AeAmt2 abundance and immunolocalization in the alimentary canal, anal papillae, and carcass of wild-collected and laboratory A. aegypti larvae reared in freshwater (FW) and septic water (Septic). (a) AeAmt2 abundance and representative Western blots (right panel) in the carcass and anal papillae (AP) of wild A. aegypti larvae (n = 3). (b) AeAmt2 abundance and representative Western blots (right panel) in the Malpighian tubules (MT) and anal papillae (AP) of laboratory A. aegypti larvae (n = 3 FW, n = 4 Septic). The abundance of AeAmt2 protein was normalized to total protein (Coomassie protein stain, not shown), and Septic values are expressed relative to the control FW group (assigned a value of 1). Data shown as mean ± S.E.M. Asterisks indicate statistical significance (*p < 0.05) compared to FW control (Unpaired, two-tailed t-test). Representative cross sections of the carcass (CAR), gastric caecae (GC), anterior and posterior midgut (MG) and Malpighian tubules (MT) and rectum (RM) showing AeAmt2 (red) immunostaining from (c–e) wild FW-reared larvae, (d–f) wild Septic-reared larvae. Representative cross sections of the anterior midgut (MG) and transverse sections of anal papillae (AP) showing AeAmt2 (red) immunostaining from (g–i) laboratory FW-reared larvae and (h–j) laboratory Septic-reared larvae. Nuclei are labelled by DAPI (blue) staining. Immunostaining of V1 subunit of V-type H+-ATPase (VA) is green (c–h). Co-localization of AeAmt2 with V1 subunit of V-type H+-ATPase is indicated (dashed arrows) (merge, yellow). Control sections (primary antibodies omitted, not shown) were devoid of red and green staining. Illustrations of the alimentary canal and anal papillae of A. aegypti larvae to the left of each immunofluorescence image indicates the region of the cross or transverse section (red rectangles). Lumen, (lm); carcass (CAR), gastric caecae (GC), midgut (MG), Malpighian tubule (MT), anal papillae (AP); rectum (RM). Scale bars: 100 µm, unless specified.