5SrRNA基因间隔区DNA序列在穿心莲道地性中的可行性研究

目的探讨5SrRNA基因间隔区DNA序列在穿心莲道地性研究中的可行性。方法提取不同产地穿心莲总DNA后,PCR特异扩增5SrRNA基因间隔区,采用荧光标记末端终止子双脱氧末端终止法测序,对测序结果进行多序列联配分析。结果成功得到321bp的5SrRNA基因间隔区碱基序列,经过多序列联配分析发现,不同产地穿心莲的此段5SrRNA基因间隔区DNA序列之间没有差异。结论5SrRNA基因间隔区DNA序列不适合用于研究穿心莲药材的道地性。     

PCR-RFLP分析16s-23srDNA间区序列鉴定分枝杆菌菌种

目的探讨16S～23srDNA间区序列DNAPCR扩增和限制性酶切分析在分枝杆菌分类鉴定中的价值。方法对19种分枝杆菌标准株的16S～23SrDNA间区序列DNA进行PCR扩增并对扩增产物进行限制性内切酶HaeⅢ、MSP1消化反应，分析不同菌种扩增片段及其限制性片段长度多态性的差异。结果，PCR扩增结果显示：分枝杆菌一般扩增出1～2条带，缓慢生长分枝杆菌扩增片段在340～480bP，快速生长分枝杆菌扩增片段集中在470～575bP，单从扩增产物的琼脂糖凝胶电泳只能鉴定33．3％的受试菌种，酶切结果显示：分枝杆菌的酶切图谱彼此不同。结论16S～23SrDNA间区序列DNAPCR扩增和RFLP分析是分枝杆菌分类鉴定的一种快速、有效的方法。     

海马类药材的分子遗传标记鉴定研究

应用古DNA研究技术从5种海马药材中提取DNA,用PCR技术扩增约450bp的12SrRNA基因片段和约490 bp的细胞色素b基因片段。对扩增产物进行了限制性片段长度多态性(RFLP)分析和DNA序列分析。用RFLP分析方法可以鉴别2种海马,用DNA序列分析方法得到的分子遗传标记可以鉴别所有5种海马。对其它动物类药材的鉴定有一定参考价值。     

乙型肝炎病毒PreS/S基因真核表达质粒的构建

目的克隆乙肝病毒PreS/S基因及构建真核表达质粒。方法以HBSAg阳性患者DNA为模板PCR法扩增PreS/S基因,PCR产物测序分析正确后克隆至真核表达载体pcDNA3.1。结果酶切鉴定和序列分析证实构建质粒含PreS/S基因。结论 PreS/S基因克隆及其真核表达质粒构建成功可用于肝癌发生发展的分子生物学研究。     

POR-RFLP分析16s～23s rDNA间区序列鉴定分枝杆菌菌种

目的 探讨16s～23s rDNA间区序列DNA PCR扩增和限制性酶切分析在分枝杆菌分类鉴定中的价值.方法 对19种分枝杆菌标准株的16s～23s rDNA间区序列DNA进行PCR扩增并对扩增产物进行限制性内切酶Hae Ⅲ、MSP1消化反应,分析不同菌种扩增片段及其限制性片段长度多态性的差异.结果 PCR扩增结果显示:分枝杆菌一般扩增出1～2条带,缓慢生长分枝杆菌扩增片段在340～480bP,快速生长分枝杆菌扩增片段集中在470～575 bP,单从扩增产物的琼脂糖凝胶电泳只能鉴定33.3%的受试菌种,酶切结果显示:分枝杆菌的酶切图谱彼此不同.结论 16s～23s rDNA间区序列DNA PCR扩增和RFLP分析是分枝杆菌分类鉴定的一种快速、有效的方法.     

小鼠CD1d2编码区基因的克隆与鉴定

目的:克隆小鼠CD1d2编码区基因。方法:提取小鼠胸腺组织总RNA,用RT-PCR技术扩增CD1d2cDNA,PCR产物连接pGEM-T载体,转化大肠杆菌,用限制性酶切反应和DNA测序对阳性克隆进行鉴定,用BLAST软件进行序列分析。结果:扩增出一条特异DNA条带,DNA序列测定表明获取了大小为1008bp的小鼠CD1d2基因编码区基因。结论:成功克隆了小鼠CD1d2编码区基因。     

人肥大细胞羧肽酶分泌型真核表达载体的构建

目的:构建人肥大细胞羧肽酶(hMC-CP)分泌型真核表达载体pcDNA3.1/CP.方法:用免疫球蛋白k链的信号肽序列置换hMC-CP自身的信号肽序列,设计并合成引物,以hMC-CP基因为模板,扩增带有分泌信号肽的hMC-CP基因,DNA测序鉴定正确后,将PCR扩增产物定向克隆至真核表达载体pcDNA3.1,通过酶切和DNA测序进行鉴定.结果:琼脂糖凝胶电泳显示PCR扩增出一条特异条带,酶切鉴定和序列测定结果表明大小为1269bp的DNA片段插入表达载体.结论:成功构建了hMC-CP分泌型真核表达载体,为进一步制备真核表达的重组hMC-CP奠定了基础.     

中药材蛇胆的DNA分子标记鉴定研究

目的　运用分子标记技术鉴定药材蛇胆的真伪,以克服目前仅依据形态、显微特征及理化性状进行鉴别的不足。方法　分别从药材蛇胆的胆衣和胆汁、原动物棕黑锦蛇的肌肉和胆汁中提取DNA,经PCR扩增得到约400bp的12SrRNA基因片段,并对该基因片段进行测序研究。结果　从少量药材蛇胆的胆衣和胆汁中可提得足够用于PCR扩增的DNA模板,扩增产物的测序结果表明同一动物的胆衣和胆汁、肌肉和胆汁的碱基序列完全一致。结论　DNA分子标记技术可用于中药材蛇胆和胆汁的鉴定,提示该技术也可用于其他动物分泌物类型药材的鉴别。目前市场上药材蛇胆来源较复杂,需加强质量监督和控制。     

基因测序技术在中药质量研究中的应用（Ⅰ）——山东郓城猴头半夏基原的DNA测序鉴别

目的：分析半夏Pinellia ternata(Thunb.)Breit.及其伪品虎常南星Pinellia pedatisecta Schott的核基因组序列,为半夏正品基原鉴别提供分子依据。方法：采用PCR直接测序技术测定半夏及其伪品的18S rRNA基因核苷酸序列并作序列变异和选择性内切酶谱（PCR－SR）分析。结果：半夏和伪品的18S rRNA序列长度均为1805bp,根据排序比较,半夏原植物与商品药材间的序列完全相同,虎掌南星亦如此。而半夏与其伪品虎掌南星间则存在序列差异（有4个变异位点）。在半夏18S rRNA序列中有一个限制性内切酶Ase Ⅰ识别位点,通过PCR－SR图谱显示800bp和900bp2个酶切片断,而虎掌南星则无此位点,PCR－SR图谱显示1个未消化的1800bp片断。结论：通过核基因组序列和PCR－SR图谱差异DNA测序技术可成为半夏正品基原鉴别准确而有效的分子方法。     

异种移植模型转人a1,2岩藻糖基转移酶基因小鼠显微注射DNA片段的制备

目的制备转人琢1,2岩藻糖基转移酶(HT)基因小鼠显微注射DNA片段。方法引物两端设计酶切识别位点,聚合酶链反应(PCR)扩增HTcDNA全长序列,两端含有EcoRⅠ和BamHⅠ酶切识序列;回收HTcDNA片段并与PMD18-T载体连接,EcoRⅠ和BamHⅠ双酶切纯化质粒鉴定;EcoRⅠ和BamHⅠ双酶切pMD18-HTcDNA重组质粒和pCMV-MCS质粒,回收HTcDNA片段和pCMV-MCS质粒片段,进而连接,转化感受态细菌,纯化质粒对其进行酶切、PCR和测序鉴定;PvuⅠ和NotⅠ依次单酶切重组质粒pCMV-MCS-HTcDNA,回收大小约2.85kb片段,溶于适量显微注射用缓冲液。结果成功构建了重组质粒pCMV-MCS-HTcDNA,酶切回收了2.85kb的显微注射DNA片段。结论通过基因工程技术可以获得转人HT基因小鼠显微注射DNA片段,包含基因表达元件,可以用于显微注射法建立转人HT基因小鼠。     

Molecular diversity of 5S-rRNA spacer domain in Fritillaria species revealed by PCR analysis.

Beimu (bulbs of Fritillaria) is an important traditional Chinese herbal medicine commonly used as an antitussive and expectorant. There are about 25 species and varieties of Fritillaria that carry the name Beimu on commercial markets. The price for each Beimu may differ by more than 100-fold. However, the identification of the origin of a particular species on the market is difficult. Here, a molecular method was used to identify various species of Fritillaria regardless of their geographical origin. The 5S-rRNA coding sequence is highly conserved in higher eukaryotes, but the spacer sequence of the 5S-rRNA gene is variable among different species. Total genomic DNA from fresh leaves and bulbs of Fritillaria cirrhosa, F. puqiensis, F. anhuiensis, and F. thunbergii was extracted. The 5S-rRNA spacer region of the extracted DNAs was amplified by PCR with a pair of primers located within the conserved coding region. The isolated cDNA clones (approximately 600 bp) covering the 5S-rRNA spacer domain were sequenced. By aligning the isolated nucleotide sequences of the four Fritillaria species, sequence diversity was found in the spacer region. Furthermore, a unique EcoR I site was used for the rapid identification of different species of Fritillaria. To our knowledge, this is the first report on the detection of 5S-rRNA spacer domain sequences of Fritillaria and their use to identify species.     

Authentic identification of stigma Croci (stigma of Crocus sativus) from its adulterants by molecular genetic analysis

Stigma Croci, stigma of Crocus sativus L., is a precious traditional Chinese medicine, which is commonly used to activate blood circulation and to dissipate blood stasis. Three plant species, Carthamus tinctorius L., Hemerocallis fulva (L.) L. and Hemerocallis citrina Baroni, could carry the name Stigma Croci in the commercial markets of South East Asia. However, C. sativus is the only one that has proven its effectiveness, while the others could act as adulterants. The authentic identification of C. sativus on the market is difficult. By using molecular genetic method, the spacer domains of 5S-rRNA were cloned from the genomic DNAs that were isolated from C. sativus, C. tinctorius, H. fulva and H. citrina. The cDNAs encoding the spacer domains, about 300 to 500 bp, were sequenced. The nucleotide sequences of these four species showed great diversity, which could serve as markers for authentic identification of Stigma Croci to distinguish from its substitution and counterfeit.     

Identification of bulb from Fritillaria cirrhosa by PCR with specific primers

Bulb of Fritillaria cirrhosa is an important traditional Chinese herbal medicine. According to the Chinese Pharmacopoeia (1995), it is commonly used as an antitussive and expectorant. Many young bulbs from species of Fritillaria are similar to those of F. cirrhosa, but they are different in price and quality. Therefore, there are many young bulbs from species of Fritillaria that could fake those of F. cirrhosa on the commercial market. The coding region of 5S-rRNA is highly conserved in higher eukaryotes. The 5S-rRNA spacer region sequences of F. thunbergii, F. pallidiflora, F. ussuriensi, F. delavayi, F.cirrhosa, F. anhuiensis, F. puqiensis were cloned by PCR with a pair of primers located within the conserved coding region. Based on sequences analyses of the 5S-rRNA spacer region from the 7 species, a specific sequence was found in F. cirrhosa. A pair of specific primers was designed for differentiating the bulbs of F. cirrhosa from each other by PCR.This result indicated that the method is rapid, more accurate and applicable in identification of the bulbs of F. cirrhosa at the DNA level.     

Authentication of Panax notoginseng by 5S-rRNA spacer domain and random amplified polymorphic DNA (RAPD) analysis

The great majority of Panax species are well-known herbal medicines in the Orient, and many of them share a close resemblance in appearance and chemical composition. Among these Panax species, the root of P. notoginseng (Sanqi) is a unique herb that has distinct clinical usage. Here, the 5S-rRNA spacer domains were isolated from P. notoginseng, P. japonicus var. major, P. stipuleanatus, P. quinquefolius, P. ginseng, P. zingiberensis, and P. wangianus, and four common adulterants of P. notoginseng including Curcuma wenyujin, Curcuma longa, Bletilla striata and Gynura segetum. The spacer domains were sequenced and compared, which showed over 75 % DNA identity among all Panax species, but not for the adulterants. In addition, random amplification of polymorphic DNA (RAPD) analysis was used to distinguish different members of Panax genus as well as the morphological variants of P. notoginseng. These molecular methods could be used in the authentic identification of P. notoginseng from other Panax species.     

Molecular authentication of Radix Puerariae Lobatae and Radix Puerariae Thomsonii by ITS and 5S rRNA spacer sequencing

In the present study, we examined nuclear DNA sequences in an attempt to reveal the relationships between Pueraria lobata (Willd). Ohwi, P. thomsonii Benth., and P. montana (Lour.) Merr. We found that internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA are highly divergent in P. lobata and P. thomsonii, and four types of ITS with different length are found in the two species. On the other hand, DNA sequences of 5S rRNA gene spacer are highly conserved across multiple copies in P. lobata and P. thomsonii, they could be used to identify P. lobata, P. thomsonii, and P. montana of this complex, and may serve as a useful tool in medical authentication of Radix Puerariae Lobatae and Radix Puerariae Thomsonii.     

射干及类似药用植物叶绿体rbcL基因序列分析

目的 对射干Belamcanda chinensis (L.) DC.,鸢尾Iris tectorum Maxim.,野鸢尾I.dichotoma Pall.,蝴蝶花I.japonica Thunb.和德国鸢尾I.germaica L.等5种药用植物进行叶绿体rbcL基因序列分析,并对其亲缘关系进行探讨。方法CTAB(Cetyl trimelhyl ammonium bromide,CTAB)法提取总DNA,用作者设计的引物对鸢尾科5种药用植物的叶绿体rbcL(ribulose 1,5-bisphosphate carboxylose Large Gene,rbcL)基因进行扩增,PCR扩增产物纯化后,用ABI310 DNA自动测序仪测序。结果获得射干和4种鸢尾属药用植物叶绿体rbcL基因部分序列(约750 bp),除德国鸢尾外, 其余4种药用植物的rbcL基因序列为首次获得;用clustal 8.0,MEGA 2.0等软件分析统计获得的目的基因片段,得到碱基突变点,遗传距离［碱基差异数(1.000～20.000)、颠换数为(0.000～9.000)、转换数为(0.000～14.000)］,根据rbcL基因部分序列数据建立分子系统树。结论根据叶绿体rbcL基因序列数据可以很好的鉴别5种鸢尾科植物。     

Authentication of medicinal Dendrobium species by the internal transcribed spacer of ribosomal DNA

Herba Dendrobii (Shihu) is a commonly used Chinese medicine derived from the stem of several orchid species belonging to the genus Dendrobium. It is rather expensive and adulteration is frequent. Proper authentication of the medicinal species is necessary to protect consumers and support conservation measures. DNA sequences of the internal transcribed spacer 2 (ITS 2) of 16 Dendrobium species were shown to be significantly different from one another by an average of 12.4% and from non-orchids and Pholidota (an adulterant of Shihu) by 29.8% and 18.8%, respectively. The intra-specific variation among the Dendrobium species studied was only about 1%. Therefore, ITS 2 regions could be adopted as a molecular marker for differentiating medicinal Dendrobium species from one another and also from non-orchids and adulterants.     

Identification of dendrobium species used for herbal medicines based on ribosomal DNA internal transcribed spacer sequence

Stems of genus Dendrobium (Orchidaceae) have been traditionally used as an herbal medicine (Dendrobii Herba) in Eastern Asia. Although demand for Dendrobium is increasing rapidly, wild resources are decreasing due to over-collection. This study aimed to identify plant sources of Dendrobii Herba on the market based on sequences of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA. We constructed an ITS1-5.8S-ITS2 sequence database of 196 Dendrobium species, and the database was employed to identify 21 herbal samples. We found that 13 Dendrobium species (D. catenatum, D. cucullatum, D. denudans, D. devonianum, D. eriiflorum, D. hancockii, D. linawianum, D. lituiflorum, D. loddigesii, D. polyanthum, D. primulinum, D. regium, and D. transparens) were possibly used as plant sources of Dendrobii Herba, and unidentified species allied to D. denudans, D. eriiflorum, D. gregulus, or D. hemimelanoglossum were also used as sources. Furthermore, it is clear that D. catenatum is one of the most important sources of Dendrobii Herba (5 out of 21 samples).     

Molecular authentication of the traditional Tibetan medicinal plant Swertia mussotii

Swertia mussotii is an important species in Tibetan folk medicine. However, it is quite expensive and frequently adulterated, so reliable methods for authentication of putative specimens and preparations of the species are needed to protect consumers and to support conservation measures. We show here that the chloroplast (cp) DNA RPL16 intron has limited utility for differentiating S. mussotii from closely related species, since the cpDNA RPL16 sequences are identical in S. mussotii and two other species of Swertia. However, the rDNA internal transcribed spacer (ITS) sequences differ significantly between S. mussotii and all of 13 tested potential adulterants. Thus, the ITS region provides a robust molecular marker for differentiating the medicinal S. mussotii from related adulterants. Therefore, a pair of allele-specific diagnostic primers based on the divergent ITS region was designed to distinguish S. mussotii from the other species. Authentication by allele-specific diagnostic PCR using these primers is convenient, effective and both simpler and less time-consuming than sequencing the ITS region.     

Characterization of medicinal Epimedium species by 5S rRNA gene spacer sequencing

Sequences of 5S rRNA gene spacer were used to identify Epimedium brevicornu Maxim., E. sagittatum (Sieb. et Zucc.) Maxim., E. wushanense T. S. Ying, E. pubescens Maxim., and E. koreanum Nakai. These species are listed as source plants of Chinese medicine 'Ying Yang Huo' in the Chinese Pharmacopoeia. The neighbor-joining method was used in a sequence analysis of Epimedium species. A position-specific nucleotide was found in the 5S rRNA gene spacer for E. pubescens, E. wushanense, and E. brevicornu. A 19-bp deletion was found for E. koreanum in the 5S rRNA gene spacer. E. koreanum was most divergent from the other four endemic Chinese species of Epimedium.