[i] Zebrafish expression data were extracted from ZFIN (Sprague et al. 2006), those of mouse from MGI (Bult et al. 2008). All comparisons were made at a time when organogenesis is completed, which in zebrafish occurs 10–48 h post-fertilization and in mouse 9.5–16.5 d post-coitum. One representative comparison is shown here for each category (for the complete list including primary references, see Supplemental Table 5). Expression domains are given in alphabetical order for ease of comparison.