Fig. 4

Fig. 4 The effects of exposure to acidic water on Na⁺ uptake in GR morphants. GR knockdown did not have any effect on Na⁺ uptake by zebrafish larvae maintained under normal pH (7) conditions (Fig. 4A, N = 6). However, while not eliminated entirely, the stimulation of Na⁺ uptake following 24-h exposure to acidic water was significantly attenuated in the GR morphants (Fig. 4A; N = 6). Data are presented as means ± SEM; different letters denote significant difference among treatment groups. The effectiveness of GR knockdown was confirmed by demonstrating via immunocytochemistry a marked reduction in the number of GR-positive cells on the yolk sac in the GR-MO’s (Fig. 4C) in comparison to the control MO’s (4C). Scale bars = 200 μm (4B and 4C).