Ends-out targeting vector, which contains rpr^Scer\UAS.cHa to help eliminate false-positive events when using derivatives of this vector and selecting for homologous recombination at the locus of interest; once the donor fragment is recombined into the target gene locus, rpr^Scer\UAS.cHa will be lost due to homologous recombination. In contrast, non targeted integrations will likely retain the donor DNA fragment including an intact rpr^Scer\UAS.cHa.