Inter- and intra-population variations in diapause attribute of the two-spotted spider mite,Tetranychus urticae Koch,in Japan

Populations of the two-spotted spider mite, Tetranychus urticae Koch collected from various localities and from various host plants in Japan showed wide variations in diapause attribute. Diapause percentages at 18°C/9L15D varied from nearly 100% in the north to 0% in the south-west. At intermediate latitudes the mites showed wide inter-population variations. Populations on herbaceous hosts in vinyl- or glass-houses gave significantly lower incidence of diapause than those on roses and deciduous fruit trees. Presence of winter hosts and better host quality under protected environments seemed to favour non-diapausing mites. The temperature threshold for diapause expression also varied widely among local populations. Northern populations consistently had higher and less variable thresholds than populations at intermediate latitudes with thresholds between 15 and 18°C. Inbred lines derived from a population in Kyoto exhibited a wide variation in diapause percentage at 18°C. These results show that diapause in T. urticae is a quantitative threshold trait and that populations in central Japan consist of a variety of genotypes with different diapause traits. This might provide a genetic source for adaptation to local and temporal variations in environmental conditions.     

Chirality in Distorted Square Planar Pd(O,N)2 Compounds

Salicylidenimine palladium(II) complexes trans‐Pd(O,N)₂ adopt step and bowl arrangements. A stereochemical analysis subdivides 52 compounds into 41 step and 11 bowl types. Step complexes with chiral N‐substituents and all the bowl complexes induce chiral distortions in the square planar system, resulting in Δ/Λ configuration of the Pd(O,N)₂ unit. In complexes 1 , 2 , 3 , 4 , 5 , 6 with enantiomerically pure N‐substituents ligand chirality entails a specific square chirality and only one diastereomer assembles in the lattice. Dimeric Pd(O,N)₂ complexes with bridging N‐substituents in trans‐arrangement are inherently chiral. For dimers 7 , 8 , 9 , 10 , 11 different chirality patterns for the Pd(O,N)₂ square are observed. The crystals contain racemates of enantiomers. In complex 12 two independent molecules form a tight pair. The (R_C) configuration of the ligand induces the same Δ chirality in the Pd(O,N)₂ units of both molecules with varying square chirality due to the different crystallographic location of the independent molecules. In complexes 13 and 14 atrop isomerism induces specific configurations in the Pd(O,N)₂ bowl systems. The square chirality is largest for complex 15 [(Diop)Rh(PPh₃)Cl)], a catalyst for enantioselective hydrogenation. In the lattice of 15 two diastereomers with the same (R_C,R_C) configuration in the ligand Diop but opposite Δ and Λ square configurations co‐crystallize, a rare phenomenon in stereochemistry. Chirality 25:663–667, 2013. © 2013 Wiley Periodicals, Inc.     

Novel mutations of CDKN1C in Japanese patients with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an imprinting-related human disease that is characterized by macrosomia, macroglossia, abdominal wall defects, and variable minor features. BWS is caused by several genetic/epigenetic alterations, such as loss of methylation at KvDMR1, gain of methylation at H19-DMR, paternal uniparental disomy of chromosome 11, CDKN1C mutations, and structural abnormalities of chromosome 11. CDKN1C is an imprinted gene with maternal preferential expression, encoding for a cyclin-dependent kinase (CDK) inhibitor. Mutations in CDKN1C are found in 40 % of familial BWS cases with dominant maternal transmission and in ~5 % of sporadic cases. In this study, we searched for CDKN1C mutations in 37 BWS cases that had no evidence for other alterations. We found five mutations—four novel and one known—from a total of six patients. Four were maternally inherited and one was a de novo mutation. Two frame-shift mutations and one nonsense mutation abolished the QT domain, containing a PCNA-binding domain and a nuclear localization signal. Two missense mutations occurred in the CDK inhibitory domain, diminishing its inhibitory function. The above-mentioned mutations were predicted by in silico analysis to lead to loss of function; therefore, we strongly suspect that such anomalies are causative in the etiology of BWS.     

Macroinvertebrate assemblages in an artificial habitat—a settling basin of a hydroelectric power plant: comparison with a natural riffle habitat

The macroinvertebrate assemblages in an artificial habitat, the settling basin of a hydroelectric power plant, were investigated and compared with those in a natural habitat, riffles in a nearby river. This study showed that macroinvertebrate density was much higher in the settling basin than in the riffles. Macroinvertebrate assemblage composition differed between the settling basin and the riffles. The difference was probably due to the widespread bryophyte beds in the settling basin. Cincticostella, Brachycentrus, Ephmerella, and chironomid midges, which are usually abundant in bryophyte beds, were present at much higher densities in the settling basin. Cheumatopsyche and Taeniopterygidae were also present at higher densities in the settling basin than in the natural riffles. In contrast, Epeorus was present at lower density in the settling basin than in the natural riffles. This study suggests that the settling basin increases β-diversity in riverine ecosystems.     

Synthesis of amide compounds of ferulic acid,and their stimulatory effects on insulin secretion in vitro

We prepared amide compounds which were derived from ferulic acid using various amines, and investigated their stimulatory effects on insulin secretion using rat pancreatic RIN-5F cells. Most of these compounds exhibited significant promotion of the insulin-release at a concentration of 10 microM and in particular, the amides having n-butyl, n-pentyl, pyrrolidine, and piperidine groups showed high activity.     

Purification and characterization of a novel aminoacylase from Streptomyces mobaraensis

A novel aminoacylase was purified to homogeneity from culture broth of Streptomyces mobaraensis, as evidenced by SDS-polyacrylamide gel electrophoresis (PAGE). The enzyme was a monomer with an approximate molecular mass of 100 kDa. The purified enzyme was inhibited by the presence of 1,10-phenanthroline and activated by the addition of Co2+. It was stable at temperatures of up to 60 degrees C for 1 h at pH 7.2. It showed broad substrate specificity to N-acetylated L-amino acids. It catalyzed the hydrolysis of the amide bonds of various N-acetylated L-amino acids, except for Nepsilon-acetyl-L-lysine and N-acetyl-L-proline. Hydrolysis of N-acetyl-L-methionine and N-acetyl-L-histidine followed Michaelis-Menten kinetics with K(m) values of 1.3+/-0.1 mM and 2.7+/-0.1 mM respectively. The enzyme also catalyzed the deacetylation of 7-aminocephalosporanic acid (7-ACA) and cephalosporin C. Moreover, feruloylamino acids and L-lysine derivatives of ferulic acid derivatives were synthesized in an aqueous buffer using the enzyme.     

Manganese(IV) oxide production by Acremonium sp. strain KR21-2 and extracellular Mn(II) oxidase activity

Ascomycetes that can deposit Mn(III, IV) oxides are widespread in aquatic and soil environments, yet the mechanism(s) involved in Mn oxide deposition remains unclear. A Mn(II)-oxidizing ascomycete, Acremonium sp. strain KR21-2, produced a Mn oxide phase with filamentous nanostructures. X-ray absorption near-edge structure (XANES) spectroscopy showed that the Mn phase was primarily Mn(IV). We purified to homogeneity a laccase-like enzyme with Mn(II) oxidase activity from cultures of strain KR21-2. The purified enzyme oxidized Mn(II) to yield suspended Mn particles; XANES spectra indicated that Mn(II) had been converted to Mn(IV). The pH optimum for Mn(II) oxidation was 7.0, and the apparent half-saturation constant was 0.20 mM. The enzyme oxidized ABTS [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] (pH optimum, 5.5; Km, 1.2 mM) and contained two copper atoms per molecule. Moreover, the N-terminal amino acid sequence (residues 3 to 25) was 61% identical with the corresponding sequence of an Acremonium polyphenol oxidase and 57% identical with that of a Myrothecium bilirubin oxidase. These results provide the first evidence that a fungal multicopper oxidase can convert Mn(II) to Mn(IV) oxide. The present study reinforces the notion of the contribution of multicopper oxidase to microbially mediated precipitation of Mn oxides and suggests that Acremonium sp. strain KR21-2 is a good model for understanding the oxidation of Mn in diverse ascomycetes.