Comparison of amino acid profiles between rats subjected to forced running and voluntary running exercises

It has been suspected that in comparison with glucose or fatty acids, the levels of amino acids may readily change with different forms of exercise. In the present study, we measured the concentrations of amino acids, glucose, triglycerides, total protein and total cholesterol in the blood and/or cerebrospinal fluid (CSF) of rats subjected to forced running exercise on a treadmill, and voluntary running exercise using a wheel, with a constant running distance of 440 m. Rats that performed no running and rats subjected to immobilization stress were used as controls. We observed a few significant changes in the levels of plasma glucose, triglycerides, total protein and total cholesterol in all groups. Whereas, plasma amino acid levels were significantly changed by exercise and stress, especially during the light period. The plasma levels of many amino acids were specifically increased by forced running; some were decreased by immobilization stress. Few amino acids showed similar changes in their levels as a result of voluntary running. In addition, there was a significant difference in the degree of amino acid imbalance between blood and CSF. These results provide the first information on changes in levels of amino acids in plasma and CSF resulting from forced and voluntary exercises.     

Efficacy of levamisole alone and in combination with mebendazole against Gongylonema pulchrum infection in rabbits

Gongylonema pulchrum is an important parasite of captive primates. Twelve rabbits were infected with 30 third-stage larvae of G. pulchrum. At 4–7 months post-infection, animals were administered levamisole at a single dose of 12 mg/kg, levamisole at 8 mg/kg three times at 2-day intervals, levamisole at a single dose of 8 mg/kg after administration of mebendazole at 70 mg/kg for 3 days or 8 ml of distilled water for 3 days (control). Necropsy at 14 days after treatment revealed that single and multiple dosages of levamisole reduced nematode burdens by 68.4% and 89.5%, respectively. The combined regimen of mebendazole and levamisole exhibited high efficacy for treating G. pulchrum located widely within the upper digestive tract, with a reduction of 98.2%. These results suggest that this combined chemotherapy treatment may be effective against G. pulchrum infection, including buccal and lingual gongylonemiasis in primates.     

Comparison of microbial communities in percolating water from plow layer and subsoil layer estimated by phospholipid fatty acid (PLFA) analysis

Abstract

The amount and composition of phospholipid fatty acids (PLFAs) in the percolating water taken from different depths of soil (10 cm, PW10; 40 cm, PW40) and floodwater (FW) in a paddy field were compared during the period of rice cultivation. The amounts of PLFAs in PW10, PW40, and FW ranged from 22.6 to 46.2 μg L^?1, from 22.3 to 54.5 μg L^?1, and from 82.9 to 179.0 μg L^?1, respectively. The PLFA profiles in PW10, PW40, and FW were similar to each other and 16 : 1ω7c, 18 : 1ω7, and 16 : 0 PLFAs were dominant components, irrespective of the sampling site and sampling time. High proportions of straight mono-unsaturated PLFAs ranging from 42.0 to 76.5% suggested that Gram-negative bacteria were the major members in the microbial communities of the water samples studied. A potential indicator of the environmental stresses imposed upon the microbiota that was represented by the trans vs. cis ratio of 16 : 17 PLFA was constantly low (< 0.05), indicating that the microbial communities at these sites were hardly stressed.     

Sites and processes of nutrient accumulation in the subsoil through water percolation from the plow layer in a submerged paddy soil microcosm

The leaching of nutrients from the plow layer by water percolation and their accumulation in the subsoil observed in a Japanese paddy field (Katoh et al. 2004: Soil Sci. Plant Nutr., 50, 721-729) were determined semi-quantitatively in a soil column experiment. Ca²⁺, Mg²⁺, K⁺, Mn²⁺, Fe²⁺, and phosphate in percolating water from the plow layer soil column were retained in the subsoil columns that were connected to the plow layer soil column. Fe²⁺, K⁺, and phosphate accumulated in the uppermost part of the subsoil. Accumulation of Fe²⁺ in the uppermost part of the subsoil was presmnably due to the cation exchange process with concomitant desorption of Ca²⁺. In contrast, Ca²⁺ and Mg²⁺ in percolating water from the plow layer soil colmnn accumulated once in the subsoil, and translocated downwards slowly with successive water percolation. Considerable amounts of inorganic carbon (IC) and dissolved organic carbon (DOC) in percolating water from the plow layer soil column were also retained in the subsoil columns. IC did not accumulate a gaseous form.     

Microbial communities responsible for the decomposition of rice straw compost in a Japanese rice paddy field determined by phospholipid fatty acid (PLFA) analysis

To identify the microbial communities responsible for the decomposition of rice straw compost in soil during the rice cultivation period, phospholipid fatty acid (PLFA) composition of rice straw compost was determined by periodically sampling the compost from a Japanese rice field under flooded conditions. About 21% of the compost was decomposed within a period of 3 months. The total amount of PLFAs, as an indicator of microbial biomass, was significantly lower under drained conditions than under flooded conditions and was relatively constant during the flooding period. This indicates that the microbial biomass in the compost samples did not increase during the gradual decomposition of rice straw compost under flooded conditions. The proportion of branched-chain PLFAs (biomarker of Grampositive and anaerobic Gram-negative bacteria) slightly decreased during the early period after placement, and increased gradually afterwards. Among the branched-chain PLFAs, i15:0, ail5:0, i16:0 and i17:0 PLFAs predominated and their proportions increased gradually except for i16:0. The proportion of straight mono-unsaturated PLFAs (biomarker of Gramnegative bacteria) was almost constant throughout the period, and 18:1ω9 and 18:1ω7 PLFAs predominated. The proportion of straight poly-unsaturated PLFAs as a biomarker of eukaryotes including fungi was also constant throughout the period, except for a decrease under drained conditions. Straight poly-unsaturated PLFAs consisted mainly of 18:2ω6c PLFA. Therefore, these results suggest that the proportions of Gram-positive and anaerobic Gram-negative bacteria increased during the decomposition of rice straw compost in flooded paddy field. Statistical analyses enabled to divide PLFA patterns of microbiota in the rice straw compost into two groups, one group consisting of rice straw compost samples collected before mid-season drainage and the other of samples collected after mid-season drainage. Small squared distances among samples in cluster analysis indicated that the community structure of microbiota was similar to each other as a whole. These results suggest that the microbial communities changed gradually during the period of placement, and that mid-season drainage may have affected the community structure of microbiota. Principal component analysis of the PLFA composition suggested that the succession of microbiota along with the decomposition in flooded soil was similar between rice straw compost and rice straw and that the changes in the community structure during the decomposition in flooded soil were more conspicuous for rice straw than for rice straw compost.     

Growth of hydrogenotrophic and acetoclastic methanogens on substrate from rice plant callus cells in anaerobic soil: an estimation to the role of slough-off root cap cells to their growth

Flooded paddy fields are the major anthropogenic sources of methane (CH₄) emission, and organic materials of rice plant origin were estimated to be important as its source. This study used rice (Oryza sativa L. cv, Yukihikari) callus cells as a model material for slough-off root cap cells, and carbon-13 (¹³C)-labelled callus cells were subjected to decomposition in aerobic and anaerobic soil microcosms for 56 days. DNA was extracted from a soil incubated with carbon-12 (¹²C)- and ¹³C-callus cells and subjected to buoyant density gradient centrifugation to identify methanogenic archaeal species that assimilated carbon from the callus cells. ¹³C-labelled 16S rRNA gene (16S rDNA) fragments from methanogenic archaea were not polymerase chain reaction (PCR)-amplified in heavy fractions under aerobic soil conditions, while they were successfully done from day 3 onwards under anaerobic soil conditions. Eighty-four denaturing gradient gel electrophoresis (DGGE) bands in heavy fractions were sequenced, revealing that they were members of Methanosarcina spp. (20 clones), Methanosaeta spp. (18 clones), Methanocella spp. (25 clones), Methanomicrobiales (10 clones), Methanobacterium spp. (7 clones) and Cluster ZC-I (2 clones). They included hydrogenotrophic and acetoclastic methanogens and were phylogenetically different from those residing in rice roots and, presumably, from those assimilating root exudate and mucilage-derived carbon. This study indicates that carbon of slough-off root cap cells propagates specific methanogenic species in rice rhizosphere under anaerobic soil conditions and thus augments the diversity of the total rhizospheric methanogenic community.     

Development of CAPS markers and their application in breeding for mango, Mangifera indica L.

To develop cleaved amplified polymorphic sequence (CAPS) markers for the identification of true hybrids in F1 progeny, we cloned sucrose synthase (SS) and sucrose phosphate synthase (SPS) genes from 19 mango cultivars. Through comparison of amino acid sequences in a BLASTX search, cloned SS and SPS genes were found to be homologs of Citrus unshiu CitSUS1 (AB022092) and CitSPS1 (O22060), respectively. Therefore, we designated the SS and SPS genes as MiSUS1 and MiSPS1, respectively. There were 11 genotypes in MiSUS1 and 10 in MiSPS1 sequences. In the MiSUS1 nucleotide sequences, 46 SNPs and 5 in/dels were detected. Twenty-six out of the 46 SNPs mapped on the restriction enzyme recognition sites were successfully converted to 25 CAPS markers. In the MiSPS1 nucleotide sequences, 99 SNPs and 6 in/dels were detected. Thirty out of 99 SNPs and 2 out of 6 in/dels mapped on the recognition sites were also converted to 32 CAPS markers. By using two CAPS markers, SS-2798 and SPS-5745, we identified 37 true hybrids that had different genotypes to ‘Irwin’ from 82 F1 progeny obtained through a cross between ‘Irwin’, the maternal parent, and paternal parents by using flies as pollinators. The method developed here to identify true hybrids is a simple, rapid and highly reliable tool for efficient mango breeding.     

Effect of co‐culture with intact embryos on development of bovine separated blastomeres

To improve embryo development in bovine separated blastomeres, we evaluated applicability of co‐culture with intact embryos. The morphological quality of blastocysts derived from separated blastomeres and rate of blastocyst formation were only slightly increased when the cells were co‐cultured with intact embryos, which did not provide significant differences when statistically analyzed. However, the cell count of inner cell mass (ICM), trophectoderm (TE) and total number of cells in Day 8 blastocysts were significantly higher when the cells were co‐cultured with the intact embryos than those with the cells cultured individually (P < 0.05). Transfer of four monozygotic pairs of blastocysts derived from the cells co‐cultured with intact embryos led to three pregnancies even when the blastomeres were produced by in vitro maturation and in vitro fertilization of oocytes collected by ovum pick‐up from elite cows. These results suggest that co‐culturing with intact embryos may enhance development of bovine separated blastomere.     

Basin-scale distribution pattern and biomass estimation of Japanese anchovy Engraulis japonicus in the western North Pacific

The distribution pattern and biomass of the Japanese anchovy Engraulis japonicus in the offshore region of the western North Pacific (north of 35°N and west of 170°E) were studied using a quantitative echosounder. This is the first attempt at such a study in this region. Data were collected in summer from 2004 to 2007. The biomass was estimated using data collected at 38?kHz. Species compositions in the backscatterings from pelagic fish were assigned based on the results of trawl hauls taking account of sea surface temperature (SST). Japanese anchovy tended to be high density to the west of 153°E and were distributed in an SST range of 9?C24?°C. Although the temporal and spatial coverage of the survey differed each year, at least 1.5?C3.4 million tons of Japanese anchovy were present in the survey area between 2004 and 2007. To take account of the spatial coverage of the survey each year, the most reliable biomass estimate for this region in the time period was 3.4 million tons (coefficient of variation?0.22).