Involvement of Sid2, Etd1, and Rho1 in signaling Spg1 activation in drc1-191-blocked cells. Cdc7-Tom (Spg1 activity marker) and Rlc1-GFP (medial ring marker) were imaged by time-lapse microscopy at 2.5-min intervals in living drc1-191 sid2-as, drc1-191, and drc1-191 rho1D/p41rho1 mutants at 36°. Sid2-as inactivation (+10 μM 1NMPP1) before and after asymmetric localization of active Spg1, actomyosin ring disassembly (+100 µM latrunculin B), and repression of nmt41x-driven expression of rho1 in the p41rho1 plasmid (+ Thiamine) are indicated (Materials and Methods).