bluuebunny/crossref_metadata_2025 huggingface dataset:
Ovarian muscularis of the stable fly Stomoxys calcitrans: Its structural, motile, and pharmacological properties
Authors: Cook Benjamin J. , Peterson Tara
Published: February 2005

The muscles of the ovary of the stable fly (Stomoxys calcitrans) appear to consist of two groups: (1) a network of stellate muscle cells that cover the surface of the ovary and (2) fibers that surround the ovarioles. Innervation of the ovaries was largely restricted to the region of the pedicels. The structural arrangements of the ovarian muscles provided the basis for two distinct patterns of movement. The contraction of the sheath that surrounds the ovary produced the appearance of a pulsing sphere, while the activation of muscle fibers that encompass the ovarioles may cause a vertical translation of eggs within the tubes. The various patterns of motility derived from the combined and separate actions of these two groups of muscles are described. Oscillations in the size of the ovary were the most prominent and frequent kind of spontaneous activity observed. A complete cycle of oscillation ranged from 200 ms to 4 s. Day‐old stable flies consistently had the highest rate (30%) of ovarian sheath compression of the three age groups examined, while 2‐day‐old flies had the lowest (less than 10%). Seven‐day flies had inconsistent rates that ranged from o to 25%. Two kinds of ovarian compression were recognized on impedance myographs on the basis of small and large amplitudes. Changes in tonus were also detected. Octopamine produced large increases in the amplitude of spherical compressions at 10−7 M. The neuropeptide proctolin (10−9 M) caused changes in both the frequency and amplitude of ovarian contractions. Glutamic acid consistently caused a marked reduction in the amplitude of ovarian compressions.
Glutathione peroxidase activity in insects: A reassessment
Authors: Ahmad Sami , Beilstein Michael A. , Pardini Ronald S.
Published: February 2005

In vertebrate species, cytotoxic H2O2 and other lipid or organic hydroperoxides (ROOH) formed in aerobic metabolism are removed by a selenoprotein, glutathione peroxidase (GPOX). The GPOX activity in most rat tissues ranges from 100 to 1,000 units (1 unit = 1 nmol NADPH oxidized·mg protein−1·min−1), except for muscles (20–30 units). In contrast, GPOX activities of two strains of the housefly (Musca domestica), cabbage looper (Trichoplusia ni), southern armyworm (Spodoptera eridania), and black swallowtail butterfly (Papilio polyxenes), were found to be in the range 2–12 units. Trivial GPOX activity was detected in the confused flour beetle (Tribolium confusum). In the earthworm (Lumbricus terrestris), banana slug (Ariolimax columbianus), and market squid (Loligo opalescens), the GPOX activity ranged from 1 to 5 units. Tissue selenium concentrations were about 500–1,000 ppb for adult M. domestica, 600 ppb in T. confusum, 32 ppb in T. ni, 17 ppb in S. eridania, and 31 ppb in P. polyxenes larvae. The form of selenium incorporated at such high levels in tissues of invertebrates such as M. domestica remains an unresolved issue. Peroxidase activity of non‐selenium glutathione‐S‐transferase (GT) against ROOH may compensate for the low GPOX activity. Catalase (CAT) has high activity and wide subcellular distribution in insects. This may be an evolutionary adaptation to GT's inability to catalyze the reduction of H2O2. The GT's peroxidase and CAT activities were not assessed for other invertebrate species, and warrants an investigation due to their reported low GPOX levels.
Cycles of protein synthesis during pupal diapause in the flesh fly, Sarcophaga crassipalpis
Authors: Joplin Karl H. , Denlinger David L.
Published: February 2005

Protein synthesis is cyclic during pupal diapause in Sarcophaga crassipalpis. These cycles are in phase with infradian MO2 cycles, which have a periodicity of about 4 days at 25°C. Mean incorporation of [35S]methionine by diapausing pupae was 5.4% during the 2 days of highest MO2 but dropped to 1.7% during the 2 days of low MO2. Diapausing pupae treated with a juvenile hormone analog prior to pupariation had a constant high MO2 similar to peak values observed in untreated pupae, and such pupae consistently incorporated [35S]methionine at a high rate (7.7%). [35S]Methionine incorporation by nondiapausing pupae and pharate adults was eightfold higher than the peak rates observed during diapause. Autoradiography of in vivo labeled proteins indicated quantitative and qualitative changes in the synthesis of proteins by diapausing pupae during different phases of the MO2 cycle. Brains from diapausing pupae labeled in vitro showed higher incorporation at the peak of the MO2 cycle than at the nadir of the cycle, but no such differences were detected for integument, fat body, or fat body supernatant. Theses differences in tissue response indicate that control of protein synthesis during diapause is not cell autonomous, but is a function of the metabolism of the intact organism.
Sex pheromone biosynthesis in the housefly: Evidence for the regulation of the fatty acyl‐CoA desaturation and elongation system by 20‐hydroxyecdysone
Authors: Vaz Apollo H. , Brownson Elizabeth A. , Blomquist Gary J. , Reitz Ronald C.
Published: February 2005

The effects of age, sex, and 20‐hydroxyecdysone treatments on fatty acyl‐CoA desaturation and elongation, key reactions in sex pheromone biosynthesis in the housefly,Musca domestica, were investigated. Radio‐HPLC analyses of the elongation products of [1‐14C] 18: 1‐CoA in the presence of malonyl‐CoA and NADPH by microsomes prepared from 0‐, 1‐, 2‐, 3‐, and 4‐day‐old males and 0‐ and 1‐day‐old female houseflies showed that all even‐numbered monounsaturated fatty acids up to 30 carbons were formed. Insects of these ages and sexes produce alkenes of 27 carbons and longer. When microsomes prepared from females 2, 3, and 4 days old (vitellogenic through postvitellogenic) were used, there was no elongation of [1‐14C] 18: 1‐CoA beyond the 24: 1 fatty acyl moiety. Similarly, neither [1‐14C]22: 1‐CoA nor [14, 15‐3H]24: 1‐CoA were efficiently elongated beyond the 24: 1‐acyl moiety in mature females. Females 2–4 days old produce, as their major alkene, the sex pheromone component (Z)‐9‐tricosene (“muscalure,” Z9‐23 Hy), and they use 24: 1‐CoA as the fatty acyl precursor. The initial precursor for the long chain monoenoic fatty acids is oleic acid. Males treated with 20‐hydroxyecdysone and 2–4‐day‐old females desaturated 18: O‐CoA to 18: 1‐CoA with 36–57% less efficiency than control males or previtellogenic females. These data demonstrate that 20‐hydroxyecdysone is involved in the regulation of (Z)‐9‐tricosene production by altering both desaturation and elongation activities.
Regional differentiation of fat bodies in larvae of the indianmeal moth, Plodia interpunctella
Authors: Shirk Paul D. , Malone Christine C.
Published: February 2005

Larvae of the Indianmeal moth, Plodia interpunctella, contain two morphologically distinct fat bodies. Tan‐colored, highly tracheated fat body located posteriorly in the abdomen was the predominant fat body tissue during the early larval instars. White, sheet fat body located more anteriorly became the predominant type during the fifth (last) larval instar and eventually occupied most of the space of the hemocoel. Ultrastructural morphology of tan fat body showed the tissue to be composed of cells containing numerous, large, spherical mitochondria, with only few lipid, glycogen, or protein storage structures. In contrast, white fat body was composed of cells that in later larval stages had organelles typical of storage functions. Both fat bodies produced storage proteins during the late fifth instar, whereas only white fat body accumulated the storage proteins. Tan fat body dispersed and apparently autolyzed in pharate pupae, whereas the white fat body metamorphosed and persisted into the adult stage. These observations indicate that fat body of the Indianmeal moth is functionally and morphologically differentiated along the anterior‐posterior axis into two regional subgroups of cells.
High‐affinity uptake of [3H]serotonin in cultured neurones of the cockroach Periplaneta americana
Authors: Bermudez Isabel , Beadle David J.
Published: February 2005

Cultured central neurons from the American cockroach, Periplaneta americana, have been used to investigate the uptake of [3H]serotonin. The neurones accumulate [3H]serotonin from the extracellular medium by both a high‐and a low‐affinity system. The activity of the high‐affinity mechanism is decreased by low temperature and metabolic poisons, and is dependent on sodium and chloride ions. Both depolarising levels of external potassium ions and veratridine decrease the high‐affinity uptake system, suggesting it is influenced by the transmembrane potential. The pyrethroid insecticides, deltamethrin and permethrin, enhance the inhibitory effect of veratridine. Pyrethroid enhancement is completely blocked by tetrodotoxin, and neither pyrethroid affects the uptake system in the absence of veratridine. Avermectin B1A is a powerful inhibitor of the high‐affinity uptake system, and its effect is blocked by picrotoxin. High‐affinity uptake of [3H]serotonin is inhibited by imipramine and amitriptyline; desipramine has no significant effect on this uptake. The activity of the high‐affinity system is also reduced by 8‐hydroxy‐dipropylaminotetralin, α‐methyl‐serotonin, and 1‐(3‐chlorophenyl)piperazine. Dopamine, noradrenaline, octopamine, and the formamidine insecticides, chlordimeform and demethylchlordimerform, are moderate inhibitors of the high‐affinity uptake system. The formamidine effect is not blocked by tetrodotoxin or picrotoxin.
Physiological interactions between the host genus Heliothis and its guild of parasitoids
Authors: Bradleigh Vinson S.
Published: February 2005

Factors produced in Hymenopteran parasitoids from their poison gland or from calyx region of the ovary or from both effect changes in host growth. In this review, the sources of these factors from parasitoids of Heliothis spp. (Lepidoptera: Noctuidae) are described and their effects on host growth are compared. An evaluation of protein, amino nitrogen, and trehalose levels in the hemolymph of parasitized Heliothis indicates that each parasitoid species exerts a different effect on Heliothis. A number of parasitoid genera still remain to be evaluated relative to their effects on host growth before a relationship can be established between parasitoid taxon and effects of their parasitism on hosts.
Venom proteins of the endoparasitic wasp Chelonus Near Curvimaculatus: Characterization of the major components
Authors: Jones Davy , Leluk Jacek
Published: February 2005

The venom apparatus of Chelonus near curvimaculatus (Braconidae) has a simple (type 2) morphology. Most of the venom is accumulated in a thin‐walled venom reservoir at the distal end of the gland filament as a 10–17% protein solution. The best results for isolation of the proteins were obtained using 7.5% sucrose in phosphate buffer, pH 7.4. There are four major proteins, with respective Mr values of 32,500, 47,000, 53,000, and 131,000. Of these, those of Mr 32,500, 53,000, and 131,000 contain carbohydrate. Most of the venom proteins are acidic with pI values between 4.9 and 6.9. The venom does not show proteolytic activity corresponding to serine or thiol proteinases, nor does it show antitrypsin or antichymotrypsin activity. Using immunoblotting techniques, it was established that during parasitization of a single host egg (Trichoplusia ni) about 1/200 of a venom reservoir equivalent is injected. All major venom proteins have been found in stung T. ni eggs; thus, no detectable changes in their molecular weight occur during injection or shortly after injection into the host.
Viruslike particle proteins from a hymenopteran endoparasitoid are related to a protein component of the immune system in the lepidopteran host
Authors: Schmidt Otto , Andersson Kerstin , Will Annette , Schuchmann‐Feddersen Imke
Published: February 2005

Insect endoparasitoids are able to circumvent the defense reactions of their habitual hosts. In the ichneumonid wasp Venturia canescens, viruslike particles found on the egg surface are responsible for the protection of the parasitoid against the encapsulation reaction of the host. Some of the particle proteins are structurally and probably functionally related to a protein in the host caterpillar Ephestia kühniella. The host protein is synthesized in hemocytes and fat body in low amounts and can be induced together with other proteins to higher levels of protein synthesis after bacterial infection. Hemocytes that show an increased expression of protein(s) are less likely to attach to a glass surface and are not involved in spreading.
The biochemical and physiological effects of insect hosts on the development and ecology of their insect parasites: An overview
Authors: Lawrence Pauline O.
Published: February 2005

The behavior, development, morphology, and ecology of parasitic insects are known to be influenced by various aspects of their hosts. These aspects include chemical cues emanating from the potential host that influence host location and acceptance by the ovipositing parasite female, as well as the age, size, and general physiological state of the host in which the immature parasite develops. Some parasitic insects develop optimally in the host egg, others in early to mid‐larval instar hosts, and still others in late‐larval to pupal stage hosts. This niche partitioning among parasites likely reflects parasite strategies to minimize competition. However, important biochemical conditions mediated by endocrine and nutritional factors within the hosts themselves dictate the extent to which these strategies are successful. In this paper I suggest that endocrine‐mediated metabolic events in late‐larval through pupal stage insects render these stages to be a nutritionally distinct resource from the early through mid‐larval stage. Consequently, members of these two groups are exploited by insect parasites which themselves have different nutritional requirements. To support this hypothesis, selected aspects of insect nutrition and endocrinology that may influence the suitability of early to mid‐stage larval hosts vs. late‐larval to pupal hosts for parasite development are reviewed. The possible impact of host suitability on aspects of parasite ecology, e.g., sex ratios and voltinism, is also briefly addressed.
Variations of biogenic amine levels in the brain of Pieris brassicae pupae during nondiapausing and diapausing development
Authors: Puiroux Jacques , Moreau Robert , Gourdoux Lucienne
Published: February 2005

The post‐embryonic development of Pieris brassicae can either be continuous (under a long photoperiod) or interrupted at the pupal stage (induced by a short photoperiod); this phenomenon is termed facultative diapause. Several studies have indicated that certain brain mechanisms could be directly involved in the perception of variations in the photoperiod and could mediate some physiological effects particular to dormancy. Biogenic amines have been particularly implicated in the response to photoperiod variations and also in the regulation of development, especially in diapause induction and termination.

High performance liquid chromatography with dual electrochemical detection has therefore been used to measure several biogenic amines in pupal nervous tissues at various stages of nondiapausing and diapausing development.

During direct development, the levels of dopamine (DA) and N‐acetyldopamine (NADA: a DA metabolite) in brain were relatively high in 3‐day‐old pupae and at the end of pupal life (on the 8th day). Dihydroxyphenylacetic acid (another metabolite of DA) showed no variation. Serotonin was mainly observed in 2–3‐day‐old pupae but 5‐hydroxyindoleacetic acid was never detected. In young diapausing insects, similar variations of DA levels were observed even though a slight decrease of DA metabolites was noted. Serotonin appeared somewhat later (4–5 days) and attained higher levels. In late diapausing pupae, a marked increase in DA levels was observed, especially when pupae were kept at low temperature (4°C). During diapause, serotonin levels were reduced or even absent.
Effects of female wasp accessory secretions, host fat body, and host hemolymph on protein synthesis and egg viability in Microplitis croceipes (Braconidae)
Authors: Ferkovich Stephen M. , Dillard Charles R.
Published: February 2005

Effects of female wasp reproductive gland secretions, host fat body and hemolymph, and mechanical constriction of the parasitoid egg on protein synthesis were studied in eggs of Microplitis croceipes (Braconidae) dissected from the wasp ovary. Protein synthesis was measured by 35S‐methionine incorporation in eggs held in tissue culture medium for 16 h after treatment. Synthesis was stimulated in oocytes obtained from three regions of the ovary (egg tube, reservoir, and calyx) by fat body and venom gland but not by calyx fluid. A combination of fat body, venom gland, and calyx fluid did not enhance the level of synthesis relative to that of fat body or venom gland alone. Host hemolymph inhibited protein synthesis when incubated directly with the dissected eggs but not when the eggs were collected from an artificial oviposition substrate (AOS) containing hemolymph. The inhibitory effect of the hemolymph is thought to be due to the occurrence of melanization. Mechanical constriction did not alter the rate of synthesis, confirming an earlier report that synthesis in newly deposited eggs is ongoing and is not dependent on mechanical activation during the act of oviposition. Mechanisms responsible for sustaining protein synthesis in eggs for 16 h in vitro after their exposure to host hemolymph in the AOSs or fat body and venom gland are not known. Only a small percentage (<2%) of dissected ovarial reservoir oocytes that were mechanically constricted and exposed to the venom gland, calyx fluid, and host fat body hatched in vitro. In contrast, an earlier study demonstrated that 38% of eggs oviposited by female wasps into AOSs developed and hatched.
Identification and molecular analysis of storage proteins from Heliothis virescens
Authors: Leclerc Robert F. , Miller Stephen G.
Published: February 2005

Three abundant storage proteins have been detected in larval and pupal hemolymph and pupal fat body of the tobacco budworm, Heliothis virescens. These polypeptides have subunit molecular weights of 74,000, 76,000, and 82,000, as determined by SDS–PAGE and exit as 450,000‐Mr hexamers in their native state. A purified 82,000‐Mr storage protein fraction has been obtained along with a preparation containing equivalent amounts of the 74,000‐Mr and 76,000‐Mr subunits, and antisera raised to each of these components have been used to document the developmental profiles of protein accumulation and synthesis by fat body. cDNA clones corresponding to each of three abundant classes of fat body mRNAs have been recovered, and at least one of these has been unambiguously demonstrated to encode the 82,000‐Mr storage protein subunit. Northern blot studies with these cDNA clones revealed that the developmental accumulation of transcripts in fat body for each was consistent with the general pattern of storage protein biosynthesis, and more interestingly, that transcirpts hybridizing to two of these cDNA sequences are also found in testes. These two cDNA have also been sequenced revealing that one encodes a polypeptide similar to arylphorins, a class of storage proteins widely distributed in Insecta. The derived amino sequence of the second cDNA, corresponding to the 82,000‐Mr protein, had no unusual compositional features and determination of its structural relationship to other hemolymph polypeptides awaits molecular analysis of related genes from other insects.
Synthesis and transport of storage proteins by testes in Heliothis virescens
Authors: Miller Stephen G. , Leclerc Robert F. , Seo Sook‐Jae , Malone Christine
Published: February 2005

The synthesis of two storage protein subunits, 76,000‐Mr and 82,000‐Mr polypeptides, by the testes sheath has been studied in Heliothis virescens. Like fat body, which is the primary site of synthesis for the large extratesticular pool, cells of the testes sheath secrete glycosylated storage proteins assembled into hexamers. The testis sheath differed from fat body in several important respects, including the failure to synthesize an abundant (in the hemolymph) 74,000‐Mr storage protein, its relatively reduced expression of the 76,000‐Mr polypeptide, and the absence of resorption of storage proteins from the lumen of the testis during pupal development. Cyst cells were also shown to import actively the 82,000‐Mr storage protein by pinocytosis of testicular fluid and transfer it to the developing spermatids. Unlike other cell types that sequester storage proteins in the form of cytoplasmic granules, their localization within spermatids was exclusively mitochondrial. These observations suggest that expression of the storage protein genes is regulated tissue specifically and reveal novel pathways for their transport and, perhaps, utilization and function during development.
Lipophorin as a yolk precursor in Hyalophora cecropia: Uptake kinetics and competition with vitellogenin
Authors: Kulakosky Peter C. , Telfer William H.
Published: February 2005

Vitellogenic follicles of Hyalophora cecropia were incubated in metabolically radiolabeled, high‐density lipophorin isolated from pharate adult hemolymph by KBr density gradient centrifugation. The follicles transferred this probe from the incubation medium to the cortical yolk spheres in the oocyte by an energy‐dependent and saturable mechanism. Vitellogenin and high‐density lipophorin competed with each other for uptake, and are therefore concentrated by the follicle with a common mechanism. Microvitellin and lipophorin, in contrast, did not compete for uptake. The Kuptake for the accumulation of high‐density lipophorin was substantially higher than the value estimated earlier for vitellogenin (133 μM vs. 18 μM). This relationship helps explain why the shared concentrating mechanism does not deplete the lipid transport capacity of the hemolymph, and how a low vitellogenin: lipophorin molar ratio in the hemolymph yields a high ratio in the mature egg.
Isolation and characterization of bacteria‐induced protein P4 from hemolymph of Manduca sexta
Authors: Ladendorff Noma E. , Kanost Michael R.
Published: February 2005

Insects synthesize several types of hemolymph proteins in response to bacterial infection. The objective of this study was to characterize a 48,000 dalton hemolymph protein induced in larvae of Manduca sexta after injection of bacteria. The protein, isolated by cation exchange and gel filtration chromatography from hemolymph of larvae injected with Micrococcus lysodeikticus, was found to be a glycoprotein with pl = 8.4. The molecular weight, isoelectric point, amino acid composition, and NH2 terminal sequence of the protein are similar to bacteria‐induced protein P4 from Hyalophora cecropia, and the M. sexta protein is also designated P4. The hemolymph concentration of M. sexta P4 (35 ± 7 μg/ml in day 3 fifth instar larvae) increases 30‐ to 45‐fold by 48 h after injection of bacteria, but it does not increase in response to injection of distilled water. Lower levels of induction occur after injection of peptidoglycan fragments, zymosan, and lipopolysaccharide. The properties of M. sexta P4 are very similar to those of a previously characterized M. sexta hemolymph protein known as postlarval protein, and antibodies against P4 bind to postlarval protein.
P1 gene expression in Drosophila larval fat body: Induction by various Ecdysteroids
Authors: Sommé‐Martin Ghislaine , Colardeau Jacqueline , Beydon Philippe , Blais Catherine , Lepesant Jean Antoine , Lafont René
Published: February 2005

Using the developmental mutant ecd1, the biological activity of 20‐hydroxyecdysone (20E) and 20E metabolites 3‐dehydro‐20‐hydroxyecdysone (3D20E), 3‐epi‐20‐hydroxyecdysone (3D20E), 3‐epi‐20‐hydroxyecdysone‐3‐phosphate (20E′3P), 20,26‐dihydroxyecdysone (20,26E), and 20‐hydroxyecdysonoic acid (20Eoic) was tested for their ability to induce the transcription of the steroid‐inducible gene P1 in the Drosophila larval fat body. 3D20E was the most efficient ecdysteroid in the initiation of P1 gene transcription therefore the formation of 3D20E and the 3‐epimer could not be regarded as an inactivation pathway in Drosophila larvae. Formation of 20,26E and 20Eoic may be an inactivation pathway in this biological model.
Sex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis (II): Biosynthesis of (E)‐ and (Z)‐12‐tetradecenyl acetate involves Δ14 desaturation
Authors: Zhao Chenghua , Löfstedt Christer , Wang Xuying
Published: February 2005

Sex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis was studied by topical application of deuterium labelled fatty acids to the pheromone gland. The incorporation of the labelled acids into pheromone components and precursors was determined by gas chromatography with flame ionization detection and mass spectrometry in the selected ion monitoring mode. The labelling experiments suggest that the pheromone components (E)‐ and (Z)‐12‐tetradecenyl acetates are biosynthesized from palmitic acid by δ14 desaturation, followed by chain shortening (β‐oxidation), reduction, and acetylation. This is the first confirmation of a Δ14 desaturase in an eukaryotic system.
Antioxidant enzyme activities in subcellular fractions of larvae of the black swallowtail butterfly, Papilio polyxenes
Authors: Ahmad Sami , Pritsos Chris A. , Pardini Ronald S.
Published: February 2005

The black swallowtail butterfly, Papilio polyxenes, larvae are specialized feeders of pro‐oxidant rich plants of Apiaceae and Rutaceae. An important defense against toxic forms of oxygen species generated by ingestion of the pro‐oxidants, are the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), GSH‐dependent glutathione peroxidases (selenium‐dependent glutathione peroxidase [GPOX] and peroxidase activity of selenium‐independent glutathione‐S‐transferase [GTpx]), and glutathione reductase (GR). The subcellular distribution of these enzymes in black swallowtail larvae was investigated and was found to resemble the patterns described for larvae of two other lepidopteran species: the southern armyworm, Spodoptera eridania, and the cabbage looper, Trichoplusia ni. The confinement of SOD in the cytosol and mitochondria was typically eukaryotic, but the relative proportion (1:1) was markedly different from the mammalian pattern (4:1; cytosol:mitochondria). The most obvious difference between the black swallowtail and other lepidoptera as a group, and mammalian species, is in very wide intracellular distributions of CAT, GTpx, and GR in insect species. Insects possess very low levels of a GPOX‐like activity which reduces both H2O2 and organic peroxides. Consequently, insects have elaborate activities with a wide subcellular distribution of both CAT which decomposes H2O2, and GTpx which decomposes organic peroxides. The reduction of peroxides is dependent on GSH, which in this process is oxidized to GSSG. GR which reduces GSSG to GSH is also of wide subcellular distribution, analogous to the distribution pattern of GTpx.
Biological effects of synthetic AKH in Manduca sexta and estimates of the amount of AKH in corpora cardiaca
Authors: Ziegler Rolf
Published: February 2005

Dose‐response curves were measured with synthetic Manduca adipokinetic hormone (AKH) for glycogen phosphorylase activation in larvae and for lipid mobilization in adults. Both responses are known hormonal functions in Manduca sexta. In ligated larvae, full activation of glycogen phosphorylase was achieved with 0.1 pmol and half‐maximal activation with 0.03–0.04 pmol. Maximal lipid mobilization in adults required 10 pmol and half‐maximal mobilization 0.15 to 0.2 pmol, respectively.

An estimate of AKH content of corpora cardiaca from M. sexta was gained by comparing the dose‐response curves for synthetic Manduca AKH with curves from gland extracts. Corpora cardiaca extracts were also quantitated by high performance liquid chromatography. According to both estimates corpora cardiaca of adults contain 10–20 pmol AKH per pair, while a pair of larval corpora cardiaca contains 0.7–2 pmol.
Proteolytic processing of Blattella germanica vitellin during early embryo development
Authors: Nordin John H. , Beaudoin Esther L. , Liu Xiaodong
Published: February 2005

In the eggs of the cockroach Blattella germanica, vitellin (Vt) utilization is initiated 4 days postovulation by the proteolytic processing of its three subunits. These reactions yield a specific set of peptides that are consumed by the developing embryo. A yolk proteinase activity, believed central to this processing event, has been investigated. First expressed at day 3 postovulation, just prior to Vt's processing, its specific activity with synthetic substrates increased four‐fold to 18‐fold through day 6. In addition, a mixing experiment showed that these proteinases(s) can also process Vt's large subunits in vitro. A relationship between Vt processing and proteinase specific activity was also noted with two B. germanica translocation heterozygotes, which displayed differences in the extent of Vt processing. One group of eggs (group A) failed to process any Vt subunit. A second group (B) processed the Mr 102,000 subunit but not the Mr 95,000. A third group (C) processed their Vt normally. Proteinase specific activities in the yolk of translocant's eggs at day 6 mirrored the extent of processing, being highest in group C eggs and effectively absent from the yolk of group A eggs. Eggs defective in Vt processing also contained arrested embryos. It is concluded that the yolk proteinase activity described here participates in Vt processing at day 4 postovulation. Microscopic examination of yolk obtained from eggs of wild type females showed that, as processing began in vivo (day 4), the yolk granules also underwent an abrupt decrease in size from diameters of 15–30 μm to 3–10 μm. Yolk granules of those translocant's eggs that were defective in Vt processing did not undergo this size decrease, suggesting that granule reorganization and Vt proteolysis may be linked functionally.
On the latency and nature of phenoloxidase present in the left colleterial gland of the cockroach Periplaneta americana
Authors: Sugumaran Manickam , Nellaiappan Kaliappan
Published: February 2005

The phenoloxidase system responsible for the sclerotization of cockroach ootheca is found to be present as an inactive form in the left colleterial gland of Periplaneta americana. The supernatant fraction obtained by centrifugation of the milky white secretions contained the inactive phenoloxidase which required both sodium dodecyl sulfate (SDS) and the insolubel sediment for exhibiting enzyme activity. Bovine serum albumin could replace the sediment in the activation process. Proteins separated from the supernatant fraction by molecular sieve chromatography on Sephadex G‐25 did not require either albumin or the sediment, but required SDS for exhibiting the phenoloxidase activity. Among the detergents tested, SDS (anionic) and cetylpyridinium chloride (cationic) activated the phenoloxidase, but CHAPS (zwitterionic) or nonionic detergents failed to activate the enzyme. The activation caused by SDS occurred well below the critical micellar concentration of SDS indicating that SDS is causing the activation by binding to the protein and altering its conformation. Chloroform‐methanol extracts of vestibulum or right gland could replace SDS confirming the presence of endogenous activator(s) of phenoloxidase system. A variety of exogenously added lipids could activate the latent enzyme, among which linoleate, oleate, laurate, linolenate, phosphatidylethanolamine, and phosphatidylglycerol proved to be the effective activators of the latent phenoloxidase.

Partially purified phenoloxidase was found to be extremely labile and lost its activity on (a) freezing and thawing, (b) dialysis, and (c) heating for 10 min at 55°C. It exhibited a pH optimum of 7 and was inhibited drastically by phenylthiourea and diethyldithiocarbamate. It readily oxidized a number of o‐diphenols such as 3,4‐dihydroxybenzylalcohol, 3,4‐dihydroxyphenethyl alcohol, catechol, N‐acetyldopamine, N‐acetylnorepinephrine, dopa, dopamine, etc., but failed to oxidize both 3,4‐dihydroxybenzoic acid and 3,4‐dihydroxybenzaldehyde. It neither converted the typical laccase substrate syringaldazine to its quinone methide product, nor oxidized the p‐diphenols, hydroquinone and methylhydroquinone. Therefore, the enzyme participating in the quinone tanning of cockroach ootheca appears to be a typical o‐diphenol oxidase and not a laccase as previously thought.
Ecdysteroids control vitellogenesis and egg maturation in pharate adult females of the Indianmeal moth, Plodia interpunctella
Authors: Shirk Paul D. , Bean Daniel W. , Brookes Victor J.
Published: February 2005

Vitellogenesis occurs during the late pharate adult stage in the Indianmeal moth, Plodia interpunctella. Repeated treatment of pharate adult females with doses of 20‐hydroxyecdysone (20HE) from 10 to 250 ng per pupa suppressed oocyte growth and inhibited yolk protein accumulation in the oocytes. Treatment of the pharate adults with a biologically inactive ecdysteroid analogue, 22–isoecdysone, had no effect on egg maturation or yolk protein accumulation. The hormonal action of 20HE was not through the inhibition of the corpora allata or juvenile hormone levels, because treatment with a juvenile hormone analogue did not reverse the inhibition by 20HE treatment. Exposure of early vitellogenic ovaries to 20HE in organ cultures in vitro showed that 20HE had a direct effect on the ovarian synthesis of YP2. At 20HE concentrations below 10 nM, YP2 synthesis was minimal, at 10 nM 20HE YP2 synthesis was maximal, and at concentrations higher than 10 nM YP2 synthesis was suppressed to 35% of the maximal level. Synthesis of most other ovarian proteins remained constant with the changing 20HE concentrations. Ovarian RNA from treated females translated in a reticulocyte lysate demonstrated that the hormonal effect of 20HE on the ovarian tissues was on the specific accumulation of translatable YP2 transcript as well as transcripts for a few other polypeptides. This study shows that 20HE controls the rate of egg development during metamorphosis and that declining titers of 20HE regulate the expression of adult genes.
Solubilization, identification, and localization of vitellogenin‐binding sites in follicles of the cockroach, Nauphoeta cinera
Authors: Indrasith Leslie S. , Kindle Helmut , Lanzrein Beatrice
Published: February 2005

Binding sites for vitellogenin were solubilized and analyzed either with a filter assay or with ligand blotting. We tested sodium dodecylsulfate (SDS), Chaps, octyl‐β‐D‐glucoside, and sodium dexocycholate and found SDS and sodium deoxycholate to be most effective in solubilizing both high and low molecular weight binding sites. In the filter assay the sodium deoxycholate extracts but not the SDS extracts, maintained binding activity after dilution of the solubilizer below its critical micellar concentration. In ligand blotting we consistently observed, in vitellogenic folicles, binding sites with an apparent Mr of approximately 200,000, 35,000, and three closely spaced bands between 14,000 and 20,000. Binding of vitellogenin to all binding sites was suppressed in the presence of the drug suramin. Analysis of corpora lutea and oothecae as well as of ovariole sheath, follicle cell/basal lamina, and oocyte plasma membrne preparations showed that the 35 and 14–20 kDa binding sites are located in the outer follicle compartments, and the 200 kDa binding site in the oocyte plasma membrane. In the latter we occasionally also observed binding sites with an apparent Mr of approximately 150,000, 95,000, 67,000 and 30,000, particularly at stages after ovulation. The 35 and 14–20 kDa binding sites, as visualized in stained gels and in ligand blotting, are rather abundant and were also seen in several other male and female tissues of Nauphoeta and even in other species. They also bound other 14C‐labeled hemolymph proteins and thus appear to be rather unsepcfic. As binding analysis with nonsolubilized and sodium deoxycholate‐solubilized membranes revealed that the quantity of vitellogenin bound by binding sites of the outer follicle compartments was low, it is conceivable that teh abundance of the 14–20 kDa and 35 kDa binding sites in ligand blotting is merely an effect of SDS and does not reflect the in vivo situation. We suppose that the 200 kDa binding site of the oocyte plasma membrane represents the vitellogenin receptor involved in endocytosis.
On the action of RH 5849, a nonsteroidal ecdysteroid agonist, on a cell line from Chironomus tentans
Authors: Spindler‐Barth Margarethe , Turberg Andreas , Spindler Klaus‐Dieter
Published: February 2005

RH 5849 competes with 3H‐ponasterone A for ecdysteroid binding sites in Chironomus tentans cells with an about fourfold lower relative affinity as compared to 20‐OH‐ecydsone. It does not interfere with glucocorticoid and estrogen binding sites in vertebrates. It is also not recognized by an ecdysteroid antibody. RH 5849 exerts typical morphological and physiological effects ascribed to the action of 20‐OH‐ecdysone on C. tentans cells, namely an increase in acetylcholinesterase activity and an inhibition of chitin synthesis.
Distribution and pharmacological characterization of muscarinic‐cholinergic receptors in the cockroach brain
Authors: Orr Gregory L. , Orr Nailah , Hollingworth Robert M.
Published: February 2005

The binding of [3H]quinuclidinyl benzilate to a cockroach brain preparation was investigated. Specific binding was saturable with a Kd of 0.25 nM and Scatchard analysis indicated a Bmax of 604 pmol/mg protein. Kinetic analysis indicated that the ligand is binding in a complex fashion while dissociation followed a simple kinetic process. The pharmacology of the site was typical of muscarinic receptors but the site cannot be characterized in terms of vertebrate muscarinic‐receptor subtypes. Affinity of the receptor for agonists was modulated by Mg2+ and guanylylimidodiphosphate but not by pertussis toxin indicating the involvement of a pertussis‐toxin insensitive G‐protein. Carbamylcholine did not inhibit basal or forskolin‐stimulated adenylate cyclase activity. The binding site was localized autoradiographically and was restricted to the median and lateral calyces of the brain.
Antioxidant enzymes as biochemical defenses against phototoxin‐induced oxidative stress in three species of herbivorous lepidoptera
Authors: Aucoin Richard R. , Philogène Bernard J. R. , Arnason John T.
Published: February 2005

Many secondary plant compounds are capable of photoactivation resulting in the production of toxic species of oxygen. One mechanism of defense for insects feeding on phototoxic plants may be the presence of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPOX), and glutathione reductase (GR). The activities of these enzymes were examined in larvae of three lepidoptera: Ostrinia nubilalis, Manduca sexta, and Anaitis plagiata. Highest levels of antioxidant enzyme activity were found in A. plagiata, a specialist feeder on Hypericum perforatum, which contains high levels of the phototoxin hypericin. Larvae of A. plagiata fed leaf discs treated with hypericin exhibited a short‐term, concentration‐dependent decline in enzyme activity. Longer term studies with A. palgiata fed either the photoxic H. perforatum, or the closely related but non‐phototoxic H. calycinum, resulted in increased CAT and GR activity in larvae fed the phototoxic plant whereas SOD activity was not significantly different. These results suggest that CAT and GR may be inducible defenses against phototoxins.
Pharmacological characterization of a 5‐hydroxytryptamine‐sensitive receptor/adenylate cyclase complex in the mandibular closer muscles of the cricket, Gryllus domestica
Authors: Baines Richard A. , Downer Roger G. H.
Published: February 2005

The mandibular closer muscles of the cricket, Gryllus domestica, contain a 5‐hydroxytryptamine (5‐HT)‐sensitive receptor that is coupled to adenylate cyclase. A structure‐activity study of the 5‐HT molecule indicates that the integrity of the ethylamine sidegroup and the presence of a negatively charged moiety at the 5 position (‐OH, ‐OCH3) are essential for activity. A pharmacological profile is presented for this receptor. The receptor differs from any reported mammalian 5‐HT receptor in that none of the mammalian agonists tested were effective. However, the mammalian antogonists for 5‐HT receptors, spiperone, mianserin, and ketanserin as well as the anti‐histaminic cyproheptadine were all effective antagonists in this preparation. Preliminary analysis of antagonism, particularly by spiperone, shows that these antagonists are probably acting non‐competitively.

On the basis of the pharmacological data, and comparisons with other insect systems, the 5‐HT receptor present in the cricket mandibular muscles has been tentatively classified as 5‐HT2‐like.
Development of male‐incubated ovaries in the gypsy moth, Lymantria dispar
Authors: Ballarino Joanne , Ma Michael , Ding Tsuey , Lamison Craig
Published: February 2005

Ovaries from Lymantria dispar females were transplanted into an environment lacking vitellogenin, the male milieu, in order to determine how the presence of vitellogenin in the hemolymph affects the process of protein uptake by gypsy moth oocytes. When undeveloped ovaries from newly ecdysed last instar females were transplanted into males of the same stage, follicles detached from the germarium and increased in size, but the growth of oocytes proceeded more slowly than those from female controls. Although chorion fromation was delayed in male‐grown ovaries, scanning electron microscopy of chorionated eggs recovered from adult males showed that a chorion with normal surface architecture was formed by the adult stage. SDS‐PAGE analysis of the male‐grown ovaries and hemolymph from males receiving ovaries showed that vitellogenin production was not stimulated by the organ transplant and only male hemolymph proteins were internalized by the male‐incubated ovaries. Thus, in the absence of vitellogenin, endocytosis of male hemolymph proteins occurred, but the rate of oocyte growth was slowed.
Ultrastructural studies of male‐incubated ovaries of the gypsy moth, Lymantria dispar
Authors: Ballarino Joanne , Ding Tsuey , Ma Michael
Published: February 2005

Ovaries from Lymantria dispar females were transplanted into an environment lacking the vitellogenin ligand; i.e., the male milieu. Transmission electron micrographs comparing the terminal oocytes of male‐grown ovaries and normal ovaries showed that yolk sphere diameters were reduced in the male‐grown oocytes. However, there were larger numbers of these small yolk spheres per unit area of cytoplasm, indicating that the coalescence of endosomes into yolk spheres is reduced in the absence of vitellogenin. Although there are larger numbers of yolk spheres in male‐grown oocytes, the smaller diameter of yolk spheres resulted in less area being taken up by yolk spheres per unit area of cytoplasm in male‐grown oocytes, yielding lowered yolk production. This lowered yolk production is a result at least in part of the lowered number of coated vesicles per unit area of submembrane space and in part of the reduced interfollicular spaces seen in male‐grown ovaries.
Superoxide dismutase in the anal gills of the mosquito larvae ofAedes aegypti: Its inhibition by α‐terthienyl
Authors: Nivsarkar Manish , Kumar G. Pradeep , Laloraya Malini , Laloraya Manmohan M.
Published: February 2005

The anal gills of the mosquito larvae ofAedes aegyptiwere shown to possess superoxide dismutase (EC 1.15.1.1) activity, which increased with the maturation of the larvae from instar 1 to instar 4. This enzyme was highly inhibited upon treatment of the larvae with α‐terthienyl (2,2′: 5,2′‐terthiophene) and subsequent exposure to long‐wave ultraviolet light. Inhibition also occurred with treatment of the crude enzyme extract in a similar fashion. Exposure of the enzyme to the ultraviolet light alone or the treatment of the enzyme with α‐terthienyl in darkness could not manifest this inhibition. This finding adds a new dimension to the complex mechanism(s) proposed for the photodynamic toxicity of α‐terthienyl.
Role of superoxide dismutase in the protection and tolerance to the prooxidant allelochemical quercetin in Papilio polyxenes, Spodoptera eridania, and Trichoplusia ni
Authors: Pritsos Chris A. , Pastore Jenny , Pardini Ronald S.
Published: February 2005

Larvae of the black swallowtail butterfly, Papilio polyxenes, the southern armyworm, Spodoptera eridania, and the cabbage looper, Trichoplusia ni, have different feeding habits and dietary breadth, which contributes to differences in their exposure and tolerance to dietary prooxidant allelochemicals. The antioxidant enzyme activities of larvae of these insects have been previously determined, with the levels being P. polyxenes > S. eridania > T. ni. The relative activities of these antioxidant enzymes are consistent with the relative exposure of these insects to prooxidants. This suggests that the antioxidant enzymes may play a role in the defense against allelochemical toxicity in these insects. Dietary diethlydithiocarbamate (DETC), a copper chelating agent and superoxide dismutase (SOD) inhibitor, was shown to inhibit SOD in all three insects. Toxicological studies were conducted using four diets for each insect. The standard diets for each insect were supplemented with either control (solvent), quercetin (a prooxidant), DETC, or DETC plus quercetin. Nontoxic doses of each compound for each insect were used. Inhibition of SOD in P. polyxenes and S. eridania dramatically increased quercetin‐induced toxicity as measured by relative growth and consumption rates in these species. DETC had no effect on quercetin toxicity in T. ni. These results elucidate the important role of SOD in the prooxidant allelochemical defense of insects.
Site of hemolymph lectin production and its activation in vitro by 20‐hydroxyecdysone
Authors: Amanai Kazuhito , Sakurai Sho , Ohtaki Tetsuya
Published: February 2005

To identify the tissues which produce hemolymph lectin in larvae of Bombyx mori, ovary, testis, fat body, and hemocytes from 5th‐instar larvae were cultured in vitro and the culture medium was partially purified and assayed for hemagglutinating activity. Among the tissues tested, hemocytes appeared to be a major source of the hemolymph lectins. Ovary produced lectins to about one‐tenth of the amount observed for the hemocytes, whereas testis and fat body were not productive. To study the hormonal control of hemolymph lectin production by hemocytes, hemocytes from 4th‐instar larvae were cultured in vitro. Hemagglutinating activity in the hemolymph of 4th‐instar larvae was immunostainable with the monoclonal antibody raised against 350,000 dalton lectin found in the 5th‐instar hemolymph, but their molecular sizes were larger than the 5th‐instar hemolymph lectins. When 20‐hydroxyecdysone was added into the medium, production of the lectin by the hemocytes was remarkably enhanced, depending upon the hormone concentration.
Juvenile hormone binding proteins of termites detected by photoaffinity labeling: Comparison of Zootermopsis nevadensis with two rhinotermitids
Authors: Okot‐Kotber B. Moses , Prestwich Glenn D.
Published: February 2005

The hemolymph of each caste of the primitive dampwood termite Zootermopsis nevadensis (Isoptera, Termopsidae, Termopsinae) contains a high molecular mass lipoprotein which functions as a specific, high affinity carrier for juvenile hormone (JH) III, as detected by JH III‐displaceable covalent modification by the tritium‐labeled photoaffinity analog (10R)‐10, 11‐epoxyfarnesyl diazoacetate ([3H]EFDA). The Formosan termite Coptotermes formosanus (Rhinotermitidae, Coptotermitinae) and Eastern subterranean termite Reticulitermes flavipes (Rhinotermitidae, Rhinotermitinae) possess analogous proteins. Variations among the major proteins and the JH‐binding lipoproteins are described.