Lunatic Fringe ( l-Fng) is one of the vertebrate homologues of Drosophila Fringe, which interacts with the Notch signal pathway and regulates activation of the Notch ligands, Delta and Serrate. To elucidate the roles of l-Fng in vertebrate neurogenesis, we transfected chick l-Fng (C- l-Fng) to chick neural tube using the in ovo electroporation technique and examined the subsequent changes in expression of Notch-related genes. We observed downregulation of C- Serrate-1 by ectopic C- l-Fng expression which implied that C- l-Fng acts on the vertebrate Notch pathway to regulate the expression of its ligand.