Vignette d'image

Guerin, Patrick

Nom
Guerin, Patrick
Affiliation principale
Site web
Fonction
Professeur associé
Email
patrick.guerin@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/310

Résultat de la recherche

Filtres

2
2
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 2 sur 2
  • Publication
    Métadonnées seulement
    Three-dimensional flight tracking shows how a visual target alters tsetse fly responses to human breath in a wind tunnel
    (2012)
    Gurba, A.
    ;
    Harraca, V.
    ;
    Perret, J. L.
    ;
    Casera, S.
    ;
    Donnet, S.
    ;
    Guerin, Patrick 
    Tsetse flies Glossina spp. (Diptera; Glossinidae) are blood-feeding vectors of disease that are attracted to vertebrate hosts by odours and visual cues. Studies on how tsetse flies approach visual devices are of fundamental interest because they can help in the development of more efficient control tools. The responses of a forest tsetse fly species Glossina brevipalpis (Newstead) to human breath are tested in a wind tunnel in the presence or absence of a blue sphere as a visual target. The flight responses are video recorded with two motion-sensitive cameras and characterized in three dimensions. Although flies make meandering upwind flights predominantly in the horizontal plane in the plume of breath alone, upwind flights are highly directed at the visual target presented in the plume of breath. Flies responding to the visual target fly from take-off within stricter flight limits at lower ground speeds and with a significantly lower variance in flight trajectories in the horizontal plane. Once at the target, flies fly in loops principally in the horizontal plane within 40 cm of the blue sphere before descending in spirals beneath it. Successful field traps designed for G. brevipalpis take into account the strong horizontal component in local search behaviour by this species at objects. The results suggest that trapping devices should also take into account the propensity of G. brevipalpis to descend to the lower parts of visual targets.
  • Publication
    Métadonnées seulement
    Pollinator Choice in Petunia Depends on Two Major Genetic Loci for Floral Scent Production
    (2011)
    Klahre, U.
    ;
    Gurba, A.
    ;
    Hermann, K.
    ;
    Saxenhofer, M.
    ;
    Bossolini, E.
    ;
    Guerin, Patrick 
    ;
    Kuhlemeier, C.
    Background: Differences in floral traits, such as petal color, scent, morphology, or nectar quality and quantity,. can lead to specific interactions with pollinators and may thereby cause reproductive isolation. Petunia provides an attractive model system to study the role of floral characters in reproductive isolation and speciation. The night-active hawkmoth pollinator Manduca sexta relies on olfactory cues provided by Petunia axillaris. In contrast, Petunia exserta, which displays a typical hummingbird pollination syndrome, is devoid of scent. The two species can easily be crossed in the laboratory, which makes it possible to study the genetic basis of the evolution of scent production and the importance of scent for pollinator behavior. Results: In an F2 population derived from an interspecific cross between P. axillaris and P. exserta, we identified two quantitative trait loci (QTL) that define the difference between the two species' ability to produce benzenoid volatiles. One of these loci was identified as the MYB transcription factor ODORANT1. Reciprocal introgressions of scent QTL were used for choice experiments under controlled conditions. These experiments demonstrated that the hawkmoth M. sexta prefers scented plants and that scent determines choice at a short distance. When exposed to conflicting cues of color versus scent, the insects display no preference, indicating that color and scent are equivalent cues. Conclusion: Our results show that scent is an important flower trait that defines plant-pollinator interactions at the level of individual plants. The genetic basis underlying such a major phenotypic difference appears to be relatively simple and may enable rapid loss or gain of scent through hybridization.