bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and molecular analysis of storage proteins from Heliothis virescens
Authors: Leclerc Robert F. , Miller Stephen G. 
Published: February 2005

AbstractThree abundant storage proteins have been detected in larval and pupal hemolymph and pupal fat body of the tobacco budworm, Heliothis virescens. These polypeptides have subunit molecular weights of 74,000, 76,000, and 82,000, as determined by SDS–PAGE and exit as 450,000‐Mr hexamers in their native state. A purified 82,000‐Mr storage protein fraction has been obtained along with a preparation containing equivalent amounts of the 74,000‐Mr and 76,000‐Mr subunits, and antisera raised to each of these components have been used to document the developmental profiles of protein accumulation and synthesis by fat body. cDNA clones corresponding to each of three abundant classes of fat body mRNAs have been recovered, and at least one of these has been unambiguously demonstrated to encode the 82,000‐Mr storage protein subunit. Northern blot studies with these cDNA clones revealed that the developmental accumulation of transcripts in fat body for each was consistent with the general pattern of storage protein biosynthesis, and more interestingly, that transcirpts hybridizing to two of these cDNA sequences are also found in testes. These two cDNA have also been sequenced revealing that one encodes a polypeptide similar to arylphorins, a class of storage proteins widely distributed in Insecta. The derived amino sequence of the second cDNA, corresponding to the 82,000‐Mr protein, had no unusual compositional features and determination of its structural relationship to other hemolymph polypeptides awaits molecular analysis of related genes from other insects.
Synthesis and transport of storage proteins by testes in Heliothis virescens
Authors: Miller Stephen G. , Leclerc Robert F. , Seo Sook‐Jae , Malone Christine 
Published: February 2005

AbstractThe synthesis of two storage protein subunits, 76,000‐Mr and 82,000‐Mr polypeptides, by the testes sheath has been studied in Heliothis virescens. Like fat body, which is the primary site of synthesis for the large extratesticular pool, cells of the testes sheath secrete glycosylated storage proteins assembled into hexamers. The testis sheath differed from fat body in several important respects, including the failure to synthesize an abundant (in the hemolymph) 74,000‐Mr storage protein, its relatively reduced expression of the 76,000‐Mr polypeptide, and the absence of resorption of storage proteins from the lumen of the testis during pupal development. Cyst cells were also shown to import actively the 82,000‐Mr storage protein by pinocytosis of testicular fluid and transfer it to the developing spermatids. Unlike other cell types that sequester storage proteins in the form of cytoplasmic granules, their localization within spermatids was exclusively mitochondrial. These observations suggest that expression of the storage protein genes is regulated tissue specifically and reveal novel pathways for their transport and, perhaps, utilization and function during development.
Lipophorin as a yolk precursor in Hyalophora cecropia: Uptake kinetics and competition with vitellogenin
Authors: Kulakosky Peter C. , Telfer William H. 
Published: February 2005

AbstractVitellogenic follicles of Hyalophora cecropia were incubated in metabolically radiolabeled, high‐density lipophorin isolated from pharate adult hemolymph by KBr density gradient centrifugation. The follicles transferred this probe from the incubation medium to the cortical yolk spheres in the oocyte by an energy‐dependent and saturable mechanism. Vitellogenin and high‐density lipophorin competed with each other for uptake, and are therefore concentrated by the follicle with a common mechanism. Microvitellin and lipophorin, in contrast, did not compete for uptake. The Kuptake for the accumulation of high‐density lipophorin was substantially higher than the value estimated earlier for vitellogenin (133 μM vs. 18 μM). This relationship helps explain why the shared concentrating mechanism does not deplete the lipid transport capacity of the hemolymph, and how a low vitellogenin: lipophorin molar ratio in the hemolymph yields a high ratio in the mature egg.
Isolation and characterization of bacteria‐induced protein P4 from hemolymph of Manduca sexta
Authors: Ladendorff Noma E. , Kanost Michael R. 
Published: February 2005

AbstractInsects synthesize several types of hemolymph proteins in response to bacterial infection. The objective of this study was to characterize a 48,000 dalton hemolymph protein induced in larvae of Manduca sexta after injection of bacteria. The protein, isolated by cation exchange and gel filtration chromatography from hemolymph of larvae injected with Micrococcus lysodeikticus, was found to be a glycoprotein with pl = 8.4. The molecular weight, isoelectric point, amino acid composition, and NH2 terminal sequence of the protein are similar to bacteria‐induced protein P4 from Hyalophora cecropia, and the M. sexta protein is also designated P4. The hemolymph concentration of M. sexta P4 (35 ± 7 μg/ml in day 3 fifth instar larvae) increases 30‐ to 45‐fold by 48 h after injection of bacteria, but it does not increase in response to injection of distilled water. Lower levels of induction occur after injection of peptidoglycan fragments, zymosan, and lipopolysaccharide. The properties of M. sexta P4 are very similar to those of a previously characterized M. sexta hemolymph protein known as postlarval protein, and antibodies against P4 bind to postlarval protein.
P1 gene expression in Drosophila larval fat body: Induction by various Ecdysteroids
Authors: Sommé‐Martin Ghislaine , Colardeau Jacqueline , Beydon Philippe , Blais Catherine , Lepesant Jean Antoine , Lafont René 
Published: February 2005

AbstractUsing the developmental mutant ecd1, the biological activity of 20‐hydroxyecdysone (20E) and 20E metabolites 3‐dehydro‐20‐hydroxyecdysone (3D20E), 3‐epi‐20‐hydroxyecdysone (3D20E), 3‐epi‐20‐hydroxyecdysone‐3‐phosphate (20E′3P), 20,26‐dihydroxyecdysone (20,26E), and 20‐hydroxyecdysonoic acid (20Eoic) was tested for their ability to induce the transcription of the steroid‐inducible gene P1 in the Drosophila larval fat body. 3D20E was the most efficient ecdysteroid in the initiation of P1 gene transcription therefore the formation of 3D20E and the 3‐epimer could not be regarded as an inactivation pathway in Drosophila larvae. Formation of 20,26E and 20Eoic may be an inactivation pathway in this biological model.
Sex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis (II): Biosynthesis of (E)‐ and (Z)‐12‐tetradecenyl acetate involves Δ14 desaturation
Authors: Zhao Chenghua , Löfstedt Christer , Wang Xuying 
Published: February 2005

AbstractSex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis was studied by topical application of deuterium labelled fatty acids to the pheromone gland. The incorporation of the labelled acids into pheromone components and precursors was determined by gas chromatography with flame ionization detection and mass spectrometry in the selected ion monitoring mode. The labelling experiments suggest that the pheromone components (E)‐ and (Z)‐12‐tetradecenyl acetates are biosynthesized from palmitic acid by δ14 desaturation, followed by chain shortening (β‐oxidation), reduction, and acetylation. This is the first confirmation of a Δ14 desaturase in an eukaryotic system.
Antioxidant enzyme activities in subcellular fractions of larvae of the black swallowtail butterfly, Papilio polyxenes
Authors: Ahmad Sami , Pritsos Chris A. , Pardini Ronald S. 
Published: February 2005

AbstractThe black swallowtail butterfly, Papilio polyxenes, larvae are specialized feeders of pro‐oxidant rich plants of Apiaceae and Rutaceae. An important defense against toxic forms of oxygen species generated by ingestion of the pro‐oxidants, are the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), GSH‐dependent glutathione peroxidases (selenium‐dependent glutathione peroxidase [GPOX] and peroxidase activity of selenium‐independent glutathione‐S‐transferase [GTpx]), and glutathione reductase (GR). The subcellular distribution of these enzymes in black swallowtail larvae was investigated and was found to resemble the patterns described for larvae of two other lepidopteran species: the southern armyworm, Spodoptera eridania, and the cabbage looper, Trichoplusia ni. The confinement of SOD in the cytosol and mitochondria was typically eukaryotic, but the relative proportion (1:1) was markedly different from the mammalian pattern (4:1; cytosol:mitochondria). The most obvious difference between the black swallowtail and other lepidoptera as a group, and mammalian species, is in very wide intracellular distributions of CAT, GTpx, and GR in insect species. Insects possess very low levels of a GPOX‐like activity which reduces both H2O2 and organic peroxides. Consequently, insects have elaborate activities with a wide subcellular distribution of both CAT which decomposes H2O2, and GTpx which decomposes organic peroxides. The reduction of peroxides is dependent on GSH, which in this process is oxidized to GSSG. GR which reduces GSSG to GSH is also of wide subcellular distribution, analogous to the distribution pattern of GTpx.
Biological effects of synthetic AKH in Manduca sexta and estimates of the amount of AKH in corpora cardiaca
Authors: Ziegler Rolf 
Published: February 2005

AbstractDose‐response curves were measured with synthetic Manduca adipokinetic hormone (AKH) for glycogen phosphorylase activation in larvae and for lipid mobilization in adults. Both responses are known hormonal functions in Manduca sexta. In ligated larvae, full activation of glycogen phosphorylase was achieved with 0.1 pmol and half‐maximal activation with 0.03–0.04 pmol. Maximal lipid mobilization in adults required 10 pmol and half‐maximal mobilization 0.15 to 0.2 pmol, respectively.An estimate of AKH content of corpora cardiaca from M. sexta was gained by comparing the dose‐response curves for synthetic Manduca AKH with curves from gland extracts. Corpora cardiaca extracts were also quantitated by high performance liquid chromatography. According to both estimates corpora cardiaca of adults contain 10–20 pmol AKH per pair, while a pair of larval corpora cardiaca contains 0.7–2 pmol.
Proteolytic processing of Blattella germanica vitellin during early embryo development
Authors: Nordin John H. , Beaudoin Esther L. , Liu Xiaodong 
Published: February 2005

AbstractIn the eggs of the cockroach Blattella germanica, vitellin (Vt) utilization is initiated 4 days postovulation by the proteolytic processing of its three subunits. These reactions yield a specific set of peptides that are consumed by the developing embryo. A yolk proteinase activity, believed central to this processing event, has been investigated. First expressed at day 3 postovulation, just prior to Vt's processing, its specific activity with synthetic substrates increased four‐fold to 18‐fold through day 6. In addition, a mixing experiment showed that these proteinases(s) can also process Vt's large subunits in vitro. A relationship between Vt processing and proteinase specific activity was also noted with two B. germanica translocation heterozygotes, which displayed differences in the extent of Vt processing. One group of eggs (group A) failed to process any Vt subunit. A second group (B) processed the Mr 102,000 subunit but not the Mr 95,000. A third group (C) processed their Vt normally. Proteinase specific activities in the yolk of translocant's eggs at day 6 mirrored the extent of processing, being highest in group C eggs and effectively absent from the yolk of group A eggs. Eggs defective in Vt processing also contained arrested embryos. It is concluded that the yolk proteinase activity described here participates in Vt processing at day 4 postovulation. Microscopic examination of yolk obtained from eggs of wild type females showed that, as processing began in vivo (day 4), the yolk granules also underwent an abrupt decrease in size from diameters of 15–30 μm to 3–10 μm. Yolk granules of those translocant's eggs that were defective in Vt processing did not undergo this size decrease, suggesting that granule reorganization and Vt proteolysis may be linked functionally.
On the latency and nature of phenoloxidase present in the left colleterial gland of the cockroach Periplaneta americana
Authors: Sugumaran Manickam , Nellaiappan Kaliappan 
Published: February 2005

AbstractThe phenoloxidase system responsible for the sclerotization of cockroach ootheca is found to be present as an inactive form in the left colleterial gland of Periplaneta americana. The supernatant fraction obtained by centrifugation of the milky white secretions contained the inactive phenoloxidase which required both sodium dodecyl sulfate (SDS) and the insolubel sediment for exhibiting enzyme activity. Bovine serum albumin could replace the sediment in the activation process. Proteins separated from the supernatant fraction by molecular sieve chromatography on Sephadex G‐25 did not require either albumin or the sediment, but required SDS for exhibiting the phenoloxidase activity. Among the detergents tested, SDS (anionic) and cetylpyridinium chloride (cationic) activated the phenoloxidase, but CHAPS (zwitterionic) or nonionic detergents failed to activate the enzyme. The activation caused by SDS occurred well below the critical micellar concentration of SDS indicating that SDS is causing the activation by binding to the protein and altering its conformation. Chloroform‐methanol extracts of vestibulum or right gland could replace SDS confirming the presence of endogenous activator(s) of phenoloxidase system. A variety of exogenously added lipids could activate the latent enzyme, among which linoleate, oleate, laurate, linolenate, phosphatidylethanolamine, and phosphatidylglycerol proved to be the effective activators of the latent phenoloxidase.Partially purified phenoloxidase was found to be extremely labile and lost its activity on (a) freezing and thawing, (b) dialysis, and (c) heating for 10 min at 55°C. It exhibited a pH optimum of 7 and was inhibited drastically by phenylthiourea and diethyldithiocarbamate. It readily oxidized a number of o‐diphenols such as 3,4‐dihydroxybenzylalcohol, 3,4‐dihydroxyphenethyl alcohol, catechol, N‐acetyldopamine, N‐acetylnorepinephrine, dopa, dopamine, etc., but failed to oxidize both 3,4‐dihydroxybenzoic acid and 3,4‐dihydroxybenzaldehyde. It neither converted the typical laccase substrate syringaldazine to its quinone methide product, nor oxidized the p‐diphenols, hydroquinone and methylhydroquinone. Therefore, the enzyme participating in the quinone tanning of cockroach ootheca appears to be a typical o‐diphenol oxidase and not a laccase as previously thought.
Ecdysteroids control vitellogenesis and egg maturation in pharate adult females of the Indianmeal moth, Plodia interpunctella
Authors: Shirk Paul D. , Bean Daniel W. , Brookes Victor J. 
Published: February 2005

AbstractVitellogenesis occurs during the late pharate adult stage in the Indianmeal moth, Plodia interpunctella. Repeated treatment of pharate adult females with doses of 20‐hydroxyecdysone (20HE) from 10 to 250 ng per pupa suppressed oocyte growth and inhibited yolk protein accumulation in the oocytes. Treatment of the pharate adults with a biologically inactive ecdysteroid analogue, 22–isoecdysone, had no effect on egg maturation or yolk protein accumulation. The hormonal action of 20HE was not through the inhibition of the corpora allata or juvenile hormone levels, because treatment with a juvenile hormone analogue did not reverse the inhibition by 20HE treatment. Exposure of early vitellogenic ovaries to 20HE in organ cultures in vitro showed that 20HE had a direct effect on the ovarian synthesis of YP2. At 20HE concentrations below 10 nM, YP2 synthesis was minimal, at 10 nM 20HE YP2 synthesis was maximal, and at concentrations higher than 10 nM YP2 synthesis was suppressed to 35% of the maximal level. Synthesis of most other ovarian proteins remained constant with the changing 20HE concentrations. Ovarian RNA from treated females translated in a reticulocyte lysate demonstrated that the hormonal effect of 20HE on the ovarian tissues was on the specific accumulation of translatable YP2 transcript as well as transcripts for a few other polypeptides. This study shows that 20HE controls the rate of egg development during metamorphosis and that declining titers of 20HE regulate the expression of adult genes.
Solubilization, identification, and localization of vitellogenin‐binding sites in follicles of the cockroach, Nauphoeta cinera
Authors: Indrasith Leslie S. , Kindle Helmut , Lanzrein Beatrice 
Published: February 2005

AbstractBinding sites for vitellogenin were solubilized and analyzed either with a filter assay or with ligand blotting. We tested sodium dodecylsulfate (SDS), Chaps, octyl‐β‐D‐glucoside, and sodium dexocycholate and found SDS and sodium deoxycholate to be most effective in solubilizing both high and low molecular weight binding sites. In the filter assay the sodium deoxycholate extracts but not the SDS extracts, maintained binding activity after dilution of the solubilizer below its critical micellar concentration. In ligand blotting we consistently observed, in vitellogenic folicles, binding sites with an apparent Mr of approximately 200,000, 35,000, and three closely spaced bands between 14,000 and 20,000. Binding of vitellogenin to all binding sites was suppressed in the presence of the drug suramin. Analysis of corpora lutea and oothecae as well as of ovariole sheath, follicle cell/basal lamina, and oocyte plasma membrne preparations showed that the 35 and 14–20 kDa binding sites are located in the outer follicle compartments, and the 200 kDa binding site in the oocyte plasma membrane. In the latter we occasionally also observed binding sites with an apparent Mr of approximately 150,000, 95,000, 67,000 and 30,000, particularly at stages after ovulation. The 35 and 14–20 kDa binding sites, as visualized in stained gels and in ligand blotting, are rather abundant and were also seen in several other male and female tissues of Nauphoeta and even in other species. They also bound other 14C‐labeled hemolymph proteins and thus appear to be rather unsepcfic. As binding analysis with nonsolubilized and sodium deoxycholate‐solubilized membranes revealed that the quantity of vitellogenin bound by binding sites of the outer follicle compartments was low, it is conceivable that teh abundance of the 14–20 kDa and 35 kDa binding sites in ligand blotting is merely an effect of SDS and does not reflect the in vivo situation. We suppose that the 200 kDa binding site of the oocyte plasma membrane represents the vitellogenin receptor involved in endocytosis.
On the action of RH 5849, a nonsteroidal ecdysteroid agonist, on a cell line from Chironomus tentans
Authors: Spindler‐Barth Margarethe , Turberg Andreas , Spindler Klaus‐Dieter 
Published: February 2005

AbstractRH 5849 competes with 3H‐ponasterone A for ecdysteroid binding sites in Chironomus tentans cells with an about fourfold lower relative affinity as compared to 20‐OH‐ecydsone. It does not interfere with glucocorticoid and estrogen binding sites in vertebrates. It is also not recognized by an ecdysteroid antibody. RH 5849 exerts typical morphological and physiological effects ascribed to the action of 20‐OH‐ecdysone on C. tentans cells, namely an increase in acetylcholinesterase activity and an inhibition of chitin synthesis.
Distribution and pharmacological characterization of muscarinic‐cholinergic receptors in the cockroach brain
Authors: Orr Gregory L. , Orr Nailah , Hollingworth Robert M. 
Published: February 2005

AbstractThe binding of [3H]quinuclidinyl benzilate to a cockroach brain preparation was investigated. Specific binding was saturable with a Kd of 0.25 nM and Scatchard analysis indicated a Bmax of 604 pmol/mg protein. Kinetic analysis indicated that the ligand is binding in a complex fashion while dissociation followed a simple kinetic process. The pharmacology of the site was typical of muscarinic receptors but the site cannot be characterized in terms of vertebrate muscarinic‐receptor subtypes. Affinity of the receptor for agonists was modulated by Mg2+ and guanylylimidodiphosphate but not by pertussis toxin indicating the involvement of a pertussis‐toxin insensitive G‐protein. Carbamylcholine did not inhibit basal or forskolin‐stimulated adenylate cyclase activity. The binding site was localized autoradiographically and was restricted to the median and lateral calyces of the brain.
Antioxidant enzymes as biochemical defenses against phototoxin‐induced oxidative stress in three species of herbivorous lepidoptera
Authors: Aucoin Richard R. , Philogène Bernard J. R. , Arnason John T. 
Published: February 2005

AbstractMany secondary plant compounds are capable of photoactivation resulting in the production of toxic species of oxygen. One mechanism of defense for insects feeding on phototoxic plants may be the presence of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPOX), and glutathione reductase (GR). The activities of these enzymes were examined in larvae of three lepidoptera: Ostrinia nubilalis, Manduca sexta, and Anaitis plagiata. Highest levels of antioxidant enzyme activity were found in A. plagiata, a specialist feeder on Hypericum perforatum, which contains high levels of the phototoxin hypericin. Larvae of A. plagiata fed leaf discs treated with hypericin exhibited a short‐term, concentration‐dependent decline in enzyme activity. Longer term studies with A. palgiata fed either the photoxic H. perforatum, or the closely related but non‐phototoxic H. calycinum, resulted in increased CAT and GR activity in larvae fed the phototoxic plant whereas SOD activity was not significantly different. These results suggest that CAT and GR may be inducible defenses against phototoxins.
Pharmacological characterization of a 5‐hydroxytryptamine‐sensitive receptor/adenylate cyclase complex in the mandibular closer muscles of the cricket, Gryllus domestica
Authors: Baines Richard A. , Downer Roger G. H. 
Published: February 2005

AbstractThe mandibular closer muscles of the cricket, Gryllus domestica, contain a 5‐hydroxytryptamine (5‐HT)‐sensitive receptor that is coupled to adenylate cyclase. A structure‐activity study of the 5‐HT molecule indicates that the integrity of the ethylamine sidegroup and the presence of a negatively charged moiety at the 5 position (‐OH, ‐OCH3) are essential for activity. A pharmacological profile is presented for this receptor. The receptor differs from any reported mammalian 5‐HT receptor in that none of the mammalian agonists tested were effective. However, the mammalian antogonists for 5‐HT receptors, spiperone, mianserin, and ketanserin as well as the anti‐histaminic cyproheptadine were all effective antagonists in this preparation. Preliminary analysis of antagonism, particularly by spiperone, shows that these antagonists are probably acting non‐competitively.On the basis of the pharmacological data, and comparisons with other insect systems, the 5‐HT receptor present in the cricket mandibular muscles has been tentatively classified as 5‐HT2‐like.