Involved in the pathway that organizes the shaping and sizing of the prospore membrane (PSM) during sporulation. May provide a meiosis-specific scaffold for the assembly of other proteins on spindle pole bodies (SPBs), and may be a limiting component for SPB formation. Interacts directly with MPC54, NUD1 and SPC42. Interacts with ADY3. Interacts with ADY4. Probable component of a SPB complex composed of ADY3, SSP1, DON1, MPC54, SPO21/MPC70, NUD1 and CNM67. Localizes to the ends of spindle microtubules in cells in meiosis. Meiosis-specific. Expressed during meiosis II, from 3 to 9 hours after induction of sporulation. Not expressed during mitosis. Belongs to the MPC70 family.