63 research outputs found

    A review of the genus Megalographa Lafontaine and Poole (Lepidoptera: Noctuidae: Plusiinae) with the description of a new species from Costa Rica

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    The classification of the genus Megalographa Lafontaine and Poole, 1991, is reviewed and the five known species diagnosed. The genus is essentially restricted to the New World, although one species M. biloba (Stephens) is migratory and has occasionally straggled to western Europe. A new species (Megalographa talamanca Lafontaine and Sullivan) endemic to the Talamanca Mountain Range in Costa Rica is described. Adults and genitalia are illustrated

    Identification of Burkholderia mallei and Burkholderia pseudomallei adhesins for human respiratory epithelial cells

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    <p>Abstract</p> <p>Background</p> <p><it>Burkholderia pseudomallei </it>and <it>Burkholderia mallei </it>cause the diseases melioidosis and glanders, respectively. A well-studied aspect of pathogenesis by these closely-related bacteria is their ability to invade and multiply within eukaryotic cells. In contrast, the means by which <it>B. pseudomallei </it>and <it>B. mallei </it>adhere to cells are poorly defined. The purpose of this study was to identify adherence factors expressed by these organisms.</p> <p>Results</p> <p>Comparative sequence analyses identified a gene product in the published genome of <it>B. mallei </it>strain ATCC23344 (locus # BMAA0649) that resembles the well-characterized <it>Yersinia enterocolitica </it>autotransporter adhesin YadA. The gene encoding this <it>B. mallei </it>protein, designated <it>boaA</it>, was expressed in <it>Escherichia coli </it>and shown to significantly increase adherence to human epithelial cell lines, specifically HEp2 (laryngeal cells) and A549 (type II pneumocytes), as well as to cultures of normal human bronchial epithelium (NHBE). Consistent with these findings, disruption of the <it>boaA </it>gene in <it>B. mallei </it>ATCC23344 reduced adherence to all three cell types by ~50%. The genomes of the <it>B. pseudomallei </it>strains K96243 and DD503 were also found to contain <it>boaA </it>and inactivation of the gene in DD503 considerably decreased binding to monolayers of HEp2 and A549 cells and to NHBE cultures.</p> <p>A second YadA-like gene product highly similar to BoaA (65% identity) was identified in the published genomic sequence of <it>B. pseudomallei </it>strain K96243 (locus # BPSL1705). The gene specifying this protein, termed <it>boaB</it>, appears to be <it>B. pseudomallei</it>-specific. Quantitative attachment assays demonstrated that recombinant <it>E. coli </it>expressing BoaB displayed greater binding to A549 pneumocytes, HEp2 cells and NHBE cultures. Moreover, a <it>boaB </it>mutant of <it>B. pseudomallei </it>DD503 showed decreased adherence to these respiratory cells. Additionally, a <it>B. pseudomallei </it>strain lacking expression of both <it>boaA </it>and <it>boaB </it>was impaired in its ability to thrive inside J774A.1 murine macrophages, suggesting a possible role for these proteins in survival within professional phagocytic cells.</p> <p>Conclusions</p> <p>The <it>boaA </it>and <it>boaB </it>genes specify adhesins that mediate adherence to epithelial cells of the human respiratory tract. The <it>boaA </it>gene product is shared by <it>B. pseudomallei </it>and <it>B. mallei </it>whereas BoaB appears to be a <it>B. pseudomallei</it>-specific adherence factor.</p

    Predicting Transcription Factor Specificity with All-Atom Models

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    The binding of a transcription factor (TF) to a DNA operator site can initiate or repress the expression of a gene. Computational prediction of sites recognized by a TF has traditionally relied upon knowledge of several cognate sites, rather than an ab initio approach. Here, we examine the possibility of using structure-based energy calculations that require no knowledge of bound sites but rather start with the structure of a protein-DNA complex. We study the PurR E. coli TF, and explore to which extent atomistic models of protein-DNA complexes can be used to distinguish between cognate and non-cognate DNA sites. Particular emphasis is placed on systematic evaluation of this approach by comparing its performance with bioinformatic methods, by testing it against random decoys and sites of homologous TFs. We also examine a set of experimental mutations in both DNA and the protein. Using our explicit estimates of energy, we show that the specificity for PurR is dominated by direct protein-DNA interactions, and weakly influenced by bending of DNA.Comment: 26 pages, 3 figure

    A revision of the Cerastis cornuta group of the genus Cerastis subgenus Metalepsis (Noctuidae)

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    Volume: 51Start Page: 237End Page: 24

    A revision of the genus Doryodes Guenée, 1857, with descriptions of six new species (Lepidoptera, Erebidae, Catocalinae, Euclidiini)

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    The genus Doryodes Guenée is revised to include ten species including six species described as new (D. desoto Lafontaine & Sullivan; D. okaloosa Sullivan & Lafontaine; D. fusselli Sullivan & Lafontaine; D. reineckei Sullivan & Lafontaine; D. broui Lafontaine & Sullivan; and D. latistriga Sullivan & Lafontaine). A key to species, descriptions, and illustrations of adults and genitalia are included

    New synonymies and combinations in Argyrostrotis Hübner (Lepidoptera, Erebidae, Erebinae, Poaphilini)

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    After examining the type specimens of species in the eastern North American genus Argyrostrotis the number of known species in the genus is reduced from 10 to six through synonymy. A key to species is included along with illustrations of the adults and genitalia of each species. Three Neotropical species currently included in Argyrostrotis (Argyrostrotis eurysaces Schaus, 1914; Argyrostrotis quadrata Dognin, 1910; and Celiptera surrufula Dyar, 1913) are transferred to other genera as Argyrosticta eurysaces (Schaus, 1914), comb. n. [Noctuidae: Bagisarinae], Heterochroma quadrata (Dognin, 1910), comb. n. [Noctuidae: Amphipyrinae], and Ptichodis surrufula (Dyar, 1913), comb. n. [Erebidae: Erebinae: Euclidiini]

    A review of the genus \u3ci\u3eMegalographa\u3c/i\u3e Lafontaine and Poole (Lepidoptera: Noctuidae: Plusiinae) with the description of a new species from Costa Rica

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    The classification of the genus Megalographa Lafontaine and Poole, 1991, is reviewed and the five known species diagnosed. The genus is essentially restricted to the New World, although one species M. biloba (Stephens) is migratory and has occasionally straggled to western Europe. A new species (Megalographa talamanca Lafontaine and Sullivan) endemic to the Talamanca Mountain Range in Costa Rica is described. Adults and genitalia are illustrated
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