Complete contact of Brassica roots with phosphorus fertilizer in a phosphorus-deficient soil

The preferential development of Brassica lateral roots for phosphorus (P) to forage for P fertilizer was observed by using alginate gel beads in which powdery dicalcium phosphate dihydrate (DCPD) was suspended (DCPD gel bead). The DCPD gel beads enabled to detect the characteristic root growth around them because of their larger diameter (1.5 cm) than that of standard fertilizer particles. The thin Brassica lateral roots completely encircled the DCPD gel beads and no soil area remained between the roots and the DCPD gel beads. This morphological plasticity of Brassica roots is highly suitable for improving the P recovery rate because even a few mm of soil with a high P retention capacity between a plant root and P fertilizer reduces the P recovery rate. The P recovery rate in the Brassica shoots exceeded 0.05 and the ratio of the shoot dry weight in the plot treated with DCPD gel beads to that in the control plot exceeded 10. Thus, the Brassica plants showed both a high P recovery rate and satisfactory growth in the P-deficient soil compared with other tested plants due to the complete contact between their roots and the DCPD gel beads. The preferential root proliferation for P was also observed in Fagopyrum esculentum Moench as well as Brassica plants among the 20 tested plants.     

Cloning of estrogen receptor-β cDNA of common Japanese conger Conger myriaster and expression of the gene during oocyte development

ABSTRACT:   Estrogen receptor (ER) cDNA was cloned from the liver of common Japanese conger Conger myriaster . Common Japanese conger ER cDNA contains 2543 nucleotides including an open reading frame that encodes 596 amino acids, with a molecular weight of 66.1 kDa. The deduced amino-acid sequence of the common Japanese conger ER shares 85% identity with that of eel Anguilla japonica ER-β, and 39–46% and 53–59% identity with the deduced sequences of ER-α and ER-β of other species, respectively. In a phylogenetic analysis, the common Japanese conger ER was found to cluster with the ER-β of other species. The common Japanese conger ER-β also has six domains (A–F), which are conserved in the nuclear receptor superfamily. The amino-acid sequences in the C and E domains were highly conserved between common Japanese conger ER-β and other ER. However, the other domains showed low homology. In the female common Japanese conger, ER-β mRNA was highly expressed in the liver and pituitary gland. The expression levels of the ER-β gene increased from the oil droplet stage to the primary yolk globule stage and were maintained until the migratory nucleus stage.     

Responsiveness of beef cattle (Bos taurus) to human approach,novelty, social isolation,restraint and trade‐offs between feeding and social companionship

This study investigated responsiveness of beef cattle to various environmental stimuli by subjecting 15–16 Japanese Black cows to five tests repeated twice. Within individual behavioral measures, cows were moderately (repeatability = 0.54–0.70) or highly (repeatability = 0.74–0.89) consistent in flight distance during grazing and resting in the human approach tests, maximum distance from the group pen and the number of total and different feed tub visits in the feeding–sociability trade‐off test, and unwillingness to enter the restraint, movement under restraint and flight speed after release from restraint in the social isolation and restraint test. By contrast, cows were not consistent in the latency to make the first contact and the number of contacts with novel object(s) in the novelty test (repeatability = 0.24–0.39). Across behavioral measures in different tests, cows showed no consistency (P ≥ 0.05) in any combinations of measures from the two human approach tests, the trade‐off test and the social isolation and restraint test. In conclusion, human approach (particularly during resting), feeding–sociability trade‐off and social isolation and restraint situations can be used for evaluating personality in Japanese Black cows, while the value of the novelty test needs to be reexamined.     

Expression of O6-methylguanine-DNA methyltransferase causes lomustine resistance in canine lymphoma cells

The DNA repair protein O⁶-methylguanine-DNA methyltransferase (MGMT) causes resistance to nitrosoureas in various human cancers. In this study, we analyzed the correlation between canine lymphomas and MGMT in vitro. Two of five canine lymphoma cell lines required higher concentrations of lomustine to inhibit cell growth by 50%, but their sensitivity to the drug increased when they were cultured with an MGMT inhibitor. Fluorometric oligonucleotide assay and real-time polymerase chain reaction of these cell lines revealed MGMT activity and high MGMT mRNA expression, respectively. We analyzed the methylation status of the CpG islands of the canine MGMT gene by the bisulfite-sequencing method. Unlike human cells, the canine lymphoma cell lines did not show significant correlation between methylation status and MGMT suppression levels. Our results suggest that in canine lymphoma MGMT activity may influence sensitivity to nitrosoureas; thus, inhibition of MGMT activity would benefit nitrosourea-resistant patients. Additional studies are necessary to elucidate the mechanism of regulation of MGMT expression.     

Salmonella isolates from cloacal swabs and footpads of wild birds in the immediate environment of Tokyo Bay

A total of 328 cloacal swabs and 163 footpads of wild birds were investigated for the presence of salmonellae. All 19 isolates from cloacal swabs were serotyped as Salmonella Typhimurium susceptible to all five conventional antimicrobial agents (ampicillin, chloramphenicol, streptomycin, oxytetracycline and nalidixic acid) tested. In contrast, 15 salmonellae isolated from footpads included S. Muenhen, S. Virchow, S. Bareily and S. Bovismorbificans, including S. Typhimurium; these non-Salmonella Typhimurium isolates showed multiple drug resistance.     

Ability of alphas-Casein to suppress the heat aggregation of ovotransferrin

The effects of alphas-casein on heat aggregation of ovotransferrin (OT) were studied by heating at 80 degrees C for 20 min in 10 mM phosphate buffer, pH 7.0. The heat interactions between alphas-casein and OT were followed by turbidity development and polyacrylamide gel electrophoresis. We found that alphas-casein can effectively suppress the heat-induced aggregation of heat-labile OT. The suppressive ability of alphas-casein was reduced by the presence of NaCl on heating. Dephosphorylated alphas-casein had less ability to suppress the aggregation of OT than native alphas-casein. Our results indicate that alphas-casein interacts with the heat-denatured OT through its exposed hydrophobic surface and phosphoserine residue. Such interactions seem to be important in helping to suppress the aggregation of heated OT. The suppressive effects of alphas-casein on heat aggregation of OT would be partially ascribed to the formation of transparent gel from egg white by the addition of alphas-casein.     

EFFECTS OF O3 AND SOIL ACIDIFICATION,ALONE AND IN COMBINATION,ON GROWTH,GAS EXCHANGE RATE AND CHLOROPHYLL CONTENT OF RED PINE SEEDLINGS

Water, Air, &; Soil Pollution - One-year-old seedlings of red pine (Pinus densiflora Sieb. and Zucc.) were grown in typic red-yellow forest soil (Typic Hapludults) artificially adjusted to pH...     

Effects of restricted feeding on growth of red sea bream and sedimentation of aquaculture wastes

For improving the economic and environmental sustainability of fish farming, it is necessary to optimize feeding regimes. From this viewpoint, we monitored the growth and mortality of red sea bream (Pagrus major), C and N fluxes and sediment chemistry at 2 commercial fish cages; cage 1 (conventional satiation feeding) and cage 2 (restricted feeding: same feeding frequency but 18% reduction in the feed amount) for 276 days. The similar specific growth rates (0.43% in cage 1 and 0.39% in cage 2) but different feed conversion efficiencies (0.54 in cage 1 and 0.62 in cage 2) and mortality (> 2-times higher in cage 1) between the 2 cages, indicate overfeeding in cage 1 culture. Elemental and stable isotopic analyses of sediment trap materials enabled the quantification of waste feed- and fecal matter-derived organic matter (OM) separately. The results shows that (1) aquaculture-derived OM comprised most of the fish-farm settling OM, excluding the period from January to April, when natural OM often accounted for a half of the bulk OM, (2) there was a difference in the seasonal trend between the fluxes of waste feed and fecal matter, and (3) there were no differences in the percentage compositions and fluxes of waste feed and fecal matter between the 2 cages. The isotopic analysis showed that the waste feed-derived OM in the sediment below cage 2 was 24% less than that below cage 1, suggesting effect of restricted feeding. Determining the relative amount of waste feed and fecal matter in settling and sedimentary OM is an effective method to evaluate the optimum feeding regime.