title: Replication orientation affects the rate and direction of bacterial gene evolution.
abstract: In many bacterial genomes, the leading and lagging strands have different skews in base composition; for example, an excess of guanosine compared to cytosine on the leading strand. We find that Chlamydia genes that have switched their orientation relative to the direction of replication, for example by inversion, acquire the skew of their new "host" strand. In contrast to most evolutionary processes, which have unpredictable effects on the sequence of a gene, replication-related skews reflect a directional evolutionary force that causes predictable changes in the base composition of switched genes, resulting in increased DNA and amino acid sequence divergence.
authors.affiliation: Department of Molecular and Medical Genetics, University of Toronto, 1 King's College Circle, Toronto, Canada, M5S 1A8. e.tillier@utoronto.ca
authors.forename: E R
authors.initials: ER
authors.lastname: Tillier
authors.forename: R A
authors.initials: RA
authors.lastname: Collins
mesh_terms: D001482:Base Composition; D002692:Chlamydia trachomatis / Q000235:genetics; D016993:Chlamydophila pneumoniae / Q000235:genetics; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D005798:Genes, Bacterial / Q000235:genetics*; D016680:Genome, Bacterial; D013045:Species Specificity
chemical_list: D004269:DNA, Bacterial