草鱼促性腺激素基因的原核表达及多克隆抗体的制备

选用原核表达载体pGEX-4T-1,分别插入草鱼GTH和FSHβ的cDNA序列,构建成N端含有GST融合蛋白标签的表达质粒,分别转化大肠杆菌BL21(DE3),在IPTG诱导下表达出2个融合蛋白,SDS-聚丙烯酰胺凝胶电泳显示重组融合蛋白GST-GTHα和GST-FSHβ的相对分子质量大约为35、38 kD.用抗GST标签的单克隆抗体分别对2个表达蛋白进行Western blot鉴定,结果显示重组蛋白表达正确.利用制备型SDS-PAGE纯化回收的蛋白并免疫新西兰大白兔,分别制备了抗GTH和抗FSHβ的具有较高效价的多克隆抗体.该结果为纯化天然GTH蛋白提供了有效的检测手段,也为进一步制备GTH单克隆抗体奠定了基础.     

人结合珠蛋白cDNA 克隆及其在大肠杆菌中的表达和鉴定

目的：克隆人结合珠蛋白（haptoglobin,Hp）cDNA ,并在大肠杆菌中表达和鉴定。方法：从Hela 细胞中分离总RNA,采用RT-PCR 方法获得人Hp cDNA,分别克隆至原核表达载体pET-32a和PGEX-4T-1,转化至大肠杆菌BL21,IPTG 诱导表达,并进行SDS-PAGE 及Western blot 鉴定。结果: 成功构建了高效原核表达质粒PET-32a-Hp 和PGEX-4T1-Hp;Western 印迹结果表明,经IPTG 诱导,在大肠杆菌中表达了分子量约30 kD和37 kD 的目的蛋白;表达产物经Ni2+-NTA 离子交换树脂纯化, 纯度>90%。结 论：在E.coli成功表达和纯化了人Hp 融合蛋白,为进一步开发人Hp 诊断试剂打下基础。     

拟态弧菌VMH蛋白的原核表达及其多克隆抗体制备

目的实现拟态弧菌热不稳定性溶血素(VMH)的原核表达,制备兔抗VMH蛋白的多克隆抗体。方法根据GenBank上已有的拟态弧菌vmh基因序列,设计并合成引物,通过PCR方法扩增vmh基因。PCR纯化产物酶切后,定向插入到PET-32a表达载体构建重组表达质粒PET-32a-vmh。重组表达质粒转化至E.coli Rosetta感受态细胞,在IPTG诱导下进行VMH蛋白表达。SDS-PAGE分析重组VMH蛋白(rVMH)的表达形式,并分别采用兔血平板扩散法和Western blot检测其溶血活性和免疫反应性。用纯化的rVMH蛋白免疫新西兰大白兔,3次免疫后采集免疫血清,采用饱和硫酸铵分级沉淀结合亲和层析法纯化多克隆抗体,并检测其纯度与效价。结果重组表达质粒PET-32a-vmh诱导表达后,经SDS-PAGE分析发现分子量约为77.8kDa的rVMH蛋白主要以包涵体形式表达,该蛋白经变性复性后具有溶血活性和免疫反应性。兔抗rVMH蛋白的多克隆抗体经纯化后,其纯度达95%,ELISA效价为1∶26843545600,琼扩效价为1∶32。结论成功制备了rVMH蛋白及其多克隆抗体,为进一步采用噬菌体肽库筛选技术鉴定VMH蛋白表位提供了物质基础。     

幽门杆菌Catalase/GST融合蛋白的表达、标签切除及鉴定

旨在利用GST融合基因表达系统表达幽门螺杆菌Catalase融合蛋白,并利用凝血酶切除GST标签.将重组质粒Catalase/pGEX-4T-1转化大肠杆菌BL21( DE3)感受态中,用IPTG进行诱导表达,菌体经反复冻融、溶菌酶裂解及超声破菌后,Catalase/GST融合蛋白以部分可溶性的形式表达在上清中.采用谷胱甘肽琼脂糖树脂Glutathione Sepharose 4B对其进行纯化,得到Catalase/GST融合蛋白,再用凝血酶进行GST标签的切除,所得产物进行Western blotting鉴定.高效表达出Catalase/GST融合蛋白的相对分子质量约85 kD,凝血酶成功地切除了GST标签,Western blotting证实Catalase蛋白能被鼠抗Catalase单克隆抗体识别.     

人结合珠蛋白cDNA克隆及其在大肠杆菌中的表达和鉴定

目的：克隆人结合珠蛋白（haptoglobin,Hp）cDNA,并在大肠杆菌中表达和鉴定。方法：从Hela细胞中分离总RNA,采用RT-PCR方法获得人Hp cDNA,分别克隆至原核表达载体pET-32a和PGEX-4T-1,转化至大肠杆菌BL21,IPTG诱导表达,并进行SDS—PAGE及Western blot鉴定。结果：成功构建了高效原核表达质粒PET-32a-Hp和PGEX-4T1-Hp;Western印迹结果表明,经IPTG诱导,在大肠杆菌中表达了分子量约30kD和37kD的目的蛋白;表达产物经Ni2^＋-NTA离子交换树脂纯化,纯度〉90％。结论：在E．coli成功表达和纯化了人Hp融合蛋白,为进一步开发人Hp诊断试剂打下基础。     

鳞状细胞癌抗原SCCA基因的构建、表达及鉴定

目的:重组人鳞状细胞癌抗原(SCCA)的基因及表达融合蛋白,为下一步建立新的肝癌诊断方法奠定基础.方法:提取子宫颈癌细胞株(hela)中的总RNA,应用RT-PCR、PCR等技术扩增出SCCA基因,将其分别与PET-32a及PGEX-4T-1载体连接,转化入DH5α菌中进行克隆,并测序鉴定.异丙基β-D-硫代半乳糖苷(IPTG)诱导转入工程质粒的BL21菌中表达SCCA融合蛋白(分别含有HIS,GST-Tag),并进行SDS-PAGE及Western blotting鉴定.结果:经RT-PCR、PCR扩增后成功获得一条450bp的DNA片段,经测序鉴定与预期序列一致;并成功在大肠杆菌中实现了高表达,经Western blotting鉴定为SCCA融合蛋白.结论:成功获得SCCA目的基因并获得高纯度的SCCA融合蛋白,为进一步开发针对肝癌的SCCA诊断试剂打下基础,开辟诊断肝癌新途径.     

靶向性DNA甲基化酶在pET32a原核表达载体中的表达和鉴定

目的:在pET32a原核表达载体中表达融合myc-6his标签的靶向性甲基化酶B1-3a并进行鉴定。方法:以含有B1-3a基因的pcDNA4.0-B1-3a-myc-6his质粒为模板,通过PCR的方法扩增获得融合有myc-6his标签序列的目的区段B1-3a,然后克隆入表达载体pET32a;以SDS-PAGE和Western blot方法对表达产物进行鉴定。结果:表达产物中在分子量43kD左右可见与目的蛋白分子量相符的条带,该条带可被6his标签单克隆抗体特异识别。结论:正确构建了靶向性甲基化酶B1-3a的原核表达载体,靶向性甲基化酶能够在pET32a中成功表达。     

盐藻小G蛋白DsRab的原核表达及纯化

前期对盐藻小G蛋白基因DsRab研究表明,在盐胁迫诱导下该基因转录水平明显提高。为进一步研究该蛋白在盐藻耐盐机制中的作用,PCR扩增DsRab的开放阅读框(ORF),并将其克隆至带有GST标签的原核表达载体pGS-21a,得到重组表达载体pGS-21a-DsRab。将重组表达载体转化E.coli BL21(DE3),IPTG诱导表达,并优化诱导表达条件,利用GST-SefinoseTM Kit进行纯化,用SDS-PAGE和Western blot鉴定。结果表明,成功构建了重组表达载体pGS-21a-DsRab,SDS-PAGE结果显示得到的蛋白与预期分子量相符,并且纯度较高;Western blot检测结果初步证明该融合蛋白为GST-DsRab。     

人β-淀粉样肽Aβ_(42)的融合表达与纯化

[目的]建立一种快速可靠、获取足量和高纯度的人β-淀粉样肽(Aβ_(42))的方法。[方法]首先利用重叠PCR技术扩增获得Aβ_(42)基因全长。随后将基因连入p GEX-4T-1载体,利用GST系统表达融合蛋白。分别在16℃、25℃、30℃和37℃诱导表达,SDS-PAGE检测融合蛋白的表达情况,确定表达的最佳温度。根据优化条件进行目的蛋白的大量表达,利用Gstrap FF柱亲和纯化GST-Aβ_(42)融合蛋白。[结果]成功构建p GEX/Aβ_(42)表达载体,确定30℃为诱导表达的最佳温度。大量表达并经过纯化可获得分子量为30.7 k Da的融合蛋白。[结论]利用GST融合系统表达纯化可得到纯度超过90%的GST-Aβ_(42)融合蛋白,重组蛋白的产率约为1.2 mg/L培养基。当用凝血酶切除GST融合标签后,Aβ_(42)易聚集沉淀。     

GST—talinl融合蛋白的原核表达及纯化

应用PCR方法扩增talinl的cDNA,并将其重组入谷胱甘肽转硫酶融合基因表达载体pGEX-4T-1中,获取人源的GST—talinl融合蛋白,为下阶段深入的研究talinl的结构、功能、及其与之相互作用的蛋白打下基础。经酶切、序列鉴定．选择正确重组子,将其质粒转化大肠杆菌BL21（DE3）,IPTG诱导表达,用Glutathione Sepharose 4B柱纯化,western blot鉴定。克隆得到了一个2400bp的talinl的cDNA片断,重组质粒目的DNA测序正确,纯化出分子量约为121、6kD的融合蛋白。用基因工程方法使GST—talinl重组质粒在原核细胞表达并成功纯化出GST—talinl融合蛋白。     

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.