bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental pathology of Heliothis virescens larvae parasitized by Microplitis croceipes: Parasite‐mediated host developmental arrest
Authors: Webb Bruce A. , Dahlman D. L. 
Published: February 2005

AbstractThe developmental pathology of Heliothis virescens larvae parasitized by the braconid wasp Microplitis croceipes was examined. Parasitized host larvae begin the same precise sequence of developmental events in preparation for pupation as observed in unparasitized larvae. This sequence is initiated even though the host larval weight is below the normal developmental threshold for larval‐pupal transformation. After parasite emergence, the host remains in a suspended advanced developmental state but never pupates. The developmental parameters altered by parasitization are normally under the host's endocrine control.Neck ligation of control larvae was used to identify the critical periods in parasitized and unparasitized fourth‐ and fifth‐instar larvae. Control ligated fourth‐instar larvae apparently released PTTH between 21:00 AZT of the second day of the instar and 1:00 AZT of the third day. Parasitized fourth‐instar larvae were smaller and apparently released PTTH between 18:00 and 23:00 AZT of the third day. Control ligated fifth‐instar larvae apparently released PTTH between day 1 and day 2 of the cell formation phase. Ligated fifth‐instar parasitized larvae never molted to the pupal stage. Parasite larvae were adversely affected by host neck ligation with their pupal plus cocoon weight being proportional to the age of the host at the time of ligation.
Purification, partial characterization, and postembryonic levels of amylases from Sitophilus oryzae and Sitophilus granarius
Authors: Baker J. E. , Woo S. M. 
Published: February 2005

AbstractAmylases from adults of Sitophilus oryzae (L.) and S. granarius (L.) were purified by using a sequential procedure of ammonium sulfate precipitation, glycogen‐complex formation, and ion exchange chromatography. Amylase of S. oryaze was purified 47.4‐fold to a specific activity of 478 units/mg protein. One amylase unit equals 1 mg maltose hydrate produced/min at 30°C. Amylase of S. granarius was purified 85.4‐fold to a specific activity of 453 units/mg protein. Amylase of S. oryzae had a Km of 0.173% for soluble starch and consisted of two anionic isozyrnes with isoelectric points of pH 3.70 and pH 3.76. Amylase of S. granarius had a Km of 0.078% for starch and was a single protein with an isoelectric point of pH 3.76. Purified amylases of both species had molecular weights of 56,000 estimated by sodium dodecyl sulfatepolyacrylamide gel electrophoresis, were activated by chloride, and had double energies of activation calculated from Arrhenius plots. Based on fresh weights of adults feeding on whole wheat through 10 weeks of age, S. oryzae contained three‐fold and eight‐fold more amylase than S. granarius and S. zeamais Motschulsky, respectively. High amylase levels in S. oryzae may provide this species with an adaptive advantage when feeding on cereals containing naturally occurring amylase inhibitors.
Interactions of charatoxins and nereistoxin with the nicotinic acetylcholine receptors of insect cns and Torpedo electric organ
Authors: Sherby Shebl M. , Eldefrawi Amira T. , David Jonathan A. , Sattelle David B. , Eldefrawi Mohyee E. 
Published: February 2005

AbstractInteractions of charatoxin (4‐methylthio‐1,2‐dithiolane; ChTX) and four openchain analogs as well as nereistoxin (NTX) with acetylcholine (ACh) receptors were studied using biochemical assays on the Torpedo electric organ and honey bee brain receptors and using electrophysiological assays on the response of the cell body of the fast coxal depressor motoneuron (Df) of the cockroach Periplaneta americana to ACh. The actions of ChTXs were complex. Except for ChTX Xl, they all potentiated the ACh‐induced current in Periplaneta neurons, but at higher concentrations all ChTXs, except for ChTX XII, caused voltage‐dependent block of this current. All CHTXs inhibited binding of [3H]perhydrohistrionicotoxin in the presence of ACh to the highaffinity noncompetitive blocker site on the Torpedo receptor, but all, except for ChTX XI, potentiated its binding in absence of ACh. The actions of ChTXs on the honey bee brain receptor were quite different from those on the Torpedo receptor. They inhibited, or had no effect on, [125I]α‐bungarotoxin (α‐BGT) binding to the Torpedo receptor, but all ChTXs, except for ChTX I, potentiated its binding to the honey bee receptor. It is suggested that the action of ChTXs on nicotinic ACh‐receptors resulted from binding to lowaffinity noncompetitive blocker site. On the other hand, NTX was more potent than ChTXs on nicotinic ACh‐receptors, and some similarities were noted between the actions of NTX on Torpedo and honey bee receptors NTX had a weak agonistlike effect in both cases and possibly bound to the ACh binding sites as well as the high‐affinity noncompetitive blocker site. Thus the mechanisms of action of ChTXs and NTX on nicotinic ACh‐receptors are different, and there are also differences in the responses to these toxins between receptors of insect central nervous system and Torpedo electric organ.
Major hemolymph proteins from larvae of the black swallowtail butterfly, Papilio polyxenes
Authors: Ryan Robert O. , Wang Xiao‐Yu , Willott Elizabeth , Law John H. 
Published: February 2005

AbstractThree major hemolymph proteins of Papilio polyxenes larvae were isolated and characterized. Density gradient ultracentrifugation of hemolymph resulted in flotation of the major lipoprotein, lipophorin. P. polyxenes larval lipophorin is composed of two apoproteins, apolipophorin‐I and apolipophorin‐II, plus a mixture of lipids, to give a density of 1.13 g/ml. Immunoblotting experiments using antisera directed against Manduca sexta apolipophorin‐I and apolipophorin‐II, respectively, revealed cross‐reactivity of apoLp‐I with Manduca sexta apoLp‐I, and apoLp‐II with M. sexta apoLp‐II.Gel permeation chromatography of the subnatant obtained following density gradient ultracentrifugation revealed the presence of a major protein peak which was shown to contain three major serum proteins, two of which were isolated and characterized. One of these proteins was purified by lectin affinity chromatography. Both proteins have native molecular weights in the range of 450,000 and appear to be hexamers of a single subunit type. Major serum protein‐1 is nonglycosylated and has a subunit molecular weight of 75,000. Major serum protein‐2 is glycosylated and has a subunit molecular weight of 74,000. Amino acid analysis of this protein revealed a tyrosine plus phenylalanine content of 20 mole percent, characteristic of the arylphorin class of insect storage proteins. Using antibodies against M. sexta larval hemolymph proteins, both the P. polyxenes major serum proteins were shown to be immunologically related to serum proteins of other lepidopteran species.
Metabolism of 26‐[14C]hydroxyecdysone 26‐phosphate in the tobacco hornworm, Manduca sexta L., to a new ecdysteroid conjugate: 26‐[14C]hydroxyecdysone 22‐glucoside
Authors: Thompson Malcolm J. , Feldlaufer Mark F. , Lozano Ruben , Rees Huw H. , Lusby William R. , Svoboda James A. , Wilzer Kenneth R. 
Published: February 2005

AbstractFollowing injection into female Manduca sexta pupae, [14C]cholesterol is converted to a radiolabeled C21 nonecdysteroid conjugate as well as ecdysteroid conjugates, which in ovaries and newly‐laid eggs consist mainly of labeled 26‐hydroxyecdysone 26‐phosphate. During embryogenesis, as the level of 26‐hydroxyecdysone 26‐phosphate decreases there is a concurrent increase in the amount of a new, labeled ecdysteroid conjugate. This conjugate, which is the major ecdysteroid conjugate (9.4 μg/g) in 0‐ to 1‐hour‐old larvae was identified as 26‐hydroxyecdysone 22‐glucoside by nuclear magnetic resonance and chemical ionization mass spectrometry. This is the first ecdysteroid glucoside to be identified from an insect. The disappearance of 26‐hydroxyecdysone 26‐phosphate in 0‐ to 1‐hour‐old larvae indicates that the 26‐hydroxyecdysone 22‐glucoside is derived from 26‐hydroxyecdysone 26‐phosphate. 3‐Epi‐26‐hydroxyecdysone was the major free ecdysteroid isolated from these larvae and 3‐epi‐20,26‐dihydroxyecdysone was the next most abundant ecdysteroid isolated. Interestingly, the 0‐ to 1‐hour‐old larvae contained the highest levels of 3α‐ecdysteroids per gram of insect tissue (8.7 μg/g) to be isolated from an insect, yet there was a complete absence of the corresponding free 3β‐epimers. The ecdysteroid conjugate profiles of ovaries and 0‐ to 1‐hour‐old larvae are discussed. Methodology is presented that permits the efficient separation of free and conjugated ecdysteroids and nonecdysteroid conjugates (C21‐steroid conjugates).
Partial purification and characterization of locust allatotropin I
Authors: Gadot Michal , Rafaeli Ada , Applebaum Shalom W. 
Published: February 2005

AbstractMethanol extracts of locust brains, corpora cardiaca (CC), and suboesophageal ganglia (SOG) were separated by gradient and/or isocratic reverse‐phase high‐performance liquid chromatography (HPLC) and allatotropic activity monitored in the eluted fractions. A major peak of activity, separated by isocratic separation with 12% 2‐propanol, designated allatotropin I, exhibited identical retention times in the three tissue extracts. Doseresponse curves of allatotropin I indicate similar content in brain and CC‐equivalents, whereas optic lobes, similarly separated by isocratic HPLC, contain only one‐tenth of this amount of allatotropin. Allatotropin I is resistant to boiling and is susceptible to tryptic and chymotryptic digestion. Methanol extracts of thoracic muscle, Malpighian tubules, fat body or ovaries, similarly prepared and boiled, did not exhibit allatotropic activity at high doses of tissue equivalents.
Diet‐induced nonmelanized cuticle in workers of the imported fire ant Solenopsis invicta buren
Authors: Williams David F. , Vander Meer Robert K. , Lofgren Clifford S. 
Published: February 2005

AbstractNonmelanized cuticle development was induced in workers of Solenopsis invicta by feeding them an insect‐free diet. The nonmelanized workers weighed less and had smaller mean headwidths than workers from normal colonies. Although nonmelanized ant colonies appeared to function normally in the laboratory, their attempts at stinging were felt only as “pin pricks.” Chemical analysis of venom alkaloids and cuticular hydrocarbons indicated no qualitative differences between nonmelanized and normal workers. Tyrosine, an essential amino acid tanning precursor, was found in adequate quantities in the free amino acid pool of nonmelanized ants. The specific cause of the nonmelanized condition is not known.
Permethrin‐ and malathion‐induced macromolecular abnormalities in adult Tribolium castaneum (herbst)
Authors: Saleem Mushtaq A. , Shakoori A. R. 
Published: February 2005

AbstractIn Tribolium castaneum adults, sublethal doses of 1 and 2 ppm permethrin and 300 ppm malathion led to significant changes in amylase, trehalase, acid phosphatase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and isocitrate dehydrogenase activities. Malathion at 150 ppm did not affect phosphatases and lactate dehydrogenase. Both malathion and permethrin significantly increased cholinesterase activity. Mixing of the two insecticides resulted in antagonistic action with reference to various enzymatic activities. Glucose and glycogen contents were at first mobilized for energy supply under insecticidal stress conditions followed by lipid and cholesterol. Soluble protein, total protein, free amino acids, and urea contents remained unaltered under all experimental conditions.
Evidence for hormonal control of diuresis after a blood meal in the mosquito Aedes aegypti
Authors: Wheelock G. D. , Petzel D. H. , Gillett J. D. , Beyenbach K. W. , Hagedorn H. H. 
Published: February 2005

AbstractIn previous studies we have presented evidence for the role of peptides, isolated from heads of the mosquito Aedes aegypti, in stimulating fluid secretion by isolated Malpighian tubules. In the present study we conducted experiments to investigate whether these peptides are involved in hormone‐mediated diuresis after a blood meal. In vivo experiments showed that the head was required to maintain diuresis after the blood meal. Whereas feeding on blood triggered a prompt diuresis in the intact mosquito, subsequent decapitation caused a gradual, not an abrupt, decline in urine excretion rate. Hemolymph collected from mosquitoes fed blood significantly stimulated fluid secretion in vitro by isolated Malpighian tubules, whereas hemolymph from unfed or blood‐fed decapitated mosquitoes did not. These results indicate that a diuretic factor was released into the hemolymph after a blood meal. This factor was not present in the hemolymph of decapitated females. We identified the head as a source of diuretic factors. Peptides isolated from a head extract by high‐performance liquid chromatography, when injected into the hemocoel of blood‐fed decapitated mosquitoes, triggered diuresis in vivo and also stimulated fluid secretion in isolated Malpighian tubules. These studies support the hypothesis that the head is a storage site for diuretic peptides that may be released after a blood meal to control diuresis.
Isolation and characterization of lipophorin from Drosophila melanogaster larvae
Authors: Fernando‐Warnakulasuriya Germain J. P. , Wells Michael A. 
Published: February 2005

AbstractThe hemolymph lipoprotein lipophorin has been isolated from third‐instar Drosophila melanogaster larvae by a technique that involves homogenization of whole larvae in a medium containing protease inhibitors and purification of the lipoprotein by density gradient centrifugation. Drosophila lipophorin has a density of 1.16 g/ml and is composed of 62.5% protein, 23.1% phospholipid, 7.4% diacylglycerol, 5.4% triacylglycerol, 0.9% hydrocarbon, and 0.7% sterol. As is the case with other insect lipophorins, Drosophila lipophorin contains two apolipoproteins, apolipophorin‐I (Mr ≈ 275,000) and apolipophorin‐II (Mr ≈ 76,000). Drosophila apolipophorin‐I does not crossreact with antibodies prepared against apolipophorin‐I from Manduca sexta.
Apolar conjugates of ecdysteroids are not used as a storage form of molting hormone in the argasid tick Ornithodoros moubata
Authors: Connat Jean‐Louis , Dotson Ellen Marie , Diehl Peter Allan 
Published: February 2005

AbstractFifth (last) instar nymphs of the tick Ornithodoros moubata convert ingested 20‐hydroxyecdysone (20E) to apolar conjugates AP2, which are then converted to the more polar conjugates AP1. Only small quantities of free hormone were transferred to the hemolymph and the carcass within the first 2 days after the blood meal. The proportion of radiolabel in these two compartments was highest at the time of the endogenous ecdysteroid peak; however, no traces of free [3H]20E were detected. The conversion probably occurs principally in the intestinal cells. Eleven days after ingestion, 84% of the radiolabel is located in the digestive tract, mainly in the form of AP1 conjugates.AP1 obtained in second instar nymphs fed with [3H]ecdysone ([3H]E) remain stable throughout the following nymphal instars. The ecdysteroid moiety of AP1 remained unchanged. The hydrolysis, although not complete, always yielded a peak comigrating with the reference E but never 20E or any other clearly distinct peaks that may have corresponded to metabolites of 20E. Less label per individual was present in adults, but its nature remained the same, viz., AP1 mainly located in the digestive tract. In females, 2.5% of the label was transferred to the progeny during the first ovipositional cycle.Apolar products (mainly AP2) that accumulated in eggs of females injected with [3H]E or [3H]20E during vitellogenesis remained unchanged during the whole embryonic development. During the molting cycle of larvae, there was only a slight conversion of AP2 to AP1, but esterase hydrolysis of these products released the same percentages of E and 20E as in the freshly laid eggs.We conclude that in this tick species apolar conjugates of ecdysteroids are inactivation metabolites that are not reutilized during the development of the animal. These metabolites are mainly retained in the tick, probably because of its peculiar blocked midgut. Several studies have shown that in other arthropod species (ticks, spiders, and insects), these apolar metabolites are excreted in the feces.
Vitellogenesis and oocyte development in azadirachtin‐induced fifth‐instar overage nymphs of Locusta migratoria (L.)
Authors: Shalom Uri , Applebaum Shalom W. , Pener M. Paul 
Published: February 2005

AbstractInjection of azadirachtin into females of Locusta migratoria at the beginning of the last nymphal instar prevented molting to the adult stage, and many of these locusts survived for long periods as overage fifth‐instar nymphs. Overage female nymphs synthesized vitellogenin; maximum vitellogenin content in their hemolymph was 6–7 times higher than that found in normal adult females. The overage female nymphs developed vitellogenic oocytes, but development was retarded to some extent: although vitellogenin did accumulate in the proximal oocytes, their maximum average length was only about 2.8 mm (compared to 6.2 mm in normal adult females) and extensive oocyte resorption was observed. Thus, attainment of adult competence of the organs and processes involved in female reproduction is independent to a considerable extent from the process of overt adult morphogenesis.
Chelonus sp. near curvimaculatus venom proteins: Analysis of their potential role and processing during development of host Trichoplusia ni
Authors: Leluk Jacek , Jones Davy 
Published: February 2005

AbstractThe venom that Chelonus sp. near curvimaculatus injects into each parasitized Trichoplusia ni egg is entirely injected within the first 8 s of the 19‐s oviposition period, before deposition of the parasitoid egg that is injected during the final 1‐2 s of the oviposition. The parasitization factor, causing precocious metamorphosis of the host, is injected after the venom, but before the parasite egg. The venom by itself does not cause developmental redirection of the host. Chelonus venom proteins are very stable in the host egg during the first 2 days of egg development. Then, on the last day before hatching, they are rapidly degraded by the proteolytic enzymes appearing in 3‐day‐old T. ni eggs. Among those that degrade the venom proteins are serine‐type proteinases, and at least one seems to be a trypsin‐like enzyme.
On the oxidation of 3,4‐dihydroxyphenethyl alcohol and 3,4‐dihydroxyphenyl glycol by cuticular enzyme(s) from Sarcophaga bullata
Authors: Sugumaran Manickam , Semensi Victor , Saul Steven J. 
Published: February 2005

AbstractThe catabolic fate of 3,4‐dihydroxyphenethyl alcohol (DHPA) and 3,4‐dihydroxyphenylethyl glycol (DHPG) in insect cuticle was determined for the first time using cuticular enzyme(s) from Sarcophaga bullata and compared with mushroom tyrosinase‐medicated oxidation. Mushroom tyrosinase converted both DHPA and DHPG to their corresponding quinone derivatives, while cuticular enzyme(s) partly converted DHPA to DHPG. Cuticular enzyme(s)‐mediated oxidation of DHPA also accompanied the covalent binding of DHPA to the cuticle. Cuticle‐DHPA adducts, upon pronase digestion, released peptides that had bound catechols. 3,4‐Dihydroxyphenyl‐acetaldehyde, the expected product of side chain desaturation of DHPA, was not formed at all. The presence of N‐acetylcysteine, a quinone trap, in the reaction mixture containing DHPA and cuticle resulted in the generation of DHPA‐quinone‐N‐acetylcysteine adduct and total inhibition of DHPG formation. The insect enzyme(s) converted DHPG to its quinone at high substrate concentration and to 2‐hydroxy‐3′,4′‐dihydroxyacetophenone at low concentration. They converted exogenously added DHPA‐quinone to DHPG, but acted sluggishly on DHPG‐quinone. These results are consistent with the enzymatic transformations of phenoloxidase‐generated quinones to quinone methides and subsequent nonenzymatic transformation of the latter to the observed products. Thus, quinone methide formation in insect cuticle seems to be caused by the combined action of two enzymes, phenoloxidase and quinone tautomerase, rather than the action of quinone methide‐generating phenoloxidase (Sugumaran: Arch Insect Biochem Physiol 8, 73–88, 1988). It is proposed that DHPA and DHPG in combination can be used effectively to examine the participation of (1) quinone, (2) quinone methide, and (3) dehydro derivative intermediates in the metabolism of 4‐alkylcatechols for cuticular sclerotization.
Storage proteins of the fall webworm, Hyphantria cunea drury
Authors: Kim Hak Ryul , Kang C. S , Mayer Richard T. 
Published: February 2005

AbstractTwo storage proteins, storage protein‐1 (SP1) and storage protein‐2 (SP2), were found in hemolymph and fat body during the development of Hyphantria cunea, the fall webworm. Both storage proteins show similiar quantitative changes during development in males and females; however, SP1 is more abundant. The hemolymph of last instar larvae contains high concentrations of the storage proteins. However, following pupation, the storage proteins accumulate in fat bodies. SP1 peaks in the hemolymph of males and females late in last instar larvae (8‐day‐old 7th instar larvae).SP1 has a native molecular weight of 460,000 and consists of six identical subunits (Mr = 76,700), while SP2 has a molecular weight of 450,000 and is composed of two different subunits (Mr = 74,100 and 72,400). Both SP1 and SP2 are hexamers and are phosphorylated glycolipoproteins. The pl values of SP1 and SP2 were determined to be 5.70 and 5.50, respectively.Antibodies raised against SP1 react positively with vitellogenin and ovary extract, as well as with proteins in the hemolymph from last instar larvae and proteins in pupal fat bodies. Storage protein synthesis starts in fat bodies of a 4‐day‐old 7th instar larvae and in female peaks at 6–8 days of the 7th instar.
Juvenile hormone biosynthesis and oocyte development in adult female Blattella germanica: Effects of grouping and mating
Authors: Gadot Michal , Burns Edina , Schal Coby 
Published: February 2005

AbstractThe roles of grouping and mating in modulating the activity of the corpora allata (CA) in adult female cockroaches were investigated using the in vitro radiochemical assay of juvenile hormone (JH) biosynthesis. Isolated virgin females have longer, asynchronous cycles of CA activity and oocyte maturation than do isolated females mated on day 8. Three factors were identified as the major contributors to this difference: (1) an experimental artifact of selection for sexually receptive females, (2) a positive effect of grouping on JH synthesis and oocyte maturation, and (3) a positive effect of copulation on oviposition and retention of the ootheca. Mated females constitute a subpopulation of receptive females that differ significantly from other females by having higher rates of JH synthesis prior to mating. The relative importance of such selection is substantial when the rate of mating is low, as in experiments with isolated females that are exposed to males for a short period of time. Long‐term exposure of females to males introduces a grouping effect, which obscures any additional effect of mating on CA activity and oocyte development. However, mating influences ootheca formation and its retention. The effect of grouping can be mimicked in isolated females by transection of the nerves connecting the CA–corpora cardiaca complex to the brain, suggesting that in this insect isolation causes brain inhibition of the CA, and grouping provides disinhibitory stimuli that release the CA from brain inhibition.