Figure 1.

Schematic representation of half-genomic PrP transgenes driven by heterologous promoters. The genomic mouse Prnp locus is shown on top (37). Construction of the “half-genomic” PrP vector (phgPrP) lacking the 12-kb intron 2 has been described (14). Using PCR with the primers PE1 and Del, a BamHI site was introduced at the 5′ end of exon 1 in phgPrP. The resulting promoterless construct pPrP-5′HG EcoRI was cloned into Bluescript, and the PrP sequence was extended up to the SalI site in the 3′ noncoding region by introducing the NarI-SalI fragment of phgPrP to yield pPrP-5′HG SalI. Promoter cassettes were inserted into the BamHI site of pPrP-5′HG SalI to yield plck-PrP-5′HG SalI, pEμ/IRF1-PrP-5′HG SalI, and pAlbumin-PrP-5′HG SalI. B, BamHI; K, KpnI; N, NarI; Nt, NotI; R, EcoRI; S, SalI; X, XbaI. Wavy lines, vector sequences.