FIGURE 7.

Schematic of the expression pattern of Fgf10 and Sox9 during salivary gland organogenesis, homeostasis and repair. Fgf10 is shown in green while Sox9 is shown in pink. During development, mesenchymal Fgf10 signals to epithelial Sox9 and directs expression in the distal region of the gland. During homeostasis, the expression of Fgf10 shifts to the ductal epithelium, while Sox9 remains expressed in the distal part of the glands (acini and intercalated ducts). During regeneration Sox9 and Fgf10 are upregulated in the ducts and may interact. Black arrows indicate a regulatory mechanism between Fgf10 and Sox9. This has been confirmed during development and needs to be tested during regeneration