bluuebunny/crossref_metadata_2025 huggingface dataset:
Insecticidal bacterial proteins identify the midgut epithelium as a source of novel target sites for insect control
Authors: Federici Brian A.
Published: February 2005

The spore‐forming bacterium, Bacillus thuringiensis (Bt), produces a crystalline parasporal body during sporulation, which in many subspecies contains one or more proteins selectively toxic to insect midgut epithelia. Most of these proteins are protoxins with a molecular mass of about 133,000. When ingested by a susceptible insect, the inclusions dissolve in the midgut juices and are activated by proteolytic cleavage, which releases a toxic peptide of about 65,000. In susceptible insects, this peptide binds to sites on the microvillar membrane, causing cytolysis, apparently by forming transmembrane pores. The cytolysis of midgut cells results in paralysis and subsequent death of the insect. Though less common, naturally truncated protein toxins with masses of about 70,000 also occur. Three major pathotypes of Bt proteins are known: Cryl and Cryll proteins toxic primarily to lepidopterous insects, Crylll proteins toxic to coleopterous insects, and CrylV proteins toxic to dipterous insects. The genes encoding more than 50 Bt crystal proteins have been cloned and sequenced and several of these have already been used to construct recombinant microbial insecticides and transgenic organisms including viruses, algae, and insect‐resistant plants. Analysis of Bt genes indicate that the protein toxins they encode consist of at least two functional domains: a series of five blocks of conserved amino acids that comprise the structural core of the molecule including the putative toxic moiety, and a hypervariable region thought to define the spectrum of activity. Determination of the mode of action at the molecular level and the genetic basis for insect specificity should enable recombinant DNA technology to be used to expand the insect host range of Bt as well as increase its toxicity against insects. Moreover, the high toxicity and specificity of the insecticidal proteins produced by Bt and their action on midgut microvilli suggest that other types of peptides or simple organic molecules could be designed as selective insecticides to attack other midgut functions such as ion channels, peptide and amino acid transport systems, and midgut proteases. © 1993 Wiley‐Liss, Inc.
A functional analysis of the P‐element gene‐transfer vector in insects
Authors: Handler Alfred M. , Gomez Sheilachu P. , O'Brochta David A.
Published: February 2005

A P‐element mobility excision assay was used to determine if non‐drosophilid insects could support P gene vector function. Present studies included the testing of Muscids, Sphaerocerids, and Phorids, none of which were able to support P mobility. A new excision indicator plasmid was developed allowing the detection and recovery of virtually all P‐element excision products. The frequency and sequence analysis of excision products from Drosophila melanogaster and another drosophilid, Chymomyza procnemis, indicated both quantitative and qualitative differences in the activity of transposase. The quantitative relationships observed in the original assay were maintained, and qualitative differences in transposase activity were reflected in the sequence of the empty donor sites. The results suggest that host factors are involved in cutting and ligating P‐element DNA during excision, with transposase facilitating these processes. Possible limitations on P mobility by abnormal transpoase transcript processing were tested in Anastrepha suspensa using transposase‐encoding plasmids having deleted intron sequences. A transposase cDNA supported normal P excision in D. Melanogaster, and a low level of mobility in A. suspensa. Possible applications of gene transfer in insects are presented, in particular methods to genetically sterilize and sex insects for the sterile‐insect technique. © 1993 Wiley‐Liss, Inc.
Natural product analogs: Stable mimics of aldehyde pheromones
Authors: Ujváry István , Dickens Joseph C. , Kamm James A. , McDonough Leslie M.
Published: February 2005

Under field conditions, the aldehyde components of the pheromones of important lepidopteran and coleopteran pests undergo chemical transformations (oxidation, polymerization, etc.) resulting in behaviorally inactive compounds. In our search for pheromone analogs with favorable chemical and biological properties, a series of nitriles, oximes and isothiocyanates, as novel functional group mimics of some cyclic and long chain pheromones, were prepared and tested. The biological activities of these nitrogen‐containing analogs were studied by electrophysiological and field experiments with three different insect species showing the nitrile analogs to be the most potent mimics, but their activities were lower than those of the natural pheromones. Thus, a 1:1 mixture of pheromone analogs in place of the corresponding natural aldehyde components III and IV elicited dose‐dependent electroantennogram (EAG) responses of antennal preparations of the female boll weevil, Anthonomus grandis. In field trials, the nitrile analogs were poor substituents for the corresponding aldehydes. In EAG experiments with antennal preparations of males of the southwestern corn borer, Diatraea grandiosella, Z11‐16:Nitrile ((Z)‐11‐hexadecenonirile) elicited dose‐dependent responses while single neuron recording from antennal preparations of this species revealed that a neuron responsive to the pheromone component was also stimulated by the mimic Z11‐16:Nitrile. In field experiments, a 97:3 mixture of nitriles Z11‐16:Nitrile and Z9‐16:Nitrile ((Z)‐9‐hexadecenonitrile) effectively attracted males of the cranberry girdler moth, Chrysoteuchia topiaria. © 1993 Wiley‐Liss, Inc.
Neutral sterols and ecdysteroids of the solitary cactus bee Diadasia rinconis cockerell (hymenoptera: Anthophoridae)
Authors: Feldlaufer Mark F. , Lusby William R. , Weirich Gunter F. , Svoboda James A. , Buchmann Stephen L.
Published: February 2005

Using high performance liquid chromatography in conjunction with radioimmunoassay and mass spectrometry, the major ecdysteroid of the solitary cactus bee, Diadasia rinconis, was determined to be 20‐hydroxyecdysone, with lesser amounts of makisterone A. Another 28‐carbon ecdysteroid thought to be the 24‐epimer of makisterone A was also detected. The neutral sterols of Diadasia consisted primarily of 24‐methylenecholesterol (92.2%) with lesser amounts of other C28 and C29 sterols. Cholesterol accounted for less than 0.1% of the total tissue sterols. The occurrence of 20‐hydroxyecdysone in a phytophagous hymenopteran is discussed in relation to the low level of cholesterol encountered. © 1993 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Sensitive enzyme immunoassay for Manduca allatotropin and the existence of an allatotropin‐immunoreactive peptide in Periplaneta americana
Authors: Veenstra Jan A. , Hagedorn Henry H.
Published: February 2005

Antisera to Manduca sexta allatoropin were raised in rabbits and were used to develop a competitive enzyme immunoassay for this neuropeptide. The detection limit of the assay is less than 2 fmol/well. A useful quantification can be obtained from 2 to 30 fmol/well. No cross‐reactivity was observed with several insect peptides, but the enzyme‐linked immunosorbent assay does recognize [Ala6, Leu7, Ser8]‐allatotropin, a myotropin recently isolated from Locusta migratoria. The assay was used to study the distribution of allatotropin within the nervous system of Manduca sexta. The peptide is present in the retrocerebral complex, the brain, and the ventral nerve cord of this species, in quantities of respectively 0.01, 1.2, and 1.7 pmol per insect. An allatotropin‐immunoreactive peptide was found in the nervous system of Periplaneta americana. It is present in the ventral nerve cord (3.3 pmol/insect), brain (1.9 pmol/insect), and retrocerebral complex (0.09 pmol/insect). These data suggest that peptides of this family are generally present in insects. © 1993 Wiley‐Liss, Inc.
Characterization of phenylalkylamine binding sites in insect (Periplaneta americana) nervous system and skeletal muscle membranes
Authors: Skeer Jacqueline M. , Sattelle David B.
Published: February 2005

This study has identified specific, stereoselective phenylalkylamine (PAA, (±)‐ [3H]verapamil) binding sites of low‐affinity and high‐density in cockroach (Periplaneta americana) nervous system and skeletal muscle membranes. Scatchard transformation of equilibrium binding data revealed a single population of binding sites in both tissues with dissociation constants (Kd) of 273 nM and 377 nM and binding capacities (Bmax) of 23 pmol·mg protein−1 and 37pmol·mg protein−1 for cockroach nervous tissue and skeletal muscle membranes, respectively. The PAA binding site in cockroach nervous tissue membranes was found to be dihydropyridine (DHP)‐insensitive, whereas the corresponding site in cockroach skeletal muscle membranes was DHP‐sensitive. This property of a DHP‐sensitive PAA receptor distinguishes the binding sites identified in cockroach skeletal muscle from those in cockroach nervous tissue and indicates that pharmacologically distinct putative Ca2+ channel subtypes are present in insect nerve and muscle. © 1993 Wiley‐Liss, Inc.
Comparison of two juvenile hormone radioimmunoassays
Authors: Goodman Walter G. , Huang Z.‐H. , Robinson Gene E. , Strambi Colette , Strambi Alain
Published: February 2005

Juvenile hormone from the hemolymph of adult worker honey bees of known age and behavioral status was extracted and analyzed by two different radioimmunoassays in two independent laboratoies. The assays are different in hapten attachment, radiolabeled tracer, and the method by which bound and unbound hormone are separated. Despite these differences in the methods, hormone determinations were in excellent agreement at lower levels (0–50 ng/ml) but diverged as the hormone concentrations increased (> 50 ng/ml). The relative changes are in good agreement, with a correlation coefficient of 0.97. © 1993 Wiley‐Liss, Inc.
Actions of a coral toxin analogue (bipinnatin‐B) on an insect nicotinic acetylcholine receptor
Authors: Bai Donglin , Sattelle David B. , Abramson Stewart N.
Published: February 2005

The lophotoxin analogue, bipinnatin‐B, is a potent neurotoxin isolated from the gorgonian coral Pseudopterogorgia bipinnata. When tested on the cell body of an identified motor neurone, the fast coxal depressor motor neurone (Df) in the cockroach metathoracic ganglion, bipinnatin‐B, at concentrations of 10 μM, partially blocked nicotine‐induced depolarization. Blockade of the response to nicotine was almost complete at 30 μM bipinnatin‐B, and was partially reversible on rebathing the preparation in normal saline. Responses of the same neurone to GABA were unaffected by 30 μM bipinnatin‐B. © 1993 Wiley‐Liss, Inc.
Defense mechanisms in insects: Certain integumental proteins and tyrosinase are responsible for nonself‐recognition and immobilization of Escherichia coli in the cuticle of developing Ceratitis capitata
Authors: Marmaras Vassilis J. , Bournazos Stavros N. , Katsoris Panagiotis G. , Lambropoulou Maria
Published: February 2005

A defense mechanism in the cuticle of developing C. capitata was demonstrated using an in vitro system consisting of isolated cuticular tyrosinase from C. capitata, cuticular tyrosinase‐free proteins, tyrosine, and E. coli. The simultaneous presence of the above components resulted in the formation of large immobilized E. coli aggregates. By contrast, omission of any of the above components failed to produce such aggregates. In other words, E. coli retained their mobility and viability. The results indicate that certain cuticular proteins are responsible for the nonself‐recognition, since they are able to bind to the E. coli surface in vitro, and a reactive tyrosine derivative is generated by the action of cuticular tyrosinase for the immobilization and probably killing of E. coli. Based on these studies the most likely explanation for the nonself‐recognition and immobilization and/or killing of bacteria is the production of E. coli‐protein complexes and their crosslinking through quinone intermediate. © 1993 Wiley‐Liss, Inc.
Purification and characterization of a cytochrome P‐450 from insecticide susceptible and resistant strains of housefly, Musca domestica L., before and after phenobarbital exposure
Authors: Scott Jeffrey G. , Lee Susanna S. T.
Published: February 2005

A cytochrome P‐450 (P‐450) was purified from abdominal microsomes of untreated and phenobarbital treated susceptible (S+) and insecticide‐resistant (LPR) houseflies using HPLC purification procedures. The purified P‐450s exhibited the same apparent molecular masses (54,400 dalton) and could not be distinguished from each other on the basis of HPLC chromatographic properties, reduced CO‐difference absorbance maxima (447 ± 0.5 nm), or partial NH2‐terminal sequences (MLLLLLLIVVTTLYIFAKL). Since these P‐450s were indistinguishable and were immunologically identical to cytochrome P‐450lpr we conclude that these P‐450s are in fact cytochrome P‐450lpr. The level of P‐450lpr was increased twofold after PB exposure in the S+ strain, while the level of P‐450lpr did not change in the LPR strain. Immunoinhibition of ECOD activity with anti‐P‐450lpr antiserum suggests that PB treatment in S+ house flies induced P‐450lpr, and other forms of cytochromes P‐450 with high activity toward this substrate. © 1993 Wiley‐Liss, Inc.
Partial characterization of allatinhibin, a neurohormone of Manduca sexta
Authors: Unni Balagopalan , Barrera Punnee , Muszynska‐Pytel Malgorzata , Bhaskaran Govindan , Dahm Karl H.
Published: February 2005

During the last larval stage, corpora allata (CA) of Manduca sexta are inactivated by a factor from the brain. Apparently the same factor (allatinhibin, Al) is secreted by day 4 Vth instar brains kept overnight in Grace's medium. Al is rapidly inactivated by heat or acid but withstands exposure to alkali and can be recovered after freezing and lyophilization. Exposure to pronase, chymotrypsin, carboxypeptidases‐A and‐Y, as well as leucine aminopeptidase eliminated Al activity completely, whereas after exposure to trypsin and protease XVII‐S, some residual activity remained. Inactivation by pyroglutamate aminopeptidase is interprefed as being due to prolinase activity of this enzyme. Incubation of CA with gentamicin, an aminoglycoside antibiotic, affects neither their ability to produce JH in vitro nor their viability in implantation assays. However, Al did not inactivate CA in the presence of low concentrations of gentamicin. This effect was used to guard against false positive assay results possibly produced by allatotoxic contamination. Al was purified by chromatography on Sephadex G‐25. All activity recovered emerged from the columns in intermediate fractions with an apparent Mr of 1,000–2,000. © 1993 Wiley‐Liss, Inc.
Steady‐state gradient in calcium ion activity across the intercellular bridges connecting oocytes and nurse cells in Hyalophora cecropia
Authors: Woodruff Richard I. , Telfer William H.
Published: February 2005

Intracellular activities of K+, H+, Mg2+, Ca2+, and Cl−, measured with ion selective microelectrodes in the oocyte and the nurse cells in ovarian follicles of Hyalophora cecropia, indicated that a Ca2+ current is a key component of the electrical potential that is maintained across the intercellular bridges connecting these two cells. In vitellogenic follicles, Ca2+ activity averaged 650 nM in the oocyte and 190 nM in the nurse cells, whereas activities of the other ions studied differed between these cells by no more than 6%. Incubation in 200 μM ammonium vanadate caused a reversal of electrical potential from 8.3 mV, nurse cell negative, to 3.0 mV, oocyte negative, and at the same time the Ca2+ gradient was reversed: activities rose to an average 3.0 μM in the nurse cells and 1.6 μM in the oocyte, whereas transbridge ratios of the other cations remained at 0–3%. In immature follicles that had not yet initiated their transbridge potentials, Ca2+ activities averaged ∼︁ 2 μM in both oocyte and nurse cells. The results suggest that vitellogenic follicles possess a vanadatesensitive Ca2+ extrusion mechanism that is more powerful in the nurse cells than in the oocyte. © 1994 Wiley‐Liss, Inc.
Hsp 78: A prominent heat shock protein of the lepidopteran Choristoneura fumiferana that is immunologically unrelated to members of the major Hsp families
Authors: Marin R. , Blaker T. W. , Tanguay R. M.
Published: February 2005

Cultured cells of the spruce budworm (Choristoneura fumiferana) respond to heat shock with the new and/or enhanced synthesis of six proteins with Mrs of 84,000, 78,000, 70,000, 68,000, 21,000, and 14,000, as measured by one‐ and two‐dimensional PAGE. The most prominent hsp of these cells is a 78,000 Da protein which is maximally induced at 39°C and which consists of three isoforms with different pl. Hsp 78 is found in the detergent‐soluble cytosolic fraction of cell lysates. In vitro translation of RNA extracted from cultured cells and from larvae shows that the induction of hsp 78 is regulated mainly at the transcriptional level. Hsp 78 does not cross‐react with a variety of antibodies made to members of the hsp 70 and hsp 83 families. In particular, antibodies to hsp 70 that do cross‐react with a 70 kDa protein of C. fumiferana do not cross‐react with hsp 78. Homologous 75–78 kDa hsps are also present in heat‐shocked cells from other lepidopterans (Spodoptera frugiperda and Bombyx mori). Cf1 cells exposed to elevated levels of arsenite or cadmium respond with the new and/or enhanced synthesis of only two of their hsps (hsp 84 and hsp 70); hsp 78 is not induced by these treatments. The data suggest that hsp 78 of C. fumiferana represents a new family of hsps unique to lepidopterans. © 1994 Wiley‐Liss, Inc.
Developmental changes and acetylcholinesterase activity in the metamorphosing brain of Tenebrio molitor: Correlation to ecdysteroid titers
Authors: Lenoir‐Rousseaux Jean‐Jacques , Delbecque Jean‐Paul , Gautron Jean
Published: February 2005

The brain of Tenebrio molitor exhibited marked fluctuations in acetylcholinesterase (AChE) activity throughout metamorphosis. This was true AChE activity, since it was inhibited by high substrate concentrations and by 10 μM of the specific AChE inhibitor BW284C51 [(1,5‐bis'4‐allyldimethylammoniumphenyl)‐pentan‐3‐one dibromide] but not by iso‐OMPA (tetraisopropylpyrophosphoramide), a cholinesterase (but not AChE) inhibitor. The histochemical AChE activity was localized in the neuropile and the nuclear envelope of neurons and glial cells. The enzyme extracted from brains with 1% Triton X‐100 and 1 M NaCl sedimented as a single peak in a sucrose density gradient, with a sedimentation coefficient of 5.4S. This single AChE sedimentation peak was mainly due to an amphiphilic dimeric form. AChE activity per brain increased in newly ecdysed pupa. AChE activity per milligram of protein exhibited a peak in the mid‐pupa which could be correlated to the increase in ecdysteroid titers. © 1994 Wiley‐Liss, Inc.
Structure and activity of Bombyx PBAN
Authors: Nagasawa Hiromichi , Kuniyoshi Hisato , Arima Rika , Kawano Tsuyoshi , Ando Tetsu , Suzuki Akinori
Published: February 2005

Two structurally related molecular species of pheromone biosynthesis activating neuropeptides (PBANs), PBAN‐I and ‐II, were isolated from adult heads of the silkworm, Bombyx mori, and characterized. PBAN‐I is a carboxyl‐terminally amidated 33‐residue peptide. Structure‐activity relationship studies revealed that 1) its carboxyl‐terminal pentapeptide is the smallest size showing activity, 2) the carboxyl‐terminal amide is indispensable for activity, and 3) oxidation of three Met residues in PBAN‐I to Met(O) (methionine sulfoxide) caused marked enhancement of activity, and the three Met(O) residues contribute equally to the enhancement of activity. Molecular design of PBAN analogs using a carboxyl‐terminal hexapeptide showed that modification of the amino‐terminal amino group brought about a dramatic increase in activity. This increase was presumed to be mainly due to the increased stability in hemolymph. PBANs share the common carboxyl‐terminal sequence, ‐Phe‐Xaa‐Pro‐Arg‐Leu‐NH2, with myotropic peptides isolated from locust and cockroach. Examination of cross‐activity of these two groups of peptides revealed that PBAN and its analogs exhibited myotropic activity comparable to myotropic peptides, while myotropic peptides showed extremely high pheromonotropic activity. In B. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesis of bombykol. © 1994 Wiley‐Liss, Inc.
Regulation of pheromone production in virgin and mated females of two tortricid moths
Authors: Foster Stephen P. , Roelofs Wendell L.
Published: February 2005

Sex pheromone titers in females of two tortricid moths, Epiphyas postvittana and Planotortrix octo, did not significantly vary between the scotophase and photophase. Pheromone production in these two species is controlled by a factor located in the head of the respective females, probably the pheromone biosynthesis‐activating neuropeptide (PBAN). Unlike that reported for the related tortricid, Argyrotaenia velutinana, the bursa copulatrix in female E. postvittana and P. octo does not appear to contain a factor that stimulates pheromone production. After mating, female E. postvittana permanently shut down pheromone production. In contrast, pheromone titer in mated P. octo females is reduced to a level approximately half that of similar‐age virgins. While the abdominal nervous system is involved in the inactivation of pheromone production in mated E. postvittana females and probably acts to stop release of PBAN from the corpora cardiaca, the abdominal nervous system is not involved in effecting the decreased pheromone titers of mated P. octo females. It is possible that in the latter species, a humoral factor(s) is responsible for effecting the decreased pheromone titers, possibly through affecting the release of PBAN from the corpora cardiaca. Bioassaying head extracts allowed changes in PBAN titer in female E. postvittana to be inferred. PBAN titers remain roughly constant in virgins but increase after mating. This suggests that PBAN is biosynthesized throughout the life of an adult virgin female at approximately the same rate as it is released. Furthermore, it appears that the decline in pheromone titer observed in older E. postvittana females is probably due to a decline in competency of the gland to produce pheromone rather than to a decrease in PBAN titer in older females. © 1994 Wiley‐Liss, Inc.
Mating‐induced loss of sex pheromone and sexual receptivity in insects with emphasis on Helicoverpa zea and Lymantria dispar
Authors: Raina Ashok K. , Kingan Timothy G. , Giebultowicz Jadwiga M.
Published: February 2005

Mating in most species of insects leads to a transient or permanent loss in sexual receptivity of the females. Among moths, this loss of receptivity is often accompanied with a loss of the sex pheromone in the absence of calling, which also could be temporary or permanent. Most of the earlier work on changes in reproductive behavior after mating was done with Diptera in which sperm and/or male accessory gland secretions were shown to be responsible for termination of receptivity. In the corn earworm moth, Helicoverpa zea, mated females become depleted of pheromone and become nonreceptive to further mating attempts, but only for the remainder of the night of mating. A pheromonostatic peptide isolated from the accessory glands of males may be responsible for the depletion of pheromone, while the termination of receptivity is independently controlled. In the gypsy moth, Lymantria dispar, the changes in behavior following mating are permanent. In this species, the switch from virgin to mated behavior involves three steps: a physical stimulation associated with mating, transfer of viable sperm to the spermatheca, and commencement of oviposition. Signals generated by these factors operate through neural pathways and, unlike in H. zea, accessory gland factors seem not to be involved. © 1994 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Storage protein uptake in helicoverpa zea: Arylphorin and VHDL share a single receptor
Authors: Wang Zhixiang , Haunerland Norbert H.
Published: February 2005

The major lepidopteran storage protein arylphorin is selectively taken up into perivisceral fat body of prepupae by receptor mediated endocytosis. The arylphorin receptor was identified by ligand blotting and in vitro binding studies. Fat body membranes contain a glycosylated receptor protein with an apparent molecular weight of 80,000 that binds arylphorin with a KD of 9.02 × 10−8 M. Competitive binding experiments revealed that the arylphorin receptor is identical with the previously identified VHDL receptor. Apparently a single receptor mediates the uptake of structurally distinct storage proteins. This storage protein receptor is present only in perivisceral fat body and only during the period around pupation when both storage proteins are sequestered. © 1994 Wiley‐Liss, Inc.
Isomeric and quaternary properties of homogenous 33 kDa protein from the venom of chelonus near curvimaculatus
Authors: Jones Davy , Krishnan Anuradha , Sarkari Neville , Wozniak Mietek
Published: February 2005

The 33,000 Dalton venom protein of Chelonus near curvimaculatus was characterized for structural properties of charge, quaternary associations, and relationship to polydnavirus encoded proteins. Homogenous isoforms of the protein were isolated from the venom by sequential steps of (1) microdissection, (2) separation based on charge (Mono‐Q column HPLC or narrow‐range electrofocusing), and (3) centrifugal filtration based on molecular weight using Centricon microconcentrators. The purified protein dimerized under native conditions, and this quaternary association became denaturation resistant under certain conditions. Chemical modification of lysine epsilon amino groups did not disrupt such dimerization. The cDNA for the protein did not possess high similarity to any sequence encoded in the polydnavirus, as indicated by results of Southern blotting, but does possess similarity in its repeats to the repeats of the immunologically protective surface glycoprotein of Leishmania amazonensis. © 1994 Wiley‐Liss, Inc.
Premature production of late larval storage proteins in larvae of trichoplusia ni parasitized by euplectrus comstockii
Authors: Coudron Thomas A. , Jones Davy , Jones Grace
Published: February 2005

Investigations were conducted to determine the titer of storage proteins in larvae of the cabbage looper, Trichoplusia ni (Hübner), that were parasitized by the ectoparasitoid Euplectrus comstockii Howard (Hymenoptera: Eulophidae). A gradual increase was noted in the titer of the storage proteins present in the hemolymph of parasitized third and fourth instar larvae and in the hemolymph of isolated thoracic and abdominal tissues of fourth instar larvae. The final amount present in parasitized third and fourth instar larvae was similar to that found in nonparasitized fifth instar larvae. The stimulation of storage proteins in envenomed larvae demonstrates the ability (competence) of early larval stages to produce a gene product that normally occurs in the last larval stadium of the lepidopteran larval host. The gene expression necessary for storage protein production in isolated tissues may be altered by mechanisms separate from inherent developmental processes and the intact endocrine system. © 1994 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Evidence for an early immunosuppressive role for related campoletis sonorensis venom and ovarian proteins in heliothis virescens
Authors: Webb Bruce A. , Luckhart Shirley
Published: February 2005

Shared epitopes among venom, ovarian, and viral proteins may indicate that related proteins have similar functional roles during parasitization of Heliothis virescens by Campoletis sonorensis. Venom and ovarian proteins are introduced directly into the hemolymph during parasitization where they may target hemocytes or other components of the immune system. Polydnavirus expression has been detected in hemocytes, fat body, and other tissues but has not been detected earlier than 4 h after parasitization. Therefore, effects on hemocytes at times earlier than 4 h may not be caused by polydnavirus proteins synthesized in the parasitized insect. Visualization of hemocyte F‐actin with fluorescently labeled phallicidin indicated that a dramatic alteration of plasmatocyte and granulocyte cytoskeletons occurred within 1.5 h after parasitization. The predominant non‐viral proteins in the ovary introduced during parasitization were immunologically related to venom and viral envelope proteins. These ovarian proteins persist in the hemolymph. Antisera to the ovarian proteins bound to granulocytes and to plasmatocytes to a lesser degree, suggesting that ovarian proteins may be involved in early suppression of the host's immune response after parasitization. © 1994 Wiley‐Liss, Inc.
Effects of a nonsteroidal ecdysone agonist, tebufenozide, on host/parasitoid interactions
Authors: Brown John J.
Published: February 2005

Tebufenozide (RH‐5992), a nonsteroidal ecdysone agonist, stimulated significant (P ≤ 0.05) growth in both testes of post‐diapausing codling moth larvae and a dormant Ascogaster larva in its overwintering host's hemocoel. Tebufenozide elicited the same responses in post‐diapausing testes and Ascogaster larvae as were reported earlier in insects treated with 20‐hydroxyecdysone (20‐OHE) [Friedlander, J Insect Physiol 35:29 (1989); Brown et al., Endocrinological Frontiers in Physiological Insect Ecology. Wroclaw: Wroclaw Technical University Press, pp 443–447 (1988)]. Only a trace (≤ 1%) of 14C‐tebufenozide was recovered from gonads and exuviae of healthy larvae, or from Ascogaster larvae removed from parasitized hosts; however, the renewed growth of testes and Ascogaster larvae and apolysis of codling moth integument were an obvious response to the hormone agonist. Most of the injected 14 C‐tebufenozide was recovered from host fat body, while the alimentary canal retained approximately 40% of the 14 C‐tebufenozide fed in an artificial diet.

Host exposure to tebufenozide did not cause apolysis in endo‐ or ectoparasitic hymenopterans feeding on treated codling moth larvae; however, the endoparasitoid trapped in the host's hemocoel died as its host's tissue deteriorated. Different results were observed on ectoparasitoids developing on treated hosts. Ectoparasitic Hyssopus sp. (Eulophidae) larvae feeding on tebufenozide treated hosts pupated in the normal length of time. Hyssopus adults which developed from larvae fed tebufenozide treated hosts were fertile and produced as many progeny as adults reared from solvent fed controls. There was no evidence of secondary poisoning to Hyssopussp. and codling moth exposure to tebufenozide may actually benefit the rearing of this eulophid by maintaining the host in the susceptible larval stage and preventing the host larva from spinning a cocoon. © 1994 Wiley‐Liss, Inc.
Characterization of genital tract growth factor‐like activity from testis sheaths and fat body of Heliothis virescens
Authors: Loeb M. J.
Published: February 2005

Testis sheaths and fat body from developing male pupae of Heliothis virescens synthesize soluble growth factor‐like products when exposed to 20‐hydroxyecdysone (20HE). These factors promote growth and development of the genital tract. Saline extracts of modified Grace's medium and 20HE‐treated testis sheaths and fat body were subjected to heat, freeze‐thaw, organic solvents, and low pressure size exclusion chromatography. Although extracts were stable to repeated freeze‐thawing, activity was lost after exposure to organic solvents; activities of fractions heavier than 6.5 KDa were inhibited by heating to 100°C. Size exclusion chromatography yielded 10 active testis extract fractions and 9 active fat body fractions. Although the approximate molecular weights of most of the extract fractions were similar, enzyme studies using protease, lipase, and α‐amylase indicated differences in the chemistry of active fractions derived from the two tissues. Active factors were inhibited by protease or lipase or both enzymes. © 1994 Wiley‐Liss, Inc.
Covalent modificaition of juvenile hormone binding proteins by photoaffinity labeling: An unexpected gel shift effect
Authors: Touhara Kazushige , Wojtasek Hubert , Prestwich Glenn D.
Published: February 2005

The 32 kD juvenile hormone binding protein (JHBP) and two 80 kD proteins in larval Manduca sexta hemolymph were labeled with [3H]FDK, a photoaffinity analog of methyl farnesoate (MF). The labeling could be completely displaced by a 30‐fold excess of either MF or JH II, demonstrating that [3H]FDK binds specifically to the JH binding sites of the 32 kD JHBP and the 80 kD proteins. In addition, a high molecular‐mass protein was labeled with [3H]FDK; labeling could be displaced by excess MF but not by JH II, demonstrating the selectivity in binding MF. The 32 kD JHBP also appeared to weakly bind the potent juvenoid, methoprene, at the JH binding site.

Covalent modification by [3H]FDK induced a change in the apparent size and the isoelectric point of the JHBP. These changes were not induced by substrate alone, nor by UV irradiation alone. The same effect was also observed during labeling with [3H]MDK, an analog of methoprene. These data provide an important caveat for anticipating artifactual changes of protein properties during chemical or photochemical affinity labeling experiments. The molecular dimensions of [3H]FDK more closely resemble those of JH II than those of [3H]EHDA, a photoactivatable analog of JH II. We suggest that covalent modification by a diazoketone photolabel involves a hydrophilic amino acid important in the recognition of the ester group of JH. © 1994 Wiley‐Liss, Inc.
Digestive enzymes in midgut cells, endo‐and ectoperitrophic contents, and peritrophic membranes of Spodoptera frugiperda (lepidoptera) larvae
Authors: Ferreira Clélia , Capella Adriana N. , Sitnik Roberta , Terra Walter R.
Published: February 2005

In the midgut of Spodoptera frugiperda larvae, subcellular fractionation data suggest that aminopeptidase and part of amylase, carboxypeptidase A, dipeptidase, and trypsin are bound to the microvillar membranes; that major amounts of soluble dipeptidase, cellobiase, and maltase are trapped in the cell glycocalyx; and finally that soluble carboxypeptidase, amylase, and trypsin occur in intracellular vesicles. Most luminal acetylglucosaminidase is soluble and restricted to the ectoperitrophic contents. Aminopeptidase occurs in minor amounts bound to membranes both in the ectoperitrophic contents and incorporated in the peritrophic membrane. Amylase, carboxypeptidase A, and trypsin are found in minor amounts in the ectoperitrophic contents (both soluble and membrane‐bound) and in major amounts in the peritrophic membrane with contents. Part of the activities recovered in the last mentioned contents corresponds to enzyme molecules incorporated in the peritrophic membrane. The results suggest that initial digestion is carried out in major amounts by enzymes in the endoperitrophic space and, in minor amounts, by enzymes immobilized in the peritrophic membrane. Intermediate and final digestion occur at the ectoperitrophic space or at the surface of midgut cells. The results also lend support to the hypothesis that amylase and trypsin are derived from membrane‐bound forms, are released in soluble form by a microapocrine mechanism, and are partly incorporated into the peritrophic membrane. © 1994 Wiley‐Liss, Inc.
Diuretic activity of Mas‐DP II, an identified neuropeptide from Manduca sexta: An in vivo and in vitro examination in the adult moth
Authors: Blackburn Michael B. , Ma Michael C.
Published: February 2005

Mas‐DP II, a recently identified 30 amino acid diuretic peptide isolated from the tobacco hornworm moth, Manduca sexta, was tested for its ability to increase fluid excretion in adult M. sexta, and for the ability to elevate the rate of fluid secretion from isolated Malpighian tubules cultured in vitro. Mas‐DP II was found to increase fluid weight loss from decapitated adult moths in a dose‐dependent manner; weight loss increased significantly at doses as low as 5 ng for female moths and 25 ng for male moths. Male moths injected with large doses of Mas‐DP II continued to exhibit increased rates of fluid loss up to 4 h post‐injection. In vitro, Mas‐DP II stimulated fluid secretion from isolated Malpighian tubules at concentrations as low as 4 nM for tubules from both male and female moths. © 1994 Wiley‐Liss, Inc.
Benzodioxole‐1,3‐benzodioxole derivatives and their effects on the reproductive physiology of insects
Authors: Chang Franklin , Jang Eric B. , Hsu Chiou‐Ling , Ma Michael C. , Jurd Leonard
Published: February 2005

Alkyl ethers of methylenedioxy analogs of obtusastyrene or benzyl‐1,3‐benzodioxole derivatives (BBDs) and related benzylphenols have been shown to interfere with various phases of reproduction in insects. BBDs have also been shown to interfere with sex attractancy, to induce precocious development, and to antagonize juvenile hormone (JH) functions in insects. Because representative BBDs were reported to show low toxicity to mammals and to be negative in assays testing for potential mutagens, these compounds held much promise to be environmentally safe insect chemosterilants. The mode of action of BBDs does not involve blocking or competition for putative JH receptor sites on follicular cells or hemolymph JH binding proteins. However, BBDs were shown to interfere with (1) in vitro biosynthesis and release of JH from corpora allata of Mediterranean fruit fly females, and (2) microtubule assembly in insects. © 1994 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Isolation and characterization of a hemocyte aggregation inhibitor from hemolymph of Manduca sexta larvae
Authors: Kanost Michael R. , Zepp Melissa K. , Ladendorff Noma E. , Andersson Laura A.
Published: February 2005

A protein that inhibits hemocyte aggregation has been isolated from hemolymph of Manduca sexta larvae and named hemocyte aggregation inhibitor protein (HAIP). HAIP has a Mr = 50,000, pI = 8.5, and contains 7% carbohydrate. It is present at 230 ± 20 μg/ml in hemolymph of day 3 fifth instar larvae. Antibodies to HAIP do not cross‐react with M. sexta hemolin, which is similar in size and charge and also inhibits hemocyte aggregation. HAIP and hemolin have some similarity in amino acid composition and NH2‐terminal sequence, but are different in overall secondary structure, as determined by CD spectroscopy. The concentration of HAIP in hemolymph is not affected by injection of larvae with bacteria. A protein of approximately 50,000 daltons that reacts with antibody to M. sexta HAIP is present in hemolymph of Bombyx mori, Heliothis zea, and Galleria mellonella. Although the function of HAIP in vivo is not yet clear, it may have a role in modulating adhesion of hemocytes during defensive responses. © 1994 Wiley‐Liss, Inc.
Immunocytochemical localization of a diuretic peptide Manduca diuresin (MasDPII) in the brain and suboesophageal ganglion of the tobacco hawkmoth Manduca sexta (Lepidoptera: Sphingidae)
Authors: Emery Sutatip B. , Ma Michael C. , Wong Wan‐Keung R. , Tips Ann , De Loof Arnold
Published: February 2005

A purified polyclonal antibody against synthetic Manduca diuresin (formerly named MasDPII) was used to localize immunoreactive cell clusters in the protocerebrum and the suboesophageal ganglion of adult, larval, and pupal stages of Manduca sexta. In adults and pharate adults, strong immunostaining was found in type IIb median neurosecretory cells and IIa1–3 cells. Moderate staining was observed in the maxillary, mandibular, and labial cell clusters in the suboesophageal ganglion. In larvae, immunostaining was found in four IIa cells and in the maxillary, mandibular, and labial cell clusters of the suboesophageal ganglion. In the early pupal stage, six to eight type IIa cells were immunopositive and two clusters of developing type IIb cells showed positive staining. Furthermore, maxillary, mandibular, and labial cell clusters in the pupal suboesophageal ganglion also contained immunoreactive material. In all stages, nervi corporis cardiaci–1+2 and the retrocerebral complex showed immunoreactivity. While preadsorption of purified antibody with another diuretic peptide from M. sexta brain, MasDH, slightly reduced the immunostaining by the Manduca diuresin antibody, preadsorption with Manduca diuresin completely abolished immunoreactivity in all of the cells previously mentioned. The findings suggest the presence of Manduca diuresin or Manduca diuresin‐like peptides in larval and pupal type IIa cells and in the suboesophageal ganglion of M. sexta in all three developmental Stages. © 1994 Wiley‐Liss, Inc.
Biosynthetic alternatives for acetogenic production of sorbic acid in the potato aphid (Homoptera: Aphididae)
Authors: Walters Frederick S. , Mullin Christopher A.
Published: February 2005

Following in vivo injection of [1‐14C]‐sodium acetate, triacylglycerols of the potato aphid, Macrosiphum euphorbiae (Thomas), were extracted and derivatized to p‐bromophenacyl fatty acid esters for two‐dimensional TLC and GLC‐MSD (mass selective detector) analysis. Radiolabeled sorbic (E, E‐2,4‐hexadienoic) acid ester was detected, demonstrating that this short chain fatty acid unique to aphids is biosynthesized via an acetogenic pathway. Crotonic (E‐2‐butenoic) or hexenoic acids were not detected in labeled or unlabeled potato aphid samples or unlabeled samples from the oleander aphid, Aphis nerii Fonscolombe. Crotonic or hexenoic acids might have been expected if an incomplete cycling by fatty acid synthetase or a novel desaturase acting on the prevalent hexanoate, respectively, were responsible for sorbic acid synthesis in aphids. A peroxisomal β‐oxidation route to sorbic acid from longer chain fatty acids was not indicated since injections of clofibrate, a peroxisomal proliferator, with or without C18 polyunsaturated lipids gave no substantial increase in C6 lipids. Also, some characteristic enzyme activities of peroxisomal β‐oxidation were not found in an ultracentrifugal “peroxisomal” fraction from the potato aphid. Although the individual biochemical steps from acetate to sorbate in aphids remain unclear, an unusual acetate‐malonate pathway is indicated. Clarification of the biosynthetic steps to sorbic acid should identify at least one novel enzyme for animals. © 1994 Wiley‐Liss, Inc.
Polydnavirus of Microplitis croceipes prolongs the larval period and changes hemolymph protein content of the host, Heliothis virescens
Authors: Fathpour Hossein , Dahlman Douglas L.
Published: February 2005

Polydnaviruses from certain parasitoid Hymenoptera have been reported to interfere with both host immunity and host development. Heliothis virescens larvae injected with either calyx fluid or sucrose gradient‐purified polydnavirus from Microplitis croceipes (McPDV) gained less weight than saline‐injected larvae. The active feeding portion of the fifth stadium larva (time to reach the burrowing‐digging stage) was doubled (7.0 vs. 3.4 days) when a 0.25 wasp equivalent (WE) of sucrose gradient‐purified McPDV was injected into a newly ecdysed fifth stadium host. Many of the treated larvae were unable to pupate, successfully and died at a point of incomplete larval‐pupal ecdysis. Pupae that did result from the treated larvae weighed significantly less than controls, even at 0.025 WE. The rate of weight gain and extent of delay of development were dose‐dependent; as little as 0.1 WE extended the time of active feeding by 1.5 days and yielded only 25% adults. A 0.05 WE dose yielded 78% adults compared to 95% for controls. The total protein content of hemolymph from individuals injected with McPDV was significantly less than that of controls at any McPDV dose equal to or greater than 0.1 WE. SDS‐PAGE profiles of hemolymph proteins from control and McPDV‐injected larvae revealed a marked inhibition of the normal accumulation of storage proteins during the fifth stadium and a lesser reduction of serine protease inhibitor protein. Thus, McPDV‐injected larvae exhibited some symptoms (less total hemolymph protein and reduced amounts of storage protein) similar to those shown by both parasitized larvae and by larvae injected with M. croceipes teratocytes. However, McPDV affected development during the active feeding stage of the larva, while teratocytes primarily impacted larvae at the time when larval‐pupal transformation processes are initiated. © 1995 Wiley‐Liss, Inc.
Proteolytic enzymes of female Anopheles: Biphasic synthesis, regulation, and multiple feeding
Authors: Hörler Emanuel , Briegel Hans
Published: February 2005

Two types of trypsin activity were detected in Anopheles albimanus, a constitutive and an inductive component, which have identical immunopatterns. The constitutive trypsin in synthesized shortly after eclosion and is retained in the midgut epithelial cells. The inductive trypsin is synthesized and released continuously after a blood meal has been ingested; maximal activities vary between 12 h and 18 h after a blood meal. Once digestion is completed, trypsin is excreted, but the constitutive trypsin level is restored within 24 h, before the next blood meal is taken. In A. gambiae, A. Stephensi, and A. quadrimaculatus, the constitutive trypsin component is also present, but at much lower levels. In A. albimanus fed multiple blood meals at 24 h intervals, trypsin oscillates at nearly maximal levels as long as blood is present in the midgut and depending on the ovarian status. Expression of the two trypsin components in A. albimanus was found to be independent of the neurosecretory system, but synthesis of the constitutive trypsin appears to require the presence of the corpora allata. In all species tested, chymotrypsin is secreted after a blood meal in a similar temporal pattern as trypsin, but it is never present before the blood meal. Reinvestigating several aedine species for the presence of chymotrypsin by using different substrates revealed measurable quantities in blood‐fed females compared to earlier reports. Equally, aminopeptidase activity is present in all species tested and characterized by a constitutive component. Its activities follow different temporal patterns than the endopeptidases. © 1995 Wiley‐Liss, Inc.
Fructose‐1,6‐bisphosphatase from a cold‐hardy insect: Control of cryoprotectant glycerol catabolism
Authors: Holden Clark P. , Storey Kenneth B.
Published: February 2005

Fructose 1,6‐bisphosphatase (FBPase) from the larvae of the gall moth, Epiblema scudderiana, was purified to homogeneity with a final specific activity of 1.6 U/mg protein. The enzyme had a native molecular weight of 74.0 ± 6.5 kD and a subunit molecular weight of 37.6 ± 3.0 kD; the dimeric structure of the enzyme in this species is unusual. The pH optimum was 7.00 in imidazole buffer at 22°C and rose to 7.31 at 5°C. An Arrhenius plot of enzyme activity vs. temperature was linear with an activation energy of 91 ± 4.1 kJ/mol−1. Km values for FBPase decreased from 4.7 ± 0.34 μM at 22°C to 1.3 ± 0.05 μM at 5°C. No allosteric activators were identified, but the enzyme was inhibited by fructose 2,6‐bisphosphate (F2,6P2), AMP, ADP, dihydroxyacetonephosphate, glycerol, and KCI. Inhibition by AMP and F2,6P2 increased at low temperature, and effects of these compounds may be key to preventing futile cycling of carbon at the FBPase/phosphofructokinase loci during the biosynthesis of glycerol cryoprotectant. Oppositely, glycerol clearance in the spring and reconversion into glycogen is promoted by interactions of temperature, inhibitors, and glycerol that promote FBPase activity: I50 values for AMP and F2,6P2 increase at 22°C (compared with 5°C), high glycerol levels override F2,6P2 inhibition of the enzyme, and deinhibitors (ATP, citrate) partially reverse AMP inhibition of the enzyme. © 1995 Wiley‐Liss, Inc.