title: The rate and molecular spectrum of spontaneous mutations in Arabidopsis thaliana.
abstract: To take complete advantage of information on within-species polymorphism and divergence from close relatives, one needs to know the rate and the molecular spectrum of spontaneous mutations. To this end, we have searched for de novo spontaneous mutations in the complete nuclear genomes of five Arabidopsis thaliana mutation accumulation lines that had been maintained by single-seed descent for 30 generations. We identified and validated 99 base substitutions and 17 small and large insertions and deletions. Our results imply a spontaneous mutation rate of 7 x 10(-9) base substitutions per site per generation, the majority of which are G:C-->A:T transitions. We explain this very biased spectrum of base substitution mutations as a result of two main processes: deamination of methylated cytosines and ultraviolet light-induced mutagenesis.
authors.affiliation: Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Ossowski
authors.forename: Korbinian
authors.initials: K
authors.lastname: Schneeberger
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: Lucas-Lledó
authors.forename: Norman
authors.initials: N
authors.lastname: Warthmann
authors.forename: Richard M
authors.initials: RM
authors.lastname: Clark
authors.forename: Ruth G
authors.initials: RG
authors.lastname: Shaw
authors.forename: Detlef
authors.initials: D
authors.lastname: Weigel
authors.forename: Michael
authors.initials: M
authors.lastname: Lynch
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects; D003596:Cytosine / Q000378:metabolism; D019175:DNA Methylation; D021901:DNA, Intergenic; D018744:DNA, Plant / Q000235:genetics*; D003641:Deamination; D018745:Genome, Plant; D054643:INDEL Mutation; D009154:Mutation; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014466:Ultraviolet Rays
chemical_list: D021901:DNA, Intergenic; D018744:DNA, Plant; D003596:Cytosine