Figure 6.

Transcription profiles of biomineralization genes. Using k-means cluster analysis, we were able to retrieve four distinct expression profiles of all annotated biomineralization genes (A). Clusters 2 and 4 represent contigs with elevated expression levels during metamorphic stages, Cluster 1 represents contigs that do not change their expression during development, and Cluster 3 represents contigs with elevated expression levels during trochophore and veliger stages. We analyzed gene expression of aragonite protein 24 (AP24) antisense probe, using whole mount fluorescent in situ hybridization (MWISH) on whole A. californica embryos and early larvae. Note that stages in Panel B–G are marked with a dashed box in panel A. Panels B–E, C–F, and D–G represent the same stages (trochophore, early veliger, and veliger stage 1, respectively B, E). The upper panel always shows the fluorescent image superimposed with the DIC image. Expression of AP24 is diffused throughout the trochophore larvae with high expression where the shell and operculum will be present. (C, F) Expression of AP24 within prehatching veliger. Some expression was detected in the operculum. (D, G) AP24 expression in posthatching stage 1 veligers is restricted to the statocyst and the digestive gland. AP24 is expressed during trochophore (A–B), prehatching early veliger stages (C–D), and posthatching stage 1 veligers (E–F), as predicted by the microarray data. F, foot; Vl, velum lobes; Op, operculum; DG, digestive gland; S, statocyst; MC, mantle cells. Scale Bars: A: 35 μm; C: 36 μm; E: 34 μm.