RESUMEN
Chlamydia are obligate intracellular eubacteria that are phylogenetically separated from other bacterial divisions. C. trachomatis and C. pneumoniae are both pathogens of humans but differ in their tissue tropism and spectrum of diseases. C. pneumoniae is a newly recognized species of Chlamydia that is a natural pathogen of humans, and causes pneumonia and bronchitis. In the United States, approximately 10% of pneumonia cases and 5% of bronchitis cases are attributed to C. pneumoniae infection. Chronic disease may result following respiratory-acquired infection, such as reactive airway disease, adult-onset asthma and potentially lung cancer. In addition, C. pneumoniae infection has been associated with atherosclerosis. C. trachomatis infection causes trachoma, an ocular infection that leads to blindness, and sexually transmitted diseases such as pelvic inflammatory disease, chronic pelvic pain, ectopic pregnancy and epididymitis. Although relatively little is known about C. trachomatis biology, even less is known concerning C. pneumoniae. Comparison of the C. pneumoniae genome with the C. trachomatis genome will provide an understanding of the common biological processes required for infection and survival in mammalian cells. Genomic differences are implicated in the unique properties that differentiate the two species in disease spectrum. Analysis of the 1,230,230-nt C. pneumoniae genome revealed 214 protein-coding sequences not found in C. trachomatis, most without homologues to other known sequences. Prominent comparative findings include expansion of a novel family of 21 sequence-variant outer-membrane proteins, conservation of a type-III secretion virulence system, three serine/threonine protein kinases and a pair of parologous phospholipase-D-like proteins, additional purine and biotin biosynthetic capability, a homologue for aromatic amino acid (tryptophan) hydroxylase and the loss of tryptophan biosynthesis genes.
Asunto(s)
Proteínas Bacterianas/genética , Chlamydia trachomatis/genética , Chlamydophila pneumoniae/genética , Genoma Bacteriano , Secuencia de Aminoácidos , Proteínas Bacterianas/metabolismo , Chlamydia trachomatis/metabolismo , Chlamydia trachomatis/patogenicidad , Chlamydophila pneumoniae/metabolismo , Chlamydophila pneumoniae/patogenicidad , Secuencia Conservada , Enzimas/genética , Enzimas/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Operón , Homología de Secuencia de Aminoácido , Triptófano/biosíntesisRESUMEN
The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.
Asunto(s)
Genoma Bacteriano , Análisis de Secuencia de ADN , Sinorhizobium meliloti/genética , Simbiosis/genética , Adhesión Bacteriana , Proteínas Bacterianas/genética , Proteínas Portadoras/genética , Cromosomas Bacterianos/genética , Biología Computacional , Elementos Transponibles de ADN , Metabolismo Energético/genética , Evolución Molecular , Duplicación de Gen , Genes Bacterianos , Genes Esenciales , Genes Reguladores , Medicago sativa/microbiología , Nitrógeno/metabolismo , Fijación del Nitrógeno/genética , Plásmidos , Polisacáridos Bacterianos/genética , Replicón , Rhizobiaceae/genética , Sinorhizobium meliloti/fisiologíaRESUMEN
In situ hybridization experiments with the use of recombinant herpes simplex virus type 1 DNA as probes have detected virus-specific RNA in herpes simplex virus type 1-transformed Syrian hamster cell lines. The relatively most abundant virus transcripts hybridized to the herpes simplex virus type 1 EcoRI-F fragment at map position 0.32-0.42.
Asunto(s)
Transformación Celular Neoplásica , Neoplasias Experimentales/microbiología , ARN Viral/genética , Simplexvirus/genética , Animales , Línea Celular , Cricetinae , Embrión de Mamíferos , Fibroblastos , Metástasis de la Neoplasia , Neoplasias Experimentales/patología , ARN Viral/aislamiento & purificaciónRESUMEN
Infection of CD-1 mouse embryo fibroblast(s) (MEF) with infectious bovine rhinotracheitis virus (IBRV) strain HMC resulted in persistent infection and subsequent transformation of these cells. IBRV-transformed MEF cultures consisted of short fibroblastoid cells, and IBRV-specific membrane and intracellular antigens were detectable in early in vitro passages by indirect imunofluorescence (IF) techniques. The presence of IBRV genetic information was confirmed in IF-positive and IF-negative cells by in situ hybridization. IBRV-transformed MEF induced fibrosarcomas in athymic nude mice given sc transplants. Infectious virus could not be rescued from the transformed cells or from tumor cells by cocultivation with rabbit kidney cells, by treatment with 5-iodo-2'-deoxyuridine, or by UV irradiation. Nontransformed control cells did not survive more than 10 in vitro passages and did not induce tumors when transplanted to athymic nude mice. These observations represent new data concerning the mouse cell-transforming potential of IBRV and confirm the presence of at least part of the virus genome in the transformants.
Asunto(s)
Transformación Celular Neoplásica/patología , Transformación Celular Viral , Herpesvirus Bovino 1 , Animales , Antígenos de Neoplasias/análisis , Antígenos Virales/inmunología , Transformación Celular Neoplásica/ultraestructura , Células Cultivadas , Embrión de Mamíferos , Fibrosarcoma/patología , Herpesvirus Bovino 1/genética , Herpesvirus Bovino 1/inmunología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Neoplasias Experimentales/microbiología , Neoplasias Experimentales/patologíaRESUMEN
A short segment of the herpes simplex virus (HSV) DNA proximal IRL region hybridized to two doublet bands of EcoRI-digested human cellular DNA. The hybridization was abolished neither by increasing stringency conditions nor by inclusion of guanine-rich DNA in the hybridization mixture. Thus, the hybridization appeared to represent authentic base sequence homology between HSV DNA and middle repetitive human DNA.
Asunto(s)
ADN Viral , ADN , Hibridación de Ácido Nucleico , Simplexvirus/genética , Enzimas de Restricción del ADN , Desoxirribonucleasa EcoRI , Humanos , Homología de Secuencia de Ácido NucleicoRESUMEN
Varicella-zoster virus (VZV) DNA exists principally as two isomers. Despite the presence of inverted repeats bounding the long sequence region, the unique long sequence, UL, is found in one (prototype) orientation in 95-98% of VZV DNA molecules and in the inverted orientation in only 2-5% of the molecules. In searching for an explanation for this disparity, we superinfected VZV-infected cells with herpes simplex virus type 1 or pseudorabies virus. Neither superinfecting virus produced a measurable change in the frequency of isomerization of the VZV DNA long sequence region.
Asunto(s)
ADN Viral , Herpesvirus Humano 3/genética , Secuencia de Bases , Mapeo Cromosómico , Enzimas de Restricción del ADN , Herpesvirus Humano 3/ultraestructura , Secuencias Repetitivas de Ácidos NucleicosRESUMEN
A small DNA fragment containing the simple sequence [GGC]10 from the long repeat of herpes simplex virus type 1 (HSV-1) DNA hybridized to cellular DNA and polyadenylated RNA from different mammalian species. The number and intensity of blot hybridization signals were increased in human compared with rodent and simian nucleic acids. The hybridization was blocked specifically by human 28S ribosomal DNA, which shares only the GGC repeats with the herpes simplex virus DNA. These data indicate that GGC repeats were common components of cellular DNA and were expressed in mRNA. Blot hybridization analysis of viral RNA from the HSV-1 gene regions encompassing the GGC repeats revealed abundant stable mRNAs from portions of the virus genome not previously analyzed in detail and indicated that the viral GGC sequence was not expressed in stable cytoplasmic mRNA.
Asunto(s)
ADN Viral/genética , ADN/genética , Hibridación de Ácido Nucleico , ARN Mensajero/genética , Simplexvirus/genética , Animales , Cricetinae , Haplorrinos , Ratones , Poli A/genética , ARN/genética , ARN Viral/genética , Secuencias Repetitivas de Ácidos Nucleicos , Transcripción GenéticaAsunto(s)
ADN , Dactinomicina , Polinucleótidos , Nucleótidos de Adenina , Sitios de Unión , Fenómenos Químicos , Química , Crustáceos , Nucleótidos de Citosina , ADN/análisis , Nucleótidos de Guanina , Matemática , Nucleótidos/análisis , Polímeros , Ribonucleasas , Espectrofotometría , Nucleótidos de UraciloAsunto(s)
Colifagos/análisis , Genes , ARN Mensajero/aislamiento & purificación , ARN Viral/aislamiento & purificación , Centrifugación por Gradiente de Densidad , ADN de Cadena Simple , ADN Viral , Electroforesis en Gel de Poliacrilamida , Escherichia coli , Genética Microbiana , Microscopía Electrónica , Conformación de Ácido Nucleico , Hibridación de Ácido Nucleico , Isótopos de FósforoAsunto(s)
Colifagos , Transcripción Genética , Aberraciones Cromosómicas , Mapeo Cromosómico , ADN Viral , ARN Polimerasas Dirigidas por ADN , Electroforesis en Gel de Poliacrilamida , Escherichia coli , Microscopía Electrónica , Modelos Biológicos , Peso Molecular , Mutación , Hibridación de Ácido Nucleico , Isótopos de Fósforo , ARN Mensajero , ARN ViralRESUMEN
Cytoplasmic RNA was isolated from varicella-zoster virus (VZV)-infected cells. By oligo(dT)-cellulose chromatography, the RNA was separated into polyadenylated, poly (A)+, and nonpolyadenylated, poly (A)-, fractions. RNA blot hybridization was employed to detect and map VZV transcripts. As VZV infection cannot be coordinated, cytoplasmic RNA was isolated from VZV-infected cells when the cells showed extensive cytopathology. Therefore, while the VZV transcripts represented heterogeneous temporal classes, it may be assumed that late VZV RNA predominated. At least 41, and as many as 67 (depending on DNA probe overlap), VZV polyadenylated transcripts have been identified. Preliminary evidence for the presence of two VZV-specific nonpolyadenylated, cytoplasmic transcripts was observed.
Asunto(s)
Herpesvirus Humano 3/genética , ARN Mensajero/genética , ARN Viral/genética , Mapeo Cromosómico , ADN Viral/genética , Genes Virales , Poli A/genética , ARN/genética , ARN Neoplásico/genética , Transcripción GenéticaRESUMEN
Latent herpes simplex virus (HSV) infection of the trigeminal ganglion of guinea pigs and latent varicella-zoster virus (VZV) infection of the trigeminal ganglion of humans were studied by in situ nucleic acid hybridization. Guinea pig trigeminal ganglia were removed during the period of viral latency (four to five weeks after corneal inoculation of HSV), and human ganglia were removed at autopsy. Radiolabeled HSV and VZV DNAs were used to probe ganglion tissue sections for viral-specified RNA. Hybridization detected only over neurons was present in 46 percent of ganglia from 22 latently infected guinea pigs and from 33 percent of ganglia from 10 human subjects. These results support the conclusion that some viral transcription occurred during HSV and VZV latency.
Asunto(s)
Herpes Simple/microbiología , Herpes Zóster/microbiología , Ganglio del Trigémino/microbiología , Nervio Trigémino/microbiología , Animales , ADN Viral/análisis , Cobayas , Humanos , Neuronas/microbiología , Hibridación de Ácido Nucleico , ARN Viral/análisisRESUMEN
Stable, relatively high-titer varicella-zoster virus (VZV) stocks as well as a high-titer anti-VZV serum prepared in inbred guinea pigs have allowed the identification of VZV immediate early proteins using the classic inhibitor approach. VZV infection was initiated in the presence of cycloheximide. Following the removal of cycloheximide, actinomycin D and radiolabel were added. After the labeling period, extracts were immunoprecipitated with anti-VZV guinea pig serum and subjected to polyacrylamide gel electrophoresis and fluorography or autoradiography. Four immediate early proteins of mol wts 185,000, 69,000, 43,000, and 34,000 were identified. The largest three were phosphoproteins.
Asunto(s)
Herpesvirus Humano 3/análisis , Proteínas Virales/análisis , Técnica del Anticuerpo Fluorescente , Técnicas Inmunológicas , Peso Molecular , Fosfoproteínas/análisisRESUMEN
Five minority populations of aberrant, varicella-zoster virus (VZV)-derived genomes were identified among the encapsidated DNAs obtained from the nuclear and cytoplasmic fractions of an in vitro infection initiated with a lyophilized sample of the BIKEN VZV vaccine (strain Oka). These were (i) VZV genomes, present within nuclear but not cytoplasmic viral capsids, which had been cleaved at a specific site within the short segment and which were, therefore, 3.15 megadaltons (approximately 4% of the VZV genome length) short of full length; (ii) highly deleted, repetitive VZV genomes which contained the errant cleavage site but not the usual VZV genome terminal sequences; (iii) VZV genomes into which multiples of 1 through 5 defective genome repeat units had been inserted into a homologous site; (iv) VZV genomes with additions of 0.1 or 0.18 megadaltons of DNA at both the terminal and internal ends of the short segment; and (v) VZV DNA which had lost the HindIII restriction site at map position 0.11.
Asunto(s)
ADN Viral/genética , Virus Defectuosos/genética , Herpesvirus Humano 3/genética , Replicación Viral , Cápside/ultraestructura , Línea Celular , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Virus Defectuosos/ultraestructura , Herpesvirus Humano 3/ultraestructura , Humanos , Peso Molecular , Vacunas Atenuadas , Vacunas ViralesRESUMEN
The DNAs of a varicella-zoster virus vaccine and its parental virus were compared by CsCl buoyant density centrifugation and restriction enzyme cleavage analysis. The varicella-zoster virus vaccine DNA showed a heterogeneous buoyant profile and altered restriction enzyme cleavage patterns. These changed properties are probably the result of the accumulation of virus containing defective varicella-zoster virus DNA during extensive cell culture passage of the vaccine virus.