天麻AFLP分析技术体系的建立

目的:建立一个适于天麻研究用的AFLP分析技术体系。方法:以11份天麻种质资源为试材,构建供试天麻的AFLP指纹图谱,同时对AFLP分析过程中DNA提取、酶切、连接、预扩增、引物筛选、选择性扩增、电泳和银染等多种因素进行分析。结果:AFLP分析体系要求DNA模板质量高,酶切连接可同时进行,37℃、9h效果较好,预扩增要求高质量DNA聚合酶,产物15倍稀释作为选择性扩增模板效果好,制胶前玻璃板的处理和银染时间的掌控对获得较好结果非常关键。P-GGA/M-GT引物构建的指纹图谱拥有可清晰辨认的扩增条带45条。结论:AFLP指纹技术具有稳定性高、重复性好等优点,可用于天麻DNA分析。     

短蛸AFLP分子标记分析体系的优化与建立

本研究构建了短蛸扩增片段长度多态性(AFLP)分析体系,对DNA提取、双酶切反应、连接反应、预扩增反应、选择性扩增反应和银染等步骤进行了分析。得到了一种适于短蛸AFLP技术分析的优化体系,该体系中各优化因素为:模板DNA浓度为200 ng/μL;酶切体系中,MseI和EcoR I各加入5 units,缓冲液使用MseI buffer Tango,反应时间为3-4 h;连接最适反应时间为12 h;预扩增产物最适稀释倍数为20倍。该体系的构建为AFLP技术在短蛸分子遗传多样性研究中的应用奠定了基础。     

蚕豆AFLP技术体系的建立与优化

对蚕豆DNA提取质量和浓度、DNA双酶切与连接、酶切连接产物的预扩增和选择性扩增等AFLP技术体系中的关键技术进行了优化处理,构建了蚕豆AFLP银染技术体系。酶切与连接可在12.5μl体系中一步完成,酶切连接温度为37℃,反应时间12~14 h;预扩增体系为20μl,选择性扩增体系为10μl。采用该技术体系应用8对引物构建的蚕豆种质资源AFLP指纹图谱,扩增条带多、多态性强且质量好,可满足遗传多样性分析要求。     

华中五昧子AFLP反应体系的建立

目的:建立一个适于华中五味子研究用的AFLP反应体系.方法:以华中五味子硅胶干燥嫩叶为试材,采用改良CTAB法提取到高质量DNA.通过琼脂糖凝胶电泳和聚丙烯酰胺凝胶电泳对Mse I/EcoR Ⅰ双酶切、连接、预扩增和选择性扩增过程中的关键因素进行分析.结果:双酶切6 h,片段主要集中在250～2 000bp;连接产物和预扩增产物最适稀释倍数均为10倍;预扩增产物经选择性引物E-ACF/M-CAT和E-ACA/M-CAG扩增,琼脂糖电泳检测其主带分别集中在250～375 bp和500～750 bp,6%聚丙烯酰胺凝胶电泳检测及银染,条带清晰可辨.结论:该体系具有稳定性高、重复性好等优点,可用于华中五味子AFLP分析.     

吉富罗非鱼AFLP反应体系的建立与优化

本文以我国水产养殖主导品种吉富罗非鱼(farmed tilapia)为研究材料,进行扩增片段长度多态性(AFLP)反应体系的研究,初步建立了一套适合罗非鱼的AFLP反应体系。对体系中关键环节的优化结果如下:基因组DNA要求无降解和RNA污染,OD260/OD280比值在1.8~2.0之间;基因组DNA EcoRⅠ/MseⅠ37℃双酶切6h、20℃连接20h,连接产物10倍稀释,PCR预扩增产物稀释45倍作为选择性扩增的模板,选择性扩增产物经6%变性丙烯酰胺凝胶电泳检测可获得条带清晰、背景干扰小的图像。该体系的构建为今后进行罗非鱼群体遗传多样性分析、种质鉴定、重要经济性状分子标记的开发及遗传连锁图谱构建等方面研究提供了参考。     

华中五味子AFLP反应体系的建立

目的：建立一个适于华中五味子研究用的AFLP反应体系。方法：以华中五味子硅胶干燥嫩叶为试材,采用改良CTAB法提取到高质量DNA。通过琼脂糖凝胶电泳和聚丙烯酰胺凝胶电泳对MseⅠ/EcoRⅠ双酶切、连接、预扩增和选择性扩增过程中的关键因素进行分析。结果：双酶切6h,片段主要集中在250～2000bp;连接产物和预扩增产物最适稀释倍数均为10倍;预扩增产物经选择性引物E-ACT/M-CAT和E-ACA/M-CAG扩增,琼脂糖电泳检测其主带分别集中在250～375bp和500～750bp,6%聚丙烯酰胺凝胶电泳检测及银染,条带清晰可辨。结论：该体系具有稳定性高、重复性好等优点,可用于华中五味子AFLP分析。     

日本沼虾AFLP反应体系的建立

目的:建立一个适于日本沼虾研究用的 AFLP 反应体系.方法:以日本沼虾 DNA 为材料,对基因组酶切时间、选择性扩增中Mg2 、dNTP浓度、预扩增产物稀释倍数及选扩性引物M 3/E 3配比等进行了比较分析.结果:酶切5h,选扩 25ul PCR 反应体系中Mg2 2mmol/L,dNTP 1.2rmnol/L,预扩产物稀释 40 倍,选扩引物M 3/E 3配比为8:1,所得产物在毛细管电泳中可得剑稳定的结果.结论:该体系的构建为 AFLP 技术在日本沼虾相关研究中的应用奠定了基础.     

甘蔗双低频酶cDNA-AFLP体系的优化

目的：建立一个适合于甘蔗（Saccharum officenarum）为研究材料的cDNA-AFLP反应的优化体系。方法：用Rever-tAidTM First Strandc DNA Synthesis Kit反转录获得第一链,用Rnase H、E.coliDNA聚合酶Ⅰ和E.coliDNA连接酶合成双链cDNA,用双低频酶EcoRⅠ和PstⅠ对dscDNA酶切,连接,预扩增,和选择性扩增的关键因素进行分析。结果：500ng的dscDNA双酶切5h,将16℃过夜连接的产物稀释1倍用作预扩增的模板,预扩增产物稀释50倍作为选择性扩增模板,6%聚丙烯酰胺凝胶检测及银染,扩增条带均匀分布,清晰可辨且主要分布在200～2000bp之间。结论：该体系具有稳定性高,重复性好等优点,可用于甘蔗cDNA-AFLP分析。     

喜旱莲子草MSAP分析技术反应体系的建立

目的：建立一个适于研究喜旱莲子草DNA甲基化的MSAP分析体系。方法：以喜旱莲子草为材料,采用改良CTAB法提取基因组DNA,并对影响MSAP分析的关键步骤包括基因组DNA酶切反应时间、模板DNA连接产物稀释倍数、预扩增产物稀释倍数等进行了优化。结果：改良CTAB方法提取的DNA质量较好,酶切反应时间5h,酶切连接产物稀释10倍进行预扩增,预扩产物稀释10倍进行选择性扩增,所得PCR产物经6%聚丙烯酰胺电泳,条带清晰可辨,并能有效检测喜旱莲子草基因组DNA甲基化的程度和状态。结论：为研究喜旱莲子草表观遗传适应机制奠定了基础。     

小叶锦鸡儿基因组DNA的提取及AFLP反应体系的建立

以小叶锦鸡儿幼嫩叶片为材料,采用改良的SDS法提取其基因组DNA,通过优化AFLP技术体系中的几个主要因素,建立了适合小叶锦鸡儿的AFLP银染反应体系。改良的SDS法能通过在提取液中加入β-巯基乙醇防止氧化、加入PVP去除酚类等物质,获得满足AFLP分析要求的纯度高、完整性好的基因组DNA;用EcoRⅠ和MseⅠ37 ℃双酶切4 h后可以将500 ng的基因组DNA完全切开。酶切产物和接头经16℃连接过夜后,用带有1个选择性碱基的引物和带有3个选择性碱基的引物分别进行预扩增和选择性扩增,扩增产物经变性聚丙烯酰胺凝胶电泳分离,用AgNO₃染色,得到了清晰的指纹式样。小叶锦鸡儿AFLP反应体系的建立为利用该技术研究小叶锦鸡儿的遗传多样性奠定了实验基础。     

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.