Fig. 3. Pattern of CPC mRNA localisation in wild-type embryos. (A) Longitudinal sections through a globular (a), an early-heart (b) and a mid-heart (c) stage embryo and schematic cellular organisation. No expression of CPC mRNA is detected in any embryonic stage. Inset: a longitudinal section hybridised with CPC sense probe shows no signal. (B-E) Transverse sections through embryos at different developmental stages probed with CPC antisense RNA and schematic representation of the cellular organisation of root and hypocotyl. The localisation of mRNA is indicated in orange on these schematics. From the left to the right of B and D the sections displayed were taken from: the root pole at the base of the embryo, the root close to the root pole, the root close to the hypocotyl, the hypocotyl. (B) Torpedo stage. CPC mRNA is present throughout the root. In the hypocotyl CPC mRNA is present throughout the epidermal and cortical layers. Inset: a transverse section hybridised with CPC sense probe shows no signal. (C) A schematic representation of the longitudinal organisation of the embryo at torpedo stage and the radial organisation in the embryonic root (a) and hypocotyl (b) as indicated. (D) Mature stage. CPC is preferentially expressed in root cap and lateral root cap cells in the root. In the hypocotyl CPC expression is confined to the vascular tissues. Inset: transverse section hybridised with CPC sense probe. (E) A schematic representation of the longitudinal organisation of the embryo at mature stage and the radial organisation in the embryonic root (a) and hypocotyl (b) as indicated. Scale bars: 40 µm.