Fig. 2. Expression pattern of INO during ovule development in wild type (A-D), ant-72F5 (E-H), ino-2 (I-L) and bel1-1460 (M-O). P is a control section hybridised with the sense probe of INO. Stages: (A,E,I,M) 1-I/II; (B,J,N,P) 2-I; (F) 2-II; (C,D,K) 2-III; (O) 2-IV; (G,L) 3-I; (H) 4-V. ant mutants were staged on the basis of their ovule, carpel and anther developmental profile relative to each other. INO expression can be detected in cells that give rise to the outer integument in wild type. The cell that undergoes a division to form two cell layers and the triangular tip cell does not express INO (arrow in C). Note the absence of INO expression in the adaxial cell layer (arrow in D). Note the absence of INO expression even at the site of outer integument initiation in ant-72F5 (arrow in G). INO expression can be detected at late stages (H,b) but only in a few epidermal cells, similar to the early stages in wild type. The typical horseshoe appearance is not present (arrow H,a). No INO expression can be detected in ino-2 (I-L) and bel1-1460 (M-O). Arrows in L indicate site of outer integument initiation in wild type. Arrows in O denote early chalazal bulges in bel1-1460. Sense probe gave no signals above background (P). Scale bars: 20 µm.