粘虫核型多角体病毒凋亡抑制基因的定位,序列和启动子结构

以ＡｃＮＰＶ凋亡抑制基因ｐ３５为探针,与ＬｓＮＰＶＤＮＡ的限制性片段和ＬｓＮＰＶＤＮＡＥｃｏＲＶ片段杂交,发现ＥｃｏＲＶ５．５ｋｂ片段有强烈的杂交信号。将此片段亚克隆后,测定了１２４４ｂｐ序列,发现一个完整的ＯＲＦ,推导的３０２个氨基酸与ＡｃＮＰＶｐ３５蛋白有７０．４％的氨基酸同源性,证明所测ＯＲＦ为ＬｓＮＰＶ的ｐ３５基因。结构分析发现其５′端有早期基因启动子元件ＧＣ、ＡＣＧＴ和ＴＡＴＡｂｏｘ。有２２ｂｐ的顺向重复序列,包括由两个重叠的ＴＡＴＡｂｏｘ和上下游两个ＡＣＧＴｍｏｔｉｆ组成的两套启动子元件,这些结构特征与ＡｃＮＰＶ的凋亡抑制基因十分相似。     

戊型肝炎病毒细胞分离株部分核苷酸序列分析

用抗原捕获／多聚酶链反应（ＡＣ／ＰＣＲ）对戊型肝炎病毒（ＨＥＶ）细胞分离株ＭＪ９０和Ｒ２５基因组的部分核苷酸序列进行扩增,获得了与ＨＥＶ缅甸株ＥＴ１·１相同的ｃＤＮＡ扩增带。该ｃＤＮＡ扩增带纯化后用双脱氧核苷酸ＤＮＡ链末端终止法测序,ＣＪ９０、Ｒ２５株的核苷酸和氨基酸序列与ＥＴ１·１克隆的同源性分别为９９．６％、１００％和９９％、９９％,从而证明ＭＪ９０和Ｒ２５毒株为ＨＥＶ．     

可溶性白细胞介素6受体基因在链霉菌的克隆表达研究

以分离提取的ＨｅＬａ细胞总ＲＮＡ为模板,通过ＲＴ－ＰＣＲ反应扩增得到了１０１７ｂｐ的人可溶性白细胞介素６受体（ｓＩＬ－６Ｒ）ｃＤＮＡ片段,将扩增片段克隆到ｐＵＣ１９质粒中进行序列测定。结果证明该片的序列与文献报道的ｓＩＬ－６ＲｃＤＮＡ的序列完全一致,将ｓＩＬ－６ＲｃＤＮＡ与链霉素信号肽ｍｅｌＣｌ的编码序列融合后得到的融合基因ｍｅｌ／ｓＩＬ－６Ｒ克隆到链霉菌质粒ｐＬＪ４５９中,构建成重组表达质粒ｐＬ     

ITS（nrDNA）片段在冷杉属植物中的长度多态性及其在松科的系统与 …

由ＰＣＲ反应扩增了２８种冷杉属（ＡｂｉｅｓＭｉｌｌ．）植物的ｎｒＤＮＡ的ＩＴＳ（包括ＩＴＳ１、ＩＴＳ２和５．８ｒＤＮＡ）片段,经过与１００ｂｐ和１ｋｂ的标准分子量ＤＮＡ进行比较和某些类群ＩＴＳ的全序列和部分序列测定,发现分布于墨西哥和２种分布于北美的冷杉属植物的ＩＴＳ片段长度约为２５００ｂｐ,而分布于欧亚大陆和其他分布于北美的冷杉植物的ＩＴＳ长度约为１７００ｂｐ,二者相差约８００ｂｐ。Ａ．ｂｒａｃ     

一种与Calpastatin具有部分同源结构的人精子膜蛋白的发现与研究

在以前工作中我们从人精子中分离纯化出一种与生育有关的糖蛋白,命名为ＢＳ－１７。本文用其多克隆抗血清从人睾丸λｇｔ１１ｃＤＮＡ表达库中克隆了编码ＢＳ－１７的ｃＤＮＡ片段。序列分析表明ＢＳ－１７ｃＤＮＡ片段长７９１ｂｐ,开放阅读框架５５８ｂｐ,可编码１８６个氨基酸。经数据库检索,该ｃＤＮＡ片段与人Ｃａｌｐａｓｔａｔｉｎ（Ｃａ￣（２＋）依赖的半胱氨酸蛋白酶ｃａｌｐａｉｎ抑制剂）基因３’端顺序具有９９．７％的同源,与Ｃａｌｐａｓｔａｔｉｎ蛋白质羧基末端同源性为９９．５％。用ｃＲＮＡ进行组织原位杂交结果表明,ＢＳ－１７基因表达于人精子减数分裂后期单倍精细胞阶段。     

人Nmi mRNA编码区存在变异形式

Ｎｍｉ基因编码一种可与Ｍｙｃ相互作用的蛋白质．在人红白血病细胞系ＴＦ－１细胞去细胞因子ＧＭ－ＣＳＦ后８ｈ,发现ＮｍｉＲＮＡ表达水平升高．利用ＰＣＲ方法从中扩增ＮｍｉｃＤＮＡ编码区,发现除正常大小的扩增片段外,还有一比公布核酸序列小约１００～２００ｂｐ的扩增片段．序列分析表明该片段为编码区第３３７～５０９位的碱基缺失,由ＧＴＴＣＣＡＴＴＧＣＧ１１个碱基取代,形成一个开放读码框架,编码２５４个氨基酸,比野生型Ｎｍｉ编码的３０７个氨基酸少５３个氨基酸．     

植物甜蛋白mabinlinⅡcDNA的克隆与序列分析

根据已由作者克隆的ｍａｂｉｎｌｉｎⅡＢ亚基１８５ｂｐ的ｃＤＮＡ片段,设计合成系列引物．从马槟榔（ＣａｐｐａｒｉｓｍａｓａｉｋａｉＬéｖｌ．）种子提取总ＲＮＡ并纯化ｍＲＮＡ,经反转录合成ｃＤＮＡ第一链．采用ＲＡＣＥ方法,快捷克隆ｍａｂｉｎｌｉｎⅡ全长ｃＤＮＡ．经序列测定与分析,该ｃＤＮＡ为５８３ｂｐ,其中编码序列长４６５ｂｐ,共编码１５５个氨基酸．     

抗人CD3单抗重、轻链可变区基因的体外扩增、克隆和序列分析

根据免疫球蛋白重链和轻链可变区基因５’端序列和Ｊ区序列,化学合成适合于体外扩增抗体重、轻链可变区基因的二对引物。从体外培养的ＯＫＴ３杂交瘤细胞中提取总ＲＮＡ,反转录生成ｃＤＮＡ,以ｃＤＮＡ为模板,分别加入合成的重、轻链可变区引物进行ＰＣＲ,扩增出抗体重、轻链可变区基因片段。将扩增产物分别插入ｐＵＣ１９质粒,筛选出阳性克隆,用链终止法进行ＤＮＡ序列测定。所测重链可变区基因全长３５７ｂｐ,编码１１９个氨基酸,轻链可变区基因全长３２１ｂｐ,编码１０７个氨基酸。     

四川鹿属动物的线粒体DNA差异和系统进化关系研究

用聚合酶链反应,从水鹿,坡鹿,梅花鹿和马鹿等四种鹿属动物中分别扩增出线粒体ＤＮＡＲ的细胞色素ｂ基因片段,并测定得到了３６７ｂｐ的碱基序列,它们之间的序列差异在４．０９％￣７．０８％之间。     

水稻矮缩病毒基因组第八号片段的cDNA克隆序列分析及在大肠杆菌中的表达

从水稻矮缩病毒（ＲＤＶ）中国福建分离物中分离出基因组第八号片段ｄｓＲＮＡ,经逆转录合成ｃＤＮＡ,应用聚合酶链式反应技术扩增了编码区ｃＤＮＡ,并克隆在ｐＧＥＭ３Ｚｆ（一）载体上。该片段编码病毒外层外壳蛋白。对重组子进行限制性内切酶分析,亚克隆及全序列测定,结果表明,克隆片段全长１３５６ｂｐ,含有一个１２６６ｂｐ的阅读框架,编码一个含４２１个氨基酸的多肽。与日本流行株相应片段比较,有核苷酸和氨基酸水平     

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.