using the allele-specific methods. We designed allele-specific methods with penultimate nucleotide mismatch in a nested manner for the exact identification and double-checking of forensic samples. The mismatch design is a novel concept in species and sex identification, making the allele-specific targeting precise. We developed three sets of markers, a 365 bp outer and a 98 bp inner marker for nested tiger species identification assay, 136 bp leopard specific marker, and carnivore sex identification markers. We validated the method with tissue/blood forensic samples of various felids and herbivorous available in our lab and on known fecal samples from Vandalur Zoo. We also collected 37 scat samples at diverse stages of deterioration from the Mudumalai Tiger Reserve, Tamil Nadu, India. The 365 bp targeted markers resulted in 70.2% (n = 22; 22/37) amplification success, while the 98 bp FAM-labelled marker amplified 89% (n = 33; 33/37) scat samples independently. The 136 bp leopard markers answered four scat samples (11%) unrequited by the tiger specific markers. We evaluated species and the sex identification with these markers in another 190 non-invasive samples provided by the Mudumalai Tiger Reserve authorities. Among which 56.3% (n = 107) of samples were recognized as tiger (64 male and 43 female) and 38.9% (n = 74) as leopard (41 male and 33 female). The method supersedes any other previous methods in this regard by its high accuracy and simplicity.

Rapid detection of ERG11 polymorphism associated azole resistance in Candida tropicalis

Increasing reports of azole resistance in Candida tropicalis, highlight the development of rapid resistance detection techniques. Nonsynonymous mutations in the lanosterol C14 alpha-demethylase (ERG11) gene is one of the predominant mechanisms of azole resistance in C. tropicalis. We evaluated the tetra primer-amplification refractory mutation system-PCR (T-ARMS-PCR), restriction site mutation (RSM), and high-resolution melt (HRM) analysis methods for rapid resistance detection based on ERG11 polymorphism in C. tropicalis. Twelve azole-resistant and 19 susceptible isolates of C. tropicalis were included. DNA sequencing of the isolates was performed to check the ERG11 polymorphism status among resistant and susceptible isolates. Three approaches T-ARMS-PCR, RSM, and HRM were evaluated and validated for the rapid detection of ERG11 mutation. The fluconazole MICs for the 12 resistant and 19 susceptible isolates were 32–256 mg/L and 0.5–1 mg/L, respectively. The resistant isolates showed A339T and C461T mutations in the ERG11 gene. The T-ARMS-PCR and RSM approaches discriminated all the resistant and susceptible isolates, whereas HRM analysis differentiated all except one susceptible isolate. The sensitivity, specificity, analytical sensitivity, time, and cost of analysis suggests that these three methods can be utilized for the rapid detection of ERG11 mutations in C. tropicalis. Additionally, an excellent concordance with DNA sequencing was noted for all three methods. The rapid, sensitive, and inexpensive T-ARMS-PCR, RSM, and HRM approaches are suitable for the detection of azole resistance based on ERG11 polymorphism in C. tropicalis and can be implemented in clinical setups for batter patient management.

Análisis de la mutación c.187 C>T en el gen ATP6V0A2 mediante PCR-ARMS

Los desórdenes congénitos de la glicosilación (CDG) son enfermedades poco frecuentes (EPOF) de tipo metabólico y hereditarias que ocurren como consecuencia de mutaciones en los genes que codifican para proteínas que participan, directa o indirectamente, en este proceso. La enfermedad clínicamente denominada Cutis Laxa Autosómica Recesiva tipo II-A (ARCL2A) es un tipo de CDG (ATP6V0A2-CDG) causado por mutaciones en ATP6V0A2, que codifica para la subunidad a2 del dominio v0 de una ATPasa vacuolar que tiene como función el transporte de iones H+ a través de las membranas celulares, regulando así el pH de los compartimentos celulares, e incluye la acidificación del aparato de Golgi. En 2014, nuestro grupo de investigación reportó por primera vez en México, la existencia de dos pacientes con ATP6V0A2-CDG. En este trabajo, se estableció una metodología para identificar a los portadores de la mutación c.187 C>T en el ATP6V0A2 mediante PCR-ARMS. 

Establishment and application of a novel method based on single nucleotide polymorphism analysis for detecting β-globin gene cluster deletions

β-Globin gene mutations reduce or terminate the production of beta globin chains, of which approximately 10% are large deletions within the β-globin gene cluster. Because gene deletion leads to loss of heterozygosity at single nucleotide polymorphism (SNP), a novel method for detecting β-globin gene cluster deletions based on SNP heterozygosity analysis was established in this study. The location range of SNPs was selected according to the breakpoint of β-globin gene cluster deletions. SNPs were screened using bioinformatics analysis and population sequencing data. A novel method which enables genotyping of multiplex SNPs based on tetra-primer ARMS-PCR was designed and optimized. Forty clinical samples were tested in parallel by this method and MLPA to verify the performance of this method for detecting β-globin gene cluster deletion. Six informative SNPs were obtained, achieving heterozygote coverage of 93.3% in normal individuals. Genotyping of six SNPs were successfully integrated into two multiplex tetra-primer ARMS-PCR reactions. The sensitivity, specificity, positive predictive value and negative predictive value of the method for detecting β-globin gene cluster deletion were 100%, 96.30%, 92.86%, and 100%, respectively. This is a simple, cost-effective and novel method for detecting β-globin gene cluster deletions, which may be suitable for use in combination with MLPA for thalassemia molecular testing.

Reply to Comment: Evaluation of the Association of Omentin 1 rs2274907 A > T and rs2274908 G > A Gene Polymorphisms with Coronary Artery Disease in Indian Population: A Case-Control Study

Coronary artery disease (CAD) is a major cause of death all over the world. CAD is caused by atherosclerosis which is induced by the interaction of genetic factors and environmental factors. Genome-wide association studies have revealed the association of certain gene polymorphisms with susceptibility to CAD. Omentin 1 is an adipokine secreted by the visceral adipose tissues and has been reported to have anti-inflammatory, cardioprotective, and enhances insulin sensitivity. In this study, we examined the role of omentin-1 common single nucleotide polymorphisms (SNPs) (rs2274907 A > T and rs2274908 G > A) in CAD. We conclude that the AT genotype and the T allele of the rs2274907 A > T is associated with Cad in the south Indian population. Our results indicated that the rs2274907 SNP may be associated with CAD in this population. This finding needs further validation in well-designed and large-sample size studies before being introduced in clinical settings.

First approach to pod dehiscence in faba bean: genetic and histological analyses

Pod dehiscence causes important yield losses in cultivated crops and therefore has been a key trait strongly selected against in crop domestication. In spite of the growing knowledge on the genetic basis of dehiscence in different crops, no information is available so far for faba bean. Here we conduct the first comprehensive study for faba bean pod dehiscence by combining, linkage mapping, comparative genomics, QTL analysis and histological examination of mature pods. Mapping of dehiscence-related genes revealed conservation of syntenic blocks among different legumes. Three QTLs were identified in faba bean chromosomes II, IV and VI, although none of them was stable across years. Histological analysis supports the convergent phenotypic evolution previously reported in cereals and related legume species but revealed a more complex pattern in faba bean. Contrary to common bean and soybean, the faba bean dehiscence zone appears to show functional equivalence to that described in crucifers. The lignified wall fiber layer, which is absent in the paucijuga primitive line Vf27, or less lignified and vacuolated in other dehiscent lines, appears to act as the major force triggering pod dehiscence in this species. While our findings, provide new insight into the mechanisms underlying faba bean dehiscence, full understanding of the molecular bases will require further studies combining precise phenotyping with genomic analysis.

A Rapid, SuperSelective Method for Detection of Single Nucleotide Variants in Caenorhabditis elegans

With the widespread use of single nucleotide variants generated through mutagenesis screens and genome editing technologies, there is pressing need for an efficient and low-cost strategy to genotype single nucleotide substitutions. We have developed a rapid and inexpensive method for detection of point mutants through optimization of SuperSelective (SS) primers for end-point PCR in Caenorhabditis elegans Each SS primer consists of a 5' "anchor" that hybridizes to the template, followed by a noncomplementary "bridge," and a "foot" corresponding to the target allele. The foot sequence is short, such that a single mismatch at the terminal 3' nucleotide destabilizes primer binding and prevents extension, enabling discrimination of different alleles. We explored how length and sequence composition of each SS primer segment affected selectivity and efficiency in various genetic contexts in order to develop simple rules for primer design that allow for differentiation between alleles over a broad range of annealing temperatures. Manipulating bridge length affected amplification efficiency, while modifying the foot sequence altered discriminatory power. Changing the anchor position enabled SS primers to be used for genotyping in regions with sequences that are challenging for standard primer design. After defining primer design parameters, we demonstrated the utility of SS primers for genotyping crude C. elegans lysates, suggesting that this approach could also be used for SNP mapping and screening of CRISPR mutants. Further, since SS primers reliably detect point mutations, this method has potential for broad application in all genetic systems.

Comparison Between Three Molecular Diagnostics for the Identification of Heterozygous Hemoglobin E

BACKGROUND AND OBJECTIVES

Hemoglobin E is a variant hemoglobin caused due to the base substitution G→A at codon 26 in the β-globin-coding gene that is followed by the alteration of glutamic acid (GAG) to lysine (AAG). Various types of molecular analysis methods such as tetra-primer amplification refractory mutation system (T-ARMS-PCR), Tm-shift real-time polymerase chain reaction (Tm-shift qPCR) and high-resolution melting analysis (HRMA) are commonly used to detect several mutations in the β-globin-coding gene. This study was conducted to compare the detection result of Cd 26 (G→A) mutation in the β-globin-coding gene of heterozygous HbE between the above-mentioned methods.

MATERIALS AND METHODS

DNA samples were isolated from blood archive of heterozygous HbE and analyzed for the detection of the mutation using HRMA and Tm-shift on a real-time PCR instrument, whereas T-ARMS analysis was performed on a conventional PCR equipment. High resolution melt v3.1 software and Bio-Rad CFX Manager software were used to analyze the result of HRMA and Tm-shift qPCR, whereas the T-ARMS-PCR result was analyzed by observing the number and size of DNA bands on gel electrophoresis.

RESULTS

Among 21 samples, the Cd 26 mutation was detected in numbers 18, 19 and 21 by HRMA, Tm-shift qPCR and T-ARMS-PCR. DNA Sequencing confirmed Cd 26 mutation on 5 ambiguous samples and revealed two homozygous mutation.

CONCLUSION

The Cd 26 (G→A) mutation was detected in proportions 100, 91 and 86% by T-ARMS-PCR, Tm-shift qPCR and HRMA, respectively.

Development of a specific marker for detection of a functional AvrLm9 allele and validating the interaction between AvrLm7 and AvrLm9 in Leptosphaeria maculans

Blackleg, which is caused by the fungus Leptosphaeria maculans (L. maculans), is a major disease of canola in western Canada and worldwide. Long-term use of one source of resistance could cause the breakdown of its effectiveness. Therefore, appropriate use of R genes is very important, and knowledge about the distribution of avirulence genes is a prerequisite for effectively deploying resistance. Of the 14 avirulence genes identified in L. maculans, AvrLm5 and AvrLm9 were recognized as the two alleles of the same gene based on two single nucleotide polymorphisms, C⁸⁵T and G¹⁶⁴A/C. In this study, a specific marker was developed to identify AvrLm5 and AvrLm9 based on two single nucleotide polymorphisms, C⁸⁵T and G¹⁶⁴A/C, which are responsible for the function of AvrLm9. The specific marker can be used to discriminate the AvrLm9 from avrLm9 accurately in L. maculans isolates, which is consistent with inoculation tests in isolates without AvrLm4-7. This specific marker was used to screen 1229 isolates collected from fields in the years 2014 through 2016 in Manitoba. From 68 to 84% of the isolates were found to contain the AvrLm9 allele; while 4-7% of them were avirulent on the variety Goéland with Rlm9 loci. Furthermore, no isolates having both AvrLm9 and AvrLm7 were detected using a cotyledon test, while 67% to 84% of isolates contained both avirulence genes via PCR detection, implying suppression of AvrLm9 by AvrLm7. In addition, avirulence gene profiles of the other 10 avirulence alleles were examined with the 1229 isolates using cotyledon tests or PCR amplifications. Taken together, this research enables the fast identification of AvrLm5/9, provides the Avr genes' landscape of western Canada and elaborates the relationship between AvrLm9 and AvrLm7 using isolates from grower fields.

Targeted genotype analyses of GWAS-derived lean body mass and handgrip strength-associated single-nucleotide polymorphisms in elite master athletes

Recent large genome-wide association studies (GWAS) have independently identified a set of genetic loci associated with lean body mass (LBM) and handgrip strength (HGS). Evaluation of these candidate single-nucleotide polymorphisms (SNPs) may be useful to investigate genetic traits of populations at higher or lower risk of muscle dysfunction. As such, we investigated associations between six SNPs linked to LBM or HGS in a population of elite master athletes (MA) and age-matched controls as a representative population of older individuals with variable maintenance of muscle mass and function. Genomic DNA was isolated from buffy coat samples of 96 individuals [consisting of 48 MA (71 ± 6 yr, age-graded performance 83 ± 9%) and 48 older controls (75 ± 6 yr)]. SNP validation and sample genotyping were conducted using the tetra-primer amplification refractory mutation system (ARMS). For the three SNPs analyzed that were previously associated with LBM (FTO, IRS1, and ADAMTSL3), multinomial logistic regression revealed a significant association of the ADAMTSL3 genotype with %LBM (P < 0.01). For the three HGS-linked SNPs, neither GBF1 nor GLIS1 showed any association with HGS, but for TGFA, multinomial logistic regression revealed a significant association of genotype with HGS (P < 0.05). For ADAMTSL3, there was an enrichment of the effect allele in the MA (P < 0.05, Fisher's exact test). Collectively, of the six SNPs analyzed, ADAMTSL3 and TGFA showed significant associations with LBM and HGS, respectively. The functional relevance of the ADAMTSL3 SNP in body composition and of TGFA in strength may highlight a genetic component of the elite MA phenotype.

Kidd Blood Group Genotyping for Thalassemia Patient in Iran

We aimed to determine the JK genotype in thalassemia patients from Iran using different molecular methods to compare with phenotyping results. We also aimed to standardize for the first time, the Tetra-Primer ARMS PCR method for JK genotyping. The serology method cannot correctly determine the phenotype of blood group antigens in patients with multiple blood transfusions. Peripheral blood samples were taken from two hundred alloimmunized thalassemic patients in Tehran Adult Thalassemic Clinic. The samples were tested phenotypically by routine serological methods. After DNA Extraction, SSP-PCR was performed. DNA sequencing and PCR-RFLP were used to confirm the SSP-PCR results. Discrepancies were found between the phenotype and genotype in 32 out of 200 cases. In 16 cases phenotype was determined as Jk (a + b +) but genotype was JK*A/JK*A, in 14 cases phenotype was Jk (a + b +) while the genotype showed JK*B/JK*B, 1 case had been phenotyped as Jk (a + b -) but it was genotyped as JK*A/JK*B and 1 case had been phenotyped as Jk (a - b +) but it was genotyped as JK*A/JK*B. Serological results for a few samples could not be confirmed because of mix-field agglutination. The genotyping however verified the presence of Kidd alleles. Molecular methods are a valuable tool to predict blood group phenotypes in multi-transfused patients in order to select RBC units for a perfect matching improving blood transfusion and preventing alloimmunization. Also Tetra-Primer ARMS PCR is simple and cost effective methods that could be alternative by conventional Molecular methods.

Haplotype-specific PCR for NAT2 diplotyping

N-acetyltransferase 2 (NAT2) is an enzyme that acetylates many kinds of drugs, including the antituberculosis drug isoniazid. The NAT2 gene is highly diverse across populations. An individual can be classified as having a slow acetylator (SA), an intermediate acetylator (IA), or a rapid acetylator (RA) phenotype based on its two haplotypes (diplotype) of NAT2. SA individuals are at a higher risk for isoniazid-induced hepatitis, while the RA phenotype contributes to failure in tuberculosis treatment. Being able to predict individual NAT2 phenotypes is important for dose adjustment of isoniazid. NAT2 haplotypes are commonly determined via an indirect method of statistical haplotype inference from SNP genotyping. Here, we report a direct NAT2 haplotyping method using haplotype-specific PCR (HS-PCR) for the 6 most commonly found NAT2 haplotypes: NAT2*4, NAT2*5B, NAT2*6A, NAT2*7B, NAT2*12A, and NAT2*13A. Validation of this HS-PCR method via comparison with a sequencing method in 650 Thai DNA samples (107 RA, 279 IA, and 264 SA samples) showed a concordance rate for diplotype calls of 99.23% (645/650 samples). The discordant results in 5 samples were due to 3 rare NAT2 haplotypes: NAT*5C (n = 3), NAT2*7C (n = 1), and NAT2*11A (n = 1). This novel HS-PCR method allows direct NAT2 diplotyping, enabling the implementation of NAT2 acetylator phenotypes in clinical pharmacogenetic testing.

Gene mutational analysis by NGS and its clinical significance in patients with myelodysplastic syndrome and acute myeloid leukemia

Background

In this study, we retrospectively summarized the differences of molecular gene mutations between MDS and AML patients, as well as the young and older age groups of MDS and AML patients. We also analyzed the response of newly diagnosed AML patients to standard DA or IA induction chemotherapy and the relationship between the chemotherapy outcome and the frequency of different gene mutation abnormalities.

Methods

NGS assay covering 43 genes was studied in 93 de novo MDS and 325 non-M3 AML patients. Bone marrow samples from all patients underwent gene mutational analysis by NGS.

Results

At least one non-synonymous gene mutation was detected in 279 AML patients (85.8%) and 85 MDS patients (91.4%). Contrary to 59 years and younger AML patients, there was a significantly higher incidence of gene mutation in 60 years and older AML patients (2.37 vs 1.94, p = 0.034). Gene mutation incidence in 60 years and older MDS patients increased, but no statistical significance was present (1.95 vs 1.64, p = 0.216). AML patients had a significantly higher gene mutation incidence compared with MDS-MLD patients (2.02 vs 1.63, p = 0.046). Gene mutation incidence was higher in patients with MDS-EB1/EB2 compared with patients with MDS-MLD but there was no statistical significance present (2.14 vs 1.63, p = 0.081). AML patients had significantly higher incidences of CEBPA, FLT3-ITD, DNMT3A, NPM1 and IDH1/2 gene mutations (p = 0.0043, 0.000, 0.030962, 0.002752, and 0.000628, respectively) and a lower incidence of TET2 and U2AF1 gene mutations (p = 0.000004 and 0.000, respectively) compared with MDS patients. Among the individual genes in different age groups, there were significantly higher incidences of RUNX1, IDH2, TP53 and SF3B1 gene mutations (p = 0.0478, 0.0028, 0.0024 and 0.005, respectively) as well as a trend of higher ASXL gene mutation (p = 0.057) in 60 years and older AML patients compared to 59 years and younger patients. There was no statistically significant difference in MDS patients with the different age groups and among the individual genes. Between AML patients and MDS patients among the different gene functional groups, AML patients had a significantly higher incidence of transcriptional deregulation (27.4% vs 15.1%, p = 0.014963), activated signalling (36.3% vs 10.8%, p = 0.000002) related gene mutations as well as a significantly lower incidence of RNA spliceosome (6.15% vs 60.1%, p = 0.000) related gene mutations. Furthermore, among the patients who received either IA or DA regimen for induction chemotherapy, patients with IA regimen had a significantly better CR rate than those with DA regimen (76.6% vs 57.1%, p = 0.0228).

Conclusions

Different gene mutations had been found in majority of MDS and AML patients. MDS and AML patients had different gene mutation patterns. AML patients with fewer or no gene mutations had a better chance of achieving CR when treated with IA and DA regimen induction chemotherapy.

An Integrated Molecular and Conventional Breeding Scheme for Enhancing Genetic Gain in Maize in Africa

Maize production in West and Central Africa (WCA) is constrained by a wide range of interacting stresses that keep productivity below potential yields. Among the many problems afflicting maize production in WCA, drought, foliar diseases, and parasitic weeds are the most critical. Several decades of efforts devoted to the genetic improvement of maize have resulted in remarkable genetic gain, leading to increased yields of maize on farmers' fields. The revolution unfolding in the areas of genomics, bioinformatics, and phenomics is generating innovative tools, resources, and technologies for transforming crop breeding programs. It is envisaged that such tools will be integrated within maize breeding programs, thereby advancing these programs and addressing current and future challenges. Accordingly, the maize improvement program within International Institute of Tropical Agriculture (IITA) is undergoing a process of modernization through the introduction of innovative tools and new schemes that are expected to enhance genetic gains and impact on smallholder farmers in the region. Genomic tools enable genetic dissections of complex traits and promote an understanding of the physiological basis of key agronomic and nutritional quality traits. Marker-aided selection and genome-wide selection schemes are being implemented to accelerate genetic gain relating to yield, resilience, and nutritional quality. Therefore, strategies that effectively combine genotypic information with data from field phenotyping and laboratory-based analysis are currently being optimized. Molecular breeding, guided by methodically defined product profiles tailored to different agroecological zones and conditions of climate change, supported by state-of-the-art decision-making tools, is pivotal for the advancement of modern, genomics-aided maize improvement programs. Accelerated genetic gain, in turn, catalyzes a faster variety replacement rate. It is critical to forge and strengthen partnerships for enhancing the impacts of breeding products on farmers' livelihood. IITA has well-established channels for delivering its research products/technologies to partner organizations for further testing, multiplication, and dissemination across various countries within the subregion. Capacity building of national agricultural research system (NARS) will facilitate the smooth transfer of technologies and best practices from IITA and its partners.

Polymorphisms within the Boule Gene Detected by Tetra-Primer Amplification Refractory Mutation System PCR (T-ARMS-PCR) are Significantly Associated with Goat Litter Size

As a gene contributing to spermatogenesis, the Boule gene (also called Boll), whose mutations result in azoospermia and sterility of flies and mice, was conserved in reductional maturation divisions. However, in goats, the polymorphisms of Boule, especially with regard to their fundamental roles in female reproduction traits, are still unknown. Therefore, the aims of this study were to detect a potential mutation (rs661484476: g.7254T>C) located in intron 2 of the Boule gene by tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) and to explore its potential association with the litter size of Shaanbei White-Cashmere goats (SBWGs). In this study, g.7254T>C was firstly detected. The TT genotype was the dominant genotype in the single-lamb group, and T was also the dominant allele in all tested groups. Additionally, the detected locus displayed moderate polymorphism with polymorphism information content (PIC) values among all studied goats ranging from 0.303 to 0.344. Notably, according to the χ² test, the distribution differences for the genotypic frequencies between the single- and multi-lamb groups was significant (p = 0.014). Furthermore, the polymorphisms of the goat Boule gene were significantly associated with the goat litter size in SBWGs (p < 0.05), which indicated that g.7254T>C could be a potential marker in the marker-assisted selection process for potential litter size in goats. These results also indicated that the Boule gene might exercise important functions in female goat reproduction, which provided new insight for female goat breeding and could accelerate the process of goat breeding.