bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid composition of housefly microsomes
Authors: Spates G. E. , Elissalde M. , Williams H. 
Published: February 2005

AbstractThe lipid composition of microsomes isolated from whole‐body preparations of a diazinon‐resistant strain of the housefly (Musca domestica L.) was determined. When calculated on a mg% basis housefly microsomes are composed of 47% neutral lipids and 53% phospholipids. The free fatty acids compose the major group of compounds among neutral lipids (60%) and the major phospholipid is phosphatidylethanolamine (47.6%). The molar cholesterol/phospholipid ratio is 0.14, ca. twofold higher than the ratio found in mammalian liver microsomes. Fatty acid composition of housefly microsomes is notable only in that there is no uniform distribution of fatty acid moieties throughout the various classes of lipids, except for linoleic acid (18:2), which accounted for 9.2‐12.6% of the neutral lipids. Eighty percent of the fatty acid moieties of phosphatidylserine (+ phosphatidylinositol) were unsaturated. The highest percentage of saturated fatty acid moieties (64.26%) was found in lysophosphatidylethanolamine. Palmitoleic acid (16:1), the major fatty acid found in higher dipterans, ranged from 13.51% in lysophosphatidylethanolamine to 37.45% in the free fatty acids. One prostaglandin (PGF1d) and leukotriene B4 were detected in the microsomal lipids at concentrations of 59.7 and 716 pg/200 mg of protein, respectively.
Isolation and characterization of a high molecular weight JH‐III transport protein in the hemolymph of locusta migratoria
Authors: Koopmanschap A. B. , De Kort C. A. D. 
Published: February 2005

AbstractThe juvenile hormone binding protein in Locusta migratoria is a very high density lipoprotein of Mr ∼ 566,000. It contains 15% lipid and is composed of six seemingly identical subunits of Mr ∼ 77,000. It is a minor protein, constituting 1–2% of the total hemolymph proteins. Its concentration fluctuates with total protein content and follows a cyclic pattern related to the molting cycles.The binding protein has a high affinity for (10R)‐juvenile hormone III. The dissociation constant for the hormone is 3.7 ∼ 0.6 nM, and one binding molecule contains six hormone‐specific binding sites. The concentration of binding sites in the hemolymph is therefore very high, reaching a value of 26 μM in the last larval instar and 11 μM in the adult male.
Juvenile hormone‐binding protein and juvenile hormone esterase activity in hemolymph from last‐instar nymphs of Leucophaea maderae
Authors: Engelmann Franz , Mala Jaroslava , Borst David 
Published: February 2005

AbstractThe concentration of the juvenile hormone‐binding protein (JHB) in hemolymph was determined throughout the last nymphal instar. It was found to be 3.9 μM at the molt to the instar, rising to 13 μM by mid‐instar, and dropping to 6.7μM the day before emergence. Endocrine control of its production during the last nymphal instar could not be established. The apparent juvenile hormone esterase (JHF) activity was low at the molt to the last instar, but rose about fivefold by mid‐instar, and then modestly declined. On the day of emergence, JHF activity rose to the highest level observed. A four‐ to fivefold increase in absolute JHF activity was determined during the first half of the last nymphal instar. This increase is not regulated by JH. Removal of the JHB from hemolymph samples by precipitation with a polyclonal specific antibody increased the JHF activity up to 1,000‐fold. Thus, changes in the concentrations of JHB can affect the apparent activity of JHE, which is unrelated to the production or degradation of the JHF.
Identification and partial characterization of digestive carbohydrases in larvae of the Hessian fly, mayetiola destructor (Say) (Diptera: Cecidomyiidae)
Authors: Grover P. B. , Ross D. R. , Shukle R. H. 
Published: February 2005

AbstractSeveral carbohydrases and glycosidases from the alimentary cancal and/or salivary glands of feeding larvae of mayetiola destructor have been identified. Pectinase activity was identified in the midgut and may be present in the salivary glands. No endocellulase activity was found in larvae; however, hemicellulase activity was detected in extract of larvae. Amylase activity was present in midguts from feeding larvae and at a low level in extract of salivary glands. Amylases detected in the midgut showed mobilities during polyacrylamide gel electrophoresis similar to the two major amylases in tissues of the insect's host plant. The possibility exists that Hessian fly larvae utilize amylases obtained from their host plant in the digestion of starch. The major glycosidases detected in the midgut lumen of larve were: α‐D‐glucosidase and α‐D‐and β‐D‐galactosidase. The role of these enzymes in the feeding process of Hessian fly larvae is discussed as well as their potential role in feeding damage to wheat.
Antioxidant enzymes of the black swallowtail butterfly, Papilio polyxenes, and their response to the prooxidant allelochemical, quercetin
Authors: Pritsos Chris A. , Ahmad Sami , Bowen Susan M. , Elliott Andrew J. , Blomquist Gary J. , Pardini Ronald S. 
Published: February 2005

AbstractThe black swallowtail butterfly larvae, Papilio polyxenes, are specialist feeders that have adapted to feeding on plants containing high levels of prooxidant allelochemicals. Third, fourth, and fifth instar larvae were tested for their antioxidant enzyme activities, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GPOX), using 850‐g supernatants from whole‐body homogenates. The overall antioxidant enzyme profile for P. polyxenes was high compared to other insects, with activities ranging as follows: SOD, 1.1–7.5; CAT, 124–343; GR, 1.0–7.5; and GPOX, 0 units.To determine whether these antioxidant enzymes were inducible, P. poly xenes larvae were given a prooxidant challenge by dipping parsley leaves (their diet in the initial studies) in solutions of quercetin, such that the leaves became coated with this prooxidant flavonoid. Mid‐fifth instar larvae fed on quercetin‐coated leaves were assayed for antioxidant enzyme activities as was previously done with the larvae fed the standard diet. Food consumption and quercetin intake were monitored. SOD activity was increased almost twofold at the highest quercetin concentration tested. CAT and GR activity, on the other hand, were inhibited by increased quercetin consumption, with GR activity completely inhibited at the highest quercetin concentration after 12 h of feeding. GPOX activity, not present in control insects, was also not inducible by a quercetin challenge. These studies point out the key role that the antioxidant enzymes play in insect defenses against plant prooxidants.
Dose‐dependent influence of Campoletis sonorensis polydnavirus on the development and ecdysteroid titers of last‐instar Heliothis virescens larvae
Authors: Dover B. A. , Davies D. H. , Vinson S. B. 
Published: February 2005

AbstractCampoletis sonorensis calyx fluid arrests the development of last‐instar Heliothis virescens larvae and is associated with the gross degeneration of the host's prothoracic glands. Through manipulations of ovary supernatant, Campoletis sonorensis polydnavirus (CsV) was found to be the only component of calyx fluid responsible for causing host developmental arrest. Venom from C. sonorensis had no effect on host development. Suspensions of CsV were quantified, and various doses were injected into last‐instar hosts. The percentage of larvae developmentally arrested was dose dependent. In addition, larvae not arrested by injection with CsV suspensions were developmentally delayed in a dose‐dependent manner. Hosts were delayed in the stage in which they were injected and, after recovery, developed at normal rates. Measurements by radioimmunoassay indicated that developmental delay was due to a suppression of ecdysteroid titers. After a dose‐dependent period of suppression, hemolymph ecdysteroid titers recovered and reached titers comparable to those observed in saline‐injected controls. Examination of prothoracic glands from developmentally delayed larvae revealed that partial degeneration occurred. Comparisons of the number and mean size of surviving gland cells and the length of developmental delay suggested that surviving gland cells may compensate for degenerated cells by increasing their ecdysone production.
Neuroparsin: A new energetic neurohormone in the African locust
Authors: Moreau R. , Gourdoux L. , Girardie J. 
Published: February 2005

AbstractThe effects of neuroparsins on hemolymph trehalose and lipid levels and on total glycogen content were analyzed in Locusta migratoria. Saline and methanol extracts of the two lobes of the corpora cardiaca were assayed. Neuroparsins (A and B) were demonstrated to be hypertrehalosemic and hyperlipemic proteins of the neural lobe. Both of these metabolic activities of neuroparsins were somewhat less potent than those of adipokinetic hormone (AKH). Neuroparsin activity could be distinguished from AKH by blockage with an antiserum specific to neuroparsin. The hypertrehalosemic response induced by neuroparsins, in contrast to that of AKH, appeared to occur without a decrease of total glycogen content. The differential modes of action of AKH and neuroparsins could contribute to the fine modulation of carbohydrate metabolism in Locusta migratoria.
Degradation of aberrant proteins by larval tobacco hornworm, Manduca sexta L. (Sphingidae)
Authors: Rosenthal Gerald A. , Dahlman Douglas L. 
Published: February 2005

AbstractThe tobacco hornworm Manduca sexta (Sphingidae) readily incorporates L‐canavanine, the L‐2‐amino‐4‐(guanidinooxy)butyric acid structural analog of L‐arginine, into newly synthesized proteins. As a result, the developing fifth‐instar larva produces structurally aberrant canavanyl proteins that can exhibit severely impaired function. This situation is exacerbated by canavanine's ability to stimulate de novo protein synthesis. M. sexta larvae can respond to anomalous protein production by degrading canavanyl proteins nearly five times faster than normal proteins. The proteases of this insect can distinguish between normal and anomalous proteins and thereby avoid destruction of essential macromolecules. Aberrant protein degradative activity is not dependent upon de novo protein synthesis induced by canavanyl proteins. The fat body appears to be the source of proteases that degrade aberrant proteins; degradation is curtailed in the presence of sulfhydryl protease inhibitors as well as inhibitors of trypsin‐like activity.
Fatty acids in insects: Composition, metabolism, and biological significance
Authors: Stanley‐Samuelson David W. , Jurenka Russell A. , Cripps Colleen , Blomquist Gary J. , de Renobales Mertxe 
Published: February 2005

AbstractThe composition, metabolism, and significance of fatty acids in insect biology are addressed. Fatty acids enter a number of metabolic pathways not directly related to energy storage and production; the unifying theme is that the fatty acids are not only structurally altered in these pathways, but that the alterations carry them from one area of biological significance into another. This theme is developed by offering a perspective on fatty acids in insects and then reviewing three major areas: 1) fatty acid composition, 2) biosynthesis of fatty acids (including polyunsaturated fatty acids and characteristics of certain biosynthetic enzymes), and 3) the biological significance of fatty acids. This last section includes discussions of the biochemistry of waxes, pheromones, and prostaglandins and the roles of fatty acids as components of defensive secretions. Little is known at the biochemical level about the regulation of fatty acid metabolism, and it is suggested that work in this area represents another frontier in insect biochemistry.
Sucrose‐dependent increase in oligosaccharide production and associated glycosidase activities in the potato aphid Macrosiphum euphorbiae (Thomas)
Authors: Walters Frederick S. , Mullin Christopher A. 
Published: February 2005

AbstractOsmotic stress due to high sucrose concentration was imposed on the potato aphid, Macrosiphum euphorbiae (Thomas), in an artificial diet situation. Thin layer chromatography resolved melezitose and six additional honeydew oligosaccharides. Significantly higher levels of these oligosaccharides were recovered from the honeydew of this species in response to feeding on increased dietary sucrose concentrations, pointing to an osmoregulatory response. In addition, carbohydrase activities from the potato aphid were described. A degree of specificity toward hydrolysis of the sucrose substrate over other α‐glucosyl sugars was demonstrated. Also, sucrose was optimal for the formation of the oligosaccharides. A strong α‐galactosidase activity was found and transgalactosylation ability was indicated. These major trends in carbohydrase activity were also found in the foxglove aphid, Acyrthosiphon solani (Kaltenbach), and the oleander aphid, Aphis nerii Fonscolombe.
Characterization of juvenile hormone hydrolysis in early larval development of Trichoplusia ni
Authors: Hanzlik Terry N. , Hammock Bruce D. 
Published: February 2005

AbstractExtensive juvenile hormone (JH) hydrolysis was detected and characterized in whole‐body homogenates of larvae and tissues of Trichoplusia ni during periods of early larval development. The capacity to hydrolyze JH that exists in homogenates of penultimate‐instar larvae is far in excess of the measured hormone levels. The major initial metabolites of JH found in diluted homogenates of early‐instar larvae and larval tissues were JH acid and JH diol as shown by thin‐layer chromatography and microchemical derivatization. Experiments using subcellular fractionation or immunoprecipitation and inhibition studies showed the two hydrolytic activities to be roughly equivalent but located in different subcellular compartments. JH epoxide hydrolase activity was present in the large particle and microsomal fractions, whereas most JH esterase activity was present in the cytosol. Subsequent studies concentrated on JH esterolysis. A titer of JH esterase activity throughout larval development showed this enzyme to be present continuously inside tissues, with periodic manifestations in the hemolymph during each larval molt. Partial purification by affinity chromatography and analysis with sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, Western blotting, and isoelectric focusing showed JH esterase from earlyinstar larvae to be indistinguishable from the enzyme from the last instar. Application of JH II or a juvenoid, Ro 10‐3108, during any time of early larval development caused no apparent abnormalities, suggesting that the action of JH esterase is not involved with elimination of JH during this period. However, application of a JH esterase inhibitor during a critical period of the third to fourth larval molt caused failure of ecdysis, suggesting that JH acid or at least some esterase or protease may be a factor required for the molt.
Inositol phospholipid hydrolysis may mediate the action of proctolin on insect visceral muscle
Authors: Lange Angela B. 
Published: February 2005

AbstractThe formation of inositol phosphates in response to the neuropeptide proctolin was studied in locust oviducts. Glycerophosphoinositol, inositol 1‐phosphate, inositol 1,4‐bisphosphate, and inositol 1,4,5‐trisphosphate were identified in the locust oviducts using anion‐exchange chromatography. Proctolin stimulated the release of inositol 1‐phosphate, inositol 1,4‐bisphosphate, and inositol 1,4,5‐trisphosphate during a 5‐min incubation. In the presence of lithium ions the effects of proctolin were enhanced, with elevations of 98%, 42%, and 45% of inositol 1‐phosphate, inositol 1,4‐bisphosphate, and inositol 1,4,5‐trisphosphate, respectively.Physiologically the effects of proctolin upon muscular contraction of locust oviducts were mimicked by the active phorbol ester, phorbol 12‐myristate 13‐acetate, and by the diacylglycerol analogue, 1‐oleoyl‐2‐acetylglycerol. The inactive phorbol ester, 12‐myristate 13‐acetate 4‐O‐methyl ether, was without effect. The effects of the active phorbol ester and the diacylglycerol analogue were calcium‐dependent requiring micromolar concentrations of calcium.The results indicate that the locust oviducts possess proctolin receptors that are linked to phosphatidylinositol metabolism and that inositol phospholipid hydrolysis may mediate the physiological action of proctolin.
Adsorptive endocytosis of vitellogenin, lipophorin, and microvitellogenin during yolk formation in Hyalophora
Authors: Telfer William H. , Pan Muh‐Liang 
Published: February 2005

AbstractYolk in Hyalophora cecropia is a mixture of proteins that are derived from the extracellular medium. We have measured for five of these proteins the number of moles deposited in each egg, the molarity of their precursors in the hemolymph at a midpoint in vitellogenesis (day 18 of adult development), and the degree to which they are concentrated by the oocyte, relative to inulin. The proteins were isolated by gel permeation and ion exchange chromatography and used to generate antibodies in rabbits. Preliminary studies established that yolk proteins are essentially quantitatively extractable in media suitable for measuring antigen concentrations by precipitation with antibodies and that yolk and hemolymph forms of the five proteins have, effectively, the same antibody‐binding specificities as the isolated standards. Content per egg was about 900 pmol for vitellogenin, 600 pmol for microvitellogenin, and 300 pmol for lipophorin. By contrast, two hemolymph storage hexamers, arylphorin and a flavoprotein, occurred at less than 3 pmol per egg. In principle, yolk precursors are taken in both as solutes in the fluid phase of the endocytotic vesicles and as ligands adsorbed to vesicle membranes. Measurements of inulin uptake indicated that fluid phase endocytosis could account for only 4% of vitellogenin, 1% of microvitellogenin, and 15% of lipophorin in the yolk, when hemolymph precursors are at their day 18 concentrations. By the same comparison, arylphorin and flavoprotein appear to be excluded from the yolk, relative to inulin.
Developmental changes in fatty acid biosynthesis and composition in the house cricket, Acheta domesticus
Authors: Crippsc Colleen , De Renobales Mertxe 
Published: February 2005

AbstractIncorporation of [1‐14C] acetate into various phospholipid and triacylglycerol fatty acids showed cyclic fluctuations in fatty acid biosynthesis that were similar for all of the major fatty acids in both male and female house crickets, Acheta domesticus, during development. All three stadia showed low levels of biosynthesis near ecdysis followed by increased synthesis to a peak at midstadium. In the phospholipid fraction, the incorporation of newly synthesized saturated fatty acids, 16:0 and 18:0, predominated near ecdysis, while at midstadium linoleic acid was the most actively synthesized fatty acid. In the triacylglycerol fraction, 18:0 and 18:1 predominated throughout the entire stadium.In contrast to the large fluctuations in fatty acid biosynthesis, the fatty acid compositions of the phospholipid and triacylglycerol fractions did not change within a stadium. However, significant differences were demonstrated between the stages and were associated primarily with differences between nymphal and adult stadia. Males and females differed in the proportions of 16:0 and 18:2 incorporated into phospholipids with females showing a greater proportion of 18:2 and a corresponding smaller proportion of 16:0 than males. The greater proportion of linoleic acid in females and in adults in general compared to nymphs and the predominance of the incorporation of newly synthesized linoleic acid into the phospholipid fraction of all stadia are consistent with the importance of this fatty acid in a number of biological roles.
Canalization of the redbanded leafroller moth sex pheromone blend
Authors: Sreng Isabelle , Glover Thomas , Roelofs Wendell 
Published: February 2005

AbstractPrevious attempts to shift the (Z)‐11‐/(E)‐11‐tetradecenyl acetate ratio of pheromone components in the redbanded leafroller moth (RBLR), Argyrotaenia velutinana, by several selection protocols showed that this ratio is strongly canalized. Analysis of the complete seven‐component blend, however, showed that a Geneva laboratory stock of RBLR had a lower percent (20%) of the E9–12:OAc minor component compared to the E11–14:OAc component than a population of RBLR from North Carolina (31%). Hybrid populations from these two cultures were used in a two‐way family truncation selection scheme in which families were selected for either the lowest (low line) or the highest (high line) ratio of E9–12:OAc/E11–14:OAc. After three generations of selection, the low line had 14% E9–12:OAc relative to E11–14:OAc and the high line had 42%. The selection pressure was removed in generations 4–9, and the low line remained unchanged at 14% E9–12:OAc; but in the high line, it drifted to 53%.Studies were conducted to estimate heritability and realized heritability. The realized heritability calculated for each generation of selection averaged 1.14 for the low line and 1.50 for the high line. These calculations, along with estimated heritability values of 0.416 and 0.644 for reciprocal crosses, indicate some plasticity in the E9–12:OAc/E11–14:OAc ratio. This ratio was positively correlated to the total amount of 12‐carbon components to 14‐carbon components, but was negatively correlated to the Z/E ratio of Δ11‐tetradecenylacetates.The results of two studies on the canalization of various components of the RBLR sex pheromone blend indicate that there is limited potential in this insect for manipulation of the blend ratios in the laboratory.
Mode of action of diptericin A, a bactericidal peptide induced in the hemolymph of Phormia terranovae larvae
Authors: Keppi Elisabeth , Pugsley Anthony P. , Lambert Jean , Wicker Claude , Dimarcq Jean‐Luc , Hoffmann Jules A. , Hoffmann Danièle 
Published: February 2005

AbstractDiptericin A is a member of a multigenic family of antibacterial peptides that are synthesized by larvae of Phormia terranovae (Diptera) in response to a bacterial injection or to injury. The 82‐residue peptide is active only against a limited range of Gram‐negative bacteria. Data presented suggest that the primary action of diptericin A is on the cytoplasmic membrane of growing bacteria.
Pheromone receptor cells in the male moth Manduca sexta
Authors: Kaissling Karl‐Ernst , Hildebrand John G. , Tumlinson James H. 
Published: February 2005

AbstractThree types of pheromone receptor cells have been identified by electrophysiological recording from single antennal sensilla trichodea of the male sphinx moth Manduca sexta. These cells responded best to the pheromone components (E,Z)‐10,12‐hexadecadienal (type A receptor cell), (E,E,Z)‐10,12,14‐hexadecatrienal (type B), and (E,E,E)‐10,12,14‐hexadecatrienal (type C). Cell type B also responded to (E,Z)‐11,13‐pentadecadienal, which has been used experimentally as a pheromone substitute. In recordings from 20 trichoid hairs, 17 were found to be innervated by one cell of type A and one of type B; 3 trichoid hairs had cell types A and C.