AFLP─一种DNA分子标记新技术

AFLP──ANovelTechniqueforDNAMolecularMarkerWengYuejin(InstituteofCropGermplasmResourees,ChineseAcademyofAgriculturalSciences,Beijing100081)公司科学家ZabeauMarc和VosPieter发明创建的一种DNA分子标记新技术,它不仅具备了其它DNA分子标记技术所具有的特点,多态性丰富,共显性表达,不受环境影响,无复等位效应,而且还具有带组丰富,用样量少,灵敏度高,快速高效等特殊优点．一个0．5mgDNA样品,可做4000个反应,获得8万个标记,650万条带纹。美国加利福尼亚大学MackillDavid[7]利用14份水稻为材料,比较AF…     

正常人各年龄组染色体着丝粒点(Cd)研究

本文运用本室改良的Cd-NOR银染技术对80例4个年龄组的正常中国人的Cd变化进行了较系统的研究, 结果表明:(1)正常人随年龄增加,Cd消失的频率、Cd变异及Cd-NOR融合频率也相应增加,特别是Ⅲ、Ⅳ组(中、老年组)增加的频率尤为显著;(2)首次对Cd消失的过程提出了独特的观点,即Cd消失首先表现为Cd变小, 随着变小程度的加大,最终导致Cd消失;(3)在本研究中首次观察到单个Cd的现象,作者认为是细胞分裂中期染色体着丝一分为二的延迟现象。各年龄组间单Cd出现频率无统计学差异,同一年龄组中,2号染色体和1号染色体上单Cd出现频率显著高于理论值;(4)随年龄增高,Cd各项观察值的增高在男性与女性间未见明显的差异。 Abstract:The Cd variation of human chromosome in four groups of different age has been investigated.The result shows that the frequencies of Cd disappearing,size variation and Cd-NOR fusion increased with the age rising,especially in the group of aged people.We suggest that the variation of Cd shows the size changes first,and then disappears completely.We also observed some cells in which a few chromosomes shows only a single Cd in centromeric region.Cd variation in different age groups has no significant difference between the male and the female.     

Differences in Variation of Human Immunodeficiency Virus Type 1 Sequences from Henan and Shanghai Regions of China

Illegally paid blood donation was a risk factor for HIV acquisition exclusively in Henan and Hubei Provinces of China,and not in Shanghai.Nucleotide sequences in the gag and env genes of HIV-1 were compared between isolates from Henan and Shanghai regions of China to test whether an expected higher degree of a common source of infections from this unique blood donation transmission risk would be evident as decreased variation among Henan isolates in an exploratory cross-sectional analysis.Among 38 isolates studied,23 of 23(100%)from Henan and 8 of 15(54%)from Shanghai were subtype B.In addition,fewer sequence differences were found in gp41 of subtype B isolates from Henan than from Shanghai isolates.Further studies with additional controls are therefore warranted to confirm the role of the degree of a common source of infections in differences in HIV variation across populations.     

盐胁迫下小麦甜菜碱和脯氨酸含量变化

运用高效液相色谱-质谱(HPLC-MS)联用技术分析了耐盐性强、中、弱3个小麦品种SW12、宁春4号和中国春苗期5个NaCl浓度胁迫下甜菜碱和脯氨酸含量的变化.方差分析表明盐胁迫下3个小麦品种之间甜菜碱的含量差异达到极显著水平(P＜0.01),SW12的含量最高,宁春4号次之,中国春最低,与小麦耐盐性表现相一致;脯氨酸在叶片中的含量差异不显著,在根中宁春4号和中国春的含量有显著差异(P＜0.05).结果表明:小麦叶和根中甘氨酸甜菜碱含量与小麦盐胁迫呈正相关,是小麦体内抵御盐胁迫的渗透调节物质之一,可作为小麦耐盐性鉴定指标.     

小麦耐盐种质遗传多样性的RAPD分析

选用２２个引物对２４份小麦耐盐种质进行ＲＡＰＤ分析,共产生２００条扩增片段,多态性片段数为１７２条,扩增片段的多态性百分率为８６％,利用ＮＹＳＴＳ软件根据Ｊａｃｃａｒｄ系统分析ＲＡＰＤ结果,并按ＵＰＧＭＡ类平均法进行聚类。２４份材料相似系数在０．２１￣０．９７之间,其中含有多枝赖草、黑麦和偃麦草等外源染色体的多１７４、ＷＲ８３０和南前１２７被分别在３个独立的组,多１７４和南前１２７的亲关系最远,相     

AFLP分析中多态性扩增产物的回收、克隆及鉴定

本研究在摸索和优化了水稻AFLP分析体系的基础上,发展了多态性AFLP产物的高效克隆方法。特异AFLP扩增产物直接从变性聚丙烯酰胺凝胶上分离纯化,再经过一至二轮PCR扩增,即可高效地克隆于pGEM-Teasy vector系统中。本实验利用该方法成功地克隆了水稻温敏核不育等位突变系546 0S和5460F间的4个多态性AFLP产物,Southern bloting分析证明其中3个产物在水稻基因组中为单拷贝序列,另一个为低拷贝序列。AFLP技术强有力的多态性检出能力再结合多态性扩增产物的高效克隆方法,为寻找与目标基因紧密连锁的分子标记提供了有力工具。 Abstracts:An efficient method for cloning DNA fragment from denaturing polyacrylamide gels was developed to allow the isolation of specific bands obtained from amplified fragment length polymorphism(AFLP)products.After isolation and purification from the thin denaturing polyacrylamide gels,specific AFLP products were successfully cloned after one or two rounds of PCR reamplification.Using this method 4 polymorphic AFLP products between a pair of rice allelic lines differing for thermo-sensitive genic male sterile(TGMS)ene were cloned and it was confirmed that 3 of the AFLP products represented single copy sequences and the other 1 represented low copy sequence in rice genome.     

Effects of ELF magnetic fields on protein expression profile of human breast cancer cell MCF7

A case-control study in 1979 on electrical wiring configurations and childhood leukemia had stimulated interest in the issue that extremely low frequency magnetic fields (ELF MF) may have harmful biologi-cal effects especially on the incidence of human can-cer[1]. Since then, a large number of studies have been conducted to follow up this important result[2]. The majority of these studies indicate a weak association between exposure to 50―60 Hz ELF MF and the in-cidence of cancer; however…     

小麦耐盐基因的标记和标记的克隆

普通小麦（Triticum aesticum L）耐盐农家品种茶淀红与盐敏感品种农大85021杂交,对杂交后代141株F2分离个体进行耐盐性鉴定。通过遗传分析和卡方检验证实小麦耐盐农家品种茶淀红含有一个主效耐盐基因,杂交后代符合1:2:1的分离规律。依据混合群体分组分析法（Bulked Segregate Analysis,BSA）建立耐盐基因池和盐敏感基因池,通过RAPD实验,从520个引物中筛选出了一个在两池间具有多态性的引物OPZ09,用双亲、F1、F2单株DNA进行RAPD实验证明了该引物扩增出的特异性片段OPZ09-590是一个与茶淀红耐盐基因连锁的RAPD标记,用JOINMAP Version1.4计算基因与标记间的重组值为5.674%,连锁距离为6.557cM。从琼脂糖凝胶回收OPZ09-590与载体pUCm-T连接,并转入受体菌JM109,对克隆片段测序表明其实际大小为591bp,故此小麦茶淀红耐盐基因的RAPD标记为OPZ09-591。     

西藏半野生小麦遗传多样性研究进展以及原位保存的建议

1995——1998年对277份西藏半野生小麦的研究表明：西藏半野生小麦形态类型多样、断穗特征稳定,是六倍体小麦中独特的小穗下节位断裂的裸粒型断穗小麦。在性状聚类中,它与栽培小麦各居一群,泾渭分明,明显特点是断穗性强、成熟早、穗密度偏稀,植株较高,千粒重偏低。通过等电聚焦同功酶分析显示,14个生化位点中有lO个位点存在遗传多样性;在RFLP分子标记中,第3、4、5、6、7同源群表现多态性,但只有在第5、6、7同源群染色体长臂或短臂上与栽培品种存在不同,因而断穗基因可能存在于5S、5L、6L或7S染色体之一上。西藏半野生小麦中有4．5％的材料具有中抗和高抗白粉病能力;蛋白质、赖氨酸含量均超过对照2～5个百分点。建议在不同海拔的加查县和察隅县建立西藏半野生小麦的原位保存点。     

普通小麦与野生二粒小麦A、B基因组的遗传进化关系的SSR分析

以29份普通小麦、野生二粒小麦及野生二粒小麦与节节麦杂交的双二倍体为材料,选取A、B染色体组特异的SSR引物,通过微卫星多态性检测方法探讨上述两物种之间A、B染色体组的遗传进化关系。经NTSYS系统软件UPGMA聚类分析表明,在遗传相似系数为0．18时可以将普通小麦与野生二粒小麦大致分为两大类群,说明野生二粒小麦的A、B染色体组在进化过程中其遗传物质发生了较大变化,但同时野生二粒小麦的D25与D13与普通小麦分为一组,尤其是D13与新疆的红冬麦遗传距离较近,也证明了其两物种间有一定的同源性,并对这些遗传物质分化发生的机制及SSR引物的保守性进行了讨论。