Meiotic resumption of porcine immature oocytes is prevented by ooplasmic Gsalpha functions

A high cyclic adenosine monophosphate (cAMP) level in fully-grown immature oocytes prevents meiotic resumption. In Xenopus, inhibitory cAMP is synthesized within oocytes depending on a stimulatory alpha-subunit of G-protein (Gsalpha). In the present study, we examined whether ooplasmic Gsalpha is involved in meiotic arrest of porcine oocytes. First, we studied the presence of Gsalpha molecules in porcine oocytes by immunoblotting, and this suggested the presence of reported isoforms (45 and 48 kDa) not only in cumulus cells but also in porcine oocytes. Then we injected an anti-Gsalpha antibody into porcine immature oocytes and found that inhibition of ooplasmic Gsalpha functions significantly promoted germinal vesicle breakdown of the oocytes, whose spontaneous meiotic resumption was prevented by 3-isobutyl-l-methylxanthine (IBMX) treatment. Although cyclin B synthesis and M-phase promoting factor (MPF) activation were largely prevented until 30 h of culture in IBMX-treated oocytes, injection of anti-Gsalpha antibody into these oocytes partially recovered cyclin B synthesis and activated MPF activity at 30 h. These results suggest that meiotic resumption of porcine oocytes is prevented by ooplasmic Gsalpha, which may stimulate cAMP synthesis within porcine oocytes, and that synthesized cAMP prevents meiotic resumption of oocytes through the signaling pathways involved in MPF activation.     

High-throughput technique for comprehensive analysis of Japanese green tea quality assessment using ultra-performance liquid chromatography with time-of-flight mass spectrometry (UPLC/TOF MS)

Applications of metabolomics techniques along with chemometrics provide an understanding in the relationship between metabolome of green tea and its quality. A coupled of ultra-performance liquid chromatography with time-of-flight mass spectrometry (UPLC/TOF MS) allowed a high-throughput and comprehensive analysis with minimal sample preparation. Using this technique, a wide range of metabolites were investigated. Data analysis was rapid, considering that the fingerprinting technique was performed. A set of green tea samples from 2006 tea contest of the Kansai area was analyzed to prove usefulness of the developed technique. Green tea with different qualities were discriminated through principal component analysis (PCA). Consequently, projection to latent structure by means of partial least-squares (PLS) was performed to create a constructive quality-predictive model by means of metabolic fingerprinting. Beside epigallocatechin, other predominant catechins, including epigallocatechin gallate and epicatechin gallate, detected in green tea were found to be significant biomarkers to the high quality of Japanese green tea (Sencha).     

Influence of foliar phosphorus and nitrogen contents on chemical properties of water extractable organic matter derived from fresh and decomposed sugar maple leaves

The effects of watershed-scale experimental acidification on the macronutrient content and decomposition of sugar maple (Acer saccharum Marsh) leaves were investigated. Bear Brook Watershed in Maine (BBWM) is a paired forest watershed study where the West Bear (WB) watershed has been treated bi-monthly with 1800 eq ha^?1 yr^?1 of (NH₄)₂SO₄ since 1989, and the adjacent East Bear (EB) watershed has acted as a reference. Leaf samples collected from the treated WB watershed had significantly higher concentrations of N and P than leaves from the reference EB watershed. Leaves from both watersheds were decomposed for a 10-day laboratory incubation. Extractable total soluble carbon (C_TS) content of the leaves decreased following decomposition to a greater extent in WB leaves than in EB leaves. Spectroscopic and chromatographic chemical analyses indicated similar chemical properties for the fresh WB and EB WEOM. However, after decomposition, the WB WEOM was more humified as compared to EB WEOM indicating that the watershed treatment resulted in leaves which were more biodegradable than those in the reference watershed. Multi-dimensional fluorescence spectroscopy with parallel factor analysis (PARAFAC) modeled five components: tyrosine-like, three humic substance-like, and terrestrial/anthropogenic associated-like fluorophores. Following decomposition, the relative concentrations of two of the humic-associated components increased to a significantly greater extent for WB than for EB WEOM. These observations were consistent with greater decomposition-related changes to the WEOM from WB samples relative to EB samples. Pearson correlation analysis showed that foliar N and P concentrations were positively correlated with indices of humification. Adsorption of WEOM to goethite and gibbsite was significantly greater for decomposed WB WEOM than EB WEOM. These results demonstrate that greater leaf N and P contents can increase short-term decomposition, accelerate production of more humic-like WEOM, and thereby potentially influence the distribution of organic matter within the soil carbon pool.     

Characteristics of growth and quality,and factors contributing to high yield in newly developed rice variety ‘Akidawara’

The newly developed rice variety ‘Akidawara’ (AKI) combines the traits of high yield and highly palatability, and its cultivation is expected to spread. We examined characteristics of growth and quality, and factors contributing to high yield in AKI by comparing with ‘Nipponbare’ (NIP). Grain yield for AKI were 703 g m^?2 (9% more than NIP) and 781 g m^?2 (14% more than NIP) under the standard and heavy fertilizer regimes. It was also suggested that increase in the sink capacity was the key contributors to the high yield in AKI resulting from a conspicuous increase in the number of spikelets, which is likely due to introgression of the high-yielding variety allele. Furthermore, AKI achieved the similar degree of sink filling in spite of its larger sink capacity. In this point, panicle dry weight increase during ripening (ΔP) was significantly higher for AKI than for NIP despite the fact that no differences in shoot dry weight increase were observed between varieties. The greater ΔP in AKI might be derived from its larger sink capacity and the difference between varieties involves the translocation of nonstructural carbohydrate. In the grain quality, the reduction in perfect grain ratio was negligible and regarded as a small trade-off for AKI’s 14% increase in yield, and grain protein content increased to a lesser degree in AKI at the same yield level. These results suggest that over 700 g m^?2 high yield can be achieved with relative high grain quality and lower protein content in AKI.     

Morphological features and functions of bluefin tuna change with growth

Morphological features of Pacific bluefin tuna Thunnus orientalis have important functions for its fast swimming. Morphological features of tuna change with growth; therefore, morphological functions may develop during this process. In this study, we precisely quantified the morphology of bluefin tuna with growth from juvenile to young adult using a three-dimensional laser profiler and evaluated the fluid dynamic characteristics of tuna using computational fluid dynamics (CFD) and an accurate model based on measured data. As results of measurement of morphological features, the aspect ratio and sweepback angle, which are indices of hydrodynamic characteristics for a hydrofoil, suggested that the lift force of caudal fin was increased as the tuna grows. The results of CFD analysis showed that the coefficient of drag force gradually decreased with growth. Pectoral fins generated lift force, and the ratio of lift force to submerged weight (FL/SW) increased as the tuna grew to 0.2 m total length (TL). After the tuna exceeded 0.2 m TL, FL/SW changed to a wider range in angle of attack as the tuna grew. These results suggest that the morphological function of bluefin tuna develops to enhance its swimming ability as it grows from juvenile to young adult.     

Dimethoxypyrimidines as novel herbicides. Part 4. Quantitative structure–activity relationships of dimethoxypyrimidinyl(thio)salicylic acids

The activity of a number of O-(4,6-dimethoxypyrimidin-2-yl)salicylic acids and their thio analogs inhibiting acetolactate synthase (ALS) preparation was measured. The effects of substituents on the salicylic-benzene ring on the inhibitory activity were analyzed quantitatively with physicochemical substituent parameters. For 6-substituted (thio)salicylic acids, the activity was shown to vary parabolically with the ‘intramolecular’ steric parameter ( E_s ). In addition, the higher steric dimension of substituents in terms of the STERIMOL width or length parameter lowered the activity. The field-inductive electron-withdrawing property of the 6-substituents in terms of the Swain–Lupton–Hansch F was favorable for the activity of salicylic acid series. In 5-substituted salicylic acids, the activity was increased by electron-donating substituents with smaller size. The relationships between ALS inhibitory and herbicidal activities were also analyzed with some weed species. Both pre- and post-emergence activities against barnyard grass, Echinochloa crus-galli, were linearly related to the ALS inhibitory activity after allowing for the hydrophobic factor that may contribute to the transport processes. Those against two broad-leaved weed species, Polygonum convolvulus and Abutilon theophrasti were linearly related to the in-vitro activity with no significant participation of the hydrophobic factor. © 1998 SCI     

Distribution patterns of five pleuronectid species on the continental slope off the Pacific coast of northern Honshu,Japan

Information on the distributions of demersal and benthic fishes is fundamental for stock assessment and management. Spatiotemporal changes in the distribution patterns of five pleuronectid species (flathead flounder Hippoglossoides dubius, Kamchatka flounder Atheresthes evermanni, roughscale sole Clidoderma asperrimum, slime flounder Microstomus achne, and Korean flounder Glyptocephalus stelleri) off the Pacific coast of northern Honshu, Japan, at depths of 150–900 m, were examined using a generalized linear mixed model (GLMM). Densities of flathead and Korean flounder were highest in the southernmost area, where the fish were small. The body lengths of both of these species increased from 2003 to 2008, suggesting that an abundant year class was recruited in 2003. The density of Kamchatka flounder was highest in the northern area. In roughscale sole and slime flounder, there were no distinctive annual and latitudinal trends in the density distributions. The density distribution of Korean flounder was bimodal; the peaks were at depths of 210 and 410 m. The body length increased as the depth increased from 150 to 410 m, and then decreased from 410 to 550 m. Moreover, “bigger–deeper” trends were observed in flathead, Kamchatka and slime flounder.     

Spatiotemporal variations in nutritional status and feeding habits of immature female bighand thornyhead <Emphasis Type="Italic">Sebastolobus macrochir</Emphasis> off the Pacific coast of northern Honshu,Japan

Nutritional status and feeding habits of immature female bighand thornyhead Sebastolobus macrochir were assessed based on Fulton’s condition factor K, hepatosomatic index (HSI), and stomach observations. Fish were obtained from bottom trawl samples taken seasonally during 2006/2007 in the Tohoku area, off the Pacific coast of northern Honshu, Japan. Results of the generalized linear model (GLM) indicated that fish condition deteriorated with depth, and small fish had a lower K, HSI, and percent stomach content index (SCI) than larger specimens. The empty stomach rate was higher in deeper waters in northern Tohoku (except for small fish from spring to autumn) and in southern Tohoku (spring/summer). Changes in the index of relative importance (%IRI) showed that the main prey items changed from nutritionally high to low prey items with depth. This suggests that deeper waters, where fish with the lowest condition values occur, are a poorer quality habitat for immature bighand thornyhead and that small fish are subordinate to larger fish. The effect on growth, due to variations in nutritional status and feeding habits, produced by the distributional changes in bighand thornyhead is also discussed.