Geminin Orchestrates Somite Formation by Regulating Fgf8 and Notch Signaling

Figure 6

The model for how geminin regulates somitogenesis. During somitogenesis, geminin simultaneously regulates Notch activity (F) and Fgf8 signaling (G) to orchestrate proper somite segmentation (H). (A, B) Geminin positively regulates the transcription of Mib by binding to intron 3 of Mib (B); it also directly regulates the expression of DeltaD (A) and then collectively regulates Notch activity. On the other way, geminin negatively regulates the expression of fgf8 (D) but positively regulates the expression of raldh2 (retinoic acid) (C). RA and Fgf8 antagonize each other to form the Fgf8 gradient retraction during somitogenesis (E).