Postsymbiotic plasmid acquisition and evolution of the <i>repA1</i>-replicon in <i>Buchnera aphidicola</i>

Buchnera aphidicola is an obligate, strictly vertically transmitted. bacterial symbiont of aphids. It supplies its host with essential amino acids, nutrients required by aphids but deficient in their diet of plant phloem sap. Several lineages of Buchnera show adaptation to their nutritional role in...

Descripción completa

Detalles Bibliográficos
Autores: Van Ham, RCHJ, González-Candelas, F, Silva, FJ, Sabater, B, Moya, A, Latorre, A
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:España
Institución:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repositorio:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:fisabio.fundanetsuite.com:p17235
Acceso en línea:https://fisabio.portalinvestigacion.com/publicaciones/17235
Access Level:acceso abierto
Descripción
Sumario:Buchnera aphidicola is an obligate, strictly vertically transmitted. bacterial symbiont of aphids. It supplies its host with essential amino acids, nutrients required by aphids but deficient in their diet of plant phloem sap. Several lineages of Buchnera show adaptation to their nutritional role in the form of plasmid-mediated amplification of key-genes involved in the biosynthesis of tryptophan (trpEG) and leucine (leuABCD). Phylogenetic analyses of these plasmid-encoded functions have thus far suggested the absence of horizontal plasmid exchange among lineages of Buchnera. Here, we describe three new Buchnera plasmids. obtained from species of the aphid host families Lachnidae and Pemphigidae. All three plasmids belong to the repA1 family of Buchnera plasmids, which is characterized by the presence of a repA1-replicon responsible for replication initiation. A comprehensive analysis of this family of plasmids unexpectedly revealed significantly incongruent phylogenies for different plasmid and chromosomally encoded lad. We infer from these incongruencies a case of horizontal plasmid transfer in Buchnera. This process may have been mediated by secondary endosymbionts, which occasionally undergo horizontal transmission in aphids.