Fig. 1. Diagrammatic representation of sporulation stages in the yeasts S. pombe and S. cerevisiae. Stage I, meiotic prophase I. Stage II, meiotic metaphase I/anaphase I. Stage III, meiotic metaphase II/anaphase II; formation of the FSM. Stage IV, completion of FSM assembly. Stage V, spore wall synthesis. Landmark events relevant to the SPB and the FSM are described with reference to cell morphology.