Diagnostic real-time PCR assay for the quantitative detection of Theileria equi from equine blood samples

We developed a TaqMan real-time polymerase chain reaction (PCR) assay for the quantitative detection of Theileria equi from the in vitro-cultured parasite and field blood samples collected from horses living in Ghana and Brazil. The detection limit for the assay was determined to be 1.5 parasites/microl per sample, and the quantitative capacity was demonstrated using the in vitro-cultured parasite. For field applications, the real-time PCR assay was compared to a previously established nested PCR assay used as the gold standard for the real-time PCR assay. Of 65 field blood samples, 46 samples were T. equi-positive in the nested PCR assay, while the real-time PCR assay also detected the parasite in all 46 of the nested PCR-positive samples but did not detect T. equi in the remaining 19 negative blood samples. This quantitative real-time PCR assay provides a valuable tool for fast laboratory diagnostic assessment of T. equi infection in horses.     

Effect of dietary fish oil intake on ubiquitin ligase expression during muscle atrophy induced by sciatic nerve denervation in mice

Dietary fish oil intake improves muscle atrophy in several atrophy models however the effect on denervation‐induced muscle atrophy is not clear. Thus, the aim of this study was to investigate the effects of dietary fish oil intake on muscle atrophy and the expression of muscle atrophy markers induced by sciatic nerve denervation in mice. We performed histological and quantitative mRNA expression analysis of muscle atrophy markers in mice fed with fish oil with sciatic nerve denervation. Histological analysis indicated that dietary fish oil intake slightly prevented the decrease of muscle fiber diameter induced by denervation treatment. In addition, dietary fish oil intake suppressed the MuRF1 (tripartite motif‐containing 63) expression up‐regulated by denervation treatment, and this was due to decreased tumor necrosis factor‐alpha (TNF‐α) production in skeletal muscle. We concluded that dietary fish oil intake suppressed MuRF1 expression by decreasing TNF‐α production during muscle atrophy induced by sciatic nerve denervation in mice.     

Population density and range use of sika deer,Cervus nippon, on Mt. Ohdaigahara, central Japan

We investigated the population density and range use of sika deer,Cervus nippon, on Mt. Ohdaigahara, central Japan, from July 1996 to July 1997. The deer population density estimated by the block count was high at 17.5–30.9 deer/km². Although the deer remained this area from spring to fall, they moved out in winter, probably because of deep snow. A spotlight count showed that the deer prefer the eastern area as spring-summer range, where the forest consists of coniferous trees over a floor cover ofSasa nipponica, andS. nipponica grassland. The deer also use dense coniferous forest for cover, especially in summer and fall. Part of this study was presented at the 108th Annual Meeting of the Japanese Forestry Society (1997). This study was financially supported by the Environment Agency, Japan.     

Reproductive traits and diel activity of adultMonochamus saltuarius (Coleoptera: Cerambycidae) at two different temperatures

To investigate the reproductive traits and diel activity ofMonochamus saltuarius, 14 pairs of the adults were reared and observed at each of 20°C and 25°C. Both sexes were more active at 25°C than at 20°C irrespective of the presence or absence of light. A diel change in behavior during 24 h was found on 33% of a total of 48 observations of three age classes of both sexes. No significant difference was found in the mean longevity between sexes or between the two temperature conditions. The time required for reproductive maturation showed no significant difference within the same sex when reared at 20°C and 25°C. The mean oviposition period was significantly longer at 25°C (28.8 days) than at 20°C (12.2 days). The mean lifetime fecundity was significantly greater at 25°C than at 20°C. There was no significant difference in the oviposition ratio (number of eggs deposited/number of oviposition wounds excavated), oviposition rate or hatchability for females between the two temperature conditions.     

Effect of Barley β-Glucan in Durum Wheat Pasta on Human Glycemic Response

High-fiber, high-carbohydrate diets, including foods with low glycemic index, have been associated with prevention and treatment of diseases such as coronary heart disease and diabetes. β-glucan, a soluble, viscous polymer found in oat and barley endosperm cell wall, was incorporated into pasta test meals. Five fasted adult subjects were fed test meals of a barley and durum wheat blend pasta containing 100 g of available carbohydrate, 30 g of total dietary fiber (TDF) and 12 g of β-glucan, or an all durum wheat pasta containing the same amount of available carbohydrate, 5 g of TDF, and negligible β-glucan. The β-glucan and durum wheat pasta resulted in a lower glycemic response as measured by average total area and maximum increment of the blood glucose curves. Lower insulin response to the β-glucan and durum wheat pasta was also indicated by lower average area and increment characteristics of the insulin curves. Barley β-glucans may be an economical and palatable ingredient for processed food products formulated to modify glycemic and insulin response.     

Effects of dietary inactivated Pediococcus pentosaceus on growth performance,feed utilization and blood characteristics of red sea bream,Pagrus major juvenile

A feeding trial was carried out to determine effects of dietary supplements of inactivated Pediococcus pentosaceus (PP) on growth, feed utilization and blood characteristics of red sea bream. Five diets containing different concentrations [0 (PP0), 1.6 × 10¹⁰ (PPI), 1.6 × 10¹¹ (PPII), 1.6 × 10¹² (PPIII) and 3.2 × 10¹² (PPIV) cells g^?1] of PP were fed to fish for 56 days. At the end of the feeding trial, the obtained results revealed a significant increase (P < 0.05) in weight gain, specific growth rate and skin mucus secretion in all PP‐supplemented groups when compared with control group. Moreover, fish fed PPIII and PPIV diets resulted in significantly higher final body weight, feed efficiency ratio and bactericidal activity than those of fish fed PP0 diet (P < 0.05). Further, fish fed the PPIII diet also had a higher feed intake, protein efficiency retention, haematocrit, mucus lysozyme activity (LA), plasma and serum proteins than those of PP0 fed group (P < 0.05). Similarly, fish fed PPIV diet resulted in a significant increase in serum LA, peroxidase activity and tolerance against low‐salinity stress test (P < 0.05). Considering these promising results, we suggest that the supplementation of PP Prep improves growth and health conditions of Pagrus major.     

Allelic variation of a clubroot resistance gene (Crr1a) in Japanese cultivars of Chinese cabbage (Brassica rapa L.)

Clubroot resistance (CR) is an important trait in Chinese cabbage breeding worldwide. Although Crr1a, the gene responsible for clubroot-resistance, has been cloned and shown to encode the NLR protein, its allelic variation and molecular function remain unknown. Here, we investigated the sequence variation and function of three Crr1a alleles cloned from six CR F₁ cultivars of Chinese cabbage. Gain-of-function analysis revealed that Crr1a^Kinami90_a isolated from the cv. ‘Kinami 90’ conferred clubroot resistance as observed for Crr1a^G004. Because two susceptible alleles commonly lacked 172 amino acids in the C-terminal region, we investigated clubroot resistance in transgenic Arabidopsis harboring the chimeric Crr1a, in which 172 amino acids of the functional alleles were fused to the susceptible alleles. The fusion of the C-terminal region to the susceptible alleles restored resistance, indicating that their susceptibility was caused by the lack of the C-terminus. We developed DNA markers to detect the two functional Crr1a alleles, and demonstrated that the functional Crr1a alleles were frequently found in European fodder turnips, whereas they were rarely introduced into Japanese CR cultivars of Chinese cabbage. These results would contribute to CR breeding via marker-assisted selection and help our understanding of the molecular mechanisms underlying clubroot resistance.     

Involvement of a host erythrocyte sialic acid content in Babesia bovis infection

Host sialic acid (SA) has recently been suggested to play an important role in erythrocyte (RBC) infection by Babesia spp. The present study attempted to further determine the specific type of SAs important in the RBC invasion. Bovine RBC was found to bear abundant alpha2-3-linked SA residues but not alpha2-6-linked SA in nature, confirmed by flow cytometric analysis of the neuraminidase (Nm)-treated RBCs. Lectin-blot analyses revealed the removal of alpha2-3-linked SAs from the 97-, 33-, and 31-kDa bands by the Nm treatment. Addition of the Nm-treated RBCs into an in vitro culture of B. bovis resulted in a decreased population of the parasitized RBCs. The thin smear samples from the cultures were then observed under a confocal laser scanning microscope after staining with the alpha2-3-linked SA-specific lectin: a selective invasion of B. bovis was found only in the intact RBCs bearing the SAs, but not in the desialylated RBCs. Furthermore, a significant reduction of the parasitized RBCs was also observed in the culture supplemented with exogenous 3'-sialyllactose containing the alpha2-3-linked SAs. However, the complete inhibition of parasite proliferation was not achieved in the culture. These findings indicate that while the alpha2-3-linked SA-dependent pathway is needed for highly efficient invasion of host RBCs by B. bovis, there might also be other potential alternative pathways.     

Replacement of squid and krill meal by snail meal (Buccinum striatissimum) in practical diets for juvenile of kuruma shrimp (Marsupenaeus japonicus)

A 60‐day feeding trial was conducted to investigate the effects of substituting squid and krill meal with marine snails (Buccinum striatissimum) into the diets of juvenile kuruma shrimps (Marsupenaeus japonicus). Five experimental diets were formulated to contain varying levels of snail meal at 0%, 25%, 50%, 75% and 100% (D1, D2, D3, D4 and D5, respectively) and fed to juvenile kuruma shrimps (initial mean weight 0.27 ± 0.02 g). The results showed that weight gain, feed intake and specific growth rate were improved significantly in D4 and D5 groups when compared with D1 group (p < 0.05). Significant differences were not detected in survival rate among all shrimps fed diets containing several levels of snail meal (p > 0.05). Crude protein content of shrimps fed the control diet was significantly lower than other treatments (p < 0.05). Lipid content in shrimps fed 50% snail meal were significantly higher than the control while cholesterol content in shrimps fed 100% snail meal were significantly decreased and polyunsaturated fatty acid contents were significantly increased in shrimps fed 75%–100% snail meal (p < 0.05). These results suggest that supplementing snail meal for complete replacement of squid and krill meal can be done to improve juvenile kuruma shrimps’ growth and reducing their cholesterol levels.     

Growth, Net Photosynthetic Rate, Nutrient Status and Secondary Xylem Anatomical Characteristics of Fagus Crenata Seedlings Grown in Brown Forest Soil Acidified with H2SO4 Solution

Dry matter production, net photosynthetic rate, leaf nutrient status and trunk anatomical characteristics of Fagus crenata seedlings grown in brown forest soil acidified by adding H₂SO₄ solution were investigated. The soil acidification leaded to decreased (Ca+Mg+K)/Al molar ratio in the soil solution. Dry mass per plant of the seedlings grown in the soil treated with H⁺ at 120 mg·L^?1 was significantly reduced compared with the control value at 0 mg·L^?1. When net photosynthetic rate was reduced in the seedlings grown in the soil treated with H⁺ at 120 mg·L^?1, the carboxylation efficiency and maximum net photosynthetic rate at saturated CO₂-concentration were lower than the control values. The addition of H⁺ to the soil at 120 mg·L^?1iinduced a reduction in the concentration of Ca in the leaf. By contrast, the concentration of Al in the leaf was increased with increasing the amount of H⁺ added to the soil. The annual ring formed in the seedlings grown in the soil treated with H⁺ at 120 mg·L^?1 was significantly narrower than that at 0 (control), 10, 30, 60 or 90 mg·L^?1. Based on the results obtained in the present study, we conclude that Fagus crenata is relatively sensitive to a reduction in the (Ca+Mg+K)/Al molar ratio of soil solution compared with Picea abies.