Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 47 (1988), S. 89-94 
    ISSN: 1570-7458
    Schlagwort(e): hyperparasitoid ; parasitoid ; aphid ; host-acceptance ; Alloxysta pleuralis ; Trioxys indicus ; Aphis craccivora
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé A. pleuralis est un hyperparasitoïde endophage de Trioxys indicus, parasitoïde d'Aphis craccivora, puceron de Cajanus cajan. Bien que les larves de T. indicus soient susceptibles d'être attaquées du début du second stade au début du quatrième stade, celles du troisième stade sont nettement préférées. L'absence de fifférence entre les fréquences de visites et de contacts avec les hôtes de différents stades a montré que le comportement de prospection de A. pleuralis s'effectue au hasard. Cependant, la fréquence des piqûres/hôte est significativement supérieure chez lez hôtes préférés, ce qui donne une indication sur le fait que A. pleuralis pique un puceron pour rechercher un hôte potentiel. Il est possible que la femelle perçoive la présence de l'hôte dans le puceron en décelant avec les récepteurs sensoiriels de sa tarière les changements physiologiques caractéristiques du puceron parasité, et qu'elle les utilise pour piquer à répétition le puceron jusqu'à ce qu'elle trouve l'hôte potentiel. Le superhyperparasitisme était relativement faible et plus fréquent dans les expériences où l'hyperparasite n'avait pas de choix.
    Notizen: Abstract Alloxysta pleuralis parasitizes the larvae of Trioxys indicus, a parasitoid of Aphis craccivora. The pattern of host-searching of A. pleuralis was random regarding the host-stage. Earlier second instar to early fourth instar larvae of T. indicus within the haemocoel of the living aphid were found susceptible for attack, however, the third instar larvae were more parasitized. The rate of oviposition was very low (8.5 eggs/h). The number of pricks into the aphid was significantly more for the aphids that contained susceptible stages of the potential host. The occurrence of superhyperparasitism was lower when the hyperparasitoids were offered a choice of all host stages than were offered no-choice.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 43 (1987), S. 11-15 
    ISSN: 1570-7458
    Schlagwort(e): hyperparasitoid ; parasitoid ; aphid ; bionomics ; Alloxysta pleuralis ; Trioxys indicus ; Aphis craccivora
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Alloxysta pleuralis, est un endohyperparasitoïde des larves de Trioxys indicus, parasite du puceron Aphis craccivora. Les deux sexes d'A. pleuralis sont aptes à l'accouplement peu après l'émergence (10–30 min). La femelle est passive pendant la pariade. Elle porte le mâle sur son dos pendant 2 à 3 min. La copulation dure 30 sec. Bien que l'espèce soit hyperparasite obligatoire, le comportement exploratoire de ponte s'observe sur les pucerons non-parasités. Cependant les oeufs ne sont pondus qu'à l'intérieur des pucerons parasités, dans l'haemocoele des larves de troisième stade de T. indicus. Les adultes ne s'alimentent pas sur l'hôte, mais sur le miellat des pucerons. Le cycle dure environ un mois. On observe souvent du superhyperparasitisme. Les adultes vivent de 4 à 13 jours.
    Notizen: Abstract Alloxysta pleuralis parasitizes the larvae of Trioxys indicus, a parasitoid of Aphis craccivora. Either of the sexes of this hyperparasitoid (A. pleuralis) was ready to mate shortly after emergence. During courtship the females carried the males on the top of her back for 2–3 min. Although the hyperparasitoid is obligatory, a similar, typical oviposition exploration pattern takes place on healthy aphids, however, then the eggs are laid only in parasitized aphids in the haemocoel of the larvae of the parasitoid. The life-cycle takes about a month. Superhyperparasitism was commonly observed. Adults survived for 4–13 days.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 40 (1995), S. 228-232 
    ISSN: 1040-452X
    Schlagwort(e): Gossypol ; Sperm ; Acrosomal enzymes ; Rabbit ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The effect of gossypol on the activities of 10 acrosomal enzymes of the rabbit sperm was evaluated. Acrosin, Azocoll proteinase, neuraminidase, and arylsulfatase were significantly inhibited or completely inactivated by 12-76 μM gossypol. Hyaluronidase, β-glucuronidase, and acid phosphatase were inhibited only at a higher concentration of gossypol (380 μM). Phospholipase C, alkaline phosphatase, and β-N-Acetyl glucosaminidase were not inhibited even at 380 μM gossypol. Gossypol was found to be a noncompetitive inhibitor of arylsulfatase with a Ki of 120 μM. The inhibition was reversible and dose-dependent. As the acrosomal enzymes were more sensitive to the inhibition by gossypol compared to sperm enzymes involved in glycolysis or energy production, these assays may serve as a more reliable indicator for monitoring the occurence of gossypol-induced sterility. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Gamete Research 14 (1986), S. 197-208 
    ISSN: 0148-7280
    Schlagwort(e): calmodulin antagonist ; spermatozoa ; capacitation ; acrosome reaction ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The effect of the calmodulin antagonist W-7 on the capacitation and the acrosome reaction of guinea pig spermatozoa was examined. The characteristic features of the acrosome reaction induced by W-7 were the dependence on the composition and pH of the medium and on the presence of sodium bicarbonate. The most effective concentration of W-7 for inducing the acrosome reaction was approximately 5 μM, which is far less than the Kd for calmodulin. Moreover, W-7 enhanced the ability of spermatozoa to acquire capacitation in a Ca2+-free medium. The spermatozoa induced to undergo the acrosome reaction by W-7 were capable of penetrating the zona-free hamster eggs. W-5, which has a lower affinity for calmodulin than W-7, also induced the acrosome reaction in the same manner as W-7. These results suggest that the naphthalenesulfonamide derivatives W-7 and W-5 can induce the acrosome reaction in guinea pig spermatozoa via capacitation in a pH-dependent, Ca2+-calmodulin-independent manner.
    Zusätzliches Material: 8 Tab.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 1-13 
    ISSN: 0148-7280
    Schlagwort(e): capacitation ; acrosomal enzymes ; rabbit sperm ; acrosomal membranes ; fertilization ; lysosomal enzymes ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Significant release of the acrosomal enzymes arylsulfatase, β-N-acetylhexosaminidase and hyaluronidase was observed following the treatment of ejaculated rabbit spermatozoa for 12 hours in 20% rabbit serum for inducing in vitro capacitation, and these sperm were capable of in vivo fertilization; however, the treatment of sperm for 15 minutes in high ionic strength (380 mOsm/kg) or low ionic strength medium (305 mOsm/kg) for in vitro capacitation did not result in any significant release of the above enzymes nor were the sperm capable of in vivo fertilization. Serum-treated spermatozoa remained significantly motile following the 12 hour treatment, 51% underwent the acrosome reaction and were capable of fertilizing 66% of the ova in vivo. Identical serum treatment of lysosomes from rabbit liver resulted in a comparable release of the lysosomal enzymes. Serum treatment for in vitro capacitation resulted in vesiculation of the anterior margin of half the spermatozoa, but left their inner acrosomal membranes and equatorial segments intact. A biochemical relationship between the release of acrosomal enzymes and capacitation is suggested.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...