Fig. 3. Ectopic and precocious expression of AG in seu single and seu lug double mutants. 8 µm longitudinal sections of Arabidopsis inflorescences were hybridized with an AG antisense probe. Numbers indicate stages of floral development [based on Smyth et al. (Smyth et al., 1990)]. (A) A wild-type inflorescence. AG mRNA is detected in the center of the stage 5 flower and is not detected in sepal primordium (arrowhead). AG mRNA is not detected in stage 2 floral meristems. (B) A seu-1 inflorescence. AG mRNA is detected in the stage 2 floral meristem and in the sepal primordia of stage 3 floral meristem (arrowhead). (C) A seu-1 lug-8 double mutant inflorescence. AG mRNA is detected as early as the stage 1 and stage 2 floral meristems. Expression of AG mRNA is also detected in groups of cells (marked with a *) in the inflorescence meristem that might represent pre-stage 1 cells. AG mRNA is detected in the sepals of all flowers (arrowheads). Note the severely reduced whorl 4 (white arrows). The pink color in the stem is residual Eosin stain and does not reflect hybridization signal.