RESUMEN
The genomes of different derivatives of Marek's disease virus (MDV) strain CVI-988, a low oncogenic isolate of a serotype 1 MDV, were analyzed by restriction enzyme analyses to detect whether alterations occurred after passages in cell culture. DNA molecules of strain 988 isolated directly from blood cells contained mainly two copies of the 132-bp repeat sequence previously reported within BamH1-H and -D fragment as previously reported for more virulent MDV strains. Although a minority of virus particles showed repeat amplification was already at the fifth passage level, amplification mainly occurred between passages 17 and 34 in cell culture. In addition, a 400-bp deletion was detected within the BamH1-A fragment of two derivatives of CVI-988, 988C and 988C/R6.
Asunto(s)
Herpesvirus Gallináceo 2/genética , Secuencias Repetitivas de Ácidos Nucleicos , Animales , Células Cultivadas , Pollos , ADN Viral/química , Enfermedad de Marek/virología , Reacción en Cadena de la Polimerasa/veterinaria , Enfermedades de las Aves de Corral/virología , Mapeo Restrictivo/veterinariaRESUMEN
Two mutant CV1988 Marek's disease virus (MDV) strains were developed in which a part of ORF L1 was replaced by lacZ with the SV40 early promoter. These mutant strains, CVIL1LacZ-A and -B, were inoculated into chickens to test the hypothesis that ORF L1 is involved in the induction and/or maintenance of latency. Mutant virus could be reisolated from lymphocytes obtained from chickens during both the lytic and latent phase of infection, indicating that ORF L1 is not essential for the induction and/or maintenance of latency or the reactivation from latency. Beta-galactosidase-positive lymphocytes were detected during the latent infection demonstrating that the SV40 early promoter can be active in recombinant MDV strains during latent infection. Although the insertion of lacZ was stable in cell culture, recombination within lacZ and the BamHI-L fragment was observed during in vivo infection.
Asunto(s)
Herpesvirus Gallináceo 2/genética , Herpesvirus Gallináceo 2/fisiología , Sistemas de Lectura Abierta , Replicación Viral/genética , Animales , Antígenos Virales/genética , Secuencia de Bases , Células Cultivadas , Embrión de Pollo , Pollos , Cartilla de ADN/genética , ADN Viral/genética , ADN Viral/aislamiento & purificación , Expresión Génica , Herpesvirus Gallináceo 2/patogenicidad , Operón Lac , Enfermedad de Marek/etiología , Enfermedad de Marek/virología , Mutagénesis Insercional , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Eliminación de Secuencia , Virus 40 de los Simios/genética , Virulencia/genéticaRESUMEN
The glycoprotein E (gE) locus in the genome of pseudorabies virus (PRV) was used as an insertion site for the expression of glycoprotein E1 of classical swine fever virus (CSFV). Transcription of E1 in the recombinants M401, M402 or M403 was regulated by the gD promoter of PRV, the immediate early gene promoter of human cytomegalovirus, or the gE promoter of PRV, respectively. Groups of four pigs were vaccinated once intramuscularly with 10(6) plaque forming units (p.f.u.) of the recombinant viruses and challenged intranasally with 100 50% lethal doses of virulent CSFV and with 10(5) p.f.u. of virulent PRV. All pigs vaccinated with M402 were fully protected against both classical swine fever and pseudorabies.
Asunto(s)
Virus de la Fiebre Porcina Clásica/inmunología , Peste Porcina Clásica/prevención & control , Regulación Viral de la Expresión Génica/inmunología , Herpesvirus Suido 1/inmunología , Regiones Promotoras Genéticas/inmunología , Seudorrabia/prevención & control , Vacunas Sintéticas/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/biosíntesis , Peste Porcina Clásica/inmunología , Virus de la Fiebre Porcina Clásica/genética , Virus de la Fiebre Porcina Clásica/patogenicidad , Herpesvirus Suido 1/genética , Herpesvirus Suido 1/patogenicidad , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/inmunología , Seudorrabia/inmunología , Porcinos , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología , VirulenciaRESUMEN
We used the polymerase chain reaction (PCR) technique to detect bovine viral diarrhea virus (BVDV) infections in cattle. Of 120 cattle screened in this study, 29 were scored positive for BVDV with both PCR and conventional virus isolation. Ninety cattle were negative in both assays. One cow was scored positive for BVDV with the PCR but was negative with virus isolation. In dilution experiments PCR analysis was at least 10 times more sensitive than BVDV isolation.
Asunto(s)
Diarrea Mucosa Bovina Viral/diagnóstico , Portador Sano/veterinaria , Virus de la Diarrea Viral Bovina/aislamiento & purificación , ARN Viral/análisis , Animales , Secuencia de Bases , Southern Blotting , Diarrea Mucosa Bovina Viral/microbiología , Portador Sano/diagnóstico , Portador Sano/microbiología , Bovinos , Línea Celular , Virus de la Diarrea Viral Bovina/genética , Leucocitos/microbiología , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Sondas de Oligonucleótidos/química , Reacción en Cadena de la Polimerasa , Valor Predictivo de las Pruebas , Temperatura , Moldes Genéticos , Transcripción GenéticaRESUMEN
At least two regions of Autographa californica Nuclear Polyhedrosis Virus (AcMNPV) DNA contain nucleotide sequences that allowed the autonomous replication of chimaeric plasmids in Saccharomyces cerevisiae. These sequences were located around position 26 and 37 per cent on the physical map of AcNPV DNA.
Asunto(s)
Replicación del ADN , ADN Viral/genética , Virus de Insectos/genética , Replicación Viral , Secuencia de Bases , Mapeo Cromosómico , Plásmidos , Saccharomyces cerevisiae/genética , Transformación GenéticaRESUMEN
The nucleotide sequence of a 1143-bp region of Autographa californica MNPV (AcMNPV) DNA containing the entire coding region of polyhedrin was determined. The coding region consisted of 732 bp without intervening sequences. The 5' leader sequence was approximately 58 nucleotides in length. A putative "TATA box" and "CAAT box" were located 20 and 52 bp upstream from the transcriptional start site, respectively. Two tandem repeats of 8 bp were found 70 and 84 bp upstream from the transcriptional start site. The molecular weight of polyhedrin, as deduced from the nucleotide sequence, was 28,872. The amino acid sequence of AcMNPV polyhedrin was very similar to the amino acid sequence of Bombyx mori polyhedrin.