Abstracts - Deutsche Zoologische Gesellschaft

Ecology Symposium 53O EC.1 (Sa) - ENPheromone communication in the model organism Nasonia vitripennisJoachim Ruther 1 , Mohatmed Abdel-latief 1 , Markus Koch 1 , Sven Steiner 1 , Leif-Alexander Garbe 21Institut für Biologie, Freie Universität Berlin; 2 Institut für Biotechnolgie, Technische UniversitätBerlinThe jewel wasp Nasonia vitripennis is a model organism for the study of parasitic wasp biology.Males release a mixture of (4R,5R)- and (4R,5S)-5-hydroxy-4-decanolides (HDL) [1] and 4-methylquinazoline[2] as a sex pheromone that attracts virgin females. Within minutes after mating, however,females are no longer attracted [1]. In an integrative research approach we studied the biosyntheticpathway of HDL in Nasonia males and localized the pheromone producing gland [3]. Experimentsusing stable isotope labeled precursors demonstrated that HDL is derived from unsaturated fattyacids after epoxidation suggesting the involvement of an epoxide hydrolase. We cloned an epoxidehydrolase gene (Nasvi-EH1) from Nasonia males and localized its gene transcripts in the male rectalpapillae by in situ RT-PCR. Involvement of Nasvi-EH1 in HDL biosynthesis was established byRNAi-mediated gene silencing. Injection of Nasvi-EH1 dsRNA into the male abdomen inhibited thepheromone biosynthesis and suppressed the targeted gene transcripts in the rectal vesicle. Chemicalanalyses in combination with histological and behavioral studies confirmed that males synthesizethe sex attractant in the rectal vesicle and release it via the anal orifice by dabbing movements ofthe abdominal tip. References [1] Ruther J, Stahl LM, Steiner S, Garbe L-A, Tolasch T (2007) J.Exp. Biol. 210: 2163-2169 [2] Ruther, J, Steiner S, Garbe L-A (2008) J. Chem. Ecol. 34: 99-102 [3]Abdel-latief M, Garbe L-A, Koch M, Ruther J (2008) Proc. Natl. Acad. Sci. USA (in press)O EC.2 (Sa) - ENTrail sharing in antsTamara Pokorny, Thomas SchmittBiology I, University of FreiburgLaying a chemical trail leading from a food site back to the nest in order to recruit other workers is awidespread behaviour in ants. These trails are often aggressively defended against ants from foreigncolonies or species, which are recognized due to their different cuticular hydrocarbon profile. However,between certain species a phenomenon called trail sharing can be observed. In a trail sharingsystem two or more species of ants share a common trail on which they do not display aggressivebehaviour towards each other. This study focuses on two trail sharing systems of Bornean ants. Themain involved species are Polyrhachis ypsilon, Colobopsis saundersi and Dolichoderus cuspidatusin one system, Crematogaster modiglianii and Camponotus rufifemur in the other. In an attemptto understand the underlying mechanisms causing trail sharing, chemical analyses of possible trailpheromones and of cuticular hydrocarbons from the different species were conducted. The chemicalcompositions were then compared in order to search for similarities which might have accounted forthe evolution of trail sharing. Another aspect of this study is the recognition of trail sharing partners.Aggression tests suggest that ants recognize their trail sharing partners not by simply toleratingevery ant belonging to the corresponding species, but that they are able to specifically recognize antsfrom the colonies they actually share their trail with.