bluuebunny/crossref_metadata_2025 huggingface dataset:
Polypeptide composition and biosynthesis of the yolk proteins in the firebrat, Thermobia domestica (insecta, thysanura)
Authors: Rousset André , Bitsch Colette , Bitsch Jacques
Published: February 2005

Ion‐exchange chromatography of crude ovarian extracts of the primitive insect Thermobia domestica allowed the separation, in native conditions, of major and minor vitellins of molecular weights of 300,000 and 430,000, respectively. Their polypeptide subunits were determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and immunotransfer using an antiserum prepared against major vitellin. This protein was resolved into large (Mr 166,000–212,000) and small (around Mr 50,000) polypeptides. Minor vitellin, on the other hand, exclusively contained small polypeptides that are immunologically different from those of the major vitellin. Vitellogenin polypeptides from the hemolymph of mature females exhibited electrophoretic mobilities and immunological properties similar to vitellin polypeptides. Pulse‐chase experiments showed that the female fat body synthesizes radioactive and immunoprecipitable proteins, whose polypeptide pattern is close to that of the major vitellogenin. However, part of the primary vitellogenic polypeptides, at Mr 210,000 and 212,000, is rapidly processed to Mr 176,000 and 182,000 subunits. These two polypeptides, as well as the precursors, enter into the composition of the major hemolymph vitellogenin. Finally, processing of the still uncleaved 210,000–212,000 polypeptides takes place in the ovary, which performs the same step of vitellogenin maturation as the fat body.
Endogenous and induced monooxygenase activity in gypsy moth larvae feeding on natural and artificial diets
Authors: Sheppard Carol A. , Friedman Stanley
Published: February 2005

NADPH oxidase activity was measured in third to sixth instar gypsy moth larvae fed oak or pine foliage. Activity levels ranged from 400 to 1,900 pmol NADPH oxidized/min/mg microsomal protein, but enzyme activity was not correlated with host plant ingested. Similarly, activity levels in larvae fed diets containing inducers, such as the terpenoid α‐pinene or pentamethylbenzene, ranged from 700 to 1,500 pmol NADPH oxidized/min/mg protein, levels that were comparable to those measured for larvae fed control diets. O‐demethylase activity in older instar gypsy moth larvae fed pine averaged 109 pmol p‐nitrophenol/min/mg protein, and activity levels in those fed diet containing α‐pinene ranged from 22 to 55 pmol/min/mg protein. Although statistically significant, these induced O‐demethylase levels are well below those observed for Heliothis zea larvae. Our findings indicate that monooxygenases play a minor, if any, role in the ability of later instar gypsy moth larvae to develop successfully on pine foliage.
Metabolism of ecdysteroid by testes of the tobacco budworm, Heliothis virescens
Authors: Loeb Marcia J. , Woods Charles W.
Published: February 2005

Testes from late last stage larvae of the tobacco budworm, Heliothis virescens, were incubated with [3H]ecdysone and [3H]cholesterol. [3H]Ecdysone was converted to six other major ecdysteroids, identified by cochromatography in reverse‐phase high‐pressure liquid chromatography (RPHPLC); four of them were verified by normal‐phase HPLC. A highly polar fraction, moderately polar ecdysteroids (20,26‐dihydroxyecdysone, 3‐epi‐20‐hydroxyecdysone, and 20‐hydroxyecdysone) and low‐polarity ecdysteroids, including 2‐deoxyecdysone, were detected after incubation with [3H]ecdysone. Compounds that reacted positively to antibodies to progesterone and testosterone were detected in the low‐polarity fractions. Testes were incubated in fractions corresponding to each of the major ecdysteroid peaks derived from [3H]ecdysone metabolism. Although most of the radioactive ecdysteroid fractions were further metabolized to high‐ and low‐polarity endpoints, 88% of the [3H]20‐hydroxyecdysone peak apparently remained unmetabolized. 20‐Hydroxyecdysone may be the primary ecdysteroid product of testes of H. virescens. [3H]Cholesterol was not metabolized to any appreciable extent.
Complete amino acid sequence of Bombyx egg‐specific protein deduced from cDNA clone
Authors: Inagaki Shyuichiro , Yamashita Okitsugu
Published: February 2005

Complementary (c)DNA coding for an insect yolk protein, the egg‐specific protein of the silkworm Bombyx mori was cloned and the nucleotide sequence determined. The sequence covers the entire coding region of 1,677 base pairs with 5′ and 3′ noncoding regions (21 and 115 base pairs, respectively). The deduced amino acid sequence of the egg‐specific protein consists of 559 amino acid residues. The NH2‐terminal 18 amino acid sequence is enriched in hydrophobic amino acids and assumed to be a signal peptide. A sequence, Asn‐X‐Thr, a potential N‐linked glycosylation site, is found at positions 191 to 193. A serine‐rich domain is localized in the region from 63 to 90, in which phosphorylation takes place. Cys His motif in 405 to 415 is analogous to a proposed metal binding sequence. Lys132‐Asn133 and Arg228‐Asp229 are probably the sites cleaved by the egg‐specific protein protease that appears during embryogenesis. The derived amino acid sequence has no appreciable homology to other sequenced proteins.
Mediation of ecdysone synthesis in Manduca sexta by a hemolymph enzyme
Authors: Sakurai Sho , Warren James T. , Gilbert Lawrence I.
Published: February 2005

The prothoracic glands of Manduca sexta synthesize dehydroecdysone, which is rapidly converted to ecdysone through the mediation of a hemolymph enzyme, a 3 β‐forming‐3‐ketosteroid reductase. The hemolymph protein fraction (HPF) containing this enzyme was obtained from diapausing and non‐diapausing pupae, isolated abdomens, surgically manipulated pupae, etc., and in all cases had the capacity to affect the conversion of dehydroecdysone to ecdysone. The enzyme is heat labile, is inactivated by trypsin, and has a molecular weight of between 20,000 and 30,000. The data indicate that the conversion of dehydroecdysone to ecdysone exhibits linear kinetics and may be dependent on both the enzyme concentration and the concentration of NADPH at the beginning of the reaction but may be limited by the absolute amount of reducing equivalents after 10 min, under the experimental conditions utilized. The capacity of the enzyme to reduce dehydroecdysone was titered in the hemolymph during the last larval instar and during prepupal and pupal life with maximum capacity exhibited at the beginning of the instar, on day 8 of larval life and at day 1 of pupal life. Even at its lowest point at day 5, 1 ml of hemolymph was able to convert 77 pmol (∼35 ng) dehydroecdysone to ecdysone in 1 min. These results require a new interpretation of the control of molting in the Lepidoptera.
Properties, synthesis, and accumulation of storage proteins in Pieris rapae L.
Authors: Kim Hak Ryul , Seo Sook J. , Mayer Richard T.
Published: February 2005

Two kinds of storage proteins (SP‐1, SP‐2) were confirmed in hemolymph and fat body of Pieris rapae during metamorphosis. Both proteins were present in high concentrations in the hemolymph during the last larval instar. Hemolymph concentrations of SP‐1 and SP‐2 dropped after pupation as the proteins were being deposited in fat bodies. SP‐2 is present in a larger amount than SP‐1. Detailed studies on storage proteins determined their properties, mode of synthesis, and accumulation in the fat body.

SP‐1 has a molecular weight of 500,000 and consists of one type of subunit (Mr 77,000), while SP‐2 has a molecular weight of 460,000 and is composed of two types of subunits (Mr 80,000 and 69,000). The pl values of SP‐1 and SP‐2 were determined to be 6.97 and 7.06, respectively.

Fat body cells from 1‐day‐old fifth instar larvae synthesized storage proteins in large amounts, whereas those from late prepupae exhibited high protein sequestration. Proteins taken up in fat body accumulated in dense granules during the pupal stage but sharply decreased at the adult stage.

Morphological changes in the fat body tissues were observed during the larval‐pupal transformation; the nuclei of fat body cells became irregularly shaped, and the boundaries between cells seemed to be obscure. Synthesis, storage, or degradation of storage proteins in fat body during development is closely associated with morphological changes in the tissues.
Identification of a pheromone blend attractive to Manduca sexta (L.) males in a wind tunnel
Authors: Tumlinson James H. , Brennan Margaret M. , Doolittle Robert E. , Mitchell Everett R. , Brabham Annette , Mazomenos Basilios E. , Baumhover Alfred H. , Jackson D. Michael
Published: February 2005

Analyses of solvent rinses of the external surfaces of pheromone glands excised from calling female tobacco hornworm moths, Manduca sexta (L.), revealed the presence of the following compounds: (Z)‐9‐hexadecenal, (Z)‐11‐hexadecenal, (E)‐11‐hexadecenal, hexadecanal, (E,Z)‐10,12‐hexadecadienal, (E,E)‐10,12‐hexadecadienal, (E,E,Z)‐10,12,14‐hexadecatrienal, (E,E,E,)‐10,12,14‐hexadecatrienal, (Z)‐11‐octadecenal, (Z)‐13‐octadecenal, octadecanal, and (Z,Z)‐11,13‐octadecadienal. The two trienals were identified by mass and PMR spectral analyses and by ozonolyses, and their structures were confirmed by synthesis. In a wind tunnel male tobacco hornworm moths exhibit the same behaviors in response to a synthetic blend of all of the components, the gland rinse, or a calling female. Both (E,Z)‐10,12‐hexadecadienal and (E,E,Z)‐10,12,14‐hexadecatrienal are required to stimulate males to complete the characteristic behavioral sequence: anemotaxis, approaching and touching the pheromone source, and bending their abdomens in apparent copulatory attempts. The other components of the blend may play more subtle roles.
Knockdown resistance to dichlorodiphenyl‐trichloroethane and pyrethroid insecticides in the napts mutant of Drosophila melanogaster is correlated with reduced neuronal sensitivity
Authors: Bloomquist Jeffrey R. , Soderlund David M. , Knipple Douglas C.
Published: February 2005

Resistance to pyrethroid insecticides and dichlorodiphenyltrichloroethane (DDT) was investigated in the napts (no action potential, temperature sensitive) mutant of Drosophila melanogaster. In surface contact bioassays, the napts strain showed threefold resistance to deltamethrin at the LC50 level when compared to susceptible Canton‐S flies. Cross‐resistance was also observed to DDT and the pyrethroids NRDC 157 [3‐phenoxybenzyl [1R,cis]‐3‐(2,2‐dibromovinyl)‐2,2‐dimethylcyclopropanecarboxylate], fenfluthrin, and MTI‐800 [1‐(3‐phenoxy‐4‐fluorophenyl)‐4‐(4‐ethoxyphenyl)‐4‐methylpentane]. The onset of intoxication by pyrethroids in napts flies was markedly delayed, a finding that is consistent with the existence of a resistance mechanism involving reduced neuronal sensitivity. Resistance at the level of the nerve was confirmed by electrophysiological recordings of spontaneous and evoked activity in the dorsolongitudinal flight muscles of poisoned flies. Preparations from napts insects treated with fenfluthrin displayed longer latencies to the appearance of spontaneous activity and also an absence or reduction in burst discharges compared to equivalent preparations from susceptible individuals. These results are discussed in light of competing hypotheses concerning the mechanism underlying knockdown resistance and reduced nerve sensitivity in insects.
Degradation of juvenile hormone and methylation of juvenile hormone acid by corpora cardiaca–corpora allata of the cockroach, Nauphoeta cinerea: II. Physiological aspects
Authors: Meyer Walter R. , Lanzrein Beatrice
Published: February 2005

In vitellogenic females of Nauphoeta cinerea, injected (10R)‐juvenile hormone (JH) III was degraded more rapidly than racemic JH III: we measured a half‐life of 21 min (with or without coinjection of lipophorin) for the former and 24 min (with coinjection of lipophorin) and 43 min (without coinjection of lipophorin) for the latter. One to two hours after injection, JH III acid was the major metabolite observed; in addition, several highly polar products were found. The half‐life of injected racemic JH III acid was 19 min with coinjection of lipophorin and 4 min without. The JH III acid titer in hemolymph was low (around 5–10 pmol/ml) in last instar larvae and previtellogenic and pregnant females and reached higher values (40–100 pmol/ml) in vitellogenic and ovulating females. Racemic JH III acid could be methylated in vitro to JH III by corpora cardiaca–corpora allata (CC‐CA) from penultimate instar larvae and females at stages between adult ecdysis and ovulation and at the very end of pregnancy, but not by CC‐CA from last instar larvae and adult females at earlier stages of pregnancy. This indicates that CC‐CA are capable of methylating JH III acid only at stages when JH III is detectable in the hemolymph. In double‐labelling experiments with CC‐CA from vitellogenic females and L‐[14C]methionine and [3H]JH III acid as precursors, we observed that only a small proportion (1–8%) of total biosynthesized JH III was derived from JH III acid when the latter was present at physiological concentration. This suggests that in vivo recycling of JH III acid by CC‐CA plays only a minor role in the regulation of the titer of JH III and JH III acid.
Control of copulation‐enhanced protein synthesis in the long hyaline gland of the male grasshopper, Melanoplus sanguinipes
Authors: Cheeseman Michael T. , Gillott Cedric
Published: February 2005

Control of copulation‐enhanced protein synthesis in the accessory reproductive gland of the male grasshopper, Melanoplus sanguinipes, has been studied by measurement of in vivo incorporation of [35S]methionine into a juvenile hormone (JH)‐regulated Mr 72,000 glycoprotein, long hyaline protein I (LHPI). In normal males, incorporation into LHPI was enhanced within 4 h of the commencement of mating and had increased even further when measured 24 h later. Short (15 min) copulations, in which small amounts of LHPI were discharged, stimulated incorporation into LHPI but brief genital contact did not. Neither severance of the nervi corporis allati nor allatectomy (CA−) on day 1 prevented copulation‐enhancement of incorporation into LHPI. Decapitation after 15 min of copulation also failed to prevent copulation‐enhanced incorporation into LHPI. This suggests that neither the CA nor the corpus cardiacum/brain complex is essential for the response. There was, however, a strong positive correlation between the amount of LHPI lost at copulation and the subsequent rate of incorporation into LHPI. These results suggest that control of copulation‐enhanced incorporation of amino acids into LHPI is peripheral and linked to the extent of gland emptying.
Effects of potential inhibitors on N‐acetylation of octopamine by tissue extracts from malpighian tubules and cerebral ganglia of Periplaneta americana L
Authors: Martin Richard J. , Downer Roger G. H.
Published: February 2005

N‐acetyltransferase activity in extracts of Malpighian tubules and cerebral ganglia from Periplaneta americana L. was monitored using high performance liquid chromatography with coulometric electrochemical detection. Several potential inhibitors were tested against the tissue preparations, and the results indicate distinct differences in the nature of the enzyme derived from the two sources. The Malpighian tubule and cerebral ganglia extracts were sensitive to sulfhydryl inhibition and divalent cations, and both preparations also showed end‐product inhibition with coenzyme A. Juglone, an inhibitor of choline acetyltransferase, inhibits N‐acetyltransferase activity from both tissues; however, separate studies with choline indicate that the N‐acetylation observed in this study is not due to choline acetyltransferase. A number of phenyl, phenol, catechol and indole derivatives were tested and the results indicate that the presence of a 4‐hydroxyl group on the phenol ring enhances the capacity of phenol and catechol derivatives to inhibit N‐acetyltransferase. Demethylchlordimeform inhibits the production of N‐acetyl‐p‐Octopamine by Malpighian tubule preparations and intact tissues whereas other formamidines, BTS‐27271 and amitraz, inhibit N‐acetyl‐p‐Octopamine production only in intact tissues.
Xenobiotic absorption and binding by proteins in hemolymph of the weevil Diaprepes abbreviatus
Authors: Shapiro Jeffrey P.
Published: February 2005

A synthetic coumarin, 7‐amino‐3‐phenyl coumarin (coumarin‐10), was used to study the uptake of ingested xenobiotics into hemolymph. Larvae were forcefed coumarin‐10 in peanut oil, and hemolymph was extracted and analyzed by fluorescence spectroscopy. Coumarin‐10 entered hemolymph within 5 min, reaching a steady state of concentration within 1 h. Assayed 2 h after feeding, hemolymph titers of 1–5 ng/μl were proportional to log dose between 10 and 100 ng/mg body weight; hemolymph did not reach saturation. Fluorescence spectra of hemolymph in saline revealed that energy was readily transferred from hydrophobic residues of hemolymph proteins to coumarin‐10. Ultracentrifugal density gradients revealed that 94% of absorbed coumarin‐10 was bound to sedimenting proteins while 6% bound to lipophorin. Native polyacrylamide gel electrophoresis (N‐PAGE) on minigels identified two major proteins responsible for binding. Though readily separated by native electrophoresis, these proteins were not fully separable by HPLC using a wide variety of columns. Gel permeation‐HPLC of the sedimenting proteins from hemolymph revealed a single major peak of 480,000 Mr. When upper and lower electrophoretic bands were isolated by preparative N‐PAGE, the upper band (band I) yielded subunits of 75,000 and 71,000 Mr, while the lower band (band II) yielded only one size subunit of 75,000 Mr on denaturing (SDS) PAGE. The fluorescent products bound by sedimenting proteins were identified by thin‐layer chromatography and scanning fluorescence densitometry as coumarin‐10 (80% of total) and a polar metabolite (20%). In addition, lipophorin‐containing fractions contained an apolar metabolite (3% of total fluorescence). In vitro binding studies utilizing fluorescent energy transfer demonstrated saturation binding with a KD of 1.5 μM.
The effect of severing the dorsal vessel on egg production in Rhodnius prolixus
Authors: Davey Kenneth G. , Chiang R.
Published: February 2005

Severing the dorsal vessel (DV) behind the corpus allatum (CA), or in the anterior part of the abdomen of Rhodnius prolixus, greatly reduces egg production, an effect which is abolished by the topical application of juvenile hormone l (JH l). Severing the DV in the posterior abdomen does not result in a marked reduction of egg production, although severing the alary muscles in segments V and VI has a similar effect to severing the DV in the anterior abdomen. Reduced egg production caused by severing the DV on day 8 postemergence does not occur if the nerves connecting the CA to the brain are severed on day 1 post emergence. However, egg production is reduced if the DV is severed on day 1 post emergence and the connections between the brain and the CA severed on day 8, suggesting that inhibition of the CA caused by severance of the DV requires innervation from the brain. An isolated CA implanted into an animal decapitated immediately after feeding escapes from the inhibition imposed by severance of the DV. Conversely, the CA in an insect, the head of which has been decapitated just anterior to the CA, remains inhibited. This result suggests that the head posterior to the brain must be present to maintain inhibition. It is concluded that DV severance acts on the brain via some humoral influence to impose inhibition on the CA, and that an endocrine center in the head is required in order to maintain the inhibition.
Changes in the hemolymph of the stable fly, Stomoxys calcitrans, after a blood meal
Authors: Chen Andrew C.
Published: February 2005

The stable fly hemolymph was analyzed after a blood meal. The hemolymph volume increased to approximately three times the pre‐feeding level 3–6 h after a blood meal and gradually returned to normal 18 h after the blood meal. The osmotic pressure decreased approximately 10% following a blood meal and gradually returned to normal with a pattern that was a mirror‐image of that of the hemolymph volume. Concentrations of cations and anions are not directly affected by the ingested blood, indicating a possible selective excretory mechanism.
Nonvitellogenic female protein in Musca domestica
Authors: Pereira Sirlei D. , Marinotti Osvaldo , de Bianchi Antonio G.
Published: February 2005

During vitellogenesis in Musca domestica, a major hemolymph protein, in addition to vitellogenin, appears preferentially in females. This protein is synthesized by the adult fat bodies, secreted into the hemolymph, and is not taken up by the ovaries during vitellogenesis. We have designated this protein nonvitellogenic female protein (NVFP). It is composed of only one type of polypeptide (Mr=70,000) and occurs in two different forms. Synthesis of NVFP is induced by a protein diet, attaining maximum concentrations in females at the middle of the gonotrophic cycle. In males its maximum concentration never surpasses 10% of the concentration in females. The quantitative variation of the NVFP is cyclic and coincident with the gonotrophic cycles of Musca domestica.
Profiles of free and conjugated ecdysteroids and ecdysteroid acids during pupal‐adult development of Manduca sexta
Authors: Lozano Ruben , Thompson Malcolm J. , Svoboda James A. , Lusby William R.
Published: February 2005

The levels of individual free and conjugated ecdysteroids and ecdysteroid acids, labeled from [14C]cholesterol, in five different age groups of male Manduca sexta during pupal‐adult development were determined by HPLC. Eight free ecdysteroids, eight ecdysteroid phosphates, and two ecdysteroid acids were identified. Newly ecdysed pupae contained predominantly 3‐epiecdysteroids in each of the free, conjugated, and acidic ecdysteroid fractions. The titer of each ecdysteroid fraction rose sharply by day 4, and this was particularly noteworthy with respect to free ecdysone and 3‐epi‐20‐hydroxyecdysonoic acid. This stage demonstrated high degrees of ecdysone biosynthesis, oxidative catabolism, and phosphorylation. As development proceeded to day 16, total ecdysteroid titer remained constant; a decreasing free ecdysteroid titer was accompanieid by increasing titers of both conjugates and acids resulting from the metabolic processes of hydroxylation, oxidation, epimerization, and phosphorylation. The predominant metabolites throughout development were 3‐epi‐20‐hydroxyecdysonoic acid and the phosphate conjugates of 3‐epi‐20‐hydroxyecdysone and 3‐epi‐20,26‐dihydroxyecdysone. The ultimate inactivation of the ecdysteroids of M. sexta during pupal‐adult development is possibly mediated by two pairs of metabolically‐linked processes, one leading to a 3‐epiecdysteroid acid, and the other to 3‐epiecdysteroid phosphates.
Stimulated synthesis of the female‐specific storage protein in male larvae of the silkworm Bombyx mori treated with juvenile hormone analog
Authors: Kajiura Zenta , Yamashita Okitsugu
Published: February 2005

Application of methoprene to fourth (penultimate) instar larvae of the silkworm Bombyx mori induced the appearance of the feeding dauer larvae at the fifth (last) instar and prevented pupal metamorphosis. Methoprene also increased the protein concentrations of hemolymph last instar larvae by preventing sequestration of storage proteins by the fat body. Usually, the female‐specific storage protein 1 (SP1)* disappears from the male hemolymph at the time of the last larval instar. However, exposure of male larvae to methoprene at the penultimate instar enhanced the accumulation of SP1 in the hemolymph. The SP1 accumulated in males did not differ in molecular weight and immunoreactivity from the SP1 produced in female larvae. Both sexes of fourth instar larvae allatectomized on day 1 instantly accumulated SP1 in the hemolymph, and methoprene application after allatectomy suppressed the hemolymph accumulation of the SP1. In contrast, if allatectomy was carried out at a later stage of the fourth larval instar, SP1 concentration in hemolymph of fifth instar larvae did not increase, suggesting the different juvenile hormone action for regulation of SP1 synthesis in the penultimate instar larvae of silkworms.
Ploidy levels and DNA synthesis in fat body cells of the adult mosquito, Aedes aegypti: The role of juvenile hormone
Authors: Dittmann Frank , Kogan Philip H. , Hagedorn Henry H.
Published: February 2005

Adult females of the mosquito Aedes aegypti showed two cycles of DNA replication in the fat body based on microspectrophotometric measurement of changes in nuclear DNA. The first cycle began after emergence and resulted in 80% of diploid fat body cells becoming tetraploid and 20% becoming octoploid by the end of the third day. The second replication cycle occurred 48–72 h after a blood meal and resulted in an increase in octoploid nuclei to 67% Topical application of juvenile hormone or methoprene to abdomens isolated at emergence stimulated an increase in ploidy levels above that normally seen in situ. Synthesis of DNA, estimated by incorporation of injected [3H]‐thymidine, rose after emergence and remained high for 2 days. Synthesis increased again after a blood meal, reached a peak by 6 h, and returned to low levels by 24 h after the meal. The timing of DNA synthesis and a measurable increase in ploidy were temporally separated. The ploidy increase, but not DNA synthesis, was correlated with increases in juvenile hormone levels.
Production of antibodies to Manduca sexta cerebral neurosecretory cells
Authors: Flanagan Thomas R. , O'Brien Martha A. , Agui Noriaki , Bollenbacher Walter E.
Published: February 2005

Understanding the neuroendocrine regulation of insect development depends upon having antibody probes to the neurohormones involved, which are usually present at trace levels, making antibody generation difficult. This report describes a simple method for producing antibodies specific to cerebral neurosecretory cells (NSC) of the tobacco hornworm, Manduca sexta, and to the neurohormone(s) they produce. The method involves the isolation of only a few hundred NSC somata (∼ 0.3 μg of protein) that serve as the immunogen. The cerebral NSC used were the L‐NSC III, the prothoracicotropes, that produce the prothoracicotropic hormone (PTTH), the principal neuroendocrine effector of insect molting and metamorphosis. A PTTH‐containing extract of microsurgically isolated somata of the L‐NSC III was injected intraperitoneally into a Balb/c mouse. The antiserum produced specifically immunostained the L‐NSC III in wholemounts of brains from different developmental stages. This antiserum also contained antibodies directed against PTTH, as shown by its ability to inhibit the neurohormone's biological activity in an in vitro prothoracic gland bioassay. Such antiserum can be used to investigate the ontogeny and phylogeny of NSCs. With the hybridoma technique, monoclonal antibodies to individual NSC proteins (PTTH) could be obtained, circumventing the need to purify them for antibody production. This method should be applicable to comparable neurosecretory cell systems in other insect species.
Neither barium nor calcium prevents the inhibition by Bacillus thuringiensis δ‐endotoxin of sodium‐ or potassium gradient‐dependent amino acid accumulation by tobacco hornworm midgut brush border membrane vesicles
Authors: Wolfersberger Michael G.
Published: February 2005

Rapid filtration assays were used to determine the effects of barium, calcium and an insecticidal δ‐endotoxin from Bacillus thuringiensis on sodium and potassium ion gradient dependent phenylalanine accumulation by brush border membrane vescles from the larval midgut of the tobacco hornworm (Manduca sexta). Neither barium nor calcium had a significant effect on sodium ion gradient dependent phenylalanine accumulation by the membrane vesicles. Both barium and calcium inhibited potassium ion gradient dependent phenylalanine accumulation by the membrane vesicles. B. thuringiensis δ‐endotoxin inhibited both sodium and potassium ion gradient dependent phenylalanine accumulation by the vesicles. Inhibition of both sodium and potassium ion gradient dependent phenylalanine accumulation increased similarly with increasing δ‐endotoxin inhibition of either sodium or potassium dependent phenylalanine accumulation by the vesicles.
How parasitoids deal with the immune system of their host: An overview
Authors: Vinson S. Bradleigh
Published: February 2005

Insects have evolved many mechanisms that reduce their potential for serving as hosts for entomophagous species. Some of these mechanisms involve escape, mimicry, and repellancy, which are effective defense mechanisms against both predators and parasitoids. But, insects have a second line of defense against parasitoids and parasites. These may include repellancy and a cuticular barrier to invasion but they include several internal defenses that are collectively referred to as immune mechanisms.

The current understanding of insect immunity is reviewed as background to examining the ways in which insect parasitoids have evolved to successfully handle the immune system of the host. The various means that parasitoids utilize to handle the insect immune systems have been divided into five approaches. These five approaches are described and current knowledge of the mechanisms used by parasitoids to deal with the immune system of their host is explored.
In vitro rearing of parasitoids: Role of host factors in nutrition
Authors: Nettles Jr. William C.
Published: February 2005

Evidence for the role of host components in the growth and development of parasitoids is briefly reviewed, and implications concerning the development of in vitro culture media are discussed. In vitro development of the entomophagous parasitoids Eucelatoria bryani Sabrosky (Diptera: Tachinidae) and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is dependent on low‐molecular‐weight host chemicals. Asparagine, but not aspartic acid, and several other free amino acids are essential dietary ingredients for E. bryani. From insect hemolymph, small, unidentified polar molecules with characteristics similar to sugars are needed for pupation of T. pretiosum. Both adaptive and nonadaptive changes likely are responsible for the dependence of parasitoids on host factors. The genetic changes have no apparent adverse effect unless the parasitoids are fed artificial media devoid of certain chemicals that are obtained in vivo from host insects. The rearing of at least several species of important entomophages to control pest insects of great economic importance is dependent on the identification of constituents from host insects and inclusion of these chemicals in artifical diets.
Possible role of teratocytes of the gregarious parasitoid, Cotesia ( = Apanteles) glomerata in the suppression of phenoloxidase activity in the larval host, Pieris rapae crucivora
Authors: Kitano Hideo , Wago Haruhisa , Arakawa Tōru
Published: February 2005

A number of theories have been proposed concerning the means of avoiding host's encapsulation by parasitoid larvae. Our available data, however, are still not sufficient to explain the encapsulation–inhibiting effects of the gregarious endoparasitoid Cotesia ( = Apanteles) glomerata on its larval host, Pieris rapae crucivora. This study was prompted initially by the observation that the hemolymph obtained from parasitized fifth instar larvae failed to melanize. Phenoloxidase (PO) activity in the hemolymph of parasitized and nonparasitized Pieris larvae was determined spectrophotometrically by measuring the degree of dopachrome formation in diluted hemolymph with Ca2+‐free saline. PO activity was inhibited in host hemolymph containing young‐phase teratocytes, 1.5‐day‐old cells 40–45 μm in diameter, but not in that containing old‐phase teratocytes, 7‐day‐old cells 90–100 μm in diameter. Similar results with young‐phase teratocytes were obtained in vitro. Our data suggest that young teratocytes may suppress PO activity in the host hemolymph and interfere with encapsulation of C. glomerata larvae by the host. However, the mechanism of PO suppression remains to be determined.
Ultrastructural and functional maturation of teratocytes of Apanteles kariyai
Authors: Tanaka Toshiharu , Wago Haruhisa
Published: February 2005

Eggs and larvae of Apanteles kariyai avoid the host defense reactions of Pseudaletia separata due to the action of calyx and venom fluids injected by females during oviposition and the teratocytes originated from the embryonic serosal cells 3.5 day postoviposition. Phenoloxidase (PO) activity in host larvae was unaffected during early stages of parasitization (4–6 days postoviposition), relative to unparasitized larvae, but was greatly reduced to 25% during the late stage of parasitization (days 7–10). Hemolymph PO activity was not affected, in vitro, by calyx and venom fluids but was reduced in the presence of teratocytes. An apparent PO inhibitor was detected in older teratocyte cells. First instar parasitoid larvae implanted into unparasitized hosts, following transfer of either young teratocytes (4 day postoviposition) or old teratocytes (8 day post‐oviposition) with calyx and venom fluids resulted in avoidance of encapsulation only when calyx and venom fluids with young (4 day) teratocytes were injected. These results indicated that during early parasitization of the host, teratocytes just released from the embryonic serosal cells (4 day) function in conjunction with calyx and venom fluids injected into the host with the parasitoid egg to prevent its encapsulation by host hemocytes. During late parasitization, the older teratocytes (8 day) may also function in preventing host encapsulation by producing an PO inhibitor suppresses host hemolymph PO activity at the time of parasitoid egression.
Physiological relationship between a diapausing endoparasitoid (Ascogaster quadridentata) and its dormant host (Cydia pomonella)
Authors: Brown John J. , Reed‐Larsen Darcy , Ahl Joanna
Published: February 2005

The facultative diapause of Ascogaster quadridentata depends upon the photoperiod experienced by its host. A host exposed to short day lengths (12L:12D) ceases development in its fourth stadium, spins a cocoon, and remains dormant throughout the winter. A first stadium parasitoid larva overwinters in a true diapause, within its dormant host.

Dormancy of both animals is due to a failure of the host's endocrine system. Upon transfer of the host from dormancy‐maintaining (OL:24D, 4°C) to dormancy‐terminating conditions (DTC = 16L:8D, 25°C) a host cephalic factor is released. The cephalic factor blocked by host ligation within 48 h of transfer to DTC was circumvented by an injection of the host with 20‐hydroxyecdysone. Parasitoid larvae that were either isolated within the abdomen of 20‐hydroxyecdysone‐injected hosts or held in vitro with the molting hormone initiated apolysis.

An increased titer of hemolymph juvenile hormone, which was present 48 h after the host was transferred to DTC, may have had a prothoracicotropic effect upon the host/parasitoid unit. A topical application of 1 ng of methoprene, concurrent to host transfer to DTC, accelerated parasitoid development. No parasitoid development was evident if the host was neck‐ligated at the time of its methoprene treatment and transfer to DTC. These data suggest that the prothoracicotropic effect of methoprene was via the host head, rather than directly on the host prothoracic glands, or the parasitoid itself.
Developmental relationships between Drosophila larvae and their endoparasitoid Leptopilina (Hymenoptera: Cynipidae) as affected by crowding
Authors: Wajnberg Eric , Boulétreau Michel , Prévost Geneviève , Fouillet Pierre
Published: February 2005

Crowding of Drosophila larvae modifies their suitability to the cynipid endoparasitoid Leptopilina boulardi. The success of parasitic development rises from 40% in uncrowded host larvae to 90% in crowded ones. Crowding reduces the imaginal size of both wasps and uninfested hosts, but it has opposite effects on their development time: That of flies is increased, whereas that of wasps is reduced.
Progress in the isolation and characterization of a host hemolymph ovipositional kairomone for the endoparasitoid Microplitis croceipes
Authors: Health Robert R. , Ferkovich Stephen M. , Greany Patrick D. , Eller Fred J. , Dueben Barbara D. , Tilden Robert L.
Published: February 2005

The purpose of this study was to (1) define further the bioassay parameters of an ovipositional stimulating kairomone (OSK) for Microplitis croceipes found in the hemolymph of the corn earworm, Heliothis zea; (2) purify and isolate the OSK; and (3) determine the viability of the eggs oviposited into an artificial ovipositional substrate (AOS). Phenylthiourea (PTU), added to hemolymph to prevent melanization, and host feces which contains a host‐seeking stimulant (Jones et al.: Sciences 173:842, 1971) [1], were eliminated as possible factors influencing egg laying in the bioassay. Extraction of hemolymph with ether, hexane, and to a lesser degree with methylene chloride removed lipids without loss of OSK activity. In contrast, extraction with polar solvents such as methanol tetrahydrofuran, and acetonitrile resulted in a loss of OSK activity. After ether extraction, the sample could be concentrated by rotoevaporation (90°C) or lyophilization without loss of OSK activity. Fractionation of the sample by gel permeation chromatography indicated a molecular weight of between 100–300 daltons. The OSK was extracted to a specific activity higher than crude hemolymph on two disposable solid‐phase adsorbants, a normal‐phase diol, and a reverse‐phase phenyl material. Subsequent fractionation of hemolymph on a phenyl adsorbent column by HPLC indicated that the OSK contained at least two components. Ovipositional activity was obtained only when two fractions with different retention volumes were combined. Preparation of the AOS's from agar plus Goodwin's tissue culture medium maintained viability of the oviposited eggs. Thirty‐seven percent of the eggs that were removed from the AOS's and held in culture media eventually hatched.
Mechanism of activation of 1,2‐dehydro‐N‐acetyldopamine for cuticular sclerotization
Authors: Sugumaran Manickam , Schinkmann Karin , Dali Hemalata
Published: February 2005

The mechanism of oxidation of 1,2‐dehydro‐N‐acetyldopamine (dehydro NADA) was examined to resolve the controversy between our group and Andersen's group regarding the reactive species involved in β‐sclerotization. While Andersen has indicated that dehydro NADA quinone is the β‐sclerotizing agent [Andersen, 1989], we have proposed quinone methides as the reactive species for this process [Sugumaran, 1987; Sugumaran, 1988]. Since dehydro NADA quinone has not been isolated or identified till to date, we studied the enzymatic oxidation of dehydro NADA in the presence of quinone traps to characterize this intermediate. Accordingly, both N‐acetylcysteine and o‐phenylenediamine readily trapped the transiently formed dehydro NADA quinone as quinone adducts. Interestingly, when the enzymatic oxidation was performed in the presence of o‐aminophenol or different catechols, adduct formation between the dehydro NADA side chain and the additives had occurred. The structure of the adducts is in conformity with the generation and reactions of dehydro NADA quinone methide (or its radical). This, coupled with the fact that 4‐hydroxyl or amino‐substituted quinones instantly transformed into p‐quinonoid structure, indicates that dehydro NADA quinone is only a transient intermediate and that it is the dehydro NADA quinone methide that is the thermodynamically stable product. However, since this compound is chemically more reactive due to the presence of both quinone methide and acylimine structure on it, the two side chain carbon atoms are “activated.” Based on these considerations, it is suggested that the quinone methide derived from dehydro NADA is the reactive species responsible for cross‐link formation between dehydro NADA and cuticular components during β‐sclerotization.
Developmental expression, synthesis, and secretion of insecticyanin by the epidermis of the tobacco hornworm, Manduca sexta
Authors: Riddiford Lynn M. , Palli Subba Reddy , Hiruma Kiyoshi , Li Wan‐Cheng , Green Janell , Hice Robert H. , Wolfgang William J. , Webb Bruce A.
Published: February 2005

Insecticyanin was found to be synthesized in several isoelectric forms and stored in the pigment granules in the epidermis. Both major epidermal forms (INS‐a, pl 5.5; INS‐b, pl 5.7) were found in the cuticle, but only the most basic form, INS‐b, was present in the hemolymph. In vitro the epidermis synthesized and secreted both forms into both the cuticle and the medium. Isolation of two cDNA clones for insecticyanin followed by hybridization to epidermal mRNA showed the presence of only one 1.1 kb mRNA, but transcription of the longer cDNA yielded a RNA which produced INS‐a but no INS‐b. Insecticyanin mRNA was present during the intermolt feeding stages of the 4th and 5th instars and absent during the larval molt and after the onset of metamorphosis. Exposure of either day 2 4th‐instar or day 1 5th‐instar larval epidermis to 20‐hydroxyecdysone (20HE) in vitro caused a dose‐dependent decline in this mRNA that was not prevented by simultaneous exposure to JH. When synthesis resumes just before ecdysis, INS‐b appears before INS‐a; then on the final day of feeding, synthesis of INS‐a ceases before that of INS‐b.
Endocrine interrelationship between the parasitoid Chelonus sp. and its host Trichoplusia ni
Authors: Grossniklaus‐Bürgin Christa , Lanzrein Beatrice
Published: February 2005

The egg‐larval parasitoid Chelonus sp. induces the precocious onset of metamorphosis in the 4th (penultimate) stadium of its host Trichoplusia ni, emerges from the prepupa, and then feeds on it. Qualitative and quantitative changes in ecdysteroids and juvenile hormone were measured. Hemolymph of 3rd‐to 4th‐instar host larvae and the parasitoids they contained, as well as nonparasitized and parasitized eggs, were analyzed. In the host hemolymph a broad peak of ecdysteroids during molting into the 4th stadium and a continuous increase from day 2 (onset of precocious wandering) until day 4 (emergence of parasitoid) were observed; 20‐hydroxyecdysone and 20,26‐dihydroxyecdysone were predominant. The juvenile hormone titer fluctuated in the 3rd and early 4th stadium and fell to undetectable levels shortly before the precocious onset of wandering. The parasitoid's ecdysteroids started to increase on the molt to the 2nd instar ( = early 4th instar of the host) and thereafter fluctuated on a high level, 20‐hydroxyecdysone, 20,26‐dihydroxy‐ecdysone, and ecdysone being predominant. The juvenile hormone titer was high in late 1st‐instar parasitoids, decreased to low levels at ecdysis into the 2nd instar, and increased again to high levels in the 2nd‐instar larvae at the time when their shape changed from flat to cylindrical. After ecdysis to the 3rd instar the juvenile hormone titer fell. A comparison revealed that both ecdysteroids and juvenile hormone fluctuate independently in parasitoid and host at most stages, suggesting that the parasitoid produces its own hormones.

The first data on ecdysteroids and juvenile hormones in the egg stage of a parasitoid/host system are reported. At the stage of eye pigmentation parasitized eggs contained more immunoreactive midpolar ecdysteroids than nonparasitized ones. 20‐Hydroxyecdysone and 20,26‐dihydroxyecdysone were the predominant ecdysteroids in both nonparasitized and parasitized eggs, but the latter contained several additional ecdysteroids which were not seen in nonparasitized egges. The titer of juvenile hormone was similar in both. Shortly before hatching the ecdysteroids were low in parasitized and nonparasitized egges, but the content of juvenile hormone was much higher in the former. At this stage the majority of parasitoids have already eclosed and teratocytes are released. The results of HPLC analysis indicated the presence of juvenile hormone lll together with juvenile hormones l and ll in parasitized eggs, but only juvenile hormones l and ll in nonparasitized eggs.
Sex‐linked control of sex pheromone behavioral responses in European corn‐borer moths (Ostrinia nubilalis) confirmed with TPI marker gene
Authors: Glover Thomas , Campbell Marlene , Robbins Paul , Roelofs Wendell
Published: February 2005

In two races of European corn‐borer moths (ECB), the E‐race females emit and males respond to 99:1 sex pheromone blend of (E)/(Z)‐11‐tetradecenyl acetates, whereas the Z‐race females and males produce and respond to the opposite 3:97 pheromone blend of (E)/(Z)‐11‐tetradecenyl acetates, respectively. We previously have shown that female production of the final blend ratio is under control of a major autosomal locus but that the sequence of male upwind flight responses to the blend is controlled by a sex‐linked (Z‐linked) locus. This sex‐linked control of behavioral responses in crosses of E and Z ECB now is confirmed by use of sex‐linked TPI (triose phosphate isomerase) allozyme phenotypes to determine the origin of the sex chromosomes in F2 populations.

F1 males from reciprocal E × Z crosses generate similar behavioral‐response profiles in wind‐tunnel studies, with moderate numbers responding to the Z pheromone and intermediate blends (35%–65% Z), but very few responding to the E pheromone. The F2 behavioral‐response profiles indicate that they are composed of 1:1 mixtures of hybrids and paternal profiles. Analysis of TPI allozyme differences allowed us to separate male F2 populations into individuals whose Z chromosomes both originated from their grandfathers, and individuals who had one Z chromosome originating from each grandparent. With these partitioned F2s, the TPI homozygotes exhibited behavioral‐response profiles very much like their grandfathers, whereas the TPI hybrids produced response profiles similar to their heterozygous F1 fathers. These results demonstrate incontrovertibly that the response to sex pheromone in male ECB is controlled by a sex‐linked gene that is tightly linked to the TPI locus and therefore is independent of the locus controlling pheromone blend production in females.
Prevalence of African DNA RELP alleles in neotropical African honeybees
Authors: Muralidharan Kasinathan , Hall H. Glenn
Published: February 2005

A few queens of the honeybee, Apis mellifera scutellata, were imported from Africa and released in Brazil in 1957. Progeny of these bees have now largely colonized the American tropics. Their imminent arrival in the United States poses a serious threat to the beekeeping industry and to agriculture dependent on honeybee pollination. African and European bees are morphologically very similar. DNA restriction fragment length polymorphisms are proving successful in distinguishing between the two. Several DNA markers specific to European honeybees have been described previously. Reported here are three cloned honeybee DNA probes that reveal polymorphisms that appear to be either African or European specific. Of fourteen alleles or haplotypes identified, five were present only in African and neotropical (Venezuelan and Mexican) African bees but absent in European‐derived bees, two were present only in European‐derived bees but absent in samples from South Africa. Another allele showed apparent frequency differences among populations. Such markers are useful in studying the genetics of neotropical African bee populations. Venezuelan and Mexican honeybee colonies show a preponderance of the African alleles with low levels of the European alleles. These observations of nuclear DNA, revealing limited paternal European introgression, together with previous mitochondrial DNA findings showing negligible European maternal gene flow into feral African populations, indicate that neotropical African bees are primarily African.