Characterization of avian frizzled genes in cranial placode development

Mech Dev. 2000 May;93(1-2):195-200. doi: 10.1016/s0925-4773(00)00263-x.


To determine the possible role of Wnt signaling in cranial placode development, we have cloned several chick frizzled genes, a family of putative Wnt receptor molecules, and analyzed their expression during chick embryogenesis. Chick frizzled-2 (cFz-2) and frizzled-7 (cFz-7) are expressed broadly in cranial ectoderm, tissue that is competent to express markers of the trigeminal placode (Stark et al., 1997. Development 124, 4287-4295; Baker et al., 1999. Development 126, 147-156). In addition, cFz-2 and cFz-7 are uniquely expressed in other cranial placodes, including the olfactory, lens, and otic placodes. Chick frizzled-1 (cFz-1) is expressed in the lens, otic placode and, along with cFz-7, in epibranchial placodes. Each frizzled gene expressed in the otic placode displays a unique domain of expression: cFz-1 transcripts are detected in the medial wall of the vesicle, cFz-2 in the rostral rim of the vesicle, and cFz-7 in the lateral half of the vesicle. Other chick frizzled family members cloned that do not show striking expression in cranial placodes include frizzled-4 (cFz-4), frizzled-8 (cFz-8), frizzled-9 (cFz-9), and frizzled-10 (cFz-10). A brief summary of their expression is given, along with a brief summary of non-placodal expression of cFz-1, cFz-2, and cFz-7. In all, frizzled genes show dynamic expression at key times during embryonic development, particularly in the cranial placodes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Chick Embryo
  • DNA, Complementary
  • Frizzled Receptors
  • Molecular Sequence Data
  • Receptors, Cell Surface / genetics*
  • Receptors, G-Protein-Coupled*
  • Receptors, Neurotransmitter / genetics*
  • Skull / embryology*


  • DNA, Complementary
  • FZD1 protein, human
  • FZD2 protein, human
  • Frizzled Receptors
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Neurotransmitter

Associated data

  • GENBANK/AF023806
  • GENBANK/AF031830
  • GENBANK/AF031831