Fig. 5. In situ STY (left panel) and GRAM expression patterns (right panel) during wild-type vegetative development. Photographs in a row are from consecutive sections. Cross sections were prepared from the apex of 7- to 8-week-old plants. Because of floral induction the leaf primordia are arranged in a spiral order. This allows more developmental stages to be observed in one section (numbered in B and D), compared to the two to four primordia arranged in decussate phyllotaxis in apices prior to induction. (A,B) In situ mRNA expression patterns. The sections were taken from the top of a shoot and do not reveal the shoot apical meristem. (C,D) The sections for immunolocalisation show the apical meristem and very young initiating primordia. (Arrowhead in C indicates the margin region expressing STY that expands in the gram mutant shown in Fig. 7A) (Insets) Magnification of a small region of a P3 primordium reveals largely nuclear localisation of STY in C and additional cytoplasmic staining for GRAM in D. (E,F) DAPI counter-staining of the sections shown in C,D. Notice dark regions that do not reveal the nuclear DAPI signal due to quenching by the immunological stain. Scale bars: 100 µm.