CEPU-1 expression in the early embryonic chick brain.

We describe the expression pattern of CEPU-1, a cell adhesion molecule of the immunoglobulin superfamily, in the early chick embryo brain. An initially broad domain of expression, encompassing forebrain, midbrain and anterior hindbrain, is subsequently narrowed down to a ring-shaped domain at the midbrain-hindbrain boundary, co-localizing precisely with the expression of Wnt1 at the isthmus. In addition, CEPU-1 is expressed in the dorsal aspect of rhombomere 4 and its emigrating neural crest cells. Later in development, we also find CEPU-1 expression in other parts of the developing nervous system such as sensory ganglia and in the ventral aspect of forebrain, midbrain and hindbrain.