Schematic diagrams of FAA retroviral vector constructs. A general schema for the two retroviral constructs used is shown with the FAA coding region subcloned as a Not I fragment into plasmid pG1 (top). (Bottom) The FAA cDNA is driven by the 5′ hybrid long terminal repeat (LTR) of murine moloney sarcoma virus; psi (ψ) retroviral packaging signal; TAG represents a mutation in authentic start codon in the molony murine leukemia virus gag.