PUBLICATION

dlx3b/4b are required for the formation of the preplacodal region and otic placode through local modulation of BMP activity

Authors
Esterberg, R., and Fritz, A.
ID
ZDB-PUB-081121-2
Date
2009
Source
Developmental Biology   325(1): 189-199 (Journal)
Registered Authors
Fritz, Andreas
Keywords
dlx3b/4b, cv2, Bmp, Fgf, preplacodal region, otic placode
MeSH Terms
  • Animals
  • Biomarkers/metabolism
  • Body Patterning
  • Bone Morphogenetic Proteins/antagonists & inhibitors
  • Bone Morphogenetic Proteins/metabolism*
  • Branchial Region/cytology
  • Branchial Region/metabolism
  • Ear, Inner/embryology*
  • Ear, Inner/metabolism
  • Embryo, Nonmammalian/cytology
  • Embryo, Nonmammalian/metabolism
  • Fibroblast Growth Factors/metabolism
  • Gene Expression Regulation, Developmental
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism*
  • Phenotype
  • Receptors, Fibroblast Growth Factor/metabolism
  • Signal Transduction
  • Somites/metabolism
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
19007769 Full text @ Dev. Biol.
Abstract
The vertebrate inner ear arises from the otic placode, a transient thickening of ectodermal epithelium adjacent to neural crest domains in the presumptive head. During late gastrulation, cells fated to comprise the inner ear are part of a domain in cranial ectoderm that contain precursors of all sensory placodes, termed the preplacodal region (PPR). The combination of low levels of BMP activity coupled with high levels of FGF signaling are required to establish the PPR through induction of members of the six/eya/dach, iro, and dlx families of transcription factors. The zebrafish dlx3b/4b transcription factors are expressed at the neural plate border where they play partially redundant roles in the specification of the PPR, otic and olfactory placodes. We demonstrate that dlx3b/4b assist in establishing the PPR through the transcriptional regulation of the BMP antagonist cv2. Morpholino-mediated knockdown of Dlx3b/4b results in loss of cv2 expression in the PPR and a transient increase in Bmp4 activity that lasts throughout early somitogenesis. Through the cv2-mediated inhibition of BMP activity, dlx3b/4b create an environment where FGF activity is favorable for PPR and otic marker expression. Our results provide insight into the mechanisms of PPR specification as well as the role of dlx3b/4b function in PPR and otic placode induction.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping