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Rahier, Martine

Nom
Rahier, Martine
Affiliation principale
Fonction
Professeure ordinaire
Email
Martine.Rahier@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/99

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  • Publication
    Accès libre
    Physiological sources of variation in chemical defense of Oreina gloriosa (Coleoptera: Chrysomelidae)
    (1993)
    Eggenberger, F.
    ;
    Rahier, Martine 
    The defensive secretion of the alpine chrysomelid Oreina gloriosa is a complex mixture of mainly cardenolides and tyrosine betaine. Individually sampled secretions of adult laboratory-reared and field-collected beetles were analyzed by reverse-phase HPLC; 16 secretion components were quantified. Quantities and concentrations of different components were significantly affected by the age, sex, and reproductive status of individual beetles. Aging was correlated with marked increases (up to 4.4-fold) and decreases (up to 2.7-fold) of quantities and concentrations of several components. Differences between the sexes were smaller, but quantities of all components and concentrations of several components were larger in laboratory-reared females than in males. There was less of one component of the secretion in mated than unmated females, but the concentrations of four secretion components were higher (up to 1.6-fold) in mated females.
  • Publication
    Accès libre
    Genetic component of variation in chemical defense of Oreina gloriosa (Coleoptera: Chrysomelidae)
    (1992)
    Eggenberger, F.
    ;
    Rahier, Martine 
    Defensive secretions of adult Oreina gloriosa, liberated at the surface of the pronotum and elytra, contain a complex mixture of cardenolides, and ethanolamine. Proportions and concentrations of constituents determined by reverse-phase HPLC show considerable variation among individual beetles. Heritabilities of proportions of five main components were estimated by mother-offspring regression providing a validation of the less reliable full-sib correlation estimates. Average heritabilities based on the two methods were 0.51 and 0.58, respectively, estimated by using offspring of two age groups. Regression estimates of 2- and 10-week-old offspring differed significantly for one secretion constituent (RT16). Heritability estimates of concentrations of 16 secretion components were calculated by full-sib correlation analysis. Average heritability was 0.45, indicating a significant genetic component. Estimates did not differ significantly between the two age groups. We also estimated heritabilities of concentrations by a two-way model including data from offspring of both age groups. Heritability estimates based on this model are thought to correspond approximately to estimates based on samples from natural populations. The average of these estimates was lower (h2 =0.31) than the average heritability of each age group separately (h2 =0.45), suggesting a developmental effect on variation in chemical defense of O. gloriosa.