title: Higher mutation rate helps to rescue genes from the elimination by selection.
abstract: Directional mutation pressure associated with replication processes is the main cause of the asymmetry between the leading and lagging DNA strands in bacterial genomes. On the other hand, the asymmetry between sense and antisense strands of protein coding sequences is a result of both mutation and selection pressures. Thus, there are two different ways of superposition of the sense strand, on the leading or lagging strand. Besides many other implications of these two possible situations, one seems to be very important - because of the asymmetric replication-associated mutation pressure, the mutation rate of genes depends on their location. Using Monte Carlo methods, we have simulated, under experimentally determined directional mutation pressure, the divergence rate and the elimination rate of genes depending on their location in respect to the leading/lagging DNA strands in the asymmetric prokaryotic genome. We have found that the best survival strategy for the majority of genes is to sometimes switch between DNA strands. Paradoxically, this strategy results in higher substitution rates but remains in agreement with observations in bacterial genomes that such inversions are very frequent and divergence rate between homologs lying on different DNA strands is very high.
authors.affiliation: Institute of Genetics and Microbiology, University of Wrocław, ul. Przybyszewskiego, Wrocław, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Dudkiewicz
authors.forename: Pawel
authors.initials: P
authors.lastname: Mackiewicz
authors.forename: Dorota
authors.initials: D
authors.lastname: Mackiewicz
authors.forename: Maria
authors.initials: M
authors.lastname: Kowalczuk
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Nowicka
authors.forename: Natalia
authors.initials: N
authors.lastname: Polak
authors.forename: Kamila
authors.initials: K
authors.lastname: Smolarczyk
authors.forename: Joanna
authors.initials: J
authors.lastname: Banaszak
authors.forename: Miroslaw R
authors.initials: MR
authors.lastname: Dudek
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Cebrat
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D005075:Biological Evolution; D025065:Borrelia burgdorferi / Q000235:genetics*; D002874:Chromosome Mapping / Q000379:methods; D003198:Computer Simulation; D004252:DNA Mutational Analysis / Q000379:methods*; D014644:Genetic Variation / Q000235:genetics*; D008957:Models, Genetic; D009154:Mutation / Q000235:genetics*; D012641:Selection, Genetic; D016019:Survival Analysis