bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purification of a 24 kD parasitism‐specific hemolymph protein from pharate pupae of the caribbean fruit fly, Anastrepha suspensa
Authors: Rolle Rosa S. , Lawrence Pauline O. 
Published: February 2005

AbstractWe report purification of a 24 kD parasitism‐specific protein (24 kD PSP) from pharate pupal hemolymph of the Caribbean fruit fly, Anastrepha suspensa, after parasitization by the braconid wasp, Diachasmimorpha (= Biosteres) longicaudata. We previously utilized isoelectric focusing (IEF) and two‐dimensional (2‐D) gel electrophoresis to demonstrate that the 24 kD PSP consists of two variants with pl 6.7 (more abundant) and pl 6.3. Purification of the more abundant 24 kD PSP variant was accomplished by Concanavalin A (Con A) sepharose B affinity chromatography followed by DEAE column chromatography. A second protocol, utilizing wheat germ agglutinin (WGA) sepharose 6MB affinity chromatography between the ConA and DEAE chromatographic steps, resulted in the purification of a partially deglycosylated form of the 24 kD PSP which retained its immunore‐activity with anti‐PSP serum but which exhibited a greater relative migration in sodium dodecyl sulfate (SDS)‐PAGE than the pl 6.7 24 kD PSP variant.For structural studies both 24 kD PSP variants were purified from whole hemolymph by flat bed IEF followed by SDS‐PAGE. Peptide cleavage profiles in 1‐D SDS‐PAGE after treatment with BNPS‐skatole, CNBr, and endproteinases Lys‐C and Asp‐N were identical for both 24 kD PSP variants. Primary N‐terminus sequences of at least the first 20 amino acid residues of both variants were identical. A secondary sequence of five amino acids residues was detected in both variants at Thr, the seventh amino acid residue from the N‐terminus of the primary sequence. These data indicate that both 24 kD PSPs are glycoforms of a branched, apparently homogeneous polypeptide. © 1994 Wiley‐Liss, Inc.
Carbohydrate metabolism during the pupal molt of the tobacco hornworm, Manduca sexta
Authors: Siegert Karl J. 
Published: February 2005

AbstractDuring the pupal molt of the tobacco hornworm, Manduca sexta, the percentage of active fat body glycogen phosphorylase increased from 5–10 to 20%, but only for a period of 5 h prior to the molt. From the time of the appearance of two sclerotized dorsal bars to the time of the molt, the concentration of total hemolymph carbohydrates doubled to 100 mM trehalose. Initially, the glucose level was high (16 mM) when compared with feeding larvae (approximately 1 mM) but decreased to zero just prior to the molt. The amount of cuticular chitosan decreased from approximately 100 mg to 10 mg at pupation; the exuvia contained approximately 7 mg. While the levels of total lipids in hemolymph were not affected, the lipid content of the fat body decreased significantly prior to the molt but increased sharply thereafter. Fat body glycogen phosphorylase in pharate pupae and pupae of M. sexta was substantially activated by the Manduca adipokinetic peptide hormone, which in pharate pupae, produced the same response at 2 and 20 pmol per insect as in ligated larval abdomens. In pupae the response was clearly reduced. Using chilling to stimulate glycogen phosphorylase, it was found that the enzyme in pharate pupae and pupae responded both in vivo and in vitro as in ligated abdomens of larvae. Thus, a transition to the adult response seems to occur during the pupal and pharate adult development. © 1995 Wiley‐Liss, Inc.
Hypertrehalosemic hormone‐regulated gene expression for cytochrome P4504C1 in the fat body of the cockroach, Blaberus discoidalis
Authors: Lu Kuang‐Hui , Bradfield James Y. , Keeley Larry L. 
Published: February 2005

AbstractHypertrehalosemic hormone (HTH) up‐regulates expression of a gene for a cytochrome P450 of family 4 (CYP4C1) in the fat body of adult male B. discoidalis cockroaches. Studies were undertaken to determine the characteristics of HTH‐dependent CYP4C1 expression. A dot‐blot assay was developed for routine measurement of the relative levels of CYP4C1‐mRNA in fat body RNA extracts. A single injection of 10 pmol HTH produced a maximum CYP4C1 response within 8 h. This dose corresponds with the dose needed for a maximum in vivo hypertrehalosemic response to HTH (Keeley et al., 1991). Multiple treatments with HTH at 8 or 24 h intervals were no more effective than a single treatment for producing CYP4C1 expression. These results indicate that CYP4C1 expression is sensitive to physiological doses of HTH and responds rapidly. CYP4C1 expression was suppressed by treatment with α‐amanitin, an inhibitor of RNA polymerase II, but was unaffected by cycloheximide, an inhibitor of protein synthesis. HTH appears to influence CYP4C1 transcription without involvement of intervening regulatory genes. These results suggest that regulation of fat body CYP4C1 expression is a major physiological action of HTH. © 1995 Wiley‐Liss, Inc.
Chitin synthesis in Spodoptera frugiperda wing imaginal discs. III: Role of the peripodial membrane
Authors: Mikołajczyk Piotr , Zimowska Grazyna , Oberlander Herbert , Silhacek Donald L. 
Published: February 2005

AbstractWe determined the contribution of the peripodial membrane to chitin synthesis in cultured wing imaginal discs of Spodoptera frugiperda. This was accomplished by examining chitin synthesis in vitro in intact imaginal discs, in the peripodial membrane, and in imaginal discs in which the peripodial membrane had been injured. Chitin synthesis in peripodial membrane‐deprived imaginal discs, peripodial membrane injured imaginal discs, and peripodial membrane fragments was assessed by measuring incorporation of [14C]GlcNAc after treatment with 20‐hydroxyecdysone in tissue culture. Removing or injuring the peripodial membrane resulted in a marked decrease in ecdysteroid‐dependent chitin synthesis in these wing discs compared with intact wing discs. In addition, a break in the ecdysteroid treatment of 4 h reduced chitin synthesis in the wing discs substantially. These biochemical experiments were supplemented with ultrastructural and immunocytochemical approaches. A wheat germ agglutinin colloidal gold complex was used to visualize the presence of chitin synthesized by wing discs including the peripodial membrane. These experiments confirmed the importance of an intact peripodial membrane for optimal production of cuticle by the wing pouch. Our results demonstrate that for opti‐ma1 production of chitin in tissue culture, wing discs must be treated with 20‐hydroxyecdysone for an uninterrupted period of 48 h, and the peripodial membrane of these imaginal discs must be present and uninjured. © 1995 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
Purification and immunological characterization of superoxide dismutase of the onion maggot, Delia antiqua
Authors: Ishikawa Yukio 
Published: February 2005

AbstractCytosolic superoxide dismutase (SOD) of the onion maggot, Delia antiqua, was purified to apparent homogeneity by ammonium sulfate fractionation followed by anion exchange, hydrophobic interaction, and gel filtration chromatographies. Native molecular mass was estimated as 32,000 daltons. SDS‐PAGE revealed only one subunit of 16,000 daltons, indicating that SOD is a homodimer. Isoelectric focusing revealed 3 charge isomers of pls 5.3, 5.5, and 5.7. The specific activity of purified SOD was 4,250 U/mg protein. A monoclonal antibody (MAb, aSOD2B7) raised against Delia SOD recognized only SOD of the same genus, but another MAb (aSOD1H11) recognized SOD of Drosophila melanogaster as well. © 1995 Wiley‐Liss, Inc.
Separation of multiple forms of acidic glutathione S‐transferase isozymes in a susceptible and a resistant strain of house fly, Musca domestica (L.)
Authors: Chien C. , Motoyama N. , Dauterman W. C. 
Published: February 2005

AbstractThe acidic glutathione S‐transferases from a CSMA (susceptible) strain and a Cornell‐R (resistant) strain of houseflies were purified and separated utilizing affinity chromatography followed by chromatofocusing. Nine fractions were isolated from each house fly strain. Fraction 1 had the highest 1‐chloro‐2,4‐dinitrobenzene vs. 1,2‐dichloro‐4‐nitrobenzene ratio (CDNB/DCNB ratio) in both strains and the ratio of all the other fractions tended to decrease as the isoelectrical points decreased except for fractions 4 and 9. Most fractions from the CSMA strain had higher CDNB conjugation activities than the fractions from the Cornell‐R strain, but all the fractions from the CSMA strain had lower DCNB conjugation activities than fractions from the Cornell‐R strain. Steady‐state kinetics of all the fractions were examined. The Km values obtained from both strains ranged from 0.36 to 1.12 mM, while the Vmax value ranged from 3.0 to 32.6 μmol/min/mg. In the 100,000 g supernatant, the CDNB specific activities in the CSMA strain was about 1/3 of the activity in the Cornell‐R strain but it was about 1.5‐fold following affinity chromatography. The specific activity for DCNB measured in the CSMA strain was only 1/5 of the activities of the Cornell‐R strain in the 100,000 g supernatant, but was about the same after affinity chromatography. The difference was due to the selectivity of the affinity column used in the current study. © 1995 Wiley‐Liss, Inc.
Developmental differences in the sterol composition of Solenopsis invicta
Authors: Ba Amadou S. , Guo De‐An , Norton Robert A. , Phillips Sherman A. , Nes W. David 
Published: February 2005

AbstractTwenty‐six sterols were isolated from eggs, larvae, workers, and queens of the red imported fire ant, Solenopsis invicta Buren. They were identified by chromatographic (TLC, GLC, and HPLC) and spectral methods (MS and 1H‐NMR). Queens possessed the most varied sterol composition (24 sterols were detected). The major sterols from queens were the doubly bioalkylated 24α‐ethyl cholest‐5‐ and 7‐en‐3β‐ols whereas the major sterol from the other developmental stages was cholesterol, a sterol which lacks a C‐24 alkyl group. From fourth instar larvae were isolated two yeasts, Candida parapsilosis and Yarrowia lipolytica. Both yeasts were found to synthesize similar sterols, primarily ergosterol and zymosterol (90% of the sterol mixture). A minor sterol (approximately 12% of the total sterol mixture) detected in eggs, larvae, and workers was 24‐methyl cholesta‐5,22E‐dien‐3β‐ol (brassicasterol). Brassicasterol may have originated from ergosterol produced by the fungal endosymbiotes. The amount of sterol in each developmental stage was as follows: approximately 24 μg sterol/queen, 3 μg sterol/worker, 2 μg sterol/larvae, and 0.02 μg sterol/egg. The sterol composition of the red imported fire ant differed from that of leaf‐cutting ants previously investigated where 24‐methyl sterols of ectosymbiotic fungal origin were the major sterols detected in soldiers and workers. © 1995 Wiley‐Liss, Inc.
Induction of diaphorase‐1 by dicoumarol in Drosophila virilis larvae
Authors: Georgieva T. G. , Jankulova E. D. , Ralchev K. H. , Dunkov B. C. 
Published: February 2005

AbstractDrosophila diaphorase‐1 (DIA‐1) is an enzyme similar to mammalian DT‐diaphorase and is inhibitied in vitro by dicoumarol. However, a ten‐fold increase in DIA‐1 activity was observed when third instar Drosophila virilis larvae were fed on a diet containing 0.1 M dicoumarol for 48 h. This induction was shown to be dose dependent and immunoprecipitation experiments with DIA‐1 antiserum demonstrated an increase in the DIA‐1 protein level in dicoumarol‐treated larvae. The induction of DIA1 by dicoumarol was found to be blocked by actinomycin D, which suggests a transcriptional mechanism of regulation. The opposite effect of dicoumarol on DIA‐1 in vitro vs. in vivo suggests that a metabolic conversion takes place after the ingestion of this compound by D. virilis larvae. © 1995 Wiley‐Liss, Inc.
Antioxidant systems in insects
Authors: Felton Gary W. , Summers Clinton B. 
Published: February 2005

AbstractInsects possess a suite of antioxidant enzymes and small molecular weight antioxidants that may form a concatenated response to an onslaught of dietary and endogenously produced oxidants. Antioxidant enzymes such as superoxide dismutase, catalase, glutathione transferase, and glutathione reductase have been characterized in insects. Water‐soluble and lipid‐soluble antioxidants such as ascorbate, glutathione, tocopherols, and carotenoids have not been well studied in insects but may play very important antioxidant roles. Additionally, the peritrophic matrix and trehalose may possess important antioxidant functions in insects. The enzymatic recycling of ascorbate, first noted in green plants, may also exist in insects. A greater understanding of these antioxidant systems may provide greater understanding about the ecological relationships of insects with their hosts. © 1995 Wiley‐Liss, Inc.
An insect model for assessing oxidative stress related to arsenic toxicity
Authors: Zaman Khalequz , MacGill Randall S. , Johnson James E. , Ahmad Sami , Pardini Ronald S. 
Published: February 2005

AbstractThe potential usefulness of an insect model to evaluate oxidative stress induced by environmental pollutants was examined with trivalent arsenic (As3+, NaAsO2) and pentavalent arsenic (As5+, Na2HAsO4) in adult female house flies, Musca domestica, and fourth‐instar cabbage loopers, Trichoplusia ni. M. domestica was highly susceptible to both forms of arsenic following 48 h exposure in the drinking water with LC50s of 0.008 and 0.011% w/v for As3+ and As5+, respectively. T. ni larvae were susceptible to dietary As3+ with an LC50 of 0.032% w/w but seem to tolerate As5+ well with an LC50 of 0.794% concentration after 48 h exposure. The minimally acute LC5 dose of both As3+ and As5+ varied considerably but averaged 0.005% for both insects. The potential of both valencies of arsenic for inducing oxidative stress in the insects exposed ad libitum to approximately LC5 levels was assessed. The parameters examined were the alterations of the antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST), the peroxidase activity of glutathione transferase (GSTPX), and glutathione reductase (GR), and increases in lipid peroxidation and protein oxidation. SOD (1.3‐fold), GST (1.6‐fold), and GR (1.5‐fold) were induced by As3+ in M. domestica but CAT and GSTPX were not affected. As5+ had no effect on M. domestica. In T. ni, the antioxidant enzyme activities were not affected by As3+ except for SOD which was suppressed by 29.4% and GST which was induced by 1.4‐fold. As5+ had no effect except the suppression of SOD by 41.2%. Lipid peroxidation and protein oxidation, which represent stronger indices of oxidative stress, were elevated in both insects by up to 2.9‐fold. However, based on the antioxidant enzyme response to the arsenic anions, the mode of action of arsenic induced oxidative stress may differ between the two insects. Until this aspect is further clarified, evidence at this time favors the prospect of As3+ as a pro‐oxidant, especially for M. domestica. © 1995 Wiley‐Liss, Inc.
Identification, purification, and partial characterization of vitellin from the eggs of Eurygaster integriceps putton (heteroptera, pentatomidae)
Authors: Daskalova Sasha M. 
Published: February 2005

AbstractA single vitellin was identified in the eggs of the wheat bug, Eurygaster integriceps, and purified by a two‐step procedure including ion exchange and gel permeation chromatography. Its nondenatured molecular mass is estimated to be 385 kDa. Under reducing conditions—SDS‐PAGE—the wheat bug vitellin gives five polypeptides at 110 kDa, 80 kDa, 69 kDa, 53 kDa, and 38 kDa. Its amino acid composition is characterized by high content of aspartic acid/asparagine and glutamic acid/glutamine and low content of methionine and histidine. The lipid moiety (5.65% by weight) includes diacylglycerols, cholesterol, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelin. Carbohydrate content amounts to 4.54% by weight. A part of the wheat bug vitellin is dimerized during the course of deposition into the yolk granules. © 1995 Wiley‐Liss, Inc.
Characterization of oxidase(s) associated with the sex pheromone gland in Manduca sexta (L.) females
Authors: Fang Nianbai , Teal Peter E. A. , Tumlinson James H. 
Published: February 2005

AbstractAn oxidase that converts primary aliphatic alcohols into aldehydes was discovered in the cuticle of the sex pheromone gland and in the papillae anales on the tip of the abdomen of Manduca sexta females. Oxidase activity was not found in the epidermal cells of the pheromone gland where fatty acid precursors of the pheromonal aldehydes are found. This oxidase requires oxygen and water to function and appears to have a rather broad substrate specificity. The activity of the oxidase is reduced by the application of piperonyl butoxide, which also interferes with the PBAN induced production of the natural pheromone aldehydes. However, endogenous alcohols cannot be found in the pheromone gland. Thus, it is not yet clear whether or not the oxidase is involved in the terminal step of biosynthesis of the pheromone aldehydes in M. sexta females. © Wiley‐Liss, Inc.This article is a U.S. Government work and, a such, is in the public domain in the United States of America.
Regulation of free arachidonic acid levels in isolated salivary glands from the lone star tick: A role for dopamine
Authors: Bowman Alan S. , Dillwith Jack W. , Madden Robin D. , Sauer John R. 
Published: February 2005

AbstractAn important regulatory step for prostaglandin synthesis is the availability of the precursor, free arachidonic acid (AA). In isolated salivary glands of the lone star tick, Amblyomma americanum (L.), the level of free AA appears to depend on higher phospholipase A2 (PLA2) activity rather than decreased rates of re‐esterification by lysophosphatide acyl transferase (LAT). This conclusion is supported by experiments where inhibition of LAT with merthiolate was without effect, while the calcium ionophore A23187, a PLA2 stimulant, increased levels of free AA. The PLA2 activity in A. americanum was reduced by the substrate analog, PLA2 inhibitor, oleyloxyethyl phosphorylcholine in a dose‐dependent manner, but was insensitive to the other mammalian PLA2 inhibitors mepacrine (20μM), aristolochic acid (45μM), and dexamethasone (50μM). No substrate preference was observed for the functional group of the phospholipid, with phosphatidylcholine and phosphatidylethanolamine being equal sources of AA in A23187‐stimulated glands. Compared to phospholipids containing other fatty acids, only arachidonyl‐phospholipid (arachidonyl‐PL) was significantly hydrolyzed by PLA2 activity in A23187‐stimulated glands. Dopamine was as effective as A23187 as a stimulant of PLA2 activity in isolated glands, but this effect was abolished in the presence of the calcium channel blocking agent verapamil. It is concluded that free AA levels in tick salivary glands are increased through activation of a Type IV‐like PLA2 following an increase of intracellular calcium caused by the opening of voltage‐dependent calcium channels due to dopamine stimulation. © 1995 Wiley‐Liss, Inc.
Hypolipemia, hypoglycemia, and inactivation of glycogen phosphorylase in Locusta migratoria
Authors: Siegert Karl J. 
Published: February 2005

AbstractFeeding starved adult migratory locusts, Locusta migratoria, caused decreases of hemolymph lipid concentrations and of the percentage of active fat body glycogen phosphorylase which suggested that a molecule(s) from the neurosecretory system or the midgut may have been released to regulate metabolism. Fat body phosphorylase was also inactivated after insects were transferred from 0 to 25 ° C. In adults with elevated hemolymph lipid levels after the injection of small doses of corpus cardiacum extract (CC), feeding did not induce a decrease in hemolymph lipid concentrations. It appears that the processes initiated by feeding could not override the effects of the continued presence of adipokinetic hormone(s) (AKHs) in the hemolymph or their long‐term effects.Aqueous, methanolic, or ethanolic extracts of brains or storage lobes (SL) of fed locust CC did not lead to decreases of hemolymph lipid concentrations. Bovine insulin was equally inactive when tested at doses which were previously reported to reduce lipid levels. Fractions of ethanolic brain extracts from 3‐day‐starved males collected after high‐performance size‐exclusion chromatography, however, produced hypoglycemic effects in fed males. Two biologically active fractions were found, one with high (≥ 10 kDa) and one with low molecular weight (approximately 1 kDa). © 1995 Wiley‐Liss, Inc.
Chemical basis of differential oviposition by lepidopterous insects
Authors: Honda Keiichi 
Published: February 2005

AbstractPhytochemical mediators serving as attractants, repellents, stimulants, or deterrents in oviposition behavior of moths and butterflies are reviewed in regard to the chemical mechanism of host selection. Ovipositing females seem generally to utilize plant volatiles as cues for orientation to host plants, and the subsequent contact evaluation of plants by means of less‐ or non‐volatile secondary metabolites is usually of great significance in host recognition. Most lepidopterans appear to be induced to oviposit in response to a single host‐specific compound, while extreme synergism of multiple components features the stimulatory system of oviposition enacted by some butterflies. Recent investigations clearly demonstrate that acceptance or rejection of a particular plant by females is regulated not only by the presence or absence of oviposition stimulants but by negative stimuli evoked by co‐occurring deterrents. The epideictic pheromones implicated in host assessment by females are also referred to in this review. © 1995 Wiley‐Liss, Inc.
Uptake of high‐density lipoprotein by Y‐organs of the crab, Cancer antennarius. I. characterization in vitro and effects of stimulators and inhibitors
Authors: Kang Byoung K. , Spaziani Eugene 
Published: February 2005

AbstractCholesterol is the obligate precursor for ecdysteroid hormone synthesis by the ecdysial glands (Y‐organs) in crustaceans, and all cholesterol in the hemolymph is bound to high‐density lipoprotein (HDL). The mechanism was studied of how Y‐organ cells acquire cholesterol. Y‐organ segments were incubated with HDL isolated from hemolymph and labeled with 125I. After incubation, tissue was homogenized in acid to determine radioactivity in acid‐precipitable (cell associated, intact) HDL and in acid‐soluble (degraded) HDL. Both HDL uptake and degradation showed saturation kinetics. At saturation most of the total counts represented degraded HDL; by 3 h, degradation was 80%. Rates of HDL uptake and breakdown were higher in Y‐organs from de‐eyestalked crabs (deprived thereby of molt‐inhibiting hormone, MIH) than in glands from intact crabs. Both parameters were depressed by inhibitors of glycolysis and oxidative phosphorylation dose dependently and by low temperature. HDL uptake also was depressed by cAMP added to the medium experimentally or through efflux from the tissue during incubation. These results indicate a mechanism for HDL uptake that entails receptor‐mediated, energy‐dependent endocytosis of the entire HDL‐cholesterol complex. Also the results suggest that HDL uptake and degradation are mediated by cAMP and depressed by an eyestalk factor, presumably MIH. © 1995 Wiley‐Liss, Inc.