Impact of cognition-related single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease

Multiple single nucleotide polymorphisms may contribute to cognitive decline in Parkinson’s disease. However, the mechanism by which these single nucleotide polymorphisms modify brain imaging phenotype remains unclear. The aim of this study was to investigate the potential effects of multiple single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease. Forty-eight Parkinson’s disease patients and 39 matched healthy controls underwent genotyping and 7 T magnetic resonance imaging. A cognitive-weighted polygenic risk score model was designed, in which the effect sizes were determined individually for 36 single nucleotide polymorphisms. The correlations between polygenic risk score, neuroimaging features, and clinical data were analyzed. Furthermore, individual single nucleotide polymorphism analysis was performed to explore the main effects of genotypes and their interactive effects with Parkinson’s disease diagnosis. We found that, in Parkinson’s disease, the polygenic risk score was correlated with the neural activity of the hippocampus, parahippocampus, and fusiform gyrus, and with hippocampal-prefrontal and fusiform-temporal connectivity, as well as with gray matter alterations in the orbitofrontal cortex. In addition, we found that single nucleotide polymorphisms in α-synuclein(SNCA) were associated with white matter microstructural changes in the superior corona radiata, corpus callosum, and external capsule. A single nucleotide polymorphism in catechol-O-methyltransferase was associated with the neural activities of the lingual, fusiform, and occipital gyri, which are involved in visual cognitive dysfunction. Furthermore, DRD3 was associated with frontal and temporal lobe function and structure. In conclusion, imaging genetics is useful for providing a better understanding of the genetic pathways involved in the pathophysiologic processes underlying Parkinson’s disease. This study provides evidence of an association between genetic factors, cognitive functions, and multi-modality neuroimaging biomarkers in Parkinson’s disease.

A single nucleotide polymorphism in the IL1RL1 gene is associated with Behcet's disease in a Chinese Han population

AIM:To explore the association of single nucleotide polymorphisms(SNPs)in the IL33/IL1RL1 gene region with the susceptibility to Behcet’s disease(BD)in a Chinese Han population.METHODS:A total of eight SNPs in the candidate gene region(rs11792633,rs7025417,rs10975519 and rs1048274 in IL33;rs2310220,rs12712142,rs13424006 and rs3821204 in IL1RL1)were genotyped in783 BD patients and 701 healthy controls by the Sequenom Mass Array i PLEX platform.RESULTS:A statistically significant association was observed between IL1RL1 rs12712142 and BD patients.The frequency of IL1RL1 rs12712142 variant allele A was significantly lower in BD patients than that in controls(OR=0.8,95%CI:0.69-0.94,Pc=0.039);the genotype distribution(Pc=0.043)and additive and dominant genetic model analyses(OR=0.8,95%CI:0.69-0.94,Pc=0.040 and OR=0.72,95%CI:0.58-0.88,Pc=0.011)also indicated a strong association between rs12712142 and BD patients.CONCLUSION:This is the first study to reveal the association between IL1RL1 rs12712142 variant allele A and the decreased risk of BD in the Chinese Han population,indicating a protective role of IL1RL1 in the pathogenesis of BD.

Development of organelle single nucleotide polymorphism (SNP) markers and their application for the identification of cytoplasmic inheritance patterns in Pyropia yezoensis (Bangiales,Rhodophyta)

The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitochondria).Due to the high copy numbers of organelles in cells,which influence the development and traits of algae,it is necessary to study their genetic mechanism.In this study,the marine red alga Pyropia yezoensis,an important economic macroalga,was selected as the study object.To investigate organelle(chloroplast and mitochondria)inheritance in P.yezoensis,the wild type RZ(maternal strain)was crossed with the red mutant HT(paternal strain)and 30 color-sectors from 11 F1 gametophytic blades were examined.The complete chloroplast and mitochondrial genomes of the red mutant(HT)were assembled for the first time.One reliable and stable single nucleotide polymorphism(SNP)loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA,respectively,in subsequent experiments.PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent,confirming that both chloroplast and mitochondrial genomes were inherited maternally in P.yezoensis.The inheritance pattern of organelles in P.yezoensis can be used to guide the hybridization and breeding of nori.Additionally,the organelle SNP markers developed in this study can be applied in subsequent genetic research.

Assessment of single nucleotide polymorphisms associated with steroid-induced ocular hypertension

AIM:To access the association of forty-eight single nucleotide polymorphisms(SNPs)identified from Caucasian population with steroid-induced ocular hypertension(OHT)in India population.METHODS:Fifty-four triamcinolone-acetonide(TA)and for ty-seven dexamethasone(Dex)administered subjects were enrolled in the study after a written consent.Intraocular pressure(IOP)values were recorded for a period of 6-month post steroid injections and patients were grouped as steroid-responders(SR:IOP≥21 mm Hg)and non-responders(NR:IOP≤20 mm Hg).Genomic DNA was isolated from peripheral venous blood.Forty-eight SNPs identified in TA treated Caucasian patients by genome wide association study(GWAS)were genotyped using iPLEXTM MassA RRAY among TA as well as Dex administered Indian patients.Genotyping data of 48 general subjects from a previous study were considered as reference controls for statistical analysis.Genotypic frequencies were calculated and P-value,Chi-square and odds ratio at 95%confidenceinterval of group A(steroid treated vs controls),group B(SR vs NR),group C(phenotype correlation:influence of time,severity and gender on IOP rise),were calculated.P<0.05 was considered to be statistically significant.RESULTS:OHT was observed in 50%of TA and 26%of Dex administered patients,respectively.IOP rise was mostly severe(>30 mm Hg)and immediate(<1 wk)among TA-SR patients while it was noticed to be mild(<30 mm Hg)and between 1-2 mo among Dex-SR patients.Logistic regression for risk factor correlation with OHT remained non-significant,hence these factors were not considered as confounding parameters for further analysis.rs133,rs34016742,rs274554,rs10936746,rs274547,rs804854,rs7751500,rs359498,and rs7547448 SNPs significantly varied even after Bonferroni corrections(P<0.0025;group A).rs1879370(TA)and rs6559662(Dex)were significantly(P<0.05)associated with OHT(group B).rs133(severe IOP rise),rs11047639 and rs1879370(male gender),and rs11171569(immediate IOP rise)significantly(P<0.05)influenced the phenotype correlation only among TAOHT patients.However,the significance of these SNPs in group B and phenotype analysis(group C)was lost upon Bonferroni corrections(P<0.0025).CONCLUSION:Prevalence of OHT in study population is observed to be similar to other studies both in TA and Dex treated patients.We can correlate rs34016742 involved in diabetes signaling pathway to the occurrence of ocular edematous and inflammatory conditions.Except rs133 that is involved in neuro-degeneration and myopia occurrence,none of the other SNPs identified in Caucasian population possess any correlation with OHT incidence in TA and Dex administered Indian subjects.

Association of eleven single nucleotide polymorphisms with refractive disorders from Eskisehir,Turkey

AIM:To investigate relationship between refractive errors and eleven single nucleotide polymorphisms(SNPs)in HGF,GC,MFN1,GNB4,and VDR genes in Turkish population.METHODS:A group of 212 participants with myopia(n=91),hyperopia(n=45),and emmetropia(n=76)were investigated in this study.SNPs in HGF,GC,MFN1,GNB4 and VDR genes were studied by Snap Shot technique.RESULTS:The patients in this study consists of 47 female/44 male(age:23.47±4.30)patients with myopia,20 female/25 male(age:31.20±8.02)with hyperopia and 33 female/43 male(age:25.22±6.60)with emmetropia.The genotype distribution of the rs7618348 polymorphism,which was the only statistically significant one between myopia and emmetropia group.The genotype distribution of the rs3819545,rs3735520,rs7041,and rs2239182 polymorphisms,which were statistically significant between hyperopia and emmetropia groups.CONCLUSION:The importance of genetic predisposition to refractive errors with respect to etiology of the disease is revealed.It is known that polymorphism studies may differ because of genetic diversity among populations so larger cohort studies are required in different populations to enlighten the etiology of the refractive errors.

Significant association of a single nucleotide polymorphism in the upstream region of FGFR1OP2/wit3.0 gene with residual ridge resorption of mandible in Saudis

Residual ridge resorption(RRR)is the decrease in the jaw structure that follows tooth extraction.It is a multifactorial disorder,but reports on the associated genetic factors are scarce,particularly amongst the Saudis.This study aimed to investigate the role of single nucleotide polymorphisms(SNPs)in fibroblast growth factor receptor 1 oncogene partner 2(FGFR1OP2)in RRR development in Saudis.The study included 192 individuals(RRR=96;controls=96)attending outpatient clinics at the College of Dentistry,King Saud University.Demographic and clinical data were collected,the digital panoramic dental radiograph was obtained,and mandibular residual ridge height was measured.DNA was extracted from saliva and genotyping was conducted on“Sequenom MassARRAY iPLEX”.Genotype and allele frequencies of three SNPs were calculated and compared.The age at first diagnosis and bone height were compared in the three genotypes of each SNP.The age of the patients,age at first edentulism,and bone height ranged 21-80 years,12-70 years,and 13-34.6 mm,respectively.All three genotypes of the studied SNPs(rs2279351,rs78054962 and rs2306852)were identified.SNP rs2279351 associated significantly with RRR,and the mutant C allele was highly predisposing.No association was observed for the other two SNPs.The genotypes of all SNPs had an influence on age at first edentulism and bone height,but the results were not statistically different.Since FGFR1OP2 plays a role in the process of rapid wound healing in the oral cavity,it may be playing a role in the development of RRR by influencing the rate of resorption of the jawbone.SNP rs2279351 may alter its expression and hence RRR development.This study is limited due to small a sample size,and further large-scale studies are required to confirm this association and to consider rs2279351 as a possible marker of RRR development.

Identification of Single Nucleotide Polymorphisms and Analysis of Linkage Disequilibrium in Different Bamboo Species Using the Candidate Gene Approach

Bamboos are one of the most beautiful and useful plants on Earth.The genetic background and population structure of bamboos are well known,which helps accelerate the process of artificial domestication of bamboo.Partial sequences of six genes involved in nitrogen use efficiency in 32 different bamboo species were analyzed for occurrence of single nucleotide polymorphisms(SNPs).The nucleotide diversityθw and total nucleotide polymorphismsπT of the sequenced DNA regions was 0.05137 and 0.03332,respectively.Bothπnonsyn/πsyn and Ka/Ks values were<1.The nucleotide sequences of these six genes were inferred to be relatively conserved,and the haplotype diversity was relatively high.The results of evolutionary neutrality tests showed that the six genes were in line with neutral evolution,and that the NRT2.1 and AMT2.1 gene sequences may have experienced negative selection.An inter-SNP recombination event at the NRT2.1 gene in the all pooled sample,of all 32 bamboo species was the lowest at 0.0645,whereas the AMT gene recombination events were all>0.1.Estimation and analysis of linkage disequilibrium of five genes revealed that with the increase in nucleotide sequence length,the degree of SNP linkage disequilibrium decreased rapidly.We inferred the population genetic structure of 32 bamboo species based on the SNP loci of six genes with frequencies>18%.32 bamboo species were divided into five categories,which indicated that the combined population of all bamboo species had obvious multivariate characteristics and was heterogeneous;red(Group 1)and green(Group 2)were the main groups.

Single nucleotide variations in the development of diabetic foot ulcer: A narrative review

Diabetes mellitus has become a global health problem,and the number of patients with diabetic foot ulcers(DFU)is rapidly increasing.Currently,DFU still poses great challenges to physicians,as the treatment is complex,with high risks of infection,recurrence,limb amputation,and even death.Therefore,a comprehensive understanding of DFU pathogenesis is of great importance.In this review,we summarized recent findings regarding the DFU development from the perspective of single-nucleotide variations(SNVs).Studies have shown that SNVs located in the genes encoding C-reactive protein,interleukin-6,tumor necrosis factor-alpha,stromal cell-derived factor-1,vascular endothelial growth factor,nuclear factor erythroid-2-related factor 2,sirtuin 1,intercellular adhesion molecule 1,monocyte chemoattractant protein-1,endothelial nitric oxide synthase,heat shock protein 70,hypoxia inducible factor 1 alpha,lysyl oxidase,intelectin 1,mitogen-activated protein kinase 14,toll-like receptors,osteoprotegerin,vitamin D receptor,and fibrinogen may be associated with the development of DFU.However,considering the limitations of the present investigations,future multi-center studies with larger sample sizes,as well as in-depth mechanistic research are warranted.

Estimated Genetic Variance Explained by Single Nucleotide Polymorphisms of Different Minor Allele Frequencies for Carcass Traits in Japanese Black Cattle

Japanese Black cattle are a beef breed and well known to excel in carcass quality, but the details of genetic architectures for carcass traits in beef breeds including this breed are still poorly understood. The objective of this study was to estimate the degree of additive genetic variance explained by single nucleotide polymorphism (SNP) marker groups with different levels of minor allele frequency (MAF) for marbling score and carcass weight in Japanese Black cattle. Phenotypic data on 872 fattened steers with the genotype information about 40,000 autosomal SNPs were analyzed using two different statistical models: one considering only SNPs selected based on MAF (model 1) and the other also considering all remaining SNPs as the different term (model 2). All available SNPs were classified into 10 groups based on their MAFs. For both traits, the estimated proportions of additive genetic variance explained by SNPs selected based on their MAFs using model 1 were always higher than the estimated ones using model 2. For carcass weight, relatively high values of the proportion of the additive genetic variance were estimated when using SNPs with MAFs which were in the ranges of 0.20 to 0.25 and 0.25 to 0.30, which may be partly due to the three previously-reported quantitative trait loci candidate regions. The results could have provided some information on the genetic architecture for the carcass traits in Japanese Black cattle, although its validity may be limited, mainly due to the sample size and the use of simpler statistical models in this study.

Relation of cytochrome P450 2C19 gene 681G>A single nucleotide polynmrphism to clopidogrel resistance after PCI in Chinese

Objectives Clopidogrel is a prodrug that has to be converted to an active metabolite by hepatic cytochrome P450(CYP) isoenzymes to inhibit platelet aggregation.Individualvariability of platelet inhibition by clopidogrel suggests a possibility for genetic factors having a significant influence on clopidogrel responsiveness.In this study,we sought to determine the association between the single nucleotide polymorphism of CYP 2C19 681G】A and the occurrence of clopidogrel resistance(CR) in Chinese.Methods The study enrolled 614 hospitalized patients who underwentsuccessful percutaneouscoronary intervention with drug-eluting stents were received the treatmentwith dual antiplatelet regimen(aspirin plus clopidogrel).All patients received loading doses of 600 mg clopidogrel and 300 mg aspirin.20μmol/L ADP-induced platelet aggregation ratio(PAR ) was assessed 24 h after clopi- dogrel administration.The maximum residual PAR≥70%was defined as CR.Genomic DNA was extracted from whole blood samples according to standard protocols,the single nucleotide polymorphism of the CYP2C19 681G】A was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in all the patients.Results CR was found in 126 patients(20.5%).There was CYP2C19 681G】A polymorphism in the study population.The frequencies of the three kinds of genotypes(GG,GA,A A) in CR group and non-CR (NCR)group were 32.5%,47.6%,19.8%and 48.0%, 45.0%,7.0%,respectively.The frequency of AA genotype was significantly higher in NCR group than that in CR group (OR =3.03,95%CI:1.889～5.784,P=0.003).The A allele carriers were more likely to develop clopidogrel resistance compared with that of G allele carriers(OR=1.85,95%CI: 1.392～2.459,P=0.002).Conclusions CYP2C19 681G/A polymorphism is associated with the risk of CR,and the A allele carriers may be a possible genetic susceptibility factor for patients with CR.

Advances in Single Nucleotide Polymorphisms of Vitamin D Metabolic Pathway Genes and Respiratory Diseases

Vitamin D is a fat-soluble vitamin.It is an essential vitamin for human body.It has a classical effect on regulating calcium and phosphorus metabolism.Participate in cellular and humoral immune processes by regulating the growth,differentiation and metabolism of immune cells.A large number of studies in recent years have shown that vitamin D deficiency increases the incidence of respiratory diseases.Respiratory diseases mainly include bronchial asthma,chronic obstructive pulmonary disease,tuberculosis,acute upper respiratory tract infection and pneumonia.Vitamin D metabolic pathway genes play a very important regulatory role in the transformation of vitamin D into active vitamin D,including CYP2R1,CYP27B1,CYP24A1,VDBP,VDR five genes.Genetic polymorphism of genes is the molecular basis of individual differences and disease development.Therefore,this paper summarizes the research on single nucleotide polymorphism of vitamin D metabolic pathway gene and respiratory diseases.In order to provide a new idea for future treatment.

Null Single Nucleotide Polymorphism in Chemokine Receptor 5 (CCR5) Genes among the Ijaw Ethnic Population of Nigeria

Background: A deletion of 32 bp in the nucleotide sequence of CCR5 gene results in a defective CCR5 which confers protection from HIV infection in the homozygous state, while reducing the rate of disease progression to AIDS and death in the heterozygous state. The status of the CCR5Δ32 gene has not been reported in Nigeria. Aim: This study was aimed at analyzing single nucleotide polymorphism of CCR5 gene among the Ijaws resident in Yenagoa, Nigeria. Methods: 100 subjects (75 HIV negative and 25 HIV positive control) were recruited for this study. The CCR5 genes were amplified by 2 Stage PCR reaction using GeneAmp 9700 PCR system utilizing specific primers that would flank 32 bp deletion, followed by agarose gel electrophoresis, DNA sequencing of 20 subjects was done followed by phylogenetic and polymorphism analysis. Results: The results showed that 75 (100%) of the HIV negative subjects had 189 base pair in their CCR5 gene. Nucleotide of the 20 (100%) of the sequenced samples were conservatively same and no SNP was observed. Conclusion: This study documented no SNPs in CCR5 gene of the study population hence;the study population has no protection from HIV infection.

Aerolysin Nanopore Identification of Single Nucleotides Using the AdaBoost Model

Nanopores employ the ionic current from the single molecule blockage to identify the structure,conformation,chemical groups and charges of a single molecule.Despite the tremendous development in designing sensitive pore-forming materials,at some extent,the analyte with the single group difference still exhibits similar residual current or duration time.The serious overlap in the statistical results of residual current and duration time brings the difficulties in the nanopore discrimination of each single molecules from the mixture.In this paper,we present the AdaBoost-based machine learning model to identify the multiple analyte with single group difference in the mixed blockages.A set of feature vectors which is obtained from Hidden Markov Model(HMM)is used to train the AdaBoost model.By employing the aerolysin sensing of 5ʹ-AAAA-3ʹ(AA3)and 5ʹ-GAAA-3ʹ(GA3)as the model system,our results show that AdaBoost model increases the identification accu-racy from~0.293 to above 0.991.Furthermore,five sets of mixed blockages of AA3 and GA3 further validate the average accuracy of training and validation,which are 0.997 and 0.989,respectively.The proposed methods improve the capacity of wild-type biological nanopore in efficiently identify the single nucleotide difference without designing of protein and optimizing of the experimental condition.Therefore,the AdaBoost-based machine learning approach could promote the nanopore practical application such as genetic and epigenetic detection.

Single-nucleotide polymorphisms based genetic risk score in the prediction of pancreatic cancer risk

BACKGROUND Disease-related single nucleotide polymorphisms(SNPs)based genetic risk score(GRS)has been proven to provide independent inherited risk other than family history in multiple cancer types.AIM To evaluate the potential of GRS in the prediction of pancreatic cancer risk.METHODS In this case-control study(254 cases and 1200 controls),we aimed to evaluate the association between GRS and pancreatic ductal adenocarcinoma(PDAC)risk in the Chinese population.The GRS was calculated based on the genotype information of 18 PDAC-related SNPs for each study subject(personal genotyping information of the SNPs)and was weighted by external odd ratios(ORs).RESULTS GRS was significantly different in cases and controls(1.96±3.84 in PDACs vs 1.09±0.94 in controls,P<0.0001).Logistic regression revealed GRS to be associated with PDAC risk[OR=1.23,95%confidence interval(CI):1.13-1.34,P<0.0001].GRS remained significantly associated with PDAC(OR=1.36,95%CI:1.06-1.74,P=0.015)after adjusting for age and sex.Further analysis revealed an association of increased risk for PDAC with higher GRS.Compared with low GRS(<1.0),subjects with high GRS(2.0)were 99%more likely to have PDAC(OR:1.99,95%CI:1.30-3.04,P=0.002).Participants with intermediate GRS(1.0-1.9)were 39%more likely to have PDAC(OR:1.39,95%CI:1.03-1.84,P=0.031).A positive trend was observed(P trend=0.0006).CONCLUSION GRS based on PDAC-associated SNPs could provide independent information on PDAC risk and may be used to predict a high risk PDAC population.

SoySNP618K array:A high-resolution single nucleotide polymorphism platform as a valuable genomic resource for soybean genetics and breeding

Innovations in genomics have enabled the development of low-cost,high-resolution,single nucleotide polymorphism(SNP)genotyping arrays that accelerate breeding progress and support basic research in crop science.Here,we developed and validated the Soy SNP618 K array(618,888 SNPs)for the important crop soybean.The SNPs were selected from whole-genome resequencing data containing 2,214 diverse soybean accessions;29.34%of the SNPs mapped to genic regions representing 86.85%of the 56,044annotated high-confidence genes.Identity-by-state analyses of 318 soybeans revealed 17 redundant accessions,highlighting the potential of the Soy SNP618 K array in supporting gene bank management.The patterns of population stratification and genomic regions enriched through domestication were highly consistent with previous findings based on resequencing data,suggesting that the ascertainment bias in the Soy SNP618 K array was largely compensated for.Genome-wide association mapping in combination with reported quantitative trait loci enabled fine-mapping of genes known to influence flowering time,E2 and Gm PRR3 b,and of a new candidate gene,Gm VIP5.Moreover,genomic prediction of flowering and maturity time in 502 recombinant inbred lines was highly accurate(>0.65).Thus,the Soy SNP618 K array is a valuable genomic tool that can be used to address many questions in applied breeding,germplasm management,and basic crop research.

Genetic association analysis of CLEC5A and CLEC7A gene single-nucleotide polymorphisms and Crohn’s disease

BACKGROUND Crohn’s disease(CD)is characterized by a multifactorial etiology and a significant impact of genetic traits.While NOD2 mutations represent well established risk factors of CD,the role of other genes is incompletely understood.AIM To challenge the hypothesis that single nucleotide polymorphisms(SNPs)in the genes CLEC5 A and CLEC7 A,two members of the C-type lectin domain family of pattern recognition receptors,may be associated with CD.METHODS SNPs in CLEC5 A,CLEC7 A and the known CD risk gene NOD2 were studied using real time PCR-based SNP assays.Therefore,DNA samples from 175 patients and 157 healthy donors were employed.Genotyping data were correlated with clinical characteristics of the patients and the results of gene expression data analyses.RESULTS In accordance with previous studies,rs2066844 and rs2066847 in NOD2 were found to be significantly associated with CD(allelic P values=0.0368 and 0.0474,respectively).Intriguingly,for genotype AA of rs1285933 in CLEC5 A,a potential association with CD(recessive P=0.0523;odds ratio=1.90)was observed.There were no associations between CD and SNPs rs2078178 and rs16910631 in CLEC7 A.Variants of rs1285933 had no impact on CLEC5 A gene expression.In contrast,genotype-dependent differences of CXCL5 expression in peripheral blood mononuclear cells were observed.There is no statistical interactionbetween the tested SNPs of NOD2 and CLEC5 A,suggesting of a novel pathway contributing to the disease.CONCLUSION Our data encourage enlarged follow-up studies to further address an association of SNP rs1285933 in CLEC5 A with CD.The C-type lectin domain family member also deserves attention regarding a potential role in the pathophysiology of CD.

HLA-G and single nucleotide polymorphism(SNP)associations with cancer in African populations:Implications in personal medicine

The immune system plays an important role in protecting the body against malignancy.During cancer immunoediting,the immune system can recognize and keep checking the tumor cells by down-expression of some self-molecules or by increasing expression of some novel molecules.However,the microenvironment created in the course of cancer development hampers the immune ability to recognize and destroy the transforming cells.Human Leukocyte Antigen G(HLA-G)is emerging as immune checkpoint molecule produced more by cancer cells to weaken the immune response against them.HLA-G is a non-classical HLA class I molecule which is normally expressed in immune privileged tissues as a soluble or membrane-bound protein.HLA-G locus is highly polymorphic in the non-coding 3′untranslated region(UTR)and in the 5′upstream regulatory region(5′URR).HLA-G expression is controlled by polymorphisms located in these regions,and several association studies between these polymorphic sites and disease predisposition,response to therapy,and/or HLA-G protein expression have been reported.Various polymorphisms are demonstrated to modulate its expression and this is increasingly finding more significance in cancer biology.This review focuses on the relevance of the HLA-G gene and its polymorphisms in cancer development.We highlight population genetics of HLA-G as evidence to espouse the need and importance of exploring potential utility of HLA-G in cancer diagnosis,prognosis and immunotherapy in the currently understudied African population.

A Thermophilic G-Quadruplex DNA/N-methylmesoporphyrin IX Sensor for Accurately Detecting Single Nucleotide Polymorphism

We found U2R1,a previously discovered G-rich DNA sequence,could form the G-quadruplex(G4)structure at high tem-perature and maintain high stability.By utilizing its specific binding ability with the N-methylmesoporphyrin IX(NMM,a fluorescent probe),a thermophilic signal transduction unit was proposed,that was the NMM-U2R1 complex.Current methods for single nucleotide polymorphism(SNP)detection relying on the room-temperature rolling circle amplification system often suffered from poor accuracy,since the low temperature lowers the sensitivity for identifying the base mismatches.In this work,we combined the thermal stable signal transduction unit with the isothermal amplification reaction to develop a thermophilic fluorescent assay.High temperature could ensure the accuracy of base pairing.Based on this,this fluorescent assay has been successfully applied for the identification of one-or two-mismatched base DNA or microRNA 21.And it is expected to be generally applicable to identify SNPs in many other sequences.Furthermore,this work will open new opportunities for development of the thermally stable G4 DNA in biosensor.

Association between single nucleotide polymorphisms of nLvALF1 and PEN2-1 genes and resistance to Vibrio parahaemolyticus in the Pacific white shrimp Litopenaeus vannamei

Vibrio parahaemolyticus carrying a plasmid encoding the PirAvp and PirBvp toxins is the causative agent of acute hepatopancreatic necrosis disease(AHPND)in penaeid shrimps.In the Pacific white shrimp farming industry,one possible strategy to reduce economic loss due to AHPND is the development of a shrimp line resistant to the disease.In this study,we identified single nucleotide polymorphisms(SNPs)in the Litopenaeus vannamei anti-lipopolysaccharide factor 1(nLvALF1)and penaeidin 2-1(PEN2-1)genes,and we analyzed the associations between these SNPs and resistance/susceptibility to V.parahaemolyticus infection in the Pacific white shrimp.Postlarvae(PL20)shrimp from a local hatchery in Prachuap Khiri Khan Province were challenged with an isolate of VPAHPND and mortality was observed for 14 days.DNA was extracted from susceptible(died within 6 days)and resistant(survived the challenge)shrimp(45 individuals/group)and used for PCR amplifications of nLvALF1(397 bp)and PEN2-1(637 bp)gene fragments.PCR products were sequenced by direct sequencing and SNPs were identified from sequencing chromatograms.Nine and seven SNPs were identified in nLvALF1 and PEN2-1 gene fragments,respectively.Analyses of allele frequencies in susceptible and resistant samples using Chi-square tests revealed that four and six SNPs in nLvALF1 and PEN2-1,respectively,were associated with resistance/susceptibility to V.parahaemolyticus infection(P<0.05).The SNPs in the candidate genes identified here are potential DNA markers for breeding V.parahaemolyticus-resistant Pacific white shrimp in the study population;however,further validation will be required if these SNPs are to be used across populations.

Single nucleotide polymorphism rs11191454 in arsenite methyltransferase is associated with flow in Chinese students:a genetic study on flow experience

Flow has been widely studied in the field of positive psychology.However,little is known regarding its biological mechanism.This study aimed to ascertain flow-related gene loci.We investigated the association between flow and five single nucleotide polymorphisms associated with common mental disorders among a sample of 870 healthy 1 st year students of Jining Medical University,Shandong Province,China.This study was approved by the Ethics Committee of Jining Medical University(approval number:JNMC-2016-KY-001)on June 1,2016.rs11191454 demonstrated significant statistical association with flow after adjusting for age and gender(P=0.004).The allele carriers achieved higher scores in all 4 dimensions of flow:merging of action and awareness,challenge-skill balance,sense of control,and clear goals.This biological research article indicates that rs11191454 in the arsenite methyltransferase(AS3MT)gene might be associated with flow in a Chinese Han population,and that might result from altered arsenic metabolism.