Fig. 6. Expression of SWN. Transcript localization by in-situ hybridisation. Tissue appears light blue, whereas the signal appears dark purple/brown. (A-F) were hybridised with an SWN antisense probe generated from a region at the 5' end of the cDNA that lacked similarity with any other Arabidopsis gene. (A) Longitudinal section through an 8-day-old seedling showing expression in the shoot apical meristem (arrowed) and young leaf primordia (P). (B) Seedling section showing expression in vasculature (arrowed) and in older leaf primordia. (C) Longitudinal section through inflorescence showing strong expression in inflorescence meristem (IM), and throughout young stage 1 and 3 floral meristems. (D) Stage 7 flower showing expression in stamens (S), carpels (C) and emerging petal primordium (arrowed). (E) Stage 9 flower showing strong expression in emerging petal primordium (arrow), stamens (S) and carpels (C). (F) Longitudinal section through carpel of stage-12 flower showing mature ovules. Expression is low in the carpel walls (W), but strong throughout the sporophytic tissue of the ovule, particularly in the funiculus (F). Expression is also visible in the embryo sac (arrow). (G) Longitudinal section through seedling hybridised with SWN sense probe. (H) Longitudinal section through inflorescence hybridised with SWN sense probe. (I) Transverse section through 8-day-old seedling hybridised with WUS antisense probe. Signal is confined to the centre of the meristem, as previously described (Mayer et al., 1998).