Figure 3

Flux studies in Xenopus laevis oocytes expressing Carcinus maenas Hiat1. (A) Absolute H³-methylamine/ammonium (MA/MA⁺) uptake of sham-injected oocytes (white bar) and oocytes expressing Carcinus maenas Hiat1 (dark grey bar) under control conditions (medium pH 7.5, bath [total MA/MA⁺] = 1 mmol = 10 μCi). (B) Net changes in MA/MA⁺ uptake (calculated as [Carcinus maenas Hiat1–sham]) at (i) pH 7.5 as referred to in panel (A), (ii) medium containing 1 mmol L⁻¹ NH₄Cl, and (iii) medium without Na⁺. Positive bars represent higher and negative bars represent lower MA/MA⁺ uptake of Carcinus maenas Hiat1-expressing oocytes relative to sham-injected oocytes. Asterisk indicates significant differences of MA/MA⁺ uptake between sham-injected and Carcinus maenas Hiat1-expressing oocytes (without sham-subtraction). Daggers indicate significant differences of MA/MA⁺ uptake between control conditions (pH 7.5 sham-subtracted, light grey bar) and treatments (black bars, sham subtracted) (Student’s T-tests with P < 0.01, N = 20). Values are presented as means ± SE. Experiments have been conducted on two different batches of oocytes (i.e., different female, different days).