Association between the planktonic larval and benthic stages of Manila clam <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis> in eastern Hokkaido,Japan

The association between planktonic larval and benthic stages of Manila clam Ruditapes philippinarum and factors determining successful recruitment were studied in Akkeshi-ko estuary and Akkeshi Bay, Hokkaido, northern Japan. The field study showed that planktonic larvae were localized mainly in the bay after dispersal from the estuary and recruitment to the estuarine fishing grounds was not always successful. A numerical analysis suggested that estuarine circulation transported tracers, used to simulate planktonic larva, from the estuary to the bay but the number of returning tracers varied depending on the river discharge and wind direction. The planktonic larvae were affected by unsuitable conditions for survival in the estuary, such as high turbidity. We conclude that most larvae develop within the bay, where conditions are more saline and less turbid, and that although return to the estuary is essential for recruitment, it is not necessarily related to the abundance of larvae.     

Turpentine-induced acute inflammatory response in Gallus gallus: oedema, vascular permeability and effects of non-steroidal anti-inflammatory drugs

Turpentine-induced acute inflammatory responses in chicks were studied experimentally. Foot pad oedema was measured using a plethysmograph. Skin vascular permeability was evaluated using the Evans blue technique. Turpentine injury induced a typical biphasic response when the two parameters of the inflammatory reaction were studied. Some unexpected alterations of the turpentine-induced inflammatory response were seen when chicks received non-steroidal anti-inflammatory drugs. Pretreatment with promethazine, phenylbutazone, methysergide and indomethacin resulted in a decrease in foot oedema. An inhibitory effect upon vascular permeability was found when promethazine, phenylbutazone and indomethacin were used. Methysergide did not inhibit the increase in vascular permeability of the skin. Possible mechanisms are discussed.     

Molecular characteristics of horse phospholipase C zeta (PLCζ)

A sperm‐specific phospholipase C (PLC), PLCzeta (PLCζ), is thought to underlie the initiation of calcium ([Ca²⁺]_i) oscillations that induce egg activation in mammals. In large domestic species, only bovine, porcine and recently equine PLCζ have been cloned, and the physiological functions of these molecules have not been fully characterized. Here, we evaluated the physiological functions of equine PLCζ (ePLCζ) in mouse oocytes. ePLCζ was cloned from testis using RT‐PCR. The expression of ePLCζ messenger RNA was confirmed in testis but not in other tissues. Microinjection of ePLCζ complementary RNA (cRNA) into mouse oocytes induced long‐lasting [Ca²⁺]_i oscillations, and most of the injected oocytes formed pronuclei (PN). The injection of cRNAs encoding horse, mouse, human and cow PLCζ into mouse oocytes showed that ePLCζ had the highest [Ca²⁺]_i oscillation‐inducing activity among the species tested. Mutation of D202R, which renders the protein inactive, abrogated the activity of ePLCζ. The nuclear translocation ability of ePLCζ was defective when expressed in mouse oocytes. Taken together, our findings show for the first time that ePLCζ has highest activity of the mammalian species studied to date. Our findings will be useful for the improvement of reproductive technologies in the horse.     

Magnesium oxide nanoparticles induce systemic resistance in tomato against bacterial wilt disease

Bacterial wilt is a serious problem affecting many important food crops. Recent studies have indicated that treatment with biotic or abiotic stress factors may increase the resistance of plants to bacterial infection. This study investigated the effects of magnesium oxide nanoparticles (MgO NP) on disease resistance in tomato plants against Ralstonia solanacearum, as well as its antibacterial activity. The roots of tomato seedlings were inoculated with R. solanacearum and then immediately treated with MgO NP; the treated plants showed very little inhibition of bacterial wilt. In contrast, when roots were drenched with a MgO NP suspension prior to inoculation with the pathogen, the incidence of disease was significantly reduced. Rapid generation of reactive oxygen species such as O₂^?˙ radicals was observed in tomato roots treated with MgO NP. Further O₂^?˙ was rapidly generated when tomato plant extracts or polyphenols were added to the MgO NP suspension, suggesting that the generation of O₂^?˙ in tomato roots might be due to a reaction between MgO NP and polyphenols present in the roots. Salicylic acid‐inducible PR1, jasmonic acid‐inducible LoxA, ethylene‐inducible Osm, and systemic resistance‐related GluA were up‐regulated in both the roots and hypocotyls of tomato plants after treatment of the plant roots with MgO NP. Histochemical analyses showed that β‐1,3‐glucanase and tyloses accumulated in the xylem and apoplast of pith tissues of the hypocotyls after MgO NP treatment. These results indicate that MgO NP induces systemic resistance in tomato plants against R. solanacearum.     

Genetic characterization and susceptibility on poultry and mammal of H7N6 subtype avian influenza virus isolated in Japan in 2009

From February to March 2009, six strains of H7N6 subtype avian influenza virus were isolated from quails in three farms in Aichi prefecture in Japan. The isolates were shown to be low pathogenic for chicken by the examination performed using the "Manual of Standards for Diagnostic Tests and Vaccines" by World organisation for Animal Health (OIE). The deduced amino acid sequence at the cleavage site was PE (I/Q/L) PKRR (nucleotide sequences were cct gaa (a/c) (t/a) a cc (a/g) aaa aga aga), suggesting persistence in domestic poultry for some time. The direct putative ancestor strain could not be elucidated by phylogenetic analysis of all genome segments of the quail isolates. Diverged date from a putative common ancestor in a non-rooted phylogenetic tree among quail viruses was estimated between March 2002 and July 2004. Three putative N-linked glycosylation sites resided in the vicinity of the receptor binding pocket of HA1 region. They are considered to decrease the reactivity of neutralizing antibody against the virus. Experiments for the infectivity and pathogenicity of a quail strain to poultry indicated that the quail isolate had higher infectivity to quails than chickens and ducks. Direct and dust-borne and/or droplet-borne transmissions among quail were proven in quails with and without direct contact with experimentally infected quails. The virus is seldom transmitted among chickens either directly or indirectly, and indirect transmission from infected quails to chickens was not observed. The pathogenicity of the quail strain for mammalian, pig and mouse was low, although it could replicate in those animals.     

Anthracnose of Christmas rose caused by <Emphasis Type="Italic">Colletotrichum</Emphasis> sp.

Leaf spots were found on Christmas rose (Helleborus niger) in Yamagata Prefecture, Japan, in October 2006. The morphology of the causal fungus was very close to that of Colletotrichum truncatum. Classifying the species from the sequences of the internal transcribed spacer regions of ribosomal DNA was inconclusive, and the isolates were identified only as Colletotrichum sp. Artificial inoculation confirmed the pathogenicity of isolates to the host plant and some legumes. We propose the name anthracnose of Christmas rose for this disease by Colletotrichum sp.     

A 12-month feeding study of reproduction/development in rats fed meat/milk powder supplemented diets derived from the progeny of cloned cattle produced by somatic cell nuclear transfer

The present 12-month feeding study was carried out with rat groups fed a diet supplemented with meat or milk (meat/milk) derived from the progeny of clones produced by somatic cell nuclear transfer (SCNT) technology. It was conducted to obtain data concerning the chronic toxicities of these edible products during the process of development and reproduction in rats fed such products. The rats were subjected to clinical observations for general health condition and examinations such as sensory/reflex function, grip strength, motor activity, body weight, food consumption, ophthalmology and urinalysis. Moreover, sexually matured rats fed the test diets were mated and examined for items such as the reproductive performances of the dams and health of their pups. After the feeding period, factors related to rat health status, based on the findings for hematology, blood biochemistry, necropsy, organ weight and histology, were examined. There were no biologically significant differences in these factors between the rat groups fed meat/milk powder supplemented diets derived from the progeny and those fed meat/milk powder supplemented diets derived from conventionally bred cattle. Therefore, the present chronic toxicity study suggests that meat and milk derived from the progeny of SCNT cattle might be equivalent to those derived from conventionally bred cattle in use as dietary supplements for rats.     

Bronchoalveolar lavage for the diagnosis and treatment of pneumonia associated with transport in Thoroughbred racehorses.

To evaluate a hypothese that use of bronchoalveolar lavage (BAL) for early treatment of pneumonia would improve their prognosis by reducing bacterial numbers and excessive numbers of neutrophils in the lung, initial experiences with BAL in the diagnosis and treatment of pneumonia were performed in 36 racehorses that became ill within 24 hr of long distance travel (1,200-1,600 km, 26-32 hr) by road. Comparisons were made of the outcomes of the 36 horses and those of 42 horses (81.0% recovered, 50.0% returned to racing) treated for transport associated pneumonia without BAL. The total amount of BAL fluid injected during hospitalization varied from 700 to 3,700 ml and the duration of antibiotic treatments ranged from 5 to 40 days. Clinical symptoms after lavages showed good results with no side effects. None of the horses required thoracic drainage. Horses treated with BAL required shorter period of antibiotic therapy, a greater percentage recovered (100%, 36/36) and a greater percentage returned to racing (77.8%, 28/36). Eight (22.2%) never raced because of lameness or other considerations.     

Relationship between various extracted basic densities and wood chemical components inEucalyptus camaldulensis

Summary Relationship between various extracted basic densities and wood chemical components were investigated by their within-tree variations inEucalyptus camaldulensis for assistance in the prediction of the properties of wood or wood derived products. Within-tree variation was not observed for basic density because extraneous compounds masked it. However, extractives-free basic density, total extractives-free basic density and extraneous compounds-free basic density were high on the bark side and top parts in the trunk. These extracted basic densities were expected to have significant relationships to the fiber morphology causing the within-tree variations, and to be very important factors for wood industries. These relationships were sought by correlations between extracted basic densities and wood chemical components based on their within-tree variations. Furthermore, fair relationships between extracted basic densities and hemicellulose composition were observed and speculation made as to the relationship to the constituent ratio of cell wall layers.The authors wish to thank Conservation and Land Management (Western Australia) for the provision of samples and Ms R. Noda and Mrs. T. Furukawa for experimental assistance