rfEPO sequence and schematic of the pLenti rfEPO vector.
The 7543 nucleotide pLenti rfEPO vector, derived from the HIV-1 based pLenti6/V5-D-TOPO (Invitrogen) is depicted schematically along with the cloned fEPO cDNA sequence. For the cDNA sequence, the start (ATG) and stop (TGA) codons are boxed while the 44th codon (GAG) is in a grey box. For the vector schematic, all of the promoter elements are light grey with an accompanying arrow. The 5′ HIV-1 LTR has a 229 nucleotide deletion in U3 replaced with the RSV enhancer/promoter (RSV prom/5′LTR). The 5′ splice donor (SD), splice acceptor (SA), packaging signal (Ψ), Rev response element (RRE), CMV promoter, feline erythopoietin cDNA (579 nucleotides), SV40 early promoter, EM7 promoter, Blasticidin resistance gene and the SV40 polyadenylation signal are depicted schematically. The 3′ HIV-1 LTR has a 52 nucleotide deletion in U3. The pUC origin and Ampicillin (bla) resistance gene/promoter are present in the vector backbone but are not depicted.