Fig. 5. (A) Sequestration of ß subunits in the egg achieved by using two alternative reagents (100 µg/ml phosducin or 200 µg/ml ßARKct, unless otherwise indicated) leads to abnormal fertilization envelope (FE) formation. Percentage of eggs forming normal FEs was determined for each treatment. Plotted are the average values of three or four independent experiments (10 eggs analyzed per each experiment; error bars, 1±s.d.). (B) ß subunits might mediate signaling initiated by disparate G subunit activation. (C) High concentrations of injected phosducin prevent FE formation altogether, whereas lower ones cause low or partial FE elevation (10-20 eggs analyzed per each injected concentration). (D) Sequestration of ß subunits leads to lower amount of membrane added to cell surface at fertilization. Each data point represents an average of 3 or 4 recordings (error bars, 1±s.d.).