Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in the Russian Far East

Field surveys were conducted from 2008 to 2011 in the Khabarovsk and Vladivostok regions of Russia to investigate the occurrence of emerald ash borer, Agrilus planipennis Fairmaire, and mortality factors affecting its immature stages. We found emerald ash borer infesting both introduced North American green ash (Fraxinus pennsylvanica Marshall) and native oriental ashes (F. mandshurica Rupr. and F. rhynchophylla Hance) in both regions. Emerald ash borer densities (larvae/m(2) of phloem area) were markedly higher on green ash (11.3-76.7 in the Khabarovsk area and 77-245 in the Vladivostok area) than on artificially stressed Manchurian ash (2.2) or Oriental ash (10-59). Mortality of emerald ash borer larvae caused by different biotic factors (woodpecker predation, host plant resistance and/or undetermined diseases, and parasitism) varied with date, site, and ash species. In general, predation of emerald ash borer larvae by woodpeckers was low. While low rates (3-27%) of emerald ash borer larval mortality were caused by undetermined biotic factors on green ash between 2009 and 2011, higher rates (26-95%) of emerald ash borer larval mortality were caused by putative plant resistance in Oriental ash species in both regions. Little (<1%) parasitism of emerald ash borer larvae was observed in Khabarovsk; however, three hymenopteran parasitoids (Spathius sp., Atanycolus nigriventris Vojnovskaja-Krieger, and Tetrastichus planipennisi Yang) were observed attacking third - fourth instars of emerald ash borer in the Vladivostok area, parasitizing 0-8.3% of emerald ash borer larvae infesting Oriental ash trees and 7.3-62.7% of those on green ash trees (primarily by Spathius sp.) in two of the three study sites. Relevance of these findings to the classical biological control of emerald ash borer in newly invaded regions is discussed.     

Transient expression and activity of human DNA polymerase iota in loach embryos

Human DNA polymerase iota (Pol ι) is a Y-family DNA polymerase with unusual biochemical properties and not fully understood functions. Pol ι preferentially incorporates dGTP opposite template thymine. This property can be used to monitor Pol ι activity in the presence of other DNA polymerases, e.g. in cell extracts of tissues and tumors. We have now confirmed the specificity and sensitivity of the method of Pol ι activity detection in cell extracts using an animal model of loach Misgurnus fossilis embryos transiently expressing human Pol ι. The overexpression of Pol ι was shown to be accompanied by an increase in abnormalities in development and the frequency of pycnotic nuclei in fish embryos. Further analysis of fish embryos with constitutive or regulated Pol ι expression may provide insights into Pol ι functions in vertebrate animals.     

Modulation of Mytilus trossulus (Bivalvia: Mollusca) larval survival and growth in culture. Short communication

Commercial importance and ability to live in a wide range of salinities have made the common mussel, Mytilus trossulus, a relevant model to study modulation of larval growth and development. We investigated the effects of various salinities combined with neomycin and ampicillin application on Mytilus larvae survival and growth. Both neomycin and ampicillin enhanced trochophore and veliger survival under condition of low salinity. The average veliger size was increasing in accordance with the increase of salinity. In case of neomycin treatment 3.6% of the larvae reached the pediveliger stage. No abnormalities of larval morphology of the FMRFamide and 5-HT systems occurred after 7 days of culturing with both antibiotics.     

Alteration of the acetylcholine response by intra- and extracellular serotonin application in intracellularly perfused neurons ofLymnaea stagnalis

1. The effect of serotonin on the acetylcholine (ACh) response has been studied by means of voltage clamp and intracellular perfusion in unidentified isolated neurons from parietal and visceral ganglia of Lymnaea stagnalis. 2. In most cells studied serotonin added to the internal or external solution decreases the response to ACh. 3. In other neurons serotonin added to the intracellular solution increases the response to ACh; when it is added extracellularly it produces the opposite effect on the same cells. 4. The decreasing effect of serotonin on ACh currents is mimicked by cyproheptadine, an antagonist of serotonin receptors, and by the intracellular application of cyclic AMP (cAMP) forskolin. 5. The enhancing effect of intracellularly applied serotonin on ACh currents is blocked by cyproheptadine and is not obtained by the intracellular administration of cAMP and forskolin. In some cells the enhancing effect of serotonin appears after forskolin. 6. The results suggest a modulating effect of serotonin on cholinergic synaptic transmission in the nervous system of mollusks. The possible existence of intracellular serotonin receptors is discussed.     

Studies on Dysmetabolic Uratemia-Associated Nephropathy in Children of the Turkmenistan Arid Region

Dysmetabolic uratemia-associated nephropathy was studied in virtually healthy children of the preschool and early school age (27 patients) in Turkmenistan in autumn and in winter. All of the children had uricemia and/or uricosuria of various levels (moderately increased and the highest level). The decreased diuresis and glomerular filtration, nicturia or monotonic urine excretion, the increased relative urine density, the urinary syndrome, the data of ultrasonic examination, uricemia uricosuria suggest (of different level) a diagnosis of dysmetabolic, or urate, nephropathy. The urate nephropathy is specified by a decrease in the creatinine and urea excretion along with an increased excretion of uric acid. The elevated or high level to be caused by a metabolic disorder in purine metabolism and seems to be determined by a hereditary hyperproduction of uric acid due to deficiency of the hypoxanthine guanine phosphorybosyl transferase enzyme.     

LET-767 is required for the production of branched chain and long chain fatty acids in Caenorhabditis elegans

LET-767 from Caenorhabditis elegans belongs to a family of short chain dehydrogenases/reductases and is homologous to 17beta-hydroxysterol dehydrogenases of type 3 and 3-ketoacyl-CoA reductases. Worms subjected to RNA interference (RNAi) of let-767 displayed multiple growth and developmental defects in the first generation and arrested in the second generation as L1 larvae. To determine the function of LET-767 in vivo, we exploited a biochemical complementation approach, in which let-767 (RNAi)-arrested larvae were rescued by feeding with compounds isolated from wild type worms. The arrest was only rescued by the addition of triacylglycerides extracted from worms but not from various natural sources, such as animal fats and plant oils. The mass spectrometric analyses showed alterations in the fatty acid content of triacylglycerides. Essential for the rescue were odd-numbered fatty acids with monomethyl branched chains. The rescue was improved when worms were additionally supplemented with long chain even-numbered fatty acids. Remarkably, let-767 completely rescued the yeast 3-ketoacyl-CoA reductase mutant (ybr159Delta). Because worm ceramides exclusively contain a monomethyl branched chain sphingoid base, we also investigated ceramides in let-767 (RNAi). Indeed, the amount of ceramides was greatly reduced, and unusual sphingoid bases were observed. Taken together, we conclude that LET-767 is a major 3-ketoacyl-CoA reductase in C. elegans required for the bulk production of monomethyl branched and long chain fatty acids, and the developmental arrest in let-767 (RNAi) worms is caused by the deficiency of the former.     

Functional analysis of Leishmania major cyclophilin

A potent immunosuppressive drug cyclosporin A (CsA) is known to inhibit human cell infection by the pathogenic protozoan parasite Leishmania major both in vitro and in vivo. The proposed mechanism of action involves CsA binding to Leishmania major-expressed cyclophilin and subsequent down-regulation of signaling events necessary for establishing productive infection. Recently, we identified a ubiquitously expressed membrane protein, CD147, as a signaling receptor for extracellular cyclophilins in mammalian cells. Here we demonstrate that, while being enzymatically active, the Leishmania cyclophilin, unlike its human homologue, does not interact with CD147 on the cell surface of target cells. CD147 facilitates neither Leishmania binding nor infection. Primary structure and biochemical analyses revealed that the parasite's cyclophilin is defective in heparan binding, an event required for signaling interaction between CD147 and human cyclophilin. When the heparan-binding motif was reconstituted in Leishmania cyclophilin, it regained the CD147-dependent signaling activity. These results underscore a critical role of cyclophilin-heparan interactions in CD147-mediated signaling events and argue against the role of Leishmania cyclophilin in parasite binding to target cells.     

Two loci on chromosome 15 control experimentally induced arthritis through the differential regulation of IL-6 and lymphocyte proliferation

Using genetic linkage analysis of proteoglycan-induced arthritis (PGIA), a murine model for rheumatoid arthritis, we identified two loci, Pgia8 and Pgia9, on chromosome 15 (chr15) that appear to be implicated in disease susceptibility. Immunization of congenic strains carrying the entire chr15 and separately each of the two loci of DBA/2 arthritis-resistant origin in susceptible BALB/c background confirmed locations of two loci on chr15: the major Pgia9 and lesser Pgia8 locus. Distal part of chr15 (Pgia9) showed a major suppressive effect on PGIA susceptibility in females (40%, p < 0.001), whereas the effect of this locus in congenic males was still significant but weaker. Proximal part of chr15 (Pgia8) demonstrated mild and transient effect upon arthritis; this effect was PGIA-promoting in males and suppressive in females. Pgia8 and Pgia9 loci demonstrated an additive mode of inheritance, since when they were both incorporated in consomic chr15 strain, the total effect was a sum of the two loci. Using F(2) population of the intercross of wild-type and chr15 consomic strain, we confirmed and refined quantitative trait locus positions and identified a strong correlation between disease susceptibility and lymphocyte-producing cytokines of TNF-alpha and IL-6. Both Pgia8 and Pgia9 loci on chr15 appear to control IL-6 production in spleen cultures of arthritic mice, providing an important link to the mechanism of autoimmune inflammation.     

Effect of Supporting Substrates on the Structure of DNA and DNA–Trivaline Complexes Studied by Atomic Force Microscopy

Linear DNA, circular DNA, and circular DNA complexes with trivaline (TV), a synthetic oligopeptide, were imaged by atomic force microscopy (AFM) using mica as a conventional supporting substrate and modified highly ordered pyrolytic graphite (HOPG) as an alternative substrate. A method of modifying the HOPG surface was developed that enabled the adsorption of DNA and DNA–TV complexes onto this surface. On mica, both purified DNA and DNA–TV complexes were shown to undergo significant structural distortions: DNA molecules decrease in height and DNA–TV displays substantial changes in the shape of its circular compact structures. Use of the HOPG support helps preserve the structural integrity of the complexes and increase the measured height of DNA molecules up to 2 nm. AFM with the HOPG support was shown to efficiently reveal the particular points of the complexes where, according to known models of their organization, a great number of bent DNA fibers meet. These results provide additional information on DNA organization in its complexes with TV and are also of methodological interest, since the use of the modified HOPG may widen the possibilities of AFM in studying DNA and its complexes with various ligands.