Structure and dynamics of the operon map of Buchnera aphidicola sp. strain APS

BMC Genomics

Research Article

Lilia Brinza¹  Karen Gaget¹  Gabrielle Duport¹  Federica Calevro²  Hubert Charles²  Christian Gautier³ 

[1] INSA-Lyon, UMR203 BF2I, INRA, Biologie Fonctionnelle Insectes et Interactions, Bât. Louis Pasteur 20 ave. Albert Einstein, F-69621, Villeurbanne, France;INSA-Lyon, UMR203 BF2I, INRA, Biologie Fonctionnelle Insectes et Interactions, Bât. Louis Pasteur 20 ave. Albert Einstein, F-69621, Villeurbanne, France;Université de Lyon, INRIA Bamboo, F-69621, France;Université de Lyon, Univ Lyon 1, CNRS UMR5557 Ecologie Microbienne, INRA, F-69622, Villeurbanne, France;Université de Lyon, INRIA Bamboo, F-69621, France;

关键词: Intergenic Region;    Gene Pair;    Transcription Unit;    Adjacent Gene;    Operon Structure;   

DOI  :  10.1186/1471-2164-11-666

 received in 2010-07-15, accepted in 2010-11-25,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundGene expression regulation is still poorly documented in bacteria with highly reduced genomes. Understanding the evolution and mechanisms underlying the regulation of gene transcription in Buchnera aphidicola, the primary endosymbiont of aphids, is expected both to enhance our understanding of this nutritionally based association and to provide an intriguing case-study of the evolution of gene expression regulation in a reduced bacterial genome.ResultsA Bayesian predictor was defined to infer the B. aphidicola transcription units, which were further validated using transcriptomic data and RT-PCR experiments. The characteristics of B. aphidicola predicted transcription units (TUs) were analyzed in order to evaluate the impact of operon map organization on the regulation of gene transcription.On average, B. aphidicola TUs contain more genes than those of E. coli. The global layout of B. aphidicola operon map was mainly shaped by the big reduction and the rearrangements events, which occurred at the early stage of the symbiosis. Our analysis suggests that this operon map may evolve further only by small reorganizations around the frontiers of B. aphidicola TUs, through promoter and/or terminator sequence modifications and/or by pseudogenization events. We also found that the need for specific transcription regulation exerts some pressure on gene conservation, but not on gene assembling in the operon map in Buchnera. Our analysis of the TUs spacing pointed out that a selection pressure is maintained on the length of the intergenic regions between divergent adjacent gene pairs.ConclusionsB. aphidicola can seemingly only evolve towards a more polycistronic operon map. This implies that gene transcription regulation is probably subject to weak selection pressure in Buchnera conserving operons composed of genes with unrelated functions.

【 授权许可】

CC BY   
© Brinza et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.