Sϵ mutation analysis. (A) Schematic map of the transgenic ϵ construct and Sϵ region that was used to evaluate the mutation frequency. The reported recombination sites are indicated within the tandem repeats. Sites D1 to D3 are reported by Dunnick et al,5 and site N1 is reported by Nikaido et al.44 (B) Pie charts depicting the proportion of sequences that carry 0, 1, 2, 3, etc mutations over the 681-bp region analyzed. The number of clones analyzed is shown in the middle. Clones with identical mutations were counted only once. The experiments are the same as the ones shown in Table 2.