DNA标记技术在冬虫夏草遗传多样性研究中的应用

随着实验方法和研究技术的发展,遗传多样性的研究从形态学水平,细胞学水平,生化水平发展到了DNA分子水平。利用这些分析方法,我们可以有效地研究物种的遗传多样性。通过冬虫夏草分子标记技术的遗传多样性研究,可获取冬虫夏草DNA的遗传标记及检测方法,有效的鉴别其品种和产地,以及在分子水平上研究冬虫夏草的遗传多样性。     

ApoE基因多态性与运动防治原发性骨质疏松效果的关系

目的：探讨不同ApoE基因型人群对适宜健骨运动处方防治原发性骨质疏松的敏感性，为制定基于基因多态性的个性化运动处方提供理论依据。方法：74名原发性骨质疏松患者按ApoE基因型随机分为ε2组、ε3组和ε4组，进行为期3个月的有氧及抗阻运动训练，双能x线骨密度吸收仪（DxA）测定运动前后骨矿含量、腰椎（L2-4及髋部骨密度（BMD）的变化。结果：ε4组BMC运动前后的变化率高于ε2组0P〈0．05）；L2-4BMD运动前后无显著变化；ε4组髋部BMD运动前后的变化率显著高于ε2组（P〈0．05）。结论：运动疗法防治原发性骨质疏松的效果受ApoE基因多态性的影响，其中ε4型人群通过运动疗法防治骨质疏松的效果较好。     

DNA分子标记技术及其原理

综述几种DNA分子标记技术：RFLP是用限制性内切酶切割不同个体基因组DNA后，含同源序列的醇切片段在长度上的差异，可靠性较高、但操作烦琐，信息含量低；染色体原位杂交是利用特异性核酸片段作探针，直接同染色体DNA片段杂交，在染色体上显示特异DNA，准确、直观，但技术非常复杂；PCR是模仿DNA在生物体内的自然复制过程来扩增DNA片段，安全性好，快速易行；RAPD是以人工合成的碱基顺序随机排列的寡核苷酸单链为引物，对所研究的基因组DNA进行PCR扩增，产生多态性的RAPD片段，可以检测多个基因位点，但不能识别杂合子位点；AFLP指纹技术是在RFLP与RAPD两种指纹技术基础上建立和发展起来的，有较高的稳定性，但对基因组纯度和反应条件要求较高；DNA芯片技术是一种以杂交测序基本理论为基础的新型生物技术，用于测序、基因表达、疾病诊断等，但造价、探针的密度与纯度还有待完善；小卫星DNA一般与RFLP技术结合以获得小卫星DNA指纹图谱，信息含量高，但它在染色体上分布不均匀；微卫星DNA既可用作探针获得指纹图谱，也可通过PCR方法进行微卫星位点多态性分析，但工作量大；ISSR即内部简单重复序列，也是一种新兴的分子标记技术，具有很好的稳定性和多态性。     

黑龙江汉族人群肌型肌酸激酶基因CKMM-NcoⅠ多态研究

目的:研究黑龙江汉族群体CKMM基因Nco Ⅰ位点的遗传多态性分布.方法:应用PCR-RFLP法测定120名黑龙江籍汉族健康大学生CKMM基因Nco Ⅰ位点的基因型和等位基因的频率分布.结果:等位基因频率是A=87%,G=13%,基因型频率为A/A=76%,A/G=22%,G/G=2%,经卡方检验符合Hardy-Weinberg遗传平衡定律,其基因型频率和等位基因频率在男女间无显著性差异,与欧美人群相比有非常显著性差异,而与我国北方汉族人及韩国人相比没有差异不显著性.     

CYP1A1多态性在上海人群中的分布

由于单核苷酸多态性(SNPs)在寻找致病基因，了解遗传多样性、环境与基因的相互作用方面有重大价值，SNPs研究已越来越多地引起了学术界和产业界的兴趣．CYP1A1编码的酶在烟草的主要几类前致癌物(如PAHs和芳香胺类物质)的代谢活化中有重要作用，其多态性与个体对环境相关的癌症的易感性密切相关．本研究采用PCR-RFLP技术在上海人群中，对CYP1Al的两个SNPs：CYP1A1 m1和m2进行了基因分型．结合其它已发表的数据，我们的研究表明，在中国人群的不同群体中，m1等位基因的频率分布比较一致，而m2等位基因的频率分布则存在着显著的不同．     

RFLP原理及在作物基因定位和育种中的应用

系统介绍了RFLP的概念、原理、特点及其在实验操作中应注意的事项,总结了RFLP技术用于玉米、水稻等作物的基因定位以及在育种上的研究成果,最后讨论了RFLP技术在实践应用中存在的问题.     

Association of Estrogen Receptor-α Gene &; Metallothionein-1 Gene Polymorphisms in Type 2 Diabetic Women of Andhra Pradesh

Type 2 diabetes mellitus (DM) is a multifactorial disease where both genetic and environmental factors contribute to its pathogenesis. Estrogen plays an important role in type 2 DM pathogenesis. A number of polymorphisms have been reported in the estrogen receptor (ESR1), including the XbaI and PvuII restriction enzyme polymorphisms of ESR1,which may be involved in disease pathogenesis. Metallothioneins (MT) act as potent antioxidants against various oxidative damages. Very few studies have indicated the association between Estrogen Receptor-α, MT1 gene polymorphisms with type2 DM. A total of 100 type 2 diabetic women and 100 age, sex matched controls were recruited. Using the PCR based RFLP method, the PvuII and XbaI polymorphisms of ESR1 and in MT1A (rs8052394 and rs11076161) gene polymorphisms were analysed. The genotype distribution and frequency of mutated allele showed no significant differences between diabetic and non-diabetic groups in PvuII (χ2 = 2.443; P = 0.1181) or XbaI (χ2 = 1.789; P = 0.1812) and rs8052394 (χ2 = 1.154; P = 0.2840) or rs11076161 (χ2 = 0.4141; P = 0.5199), polymorphisms. This is the first Indian study to conclude that ESR1 and MT1 gene polymorphisms are not associated with increased susceptibility to type 2 diabetes in Indian women.     

Analysis of bulked segregants to identify molecular markers linked with cocoon weight and cocoon shell weight in the silkworm Bombyx mori L

Two silkworm strains viz, B20 A (high cocoon shell ratio) and C.Nichi (low cocoon shell ratio) were sib mated for 10 generations to determine the homozygosis. Both bulked segregant analysis(BSA) and near isogenic lines (NIL) studies were done to identify the RFLP markers closely linked to cocoon shell parameters. Three hundred and fifty-two random clones were identified as the low copy number sequence and used for identification of Restriction Fragment Length Polymorphic (RFLP) marker linked to cocoon weight and cocoon shell character. In the bulk segregant analysis, DNA from the parents (B20 A, C.Nichi), F1 and F2 progeny of high shell ratio (HSR) and low shell ratio (LSR) were screened for hybridization with the random clones. Polymorphic banding pattern achieved through southern hybridization with different probes indicated the probable correlation of polymorphism with high and low cocoon shell character which are possible landmarks in identifying the putative marker(s) for the cocoon shell character. Out of the 100 probes tried with parents, F1, F2 and their bulks, 10 probes were found to be closely linked to cocoon shell characters.     

mtDNA D-loop 多态性与澳大利亚自行车运动员有氧运动能力关系初探

研究目的:探讨了mtDNA D-loop多态性与澳大利亚自行车运动员的VO2max及优异耐力成绩的关系.研究结果:前期研究发现虽然运动员组和对照组VO2max有显著性差异,但mtDNA D-loop的多态性在两组的分布频率没有显著性差异.     

Cytokine Gene Polymorphism in Idiopathic Nephrotic Syndrome Children

The pathogenesis of idiopathic nephrotic syndrome is not completely understood. We postulate that cytokine gene polymorphisms may influence susceptibility or clinical course in Idiopathic Nephrotic Syndrome. Polymorphisms of IL-4, IL-6, and TNF-α cytokines were investigated in 150 children with Idiopathic Nephrotic Syndrome and 569 healthy controls by using polymerase chain reaction and restriction fragment length polymorphism. On comparing patient with controls strong association were found for IL-6, TNF-α and IL-4 at allelic level (IL-6-G174C (G vs. C): P = <0.001; OR = 6.33, TNF-α-G308A (G vs. A): P = <0.001; OR = 1.99, IL-4-C590T (C vs. T): P = 0.048; OR = 1.38). Further when SR group was compared with SS group significant association was found at genotypic level in all the studied genetic polymorphisms. Studied cytokine gene polymorphisms may influence susceptibility to idiopathic nephrotic syndrome and might affect steroid response in INS patients.