Fig. 3. Ae. aegypti anterior midgut in situ hybridization CA labeling. While the GC and PMG display heavy epithelial labeling for the CA message (A), there is also specific labeling seen in muscle (B,C, large arrowheads) and nerve cells (B, small arrows). (A) A representative whole-mount larva displaying the strong epithelial label in GC and PMG along with muscle fiber staining in the AMG that can be overlooked at low magnification. (B) The beginning of the anterior midgut displays both muscle and nerve fiber labeling. The labeled fibers reveal striated muscle running longitudinally down the length of the anterior gut and circularly around the girth of the gut (B,C, large arrowheads). The nerve fibers can be distinguished by their non-striated wavy appearance (B,C, small arrows). (C) The AMG (left) displayed strong labeling in muscle and nerve fibers while displaying no epithelial cell labeling. The PMG (right, asterisk) shows fiber labeling as well as intense epithelial cell labeling. Scale bars, 300 µm (A), 25 µm (B), 50 µm (C). Abbreviations as in Fig. 2.