PUBLICATION

Genetic interactions underlying otic placode induction and formation

Authors
Solomon, K.S., Kwak, S.J., and Fritz, A.
ID
ZDB-PUB-040611-5
Date
2004
Source
Developmental Dynamics : an official publication of the American Association of Anatomists   230(3): 419-433 (Journal)
Registered Authors
Fritz, Andreas, Kwak, Su-Jin, Solomon, Keely
Keywords
dlx3b, dlx4b, foxi1, fgf3, fgf8, zebrafish, otic placode
MeSH Terms
  • Animals
  • Ear/embryology*
  • Embryo, Nonmammalian
  • Embryonic Induction*/drug effects
  • Epistasis, Genetic
  • Gene Expression Regulation, Developmental*
  • Models, Biological
  • Oligodeoxyribonucleotides, Antisense/pharmacology
  • Signal Transduction
  • Zebrafish/embryology*
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism*
PubMed
15188428 Full text @ Dev. Dyn.
Abstract
The formation of the otic placode is a complex process requiring multiple inductive signals. In zebrafish, fgf3 and fgf8, dlx3b and dlx4b, and foxi1 have been identified as the earliest-acting genes in this process. fgf3 and fgf8 are required as inductive signals, whereas dlx3b, dlx4b, and foxi1 appear to act directly within otic primordia. We have investigated potential interactions among these genes. Depletion of either dlx3b and dlx4b or foxi1 leads to a delay of pax2a expression in the otic primordia and reduction of the otic vesicle. Depletion of both foxi1 and dlx3b results in a complete ablation of otic placode formation. A strong synergistic interaction is also observed among foxi1, fgf3, and fgf8, and a weaker interaction among dlx3b, fgf3, and fgf8. Misexpression of foxi1 can induce expression of pax8, an early marker for the otic primordia, in embryos treated with an inhibitor of fibroblast growth factor (FGF) signaling. Conversely, morpholino knockdown of foxi1 blocks ectopic pax8 expression and otic vesicle formation induced by misexpression of fgf3 and/or fgf8. The observed genetic interactions suggest a model in which foxi1 and dlx3b/dlx4b act in independent pathways together with distinct phases of FGF signaling to promote otic placode induction and development. Developmental Dynamics 230:419-433, 2004. Copyright 2004 Wiley-Liss, Inc.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping