Figure 6

Proposed mechanism of FGF-BMP balancing system. In this study, FGF-9 upregulates Ameloblastin and Amelogenin, and speeds up epithelial invagination. No direct relationship between Sonic hedgehog (Shh), Jagged (Jag2) and Ameloblastin has been elucidated until now. Other genes (such as Paired box 9) were found to support antagonistic interactions between FGFs and BMPs [32] but are not shown in this graph. We propose an ‘FGF-BMP balancing system’ which manipulates the morphogenesis of ectodermal organs. “→” is the upregulate pathway proved by previous researches and our study. “⊥” is the downregulated pathway proved by previous research. “?” is the suggested pathway need to be investigated further.