bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diphenols in hemolymph and cuticle during development and cuticle tanning of Periplaneta americana (L.) and other cockroach species
Authors: Czapla T. H. , Hopkins T. L. , Kramer K. J. , Morgan T. D. 
Published: February 2005

AbstractDiphenolic compounds in cockroach hemolymph and cuticle were extracted with 1.2 N HCI, partially purified by alumina adsorption, and analyzed by liquid chromatography. Dopamine (DA) is the major catecholamine in hemolymph of Periplaneta americana, Blatta orientalis, Blattella germanica, Gromphadorhina portentosa, and Blaberus craniifer at adult ecdysis, while N‐acetyldopamine (NADA) predominates in hemolymph of Leucophaea maderae. In P. americana, NADA is the second most abundant catecholamine, while N‐β‐alanyldopamine (NBAD), norepinephrine (NE), 3,4‐dihydroxyphenylalanine, 3,4‐dihydroxyphenylethanol, 3,4‐dihydroxyphenylacetic acid, and 3,4‐dihydroxybenzoic acid occur in lesser quantities. Catecholamines occur mainly as acid labile conjugates in hemolymph. Dopamine, conjugated primarily as the 3‐sulfate ester, increases in hemolymph from 0.1 to 0.8 mM during the last instar. Concentrations decrease by 75% in pharate adults, partially because of an increase in hemolymph volume. A second smaller peak of DA sulfate occurs after ecdysis followed by a rapid disappearance as the cuticle tans. A conjugate of catechol (o‐dihydroxybenzene) is also present in relatively high concentrations at all ages examined. In cuticle, N‐β‐alanylnorepinephrine accumulates during the early period of adult tanning, while NBAD, NADA, N‐acetylnorepinephrine, and DA increase more slowly. The N‐β‐alanyl and N‐acetyl derivatives of DA and NE occure in relatively high concentrations in tanned cutical of P. americana and probably play an important role in the stablization process.
Platelet activating factor‐acetylhydrolase in insects: Identification and partial characterization of a 1‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine acetylhydrolase in a cell‐free system of Heliothis
Authors: Lambremont Edward N. , Malone Boyd , Snyder Fred 
Published: February 2005

AbstractA specific acetylhydrolase that inactivates platelet activating factor (PAF; 1‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine), a potent cellular mediator in mammalian cells, by removal of the sn‐2 acetyl moiety, has been found in the cytosolic fraction of several postembryonic developmental stages and specific tissues of the corn earworm, Heliothis zea (Boddie). Effects of magnesium, calcium, EGTA, deoxycholate, dithiothreitol, diisopropylfluorophosphate, egg phosphatidylcholine, and an acylacetyl‐glycerophosphocholine show that hydrolysis of the acetate moiety is due to a specific acetylhydrolase for PAF. The activity does not appear to be due to a typical cellular phospholipase A2 that utilizes phospholipid substrates with a long‐chain acyl group at position sn‐2 of glycerol. Specific activities and properties of the acetylhydrolase from this insect match closely with those described from tissues of vertebrate animals.
Prophenoloxidase activation in the hemolymph of Sarcophaga bullata larvae
Authors: Saul Steven J. , Sugumaran Manickam 
Published: February 2005

AbstractPhenoloxidase in the hemolymph of Sarcophaga bullata larvae is present as an inactive proenzyme form. Localization studies indicate that the majority of the prophenoloxidase is present in the plasma fraction whereas only a minor fraction (about 4%) is present in the cellular compartments (hemocytes). Inactive prophenoloxidase can be activated by zymosan, not by either endotoxin or laminarin. This activation process is inhibited by the serine protease inhibitors, benzamidine and p‐nitrophenyl‐p∼‐guanidobenzoate. Exogenously added proteases, such as chymotrypsin and subtilisin, also activated the prophenoloxidase in the whole hemolymph but failed to activate the partially purified proenzyme. However, an activating enzyme isolated from the larval cuticle, which exhibits trypsinlike specificity, activated the partially purified prophenoloxidase. Inhibition studies and activity measurements also revealed the presence of a similar activating enzyme in the hemolymph. Thus, the phenoloxidase system in Sarcophaga bullata larval hemolymph seems to be comprised of a cascade of reactions. An endogenous protease inhibitor isolated from the larvae inhibited chymotrypsin‐mediated prophenoloxidase activation but failed to inhibit the cuticular activating enzyme‐catalyzed activation. Based on these studies, the roles of prophenoloxidase, endogenous activating proteases, and protease inhibitor in insect immunity are discussed.
Metabolism of [14C]cholesterol in Manduca sexta pupae: Isolation and identification of sterol sulfates, free ecdysteroids, and ecdysteroid acids
Authors: Lozano Ruben , Thompson Malcolm J. , Lusby William R. , Svoboda James A. , Rees Huw H. 
Published: February 2005

Abstract[14C]Cholesterol was injected into fifth‐instar larvae of Manduca sexta, and the metabolites were isolated and identified from 8‐day‐old male and female pupae. A major portion of the metabolized cholesterol was esterified either with a sulfate group or with fatty acids. The predominant ecdysteroid metabolites were 20‐hydroxyecdysone, 20,26‐dihydroxyecdysone, 20‐hydroxyecdysonoic acid, and 3‐epi‐20‐hydroxyecdysonoic acid. Smaller amounts of ecdysteroids were identified as conjugates of 26‐hydroxyecdysone, 3‐epi‐20‐hydroxyecdysone, 20,26‐dihydroxyecdysone, and its 3α‐epimer. The metabolic profiles were similar for both male and female pupae. The two ecdysteroid acids were identified by nuclear magnetic resonance spectroscopy and chemical ionization mass spectrometry and by mass spectral analyses of their methyl esters. Detection of 3‐epi‐20‐hydroxyecdysonoic acid as a major metabolite is significant, as its occurrence has been scarcely reported. 3‐Epiecdysteroid acid formation is discussed as a possible ecdysteroid‐inactivating pathway that may be operating specifically in lepidopterous insects or in particular developmental stages such as eggs or pupae.
Ecdysteroid profiles for hemolymph and testes from larvae, pupae, and pharate adults of the European corn borer, Ostrinia nubilalis hubner
Authors: Gelman Dale B. , Woods Charles W. , Borkovec Alexej B. 
Published: February 2005

AbstractTotal ecdysteroid levels as well as concentrations of several individual ecdysteroids were determined for hemolymph and testes of fifth instars, pupae, and pharate adults of the European corn borer, Ostrinia nubilalis (Hubner). For total levels, the patterns of fluctuation in hemolymph and testes were similar, but the concentrations in testes were lower than those in hemolymph. In both hemolymph and testes there were two ecdysteroid peaks: the first just prior to the formation of the pharate pupa, the second just prior to the formation of the pharate adult.An examination of ecdysteroid profiles revealed some important differences. Ecdysone was either absent or present at extremely low levels in larval testes, whereas in hemolymph there was a premolt ecdysone peak. In pupal testes, ecdysone was present, but levels of 26‐hydroxyecdysone were much lower than those in hemolymph. Thus, in regard to ecdysteroids, testes have the ability to control their own internal milieu.
Novel assay for determining the metabolic fate of juvenile hormone III: A study with Drosophila melanogaster
Authors: Ottea J. A. , Harshman L. G. , Hammock Bruce D. 
Published: February 2005

AbstractA thin‐layer chromatographic assay was developed for the resolution of hydrolytic and conjugative catabolites of juvenile hormone (JH). A single‐dimension, dual‐development thin‐layer system allowed complete resolution of the catabolites. Thus, this system provided a means for the rapid and economic analysis of JH hydrolysis even when different hydrolytic activities were present concurrently. Purified hydrolytic enzymes were found to be superior to chemical methods for the generation of small amounts of standards of JH catabolites. The relative levels of activities of an epoxide hydrolase and an esterase toward JH III were found to be similar in microsomal preparations from three lines of adult Drosophila melanogaster isolated from a field population. However, selection of flies by exposure to cut orange resulted in the elevation of levels of epoxide hydrolase activities, whereas esterase levels were not affected to the same extent. The formation of the JH acid‐diol was not detected under the conditions of this study, suggesting that the JH acid and diol were not good substrates for epoxide hydrolase and juvenile hormone esterase, respectively.
On the nature of nonenzymatic and enzymatic oxidation of the putative sclerotizing precursor, 1,2‐dehydro‐N‐acetyldopamine
Authors: Sugumaran Manickam , Hennigan Brian , Semensi Victor , Dali Hemalata 
Published: February 2005

AbstractThe mode of oxidation of 1,2‐dehydro‐N‐acetyldopamine by nonenzymatic and enzymatic systems was examined. At acidic and near neutral pH, this compound is fairly stable; however, even at slightly alkaline pH it is highly labile and undergoes spontaneous, nonenzymatic aerobic oxidation. Borate, which is known to chelate with catechols, prevented such nonenzymatic reaction, indicating the participation of the o‐dihydroxyphenolic group in the oxidation process. The product of nonenzymatic oxidation was found to be not the expected o‐benzoquinone derivative, but a benzodioxan‐type dimer. Although mushroom tyrosinase also catalyzed this reaction (Sugumaran et al.: Journal of Biological Chemistry 262:10546–10549, 1987), cuticular phenoloxidase(s) from Sarcophaga bullata failed to mediate this conversion. Rather, the cuticular phenoloxidase(s) oxidized the parent compound to a reactive intermediate which got bound to cuticle irreversibly through covalent linkage. Proteolytic digests of dehydro‐N‐acetyldopamine‐treated cuticle released peptide‐bound catechols. Such cuticle which on acid hydrolysis yielded ketocatechols consistent with the binding of dehydro‐N‐acetyldopamine to the cuticle through its side chain. Based on these results, the mechanisms of oxidation of 1,2‐dehydro‐N‐acetyldopamine by nonenzymatic and enzymatic systems are discussed.
Juvenile hormone metabolism during embryogenesis in the tobacco hornworm, Manduca sexta (L.)
Authors: Share Marla R. , Venkatesh Krishnappa , Jesudason Princy , Roe R. Michael 
Published: February 2005

AbstractJuvenile hormones (JH)‐I and ‐III were metabolized in egg homogenates by two primary routes, ester hydrolysis and epoxide hydration, during embryogenesis of the tobacco hornworm, Manduca sexta (L.). The duration of embryogenesis was 3.5 days at 27°C. Preovipositional and newly oviposited eggs had the highest rate of JH metabolism, which was reduced by day 1 and remained unchanged thereafter. The decline in JH metabolism was the result of a decrease by one‐half in the JH esterase activity. JH epoxide hydrolase activity remained unchanged throughout embryogenesis. Ester hydrolysis averaged 1.9 times faster for JH‐I than JH‐III and epoxide hydration 6.6 times faster for JH‐III than JH‐I. There was a sixfold increase in the α‐naphthyl acetate (α‐NA) esterase activity during the time in embryogenesis when the JH esterase activity was declining or at low levels. Developmental, inhibitor, substrate specificity, gel filtration, and isoelectric focusing studies indicated that the egg JH esterase has some specificity for JH, compared with α‐NA, and in part is similar to the hemolymph JH esterase of the adult female. The possible functional role of JH metabolism during embryogenesis is discussed.
Developmental arrest induced by juvenile hormone in larvae of Bombyx mori
Authors: Sakurai Sho , Imokawa Hiroshi 
Published: February 2005

AbstractInjection of the juvenile hormone analog (JHA) methoprene into day 3, fifthinstar larvae of Bombyx mori induced developmental arrest. Feeding activity declined, and the larvae remained as larvae for more than 2 weeks, after which they died. After JHA injection, the hemolymph ecdysteroid titer was low, and the prothoracic glands were almost inactive for 7 days. During this period, prothoracic glands were stimulated by prothoracicotropic hormone (PTTH) in vitro, indicating that JHA did not inhibit the competence of the glands to respond to PTTH. When brain‐corpora cardiaca‐corpora allata complexes were removed from intact fifth‐instar larvae on day 4, the prothoracic glands became autonomously active and produced enough ecdysone for pupation. When PTTH injections were given to larvae previously injected with JHA (7 days before), the larvae recovered feeding activity, purged their guts, and pupated. Injections of 20‐hydroxyecdysone into larvae that had been injected with JHA 7 days earlier induced larval molting. These results suggest that JHA affects both the brain and the prothoracic gland.
Differential mechanism of oxidation of N‐acetyldopamine and N‐acetylnorepinephrine by cuticular phenoloxidase from Sarcophaga bullata
Authors: Sugumaran Manickam , Hennigan Brian , Semensi Victor , Mitchell Wayne , Rivera Theresa 
Published: February 2005

AbstractThe mechanism of oxidation of two related sclerotizing precursors—N‐acetyldopamine and N‐acetylnorepinephrine—by the cuticular phenoloxidase from Sarcophaga bullata was studied and compared with mushroom tyrosinase‐mediated oxidation. While the fungal enzyme readily generated the quinone products from both of these catecholamine derivatives, sarcophagid enzyme converted N‐acetyldopamine to a quinone methide derivative, which was subsequently bound to the cuticle with the regeneration of o‐dihydroxy phenolic function as outlined in an earlier publication [Sugumaran: Arch Insect Biochem Physiol, 8, 73 (1988)]. However, it converted N‐acetylnorepinephrine to its quinone and not to the quinone methide derivative. Proteolytic digests of N‐acetyldopamine‐treated cuticle liberated peptides that had covalently bound catechols, while N‐acetylnorepinephrine‐treated cuticle did not release such peptides. Acid hydrolysis of N‐acetyldopamine‐treated cuticle, but not N‐acetylnorepinephrine‐treated cuticle liberated 2‐hydroxy‐3′,4′‐dihydroxyacetophenone and arterenone. These results further confirm the unique conversion of N‐acetyldopamine to its corresponding quinone methide derivative and N‐acetylnorepinephrine to its quinone derivative by the cuticular phen‐oloxidase. Significance of this differential mechanism of oxidation for sclerotization of insect cuticle is discussed.
Quantitative determination of trypsinlike and chymotrypsinlike enzymes in insects
Authors: Borovsky Dov , Schlein Yosef 
Published: February 2005

AbstractA quantitative and highly specific assay for the determination of trypsinlike and chymotrypsinlike enzymes in insects has been developed. The assay is based on the specific binding of [1,3‐3H]diisopropylfluorophosphate to trypsinlike and chymotrypsinlike enzymes. Trypsinlike enzymes can be determined specifically in the presence of 10 mM TPCK (tosylamide‐2‐phenylethyl chloromethyl ketone; chymotrypsin inhibitor) and chymotrypsinlike enzymes can be determined in the presence of 10 mM TLCK (tosyl‐L‐lysine chloromethyl ketone HCI; trypsin inhibitor). The assay can easily detect 65 ng of either trypsinlike or chymotrypsinlike enzymes in midgut homogenates or whole extracts of many insect species. Using this assay, we have determined the amount of trypsinlike equivalents in Phlebotomus papatasi, Pediculus humanus, Stomoxys calcitrans, Musca domestica, Leishmania major promastigotes, Aedes aegypti, Culex nigripalpus, Culex quinquefasciatus, and Culicoides variipennis. No trypsinlike equivalents were found in Rhodnius prolixus or Ornithodoros moubata. The assay is useful for comparative studies and can be expanded for use as an electrophoretic fluorographic tool in the study of trypsinlike and chymotrypsinlike isozymes.
Disruptive effects of azadirachtin on development of Cotesia congregata in host tobacco hornworm larvae
Authors: Beckage Nancy E. , Metcalf Jeanette S. , Nielsen Barbara D. , Nesbit Dorothy J. 
Published: February 2005

AbstractInjection of the insect growth regulator (IGR) azadirachtin into Manduca sexta larvae that were parasitized by Cotesia congregata adversely affected subsequent endoparasite development when the compound was administered prior to the first larval ecdysis of the wasps. Injection of 2.5–10 μg of azadirachtin into newly ecdysed fourth or fifth instar hosts partially inhibited or totally suppressed the first larval ecdysis of the parasites. Instead of initiating rapid growth similar to parasites developing in hosts injected with the solvent carrier (ethanol) only, parasites in azadirachtin‐treated hosts never grew beyond the size normally attained in early terminal stage hosts. The host larvae survived for 2 weeks or longer following injection of azadirachtin, but their parasites never recovered and died encased within one or two exuvial cuticles. The parasitism‐specific hemolymph polypeptides previously shown to be characteristic of terminal stage hosts were undetectable in larvae in which the parasites failed to ecdyse to the second instar. The observed effects of azadirachtin on development of C. congregata differ significantly from those induced by other IGRs in parasitized M. sexta, suggesting azadirachtin has a unique, though as yet undefined, mode of action. Compared to other IGRs, this compound is extremely potent in terms of the minimum doses required to prevent emergence, but affects only the L1‐L2 ecdysis and not the L2‐L3 transition. In contrast, other compounds such as juvenoids and the JH esterase inhibitor BEPAT (S‐benzyl‐0‐ethyl phosphoramidothiolate) permit the parasite to grow and develop normally until the wasps become pharate third instar larvae, then inhibit the second larval ecdysis and emergence from the host.
On the intracellular localization of the ecdysone 20‐monooxygenase in Musca domestica. L
Authors: Agosin Moises , Srivatsan Jayanthi , Weirich Margaret 
Published: February 2005

AbstractThe cytochrome P‐450‐dependent 20‐monooxygenation of ecdysone is catalyzed both by mitochondria and microsomes isolated from Musca domestica (L.) larvae; however, about 50% of the activity is associated with mitochondria, and 37% is associated with microsomes. Pretreatment of larvae with ecdysone results in an increase in Vmax and a decrease in Km values in mitochondria but not in microsomes. Phenobarbital, a known cytochrome P‐450 inducer, increases the cytochrome P‐450 levels in microsomes without affecting the 20‐monooxygenase activity, but both the cytochrome P‐450 levels and monooxygenase activity are depressed in mitochondria from phenobarbital‐pretreated larvae. The ecdysone 20‐monooxygenase activity is equally distributed between mitochondria and microsomes in adult insects. Pretreatment of the insects with ecdysone does not significantly modify the 20‐monooxygenase activity of either mitochondrial or microsomal fractions, but the cytochrome P‐450 levels are reduced in mitochondria. Phenobarbital also depresses the mitochondrial cytochrome P‐450 levels while markedly increasing the microsomal cytochrome P‐450 levels. However, no significant changes in ecdysone 20‐monooxygenase activity are produced by phenobarbital pretreatment. The effects of ecdysone on adult cytochrome P‐450 are mostly evidenced in mitochondria isolated from females, whereas in males the changes are not statistically significant. It is concluded that the mitochondrial ecdysone 20‐monooxygenase is under regulatory control by ecdysone in the larval stage, which suggests that only the mitochondrial activity has a physiological role during insect development in M. domestica. In adults, both the mitochondrial and microsomal ecdysone 20‐monooxygenase activities are not responsive to ecdysone, which, coupled to their high Km values, indicates that the reaction may not be of physiological importance in adult insects and that the mitochondrial cytochrome P‐450 species being depressed by ecdysone in females are possibly not involved in ecdysone metabolism.
Juvenile hormone regulates the titer of a hemolymph factor that enhances ecdysone synthesis by insect (Manduca sexta) prothoracic glands in vitro
Authors: Watson R. Douglas , Haire Mary E. , Bollenbacher Walter E. 
Published: February 2005

AbstractThe hemolymph of last instar Manduca sexta larvae contains a protein factor that enhances ecdysone synthesis by prothoracic glands in vitro. The titer of the factor fluctuates during development in a pattern that suggests that it is regulated by juvenile hormone (JH). In untreated control larvae, the titer drops from 2.17 U ml−1 on day 1 to 0.27 U ml−1 on day 3. When larvae were treated with (7S)‐hydroprene (a JH analog), the titer remained elevated (2.09 U ml−1 on day 3). JH I, however, was ineffective in preventing the precommitment drop in the titer of the factor. After pupal commitment, the titer of the factor increases in untreated larvae from 0.84 U ml−1 on day 5 to 1.62 U ml−1 on day 7. This increase was blocked when the sources of JH (the corpora allata) were removed on day 5 by head ligation. When head‐ligated day 5 larvae were treated with either (7S)‐hydroprene or JH I, the titer of the factor was driven to a level (1.88 U ml−1 and 2.05 U ml−1, respectively) that was not significantly different from that found in untreated day 7 larvae (1.62 U ml−1). The combined results indicate the titer of the hemolymph factor is regulated by JH.
Production of a monoclonal antibody to the arylphorin of Heliothis zea
Authors: Lenz Cynthia J. , Greenstone Matthew H. 
Published: February 2005

AbstractA species‐specific monoclonal antibody was produced to whole plasma of fifth instar larvae of the corn earworm, Heliothis zea (Boddie) (Lepidoptera:Noctuidae). This antibody did not cross‐react with proteins from the plasma of any of the other lepidopteran larvae tested, including other Heliothis spp. The antigen recognized by this antibody was characterized and found to be arylphorin, a prominent larval storage protein. This conclusion was based on the electrophoretic as well as immunological characteristics of the antigen. Polyacrylamide gel electrophoresis indicated that the antigen had an apparent native molecular weight of 460,000, and that it was composed of subunits having apparent molecular weights of 76,000. The isoelectric point of the antigen was 5.9, with some microheterogeneity being seen. Western blotting of arylphorin against the monoclonal antibody clearly identified the antigen as arylphorin. This protein was not found in egg homogenates or early instar larval plasma, but it was present in large quantities in pupal homogenates and, at trace levels, in adult homogenates. The efficient production and selection of hybridomas producing antibodies specific to H. zea arylphorin using unfractionated plasma as immunogen illustrates the fact that monoclonal antibody technology can produce highly specific antibodies using crude antigen preparations. We discuss the tradeoffs one must accept when choosing this strategy over one using purified immunogens.
Stimulation of sex pheromone production by head extract in Spodoptera littoralis at different times of the photoperiod
Authors: Martínez Teresa , Camps Francisco 
Published: February 2005

AbstractAdult females of Spodoptera littoralis (Lepidoptera: Noctuidae) showed a cyclic pattern of sex pheromone production, and high titers of (Z,E)‐9,11‐tetradecadienyl acetate, the major component of its pheromone blend, were only detected during scotophase. Maximal amounts of pheromone were extracted approximately 2 h into second scotophase. Decapitation before the beginning of darkness inhibited normal production of pheromone, and no calling behavior was observed. Injection of brain‐suboesophageal ganglion (Br‐SOG) homogenate at the onset of scotophase restored pheromone production in decapitated females to the levels characteristic of second scotophase. Pheromone biosynthesis was also stimulated in decapitated females during photophase. The response to Br‐SOG homogenate injection was dose‐dependent. The pheromonotropic activity of Br‐SOG extract was the same when females were injected during photophase or scotophase.