Complete mitochondrial DNA sequence of the Japanese anchovy Engraulis japonicus

ABSTRACT: The complete nucleotide sequence of the mitochondrial genome for the Japanese anchovy Engraulis japonicus (Teleostei: Clupeiformes) was determined. The entire genome was purified by gene amplification using the long polymerase chain reaction (PCR) technique, and products were subsequently used as templates for PCR with 56 fish-versatile primers that amplify contiguous, overlapping segments of the entire genome. Direct sequencing of the PCR products demonstrated that the genome (16 675 base pairs [bp]) contained the same 37 mitochondrial genes (two ribosomal RNA, 22 transfer RNA and 13 protein-coding genes) as those found in other vertebrates, with the gene order being identical to that in typical vertebrates. A major non-coding region between the tRNA^Pro and tRNA^Phe genes (1024 bp) was considered to be the control (D-loop) region, as it has several conservative blocks characteristic to this region.     

Production of Avaroferrin and Putrebactin by Heterologous Expression of a Deep-Sea Metagenomic DNA

The siderophore avaroferrin (1), an inhibitor of Vibrio swarming that was recently identified in Shewanella algae B516, was produced by heterologous expression of the biosynthetic gene cluster cloned from a deep-sea sediment metagenomic DNA, together with two analogues, bisucaberin (2) and putrebactin (3). Avaroferrin (1) is a macrocyclic heterodimer of N-hydroxy-N-succinyl cadaverine (4) and N-hydroxy-N-succinyl-putrescine (5), whereas analogues 2 and 3 are homodimers of 4 and 5, respectively. Heterologous expression of two other related genes from culturable marine bacteria resulted in production of compounds 1–3, but in quite different proportions compared with production through expression of the metagenomic DNA.     

Effect of taurine supplemented practical diet on growth performance and taurine contents in whole body and tissues of juvenile Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis>

ABSTRACT:   The effect of dietary taurine on juvenile Japanese flounder was determined by feeding three taurine-supplemented experimental diets (TAU) and a commercial diet (CD) to evaluate a practical diet for juvenile Japanese flounder. Juvenile Japanese flounder were reared on the three experimental diets supplemented with taurine at 0, 0.5, 1.0% and CD. These diets were fed to juvenile Japanese flounder of an initial mean body weight of 0.2 g for 6 weeks at 20°C and the taurine contents of the whole body and tissues were analyzed. The final average body weight of juvenile Japanese flounder fed the 1.0% TAU was significantly higher than that of the other groups. Taurine contents in the whole body and tissues increased with the increase in dietary taurine level. These results indicate that juvenile Japanese flounder require at least 15 mg/g taurine in the diet, even though a combined mix of fish, krill and squid meal was the main protein source in the experimental diets.     

Validation of multi-frequency inversion method by using dummy scatterers of zooplankton

ABSTRACT:   High- and multi-frequency acoustic measurement systems and the multi-frequency inversion (MFI) method have been used to measure spatial distributions and abundances of zooplankton by size. In this study, the calibration method for high- and multi-frequency systems was developed and the validation of MFI method was carried out by scatterer measurement. The standard sphere calibration method that has not been applied to such high- and multi-frequencies was applied to calibrate our high- and multi-frequency system, TAPS-6 (Tracor Acoustic Profiling System, BAE Systems). An optimum size of standard sphere of tungsten carbide of 1 mm radius was derived to have a small target strength variation for the six frequencies of TAPS-6, and the practicability and precision of the standard sphere calibration method was confirmed for those frequencies. A school or cluster of dummy scatterers of zooplankton with small tungsten carbide spheres were designed to validate the MFI method, and volume back-scattering strength values were measured by the multi-frequency system. By comparing the result of the inversion with their real composition, the features of the MFI method could be validated and examined.     

Preliminary evidence of growth factor(s) from chicken thrombocytes--growth effects on chicken embryo fibroblasts culture

The thrombocyte extracts (TE) and thrombocyte-secretion products (TSP) prepared from chicken peripheral blood were examined for the growth activity of chicken embryo fibroblasts (CEF). When the cells were incubated with TE and TSP, the enhancement of cell spreading was observed within one hour after seeding, but the control culture showed little spreading. Three to six days after cell seeding, the increase of the cell densities in the culture supplemented with TE and TSP was noticed in comparison with the culture without thrombocyte materials. The results strongly indicate the possibility for the presence of thrombocyte-derived growth factor(s) to CEF.     

RFLP/AFLP mapping of a brown planthopper (Nilaparvata lugens Stål) resistance gene Bph1 in rice

We have constructed a linkage map of the rice brown planthopper (BPH)resistance gene, Bph1. RFLP and AFLP markers were selected by thebulked segregant analysis and used in the mapping study of 262 F₂sthat were derived from a cross of `Tsukushibare', a susceptible japonica cultivar, and `Norin-PL3', an authentic japonicaBph1-introgression line. Twenty markers were mapped within a 28.9-cMregion containing the Bph1 locus on the long arm of rice chromosome12. Combining the result of segregation analysis of BPH resistance by themass seedling test and that of the markers, the Bph1 locus wasmapped within a 5.8-cM region between two flanking markers. The closestAFLP markers, em5814N and em2802N, was at 2.7 cM proximal to theBph1 locus. Together with the previously constructed high-resolutionmap of bph2 locating the locus at ca. 10 cM proximal to the Bph1 locus, this improved version of the linkage map would facilitatepyramiding these two important BPH resistance genes.     

Leaf-lamina conductance contributes to an equal distribution of water delivery in current-year shoots of kudzu-vine shoot, Pueraria lobata

Leaf-lamina resistance, R(L), accounts for a large fraction of branch resistance across a wide range of plant species. This work hypothesized that large R(L) is essential for distributing water equally to leaves on the shoot, and tested this hypothesis through theoretical analyses and measurements using over 10-m-long current-year shoots of kudzu vine, Pueraria lobata [Willd.] Ohwi. First, the hydraulic architecture and the distribution of the motive force achieving equal distribution of water delivery were theoretically obtained by simulating water flow through a hypothetical shoot comprising an axial pathway and several lateral pathways as a stem and leaves, respectively, in a kudzu-vine shoot. The model predicts that large resistance of the lateral pathway relative to that of the axial pathway is associated strongly with small variation in the hydraulic conductance of a pathway from the base of the axial pathways to the lateral pathway among the nodes, rendering water delivery to each lateral pathway equal under small variation in motive force for water flow. For the kudzu-vine shoot, the measured ratio of the lateral (a petiole) to the axial (a stem) resistance was 115. When R(L) was added to the lateral pathway, the ratio increased to 1136. According to the model prediction, these values imply that the hydraulic conductance of a pathway comprising a stem and a petiole, K(BP), is favored strongly at the basal nodes, while the hydraulic conductance of a pathway including a stem, a petiole and a lamina, K(SL), is slightly different across the nodes. For the shoots with leaf lamina, the diurnal change in transpiration rate was not different between the leaves on the three nodes dividing the shoot into four parts. K(SL) was not related significantly to node number. Conversely, K(BP) at the distal node was ~0.06-fold that at the basal node. Furthermore, the motive force for water flow should vary by 6.64-fold among nodes to compensate for the favored distribution of K(BP), which is an unrealistic value. These results indicate that R(L) contributes largely to an equal distribution of water delivery in a shoot, supporting our hypothesis.     

Simulations of a quasi-Taylor state geomagnetic field including polarity reversals on the Earth Simulator

High-resolution, low-viscosity geodynamo simulations have been carried out on the Earth Simulator, one of the fastest supercomputers, in a dynamic regime similar to that of Earth's core, that is, in a quasi-Taylor state. Our dynamo models exhibit features of the geodynamo not only in spatial and temporal characteristics but also in dynamics. Polarity reversals occurred when magnetic flux patches at high latitudes moved poleward and disappeared; patches with reversed field at low and mid-latitudes then moved poleward.     

Endothelin: a novel peptide in the posterior pituitary system

Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, is present in the porcine spinal cord and may act as a neuropeptide. Endothelin-like immunoreactivity has now been demonstrated by immunohistochemistry in the paraventricular and supraoptic nuclear neurons and their terminals in the posterior pituitary of the pig and the rat. The presence of ET in the porcine hypothalamus was confirmed by reversed-phase high-pressure liquid chromatography and radioimmunoassay. Moreover, in situ hybridization demonstrated ET messenger RNA in porcine paraventricular nuclear neurons. Endothelin-like immunoreactive products in the posterior pituitary of the rat were depleted by water deprivation, suggesting a release of ET under physiological conditions. These findings indicate that ET is synthesized in the posterior pituitary system and may be involved in neurosecretory functions.