Sequential expression of myogenic regulatory factors in bovine skeletal muscle and the satellite cell culture

Myogenic regulatory factors (MRFs) are important in the control of skeletal muscle development. To understand myogenic regulation by MRFs in bovine adult muscle cells, their expressions, namely that of Myf5, MyoD, myogenin, and MRF4 in the biceps femoris muscle (BF) and in the satellite cell culture, were analyzed by RT-PCR. In the BF, all four MRFs were expressed and in particular, myogenin and MRF4 were strongly expressed, whereas Myf5 was faintly expressed. The satellite cells prepared from the BF expressed Myf5, but only a trace of MyoD, at day 9 of culture. During the growth of the cells to day 14, the MyoD and myogenin expressions gradually increased, and that of MyoD expression reached its maximum at the confluence of the culture. After induction of myogenic differentiation by a serum-free medium at day 14, Myf5 expression gradually decreased, and the up-regulated expression of MyoD was suppressed, whereas myogenin expression continued to increase sharply. Following the myogenin expression, MRF4 also drastically increased toward the myotube formation of the cells. When huge myotubes were formed at day 18, Myf5 was expressed at a low level, whereas the MyoD expression remained at a moderate level.     

Commercialized European bumblebee can cause pollination disturbance: An experiment on seven native plant species in Japan

Non-native pollinator species are now widely utilized to facilitate pollination of agricultural crops. Evaluation of the ecological risk of alien pollinators is necessary because they could have a large impact on native ecosystems through disturbing native plant-pollinator interactions. We conducted a greenhouse experiment to examine the impact of the non-native commercialized European bumblebees, Bombus terrestris, on the pollination success of seven Japanese bumblebee-pollinated plant species. Plants were exposed to three groups of bumblebees: native bumblebee(s) only (NATIVE treatment); the alien bee only (ALIEN) and a mix of the two (MIX). ALIEN treatment had negative effects on fruitset and/or fruit quality of five plants, including self-incompatible and compatible, herb and woody, and queen- and worker-pollinated species. The negative effects were caused by a decrease in legitimate flower visitation due to (1) physical inaccessibility to nectary in deep-corolla flowers by the alien bee with insufficient tongue length and, (2) biased flower preference between short-corolla flowers. Fruitset tended to decrease drastically for the self-incompatible species while fruit quality decreased moderately for the self-compatible species. Effects of MIX were not intermediate between NATIVE and ALIEN in most plant species, and caused pollination success to vary in an unpredictable manner amongst plant species, probably due to interaction between native and alien bees. This non-linear relationship between plants’ pollination success and the relative density of the alien suggests that the alien bee can disturb pollination of a plant species even when only representing a small fraction of the total pollinator community.     

Cellularity of developing subcutaneous adipose tissue in Landrace and Meishan pigs: Adipocyte size differences between two breeds

Experiments were designed to compare the adipocyte cellularity of subcutaneous adipose tissue between growing Landrace (low backfat) and Meishan (high backfat) pigs at 1 week, 3 weeks, 6 weeks, 3 months and 5 months of age. As pigs aged, body weight and backfat thickness of both breeds significantly increased. When compared at equal ages, backfat thickness adjusted to equal body weight was greater for Meishan pigs. The mean diameter of fat cell size also increased with age, and by 6 weeks adipocytes from both outer and inner layers of subcutaneous adipose tissue were larger in Meishan pigs. At 5 months, approximately 80% of the adipose tissue mass in Meishan pigs was attributable to adipocytes measuring 95–165 µm in diameter, whereas adipocytes of 75–145 µm comprised most of the tissue mass in the Landrace. Although the contribution of smaller adipocytes (25–45 µm) to the tissue volume was negligible, both breeds showed a biphasic diameter distribution at all ages, suggesting that adipocyte hyperplasia is still active. Our results demonstrate that cellularity differences exist between the subcutaneous adipose tissues of Landrace and Meishan pigs, and adipocyte hypertrophy is the most overwhelming contributor to the greater backfat deposition for Meishan pigs.     

A specific and potent inhibitor of brassinosteroid biosynthesis possessing a dioxolane ring

Screening for brassinosteroid biosynthesis inhibitors was performed to find azole derivatives that induced dwarfism, to resemble brassinosteroid-deficient mutants in Arabidopsis, and which could be rescued by brassinosteroid. Through this screening experiment, propiconazole fungicide was selected as a likely inhibitor of brassinosteroid biosynthesis and, thus, propiconazole derivatives with optimized activity and selectivity were synthesized. The biological activity of these compounds was evaluated by examining cress stem elongation. Among the compounds tested, 2RS,4RS-1-[2-(4-trifluoromethylphenyl)-4-n-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole (12) showed the most potent capability to retard cress stem elongation in the light. The compound-induced hypocotyl dwarfism was restored by the coapplication of 10 nM brassinolide but not by 1 microM gibberellin. These results suggest that 12 should affect brassinosteroid biosynthesis. The potency and specificity of 12 were greater than those of brassinazole, a previously reported brassinosteroid biosynthesis inhibitor.     

Analysis of strigolactones,germination stimulants for striga and orobanche,by high-performance liquid chromatography/tandem mass spectrometry

A simple and rapid analytical method for strigolactones, germination stimulants for the root parasitic weeds witchweed (Striga spp.) and broomrape (Orobanche spp.), has been developed using high-performance liquid chromatography connected to tandem mass spectrometry (LC/MS/MS). The natural strigolactones (strigol, sorgolactone, orobanchol, and alectrol) were clearly separated and identified by LC/MS/MS. As low as 0.1 pg/microL of strigol and 0.5 pg/microL of sorgolactone could be quantified, whereas 1 pg/microL was needed for the quantification of orobanchol (S/N > 10). Using this method, it was found that red clover produces orobanchol and alectrol but not strigol. The roots of red clover seedlings were found to produce 13, 70, 58, and 65 pg of orobanchol/plant 1, 2, 3, and 4 weeks after germination, respectively.     

Biological Degradation and Chemical Oxidation Characteristics of Coke-Oven Wastewater

Biological and chemical oxidation characteristics of two kinds ofcoke-oven wastewaters, A and B, discharged from a conventional batch coke-oven and a newly developed continuous coke-oven, respectively, were studied for selecting effective treatment processes of the wastewaters. Pollutants contained in Wastewater-A could be removed by biological process with a sufficient effluent quality, while those which existed in Wastewater-Bcould not be satisfactorily removed. Microbial community structure investigation using the respiratory quinone profile clarified that Pseudomonas putida (dominant quinone: ubiquinone-9) was a dominant species in the biological treatmentsystem. The refractory organic pollutants, existed in Wastewater-B,were mineralized more effectively by Fenton's reagent than by ozone. A wastewater treatment process, in which Fenton's oxidation is followed by a biological treatment, was proposed forthe treatment of Wastewater-B based on the experimental results.     

Long-Term Observation of Fogwater Composition at two Mountainous Sites in Gunma Prefecture, Japan

We made serial observations on acid fog at Mt. Akagi and Mt. Haruna, Japan for 5 years. The altitudes of the sampling sites were 1500 m (Mt. Akagi) and 1200 m (Mt. Haruna) above sea level, and the sites were approximately 30 km apart. The average liquid water content (LWC) at Mt. Akagi and Mt. Haruna was 74 mg m^?3 and 63 mg m^?3, respectively. The pH of fogwater was 2.72–7.14 (mean 3.71) at Mt. Akagi and 2.94–6.58 (mean 3.73) at Mt. Haruna. Our long-term observations indicate that there was no significant difference in the chemical components in fogwater at both sites except for ammonium ion. However, there were some cases where the chemical components of fogwater at each site were differed remarkably even in the concurrent fog event. Nitrate and sulfate ions contributed to acidification of fogwater at Mts. Akagi and Haruna and 95% of sulfate ion in the fogwater originated from air pollution. Ammonia gas in the air was the main neutralizer of acidity in fogwater. When absorption of excessive nitric acid gas over ammonia gas in the air occurred, the pH of fogwater was lowered. Our back trajectory analysis indicated that the fogwater at Mt. Akagi was mainly affected by an air mass from the Kanto Plain, including Tokyo, while the fogwater at Mt. Haruna was influenced by an air mass from large, western cities, such as Nagoya and Osaka, as well as Tokyo.     

Comparative sequence analysis of four myosin heavy chain isoforms expressed in porcine skeletal muscles: Sequencing and characterization of the porcine myosin heavy chain slow isoform

A nucleotide sequence including the full coding region for the myosin heavy chain (MyHC) slow isoform was determined from the longissimus skeletal muscle. The deduced amino acid sequence was 1935 residues, which was the same length as the human and rat MyHC-slow isoforms. The porcine MyHC-slow isoform showed 97.6% and 97.4% amino acid identities to the human and rat isoforms on their entire regions, respectively. The functional regions were also highly conserved among mammalian MyHC-slow isoforms. Amino acid substitutions between the porcine MyHC-slow and MyHC-fast isoforms were concentrated on the functional regions. Loop 1, the controlling region of nucleotide binding and release, was conserved among the fast isoforms, but not between the slow and fast isoforms. Loop 2, a part of the actin binding region, was not conserved among any of the isoform types, and the most substitutions in this region were found in the slow isoform. The myosin essential light chain binding region was conserved among the fast isoforms, except for some substitutions in the 2b isoform, but was clearly different in the slow isoform. The myosin regulatory light chain binding region was conserved among the fast isoforms, but not between the slow and fast isoforms. These results indicate that the functional difference between the porcine MyHC-slow and -fast isoforms are controlled by the sequence diversity at the four functional regions compared.     

Detection of the esp gene in high-level gentamicin resistant Enterococcus faecalis strains from pet animals in Japan

We investigated the prevalence of the esp gene and the susceptibility to gentamicin in Enterococcus faecalis and E. faecium strains obtained from pet animals. Nine of 30 E. faecalis and 2 of 38 E. faecium strains from the pet animals had the esp gene. Three esp-positive E. faecalis strains, which were isolated from two dogs and a cat, showed gentamicin MICs of > or =256 microg/ml and harbored the high-level gentamicin resistance (HLGR) gene, aac(6')-Ie-aph(2')-Ia. Of the nine esp-positive E. faecalis strains, five, including the three strains with the HLGR gene, were closely related by numerical analysis of PFGE patterns. Longitudinal investigation needs to elucidate whether the HLGR gene was incorporated into a subpopulation of the esp-positive E. faecalis.