highly significantp = 7.5 × 10 −7
Statistical comparisons showed that the difference between the fraction of clearly templated mutations in DT40 PolyLacO-λ R GFP-LacI control cells and DT40 PolyLacO-λ R LacI-HP1 transfectants (77% compared to 3%) was highly significant ( p = 7.5 × 10 −7 , Fisher's exact test).