bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of intestinal insulin‐like peptide on glucose catabolism in male adult Locusta migratoria
Authors: Khay A. Ben , Gourdoux L. , Moreau R. , Dutrieu J. 
Published: February 2005

AbstractAn insulin‐like peptide (ILP) extracted from midgut of 25‐day‐old male adult Locusta migratoria can modify the relative activity of the two main pathways of glucose catabolism. The effect of ILP on the activity of the pentose cycle and the glycolytic‐citric acid cycle in Locusta migratoria was evaluated by a radiorespirometric method by means of [1‐14C] glucose and [6‐14C]glucose as substrates. The time course of the ILP effect was determined. The insulin‐like peptide increases the relative activity of the pentose cycle. This effect is rapid and of short duration. Injected mammalian insulin has a similar effect.
The role of alcohols in pheromone biosynthesis by two noctuid moths that use acetate pheromone components
Authors: Teal P. E. A. , Tumlinson J. H. 
Published: February 2005

AbstractPrimary alcohols varying in chain length from C13 to C16, and in number, position, and geometric configuration of double bonds, were applied in dimethyl sulfoxide to the surface of the female sex pheromone glands of Heliothis subflexa (Gn.) and Hydraecia micacea (Esper). Capillary gas chromatographic analysis of extracts of the treated glands indicated that the alcohols were converted to the corresponding aldehydes by H. subflexa females and to the acetates by H. micacea females. Conversions of the alcohols showed no preferences for molecular weight, number, position, or geometry of the double bonds in either species. Application of the acetates of the primary alcohols to the gland surface of H. subflexa females resulted in the production of both the corresponding alcohols and aldehydes, while neither alcohols nor aldheydes were produced when acetates were applied to the glands of H. micacea. In addition, application of the acetates to the gland surface of Heliothis virescens (F.) resulted in the production of both the corresponding alcohols and aldehydes. However, no evidence was found to indicate that acetates are ever produced by the pheromone gland of females of H. virescens.
Protein cross‐linking by peroxidase: Possible mechanism for sclerotization of insect cuticle
Authors: Hasson Chad , Sugumaran Manickam 
Published: February 2005

AbstractIncubation of test proteins with horseradish peroxidase in the presence of hydrogen peroxide and a catechol resulted in polymerization and precipitation of test proteins. SDS‐PAGE readily revealed the generation of dimers, trimers, and higher oligomers in the reaction mixture. With the exception of 3,4‐dihydroxyphenylalanine, dopamine, and norepinephrine, most other catechols tested participated in protein polymerization. The inability of these three catechols to accomplish polymerization is attributed to their high rate of intramolecular cyclization, which results in melanin formation. Radioactive studies with [3H]N‐acetyldopamine clearly reveal both intermolecular and intramolecular cross‐linking of test proteins by peroxidase. Based on these studies a possible mechanism for sclerotization and the biological significance of peroxidase in cuticle is discussed.
Isolation and identification of 20‐hydroxyecdysone from a lepidopteran continuous cell line
Authors: Lynn D. E. , Feldlaufer M. F. , Lusby W. R. 
Published: February 2005

AbstractExtracts of three continuous cell lines from the cabbage looper, Trichoplusia ni, were assayed for the presence of ecdysteroids. While no evidence of ecdysteroids was present in the extracts of the ovarian (TN‐368) or embryonic (IPLB‐TN‐R2) cell lines, radioimmunoassays on extracts of media and extracts of cell pellets from imaginal disc cell cultures (IAL‐TND1) were positive. The immunoreactive material from both cells and media co‐migrated with a 20‐hydroxyecdysone standard on reversed‐phase high‐performance liquid chromatography (HPLC). The immunoreactive fractions from the cell extract were chromatographed on silica HPLC and subjected to mass spectral analysis. Both of these analyses indicated that the unknown compound was 20‐hydroxyecdysone. Radioimmunoassay indicated up to 28 ng of ecdysone equivalents in cells (3.75 x 107 cells) from 50 ml of IAL‐TND1 cultures, which is equivalent to 120 ng of 20‐hydroxyecdysone based on relative reactivity of the antiserum used in this study. This report presents the first evidence of 20‐hydroxyecdysone production by a continuous insect cell line and also the first to show that cells from imaginal discs are capable of ecdysteroid synthesis.
Ecdysteroid action on moth epithelial tissues and cell lines
Authors: Oberlander H. , Leach C. E. , Lanka S. , Willis J. H. 
Published: February 2005

AbstractThe spontaneous formation of multicellular, fluid‐filled vesicles in primary cultures of pupal wings of Hyalophora cecropia is inhibited by 20‐hydroxyecdysone (20‐OH‐ecdysone). Physiological levels of ecdysteroids inhibit the ability of larval hemolymph to induce such vesicles in an established cell line (IAL‐TND1) derived from imaginal discs of Trichoplusia ni (Hübner). This cell line grew as vesicles for its first year in culture even in the absence of hemolymph, but then converted to growing as multicellular aggregates. Aggregate‐conditioned media but not vesicle‐conditioned or control media displayed ecdysteroid activity in an imaginal disc bioassay. Larval hemolymph had no influence on the imaginal discs' response to ecdysteroids. Hence, its action in promoting vesicle formation is not to prevent the action of ecdysteroids. We postulate that the change in morphology of TND1 cell cultures from vesicles to aggregates was accompanied by their attaining (or enhancing) the capacity to produce ecdysteroids.
Long‐term cholesterol labeling as a convenient means for measuring ecdysteroid production and catabolism in vivo: Application to the last larval instar of Pieris brassicae
Authors: Beydon Philippe , Lafont René 
Published: February 2005

AbstractIn vivo biosynthesis of ecdysteroids during the last larval instar of Pieris brassicae was investigated by administering [3H] cholesterol followed byhigh‐performance liquid chromatography analysis of the resulting [3H] ecdysteroids. The demonstration that the specific activity of the ecdysteroids synthesized at a given time is always identical with that of cholesterol indicates that the cholesterol pool is uniformly labeled, and this allows us to easily calculate the amounts of ecdysteroids produced by animals. The total amount of ecdysone produced throughout the last larval instar was measured as 1.17 nmol/insect. This quantity is more than three‐fold the maximal level of molting hormones (ecdysone +20‐hydroxyecdysone) reached during the instar (0.37 nmol/animal) because a high catabolic activity occurs at the beginning of the hormone production period. Larvae thus differ from pupae, where catabolism is minimal when ecdysone synthesis takes place, resulting in a more “economical” system.
Succinate metabolism related to lipid synthesis in the housefly Musca domestica L
Authors: Halarnkar Premjit P. , Heisler Charles R. , Blomquist Gary J. 
Published: February 2005

AbstractThe metabolism of succinate was examined in the housefly Musca domestica L. The labeled carbons from [2,3‐14C]succinate were readily incorporated into cuticular hydrocarbon and internal lipid, whereas radioactivity from [1,4‐14C]succinate was not incorporated into either fraction. Examination of the incorporation of [2,3‐14C]succinate, [1‐14C]acetate, and [U‐14C]proline into hydrocarbon by radio‐gas‐liquid chromatography showed that each substrate gave a similar labeling pattern, which suggested that succinate and proline were converted to acetyl‐CoA prior to incorporation into hydrocarbons. Carbon‐13 nuclear magnetic resonance showed that the labeled carbons from [2,3‐13C]succinate enriched carbons 1, 2, and 3 of hydrocarbons with carbon‐carbon coupling showing that carbons 2 and 3 of succinate were incorporated as an intact unit. Radio‐high‐performance liquid chromatographic analysis of [2,3‐14C]succinate metabolism by mitochondrial preparations showed that in addition to labeling fumarate, malate, and citrate, considerable radioactivity was also present in the acetate fraction. The data show that succinate was not converted to methylmalonate and did not label hydrocarbon via a methylmalonyl derivative. Malic enzyme was assayed in sonicated mitochondria prepared from the abdomens and thoraces of 1‐ and 4‐day‐old insects; higher activity was obtained with NAD+ in mitochondria prepared from thoraces, whereas NADP+ gave higher activity with abdomen preparations. These data document the metabolism of succinate to acetyl‐CoA and not to a methylmalonyl unit prior to incorporation into lipid in the housefly and establish the role of the malic enzyme in this process.
Diflubenzuron‐Induced alterations during in vitro development of Tenebrio molitor pupal integument
Authors: Soltani N. , Quennedey A. , Delbecque J. P. , Delachambre J. 
Published: February 2005

AbstractThe effects of diflubenzuron (DFB) in Tenebrio molitor pupae were first investigated on cuticle secretion induced by 20‐hydroxyecdysone in vitro. The sternal integuments were treated by DFB either 3 days before culture or during culture. DFB, when applied before culture, did not prevent the molting hormone from inducing a new cuticle deposition by integument explants in vitro. However, this cuticle showed several architectural alterations and a thickness reduction. When applied during the culture in the presence of 20‐hydroxyecdysone, DFB at high dose (≥ 20 μg/ml) was able to inhibit cuticle secretion, but lower doses (⩽ 10 μg/ml) resulted in epicuticle deposition. These observations confirm in vivo studies showing antagonistic effects of DFB and ecdysteroids at the level of epidermal cells.In another series of experiments, the DFB effects were analyzed without addition of exogenous molting hormone in vitro. Because it had been observed in previous studies that pupal epidermal explants of Tenebrio secrete low but significant amounts of ecdysteroids in the culture medium, this in vitro secretion was measured by radioimmunoassay after DFB treatment. It was observed that DFB, when applied either before or during culture, significantly reduced the hormonal secretion in vitro. This reduction, observed at the level of epidermal cells, could be homologous with the diminution of the endogenous ecdysteroid peak previously described after in vivo DFB treatment in Tenebrio pupae.
Molecular characteristics of lipophorin, the juvenile hormone‐binding protein in the hemolymph of the Colorado potato beetle
Authors: de Kort C. A. D. , Koopmanschap A. B. 
Published: February 2005

AbstractLipophorin, the protein that specifically binds juvenile hormone in the hemolymph of the Colorado potato beetle, Leptinotarsa decemlineata, is a high‐density lipoprotein of Mr ∼ 574,000. Lipophorin contains 43% lipid and is composed of two apoproteins: apolipophorin I (Mr ∼ 251,000) and apolipophorin II (Mr ∼ 78,000). Both apoproteins contain mannose residues. Carotenoids make up a substantial part of the lipid fraction. Lipophorin constitutes about 25% of the total hemolymph proteins. Its concentration in the hemolymph (26 μM in 4‐day‐old long‐day and 40 μM in 4‐day‐old short‐day beetles) changes with different physiological conditions concomitant with changes in total protein content. Lipophorin specifically binds 10R‐juvenile hormone III with high affinity. The dissociation constant for 10R‐juvenile hormone III is 12 ± 2 nM. One lipophorin molecule contains one specific juvenile hormone‐binding site. The concentration of binding sites therefore equals that of lipophorin in hemolymph.
Major plasma proteins of larvae of the southwestern corn borer, Diatraea grandiosella
Authors: Lenz C. J. , Venkatesh K. , Chippendale G. M. 
Published: February 2005

AbstractThe major protein fraction of the larval hemolymph of the southwestern corn borer, Diatraea grandiosella, was shown to be composed of approximately six native proteins, and accounted for up to 55% of the plasma proteins. The apparent molecular weights of these proteins ranged from 350,000 to 500,000, as determined by nondenaturing electrophoresis at a neutral pH. Lower apparent molecular weights were obtained when the major protein fraction was subjected to electrophoresis at a high pH under nondenaturing conditions, indicating that these proteins dissociated under alkaline conditions. The isoelectric points of the major hemolymph proteins fell between 5.6 and 5.9. Denaturing electrophoresis and two‐dimensional electrophoresis showed that the native proteins were composed of subunits having apparent molecular weights of 78,000, 84,000, and 87,000. These subunits were the major labeled polypeptides found in the hemolymph of feeding last instar larvae 24 h after they had been injected with [3H]leucine. They were also the major polypeptides synthesized when the fat body of last instar prediapausing larvae was incubated in vitro for 4 h in Grace's medium containing [3H]leucine. Immunoelectrophoresis confirmed that the major hemolymph proteins were present in the larval fat body. In addition, these proteins were the major proteins present in the hemolymph of diapasuing larvae.
Effects of precocene II on female‐specific hemolymph polypeptides in Oncopeltus fasciatus
Authors: Martínez T. , Garcerá M. D. 
Published: February 2005

AbstractUsing polyacrylamide gel electrophoresis (PAGE) under denaturing conditions, two major polypeptides of 200,000 and 170,000 daltons were detected in the hemolymph of mature female Oncopeltus fasciatus, but they were not found in the hemolymph of males or newly emerged females. Those polypeptides constituted the two major bands of early vitellogenic oocytes; however, they were absent from the yolk of mature eggs. The slower‐migrating band (200,000 daltons) appears to correspond to a vitellogenic protein already identified in O. fasciatus, whose synthesis has been suggested to be independent of juvenile hormone (JH). Treatment of newly emerged adult females with the corpus allatum cytotoxin precocene II prevented the appearance of the female‐specific bands and induced an important accumulation of other proteins in the hemolymph. Yolk deposition was also inhibited in those animals. Topical application of JH to precocene‐treated females restored the appearance of the 200,000 and 170,000 dalton polypeptides in the hemolymph. These results suggest that JH is required for the synthesis of female‐specific polypeptides in O. fasciatus.
Regulation of long‐term oviposition in the house cricket, Acheta domesticus: Roles of prostaglandin and factors associated with sperm
Authors: Murtaugh Michael P. , Denlinger David L. 
Published: February 2005

AbstractThe transfer of spermatophore contents derived from testes during mating greatly stimulates ovipositional activity for long periods of time in the house cricket, Acheta domesticus (L.). Since prostaglandins appear to play a role in reproduction in several insect species, and since prostaglandin synthesis enzymes occur in cricket testes and spermatophores, we investigated the role of prostaglandins in the regulation of long‐term oviposition. Inactivation of prostaglandin synthesis enzymes in males or females using specific inhibitors failed to block mating‐induced increases in egg laying. However, males lacking sperm because of X‐irradiation were unable to induce oviposition even though they mated, transferred spermatophores, and had high levels of prostaglandins in both testes and spermatophores. X‐irradiation was also used to generate males with nonfunctional sperm. Females mated to these animals readily laid eggs, which failed to develop. It appeared that sperm or a factor associated with sperm induced long‐term oviposition in female house crickets. Prostaglandin synthesis enzymes transferred from the male to females may have other roles in the female, for example, in sperm maintenance in the spermatheca. Previous observations strongly suggest that prostaglandins induce egg laying behavior and activity; they may be synthesized by female enzymes that are regulated by male‐derived factors.
Monoclonal antibodies specific for apoproteins of lipophorins from the migratory locust
Authors: Schulz Thomas K. F. , Van Der Horst Dick J. , Amesz Hans , Voorma Harry O. , Beenakkers Ad M. Th. 
Published: February 2005

AbstractSpleen lymphocytes from mice immunized with locust native low‐density lipophorin A+ (LDLp) were fused with nonproducing myeloma cells, strain Sp 2/0. Hybridomas that were isolated from the fused cells produced antibodies specific for LDLp and the high‐density lipophorin Ayellow (HDLp).Monoclonal strains were generated through cloning by limiting dilution from those hybridomas synthesizing antibodies specific for apolipophorins (apoLp)‐I, ‐II, and ‐III of LDLp. Additionally, a hybridoma strain that was obtained after fusion of lymphocytes from mice immunized with apoLp‐III produced antibodies that bind to apoLp‐III and native LDLp.Some features of LDLp and HDLp were studied using these antibodies. It could be demonstrated that apoLp‐I and apoLp‐II are not immunochemically identical and are exposed in the native particle of both LDLp and HDLp. It was also shown that in both lipophorins apoLp‐II is less exposed than apoLp‐I, whereas in LDLp apoLp‐III is mainly exposed; some apoLp‐III could also be detected in HDLp.Tween‐20, a nonionic detergent, appears to affect the binding of anti‐apoLp‐I, ‐II, and ‐III to both LDLp and HDLp. The monoclonal antibodies specific for locust apolipophorins do not bind to the respective apoproteins of lipophorins from other insects.
Metabolism of polyunsaturated fatty acids by larvae of the waxmoth, Galleria mellonella
Authors: Stanley‐Samuelson David W. , Jurenka Russell A. , Loher Werner , Blomquist Gary J. 
Published: February 2005

AbstractThe metabolic fates of linoleic (18:2n6) and linolenic (18:3n3) acids injected into the hemocoel of fifth instar larvae of the waxmoth, Galleria mellonella, were examined by radio‐high‐pressure liquid chromatography and radio‐gas‐liquid chromatography. In addition to undergoing β‐oxidation and incorporation into neutral and phospholipid fractions, a portion of both of these C18 fatty acids was elongated and desaturated to longer chain and more unsaturated polyenoics. Radioactivity from linoleic acid was recovered in components that coeluted with 18:3, 18:4, 20:3, and 20:4. Radioactivity from linolenic acid was recovered in an unidentified component and in components that coeluted with 18:4, 20:3, and 20:5. Labeled arachidonic and eicosapentaenoic acids injected into waxmoth larvae were converted to prostaglandins, suggesting that one aspect of the biological significance of the elongation/desaturation reactions is to generate precursors for prostaglandin biosynthesis.
Single‐channel recordings of chloride currents in primary cultured Drosophila neurons
Authors: Yamamoto Daisuke , Suzuki Nobuyuki 
Published: February 2005

AbstractSingle‐chloride‐channel currents were recorded from primary cultured Drosophila neurons by means of the gigaohm‐seal patch‐clamp technique. Small inward‐going current channels were observed in excised inside‐out patches with the external face of the membrane exposed to bathing solutions devoid of K+, Na+, and Ca2+. The inward current was affected by changing the anions but not the cations bathing the cytoplasmic face of the patch. Complete replacement of CI− by glutamate eliminated the current. The current was maintained with intracellular solutions containing NO3− in place of CI−. The single‐channel conductance was estimated to be 7 ps with CI−, and 11 ps with NO3− at 10°C. Possible functions of this anion‐selective channel have been discussed.
Properties of an ATP‐dependent Ca2+ pump and (Ca2+ + Mg2+)‐ATPase in brain synaptosome membrane vesicles from the bertha armyworm, Mamestra configurata Wlk
Authors: Luo Ma , Bodnaryk Robert P. 
Published: February 2005

AbstractBiochemical and kinetic properties under identical substrate and reaction conditions were obtained for an ATP‐dependent Ca2+ pump and (Ca2+ + Mg2+)‐ATPase in synaptosome membrane vesicles prepared from the brain of the moth, Mamestra configurata. Both the ATP‐dependent Ca2+ pump and (Ca2+ + Mg2+)‐ATPase had single, high‐affinity binding sites for ATP (Km = 14 and 116 μM, respectively), Ca2+free (Km = 0.13 nM and 0.072 nM, respectively), and Mg2+ (Km = 1.1 mM and 0.07 mM, respectively). Both systems were relatively little affected by K+ and were insensitive to ouabain, an inhibitor of (Na+ + K+)‐ATPase. The results indicate that the ATP‐dependent Ca2+ pump and (Ca2+ + Mg2+)‐ATPase are functionally coupled in synaptic membranes and constitute a mechanism for Ca2+ transport in the brain of M. configurata.Although moth brain (Ca2+ + Mg2+)‐ATPase is maximally active at nanomolar concentrations of free calcium ion, the enzyme retains at least one‐half of its maximal activity at micromolar calcium concentrations, indicating either that the enzyme has two binding sites for calcium (a high‐affinity site at nanomolar Ca2+free and a low‐affinity site at micromolar Ca2+free), or that there are two enzymes with high and low affinity for calcium, respectively. Calcium extrusion from brain neurones of M. configurata may operate in a two‐stage, concentration‐dependent process in which a first stage, low‐affinity pump reduces intraneuronal calcium to a concentration at which a second stage, high‐affinity pump becomes activated.
Enhancement by farnesol and farnesoic acid of juvenile‐hormone biosynthesis in induced low‐activity locust corpora allata
Authors: Couillaud Franck , Mauchamp Bernard , Girardie Adrien , de Kort Stan 
Published: February 2005

AbstractExogenous farnesol or farnesoic acid (FA) stimulates juvenile hormone III (JH III) biosynthesis by isolated corpora allata from Locusta migratoria in a dose‐dependent manner. Farnesol and FA also stimulate a dose‐dependent accumulation of substantial amounts of methyl farnesoate (MF), identified by gas chromatography‐mass spectroscopy (GCMS) analysis, in the corpora allata. Lower quantities of MF were found in the incubation medium. Corpora allata, denervated 2 days prior to assay, showed low spontaneous rates of JH biosynthesis which were stimulated by farnesol and FA. The dose‐response curves for control and denervated corpora allata were similar. During oocyte maturation the rate of farnesol and FA stimulation of JH biosynthesis increased gradually. However, after transection of nervus corporis allati 1 (NCA‐1), the rate of stimulated JH synthesis was maintained at preoperative levels. Although the spontaneous rate of JH biosynthesis decreased rapidly after NCA‐1 transection, denervated glands could still be stimulated by farnesol or FA to produce large amounts of JH. These results suggest that the low spontaneous rate of JH biosynthesis in denervated corpora allata is not caused by inhibition of the final steps of JH biosynthesis.
Ecdysteroid regulation of amino sugar uptake in a lepidopteran cell line derived from imaginal discs
Authors: Porcheron P. , Oberlander H. , Leach C. E. 
Published: February 2005

AbstractThe hormonal regulation of uptake of amino sugars was examined in a cell line derived from imaginal wing discs of the Indianmeal moth, Plodia interpunctella (Hübner). The cell line, IAL‐PID2, responded to treatment with 20‐hydroxyecdysone with increased uptake of N‐acetyl‐D‐glucosamine, N‐acetyl‐galactosamine, and D‐glucosamine. Uptake was stimulated with 3‐O‐methyl D‐glucose, and to a lesser extent with 2‐deoxy‐D‐glucose, but not with D‐glucose or D‐mannose. The requirements for optimum hormonal stimulation of uptake of N‐acetyl‐D‐glucosamine were similar to those for uptake of this chitin precursor by intact wing discs. The PID2 cell line is responsive to treatment with 20‐hydroxyecdysone and offers promise of being amenable to a detailed analysis of the mode of action of ecdysteroids on the uptake of amino sugars.