Fig. 2. In situ hybridisation of AmMYBML1 in Antirrhinum flower buds. (A) Entire bud probed with AmMYBML1. Expression was observed only in the ventral petal. Se, sepal; DP, dorsal petal; St, staminal filament; C, carpel; VP, ventral petal; B, bract; arrow indicates expression. (B) Higher magnification view to show AmMYBML1 expression on the adaxial side of the ventral petal. (C) Flower bud of equivalent age (to B) probed with Cyclin D3b. There is strong labelling in ovules, anthers and in the ventral petal of the corolla (arrowed). (D) Flower bud from cyc dich double mutant showing AmMYBMl1 expression in the developing petals. All the petals in this line have ventral identity, and AmMYBML1 is expressed (arrowed) in the petals that lie in the dorsal position (DP) as well as in the ventral position (VP). Scale bars: 100 µm. (E) In situ hybridisation of bud (15-25 mm) showing expression of AmMYBML1 in the ventral petal. Labelling was observed in the adaxial epidermis of the tube, in the trichomes of the tube, and in the hinge but not in the main part of the petal lobe epidermis. (F) Expression of AmMYBML1 in the ventral petal. In the hinge region the gene is expressed in the adaxial (inner) epidermis and in mesophyll cells on the adaxial side. (G) In contrast to B, MIXTA is expressed only in epidermal cells, even in the hinge region. Scale bars: 100 µm.