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  Subjects -> BIOLOGY (Total: 2541 journals)
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BIOCHEMISTRY (188 journals)                  1 2     

AAPS PharmSciTech     Hybrid Journal   (4 followers)
Acetic Acid Bacteria     Open Access   (1 follower)
ACS Chemical Biology     Full-text available via subscription   (172 followers)
ACS Chemical Neuroscience     Full-text available via subscription   (10 followers)
Acta Crystallographica Section D : Biological Crystallography     Hybrid Journal   (8 followers)
Acta Crystallographica Section F: Structural Biology Communications     Hybrid Journal   (5 followers)
Advances and Applications in Bioinformatics and Chemistry     Open Access   (6 followers)
Advances in Biological Chemistry     Open Access   (5 followers)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (5 followers)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (6 followers)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (8 followers)
African Journal of Biochemistry Research     Open Access  
African Journal of Chemical Education     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (3 followers)
American Journal of Biochemistry     Open Access   (5 followers)
American Journal of Biochemistry and Biotechnology     Open Access   (79 followers)
American Journal of Biochemistry and Molecular Biology     Open Access   (7 followers)
Amino Acids     Hybrid Journal   (7 followers)
Analytical Biochemistry     Hybrid Journal   (121 followers)
Annals of Clinical Biochemistry     Hybrid Journal   (1 follower)
Annual Review of Biochemistry     Full-text available via subscription   (25 followers)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (8 followers)
Applied Biochemistry and Biotechnology     Hybrid Journal   (17 followers)
Applied Biochemistry and Microbiology     Hybrid Journal   (6 followers)
Applied Organometallic Chemistry     Hybrid Journal   (3 followers)
Archives of Biochemistry and Biophysics     Hybrid Journal   (9 followers)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (1 follower)
Archives Of Physiology And Biochemistry     Hybrid Journal   (1 follower)
Asian Journal of Biochemistry     Open Access   (1 follower)
Bangladesh Journal of Medical Biochemistry     Open Access   (2 followers)
BBR : Biochemistry and Biotechnology Reports     Open Access   (2 followers)
Biochemical and Biophysical Research Communications     Hybrid Journal   (13 followers)
Biochemical and Molecular Medicine     Full-text available via subscription   (2 followers)
Biochemical Engineering Journal     Hybrid Journal   (8 followers)
Biochemical Genetics     Hybrid Journal   (1 follower)
Biochemical Journal     Full-text available via subscription   (14 followers)
Biochemical Pharmacology     Hybrid Journal   (5 followers)
Biochemical Society Transactions     Full-text available via subscription   (2 followers)
Biochemical Systematics and Ecology     Hybrid Journal   (2 followers)
Biochemistry     Full-text available via subscription   (120 followers)
Biochemistry (Moscow)     Hybrid Journal   (3 followers)
Biochemistry (Moscow) Supplement Series A: Membrane and Cell Biology     Hybrid Journal   (4 followers)
Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry     Hybrid Journal   (4 followers)
Biochemistry and Cell Biology     Full-text available via subscription   (8 followers)
Biochemistry and Molecular Biology Education     Hybrid Journal   (2 followers)
Biochemistry and Molecular Biology of Fishes     Full-text available via subscription   (1 follower)
Biochemistry Research International     Open Access   (3 followers)
Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids     Hybrid Journal   (3 followers)
Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease     Hybrid Journal   (16 followers)
Biochimica et Biophysica Acta (BBA) - Molecular Cell Research     Hybrid Journal   (5 followers)
Biochimie     Hybrid Journal   (4 followers)
Bioconjugate Chemistry     Full-text available via subscription   (13 followers)
BioDrugs     Full-text available via subscription   (7 followers)
Bioelectrochemistry     Hybrid Journal   (3 followers)
Biofuels     Full-text available via subscription   (7 followers)
Biogeochemistry     Hybrid Journal   (5 followers)
BioInorganic Reaction Mechanisms     Full-text available via subscription   (1 follower)
Biokemistri     Open Access  
Biological Chemistry     Partially Free   (8 followers)
Biomedicines     Open Access  
BioMolecular Concepts     Full-text available via subscription   (2 followers)
Bioscience, Biotechnology, and Biochemistry     Open Access   (6 followers)
Biosimilars     Open Access   (1 follower)
Biotechnology and Applied Biochemistry     Hybrid Journal   (17 followers)
BMC Biochemistry     Open Access   (8 followers)
BMC Chemical Biology     Open Access   (4 followers)
Carbohydrate Polymers     Hybrid Journal   (8 followers)
Cell Biochemistry and Biophysics     Hybrid Journal   (5 followers)
Cell Biochemistry and Function     Hybrid Journal   (3 followers)
Cellular Physiology and Biochemistry     Open Access   (3 followers)
Central European Journal of Chemistry     Hybrid Journal   (5 followers)
ChemBioChem     Hybrid Journal   (2 followers)
Chemical Biology & Drug Design     Hybrid Journal   (23 followers)
Chemical Engineering Journal     Hybrid Journal   (16 followers)
Chemical Senses     Hybrid Journal   (1 follower)
Chemical Speciation and Bioavailability     Full-text available via subscription   (1 follower)
Chemico-Biological Interactions     Hybrid Journal   (2 followers)
Chemistry & Biodiversity     Hybrid Journal   (5 followers)
Chemistry & Biology     Full-text available via subscription   (16 followers)
Chemistry and Ecology     Hybrid Journal   (1 follower)
Clinical Biochemist Reviews     Full-text available via subscription   (1 follower)
Clinical Biochemistry     Hybrid Journal   (3 followers)
Clinical Chemistry and Laboratory Medicine     Full-text available via subscription   (4 followers)
Clinical Lipidology     Full-text available via subscription  
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology     Hybrid Journal   (5 followers)
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology     Hybrid Journal   (2 followers)
Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology     Hybrid Journal   (4 followers)
Comparative Biochemistry and Physiology Part D: Genomics and Proteomics     Hybrid Journal   (3 followers)
Comprehensive Biochemistry     Full-text available via subscription   (1 follower)
Computational Biology and Chemistry     Hybrid Journal   (8 followers)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (2 followers)
Current Chemical Biology     Hybrid Journal   (1 follower)
Current Opinion in Chemical Biology     Hybrid Journal   (13 followers)
Current Opinion in Lipidology     Hybrid Journal   (2 followers)
DNA Barcodes     Open Access  
Doklady Biochemistry and Biophysics     Hybrid Journal   (2 followers)
Doklady Chemistry     Hybrid Journal  
Egyptian Journal of Biochemistry and Molecular Biology     Full-text available via subscription  
FEBS Letters     Hybrid Journal   (24 followers)
FEBS Open Bio     Open Access   (1 follower)

        1 2     

Archives of Insect Biochemistry and Physiology    [3 followers]  Follow    
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0739-4462 - ISSN (Online) 1520-6327
     Published by John Wiley and Sons Homepage  [1594 journals]   [SJR: 0.572]   [H-I: 44]
  • Hormonal and nutritional regulation of insect fat body development and
           function
    • Authors: Ying Liu; Hanhan Liu, Shumin Liu, Sheng Wang, Rong‐Jing Jiang, Sheng Li
      Pages: n/a - n/a
      Abstract: The insect fat body is an organ analogue to vertebrate adipose tissue and liver and functions as a major organ for nutrient storage and energy metabolism. Similar to other larval organs, fat body undergoes a developmental “remodeling” process during the period of insect metamorphosis, with the massive destruction of obsolete larval tissues by programmed cell death and the simultaneous growth and differentiation of adult tissues from small clusters of progenitor cells. Genetic ablation of Drosophila fat body cells during larval‐pupal transition results in lethality at the late pupal stage and changes sizes of other larval organs indicating that fat body is the center for pupal development and adult formation. Fat body development and function are largely regulated by several hormonal (i.e. insulin and ecdysteroids) and nutritional signals, including oncogenes and tumor suppressors in these pathways. Combining silkworm physiology with fruitfly genetics might provide a valuable system to understand the mystery of hormonal regulation of insect fat body development and function. © 2009 Wiley Periodicals, Inc.
      PubDate: 2009-02-03T00:00:00-05:00
      DOI: 10.1002/arch.20291
       
  • FUNCTIONAL CHARACTERIZATION OF AN ANTENNAL ESTERASE FROM THE NOCTUID MOTH,
           Spodoptera exigua
    • Abstract: Odorant‐degrading esterases (ODEs) act in the fast deactivation of ester pheromone components and plant volatiles in insects. However, only few ODEs have been characterised to date. In this study, six full‐length putative ODE genes (designated SexiCXE4, 5, 17, 18, 20, and 31) were cloned from the male antennae of Spodoptera exigua. The deduced amino acid sequences possessed typical characteristics of a carboxylesterase (CXE) and shared high identities with reported insect CXEs. The tissue and temporal expression patterns were investigated by quantitative real time PCR. Although all six SexiCXEs are expressed in antennae of both sexes, SexiCXE4, 17 and 20 are antennae‐enriched; while SexiCXE5 and SexiCXE18 are dominantly expressed in wings, and SexiCXE31 is mainly expressed in proboscises, heads and legs. With the highly biased expression in antennae and proboscises, SexiCXE4 was selected for further functional assay. The recombinant SexiCXE4 were expressed in High‐five cells and purified by a Ni2+ affinity column. SexiCXE4 has much higher enzyme activity against plant volatiles (Z)‐3‐hexenyl acetate and hexyl acetate than to the sex pheromone components, suggesting that it may function mostly in the degradation of the plant volatiles.
       
  • cDNA CLONING AND TRANSCRIPTIONAL EXPRESSION PROFILES OF A HEXAMERIN IN THE
           ORIENTAL FRUIT FLY, Bactrocera dorsalis
    • Abstract: A Bactrocera dorsalis hexamerin (BdAr) cDNA was cloned (GenBank accession no. KF815528), and its transcriptional expression profiles were determined. The complete 2,530‐bp cDNA encodes a 780‐amino acid protein with a predicted molecular mass of 94.01 kDa. The proportions of phenylalanine (7.8%), tyrosine (11.2%), and methionine (2.6%) in BdAr as well as all other amino acids are reported. BdAr transcripts were detected in the brain, flight muscle, foregut, Malpighian tubules, and fat body. In the larval stage, BdAr transcripts were expressed in the early third instar and increased in the late third instar. In pupae, the highest expression of BdAr mRNA was present on day 1, then declined and persisted through day 2 to day 8. In adult females, the relative expression of BdAr was significantly higher on day 0 and day 1 compared to day 6 to day 10 while it was highest in newly eclosed adult males. The comparison of the BdAr expression between 8–10‐day‐old males and females showed a higher level in females. Our phylogenetic analysis results suggest to us that BdAr is similar to Drosophila larval serum protein 1γ.
       
  • MOLECULAR CHARACTERIZATION OF SOLUBLE AND MEMBRANE‐BOUND TREHALASES
           IN THE COTTON MIRID BUG, Apolygus lucorum
    • Abstract: Trehalose, a major hemolymph sugar in insects, is hydrolyzed by trehalase. We identified a soluble and a membrane‐bound form of trehalase and isolated the corresponding mRNA, ALTre‐1, and ALTre‐2 in the cotton mirid bug, Apolygus lucorum. The deduced amino acid sequences of ALTre‐1 and ALTre‐2 revealed mature proteins with 643 and 617 amino acids, respectively. ALTre‐1 and ALTre‐2 contained trehalase signature motifs, and ALTre‐2 contained a putative transmembrane domain near the C‐terminus, suggesting that ALTre‐1 and ALTre‐2 encoded a soluble trehalase and a membrane‐bound trehalase, respectively. Comparison of trehalase activity at different developmental stages and in six tissues indicated that soluble trehalase activity accounted for the majority of total trehalase activity in A. lucorum. ALTre‐1 and ALTre‐2 were expressed in all tissues and stages, with the highest expression of both in the second instar nymphs, ALTre‐1 in the ovary and malpighian tubules, ALTre‐2 in the flight muscles and fat body. Following the exposure of second instar nymph to 20‐E, the soluble trehalase activity increased gradually while the membrane‐bound trehalase activity remained at its initial level. Similarly, 20‐E upregulated ALTre‐1 expression but had no effect on ALTre‐2 expression. These results suggest that an increase of this soluble trehalase activity was upregulated by ALTre‐1 gene.
       
  • TRITERPENE ACIDS FROM APPLE PEEL INHIBIT LEPIDOPTERAN LARVAL MIDGUT
           LIPASES AND LARVAL GROWTH
    • Abstract: Fruit extracts from apple, kiwifruit, feijoa, boysenberry, and blueberry were screened for the presence of lipase inhibitory compounds against lepidopteran larval midgut crude extracts. From 120 extracts, six showed significant inhibition with an extract from the peel of Malus × domestica cv. “Big Red” showing highest levels of inhibition. Because this sample was the only apple peel sample in the initial screen, a survey of peels from seven apple cultivars was undertaken and showed that, despite considerable variation, all had inhibitory activity. Successive solvent fractionation and LC‐MS of cv. “Big Red” apple peel extract identified triterpene acids as the most important inhibitory compounds, of which ursolic acid and oleanolic acid were the major components and oxo‐ and hydroxyl‐triterpene acids were minor components. When ursolic acid was incorporated into artificial diet and fed to Epiphyas postvittana Walker (Tortricidae: Lepidoptera) larvae at 0.16% w/v, a significant decrease in larval weight was observed after 21 days. This concentration of ursolic acid is less than half the concentration reported in the skin of some apple cultivars.
       
  • COMPARATIVE PROTEOMIC ANALYSIS OF Bombyx mori HEMOCYTES TREATED WITH
           DESTRUXIN A
    • Abstract: Destruxin A (DA), a cyclodepsipeptidic secondary metabolite of the entomopathogenic fungus, Metarhizium anisopliae, is an important anti‐immunity agent against insect hemocytes. To understand the mechanism of the molecular responses to DA, fifth‐instar larvae of the silkworm, Bombyx mori, were injected with 2 μg of DA. The proteomics of hemocytes were then investigated using two‐dimensional electrophoresis and mass spectrometry, and validated qPCR. As a result, a total of 47 differently expressed protein spots were detected and 22 proteins in 26 spots were identified. There are eight immunity‐related proteins, including three downregulated proteins (antitrypsin isoform 3, p50 protein, and calreticulin precursor) and five upregulated proteins (C‐type lectin 10 precursor, serine proteinase‐like protein, paralytic peptide, PPO‐1, and PPO‐2). Four resistance‐ and/or stress‐related proteins (arginine kinase, carboxylesterase clade H, member 1, aminoacylase, and thiol peroxiredoxin) were upregulated. Ten proteins with other or unknown functions were also recorded. Five selected proteins were verified with qPCR. These results provide new insights into the molecular mechanism of host immune response to DA challenge.
       
  • PREFACE TO THE SPECIAL ISSUES
    •  
  • cDNA CLONING AND HETEROLOGOUS EXPRESSION OF AN
           ENDO‐β‐1,4‐GLUCANASE FROM THE FUNGUS‐GROWING
           TERMITE Macrotermes barneyi
    • Abstract: Major β‐glucosidase (BG) and endo‐β‐1,4‐glucanase (EG) activities were localized to the midgut of the fungus‐growing termite Macrotermes barneyi. Previously, we obtained the endogenous BG gene (MbmgBG1) from the midgut of M. barneyi. Here, we report the cDNA cloning of another endogenous cellulase, the EG protein MbEG1. This cellulase was partially purified from crude extract of the midgut of worker termites using zymogram analysis. Based on the N‐terminal amino acid sequence and using rapid amplification of cDNA ends (RACE), a full‐length cDNA of 1,843 base pairs was obtained. This encoded 448 amino acids and the sequence was similar to that of the members of glycoside hydrolase family 9. The MbEG1 transcript was detected primarily in the midgut using quantitative real‐time polymerase chain reaction (PCR). To confirm functional activity of MbEG1, heterologous expression was conducted in both Escherichia coli and Pichia pastoris expression systems. Results indicated that MbEG1 could be functionally expressed in P. pastoris. This study provides the information that may facilitate understanding of cellulolytic systems in fungus‐growing termites.
       
  • THE KNICKKOPF DOMON DOMAIN IS ESSENTIAL FOR CUTICLE DIFFERENTIATION IN
           Drosophila melanogaster
    • Abstract: The dopamine monoxygenase N‐terminal (DOMON) domain is found in extracellular proteins across several eukaryotic and prokaryotic taxa. It has been proposed that this domain binds to heme or sugar moieties. Here, we have analyzed the role of four highly conserved amino acids in the DOMON domain of the Drosophila melanogaster Knickkopf protein that is inserted into the apical plasma membrane and assists extracellular chitin organization. In principal, we generated Knickkopf versions with exchanged residues tryptophan299, methionine333, arginine401, or histidine437, and scored for the ability of the respective engineered protein to normalize the knickkopf mutant phenotype. Our results confirm the absolute necessity of tryptophan299, methionine333, and histidine437 for Knickkopf function and stability, the latter two being predicted to be critical for heme binding. In contrast, arginine401 is required for full efficiency of Knickkopf activity. Taken together, our genetic data support the prediction of these residues to mediate the function of Knickkopf during cuticle differentiation in insects. Hence, the DOMON domain is apparently an essential factor contributing to the construction of polysaccharide‐based extracellular matrices.
       
  • INFLUENCE OF CATALASE GENE SILENCING ON THE SURVIVABILITY OF SITOBION
           AVENAE
    • Abstract: Reactive oxygen species (ROS), such as superoxide anions and hydrogen peroxide produced in cell metabolism, result in the disruption of cellular function and structure. Catalase (CAT), an enzyme which exists in almost all organisms including plants, invertebrates and vertebrates, acts in scavenging ROS. In this study, a sequence fragment encoding a CAT‐like protein from wheat aphids ( Sitobion avenae) was cloned. Amino acid sequence alignment showed this CAT shared relatively high conservation with CAT sequences from other insects. We detected cat mRNA levels at nymphs of different stages and adults and results showed that cat expression in adults was significantly higher compared to juvenile stages. At the third instar stage, ingestion of dsCAT significantly knocked down CAT expression. Continuous feeding of dsCAT mixed in an artificial diet led to reduced survival rate and ecdysis index. This study indicates that cat, a potential target gene for management of insect pests, is important for maintaining the survival of  S. avenae.
       
  • COENZYME Q10 TREATMENTS INFLUENCE THE LIFESPAN AND KEY BIOCHEMICAL
           RESISTANCE SYSTEMS IN THE HONEYBEE, Apis mellifera
    • Abstract: Natural bioactive preparations that will boost apian resistance, aid body detoxification, or fight crucial bee diseases are in demand. Therefore, we examined the influence of coenzyme Q10 (CoQ10, 2,3‐dimethoxy, 5‐methyl, 6‐decaprenyl benzoquinone) treatment on honeybee lifespan, Nosema resistance, the activity/concentration of antioxidants, proteases and protease inhibitors, and biomarkers. CoQ10 slows age‐related metabolic processes. Workers that consumed CoQ10 lived longer than untreated controls and were less infested with Nosema spp. Relative to controls, the CoQ10‐treated workers had higher protein concentrations that increased with age but then they decreased in older bees. CoQ10 treatments increased the activities of antioxidant enzymes (superoxide dismutase, GPx, catalase, glutathione S‐transferase), protease inhibitors, biomarkers (aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase), the total antioxidant potential level, and concentrations of uric acid and creatinine. The activities of acidic, neutral, and alkaline proteases, and concentrations of albumin and urea were lower in the bees that were administered CoQ10. CoQ10 could be taken into consideration as a natural diet supplement in early spring before pollen sources become available in the temperate Central European climate. A response to CoQ10 administration that is similar to mammals supports our view that Apis mellifera is a model organism for biochemical gerontology.
       
  • Editorial Board
    •  
  • CARBOHYDRASES IN THE DIGESTIVE SYSTEM OF THE SPINED SOLDIER BUG, Podisus
           maculiventris (SAY) (HEMIPTERA: PENTATOMIDAE)
    • Abstract: The spined soldier bug, Podisus maculiventris, is a generalist predator of insects and has been used in biological control. However, information on the digestion of food in this insect is lacking. Therefore, we have studied the digestive system in P. maculiventris, and further characterized carbohydrases in the digestive tract. The midgut of all developmental stages was composed of anterior, median, and posterior regions. The volumes of the anterior midgut decreased and the median midgut increased in older instars and adults, suggesting a more important role of the median midgut in food digestion. However, carbohydrase activities were predominant in the anterior midgut. In comparing the specific activity of carbohydrases, α‐amylase activity was more in the salivary glands (with two distinct activity bands in zymograms), and glucosidase and galactosidase activities were more in the midgut. Salivary α‐amylases were detected in the prey hemolymph, demonstrating the role of these enzymes in extra‐oral digestion. However, the catalytic efficiency of midgut α‐amylase activity was approximately twofold more than that of the salivary gland enzymes, and was more efficient in digesting soluble starch than glycogen. Midgut α‐amylases were developmentally regulated, as one isoform was found in first instar compared to three isoforms in fifth instar nymphs. Starvation significantly affected carbohydrase activities in the midgut, and acarbose inhibited α‐amylases from both the salivary glands and midgut in vitro and in vivo. The structural diversity and developmental regulation of carbohydrases in the digestive system of P. maculiventris demonstrate the importance of these enzymes in extra‐oral and intra‐tract digestion, and may explain the capability of the hemipteran to utilize diverse food sources.
       
  • MOLECULAR CHARACTERIZATION OF SOLUBLE AND MEMBRANE‐BOUND TREHALASES
           OF THE WHITEFLY, Bemisia tabaci
    • Abstract: Trehalases (Tres) have been demonstrated to be the key enzymes that are involved in various trehalose‐associated physiological processes in insects. However, little attention has been devoted to the Tres in the whitefly, Bemisia tabaci. In this study, a soluble Tre (BtTre‐1) and a membrane‐bound Tre (BtTre‐2) were cloned in the invasive cryptic species Middle East‐Asia Minor 1 (MEAM1) of the whitefly B. tabaci complex. Alignment of deduced amino acids sequences of both BtTres revealed that they share common consensus regions and residues with Tres of other insect species. Levels of BtTres expression in various stages and tissues of the whitefly suggested that BtTre‐2 may play a key role in trehalose catabolism during development of the whitefly, especially for oocyte development, while BtTre‐1 may prevent trehalose in salivary gland from leaking and entering into plants along with saliva. Potential roles of trehalose catabolism in response to direct and/or plant‐mediated indirect effects of Tomato Yellow Leaf Curl China Virus (TYLCCNV) were also detected. Whiteflies feeding on virus‐infected tobacco plants showed higher BtTres expressions and accordingly higher BtTres activity but lower trehalose content than those feeding on uninfected plants. The enhanced trehalose catabolism may be beneficial to oocyte development in ovary and attenuate plant defensive responses induced by trehalose in saliva. Viruliferous and nonviruliferous whiteflies feeding on cotton, a nonhost plant for TYLCCNV, differed significantly only in trehalose content. The higher trehalose content in viruliferous whiteflies may be conducive to resisting the stress inflicted by TYLCCNV.
       
  • INHERITANCE OF ELECTROPHYSIOLOGICAL RESPONSES TO LEAF SAPS OF HOST‐
           AND NONHOST PLANTS IN TWO Helicoverpa SPECIES AND THEIR HYBRIDS
    • Abstract: The polyphagous cotton bollworm Helicoverpa armigera (Hübner) and the oligophagous oriental tobacco budworm Helicoverpa assulta (Guenée) (Lepidoptera: Noctuidae) display contrasting heritable feeding preferences for cotton and pepper leaves. In this study, electrophysiological response patterns to cotton and pepper leaf saps in gustatory sensilla styloconica on the maxillae of these two species, their reciprocal F1 hybrids, and backcrossed lines were investigated using the tip recording technique. The identity of the neurons responding to the two leaf saps has been established using action potential waveform analysis. The two plant leaf saps elicited neural activity in at least six of the eight taste neurons innervating the lateral and medial sensilla styloconica of the parental species and crosses. Discriminant analysis of this multineural input predicted that correct classification occurred in 87 – 92% of the cases. Differences in taste neuron responses between insect lines to the two plant saps were consistent with differences in feeding preference behaviors. Comparisons of taste neuron response patterns of parental species, F1 hybrids and backcrosses indicate that autosomal loci contributed to the difference in gustatory response patterns between the two Helicoverpa species with the H. armigera derived alleles being partly dominant to those carried by H. assulta. These findings contribute to the understanding of gustatory codes for preference and provide insight into taste evolution of lepidopteran insects.
       
  • PROSTAGLANDIN MEDIATES DOWN‐REGULATION OF PHENOLOXIDASE ACTIVATION
           OF Spodoptera exigua VIA PLASMATOCYTE‐SPREADING
           PEPTIDE‐BINDING PROTEIN
    • Abstract: Insect immunity is innate and highly efficient to defend against various pathogens. However, uncontrolled excessive immune responses would be highly detrimental and energy‐consuming processes. An insect cytokine, plasmatocyte‐spreading peptide (SePSP), induces hemocyte‐spreading behavior as well as activates phenoloxidase (PO) in the beet armyworm, Spodoptera exigua. A hemocyte transcriptome of S. exigua contains a partial sequence of a putative PSP‐binding protein (SePSP‐BP1). SePSP‐BP1 was expressed in most larval stages except in the last instar. However, a bacterial challenge induced SePSP‐BP1 expression in the last instar especially in hemocytes and fat body. Injecting a double‐stranded RNA specific to SePSP‐BP1 (dsPSP‐BP1) suppressed the induction of SePSP‐BP1 expression in response to bacterial challenge. The larvae treated with dsPSP‐BP1 suffered high mortality to infection of nonpathogenic bacteria due to uncontrolled high PO activity. SePSP significantly induced PO activity. The eicosanoid synthesis inhibitor, dexamethasone (DEX), inhibited SePSP‐mediated PO activation. However, treatment with prostaglandin E2 (PGE2) induced a transient increase of PO activity under DEX treatment. Treatment of dsPSP decreased the duration of PO activation induced by PGE2, while treatment of dsPSP‐BP1 increased the induced period. These results suggest that prostaglandin mediates PSP signals in both upregulation of PO activity and its subsequent downregulation via SePSP‐BP1.
       
  • TRANSCRIPTION PROFILING OF 12 ASIAN GYPSY MOTH (Lymantria dispar)
           CYTOCHROME P450 GENES IN RESPONSE TO INSECTICIDES
    • Abstract: As the main group of detoxification enzymes, cytochrome P450 monoxygenases (P450s) catalyse an extremely diverse range of reactions that play an important role in the detoxification of foreign compounds. Transcription profiling of 12 Lymantria dispar P450 genes from the CYP6 subfamily believed to be involved in insecticide metabolism was performed in this study. Life‐stage transcription profiling of CYP6 genes revealed significant variations between eggs, larvae, pupae, and adult males and females. Exposure of larvae to sublethal doses of deltamethrin, omethoate, and carbaryl enhanced the transcription of most of the CYP6 P450 genes, with induction peaking between 24 and 72 h after exposure. Transcription profiles were dependent on the levels of insecticide exposure and the various developmental stages.
       
  • SUPPRESSING THE EXPRESSION OF A FORKHEAD TRANSCRIPTION FACTOR DISRUPTS THE
           CHITIN BIOSYNTHESIS PATHWAY IN Spodoptera exigua
    • Abstract: Forkhead (Fox) transcription factors display functional diversity and are involved in various metabolic and developmental processes. The Spodoptera exigua Fox (SeFox) encodes a protein of 353 amino acids with a theoretical molecular mass of approximately 38.99 kDa and an isoelectric point of 8.86. qPCR results revealed that SeFox was expressed mainly in the brain, fat body, epidermis, midgut, Malpighian tubules, and testis. SeFox was expressed, with some changes, throughout development in the fat body and whole body. Injection of dsSeFox (SeFox dsRNA) into larvae resulted in incidences of albino plus molting deformity (4.8%), molting deformity (26.2%), and albino phenotypes (69.1%). dsSeFox injection resulted in approximately 50% knockdown of transcript levels at 36 h. Compared with control groups, hexokinase (HK) expression was reduced to approximately 40% at 48 h postinjection. Chitin synthase A (CHSA) expression was reduced to two‐thirds at 24 h, but increased at 72 h. Compared with untreated control and green fluorescent protein‐treated groups, Chitin synthase B (CHSB) expression decreased to 33% following dsSeFox injection by 36 h. We infer from our results that forkhead transcription factors act in chitin synthesis in S. exigua.
       
 
 
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