Fig. 4. The 5' 140 bp sequence of ori-ß is required for activity. (A) BP and ori-ß mutants 1-5. For convenience, ori-ß (2258 to 3098 in Fig. 1) is numbered from 1 to 840. The ß-region is indicated by shading. (B) Quantitation of amplification levels for independent transgenic lines.