Fig. 6. Hox genes and the genetic network driving axial extension, mesoderm segmentation and AP patterning. Fgf, Wnt and RA signalling are functionally involved in axial extension (orange), somitogenesis (green) and AP patterning (purple). The relationship between the Hox genes, the Cdx genes, the segmentation genes of the Notch pathway and the three morphogenetic processes are indicated. Unbroken lines indicate established interactions; broken lines represent documented interactions that have not yet been established at the molecular level.