Figure 3.

Activation is required for gamete docking. Live, activated imp12 mt- mutants were mixed with fixed, SYTOX-labeled wild-type mt+ gametes and the percentage of docked cells was determined as described in MATERIALS AND METHODS. Unactivated mt+ gametes were treated under the following conditions before fixation: A, activated with dibutyryl cAMP and papaverine; UnA→L, cell walls were removed with lysin; L→A, cells treated with lysin followed by activation; and A→L, activation followed by lysin treatment. Triplicate samples were counted for each experiment (bar, SEM).