双孢蘑菇SRAP、ISSR、RAPD标记遗传多样性和菌群分类研究

通过PCR试验,筛选能扩增清晰稳定的DNA条带的53对SRAP引物、10条ISSR引物和56条RAPD引物。SRAP、ISSR和RAPD 3种DNA分子标记扩增位点的平均多态率分别为70.21%、78.33%、61.94%。SRAP、ISSR和RAPD扩增结果用0与1表示,共获得1 046个位点的42 840个数据。采用组间距离法和Jaccard相似性系数,应用SPSS 11.0 for Windows软件进行聚类分析,构建40个双孢蘑菇样品的遗传关系树状图。当组间距离值取16时,40个双孢蘑菇品种可分为6个类群;当组间距离值取13时,40个双孢蘑菇品种被分为9个类群。     

双孢蘑菇RAPD标记的遗传多样性分析

随机抽取108个随机引物对40个双孢蘑菇栽培菌株的DNA进行RAPD-PCR扩增实验,发现有71个随机引物能够扩增出清晰的、稳定的、具有多态性的RAPD条带。结果表明,71个随机引物共扩增出567条DNA带,平均每个引物扩增出7.99条DNA带,其中434条DNA带具有多态性,占总数的76.5%。基于RAPD-PCR扩增资料,采用欧氏距离平方系数和组间连接法,应用SPSS 11.0软件进行聚类分析,探讨40个品种间的亲缘关系与类群划分。当取欧氏距离平方系数阈值为20.5时,所有品种分为三大类;当取欧氏距离平方系数阈值取8.5时,40种双孢蘑菇菌株可被分为6个类群,此结果与双孢蘑菇菌株群的同工酶分类研究结果相当吻合。     

云南省烟草镰刀菌根腐病菌遗传多样性分析

  背景和目的  尖孢镰刀菌（Fusarium oxysporum）引起的根腐病是烟草主要的土传病害,在云南烟区普遍发生。为分析云南省不同地理来源尖孢镰刀菌的遗传差异性和亲缘关系。  方法  采用ISSR（inter-simple sequence repeat）和SRAP（sequence- related amplified polymorphism）分子标记技术分析40株菌株遗传多样性。  结果  （1）采用ISSR技术,供试的7条引物共扩增出53条条带,其中多态性条带44条,平均多态性条带83.02%。菌株间的遗传相似系数为0.49~0.96,存在遗传背景差异。遗传相似系数为0.68时,40株菌株可分为3个类群。（2）采用SRAP技术,供试的7对引物共扩增出44条条带,其中多态性条带32条,平均多态性条带72.73%,菌株间的遗传相似系数为0.55~0.96。遗传相似系数为0.70时,40株菌株可分为3个类群,结果与ISSR一致。  结论  云南省烟草尖孢镰刀菌菌株间遗传差异大,ISSR和SRAP分子标记技术可用于烟草尖孢镰刀菌的遗传多样性分析。      

尖孢镰刀菌胡麻专化型（Fusarium oxysporum f.sp.lini）ISSR标记聚类分析

结合形态学特征和分子生物学方法对我国尖孢镰刀菌胡麻专化型菌株进行鉴定、聚类分析和遗传变异分析。结合传统分类方法和ITS序列分析,确定6省区96株菌株为尖孢镰刀菌。采用ISSR（简单重复序列区间）分子标记技术对这96株菌株进行分析,12条引物共扩增出800个条带,多态率条带数为797条,多态率为99.62%;在相似性系数为0.88处,96株供试菌株被分为5个类群。聚类结果表明,胡麻枯萎病菌种内存在明显的多态性,且ISSR类群与地理来源存在相关性。     

三种不同分子标记技术对灵芝单核体多态性的研究

为了探讨灵芝Ganoderma.lucidum原生质体单核体间遗传多态性,为育种材料的筛选提供分子水平依据。运用ISSR、SRAP、RAPD3种分子标记技术对制得的34株灵芝单核体进行了遗传多样性分析和聚类分析。结果显示,三种分子标记技术共扩增出347条条带,多态性条带为308条,多态比率为88.76%,其中ISSR-PCR扩增效果较好,多态性条带和多态比率最高;119-123与其余菌株相异系数最大,或已发生基因突变。根据综合分析结果,在相异系数为0.67时,可以把剩余33株菌株分为两大类群,Ⅱ类含5株菌株,分别为119-180、119-210、119-212、G0119和119-214,剩余的28株菌株为Ⅰ类。研究表明,ISSR、SRAP和RAPD分子标记可用于灵芝单核体多态性研究,这将为育种材料的筛选提供帮助,减少育种工作量和风险。     

中国猴头菇栽培菌株的系统进化研究

利用随机扩增多态性DNA(RAPD)标记对7 个猴头菇之间的亲缘关系进行研究,获得了猴头菇不同菌株的DNA 指纹图谱。结果显示：14 个随机引物中有3 个随机引物的扩增产物的DNA 条带表现出明显的多态性。这3个引物共扩增出44 条带,其中36 条为多态性条带,多态性位点比率为81.81%。同时利用NTSYSpc 2.1 生物软件分析7 个供试菌株之间的遗传相似性,并绘制系统进化树。     

不同来源酿酒酵母菌株的随机扩增多态DNA分析

研究中试用了20个随机引物对16株不同来源的酿酒酵母菌株全基因组进行了随机扩增多态DNA分析,其中OPG06,OPG11和OPG20三条适宜引物具有鉴别作用,每一引物均可扩增1～10条DNA片段,大多数片段分子量大小在100～2000bp之间,共扩增出34条RAPD谱带,多态性为85.3%,获得了稳定清晰的菌株RAPD指纹图谱。RAPD分析结果表明,不同来源的酿酒酵母菌株之间的遗传相似系数在37.5%～94.1%之间,反映出较高的遗传差异性,并可通过聚类分析将16株不同来源的酿酒酵母菌株按亲缘关系的远近分为6个类群。结果表明,利用RAPD标记技术在基因水平上对酿酒酵母菌株进行分子鉴定和分型是可行的。     

23 株酿酒酵母ISSR指纹图谱分析及SCAR标记的建立

目的：构建酿酒酵母菌株的简单重复序列间多态性指纹图谱数据库并建立序列特异性扩增区（sequencecharacterized amplified region,SCAR）标记技术,为酿酒酵母菌株的分类、遗传亲缘关系鉴定及菌种专利保护提供可靠的DNA分子标记技术依据。方法：在简单重复序列间多态性（inter-simple sequence repeat,ISSR）指纹数据分析基础上进行聚类分析并对菌种进行分类鉴定,同时将酿酒酵母菌株9号和15号中扩增获得的ISSR特异性DNA带转化为可以直接用于菌株快速鉴定的SCAR分子标记。结果：构建23 株酿酒酵母的ISSR指纹图谱,并在相似系数为0.85水平上将23 个供试菌株分为3大类,其中,1、2、4、7、15、16、17、19、20、21、23聚为第一类;10、11、12、13、14、18号菌株聚为第二类且10号和11号菌为同一菌株;3、5、6、8、9、22号菌聚为第三类且属于同一菌株。此外,利用所获得的2 个特异性条带成功转化为序列特异性扩增区分子标记。结论：在生产上酿酒酵母菌株遗传背景差异不大,常存在同物异名现象,而采用ISSR指纹及其SCAR分子标记技术快速鉴定酿酒酵母菌株在工业生产上具有重要意义。     

草菇有性世代间rDNA序列变异分析及RAPD分析

草菇的遗传与有性生殖过程存在很多的特殊性和不确定性,本研究以草菇V23菌株的成熟子实体弹射孢子,单孢分离后得13个单株,分别摇瓶培养、收集菌丝,提取总DNA,用通用引物ITS4、ITS5进行PCR扩增后连接、转化并测序,将单孢间和单孢与亲本间的ITS序列进行比对,分析草菇ITS序列多样性及变异性;同时以相应单孢菌株DNA为模板,用20条随机引物进行RAPD扩增。结果表明:草菇单孢间和单孢与亲本间的ITS序列相似度均在99%以上,相较于亲本的ITS序列,单孢序列中发现了有5个位点出现碱基转换,但没有两个以上的单孢发生同一转换;20条随机引物分别与14个样本进行RAPD扩增,其中3个引物出现多态性条带,带型结果发现单孢菌株间的带型差异呈现一定规律。草菇ITS序列变异较少,不适于单孢间的变异分析,而RAPD方法对摸索草菇有性世代间的遗传分离规律有重要价值。     

4个引进甜菜品种DNA指纹图谱的建立

利用ISSR标记技术,对4个引进的甜菜品种建立DNA指纹图谱。结果显示,用筛选出的1条引物的PCR扩增指纹图谱即可将这4个品种区分,该引物共扩增出12个清晰条带,其中6个为共有带,多态性为50％,4个品种分别有自己的特征带。研究结果表明,利用ISSR标记指纹能够从DNA水平上明确区分甜菜不同品种,为甜菜种质鉴定提供了一种有效方法。     

弧菌外膜蛋白OmpK单克隆抗体的制备及其特性

制备弧菌外膜蛋白K(outer membrane protein K,Omp K)单克隆抗体并对其特性进行研究。以原核表达系统表达野生株Vibrio parahaemolyticus B的Omp K免疫Balb/c小鼠,取免疫小鼠脾细胞与肿瘤细胞SP2/0进行细胞融合,采用有限稀释法和间接酶联免疫吸附测定法筛选出能够稳定分泌单克隆抗体的杂交瘤细胞株,小鼠体内诱导制备腹水,用饱和硫酸铵沉淀法和亲和层析柱纯化抗体。最终获得能稳定分泌抗Omp K的两株单克隆抗体杂交瘤细胞株Omp K-Mab-4B7、Omp K-Mab-3C5,2株杂交瘤细胞系所分泌的Mab亚类均为Ig G1,效价达1∶128 000,抗体3C5、4B7的敏感度IC50分别为2.5、5.0μg/m L。Western blotting结果显示单克隆抗体可以与本实验室12株副溶血性弧菌(V.parahaemolyticus A、B、C、D、E、F、G、H、I、J、ATCC17802、ATCC33847)的外膜蛋白有不同程度的结合反应,与4株溶藻弧菌中的3株(V.alginolyticus A、B、C)外膜蛋白能够较好的结合,与1株鳗弧菌(V.anguillarumMVM)外膜蛋白也有轻微的结合反应,实验制备的单克隆抗体可用于弧菌Omp K的基础研究和快速检测。     

Development of genetic marker specific for Korean hwanggi medicine (Radix Astragali)

Sequence characterized amplified region (SCAR) markers were developed to selectively detect Korean hwanggi medicine (Radix Astragali) from imported ones from China. The SCAR markers were designed based on the nucleotide sequence of the psbA/trnH intergenic region (cpDNA) and significant bands obtained by inter-simple sequence repeat (ISSR) analysis. The psF/trnH marker was developed was based on the inserted sequence (TAAAA) within all of the Chinese samples (imports and local). Based on UBC 850 primer-amplified specific bands from all Chinese hwanggi medicine, the 15F/15R marker was designed. This primer showed high stability through 6 repeated amplifications, whereas psF/trnH marker showed 50% stability. Therefore, the designed SCAR marker (15F/ 15R) could be able to identify Korean hwanggi medicine as well as that imported from China.     

甘蓝型油菜隐性细胞核雄性不育上位抑制基因（esp）的分子标记开发

9012AB是甘蓝型油菜隐性上位细胞核雄性不育两型系,其育性受2对隐性重叠不育基因（ms3ms3ms4ms4）和1对隐性上位抑制基因（espesp）互作控制。为提高其不育系及同型临保系的选育效率,本研究以9012B和T45为基本材料,构建分离群体,鉴定与esp基因紧密连锁的AFLP标记。筛选了1 024对引物组合,鉴定出5个与esp相引相连锁的AFLP标记（L1、L2、L3、L4和L5）,2个与esp相斥相连锁的AFLP标记（L6和L7）。所有标记位于esp位点的一侧,L6和L7与Esp基因共分离。其中,L1、L6和L7转化成SCAR标记SCL1、SCL2和WSCL3。在20个基因型已知的验证群体中检测,SCL1、SCL2和WSCL3的准确率分别为90%、100%和100%。结果表明三个SCAR标记可用于9012AB的分子标记辅助选择。     

Extensive chromosome translocation in a clinical isolate showing the distinctive carbohydrate assimilation profile from a candidiasis patient

Variation of the electrophoretic karyotype is common among clinical strains of Candida albicans and chromosome translocation is considered one of the causes of karyotypic variation. Such chromosome translocations may be a mechanism to confer phenotypic diversity on the imperfect fungus C. albicans. A clinical strain, TCH23, from a vaginal candidiasis patient shows distinct carbohydrate assimilation profile, serotype B, no chlamydospore formation and an atypical karyotype (Asakura et al., 1991). To examine the taxonomic relationship among C. albicans, Candida dubliniensis and this strain, we sequenced the internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA. The ITS1 sequence of TCH23 was identical with that of C. albicans but not of C. dubliniensis. Thus, strain TCH23 was classified as a variant of C. albicans with an atypical phenotype. The chromosomal DNAs of this strain were resolved into 13 bands on pulse-field gel electrophoresis (PFGE). Using DNA probes located at or near both ends of each chromosome of C. albicans, we investigated the chromosome organization of this strain. Referring to the SfiI map of C. albicans 1006 (Chu et al., 1993), we found that seven chromosomal DNA bands in strain TCH23 were reciprocal chromosome translocations. One homologue from chromosomes 1, 2 and 6 and both homologues from chromosomes 4 and 7 participated in these events. One translocation product was composed of three SfiI fragments, one each from chromosomes 2, 4 and 7. We deduced the breakpoints of chromosome translocation from the physical map of this strain; between 1J and 1J1, between 2A and 2U, both ends of 4F2, between 6C and 6O and both ends of 7F.     

远东疣柄牛肝菌化学成分分析

目的：研究远东疣柄牛肝菌子实体的化学成分。方法：采用Sephadex LH-20凝胶色谱柱和硅胶色谱柱进行分离纯化,通过波谱数据和理化常数鉴定化合物的结构。结果：从远东疣柄牛肝菌中分离鉴定出11 种化合物：5-（L）-羰基-四氢吡咯-2-甲酸甲酯（A）、5-（L）-羰基-四氢吡咯-2-甲酸（B）、腺苷（C）、尿嘧啶核苷（D）、α-甲基-D-呋喃核糖（E）、（2R,3R）-2,3,4-三羟基丁酸（F）、2,2,5,5-四甲基四氢呋喃（G）、D-阿拉伯糖酸-1,4-内酯（H）、2-乙酰胺基-1,6-脱水-2-脱氧-D-吡喃型葡萄糖（I）、2-乙酰胺基-1,6-脱水-2-脱氧-D-吡喃型半乳糖（J）和麦角甾-7,22-二烯-3β,5α,6β-三醇（K）。结论：化合物A、B和E～J为首次从远东疣柄牛肝菌中分离得到的化合物。     

Detection of recombinant DNA from genetically modified papaya

A method using polymerase chain reaction (PCR) was developed to detect the genetically modified (GM) papaya (55-1 line), of which the mandatory safety assessment has not been finished in Japan because of insufficient data. The papaya intrinsic papain gene was used as an internal control. The results of PCR amplification of the papain gene segment indicated that a commercial silica membrane type kit (QIAGEN DNeasy plant mini) was useful for extraction of DNA from papaya fruit, but not for extraction from canned papaya fruit. On the other hand, a commercial ion-exchange type kit (QIAGEN Genomic-tip) provided enough purified DNA for PCR from canned papaya fruit. Compared with the parental line and other commercial non-GM papayas, the DNA from GM papaya fruit provided specific amplification bands in PCR with five primer pairs (Nos. 2-6) including beta-glucuronidase and neomycin phosphotransferase II gene-specific ones. On the other hand, the primer pairs recognizing these genes showed false-positive results when we used DNAs from canned papaya. Therefore, we recommend that the primer pairs (Nos. 5 and 6) recognizing the sequences derived from two different species of organism should be used in order to detect specifically the GM papaya in canned fruits.     

欧洲野生甘蓝的核质遗传多样性和群体遗传结构分析

为了解欧洲野生甘蓝遗传背景,以栽培甘蓝、甘蓝型油菜和白菜型油菜作对比,对引进的7个生态地理群体共80份野生甘蓝材料进行了核质遗传多样性和群体遗传结构分析。利用10对特异性SSR引物分析叶绿体基因组多样性,获得8个差异性标记,将参试94份材料划分为3类,即甘蓝（含栽培和野生甘蓝）、甘蓝型油菜和白菜型油菜;包括6种单倍型,其中野生甘蓝2个,甘蓝型油菜3个,白菜型油菜1个。利用6对SRAP引物对核基因组多样性进行分析,获得75个多态性标记;聚类及遗传结构分析表明7个野生甘蓝群体中,F、D、G三个群体聚为独立的亚类,E群体大部分单株归于G亚类。其它3个群体A、B、C则相互混杂在一起。野生甘蓝群体Nei＇s基因多样性指数（H）和Shannon’s指数（I）分别为0.301 3和0.461 1。分子方差分析（AMOVA）表明野生甘蓝以群体内变异为主,占80%;群体间变异仅占20%。结果显示引进的野生甘蓝群体核质遗传多样性丰富。     

Authentication of Thailand jasmine rice using RAPD and SCAR methods

A protocol for jasmine rice authentication was established in order to determine whether a Thai jasmine rice product meets legal requirement. Both RAPD and SCAR methods were used on the basis of previous study of jasmine-rice specific genome characteristics. Two RAPD markers, RI2-449 and RI5-1107, were selected and SCAR primer pairs were designed for RI5-1107. Twenty-four rice cultivars, which represented typical jasmine rice and non-jasmine rice were analyzed to confirm the specificity and reproducibility of DNA method. The purity of jasmine rice was calculated by analyzing every single kernel from test sample. Five in-house prepared samples were quantified to prove the accuracy of DNA method, and 15 imported samples were analyzed by DNA method as well as physical/chemical method to confirm the consistency between DNA method and traditional method. Based on the standard deviation obtained by comparing DNA method and traditional method, a testing threshold for jasmine rice was decided. Investigation of eight commercial samples from market showed that 75% products meet the requirement.     

Characterization of an E2-type colicin and its application to treat alfalfa seeds to reduce Escherichia coli O157:H7

Several outbreaks of Escherichia coli O157:H7 infections have been associated with contaminated alfalfa seeds. A recently isolated E. coli strain Hu194 was capable of inhibiting 22 strains of E. coli O157:H7 and this inhibition was mediated by the production of a colicin named Hu194. The objectives of this study were to test the efficacy of treating alfalfa seeds with colicin Hu194 against E. coli O157:H7 strains, and to characterize this antimicrobial protein. Significant reductions (approximately 5 log CFU ml-1) in the viable cell counts of strains 43890 and 43895 were observed after 1-day incubation with semi-crude colicin, and after 2 days for strain 3081. Strain 43890 was successfully eliminated (5 log CFU g-1) from inoculated alfalfa seeds after soaking in a colicin suspension at a concentration of 10,000 AU/g. Treatment of alfalfa seeds inoculated with strains 43895 and 3081 required 20-fold higher concentrations of colicin Hu194 to achieve as much as 3 log CFU g-1 reductions. The genes encoding the colicin Hu194 operon were located on a 6 kb plasmid, and the sequence analysis revealed that this colicin was an E-type DNAse. From the sequence data, the estimated molecular masses of colicin Hu194, its immunity protein and lysis protein were 61.3, 10.0 and 4.8 kDa, respectively. Based on DNA and protein sequence comparisons with other E-type colicin, colicin Hu194 belonged to the type E2-colicin cluster. However, cross-immunity tests between E-group colicins suggested that Hu194 colicin was divergent from the previously characterized E2 colicins.