Meeting Abstract

127.2  Monday, Jan. 7  The relevance of parthenogenesis to the role of Marmorkrebs as a model organism and potential invader MARTIN, P; Humboldt University, Berlin Peer.Martin@alumni.hu-berlin.de

Animals as model organisms are indispensable tools for life sciences and thus a series of species have been firmly established in research for this purpose. Nevertheless, genetic differences between individuals often bias the results and therefore genetically identical organisms are more and more in demand as laboratory objects. Here, the use of asexual organisms would provide an opportunity. However, parthenogenetic animals are relatively rare, in particular those that combine a high reproduction rate and a complex organization. In addition, not all forms of parthenogenesis lead to genetically identical progeny. In the automictic mode, for example, meiosis occurs and diploidy is then restored by fusion between two of the resulting haploid nuclei. Thus, the genetic composition of automictically produced progeny is not absolutely identical because of recombination by crossing over during the reduction division. In contrast, Marmorkrebs propagate apomictically, i.e. meiosis is completely suppressed. The progeny develop directly from unreduced oocytes and therefore all offspring are true clones of their mother. In addition, Marmorkrebs are very robust and have a high reproductive rate and so they are very suitable as experimental animals for a number of questions. However, the advantages of apomixis for its use as a model organism are counter-balanced by the fact that this reproduction mode also makes Marmorkrebs an effective invader. Due to the parthenogenesis only a single individual is able to found a new population. Furthermore, the apomixes protects the clones from the effects of low population size such as bottlenecks, inbreeding depression and genetic drift and this enables the Marmorkrebs to also conquer areas which provide less favourable living conditions.