Figure 6

PCR assay for Ac -driven excision of Ds2 and Ds-l4 elements. (A) Ds2-21 and Ds2-31 elements. Lanes: 1 and 18, 1-kb ladder; 2 and 10, W22 inbred (Wx); 3 and 11, B73, pooled seedlings; 4 and 12, B73 plant #1; 5 and 13, B73 plant #2; 6 and 14, wx-m7 plant # 1; 7 and 15, wx-m7 plant #2; 8 and 16, F1 (B73-1 × wx-m7-2); 9 and 17, F1 (B73-2 × wx-m7-2). Only the Ac/+ heterozygous F1 individuals (lanes 8-9) showed the band expected from somatic Ds2-21 excision. The absence of that band in the wx-m7(Ac) homozygotes (lanes 6-7) can be attributed to the well-established negative dosage effect of Ac [59]. No somatic excision of Ds2-31 could be detected in the Ac/+ heterozygous F1 individuals (lanes 16-17). (B) Ds-l4-176 and Ds-l4-199 elements. Lanes: 1, B73, plant #1; 2, wx-m7 plant #2; 3, F1 (B73-1 × wx-m7-2); 4, B73, plant #1; 5, wx-m7 plant #2; 6, F1 (B73-1 × wx-m7-2); 7, 100-bp ladder; 8, 1-kb ladder. Ds-l4-176 is polymorphic, i.e., not shared between B73 and W22, and cannot be assayed. No somatic excision of Ds-l4-199 could be detected in the Ac/+ heterozygous F1 individuals (lane 6).