Search results for "Insect Science"
showing 10 items of 1011 documents
Patch size and connectivity influence the population turnover of the threatened chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenida…
2008
Chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenidae) has severely declined in many parts of Europe and is currently red-listed in many countries. We studied the population structure and turnover of the species in a lake-island system in a National Park in eastern Finland over a three-year period. The incidence of the chequered blue on the suitable islands (n = 41) and habitat patches (n = 123) was high: an average of 82% of the islands and patches were occupied over the three year period. At the island scale, the annual population turnover rate was 17%, with an extinction and colonization rate of 7% and 10%, respectively. At the patch scale, the annual population turnover…
De Novo prion aggregates trigger autophagy in skeletal muscle
2014
ABSTRACT In certain sporadic, familial, and infectious prion diseases, the prion protein misfolds and aggregates in skeletal muscle in addition to the brain and spinal cord. In myocytes, prion aggregates accumulate intracellularly, yet little is known about clearance pathways. Here we investigated the clearance of prion aggregates in muscle of transgenic mice that develop prion disease de novo . In addition to neurodegeneration, aged mice developed a degenerative myopathy, with scattered myocytes containing ubiquitinated, intracellular prion inclusions that were adjacent to myocytes lacking inclusions. Myocytes also showed elevated levels of the endoplasmic reticulum chaperone Grp78/BiP, su…
Calpain 1 and 2 Are Required for RNA Replication of Echovirus 1▿
2007
ABSTRACT Calpains are calcium-dependent cysteine proteases that degrade cytoskeletal and cytoplasmic proteins. We have studied the role of calpains in the life cycle of human echovirus 1 (EV1). The calpain inhibitors, including calpeptin, calpain inhibitor 1, and calpain inhibitor 2 as well as calpain 1 and calpain 2 short interfering RNAs, completely blocked EV1 infection in the host cells. The effect of the inhibitors was not specific for EV1, because they also inhibited infection by other picornaviruses, namely, human parechovirus 1 and coxsackievirus B3. The importance of the calpains in EV1 infection also was supported by the fact that EV1 increased calpain activity 3 h postinfection. …
Resistance toBacillus thuringiensis Cry1Ac toxin in three strains ofHeliothis virescens: Proteolytic and SEM study of the larval midgut
1999
In a previous study, we demonstrated that resistance to Bacillus thuringiensis toxins in Heliothis virescens might be related to differences in the composition of the proteolytic extracts from insect midgut. There, we found specific proteolytic bands present in the gut extracts of the resistant strain and absent from the susceptible one. Here we report related facts using a new resistant strain (KCB) and a cross between the two strains used in our previous study. As would be expected, no quantitative differences in total proteolytic activity were found between the strains, although qualitative differences related to the presence or absence of specific proteolytic activity bands using SDS-PA…
Complex formation between the NS3 serine-type proteinase of the hepatitis C virus and NS4A and its importance for polyprotein maturation
1995
Processing of the hepatitis C virus polyprotein is mediated by host cell signalases and at least two virally encoded proteinases. Of these, the serine-type proteinase encompassing the amino-terminal one-third of NS3 is responsible for cleavage at the four sites carboxy terminal of NS3. The activity of this proteinase is modulated by NS4A, a 54-amino-acid polyprotein cleavage product essential for processing at the NS3/4A, NS4A/4B, and NS4B/5A sites and enhancing cleavage efficiency between NS5A and NS5B. Using the vaccinia virus-T7 hybrid system to express hepatitis C virus polypeptides in BHK-21 cells, we studied the role of NS4A in proteinase activation. We found that the NS3 proteinase a…
Cell Susceptibility to Baculovirus Transduction and Echovirus Infection Is Modified by Protein Kinase C Phosphorylation and Vimentin Organization
2013
ABSTRACT Some cell types are more susceptible to viral gene transfer or virus infection than others, irrespective of the number of viral receptors or virus binding efficacy on their surfaces. In order to characterize the cell-line-specific features contributing to efficient virus entry, we studied two cell lines (Ea.hy926 and MG-63) that are nearly nonpermissive to insect-specific baculovirus (BV) and the human enterovirus echovirus 1 (EV1) and compared their characteristics with those of a highly permissive (HepG2) cell line. All the cell lines contained high levels of viral receptors on their surfaces, and virus binding was shown to be efficient. However, in nonpermissive cells, BV and it…
The Abundant Tegument Protein pUL25 of Human Cytomegalovirus Prevents Proteasomal Degradation of pUL26 and Supports Its Suppression of ISGylation
2018
The tegument of human cytomegalovirus (HCMV) virions contains proteins that interfere with both the intrinsic and the innate immunity. One protein with a thus far unknown function is pUL25. The deletion of pUL25 in a viral mutant (Towne-ΔUL25) had no impact on the release of virions and subviral dense bodies or on virion morphogenesis. Proteomic analyses showed few alterations in the overall protein composition of extracellular particles. A surprising result, however, was the almost complete absence of pUL26 in virions and dense bodies of Towne-ΔUL25 and a reduction of the large isoform pUL26-p27 in mutant virus-infected cells. pUL26 had been shown to inhibit protein conjugation with the in…
Dacnusa cicerina (Hymenoptera: Braconidae: Alysiinae), A New Species of Endoparasitoid of Liriomyza cicerina (Diptera: Agromyzidae)
2008
Abstract The larvae, pupa, adults, and venom apparatus of Dacnusa cicerina sp. n., an endoparasitoid of Liriomyza cicerina (Rondani), found on Cicer arietinum Linnaeus in Spain, are described, illustrated, and compared with those of allied species. The mature larva of Eurytoma sp., possibly a hyperparasitoid of D. cicerina, also is described, illustrated, and compared with those of allied species. Keys to discriminate adults are provided and morphological structures of phylogenetic value are discussed. The adults of D. cicerina are similar to those of Dacnusa rodriguezi Docavo & Tormos (1997). The immature larvae are similar to those of Dacnusa areolaris (Nees) and Dacnusa dryas (Nixon), an…
Ecological characteristics of pre-imaginal stages of blackflies (diptera: simuliidae) in Southern England
2021
Data on pre-imaginal stages of blackflies obtained in southern England during the summer and early autumn of 2020 were supplemented by additional surveys and analysed in relation to environmental factors. Fourteen taxa from 29 locations were recorded. Of these, seven are of medical and/or veterinary importance: Simulium (Wilhelmia) equinum (Linnaeus, 1758), S. (Boophthora) erythrocephalum (De Geer, 1776), S. (Simulium) intermedium Roubaud, 1906 sensu lato (s.l., a complex of species), S. (W.) lineatum (Meigen, 1804), S. (S.) morsitans Edwards, 1915, S. (S.) noelleri Friederichs, 1920 and S. (S.) ornatum (Meigen, 1818) s.l. Analyses of a variety of environmental factors recorded at the insec…
Quantitative structure-activity relationships for the toxicity of organophosphorus and carbamate pesticides to the Rainbow trout Onchorhyncus mykiss.
2006
This study has investigated the development of quantitative structure-activity relationships (QSARs) for the toxicity to rainbow trout Onchorhyncus mykiss Walbaum of 75 organophosphorus and carbamate pesticides. The toxicity data were obtained from an openly available toxicological database and were selected to be representative of a single endpoint. A large number of physicochemical and structural descriptors were calculated for the pesticides. QSAR models were developed using multiple linear regression and partial least-squares analyses. Following the removal of a small number of outliers, predictive QSARs were developed on small numbers of mechanistically relevant descriptors. Applying m…