Bovine colostral CD8-positive cells are potent IFN-gamma-producing cells

IFN-gamma plays an important role in cellular immunity contributing to microorganism elimination. We have previously reported that bovine colostrum contains high levels of IFN-gamma as well as immunoglobulin. Lymphocytes are potent producers of IFN-gamma, so establishing the lymphocyte population in colostrum will help to identify the source of colostral cytokines. In this study, we used flow cytometric analysis to quantify the population of three types of lymphocytes found in colostrum; namely, CD4 (Th) cells, CD8 (cytotoxic T) cells, and gammadelta-T cells. We also quantified the concentration of colostral IFN-gamma using ELISA. IFN-gamma concentrations were measured in colostrum obtained from 96 healthy Holstein cows; the levels tended to decrease on the first day post-parturition. Flow cytometric analysis showed that many gammadelta-T- and CD8-positive cells were present in the colostrum, and that the CD4/CD8 ratio was low. The ratios of CD8- and gammadelta-T-positive cells to cells of other types decreased during the 5 days after parturition, but that of CD4-positive cells showed no change during the observation period. To identify IFN-gamma-expressing colostral lymphocytes, we used magnetic separation technology to separate the lymphocytes (CD4, CD8 and gammadelta-T) from colostral cells, then examined them for IFN-gamma mRNA expression with real-time PCR (RT-PCR). RT-PCR analysis revealed potent expression of the IFN-gamma gene in CD8-positive cells, reaching higher levels than in CD4- or gammadelta-T-positive cells. These results suggest that the CD8-positive T cells in colostrum play a role as producers of IFN-gamma.     

Fish‐processing wastes as an alternative diet for culturing the minute rotifer Proales similis de Beauchamp

We evaluated the suitability of fish waste diet (FWD) for culturing the minute rotifer Proales similis through the observation of their population growth and particle size selective feeding. A total of five treatments either with Nannochloropsis oculata or FWD (0.75 and 0.50 g/L) or the combination of N. oculata and FWD were set up in triplicates. P. similis were cultured in diluted natural seawater (8 g/L salinity) and 26 ± 1°C with the diet treatments being applied randomly. We daily monitored the rotifer density, the number of bacteria and the water quality in all the cultures. The population density of P. similis increased exponentially in all treatments, while the mean growth in FWD 0.75 g/L was significantly higher (p < .05) than that in the control. Addition of N. oculata to FWD resulted to lowered P. similis population growth. Bacterial colony count was high in FWD and introduction of P. similis to the diet decreased their density. The estimated bacteria ingestion rates were generally in the range of 6.03 × 10²–1.24 × 10⁴ bacteria/rotifer/hr and there was a positive linear relationship between bacterivory and rotifer population growth. We also observed a shift in the particle size distribution with a reduction in the frequency and concentration of small‐sized particles (<2.5 μm) at day 6. These results accentuate the potential of fish‐processing waste as diet for culturing P. similis which feeds on bacteria and small particles (≤2.5 μm) that are by‐products of degradation of this diet.     

Residence pattern of the ayu <Emphasis Type="Italic">Plecoglossus altivelis</Emphasis><Emphasis Type="Italic">altivelis</Emphasis> larvae and juveniles occurring in the surf zone of a sandy beach,Niigata Prefecture,northern Sea of Japan

This study examined the residence pattern of ayu larvae and juveniles occurring in the surf zone of an extensive sandy beach, in the north part of the Sea of Japan. In this region, ayu larvae mainly hatched in October and November, generally appeared in the surf zone in hatching order, and were continuously present until the following January. During a short period after mid- to late January when the water temperature fell below 10°C, ayu larvae and juveniles concurrently migrated from the surf zone regardless of their size and age, resulting in a longer term residence for earlier-hatched ayu. This was in contrast to studies in other waters, which found that early-hatched ayu have a short-term residence and late-hatched a long-term residence. Furthermore, faster growth that enables ayu to reach the maximum residence size (around 40 mm BL) in the surf zone during the period when the water temperature was still over 10°C might lead to earlier migration and a shorter residence term. This process might be applicable only to the early-hatched group (defined as individuals hatched in late September and October) and depends on the size of each individual, thus leading to a gradual migration of larger individuals as they attain maximum residence size.     

Quantitative trait loci associated with lodging tolerance in soybean cultivar ‘Toyoharuka’

Lodging tolerance (LT) is an important trait for high yield and combine-harvesting efficiency in soybean [Glycine max (L.) Merr.]. Many previous studies have investigated quantitative trait loci (QTLs) for lodging score (LS) in soybean. Most of the investigated QTLs were located in the proximal region of maturity or growth habit loci. The aim of this study was to identify genetic factors for LT not associated with maturity or growth habit. QTL analysis was performed using a recombinant inbred line (RIL) population derived from a cross between ‘Toyoharuka’ (TH), a lodging-tolerant cultivar, and ‘Toyomusume’ (TM). The genotypes of TH and TM were estimated as both e1e2E3E4 and dt1. The average LS over 4 years was used for QTL analysis, identifying a major and stable QTL, qLS19-1, on chromosome 19. The LS of the near-isogenic line (NIL) with the TH allele at Sat_099, the nearest marker to qLS19-1, was significantly lower than the NIL with the TM allele at that position. The TH allele at Sat_099 rarely had a negative influence on seed yield or other agronomic traits in both NILs and the TM-backcrossed lines. Our results suggest that marker-assisted selection for qLS19-1 is effective for improving LT in breeding programs.     

Concordance between Results of Medium-term Liver Carcinogenesis Bioassays and Long-term Findings for Carcinogenic 2-Nitropropane and Non-carcinogenic1-Nitropropane in F344 Rats

This study was conducted to determine the concordance of results for a pair of structural isomers, 2-nitropropane (2-NP) and 1-nitropropane (1-NP), using the rat medium-term liver carcinogenesis bioassay (Ito test) and previously published long-term carcinogenicity tests. Male F344 rats were given a single intraperitoneal injection of DEN (200 mg/kg b.w.) to initiate hepatocarcinogenesis. After 2 weeks, they received per os 0, 0.8, 4 or 20 mg/kg/day of 2-NP or 1-NP six times a week and were subjected to two-thirds partial hepatectomy at week 3. Non-initiated groups receiving 0 or 20 mg/kg/day were also included. The animals were sacrificed for quantitative analysis of GST-P-positive foci at week 8. With the highest dose of 2-NP, significantly increased numbers and areas of GST-P-positive foci were demonstrated as compared with the respective control but were not noted with 1-NP. In the non-DEN-initiated groups, many small GST-P-positive foci of less than 0.2 mm in diameter were also induced in the rats treated with 2-NP at 20 mg/kg/day but were lacking with 1-NP. These results strongly support that 2-NP is a complete hepatocarcinogen with a potent initiation activity, whereas 1-NP is not.     

Comparative study of the Nicotiana species with respect to water deficit tolerance during early growth

Sixty Nicotiana species were examined for tolerance against various osmotica for seed germination and seedling growth in vitro. The species showed a wide variety of tolerance, and based on the results of the in vitro tests, 31 species were selected and further evaluated for salt and drought tolerance in a glasshouse. The degrees of tolerance of germination among the 57 species toward NaCl were approximately related to those toward mannitol, indicating that the osmolarity plays a majorrole in seed germination. However, the responses during the seedling growth differed in NaCl and mannitol or drought, and there was no correlation between salt and drought tolerance. Based on the responses in vitro and in the glasshouse, N. paniculata and N. excelsior were selected as the salt tolerant species, and N. arentsii as the salt sensitive species. The degrees of accumulation of dry matter and of Na⁺ in the leaves were different in the two tolerant species; during NaCl treatment, N. paniculata and N. arentsii accumulated less dry matter relative to the control plants than N. excelsior, and N. paniculata accumulated more Na⁺ in its leaves than N. excelsior and N. arentsii. It is assumed that the two salt tolerant species have different mechanisms for tolerance to the salt. This revised version was published online in July 2006 with corrections to the Cover Date.     

Role of Tween 80 in biobleaching of unbleached hardwood kraft pulp with manganese peroxidase

The role of Tween 80 in biobleaching of unbleached hardwood kraft pulp (HWKP) with manganese peroxidase (MnP) was investigated. Among the surfactants (e.g., Tween 80, Tween 20, CHAPSO) the most significant brightness increase was obtained with Tween 80. Tween 80 and Tween 20 exhibited several effects, such as dispersion of degraded lignin and activation of MnP, that partly contributed to the brightening of HWKP during MnP treatment. However, these characteristics did not explain the most appreciable effect on the brightness increase by Tween 80. Lipid peroxidation of surfactants during MnP biobleaching was determined by measuring the peroxide value (POV). The order of the POV increase was consistent with that of the brightness increase of pulp during MnP treatment in the presence of various surfactants or linolenic acid. However, radicals and peroxides derived from lipid (linolenic acid) peroxidation by lipoxidase hardly brightened the HWKP by themselves. These results suggested that Tween 80 was peroxidized by Mn(III), and that Mn(III) and lipid peroxidation of Tween 80 synergistically brightened HWKP.This study was presented in part at the 43rd lignin symposium, Fuchu, Tokyo, Oct. 26–27, 1998 and the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 2–4, 1999     

Physiological considerations for efficient mycelial colonization of Philippine strains ofVolvariella volvacea

The nutritional and physical requirements for the efficient mycelial colonization ofVolvariella volvacea (Bull. ex. Fr.). Singer were elucidated with the percentage mycelial colonization and density as references. This investigation was limited to the evaluation of two commercial strains (designated Vvc1 and Vvc2) and two wild strains (designated EAAC-0001 and EAAC-0002) ofV. volvacea from the Philippines with the aim of providing baseline data on their physiological requirements. The four strains ofV. volvacea had varying preferences for carbon. Vve1 preferred polysaccharides (starch and cellulose), whereas Vvc2 grew luxuriantly at a relatively rapid rate in sugar alcohol (sorbitol). The two wild strains preferred starch as a carbon source. In terms of nitrogen utilization, soytone, peptone, and glycine supported efficient mycelial colonization of the four strains. The vitamin utilization test revealed that ascorbic acid, calcium pantothenate, and biotin are good sources. The mycelial growth performances of the strains were also evaluated on six dehydrated mycological media. Efficient colonization of Vvc1, Vvc2, and EAAC-0002 with dense mycelial growth was noted in mycological agar. EAAC-0001, on the other hand, grew more efficiently in malt extract agar. The Philippine strains ofV. volvacea grew luxuriantly when incubated at 35°C and pH 8.0 under dark and sealed conditions. Moreover, the relatively higher moisture content (70%) of the oolong tea leaf formulation favorably stimulated efficient mycelial colonization. Under optimum physiological conditions, Vvc1, Vvc2, and EAAC-0002 were fast-growing strains, whereas EAAC-0001 was a moderately growing type.     

External factors that regulate movement in the marine rotifer Brachionus plicatilis

Fisheries Science - There are two types of movement pattern in the Brachionidae (rotifers), swimming and attachment, although the factors that induce a shift between them have not been adequately...