ZFIN ID: ZDB-PUB-000824-21
Patterning the early zebrafish by the opposing actions of bozozok and vox/vent
Melby, A.E., Beach, C., Mullins, M., and Kimelman, D.
Date: 2000
Source: Developmental Biology   224(2): 275-285 (Journal)
Registered Authors: Kimelman, David, Melby, Bess, Mullins, Mary C.
Keywords: none
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Body Patterning/genetics*
  • DNA Primers
  • Gene Expression Regulation, Developmental
  • Homeodomain Proteins/chemistry
  • Homeodomain Proteins/genetics*
  • Molecular Sequence Data
  • Repressor Proteins/chemistry
  • Repressor Proteins/genetics*
  • Sequence Homology, Amino Acid
  • Zebrafish/embryology*
  • Zebrafish Proteins/chemistry
  • Zebrafish Proteins/genetics*
PubMed: 10926766 Full text @ Dev. Biol.
Fish and frog embryos are patterned along the dorsal-ventral axis during the gastrula stage by opposing gradients of Bmps and Bmp inhibitory proteins. Three transcriptional repressors with partially overlapping expression domains have been proposed to be important mediators of Bmp function in Xenopus. We find that two related factors are expressed in the early zebrafish embryo. Although these factors are considerably divergent from the related Xenopus genes, they are expressed in domains similar to those of their Xenopus relatives throughout embryogenesis. Both of the zebrafish genes, which we have named vox and vent, are potent ventralizing factors in both zebrafish and Xenopus embryos. Using mutants in the Bmp pathway, we find that there are Bmp-dependent and Bmp-independent domains of vox expression, whereas vent is mostly dependent upon Bmp signaling. We show that ectopic vox or vent negatively regulates expression of the early dorsal gene bozozok (boz) and that ectopic boz eliminates vox and vent expression. Moreover, the normal exclusion of vox and vent from the organizer region is lost in boz mutant embryos. Our results show that boz and vox/vent are mutually antagonistic and indicate that the early establishment of the size of the organizer domain is dependent on an interplay between these early expressed transcriptional repressors.