FIG. 5.

Mapping of induced and inherited A gene deletions. (A) Southern blot of BglII-restricted genomic DNA samples. The blot was hybridized with probe d (see map in panel B). The same 13-kb BglII-BglII fragment is obtained with wild-type strains 29A and 51A. The original d48 cell line shows a diffuse band migrating at ∼10 kb, which represents a BglII telomere fragment. Lane 1, first-generation macronuclear deletion obtained by transformation with A²⁹; lane 2, stable 29AΔmac cell line derived from the clone for which results are shown in lane 1 by a few rounds of autogamy. (B) Map showing the deduced positions of the different TARs (striped boxes). The positions of probe d (solid rectangle) and the sequences covered by the injected transgene and by the E. coli dsRNA (shaded rectangles) are indicated. B, BglII; S, SalI; X, XhoI. (C) Mapping of dsRNA-induced A gene deletions. A Southern blot of BglII-restricted DNA was hybridized with probe d. Samples are individual clones from the postautogamous progeny of cells fed the control E. coli strain (lanes 3 to 5) or the dsRNA-producing strain (lanes 6 to 8) (see Fig. 4).