Figure 3

The effect of 3' and 5' deletions in the 1.3 kb macronuclear precursor sequence on DNA fragmentation. pCE18 and, as controls, pCE5 and pCE12 [27] were injected into the macronuclear anlagen in the polytene chromosome stage of 20-30 exconjugant cells. DNA was isolated from these cells 6-10 h later and a PCR analysis was performed. The PCR products were separated on a 1% agarose gel. M, molecular weight marker (1 kb ladder, Gibco BRL). (a) PCR products from cells injected with pCE12 using the primer combinations P9/P548 (lane1), pGEMP1/P20 (lane 2) and pGEMP2/P23 (lane 3). (b) PCR products from cells injected with pCE5 (lanes 1-5) using the primer combinations pUCP1/P20 (lane 1); pUCP2/P8 (lane 2); pUCP2P548 (lane 3); P20/P8 (lane 4) and P20/P548 (lane 5). Lanes 6-10: PCR products from cells injected with pCE18 using the primer combinations pGEMP1/P20 (lane 6); pGEMP2/P8 (lane 7); pGEMP2/P548 (lane 8); P20/P8 (lane 9) and P20/P548 (lane 10). (c,d) Control PCR using pCE12 (C), pCE5 and pCE18 (d) construct DNA as templates. PCR reactions in (c) are identical to those shown in (a), and PCR reactions in (d) are identical to those shown in (b).