Characterization of two frizzled8 homologues expressed in the embryonic shield and prechordal plate of zebrafish embryos

Kim, S.-H., Park, H.-C., Yeo, S.-Y., Hong, S.-K., Choi, J.W., Kim, C.-H., Weinstein, B.M., and Huh, T.-L.
Mechanisms of Development   78: 193-201 (Journal)
Registered Authors
Hong, Sung-Kook, Huh, Tae-Lin, Kim, Cheol-Hee, Kim, Seok-Hyung, Park, Hae-Chul, Weinstein, Brant M., Yeo, Sang-Yeob
zebrafish; Frizzled (fz); wnt; shield; hypoblast; axial mesoderm; polster; prechordal plate; neurectoderm; goosecoid (gsc); pronephric duct; pax2; one-eyed-pinhead (oep)
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • DNA, Complementary/genetics
  • Drosophila melanogaster/genetics
  • Embryo, Nonmammalian/metabolism
  • Embryo, Nonmammalian/ultrastructure
  • Gene Expression Regulation, Developmental*
  • Genes*
  • Humans
  • In Situ Hybridization
  • Molecular Sequence Data
  • Morphogenesis/genetics
  • Protein Isoforms/biosynthesis
  • Protein Isoforms/genetics*
  • Receptors, Cell Surface/biosynthesis
  • Receptors, Cell Surface/genetics*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription, Genetic
  • Xenopus Proteins*
  • Zebrafish/embryology
  • Zebrafish/genetics*
9858730 Full text @ Mech. Dev.
We have isolated and characterized two complete cDNA clones, Zfz8a and Zfz8b, which encode zebrafish Frizzled (Fz) homologues. The predicted protein sequences, spanning 579 and 576 amino acid residues for ZFz8a and ZFz8b, respectively, were highly homologous (78%) to each other and contained an extracellular cysteine-rich domain and seven transmembrane domains that are well conserved in Fz receptor protein members. In comparison with other Fz family members, ZFz8a and ZFz8b showed the highest homology with mouse Fz8 (MFz8), sharing 84 and 76% amino acid identity, respectively. The presence of Zfz8a and Zfz8b transcripts was detected by in situ hybridization in zebrafish embryos from the 512 cell stage, and their appearance in the future dorsal region could be observed before embryos reached the 30% epiboly stage. At shield stage, Zfz8a transcripts were expressed in both epiblast and shield whereas expression of Zfz8b was only detected in the embryonic shield. During gastrula stages, both Zfz8a and Zfz8b transcripts were found in anterior dorsal regions of the involuting mesendoderm (future prechordal plate). By the 2- to 3-somite stage, expression of both Zfz8a and Zfz8b was restricted to the prechordal plate and prospective anterior neurectoderm, although expression of the Zfz8a gene was no longer present in the most anterior portion of the prechordal plate, the polster. In one-eyed pinhead mutant embryos, which lack prechordal plate, both Zfz8a and Zfz8b transcripts were reduced, confirming the prechordal plate specificity of Zfz8a and Zfz8b gene expression. These results provide an additional evidence supporting the role of Wnt signaling in organizer-mediated axial patterning.
Genes / Markers
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes