Fig. 3. Stages of male meiosis and pollen development in wild type and duet. Optical sections of cleared anthers viewed under DIC optics. (A-D) Wild type; (E-K) duet. (A,E) Stage 5 anthers with pollen mother cells (arrowheads). (B) Stage 7 anther containing tetrads (arrowhead). (C) Microspores released from the tetrad generate an exine wall and become vacuolated (arrowhead). (D) Mature pollen. (F,G) Dyads (arrowhead in F) formed after a defective meiosis. (H,I) Cells of the dyad separate and enlarge (arrowhead in H). (J,K) The microspore-like cells released from the dyad enlarge and undergo nuclear division to form 2-3 nucleate cells (arrowhead in J), which later degenerate. Scale bars: 12.5 µm.