bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stimulation of vitellogenin production by methoprene in prepupae and pupae of manduca sexta
Authors: Satyanarayana Kotamraju , Bradfield James Y. , Bhaskaran Govindan , Dahm Karl H. 
Published: February 2005

AbstractDenaturing electrophoresis of hemolymph from prepupae of M. sexta showed trace amounts of polypeptides with mobilities corresponding to those of vitellogenin (Vg) apoproteins from adult females. Absence of the polypeptides in allatectomized insects suggested regulation by juvenile hormone (JH). Daily administration of 10 μg of the JH analog methoprene from day 4 of the fifth stage to day 0 of the pupal stage caused accumulation of these polypeptides. They were identified as apovitellogenins (apoVgs) immunochemically with Vg antiserum. Stimulation of Vg in response to methoprene varied with age. In all cases, day 0 female pupae were highly responsive. Vg synthesis was not stimulated when pupae were injected with 20‐hydroxyecdysone (20‐HE) in addition to methoprene. Methoprene‐stimulated Vg synthesis was also abolished by inhibitors of mRNA or protein synthesis (α‐amanitin, actinomycin, cycloheximide). This result indicated that methoprene‐stimulated Vg accumulation requires gene expression. A Vg cDNA (2.1 kb) obtained by immunoscreening of the λgt 11 library, when used as a radiolabelled probe, hybridized with a 5.1 kb mRNA from total RNA of female fat body. It also hybridized with fat body RNA of normal prepupae and methoprene treated day 0 pupae but not with that of early fifth instars or solvent control pupae. The results indicate that the trace amounts of Vg found in prepupal stages are due to a weak expression of the Vg gene, which is stimulated by JH and repressed by 20‐HE. © 1994 Wiley‐Liss, Inc.
Hydrocarbon biosynthesis in Triatoma infestans eggs
Authors: Juárez Patricia 
Published: February 2005

AbstractTriatoma infestans eggs are shown to synthesize hydrocarbons. Radio‐gas chromatography was used to demonstrate metabolism of [1‐14C]propionate into precursor methyl‐branched fatty acids and into methyl‐branched hydrocarbons in T. infestans eggs. These reactions have not been demonstrated previously in insect eggs. An in vivo study showed that hydrocarbons are also transported to eggs by the hemolymph. Inhibition of hydrocarbon synthesis by sodium trichloroacetate (NaTCA) was correlated with reduced oviposition, reduced hatchability, and reduced insect survival. Scanning electron microscopy showed impoverishment of the eggs' epicuticular waxes following NaTCA treatment. © 1994 Wiley‐Liss, Inc.
Chitin synthesis in Spodoptera frugiperda wing imaginal discs: I. Chlorfluazuron, diflubenzuron, and teflubenzuron inhibit incorporation but not uptake of [14C]N‐acetyl‐D‐glucosamine
Authors: Mikołajczyk Piotr , Oberlander Herbert , Silhacek Donald L. , Ishaaya Isaac , Shaaya Eli 
Published: February 2005

AbstractThe purpose of this study was to determine the effects of potent inhibitors of chitin synthesis on an organ culture test system as a basis for determining the mode of action of such compounds. Consequently, we investigated the action of chlorfluazuron (CFA), diflubenzuron (DFB), and teflubenzuron (TFB) on uptake and incorporation into chitin of [14C]N‐acetyl‐D‐glucosamine ([14C]GlcNAc) in wing imaginal discs cultured in vitro. Spodoptera frugiperda wing imaginal discs provided a highly responsive test system for studying the inhibition of ecdysteroid‐dependent chitin synthesis in a target tissue in vitro.All three inhibitors blocked ecdysteroid‐dependent [14C]GlcNAc incorporation into chitin by the wing imaginal discs. The effectiveness of the inhibitors was not affected by the time of their application, i.e., exposures before, during, or after 20‐hydroxyecdysone treatment were equally effective in inhibiting chitin synthesis. Thus, exposure of freshly dissected discs to CFA for periods as short as 15 min inhibited approximately 90% of the chitin synthesis measured 72 h later. In contrast to previous in vivo studies all three inhibitors were similar in their effectiveness in vitro. However, while all three compounds inhibited [14C]GlcNAc incorporation in a similar dose‐dependent manner, only DFB and TFB reduced but did not block uptake of GlcNAc. © 1994 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
Factors affecting pheromone production in beetles
Authors: Vanderwel Désirée 
Published: February 2005

AbstractPheromone production and/or release by beetles is coordinated with a variety of behavioral, physiological, and environmental factors. To data, two basic mechanisms for the regulation of pheromone biosynthesis in beetles have been proposed. Pheromone biosynthesis may simply be dependent on the availability of biosynthetic precursors. Alternatively, certain stimuli or events may trigger pheromone biosynthesis via juvenile hormone (JH) action. JH may either act directly at the site of pheromone biosynthesis to enhance pheromone production or may act indirectly, through a brain hormone (which might be related to the pheromone biosynthesis activating neuropeptide) or through effects on antennal sensory response. Knowledge of the regulation of the initiation and termination of pheromone biosynthesis is reviewed. Mechanisms by which pheromone stereochemistry is controlled are also discussed. This is an important aspect of pheromone production in Coleoptera, since slight changes in the stereochemistry can completely alter the activity of the molecule. © 1994 Wiley‐Liss, Inc.
Development and partial characterization of monoclonal antibodies to venom of the parasitoid microplitis demolitor
Authors: Strand Michael R. , Johnson Jena A. , Noda Takashi , Dover Barry A. 
Published: February 2005

AbstractThe venom of Microplitis demolitor consists of a mixture of proteins. On native PAGE gels three major proteins designated a, b, and g were detected, while on SDS‐PAGE gels two major proteins of Mr 64.5 and 30.8 kD and several minor proteins were detected. No proteins smaller than Mr 30.8 kD were present. Murine monoclonal antibodies were generated against different venom components. Analysis by Western blot of venom proteins separated on native and SDS‐PAGE gels confirmed that antibodies from seven hybridoma lines recognized venom components. Two of the seven hybridoma lines reacted specifically with protein g on native PAGE gels and the Mr 30.8 k protein on SDS‐PAGE gels, while four other lines cross‐reacted with these and other venom proteins. The final hybridoma line reacted with protein a when venom was separated on native PAGE gels and an array of proteins when venom was separated on SDS‐PAGE gels. Using an enzyme‐immunoassay and specific monoclonal antibodies, M. demolitor females were estimated to inject 0.02—0.05 venom gland reservoir equivalents into its host, Pseudoplusia includens, at oviposition. Venom proteins persisted in host hemolymph for 6—12 h before dropping to undetectable levels. © 1994 Wiley‐Liss, Inc.
Cloning of a VLP‐protein coding gene from a Parasitoid Wasp Venturia canescens
Authors: Theopold Ulrich , Krause Elke , Schmidt Otto 
Published: February 2005

AbstractVirus‐like particles (VLPs) that are bound to the egg surface of a parasitic wasp Venturia canescens are void of nucleic acid and unable to infect host tissue but instead provide a passive protection against the host's immune recognition. To investigate evolutionary and functional properties of Venturia particles, we isolated cDNAs coding for a VLP‐protein by screening an expression library of the wasp, using antibodies against purified VLPs. The corresponding coding DNA is present in the wasp genome as a single‐copy gene. © 1994 Wiley‐Liss, Inc.
Octopamine enhances phagocytosis in cockroach hemocytes: Involvement of inositol trisphosphate
Authors: Baines Danica , Downer Roger G. H. 
Published: February 2005

AbstractOctopamine and 5‐hydroxytryptamine (5‐HT) were previously shown to affect phagocytosis in cockroach hemocytes through unidentified receptor‐mediated events. In the present study, we examined the ability of 5‐HT and octopamine to enhance inositol trisphosphate (IP3) production using hemocyte membranes of the American cockroach, Periplaneta americana. Octopamine enhanced IP3 production with a maximal peak at 100 nM. Similarly, 5‐HT enhanced IP3 production with a maximal effect at 10 nM. The effects of 5‐HT and octopamine are not additive, suggesting that both are working through the same receptor. Phentolamine, a general octopamine antagonist, blocked the effects of octopamine and 5‐HT, while a mammalian 5‐HT2 antagonist that blocks 5‐HT‐sensitive receptors in insect peripheral tissue, ketanserin, did not. A pharmacological profile indicates that the receptor is similar to an octopamine1‐type.Octopamine at 1 μM increased phagocytosis in cockroach hemocytes exposed to Staphylococcus aureus in vitro, and this effect was mimicked by IP3 (10 μM). The octopamine‐treated hemocytes were shown to increase IP3 production in the latter stage of phagocytosis.Adult cockroaches exposed to an LD50 dose of S. aureus in conjunction with either 0.1 mM octopamine or the octopamine1 agonist, clonidine, had higher survival rates compared to saline‐treated cockroaches. Correspondingly, the octopamine1 antagonist, chlorpromazine, partially blocked the octopamine‐mediated increase in cockroach survival. © 1994 Wiley‐Liss, Inc.
Inhibition by azadirachtin of phospholipid transfer from lipophorin to the oocytes in Rhodnius prolixus
Authors: Moreira Monica F. , Garcia Eloi S. , Masuda Hatisaburo 
Published: February 2005

AbstractThe growth of oocytes was severely reduced in female Rhodnius prolixus treated with azadirachtin A (AZA). When administered in a blood meal, AZA (1 μg/ml) inhibited phospholipid transfer to the ovaries without altering the availability of yolk protein in the hemolymph or its uptake by 1 mm oocytes. The lipid composition of lipophorin, its concentration in the hemolymph, and its density were normal in AZA‐treated females. Partial inhibition of phospholipid transfer was observed when lipophorin from AZA‐treated females was injected into normal females, or when lipophorin from normal females was injected into AZA‐treated females. The two effects were additive, so that the transfer of phospholipids from the lipophorin of AZA‐treated females to the oocytes of AZA‐treated females was nearly eliminated. In combination, these effects of AZA on phospholipid transfer to the oocytes limit the capacity of AZA‐treated females to produce eggs. © 1994 Wiley‐Liss, Inc.
Aminopeptidase a from Rhynchosciara americana (Diptera) larval midguts: Properties and midgut distribution
Authors: Klinkowstrom Adriana M. , Terra Walter R. , Ferreira Clélia 
Published: February 2005

AbstractL‐aspartic acid α‐(β‐naphthylamide) (AspβNA) hydrolase activity is restricted mostly to the midgut caeca of Rhynchosciara americana larvae. The membrane‐bound activity is solubilized in detergent and, after electrophoretic separation, proved to be identical to leucine p‐nitroanilide (LpNA) hydrolases previously described. Differential centrifugation of midgut caeca homogenates, followed by assays of enzyme markers and aminopeptidase, suggests that the soluble AspβNA hydrolase is associated with the cell glycocalyx. Soluble aminopeptidases from R. americana midgut caeca are resolved into three fractions by gel electrophoresis. The slow migrating fraction hydrolyzes AspβNA well and displays a low activity on LpNA and proline β‐naphthylamide (ProβNA). Thus, this enzyme is an aminopeptidase A (EC 3.4.11.7). It has a pH optimum of 7.5, Mr 117,000 (gel filtration), and is competitively inhibited by aspartate hydroxamate (Ki 0.1 mM). Nevertheless, this enzyme, in contrast to the vertebrate enzyme, is not activated by calcium ions. The aminopeptidase A seems to have a charge variant that displays an intermediate migration and is not resolved from an aminopeptidase N (enzyme very active on LpNA). These two activities are not resolved by either gel filtration or ion‐exchange chromatography. The aminopeptidases N with intermediate and high migration, previously reported to be charge variants, were shown in this paper to differ in substrate specificities and in the strength with which they associate to the cell glycocalyx. © 1994 Wiley‐Liss, Inc.
Effect of KK‐42 on growth, development, molting, and metamorphosis of the european corn borer, Ostrinia nubilalis (Hübner)
Authors: Gelman Dale B. , Bell Robert A. , DeMilo Albert B. , Kochansky Jan P. 
Published: February 2005

AbstractKK‐42 (1‐benzyl‐5‐[(E)‐2,6‐dimethyl‐1,5‐heptadienyl]imidazole), administered by feeding, delayed the growth and development of nondiapause‐bound and diapause‐bound Ostrinia nubilalis larvae and increased the length of the instar. At doses of 80–240 ppm, 62–100% of nondiapause‐bound fourth instars precociously pupated or remained as fourth instars, while 52–100% of diapause‐bound fourth instars did not molt to the fifth instar. Injection of these nondiapause‐ and diapause‐bound KK‐42‐fed fourth instars with ecdysone elicited a molt and resulted in the production of larval‐pupal intermediates. When mature fourth instar controls were similarly injected, they molted into normal fifth instars. These results support the view that KK‐42 delays/inhibits ecdysteroid production. Both eupyrene and apyrene spermiogenesis were prematurely initiated in nondiapause‐bound fourth instars that were fed on medium containing 160 ppm KK‐42. Fenoxycarb, a potent juvenile hormone mimic, rescued nondiapause‐bound fourth instars from precocious pupation. All fenoxycarbtreated larvae either molted to the fifth instar or remained as fourth instars and eventually died. These results support the view that treatment with KK‐42 inhibits JH production. When KK‐42 treatment was begun in the third instar, a considerable number of nondiapause‐bound and some diapause‐bound third instars precociously molted to the fifth instar. There was a correlation between weight and the incidence of precocious molting in that third instars destined to skip the fourth instar attained a weight, as pharate fifth instars, of two to three times more than pharate fourth instar controls. Similarly, fourth instars that were destined to undergo precocious pupation attained a weight, as pharate pupae, that was approximately two times more than pharate fifth instar controls. More potent analogues of KK‐42 may prove useful in controlling populations of 0. nubilalis by interfering with their growth, development, and metamorphosis. © 1995 Witey‐Liss, Inc.This article is a US Government work and, as such, is, in the public domain in the United States of America.
Distribution of digestive proteinases in the alimentary tract of the european corn borer Ostrinia nubilalis (lepidoptera: Pyralidae)
Authors: Houseman Jon G. , Chin Phak‐San 
Published: February 2005

AbstractThe distribution of digestive proteinases in either the anterior and posterior midgut or between the midgut epithelium and ectoperitrophic and endo‐peritrophic spaces in the midgut were examined in the European corn borer, Ostrinia nubilalis. Trypsin, chymotrypsin, elastase, and aminopeptidase activities were the same in the anterior and posterior halves of the midgut. Of the total aminopeptidase activity, 95% was located in the midgut epithelium, and 90% of the trypsin, 97% of chymotrypsin, and 93% of the elastase activity were found in the midgut lumen. Trypsin, measured by hydrolysis of benzoyl‐L‐arginine ethyl ester, and chymotrypsin levels were significantly higher in the ectoperitrophic space compared to the endoperitrophic space. Digestion in the midgut is proposed to be sequential with tryptic digestion occurring in the endoperitrophic space. Ingested protein is digested further in the ectoperitrophic space by the action of elastase, chymotrypsin, and a second trypsin. Final digestion occurs by an intracellular aminopeptidase. © 1995 Wiley‐Liss, Inc.
Immunolocalization of a proton V‐ATPase in ovarian follicles of the tobacco hornworm Manduca sexta
Authors: Janssen I. , Hendrickx K. , Klein U. , de Loof A. 
Published: February 2005

AbstractA monoclonal antibody, directed against an H+ translocating V‐ATPase of the midgut of Manduca sexta, has been used for immunolocalization studies in ovarian follicles and testes of Manduca sexta. In testes, no distinct staining above background levels was observed. In vitellogenic follicles, V‐ATPase immunoreactivity first appears in the cytoplasm of the trophocytes and then in the oocyte, but by far the strongest reaction is present in the region of the oolemma during endocytosis. All types of follicle cells surrounding both the oocyte and the trophocyte compartments show a distinct positive reaction. In the cylindrical follicle cells surrounding the oocyte, the immunoreactivity is clearly restricted to the basal part. Our results suggest an important role for V‐ATPase in vitellogenin uptake in Manduca, similar to that suggested on electro‐physiological grounds in Hyalophora cecropia. © 1995 Wiley‐Liss, Inc.
Temperature acclimation and seasonal responses by enzymes in cold‐hardy gall insects
Authors: Joanisse Denis R. , Storey Kenneth B. 
Published: February 2005

AbstractChanges in the activity of over 20 enzymes of intermediary metabolism in 15°C or −4°C acclimated goldenrod gall moth (Epiblema scudderiana) and gall fly (Eurosta solidaginis) larvae were measured. Increased activities of glyco‐genolytic and hexose monophosphate shunt enzymes in cold‐acclimated Epiblema scudderiana suggest a role for coarse control in the conversion of glycogen reserves into glycerol cryoprotectant synthesis. In Eurosta solidaginis, high glycogen phosphorylase activity with decreased activities of glycolytic enzymes may account in part for the temperature‐dependent switch from glycerol to sorbitol synthesis in these larvae upon cold acclimation. Isoelectric focusing analyses of five enzymes in overwintering Epiblema scudderiana revealed transient mid‐winter changes in the isoelectric points of phosphofructokinase and pyruvate kinase, suggesting seasonal changes in the phosphorylation state of these enzymes. A distinct developmental pattern of aldolase isozymes suggests a role for a new isozyme during overwintering or upon spring emergence. Regulation of metabolism by changes in enzyme activities is indicated for both larvae. © 1995 Wiley‐Liss, Inc.
Characterization of midgut proteinase activities of white grubs: Lepidiota noxia, Lepidiota negatoria, and Antitrogus consanguineus (scarabaeidae, melolonthini)
Authors: McGhie Tony K. , Christeller John T. , Ford Rebecca , Allsopp Peter G. 
Published: February 2005

AbstractThe proteinases in the midguts of three scarab white grub species, Lepidiota noxia, L. negatoria, and Antitrogus consanguineus, were investigated to classify the proteinases present and to determine the most effective proteinase inhibitor for potential use as an insect control agent. pH activity profiles indicated the presence of serine proteinases and the absence of cysteine proteinases. This was confirmed by the lack of inhibition by specific cysteine proteinase inhibitors. Trypsin, chymotrypsin, elastase, and leucine aminopeptidase activities were detected by using specific synthetic substrates. A screen of 32 proteinase inhibitors produced 9 inhibitors of trypsin, chymotrypsin, and elastase which reduced proteolytic activity by greater than 75%. © 1995 Wiley‐Liss, Inc.
Phototoxicity of plant secondary metabolites: Insect and mammalian perspectives
Authors: Berenbaum May 
Published: February 2005

AbstractPhototoxic chemicals produced by plants have been studied in a number of contexts, most notably as protective agents against mammalian and insect herbivores. Although there are commonalities in the responses of these two groups of herbivores to plant phototoxins, there are differences as well. Whereas a greater range of chemical classes has been demonstrated to display phototoxicity against insects, considerably more information is available on symptomology of phototoxicity and mechanisms of action in mammals. The commonalities include alterations in behavior following ingestion, notably photophobia, disruption of integumentary integrity following contact or ingestion, and metabolic detoxification following ingestion, in the case of furanocoumarins involving cytochrome P450 monooxygenases. Not yet known to exist in insects are phototoxin‐mediated effects on sensory (particularly visual) systems and phototoxicity resulting from abnormal chlorophyll metabolism. In order to gain greater understanding of the ecological significance of phototoxin‐mediated plant defense against both insects and mammals, there is a need for more studies centered on natural associations. © 1995 Wiley‐Liss, Inc.
Plant defenses against oxidative stress
Authors: Larson Richard A. 
Published: February 2005

AbstractMany reactive oxygen species such as ozone, singlet oxygen, hydroxyl radical, and organic oxyradicals have been implicated in damage to plant organs and biopolymers such as chloroplasts, cell membranes, proteins, and DNA. The principal defenses against these reactive molecules and free radicals in plants include detoxifying enzymes (catalase, superoxide dismutase, etc.) and also lower molecular weight secondary products with antioxidant activity. These latter compounds include a great variety of phenolic compounds, carotenoids, nitrogenous, and sulfur‐containing materials. Some of the more important mechanisms of action of the secondary compounds will be discussed, with emphasis on the use of structural and kinetic data to identify the most effective antioxidants against peroxy radical‐induced damage, which is perhaps the most important of the oxidative stresses present in the usual environment of plants. © 1995 Wiley‐Liss, Inc.
Effects of dietary amino acids on the production of sexual morph by the green peach aphid, Myzus persicae
Authors: Fujita Akihiko , Mitsuhashi Jun 
Published: February 2005

AbstractIn order to complete a holocycle of the green peach aphid, Myzus persicae, on a synthetic diet, the effects of dietary amino acid contents on development of sexuals were investigated. For this purpose, the aphids were reared on holidic diets for two to three generations at 20°C under a scotophase of 15 h per diem. Under these conditions, the production of males by the aphids on a synthetic diet was very much poorer than those reared on radish seedling. On reducing the amino acid concentration of the diet, the proportion of males produced was comparable to that produced by aphids fed on radish seedlings. The obtained males were smaller and survived longer than those reared on radish seedling. Under the long night photoperiod and on the synthetic diet with reduced amino acids, gynoparae and then oviparae were also obtained. The oviparae were mated with the males grown on the synthetic diet, and laid eggs. The eggs, however, did not turn dark in color, and perished. © 1995 Wiley‐Liss, Inc.