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Embryo Sac Development

images of stages of embyonic sac development

image of Propidium Iodide Staining
Propidium Iodide Staining
image of toluidine blue sections
Toluidine Blue Sections

image of gametophyte developmentFemale gametophyte development begins with the post-meiotic degeneration of three of the daughter cells, leaving only one functional gametophyte. This single-nucleate (FG1) gametophyte undergoes nuclear division without cell division to give rise to the double-nucleate FG2 stage (Fig. 3A). The nuclei migrate to the opposite ends of the embryo sac syncytium and a large vacuole forms between them, defining the FG3 stage (Fig. 3A). Two more rounds of nuclear division (stage FG4) are followed by cellularization (stage FG5). Fusion of the two polar nuclei leads to the seven-nucleate, seven-celled embryo sac (stage FG6) containing an egg cell, two synergids, a central cell and three antipodals (Fig. 3A). Degeneration of the three antipodals yields the final four-celled embryo sac (stage FG7), ready for fertilization.          

Click the links above for images of developing Arabidopsis embryo sacs