 For example, the 16th copy of CGG might be mapped to the 13th copy of CGG in the sister chromatid since the surrounding DNA is both CGGCGGCGG…, leading to 3 extra copies of CGG in the final DNA sequence.In both E. coli and Saccromyces pombe, transcription sites tend to have higher recombination and mutation rates.The coding or non-transcribed strand accumulates more mutations than the template strand.