Fig. 3. Immunolocalization of P-type Na⁺/K⁺-ATPase (red) and V-type H⁺-ATPase (blue) in the stomach and Malpighian tubules (MTs) of adult female A. aegypti. In a mid-longitudinal optical section of a whole mount of the stomach (A,B) labelling of P-type Na⁺/K⁺-ATPase was present on the lateral membranes and V-type H⁺-ATPase was present cytoplasmically. In the paraffin cross sections of the stomach epithelium, P-type Na⁺/K⁺-ATPase was present basolaterally and V-type H⁺-ATPase was present apically (C,D). In whole mounts of Malpighian tubules, the distal principal cells expressed only V-type H⁺-ATPase (F) and the stellate cells P-type Na⁺/K⁺-ATPase (E, white arrow). There were no stellate cells observed in the proximal region of the Malpighian tubules and the principal cells expressed both P-type Na⁺/K⁺-ATPase and V-type H⁺-ATPase (G). In the sections of the proximal principal cells (H), P-type Na⁺/K⁺-ATPase and V-type H⁺-ATPase were expressed on the basal (white arrow) and apical (white arrowhead) membranes, respectively. Also in H, the anterior hindgut (AHG) expressed P-type Na⁺/K⁺-ATPase on the basal membrane and V-type H⁺-ATPase on the apical membrane. In C,D,G,H, the Cy3 and Cy5 signals are overlayed and in A,B,E,F, the signals are separated. Scale bars, 100 µm (D), 50 µm (A-C,G,H), 10 µm (E,F).