Single nucleotide polymorphism (SNP) markers for benzimidazole resistance in veterinary nematodes

Parasitology ◽  
2007 ◽  
Vol 134 (8) ◽  
pp. 1077-1086 ◽  
Author(s):  
G. VON SAMSON-HIMMELSTJERNA ◽  
W. J. BLACKHALL ◽  
J. S. McCARTHY ◽  
P. J. SKUCE

SUMMARYResistance to the benzimidazole class of anthelmintics in nematodes of veterinary importance has a long history. Research into the mechanisms responsible for this resistance is subsequently at a more advanced stage than for other classes of anthelmintics. The principal mechanism of resistance to benzimidazoles is likely to involve changes in the primary structure of β-tubulins, the building blocks of microtubules. Specifically, point mutations in the β-tubulin isotype 1 gene leading to amino acid substitutions in codons 167, 198, and 200 of the protein have been associated with resistance in nematodes. These single nucleotide polymorphisms offer a means of detecting the presence of resistance within populations. In this mini-review, we focus on the prevalence and importance of these polymorphisms in three groups of nematodes: trichostrongylids, cyathostomins, and hookworms. A brief overview of existing strategies for genotyping single nucleotide polymorphisms is also presented. The CARS initiative hopes to exploit these known polymorphisms to further our understanding of the phenomenon of BZ resistance.

2013 ◽  
Vol 11 (3) ◽  
pp. 221-224
Author(s):  
Masaru Takeya ◽  
Fukuhiro Yamasaki ◽  
Sachiko Hattori ◽  
Kaworu Ebana

The NIASGBsnp system manages data on single nucleotide polymorphisms (SNPs) of rice (Oryzasativa L.) genetic resources in the National Institute of Agrobiological Science (NIAS) Genebank. NIASGBsnp currently holds data on 768 SNP markers for 301 rice accessions and plans to add the SNP data of active rice accessions in the NIAS Genebank. It can show differences between accessions by graphical genotyping. Passport, characteristics and evaluation data of accessions can be retrieved to allow phenotype to be associated with genotype. NIASGBsnp will support various research purposes such as genomic selection and plant pathology research.


2013 ◽  
Vol 57 (11) ◽  
pp. 5658-5664 ◽  
Author(s):  
Soo-Jin Yang ◽  
Nagendra N. Mishra ◽  
Aileen Rubio ◽  
Arnold S. Bayer

ABSTRACTSingle nucleotide polymorphisms (SNPs) within themprFopen reading frame (ORF) have been commonly observed in daptomycin-resistant (DAPr)Staphylococcus aureusstrains. Such SNPs are usually associated with a gain-in-function phenotype, in terms of either increased synthesis or enhanced translocation (flipping) of lysyl-phosphatidylglycerol (L-PG). However, it is unclear if suchmprFSNPs are causal in DAPrstrains or are merely a biomarker for this phenotype. In this study, we used an isogenic set ofS. aureusstrains: (i) Newman, (ii) its isogenic ΔmprFmutant, and (iii) several intransplasmid complementation constructs, expressing either a wild-type or point-mutated form of themprFORF cloned from two isogenic DAP-susceptible (DAPs)-DAPrstrain pairs (616-701 and MRSA11/11-REF2145). Complementation of the ΔmprFstrain with singly point-mutatedmprFgenes (mprFS295LormprFT345A) revealed that (i) individual and distinct point mutations within themprFORF can recapitulate phenotypes observed in donor strains (i.e., changes in DAP MICs, positive surface charge, and cell membrane phospholipid profiles) and (ii) these gain-in-function SNPs (i.e., enhanced L-PG synthesis) likely promote reduced DAP binding toS. aureusby a charge repulsion mechanism. Thus, for these two DAPrstrains, the definedmprFSNPs appear to be causally related to this phenotype.


1996 ◽  
Vol 42 (9) ◽  
pp. 1391-1397 ◽  
Author(s):  
T Pastinen ◽  
J Partanen ◽  
A C Syvänen

Abstract We developed a multiplex, solid-phase minisequencing method to detect multiple single-nucleotide polymorphisms in an undivided sample. The amplified DNA templates are first captured on a manifold. Then, with multiple minisequencing primers of various sizes, single-nucleotide extension reactions are carried out simultaneously with fluorescently labeled dideoxynucleotides. The size of the extended product, determined by using a DNA sequencing instrument, defines the site of the polymorphisms, and the incorporated nucleotide gives the identity of the nucleotide at each site. HLA-DQA1 typing was used as a model system to evaluate the method. The DR2 subgroup of the HLA-DRB1 gene was typed along with the DQA1 gene to demonstrate the feasibility of the method in analyzing multiple genes at multiple sites simultaneously. The method is generally applicable for screening any single-nucleotide polymorphisms or point mutations, and its manifold format allows practical handling of large numbers of samples.


2015 ◽  
Vol 60 (1) ◽  
pp. 387-392 ◽  
Author(s):  
Faezeh Mohammadi ◽  
Seyed Jamal Hashemi ◽  
Jan Zoll ◽  
Willem J. G. Melchers ◽  
Haleh Rafati ◽  
...  

ABSTRACTWe employed an endpoint genotyping method to update the prevalence rate of positivity for the TR34/L98H mutation (a 34-bp tandem repeat mutation in the promoter region of thecyp51Agene in combination with a substitution at codon L98) and the TR46/Y121F/T289A mutation (a 46-bp tandem repeat mutation in the promoter region of thecyp51Agene in combination with substitutions at codons Y121 and T289) among clinicalAspergillus fumigatusisolates obtained from different regions of Iran over a recent 5-year period (2010 to 2014). The antifungal activities of itraconazole, voriconazole, and posaconazole against 172 clinicalA. fumigatusisolates were investigated using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. For the isolates with an azole resistance phenotype, thecyp51Agene and its promoter were amplified and sequenced. In addition, using a LightCycler 480 real-time PCR system, a novel endpoint genotyping analysis method targeting single-nucleotide polymorphisms was evaluated to detect the L98H and Y121F mutations in thecyp51Agene of all isolates. Of the 172A. fumigatusisolates tested, the MIC values of itraconazole (≥16 mg/liter) and voriconazole (>4 mg/liter) were high for 6 (3.5%). Quantitative analysis of single-nucleotide polymorphisms showed the TR34/L98H mutation in thecyp51Agenes of six isolates. No isolates harboring the TR46/Y121F/T289A mutation were detected. DNA sequencing of thecyp51Agene confirmed the results of the novel endpoint genotyping method. By microsatellite typing, all of the azole-resistant isolates had genotypes different from those previously recovered from Iran and from the Dutch TR34/L98H controls. In conclusion, there was not a significant increase in the prevalence of azole-resistantA. fumigatusisolates harboring the TR34/L98H resistance mechanism among isolates recovered over a recent 5-year period (2010 to 2014) in Iran. A quantitative assay detecting a single-nucleotide polymorphism in thecyp51Agene ofA. fumigatusis a reliable tool for the rapid screening and monitoring of TR34/L98H- and TR46/Y121F/T289A-positive isolates and can easily be incorporated into clinical mycology algorithms.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1081E-1082
Author(s):  
Brian W. Trader ◽  
Richard E. Veilleux ◽  
Holly L. Scoggins

The genus Astilbe (Saxifragaceae) comprises about 13 species and is ranked consistently among the top 10 landscape perennials. Through extensive hybridization, selection and marketing, the lineage of many Astilbehas been lost. Subdioecious Astilbebiternatais the only species in the genus native to North America while other members of the genus are endemic to Asia and monoecious. Due to the unusual geographic distribution of the species and the variation in floral development among them, development of genetic markers using single nucleotide polymorphisms (SNPs) would confirm phylogenetic relationships and establish lineage within the genus. Astilbespecies, hybrids, and cultivars were obtained from plant nurseries and botanical gardens across the country. To elucidate relationships among the genus, we conducted phylogenetic analysis of DNA sequences of the chloroplast gene matKand the internal transcriber spacer (ITS) of ribosomal rDNA genes. DNA was extracted, and gene primers trnK3914 and trnK2R were used to amplify matK, and primers 1406F and ITS2 were used to amplify the ITS1 region between 18S and 5.8S ribosomal DNA units. Both matKand ITS were sequenced for each plant specimen and sequences were aligned to identify nucleotide diversity and detect SNPs. Variation in nucleotide sequence for either gene yielded similar dendrograms. Nucleotide variation among the Astilbeutilized in this study has allowed the development of SNP markers that may be useful for fingerprinting unknown hybrids or cultivars in the industry, and may be used for species alignment within the genus.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 999A-999
Author(s):  
Angela Baldo ◽  
Larry Robertson ◽  
Joanne Labate

Cultivated tomato varieties are genetically extremely similar. We identified 764 Unigenes with potential single nucleotide polymorphisms (SNPs) among more than 15 cultivars from public expressed tomato data. By sequencing regions from 53 of these Unigenes in two to three cultivars, we discovered an unexpected wealth of nucleotide polymorphism (62 SNPs and 12 indels in 21 Unigenes). This included a high proportion of predicted nonsynonymous nucleotide (17 of 33 SNPs in exons) and nonconservative amino acid (6 of 16 nonsynonymous SNPs) changes. We hypothesize that five of these regions are associated with introgressions from wild relatives. Identifying polymorphic, expressed genes in the tomato genome will be useful for both tomato improvement and germplasm conservation.


2021 ◽  
Vol 24 (1) ◽  
pp. 122-135
Author(s):  
Ahmad Hamta‌ ◽  
◽  
Sahar Adl ◽  

Background and Aim: Breast cancer is the most common cancer type and the leading cause of cancer-induced deaths in women, worldwide. The Fibroblast Growth Factor Receptor 2 (FGFR2) is a tyrosine kinase receptor that plays an essential role in the growth, invasion, movement, and angiogenesis of tumor cells. Several single nucleotide polymorphisms have been found in the intron 2 of the FGFR2 gene, i.e., associated with a high risk of breast cancer. Genetic variation in this receptor is a new risk factor for breast cancer. The current study aimed to evaluate the association of single-nucleotide polymorphism rs2981582C/T in women with breast cancer. Methods & Materials: In total, 80 women with breast cancer and 80 healthy women (controls) were selected from Markazi Province, Iran to participate in this research. Polymorphism rs2981582 was analyzed to investigate its association with breast cancer. DNA extraction from blood samples was performed using a kit. The presence of these single-nucleotide polymorphisms was determined by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR - RFLP). Statistical analyses were performed by SPSS using Chi-squared test at P≤0.05. Ethical Considerations: This study was approved by the Ethics Committee of the Arak University (Code: IR.ARAKMU.REC.1395.28). Results: Significant differences were observed in the frequency of rs2981582 polymorphism in the FGFR2 gene between the control and patient groups (P=0.000). In the patient group, the TT genotype was significantly associated with the risk of breast cancer (P=0.001; OR=3.566). On the other hand, allele C indicated a protective role against the disease (P=0.000). Conclusion: The obtained data revealed a significant relationship between rs2981582 C/T polymorphism and the risk of breast cancer; thus, this single-nucleotide polymorphism could be used as a biomarker to predict breast cancer.


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