|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 9. FGF signaling is autoregulated at multiple levels and multiple FGF proteins
regulate midbrain and cerebellum development. In the mouse, FGF8 expression in
the isthmus at the four-somite stage represses the expression of
Fgfr2 and Fgfr3 and activates the expression of
Fgf18 at the five-somite stage. Fgf17 expression is
initiated in a broader domain slightly later, and by E9 the three Fgfs are
expressed in overlapping gradients radiating from the isthmus, whereas
Fgfr2 and Fgfr3 are absent in this region. Spry1/2
genes are upregulated by FGFs. FGF8b is required to maintain a cascade of gene
expression that includes absence of Otx2 in r1, allowing cerebellum
development to occur. FGF17 and FGF18, and possibly FGF8a and a low level of
FGF8b regulate growth and En expression in the midbrain.
|
