bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hormonal control of locust oviducts
Authors: Lange Angela B. 
Published: February 2005

AbstractThe oviducal muscles of the locust, Locusta migratoria, contract in a spontaneous and rhythmic fashion when isolated from the central nervous system. Hemolymph of ovipositing females, when added to isolated locust oviducts, altered the spontaneous contractility of the oviduct. This response was not evident after addition of hemolymph from a nonovipositing female and was still present after addition of the α‐aminergic receptor antagonist, phentolamine.Oviducts in which mature eggs were present responded to homogenates of the corpus cardiacum by increasing both the frequency and amplitude of muscular contraction, whereas oviducts devoid of eggs showed no response. Extracts of ventral nerve cord also increased the spontaneous activity of the oviduct musculature. Although the muscles of the oviduct responded to homogenates of the brain, this response differed in two ways from the response due to corpus cardiacum homogenates. First, oviducts devoid of mature eggs responded to brain homogenates; and second, the response caused by the brain homogenates could be eliminated by the addition of 1 μM phenoxybenzamine. The significance of these results is discussed.
Posteclosion behavior of the flesh fly, Sarcophaga crassipalpis: A comparison of wild‐type and unicorn mutants
Authors: Žďárek Jan , Denlinger David L. 
Published: February 2005

AbstractNewly emerged flies go through a stereotypic behavioral pattern of walking, grooming, abdomen contraction (pulsing), and active uptake of air (pumping). These behavioral activities can be readily distinguished on the basis of hemolymph pressure changes. Wild‐type flies and a unicorn mutant that fails to properly retract its ptilinum show identical patterns of posteclosion activity. However, a portion of the unicorns do not fully expand their wings and abdomen. Such flies are missing only the pumping component of the normal behavioral repertory, thus implying that pulsing and pumping are independently controlled.
Ecdysone metabolism in Pieris brassicae during the feeding last larval instar
Authors: Beydon Philippe , Girault Jean‐Pierre , Lafont René 
Published: February 2005

AbstractEcdysone metabolism in Pieris brassicae during the feeding last larval stage was investigated by using 3H‐labeled ecdysteroid injections followed by high‐performance liquid chromatographic (HPLCAbbreviations: 3DE = 3‐dehydroecdysone; 3D20E = 3‐dehydro‐20‐hydroxyecdysone; 2026E = 20,26‐dihydroxyecdysone; E = ecdysone; Eoic = ecdysonoic acid; 2026E′ = 3‐epi‐20,26‐dihydroxyecdysone; E′ = 3‐epiecdysone; E′oic = 3‐epiecdysonoic acid; E′8P = 3‐epiecdysone 3‐phosphate; 20E′ = 3‐epi‐20‐hydroxyecdysone; 20E′3P = 3‐epi‐20‐hydroxyecdysone 3‐phosphate; FT = Fourier transform; HPLC = high‐performance liquid chromatography; 20E = 20‐hydroxyecdysone; 20Eoic = 20‐hydroxyecdysonoic acid; NMR = nuclear magnetic resonance; NP‐HPLC = normal phase HPLC; RP‐HPLC = reverse phase HPLC; TFA = trifluoroacetic acid; Tris = tris(hydroxymethyl)‐aminomethane.
) analysis of metabolites. Metabolites were generally identified by comigration with available references in different HPLC systems. Analysis of compounds for which no reference was available required a large‐scale preparation and purification for their identification by 1H nuclear magnetic resonance spectrometry.The metabolic reactions affect the ecdysone molecule at C‐3, C‐20, and C‐26, leading to molecules which are modified at one, two, or three of these positions. At C‐20, hydroxylation leads to 20‐hydroxyecdysteroids. At C‐26, hydroxylation leads to 26‐hydroxyecdysteroids which can be further converted into 26‐oic derivatives (ecdysonoic acids) by oxidation. At C‐3, there are several possibilities: there may be oxidation into 3‐dehydroecdysteroids, or epimerization possibly followed by phosphate conjugation.Thus, injected 20‐hydroxyecdysone was converted principally into 20‐hydroxyecdysonoic acid, 3‐dehydro‐20‐hydroxyecdysone, and 3‐epi‐20‐hydroxyecdysone 3‐phosphate. Labelled ecdysone mainly gave the same metabolites doubled by a homologous series lacking the 20‐hydroxyl group.
Carbohydrate metabolism in starved fifth instar larvae of Manduca sexta
Authors: Siegert Karl J. 
Published: February 2005

AbstractThe influence of starvation on carbohydrate metabolism in fifth instar larvae of Manduca sexta was studied. The percentage of active fat body glycogen phosphorylase increased from 10% to approximately 50% within 3 h of starvation; afterward the enzyme was slowly inactivated. The increase of phosphorylase activity might have been caused by a peptide(s) from the CC. The amount of fat body glycogen in starved animals decreased over 24 h by approximately 20 mg. The released glucose molecules seem to be converted mainly to trehalose because the hemolymph trehalose concentration in starved animals was always slightly higher than in the fed controls, and the glucose concentration decreased even when phosphorylase was activated. The chitosan content in starved larvae increased during the first 9 h of treatment to the same extent as in fed controls. It is suggested that fat body glycogen phosphorylase was activated during starvation to provide substrates for chitin synthesis and energy metabolism.
Synthesis of proteins and nucleic acids by the pea aphid Acyrthosiphon pisum (aphididae) in the absence of a full complement of dietary amino acids
Authors: Srivastava P. N. , Srivastava U. , Thakur M. , Auclair J. L. 
Published: February 2005

AbstractProtein, nucleic acids, and nucleotide syntheses were studied in pea aphids, Acyrthosiphon pisum (Harris), by feeding them labeled 14C‐amino acids and [5‐3H]‐orotic acid in sucrose. It was demonstrated that in the absence of dietary essential amino acids, aphids were capable of synthesizing nucleic acids, nucleotides, and proteins when provided with a single dietary amino acid in sucrose. It is suggested that other required amino acids were possibly supplied by the symbionts present in the pea aphid and/or were obtained from the amino acid pool in the hemolymph or glucose, one of the end products of sucrose digestion. Of the various amino acids tested, synthesis of measurable amounts of protein or other compounds occurred when alanine, aspartic acid, glutamic acid, glycine, proline, or serine were provided, but no synthesis occurred with cysteine.
Effect of the brain and corpus cardiacum on egg production in Rhodnius prolixus
Authors: Davey K. G. 
Published: February 2005

AbstractUsing total egg production corrected for size of blood meal as an index of the activity of the corpus allatum (CA), the effects of various surgical manipulations of the neuroendocrine system have been examined. Isolation of the CA from its nervous connections increases egg production well beyond that of a normal insect, thus confirming that the CA is at least partly controlled by inhibitory nerves from the brain. Removal of the corpora cardiaca (CC) reduces the level of this increased egg production, and decapitation anterior to the CC results in a level of egg production that is greater than that found in females decapitated between the CA and CC. Implanting a CC together with a CA into a decapitated female results in a higher egg production than implanting a CA alone. These results demonstrate that an allatotropic influence is exerted by the CC. Experiments designed to examine the role of the brain were inconclusive and did not eliminate the possibility that the allatotropin from the CC originated in the brain.
Biochemical and immunological studies on an α‐glycerophosphate dehydrogenase from the tephritid fly, Anastrepha suspensa
Authors: Sarma Ranjit , Kitto G. Barrie , Berlocher Stewart , Bush Guy L. 
Published: February 2005

AbstractA rapid and efficient procedure has been developed for the purification of α‐glycerophosphate dehydrogenase from the tephritid fly Anastrepha suspensa. This procedure is applicable to the isolation of the enzyme from other tephritids. The A. suspensa α‐glycerophosphate dehydrogenase is dimeric with a molecular weight of 70,000 and a subunit molecular weight of 35,000. The pH optimum of the enzyme is 7.0. The amino acid composition is compared with that of other α‐glycerophosphate dehydrogenases. By means of the quantitative microcomplement fixation procedure the A. suspensa α‐glycerophosphate dehydrogenase is compared immunologically to a variety of other tephritid and dipteran α‐glycerophosphate dehydrogenases.
Variation in thickness and protein content of the cuticle of the female of Glossina austeni
Authors: Solowiej S. , Davey K. G. 
Published: February 2005

AbstractThe thickness and total protein content of the ventral abdominal cuticle of the female tsetse, Glossina austeni, increase during the early part of each pregnancy cycle, reaching a maximum at approximately 2 days after ovulation. They decrease thereafter, and reach a minimum value just before larviposition. Virgin females do not exhibit a cycle of protein content or thickness in the cuticle. Preliminary data on the incorporation of [3H]tyrosine or [3H]leucine into the water‐soluble proteins of the ventral abdominal cuticle at the time of the second larviposition suggest that there is rapid turnover of protein in the cuticle at this time. These observations are consistent with the net storage of protein in the cuticle during the early part of pregnancy cycle followed by a net depletion of that store as the nutritional demands of the rapidly growing larva in utero exceed the capacity of the ingested blood meals to supply them.
Isolation and characterization of vitellin from the fruitfly, Dacus oleae
Authors: Levedakou Eleni N. , Sekeris Constantine E. 
Published: February 2005

AbstractVitellin was isolated from mature eggs of Dacus oleae. A combination of anion‐exchange chromatography and gel filtration was used for purification of the protein. The molecular weight of isolated vitellin, as determined by Sephacryl S‐300 chromatography, was approximately 300,000. Electrophoresis on SDS‐polyacrylamide gels demonstrated the presence of vitellin subunits with molecular weight of 47,000 and 49,000. Isoelectric focusing on polyacrylamide gels revealed a series of polypeptides with isoelectric points covering an acidic pH region of 5.7 to 6.2. Immunodiffusion, immunoelectrophoresis, and immunoblotting were used for further characterization of vitellin.
Ecdysteroid production by a continuous insect cell line
Authors: Ward G. B. , Kelly T. J. , Woods C. W. , Marks E. P. 
Published: February 2005

AbstractThe spent medium from ten established cell lines was extracted and tested for ecdysteroids by radioimmunoassay. Of the seven lepidopteran lines tested, only IAL‐TNDI and MRRL‐CH showed evidence of ecdysteroid production. However, the results were erratic and difficult to evaluate and these lines were dropped from further consideration. However, of the three cockroach cell lines tested, one, UMBGE 4, produces ecdysteroid and consistently releases virtually all of it into the medium. The main ecdysteroid was identified as ecdysone and the increase was logarithmic during the first 11 days of the subculture, with a decrease from day 11 to day 14.UMBGE 4 is a vesicle cell line which also tested positive for chitin synthesis. When the pH of the medium was lowered from pH 7.4 to pH 6.3, both the chitin synthesis and the ecdysone synthesis dropped by roughly 50%.
Isolation of two arginine vasopressin‐like factors from ganglia of Locusta migratoria
Authors: Schooley David A. , Miller Christine A. , Proux Jacques P. 
Published: February 2005

AbstractTissues of Locusta migratoria are known to contain a material which crossreacts with an antibody against arginine vasopressin (AVP), and this factor has been correlated with the diuretic hormone of this species. In this paper, we report the isolation of two AVP‐like factors from suboesophageal ganglia and thoracic ganglia of Locusta migratoria. The less abundant, more hydrophobic of these AVP‐like factors shows diuretic activity in an assay where excretion of amaranth dye from Locusta migratoria hemolymph is used as the scoring criterion. After extracting a total of ∼ 51,000 ganglia with an acidic solvent, the crude extract was prepurified by batch adsorption/elution from disposable reversed‐phase cartridges. The prepurified extract was then sequentially purified by reversed‐phase liquid chromatography using solvent programs of substantially differing selectivity. The more abundant factor was isolated to apparent homogeneity in three steps, while the less abundant factor required four or five steps. Use of a C4 reversed‐phase column minimized losses of the minor, more hydrophobic factor.
Some aspects of activity regulation of Galleria mellonella PTTH cells
Authors: Muszyńska‐Pytel Malgorzata 
Published: February 2005

AbstractUsing the Galleria prothoracicotropic bioassay, five small neurosecretory cells occurring in each dorsolateral part of protocerebrum of Galleria mellonella brain were identified as prothoracicotropic hormone (PTTH) cells. It was found that the critical period for the release of PTTH from a brain implanted in neck‐ligated larva lasts up to the third day after implantation. The content of paraldehyde‐fuchsin positive neurosecretory material (NSM) in PTTH cells was determined during the penultimate and last larval instar, during pupal instar, and in starved or poststarvation fed or space‐deprived last instar larvae. Two peaks of NSM in PTTH cells were found in the penultimate instar (in freshly molted, and 76‐h‐old larvae), four peaks in the last instar larvae (in freshly molted, and in 67‐, 132‐, and 174‐h‐old larvae), and one peak in the pupal instar (in 56‐76‐h‐old pupae). It was also observed that upon starvation NSM accumulated in PTTH cells, while after 3 h of poststarvation feeding it was released. In permanent space‐deprived last instar larvae no NSM occurred in PTTH cells. In all investigated larval instars a rapid release of NSM from PTTH cells was found a few hours after molt associated with the beginning of the feeding period. The significance of the NSM content in PTTH cells is discussed in relation to ecdysteroid titer.
Sodium inward currents through calcium channels in mealworm muscle fibers
Authors: Yamamoto Daisuke 
Published: February 2005

AbstractThe contribution of Na+ ions to the nonsynaptic electrogenesis was studied in the larval muscle fibers of mealworm, Tenebrio molitor, using currentclamp and voltage‐clamp techniques. Na‐dependent graded responses were generated by depolarizing current stimuli in Ca2+‐free solutions. These responses were insensitive to tetrodotoxin and were blocked by Co2+. Large inward‐going currents were elicited by step depolarizations in Ca2+‐free solutions under voltage‐clamp conditions. The inward currents were totally eliminated by removal of Na+ from the bathing solution. These results indicate that the calcium channel of mealworm muscle is permeable to Na+.
Purification and characterization of three major hemolymph proteins of an insect, Calpodes ethlius (lepidoptera, hesperiidae)
Authors: Palli Subba Reddy , Locke Michael 
Published: February 2005

AbstractLike many other Lepidoptera, fifth‐stage Calpodes larvae have three major hemolymph proteins. Their molecular weights were estimated by 3‐15% nondenaturing polyacrylamide gel electrophoresis (N‐PAGE) as 470,000 (arylphorin; Ar), 580,000 (storage protein 2; SP2) and 720,000 (storage protein 1; SP1). Carbohydrate is associated with all three, but only Ar has lipid. The three proteins have been purified by preparative N‐PAGE and sodium dodecyl sulfate (SDS)‐polyacrylamide gel electrophoresis. On 3‐15% SDS gels, Ar dissociated into 82,000 Mr subunits, SP2 into 86,000 Mr subunits, and SP1 into both 86,000 and 90,000 Mr subunits. The 470,000 Mr protein is identified as Ar because it is rich in aromatic amino acids. The 580,000 and 720,000 Mr proteins are rich in glycine and are called storage proteins. Electron microscopy of negatively stained preparations shows that each polymer has a different geometrical arrangement of subunits. SP1 is a cube made from eight subunits. SP2 is a hexamer in the form of a pentahedral prism. Ar is probably an octahedron made from six subunits. All three geometrical arrangements could permit the presence of a central carrying space.
Mode of action of proctolin on locust visceral muscle
Authors: Lange Angela B. , Orchard Ian , Lam William 
Published: February 2005

AbstractProctolin increases the frequency and amplitude of myogenic contractions and results in a sustained contraction of the oviducts of Locusta migratoria. The possible mode of action of proctolin receptors on this visceral muscle has been investigated. Calcium‐free saline, containing either 20 mM magnesium ions or 100 μM EGTA, inhibited myogenic contractions, lowered basal tension, and abolished all the effects of proctolin following a 20 min incubation. These effects were reversible upon washing with normal saline. Similar results were obtained with normal saline containing 10 mM cobalt ions. Nifedipine at 50 μM lowered basal tension, abolished myogenic contractions, and reduced the proctolin‐induced sustained contraction by 42‐62% at 0.5 nM proctolin and by 33‐37% at 5 nM proctolin. Similar results were obtained with 100 μM verapamil. Proctolin was still capable of eliciting considerable contractions (25‐67% of controls) in preparations depolarized with 100 mM potassium saline. The removal of calcium from the high‐potassium saline reversibly abolished the potassium‐induced contraction and reversibly blocked the action of proctolin. Nifedipine was ineffective in blocking the action of proctolin in high‐potassium saline. Neither cyclic AMP levels nor cyclic GMP levels of the lateral oviducts were elevated by proctolin in the presence of a phosphodiesterase inhibitor. The results indicate that proctolin mediates its effects via an influx of external calcium ions. This calcium appears to enter through two channels, a voltage‐dependent channel and a receptor‐operated channel. Cyclic nucleotides do not appear to be involved in the action of proctolin in this visceral muscle.
Effects of steroid metabolism inhibitors and ecdysteroid analogs on honey bee sterol metabolism and development
Authors: Svoboda James A. , Herbert Elton W. , Thompson Malcolm J. 
Published: February 2005

AbstractThe effects of two azasteroids, an alkyl amine, and two ecdysteroid analogs on honey bee (Apis mellifera L.) sterol metabolism and development were compared by feeding each compound in a chemically defined diet supplemented with 24‐methylenecholesterol. Although each of the inhibitors, 25‐azacoprostane, 25‐azacholestane, or N,N‐dimethyldodecanamine, has been shown to severely inhibit steroid metabolism and larval development in a number of species of omnivorous and phytophagous insects, none of them affected honey bee brood development to the adult stage. Compared to the controls, there was a strikingly higher relative percentage of 24‐methylenecholesterol in the sterols from prepupae reared by workers fed diets containing each of these inhibitors, but the level of this sterol was reduced considerably in the adults reared from the brood in these test colonies. Each of the ecdysteroid analogs, 22,25‐dideoxyecdysone or 2,22,25‐trideoxy‐5β‐hydroxyecdysone, severely suppressed larval development when fed in the chemically defined diet. This effect apparently results from the presence of the dietary ecdysteroid or its metabolite in the brood food placed in the larval cells or the inability of the worker bees fed the ecdysteroid to include some essential factor in the brood food. The importance of this information relative to the possible application of certain steroid inhibitors to control pathogens of honey bees is discussed.
Properties of copper‐dependent o‐diphenol oxidase activity in the potato aphid Macrosiphum euphorbiae (thomas)
Authors: Skiba Paul J. , Mullin Christopher A. 
Published: February 2005

AbstractPotato aphid Macrosiphum euphorbiae (Thomas) was found to contain high amounts of o‐diphenol oxidase activity. Enzyme activity was largely distributed into the postmitochondrial supernatant from Brij‐35 extracted aphids and occurs in a latent form that was activated up to 45‐fold by pretreatment with isopropanol. The aphid enzyme has a broad pH optimum near 6, and utilized L‐dopa (Km = 1.4 mM, Vmax = 348 nmol/min‐mg protein), dopamine, and 4‐methylcatechol the best out of the twelve substrates tested. In addition, this activity is a typical copper‐dependent oxidase in that it is potently inhibited by phenylthiourea (50% inhibition at 30nM) and other copper chelators, including salicylhydroxamic acid. The above properties are common to most insect tyrosinases. However, the aphid enzyme lacked the o‐hydroxylase and laccase components and the optimal activity at higher temperatures that are typical of cuticular tyrosinases of other insects. The high levels of o‐diphenol oxidase in aphids compared to other insects is surprising, since the major function associated with these enzymes, that of melanization and sclerotization of cuticle, is of much less importance to aphids. The possibility that aphids use this enzyme to metabolize dietary phenolics is discussed.
Metabolism and excretion of acetylchromenes by the migratory grasshopper
Authors: Isman Murray B. , Proksch Peter , Witte Ludger 
Published: February 2005

AbstractThe extent of metabolism and excretion of three acetylchromenes (two toxic, one relatively nontoxic) were examined in adult migratory grasshoppers (Melanoplus sanguinipes) following topical administration. Both the total amount excreted (parent plus metabolites) and the proportion of parent compound in the excreta were inversely correlated with contact toxicity. Both toxic and nontoxic acetylchromenes are rapidly absorbed from the cuticle, with maximum excretion of parent and metabolite chromenes from 4 to 8 h posttreatment in each case. Much of the applied compounds (60–80%) apparently remains within the insect, and cannot be recovered by extraction of the insect. Metabolites formed result from simple oxidative and reductive transformations. For all of the compounds tested (including the allatocidin precocene II), the major mode of metabolism results from aliphatic hydroxylation of one of the geminal methyl groups on the chromene. No conjugated metabolites were found in the excreta.
Identification of juvenile hormone III in the hemolymph of Blattella germanica adult females by gas chromatography‐mass spectrometry
Authors: Camps Francisco , Casas Josefina , Sanchez Francisco‐Jose , Messeguer Angel 
Published: February 2005

AbstractJuvenile hormone III was identified in purified hemolymph extracts of adult females of the cockroach Blatella germanica by gas chromatography‐mass spectrometry with chemical ionization and selected ion monitoring. Under these conditions, juvenile hormones I and II were not detected within the sensitivity ranges of this analytical method. For quantification purposes a 5,5‐bisdeuterated analog of juvenile hormone III was synthesized and used as an internal standard. In general, juvenile hormone III titers obtained correlated with data on oocyte growth and with hormone titers found from in vitro corpora allata incubations along the first gonotrophic cycle.
Chitin metabolism
Authors: Chen Andrew C. 
Published: February 2005

AbstractRecent studies on chitin metabolism in insect cuticle are reviewed. Differences in enzymes involved in both synthesis and degradation of chitin are discussed. Emphasis is put on the complexity of chitin degradation involving various enzymes. Evidence for the possible existence of an alternative pathway leading to the formation of chitin is introduced. The involvement of hormones in chitin metabolism is also briefly discussed.