Figure 7.

In situ hybridization (ISH) of five protein sequences confirms the presence and locality of the target mRNA within P. vulgata foot. (a) Alcian blue stain highlights the glands present in the foot and provides context for the ISH stains. Scale bar 100 µm. Probes for P-vulgata_1 (b), P-vulgata_3 (c) and P-vulgata_4 (d) localized to a specific band of glands approximately 30–110 µm away from the epithelium. Scale bars 100 µm, 20 µm, 20 µm, respectively. Note that in (b), the weak staining around 150 µm away from the epithelium and in the mucus is unspecific background staining (orange arrowheads) that is distinct from the specific expression sites at approximately 100 µm away from the epithelium (green arrowhead). (e) P-vulgata_7 stained the pedal sole epithelium. Scale bar 20 µm. (f) P-vulgata_11 localized at the side-wall epithelium. Scale bar 50 µm.