New data on the morphology of the robber-fly genus <Emphasis Type="Italic">Theurgus</Emphasis> V. Richter, 1966 (Diptera,Asilidae)

Detailed photographs of the external structures of Theurgus kerzneri Lehr, 1974 and Th. zimini V. Richter, 1966 are given. Structures of the male genitalia in the genus Theurgus V. Richter, 1966 are illustrated for the first time.     

Three-Dimensional Structure of Recombinant Adenine Phosphoribosyltransferase from Thermophilic Bacterial Strain <Emphasis Type="Italic">Thermus thermophilus</Emphasis> HB27

Adenine phosphoribosyltransferase (APRT) from a thermophilic bacterial strain Thermus thermophilus НВ27 (TthHB27APRT) belongs to the family of type I phosphoribosyltransferases and catalyzes the magnesium-dependent transfer of 5'-phosphoribosyl group from 5'-phosphoribosylpyrophosphate to N9 adenine nitrogen with formation of adenosine-5'-monophosphate and pyrophosphate. The crystals of the recombinant enzyme suitable for X-ray study were grown in a capillary using the counter-diffusion technique. Crystals with unit-cell parameters α = 69.860 Å, b = 82.160 Å, c = 91.390 Å, α = 90.00°, β = 102.58°, and γ = 90.00° belong to the space group Р2₁ and contain six enzyme monomers in the asymmetric unit. The set of X-ray data from grown crystals was collected on a Spring-8 synchrotron radiation facility (Japan) and three-dimensional structure of the enzyme was solved at 2.7-Å resolution by molecular replacement method using the BALBES software. The polypeptide fold in the enzyme monomer and the structure of biologically active dimer were described. Based on the comparison with structures of homologous APRTs from a thermophilic strain ThtHB8 and Homo sapiens, positions of active site and a number of functionally important amino acids were located.     

The structural basis for the difference in absorbance spectra for the FMO antenna protein from various green sulfur bacteria

The absorbance spectrum of the Fenna-Matthews-Olson protein—a component of the antenna system of Green Sulfur Bacteria—is always one of two types, depending on the species of the source organism. The FMO from Prosthecochloris aestuarii 2K has a spectrum of type 1 while that from Chlorobaculum tepidum is of type 2. The previously reported crystal structures for these two proteins did not disclose any rationale that would explain their spectral differences. We have collected a 1.3 Å X-ray diffraction dataset of the FMO from Prosthecochloris aestuarii 2K, which has allowed us to identify an additional Bacteriochlorophyll-a molecule with chemical attachments to both sides of the central magnesium atom. A new analysis of the previously published X-ray data for the Chlorobaculum tepidum FMO shows the presence of a Bacteriochlorophyll-a molecule in an equivalent location but with a chemical attachment from only one side. This difference in binding is shown to be predictive of the spectral type of the FMO.     

Molecular and cytological analyses of A and C genomes at meiosis in synthetic allotriploid <Emphasis Type="Italic">Brassica</Emphasis> hybrids (ACC) between <Emphasis Type="Italic">B.napus</Emphasis> (AACC) and <Emphasis Type="Italic">B.oleracea</Emphasis> (CC)

Success of interspecific hybridization relies mostly on the adequate similarity between the implicated genomes to ensure synapsis, pairing and recombination between appropriate chromosomes during meiosis in allopolyploid species. Allotetraploid Brassica napus (AACC) is a model of natural hybridization between Brassica rapa (AA) and Brassica oleracea (CC), which are originally derived from a common ancestor, but genomic constitution of the same chromosomes probably varied among these species through time after establishment, giving rise to cytogenetic difference in the synthetic hybrids. Herein we investigated meiotic behaviors of A and C chromosomes of synthetic allotriploid Brassica hybrids (ACC) at molecular and cytological levels, which result from the interspecific cross between natural B. napus (AACC) and B.oleracea (CC), and the results showed that meiosis course was significantly aberrant in allotriploid Brassica hybrids, and chromosomes aligned chaotically at metaphase I, chromosome bridges and lags were frequently observed from later metaphase I to anaphase II during meiosis. Simultaneously, we also noticed that meiosis-related genes were abruptly down-regulated in allotriploid Brassica hybrids, which likely accounted for irregular scenario of meiosis observed in these synthetic hybrids. Therefore, these results indicated that inter-genomic exchanges of A and C chromosomes could occur frequently in synthetic Brassica hybrids, and provided an efficient approach for genetic changes of homeologous chromosomes during meiosis in polyploid B.napus breeding program.     

Morphological and molecular-genetic distinctions between adult mosquitoes <Emphasis Type="Italic">Culex torrentium</Emphasis> Martini and <Emphasis Type="Italic">C. pipiens</Emphasis> Linnaeus (Diptera,Culicidae) from Moscow Province

Morphological, biological, and molecular-genetic characteristics of Culex pipiens and C. torrentium, collected from two sites in Moscow and five sites in Moscow Province, were studied. Our results demonstrated the absence of any differences between females of these species in the R ₂/R ₂₊₃ ratio. Figures and photographs of the male genitalia are given. Differences between the species in the mDNA cytochrome oxydase I gene and the 1TS2 region of the rDNA were revealed. 90–100% of C. pipiens and 0% of C. torrentium were infested with the endosymbiotic bacterium Wolbachia pipientis.     

New data on the leaf beetles of the subfamily Cryptocepalinae (Coleoptera,Chrysomelidae) from Middle Asia and Afghanistan

A new leaf-beetle species, Acolastus paki sp. n., is described from Tajikistan. New data (including photographs of the aedeagus and habitus) on Acolastus afghanicus, A. anthracinus, A. karatavicus, A. lygaeus, A. nanus, A. nigrifrons, A. syrdariensis, and Tituboea elegantissima are reported.     

The histology of the scales ofOrvikuina (Palaeoniscoidea)

The analysis byØrvig of the structure of the scales ofScanilepis andOrvikuina is discussed. It is shown that the analysis, because it ignores the physical size of the scales, incorrectly leads to the conclusion that the scales ofOrvikuina show a stage of specialisation towards the higher teleostean condition further than, but of the same kind as, that shown byScanilepis. The specialisation ofOrvikuina is in fact of a different kind from that ofScanilepis.     

Genomic structure,expression and association study of the porcine <Emphasis Type="Italic">FSD2</Emphasis>

The fibronectin type III and SPRY domain containing 2 (FSD2) on porcine chromosome 7 is considered a candidate gene for pork quality, since its two domains, which were present in fibronectin and ryanodine receptor. The fibronectin type III and SPRY domains were first identified in fibronectin and ryanodine receptor, respectively, which are candidate genes for meat quality. The aim of this study was to elucidate the genomic structure of FSD2 and functions of single nucleotide polymorphisms (SNPs) within FSD2 that are related to meat quality in pigs. Using a bacterial artificial chromosome clone sequence, we revealed that porcine FSD2 consisted of 13 exons encoding 750 amino acids. In addition, FSD2 was expressed in heart, longissimus dorsi muscle, psoas muscle, and tendon among 23 kinds of porcine tissues tested. A total of ten SNPs, including four missense mutations, were identified in the exonic region of FSD2, and two major haplotypes were obtained based on the SNP genotypes of 633 Berkshire pigs. Both haplotypes were associated significantly with intramuscular fat content (IMF, P < 0.020) and moisture percentage (MP, P < 0.002). Moreover, haplotype 2 was associated with meat color, affecting yellowness (P = 0.002). These haplotype effects were further supported by the alteration of putative protein structures with amino acid substitutions. Taken together, our results suggest that FSD2 haplotypes are involved in regulating meat quality including IMF, MP, and meat color in pigs, and may be used as meaningful molecular makers to identify pigs with preferable pork quality.     

<Emphasis Type="Italic">Spirulina</Emphasis> extract-impregnated alginate-PCL nanofiber wound dressing for skin regeneration

In recent years, nanofibers have been developed and widely used in many products, such as cosmetics and medical supplies. They can be fabricated from various synthetic or natural polymers and attached to bioactive compounds. In previous research, polycaprolactone (PCL) nanofibers containing Spirulina extract were demonstrated to be effective on dermal wound healing in a rat model. In this study, we fabricated Spirulina extract-alginate PCL nanofibers using alginate, which has hydrophilic structures capable of holding large amounts of water, to support the backbone of the nanofibers. The morphological characteristics, hydrophilicity, water absorbance, skin adhesiveness, toxicity to human keratinocyte cells (HaCaT), and Spirulina extract emission over time were assessed. Alginate improved the efficacy of Spirulina PCL nanofibers in moisture maintenance and adhesion ability, which highly affected recovery in the rat skin wound model. In conclusion, Spirulina extract-alginate PCL nanofibers could be considered a promising candidate for wound care.     

Inhibitory activities against rice pathogens of 8-hydroxy-2,4,6-octatriynamide from <Emphasis Type="Italic">Agrocybe</Emphasis> sp.

8-Hydroxy-2,4,6-octatriynamide, a natural polyacetylene with inhibitory activities against rice pathogens, was isolated from the liquid fermentation broth of strain Agrocybe sp. YB2005 during screening for new natural chemical agents to control rice pathogens. 8-hydroxy-2,4,6-octatriynamide was purified by consecutive chromatography over a Cl8 reversed phase silica gel, sephadex LH-20 and silica gel. The chemical structure of 8-hydroxy-2,4,6-octatriynamide was elucidated through spectroscopic analyses, including 1D- and 2D-NMR, ESI mass spectrometry and X-ray single crystal diffraction. Bioassays showed that 8-hydroxy-2,4,6-octatriynamide could significantly inhibit growth of Xanthomonas oryzae with an MIC of 53.1 μM in a 96-well plate and the growth of Rhizoctonia solani at 1.02 mM in a 24-well plate. When rice leaves were inoculated with Magnaporthe grisea and cultured in artificial nutrition liquid containing 0.34 mM 8-hydroxy-2,4,6-octatriynamide, no rice blast was observed. The present study implied that 8-hydroxy-2,4,6-octatriynamide could be a candidate agent against rice pathogens.     

Enhancement of crystallinity of cellulose produced by <Emphasis Type="Italic">Escherichia coli</Emphasis> through heterologous expression of <Emphasis Type="Italic">bcsD</Emphasis> gene from <Emphasis Type="Italic">Gluconacetobacter xylinus</Emphasis>

Objectives

To evaluate the crystallinity index of the cellulose produced by Escherichia coli Nissle 1917 after heterologous expression of the cellulose synthase subunit D (bcsD) gene of Gluconacetobacter xylinus BPR2001.

Results

The bcsD gene of G. xylinus BPR2001 was expressed in E. coli and its protein product was visualized using SDS-PAGE. FTIR analysis showed that the crystallinity index of the cellulose produced by the recombinants was 0.84, which is 17% more than that of the wild type strain. The increased crystallinity index was also confirmed by X-ray diffraction analysis. The cellulose content was not changed significantly after over-expressing the bcsD.

Conclusion

The bcsD gene can improve the crystalline structure of the bacterial cellulose but there is not any significant difference between the amounts of cellulose produced by the recombinant and wild type E. coli Nissle 1917.

     

The structure of the claspettes in the male genitalia of the subgenus <Emphasis Type="Italic">Ochlerotatus</Emphasis> Lynch Arribalzaga of the genus <Emphasis Type="Italic">Aedes</Emphasis> Meigen (Diptera,Culicidae) and their diagnostic significance

The structure of the claspettes (modified projections in the male genitalia) in species of the subgenus Ochlerotatus Lynch Arribalzaga of the genus Aedes Meigen is described in detail. A thorough investigation of the three-dimensional structure of the claspettes is necessary for identification of the Ochlerotatus species from Russia. The study of 30 species of Ochlerotatus demonstrated that frequently the use of the claspette structure as a diagnostic character was incorrect when the claspettes were described as flat structures. Examination of the three-dimensional structure of the claspettes has revealed characters differentiating Aedes diantaeus, A. intrudens and A. pullatus; A. communis, A. punctor, and A. hexodontus; A. annulipes, A. excrucians, and A. euedes, as well as some other species.     

A New Subspecies of the Robber Fly <Emphasis Type="Italic">Dioctria meridionalis</Emphasis> Bezzi, 1898 (Diptera,Asilidae) from Daghestan

A new subspecies Dioctria meridionalis dagestanicasubsp. n. from Daghestan is described with photographs of details of the external structures and male genitalia, based on the collection of the Zoological Institute, Russian Academy of Sciences (St. Petersburg). Lectotype of Dioctria meridionalis Bezzi, 1898, described from Italy, is designated in the collection of the Zoological Institute, St. Petersburg, and its photographs are provided.     

Host plants influence female oviposition and larval performance in West Indian sweet potato weevils <Emphasis Type="Italic">Euscepes postfasciatus</Emphasis> (Coleoptera: Curculionidae)

Euscepes postfasciatus (Fairmaire) is an invasive pest of the sweet potato (Ipomoea batatas) and is also parasitic to other wild host plants of the Ipomoea genus. The population density of E. postfasciatus is sometimes greater in Ipomoea pes-caprae L. than in Ipomoea indica (Burm. f.). We investigated the desirability of I. pes-caprae as a host plant for E. postfasciatus in terms of reproductive and developmental potential. Females laid fewer eggs on I. pes-caprae, and the eclosion of their larvae was delayed compared with on I. indica. Furthermore, the larval growth rate was slower on I. pes-caprae than on I. indica. These results suggest that I. pes-caprae is not always the preferred host for egg laying and growth rate in the early developmental stages. However, the larval survival rate after the initial period of development was markedly better on I. pes-caprae than on I. indica. The present simulation study demonstrated that the population density of E. postfasciatus on I. pes-caprae overwhelmed that on I. indica over generations. Comparing the two wild host plant species, I. pes-caprae outweighs I. indica with respect to total population growth, but reproduction on I. indica may be advantageous for the colonization of the new habitat.     

Crystal and Molecular Structure of a 6-Methyluracil Photodimer

IRRADIATION of a frozen aqueous solution of thymine with 254 nm light resulted in the formation of a cyclobutyl dimer of thymine (T=T)^1–3. An analogous uracil dimer (U=U) is formed when uracil is irradiated under similar conditions^1,4. These results are of great importance in understanding the photochemistry and photobiology of nucleic acids (reviews, refs. 2,5,6). Thus much work has been carried out on the mechanistic study of the photodimerization of pyrimidines⁷. The photodimerization of α,β-unsaturated ketones may be examined similarly. As part of these studies the four dimers of 6-methyl-uracil (6 MU), for example, cis-syn, cis-anti, trans-syn and trans-anti, have been isolated in a pure state from 6 MU under a variety of conditions. The stereoconfigurations of these dimers of 6 MU=6 MU have been assigned (unpublished work) using techniques such as NMR, IR and chemical reactivities; however, the complete three-dimensional structure can only be determined by X-ray diffraction analysis. The crystal and molecular structure of a cis-syn type of 6 MU=6 MU has recently been reported⁸. In this communication we report the X-ray diffraction study of the cis-anti isomer.