The Act5C promoter drives expression of a dicistronic transcription unit that encodes the two halves of a rapamycin-inducible split driver system. Each open reading frame is separated by a P2A sequence (this results in separate translation of each protein). The first ORF encodes FKBP::C-dCas9(4)::VPR and the second ORF encodes N-dCas9(4)::FRB.