Figure 2.

Reversion spectra of the lys2-Bgl allele in a wild-type and three nuclease-deficient strains. The reversion window comprising nt 362–443 and 475–507 is shown and the 4 bp insertion that created the lys2-Bgl allele is indicated in lower case. Each reversion is indicated at the position of changes with symbols ∇ and V for single base pair deletions and insertions. Four base pair deletions are underlined and the short direct repeats flanking inserted sequences are italicized. The frequency of mutations is indicated in parentheses when more than one event is involved and reversions involving both deletions and base substitutions are shown in brackets. The number of revertants analyzed was: 20 for wild-type, 21 for rad27, 23 for rnh35 and 21 for rnh35/rad27.