50 research outputs found

    Genomic Sequence Analysis of Granulovirus Isolated from the Tobacco Cutworm, Spodoptera litura

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    Background: Spodoptera litura is a noctuid moth that is considered an agricultural pest. The larvae feed on a wide range of plants and have been recorded on plants from 40 plant families (mostly dicotyledons). It is a major pest of many crops. To better understand Spodoptera litura granulovirus (SpliGV), the nucleotide sequence of the SpliGV DNA genome was determined and analyzed. Methodology/Principal Findings: The genome of the SpliGV was completely sequenced. The nucleotide sequence of the SpliGV genome was 124,121 bp long with 61.2 % A+T content and contained 133 putative open reading frames (ORFs) of 150 or more nucleotides. The 133 putative ORFs covered 86.3 % of the genome. Among these, 31 ORFs were conserved in most completely sequenced baculovirus genomes, 38 were granulovirus (GV)-specific, and 64 were present in some nucleopolyhedroviruses (NPVs) and/or GVs. We proved that 9 of the ORFs were SpliGV specific. Conclusions/Significance: The genome of SpliGV is 124,121 bp in size. One hundred thirty-three ORFs that putatively encode proteins of 50 or more amino acid residues with minimal overlap were determined. No chitinase or cathepsin genes, which are involved in the liquefaction of the infected host, were found in the SpliGV genome, explaining why SpliGVinfected insects do not degrade in a typical manner. The DNA photolyase gene was first found in the genus Granulovirus. When phylogenic relationships were analyzed, the SpliGV was most closely related to Trichoplusia ni granulovirus (TnGV

    Molecular biology of baculovirus and its use in biological control in Brazil

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    Field trial of a genetically improved baculovirus insecticide

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    IMPROVEMENT of biological pesticides through genetic modification has enormous potential and the insect baculoviruses are particularly amenable to this approach1,2. A key aim of genetic engineering is to increase their speed of kill, primarily by the incorporation of genes which encode arthropod or bacterially derived insect-selective toxins3–11, insect hormones12,13 or enzymes14,15. We report here the first, to our knowledge, field trial of a genetically improved nuclear polyhedrosis virus of the alfalfa looper, Autogmpha californica (AcNPV) that expresses an insectselective toxin gene (AaHIT) derived from the venom of the scorpion Androclonus australisl6–18. Previous laboratory assays with the cabbage looper, Trichoplusia ni, demonstrated a 25% reduction in time to death compared to the wild-type virus, but unaltered pathogenicity6 and host range19. In the field, the modified baculovirus killed faster, resulting in reduced crop damage and it appeared to reduce the secondary cycle of infection compared to the wild-type virus

    Cortical sensitivity to contrast polarity and orientation of faces is modulated by temporal-nasal hemifield asymmetry

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    Behavioral studies demonstrate that the efficiency of detection of faces is dependent on configural and contrast polarity information characteristic to human faces. Stimulus inversion or contrast polarity reversal can disrupt this process. We investigated whether a face-sensitive event-related potential component, the N170, is modulated by the orientation and contrast polarity of highly degraded schematic face-like patterns (Experiment 1) in the same manner as it is for face photographs (Experiment 2). Inversion and/or contrast reversal delayed and enhanced the N170 for both kinds of stimuli, suggesting that a white oval with three black squares is sufficient to elicit face-sensitive cortical responses. In Experiment 3 we further tested whether the extrageniculate visual pathways modulate early cortical responses to faces. We found that the N170 responses to configural and contrast information are modulated by temporal-nasal visual field asymmetry under monocular viewing conditions, suggesting the involvement of subcortical, extrageniculate visual pathways in face detection. These results are consistent with the idea that an ontogenetically early and primitive bias to orient towards face-like patterns with relevant configural and contrast information influences the early stages of cortical face processing
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