Figure 12

Ca²⁺ influx in HSB61 mutant. A) Dependence of cAMP-induced Ca²⁺-influx from [Ca²⁺]_e measured in unpulsed and pulsed HSB61 cell suspensions. Dose-response curves are shown for (left) untreated cells and (right) cells treated with 20 nM cAMP pulses. In both cases, cells were tested after 4–5 hours starvation. White circles depict the HSB61 cells and black circles the AX2 cells. Data are presented for at least 4 independent experiments for each cell type. P values = 0.00068 and 0.8368 for left and right graphs, respectively (Wilcoxon test). B) cAMP-induced Ca²⁺-influx in HSB61 and wild-type cells. Single electrode recordings are shown for (a, b) mutant cells either (a) unpulsed or (b) pulsed overnight with 20 nM cAMP. For comparison (c, d) wild-type cells are shown after 5 hours of development in (c) and after 7.5 hours in (d). Addition of cAMP is indicated.