bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postendocytic vitellin processing in ovarian follicles of the stick insect Carausius morosus (Br.)
Authors: Giorgi Franco , Masetti Massimo , Ignacchiti Vincenzo , Cecchettini Antonella , Bradley James T. 
Published: February 2005

AbstractNewly laid eggs of the stick insect Carausius morosus contain two native vitellins (Vit A and Vit B). Under denaturing conditions, these vitellins resolved into 3 (A1, A2, and A3) and 2 (B1 and B2) polypeptides. All of these polypeptides had counterparts in the female hemolymph from which they were shown to be derived by in vivo labelling. During ovarian development, the 2 vitellins changed both in charge and polypeptide composition. In EV and LV follicles, Vit A resolved into 4 distinct vitellin polypeptides (A0, A1, A2 and A3). Using a panel of monoclonal antibodies, polypeptide A0 proved to be immunologically related to polypeptide A2. In follicles about to begin choriongenesis, polypeptide A3 was gradually replaced by a lower Mr polypeptide. Over the same time period, polypeptide B1 changed in charge, but not in Mr. To confirm the existence of a polypeptide processing in C. morosus, ovarian follicles of different developmental stages were exposed in vivo to [35S]‐methionine from 6 to 72 h. Data showed that A0 and B1 were the polypeptides most heavily labelled after short time exposures to the radioisotope. Polypeptides B2 and A3 were also labelled to some extent. With progressively longer exposures, polypeptides A1 and A2 also became labelled. In vivo exposure to [3H]‐GlcNAc caused all vitellin polypeptides to become heavily labelled. Autoradiographic analysis of ovarian follicles labelled this way showed that, during development, radioactivity was gradually transferred from newly formed yolk spheres in the cortical ooplasm to the central ooplasm. Data were interpreted as suggesting a causal relationship between polypeptide processing and progressive yolk sphere fusion to yield the central ooplasm. © 1993 Wiley‐Liss, Inc.
Preparation and partial characterization of amino acid transporting brush border membrane vesicles from the larval midgut of the gypsy moth (Lymantria dispar)
Authors: Wolfersberger Michael G. 
Published: February 2005

AbstractBrush border membrane vesicles were prepared from both fresh and frozen midguts of Lymantria dispar larvae by Mg/EGTA precipitation and differential centrifugation. The vesicles were enriched 10 to 13‐fold, relative to the homogenate, in aminopeptidase and gamma‐glutamyl transferase activity. No significant difference was found in enzyme enrichment of vesicles prepared from fresh and frozen midguts. Inwardly directed potassium salt gradients resulted in transient accumulation of leucine and lysine but not glutamic acid by the vesicles. © 1993 Wiley‐Liss, Inc.
Purification and characterization of a flavin‐binding storage protein from the hemolymph of Galleria mellonella
Authors: Silhacek Donald L. , Miller Stephen G. , Murphy Curtis L. 
Published: February 2005

AbstractThe 85K storage protein that accumulates in the hemolymph of Galleria mellonella during the final larval instar was isolated and purified from newly molted pupae. The separation of fresh hemolymph proteins from larvae or pupae by different chromatographic and electrophoretic procedures indicated the native protein had a Mr of 170,000 and consisted of two identical 85K subunits. Crosslinking experiments using fresh hemolymph followed by Western blotting also indicated a dimeric structure for the native protein. Analyses of the dimer purified from pupal hemolymph indicated that 85K was a glycoprotein, containing approximately 6.5% neutral sugar and about 1.9% amino sugar. Like other insect flavin‐binding proteins, 85K has a relatively high histidine content but an uncharacteristically high arginine content. The purified 85K dimer did not bind riboflavin, suggesting that the integrity of the molecule had been altered during purification. However, 85K purified in low yield by Affi‐Gel Blue chromatography, did bind riboflavin, indicating that under certain, undefined conditions the functional integrity of the protein could be retained during purification. © 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.
Toxicokinetics of [3H]‐dihydroazadirachtin in the variegated cutworm Peridroma saucia
Authors: Koul Opender , Isman Murray B. , Arnason John T. 
Published: February 2005

AbstractThe excretion, retention, and tissue distribution of [3H]‐dihydroazadirachtin was investigated in the variegated cutworm, Peridroma saucia (Noctuidae). The candidate compound was rapidly cleared from the hemolymph following either oral exposure or topical administration, with maximum concentrations at 6 h post‐treatment and peak appearance of label in the frass at 12 h. However, approximately 45 and 55% of the labelled material was retained in the body at 72 h in respective treatments. Major depots for retained radioactivity were the gut (24% of the administered oral dose, 18.8% of the administered topical dose) and integument (12.2% of the oral dose and 30.7% of the topical dose). The variation in tissue distribution of dihydroazadirachtin with respect to the mode of application is discussed. A single polar metabolite fraction was obtained from the frass of dihydroazadirachtin‐fed larvae. The physiological and behavioral effects of 22,23‐dihydroazadirachtin and azadirachtin are quantitatively similar. © 1994 Wiley‐Liss, Inc.
Yolk formation in Locusta migratoria and Schistocerca gregaria: Related ligands and oocyte receptors
Authors: Hafer Johannes , Ferenz Hans‐Joerg 
Published: February 2005

AbstractDuring vitellogenesis the transport of yolk precursor proteins, the vitellogenins (VTG), from the hemolymph into the oocyte is achieved by receptor‐mediated endocytosis. Recently the receptor for the VTG of Locusta migratoria has been isolated. Now a new protocol has been developed for the purification of the VTG receptor of this locust from ovarian membranes. By CHAPS solubilization of the membranes followed by ion exchange and immunoaffinity chromatography, a 100‐fold purification of the VTG receptor was achieved. The amino acid composition of the receptor protein has been determined. However, first attempts to sequence the receptor failed due to the N‐terminal blocking of the molecule. With the same methods the VTG receptor of another locust, Schistocerca gregaria, has been isolated, purified, and characterized. This receptor has an apparent Mr of 186 kDa under nonreducing conditions. It recognizes L. migratoria VTG and vice versa. However, in cross‐competition experiments in which the Schistocerca VTG competed with Locusta VTG for binding to the Locusta VTG receptor, the Schistocerca VTG was less efficient. Furthermore, the VTG receptor proteins of S. gregaria and L. migratoria are immunologically related as revealed by Western blotting with anti‐Locusta VTG receptor antibodies. It appears that important structural elements required for efficient and specific endocytosis of VTG have been conserved. © 1994 Wiley‐Liss, Inc.
Controlled ecdysteroid accumulation in eggs of the silkworm, Bombyx mori, by an imidazole compound (KK‐42), and embryogenesis in these eggs
Authors: Kadono‐Okuda Keiko , Amornsak Weerawan , Yamashita Okitsugu 
Published: February 2005

AbstractAn imidazole compound (KK‐42), a potent inhibitor of ecdysone synthesis, was applied to the female pharate adult of the silkworm, Bombyx mori, to control ecdysteroid accumulation in developing ovaries and mature eggs. KK‐42 applied on day 2 or later completely suppressed an increase in ecdysteroid content in developing ovaries. The inhibitory action of KK‐42 was restricted to vitellogenic follicles, i.e., those in which active ecdysteroid synthesis is occurring. Ecdysteroid content in the mature eggs of moths remained at the level accumulated in ovaries before KK‐42 application. Thus, KK‐42 was shown to be a novel agent to suppress the ecdysteroid accumulation in eggs. Eggs containing different amounts of ecdysteroids showed different levels of embryonic development. About 80% of the eggs which contained less than 10 ng free ecdysteroids/g eggs were not fertilized. More than 80% of the eggs containing less than 40 ng/g eggs of free ecdysteroids initiated embryogenesis but failed to hatch. Larvae hatched from almost all eggs which accumulated free ecdysteroids of more than 150 ng/g. Thus, maternal ecdysteroids appear to be required at different titers for fertilization, embryogenesis, and hatching of the silkworm larvae. © 1994 Wiley‐Liss, Inc.
Properties and significance of a riboflavin‐binding hexamerin in the hemolymph of Hyalophora cecropia
Authors: Magee John , Kraynack Nathan , Massey Holman C. , Telfer William H. 
Published: February 2005

AbstractA riboflavin‐binding hexamerin isolated from pupal hemolymph of Hyalophora cecropia has a native Mr of 510,000, subunit Mr of 85,000, and a 5% carbohydrate content. An intrachain cross‐link was confirmed in protease limit digests. Ellman titration confirmed the presence of a sulfhydryl group, which is needed for this linkage. Though Cu2+ is known to promote the linkage, heavy metals were not detected in the isolate. Heat denaturation released ligand with the absorbency, fluorescence spectra, and chromatographic behavior of riboflavin. Binding resulted in substantial quenching of the fluorescence of both the isoalloxazine in riboflavin and of aromatic groups in the apoprotein. Kinetic analysis indicated a KD of 2.5 × 10−7 M for riboflavin, 1.3 × 10−7 M for lumiflavin, and greater than 1 × 10−6 M for FMN and FAD. Over four moles of flavin were bound per mole of hexamerin. The amount of riboflavin in pupal hemolymph is sufficient to occupy only 2–3 of these sites. Riboflavin is also associated with lipophorin and vitellogenin, but the molar ratios after protein isolation were low. On a standard laboratory diet, riboflavin is in great excess, but most of it is apparently excreted before the apoprotein first appears in the hemolymph, just before wandering. The concentration of riboflavin‐binding hexamerin rises to 15–30 mg/ml in pupae; relative to other hexamerins, very little is stored in the fat body. All of the apoprotein and 75% of riboflavin disappear from the hemolymph during adult development. An amount of flavin at least equal to that stored in pupal hemolymph is transferred to the eggs formed during this period. © 1994 Wiley‐Liss, Inc.
Pheromonotropic stimulation of moth pheromone gland cultures in vitro
Authors: Rafaeli Ada 
Published: February 2005

AbstractThe direct neurohormonal control of pheromone biosynthesis by pheromone biosynthesis activating neuropeptide (PBAN) was demonstrated in Helicoverpa (Heliothis) spp. using pheromone gland cultures in vitro. Pheromone gland activation involved the de novo production of the main pheromone component (Z)‐11‐hexadecenal as revealed by radio‐TLC, radio‐HPLC, and radio‐GC. Activation was found to be a specific response attributed to pheromone gland cultures alone. Specificity of pheromonotropic activation was demonstrated to be limited to nervous tissue extracts. A sensitive and specific radioimmunoassay was developed using [3H]‐PBAN, and the spatial and temporal distribution of PBAN‐immunore‐activity was studied. PBAN‐immunoreactivity in brain complexes was found throughout the photoperiod and in all ages. From the distribution of PBAN‐immunoreactivity it appears that PBAN release is affected by photoperiod. Pheromone gland cultures were found to be competent to pheromone production irrespective of age and photoperiod. Therefore, the neuroendocrine control of pheromone production operates at the level of neuropeptide synthesis and/or release and not at the level of the target tissue itself. The involvement of cyclic‐AMP as a second messenger system was demonstrated. Brain extracts and PBAN were shown to stimulate dose‐ and time‐dependent changes in intracellular cyclic‐AMP levels. The role of cyclic‐AMP in this mechanism was further verified by the ability of cyclic‐AMP mimetics to mimic the pheromonotropic effect of brain extracts and PBAN. However, dose‐response studies using PBAN and a hexapeptide C‐terminal fragment of PBAN suggested that PBAN induces a two mechanism response, one occurring at low PBAN concentrations (high affinity receptor) and another at higher PBAN concentrations (low affinity receptor). Further evidence indicating a dual receptor system was obtained with the observation that the active phorbol ester (phorbol‐12‐myristate 13‐acetate), the diacyl‐glycerol analog (1,2‐dioleolyl‐sn‐glycerol), and the intracellular calcium ionophore (ionomycin) mimicked the physiological action of PBAN and that lithium chloride had a pheromonostatic effect. The results indicate that pheromone glands also possess receptors that are linked to inositol phosphate hydolysis. © 1994 Wiley‐Liss, Inc.
Effects of allatectomy and ovariectomy on cuticular hydrocarbons inCalliphora vomitoria(diptera)
Authors: Trabalon Marie , Campan Mireille , Hartmann Nadine , Baehr Jean‐Claude , Porcheron Patrick , Clément Jean‐Luc 
Published: February 2005

AbstractThe relationships between female attractiveness, cuticular hydrocarbons, and levels of juvenile hormone and ecdysteroids were studied inCalliphora vomitoria. The experiments were conducted at 48 and 72 h post‐emergence, according to attractiveness appearance and increase. The 48‐h‐old allatectomized females were less attractive than the control females, whereas no changes occurred either in cuticular hydrocarbons total mass production or in the different hydrocarbon families. However, the 72‐h‐old allatectomized females were more attractive than the control females, and, in relative proportions, allatectomy led to an increase in monomethylalkanes and a decrease in n‐alkanes.Only at 48 h were the ovariectomized females less attractive than the control females and did ovariectomy increase the relative proportions of monomethylalkanes. At 72 h, ovariectomy did not influence female attractiveness, but it decreased the total cuticular hydrocarbon production. Allatectomy and ovariectomy significantly decreased ecdysteroids levels at 48 and 72 h. Ovariectomy did not affect juvenile hormone production.These results suggest that attractiveness and cuticular hydrocarbon synthesis could be under the direct control of ecdysteroids and the indirect influence of juvenile hormone. © 1994 Wiley‐Liss, Inc.
Cellular defense mechanisms in C. capitata: Recognition and entrapment of E. coli by hemocytes
Authors: Marmaras Vassilis J. , Charalambidis Nektarios D. , Lambropoulou Maria 
Published: February 2005

AbstractThe mechanism of recognition of foreignness and entrapment of invaders by the immune system of insects is unknown. In this report using hemocyte monolayer preparations and biochemical analysis we demonstrate the requirements for recognition of E. coli in vitro, their entrapment by hemocytes, and nodule formation. A model system consisting of an isolated hemocyte protein (47 KDa), isolated hemocyte tyrosinase, isolated hemocytes, tyrosine, and E. coli was used to obtain these results. The 47 kDa polypeptide has the ability to form adducts with tyrosine derivatives generated by the action of tyrosinase and to attach to the E. coli surface. The latter process takes place independently of tyrosinase activity. When the E. coli‐47KDa protein complex was overlaid on hemocyte monolayers followed by tyrosine and tyrosinase or vice versa, the bacteria were entrapped by hemocytes. The same results were obtained when the monolayers were overlaid with 47 KDa protein, followed by E. coli‐47 KDa protein complex and then tyrosine and tyrosinase. The same experimental procedure in test tubes resulted in nodule formation. These results permit us to propose that the most likely explanation for the entrapment of E. coli to hemocytes and the formation of nodules is the production of E. coli‐47 KDa complexes, and their crosslinking through a quinone intermediate generated by the action of tyrosinase on hemocytes. © 1994 Wiley‐Liss, Inc.
Parasitoid‐host interactions: Historical perspectives and current status
Authors: Jones Davy , Strand Michael 
Published: February 2005

AbstractThe papers contained in this special issue of Archives of Insect Biochemistry and Physiology are published in connection with the symposium entitled “Physiological and Molecular Interactions Between Parasitoids and Their Hosts” held at the XIX International Congress of Entomology, Beijing, China. Speakers in the program discussed advances in the field and provided insight into future directions of study. As a preface to this special issue, we summarize the history of this field as reflected through the continuing series of symposia held in association with the International Congresses.
Biochemical and developmental alterations of Heliothis virescens (F.) (lepidoptera, noctuidae) larvae induced by the endophagous parasitoid Cardiochiles nigriceps viereck (Hymenoptera, braconidae)
Authors: Pennacchio Francesco , Vinson S. Bradleigh , Tremblay Ermenegildo , Tanaka Toshiharu 
Published: February 2005

AbstractAll larval stages of Heliothis virescens (F.) parasitized by the endophagous larval parasitoid Cardiochiles nigriceps Viereck, a braconid species belonging to the subfamily Microgasterinae, exhibit developmental arrest at last instar and fail to pupate. The major part of larval development of the parasitoid is synchronized with the arrested host last larval instar and the parasitoid first molt is never observed before the host attains the late digging stage. At this time, the total ecdysteroid titer of the hemolymph of parasitized hosts is very low and subsequently shows a slow and gradual increase, characterized by a low titer of 20‐hydroxyecdysone (20‐HE) associated with consistent amounts of inactive ecdysteroid polar metabolites. Juvenile hormone esterase (JHE) activity is high in both control and parasitized host larvae at the early digging stage of development, and juvenile hormone analogs (JHA) applied to parasitized host last instar larvae appear to suppress the parasitoid molt. Concurrent with these changes was an increase in the hemolymph titer of proteins which was maintained at a high level in parasitized larvae in contrast to the observed decrease in control larvae at the cell formation stage of development. Neck‐ligation of newly molted host 5th instar parasitized larvae, prior to both JHE release and the increase in protein titers, inhibited growth and molting of the parasitoid. In contrast, ligation after JHE release and with high hemolymph protein titers resulted in parasitoid molting and growth. These data suggest that the host ecdysteroid hormones are not directly involved in the regulation of the parasitoid molt, although high juvenile hormone (JH) levels probably prevent it. More likely, molting is triggered by other biochemical changes, such as proteins or other factors occurring in the hemolymph. Molting of C. nigriceps larvae in vitro into an ecdysone‐free semidefined medium further supported the view that host ecdysone is not necessary for the molt. Teratocytes of C. nigriceps seem to play an important role in the inactivation of 20‐HE through its conversion to inactive polar metabolites, and along with female calyx fluid and venom which depress the secretory activity of the host prothoracic glands, they are the most important sources of host regulatory factors. © 1994 Wiley‐Liss, Inc.
Immunological analysis of lipophorin in the haemolymph, ovaries, and testes of the fall webworm, Hyphantria cunea (Drury)
Authors: Yun Hwa Kyung , Kim Woo Kap , Kim Hak R. 
Published: February 2005

AbstractLipophorin (LP) was purified from haemolymph in last instar larvae of Hyphantria cunea (Drury) by KBr density gradient ultracentrifugation and gel filtration. LP is composed of Apo‐LP I and Apo‐LP II with molecular weights of 230 kDa and 80 kDa, respectively.The level of haemolymph LP in early pupae was somewhat greater than in last instar larvae. In males, this LP concentration is maintained throughout pupal development, whereas the level of haemolymph LP decreases in female pupae beginning at day 7, coincident with the onset of vitellogenesis in the fall webworm. In both male and female adults, haemolymph LP concentrations were dramatically increased in comparison to their pre‐adult levels. Actually, LP was found in the ovary by immunodiffusion, tandem‐crossed immunoelectrophoresis, and Western blotting. Location of LP in the ovary was also traced by immunogold labelling. Also, LP appeared in small amounts in protein yolk bodies of the ovary at an early stage of vitellogenesis, when nurse cells are bigger than the oocyte, but in greater amounts at those stages when the oocyte is larger than nurse cells—that is, when vitellogenesis is actively taking place. This fact clearly reveals that LP is synthesized by fat body and released into the haemolymph, and then taken up by the growing ovary during vitellogenesis. Also, LP was detected in testes by immunological analysis. Western blotting showed that LP was present in testicular fluid but not in the peritoneal sheath and cysts. To test whether LP is also synthesized in testes, testes and fat body tissues were cultured in vitro, indicating that fat body synthsizes LP but testes do not. The result showed that the haemolymph LP itself is taken up into the testes. © 1994 Wiley‐Liss, Inc.
Synthesis and deposition of PCG‐100, the main pupal cuticle glycoprotein of the medfly Ceratitis capitata
Authors: Boccaccio Graciela L. , Quesada‐Allué Luis A. 
Published: February 2005

AbstractWe have studied the developmental expression of the main pupal cuticle glycoprotein, PCG‐100, in the Medfly Ceratitis capitata. A polyclonal antiserum was raised against this protein. Western blotting analysis showed that this glycoprotein is integument‐ and stage‐specific. No PCG‐100 or immunologically related polypeptides were detected in other tissues or instars. As studied by microinjection of [35S]methionine in individual flies, in vivo synthesis and deposition of PCG‐100 begins approximately 48 h after the onset of pupariation, shortly after the time of head eversion. Synthesis is maximal at 54–64 h, decreases at 72 h, and practically ceases in fully shaped 4‐day‐old pupae. The time required for PCG‐100 deposition into the cuticle was found to be less than 10 min after its synthesis. This is the first time such in vivo analysis has been performed. © 1994 Wiley‐Liss, Inc.