科学家测出拟南芥基因组发生突变速率

Science 1 January 2010:Vol. 327. no. 5961, pp. 92 - 94　DOI: 10.1126/science.1180677

Reports

The Rate and Molecular Spectrum of Spontaneous Mutations in Arabidopsis thaliana

Stephan Ossowski,^1,* Korbinian Schneeberger,^1,* José Ignacio Lucas-Lledó,^2,*, Norman Warthmann,¹ Richard M. Clark,³ Ruth G. Shaw,⁴ Detlef Weigel,^1, Michael Lynch²

　　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:CA: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.

¹ Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
² Department of Biology, Indiana University, Bloomington, IN 47405, USA.
³ Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
⁴ Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108, USA.

^* These authors contributed equally to this work.

To whom correspondence should be addressed. E-mail: joslucas@indiana.edu (J.I.L.-L.); weigel@weigelworld.org (D.W.)