Figure 5

Expression of NHE3 protein on the apical membrane of posterior rectal cells and P-type Na⁺/K⁺ ATPase protein expressed on basolateral membrane of anterior rectal cells of A. taeniorhynchus larvae. Sectional preparation of segmented rectum of larval A. taeniorhynchus acclimated to 100% seawater showing immunolocalization of NHE3 protein (red) using NHE3 polyclonal antibody (A) and NHE3 peptide (C), on the apical membrane of PR facing the rectal lumen (indicated by white arrows). P-type Na⁺/K⁺ ATPase protein (green) was immunolocalized to the basolateral membrane of the AR (indicated by white arrows) that would face the hemocoele. (B, D). Scale bars, 50 μm (A, C, D) and 25 μm (B).