RESUMEN
The complete genome sequence of a novel duck orthoreovirus, designated DRV strain TH11(DRV-TH11), was determined and characterized. The DRV-TH11 genome is comprised of 23,417 bp and its genome organization is more similar to that of avian orthoreoviruses (ARVs) of chicken origin than other reoviruses. The results of comparative sequence analysis and dendrograms based on the µB- and σC-encoding genes indicated that TH11 may be derived from the reassortment of ARVs and classic Muscovy duck reovirus (MDRV). A possible recombinant event was identified using the SimPlot program, and it occurred in the M2 segment. The results indicated that reassortment and mutation play a role in the evolution of duck reovirus.
Asunto(s)
Patos , Orthoreovirus Aviar/aislamiento & purificación , Enfermedades de las Aves de Corral/virología , Infecciones por Reoviridae/veterinaria , Animales , China/epidemiología , Orthoreovirus Aviar/genética , Filogenia , Enfermedades de las Aves de Corral/epidemiología , Infecciones por Reoviridae/epidemiología , Infecciones por Reoviridae/virologíaRESUMEN
Both sides of the picornavirus genome have 5'-untranslated region (5'UTR) and 3'- untranslated region (3'UTR). This study demontrated that both the 5'-and 3'-UTR can form complex structures, such as stem-loop, clover and pseudoknot structure, These structures play an important role in the regulaton of the replication and translation of the viruses. This article reviewed the progress of research on the structure and function of picornavirus' 3'-UTR over recent years.
Asunto(s)
Regiones no Traducidas 3' , Infecciones por Picornaviridae/virología , Picornaviridae/química , ARN Viral/química , ARN Viral/metabolismo , Animales , Humanos , Conformación de Ácido Nucleico , Picornaviridae/genética , Picornaviridae/metabolismo , ARN Viral/genéticaRESUMEN
UNLABELLED: Cold stress causes various injuries to rice seedlings in low-temperature and high-altitude areas and is therefore an important factor affecting rice production in such areas. In this study, root conductivity (RC) was used as an indicator to map quantitative trait loci (QTLs) of cold tolerance in Oryza rufipogon Griff., Dongxiang wild rice (DX), at its two-leaf stage. The correlation coefficients between RC and the plant survival rate (PSR) at the seedling and maturity stages were -0.85 and -0.9 (Pâ=â0.01), respectively, indicating that RC is a reliable index for evaluating cold tolerance of rice. A preliminary mapping group was constructed from 151 BC2F1 plants using DX as a cold-tolerant donor and the indica variety Nanjing 11 (NJ) as a recurrent parent. A total of 113 codominant simple-sequence repeat (SSR) markers were developed, with a parental polymorphism of 17.3%. Two cold-tolerant QTLs, named qRC10-1 and qRC10-2 were detected on chromosome 10 by composite interval mapping. qRC10-1 (LODâ=â3.1, RM171-RM1108) was mapped at 148.3 cM, and qRC10-2 (LODâ=â6.1, RM25570-RM304) was mapped at 163.3 cM, which accounted for 9.4% and 32.1% of phenotypic variances, respectively. To fine map the major locus qRC10-2, NJ was crossed with a BC4F2 plant (L188-3), which only carried the QTL qRC10-2, to construct a large BC5F2 fine-mapping population with 13,324 progenies. Forty-five molecular markers were designed to evenly cover qRC10-2, and 10 markers showed polymorphisms between DX and NJ. As a result, qRC10-2 was delimited to a 48.5-kb region between markers qc45 and qc48. In this region, Os10g0489500 and Os10g0490100 exhibited different expression patterns between DX and NJ. Our results provide a basis for identifying the gene(s) underlying qRC10-2, and the markers developed here may be used to improve low-temperature tolerance of rice seedling and maturity stages via marker-assisted selection (MAS). KEY MESSAGE: With root electrical conductivity used as a cold-tolerance index, the quantitative trait locus qRC10-2 was fine mapped to a 48.5-kb candidate region, and Os10g0489500 and Os10g0490100 were identified as differently expressed genes for qRC10-2.
Asunto(s)
Adaptación Biológica/genética , Mapeo Cromosómico , Frío , Oryza/genética , Raíces de Plantas/genética , Sitios de Carácter Cuantitativo , Plantones/genética , Cromosomas de las Plantas , Ligamiento Genético , Oryza/crecimiento & desarrollo , Fenotipo , Mapeo Físico de Cromosoma , Raíces de Plantas/crecimiento & desarrollo , Plantones/crecimiento & desarrolloRESUMEN
The apoptosis of RK13 cells induced by RHDV was investigated with DAPI staining, DNA ladder, Caspase 3 activity and flow cytometry, etc. The results showed that nuclear staining of infected cells with DAPI showed gradually morphological changes of the nuclei. As shown in the paper, a canonic oligonucleosome-sized DNA ladder was observed in cells harvested at 24h, 48h and 72h post-infection, confirming that DNA fragmentation was induced by RHDV infection. The results of flow cytometry showed that about 63% of cells were in apoptosis at 48h post-infection. Besides, we also demonstrated that the activation of Caspase 3 occurred during the infection process. In conclusion, our results showed that apoptosis in RHD might be determinant in the development of the pathogenesis of RHD.
Asunto(s)
Apoptosis , Infecciones por Caliciviridae/fisiopatología , Infecciones por Caliciviridae/veterinaria , Virus de la Enfermedad Hemorrágica del Conejo/fisiología , Animales , Infecciones por Caliciviridae/genética , Infecciones por Caliciviridae/virología , Caspasa 3/metabolismo , Línea Celular , Núcleo Celular/genética , Núcleo Celular/virología , Fragmentación del ADN , ConejosRESUMEN
Biohydrogen production by anaerobic sludge was studied by using wastewater as substrate in batch process. Hydrogen production potential of different substrate species, as well as the composition of fermentation product in liquid phase, was studied in the batch culture experiments. The hydrogen production and bacterial growth dynamics were also analyzed. The experiment results demonstrated that the optimal substrate was glucose for hydrogen production. It could be obtained maximum cumulative hydrogen production 67.21 L/mol, hydrogen yield 3.23 mol/mol and hydrogen content 49.52%. The butyrate and acetate were main liquid end products, occupied 26.76%-40.49% of acetate, 37.60%-58.07% of butyrate, implying that it is butyrate-type fermentation. Butyrate/acetate could be used as the indicator for evaluating the effectiveness of H2 production, with that the higher butyrate/acetate, the higher the hydrogen yield. ORP was less than -300 mV during fermentation indicating the experiment was anaerobic. A modified Gompertz model can adequately describe the H2 production and bacterial growth.
Asunto(s)
Bacterias Anaerobias/metabolismo , Reactores Biológicos/microbiología , Hidrógeno/metabolismo , Eliminación de Residuos Líquidos/métodos , Bacterias Anaerobias/crecimiento & desarrollo , Fermentación , Glucosa/metabolismo , Hidrógeno/análisisRESUMEN
Biohydrogen production by anaerobic sludge was studied by using manure wastewater as substrate, in batch process. The influences of sludge and carbon nitrogen nutrition on hydrogen production, the liquid fermentative products and hydrogen dynamics were investigated. The results indicate both sludge and nutrition were able to enhance the hydrogen production. It can be obtained maximum hydrogen content 50.65%, cumulative hydrogen production 334.80 mL and hydrogen yield per COD 287.10 mL/g from manure wastewater with carbon nitrogen nutrition and sewage sludge. However, the cumulative hydrogen production and the hydrogen yield per COD were only 59.24 mL and 67.05 mL/g from raw wastewater. Acetic acid and butyric acid in the effluent of fermentation occupied 61%-86%. It might be acetic-butyric acid type fermentation in the batch reactor. The more the VFA content, the higher the hydrogen yield. A modified Gompertz model can adequately describe the H2 production.
Asunto(s)
Bacterias Anaerobias/metabolismo , Fuentes de Energía Bioeléctrica , Hidrógeno/metabolismo , Estiércol , Eliminación de Residuos Líquidos/métodos , Animales , Reactores Biológicos/microbiología , FermentaciónRESUMEN
Experiments were conducted to select a natural mixed microflora seed source and investigate the effect of temperature and pH on fermentative hydrogen (H2) production from cattle wastewater by sewage sludge. Sewage sludge was shown to have higher cumulative H2 production than other inoculum collected from cow dung compost, chicken manure compost, and river sludge. Experimental results show that H2 production from cattle wastewater was significantly affected by both pH and temperature of the culture. The maximum H2 yield was obtained at pH 5.5. H2 yield and the ratio of butyrate/acetate (Bu/Ac) followed a similar production trend, suggesting that butyrate formation might favor H2 production. The optimal temperature for H2 production from cattle wastewater was 45 degrees C with peak values of H2 production (368 ml), hydrogen yield of 319 ml H2/g chemical oxygen demand (COD) consumed, and butyrate/acetate ratio of 1.43. Presence of ethanol and propionic acid indicated decreased hydrogen production; their concentrations were also affected by pH and temperature. A modified Gompertz model adequately described H2 production and bacterial growth.
Asunto(s)
Bacterias Anaerobias/metabolismo , Reactores Biológicos/microbiología , Bovinos/microbiología , Técnicas de Cultivo de Célula/métodos , Hidrógeno/metabolismo , Residuos Industriales/prevención & control , Contaminantes del Agua/metabolismo , Animales , Biotransformación , Técnicas de Cocultivo , Fermentación , Concentración de Iones de Hidrógeno , Temperatura , Purificación del Agua/métodosRESUMEN
To provide an efficient and safe technology platform for studying the replication and pathogenesis mechanisms of RHDV, the interaction between the RHDV and its host cells, a replicon system of RHDV, was constructed based on the infectious cDNA clone of RHDV, in which VP60 gene encoding the capsid protein was deleted, but all the necessary protease coding regions and non-coding regions were retained. Results from RT-PCR, IFA and qRT-PCR confirmed that the replicon RNA could efficiently replicate in RK-13 cells. Besides, the results also suggested that the capsid protein which is the structural protein of RHDV is necessary for maintaining the viral infectivity.
Asunto(s)
Virus de la Enfermedad Hemorrágica del Conejo/genética , ARN Viral/biosíntesis , Replicón , Animales , Proteínas de la Cápside/fisiología , Técnica del Anticuerpo Fluorescente , Conejos , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
GP5, the most important neutralizing antigen of porcine reproductive and respiratory syndrome virus (PRRSV), has the highest genetic diversity among isolates. To more fully understand the extent of genetic diversity of PRRSV in China, we analyzed and compared the GP5 sequences of 42 PRRSV isolated from 1996 to 2006 in mainland China. We found that all of the Chinese isolates examined belong to the North American (NA) type. Among them two highly diverse subgroups were clearly demarcated on the NA-genotype phylogenetic tree. All the subgroup 1 isolates were found to be high variable in the primary neutralizing epitope and the viruses were geographically restricted to regions in southeast China. The subgroup 2 isolates shared a high identity with MLV vaccine and its parent virus VR-2332. These results may contribute to the knowledge of PRRSV epidemiology in China, and may help to explain the low efficiency of MLV or killed CH-1a vaccine to protect the subgroup 1 virus infected pigs, and the great genetic diversity should be taken into consideration for control and preventive measures.
Asunto(s)
Variación Genética , Síndrome Respiratorio y de la Reproducción Porcina/epidemiología , Síndrome Respiratorio y de la Reproducción Porcina/virología , Virus del Síndrome Respiratorio y Reproductivo Porcino/clasificación , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Secuencia de Aminoácidos , Animales , China/epidemiología , Epítopos/química , Genotipo , Glicoproteínas/química , Glicoproteínas/genética , Datos de Secuencia Molecular , Mutación , Filogenia , Porcinos/virología , Factores de Tiempo , Proteínas Virales/química , Proteínas Virales/genéticaRESUMEN
T-DNA tagging technique has provided a powerful strategy for identifying new functional genes in plants, and the key for success is the discovery of T-DNA-inserted mutants with changed phenotype. In this study, we screened 4,416 rice T1 tagged lines generated by enhancer trap system integrated with GLL4/VP16-UAS elements from two transformed parents, ZH11 and ZH15. We found many lines showed obvious morphological mutations, including two types--fake-homozygous mutation and separating mutation. The mutation phenotype was related to 14 kinds of trait such as plant height, heading date, leaf shape, leaf color, tiller number, panicle shape, spikelet number, grain shape, disease-like mutation, male sterility, awn, and so on. Among them, plant height, heading date, leaf color and male sterility had a comparatively high mutation frequency (over 1%). The mutation frequency of plant height and leaf color had no significant change between different years or transformed parents, but the frequency of heading date and male sterility varied greatly, suggesting that environment had a great effect on the expression of latter two traits. By conducting continuously co-segregating analyses in T1 and T2 generation, we identified 3 T-DNA-inserted mutants with malformed panicle or spikelets, which would provide a base for cloning correlative functional genes. At the same time, we selected randomly 42 lines with mutation phenotype and obtained 40 flanking sequences from 39 tagged lines by plasmid rescue or TAIL-PCR, of which, 26 were vector backbone sequence, 14 had good identity to rice genome sequence. The BlastN result showed the T-DNA preferentially integrated into protein-coding region in plants.