RESUMO
Endogenous retroviral gene elements have been implicated in development and formation of the feto-maternal interface. A variant of the syncytin endogenous retroviral envelope gene family, , was recently found in ruminants. We hypothesized that mRNA would be differentially expressed in utero-placental tissues and would fluctuate during key time points of early gestation in beef heifers. Commercial Angus crossbred heifers ( = 46; â¼15 mo of age; BW = 362.3 ± 34.7kg) housed in 6-animal pens were fed daily with native grass hay and supplemented with cracked corn to gain 0.3 kg/d. The heifers were estrus synchronized, artificially inseminated, (d of breeding= d 0) and ovariohysterectomized on d 16, 22, 28, 34, 40, and 50 ( = 9, 6, 6, 7, 6, and 5, respectively) of gestation and at d 16 of the estrous cycle for non-bred, non-pregnant controls (NP; = 7). Harvested tissues were separated into maternal caruncle (CAR), intercarunclar endometrium (ICAR), and fetal membranes, (FM; chorioallantois, d 22 and later). All tissues were obtained from the ipsilateral uterine horn to the CL. Statistical analyses were conducted via the GLM procedure of SAS. Maternal CAR expression of was greater ( = 0.003) on d 50 by 81.5-fold compared to NP controls. At d 50 expression of in CAR was 190.3-fold greater than ( < 0.0001) ICAR. Fetal membranes had greater ( < 0.002) expression of from d 22 until d 50 of gestation compared to maternal ICAR (d 16 not analyzed). Expression of in FM was greater ( < 0.004) than in CAR until d 40 of gestation. Therefore, we conclude that is differentially expressed in utero-placental tissues and may be involved in the establishment of pregnancy. The expression of in maternal tissues is completely novel and indicates unique functions of syncytin in ruminant pregnancy.
Assuntos
Bovinos/fisiologia , Suplementos Nutricionais , Produtos do Gene env/metabolismo , Proteínas da Gravidez/metabolismo , Animais , Cruzamento , Bovinos/genética , Retrovirus Endógenos , Ciclo Estral , Sincronização do Estro , Feminino , Produtos do Gene env/genética , Inseminação Artificial , Placenta/fisiologia , Folhas de Planta , Poaceae , Gravidez , Proteínas da Gravidez/genética , Carne Vermelha , Sementes , Zea maysRESUMO
Sixty-nine Angus-sired steer calves (332.3 kg initial BW) were used to determine the effects of single or double implant strategies on steers of high or low genetic potential (GP) determined by the GeneMax (Zoetis, Florham Park, NJ) genetic profiling test. Steers were assigned to treatments in a 2 × 2 factorial design with factors of 1) composite GP score (high, mean GP score of 86.5 [HI]; low, mean GP score of 25.3[LO]) and 2) implant strategy (single, steers implanted on d 70 [1X], or double, steers implanted d 0 and 70 [2X]). All steers were given the same implant (Revalor-S; Merck Animal Health, Summit, NJ), with the 2X group implanted on d 0 and 70 and the 1X group implanted only on d 70. A diet containing 1.38 Mcal NEg/kg DM was fed ad libitum, once daily. Ultrasound was used to measure body composition characteristics on d 0 and 70. Steers were harvested after 140 d on feed. At both the d-0 and d-70 ultrasound, HI steers had greater ( < 0.001) percent intramuscular fat (IMF) than LO steers, but no differences ( ≥ 0.24) were observed in LM area (LMA), rib fat thickness (RF), or rump fat thickness (RMFT). Steers in the 2X group had larger ( = 0.02) LMA and less ( = 0.03) IMF on d 70 than 1X steers and no differences ( ≥ 0.50) in RF or RMFT were observed. From d 0 to 70, HI steers had ADG, DMI, and G:F ( ≥ 0.60) similar to LO steers; however, 2X steers had greater ( < 0.001) ADG and were more ( < 0.001) feed efficient compared with 1X steers during the same interval. Over the entire 140-d feeding period, there were no differences ( ≥ 0.6) in BW, ADG, DMI, or G:F between GP groups; however, 2X steers had greater ( = 0.03) ADG compared with 1X steers and still had similar ( ≥ 0.12) DMI and G:F. Upon slaughter, marbling score tended to be impacted by a GP × implant interaction (499.9 ± 18.5, 545.6 ± 18.5, 487.1 ± 18.5, and 469.8 ± 18.5 for HI and 2X, HI and 1X, LO and 2X, and LO and 1X, respectively; = 0.06). No differences ( ≥ 0.7) were observed between GP groups for HCW, LMA, RF, KPH, or yield grade (YG). Steers in the 1X group had less ( = 0.003) RF than 2X steers but similar ( ≥ 0.14) HCW, marbling, LMA, KPH, and YG. A greater proportion ( = 0.03) of HI steers had choice carcasses (100 ± 0.0%) compared with LO steers (87.8 ± 3.9%). Results of this study indicate that the GP test used in the current study predicted differences in IMF, carcass marbling, and percent carcasses graded as choice.
Assuntos
Ração Animal/análise , Composição Corporal/efeitos dos fármacos , Bovinos/fisiologia , Estradiol/farmacologia , Acetato de Trembolona/análogos & derivados , Aumento de Peso/efeitos dos fármacos , Tecido Adiposo , Animais , Bovinos/genética , Dieta/veterinária , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Estradiol/administração & dosagem , Acetato de Trembolona/administração & dosagem , Acetato de Trembolona/farmacologia , Aumento de Peso/genéticaRESUMO
Aicardi-Goutiéres syndrome (AGS) is an early onset, progressive encephalopathy characterised by calcification of the basal ganglia, white matter abnormalities, and a chronic cerebrospinal fluid (CSF) lymphocytosis. Cree encephalitis shows phenotypic overlap with AGS although the conditions have been considered distinct because of immunological abnormalities observed in Cree encephalitis. We report that levels of interferon alpha (IFN-alpha), a marker of AGS, are raised in Cree encephalitis. Moreover, linkage analysis indicates that the disorders are allelic and refines the AGS1 locus to a 3.47 cM critical interval. Our data show that a CSF lymphocytosis is not necessary for the diagnosis of AGS and strongly suggest that AGS and pseudo-TORCH syndrome are the same disorder. Recognition of immunological dysfunction as part of the AGS phenotype provides further evidence of a primary pathogenic role for abnormal IFN-alpha production in AGS.
Assuntos
Anormalidades Múltiplas/genética , Doenças dos Gânglios da Base/patologia , Dano Encefálico Crônico/patologia , Calcinose/patologia , Encefalite/genética , Indígenas Norte-Americanos , Anormalidades Múltiplas/sangue , Anormalidades Múltiplas/patologia , Criança , Cromossomos Humanos Par 3/genética , Encefalite/sangue , Saúde da Família , Feminino , Predisposição Genética para Doença/genética , Haplótipos , Humanos , Interferon-alfa/sangue , Escore Lod , Linfocitose/líquido cefalorraquidiano , Masculino , Repetições de Microssatélites , Linhagem , Fenótipo , SíndromeRESUMO
BACKGROUND: In the 1940s and 1950s, prefrontal lobotomy was widely used to treat aggressive, disruptive and psychotic behavior in schizophrenics. Subsequent observations have confirmed its ineffectiveness in schizophrenia. Few studies have addressed its long-term consequences. METHODS: We conducted tests of frontal function, behavior (Frontal Behavioral Inventory), psychopathology (PANSS), neurological examinations and CT scans in 19 chronically institutionalized schizophrenic patients (mean age 74) who had undergone orbitofrontal leukotomy between 1948 and 1972 and 11 controls (mean age 74) matched for age, length of hospitalization, education, and diagnosis. RESULTS: There were no significant differences between leukotomized patients and controls on: Folstein Mini-Mental score (leuko 22.13+/-5.66; controls 23.55+/-5.93), utilization behavior, Luria alternating written and motor sequences, verbal fluency, imitation behavior, motor impersistence, primitive reflexes, or psychopathology. Significant differences were found on clock drawing and on the go/no-go test, which may reflect the presence of an orbitofrontal lesion in the leukotomized group. There was a tendency for the leukotomized group to have fewer indices of frontal behavioral dysfunction. Both groups showed comparable impairment on the Stroop test and cognitive rigidity on the Odd Man Out test of category shifting. CONCLUSIONS: With few exceptions, elderly leukotomized and nonleukotomized schizophrenic patients show varying degrees of distractibility, difficulty in set shifting, poor planning and organization, susceptibility to interference, primitive reflexes and signs of global cognitive impairment. Allowing for the small sample size, variability in the surgical frontal lesion, and the long interval from surgery to testing, these observations likely reflect the long-term consequences of severe schizophrenia in both groups.
Assuntos
Transtornos Cognitivos/etiologia , Lobo Frontal/cirurgia , Institucionalização , Complicações Pós-Operatórias/etiologia , Psicocirurgia , Esquizofrenia/cirurgia , Transtornos do Comportamento Social/etiologia , Idoso , Mapeamento Encefálico , Doença Crônica , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/fisiopatologia , Demência/diagnóstico , Demência/etiologia , Demência/fisiopatologia , Feminino , Lobo Frontal/fisiopatologia , Humanos , Masculino , Testes Neuropsicológicos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/fisiopatologia , Esquizofrenia/diagnóstico , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Transtornos do Comportamento Social/diagnóstico , Transtornos do Comportamento Social/fisiopatologiaRESUMO
Cattle were vaccinated with differing doses of an equal mixture of capripox-rinderpest recombinant viruses expressing either the fusion protein (F) or the haemagglutinin protein (H) of rinderpest virus. Animals vaccinated with 2 x 10(4) p.f.u. or greater of the combined viruses were completely protected against challenge, 1 month later, with both virulent rinderpest and lumpy skin disease viruses. Vaccination with any of the doses did not induce any adverse clinical response in the animals or transmission of the vaccine virus between animals. All cattle challenged 6 or 12 months after vaccination with 2 x 10(5) p.f.u. of the mixture of recombinant viruses were protected from severe rinderpest disease. Ten out of 18 were completely protected while the remaining 8 developed mild clinical signs of rinderpest. Cattle vaccinated with the recombinant vaccines after prior infection with the parental capripox virus showed more marked clinical signs of rinderpest after challenge with virulent rinderpest, but 9 out of 10 recovered, compared with 80% mortality in the unvaccinated controls.
Assuntos
Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinas Sintéticas/imunologia , Animais , Bovinos , Hemaglutininas/genética , Hemaglutininas/imunologia , Doença Nodular Cutânea/imunologia , Doença Nodular Cutânea/prevenção & controle , Doença Nodular Cutânea/virologia , Vírus da Doença Nodular Cutânea/imunologia , Testes de Neutralização , Peste Bovina/transmissão , Peste Bovina/virologia , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologiaRESUMO
A recombinant capripox virus was constructed containing a cDNA copy of genome segment 7 of bluetongue virus (BTV) serotype 1 from South Africa (BTV 1SA), which expressed high levels of the major BTV core protein VP7 in infected lamb testis (LT) cells. Sheep vaccinated with this recombinant virus developed antibodies to VP7 (detected by ELISA) but no neutralizing antibodies to either the homologous or heterologous BTV serotype, prior to challenge (BTV 1 or BTV 3, respectively). Following challenge with a virulent heterotypic strain of BTV (BTV3 SA), all of the animals developed clinical signs of disease, indicating that they were infected and that the challenge virus did replicate. While all of the control animals died, six of the eight animals that were vaccinated with the recombinant capripox virus expressing VP7 recovered fully. This is the first report of a significant level of cross serotype protection against the lethal effects of a challenge with virulent BTV, produced by vaccination with a single BTV core protein, which did not generate a neutralizing antibody response.
Assuntos
Vírus Bluetongue/imunologia , Bluetongue/prevenção & controle , Proteínas do Core Viral/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Capripoxvirus/genética , Expressão Gênica , Ovinos , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Core Viral/genética , Vacinas Virais/genética , VirulênciaRESUMO
The DNA sequence of the HindIII Q2 fragment near the left terminus of the capripoxvirus (KS-1 strain) genome was determined. The sequence contains two complete open reading frames (ORFs) and a part of a third. Analysis of the deduced amino acid sequence of one of these ORFs, Q2/3L, revealed that this gene has the capacity to encode a protein which is related to members of the G-protein coupled chemokine receptor subfamily, the swinepoxvirus K2R and the human cytomegalovirus US28 ORFs. It has the key structural characteristics of the G-protein-coupled receptor superfamily, e.g., seven hydrophobic regions, predicted to span the cell membrane, and the cysteine residues in the first and second extracellular loops that are implicated in formation of a disulfide bond. Southern blot analysis showed that all three species of the Capripoxvirus genus, i.e., sheep pox, goat pox, and lumpy skin disease of cattle, contain copies of this putative G-protein-coupled chemokine receptor homologue.
Assuntos
Capripoxvirus/genética , Genes Virais , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Capripoxvirus/classificação , Bovinos , DNA Viral/genética , Desoxirribonuclease HindIII , Proteínas de Ligação ao GTP/metabolismo , Dados de Sequência Molecular , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade da EspécieRESUMO
A cDNA clone containing the complete coding sequence of the hemagglutinin (H) protein gene of the RBOK vaccine strain of rinderpest virus, under the control of the vaccinia late promoter p11, was inserted by homologous recombination into the thymidine kinase gene of the KS-1 strain of capripoxvirus. The recombinant virus produced authentic H protein as judged by its electrophoretic mobility, transport to the cell surface of infected lamb testis cells, and reactivity with monoclonal antibodies specific for the H protein of rinderpest virus. The recombinant virus induced significant levels of rinderpest virus neutralizing antibodies in vaccinated cattle and protected them from clinical rinderpest after challenge with a lethal dose of a highly virulent heterologous strain of the virus. Protection was achieved using vaccine doses lower than those used with a similar recombinant expressing the fusion protein gene of rinderpest. The parental KS-1 virus is widely used as a vaccine against capripox viruses and so the rinderpest recombinant acts as a dual vaccine to protect cattle against both rinderpest and lumpy skin disease.
Assuntos
Capripoxvirus/genética , Glicoproteínas/imunologia , Doença Nodular Cutânea/prevenção & controle , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinas Sintéticas/imunologia , Proteínas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Capripoxvirus/imunologia , Bovinos , Linhagem Celular , Expressão Gênica , Genes Virais/genética , Glicoproteínas/biossíntese , Glicoproteínas/genética , Hemaglutininas Virais , Imunidade Ativa , Doença Nodular Cutânea/imunologia , Proteínas de Membrana , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/imunologia , Peste Bovina/imunologia , Vírus da Peste Bovina/genética , Timidina Quinase/genética , Vacinação , Vacinas Sintéticas/genética , Vaccinia virus/genética , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia , Proteínas Virais/biossíntese , Proteínas Virais/genética , Proteínas Estruturais Virais/genética , Vacinas Virais/genética , Vacinas Virais/imunologiaRESUMO
Cattle were protected against challenge with rinderpest and lumpy skin disease viruses by vaccination with a recombinant capripoxvirus containing the fusion protein (F) gene of rinderpest virus. The minimum protective immunising doses for rinderpest and lumpy skin disease were 5.5 x 10(4) plaque forming units (pfu) and 1.5 x 10(3) pfu, respectively.
Assuntos
Capripoxvirus/imunologia , Doença Nodular Cutânea/prevenção & controle , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinação/veterinária , Animais , Temperatura Corporal , Bovinos , Vírus da Peste Bovina/genética , Vacinas Sintéticas , Proteínas Virais de Fusão/genética , Vacinas ViraisRESUMO
A recombinant capripoxvirus has been constructed containing a full-length cDNA of the fusion protein gene of rinderpest virus. The gene was inserted in the thymidine kinase gene of the capripox genome under the control of the vaccinia virus major late promoter p11 together with the Escherichia coli gpt gene in the opposite orientation under the control of the vaccinia early/late promoter p7.5. A vaccine prepared from this recombinant virus protected cattle against clinical rinderpest after a lethal challenge with a virulent virus isolate. In addition, the vaccine protected the cattle against lumpy skin disease.
Assuntos
Glicoproteínas/imunologia , Doença Nodular Cutânea/prevenção & controle , Poxviridae/imunologia , Vírus da Peste Bovina/imunologia , Peste Bovina/prevenção & controle , Vacinas Sintéticas , Proteínas Virais de Fusão/imunologia , Vacinas Virais , Animais , Anticorpos Antivirais/biossíntese , Bovinos , DNA Viral/química , DNA Viral/genética , Escherichia coli/genética , Expressão Gênica , Glicoproteínas/genética , Masculino , Proteínas de Membrana , Poxviridae/genética , Vírus da Peste Bovina/genética , Vacinas Sintéticas/imunologia , Proteínas Virais de Fusão/genética , Vacinas Virais/imunologiaRESUMO
Equivalent regions from within the inverted terminal repeats (ITRs) of the genomes of two capripoxviruses, KS-1 and InS-1, were sequenced. The sequence from KS-1 DNA covers the major part of three contiguous open reading frames (ORFs), which match three contiguous ORFs from within the genomic ITRs of the leporipoxvirus Shope Fibroma Virus (SFV). The sequenced region of InS-1 DNA contains only two of the three ORFs. The region homologous to the third ORF has no coding potential due to the presence of several stop codons, resulting from small frameshifting deletions and insertions. The significance of a degenerate poxvirus gene, intact homologs of which are only found in other poxvirus genomes, is discussed.
Assuntos
Genes Virais , Poxviridae/genética , Pseudogenes , Sequência de Aminoácidos , Sequência de Bases , Genes , Dados de Sequência Molecular , Homologia de Sequência do Ácido NucleicoRESUMO
We have extended previous comparisons of genetic organization between poxvirus genera by sequencing a 2.5K genomic fragment from isolate KS-1 (Kenya sheep-1) of the genus capripoxvirus. The fragment is located in the central region of the capripoxvirus genome and contains three complete and two incomplete open reading frames (ORFs). One of the complete ORFs is a gene for thymidine kinase (TK). This gene, with one of the other two complete ORFs and both the incomplete ORFs, are homologous to four contiguous ORFs from the central region of vaccinia virus (VV) DNA. They also match four ORFs of fowlpox virus (FPV) DNA, three of which are contiguous and the fourth, the FPV TK gene, is located elsewhere on the FPV genome. The third complete ORF of the capripoxvirus DNA fragment is located between the TK gene and the capripoxvirus homologue of the ORF immediately downstream of the VV TK gene. We show that a homologue to this third ORF is absent from VV and FPV DNAs, but is present downstream of the TK gene on Shope fibroma virus DNA. The sequence immediately upstream of the capripoxvirus homologue of a VV late gene contains a motif which is required for VV late gene expression. The motif required for VV early gene transcription termination is present in eight positions in the capripoxvirus sequence, and five of these positions are consistent with the motif having an equivalent function in capripoxvirus to that in VV.
Assuntos
Genes Virais , Poxviridae/genética , Timidina Quinase/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular/métodos , Códon/genética , DNA Viral/genética , Dados de Sequência Molecular , Plasmídeos , Poxviridae/enzimologia , Sequências Reguladoras de Ácido Nucleico , Homologia de Sequência do Ácido NucleicoRESUMO
We report a neurological disease among Cree Indian children in a northern Quebec village. The disease manifests as severe mental retardation, cerebral atrophy with white matter changes and calcifications, and systemic immunological abnormalities. Eleven cases are known in five families. The familial incidence of cases and the high degree of parental consanguinity suggest a genetic contribution. We propose that this entity may be caused by an unusual viral infection in a genetically vulnerable host.
Assuntos
Encefalopatias/etiologia , Calcinose/etiologia , Encefalite/epidemiologia , Deficiência Intelectual/etiologia , Adolescente , Anticorpos Antivirais/sangue , Atrofia , Encefalopatias/genética , Encefalopatias/microbiologia , Calcinose/genética , Calcinose/microbiologia , Criança , Pré-Escolar , Encefalite/complicações , Encefalite/genética , Feminino , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/genética , Deficiência Intelectual/microbiologia , Masculino , QuebequeRESUMO
We report 14 cases of a severe familial leukoencephalopathy among native North American Indian infants in northern Quebec and Manitoba. Affected infants have hypotonia and mild motor delay, followed by seizures, hypotonia or spasticity, eye deviation, and abnormal posture during a febrile illness around 6 months of age. Death follows a rigid, vegetative state that manifests days to months after disease onset and is marked in some cases by prominent autonomic disturbances, blindness, and cessation of head growth. Symmetrical hemispheric white matter lucencies and diffuse hypomyelination of the cerebral hemispheres and brainstem are the radiological and pathological hallmarks. This disease differs from the known diseases of cerebral myelin. An autosomal recessive pattern of inheritance awaits statistical confirmation. The proposed cause is a delay in development or abnormal turnover of central nervous system myelin.
Assuntos
Leucoencefalopatia Multifocal Progressiva/epidemiologia , Encéfalo/ultraestrutura , Feminino , Humanos , Lactente , Leucoencefalopatia Multifocal Progressiva/genética , Masculino , Manitoba , Microscopia Eletrônica , Hipotonia Muscular/etiologia , Bainha de Mielina/ultraestrutura , QuebequeRESUMO
The proteins of sheep pox, goat pox, sheep and goat pox and lumpy skin disease (Neethling) viruses were labelled with [35S]methionine. The major structural polypeptides of these viruses co-migrated on polyacrylamide gels, demonstrating the very close biochemical relationship between them. Using the agar gel immunodiffusion (AGID) test with radiolabelled antigen preparations, a major common precipitating antigen was identified. This co-migrated on polyacrylamide gels with one of the major structural polypeptides [mol. wt. 67000 (67K)]. The use of [35S]methionine-labelled antigen preparations considerably improved the sensitivity of the AGID test as a diagnostic test for capripoxvirus antibody detection.
Assuntos
Antígenos Virais/análise , Poxviridae/análise , Proteínas Virais/análise , Animais , Células Cultivadas , Cabras , Imunodifusão , Vírus da Doença Nodular Cutânea/análise , Masculino , Metionina/metabolismo , Poxviridae/imunologia , Poxviridae/isolamento & purificação , Ovinos , Especificidade da Espécie , Radioisótopos de Enxofre , TestículoRESUMO
An mRNA-dependent reticulocyte lysate has been used to translate foot-and-mouth disease virus RNA in vitro. Polypeptides P16, P20a, and P88, which have been shown to be derived from the 5' end of the RNA by pactamycin mapping experiments with infected cells, were preferentially synthesized in vitro. Removal of VPg, the small protein covalently linked to the 5' end of the genome RNA, had no effect on the translation of the RNA. The two RNA fragments (L and S) produced by specific digestion of the polycytidylic acid [poly(C)] tract with RNase H were also translated in vitro. The L fragment, consisting of RNA to the 3' side of the poly(C) tract and including the polyadenylic acid [poly(A)] tract, directed the synthesis of the same products as those made by full-length RNA. However, no small defined products were produced when the S fragment, which contains the 5' end of the RNA, was translated. These results show that the major initiation site for protein synthesis on foot-and-mouth disease virus RNA is to the 3' side of the poly(C) tract. Furthermore, the use of N-formyl [35S]methionine tRNAfMet as a label for the initiation peptides showed that the major polypeptide labeled in lysates primed with both full-length RNA and the L fragment was P16, i.e., the protein nearest the initiation site for translation as deduced from pactamycin mapping experiments. Fragments of RNA were also translated in vitro. Those containing the poly(C) tract gave products similar to those produced when full-length RNA was translated. The polypeptides synthesized when fragments containing the poly(A) tract were used, however, did not resemble those made from full-length RNA.
Assuntos
Aphthovirus/genética , Iniciação Traducional da Cadeia Peptídica , Biossíntese de Proteínas , RNA Viral/genética , Proteínas Virais/biossíntese , Aphthovirus/metabolismo , Sistema Livre de Células , Metionina/metabolismo , Peso Molecular , Biossíntese Peptídica , Aminoacil-RNA de Transferência/metabolismo , ReticulócitosRESUMO
Three polypeptides with mol. wt. 100 (P100), 80 (P80) and 65 (P65) X 10(3) were found in calicivirus infected cells. P100 and P80 were present in sub-molar amounts compared with P65 and no precursor product relationship between the three polypeptides could be demonstrated using pulse-chase experiments or selective inhibitors of protein synthesis and of proteases. In the presence of protease inhibitors a polypeptide with mol. wt. 120 X 10(3) (P120) was demonstrated which appeared to be the precursor of P100. Possible mechanisms of translation in the caliciviruses are discussed.
Assuntos
Caliciviridae/metabolismo , Picornaviridae/metabolismo , Precursores de Proteínas/biossíntese , Exantema Vesicular de Suínos/microbiologia , Proteínas Virais/biossíntese , Animais , Aprotinina/farmacologia , Linhagem Celular , Iodoacetamida/farmacologia , Peso Molecular , Pactamicina/farmacologia , Biossíntese Peptídica , Biossíntese de Proteínas/efeitos dos fármacos , Solução Salina Hipertônica/farmacologia , Suínos , Zinco/farmacologiaRESUMO
Four primary cleavage products, mol. wt. 10(3) X 100, 88, 56 and 52 (P100, P85, P56 and P52 respectively) are present in BHK 2I cells infected with foot-and-mouth disease virus (FMDV). However, no precursor polyprotein equal to the sum of their mol. wt. was detected, even when amino acid analogues and proteolytic enzyme inhibitors were used. Three of the primary products were shown to cleave to smaller polypeptides, including the capsid polypeptides of the virus. Polypeptide P88, which was shown to be the precursor of the capsid polypeptides, is translated from the gene located at the 5'-end of the genome. The order of the structural polypeptides, determined by the use of emetine, is VP4, VP2, VP3, VP1. The order of the remaining primary cleavage products is P52, P56 and P100. P56 is a stable product, identical with the virus infection associated (VIA) antigen found in virus harvests. The function of the other two products P52 and P100 is not known. EMDV thus differs from other picornaviruses in that there is an extra primary cleavage product, apparently resulting from translation of more of the virus genome.
Assuntos
Aphthovirus/análise , Genes , Linhagem Celular , Peso Molecular , Pactamicina/farmacologia , Peptídeos/análise , Precursores de Proteínas/análise , RNA Viral/análise , Cloreto de Sódio/farmacologia , Proteínas Virais/análiseRESUMO
Methods for the purification of African swine fever virus (ASFV) and its dissection into two fractions are described. The difficulties which have been encountered previously in attempts to purify the virus, namely contamination with large amounts of cellular constituents and aggregation of the virus particles, have been overcome by treatment with Tween 80 and by the use of 1 M-NaCl in the sucrose gradients. Five major polypeptides, mol. wt. 10(3) X 125 (VP1), 76 (VP2), 50 (VP3), 44 (VP4) and 39 (VP5) were found in the purified particles. The virus was dissected by treatment with Nonidet NP 40 into (a) a fraction which had the appearance of an empty capsid shell and capsid shell and contained the polypeptides VP2 and VP3 and (b) a structure containing VP1 and VP4. The location of VP5 was not ascertained.
Assuntos
Vírus da Febre Suína Africana , Vírus de DNA , Vírus da Febre Suína Africana/análise , Vírus da Febre Suína Africana/isolamento & purificação , Vírus da Febre Suína Africana/ultraestrutura , Centrifugação com Gradiente de Concentração , Vírus de DNA/isolamento & purificação , Peptídeos/análise , Polissorbatos , Cloreto de Sódio , Proteínas Virais/análiseRESUMO
The RNA-dependent RNA polymerase induced in baby-hamster kidney cells by infection with foot-and-mouth-disease virus can be detected as early as 60min. after infection, which is 60min. before viral RNA synthesis commences. The time at which the polymerase can first be detected coincides with the latest time at which actinomycin D (50mug./10(7) cells) or guanidine (1mg./10(7) cells) inhibits virus replication. However, by increasing the concentration of guanidine, viral replication can be inhibited later in the growth cycle, casting doubt on the validity of the hypothesis that guanidine acts specifically on the formation of the viral RNA polymerase.