Expression of Frzb-1 during chick development

We cloned the chick homolog of Xenopus and mouse Frzb-1, a secreted Wnt ant agonist and performed in situ hybridisations to determine the pattern of cF rzb-1 expression in the developing chick embryo. At early stages, cFrzb-1 t ranscripts are located exclusively in the ectodermal layer corresponding to the neural plate. The labelling continues in the neural tube, but is alway s excluded from the floor plate, cFrzb-1 mRNA is expressed by migrating cep halic and truncal neural crest cells. Later, cFrzb-1 transcripts are found in a subset of neural crest derivatives such as cephalic cartilage, nerves and spinal ganglia. In addition to ectodermal derivatives, cFrzb-1 transcri pts were also observed in mesodermal derivatives such as vertebral and limb cartilage, the adrenal cortex, the gonads, and a subpopulation of blood ce lls. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.