小鼠DNA的限制性片段长度多态性分析

用人类肌红蛋白基因内含子中３３ｂｐ的小卫星ＤＮＡ重复序列为探针,经ｐＢＲ３２２的ＥｃｏＲ Ｉ正向测序引物和α－３２Ｐ－ｄＣＴＰ在Ｔａｑ ＤＮＡ聚合酶作用下做合成标记,与６种小鼠的ＤＮＡ限制性片段杂交。结果显示,每个品系平均出现可分辨带纹在１３条以上,不同品系小鼠间的杂交带纹表现出高度的多态性。多态性带纹主要分布在６￣２３ｋｂ区段;同一近交系的不同个体间的带纹特点及分布完全一致;ＣＳ７与ＡＫＲ及二者     

中国人St14/TaqⅠRFLPs及其在甲型血友病基因连锁分析与产前基因诊断中的应用

St 14(DXS 52)是人X染色体长臂远端的一段基因外DNA序列,与FVⅢ基因紧密连锁。我们分析了95个中国人的St 14/Taq I RFLPs,在44条无遗传关系的X染色体中,St14/Taq 13.6 kb片段出现的频率为31％而4.5kb、4.1kb片段出现的频率则相对较低,与国外报道明显不同。以此RFLPs作为FVⅢ基因的遗传标志,我们分析了8个甲型血友病家系。3个家系中有缺陷FVⅢ基因的可以用此RFLPs进行连锁分析,其中1例为首次应用这一RFLPs连锁分析完成的产前基因诊断。     

医学分子遗传学讲座 第五讲限制性片段长度多态性

每个个休在溃传上是不同的,而不同的本质不是 在基因产物＿匕而是在DNA水平上的差异。这些差异 大多数都是由于不编码蛋白质的区域和没有重要调节 功能的区域发生了中立突变,这些中立突变所构成的 DNA变异称为DNA多态性。DNA多态性本质是 由于进化过程中的各种原因引起染色体DNA中核营 酸排列顺序发生了改变,当这种改变涉及到限制性内 切酶识别位点时,利用限制性内切酶可将DNA切割 成不同长度的限制性片段。这类不同长度的限制性片 段类型在人群中所呈现的多态频率分布现象,就称为 限制制性片段长度多态性（RFLP)o RFLP具有广泛 的用途,它可以作为一种“遗传路标”,对人类基因组制 图提供必要的标记,当多态性顺序与人类遗传性疾病 位点连锁时,可作为遗传缺陷的产前诊断或是鉴别携 带者的标记,还可以应用于亲子鉴定和群体研究等方 面。     

中国人胃癌和正常组织基因组DNA中癌基因Ha-ras的限制性片段长度多态性研究

本文报道以PHS-49为探针,分析了中国人群中36例胃癌患者癌组织和25位正常人体组织基因组DNA中Ha-ras基因的BamHI限制性片段长度多态性(RFLPs)。发现了10种不同长度的片段和18种基因型。其中4种小于6kb的BamHI片段是迄今国外未见报道的,这可能是中国人群遗传多态性的一个特征。此外,在胃癌组织中发现Ha-ras的一些稀有等位基因和基因型的频率明显高于正常人群。对两名胃癌患者家系中的11名成员也作了RFLPs分析,发现有些成员出现3条和4条限制性片段的杂合个体,表明这些个体的染色体上含有的Ha-ras基因不只一份拷贝。对上述现象的可能原因作了分析和讨论。     

正常中国人和DMD患者X染色体Xp~(21)区的RFLP研究

本文应用从人类X柒色体Xp~(21)区不同部位分离得到的9种DNA探针,分析了100名正常中国人,38名DMD患者及其母亲X柒色体Xp~(21)区的14个限制性位点多态性(RSP;又称限制性片段长度多态性,RFLP)。发现正常的X染色体与携带DMD基因的X染色体Xp~(21)区的RFLP频率没有明显差别;在38例DMD患者中有7例的X染色体有DNA片段缺失;在本文分析的24例患者母杀中有17例是DMD基因携带者,她们在Xp~(21)区的RFLP均存在杂合的多态性,因此可以应用RFLP连锁分析对这些家系进行DMD的产前诊断。     

逆转录—聚合酶链反应结合限制性片段长度多态性分析对我国肾综合征出血热病毒分型的研究

建立准确、快速、灵敏的汉坦病毒基因分型方法,可弥补传统血清学方法的不足,对防治该病毒所致的肾综合征出血热（HFRS）具有重要意义。本试验采用逆转录－聚合酶反应（RT－PCR）和限制性片段长度多态性（RFLP）和限制性片段长度多态性（RFLP）方法,对流行于我国的两型汉坦病毒代表株－汉滩型（HTNV）76－118 和汉城型（SEOV）R22株进行基因分析。根据病毒DNA序列的电脑软件分析。不同HFRSV囊膜糖蛋白编码基因M节段1199－1497间核苷酸序列上RsaI,TaqI和HindⅢ的酶切位点存在差异（Fig.I),可用于进行限制性内切酶基因多态性分析,以确定HFRV的型别。首先,以一对引物扩增该片段（Fig.2)。然后,分析用这三种内切酶（Fig.3,4,5)进行酶切分型,共分析了从我国不同地区,不同宿主分离的毒株18株,及国际标准毒株2株,酶切图谱显示,这些毒株可以被分为三组（Table.a)：9株可定为HTNV型,8株可定为SEOV型,3株无法确定其型别（X型）,该法分型结构与血清学经典的空斑减数中和试验分型结构基本一致,说明该酶切分型方法具有一定的可行性。     

现代生物技术在环境微生物学中的应用:Ⅲ.限制性片段长度多态性分析、变性/温度梯度凝胶电泳和报道基因

这是现代生物技术在环境微生物学中的应用系列综述文章的第三篇 ,讨论限制性片段长度多态性 (RFLP)分析、变性梯度凝胶电泳 (DGGE)和温度梯度凝胶电泳 (TGGE)以及报道基因。     

裂解酶片段长度多态性分析的应用现状及发展

裂解酶片段长度多态性分析是近年来出现的一种新型分子生物学技术。它能裂解毒I对事先标记的待测DNA作特异性酶切,产生一组特异性DNA片段,经显影后形成一级结构依赖性的结构指纹图谱而检测DNA序列变化,其灵敏度,特异性和社会经济效益均等同于或优于SSCP、RFLP和DNA直接测序等方法,具有广阔的发展应用前景。本文介绍了该方法的技术原理,在遗传学基因突变筛查和基因分型等领域的应用现状以及近期取得的技术改进。     

自发性高血压大鼠原癌基因表达和限制性内切酶片段长度多态性分析

观察自发性高血压大鼠（ＳＨＲ）血管平滑肌细胞（ＶＳＭＣｓ）的生长曲线、ｃ－ｆｏｓ原癌基因表达和ｃ－ｆｏｓ基因酶切图谱的情况,与对照组京都维斯特大鼠（ＷＫＹ）进行对比．结果显示,在小牛血清作用下ＳＨＲ的ＶＳＭＣｓ生长速率和ｃ－ｆｏｓ原癌基因表达明显大于ＷＫＹ;ｃ－ｆｏｓ原癌基因限制性内切酶片段长度多态性（ＲＦＬＰ）分析表明,经ＢａｍＨⅠ或ＥｃｏＲⅠ酶切后的ＳＨＲ和ＷＫＹ的酶切图谱一致,同时也未发现ＳＨＲ的ｆｏｓ基因扩增现象．提示,ＶＳＭＣｓ的异常增殖和ｃ－ｆｏｓ原癌基因的表达异常与高血压的形成有关,而ｃ－ｆｏｓ原癌基因的过度表达可能是由于某些与基因转录调控有关的因素异常所致．     

Restriction Fragment Length Polymorphism Analysis of Epidemiologically Related Mycobacterium tuberculosis Isolates

Restriction fragment length polymorphism (RFLP) analysis of a large number of Japanese isolates of Mycobacterium tuberculosis, containing isolates from small outbreaks of M. tuberculosis infection, and clinical isolates of M. bovis BCG, was carried out using a DNA probe derived from the insertion sequence IS986. Clinical isolates of M. tuberculosis had a high degree of RFLP. The occurrences of the IS element varied from 1 to 19, the majority of isolates having 8 to 15 copies. Very similar fingerprints, however, were seen among strains isolated in the Kanto district. In particular, 3 strains were of the same pattern with or without an additional band. Similarity of the banding patterns of strains islated in the same district was observed in other areas. Six groups of strains, each group arising from a suspected common source of infection, were analyzed. Of these, 5 showed identical fingerprints within each group, but one showed different fingerprints. RFLP patterns of three strains isolated from individuals with lymphadenitis developed about two months after BCG vaccination, and one strain isolated from a bladder cancer patient with BCG instillation therapy were identical to those of BCG-Tokyo which had been used for the vaccination and therapy. These results confirm that RFLP analysis using IS986 is a suitable tool for epidemiology of tuberculosis.     

Genetic Diversity in Ralstonia solanacearum Strains from Mauritius using Restriction Fragment Length Polymorphisms

Race 1, biovar III of Ralstonia (synonym Pseudomonas ) solanacearum , causal organism of bacterial wilt, has been reported in Mauritius on several crops and plant species. The genetic relationship among 38 strains isolated from potato, tomato, bean and anthurium was determined by restriction fragment length polymorphisms (RFLPs). After hybridization with probe 5a67, five RFLP patterns could be distinguished. Types V and I were most commonly encountered. A common band of approximately 6.5 kb was found in 35 strains. Type I pattern consisted of only this band and was observed in 12 out of 16 anthurium strains tested. Type V was associated with 12 out of 16 potato strains and consisted of a band of approximately 3.3 kb in addition to the one observed in type I. RFLP patterns II, III and IV were less frequently encountered. The RFLP analysis showed that genetic diversity was present in race 1, biovar III strains. The relationship between the host and RFLP pattern is discussed.     

Restriction fragment length polymorphism analysis of somatic hybrids between Lycopersicon esculentum and irradiated L. peruvianum: evidence for limited donor genome elimination and extensive chromosome rearrangements

Summary The genome composition of asymmetric somatic hybrids, obtained by fusion of leaf protoplasts fromLycopersicon esculentum and gamma-irradiated leaf protoplasts fromL. peruvianum, was characterised by Southern blot analysis using 29 restriction fragment length polymorphism markers. Eight low dose hybrids and seven high dose hybrids (irradiation dose 50 Gray and 300 Gray, respectively) were analysed. By densitometric scanning of the autoradiographs, the number of alleles for each locus of the component species was established. In general, elimination of alleles from the irradiatedL. peruvianum donor genome was limited and ranged from 17%–69%. ThreeL. peruvianum loci, located on chromosomes 2, 4 and 7, were present in all asymmetric hybrids, suggesting linkage to the regeneration capacity trait which was used in selecting them. The loss of donor genome was dose-dependent. Low dose hybrids contained more alleles, loci and complete chromosomes fromL. peruvianum than high dose hybrids, whereas the high dose hybrids contained more incomplete chromosomes. In most hybrids someL. esculentum alleles were lost. The possible implications of these results for the use of asymmetric hybrids in plant breeding are discussed.     

人同源异型盒基因Hu-1位点的RFLPs研究

用12种限制性核酸内切酶分别对4至104条人类染色体进行酶谱分析,以寻找Hu-1基因附近的限制性酶切多态位点,仅发现了Bg 1Ⅱ酶的一个多态性位点。表现为Bg 1Ⅱ酶谱中除3.6kb片段外,杂合子型尚具6.3及6.6kb两种片段,而纯合子型则只有6.3或6.6kb一种片段。在所检查的104条染色体中6.6kb片段出现的频率为3.88％,而6.3kb片段出现的频率为96.12％。经统计分析,计算出Hu-1基因及其附近的核苷酸变异率为0.0017,大体上与人β珠蛋白基因簇及人α-1-抗胰蛋白酶基因的核苷酸变异率相似。文中对本工作的意义进行了初步讨论。     

FMMU白化豚鼠线粒体DNA RFLP分析研究

目的研究FMMU白化豚鼠的mtDNA,并与花色豚鼠mtDNA进行多态性分析比较,以确定其独特的生物学特性是否与mtDNA相关。方法用碱变性法提取FMMU白化豚鼠以及花色豚鼠的mtDNA,并用AvaⅠ、BalⅠ等12种限制性内切酶进行酶切和限制性片段长度多态性分析。结果与结论FMMU白化豚鼠mtDNA和花色豚鼠mtDNA的相对分子质量相同,约为16.7×103;FMMU白化豚鼠与花色豚鼠两品系的mtDNA经AvaⅠ、BalⅠ等内切酶酶切后有3-8个酶切位点,酶切图谱完全相同,经RFLP分析FMMU白化豚鼠与花色豚鼠的mtDNA之间缺乏多态性。本实验没有发现FMMU白化豚鼠的独特的生物学特性与mtDNA相关。     

Abdominal Visceral Fat is Associated with a BclI Restriction Fragment Length Polymorphism at the Glucocorticoid Receptor Gene Locus

Several investigations have suggested that body fat distribution is influenced by nonpathologic variations in the responsiveness to Cortisol. Genetic variations in the glucocorticoid receptor (GRL) could therefore potentially have an impact on the level of abdominal fat. A restriction fragment length polymorphism (RFLP) has previously been detected with the BelI restriction enzyme in the GRL gene identifying two alleles with fragment lengths of 4.5 and 2.3 kb. This study investigates whether abdominal fat areas measured by computerized tomography (CT) are associated with this polymorphism in 152 middle-aged men and women. The less frequent 4.5-kb allele was found to be associated with a higher abdominal visceral fat (A VF) area independently of total body fat mass (4.5/4.5 vs. 2.3/2.3 kb genotype; men: 190.7 ± 30.1 vs. 150.7 ± 33.3 cm², p=0.04; women: 132.7 ± 37.3 vs. 101.3 ± 34.5 cm², p=0.06). However, the association with AVF was seen only in subjects of the lower tertile of the percent body fat level. In these subjects, the polymorphism was found to account for 41% (p=0.003) and 35% (p=0.007), in men and women, respectively, of the total variance in AVF area. The consistent association between the GRL polymorphism detected with BelI and AVF area suggests that this gene or a locus in linkage disequilibrium with the BelI restriction site may contribute to the accumulation of AVF.     

Restriction fragment length polymorphism and allozyme linkage map of Cuphea lanceolata

Summary Cuphea lanceolata Ait. has had a significant role in the domestication of Cuphea and is a useful experimental organism for investigating how medium-chain lipids are synthesized in developing seeds. To expand the genetics of this species, a linkage map of the C. lanceolata genome was constructed using five allozyme and 32 restriction-fragment-length-polymorphism (RFLP) marker loci. These loci were assigned to six linkage groups that correspond to the six chromosomes of this species. Map length is 288 cM. Levels of polymorphism were estimated for three inbred lines of C. lanceolata and an inbred line of C. viscosissima using 84 random genomic clones and two restriction enzymes, EcoRI and HindIII. Of the probes 29% detected RFLPs between C. lanceolata and C. viscosissima lines. Crosses between these species can be exploited to expand the map.     

Molecular marker-facilitated studies in an elite maize population: I. Linkage analysis and determination of QTL for morphological traits

Restriction fragment length polymorphisms (RFLPs) and one morphological marker were used to investigate quantitative trait loci (QTL) for morphological and physiological traits evaluated on 150 F₂₃ maize (Zea mays L.) lines derived from the cross of elite U.S. Corn Belt inbreds Mo17 and H99. F₂₃ lines were grown in a replicated experiment and evaluated for plant and ear heights and flowering traits. QTL were identified for each trait, and genetic effects were determined. Estimated gene action for the flowering traits was predominantly overdominance. Both parents contributed toward increased values for anthesis and silk emergence. QTL for increased plant and ear heights were usually contributed by the taller parent, Mo17. Estimated gene action for these traits was mainly partial to overdominance. QTL for plant height were located in the vicinity of loci defined by alleles with qualitative effects on plant height.