Abstract: Provided herein are compositions and methods for genome editing and modification. In one embodiment, the composition comprises a regulatory gene expression construct that comprises a nucleic acid encoding an RNA comprising a sequence encoding a genome editing enzyme and a regulatory cassette operably linked to the sequence. In one embodiment, the regulatory cassette comprises a conditional exon and an aptamer domain which is capable of binding to an effector molecule to trigger a structural change of the RNA, thereby regulating splicing of the conditional exon and expression of the genome editing enzyme.