肠杆菌膦酸酯代谢途径中phnF基因的研究

大肠杆菌的phn操纵子与膦酸酯(Pn)的利用密切相关。实验利用PCR扩增、TA克隆等方法．获得了大肠杆菌phn操纵子中phnE、phnF和phnG基因的亚克隆,并进行了序列测定。通过P1噬菌体转导,构建了phnF的TnphoA’-9转座子插入突变体JW19,该突变仅对大肠杆菌的AEPn同化有微弱的影响,而利用phnE和phnG序列与染色体重组构建的phnF全缺失突变株JW67,则几乎不能在．AEPn培养基上生长。通过phnF基因的诱导高表达,用亲和柱层析分离纯化了PhnF。蛋白,达到电泳纯。并且用凝胶延滞的方法观察到,PhnF蛋白与加phn操纵子DNA片段相互作用后,可使凝胶图谱类型发生改变。     

人碱性成纤维细胞生长因子基因克隆,cDNA5‘端修饰及在大 …

采用ｃＤＮＡ－ＰＣＲ技术,从人胎盘ｃＤＮＡ文库ＤＮＡ中克隆了人碱性成纤维在子（ｈｂＦＧＦ）基因,用ＰＣＲ突变法对其５＆端序列进行修饰,奖天然和修饰后的ｈｂＦＧＦ基因分别克隆至表达载体ｐＢＶ２２１,免疫抑迹和ＳＤＳ－ＰＡＧＥ结果证明,经修饰后的基因在大肠杆菌ＤＳ５α中获得了表达,表达量占菌体总蛋白９％。     

小麦黄花叶病毒RNA228kDa蛋白基因的表达及表达产物抗血清的制备

根据小麦黄花叶病毒（ Ｗ Ｙ Ｍ Ｖ） 核苷酸序列测定结果,将 Ｗ Ｙ Ｍ Ｖ Ｒ Ｎ Ａ２ 上的２８ ｋ Ｄａ 蛋白基因克隆到ｐ Ｅ Ｔ１１ａ 上,构建了原核表达载体ｐ Ｅ２８３９ 。 Ｓ Ｄ Ｓ Ｐ Ａ Ｇ Ｅ 分析表明,经 Ｉ Ｐ Ｔ Ｇ 诱导,２８ ｋ Ｄａ蛋白基因在大肠杆菌 Ｂ Ｌ２１（ Ｄ Ｅ３）ｐ Ｌｙｓ Ｓ 中得到高效表达。以含表达产物的凝胶为抗原,免疫家兔,首次制备了小麦黄花叶病毒 Ｒ Ｎ Ａ２ 蛋白特异性抗血清。     

人巨噬细胞集落刺激因子（hM—CSF）基因的合成及表达

按照ｈＭ－ＣＳＦ基因的序列,适当采用大肠杆菌的优选密码子,人工合成了Ｍ－ＣＳＦ的基因。在合成中我们采用了分段克隆和顺次克隆的方法,在次级克隆中我们成功地使用多片段分组连接和多片段一次克隆战略,还尝试了多种单链战术,在表达载体的构建中,充分利用人工合成基因的灵活性,通过对Ｎ端６个氨基酸编码的变换及ＳＤ序列－ＡＴＧ间距离的改变,获得了大肠杆菌中高效表达的重组体,表达的蛋白量的变换及ＳＤ序列－ＡＴＧ间距     

甜菜坏死黄脉病毒外壳蛋白基因在大肠杆菌中的高效表达

将甜菜坏死黄脉病毒内蒙古分离物的外壳蛋白基因亚克隆到ｐＪＷ２上构建成在大肠杆菌中表达的载体。ＳＤＳ－ＰＡＧＥ及Ｗｅｓｔｅｒｎ ｂｌｏｔｔｉｎｇ检测的结果表明,该表达载体在大肠杆菌ＤＨ５α中经温度诱导后特异地表达２１ｋＤ的甜菜坏死黄脉病毒外壳蛋白。经光密度扫描估测,其表达量占大肠杆菌总蛋白的１９．５％。     

葡萄扇叶病毒外壳蛋白基因的克隆,序列分析及其在大肠杆菌中…

通过ＲＴ－ＰＣＲ方法把葡萄扇叶病毒（ＧＦＬＶ）外壳蛋白基因（ＣＰ ｇｅｎｅ）分成两部分扩增,扩增产物克隆入ｐｇＥＭ－５Ｚｆ（＋）载体,并通过ＢｇｌⅡ位点连接成一完整的外壳蛋白基因,通过序列分析测得全长外壳蛋白基因为１５１２ｂｐ,编码５０４个ＡＡ＇ｓ与国外株系ＧＦＬＶ－Ｆ１３相比,核苷酸同源性为８８．４％,氨基酸同源性为９５．８％。并且这一外壳蛋白基因在大肠杆菌Ｅ． ｃｏｌｉＤＨ－５α中得到了表达。     

拟南芥AtJ3基因的克隆和分析

克隆并分析了拟南芥（Ａｒａｂｉｄｏｐｓｉｓｔｈａｌｉａｎａ（Ｌ．）Ｈｅｙｎｈ．）ＡｔＪ３的ｃＤＮＡ核苷酸序列,并证明其翻译产物与Ｅ．ｃｏｌｉ的ＤｎａＪ蛋白高度同源。ＡｔＪ３蛋白分子中具有全部这类蛋白的典型特征包括Ｊ结构域（ｄｏｍａｉｎ）、Ｇ或ＧＦ结构域、富含半胱氨酸的锌指结构域,Ｃ末端的ＣＡＱＱ是一个蛋白法尼基化信号。用ＡｔＪ３的ｃＤＮＡ序列末端非翻译区作探针,从拟南芥基因组文库中分离获得ＡｔＪ３基因。基因序列分析表明该基因是由被５个内含子分隔的６个外显子组成。根据Ｓｏｕｔｈｅｒｎ杂交分析,ＡｔＪ３基因为单拷贝基因。Ｎｏｒｔｈｅｒｎ分析结果表明,ＡｔＪ３在子叶、叶、根、花及长角果中都表达。３５℃的热激能增加叶中ＡｔＪ３的ｍＲＮＡ表达     

基因重组人肿瘤坏死因子-α突变体的构建

在详细分析ＴＮＦ α结构及有关ＴＮＦ α结构与功能关系研究的基础上,设计并人工合成了一对ＴＮＦ α结构基因点突变引物。应用ＰＣＲ和分子克隆技术构建了一种新型人肿瘤坏死因子（ＴＮＦ α）分子的编码基因,将该编码基因插入表达质粒,转化大肠杆菌,通过温度诱导获得了表达蛋白,对突变体克隆进行了ＤＮＡ电泳、酶切位点检测以及基因序列测定,并对突变体蛋白进行了ＳＤＳ ＰＡＧＥ电泳检测。     

人睫状神经营养因子基因及突变体在大肠杆菌中的表达

人睫状神经营养因子（ｈｕｍａｎ ｃｉｌｉａｒｙ ｎｅｕｒｏｔｒｏｐｈｉｃ ｆａｃｔｏｒ,ｈＣＮＴＦ）ｃＤＮＡ克隆入具有ＰＬ启动子的表达载体,转化大肠杆菌ＨＢ１０１,构建成表达ｈＣＮＴＦ菌株。热诱导后,ｈＣＮＴＦ的表达量达菌体总蛋白量的２５％。用离子交换层析、凝胶过滤层析从菌体裂解液中纯化了ｈＣＮＴＦ。ＳＤＳ－ＰＡＧＥｈＣＮＴＦ的分子量约为２４ｋｄ,Ｎ端氨基酸序列分析结果与依基因核苷酸推导疗列相符。     

转录因子NF-κB p50基因的克隆、表达及抗p50抗体的制备

利用ＤＮＡ重组技术,将转录因子ＮＦ－κＢｐ５０基因片段插入ｐＧＥＸ－２Ｔ质粒载体,经ＤＮＡ序列分析证明克隆的正确性．将重组的ｐＧＥＸ－２Ｔ／ｐ５０转化入大肠杆菌ＪＭ１０９,表达出ｐＧＥＸ－２Ｔ／ｐ５０融合蛋白．经ＷｅｓｔｅｒｎＢｌｏｔ检测证实表达产物对抗ｐ５０ｃ的抗体呈特异性反应,表明克隆的正确性,并成功地应用纯化的ｐ５０蛋白制备了免疫血清．为进一步对ＮＦ－κＢ的功能进行研究打下了良好的基础     

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.