Fig. 5

Shell field expression of Shell Matrix Protein 1 in Crepidula fornicata and Crepidula atrasolea embryos. Using hybridization chain reaction (HCR), mRNA expression was detected for SMP1 in both species (A-D). Wheat germ agglutinin (WGA) was used to mark the larval shell. CfSMP1 is expressed throughout the shell field in late ovoid staged C. fornicata embryos (A), and more intensely around the shell field edge during organogenesis (B). Similar expression patterns are seen for CaSMP1 in late ovoid staged (C) and organogenesis staged C. atrasolea embryos (D). Hoechst is shown in gray, SMP1 in magenta, and WGA in yellow. fr, foot rudiment; ft, sf, shell field; ve, velar lobes; lk, larval kidney. Scale bars represent 100 μm