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  • Lepidoptera
  • Yeast
  • Springer  (132)
  • Wiley-Blackwell  (6)
  • American Institute of Physics
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  • 2005-2009
  • 1990-1994  (138)
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  • 1990  (138)
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  • Springer  (132)
  • Wiley-Blackwell  (6)
  • American Institute of Physics
  • Annual Reviews
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  • 2005-2009
  • 1990-1994  (138)
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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 77-83 
    ISSN: 1570-7458
    Schlagwort(e): Age ; pteridine ; Pectinophora ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé En chromatographie liqudde à haute performance (HPLC) à détection par fluorescence, 4 composés ptéridiniques: la xanthoptérine, l'isoxanthoptérine, la 6-bioptérine et la ptérine ont été décelés dans les têtes de P. scutigera Holdaway (Lep. Gelechiidae) adultes. Un autre composé, dénommé ‘xanthoptérine modifiée’, a été décelé aussi dans les têtes de papillons; de même l'isoxanthoptérine a été décelée dans les thorax et abdomens. Les concentrations de ces ptérines ont été dosées dans les têtes des papillons de 2 à 50 jours au laboratoire à 25°C. Les concentrations d'isoxatthoptérine ont été dosées dans les thorax et les abdomens de 2 à 40 jours. La xanthoptérine de la ‘xanthoptérine modifiée’ diminuent nettement avec l'âge, tandis que la ptérine diminue plus lentement et que la 6-bioptérine se maintient pratiquement sans changements. L'isoxanthoptérine diminue dans les têtes de mâles de 38,3 ng/tête à 2 j à 22,7 ng/tête à 50 j, mais chez les femelles les concentrations augmentent nettement de 41,2 ng/tête à 2 j à 150,4 ng/tête à 50 j. Des modifications de même type ont été observées dans les thorax et les abdomens des mâles et des femelles. Les modifications de concentration de la ‘xanthoptérine modifiée’ des têtes de papillons peuvent être utilisées pour évaluer l'âge physiologique de mâles et des femelles de P. scutigera. La confiance dans ces estimations peut être améliorée en se référant aux concentrations d'isoxanthoptérine dans les thorax des mâles et au rapport isoxanthoptérine/‘xanthoptérine modifiée’ dans les têtes de femelles.
    Notizen: Abstract The amounts of four pteridine compounds, xanthopterin, isoxanthopterin, 6-biopterin and pterin and a further unidentified substance, termed ‘modified xanthopterin’, were determined in the heads of adult Pectinophora scutigera (Holdaway) (Lepidoptera: Gelechiidae), aged between 2 and 50 days and reared in the laboratory at 25°C. The level of isoxanthopterin was also determined in the thoraces and abdomens of moths aged between 2 and 40 days. The levels of xanthopterin, and ‘modified xanthopterin’ decreased markedly in the heads of males and females with increasing moth age, while those of pterin decreased more slowly and 6-biopterin remained largely unchanged. Isoxanthopterin decreased in male heads from 38.3 ng/head at 2 days to 22.7 ng/head at 50 days, but in females levels increased from 41.2 ng/head at 2 days to 150.4 ng/head at 50 days. Similar changes in the amounts of isoxanthopterin with increasing moth age were observed in male and female thoraces and abdomens. The results are discussed in relation to using pteridine compounds for estimating the physiological age of P. scutigera.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1572-8889
    Schlagwort(e): cotton bollworm ; Heliothis armigera ; Lepidoptera ; Noctuidae ; sex pheromone ; flight tunnel ; male behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Six compounds were identified from gland extracts of the cotton bollworm, Heliothis armigera(Hubner): (Z)-11-hexadecenal (Z11-16:Ald), (Z)-9-hexa-decenal (Z9-16:Ald), hexadecanal, (Z)-11-hexadecenol (Z11-16:OH), (Z)-7-hexadecenal (Z7-16:Ald), and (Z)-9-tetradecenal (Z9-14:Ald). Each of the compounds that were identified was examined for its ability to elicit sexual responses from male moths in a flight tunnel. Males flew upwind to Z11-16:Ald alone, but greater levels of copulatory responses were evoked with the addition of 2.5% Z9-16:Ald to the Z11-16:Ald. Addition of hexadecanal to the binary mixture had no effect in raising the behavioral response of the males in the flight tunnel. The effect of Z7-16:Ald on male flight depended on the loading. The addition of 1% of this component to 2 mg of the binary mixture reduced levels of copulatory response, but the same addition (1 %) to 10 μg of the binary mixture increased copulatory response. The addition of 79-14:Ald or Z11-16:OH to the binary mixture reduced behavioral responses of males. High loadings of the binary mixture (200–2000 μg) were better than a low loading (10 μg) in eliciting response of males.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 54 (1990), S. 173-180 
    ISSN: 1570-7458
    Schlagwort(e): Encapsulation ; evolutionary relationships ; host suitability ; parasitization ; parasitoid complexes ; Diadegma armillata ; Hymenoptera ; Ichneumonidae ; Lepidoptera ; Yponomeutidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'étude a porté sur la valeur de 8 représentants européens du genre Yponomeuta (Lep., Yponomeutidae) comme hôtes pour Diadegma armillata (Hym., Ichneumonidae). La présence, l'état du parasitoïde, le nombre de chenilles contenant un hyménoptère et la mortalité des chenilles on été examinés par dissection et par élevage des chenilles attaquées en conditions contrôlées. Pour examiner si la mortalité des chenilles saines et parasitées diffèrent, des chenilles non contaminées par l'ichneumonide ont été utilisées comme témoins. De plus, des chenilles provenant de différentes parties des Pays-Bas et d'Allemagne ont été disséquées pour connaître leur taux de parasitisme par D. armillata. La valeur des diverses espèces diffère considérablement. Les dissections montrent que cela provient de différentes aptitudes à l'encapsulation des œufs du parasite. La comparaison des taux observés par la dissection des chenilles des différentes parties des Pays-Bas et d'Allemagne montre une surprenante uniformité pour les populations d'origines géographiques différentes. Les observations sur l'encapsulation par les différentes espèces d'yponomeutes correspondent assez bien aux différences observées parmi les divers complexes parasitaires dans lesquels D. armillata intervient. Certains éléments montrent cependant que le taux d'attaques victorieuses (sans tenir compte d'une éventuelle encapsulation ultérieure) contribue aussi aux différences observées entre les complexes parasitaires. Le classement des espèces d'yponomeutes en 3 catégories, d'après leur valeur comme hôte, montre un remarquable parallélisme avec les relations phylogéniques mises en évidence par analyse des allozymes: les espèces présentant une forte proportion d'encapsulation sont celles qui ont divergé précocement au cours de l'évolution du genre, tandis que les espèces ayant divergé le plus récemment présentent un pourcentage intermédiaire ou sont incapables d'encapsuler les œufs de D. armillata.
    Notizen: Abstract The suitability as a host of Diadegma armillata (Gravenhorst) (Hymenoptera, Ichneumonidae) was determined for eight West-European representatives of the genus Yponomeuta Latreille (Lepidoptera, Yponomeutidae) by dissecting and rearing parasitized larvae under controlled conditions. The suitability of the various species differed considerably, and dissection showed that this was mainly due to the ability of the host species to encapsulate the parasitoid eggs. Encapsulation by Yponomeuta-species corresponded fairly well to the differences between the parasitoid complexes concerning D. armillata. Classifying the Yponomeuta-species into three categories according to their suitability, showed a remarkable parallelism with the phylogenetic relationships as determined by allozyme comparison: species showing high encapsulation rates are those that have diverged early in the evolution of the genus, whereas the more recently evolved species showed an intermediate percentage or were not able to encapsulate eggs of D. armillata.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 56 (1990), S. 23-30 
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Noctuidae ; Mamestra brassicae ; sex pheromone ; calling behaviour ; calling posture ; diel periodicity of calling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé La périodicité quotidienne de l'appel et les effets de l'âge et de la photopériode ont été examinés sur des femelles vierges deMamestra brassicae (Lépido., Noctuidae). Aucun appel n'a été observé pendant la première scotophase; la plupart des femelles appelaient pour la première fois pendant les 2e et 3e scotophases après l'émergence, quelle que fût la photopériode. Les papillons conservés à 16 J/8 N ont commencé à appeler beaucoup plus tard que ceux dont la photopériode était 18 J/6 N. En vieillissant, les papillons appelaient significativement de plus en plus tôt. Avec 16 J/8 N, la moyenne du moment du début de l'appel a diminué de la scotophase 2 à la scotophase 3, après laquelle il s'est stabilisé autour de 260 min après le début de la scotophase. Avec 18 J/6 N, le moment du début de l'appel a diminué jusqu'à la scotophase 4, et s'est stabilisé ensuite autour de 130 min après le début de l'obscurité.
    Notizen: Abstract Die periodicity of calling and the effect of age and photoperiod on calling behaviour were studied in virgin females of the cabbage moth,mamestra brassicae L. (Lepidoptera: Noctuidae). No calling activity was observed during the first scotophase. Most females called for the first time during the 2nd or 3rd scotophase after emergence, regardless of the photoperiod. Moths maintained under 16L: 8D started calling significantly later in the scotophase than those maintained under 18L: 6D. With increasing age, moths initiated calling significantly earlier. Under the 16L: 8D photoregime, the mean onset calling time decreased from scotophases 2 to 3, after which it stabilized around ca. 260 min after the start of the scotophase. With 18L: 6D, the onset of calling decreased until scotophase 4, and subsequently stabilized around ca. 130 min after lights off.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Journal of industrial microbiology and biotechnology 6 (1990), S. 157-164 
    ISSN: 1476-5535
    Schlagwort(e): Lignocellulosic waste ; Yeast ; Ethanol production ; Optimization study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Summary Hardwood hemicellulose hydrolysate has been utilized as a substrate for ethanol production. Among the three different yeasts tested, the best performances have been obtained, in decreasing order, usingPachysolen tannophilus, Candida shehatae andPichia stipitis. Several pretreatments of this raw material have been studied to improve ethanol yields; in one such pretreatment a strain ofP. tannophilus produced ethanol with a yield of 0.29 gethanol/gsugars (gP/gS); which is only 15% less than the values observed with synthetic media. Neither aeration nor acetone addition improved the fermentation of this substrate; in fact, only a marked stimulation of biomass growth has been observed at the expense of both ethanol and xylitol production.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 269-273 
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Actin ; Intron ; Antisense RNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Using Northern blot analysis we have detected an approximately 840 nucleotide-long RNA which is complementary to the 5′ leader sequence and the first ten nucleotides of the coding sequence of the yeast actin (ACT1) messenger RNA. We have determined two transcription start sites for this actin antisense RNA (ASR1), both within the ACT1 intron, at about 80 and 90 nucleotides downstream from the 5′ splice site. Analysis of a cDNA clone showed that this RNA species overlaps the entire trailer sequence and approximately 20 nucleotides of the coding sequence of the nearby yeast YPT1 gene.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Mutants ; Cytochrome ; Mitochondria ; Oxidative phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary This paper reports studies of bioenergetic modifications in a TTR1 single-nuclear mutant, isolated as resistant to triethyltin, an inhibitor of mitochondrial ATPase, and effective in cAMP-dependent protein phosphorylation. This mutant appears to have lost the wildtype cell ability to respond to a decrease of oxygen concentration in the growth medium by a decrease of cytochrome concentration in the cell. ATP synthesis rate in mutant cells in both the prestationary and stationary phase of growth appeared increased in comparison to wild-type cells, as too was respiration rate. A comparative study of mitochondria extracted from wild-type and from TTR1 mutant cells showed an increase in respiration rate, an increase in ATP synthesis rate, and an increase in TPP+ uptake in mutant mitochondria. The specific ATPase activity, as well as its sensitivity to TET, appears to be similar for mitochondria extracted from both strains. It was proposed that the modification of mitochondrial biogenesis in the TTR1 mutant may be due to a response of the cell to an increase in ATP hydrolysis caused by the mutation. It is also possible that the modification in cAMP-dependent protein kinase regulation which appeared to occur in this mutant affects protein(s) involved in mitochondrial biogenesis.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Chromosome mapping ; Acidic ribosomal proteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary DNA probes from the genes encoding the acidic ribosomal proteins L44, L44′ and L45, as well as from reporter genes for chromosomes IV, VII, XII and XV, have been hybridised to Southern blots of Saccharomyces cerevisiae DNA resolved by pulsed field gel electrophoresis. The protein L44′ and protein L45 genes have been found to hybridise to chromosome IV, identified by the CAT1 gene probe, while the protein L44 probe hybridises with a band containing chromosomes VII and XV, identified by the ATPase 1 and HIS3 genes respectively.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Ribosomal protein gene ; Sequence analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Two genes encoding ribosomal protein YL41 were cloned from Saccharomyces cerevisiae chromosomal DNA. Both genes contain an uniterrupted region of only 75 nucleotides coding for a protein of 3.3 kD. Within the coding regions the nucleotide sequences are virtually identical, whereas in both the 5′-and 3′-flanking regions the two genes differ significantly from each other. The deduced protein shows an arginine and lysine content of 68 percent, i.e., 17 out of 25 residues, and the basic residues are evenly distributed over the molecule. When compared to the ribosomal protein sequences currently available no counterpart to YL41 could be found in prokaryotes and it seems likely that YL41 is a eukaryotespecific ribosomal protein.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Trans-acting Factor ; RAP1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We show by deletion mutagenesis, followed by in vivo and in vitro analysis, that the binding of a protein factor to the upstream activation sequence (USA) of the Saccharomyces cerevisiae glycolytic gene PYK, encoding pyruvate kinase, is required for efficient transcription of the corresponding coding region. In addition, gel electrophoretic mobility shift and DNase I protection studies, involving yeast gene products expressed in E. coli, suggest that this trans-acting DNA-binding protein is encoding by the RAP1 gene. The identification of RAP1 binding sites located within the UAS element of the yeast PYK, PGK (phosphoglycerate kinase) and ENO1 (enolase) genes, and in the 5′-upstream region of the ADHI (alcohol dehydrogenase) gene, suggests that a mechanism of coordinate gene expression involving several of the glycolytic genes may exist in yeast.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 18 (1990), S. 485-491 
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Ty elements ; Virus like particles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Electron microscopic analysis of thin sections of Saccharomyces cerevisiae NCYC74 has revealed the presence of many clumped cytoplasmic particles that morphologically resemble Ty element virus-like particles (VLPs). Accumulation of Ty VLPs has only previously been observed in S. cerevisiae strains that over-express a cloned Ty element. The particles in NCYC74 co-purify with Ty RNA, Ty-specific antigens and a reverse transcriptase activity. Furthermore, they appear to be recognised by antibodies to Ty VLPs during indirect immunofluorescence experiments. These observations provide compelling evidence that the cytoplasmic particle in NCYC74 are indeed Ty VLPs.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 18 (1990), S. 29-39 
    ISSN: 1432-0983
    Schlagwort(e): Recombination ; DNA repair ; UV irradiation ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A novel synthetic locus is described that provides a simple assay system for characterizing mitotic recombinants. The locus consists of the TRP1 and HIS3 genes inserted into chromosome III of S. cerevisiae between the CRY1 and MAT loci. Defined trp1 and his3 alleles have been generated that allow the selection of interchromosomal recombinants in this interval. Trp+ or His+ recombinants can be divided into several classes based on coupling of the other alleles in the interval. The tight linkage of the CRY1 and MAT loci, combined with the drug resistance and cell type phenotypes that they respectively control, facilitates the classification of the recombinants without resorting to tetrad dissection. We present the distribution of spontaneous recombinants among the classes defined by this analysis. The data suggest that the recombination intermediate can have regions of symmetric strand exchange and that co-conversion tracts can extend over 1–3 kb. Continuous conversion tracts are favored over discontinuous tracts. The distribution among the classes defined by this analysis is altered in recombinants induced by UV irradiation.
    Materialart: Digitale Medien
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  • 13
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Mitochondrial RNA splicing ; Nuclear pet - mutant ; Group I introns
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We have studied the role of the product of the nuclear gene PET157 in mitochondrial pre-mRNA splicing. Cytoduction experiments show that a mitochondrial genome deleted for the three introns bI3, aI5 and aI6 is able to suppress the pet157-1 mutation: the strain recovers respiratory competency indicating that the product of the PET157 gene is only required for mitochondrial premRNA splicing. Characterization of the high molecular weight pre-mRNAs which accumulate in the pet157 mutant demonstrate that the product of the PET157 gene is required for the excision of two group I introns bI3 and aI6 (corresponding to aI5β) located in the cob-box and coxI genes respectively. Furthermore, the pet157 mutant strain accumulates the bI3 maturase in the form of a polypeptide of 50K (p50) previously observed in mitochondrial mutants defective in the excision of bI3. We have shown by restriction analysis and allelism tests that the pet157-1 mutation is allelic to the nuclear mrs1 mutation, previously described as specifically blocking the excision of bI3. Finally, revertants obtained by the deletion of bI3 or aI6 from the mitochondrial DNA were isolated from the MRS1 disrupted allele, confirming the involvment of the product of the MRS1/PET157 gene in the excision of the two introns bI3 and aI6.
    Materialart: Digitale Medien
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  • 14
    ISSN: 1432-0983
    Schlagwort(e): S. cerevisiae ; Yeast ; Cadmium resistance ; CAD2 gene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A cadmium-resistant strain, X3382-3A, which is able to grow in a medium containing 0.2 mM cadmium sulfate, was picked out from our laboratory stock strains of Saccharomyces cerevisiae. The cadmium resistance of this strain is controlled by a single dominant nuclear gene, denoted as CAD2. The locus of CAD2 was mapped by gene linkage to a site 15.5 centimorgans to the right of the his7 locus on the right arm of chromosome II. The cadmium resistance of the strain carrying CAD2 was evaluated for its properties of cadmium uptake, cadmium distribution and cadmium-metallothionein formation, in comparison with those of some other strains. The results suggest that the novel type of cadmium resistance controlled by CAD2 does not involve production of a cadmiumm-metallothionein.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 179-183 
    ISSN: 1432-0983
    Schlagwort(e): Heme ; Cytochromes ; Regulation ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Simultaneous effects of mutations in the transcriptional regulatory genes, HAP1, HAP2 and HAP3, on all respiratory cytochromes of Saccharomyces cerevisiae were determined. Cytochrome behavior in hap mutants and in cyc4 and rhm1 mutants, altered in regulation of 5-aminolevulinate synthase, was compared. Although hap mutants were isolated as trans-acting, transcriptional regulators of the CYC1 (iso-1-cytochrome c) gene, each mutant exhibits partial deficiencies in all cytochrome types. In hap2 and hap3 strains all cytochromes were decreased proportionally to about 40–50% of wild type values. In contrast, hap1 caused a decrease in all cytochromes and an accumulation of a pigment, probably Zn porphyrin. Apparently apocytochrome and heme biosynthesis retain coordination in hap2 and hap3, but not in hap1, mutants. Unlike cyc4 and rhm1 mutants, hap mutants do not exhibit 5-aminolevulinate-dependent restoration of cytochromes. The hap1 mutant grew at nearnormal rates on glycerol, whereas hap2 and hap3 mutants grew very slowly. The frequency of [rho-] was high (16–18%) in hap2 and hap3 strains. Results are consistent with generalized control of mitochondrial replication directed by the HAP1-HAP2 system and heme-directed control of formation of all apocytochromes mediated by HAP1. Neither system exerts all-or-nothing control.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 275-280 
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; DNA replication ; Effect on mutation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Incubation in YPD medium under permissive conditions when DNA replication is going on, strongly stimulates the induction of cdc+ colonies of UV-irradiated cells of yeast strains HB23 (cdc8-1/cdc8-3), HB26 (cdc8-3/cdc8-3) and HB7 (cdc8-1/cdc8-1). Inhibition of DNA replication by hydroxyurea, araCMP, cycloheximide or caffeine or else by incubation in phosphate buffer pH 7.0, abolishes this stimulation. Thus the replication of DNA is strongly correlated with the high induction of cdc+ colonies by UV irradiation. It is postulated that these UV-induced cdc+ colonies arise as the result infidelity in DNA replication.
    Materialart: Digitale Medien
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  • 17
    ISSN: 1432-0983
    Schlagwort(e): Yarrowia lipolytica ; 7SL RNA ; Essential genes ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Cells containing a deletion of either the SCR1 or SCR2 genes, which code for the 7SL RNA component of the signal recognition particle (SRP) homologue, were found to be viable. Two independent approaches demonstrated that cells containing deletions of both genes were inviale. Therefore, Yarrowia lipolytica contains two (and only two) functional 7SL RNA genes.
    Materialart: Digitale Medien
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  • 18
    ISSN: 1432-0983
    Schlagwort(e): Mitotic recombination ; Hyper-recombination ; RAD50 ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Mutations in the RAD50 gene of Saccharomyces cerevisiae have been shown to reduce double strand break repair, meiotic recombination, and radiation-inducible mitotic recombination. Several different point mutations (including ochre and amber alleles) have been previously examined for effects on spontaneous mitotic recombination and did not reduce the frequency of recombination. Instead, the rad50 mutations conferred a moderate hyper-rec phenotype. This paper examines a deletion/interruption allele of RAD50 that removes 998 of 1312 amino acids and adds 1.1 kb of foreign DNA. The results clearly indicate that spontaneous mitotic recombination can occur in the absence of RAD50; in fact, the frequency of recombination is elevated over the wild-type cell. One possible interpretation of these observations is that the initiating lesion in spontaneous recombination events in mitosis might not be a double strand break.
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  • 19
    ISSN: 1432-0983
    Schlagwort(e): Flow cytometry ; Rhodamine 123 ; Respiratory chain ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The cationic lipophilic dye Rhodamine 123 (Rh123) is selectively enriched in mitochondria in a membrane potential-dependent manner. Application of drugs which interfere with the electron flow of the respiratory chain lead to a severe reduction of mitochondrial dye uptake. In this communication we show that the same effect is observed after Rh123-staining of respiratory-deficient yeast mutants. Based on this observation we used flow cytometry to discriminate respiratory-compentent and respiratory-deficient yeast cells. Combined with a cell sorter we were able to selectively enrich respiring and non-respiring yeast cells, repectively, from a mixture of cells.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 459-464 
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; QH2: cytochrome c oxidoreductase ; Mitochondrial biogenesis ; Transcription
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In Saccharmmyces cerevisiae, the COR2 gene codes for the 40 kDa subunit II of the QH2: cytochrome c oxidoreductase, an enzyme of the mitochondrial respiratory chain. Regions in the 5′ flank of this gene important for regulated expression were identified by assaying β-galactosidase activities in cells carrying different COR2-lacZ fusion genes. Sequences downstream of position-201 relative to the translational initiation codon are sufficient to confer regulation by carbon source, whereas sequences downstream of position-153 do not give rise to significant expression. A binding site for the abundant general transcription factor GFI is present in the region between-201 and-153 just upstream from sequences which resemble the consensus DNA recognition sequence of the regulatory protein complex HAP2/HAP3: 5′-TNATTGGT-3′. By quantitating RNA levels and assaying β-galactosidase activities we show that synthesis of COR2, which is not a hemoprotein, is regulated by HAP1, HAP2/HAP3 and heme.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 465-472 
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Mutant ; Triethyltin chloride ; Protein phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Three mutants of Saccharomyces cerevisiae resistant to triethyltin (an inhibitor of mitochondrial ATPase) on non-fermentative media, and non-resistant to this drug on fermentative media, were isolated and named TTR1, TTR2 and TTR3. Apart from triethyltin resistance, these mutants show the following common characteristics: (1) Increased intracellular cytochrome c concentration. (2) Increased respiration rate. (3) Decreased growth yield. (4) Increased growth sensitivity to several drugs inhibiting oxidative phosphorylation: namely, CCCP (permeabilizing inner mitochondrial membrane to protons), valinomycin (permeabilizing inner mitochondrial membrane to potassium) and oligomycin (inhibitor of mitochondrial ATPase). (5) Increased sensitivity to carbon source starvation. For each mutant, these characteristics appeared to be due to a single pleiotropic nuclear mutation. Mutation TTR1 causes additional phenotypic characteristics which do not appear in mutants TTR2 and TTR3: (1) Pinkish coloration of colonies which is more pronounced after a long growth period. (2) Inability of the cells to store glycogen. (3) Growth defect of the cells on a galactose-containing medium. (4) Inability of a diploid homozygote mutant strain to sporulate. All these phenotypic characteristics have already been described in yeast mutants deregulated in cAMP-dependant protein phosphorylation. Crossing of a strain bearing the TTR1 mutation with a strain mutated in the adenylate cyclase structural gene suggested that the TTR1 phenotype is due to a modification in regulation of cAPK by cAMP, making cell multiplication possible without intracellular cAMP.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 493-497 
    ISSN: 1432-0983
    Schlagwort(e): Mitochondria ; Yeast ; Petites
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A pleiotropic, respiration-deficient mutant was isolated from the petite negative yeast Pachysolen tannophilus after UV mutagenesis. The mutant is unable to utilize xylose, arabinose, galactose or glycerol, and shows no detectable respiration when grown on glucose. Cytochrome c oxidase, xylose reductase and xylitol dehydrogenase activities are lacking. Mitochondrial ultrastructre is altered. The results support the hypothesis that functioning mitochondria are necessary for xylose utilization in this organism.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Ty2 ; Protein/DNA binding ; Transcription
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A series of transposable element-induced mutations at the HIS4 locus in Saccharomyces cerevisiae have been attributed to the transposition of a Ty element into the 5′ regulatory region of this gene. Various Ty-containing His+ revertants have been isolated and the HIS4/Ty junction region sequenced. The only difference found in this region between a His- and a weak His+ strain was a single point mutation, an A→G transition. The position of Ty remained unaltered. Examination of lacZ fusion plasmids further implicated this A→G transition as being reponsible for the altered phenotype, the bp transition representing an allele of a cis-acting regulatory element. Subsequent gel retardation and methylation interference experiments revealed that this A→G mutation enabled the binding of a trans-acting factor (TyBf) in vitro. In this paper we show that the TyBf binding site is in a region of chromatin hypersensitive to digestion by DNase I. The binding site is protected in vivo from digestion with exonuclease III, suggesting the presence of a bound protein in His+ (“on”) but not His- (“off”) Ty-containing strains. We propose that a trans-acting factor binding in vivo, presumably TyBf, is responsible for the activation of HIS4 expression in these insertion mutants.
    Materialart: Digitale Medien
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  • 24
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Mitochondria ; Cytochrome c oxidase ; Post-translational regulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Biogenesis of functional cytochrome c oxidase in yeast requires the product of the nuclear gene SCO1. Strains deleted for this gene fail to accumulate the mitochondrially-synthesized cytochrome c oxidase subunits I and II, despite the presence of the respective mRNAs. Here we present data which demonstrate that the observed phenotype does not result from a failure to translate the mRNAs, but from a preferential degradation of the newly synthesized subunits. The SCO1 protein is therefore involved in a post-translational step in the accumulation of cytochrome c oxidase subunits I and II. We propose that the SCO1 protein is required for the correct assembly of both subunits into the cytochrome c oxidase complex.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    ISSN: 1423-0445
    Schlagwort(e): chemical defence ; comparative sequestration ; feeding guilds ; insect herbivory ; natural enemies ; cardenolides ; Lepidoptera ; Danainae ; Danaus plexippus (L.) ; Homoptera ; Aphidae ; Aphis nerii B. de F. ; Asclepiadaceae ; Asclepias curassavica L
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Cardenolide sequestration by a hemimetabolous aphid and a holometabolous butterfly from the neotropical milkweed,Asclepias curassavica L., is compared. The oleander aphid,Aphis nerii B. de F., sequestered a similarly narrow range of cardenolide concentrations to the monarch butterfly,Danaus plexippus (L.), from the wide range of concentrations available in leaves of A.curassavica. However, A.nerii sequestered significantly less cardenolide (269 µg/0.1 g) thanD. plexippus (528 µg/0.1 g). The honeydew excreted by A.nerii was comprised of 46% cardenolide. The complete polarity range of 25 cardenolides detected by thin layer chromatography in A.curassavica was represented in the 17 whole aphid cardenolides and the 20 aphid honeydew cardenolides detected. D.plexippus sequestered a narrower polarity range of 11 cardenolides, having eliminated low polarity cardenolide genins and glycosides. It is suggested that these chemical differences may be related to interactions among the broad feeding tactics of sucking or chewing milkweed leaves, life history constraints of holometabolyversus hemimetaboly, the distribution of milkweed food resources in space and time, and the dynamics of natural enemies.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    ISSN: 1423-0445
    Schlagwort(e): variation of secondary substances ; pharmacophagy ; pyrrolizidine alkaloids ; Lepidoptera ; Ithomiinae ; Aeria olena ; Tithorea harmonia ; Mechanitis polymnia ; Apocynaceae-Echitoideae ; Solanaceae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The primitive, Apocynaceae-feeding Ithomiine,Tithorea harmonia, incorporates dehydropyrrolizidine alkaloids (PAs) from its larval foodplant (Prestonia acutifolia), rarely visiting PA sources pharmacophagously in the adult; females show higher concentrations of PAs than males, with similar variance. The close relativeAeria olena (feeding onP. coalita, without PAs) shows similar PA concentrations in both sexes and greater variation in males, like more advanced Solanaceae-feeding Ithomiine such asMechanitis polymnia, which likeA. olena obtain PAs by pharmacophagy in the adult (mainly males). This difference is due to the dynamics of PA incorporation in these species. Little variation in PA content was found among allopatric populations of the same species, but variation in available PA sources in different months was correlated with different average storage levels in the butterflies.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    ISSN: 1423-0445
    Schlagwort(e): chemical defense ; mimicry ; evolutionary strategies ; hostplants ; cyanogenesis ; linamarin ; pyrrolizidine alkaloids ; Lepidoptera ; Acraeinae ; Asteraceae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary American Acraeinae butterflies often ingest large amounts of dehydropyrrolizidine alkaloids (PAs) from their Asteraceae hostplants in both larval and adult stages, but do not normally store these compounds for defence, instead biosynthesizing large amounts of the cyanogenic glucoside linamarin in all stages. This defence syndrome (rejection of plant toxins andde novo synthesis of protective chemicals) is considered to be the most evolved among aposematic (unpalatable mimicry-model) butterflies, as are the Acraeinae and Heliconiini which also synthesize cyanogens. Storage or minimal processing of larval hostplant-derived defensive chemicals is widespread and characterizes the most primitive model groups; an intermediate series (Danainae/Ithomiinae) also obtains the principal defensive chemicals (PAs) from plants, but mostly in the adult stage. These syndromes are discussed and contrasted with the pattern seen in Chrysomelidae beetles, wherede novo synthesis is widespread and considered primitive.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Chemoecology 1 (1990), S. 81-85 
    ISSN: 1423-0445
    Schlagwort(e): phototoxicity ; harmane ; harmine ; harmalol ; alpha-terthienyl ; skimmianine ; Lepidoptera ; Oecophoridae ; Depressaria pastinacella ; parsnip webworm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The parsnip webworm,Depressaria pastinacella (Lepidoptera: Oecophoridae), feeds exclusively on apiaceous hostplants containing furanocoumarins, compounds capable of oxygen-dependent and oxygen-independend photosensitization. Despite high titers of antioxidant enzymes relative to other herbivorous insects, webworms cannot tolerate nonhost photosensitizers such as alpha-terthienyl or beta-carboline alkaloids at dietary concentrations of 0.01% or less. Tolerance of skimmianine, a furano-quinoline alkaloid, may be due to its structural resemblance to furanocoumarins, which are metabolized by cytochrome P450 monooxygenases in this species.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Chemoecology 1 (1990), S. 69-76 
    ISSN: 1423-0445
    Schlagwort(e): green leaf volatile ; semiochemical ; synomone ; volatile attractant ; tritrophic ; host location ; parasitoid behavior ; Hymenoptera ; Braconidae ; Microplitis ; Ichneumonidae ; Netelia ; Lepidoptera ; Noctuidae ; Heliothis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    ISSN: 1423-0445
    Schlagwort(e): taste aversion ; toxicology ; chemical defense ; cardiac glycoside ; cardenolides ; digitoxin ; pyrrolizidine alkaloids ; monocrotaline ; Mammalia ; Muridae ; Peromyscus ; Reithrodontomys ; Lepidoptera ; Danainae ; Danaus plexippus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Of three common mouse species at the Mexican overwintering sites of the monarch butterfly, onlyPeromyscus melanotis eats monarchs. We hypothesized thatP. aztecus andReithrodontomys sumichrasti reject monarchs because they are more sensitive to the bitter taste and/or toxic effects of the cardiac glycosides (CGs) and pyrrolizidine alkaloids (PAs) in the butterflies. Two-choice preference tests revealed no difference in taste avoidance thresholds to free base and N-oxide forms of the PA, monocrotaline, but very different avoidance thresholds to the CG, digitoxin. Avoidance thresholds forR. sumichrasti andP. aztecus were, in respective order, 1020 and 34 times less than that forP. melanotis. We also tested the toxic sensitivity of juvenile mice by chronically feeding diets containing digitoxin or monocrotaline at concentrations similar to those used in the preference tests. No species developed CG toxicity, but bothP. melanotis andP. aztecus developed moderate PA toxicity (R. sumichrasti was not tested for PA toxicity).P. aztecus grew more slowly and manyP. melanotis had hepatic metabolic lesions. Thus, the three mouse species responded very differently to the taste and toxic properties of CGs and PAs at ecologically relevant concentrations: 1) CGs were taste rejected by all species exceptP. melanotis, while PAs were not; and 2) PAs were toxic, while CGs were not.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Chemoecology 1 (1990), S. 124-130 
    ISSN: 1423-0445
    Schlagwort(e): taste aversion ; chemical defense ; predatory attack patterns ; insectivory ; cardiac glycosides ; cardenolides ; Mammalia ; Muridae ; Peromyscus ; Reithrodontomys ; Lepidoptera ; Danainae ; Danaus plexippus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Peromyscus melanotis is the only one of three mouse species that eats monarch butterflies at their overwintering sites in Mexico. I tested two hypotheses: 1)P. aztecus avoids monarchs because of a bitter taste aversion to cardiac glycosides (CGs) and an inability to reject CG-rich body parts; 2)Reithrodontomys sumichrasti avoids monarchs principally because of a bitter taste aversion to the CGs. None of the species are sensitive to the toxic effects of ingested CGs. Feeding responses of laboratory-reared mice of each species to monarchs with low, medium and high CG concentrations were compared. BothP. aztecus andR. sumichrasti ate significantly fewer of all three types of monarchs thanP. melanotis. ForP. aztecus andR. sumichrasti, the number of monarchs eaten decreased with increasing CG concentration, whereas forP. melanotis, the number remained constant.Peromyscus melanotis andR. sumichrasti developed a feeding technique for rejecting the CG-laden cuticular material, which reduced the bitterness of ingested monarch material. However,R. sumichrasti displayed the technique significantly less often thanP. melanotis; andP. aztecus never developed it. I conclude that high taste sensitivity to CGs and less versatile food handling preventP. aztecus andR. sumichrasti from overcoming the monarch's chemical defenses.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 46 (1990), S. 269-273 
    ISSN: 1420-9071
    Schlagwort(e): Sex pheromone ; biosynthesis ; Lepidoptera ; Epiphyas postvittana ; deuterium-labelling ; (E)-11-tetradecenyl acetate ; (E,E)-9,11-tetradecadienyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Fatty acyl moieties present in the female sex pheromone gland of the lightbrown apple moth,Epiphyas postvittana, include the analogues of the two sex pheromone components, (E)-11-tetradecenyl acetate and (E,E)-9,11-tetradecadienyl acetate. Application of deuterium-labelled fatty acids followed by analysis by gas chromatographymass spectrometry showed that biosynthesis of the two pheromone components involved initial Δ11-desaturation of myristic and palmitic acids respectively.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Journal of comparative physiology 167 (1990), S. 309-320 
    ISSN: 1432-1351
    Schlagwort(e): Chemosensory integration ; Olfaction ; Brain ; Larva ; Caterpillar ; Manduca sexta ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. The physiology and morphology of olfactory interneurons in the brain of larval Manduca sexta were studied using intracellular recording and staining techniques. Antennal olfactory receptors were stimulated with volatile substances from plants and with pure odorants. Neurons responding to the stimuli were investigated further to reveal their response specificities, dose-response characteristics, and morphology. 2. We found no evidence of specific ‘labeled-lines’ among the odor-responsive interneurons, as none responded exclusively to one plant odor or pure odorant; most olfactory interneurons were broadly tuned in their response spectra. This finding is consistent with an ‘across-fiber’ pattern of odor coding. 3. Mechanosensory and olfactory information are integrated at early stages of central processing, appearing in the responses of some local interneurons restricted to the primary olfactory nucleus in the brain, the larval antennal center (LAC). 4. The responses of LAC projection neurons and higher-order protocerebral interneurons to a given odor were more consistent than the responses of LAC local interneurons. 5. The LAC appears to be functionally subdivided, as both local and projection neurons had arborizations in specific parts of the LAC, but none had dendrites throughout the LAC. 6. The mushroom bodies and the lateral protocerebrum contain neurons that respond to olfactory stimulation.
    Materialart: Digitale Medien
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  • 34
    ISSN: 1432-072X
    Schlagwort(e): Candida boidinii ; Yeast ; Peroxisomes ; β-Oxidation ; d-Amino acid oxidase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have studied the induction of peroxisomes in the methylotrophic yeast Candida boidinii by d-alanine and oleic acid. The organism was able to utilize each of these compounds as the sole carbon source and grew with growth rates of μ=0.20 h-1 (on d-alanine) or μ=0.43 h-1 (on oleic acid). Growth was associated with the development of many peroxisomes in the cells. On d-alanine a cluster of tightly interwoven organelles was observed which made up 6.3% of the cytoplasmic volume and were characterized by the presence of d-amino acid oxidase and catalase. On oleic acid rounded to elongated peroxisomes were dominant which were scattered throughout the cytoplasm. These organelles contained increased levels of β-oxidation enzymes; their relative volume fraction amounted 12.8% of the cytoplasmic volume.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 154 (1990), S. 267-273 
    ISSN: 1432-072X
    Schlagwort(e): Yeast ; Saccharomyces cerevisiae ; (R)-2,3-Butanediol dehydrogenase ; Stereospecificity ; Gas chromatographic analysis of enantiomers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A NAD-dependent (R)-2,3-butanediol dehydrogenase (EC 1.1.1.4), selectively catalyzing the oxidation at the (R)-center of 2,3-butanediol irrespective of the absolute configuration of the other carbinol center, was isolated from cell extracts of the yeast Saccharomyces cerevisiae. Purification was achieved by means of streptomycin sulfate treatment, Sephadex G-25 filtration, DEAE-Sepharose CL-6B chromatography, affinity chromatography on Matrex Gel Blue A and Superose 6 prep grade chromatography leading to a 70-fold enrichment of the specific activity with 44% yield. Analysis of chiral products was carried out by gas chromatographic methods via pre-chromatographic derivatization and resolution of corresponding diasteromeric derivatives. The enzyme was capable to reduce irreversibly diacetyl (2,3-butanediol) to (R)-acetoin (3-hydroxy-2-butanone) and in a subsequent reaction reversibly to (R,R)-2,3-butanediol using NADH as coenzyme. 1-Hydroxy-2-ketones and C5-acyloins were also accepted as substrates, whereas the enzyme was inactive towards the reduction of acetone and dihydroxyacetone. The relative molecular mass (M r) of the enzyme was estimated as 140 000 by means of gel filtration. On SDS-polyacrylamide gel the protein decomposed into 4 (identical) subunits of M r 35 000. Optimum pH was 6.7 for the reduction of acetoin to 2,3-butanediol and 7.2 for the reverse reaction.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 154 (1990), S. 175-178 
    ISSN: 1432-072X
    Schlagwort(e): Killer toxin ; Hanseniaspora uvarum ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with ethanol and purified by ion exchange chromatography. SDS-PAGE of the electrophoretically homogenous killer protein indicated an apparent molecular mass of 18,000. Additional investigations of the primary toxin binding sites within the cell wall of sensitive yeast strains showed that the killer toxin of Hanseniaspora uvarum is bound by β-1, 6-d-glucans.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    ISSN: 1432-072X
    Schlagwort(e): 13C NMR spectroscopy ; Yeast ; Debaryomyces hansenii ; Osmoregulation ; Compatible solute ; Salt stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract High resolution 13C NMR combined with chemical analysis were used to study the formation of metabolites from [1-13C]-labelled glucose by the salt-tolerant yeast Debaryomyces hansenii after transfer to media containing 8% NaCl. Time course spectroscopy of an aerobic cell suspension showed [1,3-13C]glycerol as the predominant end product. Perchloric acid extracts revealed additional less prominent incorporation of label into arabinitol, trehalose, glutamic acid, and alanine. The incorporation into trehalose and arabinitol showed a transient increase after shift to the high salinity medium. It is concluded that glycerol and arabinitol are the major organic solutes in D. hansenii, the production of glycerol being strongly induced by high salinity. Analysis of labelled extracts of D. hansenii after transfer to 8% NaCl media containing [1-13C]- or [6-13C]glucose, demonstrated that glucose is dissimilated via a combination of the Embden-Meyerhof-Parnas pathway and the pentose phosphate pathway, with the former playing a major role in glycerol formation and the latter in arabinitol production. The almost exclusive labelling of C5 of arabinitol from [6-13C]glucose indicates that the pathway to arabinitol proceeds via reduction of ribulose-5-phosphate.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    ISSN: 1432-072X
    Schlagwort(e): cAMP ; Cat mutants ; Glucose repression ; Glucose-induced ; Intracellular pH ; Ras ; Saccharomyces cerevisiae ; Signal transduction ; Trehalase ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Addition of glucose to derepressed cells of the yeast Saccharomyces cerevisiae induces a transient, specific cAMP signal. Intracellular acidification in these cells, as caused by addition of protonophores like 2,4-dinitrophenol (DNP) causes a large, lasting increase in the cAMP level. The effect of glucose and DNP was investigated in glucose-repressed wild type cells and in cells of two mutants which are deficient in derepression of glucose-repressible proteins, cat1 and cat3. Addition of glucose to cells of the cat3 mutant caused a transient increase in the cAMP level whereas cells of the cat1 mutant and in most cases also repressed wild type cells did not respond to glucose addition with a cAMP increase. The glucose-induced cAMP increase in cat3 cells and the cAMP increase occasionally present in repressed wild type cells however could be prevented completely by addition of a very low level of glucose in advance. In derepressed wild type cells this does not prevent the specific glucose-induced cAMP signal at all. These results indicate that repressed cells do not show a true glucose-induced cAMP signal. When DNP was added to glucose-repressed wild type cells or to cells of the cat1 and cat3 mutants no cAMP increase was observed. Addition of a very low level of glucose before the DNP restored the cAMP increase which points to lack of ATP as the cause for the absence of the DNP effect. These data show that intracellular acidification is able to enhance the cAMP level in repressed cells. The glucose-induced artefactual increase occasionally observed in repressed cells is probably caused by the fact that their low intracellular pH is only restored after the ATP level has increased to such an extent that it is no longer limiting for cAMP synthesis. It is unclear why the artefactual increases are not always observed. Measurement of glucose- and DNP-induced activation of trehalase confirmed the physiological validity of the changes observed in the cAMP level. Our results are consistent with the idea that the glucose-induced signaling pathway contains a glucose-repressible protein and that the protein is located before the point where intracellular acidification triggers activation of the pathway.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 3277-3290 
    ISSN: 1573-1561
    Schlagwort(e): Plant-insect interactions ; redox ; reduction potential ; digestion ; Lepidoptera ; Danaus plexippus ; Lymantria dispar ; Manduca sexta ; Papilio glaucus ; Polia latex ; Danaidae ; Lymantriidae ; Sphingidae ; Papilionidae ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Large interspecific differences in redox potential exist among herbivorous lepidopteran larvae. Reducing conditions occur in the midguts ofManduca sexta (Sphingidae) andPolia latex (Noctuidae), whereas oxidizing conditions prevail in the midguts ofLymantria dispar (Lymantriidae),Danaus plexippus (Danaidae), andPapilio glaucus (Papilionidae). The epithelium of the posterior midgut ofM. sexta fed a diet containing bismuth subnitrate accumulates bismuth sulfide, suggesting that sulfide might be one of the reducing agents responsible for the maintenance of reducing conditions in this species. We propose that the effects of plant allelochemicals in insect herbivores will be strongly affected by gut redox conditions and that the regulation of gut redox conditions is an important adaptation of insect herbivores to the chemical defenses of plants. The redox state of the gut is yet another insect trait that must be included in the analysis of plant-insect interactions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 3373-3382 
    ISSN: 1573-1561
    Schlagwort(e): Asclepias fruticosa ; milkweed ; Danaus plexippus ; monarch butterfly ; Lepidoptera ; Danaidae ; cardenolides ; HPLC ; gomphoside ; afroside ; digitoxin ; calactin ; calotropin ; cardenolide fingerprint ; cardiac glycosides ; internal standard
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The cardenolide extracts from latex and aerial parts ofAsclepias fruticosa and ofDanaus plexippus reared onA. fruticosa orA. curassavica were purified by adsorption chromatography on silica gel. HPLC analysis on a C18 reverse-phase column with an acetonitrile-water gradient as mobile phase, separated 28 compounds with a UV spectrum typical forcardenolides. Afroside and gomphoside (major components), as well as calotropagenin, calotoxin, calotropin, calactin, uscharidin, uscharin, and voruscharin, occurred as single peaks in the profiles of latex and aerial plant parts ofA. fruticosa. Calactin and calotropin were the major cardenolides inDanaus plexippus reared onA. fruticosa orA. curassavica. Quantitative data obtained with digitoxin as internal standard showed that 1.3–1.5% of the leaf cardenolides were sequestered byDanaus plexippus in which levels of 70–80μg cardenolide per butterfly were measured. The calotropin from the leaves was almost completely sequestered, and 10–13% of the calactin was stored by the butterfly, assuming that no conversion occurred in larval tissues.
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  • 41
    ISSN: 1573-1561
    Schlagwort(e): Hepialus ; Lepidoptera ; Hepialidae ; swift moth ; pheromone ; dihydropyrone ; 2,9-dioxabicyclo[3.3.1] nonane ; behavior ; electrophysiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract (R)-6-Ethyl-2-methyl-2,3-dihydro-4H-pyran-4-one, (1R,3S,5R)-3-ethyl-1,8-dimethyl-2,9-dioxabicyclo[3.3. 1]non-7-ene, and (1R,3S,5R)-3-ethyl-1,8-dimethyl-2,9-dioxabicyclo[3.3.1]non-7-en-6-one represent the main components in the male pheromone of the swift moth,Hepialus hecta. The amounts of the three components were 40, 5, and 5 μg per male, respectively. Structure elucidation of the compounds was based on spectroscopic data as compared to synthetic reference samples. The absolute configurations were determined by gas chromatography on chiral stationary phases; optically active samples served as reference compounds. Electrophysiological and behavioral experiments with natural material and synthetic samples clearly showed the three heterocyclic compounds to act as pheromones. (E, E)-α-Farnesene represents the main component of the scent secretion of maleHepialus humuli.
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  • 42
    ISSN: 1573-1561
    Schlagwort(e): Lepidoptera ; Yponomeutidae ; Yponomeuta malinellus ; sex pheromone ; apple ermine moth ; (Z)-9-dodecen-1-ol acetate ; (Z)-11-tetradecen-1-ol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract When electroantennographic responses of maleYponomeuta malinellus Zeller to model compounds were determined at dosages of 0.3–30 ng, the strongest responses were obtained from (Z)-9-dodecen-1-ol acetate (Z9–12∶Ac). Also, strong responses were obtained from (Z)-11-tetradecenal (Z11–14∶A1) and (Z)-11-tetradecen-1-ol (Zl1–14∶OH). At a dosage of 0.3 ng,Z11–14∶A1 produced a stronger response thanZ11–14∶OH, while at a dosage of 30 ng,Z11–14∶OH andZ11–14∶A1 produced equal responses. Gas chromatographic and mass spectral analysis of extracts of female sex pheromone glands showed the presence ofZ9–12∶Ac, tetradecan-1-ol (14∶OH), (E)-11-tetradecen-1-ol (E11–14∶OH),Z11–14∶OH, hexadecan-1-ol, and hexadecan-1-ol acetate in a ratio of 0.6∶200∶37∶100∶140∶35. In field tests,Z9–12∶Ac andZ11–14∶OH together were required for trap catch, and addition ofZ11–14∶A1,E11–14∶OH, 14∶OH, or (Z)-11-tetradecen-1-ol acetate did not increase catch. Ratios in rubber septa of 0.5∶99.5 to 1.5∶98.5 (Z9–12∶ Ac/Z11–14∶OH) captured the most males and captures were statistically equivalent for dosages of 10–1000 μg/rubber septum. Traps baited with the synthetic lure produced better catches than those baited with females.
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 509-519 
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; (Z)-7-dodecenyl acetate ; (Z)-5-dodecenyl acetate ; 11-dodecenyl acetate ; dodecyl acetate ; (Z)-9-tetradecenyl acetate ; (Z)-7-tetradecenyl acetate ; Lepidoptera ; Noctuidae ; Trichoplusia ni
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Female cabbage looper moths,Trichoplusia ni, from laboratory colonies initiated from three locations across the United States emitted similar quantities and blend ratios of the six known pheromone components. In contrast, females from a long-established laboratory colony emitted a greater proportion of four of the five minor components relative to the major component, (Z)-7-dodecenyl acetate; only the relative proportion of 11-dodecenyl acetate was similar in all of the populations sampled. Females from this population emitted (Z)-7-dodecenyl acetate at a rate similar to that from females from field-collected colonies. Within each population there were highly significant correlations among the quantities of pheromone components of similar molecular weights. Correlations between components of different molecular weights were not as great, but often were significant. Similarities of blend ratios among field populations may indicate that the chemical signal in this species is conservative. The difference of the blend ratios in our laboratory population from the other populations may indicate a decrease in the intensity of selection pressure that usually would maintain these values.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2203-2216 
    ISSN: 1573-1561
    Schlagwort(e): Yponomeuta cagnagellus ; caterpillars ; Lepidoptera ; Yponomeutidae ; trail following ; chemical marker ; trail pheromone ; stability ; pheromone secretory site
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Trail following in lepidopterous larvae is often attributed to chemical markers, but only a few clear-cut examples are found in the literature. In this paper evidence is presented for a chemical basis of the trail following behaviour ofYponomeuta cagnagellus. (Lepidoptera: Yponomeutidae) The marker is shown to be very persistent under laboratory conditions and is water soluble. Several possible secretory sites were investigated, and it is concluded that the marker is probably secreted together with the silk from the labial gland. Problems associated with the demonstration of trail markers in caterpillars are discussed.
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  • 45
    ISSN: 1573-1561
    Schlagwort(e): Lepidoptera ; Geometridae ; sex pheromone ; sex attractant ; behavioral antagonist ; enantiomer ; (6Z,9Z,3S,4R)-epoxy-heptadecadiene ; (6Z,9Z,3R,4S)-epoxy-heptadecadiene ; (3Z,9Z,6S,7R)-epoxyheptadecadiene ; (6Z,9Z,3S,4R)-epoxy-nonadecadiene ; (6Z,9Z,3R,4S)-epoxy-nonadecadiene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Stereoselective syntheses of chiral C17 to C21 6Z,9Z-cis-3,4-epoxydienes were developed. Field tests of the enantiomerically enriched epoxides as components of synthetic sex attractant lures were carried out, and those with C17 and C19 chain lengths, particularly, were attractive to male moths of several species. Moths were usually specifically attracted by one of a pair of enantiomers, and the opposite enantiomer could actually be a behavioral antagonist. Males belonging to nine species of Geometridae were captured.Probole amicaria (Herrich-Schäffer) males were taken in traps baited with the mixture (6Z,9Z,3S,4R)-epoxy-nonadecadiene (6Z,9Z,3S,4R-epoxy-19∶H) + 3Z,9Z,6R,7S-epoxy-19∶H + 3Z,6Z,9Z-19∶H(9∶1∶8). Other species responding to the C19 compounds included (attractant components follow in parentheses);Sicya macularia (Harris) (6Z,9Z,3S,4R-epoxy-19∶H + 3Z,6Z,9Z-19∶H),Anavitrinella pampinaria (Guenée) (6Z,9Z-cis-3,4-epoxy-19∶H + 3Z,9Z,6S,7R-epoxy-19∶H), andLycia ursaria (Walker) (6Z,9Z-3S, 4R-epoxy-19∶H + 3Z,6Z,9Z-19∶H). Males of the following species were captured byC 17 epoxides:Itame occiduaria (Packard) (6Z,9Z,3R,4S-epoxy-17∶H + 3Z,6Z,9Z-17∶H),Itame brunneata (Thunberg) (6Z,9Z,3S,4R-epoxy-17∶H),Epelis truncataria (Walker) (both enantiomers of 6Z,9Z-cis-3,4-epoxy-17∶H),Semiothisa ulsterata (Pearsall) (3Z,9Z-6S,7R-epoxy-17∶H), andS. signaria dispuncta (Walker) (3Z,9Z-cis-6,7-epoxy-17∶H + 3Z,6Z,9Z-17∶H). The interactions among enantiomers and regioisomers are discussed as a mechanism by which cross attraction between sympatric species is limited.
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2581-2588 
    ISSN: 1573-1561
    Schlagwort(e): Vitex fisherii ; Verbenaceae ; phytoecdysteroid ; vitexirone ; 20-hydroxyecdysone ; ajugasterone C ; turkesterone ; pink bollworm ; Pectinophora gossypiella ; Lepidoptera ; Gelechiidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A novel phytoecdysteroid, vitexirone, has been isolated from a MeOH extract of the root bark of the East African medicinal plantVitex fisherii by recycling high-performance liquid chromatography on a semipreparative scale. In addition, three known phytoecdysteroids, 20-hydroxyecdysone, ajugasterone C, and turkesterone, also were isolated. The structure of vitexirone has been established spectroscopically. The position and stereochemistry of the 11-α-hydroxy group of ajugasterone C and vitexirone were confirmed by the1H-1H homonuclear COSY NMR data. These phytoecdysteroids disrupt the molting process of the pink bollwormPectinophora gossypiella.
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2677-2690 
    ISSN: 1573-1561
    Schlagwort(e): Resistance ; Spodoptera frugiperda ; Lepidoptera ; Noctuidae ; antibiosis ; bioactivity ; plant biochemicals ; chlorogenic acid ; maysin ; luteolin ; fall armyworm ; centipedegrass ; Spodoptera frugiperda (J.E. Smith)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Centipedegrass,Eremochloa ophiuroides (Munro) Hack, severely inhibits growth of the fall armyworm larva,Spodoptera frugiperda (J.E. Smith). Fresh centipedegrass extracts and extract fractions were deposited on Celufil, incorporated into meridic-based diets and bioassayed against neonate larvae of the fall armyworm in the laboratory. The methanol extract (F1) caused the greatest reduction in larval weight. When F1, was partitioned between méthylene chloride and water, the activity was transferred to the water-soluble fraction (F5), which, when further fractionated using preparative C-18 reverse-phase chromatography, yielded active F7 and F8 fractions. Gas chromatograph-mass spectrometry and high-pressure liquid chromatography (HPLC) showed F7 to be 95% caffeoylquinic acids with chlorogenic acid as the major constituent. HPLC analysis of F8 revealed maysin [2″-O- α-L-rhamnosyl-6-C-(6-deoxy-Xylo-hexos-4-ulosyl)luteolin] and other luteolin derivatives. Chlorogenic acid and other caffeoylquinic acids, maysin, and other luteolin derivatives are the major factors responsible for the antibiotic resistance of centipedegrass to larvae of the fall armyworm.
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2771-2786 
    ISSN: 1573-1561
    Schlagwort(e): Colias ; Lepidoptera ; Pieridae ; courtship pheromone ; pheromone variation ; pheromone production ; cuticular hydrocarbons ; n-heptacosane ; 13-methylheptacosane ; n-nonacosane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Body size, age, ambient temperature, wing wear, and flight activity were investigated as possible sources of variation in the quantities and relative proportions of the three chemical components [n-heptacosane (C27), 13-methylheptacosane (13MH), andn-nonacosane (C29)] of the male courtship pheromone ofColias eurytheme butterflies. Size of the male has very little influence on the amount of any of the pheromone components present on the wings. Most of the deposition of all three components onto the surface of the hindwing occurs between 3 and 9 hr after emergence from the pupa. 13MH is deposited more rapidly than C27 and C29, and C27 more rapidly than C29. After the first 12 hr posteclosion, the pheromone phenotype of an individual male remains relatively constant through at least 96 hr of age. Experiments showed that none of the three chemicals volatilize to any appreciable extent at temperatures likely to be experienced in the field. The pheromones of actively searching and courting males did not differ from those of less-active feeding and resting males, suggesting that volatilization induced by flight activity is not an important source of pheromone variation. Loss of scales with age does seem to affect pheromone phenotype, but not in a readily interpretable way. Although the quantity of 13MH was lower in worn males than in fresh, C27 was higher.
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1221-1236 
    ISSN: 1573-1561
    Schlagwort(e): Baculovirus ; nuclear polyhedrosis virus ; plant phenolics ; polyphenol oxidase ; tritrophic interactions ; Heliothis zea ; Lepidoptera ; Noctuidae ; Lycopersicon esculentum ; host plant resistance ; biological control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The infectivity of the nuclear polyhedrosis virus, HzSNPV toHeliothis zea was significantly reduced when viral occlusion bodies were exposed to the plant phenolic chlorogenic acid in the presence of polyphenol oxidase. Chlorogenic acid is rapidly oxidized to the ortho-quinone, chlorogenoquinone, by foliar polyphenol oxidases of the tomato plant, Lycopersicon esculentum, when foliage is damaged during feeding by larvalH. zea. Our results indicate that chlorogenoquinone, a powerful oxidizing agent, covalently binds to the occlusion bodies of HzSNPV and significantly reduces their digestibility and solubility under alkaline conditions. This binding is proposed to interfere with the infection process by impairing the release of infective virions in the midgut.
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  • 50
    ISSN: 1573-1561
    Schlagwort(e): Erannis defoliaria (Z,Z,Z)-3,6,9-nonadecatriene ; (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene ; sex pheromone ; identification ; electroantennogram ; single sensillum ; peripheral inhibitor ; Agriopis marginaria ; Colotois pennaria ; Lepidoptera ; Geometridae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract (Z,Z,Z)-3,6,9-nonadecatriene (Z3,Z6,Z9–19Hy) and (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene (Z3,Z9-cis-6,7-epo-19Hy) were identified in pheromone gland extracts from femaleErannis defoliaria. The two components were found in a 1∶3 ratio, with the main component,Z3,Z9-cis-6,7-epo-19Hy present at an amount of about 1.5 ng per female. The components were identified by means of gas chromatography-mass spectrometry, gas chromatography-electroantennography and gas chromatography-single sensillum recordings. Single sensillum measurements on the male antenna showed two physiological types of sensilla. One type was characterized by a large spike amplitude cell responding toZ3,Z9-cis-6,7-epoxy-19Hy and a small spike amplitude cell responding toZ3,Z6,Z9–19Hy. A second type responded only with a large spike amplitude cell to the epoxide, and this cell was inhibited by the triene. Of the two pheromone components, the epoxide gave the higher response in the EAG tests. Preliminary field tests support the identification of the pheromone components. The epoxide was also found to be present in the extract of the pheromone gland ofColotois pennaria, and males ofC. pennaria andAgriopis marginaria were trapped by the mixture of the identified compounds.
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1911-1920 
    ISSN: 1573-1561
    Schlagwort(e): Peridroma saucia ; variegated cutworm ; Lepidoptera ; Noctuidae ; feeding behavior ; growth inhibitors ; conversion efficiency ; asarones ; Acorus calamus ; antifeedants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Asarones (2, 4, 5-trimethoxypropenylbenzenes) isolated from the essential oil ofAcorus calamus L. rhizomes, are potent growth inhibitors and antifeedants to the variegated cutworm,Peridroma saucia Hubner.cis-Asarone added to artificial diet significantly inhibited growth and feeding by first-, third-, and fourth-instar larvae, whereas thetrans isomer produced an antifeedant effect alone. Gross dietary utilization (efficiency of conversion of ingested food, ECI) was decreased when the diet was supplemented withcis-asarone or when this compound was topically applied to fourth-instar larvae. Inhibition of growth occurred even at a moderate topical dose (5 μg/larva) primarily as a result of decreased efficiency of conversion of digested food (ECD), even though the approximate digestibility (AD) of the food was unchanged. Oral or topical treatment withtrans-asarone also significantly inhibited larval growth, but in this case the effect can be strictly attributed to decreased consumption, as dietary utilization (ECI) was not affected. Both isomers displayed a direct antifeedant effect based on leaf disk choice tests. Thecis isomer was 7.0 and 5.5 times more potent thant thetrans isomer against fourth- and fifth-instar larvae, respectively. Our data suggest that the two asarone isomers have different modes of action.cis-Asarone is toxic in addition to having strong antifeedant activity, whereas thetrans isomer acts only as an antifeedant with no appreciable toxicity.
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1977-1995 
    ISSN: 1573-1561
    Schlagwort(e): Fall armyworm ; Spodoptera frugiperda ; Lepidoptera ; Noctuidae ; corn ; Zea mays ; plant-insect interaction ; amino acids ; herbivory ; feeding resistance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The free amino acids have been shown by isolational work and choice bioassays to be more important than all other factors evaluated in defining leaf-feeding resistance of corn (Zea mays L.) to fall armyworm (FAW) [(Spodoptera frugiperda J.E. Smith)] larvae. 6-MBOA (6-methoxybenzoxazolinone) and maysin, toxins present in corn, were shown not to be significant factors for leaf-feeding resistance to first-instar FAW larvae because of their low concentrations in the whorl. Amino acid analysis showed that while the ratios of the essential amino acids in susceptible (S) and resistant (R) lines were similar, there were differences in the nonessential amino acids, particularly aspartic acid, which was higher in R lines. Also, the ratio of essential amino acids to nonessential amino acids was important, being too low in expressed whorl leaf juice (obtained from V8–V10 growth stage plants) to support larval growth, although juice was stimulatory in choice tests. The total protein content of whorls in S lines was about 15% higher than in R lines, but the significance of this difference is uncertain, because nutritional tests showed that larval growth increased with total protein only up to 12% protein. Sugars were only slightly stimulatory. Thus, the amino acids along with higher hemicellulose content of R lines, established by us earlier, appear to explain much of the basis of resistance in corn to larval leaf-feeding of the FAW.
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2009-2017 
    ISSN: 1573-1561
    Schlagwort(e): Apanteles kariyai ; Hymenoptera ; Braconidae ; Acantholeucania loreyi ; Pseudaletia separata ; Lepidoptera ; Noctuidae ; 2,5-dialkyltet-rahydrofuran ; arrestant ; allelochemical ; antimone ; kairomone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Females of the larval parasitoidApanteles kariyai (Watanabe) (Hymenoptera: Braconidae) are arrested on fecal pellets ofAcantholeucania loreyi (Duponchel) (Lepidoptera: Noctuidae) larvae. Upon subsequent antennal contact with anA. loreyi larva, females sting it with their ovipositor. However, such stinging did not result in any offspring. The allelochemical involved in feces has been identified and is identical to a kairomone of the hostPseudaletia separata (Lepidoptera: Noctuidae). In contrast toA. loreyi, P. separata is a suitable host forA. kariyai, and oviposition inP. separata results in offspring production. The allelochemical mediating the interaction betweenA. loreyi andA. kariyai is discussed in the context of current allelochemical terminology.
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  • 54
    ISSN: 1573-1561
    Schlagwort(e): Attractant ; Geometridae ; Noctuidae ; Eufidonia convergaria ; Caripeta angustiorata ; Rivula propinqualis ; (3Z,6Z,9Z)-nonadecatriene ; (3Z,9Z)-(6R,7S)-epoxy-nonadecadiene ; (3Z,9Z)-(6S,7R)-epoxy-nonadecadiene ; (3Z,9Z)-cis-6,7-epoxy-nonadecadiene ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Sex attractants for the geometrid mothsEufidonia convergaria andCaripeta angustiorata, and the noctuid mothRivula propinqualis have been elucidated during field screening of a series of (3Z,6Z,9Z)-triene hydrocarbons (C17–22), and the racemic and enantiomerically enriched monoepoxydienes derived from those hydrocarbons. Biologically active compounds were identified by a combination of field testing of synthetic standards, electroantennography, and coupled gas chromatography-electroantennogram detection.E. convergaria males were optimally attracted by a 1∶1 blend of (3Z,9Z)-(6S,7R)-epoxy-nonadecadiene (3Z,9Z-6S,7R-epoxy-19∶H); other abbreviations follow the same system) with (3Z,6Z,9Z)-nonadecatriene (3Z,6Z,9Z-19∶H). The 6R,7S enantiomer of the epoxide had no apparent biological activity, either as an attractant or as a behavioral antagonist. Male moths also were attracted to blends of the C18 and C20 homologs of the triene and the epoxide. 3Z,6Z,9Z-19∶H and 3Z,6Z-cis-6,7-epoxy-19∶H were identified inE. convergaria female pheromone gland extracts. Males of the geometrid moth speciesC. angustiorata were attracted by a 1∶1 blend of 3Z,6Z,9Z-19∶H and enantiomerically enriched 3Z,9Z-6R,7S-epoxy-19∶H. Males of the noctuid mothR. propinqualis were attracted by an approximately 10∶1 blend of 3Z,6Z,9Z-19∶H and enantiomerically enriched 3Z,9Z-6S, 7R-epoxy-19∶H. The components were synergistic, with neither being attractive alone. The blend ratio was quite specific, as the attractiveness of blends decreased sharply on either side of the optimum ratio.
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  • 55
    ISSN: 1573-1561
    Schlagwort(e): Rice leaffolder ; Cnaphalocrocis medinalis ; Lepidoptera ; Pyralidae ; Oryza officinalis ; Oryza punctata ; Oryza sativa ; rice plant volatiles ; egg hatchability ; egg laying
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Rice plant volatiles extracted as steam distillates significantly affected the behavior of the rice leaffolder,Cnaphalocrocis medinalis (Guenée). Leaffolder moths laid significantly fewer eggs on TN1 rice plants treated with extracts of resistant wild species of rice,Oryza officinalis andOryza punctata, than on TN1 plants treated with extracts of resistant cultivated rices. Extracts ofO. officinalis andO. punctata adversely affected egg hatchability.O. officinalis andO. punctata extracts were more toxic to first-instar larvae than extracts of other resistant varieties. Leaf area consumed by the larvae was reduced on TN1 plants treated withO. officinalis andO. punctata extracts compared with that on plants treated with extracts of resistant cultivated rice varieties.
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 3067-3089 
    ISSN: 1573-1561
    Schlagwort(e): Semiochemicals ; kairomones ; parasitoid behavior ; parasitoid manipulation ; foraging environment ; Heliothis zea ; Lepidoptera ; Noctuidae ; Microplitis croceipes ; Hymenoptera ; Braconidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Allelochemicals are known to serve important roles at all steps in the host-searching sequence of parasitoids. We discuss the various roles of these allelochemics and the type of information needed to develop their use in pest control, which to date has been very limited. Rapid advancements are being made with respect to airborne chemicals and longer-range foraging behavior. Moreover, recent discoveries have shown that genetic diversity in parasitoid populations and phenotypic plasticity of individuals, together with their physiological state, often result in substantial variations in the response to chemical cues. Successful application of semiochemical-parasitoid systems will require management of these intrinsic parasitoid variables as well as management of the foraging environment. We illustrate emerging technology for such an application. For the immediate future, the development of this technology will allow us to: (1) define the genetic and phenotypic foraging profiles important to consistent and efficient parasitoid foraging, and (2) establish the proper propagation and release procedures and monitoring bioassays necessary to ensure appropriate behavioral and physiological qualities of released organisms. For the long term, we envision technology for comprehensively manipulating the pest/crop environment in ways that would provide foraging stimuli and other needs important to retention and efficiency of parasitoids.
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  • 57
    ISSN: 1573-1561
    Schlagwort(e): Pheromone ; attractant ; 6(Z),9(Z)-nonadecadiene ; 3(Z),6(Z),9(Z)-nonadecatriene ; 3(Z),6(Z),9(Z)-eicosatriene ; 6(Z),9(Z)-cis-3 ; 4-epoxynonadecadiene ; Paleacrita vernata ; spring cankerworm ; Lepidoptera ; Geometridae ; trap height ; behavioral antagonist
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Two sex pheromone components, 3(Z),6(Z),9(Z)-nonadecatriene (3Z,6Z,9Z-19 ∶ H), and 3(Z),6(Z),9(Z)-eicosatriene (3Z,6Z,9Z-20∶ H), have been positively identified, and a third component, 6(Z),9(Z)-nonadecadiene (6(Z),9(Z)-19 ∶ H) has been tentatively identified from abdominal tip extracts of female spring cankerworm moths,Paleacrita vernata Peck (Lepidoptera∶ Geometridae). The pheromone components were identified by a combination of gas chromatography, electroantennography, mass spectrometry, chemical tests, comparison with standards, and field testing. Only 3Z,6Z,9Z-20 ∶ H exhibited significant attractant activity when tested alone, and it was potentiated by the other two components. The attractive blend was an 8∶2∶1 ratio of 3Z,6Z,9Z-20∶H/3Z,6Z,9Z-19∶H/6Z,9Z-19∶H. However, the two-component blend of 3Z,6Z,9Z-20 ∶ H and 6Z,9Z-19 ∶ H (8∶1 ratio) was as attractive as the three-component blend in further field tests. A series of related compounds, the diene monoepoxides available from epoxidation of C19 and C20 3Z,6Z,9Z-trienes, some of which have been found in the pheromone blends of other moth species, were tested as behavioral antagonists. The attraction of male moths to synthetic lures was suppressed by the addition of 6Z,9Z-cis-3,4-epoxy-nonadecadiene to the lures. Additional experiments were performed to determine the effects of lure dosage, trap height, and trap design on the numbers of male moths captured.
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  • 58
    ISSN: 1573-1561
    Schlagwort(e): Courtship pheromone ; Utetheisa ornatrix ; Lepidoptera ; Arctiidae ; sexual selection ; hydroxydanaidal ; pyrrolizidine alkaloid ; Crotalaria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Hydroxydanaidal, the corematal courtship pheromone of maleUtetheisa ornatrix, shows pronounced quantitative variation in natural populations of the moth. Males that, as larvae, fed on seed-bearing rather than immature food plants (Crotalaria spectabilis orC. mucronata) produce higher levels of hydroxydanaidal. Such males also have higher systemic loads of pyrrolizidine alkaloid, the known metabolic precursor of hydroxydanaidal, whichUtetheisa sequester from their larval diet and which is concentrated in the seeds ofCrotalaria. Males raised on seed-bearing plants also achieve higher adult weight. In the context of sexual selection, therefore, femaleUtetheisa could, through assessment of male hydroxydanaidal levels, gauge both the alkaloid content and body weight of their suitors.
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  • 59
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; individual variation ; pheromone titer ; periodicity ; (E,Z)-4,7-tridecadien-1-yl acetate ; (E,Z,Z)-4,7,10-tridecatrien-1-yl acetate ; Lepidoptera ; Gelechiidae ; potato tuberworm moth ; Phthorimaea operculella
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The ratios and quantities of the pheromone components, (E,Z)-4,7-tridecadien-1-yl acetate (diene) and (E,Z,Z)-4,7.10-tridecatrien-1-yl acetate (triene), in the glands of individual female potato tuberworm moths (Phthorimaea operculella) originating from the United States (California) and Japan (Nagoya) were analyzed by gas chromatography. Quantities of glandextracted pheromone components of Nagoya females fluctuated in a periodic fashion during the photoperiod. Maximal titers coincided with the onset of scotophase (and calling), then gradually declined to minimal levels soon after lights-on. The average daily pheromone quantities decreased significantly as females aged. Both populations exhibited considerable variation in the ratio of the two components. The proportions of triene in the blend ranged from 27% to 88% (triene −X = 56 ± 13% SD; CV = 23%) for California females and from 16% to 71% (42 ± 13%; CV = 31%) for Nagoya females. Nagoya females also stored significantly higher amounts of pheromone in their glands (8.6 ± 3.9 ng) than did California females (2.7 ± 1.4). The differences between the populations, while substantial, would probably not be sufficient to impart a barrier to panmixis, given the wide range of component ratios favored by the males.
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2615-2621 
    ISSN: 1573-1561
    Schlagwort(e): Lacinipolia renigera ; Lepidoptera ; Noctuidae ; bristly cutworm ; insect pheromones ; (itZ)-9-tetradecenyl acetate ; (Z, E)-9 ; 12-tetradecadienyl acetate ; bolas spider ; Mastophora hutchinsoni
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The sex pheromone of the bristly cutworm moth,Lacinipolia renigera was identified as a blend of (Z)-9-tetradecenyl acetate (itZ9–14): Ac and (Z, E)-9,12-tetradecadienyl acetate (ZE-9,12–14: Ac). Extracts of female glands were analyzed by capillary gas chromatography on three columns of different polarities. In each analysis, peaks with retention times identical to Z9–14:Ac andZE–9, 12–14: Ac were observed. GC-MS analysis of gland extracts supported the identification of these two compounds. Volatiles emitted from female sex pheromone glands during 10-min collection periods contained 7.8 ±2.01 ng ofZ9- 14: Ac. On average the blend contained 3.8 ± 1.43%ZE-9,12–14: Ac. Blends ranging from 1% to 10%ZE- 9,12–14: Ac in Z9-14: Ac (1 mg) were effective in capturing males in the field. The number of males captured in traps baited with a 3 % blend ofZE- 9,12-14: Ac in Z9-14: Ac was not significantly different than the number caught in traps containing two virgin females.
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  • 61
    ISSN: 1573-1561
    Schlagwort(e): Cnaphalocrocis medinalis ; electroantennogram ; green leaf volatiles ; host-plant resistance ; Lepidoptera ; Marasmia patnalis ; olfaction ; plant volatiles ; Pyralidae ; rice leaf folder
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Electroantennograms (EAGs) were recorded from male and female moths of two sympatric leaf folder species,Cnaphalocrocis medinalis (Gue-née) andMarasmia patnalis Bradley (Lepidoptera: Pyralidae) to 91 volatile chemicals of plant origin. Responses of both leaf folder species were similar to all compounds except to three monoterpenes-β-myrcene, menthone, and isomenthone- and two sesquiterpenes-cis-nerolidol and isophytol. Response ofM. patnalis, an oligophagous leaf folder, to these compounds was higher compared with that of polyphagousC. medinalis. EAG responses of males to saturated and unsaturated aliphatic aldehydes were significantly higher than those of conspecific females in both species. A higher response ofC. medinalis males also was observed for 1-nonanol, 3-nonen-2-one, andtrans, trans-2,6-dimethyl-2,4,6-octatriene. In contrast, females of both species responded more to monoterpenes, borneol, isoborneol, and fenchyl alchohol. Response ofC. medinalis female was higher for terpinen-4-ol, carveol, dihydrocarveol, (−)-myrtenal, and perillaldehyde. In both species and sexes, high EAG responses were recorded for compounds of the green leaf odor complex. EAG responses to nonanal and hexanal were maximum among the aliphatic aldehydes while 1-hexanol elicited the highest response among the alcohols tested. EAG responses to terpene compounds-citronellal,α-terpineol, and (−)-myrtenal-were equal to the response to 1-hexanol. While all compounds tested elicited a negative potential, thymol and carvacrol elicited a positive EAG potential. The EAG data are discussed with regard
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  • 62
    ISSN: 1617-4623
    Schlagwort(e): Yeast ; Cell cycle ; Meiosis ; DNA primase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Mitotic cultures synchronised either by a feed-starve protocol or by elutriation have been used to show that the Saccharomyces cerevisiae DNA primase I gene is periodically expressed in the cell cycle. The transcript increases many-fold in late G1 and reaches a peak at the same time as four other genes essential for DNA synthesis, CDC8, CDC9, CDC21 and POL1. The primase I transcript is also regulated in meiosis, reaching maximal levels during premeiotic DNA synthesis.
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  • 63
    ISSN: 1617-4623
    Schlagwort(e): Meiosis ; Sporulation ; Northern hybridization ; Regulatory circuit ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary SME1 was cloned due to its high copy number effect: it enabled MATα/MATα diploid cells to undergo meiosis and sporulation in a vegetative medium. Disruption of SME1 resulted in a recessive Spo− phenotype. These results suggest that SME1 is a positive regulator for meiosis. DNA sequencing analysis revealed an open reading frame of 645 amino acids. An amino terminal peptide of ca 400 amino acids in the deduced protein was similar to known protein kinases. Transcription of SME1 was regulated negatively by nitrogen and glucose and positively by MATα/MATα and IME1, another positive regulator gene of meiosis. By complementation analysis, SME1 was found to be identical to IME2, which had been shown to be important in meiosis. These results suggest that IME1 product stimulates meiosis by activating transcription of SME1 (IME2) and that protein phosphorylation is required for initiation of meiosis.
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 224 (1990), S. 209-221 
    ISSN: 1617-4623
    Schlagwort(e): Aminoacyl-tRNA synthetase ; RNA splicing ; Group I introns ; RNA maturase ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The Saccharomyces cerevisiae nuclear gene NAM2 codes for mitochondrial leucyl-tRNA synthetase (mLRS). Herbert et al. (1988, EMBO J 7:473–483) proposed that this protein is involved in mitochondrial RNA splicing. Here we present the construction and analyses of nine mutations obtained by creating two-codon insertions within the NAM2 gene. Three of these prevent respiration while maintaining the mitochondrial genome. These three mutants: (1) display in vitro a mLRS activity ranging from 0%–50% that of the wild type: (2) allow in vivo the synthesis of several mitochondrially encoded proteins; (3) prevent the synthesis of the COXII protein but not of its mRNA; (4) abolish the splicing of the group I introns bI4 and aI4; and (5) affect significantly the excision of the group I introns bI2, bI3 and aI3. Importation of the bI4 maturase from the cytoplasm into mitochondria in a nam2 − mutant strain does not restore the excision of the introns bI4 and aI4 implying that the splicing deficiency does not result from the absence of the bI4 maturase. We conclude that the mLRS is a splicing factor essential for the excision of the group I introns bI4 and aI4 and probably important for the excision of other group I introns.
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  • 65
    ISSN: 1617-4623
    Schlagwort(e): General amino acid permease ; Protein kinase ; Serine-rich protein ; Transport protein ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary TheNPR1 gene ofSaccharomyces cerevisiae plays a central role in controlling permease activity; its product is required to promote the activity of at least six distinct transport systems for nitrogenous nutrients under conditions of nitrogen catabolite derepression. We report here the nucleotide sequence of the clonedNPR1 gene. The predicted amino acid sequence indicates thatNPR1 encodes a protein of 86 kDa which appears to be organized into two distinct structural domains. The amino-terminal domain of NPR1 (residues 1 to 440) contains 26% serine residues and several regions strongly enriched for PEST residues suggesting a short half-life for the NPR1 protein. The carboxy-terminal region of NPR1 contains consensus sequences characteristic of the catalytic domains of protein kinases. Therefore, NPR1-dependent positive control of nitrogen transport systems most likely involves protein phosphorylation. Northern analysis indicates that the absence of general amino acid permease (GAP1) activity innpr1 mutants is not due to reduction in transcription or messenger stability. Hence, the NPR1 protein probably acts at the post-transcriptional level. Proteins that may serve as substrates for phosphorylation are discussed.
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  • 66
    ISSN: 1617-4623
    Schlagwort(e): Yeast ; Arginine ; Regulatory protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We present here a functional analysis of ARGRI and ARGRIII regulatory proteins which are involved together with ARGRII in specific regulation of arginine anabolic and catabolic pathways. Unlike ARGRII, ARGRI and ARGRIII have no transcriptional activation capacity. The first 60 amino acids of ARGRI (out of 177) are dispensable for its activity. The functional domain of the protein is located in the region of homology with MCM1 and SRF proteins. ARGRIII contains in its C-terminal portion a stretch of 17 aspartate residues which are indispensable for arginine regulation. Gene disruption of theARGRIII gene impairs the growth of the mutant on rich medium, showing that ARGRIII has a pleiotropic role in the cell.
    Materialart: Digitale Medien
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 342-344 
    ISSN: 1617-4623
    Schlagwort(e): rRNA genes ; Growth rate ; Yeast ; Pulsed field gel electrophoresis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary By employing pulsed field gel electrophoresis we find that slow growing strains of Kluyveromyces lactis have only 43%–55% of the wild-type level of ribosomal DNA (rDNA) repeats. When subjected to prolonged vegetative growth these strains can increase both the number of rDNA repeats and their growth rate.
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 394-400 
    ISSN: 1617-4623
    Schlagwort(e): Yeast ; Mitochondria ; CBS2 antibodies ; CBS2 protein ; In vitro import
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The nuclear genome encoded yeast protein CBS2 is required for translational activation of mitochondrial cytochrome b RNA. Genetic studies have shown that the target sequence of the CBS2 protein is the 5′ untranslated leader sequence of cytochrome b RNA. Here we report on the intracellular localization of CBS2. CBS2 protein, expressed in Escherichia coli and prepared from inclusion bodies, was used as an antigen to raise a polyclonal rabbit antiserum. Affinity-purified CBS2 antibodies detect a 45 kDa protein in mitochondrial lysates of wild-type cells, which is absent in a strain in which the CBS2 gene has been deleted. The protein is overexpressed in mitochondrial extracts of a transformant carrying the CBS2 gene on a high copy number plasmid, but undetectable in the post-mitochondrial supernatant. Intramitochondrial localization of CBS2 was verified by in vitro import of CBS2 protein that had been synthesized in a reticulocyte lysate programmed with CBS2 mRNA transcribed in vitro. Mitochondrial import of CBS2 is not accompanied by any detectable proteolytic processing.
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 474-480 
    ISSN: 1617-4623
    Schlagwort(e): Yeast ; Promoter ; Argininosuccinate lyase ; ARG4
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Transcription of the ARG4 gene of Saccharomyces cerevisiae is regulated by general control of amino acid biosynthesis but not by a specific regulatory mechanism. Three deletion mutants (ΔI, ΔII,, ΔIII) successively removing DNA sequences upstream from the coding sequence have been phenotypically analyzed after insertion into a single copy plasmid. As expected, ΔI, which lacks the sequences upstream to −155, including the two putative upstream activation sequences (UAS), was unable to derepress argininosuccinate lyase biosynthesis under conditions of amino acid starvation. In ΔII (deleted up to −126) the enzyme activity was very low and cells harbouring this allele were arginine dependent. These drastic phenotypic changes can be attributed to the loss of 12 out of 14 dA residues from positions −124 to −137. This poly (dAdT) sequence most likely serves as an upstream promoter element for constitutive expression of ARG4. The ΔIII deletion removes all 5′ sequences including the putative TATA box. This inactive allele has been successfully used for selecting yeast promoters of unknown origin.
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 173 (1990), S. 143-157 
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Winteraceae ; Zygogynum ; Lepidoptera ; Micropterigidae ; Sabatinca ; Coleoptera ; Pollination biology ; coevolution ; floral volatiles ; parallel radiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Flower visitors on 12 species of New CaledonianWinteraceae were studied. The visitors were two species of ancestral moths (Sabatinca; Micropterigidae), three species of weevils (Palontus; Curculionidae), and a species of thrips. Behavior observations and pollen records suggest that the beetles and occasionally the moths serve as pollinators ofZygogynum and Exospermum, andBelliolum is pollinated primarily by thrips. The floral volatiles are simple in composition, usually dominated by short esters. Preliminary experiments showed that ethyl acetate elicited alighting, and a distinctive huddling behavior was elicited by artificially mixed fragrance. The host associations of otherSabatinca andPalontus spp. do not support the hypothesis that theWinteraceae have radiated in association with their pollinators. The available evidence supports the notion of opportunistic isolated host colonizations at some point in the radiation of the pollinator groups.
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 221 (1990), S. 353-357 
    ISSN: 1617-4623
    Schlagwort(e): Yeast ; DNA alkylation ; DNA repair
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Repair of methylated bases in Saccharomyces cerevisiae was measured by two methods: in vitro in cell extracts, and in vivo, by determining the loss of methylated bases from yeast DNA after treatment of stationary cultures with [3H]-N-methyl-N′-nitro-N-nitrosoguanidine. Whereas no repair activity could be detected by the in vitro method, the methylated bases were removed in vivo very efficiently. These contradictory results of in vitro and in vivo repair measurements suggest that either the repair enzymes of yeast are sufficiently different from those of bacteria and mammalian cells that they are not active in the in vitro assay, or that methylated bases are repaired in yeast by a different pathway.
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 438-442 
    ISSN: 1617-4623
    Schlagwort(e): Transcription ; Promoter ; Oligo(dA-dT) stretch ; Gel shift assays ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Oligo(dA-dT) tracts are frequently found in the intergenic regions of the yeast Saccharomyces cerevisiae and have been proposed to act as upstream promoter elements for constitutive transcription. An oligo(dA-dT) tract of 23 bp is also found as a characteristic sequence motif in the centre of the 230 by segment which separates the open reading frames of the CBS2 gene and its 5′-flanking gene on chromosome IV. Recently we have reported that transcription of CBS2 is initiated immediately adjacent to this oligo(dA-dT) tract (Michaelis et al. 1988). Here we report that the flanking gene of unknown function is divergently transcribed into an RNA with heterogeneous 5′ ends. Two of these 5′ ends map within the oligo(dA-dT) stretch, while the third is located upstream, leading to an RNA species which is partially complementary to the CBS2 transcript. Gel shift assays show that the oligo(dA-dT) stretch is specifically recognized by (a) binding factor(s) in nuclear extracts. We discuss these results with respect to the role of oligo(dA-dT) stretches in gene expression in yeast.
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2935-2946 
    ISSN: 1573-1561
    Schlagwort(e): Genetics ; sex pheromone ; Lepidoptera ; Noctuidae ; Trichoplusia ni ; cabbage looper moth ; reproductive isolation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The genetic basis of interpopulational differences in the pheromone blend emitted by the cabbage looper moth,Trichoplusia ni (Hübner), was examined by crossing individuals from a field-derived population (P1) with individuals from a long-maintained laboratory colony (P2). These colonies differed in the emission rate and relative proportions of four of the five known minor pheromone components, but not in the emission rate of the major component, (Z)-7-dodecenyl acetate (Z7-12∶Ac). These differences in pheromone blend were quantitatively small but biologically significant, because in the field, males responded preferentially to traps baited with a pheromone blend that is similar to that emitted by P1 females relative to a blend similar to that emitted by P2 females. In initial crosses, variation in the quantity and quality of pheromone blends among families of P1, P2, and F1 hybrid females was examined. In F1 females the relative proportions (quantity relative to the major component) of (Z)-5-dodecenyl acetate (Z5-12∶Ac) and (Z)-7-tetradecenyl acetate (Z7-14∶Ac) were intermediate to parental lines. In a second more extensive set of crosses, analyses included P1, P2, F1, F2, and selected backcrosses. The relative proportion of Z5-12∶Ac, Z7-14∶Ac, and Z9-14∶Ac emitted by F1 females were intermediate to parental lines. The frequency distributions of relative proportions of these components emitted by females were not consistent with those expected under a single autosomal or sex-linked gene hypothesis, suggesting that more than one gene is involved in the quantitative differences in the pheromone blend.
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  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2981-2992 
    ISSN: 1573-1561
    Schlagwort(e): Feltia jaculifera ; Feltia ducens ; dingy cutworm ; Lepidoptera ; Noctuidae ; sex pheromone ; pheromone polymorphism ; pheromonal phenotypes ; sibling species ; (Z)-7-dodecenyl acetate ; (Z)-9-tetradecenyl acetate ; (Z)-11-hexadecenyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The sex pheromone components of the two sibling species of the dingy cutworm that occur on the prairies of western Canada were identified in abdomen-tip extracts from calling female moths. Three monounsaturated acetates, (Z)-7-dodecenyl acetate, (Z)-9-tetradecenyl acetate, and (Z)-11-hexadecenyl acetate, are common to both species in ratios of 100∶13∶3 for species A and 0.3∶0.5∶100 for species B. The most effective synthetic blends for the attraction of male moths in the field consisted of these three components in ratios of 10∶1∶0 at 8.8Μg/lure for species A and 1∶1∶2000 at 500Μg/lure for species B. The addition of Z5-12∶Ac to either blend reduced the catches and the addition of Z7-12∶OH orZ11-16∶OH to the three-component blend reduced the catches of species B males. The species are morphologically indistinguishable, but the identity of the males attracted to the synthetic blends could be confirmed by their antennal responses to a test blend of the three components using a GC-EAD system. Both synthetic attractant blends are competitive with females and will be useful for studying the distribution, biology, and relative abundances of the two species.
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 521-529 
    ISSN: 1573-1561
    Schlagwort(e): Behavior ; hydrocarbons ; kairomone ; kinesis ; Ostrinia nubilalis ; Lepidoptera ; Pyralidae ; Trichogramma nubilale ; Hymenoptera ; Trichogrammatidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A kairomone that effects host-seeking behavior inTrichogramma nubilale Ertle and Davis, an egg parasitoid of the European corn borer,Ostrinia nubilalis (Hübner), was isolated from moth scales of the European corn borer. The kairomone was identified as a mixture of 11,15-, 13,17-, and 15,19-dimethylnonatriacontanes. The three dimethylnonatriacontanes were synthesized, and bioassays showed that the 13,17 isomer was the most active in terms of klinokinetic and retention effects. The 11,15 isomer and the 15,19 isomer had some effect on klinokinesis, but they failed to effect retention of the wasps. The 13,17-dimethylnonatriacontane is considered to be the most important component of the kairomone.
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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 3043-3052 
    ISSN: 1573-1561
    Schlagwort(e): oviposition-deterring pheromone ; Pieris brassicae ; Pieris rapae ; oviposition ; Lepidoptera ; Pieridae ; dispersal behavior ; pheromone perception ; oviposition-deterring pheromone receptors ; electroantennogram
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Adult females of several lepidopteran species avoid oviposition near conspecific eggs. Laboratory and field studies indicate that visual factors as well as chemical host markers may be involved in egg avoidance behavior. The oviposition-deterring pheromones (ODP) of two pierids,P. brassicae andP. rapae have been studied in considerable detail. The ODPs are probably produced in the female accessory glands and contain volatile and nonvolatile components. They are perceived by nonspecialized antennal or tarsal receptors, respectively. The ODP ofP. brassicae affects oviposition ofP. rapae females and vice versa. ODPs show promise for insect control programs, but more information on oviposition behavior in the presence of ODP under field conditions is required.
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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 499-508 
    ISSN: 1573-1561
    Schlagwort(e): Behavior ; biological control ; Eucelatoria bryani ; Diptera ; Tachinidae ; parasitoid ; habitat selection ; semiochemical ; Heliothis spp ; Lepidoptera ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The response of the parasitoidEucelatoria bryani Sabrosky to fresh plant material and several plant extracts was examined in an olfactometer. The plants tested can serve as a food source for hosts (Heliothis spp.) of the parasitoid. Females responded positively to 13 of the 19 fresh plant tissues tested, and all of the extracts tested. Males responded to only two of the fresh plant tissues and to none of the extracts. The significance of plant variety, morphology, and phenology on the host habitat-selection behavior of this parasitoid is discussed.
    Materialart: Digitale Medien
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  • 78
    ISSN: 1573-1561
    Schlagwort(e): Structure-activity ; single-cell recordings ; receptor interaction ; (Z)-5-decenyl acetate ; chain-shortened analogs ; volatility ; vapor pressure ; Agrotis segetum ; Lepidoptera ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Structure-activity relationships for chain-shortened analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, have been studied by electrophysiological single-sensillum technique and interpreted in terms of a previously reported receptor-interaction model. The results indicate that the terminal methyl group, as well as the acetate group, interacts with highly complementary receptor sites. The terminal alkyl chain is suggested to interact with a hydrophobic “pocket” extending over the two methylene groups closest to the terminal methyl group. The amounts of stimulus actually released from the odor source have been studied. The results demonstrate the necessity to take differences of volatility into account in comparisons of electrophysiological data for compounds of different chain lengths. It is shown that relative vapor pressures may to a good approximation be employed to estimate correction factors.
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  • 79
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 743-748 
    ISSN: 1573-1561
    Schlagwort(e): Sarpedobilin ; bile pigment ; butterfly ; Papilio graphium stresemani stresemani ; P. sarpedon ; P. weiskei ; Lepidoptera ; Papilionidae ; bioecological relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The doubly cyclized bile pigment sarpedobilin (3) represents a unique case in nature. In spite of being present in trace amounts in many butterfly and moth species containing pterobilin (1) or phorcabilin (2) as the main bilin, this substance occurs as the main pigment in a restricted number of species geographically limited to Southeast Asia. We have isolated and identified sarpedobilin3 (as the dimethyl ester) as the main bile pigment fromPapilio graphium stresemani stresemani (from Ceram island, Indonesia) in the amount of ca. 0.1 mg per individual, double that found inPapilio sar-pedon orP. weiskei. We conclude thatP. sarpedon (and subspecies)P. weis-kei, andP. stresemani represent, in terms of evolution (see article), a group of closely related species. By comparison of colored wing patterns and resistance of the chromoproteins to hydrolysis by MeOH-H2SO4,P. stresemani is nearP. weiskei. The bioecological relationships of the three sarpedobilin-containing species is discussed.
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  • 80
    ISSN: 1573-1561
    Schlagwort(e): Antioxidant ; insecticide ; cabbage looper ; Trichoplusia ni ; Lepidoptera ; Noctuidae ; antagonist ; Synergist ; chemical heterogeneity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Plant chemicals naturally exist in complex mixtures, which can interact either additively, synergistically, or antagonistically. We investigated the potential interactions of three naturally occurring antioxidants— nordihydroguaiaretic acid (NDGA), safrole, and α-tocopherol—with the general insecticide carbarayl to affect the performance of cabbage looper larvae (Trichoplusia ni). The cabbage looper is known to produce a mixed-function oxidase enzyme system in response to the presence of carbaryl. We proposed that plant antioxidants would interfere with enzymatic oxidation, enhancing the susceptibility of this insect to carbaryl. Insects were fed artificial diets containing each antioxidant alone or in pairwise combinations with the insecticide carbaryl to test for their effects on the insect's nutritional measurement indices. The three antioxidants tested were not equally effective individually against insect survivorship and interacted differentially in combination with the insecticide. The nutritional indices were measured on insects fed diets containing the chemicals at nonlethal doses. Insects fed 0.001 % wet wt NDGA diets grew 1.62 times less, and had gross and net conversion efficiencies reduced 3.20 and 3.63 times, respectively, compared to the control larvae. Carbaryl (0.002% wet wt) in combination with NDGA acts as an antagonist to the effects mentioned above, while safrole (1 × 10−4 wet wt) had an additive effect when combined with the insecticide, reducing 1.76 times larval relative growth rate and efficiency of conversion of ingested food in respect to the control. The larvae fed significantly more (1.2 times) on both insecticide and safrole diets than on the controls or their combined diets. Larvae fed α-tocopherol alone or in combination with carbaryl had similar growth and conversion efficiencies as controls. We conclude that the effects of different combinations of compounds cannot be predicted a priori and must be determined experimentally.
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  • 81
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; Leucoptera malifoliella ; identification ; minor component ; synergism ; Lepidoptera ; Lyonetiidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A new minor component in the female volatile extract ofLeucoptera malifoliella (Costa) (Lepidoptera, Lyonetiidae) has been identified as 5,9-dimethyloctadecane (2). The amount detected of the minor compound2 ranged from 4 to 8% in comparison with the major component 5,9-dimethylheptadecane (1). Neither compound has been found in the male volatile extract. The identification has been based on its spectroscopic properties and Chromatographic behavior in comparison with an authentic synthetic sample. The synthesis has been carried out through a short route from 2,6-dimethylcyclohexanone (3). In field tests, compound2 appears to act as a Synergist of the major component1 when mixed with the latter in a 100∶0.1– 5 ratio.
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1459-1470 
    ISSN: 1573-1561
    Schlagwort(e): Monarch butterfly ; Danaus plexippus ; Lepidoptera ; Danaidae ; pyrrolizidine alkaloids ; sarracine ; 7-angelylplatynecine ; retronecine ; Senecio mikanioides ; overwintering ; defense
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract California overwintering monarch butterflies contain both pyrrolizidine alkaloids (PAs) and theirN-oxides. Analysis of 76 individual monarchs by TLC, HPLC, GLC, and GC-MS has shown the presence of three types of PAs, the saturated diester sarracine, the saturated monoester 7-angelylplatynecine, and the unsaturated dialcohol retronecine. Monarchs arriving at the overwintering site in Santa Cruz, California, showed a wide variation in both the type and amount of PA present. Those sampled after a PA-containing plant (Senecio mikanioides) had bloomed at the site showed an altered PA profile. While the plant was found to contain sarracine and 7-angelylplatynecine, which are nontoxic to mammals, the monarchs showed an increase in retronecine levels, a toxic PA, after the plant bloom. Apparently monarchs utilize PA-containing plants both en route to their overwintering site and at the site, and potentially alter those PAs to forms toxic to mammals.
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1485-1493 
    ISSN: 1573-1561
    Schlagwort(e): Acetate ester ; acetate esterase ; alcohol ; oxidase ; Choristoneura fumiferana ; Choristoneura orae ; Lepidoptera ; Tortricidae ; pheromone ; spruce budworm ; biosynthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The released pheromone and the glandular lipids, labeled with [14C]acetate, were analyzed fromChoristoneura orae andChoristoneura fumiferana budworm moths by thin-layer chromatography and autoradiography. Radiolabeled lipids in the gland appeared to be identical in the two moths with both insects containing high amounts of 11-tetradecenyl acetates. In contrast, theC. orae moths released primarily labeled acetate ester and alcohol, and the spruce budworm moths (C. fumiferana) labeled aldehyde consistent with the known composition of their respective pheromones. The levels of the enzymes responsible for converting the acetate ester into aldehyde were found to be significantly lower in gland extracts fromC. orae moths than fromC. fumiferana moths. These results implicate an acetate esterase and an alcohol oxidase in controlling the composition of the pheromone blend released from closely related budworm species.
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  • 84
    ISSN: 1573-1561
    Schlagwort(e): Poladryas minuta ; Lepidoptera ; Nymphalidae ; checkerspot ; Penstemon virgatus ; Penstemon secundiflorus ; Scrophulariaceae ; iridoid glycosides ; catalpol ; sequestration ; metabolism ; herbivory
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A bivoltine checkerspot butterfly,Poladryas minuta, is aPenstemon specialist, not known to utilize any other plant genus for oviposition and larval feeding. At several intermontane plains sites of central Colorado, the butterfly utilizesPenstemon virgatus as its sole host plant. Analysis of the host plant showed it to contain three cinnamyl-type catalpol esters (scutellarioside-II, globularin, globularicisin) and catalpol. The host plant contained an average of 10% dry weight iridoids, but some variation among individual plants and leaves within plants was noted. Field-collected butterflies contained 2.1–8.7% dry weight catalpol, but no other iridoids. Adults from larvae fedP. virgatus in the lab contained 4.2–9.0% dry weight catalpol and excreted large amounts of catalpol in the meconium. No catalpol was found in the larval frass. Larvae did not consume three alternate iridoid-containing host-plant species, and most eventually died rather than feed on the alternate plants. Larvae did consume small amounts of artificial diets containing the alternate species andP. virgatus, but most went into diapause and some died. Survival was good on artificial diet containing 10% dry weight of the iridoid esters fromP. virgatus. Only catalpol was found in pupae and adults, but it was absent from the larval frass. The cinnamic-type acids expected from larval hydrolysis of the esters were not found in larval frass, pupae, or adults. These results are contrasted with those found for another checkerspot,Euphydryas anicia, which consumes a different host-plant species but was present at one of the same sites withPoladryas minuta.
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1517-1530 
    ISSN: 1573-1561
    Schlagwort(e): Choristoneura occidentalis ; Lepidoptera ; Tortricidae ; sex pheromones ; behavior ; flight tunnel ; minor components ; electroantennograms
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The behavior of male western spruce budworm moths,Choristoneura occidentalis Freeman, was observed in a flight tunnel in response to virgin females and synthetic sex pheromone components, alone and in blends. Pheromone blends were also compared in the field using sticky trap bioassays. Pheromones were incorporated into small rods of polyvinyl chloride. The blend of 92∶8 (E/Z)-11-tetradecenal-89∶11 (E/Z)-11-tetradecenyl acetate-85∶15 (E/Z)-11-tetradecenol (Ald∶Ac∶OH) that approximated that released from a virgin female moth elicited levels of response similar to those elicited by the female. This blend induced a significantly greater percentage of moths to fly upwind and land at the lure than did the Ald lure. In contrast to the flight-tunnel bioassays, the numbers of moths caught in Ald-baited sticky traps in the field were not significantly increased by the addition of Ac and OH lures. The net upwind groundspeed of flight in response to the 0.05% Ald lure was lower than that in response to the virgin females and was significantly increased by the addition of Ac + OH lures in two of three bioassays. The flight-tunnel bioassays support the hypothesis that the natural blend of major (Ald) and minor (Ac + OH) components stimulates the precopulatory behavior of western spruce budworm male moths at long range (〉 1 m downwind) as well as at close range.
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1531-1546 
    ISSN: 1573-1561
    Schlagwort(e): Choristoneura occidentalis ; Lepidoptera ; Tortricidae ; sex pheromone concentration ; behavior ; flight tunnel ; population differences
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The responses of male western spruce budworm moths,Choristoneura occidentalis Freeman, to a range of concentrations of the major sex pheromone, 92∶8 (E/Z)-11-tetradecenal (Ald), in polyvinyl chloride lures, were observed using the electroantennogram technique, a flight tunnel, and field-trapping bioassays. The responses to virgin female moths were also observed in the flight tunnel and field bioassays. The moths were from three strains: a nondiapausing laboratory colony; field-collected wild budworm; and laboratory-wild crosses. The mean peak amplitude of antennal response and the time required for the electroantennogram signal to return to the baseline after stimulation (lag) increased with Ald concentration in both laboratory and wild moths. However, at Ald concentrations of 0.005% and greater, the lag period of the wild male's antennae was significantly shorter than that of the laboratory male's. The mean number of moths caught in the field in delta sticky traps increased with Ald concentration, but the number of moths caught per trap was not significantly different between concentrations of 0.005 % and 0.5 %. The threshold concentration required to elicit upwind flight in the flight tunnel was between 0.0005 and 0.005% Ald; peak response occurred to 0.05 % Ald but was not significantly different from that to 0.005 % or 0.5% Ald. Moths from all three populations significantly reduced their net upwind groundspeed as they approached the pheromone lure. When pheromone concentration was increased, the net upwind groundspeed of laboratory and lab-wild moths, but not wild moths, was significantly reduced between 2 m and 1 m downwind from the pheromone lure. The three populations of moths differed significantly in the percentage of wing-fanning and copulatory attempts, and in the net upwind groundspeed of flight from 2 m to 1 m downwind from the lure.
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1557-1564 
    ISSN: 1573-1561
    Schlagwort(e): Condensed tannins ; protein ; Spodoptera eridania ; Lepidoptera ; Noctuidae ; Lotus corniculatus ; plant-insect interaction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Plant secondary compounds such as tannins may influence herbivore choice. To determine if herbivory was influenced by tannin concentration,Spodoptera eridania larvae were given a choice ofLotus corniculatus plants whose chemical profiles were altered by fertilization. Herbivores chose plants that had been grown with symbiotic nitrogen fixation as their only nitrogen source more often than fertilized plants. Choice was related to protein concentration, but not to tannin concentration.
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1591-1604 
    ISSN: 1573-1561
    Schlagwort(e): Ostrinia nubilalis ; Lepidoptera ; Pyralidae ; European corn borer ; (E)- and (Z)-11-tetradecen-1-ol acetate ; pheromone analogs ; insect behavior ; sex pheromone ; inhibition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The male sexual behavior-stimulating and inhibiting properties of a series of analogs of the European corn borer sex pheromone were determined in a flight tunnel. The structural requirements for inhibition of pheromonal response were far less restrictive than those for elicitation of that response. Analogs that by themselves elicited upwind flight response from males at a low dose were generally less inhibitory to male response than many of the analogs that had no pheromonal activity. These findings suggest that many pheromone analogs bind to pheromone receptors without provoking behavioral response and possibly undergo slower degradation on the antenna than pheromonally active compounds. The disparity of response to analogs by two pheromonal types of the European corn borer indicates that the pheromone receptor and pheromone catabolic systems are biochemically very different in the two types.
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  • 89
    ISSN: 1573-1561
    Schlagwort(e): Trichothecenes ; sesquiterpines ; Fusarium sporotrichioides ; fungal toxins ; insecticidal activity ; fungal pathogen ; Paecilomyces farinosus ; spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Trichothecene mycotoxins were produced byFusarium sporotrichioides DAOM 197255 isolated from a spruce budworm cadaver. An extract from the culture filtrate containing these metabolites was toxic to budworm when ingested at concentrations as low as 10 ppm in diet, and survivors were predisposed to infection with a fungal entomopathogen. The possible role of these metabolites in the balsam fir-spruce budworm habitat is discussed.
    Materialart: Digitale Medien
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  • 90
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; Agrotis segetum ; Lepidoptera ; Noctuidae ; (Z)-5-decenyl acetate ; (Z)-7-dodecenyl acetate ; (Z)-9-tetradecenyl acetate ; population variation ; olfactory receptors ; single sensillum response ; gas chromatography ; field trapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The female sex pheromone composition and the male electro-physiological response with respect to the three main sex pheromone components, (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate, were investigated in populations ofAgrotis segetum from Armenia and Bulgaria. The percentage composition of the female-produced pheromone was 1∶52∶47 and 1∶42∶57 for the respective populations. Corresponding male receptor frequencies were 9∶90∶1 and 6∶92∶2. EAG response profiles of the male antennae were similar for the two populations. The populations from Armenia and Bulgaria differed from the earlier investigated French and Swedish populations, which have larger amounts of (Z)-5-decenyl acetate in gland extracts and have a majority of (Z)-5-decenyl acetate-sensitive receptors. Investigation of receptor frequencies on antennae of male Hungarian moths showed that individuals could be classified as either Swedish or Armenian/Bulgarian type. Males of the Swedish type were preferentially attracted to the three-component pheromone blend, whereas blends of (Z)-7-dodecenyl and (Z)-9-tetradecenyl acetate, and (Z)-7-dodecenol [pure or in mixture with (Z)-5-decenol] attracted the Armenian/Bulgarian type. The nature of pheromone variation among European and Asian populations of the turnip moth and possible mechanisms maintaining the variation are discussed.
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1649-1655 
    ISSN: 1573-1561
    Schlagwort(e): Pieris rapae ; Lepidoptera ; Pieridae ; imported cabbageworm ; oviposition deterring pheromone ; egg dispersion ; chemoreception
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Eggs ofPieris rapae (L.) contain a water- and methanol-soluble oviposition-deterring pheromone (ODP) that is avoided by ovipositing females offered treated and untreated cabbage leaves in a choice situation. Water extracts of female accessory glands also deter oviposition. Egg washes and gland extracts stimulate a contact chemoreceptor in sensilla on the fore tarsi. Electroantennogram (EAG) recordings show that antennal receptors respond to volatiles from conspecific eggs, but not to volatiles from eggs ofMamestra brassicae. No differences were detected between North American and European insects with regard to production and perception of ODP. These results differ from conclusions in the literature based upon field observations. It is concluded that this discrepancy in due to methodological differences.
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1731-1738 
    ISSN: 1573-1561
    Schlagwort(e): Ilex opaca ; Aquifoliaceae ; Lymantria dispar ; gypsy moth ; Lepidoptera ; Lymantriidae ; saponins ; siaresinolic acid ; qualitative plant defenses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A greater variety of qualitative chemical defenses has been reported in eastern forest trees than might be expected from current interpretation of the plant apparency theory. For the gypsy moth there is an association between the occurrence of alkaloids and unfavorability of certain tree species, as well as the presence of saponins. The latter association, however, is not statistically significant. Species in the genusIlex have been reported to contain both alkaloids and saponins (Barbosa and Krischick, 1987). In this study, determinations were made of the occurrence of alkaloids and saponins inI. opaca and their changes in concentration over time. No alkaloids were detected. Saponins were isolated, and the aglycone siaresinolic acid was identified. Saponin concentration changes seasonally, being highest in early May and lowest in early June leaves.
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  • 93
    ISSN: 1573-1561
    Schlagwort(e): Lymantria dispar ; Lepidoptera ; Lymantriidae ; Liriodendron tulipifera ; Acer rubrum ; Cornus florida ; gypsy moth ; alkaloids ; N-methyl-crotsparine ; 1-(3,4,5-trimethoxyphenyl)-2-(4-allyl-2,6-dimethoxy)propane ; bisphenylpropanoid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Early theories on plant chemical defense against herbivory emphasized that apparent and unapparent plants were primarily defended by different types of compounds. More and more evidence suggests that both quantitative and qualitative defenses are found in apparent plants and that they can play a defensive role against herbivores. A survey of the literature on the gypsy moth suggests not only that there is a large variety of qualitative compounds, as well as the expected quantitative ones, but that unfavored hosts of the gypsy moth are associated with the presence of alkaloids. Foliage of three tree species,Liriodendron tulipifera L.,Acer rubrum L., andCornus florida L., was examined to confirm the presence of alkaloids and other major secondary metabolites. The known sesquiterpene lactone, lipiferolide, and the sugar derivative, liriodendritol, were components ofL. tulipifera leaves, along with a bisphenylpropanoid previously found only in nutmeg. Alkaloid content [i.e., (−)-N-methylcrotsparine content] was low and leaves tested positive for HCN. Leaves ofA. rubrum L. were examined for the presence of gramme, but none could be detected. No alkaloids were detected inCornus florida.
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1743-1750 
    ISSN: 1573-1561
    Schlagwort(e): Diadromus pulchellus ; Hymenoptera ; Ichneumonidae ; Acrolepiopsis assectella ; Lepidoptera ; Acrolepiidae ; leek ; frass ; methyl disulfide ; propyl disulfide ; kairomones ; host plant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Feeding leek moths on an artificial diet has shown that dimethyl and dipropyl disulfides and methyl-propyl disulfide found in frass arise from sulfur compounds specific toAllium. The addition of either propyl or methyl disulfide or their precursors to the diet leads to appearance of the three disulfides in the frass. This implies the transformation of theS-propyl moiety toS-methyl and vice versa by an as yet unknown mechanism.
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1751-1759 
    ISSN: 1573-1561
    Schlagwort(e): Heliothis zea ; Lepidoptera ; Noctuidae ; Nomuraea rileyi ; Deuteromycotina ; fungi ; α-tomatine ; allelochemical ; third trophic level
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract To determine the impact of α-tomatine at the third trophic level, the following model was developed:Nomuraea rileyi (Farlow) Samson, the secondary consumer, acting onHeliothis zea (Boddie), the primary consumer, fed an artificial diet modified with α-tomatine. In vitro, the allelochemical inhibited colony formation and growth of the fungus. The in vivo test revealed that larval growth and developmental time were affected by α-tomatine andN. rileyi. Detrimental effects on pupal development were observed in larvae fed diet containing α-tomatine and also treated withN. rileyi (LC90). The fungus was detected in the hemolymph and tissue of larvae treated with two lethal concentrations (LC50 and LC90) ofN. rileyi, including those fed α-tomatine. At the LC50, α-tomatine protected larvae againstN. rileyi and increased survivorship; at the LC90, it inhibited the development ofN. rileyi, thereby reducing production of conidia. Thus, the allelochemical α-tomatine retains its antifungal qualities beyond the second trophic level, inhibiting the development ofN. rileyi inH. zea.
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1817-1827 
    ISSN: 1573-1561
    Schlagwort(e): Cotton ; groundcherry ; tobacco ; Gossypium ; Desmodium ; Physalis ; plant-insect interaction ; host-plant resistance ; Heliothis spp. ; Lepidoptera ; Noctuidae ; oviposition stimulant ; oviposition deterrent
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The role of plant allelochemicals on the oviposition behavior ofHeliothis virescens (F.),H. subflexa (Guenee), andH. zea (Boddie) was investigated in the laboratory using a “choice” bioassay system. Fresh young leaves of tobacco,Desmodium tortuosum (Swartz) de Candolle, groundcherry (Physalis angulata L.), and cotton (Gossypium hirsutum L.) squares (flower buds) were washed in methylene chloride or methanol, concentrated to 1 g equivalent of washed material, and applied to a cloth oviposition substrate. Each of the extracts—including groundcherry, a nonhost—stimulated oviposition byH. virescens. H. subflexa were stimulated to oviposit by groundcherry extract, its normal host, and extract from cotton squares, a nonhost. None of the extracts stimulated oviposition byH. zea, although all except groundcherry were from reported hosts. The sensitivity of the bioassay was confirmed by givingH. virescens andH. subflexa an opportunity to choose between extracts that showed stimulant qualities when tested independently versus only solvent-treated controls. In these tests, tobacco showed the highest level of stimulant activity forH. virescens; groundcherry exhibited the highest level of stimulation forH. subflexa.
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  • 97
    ISSN: 1573-1561
    Schlagwort(e): Uresiphita reversalis ; Lepidoptera ; Pyralidae ; Genista ; French broom ; quinolizidine alkaloids ; sequestration ; aposematism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Larvae ofUresiphita reversalis feed almost exclusively on legumes in the tribe Genisteae, which characteristically contain a variety of quinolizidine alkaloids. The larvae are aposematic, and onGenista monspessulana, a major host in California, they feed on the youngest leaves, at the periphery of the plant. These leaves, which were preferred over older foliage in choice tests, contained four to five times the level of alkaloid found in older leaves. The major alkaloids detected in these plants were dehydroaphylline andN-methylcytisine, together accounting for 74% of the total. Preliminary analyses showed the alkaloid profile of exuviae from larvae feeding on these plants was very similar to that of the plants. Two alkaloids, sparteine and cytisine, which are known components of some hosts ofU. reversalis, were phagostimulants for fifth-instar larvae when added to sucrose-impregnated glass-fiber disks. In addition, when sparteine was added to foliage ofG. monspessulana, effectively doubling the percent dry weight of alkaloid, the growth rate of late-instar larvae was positively affected. Cytisine added to plants had no discernible effect on growth of larvae. Alkaloid levels in larvae and in their frass were proportional to levels in the plants on which they fed. Although the majority of alkaloid was excreted, that which was sequestered by the insect was found entirely in the integument, possibly confering some protection from predators.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    ISSN: 1573-1561
    Schlagwort(e): Trichogramma pretiosum ; Hymenoptera ; Trichogrammatidae ; Heliothis zea ; Spodoptera frugiperda ; Lepidoptera ; Noctuidae ; sex pheromone ; kairomone ; wind tunnel ; orientation behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The behavior ofTrichogramma pretiosum Nixon wasps when exposed to different olfactory cues was studied in a wind tunnel. Compared to clean air, the sex pheromone of its hostHeliothis zea (Boddie) increased wasp residence times, walking times, and path lengths on a platform and decreased walking velocity. If wasps were released on top of a glass rod above a platform, the odor caused the wasps to land shortly after takeoff. In addition, a clear dose effect with regard to total residence and walking times was found. These responses were not elicited by three dosages of the sex pheromone ofSpodoptera frugiperda (J.E. Smith) or by a blend of saturated acetates. These results correspond with the observation thatH. zea is a common field host ofT. pretiosum, whereas eggs ofS. frugiperda are rarely attacked by this parasitoid.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; sex attractant ; Cydia caryana ; Lepidoptera ; Tortricidae ; Olethreutinae ; (Z)-8-dodecen-1-ol acetate ; (E)-9-dodecen-1-ol acetate ; dodecanol acetate ; (E, E)-8 ; 10-dodecadien-1-ol acetate ; (E, Z)-8,10-dodecadien-1-ol acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Extracts of the sex pheromone glands of femaleCydia caryana were evaluated by electroantennography and gas chromatography-mass spectrometry. These studies suggested the following compounds were potential sex pheromone components: (Z)-8- and/or (E)-9-dodecenyl acetate (50 pg/female), dodecyl acetate (40 pg/female), and (E, E)-8,10-dodecadienyl acetate (25 pg/female). In field tests only the diene produced trap catch, and when the other components were added to the diene, trap catch was not increased. When the diene was formulated in red natural rubber septa, only transient and low catches were obtained, but when gray halobutyl isoprene elastomeric septa were used, high and consistent catches were obtained for eight weeks. Catches depended on the ratio of (E, E)-8,10 to (E, Z)-8,10 isomers. High catches were obtained for anEE toEZ ratio of 100 ∶ 0.6, and insignificant catches were obtained when the ratio was 100 ∶ 3. Equivalent catches were obtained for dosages of 50, 100, and 200 μg/septum.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 2533-2547 
    ISSN: 1573-1561
    Schlagwort(e): Detoxification enzymes ; glutathione transferase ; gypsy moth ; Juglandaceae ; juglone ; Lymantria dispar ; Lepidoptera ; Lymantriidae ; nutritional ecology ; protein ; quinone ; quinone reductase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The individual and interactive effects of dietary protein and juglone on larval performance and midgut detoxification enxymes were investigated for the gypsy moth,Lymantria dispar. The experimental design was a 2 × 3 factorial, with two levels of protein and three levels of juglone. We monitored survival/development rates from egg hatch to pupation and conducted fourth-instar feeding trials for determination of nutritional indices. Enzyme solutions were prepared from midguts of fifth instars and assayed for polysubstrate monooxygenase, esterase, quinone reductase, and glutathione transferase activities. Results showed that low protein levels prolonged development times, increased consumption rates, and reduced pupal weights. Juglone markedly reduced survival, growth, and consumption rates, increased development times, and reduced pupal weights. The interaction between protein and juglone influenced larval digestion efficiencies and female pupal weights. Polysubstrate monooxygenase activities were unaffected by diet, whereas esterase activities increased in response to both low dietary protein and presence of juglone. Low protein levels increased soluble quinone reductase activities but decreased glutathione transferase activities. Glutathione transferase activities were lowest in larvae fed low-protein, high-juglone diets and may have contributed to the especially poor performance of larvae on those diets. Quinone reductase and glutathione transferase are the systems of importance in detoxification of juglone, and moderate to low activities of these enzymes may explain why gypsy moths perform poorly on members of the Juglandaceae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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