土壤氮素有效性与克隆整合性对结缕草分枝行为的影响效应

在一个生长季内,对生长于4种生境类型(其中土壤氮素含量呈4种水平)中的克隆植物结缕草的主匍匐茎采取了2种对照处理:保持连接状态和实施节间切断,并检验对其分枝行为产生的生态影响。随着生境内土壤氮素水平的降低,保持连接状态的结缕草植株的分枝强度(按照分枝数量、长度和生物量计测)趋于降低,而实施切断处理的结缕草植株的分枝强度趋于增加。复合节在产生分枝时的根系生物量通常高于未产生分枝时的根系生物量。着生于贫瘠土壤中的根系生物量与着生于肥沃土壤中的根系生物量相比趋于增加。从肥沃土壤斑块中生长出的分枝比从贫瘠土壤斑块中生长出的分枝在数量上占优势。以多个形态学指标衡量,结缕草克隆的A分枝比B分枝具有明显的生长优势。方差分析结果揭示出结缕草克隆的分枝行为对于生境土壤氮素水平以及连接和切断两种处理的响应方式不同。分枝对于结缕草克隆总生物量具有较高的贡献率,而其中A分枝占有较大比例。     

Identification of endotrypanum species from a sloth,a squirrel and Lutzomyia sandflies in ecuador by PCR amplification and sequencing of the mini-exon gene

PCR amplification and nucleotide sequencing of the mini-exon gene revealed that four strains isolated from a sloth (Choloepus hoffmanni), a squirrel (Sciurus granatensis) and two sandflies (Lutzomyia hartmanni) in Ecuador were indistinguishable from Endotrypanum monterogeii. Another strain isolated from Lu. hartmanni showed the high sequence similarity to E. schaudinni. Since three of these strains have been previously identified as Leishmania (Viannia) equatorensis, the results demonstrate that L. (V.) equatorensis is genetically closely related to the genus Endotrypanum. The present study also indicates that Endotrypanum species are distributed in arboreal animals and sandflies in Ecuador, and that mini-exon gene amplification is useful for epidemiological studies of Leishmania and Endotrypanum in the New World.     

Proliferation capacity, neuronal differentiation potency and microstructures after the differentiation of canine bone marrow stromal cells into neurons

We examined the proliferation capacity and neuronal differentiation potency of canine bone marrow stromal cells (BMSCs). In addition, the microstructures of neuron-like cells after neuronal differentiation were observed under a scanning electron microscope. Canine BMSCs grew to confluency at 10.0 ± 2.5 days, and 3.8 ± 2.1 × 10(6) BMSCs were collected in one passage. Approximately 65% of canine BMSCs changed to neuron-like morphology after neuronal differentiation, and nearly all neuron-like cells stained positive against neuron-specific enolase. In addition, microstructures such as the cellular organelles, filaments and growth cones of these cells bore a close resemblance to those of the original mature neurons. These results suggested that canine BMSCs might be capable of differentiating into neurons.     

Lectin binding patterns in the olfactory bulb of mallard ducks (Anas platyrhynchos)

We histologically examined lectin binding patterns in the olfactory bulb of mallard ducks (Anas platyrhynchos) using 21 biotinylated lectins. Positive staining for the N‐acetylglucosamine‐specific lectins (Bandeiraea simplicifolia II, Datura stramonium, Lycopersicon esculentum, Solanum tuberosum, Triticum vulgare), galactose or N‐acetylgalactosamine‐specific lectins (Artocarpus intergrifolia, Phaseolus vulgaris erythroagglutinin, Phaseolus vulgaris leucoagglutinin, Ricus communis) and the mannose‐specific lectins (Lens culinaris and Pisum sativum) was observed in the olfactory nerve and glomerular layers. Canavalia ensiformis staining showed a similar pattern to that obtained with the lectins and there was also faint staining in the mitral cells. Olfactory nerve axons terminate in the glomeruli, where they make excitatory synapses with the dendrites of mitral cells. This finding indicates that glycoconjugates that bind Canavalia ensiformis play an important role in formation of glomeruli. No positive staining for the other lectins was seen in the olfactory bulb. Based on these results, we conclude that cell surface sugar moieties of the olfactory bulb in mallard ducks express N‐acetylglucosamine and mannose residues rather than N‐acetylgalactosamine residues. The carbohydrate composition of mallard duck olfactory bulb differed from that of other vertebrates found in previous studies.     

Preparation of phytate-removed deamidated soybean globulins by ion exchangers and characterization of their calcium-binding ability.

Phytate-removed deamidated soybean globulins were prepared using ion-exchange resins to provide them with a functional property to enhance calcium absorption in the body. The phosphorus level was reduced from 45 to 20 micromol/g using 0.05 g/mL of AE-4, an anion-exchange resin with a (2-hydroxyethyl)dimethylammonium group, in 0.2% soybean globulin solution for 1 h at 4 degrees C, and 90-92% of the phosphorus in defatted soybeans could be removed. As for deamidation, CE-4, a cation-exchange resin of the carboxylate type, showed a much higher deamidation activity than CE-1 and CE-2, cation-exchange resins of the sulfonate type. No peptide bond hydrolysis was observed for any cation-exchange resin treated at 4 degrees C. There was no significant difference in the amount of acid amide deamidated at temperatures between 4 and 50 degrees C. The deamidation level was able to increase to 73% using 0.10 g/mL of CE-4 in a 0.2% soybean globulin solution for 6 h at 4 degrees C. The amount of calcium bound to the soybean globulins decreased with removal of the phytate but increased with deamidation.     

Detection of chromogranin A in the adrenal gland extracts of different animal species by an enzyme-linked immunosorbent assay using Thomsen-Friedenreich antigen-specific Amaranthus caudatus lectin

The reactivity of different lectins with crude chromogranin A (CgA) obtained from different animals, namely, cow, horse, dog, pig, and dolphin, was examined to identify lectin(s) that would be useful as coating reagent(s) in a sandwich enzyme-linked immunosorbent assay (ELISA). Of the different lectins studied, the Amaranthus caudatus lectin (ACA), which is specific for the Thomsen-Friedenreich (T)-antigen (Galβ1-3GalNAc), was found to react with the CgA from different animals by western blotting. Purified rabbit anti-bovine CgA antibody was also found to cross-react with the crude CgA preparations. On the basis of these findings, a sandwich ELISA was developed with ACA as the coating reagent and anti-bovine CgA antibody as the probing antibody. Using this method, concentration-dependent curves ranging from 0.003 μg/mL to 25 μg/mL and from 0.02 μg/mL to 25 μg/mL were obtained for bovine CgA and canine CgA, respectively. Similarly, concentration-dependent curves were obtained for the equine, swine, and dolphin crude CgA extracts. Thus, ACA is concluded to be a valuable reagent for CgA detection in crude extracts from different animal species, and for CgA isolation/purification.     

Mitotic disruption by a novel pyrimidine herbicide, NS-245852, in oat (Avena sativa L.) roots

The effects of a novel pyrimidine herbicide, NS-245852 [2-chloro-6-fluorophenyl-4-(trifluoromethyl)thieno[2,3-d]pyrimidine-2-yl-ketone], on mitosis in oat ( Avena sativa L. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10⁻⁷ mol L⁻¹ of NS-245852, and swollen root tips were induced at 5 × 10⁻⁸ mol L⁻¹. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS-245852 is the inhibition of polymerization of tubulin into microtubules.