The objective of our research is to understand the molecular mechanisms that control early vertebrate neural development, focusing on ectoderm specifcation during germ layer formation and the problems of neurogenesis and patterning in the developing spinal cord and cerebral cortex. For this, we use the frog embryo which is an invaluable model to study fundamental cellular and developmental problems due to several factors, including the ability to obtain large amount of eggs and the external development of the embryos. In this system, gene expression patterns in the early embryo can be followed by whole-mount in situ hybridization and the large size of the eggs and embryos readily permit microsurgical manipulations and injections to study gene function by overexpression or misexpression. To gain a fuller understanding of the requirement of the genes of interest in the developing embryo, functional assays in Xenopus are complemented by the generation and analysis of knockout mice. Molecules that are important for frog embryogenesis are also important in mammals, and our research is therefore relevant for understanding normal and abnormal human development.