bluuebunny/crossref_metadata_2025_split huggingface dataset:
Host regulation effects on Heliothis virescens (F.) larvae inducd by teratocytes of Cardiochiles nigriceps Viereck (Lepidoptera, Noctuidae‐Hymenoptera, Braconidae)
Authors: Pennacchio Francesco , Vinson S. Bradleigh , Tremblay Ermenegildo 
Published: February 2005

AbstractTeratocytes deriving from the serosal membrane of Cardiochiles nigriceps Viereck, obtained “in vitro” from embryos hatched on a semidefined medium, were injected at different numbers and in different developmental stages of nonparasitized Heliothis virescens (F.) last instar larvae. Host development was affected by teratocyte injections and the responses registered ranged from normal to complete inhibition of pupation, according to the number of teratocytes injected and the developmental stage of the larva at time of injection. Complete pupation failure was observed when teratocytes derived from 4C nigriceps embryos were injected into 1st day 5th instar (new‐slender stage) host larvae. Complete pupation occurred when teratocytes from 2 embryos were injected into 3rd or 4th day 5th instars (burrow‐digging or day 1 cell formation stage). Intermediate responses, such as the formation of pupal cuticle without ecdysis or with only partial ecdysis, were obtained with intermediate teratocyte numbers, or host developmental stages. All pupae derived from teratocyte injected larvae failed to develop into adults normally obtained from control injected larvae. The larval weight just before pupation was negatively affected only when teratocyte injections were performed on 1st day 5th instar H. virescens larvae.Teratocyte injections altered the hemolymph protein titer to a level similar to that occurring in parasitized larvae. At the same time the ecdysteroid titer was characterized by a late significant increase, which reached values almost 3 times greater than found in normally parasitized larvae, and also surpassed the highest values registered for nonparasitized larvae. Ligation of parasitized larvae between the meso‐ and metathorax demonstrated that when the prothoracic glands were excluded, there was almost no ecdysteroid production posterior to the ligation. Ligations performed on parasitized larvae to isolate parasitoid eggs before hatching in the last abdominal segments, demonstrated that only virus and venom determined a reduction of the ecdysteroid titer. On the basis of these results the possible role of teratocytes in affecting the biological activity of ecdysteroids is postulated and discussed in a wider context of host‐parasitoid physiological interactions.
Regulation of fat body glycogen phosphorylase activity during refeeding in Manduca sexta larvae
Authors: Siegert Karl J. , Mordue William 
Published: February 2005

AbstractIn 12‐h‐starved larvae of the tobacco hornworm, Manduca sexta, fat body glycogen phosphorylase was quickly inactivated when insects were refed with normal diet and agar which contained 3% sucrose. Only the first 2 min of refeeding were necessary to induce enzyme inactivation. During this short period, larvae did not ingest enough sucrose to increase the hemolymph glucose concentration. This may indicate that the gut released a hormone(s) which directly or indirectly led to the inactivation of fat body glycogen phosphorylase.Inactivation of the enzyme could also be induced by injection of glucose (30 mg) into the hemolymph of starving M. sexta larvae suggesting that there may be separate control from a neuroendocrine site such as the brain or the corpora cardiaca. Trehalose was less effective.Bovine insulin (2 and 4 μg/starved larva) did not induce phosphorylase inactivation over 20 min or decrease hemolymph carbohydrate or lipid concentrations within 60 min. It is, therefore, necessary to screen insect tissues for substances which could bring about inactivation of fat body glycogen phosphorylase. © 1992 Wiley‐Liss, Inc.
Effects of prococene II on the nutritional physiology of last instar Heliothis zea larvae
Authors: Binder Bradley F. , Bowers William S. 
Published: February 2005

AbstractWhen precocene II was fed to last instar larvae of Heliothis zea, it caused significant reductions in the calculated rate of growth, rate of nutrient assimilation, and conversion of ingested and digested food to body mass. No change in the rate of food consumption occurred but respiration was significantly higher. Transport of the nutrient [1‐14C] linoleic acid across midgut tissue was hindered when larvae were fed precocence II. There was also a precocene‐induced change in the apical (luminal) morphology of midgut cells, including absence of the glycocalyx and loss of the microvillar absorptive surface. The influence of precocene II on the midgut physiology and metabolic processes in last instar larvae of H. zea may account for the observed reduced growth and delayed development. © 1992 wiley‐Liss, Inc.
Immunochemical and biological analysis of pheromone biosynthesis activating neuropeptide in Heliothis peltigera
Authors: Gazit Yoav , Dunkelblum Ezra , Ben‐Aziz Orna , Altstein Miriam 
Published: February 2005

AbstractThis study describes the preparation and characterization of a highly specific antiserum to Helicoverpa zea pheromone biosynthesis activating neuropeptide (Hez‐PBAN), and the use of thsi antiserum, in an enzyme linked immunosorbent assay (ELISA), to determine: (a) the content of endogenous PBAN in head extracts of male and female Heliothis peltigera; (b) the level of PBAN at different developmental stages; and (c) the content of PBAN in four different moth species. Cross‐reactivity studies revealed that the antiserum is directed mainly toward the N‐terminal region of the neuropeptide, and that it exhibits similar binding affinities toward the oxidized and reduced forms of PBAN. Analysis of PBAN content in head extracts of male and female H. peltigera, at scotophase, revealed the presence of 4.97 and 4.58 pmol, respectively, in 3‐day‐old moths, and 5.33 and 4.78 pmol, respectively, in 7‐day‐old moths. The similarity in the content of PBAN at both ages and sexes was in accordance with the amount of pheromonotropic activity in these extracts which stimulated pheromone biosynthesis to a similar level. Analysis of PBAN‐like immunoreactivity (IR) in head extracts of H. peltigera larvae and pupae demonstrated the existence of the neuropeptide in the 4th larval instar and continued to increase as a function of development. No IR could be detected in the first three larval instars. The larval and pupal extracts also exerted pheromonotropic activity which followed a similar pattern. The activity in these extracts, however, was considerably lower than that found in adult male and female heads. IR was also detected in head extracts of three other Noctuidae moths: Helicoverpa armigera, Cornutiplusia circumflexa and Spodoptera littoralis, indicating a high degree of chemcial and structural similarity of PBAN in these moths. © 1992 Wiley‐Liss, Inc.
Lipophorin lipase from the yolk of Manduca sexta eggs: Identification and partial characterization
Authors: Van Antwerpen Rik , Law John H. 
Published: February 2005

AbstractIn the hawkmoth Manduca sexta high density lipophorin from adult insects (HDLp‐A) delivers lipids to developing oocytes. During this lipid delivery HDLp‐A is taken up by the oocyte and converted to a very high density lipophorin (VHDLp), which is stored in protein storage granules (yolk bodies). A membrane‐free lysate of isolated M. sexta yolk bodies was demonstrated to contain lipoprotein lipase activity that hydrolyses the diacylglycerol of HDLp‐A. With HDLp‐A as a substrate yolk body lipophorin lipase (YBLpL) activity was shown to be maximal between pH 9 and pH 9.5. NaCl concentration was optimal between 0.7 M and 1 M. YBLpL activity required neither bovine serum albumin nor calcium ions but appeared to be stimulated by 5 mM EDTA. Diisopropyl fluorophosphate effectively inhibited YBLpL activity, indicating the presence of a serine in the active site of the enzyme. The identified lipase activity co‐eluted with lipophorins and vitellins from the yolk in the void volume of a Sephadex G‐75 gel filtration column. This observation suggests that the lipase has a Mr of more than 80,000, or that the enzyme is associated with the lipoproteins. Incubation of HDLp‐A with yolk body lysate converted HDLp‐A to two classes of higher density lipophorins. The highest density lipophorins produced during this incubation approached the density of VHDLp as it is isolated from mature eggs. The possible role of YBLpL activity in the delivery of lipids to developing oocytes is discussed. © 1992 Wiley‐Liss, Inc.
Sterols and symbiosis in the leaf‐cutting ant Acromyrmex octospinosus (Reich) (Hymenoptera, Formicidae: Attini)
Authors: Maurer Patricia , Debieu DanièLe , Leroux Pierre , Malosse Christian , Riba Guy 
Published: February 2005

AbstractThe leaf‐cutting ants Acromyrmex octospinosus live in symbiosis with a fungus they cultivate on leaf fragments. The symbiote forms characteristic hyphal apical swellings called “gongylidia,” which are consumed in preference to the mycelium by the ants. However, the ants also ingest fluids derived from the plant leaves they handle to make the culture substrate. The 4‐desmethylsterols of the ants were essentially (83%–94% of total 4‐desmethylsterols) Δ5,7‐sterols which were identified as ergosta‐5,7,24(28)‐trien‐3β‐ol, ergosta‐5,7‐dien‐3β‐ol, and ergosterol. These Δ5,7‐sterols were all found in the gongylidia, whereas ergosterol mainly was found in the mycelium. Some Δ5‐sterols were detected in the whole body, as well as in the expressed rectal fluid of the ants which partly contains the nonabsorbed material. However, the rectal fluid, as compared to the whole body, contained much higher amounts of Δ5‐sterols originating mainly from the plant leaves. Leaf‐cutting ants preferentially retained Δ5,7‐sterols originating from the specialized gongylidia formed by the fungal symbiote, from a mixed diet of fungal and plant leaf sterols. © 1992 Wiley‐Liss, Inc.
Mode of action studies on a Manduca sexta diuretic hormone
Authors: Troetschler Ruth G. , Kramer Steven J. 
Published: February 2005

AbstractThe mode of action of a diuretic hormone from pharate adult Manduca Sexta heads, which triggers fluid loss in M. sexta larvae and Pieris rapae adults, was studied. In vivo, Mas‐DH (M. sexta diuretic hormone) decreased fluid absorption from larval recta, and increased levels of the second messenger cAMP in recta and Malpighian tubules (Mt) from larvae, and in fat body of larvae and adult M. sexta. In vitro, Mas‐DH triggered minor changes in fluid loss from adult Mt, but did not affect levels of cAMP in Mt from larvae, pharate adults, or adults, though it elevated cAMP levels in fat body of these stages. © 1992 Wiley‐Liss, Inc.
Storage proteins are present in the hemolymph from larvae and adults of the Colorado potato beetle
Authors: Koopmanschap Bertha , Lammers Hans , De Kort Stan 
Published: February 2005

AbstractThe protein composition of larval and adult hemolymph from the Colorado potato beetle, Leptinotarsa decemlineata, was investigated and some abundant, high molecular weight proteins were identified and characterized. Diapause protein 1, which occurs in the hemolymph of last instar larvae and short‐day adults, appeared to be a storage protein. This protein dissociated into two bands due to the high pH used in nondenaturing gels. Its quaternary structure was established by chemical crosslinking. It appeared to be a hexamer. Diapause protein 1 is composed of ≈82,000 subunits. The amino acid composition and N‐terminal sequence of this protein has been determined. Specific antibodies against diapause protein 1 have been developed. Topical application of 1 μg pyriproxyfen, a juvenile hormone analog, to last instar larvae and short‐day adults suppressed the appearance of this protein in the hemolymph. Pyriproxyfen prematurely induced vitellogenin, when applied to last instar larvae.A larval specific protein was also identified in the hemolymph. Its temporary appearance in the hemolymph of last instar larvae, its subunit composition (Mr ≈82,000) and its suppression by pyriproxyfen suggests that this protein is a storage protein as well. © 1992 Wiley‐Liss, Inc.
Allatotropin‐Induced formation of inositol phosphates in the corpora allata of the moth, Manduca sexta
Authors: Reagan Jeff D. , Miller Wilma H. , Kramer Steven J. 
Published: February 2005

AbstractAllatotropin (AT) is a 13 amino acid neuropeptide isolated from the tobacco hornworm, Manduca sexta, which stimulates the biosynthesis of juvenile hormone (JH) in adult females of this insect. In this paper we report that AT stimulates inositol phosphate formation in both female and male corpora allata (CA) of adult Manduca sexta. Furthermore, thapsigargin, a potent Ca2+‐ATPase inhibitor, staurosporine, a potent inhibitor of protein kinases A and C, and 2,5‐di‐(tert‐butyl)‐1,4‐hydroquinone (DBHQ), a potent inhibitor of liver microsomal ATP‐dependent Ca2+ sequestration, all stimulate JH biosynthesis without changing the basal level of inositol phosphates. These data suggest that AT activates an inositol 1,4,5‐trisphosphate (IP3) pathway. Furthermore, increases in the free intracellular Ca2+ concentration in the CA stimulate JH biosynthesis. © 1992 Wiley‐Liss, Inc.
Photoperiod cues and the modulatory action of octopamine and 5‐hydroxytryptamine on locomotor and pheromone response in male gypsy moths, Lymantria dispar
Authors: Linn Charles E. , Campbell Marlene G. , Roelofs Wendell L. 
Published: February 2005

AbstractExperiments were conducted to determine whether the biogenic amines octopamine (OA) and 5‐hydroxytryptamine (5‐HT) exert modulatory effects on pheromone responsiveness and random locomotor activity in male gypsy moths. When injected into males, OA significantly enhanced sensitivity to pheromone, while 5‐HT enhanced general locomotor activity, results that were very similar to those previously shown for the cabbage looper. Maximal effect of the amines, however, was observed when injection occurred just prior to the onset of scotophase, rather than photophase, as we had originally hypothesized for this diurnally active insect. Male gypsy moths also displayed a prominent scotophase response, with sensitivity to pheromone greater in the scotphase compared with photophase, but with the level of random locomotor activity lower in scotophase than in photophase. The upwind flight behavior of males to a pheromone source in a wind tunnel, as well as the time spent at the source, were also significantly different in the two light regimes. Furthermore, when exposed to a 1 h scotophase (instead of the normal 8), or to continuous dark conditions, while males exhibited response to pheromone and locomotor activity during the same scotophase and photophase periods as observed in a 16:8 light : dark cycle, the levels of response, as well as qualitative aspects of the upwind flight behaviors in both periods were a function of the light intensity. Our combined results suggest that male gypsy moths display a bimodal rhythm of locomotor and pheromone response over the diel cycle, with light intensity and scotophase onset providing critical cues for the expression of behaviors, as well as the modulatory action of the amines. © 1992 Wiley‐Liss, Inc.
Role of photoperiod cues in regulating the modulatory action of octopamine on pheromone‐response thresholds in the cabbage looper moth
Authors: Linn Charles E. , Roelofs Wendell L. 
Published: February 2005

AbstractExperiments were conducted to determine the relationship between photoperiod cues and the modulatory action of octopamine (OA) on male sensitivity to sex pheromone in the cabbage looper moth. Results showed that levels of random locomotor activity and response to pheromone, as well as the effectiveness of OA in enhancing male sensitivity, were dependent on the light intensity during the scotophase period. The importance of scotophase onset was further demonstrated by the fact that a 1 h period of dark (instead of the normal 8) was sufficient to elicit male response to pheromone, and the modulatory action of the amine, several hours later in photophase conditions during the “expected” mid‐scotophase period when peak response normally occurs. Furthermore, expression of the response rhythms and the effect of octopamine were maximal when injection of the amine and scotophase onset occurred during a narrow temporal window around the expected time of scotophase onset. Delays or advances in scotophase onset or injection of octopamine resulted in decreased levels of behavior and loss of effectiveness of the amine. Studies involving a reversal in the photoperiod also support the idea that scotophase onset is a critical time in the regulation of the general locomotor and pheromone‐response rhythms exhibited by males. The combined results support a hypothesis that the modulatory action of octopamine is associated with physiological changes occurring at the onset of scotophase, and that the periodicity of this action is influenced by an endogenous oscillator. © 1992 Wiley‐Liss, Inc.
Development of specific RIA and ELISA to study trypsin modulating oostatic factor in mosquitoes
Authors: Borovsky Dov , Powell Charles A. , Carlson David A. 
Published: February 2005

AbstractTrypsin modulating oostatic factor (TMOF), a decapeptide (H‐YDPAPPPPPP‐OH) that signals the termination of trypsinlike enzyme biosynthesis in the mosquito midgut, was covalently bound to Keyhole Limpet Hemocyanin using N‐hydroxysuccinimide and dicyclohexylcarbodiimide. Polyclonal antibodies raised in rabbits against this conjugate were used to develop specific RIA and enzyme linked immunosorbent assay (ELISA) to detect the peptide hormone in female Aedes aegypti. TMOF and its analogs TMOF(B) (H‐DYPAPPPPPP‐OH), P4 (H‐YDPAPPPP‐OH), P1 (H‐YDPAP‐OH), and poly‐L‐proline were tested with the antiserum. The antiserum fully recognized TMOF and partially recognized P4. Using both RIA and ELISA, we report that the amount of TMOF in the mosquito ovary is 100 ± 20 ng (S.E.) and 96 ± 1.4 ng (S.E.), respectively, for each assay. Minute quantities of TMOF a thousandfold lower than in the ovary were found in the mosquito brain, indicating that the hormone is probably not neural but ovarian in origin. © 1992 Wiley‐Liss, Inc.
3‐Oxoecdysteroid reductases in Manduca sexta midgut
Authors: Weirich Gunter F. , Svoboda James A. 
Published: February 2005

AbstractThe 80,000g supernatant o larval midgut homogenates of the tobacco hornworm, Manduca sexta, was fractionated by affinity chromatography on Blue Sepharose CL‐6B and by anion exchange chromatography on Q Sepharose. Both methods resolved one major 3‐oxoecdysteroid 3α‐reductase and three major 3‐oxoecdysteroid 3β‐reductases. The 3β‐reducates reacted only with BADPH as cosubstrate. The 3α‐reductase was active with both NADPH and NADH, and the NADPH/NADH activity ratio increased with the NaCl concentration (0–0.5 M) in the incubation mixtures. The 3‐α‐reductase and one of the 3‐β‐reductases showed very similar chromatographic properties, and their isoelectric points were 5.2 and 5.8, respectively. © 1992 Wiley‐Liss, Inc.
Lipid composition of the pea aphid, Acyrthosiphon pisum (Harris) (homoptera: Aphididae), reared on host plant and on artificial media
Authors: Febvay Gérard , Pageaux Jean‐François , Bonnot Guy 
Published: February 2005

AbstractPolar and neutral lipids and their constitutive fatty acids were quantified in the pea aphid, Acyrthosiphon pisum (Harris), grown on host plant or on a lipid free artificial diet. The results were compared to determine if lipids were involved in the suitability of the diet for continuous rearing of this A. pisum biotype. For apterous adults grown on plants, the lipids were characterized by a low amount of neutral lipids (2.5% weight/fresh weight) almost entirely (96.4%) composed of hexanoyl and sorboyl dimyristin. These storage lipids were higher in the alatae (3.8%), probably correlated with potential flight activity. The phospholipid amounts were identical in these two morphs (1.3–1.4% weight/fresh weight), comprised mainly of phosphatidylethanolamines (52%) and phosphatidylcholines (40.6%). These phospholipids contained a still unidentified fatty acid, with a retention time close to that of linolenic acid and synthesized by the aphid or its bacterial symbionts (not found in plants). The apterous adult aphids reared on an artificial diet showed an accumulation of neutral lipids (8.9% for the first generation); this increase was shown to be slightly greater for the hexanoyl and sorboyl triglycerides. In contrast, the phospholipids decreased in aphids reared on an artificial diet (1.1% and 0.9%, respectively, for first and second generation), correlated with a phospholipid fatty acid profile significantly deficient in C18:3 and in the unidentified peculiar fatty acid. These phospholipids are essential components of biological membranes and a diet‐driven deficient synthesis in some of their components may result in the observed symptoms. © 1992 Wiley‐Liss, Inc.
Biochemical characterization of insect neuronal sodium channels
Authors: Gordon Dalia , Moskowitz Haim , Zlotkin Eliahu 
Published: February 2005

AbstractThe pharmacological uniqueness of the insect sodium channels is indicated by their ability to bind the excitatory and depressant insect selective neurotoxins derived from scorpion venom. The latter were shown to bind and modify sodium conductance exclusively in insect neuronal membranes. The insect sodium channel polypeptides were identified by immunoprecipitation using site‐directed antibody, anti SP19 (corresponding to a highly conserved segment in the sodium channel α subunits), followed by radiophosphorylation and SDS‐PAGE autoradiography. Sodium channel polypeptide in the central nervous system (CNS) of insects belonging to four distinct orders (Orthoptera, Dyctioptera, Diptera, and Lepidoptera) were shown to (1) serve as substrates for phosphorylation by cAMP‐dependent protein kinase; (2) be devoid of disulfide linkage to smaller subunits unlike sodium channels in vertebrate CNS; (3) be glycoproteins as demonstrated by endoglycosidase F treatment and binding to lectins; and (4) reveal a diversity with regard to their apparent molecular mass (Mr 240,000–280,000) and partial peptide maps. The locust sodium channels were functionally solubilized (monitored by [3H]saxitoxin (STX) binding) by 1% cholate, 0.2% Triton X‐100, and 0.22% phosphatidylcholine. About 40% of STX binding activity was recovered in the solubilized fraction without affecting affinity (Kd = 0.5 nM). The time and temperature dependent lability of STX binding activity, in the solubilized fraction, was prevented by 20 nM STX. Partial purification of the insect sodium channel by an anion exchanger yielded 20% recovery and a 3.5 times increase in specific STX binding activity. The presence of a radiophosphorylated 245,000 α‐subunit band coincided with the STX binding activity during purification. In sum, the above information concerning the solubilization and characterization of the insect sodium channel will pave the way to the molecular identification of the receptor sites of the insect selective neurotoxins. © 1993 Wiley‐Liss, Inc.