Comparison of male gametogenesis in wild-type and oshub1 plants. A to D and M to P show the wild type. E to H, I to L, and Q to T show the oshub1-1, oshub1-2, and oshub1-1 mutant, respectively. E, Epidermis; En, endothecium; ML, middle layer; T, tapetum; Msp, microspore; MP, mature pollen; AMsp, aborted microspore. A, E, and I, Cross section of anthers at stage 9. B, F, and J, Cross section of anthers at stage 10. C, G, and K, Cross section of anthers at stage 11. D, H, and L, Anthers at stage 13. M and Q, N and R, O and S, and P and T show microspores at stage 8b, stage 10, stage 11, and stage 12, respectively. N to P and R to T are DAPI stained to show nuclei. M and Q are karbol fuchsin stained to show tetrad. Bars = 100 µm (A–L) and 10 µm (M–T).