苛求芽孢杆菌基因组DNA提取方法的比较

目的:比较不同方法提取苛求芽孢杆菌基因组DNA的差异。方法:用经典CTAB提取法、改进CTAB法(溶菌酶处理结合CTAB提取法)、UniQ柱吸附提取法制备苛求芽孢杆菌基因组DNA,比较产物完整性和用于PCR扩增的有效性。结果:三种方法制备基因组DNA纯度接近,但改进CTAB法产率最高,UniQ法产率最低。经典CTAB法和UniQ法提取基因组DNA易降解。三种方法所得基因组DNA用于PCR扩增效率接近。结论:溶菌酶裂解结合CTAB提取更适合制备苛求芽孢杆菌基因组DNA。     

利用改良CTAB法快速小量提取微胚乳玉米基因组DNA

为了能快速小量提取微胚乳玉米基因组DNA,以微胚乳玉米幼叶为试材,采用改良CTAB法和传统CTAB法提取微胚乳玉米基因组DNA,并对所提取的DNA通过紫外分光光度计、琼脂糖凝胶电泳和PCR扩增等方法进行检测。两种方法所得基因组DNA的OD260/OD280在1.8~1.9之间,电泳条带清晰,无蛋白质和RNA污染,DNA无明显降解,其浓度和纯度都适合基因工程实验操作的条件。改良CTAB法与传统CTAB法相比更简便快捷,可实现大批量的不同样本基因组DNA的同时提取,提供了一种简便、快捷、有效和实用的微量提取微胚乳玉米基因组DNA方法,可满足以PCR为基础的分子生物学研究。     

松科植物基因组总DNA提取方法的比较

目的:研究对比了用不同方法提取红松、樟子松和红皮云杉等3种松科植物叶片基因组DNA的效果,以寻找适合提取松科植物叶片基因组DNA的方法。方法:分别比较了用传统的CTAB法、SDS法以及3种改良的CTAB法提取的上述3种松科植物叶片基因组DNA的电泳、纯度和酶切效果。结果:采用不同方法提取的3种松科植物叶片基因组DNA的质量差异较大。结论:常规CTAB法和SDS法无法提取出高质量松科植物基因组DNA,而改良后的CTAB法的提取效果较好。     

几种中药DNA提取方法的比较研究

以丹参、绞股蓝、三七为材料,分别采取CTAB法和SDS法提取基因组DNA,并通过紫外分光光度法和琼脂糖凝胶电泳对所提取的DNA样品进行检测,将它们在DNA产量、质量等方面的优缺点进行总结。结果表明,CTAB法能从丹参、绞股蓝中提取高质量的DNA,而三七的DNA更适合用SDS法提取。     

三种提取柱状黄杆菌基因组DNA方法的比较

采用酚氯仿抽提法、CTAB法和SDS-蛋白酶K法分别对鱼类病原菌柱状黄杆菌提取基因组DNA。使用超微量紫外分光光度计和琼脂糖凝胶电泳检测所提取的基因组DNA的产量和质量,并用PCR扩增对DNA进行了评价。结果显示,3种方法均可提取到柱状黄杆菌的基因组DNA,并能有效扩增细菌16S rDNA序列,但CTAB法提取的DNA产量和质量最高,CTAB法可以作为柱状黄杆菌DNA提取以开展分子生物学研究的首选方法。     

油用牡丹‘凤丹’叶片DNA提取方法研究

以新鲜的牡丹叶片为材料,采用CTAB法、SDS法以及改良CTAB法提取基因组DNA,通过紫外光谱分析法、琼脂糖凝胶电泳等检测方法对牡丹基因组DNA的提取方法进行筛选。在这三种DNA提取方法中,SDS法略好于CTAB法。SDS法DNA得率虽低,但其纯度高,去糖去蛋白等杂质比较干净,且在未加RNA酶的情况下,RNA污染较少。改良CTAB法浓度比CTAB法增大,但纯度仍低于SDS法。所以,牡丹叶片DNA的最佳提取方法为SDS法。     

蚧虫基因组DNA不同提取方法的比较

实验以日本龟蜡蚧CeroplastesjaponicusGreen,白蜡绵粉蚧PhenacoccusfraxinusTang ,朝鲜球蚧DidesmococcuskoreanusBorchseniush和瘤大球坚蚧EulecaniumgiganteaShinji等 4种蚧虫为材料 ,分别用十二烷基硫酸钠 (SDS)法、十六烷基三乙基溴化铵 (CTAB)法、醋酸钾 (KAc)法和氯化钠 (NaCl)法等 4种方法 ,对单只蚧虫进行基因组DNA提取 ,用 0 8%琼脂糖凝胶电泳检测所提DNA。结果表明 ,4种方法都可以提取到基因组DNA ,但是比较而言 ,CTAB法和NaCl法所提取的DNA质量明显优于SDS法和KAc法 ,并适用于PCR。因此认为 ,CTAB法和NaCl法是实验室提取单只蚧虫基因组DNA更有效而实用的方法。     

降香黄檀基因组DNA的提取方法研究

目的：建立适合降香黄檀基因组DNA的提取方法。方法：采用常规SDS法、常规CTAB法和改良CTAB法等3种方法提取降香黄檀叶片基因组DNA,经电泳、吸光度、酶切检测比较提取结果;对采用改良CTAB法提取的基因组DNA进行ISSR-PCR检测。结果：改良CTAB法通过增加洗涤样品步骤,有效去除了多糖和多酚类物质,提取的DNA质量好,无降解现象,无蛋白质、盐离子及RNA污染。结论：改良CTAB法是一种高效的提取方法,使用该方法所得DNA的质量完全能够满足相应的分子操作需要。     

短序十大功劳基因组总DNA提取方法研究

以短序大功劳嫩叶为材料,采用CTAB法、CTAB改良法1、CTAB改良法2、SDS法和试剂盒法五种方法提取短序十大功劳基因组总DNA,用分光光度计和琼脂糖凝胶电泳方法检测所得总DNA的纯度和得率,用ISSR-PCR扩增的方法检测所得总DNA的质量。结果表明,五种方法均能从短序大功劳叶片中提取到基因组DNA,但不同方法提取得的基因组DNA的纯度、浓度和得率存在明显的差异。CTAB改良法2和试剂盒法提取的DNA纯度高,可直接用于下游分子生物学实验,CTAB法、CTAB改良法1和SDS法提取的总DNA质量较差,不利于下游的分子生物学实验;五种方法提取的总DNA的得率在10.836~451.709μg/g之间,呈CTAB法>SDS法>CTAB改良法1>CTAB改良法2>试剂盒法的现象。此实验获得的结果可以为短序十大功劳分子生物学研究提供基础。     

三种提取冬虫夏草菌丝体基因组DNA方法的比较

采用改良氯化苄法、CTAB法、蛋白酶K裂解法这三种方法,对冬虫夏草菌丝体基因组DNA进行提取,将提取的基因组DNA经过紫外分光光度计检测纯度和计算浓度、琼脂糖凝胶电泳分析及PCR扩增,结果表明,3种方法均能提取到符合分子生物学的DNA,其中蛋白酶K裂解法纯度最高,含蛋白质少,改良氯化苄法、CTAB法次之。而浓度则是改良氯化苄法最高,CTAB法、蛋白酶K裂解法次之。3种方法所提取的DNA均能扩增出理想条带。     

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.