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  • Coleoptera  (268)
  • Saccharomyces cerevisiae  (233)
  • Springer  (501)
  • National Academy of Sciences
  • Periodicals Archive Online (PAO)
  • 1985-1989  (339)
  • 1980-1984  (162)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 4 (1989), S. 49-53 
    ISSN: 1476-5535
    Keywords: l-Phenylacetyl carbinol ; Saccharomyces cerevisiae ; Yeast ; Benzaldehyde ; Biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The rate of production ofl-phenylacetyl carbinol bySaccharomyces cerevisiae in reaction mixtures containing benzaldehyde with sucrose or pyruvate as cosubstrate was investigated in short 1 h incubations. The effect of yeast dose rate, sucrose and benzaldehyde concentration and pH on the rate of reaction was determined. Maximum biotransformation rates were obtained with concentrations of benzaldehyde, sucrose and yeast of 6 g, 40 g and 60 g/l, respectively. Negligible biotransformation rates were observed at a concentration of 8 g/l benzaldehyde. The reaction had a pH optimum of 4.0–4.5. Rates of bioconversion of benzaldehyde and selected substituted aromatic aldehydes using both sucrose and sodium pyruvate as cosubstrate were compared. The rate of aromatic alcohol production was much higher when sucrose was used rather than pyruvate.o-Tolualdehyde and 1-chlorobenzaldehyde were poor substrates for aromatic carbinol formation although the latter produced significant aromatic alcohol in sucrose-containing media. Yields of 2.74 and 3.80 g/l phenylacetyl carbinol were produced from sucrose and pyruvate, respectively, in a 1 h reaction period.
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  • 2
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 81-84 
    ISSN: 1476-5535
    Keywords: Ethanol fermentation ; Wheat starch ; Saccharomyces cerevisiae ; immobilization ; Continuous dynamic immobilized biocatalyst bioreactor ; Biocatalyst bioreactor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A simple and efficient method of conversion of wheat starch B to ethanol was investigated. Employing a two-stage enzymatic saccharification process, 95% of the wheat starch was converted to fermentable sugars in 40 h. From 140 g/l total sugars in the feed solution, 63.6 g/l ethanol was produced continuously with a residence time of 3.3 h in a continuous dynamic immobilized biocatalyst bioreactor by immobilized cells ofSaccharomyces cerevisiae. The advantages and the application of this bioreactor to continuous alcoholic fermentation of industrial substrates are presented.
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  • 3
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    European journal of nutrition 22 (1983), S. 205-212 
    ISSN: 1436-6215
    Keywords: Schwermetallwirkung ; Malatdehydrogenase ; Glutamatdehydrogenase ; Glycerinaldehyd-3-phosphatdehydrogenase ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The difference between cadmium, zinc, lead, and mercury in regard of their effects on the activity of the enzymes tested is very slight. Concentrations higher than 10−5 M reduce significantly the activity of the enzymes, and concentrations of approximately 10−3 M inhibit it completely. An increase of the activity cannot be detected. The addition of combinations of cadmium, zinc, and lead results in a summing up of the toxic effects, whereas the interaction between mercury and the other three heavy metals shows a cumulative effect, which is appointed nearly completely by the heavy metal more toxic. The findings suggest that under in-vitro conditions there exists a direct interaction between the heavy metals and the enzymes.
    Notes: Zusammenfassung Die vier Schwermetalle Cadmium, Zink, Blei und Quecksilber unterscheiden sich in ihrer Wirkung auf die Aktivität der untersuchten Enzyme nur sehr wenig. Konzentrationen über 10−5 M vermindern die Enzymaktivität signifikant, und Konzentrationen von etwa 10−3 M unterbinden sie völlig. Eine Steigerung der Enzymaktivität läßt sich nicht feststellen. Die Zugabe von Cadmium-, Zink- und Bleikombinationen führt zu einer Addition der toxischen Effekte, während bei der Interaktion zwischen Quecksilber und den anderen drei Schwermetallen die Gesamtwirkung fast ausschließlich durch das stärker hemmende Schwermetall allein bestimmt wird. Die erhaltenen Ergebnisse lassen vermuten, daß es unter Invitro-Bedingungen zu einer direkten Wechselwirkung zwischen den Schwermetallen und den Enzymen kommt.
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  • 4
    ISSN: 1570-7458
    Keywords: Ceutorhynchus constrictus ; Coleoptera ; Curculionidae ; Ceutorhynchinae ; Alliaria petiolata ; garlic mustard ; Brassicaceae ; Cruciferae ; glucosinolates ; sinigrin ; host plant selection ; monophagous ; feeding stimulants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Ceutorhynchus constrictus Marsh. (Coleoptera: Chrysomelidae: Ceutorhynchinae) ist ein monophager Rüsselkäfer, der an Knoblauchhederich frisst. Das Wirtswahl-Verhalten dieses Käfers ist im Labor untersucht worden. Die meisten Crucifiren waren im Wahlversuche nicht akzeptiert, wenn Knoblauchhederich als Vergleichspflanze vorhanden war. Von Brassica nigra, Sinapis alba, und Thlaspi arvense wurden im Vergleich gleiche Mengen verzehrt wie von der Wirtspflanze. Blühende Descurainia sophia Pflanzen wurden, im Gegensatz zu Jungpflanzen der gleichen Art, angenommen. Die wichtichsten Phagostimulanten in Extrakten von Knoblauchhederich-Blättern waren ungeladene, wasserlösliche Substanzen. Das häufigste Glukosinolat im Knoblauchhederich, Sinigrin, war auch ein Phagostimulant. Doch war die phagostimulierende Wirkung von Sinigrin nur in Kombinationen mit noch nicht identifizierten, ungeladenen Substanzen aus Knoblauchhederich-Blätter nachweisbar. Wirtspfanzen-Beziehungen von monophagen Insekten werden diskutiert im Zusammenhang mit der Eigenart des Glukosinolat-Inhaltes ihrer Wirtspflanzen.
    Notes: Abstract Host plant relations of the monophagous weevil Ceutorhynchus constrictus Marsh. (Coleoptera: Curculionidae: Ceutorhynchinae) feeding on garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Cruciferae) were studied in the laboratory. Most other crucifers were rejected in choice tests using garlic mustard as a reference plant, but Brassica nigra, Sinapis alba and Thlaspi arvense were as acceptable as the host plant. Flowering plants of Descurainia sophia were acceptable while young plants of this species were not. The most important feeding stimulants in extracts of garlic mustard were uncharged, water soluble compounds. The most abundant glucosinolate in garlic mustard, sinigrin, was a feeding stimulant, too. However, the feeding stimulatory activity of sinigrin was only expressed in the presence of still unidentified uncharged compounds from garlic mustard leaves. Host plant relations in monophagous crucifer-feeding insects is discussed in relation to the distinctness of glucosinolate patterns found in their host plants.
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  • 5
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    Entomologia experimentalis et applicata 37 (1985), S. 241-245 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Bruchidae ; Callosobruchus ; cowpea weevil ; egg recognition ; oviposition deterrents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Plusieurs expériences ont été réalisées pour déterminer pour quelles raisons les femelles de Callosobruchus maculatus évitent de pondre sur les graines portant des oeufs. La répulsion a été associée à l'oeuf lui-même et non à une autre activité de l'adulte sur la graine. Des stimuli tant chimiques que physiques (tactiles) ont semblé impliqués dans la découverte des oeufs; la substance répulsive était plus soluble dans le méthanol que dans l'éther ou l'eau. Contrairement à des études antérieures sur C. chinensis, nous avons observé que les femelles n'étaient pas dissuadées de pondre sur des graines exposées préalablement à de fortes densités de mâles.
    Notes: Abstract Several experiments were conducted to determine the mechanism by which ovipositing cowpea weevils, Callosobruchus maculatus (F.), avoid egg-laden seeds. Deterrence was associated with the egg itself and not with other adult activities on the host. Both chemical and physical (tactile) stimuli appear to be involved in egg recognition; the chemical deterrent was more soluble in methanol than in ether or water. Contrary to a previous study using C. chinensis (L.), we found that females were not deterred from ovipositing on seeds that had been exposed to high densities of males.
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  • 6
    ISSN: 1570-7458
    Keywords: Pterostichus melanarius ; Coleoptera ; Carabidae ; pitfall traps ; insecticides ; prey ; hunger ; activity ; Rhopalosiphum padi ; Fenitrothion ; Sumicidin (Fenvalerate) ; spring barley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Au cours d'essais à grande échelle, effectués en 1981 et 1982, sur orge de printemps, pour évaleur l'effet des insecticides Fenitrothion et Sumicidine (fenvalerate) sur les arthropodes utiles, un accroissement significatif des captures, dans des trappes pièges de Barber, de Pterostichus melanarius (Illiger) a été observé plusierus semaines après le traitement dans les lots traités par rapport aux lots témoins. Significativement plus de femelles de P. melanarius ont été capturées dans les parcelles traitées pendant cette période d'accroissement après traitement. Une diminution correspondante dans les populations de proies a été observée à la suite des traitements. Chaque femelle de P. melanarius des parcelles traitées avait une fraction significativement moins importance de son intestin remplie d'aliments solides (arthropodes) que celles des parcelles non traitées. Des auteurs précédents avaient observé des taux de capture plus rapides dans les trappes et ne plus grande mobilité des carabes affamés. La réduction des populations proies par l'application d'insecticides affamerait les carabes dont l'activité serait par suite plus élevée. Comme le taux de captures dans les trappes est dû à la fois à la taille de la population et à son activité, on en déduit que la capture par trappes seule ne peut donner une image exacte de l'effet des insecticides sur les populations de carabes dans les champs.
    Notes: Abstract During large-scale field experiments in 1981 and 1982, designed to assess the effects of the insecticides Fenitrothion and Sumicidin (Fenvalerate) on beneficial arthropods in spring barley, significant increases in pitfall-trap catches of Pterostichus melanarius (Illiger) were observed in treated plots compared to untreated controls, several weeks after treatment. Significantly more female P. melanarius were caught in treated plots during these post-treatment increases. Corresponding decreases were observed in prey populations following treatments. Individual female P. melanarius from treated plots had significantly fewer of their gut areas full of solid (arthropod) food when compared to those from untreated control plots. Earlier workers observed both faster recapture rates in pitfalls and higher mobility in hungry carabid beetles. The following hypothesis is suggested: reducing prey populations by the application of insecticides results in hungrier carabid beetles with consequently higher activity. Since pitfall-trap catch is determined not only by population size but also activity, it is argued that pitfall-trap catches alone cannot give a true measure of the effects of insecticides on carabid populations in the field.
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  • 7
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    Journal of insect behavior 2 (1989), S. 139-141 
    ISSN: 1572-8889
    Keywords: Coleoptera ; Heteroceridae ; egg guarding ; parental care ; predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 8
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    Journal of insect behavior 2 (1989), S. 841-847 
    ISSN: 1572-8889
    Keywords: cost of mating ; semelparous ; Photinus collustrans ; Coleoptera ; Lampyridae
    Source: Springer Online Journal Archives 1860-2000
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  • 9
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    Journal of insect behavior 1 (1988), S. 111-115 
    ISSN: 1572-8889
    Keywords: Coleoptera ; Anobiidae ; Anobium punctatum ; sex pheromone ; flying beetles ; wind tunnel ; Stegobium paniceum
    Source: Springer Online Journal Archives 1860-2000
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  • 10
    ISSN: 1572-8773
    Keywords: Manganese ; Electron spin resonance ; Superoxide dismutase ; Saccharomyces cerevisiae ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Manganese accumulation was studied by room-temperature electron spin resonance (ESR) spectroscopy inSaccharomyces cerevisiae grown in the presence of increasing amounts of MnSO4. Mn2+ retention was nearly linear in intact cells for fractions related to both low-molecular-mass and macromolecular complexes (‘free’ and ‘bound’ Mn2+, respectively). A deviation from linearity was observed in cell extracts between the control value and 0.1 mM Mn2+, indicating more efficient accumulation at low Mn2+ concentrations. The difference in slopes between the two straight lines describing Mn2+ retention at concentrations lower and higher than 0.1 mM, respectively, was quite large for the free Mn2+ fraction. Furthermore it was unaffected by subsequent dialyses of the extracts, showing stable retention in the form of low-molecular-mass complexes. In contrast, the slope of the line describing retention of ‘bound’ Mn2+ at concentrations higher than 0.1 mM became less steep after subsequent dialyses of the cell extracts. This result indicates that the macromolecule-bound Mn2+ was essentially associated with particulate structures. In contrast to Cu2+, Mn2+ had no effect on the major enzyme activities involved in oxygen metabolism except for a slight increase of cyanide-resistant Mn-superoxide dismutase activity, due to dialyzable Mn2+ complexes.
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  • 11
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    Entomologia experimentalis et applicata 39 (1985), S. 81-84 
    ISSN: 1570-7458
    Keywords: induced change ; induced resistance ; chemical change ; feeding ; herbivore ; feeding tests ; feeding preferences ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les choix alimentaires d'un groupe de chrysoméles spécialistes ou généralistes a été étudié en utilisant 3 méthodes: plantes entières, feuilles coupées, rondelles de feuilles. Les méthodes utilisées out eu un effet très significatif sur les préférences relatives des chrysomèles du maïs, du haricot et de la courge. Dans quelques cas le seuil de signification statistique pour un choix particulier a été modifié par la méthode utilisée et dans d'autres cas l'ordre de préférence a été totalement inversé. Les choix alimentaires des spécialistes ont été moins affectés par la méthode utilisée que pour les espèces les plus généralistes. Il y a eu aussi un effet plus important des différences entre les méthodes rondelle de feuilles et feuille entière qu'entre feuille entière et plante entière. Les changements chimiques induits dans les plantes par les dégâts sont probablement très répandus et les chercheurs devraient en tenir compte quand ils programment et interprètent des expériences sur les préférences alimentaires.
    Notes: Abstract Feeding preferences of a group of specialist and generalist chrysomelid beetles were examined using three test methods: whole plants, excised leaves and leaf discs. Method of testing had a very significant effect on relative preferences of the beetles for corn, bean and squash. In some cases the level of statistical significance for a particular preference was affected by test methodology and in other cases the direction of preference was reversed altogether. The feeding preferences of the specialist beetle species were less affected by test method than were the more generalist species. There was also a much greater effect of the difference in test method between the disc test and whole leaf test than between the whole leaf test and whole plant test. Chemical changes in plants induced by damage are probably quite widespread in plants and investigators should take this into account when designing and interpreting tests of insect feeding preference.
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  • 12
    ISSN: 1570-7458
    Keywords: Aggregation pheromone ; sitophilate ; 1-ethylpropyl 2-methyl-3-hydroxypentanoate ; stereoisomers ; enantiomers ; Sitophilus granarius ; granary weevil ; Coleoptera ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé S. granarius L. est un déprédateur important des grains stockés. Le (R*,S*)-1-éthylpropyl 2-méthyl-3-hydroxypentanoate a été identifié en 1987 comme le principal composé du sitophilate, la phéromone mâle d'agrégation de S. granarius. La composition énantiométrique du sitophilate a été déterminée par 3 méthodes: 1) tests biologiques des énantiomères synthétiques (2S,3R) et (2R,3S) du diastéréomère actif (R*,S*); 2) spectrométrie RMN 1H des esters Mosher dérivés de la phéromone naturelle et des sitophilates de synthèse (2S*,3R*)-et (2R*,3S*); 3) comparaison en capillarité GLC des temps de rétention des dérivés naturels de la phéromone et des 2 éniantiomères de synthèse. La combinaison des 3 méthodes confirme que le (2S,3R) énantiomère est la forme active du sitophilate. Le mâle produit 〉96% de l'énantiomère (2S,3R). Il n'y a pas eu attraction de S. granarius par le (2R,3S) sitophilate. S. oryzae L. et S. zeamais Motsch n'ont pas été attirés par le (2S,3R)-sitophilate. L'utilisation du (2S,3R)-1-éthylpropyl 2-méthyl-3-hydroxypentanoate dans les pièges devrait permettre une détection précoce de la présence de S. granarius dans des stocks de grains.
    Notes: Abstract The enantiomeric composition of sitophilate, the granary weevil [Sitophilus granarius (L.)] male-produced aggregation pheromone [(R*,S*)-1-ethylpropyl 2-methyl-3-hydroxypentanoate)], was determined by three methods: (1) bioassaying the synthetic (2S,3R) and (2R,3S) enantiomers of the active (R*,S*) diastereomer; (2) 1H NMR spectroscopy of Mosher ester derivatives of the natural pheromone and synthetic (2S,3R)-and (2R,3S)-sitophilate; and (3) capillary GLC comparisons of the retention times of derivatized natural pheromone and the two synthetic enantiomers. The combined methods confirmed the (2S,3R) enantiomer as the active form of sitophilate. Male granary weevils were shown to produce 〉96% (2S,3R)-sitophilate. No significant attraction of S. granarius by the (2R,3S) enantiomer was observed. Rice and maize weevils [S. oryzae (L.) and S. zeamais Motschulsky] were not attracted by (2S,3R)-sitophilate.
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  • 13
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    Entomologia experimentalis et applicata 51 (1989), S. 133-140 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; potato ; plant resistance ; glandular trichomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les mécanismes de défense de la pomme de terre sauvage, S. berthaultii Hawkes, aux larves de Leptinotarsa decemlineata Say, ont été étudiés par ablation sélective des trichomes glandulaires et par l'élimination de leur exsudat des folioles, et par comparaison avec S. tuberosum L. qui a perdu les trichomes glandulaires défensifs A et B. L'ablation des trichomes A a augmenté la proportion de larves ayant consommé S. berthaultii. L'élimination de l'exsudat des trichomes B a augmenté la proportion de consommatrices et réduit la mortalité. Les principaux composés actifs de l'exsudat B, c'est-à-dire des esters d'acides gras de sucrose, n'étaient actifs qu'en présence de trichomes A. Les esters de sucrose n'ont pas modifié la consommation larvaire sur folioles de S. tuberosum, ou sur disques de feuilles de S. berthaultii dont les trichomes A avaient été enlevés. La croissance des larves survivantes n'a pas été modifiée significativement par l'ablation des trichomes A ou l'élimination de l'exsudat de B. La croissance des larves a été significativement augmentée quand les folioles de S. berthaultii ont été incorporés dans l'aliment artificiel après élimination de la barrière physique due aux pédoncules B. La croissance a été de même importance sur aliments artificiels contenant des feuilles (fraiches ou en poudre lyophylisée) de S. berthaultii ou de S. tuberosum, mais plus faible que sur folioles de S. tuberosum. La présence de trichomes A est indispensable à la résistance de S. berthaultii aux L, de L. decemlineata. Les gouttelettes de type B contenant des esters de sucrose augmentent l'expression de la résistance en présence d'une défense active par trichomes A.
    Notes: Abstract The defensive mechanisms of the wild potato, solanum berthaultii Hawkes, to larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say), were studied by selective removal of glandular trichomes and trichome exudates from leaflets, and by comparing performance on S. berthaultii and on the cultivated potato, S. tuberosum L., which lacks defensively active type A and B glandular trichomes. Removal of type A trichomes increased the proportion of larvae that fed on S. berthaultii. Removal of the exudate from type B trichomes increased the proportion of larvae that fed and led to a decrease in mortality. The predominant active compounds in type B exudate, i.e. fatty acid esters of sucrose, were only effective in the presence of type A trichomes. Sucrose esters did not affect larval feeding on S. tuberosum leaflets or on S. berthaultii leaf discs from which the type A trichomes had been removed. Growth of surviving larvae was not significantly affected by removing type A trichomes or type B exudate. Growth of larvae was significantly increased when S. berthaultii leaflets were presented in artificial diet which eliminated the physical barrier of the type B stalks. Growth was no different on artificial diet containing either S. berthaultii or S. tuberosum leaf material (fresh or lyophilized powder) but was poorer on these diets than on S. tuberosum leaflets. The presence of type A trichomes is a fundamental requirement for expression of S. berthaultii resistance to L1 L. decemlineata. Type B droplets containing sucrose esters increase the expression of resistance in the presence of defensively-active type A trichomes.
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  • 14
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    Cellular and molecular life sciences 40 (1984), S. 1159-1161 
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; 5-trifluoromethyl-6-àzauracil ; yeast cell cultures ; cell division ; inhibition of
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cell division, as studied in asynchronous cultures of yeast cells, is sensitive to 5-trifluoromethyl-6-azauracil (F3CAzU). Under defined conditions (10 mmoles l−1 F3CAzU) this compound blocks immediately and completely the process of cell division. Using synchronized cells, the time-point at which division process of yeast cell can be inhibited by F3CAzU has been determined. The inhibitor effect of this compound is completely reversed by thymine, thymidine and uracil.
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  • 15
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    Cellular and molecular life sciences 43 (1987), S. 886-888 
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; trichothecenes ; mycotoxins ; vitamins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several trichothecene mycotoxins were shown to inhibit the growth ofSaccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 μg of toxin per disc. Incubation ofS. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and α-tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.
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  • 16
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    Cellular and molecular life sciences 43 (1987), S. 888-890 
    ISSN: 1420-9071
    Keywords: Thiaminase ; thiamine ; thiamine antagonist ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It was found that cell-free extracts ofSaccharomyces cerevisiae contain thiaminase II which hydrolyzes thiamine and thiamine analogs. The possible involvement of this enzyme and thiamine-synthesizing enzymes in thiamine production from thiamine antagonists is discussed.
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  • 17
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    Cellular and molecular life sciences 42 (1986), S. 204-207 
    ISSN: 1420-9071
    Keywords: Coleoptera ; chemical defense ; feeding deterrent ; alkaloid ; homotropane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The blood of the Mexican bean beetle (Epilachna varivestis) contains a homotropane alkaloid, euphococcinine (1). The beetles ‘reflex bleed’ when disturbed, thereby deploying the alkaloid, which is provenly deterrent to spiders and ants. Newly emerged adults lack the alkaloid, but the compound builds up to deterrent levels in their blood within days. Eggs and larvae ofEpilachna are devoid of the compound.
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  • 18
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    Entomologia experimentalis et applicata 30 (1981), S. 151-156 
    ISSN: 1570-7458
    Keywords: Xyleborus ferrugineus ; pupae ; ecdysteroids ; pharate adult ; radioimmunoassay ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Ecdysteroidtiter weiblicher Puppen von Xyleborus ferrugineus (Fabr.) wurde geschätzt, indem ganze Tiere homogenisiert und radioimmunologisch untersucht wurden. Ein ausgeprägtes Maximum an Ecdysteroiden wurde bei 36 Stunden Puppenent-wicklung beobachtet (743 pg/mg Körpergewicht). Der Titer nahm ab auf 299 pg/mg im Pharatstadium und auf 193 pg/mg unmittelbar vor Schlüpfen der Adulten. Qualitative Studien mit HPLC ergaben in frischen Puppen ein Verhältnis von 3:1 Ecdyson zu 20-Hydrooxyecdyson. Pharatstadien enthielten vor allem 20-Hydrooxyecdyson. Das beobachtete einzige Maximum im Titer stimmt überein mit den Resultaten bei andern untersuchten Coleopteren.
    Notes: Abstract Ecdysteroid titers were estimated on the whole body homogenates of Xyleborus ferrugineus (Fabr.) female pupae during development by radioimmunoassay. A distinct peak of ecdysteroids was observed at 36-hr pupal development (743 pg/mg body wt). Titer declined to 299 pg/mg by the pharate adult stage and to 193 pg/mg body wt just before adult emergence. Qualitative studies by HPLC revealed a ratio of 3:1 ecdysone to 20-hydroxyecdysone in the initial pupal stage. Pharate adults had mainly 20-hydroxyecdysone. The observed single peak in ecdysteroid titer agrees with findings in other studied coleopteran species.
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  • 19
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    Entomologia experimentalis et applicata 37 (1985), S. 113-121 
    ISSN: 1570-7458
    Keywords: Hypera postica ; alfalfa weevil ; allozyme analysis ; Coleoptera ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les allozymes d'Hypera de l'est des USA (Beltsville, Maryland; Washington Co., Illinois), de l'ouest des USA (Logan et St Georges, Utah) et ‘égyptiens’ (Yuma, Arizona; Westmorland, Californie) ont été analysés par électrophorèse sur gel d'acrylamide. L'étude a porté sur 22 loci de 12 enzymes (ACPH, ADH, AMY, AO, EST, GOT, G-6PDH, MDH, ME, SOD, TYR, XDH). L'hétérozygotie moyenne de la population était 0.231, avec une moyenne de loci polymorphes de 0.536. La distance génétique moyenne de l'ensemble des populations était de 0.033 et l'indice de fixation de 0.024. Des loci caractéristiques ont été trouvés qui pourraient permettre de distinguer les Hypera occidentaux des orientaux et des ‘égyptiens’. La faible distance génétique entre les Hypera orientaux et ‘égyptiens’ suggère qu'ils appartiennent à la même souche et sont certainement différents des occidentaux. A partir de cela et d'autres éléments, nous concluons que tous les Hypera des USA sont H. postica Gyllenhal et que l'utilisation d'H. brunneipennis Boheman pour désigner les Hypera ‘égyptiens’ d'Amérique du Nord doit être abandonnée.
    Notes: Abstract Allozyme profiles of eastern weevils (Beltsville, Maryland; Washington Co., Illinois), western weevils (Logan and St. George, Utah), and Egyptian weevils (Yuma, Arizona; Westmorland, California) were compiled by acrylamide gel electrophoresis. Twenty-two gene loci from 12 enzymes (ACPH, ADH, AMY, AO, EST, GOT, G-6PDH, MDH, ME, SOD, TYR, XDH) were analyzed. Mean heterozygosity of these populations was 0.231, with an average proportion of polymorphic loci of 0.536. The mean genetic distance of all weevil populations was 0.033 and the fixation index was 0.024. Diagnostic loci were found which could distinguish western weevils from eastern and Egyptian weevils. The small genetic distance between the eastern and Egyptian weevils suggests that they may be the same strain and are certainly different from the western weevil strain. Based on this and other evidence, we conclude that all weevil strains in the United States are Hypera postica (Gyllenhal), and that the use of H. brunneipennis (Boheman) for the Egyptian alfalfa weevil of North America should be discontinued.
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    Entomologia experimentalis et applicata 34 (1983), S. 291-296 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cyrtobagous ; Salvinia weevil ; Feeding characteristics of larvae ; Development of larvae ; Plant nutrition ; Temperature effects on development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Après leur naissance, les larves de Cyrtobagous sp. passent de 1 à 4 jours à brouter les racines, et de 0 à 9 jours dans les bourgeons de la plante hôte, Salvinia molesta, avant d'y creuser une galerie dans le rhizome. Bien que les larves aient été capables de survivre jusqu'à 38 jours en broutant les racines, quant elles furent privées de rhizome, elle ne purent achever leur développement. Quand les galeries furent commencées, le développement larvaire, entre 21° et 31°, dépendit de la température et de la teneur en azote de l'hôte. Les larves ne se développèrent pas à 17°. Une haute valeur nutritive de l'aliment consommé par les larves réduisit la durée du développement, mais n'influença pas la durée ultérieure de leur développement nymphal. Les lieux de prise de nourriture et les dégâts produits par des larves isolées furent précisés.
    Notes: Abstract Newly-emerged larvae of a salvinia weevil, Cyrtobagous sp. spent from 1–4 days browsing on the roots and from 0–9 days in the buds of the host plant, Salvinia molesta, prior to tunnelling into the rhizome of this aquatic weed. Although larvae were able to survive up to 38 days browsing on roots when rhizomes were withheld, they were unable to complete development. After tunnelling began, larval development between 21° and 31° was dependent on temperature and nitrogen levels in the host. Larvae failed to develop at 17°. High nutritional intake by the larvae reduced larval development time but did not influence duration of their subsequent pupal development. The feeding sites and plant damage produced by individual larvae were assessed.
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  • 21
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    Entomologia experimentalis et applicata 37 (1985), S. 229-233 
    ISSN: 1570-7458
    Keywords: alfalfa weevil ; Coleoptera ; Curculionidae ; Hypera postica ; mutation ; vestigial-wing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des H. postica aux ailes postérieures vestigiales ont été découverts dans une population de Wageningen (Pays Bas) et deux des USA—une lignée orientale de Beltsville (Maryland) et une lignée de H. brunneipennis d'Atascadero (Californie). Ce mutant était absent de 23 autres populations examinées aux USA: 3 de l'est, 7 de l'ouest et 13 de H. brunneipennis. Cette mutation est due à un gène dominant antosomal avec aile normale comme récessif. Le gêne mutant peut être transféré des lignées orientales aux lignées occidentales. Le caractère aile courte peut être pratique pour les manipulations génétiques destinées à maîtriser les populations d'H. postica.
    Notes: Abstract Alfalfa weevils (Hypera postica (Gyllenhal)) with vestigial hind wings were discovered in a population from Wageningen, the Netherlands, and two populations from the United States—an eastern weevil strain from Beltsville, Maryland and an Egyptian weevil strain from Atascadero, California. Such a mutant was absent from 23 other populations surveyed in the United States—three from eastern, seven from western, and 13 from Egyptian weevil strains. This mutation is due to a dominant autosomal gene with normal-wing individuals as recessive. The mutant gene can be transferred from eastern weevil to the western weevil strain. The short-wing trait may be useful for genetic manipulation to control the alfalfa weevil.
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  • 22
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    Entomologia experimentalis et applicata 44 (1987), S. 187-193 
    ISSN: 1570-7458
    Keywords: Calosoma sycophanta ; Carabidae ; Coleoptera ; emigration ; gypsy moth ; Lymantria dispar ; spatial dispersion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude par capture-recapture de Calosoma sycophanta L. (Carabidae) a été effectuée dans deux parcelles de 4 ha en utilisant des pièges distribués sur une grille de 10 sur 10. Pendant la première année d'échantillonnage, Lymantria dispar L. (Lymantriidae) était abondant et les calosomes se sont reproduits, tandis que la seconde année les papillons étaient beaucoup moins nombreux. La distribution des larves de carabes a été examinée aussi pendant la première année sur l'une des stations, et celle des chenilles pendant les deux années avec des toiles d'emballage sur l'autre station. Les dispersions des adultes et larves de calosomes et des chenilles de Lymantria ont été calculées en utilisant la régression du logarithme naturel de la variance de l'échantillon sur le logarithme naturel de la moyenne (méthode de Taylor) et la régression de l'indice de Lloyd d'agrégation moyenne sur la moyenne (méthode d'Iwao). La méthode de Taylor a donné les résultats les plus logiques, et les pentes ont servi à mesurer le degré d'agrégation. Les recaptures de calosomes adultes ont été analysées par les méthodes de Fisher-Ford et Jolly-Seber, associées à la méthode de Jackson pour séparer survie et migration. De même, une nouvelle méthode pour déterminer directement la migration en découvrant combien d'insectes recapturés ont abandonné les microparcelles s'est révélée comme la plus cohérente avec le procédé Fisher-Ford-Jackson. La tendance à l'agrégation est plus forte chez les mâles (d'après la pente du logarithme de la moyenne par rapport au logarithm e de la variance de l'échantillon). La migration et le degré d'agrégation paraissent varier ensemble dans une station, tandis que dans l'autre une telle relation n'apparaît pas clairement. Les femelles malgré des taux de migration variés mais généralement faibles, n'ont jamais pr'esenté de tendance significative à l'agrégation. A l'opposé, les larves de calosomes et de Lymantria ont presenté des distributions agrégatives.
    Notes: Abstract Mark-release studies of Calosoma sycophanta L. (Carabidae) in two 40000 m2 areas were done using traps deployed in 10 by 10 grids. In both areas, gypsy moths, Lymantria dispar L. (Lymantriidae), were abundant the first but not the second year of sampling. The distribution of carabid larvae was also investigated in the first year at one of the sites and the distribution of gypsy moth larvae found under burlap bands determined for 2 years at the other site. Dispersions of beetles and prey were evaluated by Taylor's logarithmic meanvariance method and Iwao's mean-mean crowding method. Taylor's method gave the most consistent results, and the slopes of the regression lines were used to determine degree of clumping. To evaluate dispersal of adult beetles, recapture data were analysed using the Fisher-Ford and Jolly-Seber methods in conjunction with Jackson's method for separating survival and emigration. A new method for estimating emigration was found to be most consistent with the Fisher-Ford-Jackson procedure. The tendency of the beetles to aggregate (measured via Taylor's method) was generally highest for males. In one site, emigration and degree of aggregation for males appeared to vary together, while at the other site no relationship was evident. Females showed few tendencies to aggregate. Both beetle larvae and gypsy moth larvae had clumped distributions.
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    Entomologia experimentalis et applicata 45 (1987), S. 102-104 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Bembidion ; Trechus ; Agonum ; sex determination ; adhesion ; male setae ; tarsomere
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  • 24
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    Entomologia experimentalis et applicata 39 (1985), S. 223-232 
    ISSN: 1570-7458
    Keywords: Onitis alexis ; Coleoptera ; Scarabaeinae ; dung beetle ; crepuscular flight ; superposition eyes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'examen a porté sur le rôle de l'intensité lumineuse et de la température sur l'incitation au vol chez Onitis alexis. Le vol en lumière naturelle est fortement synchronisé, avec les deux tiers des adultes qui s'envolent en 10–12 min. Sur six vols pour différents jours, le moment moyen d'envol variait de 13 min, mais l'envol moyen avait lieu à une intensité lumineuse déterminée. La valeur absolue de l'intensité lumineuse paraît ainsi un signal crucial dans la détermination et l'incitation au vol. Le moment d'envol se maintient à cette intensité quand le crépuscule est artificiellement avancé jusqu'à 8 min environ. Cependant, quand le crépuscule est rendu encore plus précoce, l'envol moyen se produit à des intensités plus basses et est étalé. Ceci peut être interprété comme un chevauchement de la période des intensités lumineuses favorables à l'envol avec le rythme circadien qui conduit les bousiers à la surface. Aucun adulte ne vole quand il y a maintien de lumière constante ou d'obscurité à l'heure du crépuscule. En présence de crépuscule constant, les réponses sont hétérogènes, et, bien que le moment médian d'envol ne soit retardé que de 3 min, par rapport aux témoins, l'incitation à l'envol est étalée sur une période plus longue. Avec des températures au sol de 20–22 °C, plus de 90% des adultes s'envolent. Le pourcentage diminue avec la température, et moins de 10% s'envolent à 16–17 °C.
    Notes: Abstract The role of light intensity and temperature in determining the onset of flight in the crepuscular dung beetle Onitis alexis Klug (Coleoptera: Scarabaeidae) was examined. Flight under natural light was highly synchronized, with two-thirds of the beetles that flew flying over a period of 10–12 min. In six flights on different days, the mean time of onset varied by up to 13 min, but mean onset occurred at fixed light intensity. Absolute light intensity therefore appears to be a vital cue in determining flight onset. Mean onset remained at this intensity when dusk was advanced artificially by up to about 8 min. However, when dusk was brought further forward, mean flight occurred at lower intensities and onset of flight took place over a longer period. This is interpreted as an overlapping of the period of light intensities suitable for flight with the circadian rhythm that brings the beetles to the surface. No beetles flew when kept under constant bright light or in the dark during the dusk period. Under conditions of constant dusk, the beetles appeared uncoordinated and, although the median time of onset of flight was only 3 min later than in the control flight, onset of flight was spread out over a much longer period. At soil temperatures of 20–22 °C, over 90% of the beetles flew. This percentage decreased with decreasing temperature, and less than 10% flew at temperatures of 16–17 °C.
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    Entomologia experimentalis et applicata 40 (1986), S. 81-88 
    ISSN: 1570-7458
    Keywords: Ips typographus ; spruce bark beetle ; Coleoptera ; Scolytidae ; model ; reemergence ; density dependent ; temperature dependent ; degree-days ; poikilotherm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Ce modèle décrit la réémergence d'adultes d'I. typographus L. (Coleoptera, Scolytidae) en fonction de la densité et de la température. Les résultats obtenus en laboratoire à des températures constantes fournissent la distribution des réémergences et pour les dates de réémergence moyenne les différentes combinaisons de température de seuil et de degré de jour (°D). De toutes ces combinaisons, 167.71 °D au-dessus de 7,5 °C fournit la meilleure concordance entre les prévisions du modèle et les observations dans la nature à partir d'arbres fortement attaqués. Le modèle a montré un bon accord avec la réémergence observée dans deux groupes de branches attaquées dans différentes conditions de la température quand il a été ajusté aux faibles densités d'élevage. La discussion examine les possibilités d'application du modèle à l'étude de la biologie de la reproduction d'I. typographus et à l'aménagement forestier. La méthode utilisée pour construire le modèle pourrait être employée pour en développer d'autres chez des poikilothermes.
    Notes: Abstract A model is presented that describes the reemergence of parent spruce bark beetles, Ips typographus, based on breeding density and temperature conditions. Laboratory data obtained at one constant temperature provide the distribution of reemergence time and different combinations of threshold temperatures and degreedays (°D) at mean reemergence. Of these combinations, 167.71 °D above 7.5 °C gave the best correspondence between model prediction and field data obtained from densely infested standing trees. The model was in good agreement with the reemergence pattern found for two groups of infested logs under different temperature conditions when adjusted for the lower breeding density. The applicability of the model in the study of bark beetle reproductive biology and in forest management is discussed. The method used to construct the model should be useful in developing other models for poikilothermic processes.
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    Entomologia experimentalis et applicata 47 (1988), S. 173-182 
    ISSN: 1570-7458
    Keywords: Bembidion lampros ; Pterostichus cupreus ; Carabidae ; Coleoptera ; behaviour ; temperature ; searching ; consumption ; cereal aphid ; Rhopalosiphum padi ; prey ; density ; barley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les taux maximum de consommation de R. padi L. à différentes températures ont été déterminés au laboratoire chez deux carabes, B. lampros Herbstet P. cupreus L. La consommation moyenne a augmenté avec la température chez les deux espèces, B. lampros consommant un maximum de 15,9 larves des stades 1 à 3 et 9,1 pucerons adultes aptères, à 25°C. P. cupreus a été particulièrement vorace et a consommé 125,3 adultes aptères par jour à 20°C. Le comportement des deux espèces a été observé en filmant en vidéo des carabes à jeun, maintenus à différentes températures constantes, dans des enceintes semées en orge de printemps. Des éléments du comportement, communs aux deux espèces, ont été définis: 1) immabilité, 2) marche et course, 3) recherche, 4) affrontement. P. cupreus a été plus actif à toutes les températures, B. lamprosa été inactif au-dessous de 10°C. La part de temps consacrée à la recherche, le nombre de plantes prospectées, et la vitesse ont augmenté avec la température chez les deux espèces. Dans des enceintes similaires colonisées par R. padi, P. cupreus a significativement augmenté le temps consacré à la recherche dans les enceintes, parallèlement à l'augmentation de la densité des pucerons. Après la découverte d'une colonie de pucerons, P. cupreus escalade et prospecte la plante et ses voisines immédiates; tandis que les plantes des enceintes sans pucerons sont rarement escaladées. B. lampros n'a pas été observé escaladant des plantes d'enceintes avec ou sans pucerons, et il n'a pas accru son temps de prospection en fonction de la densité de pucerons. Les quelques B. lampros qui ont capturé des pucerons l'ont fait lorsque ceux-ci marchaient sur la surface du sol. La discussion a porté sur l'efficacité relative des deux carabes comme prédateurs de R. padi, et les résultats ont été comparés à ceux d'études du même type, menées ailleurs, avec des prédateurs de Sitobion avenae sur blé d'hiver.
    Notes: Abstract Maximum consumption rates were determined for two carabids, Bembidion lampros Herbst. and Pterostichus cupreus L., feeding on the cereal aphid Rhopalosiphum padi L. at different temperatures in the laboratory. Mean daily consumption increased with increasing temperature for both species, B. lampros consuming a maximum of 16 1–3 instar nymphs and 9 apterous adult aphids at 25°C. P. cupreus was particularly voracious and consumed 125 apterous adult R. padi per day at 20°C. The behaviour of both species was analysed by video filming starved beetles, maintained at different constant temperatures, in arenas sown with spring barley. The behavioural components (1) still; (2) run/walk; (3) search and (4) confrontation were identified and were common to both species. P. cupreus was more active over the temperature range tested; B. lampros was inactive under 10°C. The proportion of time spent searching, number of plants searched, and velocity increased with increasing temperature for both species. When observed in similar arenas seeded with R. padi colonies, individuals of P. cupreus significantly increased their time spent searching in arenas with increasing aphid density. Following discovery of an aphid colony, individuals climbed and searched the host plant and its nearest neighbours. Plants in aphid free arenas were rarely climbed. B. lampros was not observed climbing in either aphid free arenas or in arenas with increasing aphid densities, and did not significantly increase its time spent searching in response to increased prey density. The few B. lampros that found aphids caught them walking on the soil surface. The relative efficiences of these two carabids as predators of R. padi are discussed, and the results are compared with similar studies elsewhere with predators of Sitobion avenae on winter wheat.
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    Entomologia experimentalis et applicata 48 (1988), S. 43-50 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Pterostichus ; mandible size ; wear pattern ; feeding behaviour ; burrowing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'analyse de l'influence de la texture des aliments et du fouissage, sur l'usure des mandibules a été effectuée en nourrissant P. melanarius avec des aliments de différentes duretés dans des récipients contenant ou non du sol. Les aliments durs seuls usent moins le bord incisif (extrémité de la mandibule) et la surface coupante, que leur association avec le fouissage. En présence exclusive d'aliments durs, les femelles avaient érodé plus vite leurs mandibules que les mâles, tandis que chez ceux-ci le fouissage seul les avaient usé plus vite que chez les femelles. Des femelles récoltées dans un champ de céréales contenaient plus d'aliments durs que les mâles. Les différences de comportement avaient provoqué apparemment des types d'usure différents suivant les sexes. Les adultes usent leurs mandibules au cours de leur première année de vie imaginale. Cependant, la taille des mandibules des femelles échantillonnées dans la nature correspondait mieux à celle des femelles (de même âge) provenant des expériences ayant provoqué une forte usure (aliment dur et fouissage du sol). Les mandibules des mâles échantillonnés présentaient seulement une usure modérée et ressemblaient à celles des mâles ayant consommé soit des aliments durs, soit foui le sol. La discussion a traité des relations entre l'usure des mandibules, la fécondité et la longévité de P. melanarius et d'autres espèces de carabes.
    Notes: Abstract The effects of food texture and burrowing on mandible wear in the predatory carabid beetle Pterostichus melanarius Illiger were investigated by feeding adults soft or hard food in jars with or without soil. Both the incisor cusp (mandible tip) and cutting surface of the mandibles erode more in response to the combination of hard food and burrowing than to hard food alone. Females were found to erode their mandibles more than males in the hard-food-only treatment, whereas males wore down their mandibles more than females in the soil-only treatment. Female P. melanarius collected in a cereal field contained signficantly more solid food items compared with males. Differences in behaviour apparently resulted in differential wear patterns between the sexes. It is shown that the process of mandible wear in P. melanarius will result in worn mandibles in their first year as adults. However, mandible size of field-sampled females were found to be best correlated with females (of similar age) in the experiment exhibiting extensive wear (foraged hard food and burrowed in soil). The mandibles of field-sampled males were similar to those of males in the hard-food-only and the soil-only treatments, which showed only slight to moderate wear. The influence of mandible wear on fecundity and survival in P. melanarius as well as in other carabid species is discussed.
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    ISSN: 1570-7458
    Keywords: Coleoptera ; Cerambycidae ; Morimus funereus ; development ; laboratory conditions ; food quality ; temperature ; season
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    Description / Table of Contents: Résumé L'étude a porté sur les effets d'une température constante (23 °C), de la qualité de l'aliment,-B = aliment naturel, c'est-à-dire de l'écorce de chêne pulvérisée; B+C = aliment naturel enrichi avec de la poudre de biscuits sucrés-, et de la saison sur le développement larvaire de M. funereus L. La température de 23 °C a été défavorable aux larves récoltées en septembre dans des souches de chênes et élevées sur aliment B: les larves étaient mortes en 30 jours. Avec aliment B+C, l'effet défavorable a été neutralisé et le poids des larves augmenté de 543%, 897% et 1179% en 1, 2 et 3 mois. Des larves néonates d'été ou d'hiver se sont bien développées sur B+C, mais toutes les larves d'hiver étaient mortes sur B en 40 j. Des larves de mêmes parents, écloses à différentes époques de l'année, ont présenté des différences saisonnières du taux de survie et de la vitesse de développement lors de leur élevage à 23 °C sur B+C. Le développement le plus rapide et la meilleure survie ont été obtenus avec des larves écloses au début ou au milieu de l'été; tandis que le développement le plus lent et la plus mauvaise survie ont été obtenus avec les larves écloses à la fin de l'été. Les changements saisonniers synchrones des adultes et de leurs descendants, exprimés à différents niveaux d'organisation biologique, suggèrent l'existence d'un rythme annuel endogène qui dépend de l'expression de différents gènes au cours du cycle annuel.
    Notes: Abstract The effects of constant temperature (23 °C), food quality (B, natural diet i.e. powdered oak bark; B+C, natural diet enriched with powdered sweet crackers) and season on larval development of the cerambycid Morimus funereus L. were studied. The temperature of 23 °C exerted an unfavourable effect on larvae collected from oak stumps in September and bred on B; i.e. the larvae died within 30 days. When the larvae consumed B+C the unfavourable effect of temperature was abolished and the larvae increased their weight by 543%, 897% and 1179% in 1, 2 and 3 months, respectively. Newly hatched summerand winter-larvae developed successfully on B+C, while all the winter-larvae died within 40 days on B. Larvae of an identical parentage hatched in different phases of the annual cycle and showed seasonal differences in the rate of development and survival when reared on B+C at 23 °C. The fastest development and the highest survival rate were observed in larvae which emerged in early- and midsummer, whereas the slowest development and the lowest survival rate were in those hatched in late summer. The synchronized seasonal changes of adults and their offspring, as expressed at different levels of biological organization, suggest the existence of an endogenous annual rhythm which is dependent upon the expression of different genes in the course of the annual cycle.
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    ISSN: 1570-7458
    Keywords: Diabrotica spp. ; corn rootworms ; Chrysomelidae ; Coleoptera ; plant-derived semiochemicals ; starch matrix ; encapsulation ; controlled release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le programme expérimental de 1987 était destiné à déterminer: 1) si les substances dérivées de végétaux et attractives pour Diabrotica pouvaient être encapsulées dans de l'amidon additionné d'acide borique; 2) si différentes formules attireraient les différentes espèces de Diabrotica dans un champ de maïs. L'indol, l'estragol, le vératrol, le phénylacétaldéhyde et le trans-anéthol n'ont pas été retenus, tandis que le trans-cinnamaldéhyde, la \-ionone, le 1,2,4-triméthobenzène, l'eugénol et l'isœugénol ont été encapsulés avec succès dans des pièges attachés à des pieds de maïs (les détails techniques sont fournis). Les pièges ont été relevés tous les 4 jours du 11 juillet au 8 septembre. Les résultats montrent que les substances allélochimiques sont conservées dans la capsule pendant des durées variables et libérées à des concentrations attractives pour les Diabrotica adultes. Un mélange de trans-cinnamaldéhyde et de 1,2,4,-triméthoxybenzène a été la formule la plus efficace, à l'exception des périodes de formation des barbes et du pollen, où aucune formule n'a été attractive. Bien que la variation saisonnière des réactions de Diabrotica limite l'utilisation des substances allélochimiques d'origine végétale, la capsule d'amidon peut être employée pour libérer des substances allélochimiques et constitue un outil potentiel pour la mise au point d'une méthode plus rationnelle de lutte contre Diabrotica.
    Notes: Abstract The concept of encapsulating semiochemicals into a starch matrix is being studied for potential use in corn rootworm (CRW) management programs. During 1987, experiments were conducted to determine: 1) If volatile plant-derived Diabrotica spp. attractants could be encapsulated in a starch borate matrix (SBM), and 2) If various SBM-semiochemical formulations would attract Diabrotica species over time in field corn. Chemical analyses of fresh SBM formulations indicated that indole, estragole, veratrole, phenylacetaldehyde, and trans-anethole were not retained during formulation but trans-cinnamaldehyde, Beta-ionone, 1,2,4,-trimethoxybenzene, eugenol and isœugenol were successfully encapsulated. Encapsulated semiochemical formulations were made into 20 mesh granules, placed in Pherocon ® 1C traps that were tied to corn plants, and sampled for CRW adults every 4 days from 11 July to 8 September. Field data indicated that encapsulated semiochemicals were retained in the SBM for varying lengths of time and were released at rates attractive to CRW adults. A two-component mixture of trans-cinnamaldehyde and 1,2,4-trimethoxybenzene was the most effective formulation tested; however, no formulation was effective during corn silking and pollination. Although seasonal variation in CRW response could limit the usefulness of some plant-derived semiochemicals, the starch matrix concept may be useful as a delivery system for semiochemicals and may have potential as a tool that could be used in the development of new more biorational CRW management programs.
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    Entomologia experimentalis et applicata 50 (1989), S. 61-67 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; northern corn rootworm ; western corn rootworm ; dispersal ; malaise trap ; habitat selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les activités de vol de D. barberi (NCR) et D. virgifera virgifera (WCR) ont été contrôlées par l'utilisation de pièges ‘malais’ placés en lisière de deux petits champs de maïs. Les populations de ces coléoptères sont maximales quand le maïs fleurit, mais leurs captures sont restées faibles jusqu'à ce que les barbes du maïs aient été sèches. Les captures de NCR et, dans une plus faible mesure, celles de WCR ont alors augmenté et sont restées importantes pendant toute la saison. Les pièges ‘malais’ ont été conçus pour que les adultes pénétrant par les côtés opposés soient récoltés séparément. Les femelles de NCR capturées face au champ de maïs avaient tendance à contenir moins d'ovocytes mûrs que celles capturées du côté opposé. Ces observations appuient l'hypothèse que les femelles NCR émigrent des champs de maïs pour s'alimenter, quand les barbes et le pollen de maïs, aliments préférés, deviennent indisponibles, mais que les femelles NCR pleines d'ovocytes mûrs recherchent le maïs quand elles sont en quête de lieux de ponte.
    Notes: Abstract Flight activity of corn rootworm beetles, the northern (NCR), Diabrotica barberi (Coleoptera: Chrysomelidae), and western (WCR), D. virgifera virgifera, was monitored using malaise traps placed at the edges of two small cornfields. Populations of beetles in the fields peaked while corn was flowering, but capture in malaise traps remained low until silks had dried. Capture of NCR and (to a lesser extent) WCR then increased and remained high through the season. Malaise traps were constructed to permit separate collections of beetles that entered on each of two opposite sides. Female NCR that were captured in sides that faced toward corn tended to contain fewer mature eggs than those in sides facing away from corn. These findings support the hypothesis that female NCR emigrate from cornfields to feed when fresh silk and corn pollen (favored foods) become unavailable, but that egg-laden NCR actively seek corn when searching for oviposition sites.
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  • 31
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cylas formicarius elegantulus ; sweetpotato weevil ; sweet potato ; digestion ; enzyme distribution ; trypsin-inhibitors ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'activité endoprotéinase était limitée au liquide de la lumière des régions ventriculaires antérieure et postérieure de l'intestin moyen des larves deCylas formicarius elegantulus Summers. Les aminopeptidases ont été trouvées dans le liquide de la lumière (18%), mais étaient principalement associées avec les fractions insolubles des cellules du ventricule postérieur (82%). Suivant le substrat, l'activité carboxypeptidase était à peu près également répartie entre le liquide de la lumière et les fractions insolubles des cellules du ventricule postérieur. L'amylase, enzyme secrétée, a été observée à la fois dans la lumière antérieure et postérieure. Cinq bandes d'activité amylase ont été révélées sur zymogrammes d'amidon après électrophorèse d'intestins moyens entiers. Trois des bandes d'amylase pouvaient provenir de la plante. Il y avait au moins 2 α-glucosidases, une secrétée et une liée aux cellules du ventricule antérieur. L'activite β-glucosidase était liée aux cellules du ventricule antérieur, fandis que l'activité α-galactosidase était limitée au fluide de la lumière. Les activités β-galactosidase et cellulase ont été trouvées à la fois dans le liquide de la lumière et dans la fraction cellulaire insoluble. Ainsi, la digestion initiale des grosses protéines et des polymères de carbohydrates se produit dans le liquide de la lumière dans les régions ventriculaires antérieure et postérieure. Cependant, l'achèvement de la digestion des oligopeptides se produit principalement dans le ventricule postérieur, tandis que la fin de la digestion des oligosaccharides se produit dans le ventricule antérieur. Les concentrations en inhibiteurs de trypsine de 5 cultivars d'I. batatas L. diffèrent de 1 à 20. Les endoprotéinases deC. formicarius elegantulus ont été inhibées par des extraits de cultivars, mais les cultivars avec des concentrations relativement élevées d'inhibiteur avainent antérieurement montré être susceptibles d'être attaqués par le coléoptère dans des essais en champs.
    Notes: Abstract Endoproteinase activity was confined to luminal fluid from anterior and posterior ventricular regions of midguts of larvae of the sweetpotato weevil,Cylas formicarius elegantulus (Summers). Aminopeptidase was found in luminal fluid (18%) but was primarily associated with insoluble fractions from cells of the posterior ventriculus (82%). Depending on substrate, carboxypeptidase activity was about equally distributed between luminal fluid and insoluble fractions from posterior ventriculus cells. Amylase was found in luminal fluid in both the anterior and posterior ventriculus. Five bands of amylase activity were detected on starch zymograms following electrophoresis of whole midgut samples. Three of the amylase bands may be plant-derived. At least two α-glucosidases were present, one secreted and one bound to anterior ventriculus cells. β-Glucosidase activity was bound to anterior ventriculus cells whereas α-galactosidase activity was confined to luminal fluid. β-Galactosidase and cellulase activities were found in both luminal fluid and the insoluble cell fraction. Thus, initial digestion of large protein and carbohydrate polymers occurs in luminal fluid in both anterior and posterior ventriculus regions. However, terminal digestion of oligopeptides occurs primarily in the posterior ventriculus while terminal digestion of oligosaccharides occurs in the anterior ventriculus. A 20-fold difference in trypsin-inhibitor concentration was found among five sweetpotato cultivars. Endoproteinases from sweetpotato weevil larvae were inhibited by extracts from the cultivars but cultivars with relatively high concentrations of inhibitor were previously shown to be susceptible to weevil attack in field trials.
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  • 32
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    Entomologia experimentalis et applicata 37 (1985), S. 123-127 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Poecilus cupreus ; larva ; starvation ; digestion ; enzyme-linked immunosorbent assay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Mit eine quantitativen enzymabhängigen Immunoabsorptionstest wurde immunoreaktives Material aus Beutetieren als Eiweissgehalt (IRM/P) in Larven eines polyphagen räuberischen Carabiden, Poecilus cupreus, bestimmt. Wir bestimmten den Beuteverzehr und die Geschwindigkeit des IRM/P Abbaus bei Larven, die während verschiedener Zeit gehungert hatten. Der Beuteverzehr nahm exponentiell zu über 7 Tage Hunger. Die Geschwindigkeit des Beute- IRM/P Abbaus schien logarithmisch. Die Beuteaufnahme nahm fast zwanzigfach zu über 7 Tage Hunger von 2.7 ng auf 50.2 ng IRM/P/10 Mikroliter Larvenextrakt. Der grösste Teil der Verdauung erfolgte am zweiten bis dritten Tag nach der Nahrungsaufnahme, unabhängig von der verdauten Menge. Das Niveau 4 Tage nach der Fütterung zeigte, dass Larven, die vorgängig 7 Tage gehungert hatten, 5.0 ng IRM/P/10 Microliter Extrakt zurückhielten; dies war mehr als die Aufnahmemenge nichthungernder Larven. Die Verdauungsgeschwindigleit nahm zu mit der Dauer des Hungerns, doch wurde auch mehr Beute im Nahrungskanal zurückgehalten.
    Notes: Abstract Prey antigen levels were determined by a quantitative enzyme-linked immunosorbent assay in larvae of a carabid predator, Poecilus cupreus L. under laboratory conditions. We determined prey consumption and rate of prey protein decay in larvae having starved for different periods. Prey consumption increased exponentially over 7 days of starvation. The rate of prey immunoreactive material decay seemed to be logarithmic, similar in larvae which had starved for different periods. Most of the digestion took place in the first 3 days period after feeding, irrespective of the amounts ingested. The rate of decay increased with increasing period of starvation. There were also signs of food retention in the alimentary canal in larvae which starved longer.
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    Entomologia experimentalis et applicata 42 (1986), S. 201-212 
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Bruchidae ; Coleoptera ; behavior ; evolution ; genetic variation ; insect-plant interactions ; oviposition preference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Vingt-deux lignées deC. maculatus Fab., liées à 6 plantes-hôtes, ont été examinées quant à leurs préférences — sans choix—parmi les graines de 9 légumineuses. Ces préférences se sont révél'ees semblables à celles observées lors de choix binaires; 3 paramètres ont donné les mêmes résultats: nombre moyen d'oeufs pondus par l'ensemble des femelles, nombre moyen d'oeufs émis par l'ensemble de celles acceptant la plante, fréquence des femelles acceptant la plante. L'analyse en composantes principales des préférences pour les 9 plantes a révélé que la majorité des mesures se situe sur les 2 premiers axes, qui ont rendu compte de 89% de la variation. Les performances des lignées sur le premier axe suggèrent qu'il s'agit d'un critère général de préférence. La classification automatique des plantes a montré un aspect général semblable à celui des composantes principales. Par ces 2 méthodes, les plantes ne se sont pas classées nettement selon leurs affinités taxonomiques. Bien que la classification automatique n'ait pas mis en évidence une similarité de comportement chez les insectes liés au même hôte, ceci était apparemment le cas. Les lignées liées à des hôtes présentant de fortes — ou à l'opoosé — de faibles préférences, ont montré différents seuils d'acceptation pour les 9 substrats de ponte. A l'opposé, il n'y a aucune preuve d'altération évolutive de la hiérarchie de préférences. On en a déduit que ces insectes étaient motivés par un petit nombre de stimulus, tels que les allélochimiques et al texture de tégument, pour déceler l'adéquation des substrats potentiels. (La microscopie électronique a suggéré une corrélation entre la texture du tégument et la hiérarchie des préférences de ces populations). La confiance dans les stimulus recueillis contribue à limiter les stratégies évolutives disponibles pour la population. A partir de là, la sélection en faveur —ou contre — des plantes, à l'origine, faiblement préférées, peut conduire, dans la niche de ponte, à l'incorporation — ou à l'exclusion — d'un groupe d'espèces taxonomiquemment éloignées, mais phénétiquement semblables. La probabilité d'altérations importantes de la hiérarchie des préférences paraît extrémement faible.
    Notes: Abstract A survey of 22 strains ofCallosobruchus maculatus associated with six different leguminous hosts indicates extensive genetic differentiation for oviposition preference. Female behavior suggests the existence of two distinct host preference groups among the nine oviposition substrates tested. Strains associated with plants in these two groups show distinct preference profiles. Genetic differentiation of oviposition preference is due to evolutionary modification of the threshold of acceptance of host plants, not to alteration of the preference hierarchy. From principal components analysis of these results, it is likely that very few independent plant traits govern oviposition preference.
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  • 34
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    Entomologia experimentalis et applicata 45 (1987), S. 23-27 
    ISSN: 1570-7458
    Keywords: Coléoptère ; Bruchidae ; Olfactométrie ; phéromone sexuelle ; plante hôte ; régulation de la réproduction ; Coleoptera ; Bruchidae ; olfactometer ; sex pheromone ; host plant ; reproductive regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary In order to meet its sexual partner, Zabrotes subfasciatus must rely on the olfactory signals emitted either by the female or the male insect. The attractiveness of male and female odours were therefore studied and compared in an olfactometer. The behaviour of virgin and inseminated females and males, left in contact with the host plant's seeds or not, was studied in terms of the age of the imagos. In all cases examined, male odours did not attract female insects. Virgin females kept without seeds of the host plant did not attract males. On the other hand, the odour of virgin females left in contact with bean seeds significantly attracted virgin males. The females' attractive power varied according to their age: older females released a chemical cue that was more attractive for the males. Emission of the sex-pheromone stops after insemination of the females but begins again after a certain period of time. Results are discussed in terms of what is known on the reproductive regulation of this bruchid.
    Notes: Abstract Pour rechercher son partenaire sexuel Zabrotes subfasciatus doit utiliser les signaux olfactifs émis soit par les mâles ou par les femelles. Le pouvoir attractif de l'odeur des mâles et des femelles sont donc étudiés et comparés par olfactométrie. Le comportement de mâles et de femelles vierges et inséminées, mis en contact des graines de la plante hôte ou non, est observé en fonction de l'âge des imagos. En aucun cas, les odeurs des mâles n'exercent une attraction sur les femelles. Les femelles vierges en absence de graines de haricot (Phaseolus vulgaris) n'exercent pas d'attraction sur les mâles vierges. Par contre les odeurs des femelles vierges mises en contact avec les graines de haricot sont très attractives pour les mâles vierges et varie en fonction de l'âge: il est plus affirmé chez les femelles plus âgées. L'émission de la phéromone sexuelle est interrompue après l'insémination des femelles mais reprend au bout d'un certain temps après celle-ci.
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  • 35
    ISSN: 1570-7458
    Keywords: body weight ; flight ; Ips calligraphus ; lipid ; longevity ; phloem ; pine ; Scolytidae ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le comportement de vol d'Ips calligraphus GERMAR (Scolytidae) a été examiné au laboratoire par une technique de vol captif. La génération parentale avait été artificiellement introduite, suivant la taille des adultes (1,6 à 2,1 mm) dans des morceaux de Pinus elliottii Engelm. variété elliottii au phloeme épais (TK=2,5 à 3,5 mm) ou fin (TN=0,5 à 1,5 mm) les larves se sont développées dans ces morceaux de pin. Le poids et la teneur en lipide des adultes obtenus à partir de TN étaient significativement inférieure à ceux de TK. Le poids des mâles les plus gros a été plus réduit que celui des femelles; les mâles les plus petits semblaient être moins efficaces dans l'initiation des attaques sur les arbres, et les femelles les plus petites ont eu une fécondité réduite. Les durées de vol quotidiennes pendant la vie des mâles TK vierges étaient en moyenne deux fois plus longues que celles des mâles TN. Les durées de vol quotidiennes étaient très variables: en moyenne moins de 20 minutes, mais la plus longue a été de 173 mn. En moyennes les adultes TN et TK ont commencé à voler, et volaient en plus grand nombre, le premier et le second jour après l'émergence. Ensuite la fréquence d'adultes volants et le pourcentage de surviveants, ont graduellement diminué jusqu'à tomber à zéro le neuvième jour. Les mâles TN et TK avaient des vols quotidiens plus longs et volaient environ 1 jour de plus que les femelles. L'activité de vol accrue des mâles reflète leur besoin de trouver dans la nature des arbres convenables; les vols des femelles peuvent généralement être plus brefs, étant plus directement orientés comme une réponse aux phéromones mâles. Les voiliers ont vécu environ 2 fois plus longtemps que les non-voiliers. Parmi les voiliers TK et TN il y avait une corrélation positive étroite entre le poids du corps et la durée totale des vols. Il n'y en a qu'une faible corrélation entre cette durée totale des vols et la longévité, suggérant un faible coût physiologique du vol. L'influence de cette durée des vols et du prélèvement consécutif de lipides sur la fécondité n'a pas été examinée. L'initiation au vol chez les individus fécondés a été sérieusement retardée (maximum le sixième jour) par rapport aux vierges, ce qui suggère un dégénérescence des muscles du vol associée à la reproduction, suivie d'une régénération importante, comme cela a été signalé chez d'autres Scolytes. Ces résultats contribuent à notre compréhension des facteurs conditionnant le comportement de vol et d'autres aspects fondamentaux de la biologie des insectes des pins. Une telle connaissance est nécessaire au développement d'une politique efficace de protection.
    Notes: Abstract Rearing larvae of Ips calligraphus (Germar) (Coleoptera: Scolytidae) in bolts of typical slash pine, Pinus elliottii Engelm. var. elliottii, with ‘thin’ (TN; 0.5–1.5 mm) phloem (inner bark) relative to adult beetle body width significantly reduced body weight and lipid content of emerging adults compared with ‘thick’ (TK; 2.5–3.5 mm) phloem-reared adults. Unmated (pre-nuptial) TK beetles averaged 2-fold longer daily and life-time flight duration than TN beetles. Daily flights were highly variable, averaging 〈20 min (longest daily flight=173 min). TK and TN beetles initiated flight, and the greatest number flew, on the first or second day after emergence form their rearing bolt; % of beetles flying and survival gradually declined to zero by day 9. Males (both TK and TN) averaged 2.5 days of flight, ca. 1 day longer than females. Fliers lived ca. 2-fold longer than non-fliers. Among TK and TN fliers, significant but weak positive correlations occurred between body weight and lifetime flight duration. Poor correlation between lifetime flight duration and longevity suggests little physiological cost to flight, but effects on fecundity were not assessed. Flight by mated, egg-laying (post-nuptial) beetles was substantially delayed (peaking on day 6), suggesting degeneration and subsequent regeneration of flight muscles.
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  • 36
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    Entomologia experimentalis et applicata 43 (1987), S. 205-208 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Diabrotica virgifera ; corn rootworms ; prehatch development ; posthatch development ; protandry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'observation, au laboratoire, pendant une période d'éclosion de dix jours, des oeufs de D. v. virgifera LeConte, a montré que les oeufs mâles prédominent les deux premiers jours d'éclosion, que les oeufs des deux sexes, avec des fréquences 0,5/0,5, ont éclos les troisième et quatrième jours, et que les oeufs éclos du cinquième au dixième jour étaient presque tous femelles. Globalement, les oeufs femelles ont éclos en moyenne 2,9 jours plus tard que les oeufs mâles. De plus, la durée du développement post-embryonnaire des femelles a demandé 1,8 jour en plus. Une éclosion plus tardive et un développement post-embryonnaire plus long ont entrainé une émergence des femelles en moyenne 4,7 jours après les mâles. La période d'émergence des adultes s'est étalée sur 14 jours; les mâles ayant dominé pendant les 5 premiers jours et les femelles pendant les 9 derniers. Les mâles de D. v. virgifera semblent avoir évolué vers la protandrie en acquerant, tant une diapause post-embryonnaire que des stades de développements larvaire et nymphal plus brefs.
    Notes: Abstract Laboratory tests with eggs of Diabrotica virgifera virgifera LeConte showed that during a 10-day hatching period, hatch of male eggs predominated on the first and second days, eggs of mixed sex, with ca. 1:1 ratio, hatched on the third and fourth days, and eggs hatching from the fifth to the tenth days were nearly all female. Overall, female eggs hatched a mean of 2.9 days later than male eggs. Not only did female eggs hatch later, but the time for posthatch development to the adult stage was 1.8 days longer for females. The later egg hatch and longer posthatch development for females resulted in female adults emerging a mean of 4.7 days later than male adults. Total adult emergence lasted 14 days; of this, males predominated during the first 5 days, and females predominated during the last 9 days. Males of D. v. virgifera appear to have evolved protandry (the tendency for males to emerge before females) by developing both a postdiapause embryonic stage and a combined larval and pupal stage of shorter duration.
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  • 37
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    Entomologia experimentalis et applicata 44 (1987), S. 15-21 
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Coleoptera ; Bruchidae ; intraspecific competition ; oviposition strategies ; resource exploitation ; vibrations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Lors de la compétition, les larves réagissent l'une par rapport à l'autre, même lorsque leurs galeries sont séparées. L'une est inhibée, tandis que l'autre se comporte comme si elle était seule. Le signal provoquant ces réactions, qui peut traverser du papier métallique, est dû vraisemblablement aux vibrations de mastication des larves; ces dernières perçoivent ces signaux tout au long de leur vie active. La larve la plus âgée ne l'emporte pas obligatoirement, ce qui signifie que le signal indique plus que l'âge. Les conditions expérimentales peuvent inverser les réponses des unes et des autres, bien que la larve la plus âgée puisse souvent mourir de ces conditions anormales de compétition. L'avantage potentiel associé à l'inhibition du futur perdant est mis en évidence en collant ensemble des graines. Quand la larve dominante se nymphose, la larve inhibée recommence à s'alimenter et achève son développement. En ayant eu son alimentation interrompue et en restant dans une galerie superficielle, la larve inhibée évite les affrontements et peut se développer lorsque la larve dominante meurt ou se nymphose, puisque la galerie de la larve inhibée n'avait pas été sectionnée. La stratégie de ponte réduit la fréquence de la compétition en uniformisant la distribution des oeufs; elle augmente les chances de survie des larves vaincues avec l'addition des oeufs sur les graines les plus grosses quand les disponibilités sont limitées. L'étude de l'évolution de ces adaptations a été possible puisque, comme on le sait, C. maculatus est génétiquement polymorphe pour les caractères déterminant le comportement de ponte des femelles et la compétition larvaire.
    Notes: Abstract Larvae of the bean weevil C. maculatus feeding in a single bean apparently respond to vibrations from each other's chewing: one larva feeds normally, the other is inhibited. If the burrows of the larvae intersect, the inhibited larva dies. If the dominant larva pupates or dies without the burrows intersecting, the inhibited larvae then feeds and matures if enough food remains. Since females add second eggs to the largest beans after most beans carry a single egg, competition is most common in the largest available beans, precisely where inhibited larvae can benefit from avoiding a contest.
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  • 38
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    Entomologia experimentalis et applicata 34 (1983), S. 124-126 
    ISSN: 1570-7458
    Keywords: Negret ; Melanic mutant ; X-linked mutation ; Flour Beetle ; Tribolium confusum ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
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  • 39
    ISSN: 1570-7458
    Keywords: Storage pests ; Coleoptera ; Bostrichidae ; Prostephanus truncatus ; (±)-1-methylbutyl (E)-2-methyl-2-pentenoate ; Rhyzopertha dominica ; (±)-1-methyl-butyl (E)-2,4-dimethyl-2-pentenoate ; Dominicalure ; Aggregation pheromone ; Monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les réponses de Prostephanus truncatus Horn (Coleoptera: Bostrichidae) à deux constituants de la phéromone d'agrégation de Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), le (±)-1-méthylbutyl (E)-2-méthyl-2-penténoate et le (±)-1-méthylbutyl (E)-2,4-diméthyl-2-pentéoate, connus comme “Dominicalure 1” et “Dominicalure 2”, ont été étudiées au laboratoire et au champ. Auslaboratoire ces composés ont été essayés individuellement et en mélange 1:2. Une membrane de caoutchouc imprégnée de phéromone a été utilisée comme émetteur lent, et une courbe de réponse en fonction de la dose a été établie. P. truncatus répondait plus vigoureusement à la Dominicalure 2 seule. Tous ces traitements ont été comparés dans un essai aux champs en Tanzanie, dans lesquels des pièges en carton ondulé contenant des diffuseurs de phéromone étaient placés dans des entrepôts de maïs dans les fermes. La Dominicalure 1 et le mélange de 1 et 2 étaient tous deux efficaces pour piéger R. dominica. La Dominicalure 2 a piégé plus de P. truncatus que les autres traitements et était à peu près aussi efficace que le contrôle visuel pour détecter la présence de cet insecte dans les stocks. On peut envisager que la Dominicalure 2 pourrait servir de base à un programme pour lutter contre P. truncatus en Afrique de l'Est.
    Notes: Abstract Laboratory and field studies have been made of the responses of Prostephanus truncatus (Horn) to two components of the aggregation pheromone of Rhyzopertha dominica (Fabricius) — (±)-1-methylbutyl (E)-2-methyl-2-pentenoate and (±)-1-methylbutyl (E)-2,4-dimethyl-2-pentenoate, known as “Dominicalure 1” and “Dominicalure 2” respectively. In the laboratory, these compounds were tested individually and as a 1:2 mixture; P. truncatus responded most strongly to Dominicalure 2 alone. All three treatments were compared in a field trial in Tanzania to monitor both R. dominica and P. truncatus in farm stores. Dominicalure 1 or a mixture of 1 and 2 were both highly effective for trapping R. dominica. In contrast, Dominicalure 2 trapped more P. truncatus than the other treatments and was about as effective as visual inspection at demonstrating the presence of the beetle in stores. Dominicalure 2 could form the basis of a monitoring programme for P. truncatus in East Africa.
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  • 40
    ISSN: 1570-7458
    Keywords: Coleoptera ; Bruchidae ; diapause reproductrice ; inflorescence ; Vigna unguiculata ; activité sexuelle mâle ; ovogenèse ; ponte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Bruchidius atrolineatus (Pic) is a widely distributed bruchid in the Sahelian zone which shows a reproductive diapause during the dry season and part of the rainy season. Diapausing females do not produce vitellogenin and their ovaries are reduced to the germarium. Spermatogenesis is very much reduced and male accessory glands are inactive. When these insects were placed in the presence of inflorescences of Vigna unguiculata which were renewed daily, the reproductive diapause of both males and females was interrupted after 15–20 days. Vitellogenesis occurred in the females and spermatogenesis increased in the males whilst their accessory glands became functional. When diapausing bruchids, found in stores of on V. unguiculata seeds during the dry season, were placed near the host plant's inflorescences, diapause was also terminated. In all cases, diapause was not interrupted when the insects were offered dry pods of V. unguiculata in a water-saturated atmosphere. The pollen, which is hardly eaten by this bruchid, did not seem to stimulate termination of diapause. Sensory stimulations derived from the flowers or/and nutritional factors may be the cause of the development of the reproductive organs. After termination of the diapause the males showed normal sexual activity whereas female fecundity was rather low, at least in our experimental conditions. This type of reproductive regulation allows this sahelian bruchid to resume its sexual activity when the host plant's flowers appear in the field at the end of the rainy season. Then the beetles lay their eggs on the pods as soon as the pods are developed.
    Notes: Abstract Bruchidius atrolineatus (Pic) présente en zone sahélienne une diapause reproductrice durant la saison sèche et une partie de la saison des pluies. Les femelles diapausantes ne produisent pas de vitellogénine et le germarium des ovarioles est seul développé. Chez les mâles la spermatogenèse est très ralentie et les glandes annexes sont inactives. Lorsque les insectes diapausants sont placés en présence d'inflorescences de Vigna unguiculata Walp, leurs organes reproducteurs deviennent fonctionnels après un temps de latence de 15 à 20 jours. Il n'y a par contre aucune levée de la diapause chez des bruches placées en présence de gousses sèches de V. unguiculata dans une atmosphère saturée. Des informations sensorielles issues des pièces florales ou (et) des facteurs nutritionnels sans doute liés a la consommation de nectar semblent être à l'origine de cette levée de la diapause. Le pollen fort peu consommé n'a par contre aucun rôle. Cette régulation du cycle reproducteur de B. atrolineatus par les inflorescences de V. unguiculata permet l'émission des oeufs dès que les gousses commencent à se former à la fin de la saison des pluies.
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  • 41
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    Entomologia experimentalis et applicata 41 (1986), S. 219-230 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Scolytidae ; Ips typographus ; Y-tube olfactometer ; bioassay ; pheromone ; attack phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Un olfactomètre à tube en Y, dont la description est donnée, a été utilisé pour examiner les réactions d'I. typographus L. par la marche à la présence de phéromones de congénères creusant des galeries dans des bûches d'Epicéa (Picea abies L.). Les insectes dans les bûches ont été répartis en 7 classes séquentielles, depuis l'élaboration de la chambre nuptiale par le mâle (phases 1–3), l'accouplement (4), et la ponte jusqu'à ce que les galeries de ponte aient 5 cm (5–7). Les mâles dans les phases précoces (1–2) étaient attractifs pour les 2 sexes dès 0,5 à 2,5 h après leur introduction, et ils le restaient pendant plus de 2 semaines. Les femelles qui se déplacent par la marche ont préféré nettement les bûches avec des mâles vierges à des bûches non habitées. De même elles ont préféré des bûches avec des mâles unis aux femelles à des bûches sans Ips. Ayant à choisir entre des bûches infestées par des mâles vierges ou expérimentés, les femelles ont préféré nettement les mâles vierges. Les mâle ont présenté une plus faible attraction aussi bien pour les bûches avec mâles vierges qu'avec mâles expérimentés, ils n'ont pas manifesté de préférence entre les 2. Les résultats sont interprétés comme des réponses adaptatives des 2 sexes aux variations dans la libération de phéromones par les insectes pendant les phases successives d'attaque et de colonisation de l'hôte.
    Notes: Abstract A Y-tube olfactometer is described which was used to assay the response of walking Ips typographus (L.) towards the pheromone from beetles excavating galleries in logs of Norway spruce [Picea abies (L.) Karst]. Beetles in the logs were categorized into seven sequential attack phases. Males in the early attack phases were attractive as early as 0.5 to 2.5 h after their introduction. These logs remained attractive for more than 2 weeks. Walking females strongly preferred logs with unmated males over uninfested logs and over logs containing males and females. They also preferred logs with males and females over uninfested logs. Responding males showed a weaker attraction than females to logs with unmated males. The results are interpreted as adaptive responses of the sexes to variation of pheromone release from beetles in the host during subsequent phases of attack and colonization.
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  • 42
    ISSN: 1570-7458
    Keywords: Aleochara bilineata ; Staphylinidae ; Coleoptera ; Delia radicum ; carbofuran ; diflubenzuron ; Dimilin ; Furadan ; insect growth regulator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Lorsqu' appliqué dans des concentrations efficaces contre la mouche du chou Delia radicum L. (0.1, 0.01, 0.001% p/v dans de l'eau distillée), le Dimilin (diflubenzuron), un régulateur de croissance des insectes, n'a pas affecté l'éclosion des oeufs de Aleochara bilineata Gyllenhal, un staphylin prédateur et parasite. En application externe, à la plus forte concentration (0.1% p/v dans de l'eau distillée), cet inhibiteur de synthèse de la chitine s'est avéré non toxique pour les larves du premier stade, les stades larvaires qui se développent à l'intérieur du puparium de l'hôte, et les adultes. Le traitement au Dimilin n'a pas affecté la fertilité des staphylins adultes. Cependant, lorsque le diflubenzuron était dissous dans du diméthylsulfoxyde et appliqué sur l'exosquelette du puparium de l'hôte, l'émergence des adultes de A. bilineata était éliminée. L'insecticide conventionnel Furadan (carbofurane), à une concentration égale à la plus faible concentration de Dimilin utilisée (0.001% p/v dans de l'eau distillée), s'est avéré toxique à la fois pour les oeufs et pour les larves de A. bilineata.
    Notes: Abstract The insect growth regulator Dimilin®, common name: diflubenzuron, applied at concentrations effective against the cabbage maggot Delia radicum L., did not affect the hatching of eggs of the staphylinid predator and parasite, Aleochara bilineata Gyllenhal. Applied externally in distilled water, Dimilin was non-toxic to first instar larvae, to larval instars developing within host puparia, and to adults. When Dimilin was dissolved in dimethylsulfoxide, then applied to the exoskeleton of host puparia, emergence of A. bilineata adults was suppressed. The conventional insecticide Furadan, at a concentration (0.001% in distilled water) equal to the lowest concentration of Dimilin used, was toxic to both eggs and larvae of A. bilineata.
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  • 43
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    Entomologia experimentalis et applicata 46 (1988), S. 47-54 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Sitophilus ; S. oryzae ; S. zeamais ; rice weevil ; maize weevil ; geographical strains ; digestion ; amylase ; diet ; barley ; corn ; maize ; rice ; wheat ; amylase inhibitors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La transformation de rang des valeur d'activité spécifique de l'α-amylase de 4 souches de S. oryzae et de 4 souches de S. zeamais montre que les niveaux les plus élevés de ces enzymes prédominantes s'observent chez les adultes nourris d'orge mondé ou de riz brun á grains longs. Des niveaux intermédiaires d'activité ont été obtenus chez les insectes élevés sur maïs jaune, et les niveaux les plus faibles chez ceux élevés sur blé. Bien que les extraits préparés à partir d'orge présentent une activité inhibitrice de deux isoamylases purifiées de S. oryzae, les niveaux des inhibiteurs naturels α-amylase de ces deux enzymes sont environ respectivement 2,2 et 6,1 fois plus concentrés dans le blé. L'ingestion de ces inhibiteurs d'amylase et la formation d'un complexe enzyme inactive/inhibiteur avec l'amylase secrétée antérieurement, peut rendre compte de la plus faible activité de l'amylase chez les charançons consommant du blé. Le niveau d'amylase de S. oryzae est 2 fois plus élevé que celui de S. zeamais pour toutes les souches élevées sur un régime donné. Des niveaux d'activité significativement différents ont été trouvés suivant les souches pour chacune des deux espèces. Puisque l'amylase est la principale hydrolase digestive de ces espèces, l'intensité de la modification des teneurs en amylase par la consommation de céréales peut indiquer leur adéquation comme hôtes potentiels.
    Notes: Abstract Rank transformation of specific activity values of α-amylase across four strains of Sitophilus oryzae (L.) and four strains of S. zeamais Motschulsky indicates that levels of these predominant enzymes are highest in adults feeding on hulled barley or long-grain brown rice. Intermediate activity levels are found in weevils feeding on yellow corn (maize) and lowest levels are found in wheat-fed weevils. Although extracts prepared from barley contain inhibitory activity against two purified isoamylases from S. oryzae, levels of the naturally-occurring α-amylase inhibitors against these two enzymes are about 2.2-fold and 6.1-fold, respectively, more concentrated in wheat. Ingestion of these amylase inhibitors and formation of an inactive enzyme:inhibitor complex with previously secreted amylase may account for the lower activity of amylase in weevils of both species feeding on wheat. Amylase levels across all strains feeding on a given diet are about 2-fold higher in S. oryzae than in S. zeamais. Significant differences in activity levels were also found between strains in both species. Since α-amylase is a predominant digestive hydrolase in these species, the degree to which cereal diets affect amylase levels may indicate their suitability as potential hosts.
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  • 44
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    Entomologia experimentalis et applicata 44 (1987), S. 53-58 
    ISSN: 1570-7458
    Keywords: Tomicus piniperda ; Coleoptera ; Scolytidae ; host recognition ; host volatiles ; attraction ; low vigor trees ; attacked trees
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Anflug von Tomicus piniperda (L.) (Coleoptera: Scolytidae) an Kiefern in schlechtem oder besserem Gesundheitszustand, mit oder ohne vorherigen Befall, wurde mit Hilfe von Leimfallen untersucht. An Bäumen in schlechtem Zustand wurden etwas mehr Käfer gefangen als an Bäumen in besserem Gesundheitszustand. Das deutet auf Unterschiede in Geruchsreizen zwischen den beiden Klassen des Baumzustands hin. An Kiefern, die von T. piniperda befallen waren oder simulierte Einbohrungen (von Hand gebohrte Löcher) hatten, wurden viel mehr Käfer gefangen als an Kontrollbäumen ohne oder mit sehr geringem Befall. Der starke Anflug von Käfern an befallene Bäume wird gedeutet als Reaktion auf Duftstoffe des Wirts, die aus den Borkenkäfergängen abgegeben werden.
    Notes: Abstract The attraction of Tomicus piniperda (L.) (Coleoptera: Scolytidae) to Scots pine trees of low and higher vigor with and without previous attacks was monitored with sticky traps. Somewhat higher numbers of beetles were caught on low vigor trees than on trees of higher vigor, indicating differences in olfactory stimuly between the two classes of trees. Many more beetles were caught on trees attacked by T. piniperda and on trees with simulated bark beetle galleries (manually drilled holes) than on control trees with no or only a few attacks. The strong attraction of beetles to attacked trees is attributed to the beetles responding to host volatiles released from the galleries.
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  • 45
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    Entomologia experimentalis et applicata 48 (1988), S. 157-163 
    ISSN: 1570-7458
    Keywords: sweet potato weevil ; Cylas formicarius elegantulus ; Coleoptera ; Curculionidae ; sweet potato ; Ipomoea batatas ; feeding ; host-plant preference ; leaf surface chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude a porté sur la consommation pendant 12 h, en boîtes de Pétri de diamètre 9 cm, de rondelles de 2 cm de diamètre de feuilles de 4 cultivars,—Centennial, Jewel, Resisto, Regal—, d'I. batatas par C. formicarius elegantulus. Les charançons ont consommé le long des nervures, préférant la face inférieure à la face supérieure des feuilles. Un index de consommation a été calculé en fonction de la longueur de nervure ayant servi à la consommation, rapportée à la longueur totale des nervures de la surface exposée. Les niveaux de consommation des mâles et des femelles étaient semblables. En présence de choix binaires, le cultivar Centennial a été le plus consommé, et le cultivar Resisto, le moins, par les femelles. De telles préférences n'ont pas été observées en l'absence de choix. La composition chimique de la surface de la feuille a été analysée par chromatographie en phase gazeuse. 8 pics principaux identiques ont été observés chez les 4 cultivars, mais ils avaient différentes hauteurs.
    Notes: Abstract A bioassay was developed to quantify the feeding of adult sweet potato weevils, Cylas formicarius elegantulus (Summers) (Coleoptera; Curculionidae) on the foliage of four cultivars (Centennial, Jewel, Resisto and Regal) of sweet potato (Ipomoea batatas (L.) Lam.) (Convolvulaceae). Weevils fed along the leaf veins, preferring the lower to the upper leaf surface. Males and females had similar levels of feeding. Different levels of feeding by female weevils were observed between cultivars in dual-choice bioassays with Centennial, a susceptible cultivar in field-plot experiments, being most preferred and Resisto least preferred. However, these feeding differences were not observed in no-choice bioassays. Little difference was observed in the leaf surface chemistry of the four cultivars.
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  • 46
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    Current genetics 12 (1987), S. 577-582 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Cell cycle ; Cyclic AMP ; G0 protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When the cyr1-1 cells of Saccharomyces cerevisiae, which require cyclic AMP (cAMP) for growth, were starved for cAMP, cell division was arrested at the G1 state of the mitotic cell cycle and the cells entered the resting state (G0) also observed in wild-type cells transferred to sulfur-free medium. The level of cAMP in wild-type cells decreased rapidly when the cells were starved for sulfur and subsequently increased following its addition. The cyr1-1 cells starved for cAMP preferentially synthesized nine G0 proteins. The synthesis of these G0 proteins in the sulfur-starved cells was repressed by the addition of cAMP. The RAS2 val19 or bcy1 cells, which produced an elevated level of cAMP or cAMP-independent protein kinase, did not synthesize the G0 proteins under the sulfur-starved condition. The results suggest that cAMP plays a role in the transition between the proliferating state and G0 state.
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  • 47
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Site specific recombination ; 2 μ DNA plasmid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The purpose of this work is to identify and quantitate in vivo 2 μ plasmid FLP-independent recombination in yeast, using a nonselective assay system for rapid detection of phenotypic expression of the recombination events. A tester plasmid was constructed such that in vivo recombination between 2 μ direct repeat sequences produces the resolution of the plasmid into two circular DNA molecules. This recombinational event is detected as a phenotypic shift from red to white colonies, due to the mitotic loss of the plasmid portion containing the yeast ADE8 gene in a recipient ade1 ade2 ade8 genetic background. In the absence of the 2 μ FLP recombinase and/or its target DNA sequence, recombination is not abolished but rather continues at a high frequency of about 17%. This suggests that the FLP-independent events are mediated by the chromosomally-encoded general homologous recombination system. We therefore conclude that the totality of 2 μ DNA recombination events occurring in FLP+ cells is the contribution of both FLP-mediated and FLP-independent events.
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  • 48
    ISSN: 1432-0983
    Keywords: Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; Argininosuccinate lyase ; Gene cloning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A gene bank of Sau3A partially restricted Schizosaccharomyces pombe DNA in YEp13 was used to transform an arg4 mutant of Saccharomyces cerevisiae. One colony was recovered which contained the YEp13 plasmid bearing a large insert complementing the argininosuccinate lyase (ASL) mutation. As shown by restriction mapping and subcloning experiments, the DNA sequence required for complementation is localized on a 2 kb BamHI-BamHI fragment. The plasmid complemented several S. cerevisiae arg4 mutants of independent origin and a S. pombe arg7 mutant lacking ASL. Low but significant ASL activities were detected in crude extracts of these transformants. No complementation of the E. coli argH mutant was observed. Southern blot hybridizations showed that the insert originates from the S. pombe genome. No cross-hybridization was found between this sequence and S. cerevisiae DNA. It can be concluded that the cloned DNA fragment bears the S. pombe ARG7 gene coding for ASL.
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  • 49
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    Current genetics 14 (1988), S. 413-418 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Chromosome length polymorphisms ; FIGE ; OFAGE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Although Saccharomyces cerevisiae strains generally have similar chromosomal band patterns as revealed by pulsed field gel electrophoresis, individual bands often move slightly differently from one strain to the other. Surveying strains from our stock collection, we found that nearly all the bands of a certain pair of strains differed in their mobility. Some of these chromosome length polymorphisms segregated in a 2:2 ratio, indicating that they resulted from single structural alterations (i.e. additions or deletions). One of these was mapped on the right arm of chromosome 1. Others did not segrate in a simple 2:2 ratio. That is, there were progenies which had bands not present in either parent. We suggest that these new bands are the products of recombination between homologous chromosomes having two or more structural alterations.
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  • 50
    ISSN: 1432-0983
    Keywords: ARS ; Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; Tetrahymena thermophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have isolated several Tetrahymena thermophila chromosomal DNA fragments which function as autonomously replicating sequences (ARS) in the heterologous Saccharomyces cerevisiae and Schizosaccharomyces pombe selection systems. The Tetrahymena ARS sequences were first isolated in S. cerevisiae and were derived from non-ribosomal micro- and macronuclear DNA. Sequence analysis of the ARS elements identified either perfect or close matches with the 11 by S. cerevisiae ARS core consensus sequence. Subcloning studies of two Tetrahymena ARS elements defined functional regions ranging in size from 50 to 300 bp. Testing of the ARS elements in S. pombe revealed that most of the T. thermophila inserts confer ARS function in both yeasts, at least in the sense of promoting a high transformation frequency to plasmids which contain them. However, the actual sequences responsible for ARS activity were not always identical in the two yeasts.
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  • 51
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Ribosomal protein genes ; CYH2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A diploid strain of the yeast Saccharomyces cerevisiae has been constructed that has one copy of the ribosomal protein gene CYH2 completely deleted and replaced with the TRP1 gene using the method of Rothstein (1983). There are only small differences in growth rate and no detectable difference in steady state level of CYH2 mRNA between the diploid that is heterozygous for the CYH2 deletion and the parent diploid with two normal copies of this gene. This suggests that the diploid must partially compensate for the loss of one CYH2 gene. Tetrad dissection shows that haploid spores lacking the CYH2 gene cannot germinate. The lethality of this deletion can be rescued by a CYH2 cDNA on a low copy vector. Haploids which lack the genomic copy of the CYH2 gene, but contain a plasmid copy of the CYH2 cDNA are able to grow normally. These CYH2 deleted yeast haploids should be useful to analyze mutationally altered CYH2 genes and genes homologous to CYH2 from other organisms without interference from a genomic copy.
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  • 52
    ISSN: 1432-0983
    Keywords: Yeast ; Gene regulation ; Saccharomyces cerevisiae ; PDCI promoter
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary A 870 by promoter fragment of the PDC1 gene that includes the carbon source dependent regulatory regions was investigated using 5′ and 3′ promoter deletions. The results indicate that glucose and ethanol regulation of PDC1 transcription are independently controlled by distinct cis-acting regions. The consensus sequence AAATCGATA may play a role in this regulation, while the sequence (ATCA)AACCT may be important in transcription initiation.
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  • 53
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Vector ; Glyphosate resistance ; Transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The E. coli aroA gene was inserted between yeast promoter and terminator sequences in different shuttle expression plasmids and found to confer enhanced EPSP synthase activity as well as resistance to glyphosate toxicity. Subsequently, a transformation system using these newly constructed vectors in yeast was characterized. The efficiency of the glyphosate resistance marker for transformation and selection with plasmid pHR6/20-1 in S. cerevisiae laboratory strain SHY2 was found to be relatively high when compared with selection for LEU2 prototrophy. The fate of the recombinant plasmid pHR6/20-1 in the transformants, the preservation of the aroA E. coli DNA fragment in yeast, mitotic stability, EPSP synthase activity, and growth on glyphosate-containing medium have been investigated. As this plasmid also allows direct selection for glyphosate resistant transformants on rich media, the glyphosate resistance marker was used for transforming both S. cerevisiae laboratory strain SHY2 and brewer's yeast strains S. cerevisiae var. “uvarum” BHS5 and BHS2. In all cases, the vector pHR6/20-1 was maintained as an autonomously replicating plasmid. The resistance marker is, therefore, suitable for transforming genetically unlabeled S. cerevisiae laboratory, wild, and industrial yeast strains.
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  • 54
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Chromosome V ; Ty elements ; tRNA genes ; Transposition hot-spots ; Yeast polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ty4 is a novel transposable element in the yeast, Saccharomyces cerevisiae, which is present in only a few copies in the genome (Stucka et al. 1989). In strain C836 one of the three copies (Ty4-90) is contained in cosmid clone c90, where it resides on chromosome V. Analysis of this region reveals a “hot-spot” of transposition: in addition to Ty4-90, the locus contains a complete Ty3 element and seven singular delta, sigma and tau elements. Three tRNA genes (for His, Lys, and Ile) are located in this region, and these are closely associated with one or the other of the elements, a phenomenon commonly observed in yeast. A comparison of c90 with corresponding regions from other strains shows that the locus is highly polymorphic and that this polymorphism is explicitly associated with Ty transposition and recombination events.
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  • 55
    ISSN: 1432-0983
    Keywords: Gene cloning ; Saccharomyces cerevisiae
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    Topics: Biology
    Notes: Summary We have carried out experiments aimed at explaining the observed variations in transformation frequencies when Saccharomyces cerevisiae or Saccharomyces carlbergensis are transformed with chimeric plasmids that contain one of 4 possible EcoRI fragments of the yeast 2-μm circle. These plasmids fall into 2 classes when used to transform 2 different yeast his3 auxotrophs, one (strain LL20) harbours indigenous 2-μm circle, and the other (strain YF233) is devoid of this plasmid. Hybrid plasmids containing either the 2.4 mega-dalton (mD) R-form EcoRI fragment (pYF88) or the l.4 mD L-form EcoRI fragment (pYF177) of 2-μm circle transform either of the two hosts at a high frequency (50,000 colonies per Mg in LL20 and 10,000 colonies per μg in YF233). Hybrid plasmids containing the 1.5 mD R-form EcoRI fragment (pYF87) or the 2.5 mD L-form EcoRI fragment (pYF178) of the 2-μm circle transform LL20 at a reduced frequency (6,000–16,000 colonies per μg) and YF233 at extremely low frequencies (1–5 colonies per μg). All plasmids retrieved from strain YF233 that had been transformed with pYF88 or pYF177 were identical to the original transforming plasmid. Of the plasmids retrieved from strain LL20 that had been transformed with pYF87 and pYF178, approximately half had acquired an extra copy of the 2-μm circle. Of the plasmids retrieved from strain LL20 that had been transformed with pYF88 and pYF177, an average of only approximately 13% had acquired an extra copy of 2-μm circle. Taken together, these observations indicate that the transformation of yeast by a plasmid lacking the ability to replicate (pYF87 and pYF1780) occurs by the recombinational acquisition of 1 copy of the host 2-μm circle, which serves to supply the incoming plasmid with missing essential sequences. A comparison of 2-μm circle DNA fragments carried by pYF88 and pYF177 indicates that the region of 2-μm circle required for high frequency transformation is a 1.2 mD segment that is common to the 2.4 mD R-form and 1.4 ml) L-form EcoRI fragments. This region extends from the EcoRI cut site adjacent to the PstI site, through to the end of the inverted repeat. However, the inverted repeat sequence alone is not sufficient to bestow high frequency transformation of yeast.
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  • 56
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    Current genetics 10 (1986), S. 943-945 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; α-factor ; Protoplasts
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    Topics: Biology
    Notes: Summary When Mat a cells are treated with α-factor prior to being protoplasted and fused, the frequency of karyogamy is higher than in unarrested controls.
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  • 57
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    Current genetics 10 (1985), S. 179-185 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Resistance ; Mercury ; Tyrosine
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    Topics: Biology
    Notes: Summary From a cross of two strains ofSaccharomyces cerevisiae, both of which had the same (wild type or normal) level of resistance to inorganic mercury, segregants having three distinguishable resistance levels, normal, sensitive and semi-sensitive, were obtained. Genetic analyses of the parents and the progeny indicated that the levels of inorganic mercury sensitivity were determined by three distinct loci,HGS1, HGS2 andMSM1. The recessive allele of theHGS1 locus,hgsl-1, and the codominant allele of theHGS2 locus,HGS2-1, were necessary for the sensitive phenotypes, and alleles in theMSM1 locus,MSMI-1 andmsml-2, were responsible for the different sensitivity levels. In short, the strains of genotypeshgs1-1 HGS2-1 msml-2 andhgsl-1 HGS2-1 MSMI-1 were sensitive and semi-sensitive, respectively, while the strains of all other genotypes were normal. Although thehgs1-1 allele was identified as thearo7-1 mutation which confers deficiency of tyrosine and phenylalanine, mutations such asaro1B (deficiency of tyrosine, phenylalanine and tryptophan) andtyr1 (deficiency of tyrosine) had similar effects asaro7-1 on inorganic mercury sensitivity. From these results we conclude that theHGS2-1 allele causes inorganic mercury sensitivity when the cells are defective in the tyrosine biosynthesis. In fact, addition of tyrosine to the growth medium containing inorganic mercury resulted in increase of colony forming ability of the sensitive strains.
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  • 58
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    Current genetics 10 (1986), S. 665-670 
    ISSN: 1432-0983
    Keywords: Multiple drug resistance ; Genetic mapping ; Saccharomyces cerevisiae
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    Topics: Biology
    Notes: Summary In the yeast Saccharomyces cerevisiae, two nuclear pleiotropic drug resistance mutations pdr3-1 (former designation muc PR) and pdr3-2 (former designation DRI9/T7) have been selected as resistant to mucidin and as resistant to chloramphenicol plus cycloheximide, respectively. The pdr3 mutations were found not to affect the plasma membrane ATPase activity measured in a crude membrane fraction. Meiotic mapping using strains with standard genetic markers revealed that mutation pdr3-1 is centromere linked on the left arm of chromosome II at a distance of 5.9 ± 3.3 cM from its centromere and 11.6 ± 3.1 cM from the marker pet9. The centromere linked pdr3-2 mutation exhibited also genetic linkage to pet9 with a map distance of 9.8 ± 3.2 cM. These results indicate that pdr3-1 and pdr3-2 are alleles of the same pleiotropic drug resistance locus PDR3 which is involved in the control of the plasma membrane permeability in yeast.
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  • 59
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    Current genetics 10 (1986), S. 657-664 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Amino acid biosynthesis ; General control ; GCD-genes ; GCN-genes
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    Topics: Biology
    Notes: Summary Mutant strains, resistant against the amino acid analogues 5-methyltryptophan, 5-fluorotryptophan and canavanine were isolated, starting with a trp2 leaky auxotrophic strain. Of 10 such strains, only four turned out to be of the “general control derepressed” (gcd) mutant type. Three other isolates were shown to be defective in the general amino acid permease system, while the remaining three strains displayed low spore viability and were not further investigated. Complementation tests amongst the four new gcd-mutant strains, including strain RH558 gcd2-1 isolated earlier, yielded five complementation groups: GCD2, GCD3, GCD4, GCD5, and GCD6. All mutant strains showed a dual phenotype, which was not separable by wild type backcrosses: “constitutive derepression” and “slow growth”. Epistatis of all gcd mutations over gcn1-1, gcn2-1 and gcn3-1 was found with respect to both phenotypes, except for gcd5-1, which was lethal in these combinations. On the other hand gcn4-101 was found to be epistatic over all gcd mutations, but only with respect to the “constitutive derepression” phenotype, and not to “slow growth”; again the combination with gcd5-1 was lethal. Mutation gcd2-1 was mapped on chromosome VII, 50 cM from leu1 and 22 cM from ade6. A new model is discussed, in which GCD-genes are involved in the amino acid uptake into the vacuoles.
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  • 60
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Inducible repair ; Plasmid transformation
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    Notes: Summary Many reports show that resistance of Saccharomyces cerevisiae to a large UV dose can be enhanced by pre-induction with a smaller one given some hours before. This work tests if such increased cell survival is associated with increased DNA repair on UV damaged plasmid transformed into yeast. There was no change in transformation efficiency of UV-damaged plasmid DNA under conditions where RAD cell survival increased 5-fold, and where rad1-1 and rad6-1 survival increased 2-fold. It is concluded that DNA repair activity involving the RAD6 and RAD3 pathways is either not inducible or is unable to work on plasmid DNA. It is suggested that the enhancement of cellular survival detected may be based on changes in cell-cycle behaviour which permit cells generally proficient in repair a greater chance to recover.
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  • 61
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; 2 μ plasmids ; Plasmid free segregants
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    Notes: Summary The maximum specific growth rates (μmax) of 2 μ-plasmid-free ([cir°]) segregants of three haploid and one diploid strain of Saccharomyces cerevisiae have been determined and compared with the μmax of their 2 μ-plasmid-containing ([cir +]) progenitors. Two classes of [cir°] strains have been examined: those induced by transformation with a 2 μ-based recombinant plasmid according to the method of Dobson et al. (1980) and those isolated as spontaneous [cir°] segregants from glucose-limited continuous cultures. The μmax of the spontaneous [cir°] segregants was not found to differ significantly from that of their [cir +] parents. In all cases, however, the induced [cir°] strains had a μmax which was significantly less than that of their [cir +] counterparts. This effect was particularly marked in the case of the diploid strain where a 34% reduction in μmax was observed. The implications of these results are discussed in terms of the effect of the transformation process on host yeast cells.
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  • 62
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Minor tRNAs ; Codon usage ; Transposable elements ; Delta ; Tau
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    Notes: Summary During characterization of the whole tRNA(Glu) family from the yeast, Saccharomyces cerevisiae, we isolated one cosmid clone bearing a tRNA(Glu) gene copy that is deviant from the major tRNA(Glu3) gene members in only five positions. This divergent tRNA(Glu) is a minor species and is represented by a single gene copy. One of the nucleotide exchanges concerns the anticodon which is modified from T-T-C in the tRNA(Glu3) gene to C-T-C which implies that this tRNA serves the codon triplet G-A-G. Two other minor yeast tRNA species have been reported which appear to be particularly designed for the translation of those codons that have a G in its third (Wobble) position. The low abundance of such minor tRNA species correlates positively to the low occurrence of most of the N-N-G codons in yeast. Furthermore, the GAGtRNA(Glu) locus represents another case of the general phenomenon in which the majority of the tRNA genes in yeast are associated with one or several transposable elements forming complex patterns. In this particular case, divergent segments of delta and tau are present in the 5′ flanking region of the tRNA gene and arranged in a novel configuration. The sequence data lend support to the view that tau is not an evolutionary young element as was earlier anticipated.
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    Current genetics 16 (1989), S. 315-321 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Antisuppressor ; ADE3 ; Translation
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    Notes: Summary Mutations in a known yeast gene, ADE3, were shown to act as an antisuppressor, reducing the efficiency of the omnipotent suppressor, sup45-2. The ADE3 locus encodes the trifunctional enzyme C1-tetrahydrofolate synthase, which is required for the biosynthesis of purines, thymidylate, methionine, histidine, pantothenic acid and formylmethionyl-tRNAfmet. The role of this enzyme in translational fidelity had not previously been suspected.
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  • 64
    ISSN: 1432-0983
    Keywords: Yeast ; Saccharomyces cerevisiae ; Nonsense suppression ; Omnipotent suppressors ; Gene mapping
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    Notes: Summary Ten dominant omnipotent suppressors of Saccharomyces cerevisiae, which were previously shown to be different from SUP46, have been examined. Nine are mapped in a region between lys5 and cyh2 on the left arm of chromosome VII. These suppressors, like SUP46, manifest sensitivity to increased temperature and the antibiotics paromomycin and hygromycin B. In addition, they have an identical action spectrum. These results strongly suggest that they are allelic to each other and they are designated SUP138. The tenth is mapped to a position between his1 and arg6 on the right arm of chromosome V. This suppressor, named SUP139, does not manifest temperature sensitivity nor antibiotic sensitivity. SUP139 and SUP138, which are clearly distinguished by means of action spectrum, act on much fewer nonsense mutations than SUP46. It is now clear that dominant omnipotent suppressors arising at a single locus are homogeneous and that their efficiency is locus-dependent. The order of efficiency is SUP46〉SUP138〉SUP139.
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    Current genetics 13 (1988), S. 21-23 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Transformation ; Plasmid ; Colony ; Polyethylene glycol
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    Topics: Biology
    Notes: Summary A rapid and simple yeast transformation procedure has been developed using colonies on agar plates. Saccharomyces cerevisiae SHY3 cells were picked up from colonies on YPD plates grown freshly or stored at 4 °C and incubated with M13RK9-T DNA at 30 °C for 1–2 h in a solution of Li+, Ca2+, Mg2+, triacetin and polyethylene glycol. About 3,500 transformants were obtained per µg of double stranded M13RK9-T DNA. Unlike the existing spheroplast techniques, single stranded M13RK9-T DNA transformed intact cells below one-hundredth frequency of the duplex form.
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  • 66
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    Keywords: Aspergillus terreus clonotheque ; Saccharomyces cerevisiae ; Homologous integration ; 2 μ circledirected chromosome destabilization
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    Notes: Summary A genome clonotheque consisting of 25- to 40-kb Sau3A1 fragments of Aspergillus terreus DNA was constructed in the episomal cosmid vector pES33 containing the yeastARG4 gene. From the 475 transformants of cir° yeast strain ESH-0, 23 stable Arg + transformants were independently selected. Genetic and Southern analysis of these stable transformants showed that 39% arose as a result of recombination between cloned A. terreus DNA sequences and yeast chromosome XII. The recombination events most likely occurred in the regions of homology within the rDNA clusters of A. terreus and Saccharomyces cerevisiae.
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  • 67
    ISSN: 1432-0983
    Keywords: Yeast ; Repair ; Complementation ; Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; Gene cloning
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    Notes: Summary Two Saccharomyces cerevisiae genes necessary for excision repair of UV damage in DNA, RAD1 and RAD2, were introduced individually, on a yeast shuttle vector, into seven Schizosaccharomyces pombe mutants — rads1, 2, 5, 13, 15,16 and 17. The presence of the cloned RAD1 gene did not affect survival of any of the S. pombe mutants. The RAD2 gene increased survival of S. pombe rad13 to near the wild-type level after UV irradiation and had no effect on any of the other mutants tested. S. pombe rad13 mutants are somewhat defective in removal of pyrimidine dimers so complementation by the S. cerevisiae RAD2 gene suggests that the genes may code for equivalent proteins in the two yeasts.
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  • 68
    ISSN: 1432-0983
    Keywords: DNA transformation ; Saccharomyces cerevisiae ; Site-specific recombination ; 2μ DNA plasmid
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    Notes: Summary The 2μ DNA plasmid of the yeast Saccharomyces cerevisiae does not confer any known selectable phenotype to the host cell carrying it. Selection of cells transformed with purified 2μ DNA therefore cannot be achieved, and the intracellular presence of 2μ can only be assessed by molecular analysis of the DNA complement. In addition, 2μ alone does not replicate in bacterial hosts, thus rendering its amplification by conventional methods impossible. We have isolated a shuttle plasmid, pBH-2L, generated by in vivo sites-pecific recombination between the endogenous 2μ DNA plasmid and pRL, a pBR322 derivative containing the yeast LEU2 gene and one 2μ repeat sequence associated with the origin of replication. This new shuttle plasmid has the property, when transformed into yeast, of undergoing site-specific recombinational resolution between its two direct repeat sequences. This releases 2μ plasmid and pRL as individual molecules. The latter can undergo progressive mitotic loss during growth in nonselective medium, ultimately leaving leucine auxotrophic transformants that contain only 2μ DNA plasmid. This system can be utilized to introduce 2μ DNA alone into cells lacking it, thereby providing a novel means to study the biology and the molecular genetics of the plasmid and its potential practical applications as a vector.
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  • 69
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    Current genetics 15 (1989), S. 113-120 
    ISSN: 1432-0983
    Keywords: Calmodulin mutant ; Nuclear division ; Chromosome stability ; Saccharomyces cerevisiae
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    Notes: Summary The coding region of a yeast calmodulin gene was fused to a galactose-inducible GAL1 promoter, and a conditional-lethal mutant of Saccharomyces cerevisiae, in which the expression of calmodulin was regulated by galactose, was constructed. The mutant grew normally in galactose medium, but in glucose medium, in which the promoter was repressed, it ceased growing after 12–15 h. The growth arrest was associated with a decrease in intracellular calmodulin levels: after 12h, no intracellular calmodulin protein was detectable. Analysis of the terminal phenotype showed that when the cell stopped growing, it had a bud, a nucleus after S-phase and a short mitotic spindle. Thus, the defect was mainly in nuclear division. Bud growth was partially inhibited in these cells: 27% of the cells stopped growing with a small bud. Furthermore, calmodulin-deficient cells showed elevated rates of chromosome loss, possibly as the result of a defect in the precise segregation of chromosomes.
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    Current genetics 15 (1989), S. 235-237 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Mitochondrial DNA ; Method of extraction
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    Notes: Summary A rapid method for the extraction of yeast mitochondrial DNA (mtDNA) is described. In comparison with previous methods, it simplifies several steps, does not require either the isolation of mitochondria or phenol treatment and is less time consuming. This protocol gives a high yield of pure mtDNA (50–120 μg from a 100-ml culture), which can be directly used in various molecular applications: restriction enzyme digestion, electrophoresis, blotting, labeling, cloning and sequencing.
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  • 71
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Mutagen hyperresistance ; Southern, Northern analysis ; Gene transplacement ; Transposon mapping
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    Notes: Summary The genes SNQ and SFA confer hyperresistance to 4-NQO and FA when present on a multi-copy plasmid in yeast. Both are non-essential genes since transplacement of SNQ by a disrupted snq-0::LEU2 yielded stable and viable haploid integrants. Southern analysis revealed that SNQ and SFA are single-loci genes, and OFAGE analysis showed that they are located on chromosome XIII and IV, respectively. Northern blot analysis of SNQ and SFA revealed poly(A)+ RNA transcripts of 2 kb and 1.7 kb, respectively. Nuclease S 1 mapping showed SNQ to have a coding region of 1.6 kb and SFA, one of 1.3 kb. The 5′ coding regions were determined for both genes, while the 3′ end could only be determined for gene SNQ. Both genes do not appear to contain introns. The SFA locus was also mapped by transposon mutagenesis. Tn10-LUK integrants disrupted the SFA gene function at sites that were determined by subcloning to lie within the SFA transcription unit.
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  • 72
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; SKI3 ; SKI5 ; M1 dsRNA
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    Notes: Summary We have identified a mutant strain of the yeast Saccharomyces cerevisiae which overproduces killer toxin. This strain contains a single mutation which fails to complement defects in both the SKI3 and SKI5 genes, while a cloned copy of this gene complements both the ski3 and ski5 defects. The level of secreted toxin from a cDNA based plasmid is not increased in a ski3 strain, showing that the overproduction phenotype is dependent upon an increased level of M1 dsRNA.
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  • 73
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Psoralen photoaddition ; Interstrand cross-link ; Repair deficiency ; Genotoxicity
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    Notes: Summary Two different UVA irradiation systems were initially biologically calibrated with two haploid yeast strains proficient and deficient, respectively, in nucleotide excision repair. The number of DNA lesions introduced into the cell's genome by the photoactivated bifunctional furocoumarin 8-MOP was then calculated by means of the applied UVA exposure doses. At LD37 the repair-proficient wild type had about 14 ICL and 34 furan-side monoadducts in its DNA, while doubly blocked repair mutant rad3-12 pso1-1 had 2 ICL and 3 monoadducts. Locus-specific reversion of lys1-1 followed two-hit kinetics in the repair-proficient wild type and one-hit kinetics in an excision-deficient rad2-20 mutant, as would be expected if ICL was the main type of mutagenic lesion in the wild type and monoadducts the main mutagenic lesion type in the excision-deficient strain. Quantitative comparison of 8-MOP + UVA-induced ICL with those induced by bifunctional mustard revealed the former to have a much higher genotoxicity.
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    Current genetics 2 (1980), S. 115-120 
    ISSN: 1432-0983
    Keywords: Galactose fermentation ; Saccharomyces cerevisiae ; Regulatory mutant
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    Notes: Summary A novel type of regulatory mutation for galactose metabolism in Saccharomyces cerevisiae is described. The mutation named gal11 was recessive, non-allelic to GAL4, GAL80, GAL2, or GAL3, and unlinked to the gene cluster of GAL1, GAL10, and GAL7. It caused a ‘coordinate’ reduction of galactokinase, galactose-1-P uridylyl transferase, and UDP-glucose 4-epimerase by a factor of more than 5, rendering the mutant cells galactose-nonfermenting. The effect of the mutation was manifested not only in cells grown on galactose but also in cells constitutively synthesizing the galactose-metabolizing enzymes.
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    Current genetics 2 (1980), S. 223-228 
    ISSN: 1432-0983
    Keywords: Transcriptional Units ; GAL Genes ; Saccharomyces cerevisiae ; UV mapping
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    Topics: Biology
    Notes: Summary The size of the transcriptional unit of the structural genes for three galactose-metabolizing enzymes which form a cluster on chromosome II in Saccharomyces cerevisiae was studied by the ultraviolet light (UV)-mapping technique. Thus the size of the primary transcripts of GAL7 for galactose-1-phosphate uridylyl transferase, GAL10 for uridine diphosphoglucose 4-epimerase, or GAL1 for galactokinase were estimated to be 0.81 x 106, 1.1 x 106, or 1.3 x 106 respectively. In the light of these data together with the known directions of transcription of the genes, we concluded that each of three genes was transcribed from its own promoter.
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  • 76
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Yeast transformation ; Centromere-containing plasmids ; Mitotic stability of minichromosomes
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    Notes: Summary A mutant with unstable maintenance of hybrid plasmids containing either one of the centromeric loci CEN3, CEN6, CEN11 and arsl or the replicator of the 2 μ plasmid has been obtained. The frequency of loss of hybrid plasmids in the mutant was up to 3 · 10−1 per one generation versus 10−2 in the original strain. The unstable maintenance of minichromosomes in the mutant is controlled by a recessive nuclear gene, named SMC for stability of minichromosomes. Loss of some minichromosomes is connected with impairment of their segregation in cell division. In diploids homozygous for smc mitotic chromosomal segregation is not affected but sporulation is impaired. The question of adequacy of usage of minichromosomes for selection of mutants with impaired function of centromeric loci is discussed.
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    Current genetics 10 (1985), S. 171-177 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Nuclear mutations ; Mitochondrial DNA stability ; Uncoupling of phenotypes
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    Topics: Biology
    Notes: Summary We have studied a pleiotropic mutationpetD inS. cerevisiae which both confers the inability to grow on glycerol (Gly−) and greatly increases the frequency of cytoplasmic petites (Het). The first phenotype, Gly−, is recessive, whereas the second, Het, is dominant. Genetic and biochemical analysis showed that the majority of the petites inpetD strains are not of therho° type (completely lacking mit-DNA),but of therho − type (containing partially deleted mit-DNA). This finding and the fact that the phenotype Het is dominant argue in favour of the involvement of thepetD product in the excision process of the mit-DNA. Another nuclear mutation,mod, was shown to exhibit a dominant epistasy with respect to the Het phenotype of the mutationpetD. Two types of Gly+ revertants frompetD mutants were isolated:rpa revertants, which restore completely the wild-type phenotype, andrpb revertants, which restore only the growth on glycerol, but still allow the production of high frequencies of cytoplasmic petites. Thus the mutationsmod andrpb permit the genetic uncoupling of two phenotypes induced by the mutationpetD.
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    Current genetics 10 (1985), S. 187-195 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Inorganic mercury ; Catabolite regulation ; Sugar uptake
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    Topics: Biology
    Notes: Summary Saccharomyces cerevisiae strains sensitive to inorganic mercury (Ono and Sakamoto 1985) did not grow well on the medium rich in glucose and poor in peptone. This growth inhibition, like growth inhibition caused by inorganic mercury, was relieved by exogenous tyrosine. Sugars such as fructose and mannose were as inhibitory as glucose, but glycerol was not at all. Galactose was inhibitory but not so much as glucose. Agal2l mutation (defective in galactose uptake) partly relieved growth inhibition caused by excess galactose. Moreover, it was found that some of revertants which gained ability to grow well in the presence of excess glucose were defective in the glucose uptake. From these observations, we conclude that growth inhibition of the inorganic mercury sensitive strains by excess sugar is a consequence of the catabolite regulation. In other words, the inorganic mercury sensitive strains are hyper-sensitive to the catabolite regulation due to the presence of theHGS2-1 allele.
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    Current genetics 10 (1986), S. 491-494 
    ISSN: 1432-0983
    Keywords: Protoplast fusion ; Saccharomyces cerevisiae ; Schwanniomyces castellii ; Starch fermentability
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    Topics: Biology
    Notes: Summary Prototrophic hybrids have been obtained by the fusion of various auxotrophic haploid strains of Saccharomyces cerepisiae and Schwanniomyces castellii. The fusion hybrids showed starch fermentability which derived from one of the fusion parents, S. castellii. Surprisingly, these fusion hybrids were found to exhibit excellent sporulation and spore germination. The progenies of these fusion hybrids showed a few aberrant segregations, but mostly normal segregation for auxotrophic genetic markers. They also showed many tetrads with an apparently digenic segregation (2:2, 3:1 and 4:0) for starch fermentation. On the other hand, mating types of segregants of the fusion hybrids were determined by the prototrophic recovery method. Consequently, tetrad types for mating type were mostly 2a:1α:1 non-mater and several asci showed tetrad types of 2a:2 non-mater and 2a:2α. The 60 prototrophic fusion hybrids and its segregants did not secrete α-amylase on the starch agar plate. However, all of the data suggested that fusion hybrid could carry two dominant genes (STAB and STAC) to ferment starch, and that the two genes STAB and STA2 may be identical or allelic as may be the genes STAC and STA3.
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    Current genetics 11 (1986), S. 93-96 
    ISSN: 1432-0983
    Keywords: Uracil permease gene ; Saccharomyces cerevisiae ; Chromosomal mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The gene FUR4, coding for the uracil permease in Saccharomyces cerevisiae, was mapped on chromosome II, at a distance of 7.8 cM from the centromere on the right arm of the chromosome. In a first step, we used the chromosome loss mapping method developed by Falco and Botstein (1983) to determine on which chromosome the gene mapped. After the observation that FUR4 was closely linked to GAL10, one of the three genes forming the gal cluster (Bassel and Mortimer 1971), we could determine precisely the position of the gene on chromosome II.
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  • 81
    ISSN: 1432-0983
    Keywords: Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; DNA ligase ; DNA damage
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    Topics: Biology
    Notes: Summary UV-irradiation of stationary phase cells of Saccharomyces cerevisiae and Schizosaccharomyces pombe leads to a 9-fold and 90-fold increase in transcript levels from the respective DNA ligase genes CDC9 and CDC17, whereas exponential cells show only 3-fold and 2-fold increases. Induction of CDC9 after MMS treatment and γ-irradiation was also observed by using a CDC9-lacZ translational fusion and assaying for β-galactosidase. Surprisingly, irradiation of S. cerevisiae induces only a 50% increase in DNA ligase itself, probably reflecting the extremely high in vivo stability of the enzyme. The UV-induction of ligase may be part of a “fail-safe” mechanism which, together with the enzyme stability, ensures adequate supplies of this essential enzyme.
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  • 82
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    Current genetics 11 (1986), S. 193-200 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Ty elements ; Transposable elements ; Retroviruses ; tRNA genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have isolated and characterized a Ty element from a yeast cosmid library which exhibits several unsual features: it is flanked by non-homologous delta elements and directly associated with a singular delta element. A tRNA(Glu3) gene and tRNA(Cys) gene are found in conjunction with this element, located in opposite orientation on either end of it. The sequence information now available for several Ty elements has been used in a detailed comparative analysis to determine conserved features among the Ty elements, preferably between class I elements and a class II element. Highly conserved sequence motifs appear to be located at the borders of particular segments that correspond to the putative protein domains of the Tys. Furthermore, we include a comparison of the best-conserved amino acid homologies for these putative proteins of Ty elements, transposable elements from other organisms and several retroviral proviruses to confirm their close structural resemblance.
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  • 83
    ISSN: 1432-0983
    Keywords: Rho°-petites ; Lycorine ; Mitochondrial DNA replication ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper describes the isolation and characterization of mutants affected in the maintenance of the mitochondrial (mt) genome. The rationale of the screening procedure is based on the observation that the alkaloid lycorine inhibits growth of rho −-mutants, whereas rho°-mutants, devoid of mt DNA, are resistant to this drug (Del Giudice et al. 1984). Fourteen temperature sensitive mutants have been isolated that display the following phenotype: -Growth on fermentable medium at 23°C and 35°C (exclusion of general temperature-sensitive mutants). -no growth at 23°C and growth at 35°C on fermentable medium containing lycorine (selection for mutants producing rho°-petites). -growth at 23°C and no growth an 35°C on non-fermentable medium (selection for temperature-dependent loss of respiratory competence). These mutants were termed tmm (for temperature sensitive maintenance of mt genome). Mutant tmm1-1 was analyzed genetically and biochemically. It carries a recessive nuclear mutation which gives rise to 90–95% cytoplasmic petites at the non-permissive temperature. The population of petites consists of more than 95% rho°-petites as shown by their resistance to lycorine, by staining with 4′,6-diamidino-2-phenylindole (DAPI), and by Southern hybridization with mt DNA probes. Wild-type control cultures produced approximately 1% petites with less than 10% rho°-mutants.
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  • 84
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    Current genetics 11 (1986), S. 211-215 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Hyperresistance ; DNA damaging agents ; Genotoxic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In order to study resistance to DNA damaging agents, yeast DNA segments conferring hyperresistance in this organism to such genotoxic agents were selected for among yeast cells transformed by a yeast genome library based on the multi-copy vector plasmid YEp13. Genetic variants hyperresistant to 4-nitroquinohne-N-oxide, formaldehyde, and alkylating agents were isolated and the respective hyperresistance determinants shown to co-segregate with the vector plasmid. Phenotypical characterization indicated different degrees of resistance, few cases of cross-resistance and differing structural stability of the cloned DNA. By transfer to E. coli and subsequent retransformation of yeast a number of plasmids was shown to stably carry the genetic information for hyperresistance.
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  • 85
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    Current genetics 11 (1986), S. 217-225 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Gene cloning ; Invertase genes ; Multicopy vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Six unlinked loci for invertase structural genes are known in the yeast Saccharomyces cerevisiae: SUC1-SUC5 and SUC7. These genes are similar in structure and expression but not identical. Different yeast strains possess none, one or several of these genes. We have isolated the genes SUC1-SUC5, subcloned them into the multicopy vector YEp24 and compared the expression of the five SUC genes in one recipient strain. SUC2 was isolated by transformation of a suc0 strain with a gene pool and complementation to sucrose fermentation. SUC4 was cloned from a minipool of chromosomal fragments which were shown to contain SUC4 by Southern hybridization. SUC1, SUC3 and SUC5 were isolated using the method of plasmid eviction. A plasmid containing regions flanking SUC4 was integrated next to these SUC genes. The plasmid together with the SUC genes were then cut out of the chromosome using an appropriate restriction endonuclease. The length of chromosomal DNA fragments containing the different SUC genes were 4.8 kb for SUC1, 5.2 kb for SUC2, 4.8 kb for SUC3, 12.8 kb for SUC4 and 17.2 kb for SUC5. Fragments containing the complete SUC genes and the sequences controlling their expression were subcloned into YEp24 and transformed into a strain without any active invertase gene. Invertase activity of transformants was measured after growth repressing (8% glucose) and derepressing (2% raffinose) conditions. As expected from results with strains carrying the individual SUC genes in a chromosomal location, the SUC genes were expressed to a different extent.
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  • 86
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Nucleo-mitochondrial interactions ; Mitochondrial status ; Dominant lycorine resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutants resistant to 200 µg/ml of the alkaloid lycorine (LYC R) in non-fermentable substrate were isolated after nitrosoguanidine mutagenesis. Tetrad analysis and growth of heterozygous (LYC R/lyc s) diploids from two different mutants revealed that a single nuclear and dominant mutation is responsible for the resistant phenotype. In the wild type total protein synthesis is only slightly inhibited, whereas DNA and RNA synthesis is lowered to about 30% of the control. In the lycorine resistant mutants all macromolecular syntheses are unaffected by the drug.
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  • 87
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    Current genetics 11 (1987), S. 399-406 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Mercury resistance ; Tyrosine uptake ; Catabolite regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In Saccharomyces cerevisiae, the HGS2-1 allele confers sensitivities to inorganis mercury (Ono and Sakamoto 1985) and to excess fermentable sugars such as glucose (Sakamoto et al. 1985); exogenous tyrosine antagonizes both inorganic mercury and excess glucose. In this sutdy, the inorganic mercury sensitive strain has been shown to have about twice more glucose-1,6-bisphosphate and slightly less pyruvate than the normal strains, suggesting that the inorganic mercury sensitive strain has the reduced aldolase activity. It has been also shown that the growth retarded cells accumulate trehalose, by which the lower level of glucos-6-phosphate in the inorganic mercury sensitive strain is accounted for, and that inorganic mercury, presumably excess glucose also, causes growth inhibition via depletion of cellular tyrosine. The mechanism how cellular tyrosine is depleted by inorganic mercury or excess glucose is accounted for by the facts that (1) the tyrosine uptake activity is decreased with increase of glucose concentration in growth medium, (2) HGS2-1 enhances the effect of glucose on the tyrosine uptake activity, and (3) inorganic mercury inhibits the tyrosine uptake system by binding to its SH-group(s). Thus, it is concluded that the role of tyrosine is not to detoxify inorganic mercury nor excess fermentable sugars but simply to counteract depletion of cellular tyrosine induced by them.
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  • 88
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    Current genetics 11 (1987), S. 445-450 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Ribosomal protein genes ; Genetic mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have used the 2 μ mapping method described by Falco and Botstein (1983) and tetrad analysis to map four ribosomal protein genes (two linked pairs) in S. cerevisiae. One pair (rp28–rp55 copy 1) is on chromosome XV, 14 cM proximal to ARG8. The other pair (rp55–rp28 copy 2) is 19 cM from the centromere on the left arm of chromosome XIV. To map copy 1 we used the E. coli β-galactosidase gene rather than a yeast gene to mark the ribosomal protein chromosomal locus. This provided a more sensitive color screening assay for chromosome loss in the 2 μ method. It also removed the restriction that the mapping tester strains must be mutant for the plasmid marker.
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  • 89
    ISSN: 1432-0983
    Keywords: Double-stranded RNA (dsRNA) ; Yarrowia lipolytica ; Saccharomyces cerevisiae ; Virus-like particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Some strains of the yeast Yarrowia lipolytica possess virus-like particles (VLPs) which encapsidate a double-stranded RNA (dsRNA) genome designated Ly. We report here that these VLPs have two associated polypeptides of molecular weights 83 kd (VLy-P1) and 77 kd (VLy-P2). Denatured Ly-dsRNA was used to program a cell-free rabbit reticulocyte translation system, resulting in the appearance of four major products, viz. Ly-P1 (83 kd); Ly-P2 (77 kd); Ly-P3 (74 kd) and Ly-P4 (68 kd). The in vivo viral-associated protein VLy-P1 co-migrated on SDS-polyacrylamide gels with the in vitro product Ly-P1 and, similarly, VLy-P2 co-migrated with Ly-P2. Peptide mapping data confirm the identity of the in vivo products (VLy-P1 and VLy-P2) and their in vitro counterparts. The conclusion made is that VLy-P1 and VLyP2 are almost identical primary translation products of the Ly genome, derived from a single or multiple species of Ly-dsRNA. RNA blot hybridizations using L1A M1 and separately, L2A M2 probes prepared from appropriate K1 and K2 Saccharomyces cerevisiae killer strains, failed to show any detectable homology to Ly-dsRNA, substantiating the uniqueness of the Ly genome with respect to the K1 and K2 S. cerevisiae dsRNA killer systems.
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  • 90
    ISSN: 1432-0983
    Keywords: ARS ; Linear DNA killer plasmid ; Replication ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary By use of linear DNA plasmid pGKL2 from the yeast Kluyveromyces lactis we have constructed hybrid plasmids carrying a LEU2 gene of Saccharomyces cerevisiae as a selectable marker. The replication properties of hybrid plasmids in yeasts were investigated. We demonstrated that the insertion of a LEU2 gene into pGKL2 resulted in circularization of the hybrid plasmids and pGKL2 segment supported autonomous replication of the plasmids. Moreover, the hybrid plasmids propagated autonomously, independently of the presence of the natural pGKL2 plasmid.
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  • 91
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    Current genetics 12 (1987), S. 511-517 
    ISSN: 1432-0983
    Keywords: Mating-type switching ; Cytoduction ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Use of a selective system for cytoduction in Saccharomyces cerevisiae allowed us to monitor hybrid formation and to clone the haploid nuclei of cells which have participated in illegitimate matings: a × a, α × α. Our approach has made it possible to select nuclei with mating-type switches and mutations within the MAT locus. It was shown that matings in α × α crosses often proceed through nonheritable genetic changes located within chromosome III. We suggest that these non-heritable genetic changes are due to premutational lesions, expressed phenotypically as transient α-matingtype. After a mating event these lesions are either repaired or converted to true mutations within the MAT locus.
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  • 92
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    Current genetics 13 (1988), S. 283-289 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Inducible antisense gene ; Acetolactate synthase ; Bradytrophic phenocopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We report for the first time on the regulation of gene expression in yeast by antisense RNA. Chimaeric genes were constructed containing the 5′ upstream and partial coding sequence of SMR1 — a sulfometuron methyl resistant allele of the ILV2 locus. Such fragments were placed 5′ to 3′ and 3′ to 5′ under control of the GAL10 promoter and CYCl terminator in a high copy YEp plasmid. Following galactose induction only transformants containing antisense RNA genes showed biological activity against SMR1 gene expression. Antisense RNA inhibited synthesis of the SMR1 gene product acetolactate synthase and thus repressed cellular growth which resulted in a bradytrophic auxotroph revertable by addition of isoleucine and valine. Antisense RNA inhibition was enhanced in galactose medium containing sulfometuron methyl and in gcn4 cells deficient for positive regulation of the ILV2 locus. This system can be used to study factors that interfere with antisense RNA function and to assign biological function to randomly cloned DNA fragments.
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  • 93
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    Current genetics 14 (1988), S. 331-335 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Meiosis ; Deletion mutations ; Sequence dissimilarities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A diploid yeast strain with extensive sequence dissimilarity in homologous regions near the LYS2 locus was sporulated, and spontaneous lys2 and lys5 mutant spores, selected on α-amino adipate, were analyzed. As many as 50% of the mutant spores contained a deletion in LYS2. These deletions occurred at a frequency of 5.0 × 10−7. While deletions of various sizes and endpoints were obtained, all the deletions recovered in this study included the border between homologous and non-homologous sequences located 4 kb upstream of LYS2. Large lys2 deletions that extended into an adjacent CYH2 duplication occurred at a frequency of 2.0 × 10−7, more than 1,000 times the frequency of the CYH2-LYS2 deletions found in a related haploid strain. This high frequency of CYH2-LYS2 deletions was observed only after sporulation of the diploid strain, and was dependent upon extensive sequence dissimilarity near the LYS2 locus.
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  • 94
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Allosuppressor ; Translation ; Fidelity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Allosuppressor (sal) mutations enhance the efficiency of the yeast ochre suppressor SUQ5 and define five unlinked loci, SALT-SALS. A number of sal4 mutants were isolated and found to have pleiotropic, allele;specific phenotypes, including hypersensitivity in vivo to paromomycin and other antibiotics that stimulate translational errors in yeast. To examine further the nature of the SAL4 gene product, the wild type SAL4 gene was isolated by complementation of a conditional lethal allele sal4-2, and demonstrated to be a single copy gene encoding a single 1.6 kb transcript. Restriction mapping and DNA hybridisation analysis were used to demonstrate that the SAL4 gene is identical to the previously identified omnipotent suppressor gene SUP45 (SUPT). Our results implicate the SAL4 gene product as playing a major role in maintaining translational accuracy in yeast.
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  • 95
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Protoplast fusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The percentage of hybrids formed during protoplast fusion in Saccharomyces cerevisiae is determined by the percentage of protoplasts at the GI/S boundary of the cell cycle.
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  • 96
    ISSN: 1432-0983
    Keywords: Peroxisomes ; Protein import ; Saccharomyces cerevisiae ; Hansenula polymorpha
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The DAS gene of Hansenula polymorpha was expressed in Saccharomyces cerevisiae under the control of different promoters. The heterologously synthesized dihydroxyacetone synthase (DHAS), a peroxisomal enzyme in H. polymorpha, shows enzymatic activity in baker's yeast. The enzyme was imported into the peroxisomes of S. cerevisiae not only under the appropriate physiological conditions for peroxisome proliferation (oleic acid media), but also in glucose-grown cells where it induced the enlargement of the few peroxisomes present. This growth process was not accompanied by an increase in the number of microbodies, which suggests a separate control mechanism for peroxisomal proliferation.
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  • 97
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    Current genetics 15 (1989), S. 399-401 
    ISSN: 1432-0983
    Keywords: Saccharomyces exiguus ; Saccharomyces cerevisiae ; HO gene ; MAT gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The DNA of Saccharomyces exiguus was analyzed by Southern hybridization using cloned MATa, MATα, and HO genes of Saccharomyces cerevisiae as probes. It was shown that S. exiguus has a DNA sequence homologous with the HO gene of S. cerevisiae and that this DNA sequence is on a chromosome of about 940 kb of DNA in S. exiguus. However, there is no DNA sequence in S. exiguus that is homologous with the MAT genes of S. cerevisiae.
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  • 98
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    Applied microbiology and biotechnology 16 (1982), S. 75-80 
    ISSN: 1432-0614
    Keywords: Immobilization of yeast ; Saccharomyces cerevisiae ; Ethanol production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Baker's yeast (Saccharomyces cerevisiae) was immobilized in gels made of prepolymerized, linear, water soluble polyacrylamide, partially substituted with acylhydrazide groups. Gelation was effected by the addition of controlled amounts of dialdehydes (e.g. glyoxal). The immobilized yeasts retained full glycolytic activity. Moreover, the entrapped cells were able to grow inside the chemically corsslinked gel during continuous alcohol production. Glyoxal was found to be the most favourable crosslinking agent for this system. the system employed allowed for the free exchange of substrate and products. The gel surrounding the entrapped cells had no effect on temperature stability profile. On the other hand, substantial enhancement in survival of cells in presence of high ethanol concentrations was recorded for the entrapped yeast. The capability of the immobilized yeast to carry out continuous conversion of glucose to ethanol was demonstrated.
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  • 99
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    Cellular and molecular life sciences 43 (1987), S. 458-460 
    ISSN: 1420-9071
    Keywords: Defensive secretions ; glands ; Chrysomelidae ; Coleoptera ; phenylethanol ; linalool ; 6-methyl-5-hepten-2-one ; 6-methyl-5-hepten-2-ol ; 2-hexenal ; chemotaxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The leaf beetle larva ofGonioctena (Phytodecta) viminalis L. has been shown to produce five volatile constituents within its paired abdominal defensive gland reservoirs. It is the first time that these compounds have been reported to occur in coleopteran defensive glands (linalool, phenylethanol) and Chrysomelidae larvae (6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, 2-hexenal). In addition to the gross morphology of theGonioctena gland and its discharge behavior, the natural products found are discussed in terms of chemotaxonomy.
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    Cellular and molecular life sciences 43 (1987), S. 460-462 
    ISSN: 1420-9071
    Keywords: Biosynthesis ; cardenolides ; Coleoptera ; chrysomelid beetles ; [23-14C]-cholesterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Labeling experiments have shown that the chrysomelid beetleChrysolina coerulans is able to biosynthesize its own defensive cardenolides from cholesterol, via a pathway involving a C21 intermediate, as in plants.
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