"General objective of the research project is the genomic and where applicable metagenomic analysis of novel, recently emerged or in the coming years emerging data on genome sequences of diverse bacterial insect endosymbionts. These organisms include especially the endosymbiont Blattabacterium sp. of the cockroach Blattella germanica, primary and secondary endosymbionts of the silver leaf whitefly Bemisia tabaci (primary esb: ""Candidatus Portiera aleyrodidarum"", secondary esbs: ""Candidatus Hamiltonella defensa"", and Arsenophonus sp.) and the endosymbiont ""Candidatus Erwinia dacicola"" of the olive fly Bactrocera oleae In all cases, the endosymbionts are intricately linked to the respective host and the kind of symbiosis is a mutually obligate one. However, knowledge on the nature of the symbiosis and the functional constraints between the two partners is in all these cases rather scarce. The function of the endosymbionts for the host is not (completely) revealed yet. An emerging whole sequence of the reduced genome of the endosymbiont of Blattella germanica, the first one of a non-proteobacterial insect endosymbiont will provide the opportunity for a comprehensive and comparative genomic analysis. Similarly, in the near future sequence data for the whitefly endosymbionts, obtained in a metagenomic approach, will be accessible for our research group. For Cand. E. dacicola we pursue an own medium-sized metagenomic sequencing project to obtain representative data. In the frame of the project genomic and metagenomic studies using bioinformatic tools via comparative analysis will be performed: gene annotation, study of present cellular functions (metabolic routes, regulatory capacity), deduction of the role(s) in the respective symbiosis. In this way, the functional contexts within the specific symbiosis will be revealed."