(A) Each cell of the multicellular dikaryotic filament contains two distinct nuclei. (B) During cell division, the two nuclei are synchronously replicated via mitosis. (C) One daughter from each parent nucleus is maintained near the hyphal tip to generate the nascent filament cell. Simultaneously, one of the remaining parent nuclei moves into a clamp cell (hook-shaped cells required for proper nuclear distribution along the filament), while the other parent nucleus moves further away from the hyphal tip. (D) Septa emerge to produce a dikaryotic apical cell, monokaryotic clamp cell, and a monokaryotic subapical cell. (E, F) The clamp cell then fuses with the subapical cell to deliver its nucleus and restore dikaryosis along the filament.