Fig. 3. Flower and anther development in jag nub mutants. SEM images are of stamens taken from stage 12 flowers. (A-C) Wild type (A), jag (B) and jag nub (C) flowers. Sepal and petal development is similar between jag and jag nub mutant flowers; however, anthers are reduced to stubs of tissue and the distal region of the jag nub gynoecium is abnormal. (D-F) SEM images of the adaxial side of anthers from wild-type (D), jag (E) and jag nub (F) stamens. Four elongated sacs of tissue (microsporangia) are apparent in wild type and jag mutants. In jag nub mutants, however, a small stub of tissue develops instead, with epidermal characteristics of the connective in the apical region and cells of uncertain identity in the basal region. (G) SEM image of the abaxial side of a wild-type anther revealing the connective that develops in between the microsporangia. (H,I) SEM images of epidermal cells taken from the connective region of wild-type anthers (H) and the connective-like region of jag nub anthers (I). (J) SEM image of a stamen from a jag nub^+/- mutant showing partial development of the microsporangia. (K-M) Plastic-thin sections (3 µm) of wild type (K), jag (L) and jag nub (M) anthers. (K) In wild-type anthers, four locules develop on the adaxial side separated by the connective on the abaxial side. Black arrowheads indicate dehiscence zones. (L) In jag mutants, two locules appear to develop and will split through a dehiscence zone that develops down the middle of the microsporangia (black arrowheads). (M) In jag nub mutants, no locule or pollen development is apparent. Inset is the same magnification as K and L. an, anther; co, connective; fi, filament; lo, locule; ms, microsporangia. Scale bars: 0.5 mm for A-C; 100 µm for D-G,J; 25 µm for H,I; 50 µm for K-M.