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1.
RNA tumor viruses and viruslike particles from human milk are quantitated by hybridization of the polyadenylic acid regions in their 60S to 70S RNA to radioactive polyribouridylic acid of known specific activity. The length of the polyadenylic acid region in the 60S to 70S RNA of the human milk particle is identical to that of the known oncogenic RNA viruses.  相似文献   

2.
A study was conducted of the genetic relation between human T-cell lymphotropic retroviruses and visna virus. The human T-cell lymphotropic viruses include those associated with T-cell malignancies (HTLV-I and HTLV-II) as well as the etiologic agent of the acquired immune deficiency syndrome (HTLV-III). Visna virus, a slowly replicating and pathogenic but nononcogenic retrovirus of sheep, is a member of the subfamily Lentivirinae. Results obtained by molecular hybridization and heteroduplex analysis indicated that a greater extent of nucleotide sequence homology exists between HTLV-III and visna virus than between HTLV-III and any of the other viruses. The homology observed under conditions of low stringency spanned the entire genome, but was strongest in the gag/pol region. The morphogenesis and fine structure of HTLV-III and visna virus also demonstrated striking similarities. The data provide strong evidence for a close taxonomic and thus evolutionary relation between HTLV-III and the Lentivirinae subfamily.  相似文献   

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The RNA interference (RNAi) pathway is found in most eukaryotic lineages but curiously is absent in others, including that of Saccharomyces cerevisiae. We show that reconstituting RNAi in S. cerevisiae causes loss of a beneficial double-stranded RNA virus known as killer virus. Incompatibility between RNAi and killer viruses extends to other fungal species in that RNAi is absent in all species known to possess double-stranded RNA killer viruses, whereas killer viruses are absent in closely related species that retained RNAi. Thus, the advantage imparted by acquiring and retaining killer viruses explains the persistence of RNAi-deficient species during fungal evolution.  相似文献   

6.
cis- and trans-acting transcriptional regulation of visna virus   总被引:23,自引:0,他引:23  
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7.
用小RNA深度测序鉴定广西冬种马铃薯病毒   总被引:3,自引:0,他引:3  
【目的】对广西冬种马铃薯病毒进行鉴定,为无病毒种薯选择和大田防治提供依据。【方法】2012年在马铃薯主要产区采集具有明显病毒病症状的样品,在血清学ELISA检测的基础上,进一步用小RNA深度测序对按症状分类的样品进行混合样本的病毒种类鉴定,再用RT-PCR方法对分组混合样本进行验证。【结果】在109个样本中检测到马铃薯卷叶病毒(Potato leafroll virus,PLRV)、马铃薯A病毒(Potato virus A,PVA)、马铃薯H病毒(Potato virus H,PVH)、马铃薯M病毒(Potato virus M,PVM)、马铃薯S病毒(Potato virus S,PVS)、马铃薯Y病毒(Potato virus Y,PVY)和马铃薯纺锤块茎类病毒(Potato spindle tuber viroid,PSTVd),同时发现PVS有丰富的株系分化。【结论】近年广西冬种马铃薯病毒种类增多,病症多样,亟需加强种薯管理,培育无毒健康种薯。  相似文献   

8.
Inhibition of chemical carcinogenesis by viral vaccines   总被引:3,自引:0,他引:3  
The incidence of 3-methylcholanthrene-induced subcutaneous tumors was significantly reduced by a single injection of inactivated type C RNA viral vaccine. Rauscher leukemia virus vaccine reduced the incidence of sarcomas from 78 to 50 percent in the BALB/cCr mouse. Radiation leukemia virus vaccine and a vaccine from a wild murine leukemia virus derived from a 3-methylcholanthrene tumor reduced the incidence of sarcoma from 86 percent to 33 and 37 percents, respectively, in the C57BL/6 mouse. These reductions in tumor incidence by virus vaccines help support the concept that type C RNA viruses serve as determinants of chemically induced cancer; additional studies of vaccines made with more purified virus preparations are necessary.  相似文献   

9.
HTLV-III infection in brains of children and adults with AIDS encephalopathy   总被引:85,自引:0,他引:85  
Unexplained debilitating dementia or encephalopathy occurs frequently in adults and children with the acquired immune deficiency syndrome (AIDS). Brains from 15 individuals with AIDS and encephalopathy were examined by Southern analysis and in situ hybridization for the presence of human T-cell leukemia (lymphotropic) virus type III (HTLV-III), the virus believed to be the causative agent of AIDS. HTLV-III DNA was detected in the brains of five patients, and viral-specific RNA was detected in four of these. In view of these findings and the recent demonstration of morphologic and genetic relatedness between HTLV-III and visna virus, a lentivirus that causes a chronic degenerative neurologic disease in sheep, HTLV-III should be evaluated further as a possible cause of AIDS encephalopathy.  相似文献   

10.
Each clone of BALB/c mouse embryo cells that has been tested can be induced to form C-type virus. The individual cells therefore contain a complete copy of the genetic information for making the murine RNA tumor viruses.  相似文献   

11.
RNA viruses infect marine organisms from bacteria to whales, but RNA virus communities in the sea remain essentially unknown. Reverse-transcribed whole-genome shotgun sequencing was used to characterize the diversity of uncultivated marine RNA virus assemblages. A diverse assemblage of RNA viruses, including a broad group of marine picorna-like viruses, and distant relatives of viruses infecting arthropods and higher plants were found. Communities were dominated by distinct genotypes with small genome sizes, and we completely assembled the genomes of several hitherto undiscovered viruses. Our results show that the oceans are a reservoir of previously unknown RNA viruses.  相似文献   

12.
双链RNA分析技术在鉴定RNA病毒中的应用   总被引:3,自引:0,他引:3  
dsRNA技术是以无RNA病毒或类似病毒因子侵染的植物组织中不含有容易鉴定的同原大分子的dsRNA(>0.1×106)存在为前提。在植物体内dsRNA是RNA病毒和类病毒因子存在的迹象,dsRNA包括dsRNA病毒的基因或ssRNA病的复制中间型。dsRNA在寄主组织相当稳定,可以用物理和化学的方法分离出来。叙述了dsRNA技术用于植物病毒群、成员、同一病毒的不同株系、感染作物的新病毒及其复合侵染、类病毒、卫星病毒等的鉴定。证明该方法使用广泛、快速准确,不需要贵重设备,在一般实验室中即可进行。该方法有重要应用和学术价值,已引起植物病毒和植物病理学工作者广泛兴趣。  相似文献   

13.
Visna virus infection of American lambs   总被引:3,自引:0,他引:3  
Random-bred fetal and 4-week-old American lambs, inoculated intracerebrally with visna virus, developed a persistent infection in the brain and sometimes in the lung. The pathologic changes present in these lambs were similar to the early lesions of visna in Icelandic sheep, thus providing a possible model for the study of virus-induced demyelinating disease.  相似文献   

14.
Functional chloroplast polyribosomes from tobacco leaves   总被引:2,自引:0,他引:2  
Incubation of isolated to bacco chloroplasts with ingredients re quired for protein synthesis resulted in liberation of 70S ribosomnes and poly ribosomes that no longer sedimented with the chloroplasts. With increasing time of incubation, polyribosomes broke down to 70S monosomes. Similarly, microgram quantities of ribonuclease caused chloroplast polyribosomes to break down into monosomes. Both polyribosomes and 70S ribosomes that were isolated on sucrose density gra dients and tested separately in cell-free systems were capable of protein syn thesis; however, polyribosomes formed more protein per unit of RNA than monosomes did.  相似文献   

15.
为利用RNAi技术获取抗水稻黑条矮缩病毒(RBSDV)和南方水稻黑条矮缩病毒(SRBSDV)植株,分别针对两种病毒的S6和S10基因构建RNA沉默载体。采用重组PCR方法将RBSDV S6基因片段(R6)和SRBSDVS6基因片段(SR6)进行融合,获得600 bp的R6-SR6融合基因;将RBSDV S10基因片段(R10)和SRBSDV S10基因片段(SR10)进行融合,获得600 bp的R10-SR10融合基因。融合基因以反向重复的方式连入pBS载体,并定向插入到pCAMBIA1301载体上,获取了含有发夹结构的植物表达载体pCAMBIA1301-hp(R6-SR6)和pCAMBIA1301-hp(R10-SR10)。抗RBSDV和SRBSDV RNA沉默载体的构建为利用RNA沉默进行植物抗病毒研究奠定了基础。  相似文献   

16.
In an examination of the molecular basis of oral transmission of bunyaviruses by mosquitoes., La Crosse (LAC), snowshoe hare (SSH), and LAC-SSH reassortant viruses were compared in their ability to be transmitted to laboratory mice by the natural mosquito vector of LAC virus, Aedes triseriatus. Both LAC virus and the reassortment viruses containing the middle-sized (M) segment from the LAC parent were efficiently transmitted. In contrast, SSH virus and reassortment viruses containing the M RNA from the SSH parent were inefficiently transmitted. Thus, the M RNA segment, which codes for the virion glycoproteins, may be a major determinant of oral transmission of bunyaviruses by mosquitoes.  相似文献   

17.
(S)-9-(2,3-Dihydroxypropyl)adenine, a novel nucleoside analog, the sugar moiety of which is replaced by an aliphatic chain, inhibits the replication in vitro of several DNA and RNA viruses, including vaccinia, herpes simplex (types 1 and 2), measles, and vesicular stomatitis. It is also effective in vivo in reducing the mortality rate of mice inoculated intranasally with vesicular stomatitis virus.  相似文献   

18.
应用PCR技术进行Puumala病毒核酸片段的特异性扩增.将为进一步研究Puumala病毒和相关病毒.以及检测此类病毒感染提供更加特异、敏感、快速的方法。依据已知的Puumala病毒核酸序列,从M节段选出5对寡核苷酸作为PCR反应中的引物,以Puumala病毒RNA作为模板。做PCR。PCR产物分别经凝胶电泳和核酸杂交的方法进行测定,结果表明。目的核酸片段得到了很好的扩增。  相似文献   

19.
RNA沉默是一种由双链RNA诱导同源RNA降解的现象,是植物的一种天然抗病毒机制.但是由于长期的共进化过程,一些病毒会在siRNA沉默途径以及miRNA沉默途径中编码一些抑制蛋白来对抗这种机制,使其作用受到抑制.文章对RNA沉默的发现、过程、抑制及其由RNA沉默介导的对RNA病毒、DNA病毒的抗性、以及由转病毒基因介导的病毒抗性等几种植物抗病机制.同时,对研究中所存在的一些问题作了分析,并就今后的研究重点和方向作了展望.  相似文献   

20.
Virazole is a synthetic nucleoside active in tissue culture against at least 16 DNA and RNA viruses. Applied topically, it inhibits herpetic keratitis in rabbits and tail lesions induced by herpes, vaccinia, and vesicular stomatitis viruses in mice. Injected intraperitoneally into mice, it inhibits splenomegaly and hepatomegaly induced by Friend leukemia virus and respiratory infections caused by influenza A(O), A(2), and B viruses and parainfluenza 1 virus. infections is also effective.  相似文献   

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