Fig. 4. Mutant leaves show ectopic expression of rough sheath1 and gnarley1 transcripts. Following 40 cycles of RT-PCR, rs1 (A) and gn1 (B) transcripts are detected in sem mutant adult leaves. Inconsistent results are obtained using lg3-specific primers (B). (C) Semi-quantitative RT-PCR of kn1, gn1 and kn1 transcripts in sem1-R mutant (top), rs2-R mutant (center) and non-mutant B73 seedling leaves (bottom). No knox transcripts are detected in non-mutant leaves (Fig. 4A, B, C bottom), even after 50 RT-PCR cycles (data not shown). Sizes of predicted RT-PCR products are: ubiquitin, 208 bp; rough sheath1, 625 bp; knotted 1, 342 bp; liguless3, 248 bp; gnarley, 190 bp, indicated by arrows to distinguish from primer-dimers.