Abstracts - Deutsche Zoologische Gesellschaft

Evolutionary Biology Symposium 47O EB.18 (Mo) - ENGeographic parthenogenesis in bushcricketsArne Lehmann, Gerlind LehmannInstitut für Zoologie, Freie Universität BerlinSexual reproduction is the main way that higher animals reproduce, but parthenogenesis is an alternativemode that is relatively common among invertebrates. In ‘geographical parthenogenesis’ theclones have a wider distribution than the sexual forms they originate from. The text book example inbushcrickets is Saga pedo, a tetraploid that originated from crosses of distantly related species (Lehmann& Lehmann unpubl. data), ranging from Portugal to Siberia. We studied the species Poecilimonintermedius, so far not investigated. Its range is similar large, but in contrast to Saga pedo, P. intermediushas a diploid chromosome set (Warchałowska-Śliwa et al. 1996). Mass rearing confirmedobligate parthenogenesis in this bushcricket. In other parthenogenetic species antibiotics has resultedin the production of males, but antibiotic treatment of P. intermedius was not effective in restoringmale production. This and negative results from PCR screening exclude feminizing endosymbionts,such as Wolbachia, as a reason for the lack of males (Lehmann et al. submitted). Heterospecific matingswith males of a closely related species were rapidly achieved, spermatophores transferred andsperm successfully entered the females. However, the resulting offspring were all female, suggestingthat successful fertilisation did not occur. We further model how P. intermedius could have reachedits widespread distribution from a Balkan origin far into Siberia bypassing the “Allee effect”.O EB.19 (Mo) - ENTracing speciation in the Nasonia species complex – first hints on gene loci responsiblefor species-specific cuticular hydrocarbonsJan Büllesbach, Thomas SchmittSpemann Graduate School for Biology and Medicine, Institut für Biologie I, Universität FreiburgThe main focus of speciation genetics is the investigation of genetic factors associated with reproductiveisolation. The central challenge in this field is to determine the complex, coevolved andlikely polygenic traits mainly responsible for reproductive isolation. In many insect species, it hasbeen shown that cuticular hydrocarbons (CHC) are crucial for species recognition and sexual communicationand thus have the potential to reproductively isolate a species. The parasitoid jewel waspNasonia vitripennis uses certain CHC compounds as sex pheromones. Assuming similar functions inother Nasonia species, CHC components might also play a major role in species recognition withinthis genus. Hence, we selected nine CHC compounds significantly differing between Nasonia vitripennisand Nasonia giraulti males, which were characterized using gas-chromatography coupledwith mass-spectrometry. Establishing distinctive “N. giraulti” and “N. vitripennis” phenotypes forthe CHC compounds that way, we then determined one of the two phenotype affiliations for eachcompound in 120 N. vitripennis / N. giraulti hybrid males. A subsequent quantitative-trait-locus(QTL) interval mapping of those hybrids identified 22 gene loci accounting for the CHC variation,distributed over all five chromosomes. These findings provide the first gene loci candidates in Nasoniafor CHC cues potentially distinguishing the respective species.