赤羽病病毒核蛋白基因克隆和序列分析

参考GeneBank发表的赤羽病病毒(Akabane virus,AKAV)的核蛋白基因(SmRNA)序列,设计合成一对引物,从分离自牛体的AKAVBHK21细胞培养物巾提取总RNA,对．AKAV核蛋白基因进行RT-PCR扩增,产物经琼脂糖电泳分析,呈现一条约696bp的条带,同收纯化后,将其克隆至pMD18-T质粒载体中,然后进行核苷酸序列分析。与GenBank中报道的多株AKAV编码核衣壳蛋白(N)的SmRNA基因比较后发现,与其它株的核苷酸的同源性为94．2％～98．3％,推导的氨荜酸的同源性为97．6％～100％,证实为AKV的N基冈。为生产AKAV特异性核蛋白抗原、免疫血清学诊断试剂的制备和分子生物学研究打下了坚实基础。     

贵州省25株狂犬病病毒核蛋白基因序列分析

分析贵州省25株狂犬病病毒的核蛋白基因(N基因)序列,探讨贵州省狂犬病流行特征与狂犬病病毒变异情况。以RT-nested PCR检测来自贵州省2005年至2010年不同地区的病人脑组织、病人唾液以及犬脑组织标本狂犬病病毒RNA,经测序与拼接后得到25条N基因全长序列,采用生物信息学软件对N基因序列进行分析。25株狂犬病病毒核蛋白在核苷酸及氨基酸水平上彼此的同源性分别为89.3%～100%和98.%～100%;与国内其他省已发表基因1型狂犬病病毒核苷酸和氨基酸序列同源性分别为88%～99.1%和88%～99.7%,与已知的基因1型狂犬病病毒比较,25株病毒核蛋白氨基酸序列发生了若干位点的取代。进化树分析显示,同一地区内与相邻地区,以及同一时间段与相邻时间段内狂犬病病毒N基因进化亲缘关系相近。25株贵州省狂犬病病毒流行毒株均属基因1型,其核蛋白在基因的核苷酸及推导的氨基酸水平上均有变异,且这些变异具有地域和时间分布特性。     

鸡传染性支气管炎病毒变异株(793/B)核蛋白基因的克隆与序列分析

根据GenBank已经发表的传染性支气管炎病毒(IBV)N全基因组序列设计引物,对IBV 793/B分离毒株N基因进行克隆与序列分析.结果表明,IBV 793/B的N基因由1229bp组成,与GenBank已发表的11株IBV的N基因相比较,IBV 793/B的N基因共有88处点突变,在第991位发生了一个核苷酸的缺失.N基因的核苷酸同源性为86.9%～91.4%,氨基酸同源性为75.8%～77.5%.表明IBV 93/B的N基因存在着较大的变异性.     

浙江省麻疹病毒分离株的基因特性与免疫原性研究

为了研究浙江省1999～2003年麻疹病毒分离株的抗原性变化以及基因特性,阐明其基因特性与麻疹流行的关系,以及抗原性变化对疫苗免疫效果的影响.我们从麻疹患者含漱液中分离麻疹病毒株,制备大鼠免疫血清,与疫苗株沪191和Edmonston株等进行交叉中和试验,测定各毒株之间抗原比;并采集儿童麻疹疫苗免疫前后血清,分别测定其对不同毒株的中和抗体滴度;采用RT-PCR法扩增麻疹毒株血凝素蛋白(H)及核蛋白(N)基因,进行核苷酸序列测定.结果浙江99-1和浙江02-2株与沪191株之间的抗原比分别为3.0和7.3;儿童免疫后血清对浙江02-2株的麻疹中和抗体平均几何滴度(GMT)为15.03,明显低于沪191疫苗株(GMT为68.12);浙江省1999～2003年麻疹分离株之间,H基因氨基酸同源性为99.8%,N基因氨基酸同源性为98.5%～100.0%;与沪191疫苗株的H基因和N基因相比较,分离株与其在氨基酸水平上同源性分别为95.5%～95.7%和95.9%～96.3%.从基因进化树显示,1999～2003年浙江省分离到的麻疹毒株属于H1基因型,但与疫苗株沪191在抗原性和基因特性上已存在明显的差异.     

麻疹病毒S191疫苗株N基因稳定性研究及免疫细胞表位分析

研究麻疹病毒(Measles virus,MeV)疫苗株S191毒种和传代病毒核蛋白(Nucleoprotein,N)基因稳定性及其遗传与变异特点;对该序列一些重要位点的氨基酸进行比较,探讨其功能结构及生物学活性变化以及S191疫苗株的保护效果。利用RT-PCR方法扩增S191减毒株23、26、27、29、32、37不同代次N基因,测序进行比对分析。S191传代病毒N基因序列之间核苷酸同源性99.7%~100%,氨基酸同源性为99.6%~100%;S191株与7个疫苗株之间核苷酸序列同源性达99.1%~99.4%;S191和中国流行代表株序列同源性在95.0%~95.4%;S191与世界流行代表株同源性达94.7%~99.4%;S191疫苗株和中国流行代表株CHN93/7(H1a)的4个重要T细胞表位氨基酸保持一致。S191各传代病毒基因具有较高稳定性,该疫苗有一定的保护作用。     

鸡传染性支气管炎病毒变异株（793／B）核蛋白基因的克隆与序列分析

根据GenBank已经发表的传染性支气管炎病毒(IBV)N全基因组序列设计引物,对IBV793/B分离毒株N基因进行克隆与序列分析。结果表明,IBV793/B的N基因由1229bp组成,与GenBank已发表的11株IBV的N基因相比较,IBV793/B的N基因共有88处点突变,在第991位发生了一个核苷酸的缺失。N基因的核苷酸同源性为86.9%～91.4%,氨基酸同源性为75.8%～77.5%。表明IBV93/B的N基因存在着较大的变异性。     

浙江省麻疹病毒分离株的基因特性与免疫原性研究

为了研究浙江省1999～2003年麻疹病毒分离株的抗原性变化以及基因特性,阐明其基因特性与麻疹流行的关系,以及抗原性变化对疫苗免疫效果的影响。我们从麻疹患者含漱液中分离麻疹病毒株,制备大鼠免疫血清,与疫苗株沪191和Edmonston株等进行交叉中和试验,测定各毒株之间抗原比;并采集儿童麻疹疫苗免疫前后血清,分别测定其对不同毒株的中和抗体滴度;采用RT-PCR法扩增麻疹毒株血凝素蛋白(H)及核蛋白(N)基因,进行核苷酸序列测定。结果浙江99-1和浙江02-2株与沪191株之间的抗原比分别为3.0和7.3;儿童免疫后血清对浙江02-2株的麻疹中和抗体平均几何滴度(GMT)为15.03,明显低于沪191疫苗株(GMT为68.12);浙江省1999～2003年麻疹分离株之间,H基因氨基酸同源性为99.8%,N基因氨基酸同源性为98.5%～100.0%;与沪191疫苗株的H基因和N基因相比较,分离株与其在氨基酸水平上同源性分别为95.5%～95.7%和95.9%～96.3%。从基因进化树显示,1999～2003年浙江省分离到的麻疹毒株属于H1基因型,但与疫苗株沪191在抗原性和基因特性上已存在明显的差异。     

2012年在上海市发现中国大陆首例输入性D8基因型麻疹病例

本文对中国首例输入性D8基因型麻疹病毒基因特征进行分析。用ELISA法检测血清麻疹病毒IgM抗体;用Vero/Slam细胞对采集的咽拭子标本进行病毒分离,分离到的麻疹毒株用RT-PCR方法扩增其核蛋白基因3′端的部分序列,并对扩增产物进行核苷酸序列测定和分析,以3′端456个核苷酸为目的片段进行基因亲缘性关系分析。结果表明,上海市2012年共报告1 105疑似麻疹病例,其中实验室确诊590例,临床符合病例2例,排除513例,报告发病率为2.52/10万;共采集到984份疑似麻疹病例咽拭子标本,分离到247株麻疹病毒,病毒分离阳性率为25.3%;除Shanghai12-239为D8基因型外,其他均为H1a基因亚型。Shanghai12-239与世界卫生组织(World Health Organization,WHO)参考株(Manchester.UNK30.94(D8)AF280803)核苷酸序列同源性为97.8%,氨基酸序列同源性为98.6%。与WHO其他基因型参考株核苷酸序列同源性为89.6%~94.5%,氨基酸序列同源性为88.7%~95.3%。     

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.