bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative studies on the mode of action of proctolin and phorbol‐12, 13‐dibutyrate in their ability to contract the locust mandibular closer muscle
Authors: Baines Richard A. , Downer Roger G. H. 
Published: February 2005

AbstractThe role of proctolin has been further investigated in the locust (Locusta migratoria) mandibular closer muscles. Radioactive calcium uptake measurements were made using protease‐dissociated muscle cells. Both the phorbol ester, phorbol‐12, 13‐dibutyrate, and proctolin produce tonic contractions which are associated with the influx of extracellular calcium. The thresholds for proctolin and the phorbol ester to contract the muscle were 1‐10 nM and 10‐100nM, respectively, while their respective thresholds for evoking measurable calcium influx into the muscle cells were 0.1‐1 nM for proctolin, and 0.1‐1 pM for phorbol‐12, 13‐dibutyrate. The effect of phorbol‐12, 13‐dibutyrate is blocked by a number of protein kinase inhibitors (at a concentration of 0.1 mM), suggesting that an activation of protein kinase can lead to calcium influx. These inhibitors, however, do not block the effect of proctolin, indicating that these two compounds work through different pathways, possibly coverging on the same final target. In light of this finding, a number of other compounds have been tested to try to ascertain how proctolin mediates an increased calcium influx. © 1992 Wiley‐Liss, Inc.
Separation of insect hemolymph proteins by cascade‐mode multiaffinity chromatography
Authors: Samaraweera Preminda , Law John H. , Porath Jerker 
Published: February 2005

AbstractThe hemolymph of the adult female Manduca sexta was fractionated by cascade‐mode multiaffinity chromatography (CASMAC) on a main‐line tandem column chain containing Zn2+‐TED, T‐gel, Ni2+‐DPA, and phenylsepharose and a side‐line column containing Zn2+‐DPA. The technique separated some of the previously described major hemolymph proteins, and yielded a number of fractions with simple composition. Some of these fractions contained only less abundant proteins of Manduca hemolymph. Thus, it appears that CASMAC would be a very useful fractionation technique for purification and characterization of the minor proteins of insect hemolymph. © 1992 Wiley‐Liss, Inc.
Storage proteins of the larval root weevil Diaprepes abbreviatus (Coleoptera: Curculionidae): Riboflavin binding and subunit isolation
Authors: Shapiro Jeffrey P. , Niedz Randall P. , Silhacek Donald L. 
Published: February 2005

AbstractProteins present at high concentrations in hemolymph of the larval weevil Diaprepes abbreviatus were previously shown to bind a synthetic coumarin, 7‐amino‐3‐phenyl coumarin (coumarin‐10). One of the two native proteins previously identified (protein I) is now shown to separate into two distinct bands (proteins la and lb) using native gradient pore‐limiting electrophoresis. The high concentration of proteins la, lb, and ll in larval hemolymph, their disppearance from hemolymph upon pupation, and an apparent hexameric structure shown by chemical crosslinking identify them as hexameric storage proteins (hexamerins). At least one chromatographic form of lb isolated by anion exchange HPLC is now shown to bind riboflavin (Rb). Binding was also demonstrated by quenching of Rb fluorescence by a partially isolated mixture of the storage proteins. Lipophorin did not quench Rb fluorescence. Rb was heat‐extracted from whole hemolymph and identified by its fluorescence spectra and by reverse phase HPLC with fluorescence detection. The two subunits shared by the three holoproteins have been isolated by sequential density gradient ultracentrifugation, gel permeation HPLC, and reverse phase HPLC. All three holoproteins shared the α subunit (M, 75,000), while the β subunit (M, 71,000) was lacking from one of the three. Repeated passage through an anion exchange column yielded two of the three proteins (lb and ll) in homogeneous form. Chemical crosslinking with dimethylsuberimidate indicated a hexameric structure for the holoproteins. All subunits and holoproteins stained as high mannose glycoproteins when probed with biotinylated concanavalin A on PVDF membranes. The α subunit was high in Met, His, and Thr, and the β subunit was high in Lys. Both were high in Pro and had approximately 16% Phe + Tyr. Sequences of the 20 N‐terminal amino acid residues of each subunit showed 45–60% homology between subunits. These coleopteran proteins also showed some sequential homology but no immunological cross‐reactivity with storage proteins from the lepidopterans Galleria mellonella and Heliothis virescens. © Wiley‐Liss, Inc.
Regulation of fat body glycogen phosphorylase in larval tobacco hornworm, Manduca sexta
Authors: Siegert Karl J. 
Published: February 2005

AbstractActivation and inactivation of fat body glycogen phosphorylase was investigated in ligated abdomens of larval Manduca sexta and in vitro. After maximal activation through Manduca adipokinetic hormone (AKH) or chilling, inactivation of glycogen phosphorylase commenced as soon as the stimulus for the activation was removed indicating that the enzyme system in the fat body is fine‐tuned to low phosphorylase activities which is necessary to allow glycogen synthesis. In intact ligated abdomens phosphorylase can be activated repeatedly by either stimulus showing that the fat body system does not lose its responsiveness. It was impossible to achieve complete conversion of the inactive form of phosphorylase into the active form even after administration of AKH and simultaneous chilling. © 1992 Wiley‐Liss, Inc.
Colocalization and differential expression of PBAN‐ and FMRFamide‐like immunoreactivity in the subesophageal ganglion of Helicoverpa zea (Lepidoptera: Noctuidae) during development
Authors: Blackburn Michael B. , Kingan Timothy G. , Raina Ashok K. , Ma Michael C. 
Published: February 2005

AbstractPheromone biosynthesis activating neuropeptide (PBAN) stimulates sex pheromone production in several species of moths. We have used an antiserum to PBAN to map the distribution of PBAN‐like immunoreactivity (PLI) in the subesophageal ganglion (SEG) of the larval and pupal stages of the corn earworm, Helicoverpa zea, and compared this distribution with that of the adult. The distribution of PLI within the SEG of larvae and pupae was quite similar to that found in adults, suggesting a function for PBAN other than the stimulation of pheromone biosynthesis. In all developmental stages studied, three groups of nerve cells in the SEG, and their projections, contained PLI. In adults and larvae, most of the cells containing PLI also had FMRFamide‐like immunoreactivity (FLI). In pupae, however, a number of cells which appeared to have PLI and FLI in both larvae and adults, did not contain andy detectable FLI, while the PLI appeared unchanged. The FLI returns to these cells during adult development. These immunocytochemical observations were corroborated by quantifying PLI and FLI by competitive ELISA; the level of extractable FLI in pupae was about 25% of that found in larvae, while PLI levels were unchanged. © 1992 Wiley‐Liss, Inc.
Characterization of fall armyworm mitochondrial DNA (Lepidoptera: Noctuidae)
Authors: Ke Li Dao , Pashley Dorothy P. 
Published: February 2005

AbstractMitochondrial DNA from the fall armyworm, Spodoptera frugiperda (J.E. Smith), was cloned and characterized using restriction enzyme mapping. Genome size is approximately 16.3 kilobase (Kb), consistent with that of most animals. Three fragments, 8.1 Kb, 6.2 Kb, and 2.0 Kb, were produced by digestion with restriction enzyme Xbal and cloned into a pUC19 vector. Twenty‐nine restriction enzymes were used to generate a detailed physical restriction enzyme map of the three cloned fragments. These data represent the first detailed characterization of a lepidopteran mitochondrial genome. © 1992 Wiley‐Liss, Inc.
Certain hemocyte proteins of the medfly, Ceratitis capitata, are responsible for nonself recognition and immobilization of Escherichia coli in vitro
Authors: Marmaras Vassilis J. , Charalambidis Nektarios 
Published: February 2005

AbstractThe results indicate that certain hemocyte proteins of the medfly, Ceratitis capitata, are responsible for the recognition of foreignness, since they are able to bind to the surface of Escherichia coli in vitro. Furthermore, when the E. Coli‐hemocyte protein complex was incubated in the presence of tyrosine and phenoloxidase, the bacteria were immobilized, forming large aggregates. The formation of aggregates seems to be due to reactive tyrosine intermediate (quinone) generated by the action of phenoloxidase. © 1992 Wiley‐Liss, Inc.
Acetylcholine receptors of thoracic dorsal midline neurones in the cockroach, Periplaneta americana
Authors: Bai Donglin , Erdbrugger Heinrich , Breer Heinz , Sattelle David B. 
Published: February 2005

AbstractThe actions of acetylcholine and cholinergic ligands have been studied using dorsal midline neurones from the metathoracic ganglion of the cockroach Periplaneta americana. Both nicotine and oxotremorine depolarized dorsal midline neuronal cell bodies. Dose‐response curves for nicotine and oxotremorine saturated at different levels. Nicotine‐induced depolarizations were completely or partially blocked by mecamylamine, d‐tubocurarine, strychnine, and bicuculline, but were insensitive to α‐bungarotoxin (100 nM), atropine (100 μM), scopolamine (10 μM), and pirenzepine (50 μM). Following pretreatment with collagenase, the dorsal midline neurones were sensitive to high doses of α‐bungarotoxin (3 μM). Oxotremorine‐induced depolarizations were blocked by scopolamine (10 μM), atropine (100 μM), and pirenzepine (50 μM) and were insentive to mecamylamine (10 μM) and d‐tubocurarine (100 μM). The results indicate the coexistence of at least two distinct acetylcholine receptors on dorsal midline neuronal cell bodies in the cockroach metathoracic ganglion. © 1992 Wiley‐Liss, Inc.
Interference of the insect growth regulator methoprene in the process of larval‐pupal differentiation
Authors: Shaaya Eli 
Published: February 2005

AbstractStudies with epidermal cells of a number of insects showed that a sequence of physiological events takes place prior to and during the process of commitment of the epidermal cells from the larval to the pupal stage. At the onset of metamorphosis RNA synthesis, including that of RNA, was suppressed for about 30 h just prior to the wandering stage. At the completion of the wandering stage, pupally committed epidermal cells synthesize a new type of RNA termed hetero‐disperse nuclear RNA (hnRNA). It is suggested that this RNA species could play a role in the permanent shutting‐off of larval‐specific genes. Methoprene, a juvenile hormone analogue (JHA), delayed the larval‐pupal transformation and prevented these changes in RNA synthesis when applied prior to the appearance of the hnRNA, but had no effect when applied after this period. Treatment with the JHA in the early last larval instar prevented not only the normal rise in ecdysteroid titer, but also the increase in the activity of chitinolytic enzymes. Treatment of young pupae had no effect on either the ecdysteroids titer or on enzyme activity. A causal relationship between molting hormone titer and the activity of chitinolytic enzymes is proposed. © 1993 Wiley‐Liss, Inc.
Insecticidal bacterial proteins identify the midgut epithelium as a source of novel target sites for insect control
Authors: Federici Brian A. 
Published: February 2005

AbstractThe spore‐forming bacterium, Bacillus thuringiensis (Bt), produces a crystalline parasporal body during sporulation, which in many subspecies contains one or more proteins selectively toxic to insect midgut epithelia. Most of these proteins are protoxins with a molecular mass of about 133,000. When ingested by a susceptible insect, the inclusions dissolve in the midgut juices and are activated by proteolytic cleavage, which releases a toxic peptide of about 65,000. In susceptible insects, this peptide binds to sites on the microvillar membrane, causing cytolysis, apparently by forming transmembrane pores. The cytolysis of midgut cells results in paralysis and subsequent death of the insect. Though less common, naturally truncated protein toxins with masses of about 70,000 also occur. Three major pathotypes of Bt proteins are known: Cryl and Cryll proteins toxic primarily to lepidopterous insects, Crylll proteins toxic to coleopterous insects, and CrylV proteins toxic to dipterous insects. The genes encoding more than 50 Bt crystal proteins have been cloned and sequenced and several of these have already been used to construct recombinant microbial insecticides and transgenic organisms including viruses, algae, and insect‐resistant plants. Analysis of Bt genes indicate that the protein toxins they encode consist of at least two functional domains: a series of five blocks of conserved amino acids that comprise the structural core of the molecule including the putative toxic moiety, and a hypervariable region thought to define the spectrum of activity. Determination of the mode of action at the molecular level and the genetic basis for insect specificity should enable recombinant DNA technology to be used to expand the insect host range of Bt as well as increase its toxicity against insects. Moreover, the high toxicity and specificity of the insecticidal proteins produced by Bt and their action on midgut microvilli suggest that other types of peptides or simple organic molecules could be designed as selective insecticides to attack other midgut functions such as ion channels, peptide and amino acid transport systems, and midgut proteases. © 1993 Wiley‐Liss, Inc.
A functional analysis of the P‐element gene‐transfer vector in insects
Authors: Handler Alfred M. , Gomez Sheilachu P. , O'Brochta David A. 
Published: February 2005

AbstractA P‐element mobility excision assay was used to determine if non‐drosophilid insects could support P gene vector function. Present studies included the testing of Muscids, Sphaerocerids, and Phorids, none of which were able to support P mobility. A new excision indicator plasmid was developed allowing the detection and recovery of virtually all P‐element excision products. The frequency and sequence analysis of excision products from Drosophila melanogaster and another drosophilid, Chymomyza procnemis, indicated both quantitative and qualitative differences in the activity of transposase. The quantitative relationships observed in the original assay were maintained, and qualitative differences in transposase activity were reflected in the sequence of the empty donor sites. The results suggest that host factors are involved in cutting and ligating P‐element DNA during excision, with transposase facilitating these processes. Possible limitations on P mobility by abnormal transpoase transcript processing were tested in Anastrepha suspensa using transposase‐encoding plasmids having deleted intron sequences. A transposase cDNA supported normal P excision in D. Melanogaster, and a low level of mobility in A. suspensa. Possible applications of gene transfer in insects are presented, in particular methods to genetically sterilize and sex insects for the sterile‐insect technique. © 1993 Wiley‐Liss, Inc.
Natural product analogs: Stable mimics of aldehyde pheromones
Authors: Ujváry István , Dickens Joseph C. , Kamm James A. , McDonough Leslie M. 
Published: February 2005

AbstractUnder field conditions, the aldehyde components of the pheromones of important lepidopteran and coleopteran pests undergo chemical transformations (oxidation, polymerization, etc.) resulting in behaviorally inactive compounds. In our search for pheromone analogs with favorable chemical and biological properties, a series of nitriles, oximes and isothiocyanates, as novel functional group mimics of some cyclic and long chain pheromones, were prepared and tested. The biological activities of these nitrogen‐containing analogs were studied by electrophysiological and field experiments with three different insect species showing the nitrile analogs to be the most potent mimics, but their activities were lower than those of the natural pheromones. Thus, a 1:1 mixture of pheromone analogs in place of the corresponding natural aldehyde components III and IV elicited dose‐dependent electroantennogram (EAG) responses of antennal preparations of the female boll weevil, Anthonomus grandis. In field trials, the nitrile analogs were poor substituents for the corresponding aldehydes. In EAG experiments with antennal preparations of males of the southwestern corn borer, Diatraea grandiosella, Z11‐16:Nitrile ((Z)‐11‐hexadecenonirile) elicited dose‐dependent responses while single neuron recording from antennal preparations of this species revealed that a neuron responsive to the pheromone component was also stimulated by the mimic Z11‐16:Nitrile. In field experiments, a 97:3 mixture of nitriles Z11‐16:Nitrile and Z9‐16:Nitrile ((Z)‐9‐hexadecenonitrile) effectively attracted males of the cranberry girdler moth, Chrysoteuchia topiaria. © 1993 Wiley‐Liss, Inc.
Neutral sterols and ecdysteroids of the solitary cactus bee Diadasia rinconis cockerell (hymenoptera: Anthophoridae)
Authors: Feldlaufer Mark F. , Lusby William R. , Weirich Gunter F. , Svoboda James A. , Buchmann Stephen L. 
Published: February 2005

AbstractUsing high performance liquid chromatography in conjunction with radioimmunoassay and mass spectrometry, the major ecdysteroid of the solitary cactus bee, Diadasia rinconis, was determined to be 20‐hydroxyecdysone, with lesser amounts of makisterone A. Another 28‐carbon ecdysteroid thought to be the 24‐epimer of makisterone A was also detected. The neutral sterols of Diadasia consisted primarily of 24‐methylenecholesterol (92.2%) with lesser amounts of other C28 and C29 sterols. Cholesterol accounted for less than 0.1% of the total tissue sterols. The occurrence of 20‐hydroxyecdysone in a phytophagous hymenopteran is discussed in relation to the low level of cholesterol encountered. © 1993 Wiley‐Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
Sensitive enzyme immunoassay for Manduca allatotropin and the existence of an allatotropin‐immunoreactive peptide in Periplaneta americana
Authors: Veenstra Jan A. , Hagedorn Henry H. 
Published: February 2005

AbstractAntisera to Manduca sexta allatoropin were raised in rabbits and were used to develop a competitive enzyme immunoassay for this neuropeptide. The detection limit of the assay is less than 2 fmol/well. A useful quantification can be obtained from 2 to 30 fmol/well. No cross‐reactivity was observed with several insect peptides, but the enzyme‐linked immunosorbent assay does recognize [Ala6, Leu7, Ser8]‐allatotropin, a myotropin recently isolated from Locusta migratoria. The assay was used to study the distribution of allatotropin within the nervous system of Manduca sexta. The peptide is present in the retrocerebral complex, the brain, and the ventral nerve cord of this species, in quantities of respectively 0.01, 1.2, and 1.7 pmol per insect. An allatotropin‐immunoreactive peptide was found in the nervous system of Periplaneta americana. It is present in the ventral nerve cord (3.3 pmol/insect), brain (1.9 pmol/insect), and retrocerebral complex (0.09 pmol/insect). These data suggest that peptides of this family are generally present in insects. © 1993 Wiley‐Liss, Inc.
Characterization of phenylalkylamine binding sites in insect (Periplaneta americana) nervous system and skeletal muscle membranes
Authors: Skeer Jacqueline M. , Sattelle David B. 
Published: February 2005

AbstractThis study has identified specific, stereoselective phenylalkylamine (PAA, (±)‐ [3H]verapamil) binding sites of low‐affinity and high‐density in cockroach (Periplaneta americana) nervous system and skeletal muscle membranes. Scatchard transformation of equilibrium binding data revealed a single population of binding sites in both tissues with dissociation constants (Kd) of 273 nM and 377 nM and binding capacities (Bmax) of 23 pmol·mg protein−1 and 37pmol·mg protein−1 for cockroach nervous tissue and skeletal muscle membranes, respectively. The PAA binding site in cockroach nervous tissue membranes was found to be dihydropyridine (DHP)‐insensitive, whereas the corresponding site in cockroach skeletal muscle membranes was DHP‐sensitive. This property of a DHP‐sensitive PAA receptor distinguishes the binding sites identified in cockroach skeletal muscle from those in cockroach nervous tissue and indicates that pharmacologically distinct putative Ca2+ channel subtypes are present in insect nerve and muscle. © 1993 Wiley‐Liss, Inc.
Comparison of two juvenile hormone radioimmunoassays
Authors: Goodman Walter G. , Huang Z.‐H. , Robinson Gene E. , Strambi Colette , Strambi Alain 
Published: February 2005

AbstractJuvenile hormone from the hemolymph of adult worker honey bees of known age and behavioral status was extracted and analyzed by two different radioimmunoassays in two independent laboratoies. The assays are different in hapten attachment, radiolabeled tracer, and the method by which bound and unbound hormone are separated. Despite these differences in the methods, hormone determinations were in excellent agreement at lower levels (0–50 ng/ml) but diverged as the hormone concentrations increased (> 50 ng/ml). The relative changes are in good agreement, with a correlation coefficient of 0.97. © 1993 Wiley‐Liss, Inc.
Actions of a coral toxin analogue (bipinnatin‐B) on an insect nicotinic acetylcholine receptor
Authors: Bai Donglin , Sattelle David B. , Abramson Stewart N. 
Published: February 2005

AbstractThe lophotoxin analogue, bipinnatin‐B, is a potent neurotoxin isolated from the gorgonian coral Pseudopterogorgia bipinnata. When tested on the cell body of an identified motor neurone, the fast coxal depressor motor neurone (Df) in the cockroach metathoracic ganglion, bipinnatin‐B, at concentrations of 10 μM, partially blocked nicotine‐induced depolarization. Blockade of the response to nicotine was almost complete at 30 μM bipinnatin‐B, and was partially reversible on rebathing the preparation in normal saline. Responses of the same neurone to GABA were unaffected by 30 μM bipinnatin‐B. © 1993 Wiley‐Liss, Inc.
Defense mechanisms in insects: Certain integumental proteins and tyrosinase are responsible for nonself‐recognition and immobilization of Escherichia coli in the cuticle of developing Ceratitis capitata
Authors: Marmaras Vassilis J. , Bournazos Stavros N. , Katsoris Panagiotis G. , Lambropoulou Maria 
Published: February 2005

AbstractA defense mechanism in the cuticle of developing C. capitata was demonstrated using an in vitro system consisting of isolated cuticular tyrosinase from C. capitata, cuticular tyrosinase‐free proteins, tyrosine, and E. coli. The simultaneous presence of the above components resulted in the formation of large immobilized E. coli aggregates. By contrast, omission of any of the above components failed to produce such aggregates. In other words, E. coli retained their mobility and viability. The results indicate that certain cuticular proteins are responsible for the nonself‐recognition, since they are able to bind to the E. coli surface in vitro, and a reactive tyrosine derivative is generated by the action of cuticular tyrosinase for the immobilization and probably killing of E. coli. Based on these studies the most likely explanation for the nonself‐recognition and immobilization and/or killing of bacteria is the production of E. coli‐protein complexes and their crosslinking through quinone intermediate. © 1993 Wiley‐Liss, Inc.