|ZFIN ID: ZDB-PUB-030707-10|
vhnf1 and Fgf signals synergize to specify rhombomere identity in the zebrafish hindbrain
Wiellette, E.L. and Sive, H.
|Source:||Development (Cambridge, England) 130(16): 3821-3829 (Journal)|
|Registered Authors:||Sive, Hazel, Wiellette, Elizabeth|
|Keywords:||Vhnf1, Fibroblast growth factor, Fgf3, Fgf8, Zebrafish, Hindbrain, Valentino, Krox20, Rhombomere, Neural patterning|
|PubMed:||12835397 Full text @ Development|
Wiellette, E.L. and Sive, H. (2003) vhnf1 and Fgf signals synergize to specify rhombomere identity in the zebrafish hindbrain. Development (Cambridge, England). 130(16):3821-3829.
ABSTRACTVertebrate hindbrain segmentation is a highly conserved process but the mechanism of rhombomere determination is not well understood. Recent work in the zebrafish has shown a requirement for fibroblast growth factor (Fgf) signaling and for the transcription factor variant hepatocyte nuclear factor 1 (vhnf1) in specification of rhombomeres 5 and 6 (r5+r6). We show here that vhnf1 functions in two ways to subdivide the zebrafish caudal hindbrain domain (r4-r7) into individual rhombomeres. First, vhnf1 promotes r5+r6 identity through an obligate synergy with Fgf signals to activate valentino and krox20 expression. Second, vhnf1 functions independently of Fgf signals to repress hoxb1a expression. Although vhnf1 is expressed in a broad posterior domain during gastrulation, it promotes the specification of individual rhombomeres. This is achieved in part because vhnf1 gives cellular competence to respond to Fgf signals in a caudal hindbrain-specific manner.