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  • Digitale Medien  (4)
  • 1990-1994  (4)
  • 1970-1974
  • Dineura virididorsata  (2)
  • 25.70.Hi  (1)
  • Angiotensinogen  (1)
Materialart
  • Digitale Medien  (4)
Erscheinungszeitraum
  • 1990-1994  (4)
  • 1970-1974
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 70 (1994), S. 83-90 
    ISSN: 1570-7458
    Schlagwort(e): Hymenoptera ; Symphyta ; Tenthredinidae ; Dineura virididorsata ; sawfly ; sex ratio ; oviposition behaviour ; mating behaviour
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sex ratios of the arrhenotokous sawflyDineura virididorsata Retz. (Hymenoptera: Tenthredinidae) are variable among populations in the field, but are biased in favour of females. We have concluded elsewhere that the sex ratios of this species cannot be satisfactorily explained by any general sex ratio model that is available. Here we present data on the different behavioural traits that are relevant to interpretation of the evolution of female-biased sex ratios under local mate competition. We report on oviposition behaviour, mating behaviour and the patterns of movement of ovipositing virgin and mated females. Our results show that adult emergence is synchronous and females will mate daily with different males (in the laboratory, at least). This would decrease the relatedness of offspring should it also take place in the field. In addition, ovipositing females (mated and virgin) leave their site of release in a relatively short time and deposit few eggs relative to their capabilities, so siblings are unlikely to be clumped. The time that virgins spend in deposition of an egg is not different from that spent by mated females, so there is no differential ‘investment’ in this regard. These behavioural observations agree with our previous conclusion that the preconditions of current sex ratio theories are not met byD. virididorsata.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1434-601X
    Schlagwort(e): 25.70.Mn ; 25.70.Hi ; 27.40.+Z
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Beta-coincidentγ-rays were measured from implanted44V and42Sc nuclei. These were selected after58Ni+nickel reactions by means of the LISE3 spectrometer at GANIL. The production of the isomeric states was identified by detecting their typicalβ-delayedγ-ray cascades. From the intensities of the detectedγ-lines the ratio between isomer and ground-state production of44V follows to be 1 to 3.0(4).
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-1939
    Schlagwort(e): Biased sex ratios ; Dineura virididorsata ; Sex-related survival ; Local mate competition ; Foliage quality
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The sex ratio in final-instar larvae of a birch-feeding, free-living solitary sawfly, Dineura virididorsata, was investigated in Finnish Lapland. The prepupal proportion of females, pooled over ten sites, was 56%, and at four individual sites the sex ratio was significantly female-biased. Larval survival from egg to prepupae did not differ between the sexes. This suggests a femalebiased primary sex ratio in the field. The sex ratio varied among the sites but not among host trees within sites. Contrary to previous results with hymenopterans, we did not find that differences in the sex ratio depended on forage quality: site-specific or tree-specific sex ratios did not correlate with the average prepupal weight. A literature search indicated that female-biased sex ratios are also common in other free-living sawflies. We are unable to explain sex ratios of Dineura virididorsata or other free-living sawflies with existing general models.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 261 (1990), S. 367-373 
    ISSN: 1432-0878
    Schlagwort(e): Angiotensinogen ; Ovary ; Estrous cycle Renin-angiotensin system ; Atresia ; Immunocytochemistry ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study examined the presence and cellular distribution of angiotensinogen, the precursor to the angiotensin peptides, in the ovary of the normal cycling rat by immunocytochemistry. Angiotensinogen staining was present in the granulosa cells of maturing follicles and to a lesser extent in those undergoing atresia. Staining was not seen in the granulosa cells of primordial or early primary follicles. In maturing follicles intense staining for angiotensinogen was confined to the antral cell layers, cells of the cumulus oophorus and in the follicular fluid. Strong immunostaining was also seen in the germinal epithelium covering the ovary. Lighter angiotensinogen staining was observed in some parts of the cortical and medullary stroma and occasionally in corpora lutea. No variation in the intensity or pattern of angiotensinogen staining was observed throughout the estrous cycle. Comparison of the distribution of angiotensinogen with the previously described localization of renin, AII, angiotensin converting enzyme and AII receptors, suggests that there are a number of intra-ovarian sites at which AII could be produced.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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