frizzled 9 is expressed in neural precursor cells in the developing neural tube.

The wnt signaling pathway has important functions in nervous system development. To better understand this process we have cloned and analyzed the expression of the wnt receptor, frizzled 9, in the developing nervous system in mouse, chick and zebrafish. The earliest expression of mouse frizzled 9 mRNA expression begins at E8.5 with expression throughout the entire rostral-caudal neuraxis. This early expression pattern within the neural tube appears to be conserved between chick and zebrafish. Expression becomes restricted to a ventral domain in the mouse ventricular zone at E11.5, a region specified to give rise to neurons and glia. Using a polyclonal antibody to MFZ9 further shows expression limited to neural restricted precursors cells.