马尾松毛虫质型多角体病毒S4的cDNA克隆及序列分析

从马尾松毛虫质型多角体病毒湖南株中提取病毒核酸,回收、纯化第四片段s4,经RT-PCR扩增得到了S4的cDNA克隆并测定了其全序列.结果表明,S4全长由3 262个碱基组成,包含一个编码1058个氨基酸的完整开放阅读框架.Blast同源分析显示,DpCPV S4与LdCPV S4、BmCPV S4和RRSV S2编码蛋白氨基酸的同源性分别为94%、92%和22%.另外,氨基酸序列部分区域与Methanosarcina mazei Goel的甲基化转移酶有同源性,且序列中含有鸟苷酸转移酶活性位点.     

中国分离巴泰病毒基因组全编码区序列测定和分析

采用RT-PCR和TAIL-PCR方法,首次对我国分离的巴泰病毒(YN92-4株)基因组的全编码区进行序列测定和分析。结果显示,YN92-4株病毒基因组由S、M、L三个片段组成,长度分别为947、4 371、6 860个核苷酸。其中,S片段基因编码由234个氨基酸残基组成的核衣壳蛋白和由102个氨基酸残基组成的非结构蛋白,M片段基因编码由1 435个氨基酸残基组成的前体蛋白,L片段基因编码由2 239个氨基酸残基组成的RNA聚合酶。与国外其它地区的巴泰病毒分离株进行基因组全编码区序列比较后发现,YN92-4株与日本牛血清分离株(ON-7/B/01株)在S、M片段核苷酸(氨基酸)的同源性最高,分别为97.7%(100%)和95.7%(98%);由于本研究首次开展对巴泰病毒L基因片段核苷酸序列的研究,因此国际基因库尚无可参考的序列信息,本研究比较了我国分离的巴泰病毒与同一血清组的代表病毒Bunyamwera病毒L片段的核苷酸和氨基酸序列同源性,分别为73.5%和81.6%。系统进化分析显示,YN92-4株基因组与其它巴泰病毒分离株在各自分支下形成独立分支。本研究提示我国分离的巴泰病毒YN92-4株未发生基因重配(...     

蓝舌病毒血清5型毒株S7基因编码区的分子克隆与序列分析

目的:对蓝舌病毒(BTV)血清5型毒株(BTV-5)的S7基因编码区(ORF)进行克隆和序列分析。方法:用TRIzol LS试剂提取病毒总RNA,经反转录-聚合酶链反应(RT-PCR)扩增BTV-5型毒株S7基因的编码区,将扩增片段克隆到pGEM-T Easy载体上,对阳性克隆进行核苷酸序列测定;采用DNAStar和DNASIS v2.5软件对环状病毒属不同种群的S7基因ORF序列及其推导的氨基酸序列进行同源性及系统进化树分析。结果:克隆的基因片段长1050bp,为S7基因开放性读码框的全长序列,编码349个氨基酸残基;与环状病毒属不同血清型毒株比较,核酸序列同源性范围为42.2%～96.6%,推导的氨基酸序列同源性范围为40.4%～99.7%。结论:蓝舌病毒与非洲马瘟病毒、鹿流行性出血热病毒分属于不同种群,群内不同血清型的S7基因ORF序列及其推导的氨基酸序列显示出很高的同源性,而不同种群之间的同源性很低。     

两个猪瘟病毒野毒株gp55基因抗原编码区序列的分析及比较

利用反转录－PCR方法扩增了吉林省猪瘟病毒（HCV）两个野毒株gp55基因的主要保护性抗原编码区,并将其克隆到pGEM－T载体中,然后用Sanger双脱氧法测定了其核苷酸序列,并推导了其氨基酸序列。将测定的这两个HCV野毒株的部分序列（350bp）与国内外已知的HCV序列进行比较,结果表明：这两个野毒株的核苷酸序列的同源性为94．9％,氨基酸序列同源性为97．4％,与1985～1992年意大利中部分离4个野毒株的同源性明显高于其它HCV毒株,核苷酸同源性分别为97．2％～98．3％和94.0％～949％,氨基酸同源性分别为98．3％～991％和97.4％～98.3％,而与我国的HCV标准强毒株即石门株的核苷酸同源性仅分别为83.1％和83.1％,氨基酸同源性仅分别为90.6％和91.4％。因此认为吉林省这两个野毒株与意大利中部的4个野毒株具有密切的关系,而与石门株很可能来源不同。     

马尾松毛虫CPV基因组S7的序列分析及部分序列的原核表达

马尾松毛虫质多角体病毒(湖南株)基因组S7节段(AY180908)cDNA克隆及序列分析结果表明：S7由1501个碱基组成,编码由448个氨基酸组成的分子量为49．8kDa的多肽P50。5’末端和3’末端具有5’-AGTAA-3’和5’-GTTAGCC-3’末端保守序列。该基因组与舞毒蛾质多角体病毒1型和家蚕质多角体病毒1型s7节段有很高的同源性,核苷酸序列同源性分别为97．2％和87．0％,氨基酸序列同源性分别为98．7％和92．8％。P50多肽与人型支原体的DnaK样蛋白在C-末端有相似性。本文报道了编码P50 C259的cDNA序列的克隆并作了原核表达,当用1．0mmol／L IPTG诱导2h,分子量约为37.3kDa的融合蛋白在大肠杆菌BL21中得到大量表达。     

汉坦病毒汉滩型特殊新亚型的发现

应用RT－PCR扩增了皖南山区分离株AH09的M和S片段全基因,克隆于T载体,纯化后测定序列。结果AH09株M片段的全基因序列共3625个核苷酸,编码1135个氨基酸;S片段的全基因序列共1724个核苷酸,编码430个氨基酸。M和S片段全基因核苷酸和氨基酸与汉坦病毒各型株的代表株和HTN型毒株的同源性比较表明,AH09株分枝与HTN型接近,与其它各型病毒则相距较远,故确定为HTN型毒株,但AH09株与HTN型毒株的M和S片段全基因序列有差异,其差异分别高达23．6％和20．4％,经种系发生分析,AH09株是迄今为止所发现的HTN型病毒中差异最大的新基因亚型病毒株,AH09株病毒M片段的氨基酸与HTN型相差13．5％至14．8％,而S片段仅相差7％－8．1％,说明AH09毒株的变异主要发生在M片段。而ORF和3‘端的NCR区核苷酸序列分析比较说明,病毒的变异更主要集中在该片段的3‘端的NCR区。     

麻疹病毒F基因测序及其进化关系的初步分析

研究麻疹病毒疫苗株S191毒种及其传代的病毒溶血素F(Haemolysin,HL)基因稳定性;对该序列一些重要位点的氨基酸进行比较,推测其功能结构及生物学活性变化;同时对该基因与M蛋白基因之间的非编码序列进行比对分析。利用RT-PCR方法扩增S191减毒株MeV23、26、27代及一株流行株YunnanLC-10的F基因,测序后进行比对分析。S191传代病毒F基因序列之间核苷酸同源性为99.8%,氨基酸同源性为99.5%～99.6%;S191疫苗株与流行株之间核苷酸序列同源性达95.2%;疫苗株与流行株1003nt的非编码区序列同源性为85.0%。S191传代病毒F基因具有较高遗传稳定性,关键功能位点氨基酸未发生传代改变;1003nt非编码区序列变异速度较快。     

草鱼呼肠孤病毒HZ08株S4基因序列分析

草鱼呼肠孤病毒HZ08株是本实验室从患出血病草鱼体内分离到的一个新毒株,已完成部分基因序列的分析,其氨基酸序列的同源性和873株相比,仅为20%~30%之间.因序列差异较大,无法通过设计特异性引物来扩增和分析其基因序列,采用单引物扩增技术,对HZ08株S4基因进行序列分析表明:S4全长为2263 bp,最大的ORF编码717个氨基酸,推导出其表达的蛋白约为79 kDa.正如其他基因节段,基因末端也含有保守碱基序列5′(GUAAUUU…UUCAUC),3′.S4基因推导的氨基酸序列与同宿主的其他呼肠孤病毒的非结构蛋白NS1同源性最大,其次是和哺乳动物正呼肠孤病毒的非结构蛋白mu-NS以及禽呼肠孤病毒非结构蛋白NS1同源性较大,表明S4可能表达细胞骨架相关蛋白.基于S4推导出的氨基酸序列构建的系统进化树HZ08株单独作为一个分支,与同宿主的其他呼肠孤病毒亲缘关系比较近,而与其他呼肠孤病毒则相对较远.这提示HZ08株可能是多个毒株的遗传信息经长期的遗传进化而得,综合其它已知序列信息,推测HZ08株可能为呼肠孤病毒的一个新成员.     

一株辛德毕斯病毒的基因组序列测定及分析

目的：对引进的一株辛德毕斯病毒的基因组序列进行测定,阐明其与已报道毒株序列的关系。方法：对辛德毕斯病毒基因组编码区进行分段RT-PCR扩增,对非编码区采用RACE法进行扩增,将扩增产物直接进行测序,应用DNAStar软件将测序结果拼接得到基因组序列,采用MEGA3.1软件对9株辛德毕斯病毒基因组序列进行系统进化发生树的构建。结果与结论：此株辛德毕斯病毒基因组共11663nt,编码3745个氨基酸残基,其中5＇端的2/3基因组编码4种非结构蛋白NSp1、NSp2、NSp3和NSp4,3＇端的1/3基因组编码5种结构蛋白E1、E2、E3、6K和C;结构基因和非结构基因之间有48nt的连接区为非翻译区;病毒基因组5＇末端和3＇末端分别有59、318nt的非编码区;序列同源性分析结果表明,此株病毒与S.A.AR86株的同源性最高,两者核苷酸序列的同源性为99.7%,氨基酸序列的同源性为99.6%,而与本室保存的另一辛德毕斯病毒MEI株的遗传进化关系稍远,系统进化发生树处于不同分支上。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。