Comparison of transverse anther sections. Anther cross sections from the wild type (A–D and I–K) and arf17 (E–H and L–N) were stained by toluidine blue. A and E, Anthers at stage 5 from the wild type (A) and arf17 (E). B and F, Anthers at stage 6 from the wild type (B) and arf17 (B). C and G, Stage 7 anthers from the wild type (C) and arf17 (G). D and H, Stage 8 anthers from the wild type (D) and arf17 (H). I and L, Stage 9 anthers from the wild type (I) and arf17 (L). J and M, Stage 10 anthers from the wild type (J) and arf17 (M). K and N, Stage 12 anthers from the wild type and arf17 (N). Dmsp, Degraded microspore; Dpg, degraded pollen grain; E, epidermis; En, endothecium; Ml, middle layer; Ms, microsporocyte; Msp, microspore; Pg, pollen grain; Sp, sporopollenin; T, Tapetum; Tds, tetrads. Bars = 20 μm. [See online article for color version of this figure.]