title: New Insights on the Evolutionary History of Aphids and Their Primary Endosymbiont Buchnera aphidicola.
abstract: Since the establishment of the symbiosis between the ancestor of modern aphids and their primary endosymbiont, Buchnera aphidicola, insects and bacteria have coevolved. Due to this parallel evolution, the analysis of bacterial genomic features constitutes a useful tool to understand their evolutionary history. Here we report, based on data from B. aphidicola, the molecular evolutionary analysis, the phylogenetic relationships among lineages and a comparison of sequence evolutionary rates of symbionts of four aphid species from three subfamilies. Our results support previous hypotheses of divergence of B. aphidicola and their host lineages during the early Cretaceous and indicate a closer relationship between subfamilies Eriosomatinae and Lachninae than with the Aphidinae. They also reveal a general evolutionary pattern among strains at the functional level. We also point out the effect of lifecycle and generation time as a possible explanation for the accelerated rate in B. aphidicola from the Lachninae.
authors.affiliation: Área de Genómica y Salud, Centro Superior de Investigación en Salud Pública (CSISP), Avenida de Cataluña 21, 46020 Valencia, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Pérez-Brocal
authors.forename: Rosario
authors.initials: R
authors.lastname: Gil
authors.forename: Andrés
authors.initials: A
authors.lastname: Moya
authors.forename: Amparo
authors.initials: A
authors.lastname: Latorre