Abstract: Methods and compositions for evaluating the efficiency of chromosomal rearrangement are provided. In some examples, systems comprising a first DNA molecule comprising the N-terminal portion of a first split reporter coding sequence linked to the C-terminal portion of a second split reporter coding sequence via a first intron, and a second DNA molecule comprising the N-terminal portion of said second split reporter coding sequence linked to the C-terminal portion of said first split reporter coding sequence via a second intron. The introns comprise at least one target site recognized by a genome editing reagent, such as a recombinase or endonuclease, such that recombination results in expression of the first or second reporter coding sequence following splicing of the introns.