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Qili Feng - One of the best experts on this subject based on the ideXlab platform.

  • molecular cloning and structural characterization of ecdysis triggering hormone from Choristoneura fumiferana
    International Journal of Biological Macromolecules, 2016
    Co-Authors: Bhagath P Kumar, Peter J. Krell, Arthur Retnakaran, Qili Feng, Daniel Doucet, Kasi Viswanath, Tuleshwori S Devi, Sampath R Kumar, Dinakara Rao Ampasala
    Abstract:

    At the end of each stadium, insects undergo a precisely orchestrated process known as ecdysis which results in the replacement of the old cuticle with a new one. This physiological event is necessary to accommodate growth in arthropods since they have a rigid chitinous exoskeleton. Ecdysis is initiated by the direct action of Ecdysis Triggering Hormones on the central nervous system. Choristoneura fumiferana is a major defoliator of coniferous forests in Eastern North America. It is assumed that, studies on the ecdysis behavior of this pest might lead to the development of novel pest management strategies. Hence in this study, the cDNA of CfETH was cloned. The open reading frame of the cDNA sequence was found to encode three putative peptides viz., Pre-Ecdysis Triggering Hormone (PETH), Ecdysis Triggering Hormone (ETH), and Ecdysis Triggering Hormone Associated Peptide (ETH-AP). The CfETH transcript was detected in the epidermal tissue of larval and pupal stages, but not in eggs and adults. In order to explore the structural conformation of ETH, ab initio modelling and Molecular Dynamics (MD) Simulations were performed. Further, a library of insecticides was generated and virtual screening was performed to identify the compounds displaying high binding capacity to ETH.

  • an epidermis specific chitin synthase cdna in Choristoneura fumiferana cloning characterization developmental and hormonal regulated expression
    Archives of Insect Biochemistry and Physiology, 2011
    Co-Authors: Dinakar R Ampasala, Peter J. Krell, Arthur Retnakaran, Tim R Ladd, Daniel Doucet, Sichun Zheng, Dayu Zhang, Qili Feng
    Abstract:

    Chitin synthase catalyzes chitin synthesis in the exoskeleton, tracheal system and gut during insect development. A chitin synthase 1 (CfCHS1) cDNA was identified and cloned from the spruce budworm, Choristoneura fumiferana. The CfCHS1 cDNA is 5,300 bp in length and codes a 1,564-amino acid protein with a molecular mass of 178 kDa. The deduced protein contains 16 transmembrane helixes in its domains A and C. The single copy CfCHS1 gene expressed during each of the larval molts from the 3rd to the 6th instar. The gene expressed highly and periodically in the epidermis during each of molts, whereas no transcripts were detected in the midgut and fat body. 20-hydroxyecdysone and the ecdysone agonist RH5992 suppressed CfCHS1 expression, whereas the juvenile hormone analog methoprene induced CfCHS1 expression. These results implicate that CfCHS1 is involved in the chitin synthase and new chitin formation during molting in the insect. © 2010 Wiley Periodicals, Inc.

  • cloning expression and localization of a trypsin like serine protease in the spruce budworm Choristoneura fumiferana
    Insect Science, 2009
    Co-Authors: Yiping Zheng, Michel Cusson, Catherine Béliveau, Daniel Doucet, Sichun Zheng, Lin Tang, Qili Feng
    Abstract:

    A trypsin-like molting-related serine protease cDNA (CfMRSP) was cloned from the spruce budworm, Choristoneura fumiferana. The full-length CfMRSP comple- mentary DNA (cDNA) encoded a 43 kDa protein that contained a trypsin-like serine protease catalytic domain, but no clip domain. The C-terminal extension contained five cystein residues, which may allow the protein to form a homodimer through interchain disulfide bonds and regulate the activity of CfMRSP. Phylogenetic tree analysis showed that CfMRSP clusters with lepidopteran homologues such as serine protease 1 of Lonomia obliqua, hemolymph proteinase 20 (HP20), pattern recognition serine proteinase precursor (ProHP14) and a trypsin-like protein of Manduca sexta. Northern blot analysis of devel- opmental expression of CfMRSP indicated that its transcripts were found primarily in the epidermis and were produced during all of the tested stadia, from 4th instar larvae to pupae, but increased levels of CfMRSP transcripts were always found after each molt. A high level of the protein was found in the epidermis by immunohistochemistry analysis. Altogether these data suggest that CfMRSP plays a role in the epidermis during molting and metamorphosis.

  • cloning expression and characterization of four serpin 1 cdna variants from the spruce budworm Choristoneura fumiferana
    Comparative Biochemistry and Physiology B, 2009
    Co-Authors: Y P Zheng, Michel Cusson, Catherine Béliveau, Daniel Doucet, Sichun Zheng, A Nisole, Don Stewart, Qili Feng
    Abstract:

    Four cDNAs (Cfserpin-1a, Cfserpin-1b, Cfserpin-1c and Cfserpin-1d) of the Choristoneura fumiferana serpin-1 gene were cloned from an epidermis cDNA library. Analysis of the deduced amino acid sequences indicated that the cloned cDNAs encode four different proteins displaying identical N- but distinct C-termini, the latter region containing the inhibitory loop. The entire CfSerpin-1 gene is transcribed while the variants are generated. Antibodies generated against the purified recombinant serpins cross-reacted with the other three. Each of the four Cfserpin-1 cDNA variants was transcribed throughout larval development, from the 4th to the 6th instar, but transcript levels during the intermolt phases were generally higher than during the molting phase. The epidermis and fat body had higher levels of Cfserpin-1 transcripts than the midgut. Cfserpin-1 proteins, detected with the Cfserpin-1a antibody, were found in the epidermis, midgut, fat body, plasma and molting fluid of 6th instar larvae and pre-pupae. Prepupal and pupal insects had higher levels of the proteins than the 6th instar feeding larvae, despite a drop in transcript levels. Cfserpin-1a could bind with the serine proteinase elastase and form a complex in vitro. We hypothesize that the cloned serpins could be involved in the regulation of cuticle degradation during the insect molting cycle.

  • cloning expression and localization of a molt related β n acetylglucosaminidase in the spruce budworm Choristoneura fumiferana
    Archives of Insect Biochemistry and Physiology, 2008
    Co-Authors: Basil M Arif, Peter J. Krell, Qili Feng, Daniel Doucet, Y P Zheng
    Abstract:

    A β-N-acetylglucosaminidase cDNA (Cf GlcNAcase) was cloned from the spruce budworm, Choristoneura fumiferana. Western blotting analysis of developmental Cf GlcNAcase expression revealed high levels of expression of the gene on the last day of the 5th instar larvae and the first day in the 6th instar larvae, followed by a decrease to background levels during the intermolt of the 6th instar. Cf GlcNAcase was detected again from the last day of the 6th instar to day 2 of pupal stage. Cf GlcNAcase expression was induced by tebufenozide at 24 h post treatment and remained at high levels until 72 h. Immunohistochemical localization analysis of Cf GlcNAcase indicated that Cf GlcNAcase was present in the molting fluid, epidermis, trachea, and hemolymph in prepupae during the transformation from larva to pupa. Cf GlcNAcase cDNA was expressed into a recombinant protein in bacterial and baculovirus systems and the protein expressed in the baculovirus system had a higher chitinolytic activity than in the bacterial system and appeared to be secreted. Arch. Insect Biochem. Physiol. 68:49–59, 2008. © 2008 Wiley-Liss, Inc.

Michel Cusson - One of the best experts on this subject based on the ideXlab platform.

  • genome wide snps resolve phylogenetic relationships in the north american spruce budworm Choristoneura fumiferana species complex
    Molecular Phylogenetics and Evolution, 2017
    Co-Authors: Julian R Dupuis, Bryan M. T. Brunet, Lisa M. Lumley, H M Bird, Giovanny Fagua, Brian Boyle, Roger C Levesque, Michel Cusson
    Abstract:

    High throughput sequencing technologies have revolutionized the potential to reconcile incongruence between gene and species trees, and numerous approaches have been developed to take advantage of these advances. Genotyping-by-sequencing is becoming a regular tool for gathering phylogenetic data, yet comprehensive evaluations of phylogenetic methods using these data are sparse. Here we use multiple phylogenetic and population genetic methods for genotyping-by-sequencing data to assess species relationships in a group of forest insect pests, the spruce budworm (Choristoneura fumiferana) species complex. With few exceptions, all methods agree on the same relationships, most notably placing C. pinus as basal to the remainder of the group, rather than C. fumiferana as previously suggested. We found strong support for the monophyly of C. pinus, C. fumiferana, and C. retiniana, but more ambiguous relationships and signatures of introgression in a clade of western lineages, including C. carnana, C. lambertiana, C. occidentalis occidentalis, C. occidentalis biennis, and C. orae. This represents the most taxonomically comprehensive genomic treatment of the spruce budworm species group, which is further supported by the broad agreement among multiple methodologies.

  • composition of the spruce budworm Choristoneura fumiferana midgut microbiota as affected by rearing conditions
    PLOS ONE, 2015
    Co-Authors: Mathieu Landry, Michel Cusson, Andre M Comeau, Nicolas Derome, Roger C Levesque
    Abstract:

    The eastern spruce budworm (Choristoneura fumiferana) is one of the most destructive forest insect pests in Canada. Little is known about its intestinal microbiota, which could play a role in digestion, immune protection, communication and/or development. The present study was designed to provide a first characterization of the effects of rearing conditions on the taxonomic diversity and structure of the C. fumiferana midgut microbiota, using a culture-independent approach. Three diets and insect sources were examined: larvae from a laboratory colony reared on a synthetic diet and field-collected larvae reared on balsam fir or black spruce foliage. Bacterial DNA from the larval midguts was extracted to amplify and sequence the V6-V8 region of the 16S rRNA gene, using the Roche 454 GS-FLX technology. Our results showed a dominance of Proteobacteria, mainly Pseudomonas spp., in the spruce budworm midgut, irrespective of treatment group. Taxonomic diversity of the midgut microbiota was greater for larvae reared on synthetic diet than for those collected and reared on host plants, a difference that is likely accounted for by several factors. A greater proportion of bacteria from the phylum Bacteroidetes in insects fed artificial diet constituted the main difference between this group and those reared on foliage; within the phylum Proteobacteria, the presence of the genus Bradyrhizobium was also unique to insects reared on artificial diet. Strikingly, a Bray-Curtis analysis showed important differences in microbial diversity among the treatment groups, pointing to the importance of diet and environment in defining the spruce budworm midgut microbiota.

  • cloning expression and characterization of an insect geranylgeranyl diphosphate synthase from Choristoneura fumiferana
    Insect Biochemistry and Molecular Biology, 2013
    Co-Authors: Aline Barbar, Michel Cusson, Catherine Béliveau, Manon Couture, Stephanie E Sen, Audrey Nisole, Marie Bipfubusa
    Abstract:

    Geranylgeranyl diphosphate synthase (GGPPS) catalyzes the condensation of the non-allylic diphosphate, isopentenyl diphosphate (IPP; C5), with allylic diphosphates to generate the C20 prenyl chain (GGPP) used for protein prenylation and diterpenoid biosynthesis. Here, we cloned the cDNA of a GGPPS from the spruce budworm, Choristoneura fumiferana, and characterized the corresponding recombinant protein (rCfGGPPS). As shown for other type-III GGPPSs, rCfGGPPS preferred farnesyl diphosphate (FPP; C15) over other allylic substrates for coupling with IPP. Unexpectedly, rCfGGPPS displayed inhibition by its FPP substrate at low IPP concentration, suggesting the existence of a mechanism that may regulate intracellular FPP pools. rCfGGPPS was also inhibited by its product, GGPP, in a competitive manner with respect to FPP, as reported for human and bovine brain GGPPSs. A homology model of CfGGPPS was prepared and compared to human and yeast GGPPSs. Consistent with its enzymological properties, CfGGPPS displayed a larger active site cavity that can accommodate the binding of FPP and GGPP in the region normally occupied by IPP and the allylic isoprenoid tail, and the binding of GGPP in an alternate orientation seen for GGPP binding to the human protein. To begin exploring the role of CfGGPPS in protein prenylation, its transcripts were quantified by qPCR in whole insects, along with those of other genes involved in this pathway. CfGGPPS was expressed throughout insect development and the abundance of its transcripts covaried with that of other prenylation-related genes. Our qPCR results suggest that geranylgeranylation is the predominant form of prenylation in whole C. fumiferana.

  • spruce budworm, Choristoneura fumiferana
    2013
    Co-Authors: Catherine Be Liveau, Michel Cusson, Marle Ne Laforge, Guy Bellemare
    Abstract:

    The endoparasitic wasp Tranosema rostrale (Ichneumonidae) transmits a polydnavirus (PDV) to its host, Choristoneura fumiferana, during oviposition. Unlike most other PDVs examined, the virus of T. rostrale (TrPDV) does not appear to play an important role in suppressing the host cellular immune response. However, it inhibits host metamorphosis. In the present study, TrPDV gene expression was examined in parasitized and virus-injected last-instar caterpillars. Northern analysis with viral DNA as a probe revealed only one detectable mRNA, of about 650 bp. The corresponding cDNA, termed TrV1, was cloned and sequenced and found to encode a protein of 103 amino acids which, following cleavage of the putative signal peptide, has a predicted molecular mass of 9�3 kDa. This protein displays limited similarity to the VHv1.4 cysteine-rich protein from the PDV of Campoletis sonorensis, mostly within the signal peptide region. By using a TrV1-specific probe, the TrV1 gene was localized to segment G of the TrPDV genome. The cuticle and fat body were identified as the principal sites of TrV1 transcription, with little transcription observed in haemocytes and midgut. Western analysis of proteins extracted from selected tissues of parasitized insects suggested that the TrV1 protein is secreted in the haemolymph. As observed for other PDVs, injection of TrPDV did not suppress transcription of the gene that encodes juvenile hormone esterase, the activity of which is inhibited by the virus. We speculate that the TrV1 protein may play a role in the inhibition of C. fumiferana metamorphosis

  • cloning expression and localization of a trypsin like serine protease in the spruce budworm Choristoneura fumiferana
    Insect Science, 2009
    Co-Authors: Yiping Zheng, Michel Cusson, Catherine Béliveau, Daniel Doucet, Sichun Zheng, Lin Tang, Qili Feng
    Abstract:

    A trypsin-like molting-related serine protease cDNA (CfMRSP) was cloned from the spruce budworm, Choristoneura fumiferana. The full-length CfMRSP comple- mentary DNA (cDNA) encoded a 43 kDa protein that contained a trypsin-like serine protease catalytic domain, but no clip domain. The C-terminal extension contained five cystein residues, which may allow the protein to form a homodimer through interchain disulfide bonds and regulate the activity of CfMRSP. Phylogenetic tree analysis showed that CfMRSP clusters with lepidopteran homologues such as serine protease 1 of Lonomia obliqua, hemolymph proteinase 20 (HP20), pattern recognition serine proteinase precursor (ProHP14) and a trypsin-like protein of Manduca sexta. Northern blot analysis of devel- opmental expression of CfMRSP indicated that its transcripts were found primarily in the epidermis and were produced during all of the tested stadia, from 4th instar larvae to pupae, but increased levels of CfMRSP transcripts were always found after each molt. A high level of the protein was found in the epidermis by immunohistochemistry analysis. Altogether these data suggest that CfMRSP plays a role in the epidermis during molting and metamorphosis.

Peter J. Krell - One of the best experts on this subject based on the ideXlab platform.

  • identification and expression analysis of multiple small heat shock protein genes in spruce budworm Choristoneura fumiferana l
    Cell Stress & Chaperones, 2018
    Co-Authors: Guoxing Quan, Jun Duan, Tim R Ladd, Peter J. Krell
    Abstract:

    Fifteen small heat shock protein (sHSP) genes were identified from spruce budworm, Choristoneura fumiferana (L.), an important native forest pest in North America. The transcript levels of each CfHSP were measured under non-stress conditions in all life stages from egg to adult and in five different larval tissues. CfHSP transcript levels showed variation during development, with highest levels in adults and lowest in eggs. Most CfHSP transcripts are highly expressed in larval fat body and Malpighian tubules; two CfHSPs display extremely high expression in the head and epidermis. Upon heat stress, nine CfHSP genes are significantly upregulated, increasing by 50- to 2500-fold depending on developmental stage and tissue type. Upon starvation, eight CfHSPs are upregulated or downregulated, whereas six others retain constant expression. These results suggest that CfHSPs have important and multiple roles in spruce budworm development and in response to heat stress and starvation.

  • molecular cloning and structural characterization of ecdysis triggering hormone from Choristoneura fumiferana
    International Journal of Biological Macromolecules, 2016
    Co-Authors: Bhagath P Kumar, Peter J. Krell, Arthur Retnakaran, Qili Feng, Daniel Doucet, Kasi Viswanath, Tuleshwori S Devi, Sampath R Kumar, Dinakara Rao Ampasala
    Abstract:

    At the end of each stadium, insects undergo a precisely orchestrated process known as ecdysis which results in the replacement of the old cuticle with a new one. This physiological event is necessary to accommodate growth in arthropods since they have a rigid chitinous exoskeleton. Ecdysis is initiated by the direct action of Ecdysis Triggering Hormones on the central nervous system. Choristoneura fumiferana is a major defoliator of coniferous forests in Eastern North America. It is assumed that, studies on the ecdysis behavior of this pest might lead to the development of novel pest management strategies. Hence in this study, the cDNA of CfETH was cloned. The open reading frame of the cDNA sequence was found to encode three putative peptides viz., Pre-Ecdysis Triggering Hormone (PETH), Ecdysis Triggering Hormone (ETH), and Ecdysis Triggering Hormone Associated Peptide (ETH-AP). The CfETH transcript was detected in the epidermal tissue of larval and pupal stages, but not in eggs and adults. In order to explore the structural conformation of ETH, ab initio modelling and Molecular Dynamics (MD) Simulations were performed. Further, a library of insecticides was generated and virtual screening was performed to identify the compounds displaying high binding capacity to ETH.

  • an epidermis specific chitin synthase cdna in Choristoneura fumiferana cloning characterization developmental and hormonal regulated expression
    Archives of Insect Biochemistry and Physiology, 2011
    Co-Authors: Dinakar R Ampasala, Peter J. Krell, Arthur Retnakaran, Tim R Ladd, Daniel Doucet, Sichun Zheng, Dayu Zhang, Qili Feng
    Abstract:

    Chitin synthase catalyzes chitin synthesis in the exoskeleton, tracheal system and gut during insect development. A chitin synthase 1 (CfCHS1) cDNA was identified and cloned from the spruce budworm, Choristoneura fumiferana. The CfCHS1 cDNA is 5,300 bp in length and codes a 1,564-amino acid protein with a molecular mass of 178 kDa. The deduced protein contains 16 transmembrane helixes in its domains A and C. The single copy CfCHS1 gene expressed during each of the larval molts from the 3rd to the 6th instar. The gene expressed highly and periodically in the epidermis during each of molts, whereas no transcripts were detected in the midgut and fat body. 20-hydroxyecdysone and the ecdysone agonist RH5992 suppressed CfCHS1 expression, whereas the juvenile hormone analog methoprene induced CfCHS1 expression. These results implicate that CfCHS1 is involved in the chitin synthase and new chitin formation during molting in the insect. © 2010 Wiley Periodicals, Inc.

  • Autographa californica multiple nucleopolyhedrovirus and Choristoneura fumiferana multiple nucleopolyhedrovirus v-cath genes are expressed as pre-proenzymes.
    The Journal of general virology, 2009
    Co-Authors: Jeffrey J. Hodgson, Basil M Arif, Peter J. Krell
    Abstract:

    Intracellular processing and trafficking of the baculovirus v-cath expressed cathepsin (V-CATH), which lacks canonical targeting signals, are poorly understood. The cathepsins of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), Choristoneura fumiferana multiple nucleopolyhedrovirus (CfMNPV) and most other alphabaculovirus group I nucleopolyhedroviruses have well-conserved N-termini containing overlapping chymotrypsin-cleavage (Y(11)) and myristoylation (G(12)) motifs, which are suggestive of proteolytic signal-peptide cleavage to generate proV-CATH and subsequent acylation. To determine proteolytic N-terminal processing of V-CATH, haemagglutinin epitope-coding tags were fused to the 5' and/or 3' ends of AcMNPV and CfMNPV v-cath. Immunoblot analysis suggested that a small N-terminal peptide is cleaved for both viruses, indicating that v-cath is expressed as a pre-proenzyme. The two viral homologues undergo similar proteolytic processing, but have different glycosylation or other post-translational modifications. An AcMNPV V-CATH-DsRED fusion protein co-localized to the endoplasmic reticulum with an HDEL motif-containing green fluorescent protein. Based on these findings, pre-proV-CATH processing and trafficking mechanisms are postulated.

  • cloning expression and localization of a molt related β n acetylglucosaminidase in the spruce budworm Choristoneura fumiferana
    Archives of Insect Biochemistry and Physiology, 2008
    Co-Authors: Basil M Arif, Peter J. Krell, Qili Feng, Daniel Doucet, Y P Zheng
    Abstract:

    A β-N-acetylglucosaminidase cDNA (Cf GlcNAcase) was cloned from the spruce budworm, Choristoneura fumiferana. Western blotting analysis of developmental Cf GlcNAcase expression revealed high levels of expression of the gene on the last day of the 5th instar larvae and the first day in the 6th instar larvae, followed by a decrease to background levels during the intermolt of the 6th instar. Cf GlcNAcase was detected again from the last day of the 6th instar to day 2 of pupal stage. Cf GlcNAcase expression was induced by tebufenozide at 24 h post treatment and remained at high levels until 72 h. Immunohistochemical localization analysis of Cf GlcNAcase indicated that Cf GlcNAcase was present in the molting fluid, epidermis, trachea, and hemolymph in prepupae during the transformation from larva to pupa. Cf GlcNAcase cDNA was expressed into a recombinant protein in bacterial and baculovirus systems and the protein expressed in the baculovirus system had a higher chitinolytic activity than in the bacterial system and appeared to be secreted. Arch. Insect Biochem. Physiol. 68:49–59, 2008. © 2008 Wiley-Liss, Inc.

Arthur Retnakaran - One of the best experts on this subject based on the ideXlab platform.

  • molecular cloning and structural characterization of ecdysis triggering hormone from Choristoneura fumiferana
    International Journal of Biological Macromolecules, 2016
    Co-Authors: Bhagath P Kumar, Peter J. Krell, Arthur Retnakaran, Qili Feng, Daniel Doucet, Kasi Viswanath, Tuleshwori S Devi, Sampath R Kumar, Dinakara Rao Ampasala
    Abstract:

    At the end of each stadium, insects undergo a precisely orchestrated process known as ecdysis which results in the replacement of the old cuticle with a new one. This physiological event is necessary to accommodate growth in arthropods since they have a rigid chitinous exoskeleton. Ecdysis is initiated by the direct action of Ecdysis Triggering Hormones on the central nervous system. Choristoneura fumiferana is a major defoliator of coniferous forests in Eastern North America. It is assumed that, studies on the ecdysis behavior of this pest might lead to the development of novel pest management strategies. Hence in this study, the cDNA of CfETH was cloned. The open reading frame of the cDNA sequence was found to encode three putative peptides viz., Pre-Ecdysis Triggering Hormone (PETH), Ecdysis Triggering Hormone (ETH), and Ecdysis Triggering Hormone Associated Peptide (ETH-AP). The CfETH transcript was detected in the epidermal tissue of larval and pupal stages, but not in eggs and adults. In order to explore the structural conformation of ETH, ab initio modelling and Molecular Dynamics (MD) Simulations were performed. Further, a library of insecticides was generated and virtual screening was performed to identify the compounds displaying high binding capacity to ETH.

  • an epidermis specific chitin synthase cdna in Choristoneura fumiferana cloning characterization developmental and hormonal regulated expression
    Archives of Insect Biochemistry and Physiology, 2011
    Co-Authors: Dinakar R Ampasala, Peter J. Krell, Arthur Retnakaran, Tim R Ladd, Daniel Doucet, Sichun Zheng, Dayu Zhang, Qili Feng
    Abstract:

    Chitin synthase catalyzes chitin synthesis in the exoskeleton, tracheal system and gut during insect development. A chitin synthase 1 (CfCHS1) cDNA was identified and cloned from the spruce budworm, Choristoneura fumiferana. The CfCHS1 cDNA is 5,300 bp in length and codes a 1,564-amino acid protein with a molecular mass of 178 kDa. The deduced protein contains 16 transmembrane helixes in its domains A and C. The single copy CfCHS1 gene expressed during each of the larval molts from the 3rd to the 6th instar. The gene expressed highly and periodically in the epidermis during each of molts, whereas no transcripts were detected in the midgut and fat body. 20-hydroxyecdysone and the ecdysone agonist RH5992 suppressed CfCHS1 expression, whereas the juvenile hormone analog methoprene induced CfCHS1 expression. These results implicate that CfCHS1 is involved in the chitin synthase and new chitin formation during molting in the insect. © 2010 Wiley Periodicals, Inc.

  • diapause disruption with tebufenozide for early instar control of the spruce budworm Choristoneura fumiferana
    Pest Management Science, 2007
    Co-Authors: Daniel Doucet, Basil M Arif, Subba Reddy Palli, Michel Cusson, Éric Bauce, Bill L Tomkins, Caroline Frisco, Arthur Retnakaran
    Abstract:

    In North America, the eastern spruce budworm, Choristoneura fumiferana Clem., is an important coniferous pest against which tebufenozide has proven effective as a control product. By acting as an ecdysone agonist, tebufenozide can induce precocious moulting in late (fifth–sixth) instars but can also be carried over to the next generation owing to its persistence on foliage. The authors conducted laboratory experiments on first-instar larvae treated with tebufenozide dissolved in acetone. Larvae exposed to doses equal to or above 0.1 µg cm−2 displayed precocious moulting in the second instar after hibernaculum spinning, which effectively disrupted diapause. Larger doses induced moulting in first instars. Evidence is provided that this dose–response difference is related to whether or not an effective dose of tebufenozide is ingested by the first instar prior to the peak of moulting hormone (20-hydroxyecdysone) in first instars. Doses ineffective to kill first instars are carried over to the second instar, where they induce a precocious moult. This type of response to tebufenozide is dependent on the presence of a moulting machinery (the EcR–USP receptor complex) that is ready for ecdysone transduction. Interestingly, ecdysone levels are low in second instars, as measured by a radioimmunoassay, which suggests that diapause in spruce budworm is maintained by a suppression of ecdysone production. Thus, diapause disruption by tebufenozide may well provide an alternative control strategy for this important pest. Copyright © 2007 Society of Chemical Industry

  • dna versus protein immunisation for production of monoclonal antibodies against Choristoneura fumiferana ecdysone receptor cfecr
    Vaccine, 2006
    Co-Authors: Danhui Yang, Basil M Arif, Subba Reddy Palli, Arthur Retnakaran, Qili Feng, Amina Makhmoudova, Peter J. Krell
    Abstract:

    The full-length ecdysone receptor cDNA of Choristoneura fumiferana (CfEcR-B) was cloned into bacterial expression systems and the recombinant protein was expressed either with a His-tag (His-EcR-B) or glutathione-S-transferase (GST) fusion (GST-EcR-B). The His-EcR-B was expressed mostly as insoluble aggregates, while the GST-EcR-B was partially soluble and could be purified using affinity chromatography. Mice were then immunised with the purified GST-EcR-B protein. Due to the time-consuming protein expression and purification procedures and the solubility problem of the recombinant protein, we also inserted the full-length CfEcR-B cDNA into the mammalian DNA vaccine expression vector, pVAC1-mcs for DNA immunisation. In vitro expression of CfEcR-B in mammalian cells transfected with the pVAC-EcR-B plasmid was confirmed prior to the delivery of the DNA vaccine into mice. The anti-CfEcR-B MAbs generated from both DNA and protein vaccines were characterised and shown to recognise native CfEcR-B protein induced by 20E in CF-203 insect cells. DNA immunisation was shown to overcome the solubility problem of the bacterial expressed EcR and created a more direct route for monoclonal antibody production for this receptor protein obviating the need for EcR expression and purification to generate the antigen.

  • cloning and expression of a putative transferrin cdna of the spruce budworm Choristoneura fumiferana
    Insect Biochemistry and Molecular Biology, 2004
    Co-Authors: Basil M Arif, Peter J. Krell, Arthur Retnakaran, Dinakara Rao Ampasala, S Zheng, Qili Feng
    Abstract:

    Abstract A spruce budworm ( Choristoneura fumiferana ) transferrin cDNA (CfTf) was isolated and cloned from a cDNA library that was constructed using mRNA from fifth to sixth instar larvae. CfTf cDNA encoded a predicted protein of 681 amino acids with a molecular mass of approximately 76 kDa. CfTf shared 72% and 74% identities at the amino acid level with transferrins of Manduca sexta and Bombyx mori , respecitvely. Like other transferrins, CfTf retains most of the N-terminal, iron-binding amino acid residues. Northern blot analyses indicated that CfTf mRNA was present at high levels after ecdysis, but that the expression level was low prior to ecdysis at the fourth–sixth instar stages. The highest level of CfTf expression was detected in the fat body. Relatively low levels of expression were detected in the epidermis and no expression was found in the midgut. Expression of CfTf mRNA could be induced by bacteria but not fungi. Expression of CfTf mRNA was suppressed by iron load.

Basil M Arif - One of the best experts on this subject based on the ideXlab platform.

  • Autographa californica multiple nucleopolyhedrovirus and Choristoneura fumiferana multiple nucleopolyhedrovirus v-cath genes are expressed as pre-proenzymes.
    The Journal of general virology, 2009
    Co-Authors: Jeffrey J. Hodgson, Basil M Arif, Peter J. Krell
    Abstract:

    Intracellular processing and trafficking of the baculovirus v-cath expressed cathepsin (V-CATH), which lacks canonical targeting signals, are poorly understood. The cathepsins of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), Choristoneura fumiferana multiple nucleopolyhedrovirus (CfMNPV) and most other alphabaculovirus group I nucleopolyhedroviruses have well-conserved N-termini containing overlapping chymotrypsin-cleavage (Y(11)) and myristoylation (G(12)) motifs, which are suggestive of proteolytic signal-peptide cleavage to generate proV-CATH and subsequent acylation. To determine proteolytic N-terminal processing of V-CATH, haemagglutinin epitope-coding tags were fused to the 5' and/or 3' ends of AcMNPV and CfMNPV v-cath. Immunoblot analysis suggested that a small N-terminal peptide is cleaved for both viruses, indicating that v-cath is expressed as a pre-proenzyme. The two viral homologues undergo similar proteolytic processing, but have different glycosylation or other post-translational modifications. An AcMNPV V-CATH-DsRED fusion protein co-localized to the endoplasmic reticulum with an HDEL motif-containing green fluorescent protein. Based on these findings, pre-proV-CATH processing and trafficking mechanisms are postulated.

  • cloning expression and localization of a molt related β n acetylglucosaminidase in the spruce budworm Choristoneura fumiferana
    Archives of Insect Biochemistry and Physiology, 2008
    Co-Authors: Basil M Arif, Peter J. Krell, Qili Feng, Daniel Doucet, Y P Zheng
    Abstract:

    A β-N-acetylglucosaminidase cDNA (Cf GlcNAcase) was cloned from the spruce budworm, Choristoneura fumiferana. Western blotting analysis of developmental Cf GlcNAcase expression revealed high levels of expression of the gene on the last day of the 5th instar larvae and the first day in the 6th instar larvae, followed by a decrease to background levels during the intermolt of the 6th instar. Cf GlcNAcase was detected again from the last day of the 6th instar to day 2 of pupal stage. Cf GlcNAcase expression was induced by tebufenozide at 24 h post treatment and remained at high levels until 72 h. Immunohistochemical localization analysis of Cf GlcNAcase indicated that Cf GlcNAcase was present in the molting fluid, epidermis, trachea, and hemolymph in prepupae during the transformation from larva to pupa. Cf GlcNAcase cDNA was expressed into a recombinant protein in bacterial and baculovirus systems and the protein expressed in the baculovirus system had a higher chitinolytic activity than in the bacterial system and appeared to be secreted. Arch. Insect Biochem. Physiol. 68:49–59, 2008. © 2008 Wiley-Liss, Inc.

  • development of an oligonucleotide based dna microarray for transcriptional analysis of Choristoneura fumiferana nucleopolyhedrovirus cfmnpv genes
    Journal of Virological Methods, 2007
    Co-Authors: Danhui Yang, Basil M Arif, Mehrnoosh Barari, Peter J. Krell
    Abstract:

    A modified oligonucleotide-based two-channel DNA microarray was developed for characterization of temporal expression profiles of select Choristoneura fumiferana nucleopolyhedrovirus (CfMNPV) ORFs including its 7 unique ORFs. The microarray chip contained oligonucleotide probes for 23 CfMNPV ORFs and their complements as well as five host genes. Total RNA was isolated at different times post infection from Cf203 insect cells infected with CfMNPV. The cDNA was synthesized, fluorescent labelled with Cy3, and co-hybridized to the microarray chips along with Cy5-labelled viral genomic DNA, which served as equimolar reference standards for each probe. Transcription of the 7 CfMNPV unique ORFs was detected using DNA microarray analysis and their temporal expression profiles suggest that they are functional genes. The expression levels of three host genes varied throughout virus infection and therefore were unsuitable for normalization between microarrays. The DNA microarray results were compared to quantitative RT-PCR (qRT-PCR). Transcription of the non-coding (antisense) strands of some of the CfMNPV select genes including the polyhedrin gene, was also detected by array analysis and confirmed by qRT-PCR. The polyhedrin antisense transcript, based on long-range RT-PCR analysis, appeared to be a read-through product of an adjacent ORF in the same orientation as the antisense transcript.

  • diapause disruption with tebufenozide for early instar control of the spruce budworm Choristoneura fumiferana
    Pest Management Science, 2007
    Co-Authors: Daniel Doucet, Basil M Arif, Subba Reddy Palli, Michel Cusson, Éric Bauce, Bill L Tomkins, Caroline Frisco, Arthur Retnakaran
    Abstract:

    In North America, the eastern spruce budworm, Choristoneura fumiferana Clem., is an important coniferous pest against which tebufenozide has proven effective as a control product. By acting as an ecdysone agonist, tebufenozide can induce precocious moulting in late (fifth–sixth) instars but can also be carried over to the next generation owing to its persistence on foliage. The authors conducted laboratory experiments on first-instar larvae treated with tebufenozide dissolved in acetone. Larvae exposed to doses equal to or above 0.1 µg cm−2 displayed precocious moulting in the second instar after hibernaculum spinning, which effectively disrupted diapause. Larger doses induced moulting in first instars. Evidence is provided that this dose–response difference is related to whether or not an effective dose of tebufenozide is ingested by the first instar prior to the peak of moulting hormone (20-hydroxyecdysone) in first instars. Doses ineffective to kill first instars are carried over to the second instar, where they induce a precocious moult. This type of response to tebufenozide is dependent on the presence of a moulting machinery (the EcR–USP receptor complex) that is ready for ecdysone transduction. Interestingly, ecdysone levels are low in second instars, as measured by a radioimmunoassay, which suggests that diapause in spruce budworm is maintained by a suppression of ecdysone production. Thus, diapause disruption by tebufenozide may well provide an alternative control strategy for this important pest. Copyright © 2007 Society of Chemical Industry

  • dna versus protein immunisation for production of monoclonal antibodies against Choristoneura fumiferana ecdysone receptor cfecr
    Vaccine, 2006
    Co-Authors: Danhui Yang, Basil M Arif, Subba Reddy Palli, Arthur Retnakaran, Qili Feng, Amina Makhmoudova, Peter J. Krell
    Abstract:

    The full-length ecdysone receptor cDNA of Choristoneura fumiferana (CfEcR-B) was cloned into bacterial expression systems and the recombinant protein was expressed either with a His-tag (His-EcR-B) or glutathione-S-transferase (GST) fusion (GST-EcR-B). The His-EcR-B was expressed mostly as insoluble aggregates, while the GST-EcR-B was partially soluble and could be purified using affinity chromatography. Mice were then immunised with the purified GST-EcR-B protein. Due to the time-consuming protein expression and purification procedures and the solubility problem of the recombinant protein, we also inserted the full-length CfEcR-B cDNA into the mammalian DNA vaccine expression vector, pVAC1-mcs for DNA immunisation. In vitro expression of CfEcR-B in mammalian cells transfected with the pVAC-EcR-B plasmid was confirmed prior to the delivery of the DNA vaccine into mice. The anti-CfEcR-B MAbs generated from both DNA and protein vaccines were characterised and shown to recognise native CfEcR-B protein induced by 20E in CF-203 insect cells. DNA immunisation was shown to overcome the solubility problem of the bacterial expressed EcR and created a more direct route for monoclonal antibody production for this receptor protein obviating the need for EcR expression and purification to generate the antigen.