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Kazuo Yoshida

Publications and source records attributed to Kazuo Yoshida.

33 records · Page 2Linked to original sources
PubMed2003

Sequence analysis of the medium RNA segment of three Simbu serogroup viruses, Akabane, Aino, and Peaton viruses.

The sequence analysis was carried out for the medium (M) RNA segment of the Akabane virus (AKAV), Aino virus (AINV), and Peaton virus (PEAV) of the Simbu serogroup of the genus Orthobunyavirus of the family Bunyaviridae. The complementary sequences of the M RNA segments of AKAV, AINV, and PEAV contain a single large open reading frame (ORF), like other orthobunyaviruses. The ORFs potentially encode 1401 amino acids (aa), 1404 aa, and 1400 aa polypeptides, respectively. The identity of the M segment among these viruses is remarkably low, although previous researchers reported that the small RNA segments are highly conserved. Because the M segment codes for the viral surface glycoproteins G1 and G2, the variability of the M segment may affect the antigenicity of these viruses. Phylogenetic studies based on the M and S segment sequences suggested that genetic reassortment has been occurring among ancestral viruses of the three Simbu serogroup viruses throughout their evolution.

Animals↗
PubMed2003

Gene design of signal sequence for effective secretion of protein.

To improve the secretion level of recombinant protein, the gene sequence coded the chicken lysozyme signal peptide (CLSP) connected with human lysozyme (HLY) was altered to substitute the amino acid sequence, and the effect of mutations on secretion of HLY in yeast was elucidated. The effect of mutations on secretion of recombinant HLY was elucidated in yeast. As the result of experiments, it has been shown that the positive charge in the N-terminal region of signal peptide plays an important role in the function of the eukaryotic signal peptide as well as that of prokaryote. This result enable us to design the ideal sequence for effective secretion of recombinant protein. Using such signal sequence containing additional Arginine residues, secretion levels of HLY in yeast were notably increased.

Amino Acid Sequence↗
PubMed2003

Physical and gene maps of Agrobacterium biovar 2 strains and their relationship to biovar 1 chromosomes.

Diverse types of genomic DNA organization have been found in Rhizobiaceae, especially among Agrobacterium species. Previous studies of Agrobacterium concentrated mainly on biovar 1 strains. Little attention has been given to biovar 2 strains. The biovar 2 genome consists of a large, circular chromosome and second megabase-sized replicon, as well as several plasmids. In this study two biovar 2 strains were analysed, A. rhizogenes (A. radiobacter) K84 and A. rhizogenes A4, by constructing physical maps of their chromosomes and mega-replicons. The maps revealed that in both strains their chromosomes consist of approximately 3.7 Mbp, while the mega-replicons are 2.6 Mbp circular DNAs. Gene mapping and comparative genomic analysis were performed based on the physical maps using Southern hybridization. It was found that rDNA, as well as analysed virulence and virulence-related genes, are present only on the chromosomes. The inter-chromosomal relationship between biovar 1 and biovar 2 strains was also analysed. Interestingly, there was a high similarity between the chromosomes of biovar 2 and the circular chromosomes of biovar 1, whereas similarity among the smaller megabase-sized replicons was restricted to each biovar. Based on these observations the possible relationship among large replicons in Agrobacterium biovars 1 and 2 is discussed.

Chromosomes, Bacterial↗
PubMed2003

Structural and functional analysis of a putative gene cluster for palatinose transport on the linear chromosome of Agrobacterium tumefaciens MAFF301001.

We identified a putative pal gene cluster (palR, palE, palF, palG, palK, palA, and palB) in the plant-tumorigenic bacterium Agrobacterium tumefaciens MAFF301001; by sequencing analyses, this cluster was found to be involved in palatinose transport, and its functional importance was revealed by mutational analyses. The pal gene products were highly homologous to those of putative trehalose/maltose ABC-type transport systems but were not essential to bacterial growth on trehalose. Insertion mutations in the palK and palE genes showed the necessity of these genes for bacterial growth and chemotaxis with palatinose as the carbon source, but no inhibition of tumorigenesis was observed. Growth on trehalose and maltose was not influenced by the mutations.

ATP-Binding Cassette Transporters↗
PubMed2002

The complete nucleotide sequence of the PanAsia strain of foot-and-mouth disease virus isolated in Japan.

The complete nucleotide sequence of the foot-and-mouth disease virus (FMDV) O/JPN/2000 strain, the PanAsia strain, was determined by cycle sequencing and primer walking. The 5' end of the genome upstream from homopolymeric poly(C) tract (S-fragment) was 367 nucleotides in length, and the remainder of the genome (L-fragment), excepting the poly(A) tail, was 7808 nucleotides. The L-fragment contains a single open reading frame of 6996 nucleotides terminating at a UAA codon 96 bases from the 3' poly(A) sequence. Comparison of sequences shows that the length of the structural and non-structural protein coding regions are identical to those in the O1/Kaufbeuren strain, and no striking differences such as deletion or insertion were observed between them.

Animals↗
PubMed2002

Characterization of four ribosomal RNA operons in the genome of Agrobacterium tumefaciens MAFF301001.

The four ribosomal RNA (rrn) operons rrnA, rrnB, rrnC and were identified, sequenced completely and characterized individually rrnD in the whole genome of A tumefaciens MAFF301001. These rrn operons were located in the two topologically different chromosomal DNAs; rrnA and rrnD in the linear chromosome and rrnB and rrnC in the circular chromosome. Each operon coded for three ribosomal RNA subunit genes; 16S, 23S and 5S rRNA. The 16S-23S internal transcribed spacers (ITS) of the four rrn operons contain genes for tRNA-Ile and tRNA-Ala and tRNA-Met downstream of 5S rDNA gene while the intergenic spacer between 23S rDNA and 5S rDNA lacked tRNA genes. Sequence alignment of 23S rRNAs of A. tumefaciens MAFF301001 and C58 strains showed unrelated sequences near the 5' end region suggesting the presence of intervening sequence (IVS). Primer extension analyses revealed that the primary transcription products for 16S and 23S rRNAs are 1497 and 2877 bases long, respectively.

Agrobacterium tumefaciens↗
PubMed2002

Analysis of intratypic variation evident in an Ibaraki virus strain and its epizootic hemorrhagic disease virus serogroup.

A new strain of Ibaraki virus (IBAV) was isolated from cattle showing atypical symptoms of Ibaraki disease. The isolate was genetically characterized, and the genetic diversity and evolution of the capsid proteins of viruses in the epizootic hemorrhagic disease virus (EHDV) serogroup were investigated. The nucleotide sequences of the isolate's viral RNA segments 2, 3, 6, and 7, which encode the viral structural proteins VP2, VP3, VP5, and VP7, respectively, were determined and were then compared against those of the existing strains of IBAV and EHDV, to which IBAV belongs serologically. The nucleotide sequences of segments 3 and 7 were conserved within the EHDV serogroup, particularly well among the strains of IBAV and Australian EHDV. The similarity of the sequence of segment 6 of the isolate to sequences of corresponding segments of the other strains of IBAV and EHDV was found to be about 93%. The similarity of segment 2 of the isolate to segments 2 of the other strains of IBAV and EHDV was less than 70%. Phylogenetic analysis based on the deduced amino acid sequences of segments 3 and 7 revealed that the viruses differed according to their geographical distributions. However, the new isolate of IBAV was categorized as having a distinct lineage in the phylogenetic tree of VP2. These results suggest that the isolate was modified by a reassortment of segment 2 and that it exhibits unique genetic and antigenic characteristics.

Animals↗
PubMed2002

A novel plasmid curing method using incompatibility of plant pathogenic Ti plasmids in Agrobacterium tumefaciens.

Ti (Tumor inducing) plasmids in Agrobacterium tumefaciens can transfer their T-DNA region into dicotyledonous plants, in which the expression of T-DNA genes causes plant tumors and the production of bacterial nutrients, e.g., opines such as nopaline. Naturally occurring Ti plasmids (pTi) are difficult to cure by conventional curing methods because of their high stability. Here, we developed a novel curing method based on plasmid incompatibility. For this, a curing plasmid, pMGTrep1, was newly constructed and subsequently introduced into A. tumefaciens strains harboring pTi by conjugation with Escherichia coli harboring pMGTrep1. The conjugation yielded 32-99% nopaline non-utilizing agrobacterial transconjugants in which pMGTrep1 replaced pTi due to incompatibility. Then, pMGTrep1-less derivatives of the transconjugants are easily selected in the presence of sucrose because pMGTrep1 contains a sucrose-sensitive sacB gene. This efficient method is directly applicable for curing plasmids with the same incompatibility group and shoud also applicable to other types of plasmids in Agrobacterium groups, including A. rhizogenes, by replacing the rep gene region of the curing plasmid with that of the corresponding incompatibility.

Agrobacterium tumefaciens↗
PubMed2002

Gene cluster for ferric iron uptake in Agrobacterium tumefaciens MAFF301001.

Agrobacterium tumefaciens harboring a Ti plasmid causes crown gall disease in dicot plants by transferring its T-DNA into plant chromosomes. Iron acquisition plays an important role for pathogenicity in animal pathogens and several phytopathogens and for growth in the rhizosphere and on plant surfaces. Under iron-limiting condition, bacteria produce various iron-chelating agents called siderophores. Agrobacterium strains have the diversity in producing siderophores and a certain strain produces a typical catechol-type siderophore, called agrobactin, although its biosynthesis genes have not been analyzed yet. Here we describe the cloning and characterization of a functional gene cluster involved in ferric iron uptake in A. tumefaciens strain MAFF301001. Four complete open reading frames (ORFs) were found in 5-kb region of a genomic library clone 1A3. We named these genes agb, after agrobactin. agbC, agbE, agbB and agbA genes were identified in this order, and narrow intergenic spaces suggested that these genes constitute an operon. Predicted agb gene products and their phylogenetic analysis showed sequence similarity with enzymes which are involved in ferric iron uptake in other bacteria. Southern hybridization analysis clearly indicated the location of agb genes on the linear chromosome in strain MAFF301001 but the complete lack in another A. tumefaciens strain C58. Mutation analysis of agbB revealed that it is essential for growth and production of catechol compounds in iron-limiting medium.

Agrobacterium tumefaciens↗
PubMed2002

Isolation of foot-and-mouth disease virus from Japanese black cattle in Miyazaki Prefecture, Japan, 2000.

Four outbreaks of foot-and-mouth disease (FMD) occurred from March to May 2000 in Miyazaki and Hokkaido Prefectures, Japan. FMD virus isolation was achieved by sampling probang materials from Japanese Black cattle in the third case found in Miyazaki Prefecture. The probang materials were inoculated to bovine kidney (BK) and bovine thyroid cell cultures. CPE was observed in the BK at two days post-inoculation. Specific amplified DNA segments for FMD virus (FMDV) were detected by reverse transcriptase polymerase chain reaction in the culture fluid. The FMDV was identified as type O by enzyme-linked immunosorbent assay (ELISA) for antigen detection and the nucleotide sequence encoding the VPI was determined. This FMDV is a strain that is widespread in Pan-Asia and was designated as O/JPN/2000 by the World Reference Laboratory of the Pirbright Institute, England. This report marks the first isolation of FMDV in Japan.

Animals↗
PubMedDate not supplied

Arthrogryposis, hydranencephaly and cerebellar hypoplasia syndrome in neonatal calves resulting from intrauterine infection with Aino virus.

To determine the teratogenic potential of Aino virus (AINOV) in cattle, pregnant cows and fetal cattle were infected with a fresh isolate of AINOV. Five pregnant cows were inoculated intravenously with the virus at 122 to 162 days of gestation and allowed to give birth. All of the cows developed neutralizing antibodies to the virus, indicating that the cows had been infected with the virus; however, no clinical abnormalities were seen in their six newborn calves, and no specific antibodies to the virus were detected in the precolostral serum of calves. Five fetuses with fetal ages ranging from 132 to 156 days were inoculated in utero with the virus. One weak newborn and four stillborn calves were delivered at gestation days 256 to 263, i.e., less than the standard gestation term; they had congenital abnormalities including arthrogryposis, hydranencephaly and cerebellar hypoplasia. Antibodies specific to AINOV were detected in their precolostral serum. These results demonstrate that AINOV is a potential etiological agent of congenital malformation of cattle.

Abnormalities, Multiple↗