A. All putative combinations of ZAC pentamers that potentially can be assembled in oocytes co-expressing ZACThr128 and ZACAla128 subunits. B,C. Averaged current amplitudes evoked by Zn2+ (10 mM) (B) and H+ (pH 4.0) (C) in ZACThr128- and ZACAla128-oocytes (injected with 1.84 ng cRNA), in oocytes injected with ZACThr128:ZACAla128 cRNA ratios of 1:1, 1:3 and 3:1 (0.92:0.92 ng, 0.46:1.38 ng, 1.38:0.46 ng, respectively), and in the control oocytes injected with the corresponding ZACThr128 cRNA quantities (0.92 ng, 0.46 ng, 1.38 ng) (mean ± S.E.M., n = 7–12). Statistical analysis was performed using one-way ANOVA followed by Tukey’s multiple comparisons test. Statistical values for the comparisons of Zn2+ (10 mM)-evoked current amplitudes: 1:1 ratio: P = 0.8355, 1:3 ratio: P = 0.8990, 3:1 ratio: P = 0.9975, F(7,63) = 18.71. Statistical values for the comparisons of H+ (pH 4.0)-evoked current amplitudes: 1:1 ratio: P = 0.8657, 1:3 ratio: P = 0.8373, 3:1 ratio: P = 0.3657, F(7,47) = 24.49. n.s. indicates non-significant difference (P > 0.05).