A Novel Real-time Fluorescence Mutant-allele-specific Amplification Method for Rapid Single Nucleotide Polymorphism Analysis

Current methods for single nucleotide polymorphism （SNP） analysis are timeconsuming and complicated. We aimed at development of one-step real-time fluorescence mutant-allele-specific amplification （MASA） method for rapid SNP analysis. The method is a marriage of two technologies： MASA primers for target DNA and a double-stranded DNA-selective fluorescent dye, SYBR Green I. Genotypes are separated according to the different threshold cycles of the wild-type and mutant primers. K-ras oncogene was used as a target to validate the feasibility of the method. The experimental results showed that the different genotypes can be clearly discriminated by the assay. The real-time fluorescence MASA method will have an enormous potential for fast and reliable SNP analysis due to its simplicity and low cost.

Allele-specific amplification and electrochemiluminescence method for single nucleotide polymorphism analysis

A new approach combined the specificity of allele-specific amplification （ASA） with the sensitivity of electrochemiluminescence （ECL） assay for single nucleotide polymorphism （SNP） analysis was proposed. Briefly, target gene was amplified by a biotin-labeled allele-specific forward primer and a Ru（bpy）3 ^2＋（TBR）-labeled universal reverse primer. Then, the amplicon was captured onto streptavidin-coated paramagnetic beads through biotin label, and detected by measuring the ECL signal of TBR label. Different genotypes were distinguished according to the ECL values of the amplicons by different genotypic primers. K-ras oncogene was used as a target to validate the feasibility of the method. The experiment results show that the different genotypes can be clearly distinguished by ASA-ECL assay. The method is useful in SNP analysis due to its sensitivity,safety, and simplicity.

Single Nucleotide Polymorphism Genotyping of Calpastatin Gene Using the ARMS Compared with the RFLP

Calpastatin is an endogenous inhibitor of calpain which is responsible for the breakdown of myofibrillar proteins, The association of Single Nucleotide Polymorphism （SNP） in the calpastatin gene with meat tenderness is an important topic in meat production. Therefore efficient procedure to investigate the SNP is necessary. The objectives of this study were to detect the SNP of calpastatin gene at domain L marker （G/C transversion） of the Kamphaengsaen beef breed （KPS cattle; n = 26） by the Amplification Refractory Mutation System （ARMS） compared with the Restriction Fragment Length Polymorphism （RFLP） methods and to determine the genotypes of the KPS cattle at that marker. Genomic DNA of calpastatin gene extracted from blood of the KPS cattle was detected with ARMS and RFLP methods. The ARMS system has utilized two primer pairs to amplify the two different alleles of a polymorphism in single PCR reaction to detected single base mutation. In this method, the alleles-specific primers had a mismatch at 3＇ terminal base and a second deliberate mismatch at position -2 from 3＇ terminus. While the RFLP method detected a polymorphism using PCR-base technique follow by RsaI restriction enzyme. Amplification of the ARMS method revealed that the results were not different from the conventional method of RFLP. Analysis of genotypes revealed that the KPS cattle inherited the CC, CG and GG genotypes at domain L marker. These were reliable when verified by nucleotide sequence analysis of PCR products. The animals were genotyped and determined for tenderness phenotype with this marker that predicted variation of an intronic polymorphism at domain L of the calpastatin gene. Therefore, the ARMS method was simple, efficient technique, and suitable for detecting SNP at domain L marker of the calpastatin gene.

Integration of rolling circle amplification and cationic conjugated polymer for the homogeneous detection of single nucleotide polymorphisms

A novel, homogeneous and sensitive assay for the detection of single nucleotide polymorphisms (SNPs) by integration of rolling circle amplification (RCA) and cationic conjugated polymer (CCP) has been developed and tested. Mutant DNA serves as the template for specifically circularizing a padlock probe (PLP) with a sequence that is complementary to the mutant DNA. Afterwards, the mutant DNA directly acts as the primer to initiate the RCA reaction in the presence of phi29 DNA polymerase that generates a long, tandem single-strand DNA product. During the RCA reaction, fluorescein-labeled dUTPs are incorporated into the RCA products. When the CCP is introduced, efficient FRET from CCP to fluorescein occurs as a result of the strong electrostatic interactions between the CCP and the DNA produced by RCA. The wild-type DNA contains a single base mismatch with PLP with the result that the PLP is not circularized, RCA is not triggered and inefficient FRET results. By measuring the change of the emission intensities of CCP and fluorescein, it was possible to detect the SNP in a homogeneous manner. The method is sensitive and specific enough to detect 0.1 pmol/L mutant DNA and to determine a mutant allele frequency as low as 2.0%.

Genotype-based precision nutrition strategies for the prediction and clinical management of type 2 diabetes mellitus

Globally,type 2 diabetes mellitus(T2DM)is one of the most common metabolic disorders.T2DM physiopathology is influenced by complex interrelationships between genetic,metabolic and lifestyle factors(including diet),which differ between populations and geographic regions.In fact,excessive consumptions of high fat/high sugar foods generally increase the risk of developing T2DM,whereas habitual intakes of plant-based healthy diets usually exert a protective effect.Moreover,genomic studies have allowed the characterization of sequence DNA variants across the human genome,some of which may affect gene expression and protein functions relevant for glucose homeostasis.This comprehensive literature review covers the impact of gene-diet interactions on T2DM susceptibility and disease progression,some of which have demonstrated a value as biomarkers of personal responses to certain nutritional interventions.Also,novel genotype-based dietary strategies have been developed for improving T2DM control in comparison to general lifestyle recommendations.Furthermore,progresses in other omics areas(epigenomics,metagenomics,proteomics,and metabolomics)are improving current understanding of genetic insights in T2DM clinical outcomes.Although more investigation is still needed,the analysis of the genetic make-up may help to decipher new paradigms in the pathophysiology of T2DM as well as offer further opportunities to personalize the screening,prevention,diagnosis,management,and prognosis of T2DM through precision nutrition.

Association of polymorphism of tumor necrosis factor-alpha gene promoter region with outcome of hepatitis B virus infection

AIM： To determine whether -238G/A and -857C/T polymorphisms of tumor necrosis factor-alpha （TNF-α）, gene promoter and hepatitis B （HB） viral genotypes were associated with outcomes of HBV infection. METHODS： A total of 244 HBV self-limited infected subjects, 208 asymptomatic carriers, and 443 chronic HB patients were recruited to conduct a case-control study. TNF-α -238G/A and -857C/T gene promoter polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）, and HBV genotypes were examined by nested PCR. RESULTS： The positive rate of HBV DNA in asymptomatic carder group and chronic HB group was 46.6% and 49.9%, respectively. HBV genotype proportion among the asymptomatic carriers was 2.1% for genotype A, 25.8% for genotype B, 68.0% for genotype C, and 4.1% for genotype B＋C mixed infection, and 0.9% for genotype A, 21.7% for genotype B, 71.5% for genotype C, 5.9% for genotype B＋C mixed infection in chronic HB group. There was no significant difference in genotype distribution between the asymptomatic carrier group and chronic HB group （X^2 = 1.66, P = 0.647）. The frequency of -238GG genotype in self-limited group was 95.1%, significantly higher than 90.7% in chronic HB group and 89.0% in asymptomatic carrier group （P = 0.041 and P = 0.016, respectively）.The frequency of TNF-α-857 CC in chronic HB group was 79.7%, significantly higher than 64.4% in asymptomatic carrier group and 70.9% in self-limited group （P〈0.001 and P = 0.023, respectively）. A multiple logistic regression analysis revealed that TNF-α-238GA and -857CC were independently associated with chronic HB after gender and age were adjusted.CONCLUSION： TNF-α promoter variants are likely to play a substantial role in the outcome of HBV infection.

Genetic polymorphisms predict response to anti-tumor necrosis factor treatment in Crohn's disease

To investigate genetic factors that might help define which Crohn’s disease (CD) patients are likely to benefit from anti-tumor necrosis factor (TNF) therapy. METHODSThis was a prospective cohort study. Patients were recruited from a university digestive disease practice database. We included CD patients who received anti-TNF therapy, had available medical records (with information on treatment duration and efficacy) and who consented to participation. Patients with allergic reactions were excluded. Patients were grouped as ever-responders or non-responders. Genomic DNA was extracted from peripheral blood, and 7 single nucleotide polymorphisms (SNPs) were assessed. The main outcome measure (following exposure to the drug) was response to therapy. The patient genotypes were assessed as the predictors of outcome. Possible confounders and effect modifiers included age, gender, race, and socioeconomic status disease, as well as disease characteristics (such as Montreal criteria). RESULTS121 patients were included. Twenty-one were non-responders, and 100 were ever-responders. Fas ligand SNP (rs763110) genotype frequencies, TNF gene -308 SNP (rs1800629) genotype frequencies, and their combination, were significantly different between groups on multivariable analysis controlling for Montreal disease behavior and perianal disease. The odds of a patient with a Fas ligand CC genotype being a non-responder were four-fold higher as compared to a TC or TT genotype (P = 0.009, OR = 4.30, 95%CI: 1.45-12.80). The presence of the A (minor) TNF gene -308 allele correlated with three-fold higher odds of being a non-responder (P = 0.049, OR = 2.88, 95%CI: 1.01-8.22). Patients with the combination of the Fas ligand CC genotype and the TNF -308 A allele had nearly five-fold higher odds of being a non-responder (P = 0.015, OR = 4.76, 95%CI: 1.35-16.77). No difference was seen for the remaining SNPs. CONCLUSIONThe Fas-ligand SNP and TNF gene -308 SNP are associated with anti-TNF treatment response in CD and may help select patients likely to benefit from therapy.

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.

PNPLA3 and TM6SF2 polymorphisms in Brazilian patients with nonalcoholic fatty liver disease

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is becoming the most common chronic liver disease worldwide,with significant morbidity associated with nonalcoholic steatohepatitis(NASH).Genome-wide association studies demonstrated that the variants rs738409 C/G in the PNPLA3 and rs58542926 C/T in the TM6SF2 genes are determinants of inter-individual and ethnicity-related differences in hepatic fat content and NAFLD progression.AIM To investigate PNPLA3 and TM6SF2 genotype frequency and their association with NAFLD development and progression in Brazilian patients.METHODS This cross-sectional case-control study enrolled 285 individuals from the Gastroenterology and Hepatology clinics at a university hospital in Brazil.The case patients(n=148)were confirmed to have NAFLD by the identification of hepatic steatosis on ultrasonography and exclusion of other causes of liver disease.According to the clinical protocol,patients underwent liver biopsy when at high risk for NASH and/or advanced fibrosis(n=65).Steatohepatitis was confirmed in 54 patients.Individuals who did not have biopsy indication or NASH on histology were considered to have simple steatosis(n=94).The control group(n=137)was selected among patients that attended the Intestinal Disease clinic and was composed of subjects without abnormalities on abdominal ultrasonography and normal liver biochemical tests.All individuals underwent PNPLA3 and TM6SF2 genotype analysis.RESULTS PNPLA3 CC,CG and GG genotype frequencies were 37%,44%and 19%,respectively,in NAFLD patients and were 58%,31%and 10%in controls(P<0.001).In a model adjusted for gender,age,body mass index and type 2 diabetes mellitus,the G allele increased the chance of NAFLD(OR=1.69,95%CI:1.21-2.36,P=0.002)and NASH(OR=3.50,95%CI:1.84-6.64,P<0.001).The chance of NASH was even higher with GG homozygosis(OR=5.53,95%CI:2.04-14.92,P=0.001).No association was found between G allele and the features of metabolic syndrome.In histological assessment,PNPLA3 genotype was not associated with steatosis grade,although GG homozygosis increased the chance of significant NASH activity(OR=17.11,95%CI:1.87-156.25,P=0.01)and fibrosis(OR=7.42,95%CI:1.55-34.47,P=0.01)in the same adjusted model.TM6SF2 CC,CT and TT genotype frequencies were 83%,15%and 0.7%,respectively,in NAFLD patients and were 84%,16%and 0.7%in controls(P=0.78).The T allele presence was not associated with NAFLD or NASH,and was not associated with histological features.CONCLUSION PNPLA3 may be involved in susceptibility and progression of NAFLD and NASH in the Brazilian population.More advanced histological liver disease was associated with the G allele.The TM6SF2 genetic variants were not associated with NAFLD susceptibility and progressive histological forms in the population studied,but further studies are required to confirm these findings.

基于GBS测序的湘东黑山羊的亲缘关系及近交系数

利用基因分型测序(GBS)对60只湘东黑山羊(9只公羊、51只母羊)进行基因组测序,获得湘东黑山羊染色体上的SNP数据和连续纯合子片段(ROH)数据。通过SNP数据进行基于G矩阵的基因组亲缘关系分析和NJ聚类分析,构建湘东黑山羊的群体家系结构,并通过ROH数据得到群体平均近交系数。结果表明,60只湘东黑山羊的平均测序深度为9.15X,与参考基因组比对率平均为99.59%;在SNP检测过程中,3只母羊不符合基因型数据质控标准,将其过滤后获得其他57只黑山羊29条染色体上153046个SNPs位点和1937个ROH片段;构建的湘东黑山羊8个家系,其中9只公羊和6只母羊被分为7个家系,另42只母羊被单独分类;基于ROH片段分析的湘东黑山羊群体中每个个体的近交系数均值为0.047,说明湘东黑山羊公羊在繁育过程中有较大的利用空间。

SNP分型检测技术及其在大鼠遗传检测中的应用

单核苷酸多态性(SNP)是第三代分子遗传标记,由于其广泛性、遗传稳定性、二态性及易于自动化分型的特点,成为当前实验动物遗传检测领域中重要研究的遗传标记。本文概述了SNP概念及特点,重点阐述不同种类SNP分型技术,并对该技术在大鼠遗传检测研究中的应用进行回顾和展望。

哺乳动物不育系20样激酶1基因多态性与结直肠癌的关联分析

目的通过病例-对照关联研究的方法,在包头地区汉族人群中探讨哺乳动物不育系20样激酶1(Mammalian sterile 20-like kinase 1,MST1)基因多态性及其单体型与结直肠癌、直肠癌和结肠癌发病风险的关联性。方法收集经病理学确诊的结直肠癌患者390例和正常体检人群413例,留取2 ml外周血用于后续基因分型;根据美国国家生物技术信息中心-人类单体型图数据库提供的中国汉族人群遗传多态性数据筛选MST1基因的单核苷酸多态性(SNP);采用Taqman探针法进行基因分型;Logistic回归计算各SNP在共显性、显性、超显性、隐性四种遗传模型下与结直肠癌、直肠癌和结肠癌发病风险之间的关联性。结果共筛选出4个MST1基因SNP,即rs8000、rs2234197、rs2267853、rs6073629,其中SNP rs2234197与直肠癌发病风险有关,相对于GG+AA基因型,AG基因型可降低直肠癌发病风险,OR[95%置信区间(CI)]=0.657(0.442~0.976);SNP rs8000与结肠癌发病风险有关,相对于TT+GT基因型,GG基因型可降低结肠癌发病风险[OR(95%CI)=0.425(0.182~0.992)]。结论MST1基因SNP rs2234197 AG基因型和SNP rs8000 GG基因型可能分别是直肠癌和结肠癌的保护性因素。

安顺地区受检妇女中高危型人乳头瘤状病毒的检出及单核苷酸多态性特征

目的 探讨安顺地区受检妇女中高危型人乳头瘤病毒(HR-HPV)的检出及单核苷酸基因多态性(SNP)特征。方法 采集10 774例行HPV分型检测妇女的宫颈脱落细胞为细胞标本来源,选取其中HR-HPV阳性且有组织病理学活检指征的298例受检者的宫颈组织为组织标本来源,采用聚合酶链式反应(PCR)体外扩增和反向点杂交相结合检测宫颈脱落细胞的HPV基因分型,进一步采用SnapGene、MEGA11分析HPV52、HPV58型的SNP,采用苏木精-伊红(HE)染色判定宫颈组织的宫颈病变级别。结果 受检妇女中HR-HPV以单一感染为主、阳性率为20.36%,HR-HPV感染亚型主要为HPV52、HPV16、HPV58、HPV53及HPV51;宫颈病变中HR-HPV优势型别为HPV16、HPV52、HPV58、HPV18及HPV33;SNP和进化树分析发现,HPV52型E6和E7区SNP点分别有7个(其中A125T、A294G是新的突变位点,G350T、A379G突变率最高)和3个(其中T666C是新的突变位点,C751T、A801G突变率最高)、且HPV 52型均分布于B谱系,HPV58型E6、E7区SNP点分别有3个和8个、突变位点最高的是T744G、且HPV58型均分布于A谱系。结论 安顺地区受检妇女主要HPV阳性型别为HPV52、HPV16及HPV58型,宫颈病变中主要优势型别为HPV16、HPV52及HPV58型,且HPV52、HPV58有其特定的SNP。

RNA SNP Detection Method With Improved Specificity Based on Dual-competitive-padlock-probe

Objective The detection of RNA single nucleotide polymorphism(SNP)is of great importance due to their association with protein expression related to various diseases and drug responses.At present,splintR ligase-assisted methods are important approaches for RNA direct detection,but its specificity will be limited when the fidelity of ligases is not ideal.The aim of this study was to create a method to improve the specificity of splintR ligase for RNA detection.Methods In this study,a dualcompetitive-padlock-probe(DCPLP)assay without the need for additional enzymes or reactions is proposed to improve specificity of splintR ligase ligation.To verify the method,we employed dual competitive padlock probe-mediated rolling circle amplification(DCPLP-RCA)to genotype the CYP2C9 gene.Results The specificity was well improved through the competition and strand displacement of dual padlock probe,with an 83.26%reduction in nonspecific signal.By detecting synthetic RNA samples,the method demonstrated a dynamic detection range of 10 pmol/L-1 nmol/L.Furthermore,clinical samples were applied to the method to evaluate its performance,and the genotyping results were consistent with those obtained using the qPCR method.Conclusion This study has successfully established a highly specific direct RNA SNP detection method,and provided a novel avenue for accurate identification of various types of RNAs.

基于PCR-SSP技术的RhCE血型基因型检测方法

目的 基于序列特异性引物PCR(PCR-SSP)技术建立一种用于检测临床标本红细胞RhCE血型基因型的快速定型方法。方法 将2023年9至12月宁波大学附属第一医院收检的152例乙二胺四乙酸抗凝血样分别采用试管法、间接抗人球法和微柱凝胶卡法检测RhD血型和RhCE血型。采用硅基质柱法提取样本DNA。采用Sanger测序法选择RhCE基因标准品序列。采用PCR-SSP法确定检测RhC和Rhc、RhE和Rhe两对等位基因的4对序列特异性引物。采用TA克隆技术得到重组质粒并评估序列特异性引物的灵敏度和抗干扰性能。采用PCR-SSP法检测样本,并与血清学结果进行一致性评价。结果 用表型分别为CCee、CcEe、ccEE的3个标本成功确定不同RhCE基因型的标准品序列。4对序列特异性引物能有效区分RhC和Rhc、RhE和Rhe两对等位基因。序列特异性引物在对应等位基因1:128干扰下仍能检测出且灵敏度为10~4~10~5拷贝数/μL。临床样本RhE、Rhe和Rhc基因型检测结果与表型一致性为100.00%,但RhC基因型与表型一致性只有92.76%,其中RhD阳性背景人群中的一致率为98.39%,RhD阴性背景人群中一致率为88.89%。结论 PCR-SSP技术在红细胞RhCE血型基因型快速鉴定方面具有可行性,检测RhE、Rhe和Rhc基因型与表型具有较高的一致性,对RhC基因型的检测,需区分不同RhD血型背景,建议使用两种及以上的方法进行综合判断。

DNATyper mtDNA-SNP60^(TM)试剂盒在案件中的应用研究

本文探讨DNATyper mtDNA-SNP60^(TM)试剂盒在案件中应用的可行性。应用DNATyper mtDNASNP60^(TM)试剂盒对100个汉族无关个体和20组全同胞进行mtDNA SNP检验;取25 pg/μL马、牛、羊、猪、鸡、鸭、猫、狗、兔、鼠和大肠杆菌的DNA样品进行种属特异性测试;取5、10、20、40μmol/L血红素进行抗抑制性测试;取两个批次的DNATyper mtDNA-SNP60^(TM)试剂盒经反复冻融10次后进行稳定性测试;分别应用VeriFiler^(TM)Plus PCR扩增试剂盒和DNATyper mtDNA-SNP60^(TM)试剂盒对100份陈旧、腐败、降解检材进行检验。结果表明,100个汉族无关个体均获得清晰的mtDNA SNP分型结果,其检验结果与通过mtDNA测序获得的结果完全一致;100个汉族无关个体含有100种不同的单倍型;20组全同胞中每组个体之间mtDNA SNP分型结果相同;DNATyper mtDNA-SNP60^(TM)试剂盒对马、牛、羊、猪、鸡、鸭、猫、狗、兔、鼠和大肠杆菌的DNA样品进行检测,均未出现特异性分型;当血红素浓度≤40μmol/L时,所有mtDNA SNP位点均获得正确分型;两个批次的DNATyper mtDNA-SNP60^(TM)试剂盒经反复冻融10次后,所有mtDNA SNP位点均可正确分型;对于100份陈旧、腐败、降解检材,STR检出率为55%,mtDNA SNP的检出率为86%,mtDNA SNP的检出率显著高于STR。当模板DNA浓度大于5 pg/μL时,DNATyper mtDNA-SNP60^(TM)试剂盒能得到完整的分型谱图。综上,DNATyper mtDNA-SNP60^(TM)试剂盒可应用于陈旧、腐败、降解检材的检验,具有很好的实战应用价值。

Acute hepatitis B of genotype H resulting in persistent infection

A 47-year-old man presented with general fatigue and dark urine.The laboratory data showed increased levels of hepatic transaminases.The patient was positive for hepatitis B virus(HBV)markers and negative for antihuman immunodeficiency virus.The HBV-DNA titer was set to 7.7 log copies/mL.The patient was diagnosed with acute hepatitis B.The HBV infection route was obscure.The serum levels of hepatic transaminases decreased to normal ranges without any treatment,but the HBVDNA status was maintained for at least 26 mo,indicating the presence of persistent infection.We isolated HBV from the acute-phase serum and determined the genome sequence.A phylogenetic analysis revealed that the isolated HBV was genotype H.In this patient,the elevated peak level of HBV-DNA and the risk alleles at human genome single nucleotide polymorphisms s3077and rs9277535 in the human leukocyte antigen-DP locus were considered to be risk factors for chronic infection.This case suggests that there is a risk of persistent infection by HBV genotype H following acute hepatitis;further cases of HBV genotype H infection must be identified and characterized.Thus,the complete determination of the HBV genotype may be essential during routine clinical care of acute hepatitis B outpatients.

NOS3单核苷酸多态性检测在妊娠高血压患者中的表达及临床指导价值研究

目的研究内皮型一氧化氮合酶(Nitric oxide synthase 3,NOS3)单核苷酸多态性检测在妊娠高血压患者中的表达及临床指导价值。方法选择2016年3月—2018年1月本院收治的妊娠高血压患者(妊娠高血压组,74例)和正常妊娠孕妇(正常妊娠组,80名)作为研究对象,采集孕妇外周血,提取DNA,PCR-RFLP技术分析NOS3基因Glu298Asp位点的基因型。分析妊娠高血压患者NOS3基因Glu298Asp位点基因型、等位基因与妊娠高血压严重程度关系。分析妊娠高血压患者并发症、妊娠不良结局患者与基因型频率关系。结果正常妊娠组和妊娠高血压组孕妇NOS3基因Glu298Asp位点TT、GT、GG基因型频率比较,差异存在统计学意义(P<0.05)。正常妊娠组和妊娠高血压组孕妇NOS3基因Glu298Asp位点等位基因G和T频率比较,差异存在统计学意义(P<0.05)。比较轻度、中度和重度妊娠高血压患者NOS3基因Glu298Asp位点基因型频率,差异无统计学意义(P>0.05)。轻度、中度、重度妊娠高血压患者NOS3基因Glu298Asp位点等位基因T频率逐渐升高。基因型为GT的妊娠高血压患者并发胎盘早剥、左心力衰竭、HELLP综合征、DIC、急性肾功能衰竭总发生率明显高于基因型TT和基因型GG患者(P<0.05)。基因型为GT的妊娠高血压患者新生儿窒息、剖宫产、胎儿宫内窘迫、围生儿死亡妊娠不良结局总发生率明显高于基因型TT和基因型GG患者(P<0.05)。结论NOS3基因Glu298Asp位点基因型、等位基因频率与妊娠高血压有关,等位基因T频率越高,妊娠高血压严重程度增加,基因型为GT的妊娠高血压患者并发症和妊娠不良结局的总发生率增加。

基于SNP标记的青海湖裸鲤遗传多样性及种群结构研究

为探究青海湖裸鲤(Gymnocypris przewalskii)的种质资源现状,为该物种保护措施的制定提供参考依据。首次利用基因分型技术(Genotyping-by-sequencing,GBS),对青海湖水域的6个地理群体共72尾青海湖裸鲤进行单核苷酸多态性(Single nucleotide polymorphism,SNP)标记开发和遗传特征分析。共检测出1600061个SNP位点,质控后筛选出45266个高质量的SNP位点用于遗传分析,发现核苷酸多样性(Pi)为0.3170~0.3274,观测杂合度(Ho)和期望杂合度(He)分别为0.4594~0.4823和0.3367~0.3444。6个地理群体的遗传距离(D)为0.0184~0.0233,两两群体的遗传分化系数(Fst)均不显著(P>0.05)。分子方差分析(Analysis of molecular variances,AMOVA)显示102.37%的遗传变异来自群体内;群体遗传结构和系统发育进化树分析均显示6个群体属于一个集群,具有遗传同质性;而主成分判别分析(Discriminant analysis of principal components,DAPC)表明哈尔盖河、黑马河和沙柳河群体相互交叉聚类,其余3个地理群体分别聚类。综上,6个青海湖裸鲤群体的Ho均大于He,种群结构单一。

基于基因分型测序(GBS)技术的堇叶紫金牛遗传结构分析

采用基因分型测序(GBS)技术对堇叶紫金牛[Ardisia violacea(T.Suzuki)W.Z.Fang et K.Yao]13个野生居群77份样本进行单核苷酸多态性(SNP)位点挖掘,在此基础上,对13个居群77份样本的遗传多样性、系统发育树、亲缘关系等进行分析。结果表明:共获得有效SNP位点246307个,每份样本检测到SNP位点1154~3789个。13个居群的观测杂合度为0.1569~0.4289,多态信息含量为0.0785~0.3244,核苷酸多样性指数为0.0002~0.0007,Tajima’s D值为0.2247~1.0936,Shannon’s多样性指数为0.2175~0.6649,表明堇叶紫金牛整体遗传多样性水平偏低。系统发育树、主成分分析和遗传结构分析结果显示77份样本可划分为6组。亲缘关系分析结果显示:居群内个体间的亲缘关系整体较近;居群间的亲缘关系与地理距离有一定的相关性。遗传分化和基因流分析结果显示:大部分居群间存在较高的遗传分化,各居群间存在一定程度的基因交流。综上所述,堇叶紫金牛13个居群的整体遗传多样性偏低,但居群间的遗传分化程度较高,这与居群间的地理距离较远、基因交流较少有关。建议优先保护安徽省黄山市祁门县牯牛降、浙江省舟山市定海区蔡家岙和浙江省宁波市象山县屠家园村3个遗传多样性较高的居群,并开展相关繁育工作以维持和扩大居群数量。