转豇豆胰蛋白酶抑制剂基因抗虫基蓝植株的获得

利用根癌农杆菌介导,将豇豆胰蛋白酶抑制剂（ＣｐＴＩ）基因导入甘蓝栽培品种“京丰”和“迎春”,并分别获得了转基因再生植株。对ＮＰＴⅡ的ＥＬＩＳＡ检测表明,标记基因ＮＰＴⅡ已在再生植株中得到有效表达。对转化植株进行Ｓｏｕｔｈｅｒｎ ｂｌｏｔ分子杂交实验进一步证明ＣｐＴＩ基因已整合到甘蓝的基因组。实验室内的叶片离体饲虫及盆栽饲虫试验表明,转基因甘蓝对菜青虫具有一定抗性。实验中还观察到,采用愈伤组织分化途     

豇豆胰蛋白酶抑制剂基因转化芥菜及抗虫鉴定

用农杆菌介导将豇豆胰蛋白酶抑制剂 (CpTI)基因导入芥菜 ,获得了Kan抗性植株 .经PCR扩增、PCR Southern印迹和Northern印迹分析 ,转化再生植株大部分呈阳性 ,而非转化的再生植株均为阴性 ,证明CpTI基因已存在于芥菜基因组中 .在室内进行了喂虫试验 ,结果表明转基因芥菜抗虫性明显高于对照 ,转基因植株之间存在抗虫性差异     

豇豆胰蛋白酶抑制剂(CpTI)基因转化欧美杨的研究

本研究建立了欧美107杨的高频再生体系,用改良的根癌农杆菌介导法将豇豆胰蛋白酶抑制剂(CpTI)基因导入107杨中。经过严格的卡那霉素(Km)筛选,得到了Km抗性(Kmr)植株。对部分Kmr植株进行PCR及PCR-Southern杂交鉴定,证实CpTI基因已整合进杨树基因组中。转基因植株的饲虫实验表明,其中部分株系的叶片可在一定程度上抑制扁刺蛾幼虫的生长。     

基因枪轰击成熟花粉粒转化玉米的研究

利用基因枪轰击花粉粒再授粉的基因转化途径,将豇豆胰蛋白酶抑制剂基因（CpTI）成功导入玉米受体中。经卡那霉素筛选结果表明,非转化植株经1000ppm卡那霉素溶液处理后白化、死亡,余下大量健壮、可育的抗性植株,转化率约1．59％。通过对抗性植株进行PCR和PCR—Southern检测,初步确定CpTI基因已导入玉米基因组。饲虫实验结果表明转化植株具有较强的抗虫性。     

利用Cre/lox重组系统获得无选择标记的SKTI抗虫转基因烟草

将置于两个同向lox位点之间的Bar基因表达盒与大豆胰蛋白酶抑制剂SKTI基因表达盒融合后获得相应植物表达载体,转化烟草Wisconsin 38后获得对棉铃虫具有明显抗性的SKTI转基因植株。SKTI转基因植株通过叶盘二次转化法导入Cre基因,对再生植株叶盘进行Basta的抗性检测,检测Bar基因的删除情况。结果表明:绝大多数再生植株对应叶盘在含8 mg/L PPT的筛选培养基上无法再生,Bar基因被删除的效率在38%~100%之间。对Bar基因删除区域进行PCR及克隆测序后发现Bar基因表达盒被精确删除。对Bar基因删除植株开花自交获得的分离后代进行NPTⅡ抗性检测,5株NPTⅡ敏感植株分子检测显示均只含有SKTI基因而无Cre基因存在,为无选择标记基因的SKTI转基因植株。     

烟草MnSOD基因在保定苜蓿中的转化

通过农杆菌介导的转基因方法 ,将烟草MnSOD基因的cDNA序列导入保定苜蓿中 ,成功地诱导了转基因植株的再生。转基因植株生长和发育良好 ,NPTⅡ基因和MnSOD基因的PCR检测和Southern杂交表明MnSOD基因已经导入到保定苜蓿的再生植株中 ,MnSOD活性检测表明部分转基因植株的MnSOD活性显著高于对照植株     

通过花粉管途径建立泡桐转化系统的初探

在木本科植物的遗传转化中,迄今所见到的报道全是将某一特定克隆基因导人木本植物．我们利用植物粘粒载体克隆了欧洲黑杨30kb左右的DNA片段,并利用其中的一个克隆片段,通过花粉管途径进行了导人泡桐的研究．泡桐转化植株经DNA分子杂交实验及NPTⅡ酶活性侧定证实外源DNA片段已经转移到泡桐细胞中,NPTⅡ基因得到了表达,获得了转基因泡桐植株．     

利用激光微束穿刺法将杀虫蛋白基因导入油菜的研究

利用激光微束照射油菜子叶柄,将来自苏云金杆菌的杀虫蛋白（Ｉｎｓｅｃｔｉｃｉｄａｌｃｒｙｓｔａｌｐｒｏｔｅｉｎ,ＩＣＰ）基因导入油菜细胞中,经植株再生和卡那霉素筛选,获得了转基因植株。对转基因植株进行了ＰＣＲ检测和饲虫实验,发现转基因植株为ＰＣＲ扩增阳性,某些植株表现出了较强的抗虫性。实验结果表明外源抗虫基因已被整合到油菜基因组并得到了表达。     

农杆菌介导抗储粮害虫转基因小麦(Triticum aestivum L.)的获得及分析

以本实验室选育的小麦优良品系的胚性愈伤组织为材料,采用农杆菌介导将抗虫基因豇豆胰蛋白酶抑制剂基因CpTI转入小麦培养细胞,经筛选获得抗卡那霉素的愈伤组织并再生植株。经PCR和实时PCR检测、PCR-Southern和Southernblot验证,确定了3株独立再生植株为含有CpTI的转基因植株。农杆菌菌浓度、侵染时间及转化处理方式对小麦转化率均有明显影响。3株转基因植株正常可育并结籽,形成转基因株系。外源基因在转基因植株T1代中的分离呈多样性,部分株系(转基因株系T-Ⅰ、T-Ⅲ)表现出孟德尔遗传规律。抗虫试验表明,3株转基因植株T2代籽粒对储粮害虫麦蛾具有一定的抗性,转基因株系T-Ⅰ、T-Ⅱ、T-Ⅲ及非转基因植株的T2代籽粒虫蛀率分别为19·8%、21·9%、32·9%和58·3%。转基因植株T1代群体农艺性状调查显示,3个株系具有良好的农艺性状,为小麦的遗传改良提供了新的种质抗虫材料。     

酵母pro 2基因转化紫云英的研究

用外植体一农杆菌共培养法将酵母脯氨酸合成酶基因2(pro 2)导入豆科牧草紫云英,获得转基因植株。Southern blot分析检测到转化植株基因组中存在外源DNA的同源顺序,证明酵母pro 2基因已整合到紫云英细胞基因组中。转化植株具有强的NPT Ⅱ酶活性,而对照植株呈阴性反应。在含0.5%NaCl的培养基上,紫云英植株内游离脯氨酸含量增高,一些转化植株叶片内游离脯氨酸含量显著高于对照,而且耐盐性有所提高。转化植株移栽到土壤中开花结实,收获到R_1代种子。     

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.