ERIC-PCR在人工混合菌体系中的检出灵敏度*

提取大肠杆菌DH5α和阴沟肠杆菌 (E 2 6R)的基因组DNA ,进行ERIC PCR ,可以分别得到稳定而独特的DNA指纹图谱 ;模板量的变动范围从 1 0～ 1 0 0ng都不会影响其图谱的稳定性 ;在图谱中DH5α和E 2 6R各自均有一条含量最大的特征带 ,其不易受实验环境和实验条件的干扰而发生变化。把DH5α和E 2 6R按比例混合 ,提取混合菌基因组DNA ,进行ERIC PCR ,结果表明 :混合菌的DNA指纹图谱为各纯菌图谱的叠加 ,亦具有稳定性 ;通过对凝胶电泳图谱中特征带的分析 ,可     

煤地质环境微生物总基因组DNA提取方法的优化

高质量的DNA是进行分子生物学研究的基础。通过对传统DNA抽提方法(酚-氯仿法)进行改进,并以Rhodococcus sp.R04和煤粉为实验材料对细胞破碎条件进行优化,建立了一种可用于煤地质环境微生物基因组DNA高效提取的改良方法。以改良法和商业试剂盒提取煤地质环境微生物基因组DNA,通过琼脂糖凝胶电泳、细菌及古菌特异性片段的PCR扩增来评价所提取DNA的质量。改良法和试剂盒法均能获得煤地质环境微生物基因组DNA,并能用于多种特异性PCR扩增。与试剂盒提取的DNA相比,改良法获得的DNA片段主带明显,约占总DNA含量的50%,分子量大小接近23 kb,并且提取量大,约为试剂盒的5-10倍。同时,能用于如DNA文库构建和宏基因组测序等。此外,改良法所用试剂普通,价格便宜,提取的煤地质环境微生物基因组DNA质量较高,适于实验室和科学研究。     

DNA指纹图技术分析微生物肥料菌种组成稳定性

目的 分析2种市售微生物肥料在不同生产批次中微生物菌种组成的稳定性。方法 利用ERIC-PCR基因组DNA指纹图技术和16S rDNA V3扩增一温度梯度凝胶电泳（PCR-TGGE）指纹图技术。结果 这2种微生物肥料在同一个生产批次不同包装之间的2种DNA指纹图谱相似性较高,分别在78%～95%和96%～100%,表明同一个批次内的菌种组成比较一致,但其在不同的生产批次之间菌种组成差异存在显著性,反映在2种DNA指纹图谱上,不同生产批次样品间ERIC-PCR指纹图相似性最低只有10%,PCR-TGGE指纹图相似性最低为46%。结论 通过ERIC-PCR和PCR-TGGE DNA指纹图技术可以对微生物肥料中菌种组成的稳定性进行快速、准确的分析,如何保持菌种组成在批次之间的稳定一致,是复合菌种微生物肥料质量控制中面临的难题。     

ERIC-PCR技术在李斯特氏菌种、菌株鉴定中的应用

应用肠杆菌基因间重复一致序列聚合酶链反应技术（ERIC-PCR）对李斯特氏菌基因组DNA进行分析,结果显示,李斯特氏菌种间DNA指纹图谱带型差异较大;单核细胞增生性李斯特氏菌株间及相同血清型不同来源的菌株,其DNA指纹图谱带型也有明显差异。在单核细胞增生性李斯特氏菌各株的DNA指纹图谱中发现1600bp的种专一性扩增带。结果表明,ERIC-PCR技术可用于李斯特氏菌种、菌株的鉴定及进一步分型研究。 Abstract:Enterobacteia repetitive intergenic consensus sequences-based PCR(ERIC-PCR) was used to generate DNA fingerprints for Listeria spp.We got the specific profiles with ERIC-PCR technique that enables to identify Listeria species and the L.monocytogenes strains of different sterotype,and the same sterotype of L.monocytogenes from different sources also could be identified.Moreover,the species-spcific 1600bp DNA fragment was obtained from the fingerprint of L.monocytogenes.The study indicates that ERIC-PCR technique can be used in the identification of Listeria species and strains and its further typing,which is simple and quickly.     

基于ERIC-PCR指纹图谱技术的小鼠肠道菌群失调分析方法的建立

目的采用常规菌群分析方法和ERIC-PCR技术对正常小鼠和抗生素相关性腹泻小鼠模型分别进行肠道菌群检测,结合细菌培养和DNA指纹图谱检测结果分析小鼠肠道内主导菌群数量和种类的改变情况,建立利用ERIC-PCR技术分析小鼠肠道菌群失调的检测方法。方法先利用常规菌群分析方法鉴定正常小鼠和抗生素相关性腹泻小鼠的菌群状况,再提取其基因组DNA,最后以肠杆菌科基因间重复序列(ERIC)为模板,利用ERIC-PCR方法获得正常小鼠和模型小鼠的肠道菌群指纹图谱,与常规菌群分析结果作比较,验证ERIC-PCR技术的准确性。结果常规菌群分析结果表明四种优势菌群在数量上出现明显的变化,证实造模成功。经ERIC-PCR技术成功获得两组小鼠粪便基因组DNA图谱,两组间呈现具有一定对比性的特异性指纹图谱。结论从小鼠粪便基因组经ERIC-PCR后的图谱中特异性条带的分布、数目和亮度来看,能说明肠道菌群的分布状况存在明显差异,结合常规菌群分析方法作对比,说明ERIC-PCR技术是一种分析小鼠肠道菌群失调高效快捷的检测方法。     

健康儿童与发育不佳儿童肠道菌群结构的比较研究

目的对健康儿童与发育不佳(FTT)儿童肠道中微生物区系的ERIC-PCR指纹图谱异同进行研究。方法根据美国疾病预防控制中心(CDC)对儿童生长发育的评价指标对某幼儿园200例4～6岁儿童进行评价,筛选出16例健康儿童和13例FTT儿童,每周1次连续3周跟踪取样,提取粪便样品中细菌总DNA,获得其ERIC-PCR指纹图谱,再将其中一个样品的ERIC-PCR产物作为混合探针通过杂交对指纹图谱上DNA条带序列的异同进一步比较。结果同一个体的肠道菌群结构在取样期间稳定性较好;虽然健康儿童间的肠道菌群结构也有一定差异,但它们却有着共同的结构特征;而健康儿童与FTT儿童的肠道菌群结构差异较大。结论儿童发育状况与肠道菌群结构有一定的关系。     

ERIC-PCR鉴别苏云金芽胞杆菌与蜡状芽胞杆菌的研究

利用ERIC-PCR技术对苏云金芽孢杆菌(Bt)、蜡状芽孢杆菌(Bc)和对照菌基因组DNA进行扩增,回收、标记BtPCR扩增片段,分别与各菌株的基因组DNA进行斑点杂交和Southern杂交,筛选Bt标识序列。结果显示:Bt各菌株均可扩增得到250bp的特异片段;Bt和Bc均可得到600bp的共有扩增片段;以筛选得到的569bp片段为探针,可特异性地与Bt基因组DNA杂交;ERIC-PCR技术可以在DNA指纹图谱水平区分鉴别Bt与Bc菌,正确反映出两者的亲缘关系。结果表明ERIC-PCR技术在Bt的检测及在Bt与Bc的鉴定中具有较强的实用性。     

ERIC-PCR分子杂交技术分析大熊猫肠道菌群结构

目的了解大熊猫肠道微生物区系结构的相似性和稳定性,并找出大熊猫肠道微生物群落结构的变化与健康状况的关系。方法对上海动物园及上海野生动物园所饲养的3只大熊猫2次采集的粪便样品进行微生物群落总DNA的抽提,并以此为模板获得反映肠道微生物群落结构特征的ERIC—PCR和Southern杂交指纹图谱,比较各DNA样品指纹图谱的相似性指数。结果除国庆(大熊猫)的第1次采集的样品(当时处于腹泻状态),其他各DNA样品的ERIC-PCR及Southern杂交指纹图谱的相似性都达到85％～100％;佳斯及川川(大熊猫)2个个体2次采集的样品之间ERIC指纹图谱的相似性分别为93％和87％,而国庆腹泻时的样品与健康时的样品之间则为71％。结论大熊猫不同个体之间肠道微生物群落结构比较相似,而且同一个体在不同时期表现出比较高的稳定性,但当个体的健康出现问题时肠道优势菌菌群结构有一定波动。所采用的DNA提取方法、ERIC—PCR和Southern杂交指纹图谱的高度重复性证明了之一分子生态学技术在大熊猫肠道微生物区系动态监测中的可行性。     

直接从人工老化的菜心干种子中提取基因组DNA用于RAPD分析

利用40℃、100％朋对菜心种子进行人工加速老化处理获得了不同活力的种子批,利用平衡酚-氯仿法直接从人工老化的菜心干种子中提取基因组DNA,并对提取的基因组DNA进行了趾PD扩增。结果表明,所提取的基因组DNA量多,而且比较整齐一致。引物S208扩增所获得的基因组DNA指纹图谱上的DNA带清晰、明亮,从而表明利用本方法从人工老化菜心干种子中直接提取的基因组DNA完全可以用于RAPD分析。     

直接从人工老化的菜心干种子中提取基因组DNA用于RAPD分析

利用 4 0℃、1 0 0 %RH对菜心种子进行人工加速老化处理获得了不同活力的种子批 ,利用平衡酚_氯仿法直接从人工老化的菜心干种子中提取基因组DNA ,并对提取的基因组DNA进行了RAPD扩增。结果表明 ,所提取的基因组DNA量多 ,而且比较整齐一致。引物S2 0 8扩增所获得的基因组DNA指纹图谱上的DNA带清晰、明亮 ,从而表明利用本方法从人工老化菜心干种子中直接提取的基因组DNA完全可以用于RAPD分析。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.