苹毛丽金龟痘病毒的显微镜研究

使用显微镜技术对苹毛丽金龟(Proagopertha lucidula Falderman)幼虫痘病毒进行研究。寄主受感染的部位是脂肪体细胞和血细胞的细胞质。病毒包涵体有三种形状:纺锤体、球状体、椭球体,大小分别为3.69x 6.30μ,8.10μ,7.78×9.84μ。前者中无病毒粒子存在,后二者含病毒粒子。在被感染的脂肪体细胞内,病毒粒子成熟一般需要经过六个阶段:1)在病毒基质周缘形成部分弧形囊膜;2)囊膜完全形成;3)在囊膜内产生内核物质;4)内核物质分化;5)内核外膜出现;6)单个侧体产生,病毒粒子由圆形被压抑成长圆形,最后被包埋进入球状体或椭球体的蛋白质晶格内。在包涵体内的成熟病毒粒子的大小为250 ×500 nm,由下列几部分组成: 1)电子高度致密的内核;2)内核中的绳索物质,直径为20nm,叠成4-5折,按病毒粒子的长轴方向排列;3)内核的外膜,分为三层;4)单侧体,位于内核的凹窝处;5)囊膜和囊膜外面的球状亚单位,其直径为12nm。这些球状亚单位使病毒粒子似桑葚外形。     

湖北恒河猴体内恰氏内阿米巴的形态学观察

调查武汉动物园的恒河猴,发现自然感染恰氏内阿米巴(EntamoebachattoniSwellen-grebel,1914),采用生理盐水直接涂片法、卢戈氏碘液染色及铁苏木素染色封片,对滋养体和胞囊进行观察,并对滋养体、体核、包囊、囊核作了显微测量。恰氏内阿米巴滋养体大小为11—17μm,平均13.70±0.37μm(X±Sx),核为2.89±0.02μm,包囊为10.30±0.09μm和囊核2.83±0.03μm。双核型包囊少于1%,含有包涵体的包囊占50%,恒河猴自然感染恰氏内阿米巴为国内首次发现。     

斜带髭鲷外周血嗜中性粒细胞核内包涵体的超微结构

目的在对斜带髭鲷（Hapalogenys nitens）外周血细胞结构进行透射电镜观察时发现嗜中性粒细胞存在大量的核内包涵体,系统研究了这些核内包涵体的超微结构,以探讨其来源和形成过程。方法应用电镜技术对这些核内包涵体的超微结构进行研究。结果斜带髭鲷外周血嗜中性粒细胞的核内包涵体可分为假包涵体和真包涵体两种类型,包涵体中的内含物来自胞质。胞核首先是以核膜内陷的方式将胞质及其各种有形成分包绕进核内而在核质外层形成具有双层膜包裹的典型假包涵体,随后假包涵体双层膜降解消失而转化成无被膜包裹的真包涵体,即核内糖原包涵体。结论假包涵体是形成真包涵体的开始阶段。随着假包涵体向真包涵体的转变,包涵体内含物的组成及其超微结构也出现了显著变化。     

一株新的类猪圆环病毒因子的核苷酸全序列和体外感染性

在中国猪血清中分离到一新因子,命名为P2．P2为闭合环状基因组,全长993个核苷酸．序列分析表明其与猪圆环病毒密切相关．随后对构建的P2因子分子克隆的体外感染性进行了研究．结果表明,在转染PK-15细胞后,只有P2因子的双拷贝串联分子克隆具有感染性,表现为可在细胞的胞浆和胞核中形成包涵体,胞浆包涵体为圆形或不规则形,直径0．1～0．4gm;胞核包涵体有两种类型,一种为小而圆、直径约0．1μm的包涵体,另一种为大而呈六角性的包涵体,直径约为0．5～1．4μm．胞浆包涵体和胞核包涵体都没有外膜,相比较而言,后者有更高的电子密度．将转染后的细胞连续传代,对第5代细胞培养物抽提DNA,进行PCR,结果也只有在转染P2因子双拷贝串联分子克隆的细胞培养物中检测到P2的DNA．而转染空载体、P2因子单分子克隆和未转染的PK-15细胞微观结构未见变化,在第5代细胞培养物中也未能检测到P2的DNA．同样,只有在转染P2因子双拷贝串联分子克隆的细胞和随后传代的细胞中能检测到P2抗原．这是首次报道如此小基因组的类猪圆环病毒P2的全序列和其在体外具有感染性．     

鳙团移核鱼的形态性状与个体生长

本文报道了鳙国移核鱼的形态性状及其个体生长等特性,为研究核质关系和细胞质遗传提供了一些有价值的结果．鳙团移核鱼的形态性状有些与供核体鳙鱼相似,有的与受核体团头纺相似,还有的出现中间型性状。二龄移核鱼的生长都明显比团头纺快,但都慢于鳙鱼．     

亚洲小车蝗痘病毒形态及发育研究(英语)

本文报道亚洲小车蝗痘病毒感染黄胫小车蝗引起的病理学变化.该病毒主要感染寄主脂肪体,其次为血细胞.球状体有3种类型:大球体、椭球体和小球体,大小分别为30.41μm×25.40μm、6.58μm×4.78μm和3.35μm×2.60μm.病毒粒子为椭球形,大小为230 nm×176 urn,囊膜表面具有球状亚单位,直径为16nm,使病毒粒子看上去似桑椹,侧体为圆筒形,髓核内绳索状物质似有2折,在横切面上是2个圆点.病毒粒子的发育包括以下4个主要阶段:病毒发生基质的产生;球状颗粒的形成;内核和侧体的分化;髓核和衣壳的进一步分化.成熟病毒粒子逐渐包入球状体.该病毒可感染同属蝗虫.     

腺病毒感染胞核特殊型类包涵体的电镜观察

一株分离的4型腺病毒在感染细胞核内病毒晶体中出现特殊型类包涵体。该包涵体呈长空芯管样,长度可达1.5μ,外径约为70nm,内径约20nm,可视为与病毒衣壳发育形成有关的形态结构。     

细胞核存在独立的钙运输系统

细胞核具有独立的钙运输系统,可以以依赖于胞质游离钙浓度而对核内钙浓度进行调节。核膜为核钙库,其外核膜上存在钙泵和ＩＰ４受体,内核膜上存在的ＩＰ３受体和利苦丁（ｒｙｎｏｄｉｎｅ）受体,核膜经外核膜摄入钙,并在ＩＰ３或环化二磷酸腺核糖（ｃＡＤＰＲ）介导了内核膜向核内释放钙,产生核内钙信号。     

新疆棉花枯萎病菌异核体及其不同表型分离子核DNA的差异

为探索丝状真菌异核体的产生机制,从新疆地区患枯萎病的棉杆中分离出棉花枯萎病菌Fusarium oxysporum f.sp．vasinfectum异核体菌株X515,并自其菌落出现的不同角变处分离出三个不同表型的分离子,X515-I、X515-Ⅱ和X515-Ⅲ。选用200种随机引物对它们进行核．DNA的RAPD分析,只在OPB-16引物对致病力强的分离子X515-I核DNA的PCR扩增产物中出现了一条354bp的差异片段,其部分碱基序列与Fusarium oxysporum f．sp．lycopersici的短散布序列(Foxy)末端序列的相似性达88％。本研究结果提示,随着所采用引物数量的增加,可有望找出异核体及其不同分离子之间核DNA的差异,为最终阐明异核体形成的机制提供线索。     

意大利蝗痘病毒一些特性研究

电镜观察意大利蝗痘病毒的包涵体大多数为椭圆形,少数为近圆形,大小相差极为悬殊。病毒粒子呈卵圆形,表面桑椹状。病毒粒子髓核呈圆筒状,其纵切面内绳索结构折叠2—3次,横切面可以看到2—3个圆点,侧体也圆筒状,均匀包围在核衣壳外面。DNA经限制性内切酶LoR I酶切产生16个DNA片段,据此求得DNA分子量为135.7×106D。 意大利蝗痘病毒包涵体的裂解释放病毒速度快,在相同条件下比亚洲小车蝗痘病毒包涵体裂解释放病毒粒子快。当温度恒定(37℃),在一定的pH值内(pH 9.0—11.5),随pH值的升高包涵体裂解释放病毒粒子速度加快。当pH值恒定(11.2),在一定的温度范围内(25～40℃),随温度的升高包涵体的裂解释放病毒粒子速度加快。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various