bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of light on plant allelochemicals: A synergistic defense in higher plants
Authors: Downum Kelsey R. , Swain Lee A. , Faleiro Lavina J. 
Published: February 2005

AbstractPlant phototoxins are broad‐spectrum biocides which adversely affect an array of potential plant enemies, including among others disease‐causing pathogens, nematodes, insect herbivores, and competing plant species. Thus far, plants which contain these broad‐spectrum allelochemicals have been found to occur in open habitats (i.e., in full sunlight) where a defensive mechanism mediated by light would seem to operate most effectively. The levels of available light in shaded environments, although considerably lower than full sun (1–10% of full sun), are equivalent to the intensities of light used to kill phototoxin‐treated insects in laboratory studies. This suggests that phototoxic reactions might mediate important organismal interactions in shaded environments as well. In this study, more than 230 Costa Rican rainforest plants were bioassayed for phototoxic metabolites in an effort to ascertain their prevalence among plants growing in moderate to extreme shade. Microbial bioassays, employing Bacillus cereus (a gram positive bacterium), Escherichia coli (a gram negative bacterium), and Saccharomyces cerevisiae (a yeast) were used to rapidly and sensitively indicate phototoxic action and potential for insecticidal action. Tissue extracts from 12 plant families tested positive for phototoxins. This is the first report of phototoxins occurring in eight of those families (Acanthaceae, Campanulaceae, Gesnariaceae, Loganiaceae, Malpigaceae, Phytolaccaceae, Piperaceae, and Sapotaceae). The presence of phototoxins in rainforest plants suggests that phototoxic plant allelochemicals may function as important defenses in low‐light, as well as high‐light, environments.
Spotted alfalfa aphid, Therioaphis maculata, fatty acids relative to the condition and susceptibility of its host
Authors: Bergman Douglas K. , Dillwith Jack W. , Berberet Richard C. 
Published: February 2005

AbstractFatty acids of spotted alfalfa aphids, Therioaphis maculata (Buckton), were compared to determine what effects host condition and susceptibility to aphids have on fatty acid metabolism. Myristic acid was the predominant fatty acid in aphids that were feeding on newly infested, green alfalfa tissues. In contrast, linoleic acid was the predominant fatty acid in aphids that were feeding on chlorotic leaves 14 days after the plants were infested. Amounts of myristic acid per mg of aphid, examined 14 days after the plants were infested, were ca. 71% less than that for aphids collected from alfalfa 4 days after the plants were infested. Amounts of linoleic acid per mg of aphid live weight did not change over this period. These changes in spotted alfalfa aphid fatty acids were not due to variations in either fatty acid compositions of aphid life stages or alfalfa fatty acids.Ratios of myristic acid to linoleic acid varied in aphids removed from plants 4 days after infestation compared to aphids with which the plants were originally infested. These ratios increased in aphids feeding on alfalfa plants that were susceptible to spotted alfalfa aphids and decreased in aphids feeding on plants that exhibited resistance characteristics of antibiosis and/or antixenosis.
Physical properties of β‐N‐acetyl‐D‐glucosaminidase and β‐N‐acetyl‐D‐hexosaminidase from Drosophila Kc‐cells
Authors: Sommer Ulrich , Spindler Klaus‐Dieter 
Published: February 2005

AbstractKc‐cells from Drosophila produce two different β‐D‐hexosaminidases, a β‐N‐acetyl‐D‐glucosaminidase (E.C.3.2.1.30) and a β‐N‐acetyl‐D‐hexosaminidase (E.C.3.2.1.52), which are also secreted into the medium. The Mr of both enzymes is about 126,000 ± 9,700; the S‐values are 8.37 ± 0.44. Both enzymes have about the same pH optima at 5.5 and the same thermal stability. The temperature optima are identical (50°C) for both enzymes if p‐nitrophenyl‐N‐acetylglucosaminide is used as a substrate. However, when p‐nitrophenyl‐N‐acetylgalactoseaminide is used as the substrate the β‐N‐acetyl‐D‐hexosaminidase has a temperature optimum about 10°C higher. With higher salt concentrations, the activity of the β‐N‐acetyl‐D‐glucosaminidase increases, whereas β‐N‐acetyl‐D‐hexosaminidase is inhibited. Both enzymes also differ in their sensitivity to urea, the β‐N‐acetyl‐D‐hexosaminidase being less sensitive than the β‐N‐acetyl‐D‐glucosaminidase.
Development of continuous cell lines from the egg parasitoids Trichogramma confusum and T. exiguum
Authors: Lynn Dwight E. , Hung Akey C. F. 
Published: February 2005

AbstractAlthough numerous insect cell lines have been developed over the past three decades, few of these have been from the order Hymenoptera. This report describes two new continuous cell lines from trichogrammid wasps. The extremely small size of these insects has made physiological and biochemical studies difficult. Now, with the development of the cell lines, a limitless supply of biologically active material is available for a wide variety of basic biological studies. The Trichogramma confusum and T. exiguum cell lines (designated IPLB‐Tcon1 and IPLB‐Tex2) were characterized by chromosome and isozymes techniques. Evidence of their utility is shown by morphological response to the developmental hormone, 20‐hydroxyecdysone. The morphological change in IPLB‐Tex2 is accompanied by an induction of highly contractile cells which indicates this cell line may be composed of myoblast cells.
Acidification of yolk granules in Blattella germanica eggs coincident with proteolytic processing of vitellin
Authors: Nordin John H. , Beaudoin Esther L. , Liu Xiaodong 
Published: February 2005

AbstractIn eggs of the cockroach Blattella germanica, vitellin (Vt) utilization by the embryo is initiated at day 4 postovulation by the proteolytic processing of its three subunits to a specific set of peptides. A report from our laboratory (Nordin et al.: Archives of Insect Biochemistry and Physiology 15:119, 1990) described a yolk proteinase, activated at days 3–4, which processes the Vt. Further investigation of this event has focused on the yolk granules. Granules from eggs 4–6 days postovulation contained a significant subpopulation which accumulated high concentrations of the dye acridine orange (AO), a fluorescent probe of vesicle acidification, while those from eggs 0–3 days postovulation did not. AO accumulation was caused by proton translocation and was not due to dye binding or a Donnan equilibrium. The temporal correlation of granule acidification with Vt processing suggests a role for this event in yolk proteinase activation in B. germanica. This hypothesis was supported by the finding that incubation of yolk from freshly ovulated eggs in vitro at pH of 5 and below resulted in Vt processsing. Yolk granules of the blowfly Phormia regina also became acidified but this occurred in the oocyte prior to egg deposition.
Structure‐activity studies on adipokinetic hormones in Manduca sexta
Authors: Ziegler Rolf , Eckart Klaus , Jasensky Ronald D. , Law John H. 
Published: February 2005

AbstractStructure‐activity studies were performed for adipokinetic hormone (AKH) in Manduca sexta. Seven naturally occurring and four synthetic peptides of the red pigment concentrating hormone (RPCH)/AKH family were tested in larvae of M. sexta for activation of glycogen phosphorylase in fat body. pGlu at the N‐terminal was found to be important for activity of peptides; however, Manduca AcGly1 AKH is partially active. The amino acids at all positions appear to be of importance for activity, with the possible exception of the two serine residues in positions six and seven. Generally, the more amino acids are exchanged, the less the peptide will bind to the receptor. In M. sexta a β‐bend appears not to be important for the binding of peptides. Peptides ten amino acids long appear to be more active than shorter ones.
Expression of heat shock proteins in response to high and low temperature extremes in diapausing pharate larvae of the gypsy moth, Lymantria dispar
Authors: Yocum George D. , Joplin Karl H. , Denlinger David L. 
Published: February 2005

AbstractDiapausing pharate first instars of the gypsy moth, Lymantria dispar, respond to high temperature (37–41°C) by suppressing normal protein synthesis and synthesizing a set of seven heat shock proteins with Mrs of 90,000, 75,000, 73,000, 60,000, 42,000, 29,000, and 22,000 as determined by SDS‐PAGE. During recovery at 25°C from heat shock, synthesis of the heat shock proteins gradually decreases over a period of 6 h, while normal protein synthesis is restored. A subset of these same heat shock proteins is also expressed during recovery at 4°C or 25°C from brief exposures to low temperature (‐10 to 20°C), and its expression is more intense with increased severity of cold exposure. During recovery at 4°C after 24 h at −20°C, both 90,000 and 75,000 Mr heat shock proteins are expressed for more than 96 h. While normal protein synthesis is suppressed during heat shock and recovery from heat shock, normal protein synthesis coincides with synthesis of the heat shock proteins during recovery from low temperatures, thus implying that expression of the heat shock proteins is not invariably linked to suppression of normal protein synthesis. Western transfer, using a monoclonal antibody that recognizes the inducible form of the human 70,000 Mr heat shock protein, demonstrates that immunologically related proteins in the gypsy moth are expressed at 4°C and during recovery from cold and heat shock.
Characterization and regulation of HMG‐Coa synthase in Locusta migratoria corpora allata
Authors: Couillaud Franck , Rossignol Françoise 
Published: February 2005

AbstractThe conversion of acetyl‐coenzyme A (CoA) to 3‐hydroxy‐3‐methylglutaryl (HMG)‐CoA was measured by a radioenzymatic assay in locust corpora allata (CA) which produce juvenile hormone (JH‐III). The conversion of acetyl‐CoA to HMG‐CoA was limited to the cytosolic fraction of the CA with an apparent KM = 400 μM. The HMG‐CoA synthase activity measured during the first 15 days of the female adult life did not follow the pattern of JH‐III biosynthesis. No relationship was found between JH‐III release and HMG‐CoA synthase activity when measured sequentially on the same CA pair. HMG‐CoA synthase activity did not reflect the asymmetry in spontaneous rates of JH biosynthesis observed in left and right corpora allata. Decline of JH release after in situ transection of the nervus corporis allati 1 (NCA‐1) was not associated with a decline in HMG‐CoA synthase activity. The results suggest that HMG‐CoA synthase activity does not have a prime influence on the spontaneous rate of JH biosynthesis, and that HMG‐CoA synthase does not appear to be a target for the allatostimulating factors acting on the CA through the NCA‐I.
Differential alaserpin expression during development of the antennae in the tobacco hawkmoth, Manduca sexta
Authors: Hanneman Eric H. , Kanost Michael R. 
Published: February 2005

AbstractThe expression of alaserpin, a serine protease inhibitor, was studied in the developing adult olfactory system of Manduca sexta. Alaserpin mRNA in the antenna was identical to alaserpin from larval fat body, by restriction mapping and partial sequencing of clones isolated from a male pupal stage 6 antennal cDNA library. Northern and primer extension analysis showed that alaserpin transcripts were the same length at all stages and were present at stages 3 and 6, declined at stages 9–15, reappeared at stage 18, and persisted in adults. Western blotting revealed that alaserpin was present at stages 3–12, declined at stage 15, and disappeared at stage 18 and in adults. Immunocytochemistry at stage 6 revealed labeled cells closely associated with neurite bundles and scattered throughout the receptor cell layer. An occasional cell was seen in the antennal lumen. Labeled cells were segmentally distributed along the length of the antenna. The results suggest that alaserpin may have a role in antennal morphogenesis and olfactory neuron axon outgrowth.
Purification and characterization of pyruvate carboxylase from the honeybee and some properties of related biotin‐containing proteins in other insects
Authors: Tu Zhijian , Hagedorn Henry H. 
Published: February 2005

AbstractOur discovery of a Mr 128 k biotin‐containing protein in an extract of the white‐fly was an unexpected outcome of the use of an avidin‐biotin‐peroxidase method to visualize a western blot. This major biotin‐containing protein was shown to be present in several tissues of 10 different species of insects by doing a western blot and staining it with streptavidin‐linked peroxidase. The amount of this protein in the thorax of the mosquito, Aedes aegypti, increased during development. The non‐flying grasshopper, Barytettix psolus, had reduced amounts of this protein in their thoraces compared to a flying grass‐hopper, Schistocerca americana. The major biotin‐containing protein was purified from the thoraces of honeybee, Apis mellifera, using an avidin Sepharose affinity column. The purified biotin‐containing protein was shown to be pyruvate carboxylase, an enzyme that catalyzes the specific transfer of a carboxyl group to pyruvate, yielding oxaloacetate. The purified honeybee pyruvate carboxylase was characterized enzymatically and structurally. This protein had a single subunit of Mr 128 k and formed a native molecule of about Mr 500 k consisting of four of these subunits. The amino acid composition of the protein was also obtained. The enzymatic activity of this protein required acetyl‐CoA, ATP, and Mg2+. The Kms of the enzyme for bicarbonate and pyruvate were similar to pyruvate carboxylase from other oganisms. The biotin‐containing protein was also partially purified from mosquito thoraces using the same methods and was shown to be pyruvate carboxylase. The comparison between insect pyruvate carboxylase and that of other organisms is provided and the possible physiological role of the pyruvate carboxylase in the thoracic muscles of insects is discussed.
The oviduct musculature of the stable fly Stomoxys calcitrans: Properties of its spontaneous motility and neural regulation
Authors: Cook Benjamin J. 
Published: February 2005

AbstractThe muscles of the stable fly oviduct were striated and in the common oviduct both circular and longitudinal fiber layers were present. Although two muscle layers were evident in the lateral oviducts, both consisted of an irregular lattice of longitudinal fibers with extensive branching. This branching between fibers seemed to provide a pathway for the spread of excitation because semi‐isolated preparations of the oviduct severed from their connections to the central nervous system continued to contract in a spontaneous and rhythmic manner. Compression or shortening of the longitudinal muscles of the oviduct was the predominant mode of activity. Both phasic contractions (1–2 s in duration) and tonic events (15–30 s in duration) were observed. Innervation of the oviduct arises from the four major branches of the median abdominal nerve trunk that enter the ovipositor. Five to seven peripheral nerve cells were found along these four branches. Electrical stimulation of the severed median abdominal nerve trunk caused the oviduct to respond to a single pulse. However, these individual responses approached a fusion at 6 pulses per second (pps). Two of five preparations showed an inhibition of spontaneous phasic concentrations and a noticeable drop in baseline tonus during and after a 10–20 s interval of stimulation at a frequency of 0.5–2 pps. Endogeneous electrical activity was recorded from branch nerves in the ovipositor after connections to the central nervous system were cut. Potentials of two distinct durations were evident in this recorded activity. The significance of this and other findings are discussed.
Partial characterization of digestive tract proteinases from western corn rootworm larvae, Diabrotica virgifera
Authors: Gillikin Jeffrey W. , Bevilacqua Steven , Graham John S. 
Published: February 2005

AbstractWe have partially characterized the proteolytic activity within luminal contents of the digestive tracts of larvae of the western corn rootworm, Diabrotic virgifera LeConte. At least 15 proteinases were detected based on chromatographic behavior on ion exchange high‐performance liquid chromatography and their mobility on sodium dodecyl sulfate gels containing gelatin. Inhibitors of proteolytic activity indicated that these enzymes are primarily sulfhydryl proteinases. Native polycrylamide gel electrophoresis revealed that a single proteinaceous inhibitor, egg white cystatin, was capable of abolishing a substantial part of the proteolytic acitivity. Our data suggest, accordingly, that gene transfer experiments utilizing the cystatin gene may generate lines of maize which have increased resistance to western corn rootworm larvae. © 1992 Wiley‐Liss, Inc.
Regulation of ooplasmic sodium and potassium activities in developing locust eggs
Authors: Hawkins Erika , O'Donnell Michael J. 
Published: February 2005

AbstractOoplasmic activities of potassium and sodium were measured with ion sensitive microelectrodes before and during the period of maximal water uptake which occurs 3–5 days after oviposition for eggs incubated at 37°C. Potassium activity increased from 84 mM in eggs before fertilization at 118 mM in eggs 1 day after fertilization (d1). Sodium activity increased from 8 mM to 29 mM over the same period. These changes exceeded those predicted from the decrease in water content (8%) during the first day after oviposition. Between d1 and d3, potassium and sodium activities decreased to values predicted on the basis of the 88% increase in egg water content. Although water content increased an additional 46% between d3 and d5, ooplasmic sodium activity remained constant at 11 mM and potassium activity increased from 64 mM to 74 mM during this time. Declines in concentrations of sodium and potassium measured in whole eggs by atomic absorption spectrometry mirrored the increase in egg water content. The results suggest that regulation of ooplasmic sodium and potassium activities is accomplished by release of these ions from internal stores, possibly the york spheres. © 1992 Wiley‐Liss, Inc.
Stimulation of sex pheromone production by proteinaceous extracts of the bursa copulatrix in the redbanded leafroller moth
Authors: Fabriás Gemma , Jurenka Russell A. , Roelofs Wendell L. 
Published: February 2005

AbstractPheromone biosynthesis in the redbanded leafroller moth, Argyrotaenia velutinana, was stimulated by homogenates of the bursa copulatrix. Although pheromonotropic activity was also extractable from the ovary, the activity of pheromone biosynthesis activating neuropeptide (PBAN) or bursa extracts was not impaired in isolated abdomens by removal of the ovary. Response to the bursa extracts was dependent on the dose administered and the time of incubation. Amounts of pheromone present in adult females of different ages appeared to be correlated with the extractable amount of pheromonotropic activity from their bursa copulatrix. Decapitation did not result in the suppression of burse factor production. Homogenates of the bursa elicited similar effects in both isolated gland and isolated abdomen incubations, but the brain neuropeptide, PBAN, was less active in the former than in the latter. Bursa extracts stimulated pheromone production in isolated abdomen incubations deprived of the bursa copulatrix, but PBAN did not. Loss of activity of bursa homogenates after treatment with either pronase E or carboxypeptidase Y indicated that the pheromonotropic factor is a proteinaceous substance. The mechanism through which pheromone production is regulated in redbanded leafroller moths is discussed. © 1992 Wiley‐Liss, Inc.
Juvenile hormone analog and injection effects on locust hemolymph protein synthesis
Authors: Wyatt Gerard R. , Kanost Michael R. , Chin Beth C. , Cook Kathryn E. , Kawasoe Barbara M. , Zhang Jianzhong 
Published: February 2005

AbstractIn adult female Locusta migratoria, at about day 8 after eclosion, when vitellogenin (Vg) is first produced as a result of induction by juvenile hormone (JH), the intensity of hemolymph protein electrophoretic bands at about 75 kDa and 20 kDa increases sharply, suggesting that JH may induce additional proteins. A major component of the elevated protein is persistent storage protein (PSP; subunit 74 kDa). Administration of the JH analog, methoprene, to precocene‐treated adult locusts was followed by a rise in hemolymph levels of PSP but not in apolipophorin III (19 kDa), identified immunochemically and electrophoretically. The synthesis of PSP in adult fat body was confirmed by incorporation of [3H]leucine. At 48 h after treatment with methoprene, Vg synthesis was induced in females (as previously observed) and synthesis of PSP in both sexes was elevated above controls, while synthesis of apolipophorin III was not stimulated. We conclude that in adult locust fat body the synthesis of several proteins responds in different ways to the JH analog: Vg (and a 21 kDa protein described elsewhere) is induced de novo solely in females; PSP (and a 19 kDa protein described elsewhere) is stimulated in both sexes but is not fully JH‐dependent; apolipophorin III is not stimulated. In these experiments, methoprene was administered both by injection in mineral oil and topically in acetone. After injection of mineral oil as a vector control, incorporation into secreted proteins was stimulated at 24 h, presumably due to a wound effect; topical application of acetone avoids this effect and is a preferred route for administration of JH analog. © 1992 Wiley‐Liss, Inc.
Effects of diet and temperature on Morimus funereus larval hemolymph cation concentrations
Authors: Janović‐Hladni Miroslava , Chen Andrew C. , Ivanović Jelisaveta , Djordjević Suzana , Stanić Vlasta , Perić Vesna , Frusić Marina 
Published: February 2005

AbstractThe effects of diet and different constant temperatures on hemolymph cation concentrations (Na+, K+, Mg2+, Ca2+) have been studied in Morimus funereus larvae collected from natural habitat, fed natural (oak or beech bark) or artificial diet, as well as in larvae reared from hatching on an artificial diet. In the hemolymph of larvae maintained under natural conditions Mg2+ was dominant, whereas Na+ concentration was very low. In their natural diets concentrations of Na+ and K+ were very low, while those of Ca2+ and Mg2+ were high. In larvae continuously reared on an artificial diet, hemolymph Mg2+ concentration was significantly decreased and Na+ concentration increased more than fourfold compared to the results obtained in oak‐fed larvae. Na+ and K+ are the dominant cations in the artificial diet. The concentrations of K+ and Ca2+ in the hemolymph of larvae fed natural or artificial diet are nearly identical, suggesting the existence of an internal regulatory mechanism in this insect for these cations. The hemolymph cation concentrations of M. funereus larvae are predominantly dependent upon the diet consumed, much less upon the environmental temperatures. The most stable concentrations of cations were observed in larvae continuously fed an artificial diet and exposed to different constant temperatures. There was much less stability in the hemolymph cation concentration in oak larvae fed either natural or artificial food after their transfer to constant temperatures. With respect to the response to the external factors studied, the most sensitive are the Na+ concentrations, the most stable seems to be K+. © 1992 Wiley‐Liss, Inc.