Figure 6.

CMADS1 RNA localization in developing sporangia. Transverse section of a young (1 cm; A–D) and older (15 cm; E–G) fertile leaf showing sporangium development. (A) A sporangium initial cell divided to form an inner cell (i) and an outer cell (o). The arrow head of “i” points to a nucleus of the inner cell. (B–D) The apical cell (ac) of the sporangium (B and C) divides to form an internal cell (ic) (D). (E) Derivatives of the internal cell will form the sporogenous cells (sc) and tapetum cells (tc). (F) A portion of the mature sporangium including some spores (s). (G) A late developing sporangium (arrowhead). [Bar = 10 μm (A–F) or 50 μm (G).]