pCAG-GFP (Addgene plasmid 11150) 39 (link), pCAG-YFP (Addgene plasmid 11180) 39 (link), pCAG-CFP (Addgene plasmid 11179) 39 (link), pCAG-tdT (Cepko lab, Harvard Medical School), pCAG-mCherry (Cepko lab, Harvard Medical School), pCAG-DsRed (Addgene plasmid 11151) 39 (link), pRL-TK (Promega, #E2241), pRho-GFP-IRES-AP (referred to as Rho-GFP in main text) 40 (link), pCAG-nlacZ (Cepko lab, Harvard Medical School). pAAV-CAG-FLEX-tdT was a gift from Edward Boyden (Addgene plasmid #28306), pCALNL-DsRed (Addgene plasmid #13769) 41 (link).