An Antibody Against the SecA Membrane Protein of One Phytoplasma Reacts with Those of Phylogenetically Different Phytoplasmas

ABSTRACT Antisera raised against phloem-limited phytoplasmas generally react only with the phytoplasma strain used to produce the antigen. There is a need for an antiserum that reacts with a variety of phytoplasmas. Here, we show that an antiserum raised against the SecA membrane protein of onion yellows phytoplasma, which belongs to the aster yellows 16S-group, detected eight phytoplasma strains from four distinct 16S-groups (aster yellows, western X, rice yellow dwarf, and elm yellows). In immunoblots, approximately 96-kDa SecA protein was detected in plants infected with each of the eight phytoplasmas. Immunohistochemical staining of thin sections prepared from infected plants was localized in phloem tissues. This antiserum should be useful in the detection and histopathological analysis of a wide range of phytoplasmas.     

Survey of coccidial oocysts and parasite eggs in feces of free-ranging Grus japonensis

Fecal survey of Eimeria oocysts and parasite eggs was conducted for 219 fecal samples of free-ranging Grus japonensis in Kushiro district in Hokkaido in April 2003. Positive rate and mean oocysts (or eggs) per gram in positive samples were 26% (57/219) and 8.8 (0.2-136) in oocysts of Eimeria reichenowi, 18.3% (40/219) and 320 (100-1,000) in trematode eggs, 0.1% (2/219) and 0.2 (0.2-0.3) in eggs of Nematoda A, and 4.1% (9/219) and 0.8 (0.2-3.6) in eggs of Nematoda B, respectively.     

Autophagy defends cells against invading group A Streptococcus

We found that the autophagic machinery could effectively eliminate pathogenic group A Streptococcus (GAS) within nonphagocytic cells. After escaping from endosomes into the cytoplasm, GAS became enveloped by autophagosome-like compartments and were killed upon fusion of these compartments with lysosomes. In autophagy-deficient Atg5-/- cells, GAS survived, multiplied, and were released from the cells. Thus, the autophagic machinery can act as an innate defense system against invading pathogens.     

Pathogenicity, Mating Ability and DNA Restriction Fragment Length Polymorphisms of Pyricularia Populations Isolated from Gramineae, Bambusideae and Zingiberaceae Plants

Eighty-five Pyricularia isolates were collected from 29 host species of Gramineae, Bambusideae and Zingiberaceae plants sampled in Brazil, Uganda, Ivory Coast, India, Nepal, China, Indonesia and Japan. These isolates were compared on the basis of pathogenicity, mating ability and restriction fragment length polymorphisms with single-copy DNA probes. Based on the pathogenicity to eight differential gramineous plants, these isolates were classified into seven pathotypes: finger millet type, foxtail millet type, common millet type, rice type, crabgrass type, Italian ryegrass/ weeping lovegrass type, and non-cereal/grass type. Genetic variation among these isolates was assessed by RFLP analysis with two restriction enzymes and nine single-copy DNA probes isolated from a finger millet strain. An UPGMA dendrogram based on the RFLPs revealed that the 85 isolates could be classified into seven major groups. Isolates from cereal crops (finger millet, foxtail millet, common millet, wheat and rice) and a grass, Brachiaria plantaginea, were clustered into a single group. They were further divided into six subgroups corresponding to the pathotypes. Among cereal crop isolates only an isolate from pearl millet was located into a different group. The remaining isolates were clustered into five groups designated as the crabgrass group, the buffelgrass and jungle rice group, the rice cutgrass, knotroot bristlegrass and Setaria tomentosa group, the bamboo and bamboo grass group and the Zingiber mioga group. The isolates from cereal crops were generally capable of mating with finger millet strains and constituted a closed mating compatibility group. These results suggested that the isolates from cereal crops form a single group with a common ancestor although they are pathogenic to taxonomically diverse plants. A combined analysis of the pathogenicity and genetic similarity suggested that the transmission of M. grisea isolates occurs in natural agroecosystems between finger millet and Eleusine africana, goosegrass or Bambusa arundinacea, between foxtail millet and green bristlegrass, and between rice and tall fescue, Italian ryegrass, sweet vernalgrass, reed canarygrass or Oryza longistaminata. Received 9 August 1999/ Accepted in revised form 12 November 1999     

New method for ethephon ((2-chloroethyl)phosphonic acid) residue analysis,and detection of residual levels in the fruit and vegetables of Western Japan

A new method for the detection and quantification of ethephon residues in fruit and vegetables was developed. The present study indicates that fruit and vegetables require a rapid and simple cleanup step before using gas chromatograph/mass spectrometry. The recovery and precision of the new method were evaluated by spiking the fruit and vegetable samples with 0.01-0.1 microg/g of ethephon. The amount of ethephon residue can be determined with good accuracy (recovery, 78.6-109%; coefficient variation, 2.65-6.41%), and the detection limit, defined as the amount of ethephon equivalent to three standard deviations (SD) of the noise level in observations at the baseline level of the selected ion (m/z 110), was 4 pg. The determination limit, defined as the equivalent to 8 SD of the noise level, was 11 pg. The working range was between 10 and 1000 ng/mL, and the correlation coefficient was 0.999 in the five experiments. Ethephon residues were determined between <2 and 97 ng/g in commercial pineapples from Western Japan.     

Acknowledgment to Reviewers

Acknowledgment to Reviewers

Acknowledgment to Reviewers     

Application of repetitive extragenic palindromic (REP)-PCR and enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis to the identification and classification of Japan and Thai local isolates of Bradyrhizobium japonicum,Shinorhizobium meliloti,Rhizobium leguminosarum

Repetitive extragenic palindromic (REP)-PCR and enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis was applied to the identification and classification of local isolates of 44 Bradyrhizobium japonicum, 7 Sinorhizobium meliloti, 10 Rhizobium leguminosarum strains from Japan and Thai. Using genomic DNA of the 61 strains, both REP and ERIC primers induced reproducible PCR band patterns, although REP-PCR generated more bands and appeared to be more useful for distinguishing the isolates from each other. Using mixed matrix data from both REP- and ERIC-PCR data, it become possible to distinguish all the isolates analyzed in this experiment from each other. When cluster analysis was applied to both PCR matrix data of 44 B. japonicum isolates, only the REP-PCR dendrogram showed a grouping profile corresponding to the exo-polysaccharide phenotype with a exceptions. When the matrix data of R. leguminosarum and S. meliloti were subjected to cluster analysis, S. meliloti appeared to form a different subgroup from R. leguminosarum in the dendrogram of REP-PCR data except for one strain. In the case of ERIC-PCR, isolates of R. leguminosarum from northern Thailand formed a separate subgroup from other R. leguminosarum and S. meliloti which were dispersed in the dendrogram. These data suggest that REP-PCR and ERIC-PCR were effective for the identification of individual isolates even though the isolates showed a wide genetic diversity and the same phenotype. When the data of the local isolates from Japan and Thailand were subjected to cluster analysis, REP- and ERIC-PCR analysis revealed different grouping characteristics.     

A novel phenomenon predicting the entry into a state of hibernation in Syrian hamsters (Mesocricetus auratus)

When Syrian hamsters (Mesocricetus auratus) are bred in a cold and short-day environment, most animals go into hibernation after a certain period of time. However, to date it has not been possible to predict which hamster will enter hibernation. In this study, we subcutaneously implanted thermo-loggers in hamsters bred in the cold environment, and recorded the subcutaneous temperature at short intervals until they went into hibernation. A time series analysis of temperature disclosed that a fall of 0.4 to 0.8 degrees C in subcutaneous temperature was seen 5 to 16 days before entering hibernation, and this phenomenon continued for three days or more. No hamster went into the hibernation without displaying this signal. Although the mechanism by which this phenomenon takes place is not clear, it is a sign from the body, which is useful for indicating if a hamster will enter hibernation shortly.     

Cytopathogenicity of classical swine fever viruses that do not show the exaltation of Newcastle disease virus is associated with accumulation of NS3 in serum-free cultured cell lines

Pestiviruses can be distinguished as two biotypes, cytopathogenic (cp) and noncytopathogenic (noncp), by the morphological changes that they induce during growth in cultured cells. In this study, the cp phenotype of several classical swine fever viruses (CSFV) was evaluated by the detections of the nonstructural proteins NS2-3 and NS3 using immunoprecipitation and Western blotting in different porcine cell lines. Most CSFVs that showed the exaltation of Newcastle disease virus (END) phenomenon (END(+) viruses) did not induce cytopathic effect (CPE) in any cell line, and detections of NS2-3 and NS3 showed a strong signal for NS2-3 in the END(+) virus-infected cells. However, clear CPE was observed in serum-free cultured cells (FS-L3 and CPK-NS) infected with viruses that induce intrinsic interference but did not show the END phenomenon (END(-) viruses), and signal of NS3 was strongly detected than that of NS2-3 in these cells at 72 hr after infection. As the results of the analysis of FS-L3 cells infected with ALD (END(+) virus) and ALD-END(-) virus (END(-) virus) at several incubations, the signal of NS3 detected was strengthened with CPE that become evident progressively. These results suggest that CPE is associated with the accumulation of NS3, which is promoted in serum-free cell lines infected with END(-) viruses. Thus, indicating there is a close relationship between CPE and the quantity of NS3 produced in END(-) CSFV infection.