中国西藏近缘野生大麦5S rDNA NTS序列分析

选取来自西藏不同地理区域的17份近缘野生大麦材料和1份国外的近缘野生大麦材料,利用直接PCR、T-载体转化克隆、克隆产物测序的方法获得了它们的5S核糖体DNA NTS(Nontranscribed intergenic spacer)序列.对这些序列进行测定、分析和比较,构建了分子系统树.结果表明,西藏近缘野生大麦NTS序列包括两段相对保守的保守区A和保守区B以及一段变异较大的变异区V,变异区由若干个TAG碱基的重复序列构成.两段保守区总长度为168～169 bp,长度变异较小,仅相差1 bp.保守区的GC%含量为43.8%,其中有12个核甘酸位点发生变异(占总核甘酸数目的7.1%),变异位点基本上是颠换多于转换,颠换/转换率为1.0～2.0.变异区中TAG重复序列的重复次数从4到17次,而且有部分TAG重复发生了颠换和转换(TAG→TCG,TAG*→TAC).TAG重复序列的多态性是决定NTS序列多态性的主要因素.对西藏近缘野生大麦和麦属其他作物的比较,认为rDNA NTS适合作为属内分类的分子标记.

杉虎杂交斑5S rRNA基因甲基化分析

核糖体RNA是构成核糖体的重要组成部分,在蛋白质合成过程中起着重要作用。利用雌性棕点石斑鱼(Epinephelus fuscoguttatus)与雄性清水石斑鱼(Epinephelus polyphekadion)杂交,获得在生长、肉质等方面具有一定优势的子代——杉虎杂交斑。对杉虎杂交斑及其亲本5S rRNA基因编码区前1 000 bp、编码区以及非转录区的DNA甲基化水平进行测定和比较分析。结果表明,杉虎杂交斑5S rRNA基因整体甲基化水平(0.418)高于棕点石斑鱼(0.379)和清水石斑鱼(0.037),但与母本棕点石斑鱼不具有显著性差异,与父本清水石斑鱼存在显著性差异。对5S rRNA基因编码区和非转录区的甲基化位点进行分析发现,在棕点石斑鱼与杉虎杂交斑中所有甲基化位点是一致的,但在清水石斑鱼中均未发现这些位点,表明杉虎杂交斑的5S rRNA基因甲基化模式与母本棕点石斑鱼一致。结果阐明了杉虎杂交斑5S rRNA基因的DNA甲基化水平和模式,为石斑鱼杂交育种提供理论基础。

Molecular Diversity of the 5S rRNA Gene in Cultivated and Wild Rice Species

We have used the polymerase chain reaction to analyze variation in the size of 5S ribosomal gene spacer sequence. Eighty accessions, including 65 cultivated rice and 15 wild rice, were analyzed. Among them seven size classes of 5S DNA spacer were observed. Classification asindica orjaponica on the basis of 5S DNA spacer patterns generally agrees with classification based on morphological studies, indicating that the length polymorphism of 5S DNA spacer could be used as a molecular marker for taxonomic and phylogenetic analysis.

植物核基因组核糖体基因间隔区序列的结构特点及其在系统发育研究中的应用

目前,在植物系统发育研究中应用较多的核基因组的核糖体DNA基因间隔区序列主要有5S rDNA基因间隔区、内转录间隔区ITS和基因间间隔区IGS。虽然这些间隔区序列在长度、结构等方面各不相同,但都具有进化速率较快的特点,在植物属及属下分类水平的系统发育关系研究中非常有用。本文重点就核基因组的5S rDNA基因间隔区以及IGS在植物中的特点以及各自在植物系统发育研究中的应用进行了综述。

普通小麦与簇毛麦原生质体的紫外线融合(英文)

从来源于普通小麦品种济南 1 77(Triticumaestivumcv .Jinan 1 77)悬浮细胞系的原生质体与来源于簇毛麦 (Haynaldiavillosa)胚性愈伤组织的原生质体融合获得体细胞杂种。供体簇毛麦原生质体在融合之前用紫外线照射 3 0s或 1min ,紫外线剂量为 3 6 0 μW /cm2 。仅由紫外线照射 3 0s的组合获得再生愈伤组织克隆。细胞学、生物化学及PCR分析结果证实了再生克隆的杂种性质。用线粒体基因特异的探针进行的RFLP分析的结果表明 ,杂种中含有融合双亲的线粒体并且发生了重组。由杂种愈伤组织再生得到白化苗。讨论了紫外线对融合产物的影响。

Identification of Stellaria media by PCR

Aim To provide a rapid and reliable method for identifying the fork medicine Stellaria media （Linn. ） Cyr. （Herba Stellariae mediae） （Caryophyllaceae） from its adulterant Myosoton aquaticure （L.） Fries （Herba Myosoti aquatici） （Caryophyllaceae） by polymerase chain reaction （PCR） technology. Methods A molecular genetic approach has been developed to identify S. media for the first time. 5S-rRNA spacer domain was amplified by PCR from the isolated genomic DNA, and the PCR products were then sequenced. Results The nucleotide sequences of S. media and M. aquaticum were measured to determine their identity. Furthermore, the nucleotide sequences of three Stellaria species, S. vestita, S. longifolia and S. radians, were also measured for the sake of providing the evidence of the biological phylogeny of SteUaria. Diversity between DNA sequence and restriction enzyme mapping among a variety of the species was found in their 5S-rRNA spacer domains. Conclusion The 5S-rRNA spacer domains can be used as a molecular marker for differentiating S. media from M. aquaticum and in phylogenetie studies of Stellaria.

胡萝卜与狭叶柴胡不对称体细胞杂种的分子鉴定

目的 对经同工酶初步确认的 4个胡萝卜与狭叶柴胡体细胞杂种进一步从分子水平上证实他们的杂种性质。方法 随机扩增多态性DNA(RAPD)分析和 5SrDNA间隔序列差异。结果 4个克隆均含有双亲特征谱带及新带。结论 从分子水平上证实了他们的杂种性质。为进一步分析杂种中柴胡药效成分的含量及筛选出高药效成分含量的细胞系奠定基础。

Determination of copy number for 5S rDNA and centromeric sequence RCS2 in rice by Fiber-FISH

The copy number of 5S rDNA and centromerie sequence RCS2 was determined by extended DNA fiber based fluorescence in situ hybridization (Fiber-FISH) in rice (Oryza sativa ssp. indica cv. Guangluai No. 4) genome. In order to determine the copy number, it is necessary to know the basepair number that a given length DNA fiber contains under a microscope. Therefore, the length of two DNA frag-ments, in which the basepair number had been already known, was measured. The insert sequence of the tested BAC 38D17 was 136 kb and its extended DNA was 56.4 μm long, 2.41 kb/μm on average, while that of the tested BAC 44B4 was 144.5 kb in total and 55.7 μm long, 2.60 kb/μm on average under the microscope. They were very close to the theoretical value of B-DNA in the Watson-Crick DNA model, which is 2.97 kb/μm. According to the average value of basepair number per μm of the two samples mentioned above, that is, 2.51 kb/μm, it could be estimated that the copy number was about 686 for 5S rDNA and 286-1121 for the

Genetic Characterization of Four Strains Borrelia Burgdorferi Isolated in China

To study the genetic characterization of four strains of Borrelia burgdorferi isolated in China. PCR technique was used to amplify the 5S-23S rRNA intergenic spacer DNA from the whole cellular DNA of isolated GXLD-4, 9, 18 and Chang 14, and then the amplified products were cloned into plasmid pGEM-T Easy and sequenced. It was found that the 5S-23S rRNA intergenic spacer DNA of the four isolates was 242?bp, revealing the nucleotide sequence identity of more than 99%. The four isolates had higher sequence identify with Borrelia valaisiana than with other genetic groups. These four isolates most likely belong to Borrelia valaisiana genomic group.

新疆硬粒小麦5个品种5S rRNA基因重复单元间序列分析

本研究参照Gen Bank禾本科以及前期新疆7个小麦种5S r DNA NTS序列,通过PCR技术扩增获得新疆5个硬粒小麦品种5S r DNA NTS序列,并通过与5S r RNA序列比对,得到5S r DNA NTS序列结构和边界范围。结果显示:5个硬粒小麦品种均存在两种类型5S r DNA NTS序列且相似程度不同,长NTS序列保守性较高,短NTS片段相对较低;短NTS序列存在两处序列缺失现象,两种类型NTS序列存在不同位置和程度的变异位点和变异频率。利用MEG4.0软件,采用邻接法构建了分子进化树并计算获得了品种间遗传距离。对来自不同品种克隆单元基的序列进行比对,得知对于几个组直向是存在的。直系群体的5S r DNA序列有益于硬粒小麦进一步的系统发育分析。

中国4株伯氏疏螺旋体基因型鉴定

目的 对广西和贵州 4株伯氏疏螺旋体分离株基因型进行鉴定。方法 应用聚合酶链反应从 3株广西及 1株贵州伯氏疏螺旋体分离株的全基因组DNA中将 5s 2 3srRNA间隔区基因调出 ,并克隆至质粒pGEM TEasy中 ,构建重组质粒 ,测序后与国外其它分离株进行同源性比较。结果 4株伯氏疏螺旋体均扩增出约 2 4 2bp的 5s 2 3srRNA间隔区基因 ,同源性 99%以上 ,与B .valaisiana基因型的同源性均比其它基因型高。结论 4株莱姆病螺旋体均属于B .