ABSTRACT
A hammerhead ribozyme (Rz) with long hybridizing arms targeting the mRNA of rice dwarf virus (RDV) segment 5 and a mutated nonfunctional ribozyme (mRz) were constructed. As predicted, Rz transcribed in vitro cleaved the target mRNA of RDV segment 5 into two fragments of 138 and 238 nucleotides in length. The Rz and mRz genes were each placed under the control of the CaMV 35S promoter and used to transform Japonica rice variety 'Tongling No. 1' via Agrobacterium tumefaciens. A total of 32 independent lines containing Rz or mRz was obtained as demonstrated by Southern blot analysis. Challenge inoculation with RDV viruliferous leafhoppers (Nephotettix cincticeps) showed that T1 plants containing the Rz transgene displayed high resistance or delayed and attenuated viral symptoms. In contrast, transgenic lines expressing mRz showed severe symptoms similar to the control plants transformed with the vector alone. These results suggest that Rz confers RDV resistance in transgenic rice. Genomic DNA PCR analysis confirmed that all of the examined T6 progeny plants contained the Rz transgene. However, accumulation of the Rz transcripts was detectable by RT-PCR only in the plants that were resistant to RDV. This suggested that loss of RDV resistance in progeny plants containing the Rz transgene may result from silencing of the Rz transgene.
Subject(s)
Gene Silencing , Oryza/virology , Plant Diseases/genetics , Plant Proteins/genetics , Plant Viruses/genetics , Plants, Genetically Modified/genetics , RNA, Catalytic/genetics , Viral Proteins , Base Sequence , Biological Assay , Blotting, Southern , DNA/analysis , DNA Primers/chemistry , Disease Susceptibility , Genetic Vectors , Plant Diseases/virology , Plant Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic , Transformation, GeneticABSTRACT
Chlorella virus FJ-1 was isolated in Fujian Province of China. It can be precipitated by polyethylene glycol(PEG8000) and the best condition if 7% PEG8000 and 4% NaCl. But the precipitation efficiency of PEG8000 is lower than that of ultracentrifugation.
Subject(s)
Phycodnaviridae/isolation & purification , Polyethylene Glycols , Chemical Precipitation , Sodium ChlorideSubject(s)
Enhancer Elements, Genetic , Interferon-beta/genetics , Saccharomyces cerevisiae Proteins , Acetyltransferases/metabolism , Animals , DNA Polymerase II/metabolism , Gene Expression Regulation , High Mobility Group Proteins/metabolism , Histone Acetyltransferases , Humans , Macromolecular Substances , Models, Biological , Signal Transduction , Transcription Factor TFIID , Transcription Factors, TFII/metabolismABSTRACT
An extensive survey for Chlorella viruses revealed that Chlorella viruses are widely distributed over China. Eleven isolates of Chlorella viruses have been isolated, which lysis the Chlorella viruses sp. (strain NC64A). These isolates were named BJ-1, BJ-2, BJ-3, BJ-4, FJ-1, FJ-2, NJ-1, CDT-1, HCJ-1, SCB-1 and SCC-1 respectively. They have several common properties, including polyhedral morphology, and linear dsDNA genomes. However, the restriction patterns of viral DNA, the concentration of m5dC and m6dA in viral DNA, and the composition of viral structure protein are different among these isolates. All of viral major capsid proteins are 54,000 except FJ-1, whose major capsid protein is smaller than 54,000. Western blot analysis showed strong immunological cross reaction among all of viral proteins with PBCV-1's antiserum except FJ-1. It indicates that the homology between these isolates and PBCV-1 is high. Among these isolates, FJ-1 has some special properties.
Subject(s)
Chlorella/virology , Phycodnaviridae/genetics , Water Microbiology , Base Composition , Cells, Cultured , China , DNA, Viral/analysis , Phycodnaviridae/chemistry , Viral Proteins/analysisABSTRACT
A hammerhead ribozyme [R(-)] targeting the minus strand RNA of potato spindle tuber viroid (PSTVd) and a mutated nonfunctional ribozyme [mR(-)] were designed, cloned, and transcribed. As predicted, both monomer and dimer transcripts of the active R(-) ribozyme gene could cleave the PSTVd minus strand dimer RNA into three fragments of 77, 338, and 359 bases in vitro at 25 and 50 degrees C. The tandem dimer genes of R(-) and mR(-) were subcloned separately into the plant expression vector pROK2. Transgenic potato plants (cultivar Desirée) were generated by Agrobacterium tumefaciens-mediated transformation. Twenty-three of 34 independent transgenic plant lines expressing the active ribozyme R(-) resulted in having high levels of resistance to PSTVd, being free of PSTVd accumulation after challenge inoculation with PSTVd, but the remaining lines showed weaker levels of resistance to PSTVd with low levels of PSTVd accumulation. In contrast, 59 of 60 independent transgenic lines expressing the mutated ribozyme mR(-) were susceptible to PSTVd inoculation and had levels of PSTVd accumulation similar to that of the control plants transformed with the empty vector. The resistance against PSTVd replication was stably inherited to the vegetative progenies.
Subject(s)
Plants, Genetically Modified , Potyvirus/physiology , Potyvirus/pathogenicity , RNA, Catalytic/physiology , Solanum tuberosum/virology , Virus Replication , Base Composition , Base Sequence , Immunity, Innate , Molecular Sequence Data , Nucleic Acid Conformation , RNA, Catalytic/biosynthesis , RNA, Catalytic/chemistry , Solanum tuberosum/physiology , Transcription, Genetic , Viroids/pathogenicity , Viroids/physiologyABSTRACT
Rice stripe virus (RSV), a planthopper-transmitted virus, was inoculated into rice protoplasts, and a one-step growth curve was determined. The amount of virus in the protoplasts decreased following the inoculation, and then increased after 8 h. The replication of RSV reached its peak 20 h after inoculation. RSV replication in the inoculated protoplasts was further demonstrated by electron microscopy.
Subject(s)
Plant Viruses/isolation & purification , RNA Viruses/isolation & purification , Animals , Enzyme-Linked Immunosorbent Assay , Insect Vectors/virology , Insecta/virology , Oryza/virology , Plant Viruses/metabolism , Plant Viruses/physiology , Protoplasts/virology , RNA Viruses/metabolism , RNA Viruses/physiology , Viral Proteins/analysis , Virus ReplicationABSTRACT
A chimeric vector was constructed to express cucumber mosaic virus (CMV) satellite (Sat) RNA and coat protein (CP). Transgenic lines of tobacco cultivar G-140 expressing CP and Sat-RNA were obtained; these lines had high resistance to CMV. Fifty to 70% of the transgenic plants were symptomless 90 days after inoculation with 25-50 micrograms/ml of CMV. Resistance was about twice that conferred by the Sat-RNA or the CP gene alone in transformed plants.
Subject(s)
Capsid/genetics , Genetic Vectors , Mosaic Viruses/physiology , Nicotiana/microbiology , Plants, Toxic , RNA, Viral/genetics , RNA/genetics , Base Sequence , Chimera , Cloning, Molecular , DNA, Single-Stranded , Genes, Viral , Immunity, Innate/genetics , Molecular Sequence Data , Plant Diseases , Plants, Genetically Modified , RNA, Satellite , Nicotiana/genetics , Nicotiana/immunology , Transformation, GeneticABSTRACT
The incidence of congenital nasolacrimal duct stenosis in 587 neonates surveyed was found to be 0.17%, while a familial investigation of 100 consecutive patients revealed the incidence of the first, second and third degree relatives were respectively 2.32%, 0.95%, and 0.45%; the obvious differences of incidence (P less than 0.05) indicated an apparent genetic involvement. 86 of the 100 patients were sporadic, and the pedigree study of 14 patients with positive family history did not produce sufficient evidence of autosomal dominant, recessive, or sex-linked inheritance. In conclusion, the mode of inheritance of the disease was thought to be multigenic and the inheritability calculated to be 58%.
Subject(s)
Lacrimal Apparatus , Lacrimal Duct Obstruction/congenital , Nasolacrimal Duct , Female , Humans , Infant, Newborn , Lacrimal Duct Obstruction/genetics , Male , PedigreeABSTRACT
In this paper, trace element analysis of the hairs from the patients with nasopharyngeal carcinoma (NPC) and osteoma was made using particle induced X-ray emission (PIXE) technique in order to obtain some information on the correlation between trace element and these two tumors. The hair samples of 34 NPC patients were each collected before and three months after radiotherapy (60Co) (group 1). The hair specimens from 34 osteoma patients were collected preoperatively and postoperatively. For comparison, 65 hair samples were collected from 40 normal subjects (group 2) and 25 NPC patients, who had received radiotherapy (60Co) five years before without any recrudescence (group 3). The trace element analysis of all specimens was made by PIXE. The results show that there is a significant difference between groups 1 and 2 (P less than 0.01) but no difference is found between groups 2 and 3 for Mn, Cu, Zn, As etc. content in the hairs. Cu and Zn content in the hairs of the osteoma patients is much lower than that of the normal subjects (P less than 0.01) while for K, Ti and Mn content, the former is higher than the latter. The above experimental results are discussed in detail.
