Polyadenylic acid in Visna virus RNA

Visna virus 70S RNA contains long stretches of polyadenylic acid [poly(A)]. The homogeneity in length of poly(4) regions is observed in 70S RNA from visna virus and all RNA tumor viruses tested, and not with other types of RNA. By this criterion visna virus resembles RNA tumor viruses.     

Detergent-solubilized RNA polymerase from cells infected with foot-and-mouth disease virus

The foot-and-mouth disease virus RNA polymerase complex was dissociated from cellular membranes with deoxycholate in the presence of dextran sulfate. The soluble polymerase complex was active in the cell-free synthesis of virus-specific RNA; solubilization of the complex permitted direct analysis of the cell-free reaction mixtures without recourse to RNA extraction. A major RNA-containing component found early during cell-free incubation ranged from approximately 140 to 300S. The final major products of the cell-free system were 37S virus RNA, 20S ribonuclease-resistant RNA, and a 50S component containing RNA.     

用小RNA深度测序鉴定广西冬种马铃薯病毒

【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。     

RNA-dependent RNA polymerases,viruses, and RNA silencing

Most viruses have RNA genomes that are replicated and transcribed into messenger RNA by viral RNA-dependent RNA polymerases (RdRps), usually in concert with other viral and host factors. Many, if not most, eukaryotes also encode putative RdRps that have been implicated in sequence-specific, RNA-triggered gene silencing. Although the viral and cellular RdRps have no sequence homology, they share functional similarities such as copying messenger RNA templates and intercellular spread of the amplified sequences. Better understanding of viral and host RdRps will improve our ability to control viruses and to use RNA silencing and viruses as tools for research, biotechnology, and medicine.     

Polyadenylic acid sequences in the virion RNA of poliovirus and Eastern Equine Encephalitis virus

Poliovirus virion RNA contains a single covalently bound sequence of polyadenylic acid which is approximately 49 nucleotides long. A single, slightly longer polyadenylic acid sequence is contained in Eastern Equine Encephalitis virus RNA. Since these viruses are otherwise dissimilar these sequences may play a common role in viral replication, possibly in translation of the viral RNA.     

DNA rearrangement and altered RNA expression of the c-myb oncogene in mouse plasmacytoid lymphosarcomas

Three types of tumors termed plasmacytomas (ABPC's), lymphosarcomas (ABLS's), and plasmacytoid lymphosarcomas (ABPL's) arise in BALB/c mice treated with pristane and Abelson murine leukemia virus (A-MuLV). While most ABPC's and BLS's contain integrated A-MuLV proviral genome and synthesize the v-abl RNA, most ABPL's do not. The ABPL tumors were examined for the expression of other oncogenes that may be associated with their transformed state, in the absence of transforming virus. These tumors expressed abundant c-myb RNA of unusually large size and showed DNA rearrangements of the c-myb locus.     

Effect of cocksfoot mottle virus defective RNA on accumulation of virus capsid protein in wheat plants

The functional role of defective cocksfoot mottle virus RNA in regulating the expression of the viral genome was investigated for testing the hypothesis of its possible participation in transactivation of the synthesis of subgenomic RNA encoding the virus coat protein gene.     

黄瓜花叶病毒卫星RNA生防制剂防治辣椒病毒病的研究

在宁夏银川地区4个主要蔬菜基地采集表现病毒病症状的辣椒标样68个,采用鉴别寄主的生物学反应和双抗夹心ELISA法鉴定,结果表明引起银川地区辣椒病毒病的主要病原是黄瓜花叶病毒(CMV).用黄瓜花叶病毒的卫星RNA生防制剂S52免疫辣椒,能防治辣椒由CMV引起的病毒病.用S52免疫接种辣椒进行田间对比试验,免疫接种50 d的防效达71.2%~84.2%,免疫接种80 d的防效达55.9%~70.2%.     

Cofolding organizes alfalfa mosaic virus RNA and coat protein for replication

Alfalfa mosaic virus genomic RNAs are infectious only when the viral coat protein binds to the RNA 3' termini. The crystal structure of an alfalfa mosaic virus RNA-peptide complex reveals that conserved AUGC repeats and Pro-Thr-x-Arg-Ser-x-x-Tyr coat protein amino acids cofold upon interacting. Alternating AUGC residues have opposite orientation, and they base pair in different adjacent duplexes. Localized RNA backbone reversals stabilized by arginine-guanine interactions place the adenosines and guanines in reverse order in the duplex. The results suggest that a uniform, organized 3' conformation, similar to that found on viral RNAs with transfer RNA-like ends, may be essential for replication.     

Homologous viral interference: induction by RNA from defective particles of vesicular stomatitis virus

The viral RNA isolated from the defective particles of vesicular stomatitis virus was capable of interfering with the replication of this virus in chick embryo cells. The data indicate that the interfering ability of the defective particles of this virus is due to their nucleic acid component.     

应用分析双链RNA技术诊断苹果潜隐性病毒病

本文报导一种以分析病毒双链RNA为依据,检测苹果潜隐性病毒的新方法。这种方法能快速、准确地从苹果组织中分离和分析病毒的双链RNA(ds RNA),因此能直接、有效地从病毒侵染的组织诊断苹果潜隐性病毒。双链RNA是从自然侵染的苹果叶片或花瓣用酚萃取,经CF-11纤维素层析纯化,再用6％聚丙烯酰胺凝胶电泳和溴乙锭或银盐染色分析ds RNA电泳图谱。经脱毒的苹果树叶片,未发现有病毒的ds RNA存在。文中还报导了使用这一技术诊断苹果潜隐性病毒的有关技术条件。     

U1 small nuclear RNA genes are subject to dosage compensation in mouse cells

Multiple copies of a gene that encodes human U1 small nuclear RNA were introduced into mouse C127 cells with bovine papilloma virus as the vector. For some recombinant constructions, the human U1 gene copies were maintained extrachromosomally on the viral episome in an unrearranged fashion. The relative abundance of human and mouse U1 small nuclear RNA varied from one cell line to another, but in some lines human U1 RNA accounted for as much as one-third of the total U1. Regardless of the level of human U1 expression, the total amount of U1 RNA (both mouse and human) in each cell line was nearly the same relative to endogenous mouse 5S or U2 RNA. This result was obtained whether measurements were made of total cellular U1 or of only the U1 in small nuclear ribonucleoprotein particles that could be precipitated with antibody directed against the Sm antigen. The data suggest that the multigene families encoding mammalian U1 RNA are subject to some form of dosage compensation.