Cell types in which GUS/GFP expression was observed in the embryo sac and developing seed. A, AGL100 in the functional megaspore (FG1; Christensen et al., 1997). B, AGL100 in the two-nucleate embryo sac (FG2-3). C, AGL52 in the central cell (FG6). D, Schematic representation of the embryo sac in stage FG6. E, AGL53 in the antipodal cells. F, PHE1 in the endosperm nuclei approximately 16 h after pollination (hap). G, PHE2 in the peripheral and chalazal endosperm nuclei approximately 42 hap. H, Schematic representation of the developing seed approximately 16 hap. I, AGL28 in the globular embryo approximately 60 hap. J, AGL46 in the peripheral endosperm nuclei approximately 48 hap. K, AGL35 in the chalazal endosperm approximately 60 hap. L, Schematic representation of the developing seed approximately 60 hap. ap, Antipodal cells; cc, central cell; ce, chalazal endosperm; ec, egg cell; em, embryo; en, endosperm nuclei; pe, peripheral endosperm; sn, synergids; zy, zygote. Images A to F have the same scale (bar in B), and images G to K have the same scale (bar in G).