Mutations in FBW2 enhance the se-1, hst-3, hyl1-2 and hen1-6 mutant phenotypes. Twenty-one-day-old plants singly and doubly mutant for fbw2-1 and hst-3 (A and B) se-1 (C and D), or hyl1-2 (E and F), and 28-day-old hen1-6 and hen1-6 fbw2-4 plants (G and H). hyl1-3 fbw2-1 and se-1 fbw2-1 double mutants have phenotypes similar to hyl1-3 and se-1 plants transformed with ARGONAUTE1::FLAG-AGO1 (I and J) or WT plants containing the miR168 insensitive 2m-AGO1 construct (K). (L) Western blot of protein extracts from 14 day-old seedlings probed with an anti-AGO1 antibody. Ponceau staining and a nonspecific band (*) were used as a loading control.