Induction of reactive oxygen generation and functional changes in mitochondria and their involvement in the development of bacterial rot in lettuce caused by Pseudomonas cichorii

Pseudomonas cichorii is the major causal agent of bacterial rot disease in lettuce, and apoptosis-like programmed cell death is closely associated with disease development. Depletion of cellular ATP and expression of the alternative oxidase gene was observed in lettuce leaves inoculated with P. cichorii suggesting mitochondrial dysfunction. Cytochemical observation showed production of reactive oxygen species in mitochondria of P. cichorii-inoculated lettuce leaf cells. Release of cytochrome c into the cytosol was also induced by inoculation with the bacterium. Superoxide production was observed in the mitochondrial fraction isolated from P. cichorii-infected leaves much more intense than water-treated leaves. Loss of swelling ability was also observed in the mitochondrial fractions following inoculation with P. cichorii. Intriguingly, inhibitors of the mitochondrial respiratory complex III prevented loss of swelling ability, whereas superoxide generation was scarcely affected by inhibitors of mitochondrial permeability transition in the mitochondrial fractions. Inhibitors of the mitochondrial respiratory complex III and mitochondrial permeability transition delayed not only P. cichorii-induced cell death, but also disease development. In contrast, P. cichorii-induced DNA fragmentation was not inhibited in the presence of either type of inhibitor. The findings suggest that mitochondria may play a crucial role in DNA fragmentation-independent cell death pathway(s).     

Cerebrospinal fluid S-100B concentrations in normal and diseased cattle

We measured the concentrations of S-100B, a marker protein used in humans to detect brain damage, in the cerebrospinal fluid (CSF) of clinically normal cattle (n=15, mean age +/- SD: 31.8 +/- 37.5 months) and of cattle with various inflammatory disorders (n=43, 70.6 +/- 31.9 months). The mean +/- SD CSF S-100B level was 2.9 +/- 1.6 ng/ml in the normal group and 7.0 +/- 7.4 ng/ml in the diseased group. Thirteen diseased cattle that had developed no obvious neurological signs showed abnormally high S-100B concentrations (> 8.0 ng/ml), whereas the two cattle with neurological disorders did not. No particular disease could be related to the S-100B rise. Therefore, it remains inconclusive whether measurement of CSF S-100B concentration is useful in veterinary neurological diagnosis.     

Changes in hepatic enzyme activities in transgenic mice carrying human prototype c-Ha-ras gene treated with diethylnitrosamine

Activities of malate dehydrogenase (MDH) and aspartate aminotransferase in the malate-aspartate shuttle were significantly increased in the cytosolic fractions of livers with early neoplastic symptoms such as swelling and discoloration in transgenic mice carrying the prototype human c-Ha-ras gene, Tg-rasH2 mice, which were administered with diethylnitrosamine (DEN) as a carcinogenic chemical at a dose of 200 mg/kg body weight. Cytosolic MDH/LDH (lactate dehydrogenase) (ML) ratio increased significantly and was considered to be a useful marker to characterize the energy metabolism at early neoplastic stage in livers of the Tg-rasH2 mice.     

Origin of cultivated Tatary buckwheat (Fagopyrum tataricum Gaertn.) revealed by RAPD analyses

The phylogenetic relationships among cultivated landraces and natural populations of wild subspecies of Tatary buckwheat were investigated at the individual level by constructing a phylogenetic tree based on RAPD markers. As the PCR templates, DNA of individuals rather than bulked samples, was used. Ten individuals from 10 cultivated landraces, 71 individuals from 21 natural populations of wild subspecies, and 7 individuals from 3 weedy Tatary buckwheat were provided for RAPD analyses. Three groups were recognized: (1) all cultivated landraces and wild subspecies from central Tibet and northern Pakistan; (2) 10 individuals of wild subspecies from northwestern Yunnan; (3) the remaining individuals of wild subspecies from northwestern Yunnan and all individuals of wild subspecies from Sichuan. Group (2) was phylogenetically closely related to group (1). The origin of cultivated Tatary buckwheat, the hybrid origin of weedy Tatary buckwheat and of the wild populations from central Tibet and northern Pakistan are discussed. We arrive at the conclusion that cultivated Tatary buckwheat probably originated in northwestern Yunnan in China.     

Replication of Tomato spotted wilt virus After Ingestion by Adult Thrips setosus is Restricted to Midgut Epithelial Cells

ABSTRACT If acquisition access feeding (AAF) is first given after adult eclosion, none of the nine thrips species able to serve as tospovirus vectors can become infective. The previous cellular investigations of this phenomenon, carried out only in Frankliniella occidentalis, suggested that infectivity was prevented because the type member of the tospoviruses, Tomato spotted wilt virus (TSWV), was unable to enter the midgut of adult thrips. The present study extends a cellular view of tospovirus-thrips interactions to a species other than the western flower thrips, F. occidentalis. Our findings show that TSWV enters and replicates within the midgut of adult Thrips setosus, but does not infect cells beyond the midgut epithelia. After AAF as adult, TSWV replicated in T. setosus midgut cells as indicated by significant increases in nucleocapsid (N) protein detected by double-antibody sandwich enzyme-linked immunosorbent assay, and the presence of inclusions containing the S RNA-encoded nonstructural and N proteins revealed by microscopic observations. Electron microscopic observations of adult insects showed that no infection occurred in cells beyond the midgut epithelia, and insects subsampled from the same cohorts could not transmit TSWV. In contrast, electron microscopy observations of larval T. setosus revealed that TSWV infected the midgut and muscle cells, and adult insects developing from these cohorts had infected salivary glands and were able to transmit TSWV. Mature virions were observed only in the salivary glands of adults developing from infected larvae. Our findings suggest that the barrier to infectivity in T. setosus adults differs from that shown for F. occidentalis adults.     

Hemoglobin aggregation in single red blood cells of sickle cell anemia

A laser light scattering technique was used to observe the extent of hemoglobin aggregation in solitary red blood cells of sickle cell anemia. Hemoglobin aggregation was confirmed in deoxygenated cells. The light scattering technique can also be applied to cytoplasmic studies of any biological cell.     

Silkworm Bombyx mori L.: Nature of Diapause Factor

The diapause factor which is responsible for the induction of embryonic diapause in the silkworm (Bombyx mori L.) was isolated from the heads of female moths. It was extracted with 80 percent ethanol or 80 percent methanol and was heat-stable and not dialyzable. Since the active material was precipitated with ammonium sulfate and lost when incubated with proteolytic enzymes, it is highly probable that the diapause factor is a protein or a complex molecule containing peptide bonds. Molecular sieve techniques revealed two species of the diapause factor. The molecular weight of the smaller species lies between 5,000 and 10,000.     

The Distribution of <Emphasis Type="Italic">Perilla</Emphasis> Species

Perilla (Lamiaceae) contains one tetraploid species, P. frutescens (L.) Britt. and three diploid species, P. citriodora (Makino) Nakai, P. hirtella Nakai and P. setoyensis G. Honda. Tetraploid species have been traditionally cultivated in Asia for their seed oil and for their fragrant leaves that are used as medicine or as a garnish for fish. The center of diversity is still obscure. To conserve the genetic resources, it is important to know the diversity of the tetraploid species. The three diploid species, which are possible parents of the tetraploid species, are all believed to be indigenous to Japan. Their distribution in China and Korea was clarified on the basis of herbarium and field surveys. The tetraploid species is assumed to have originated somewhere around the mid-to downstream area of the Changjiang River. Though Perilla is not cultivated as often in these areas as in northern China, Korea, the Himalayan region, or Myanmar, these areas should also be important for the conservation of genetic resources of tetraploid Perilla crops because of the expected high genetic diversity.     

Sex and age differences in meat composition of Yeso sika deer (Cervus nippon yesoensis) reared for a short period after capture in the wild

Yeso sika deer captured in winter around Lake Akan in Hokkaido were reared for 8–10 months at Tokyo University of Agriculture in Abashiri. Six 1‐year‐old females and males and six 2‐year‐old or older (adult) females and males were slaughtered and their carcasses were processed. The chemical composition, mineral contents and fatty acid composition of the loin were measured. No marked influence of gender or age was noted in the chemical composition of loin. In the mineral contents, significant differences were noted. The potassium and sulfur contents were lower and the sodium content was higher in adult deer meat (P < 0.05, respectively) and the potassium content was higher in male deer meat (P < 0.05). Arsenic, cadmium or lead were not detected. In the unsaturated fatty acid, a significant interaction was detected (P < 0.05), and it was high in 1‐year‐old female deer meat and low in 1‐year‐old male deer meat. Significant gender or age differences were noted only in the mineral contents in the loin of deer reared for a short period after capture.     

Isolation and Characterization of Cadmium- and Arsenic-Absorbing Bacteria for Bioremediation

The contamination of hazardous metal(loid) is one of the serious environmental and human health risks. This study isolated a total of 40 cadmium (Cd)- and arsenic (As)-resistant bacterial isolates from coastal sediments by pour plate technique using tryptic soy agar supplemented with Cd or As (50 mg l^?1) for use as metal(loid) bioremediation agents. Out of 40, 4 isolates, RCd3, RCd6, RAs7, and RAs10, showed a relatively higher growth rate in Cd- or As-supplemented culture media which were selected for further study. The selected isolates showed a high minimum inhibitory concentration (60–400 mg l^?1 for Cd and 400–2200 mg l^?1 for As), which demonstrated their remarkable Cd and As resistance capabilities. The metal(loid) removal efficiencies (0.032–0.268 μg Cd h^?1 mg^?1 and 0.0003–0.0172 μg As h^?1 mg^?1 [wet weight cell]) of selected isolates indicated their greater magnitude in absorbing Cd compared to As from water. Phylogenetic analysis of the 16S rDNA sequences revealed that isolates RCd3, RCd6, RAs7, and RAs10 were closely related to Acinetobacter brisouii, Pseudomonas abietaniphila, Exiguobacterium aestuarii, and Planococcus rifietoensis, respectively. Because of high Cd and As resistance and removal efficiency, the selected isolates can survive in a high metal(loid)-contaminated environment and could be a potential tool for bioremediation of high metal(loid)-contaminated effluents to protect the aquatic environment.