0000000000284512
AUTHOR
Eugenio Belda Cuesta
Massive presence of insertion sequences in the genome of SOPE, the primary endosymbiont of the rice weevil Sitophilus oryzae
Bacteria that establish an obligate intracellular relationship with eukaryotic hosts undergo an evolutionary genomic reductive process. Recent studies have shown an increase in the number of mobile elements in the first stage of the adaptive process towards intracellular life, although these elements are absent in ancient endosymbionts. Here, the genome of SOPE, the obligate mutualistic endosymbiont of rice weevils, was used as a model to analyze the initial events that occur after symbiotic integration. During the first phases of the SOPE genome project, four different types of insertion sequence (IS) elements, belonging to well-characterized IS families from alpha-proteobacteria, were ide…
Genome evolution and systems biology in bacterial endosymbionts of insects
Gene loss is the most important event in the process of genome reduction that appears associated with bacterial endosymbionts of insects. These small genomes were derived features evolved from ancestral prokaryotes with larger genome sizes, consequence of a massive process of genome reduction due to drastic changes in the ecological conditions and evolutionary pressures acting on these prokaryotic lineages during their ecological transition to host-dependent lifestyle. In the present thesis, the process of genome reduction is studied from different perspectives. In the first chapter, genome rearrangements have been studied in a set of 31 complete γ-proteobacterial genomes that includes five…