title: Overlapping genes: a window on gene evolvability.
abstract: BACKGROUND
  The forces underlying genome architecture and organization are still only poorly understood in detail. Overlapping genes (genes partially or entirely overlapping) represent a genomic feature that is shared widely across biological organisms ranging from viruses to multi-cellular organisms. In bacteria, a third of the annotated genes are involved in an overlap. Despite the widespread nature of this arrangement, its evolutionary origins and biological ramifications have so far eluded explanation.
  
  
  RESULTS
  Here we present a comparative approach using information from 699 bacterial genomes that sheds light on the evolutionary dynamics of overlapping genes. We show that these structures exhibit high levels of plasticity.
  
  
  CONCLUSIONS
  We propose a simple model allowing us to explain the observed properties of overlapping genes based on the importance of initiation and termination of transcriptional and translational processes. We believe that taking into account the processes leading to the expression of protein-coding genes hold the key to the understanding of overlapping genes structures.
authors.affiliation: Theoretical Systems Biology Group, Department of life sciences, Imperial College London, London SW7 2AZ, UK. m.huvet@imperial.ac.uk.
authors.forename: Maxime
authors.initials: M
authors.lastname: Huvet
authors.forename: Michael P H
authors.initials: MP
authors.lastname: Stumpf
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics; D018387:Codon, Initiator; D018388:Codon, Terminator; D019295:Computational Biology; D019143:Evolution, Molecular; D005807:Genes, Overlapping; D016678:Genome; D023281:Genomics; D010802:Phylogeny; D020506:Untranslated Regions
chemical_list: D018387:Codon, Initiator; D018388:Codon, Terminator; D020506:Untranslated Regions