Fig. 1.

Schematic diagram of the γ-retrovectors. The integrated « proviral » form is depicted. The pSERS11 GFP pre [15] was used as a starting vector to generate a β-specific SIN γ-retrovector. LTRΔU3: Long Terminal Repeat without the U3 region (SIN deletion) Ψ: packaging sequence. RIP: 405 bp promoter of rat insulin II gene. SF: U3 enhancer/promoter region from Spleen Focus Forming Virus. M: Multi Cloning Sites are depicted in two colors (grey or black) because they are different in pPRI 3HAH2BYFP and in pSERS RIP/SF MCS (only the latter is detailed). The cDNAs subsequently inserted in these derivatives are indicated. W: Woodchuck hepatitis virus post-transcriptional regulatory element. 3HAH2BYFP: YFP fluorescent protein fused in 5′ with 3 copies of the HA epitope followed by the H2B histone. The position of the restriction sites relevant for subsequent constructs are indicated (see Methods). The different parts of the diagrams are not at scale