S-isorobinal as the female sex pheromone from an alarm pheromone emitting mite, Rhizoglyphus setosus

The female sex pheromone of Rhizoglyphus setosus Manson (Astigmata: Acaridae) was identified as S-isorobinal (4S-4-isopropenyl-3-oxo-1-cyclohexene-1-carboxyaldehyde), which stimulated males sexually and enhanced the frequency of the male’s tapping and mounting behavior. Although the female hexane extract indicated no sign of sex pheromone activity against tested males, possibly due to the presence of the alarm pheromone neryl formate, an SiO₂ column fraction containing isorobinal elicited sex pheromone activity at a dose of one female equivalent. The stereochemistry of natural isorobinal was identified as S by an HPLC using a chiral column. Both S- and R-isorobinals exhibited maximum activity at the same dose of 1 and 10 ng with a convex dose–response relationship. Amounts of S-isorobinal were determined to be 11.7 ± 1.0 ng per female and 6.4 ± 1.3 ng per male by GLC. This is the second example of two pheromones (the alarm pheromone neryl formate, and the sex pheromone S-isorobinal) demonstrated to be components of the same opisthonotal gland secretion.     

Loss of EGF‐dependent cell proliferation ability on radioresistant cell HepG2‐8960‐R

Acquired radioresistance of cancer cells interferes with radiotherapy and increases the probability of cancer recurrence. HepG2‐8960‐R, which is one of several clinically relevant radioresistant (CRR) cell lines, has a high tolerance to the repeated clinically relevant doses of X‐ray radiation. In this study, HepG2‐8960‐R had slightly lower cell proliferation ability than HepG2 in the presence of FBS. In particular, epidermal growth factor (EGF) hardly enhanced cell proliferation and DNA synthesis in HepG2‐8960‐R. Additionally, EGF could not induce the activation of Erk1/2, because the expression of EGF receptor (EGFR) protein decreased in HepG2‐8960‐R in accordance with the methylation of the EGFR promoter region. Therefore, cetuximab did not inhibit HepG2‐8960‐R cell proliferation. Our study showed that HepG2‐8960‐R had radioresistant and cetuximab‐resistant abilities. Copyright © 2015 John Wiley & Sons, Ltd.     

Nature of monocyclic beta-lactam antibiotic Nocardicin A to beta-lactamases

Nocardicin A is the antibiotic which was first found to possess a monocyclic beta-lactam ring. This antibiotic was inactivated by the cleavage of its beta-lactam ring. The direct spectrophotometric assay was applied to measure the rate of enzymatic hydrolysis of Nocardicin A. Nocardicin A was highly stable to both chromosomal and plasmid-mediated beta-lactamases. Of the nine beta-lactam antibiotics including cefoxitin and cefuroxime, Nocardicin A was the most stable to the beta-lactamases tested excluding those from Klebsiella oxytoca and Proteus vulgaris. The latter broad-spectrum beta-lactamases hydrolyzed Nocardicin A rather intensively. Extreme stability of Nocardicin A to beta-lactamases was suggested to be due to the combination of its low affinity to the enzymes and stabilization of its monocyclic beta-lactam ring. Nocardicin A was shown to have inducing ability toward beta-lactamases.     

Parkinson's disease-associated mutant LRRK2 phosphorylates Rab7L1 and modifies trans-Golgi morphology

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the major genetic cause of autosomal-dominantly inherited Parkinson's disease. LRRK2 is implicated in the regulation of intracellular trafficking, neurite outgrowth and PD risk in connection with Rab7L1, a putative interactor of LRRK2. Recently, a subset of Rab GTPases have been reported as substrates of LRRK2. Here we examine the kinase activity of LRRK2 on Rab7L1 in situ in cells. Phos-tag analyses and metabolic labeling assays revealed that LRRK2 readily phosphorylates Golgi-localized wild-type Rab7L1 but not mutant forms that are distributed in the cytoplasm. In vitro assays demonstrated direct phosphorylation of Rab7L1 by LRRK2. Subsequent screening using Rab7L1 mutants harboring alanine-substitution for every single Ser/Thr residue revealed that Ser72 is a major phosphorylation site, which was confirmed by using a phospho-Ser72-specific antibody. Moreover, LRRK2 pathogenic Parkinson mutants altogether markedly enhanced the phosphorylation at Ser72. The modulation of Ser72 phosphorylation in Rab7L1 resulted in an alteration of the morphology and distribution of the trans-Golgi network. These data collectively support the involvement of Rab7L1 phosphorylation in the LRRK2-mediated cellular and pathogenetic mechanisms.     

Carbohydrate interference in assays based on the periodate-coupled thiobarbituric acid reagent

Interference with a procedure for measuring free sialic acids was encountered during a study on a neuraminidase in a rabies vaccine. This led to an investigation of the ability of carbohydrates to interfere in thiobarbituric acid-based assays. In addition to glucose and glycerol, 2-ketohexoses and 6-deoxyhexoses caused little interference, while glycosides caused strong interference. The generation of substances capable of forming pigments after reaction with thiobarbituric acid was due to the fact that the amount of periodic acid added to samples was less than the amount needed for complete degradation of the carbohydrate present. Glyceraldehyde, glycolaldehyde, and hydroxymalonaldehyde appeared to be the substances reponsible for the interfering colors.     

Characterization of “Pasteurella” piscicida Isolated from White Perch and Cultivated Yellowtail

The morphological, physiological, and biochemical characteristics of twelve “Pasteurella” piscicida strains isolated from white perch and yellowtail are described and the present uncertain taxonomic status of the organisms is discussed. The organisms isolated were gram-negative rods showing bipolar staining and pleomorphism. No spores or flagella were observed. They were non motile and viscid colonies were formed. Growth was observed in a temperature range of 20 to 30 C and the salinity range of growth was between 0.5% and 4.0%. They were aerobic and facultative anaerobic. Oxidase and catalase were produced. Nitrates were not reduced to nitrites. Lysine and ornithine decarboxylases were not produced but arginine dihydrolase was produced. The egg yolk reaction was positive. Tween 80 and tributyrin were decomposed. Phosphatase was produced. Beta hemolysis was revealed on a medium containing defibrinated blood from chickens or carp but not from mammals. Methyl red and Voges–Proskauer tests were positive, and acetoin was produced from 2, 3-butanediol. Glucose was fermented without gas production. Acid was produced from fructose, mannose, galactose, sucrose, maltose, dextrin and glycerol. These organisms differed from all other members of the genus Pasteurella with respect to nitrate reduction, arginine dihydrolase, Voges–Proskauer and methyl red tests. The formation of viscid colonies and inability to grow in a medium without sodium chloride or at 37 C were additional characteristics of these organisms.     

Genome Analysis of Bacteroides by Pulsed-field Gel Electrophoresis: Chromosome Sizes and Restriction Patterns

The chromosomal DNAs of nine strains of seven Bacteroides speciesincluding B. fragilis, the type species of the genus Bacteroides,were digested with rare-cutting restriction enzymes I-Ceu I,Not I, and Asc I and analysed by pulsed-field gel electrophoresis.The genome sizes of B. fragilis, B. distasonis, B. eggerthii,B. ovatus, B. thetaiotaomicron, B. uniformis, and B. vulgatuswere determined to be 5.3, 4.8, 4.4, 6.9, 4.8, 4.6, and 5.1Mbp, respectively. B. distasonis and B. vulgatus, and also B.uniformis and B. eggerthii, showed simillar I-Ceu I restrictionprofiles. I-Ceu I cut B. uniformis and B. eggerthii genomesinto four, B. ovatus into five, B. fragilis and B. thetaiotaomicroninto six, and B. distasonis and B. vulgatus into seven fragments.On the basis of genome size, restriction profile, and I-CeuI fragment number, a phylogenetic tree of the Bacteroides specieswas proposed. This was in overall agreement with the previousphylogenetic tree obtained by 16S rRNAdata, with the exceptionsof B. distasonis and B. ovatus.     

STEEREELLA,A NEW GENUS OF HEPATICAE FROM THE WEST INDIES

In addition to the complete lack of the usual spiral bands of thickenings in the elaters, the new genus Steereella is unique among the Hepaticae for the resemblance of its cellular organization in the thalloid gametophyte to that of some moss leaves. The taxon recognized is one genus, Steereella, gen. n., and one species S. linearis (Swartz) Kuwah. comb. nov., in which the variable nature of the gametophyte is particularly noted. The genus appears to be restricted to the West Indies.