环介导等温扩增核酸技术及其应用

环介导等温扩增(loop-mediated isothermal amplification,简称LAMP)是利用4个特殊设计的引物和具有链置换活性的DNA聚合酶,在恒温条件下特异、高效、快速地扩增DNA的新技术。该技术在1h内能扩增出109靶序列拷贝,扩增产物是一系列反向重复的靶序列构成的茎环结构和多环花椰菜样结构的DNA片段的混合物,电泳后在凝胶上显现出由不同大小的区带组成的阶梯式图谱。LAMP技术以其特异性强、灵敏度高、快速、准确和操作简便等优点在核酸的科学研究、疾病的诊断和转基因食品检测等领域得到了日益广泛的应用。     

环介导等温扩增核酸技术及其在食品安全检测领域的应用

环介导等温扩增(Loop-mediated isothermal amplification,简称LAMP)是利用能识别靶序列上6个位点的4个特殊设计的引物和一种具有链置换活性的DNA聚合酶,在恒温条件下,特异、高效、快速地扩增核酸的新技术。该技术在1h内扩增效率可达到109-1010个数量级,扩增产物是一系列反向重复的靶序列构成的茎环结构和多环花椰菜样结构的DNA片段混合物,电泳后在凝胶上显现出由不同大小的区带组成的阶梯式图谱。近年来LAMP技术以其特异性强、等温灵敏、操作简单、产物易检测等优点已经应用于食品安全检测领域的多个方面。     

基于LAMP技术建立解脲支原体基因试纸条检测方法

目的建立一种灵敏度高、特异性强、检测速度快的方法检测解脲支原体。方法基于环介导恒温扩增技术（LAMP）,根据解脲支原体序列特征设计3对引物进行解脲支原体DNA切口酶核酸恒温扩增,扩增过程在一对引物中标记生物素,随着扩增的进行生物素直接引入扩增片段中,扩增结束后产物在密闭装置中进行免疫试纸条显色反应,根据显色卡的颜色判定结果的阴阳性。结果该技术检测解脲支原体较实时荧光PCR技术灵敏度要高10倍以上,其它病原体检测均阴性该方法特异性与实时荧光PCR技术相当。结论恒温扩增联合试纸条技术检测解脲支原体具有较高的敏感性和特异性,检测速度快,适合各医院开展。     

一种新的高效快速核酸恒温扩增方法--LAMP法

介绍一种新式恒温核酸扩增方法LAMP(Loop—Mediated Isothermal Amplification)法,其原理是采用四条特异引物及一种具有链置换活性的DNA聚合酶,在65℃左右对核酸进行扩增。短时间扩增效率可达到10^9-10^10个拷贝。LAMP法具有高特异性、高效性、快速、廉价、易检测等特点。预计在临床诊断、食品卫生检疫及微阵列基因芯片的开发上将有广阔的应用前景。     

环介导恒温扩增技术快速检测溶藻弧菌

溶藻弧菌是中国南部水产养殖业中弧菌病的最主要病原菌,其快速检测具有重要意义.根据溶藻弧菌外膜蛋白OmpK基因序列,设计一套引物,通过条件优化.成功建立了针对致病性溶藻弧菌的环介导恒温扩增检测技术(loop-mediated isothennal amplification.LAMP).应用LAMP技术,在65℃温育1 h的条件下扩增溶藻弧菌基因组DNA.琼脂糖凝胶电泳得到特异性梯度条带.该研究建立的LAMP法特异性检出致病性溶藻弧菌,其检测下限比PCR法低一个数量级,相当于n(cell)=38/mL的菌液浓度,灵敏度更高.综合分析表明,LAMP技术是快速、简易、实地诊断溶藻弧菌的理想工具.     

环介导等温扩增技术的应用进展

环介导等温扩增(loop-mediated isothermal amplification,LAMP)是一种新式核酸扩增技术,它依靠一种具有链置换活性的DNA聚合酶与2对特殊设计的引物,在等温条件下即可高效快速地完成扩增反应。相较于传统扩增检测方法,LAMP技术具有特异性强、灵敏度高、操作简单快速等优点,更能在现场快速检测和基层应用中广泛推广,目前LAMP技术已广泛应用于植物病害检测、动物病害检测、食品安全检测等领域。基于此,简要介绍了LAMP技术的基本原理、反应产物的检测方法,重点阐述了LAMP技术的改进与发展,综述了近年来其在科研生产中的应用进展,并对其发展前景进行了展望,以期为LAMP技术的进一步发展提供合理的研究方向。     

快速检测NDM-1基因的环介导恒温扩增技术的建立与评价

基于DNA环介导恒温扩增技术 (Loop-mediated isothermal amplification,LAMP),探索建立一种应用于NDM-1基因 (New Metallo-β-Lactamase-1 Gene,NDM-1) 的快速检测方法,以适应临床实验室等的检测需求。利用LAMP技术,以NDM-1基因为靶序列,设计4组LAMP引物,并筛选最优引物组,建立LAMP反应体系与条件,进行灵敏度和特异性实验。结果表明整个检测过程仅需1 h,即可通过肉眼直接目测实验结果。在灵敏度试验中,NDM-1基因的最低检测限为6 拷贝/反应。在特异性实验中,以4株病原菌 (肺炎克雷伯氏菌、大肠埃希氏菌、金黄色葡萄球菌、肺炎链球菌) 以及肠道菌群元基因组DNA、土壤菌群元基因组DNA为模板对NDM-1基因进行检测,结果显示均没有发生非特异性扩增反应。文中建立的LAMP检测方法能够快速检测NDM-1基因,且可直接观察到实验结果,实现了检测结果的可视化。具有操作简单安全、检测灵敏度高、特异性高的特点,能够满足基层实验室、应急检测或现场监测等方面的使用需求,具有良好的应用价值。     

LAMP技术快速诊断布鲁氏菌病的研究

旨在应用环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP)对布鲁氏菌进行研究。针对布鲁氏菌保守基因16S r DNA设计LAMP引物,通过浊度法对LAMP反应条件进行优化,应用建立好的LAMP反应条件进行特异性及灵敏性试验。结果显示:(1)优化后的反应条件是62℃恒温60 min,内引物1.50μmol/μL、外引物0.20μmol/μL、环引物1.0μmol/μL。(2)该LAMP方法与3株布鲁氏菌均发生了扩增反应,达到阳性浊度值,而与小肠耶尔森(ATCC9510)、大肠杆菌(ATCC25922)、沙门氏菌(ATCC10708)和金黄色葡萄球菌(ACTT33591)等标准菌株没有扩增反应。(3)浊度法和实时荧光法两种方法的检测最低限分别为4.36 fg/μL和436 fg/μL,其灵敏度均高于普通PCR的最低检出值4.36 pg/μL。LAMP检测技术用于布病临床诊断具有快速、高效、便捷等特点,对于基层布病的病原学诊断具有实用价值。     

多重环介导等温扩增技术研究进展

环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP)因其扩增速度快、灵敏度和特异性高、仪器要求低等优点而被广泛应用于核酸诊断领域。为充分利用LAMP技术优势、提高诊断检测的效率与可靠性、扩展其应用范围,同时节约试剂成本,近年来多重LAMP技术的研究成为一大热点。常规的LAMP扩增产物检测方法多数以聚合反应的双链DNA产物或其副产物为基础,只能判断有无扩增反应发生,而难以识别多重扩增产物的靶标来源及其特异性。为实现多重扩增产物的高特异检测,各国学者通过对该技术巧妙的改进或与其他技术相偶联,发展了一系列多重LAMP扩增检测技术。然而上述狭义的多重LAMP技术依然存在因引物间相互干扰、扩增效率存在差异而引发歧视性扩增的局限,限制了多重扩增的重数。近年研究活跃的微型扩增技术以其实现多个平行、互不干扰的小体积单重扩增的技术优势打破了这一局限,由此产生了新型的广义多重LAMP扩增技术。这些技术还具有试剂消耗少、自动化程度较高、交叉污染风险更小以及更适合对较多靶标进行现场快速检测等优势。本文分别从狭义多重LAMP的方法原理及其扩增反应体系优化、广义多重LAMP的方法原理以及多重LAMP技术在诊断检测中的应用等方面对近年来多重LAMP技术的研究进展进行了综述。     

基于环介导等温扩增技术的微流控芯片在病原菌检测方面的研究进展

环介导等温扩增(LAMP)技术是一种新兴的核酸恒温扩增技术,与微流控芯片技术相结合,可实现对病原菌的快速检测,具有特异性强、灵敏度高、操作简单等优点。本文根据不同终产物的检测方法对目前检测病原菌的相关微流控LAMP芯片进行了分类与介绍,并对技术的改进和存在的问题进行了分析,以期为后续的相关研究提供参考。     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.