1. Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Centre for Neurobiology and Behavior, and
2. Department of Genetics and Development, Columbia University, New York, New York 10032, USA

Correspondence to: Thomas M. Jessell¹ Correspondence and requests for materials should be addressed to T. M. J. (e-mail: Email: tmj1@columbia.edu).

Abstract

During neural development in vertebrates, a spatially ordered array of neurons is generated in response to inductive signals derived from localized organizing centres. One organizing centre that has been proposed to have a role in the control of neural patterning is the roof plate. To define the contribution of signals derived from the roof plate to the specification of neuronal cell types in the dorsal neural tube, we devised a genetic strategy to ablate the roof plate selectively in mouse embryos. Embryos without a roof plate lack all the interneuron subtypes that are normally generated in the dorsal third of the neural tube. Using a genetically based lineage analysis and in vitro assays, we show that the loss of these neurons results from the elimination of non-autonomous signals provided by the roof plate. These results reveal that the roof plate is essential for specifying multiple classes of neurons in the mammalian central nervous system.

1. Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Centre for Neurobiology and Behavior, and
2. Department of Genetics and Development, Columbia University, New York, New York 10032, USA

Correspondence to: Thomas M. Jessell¹ Correspondence and requests for materials should be addressed to T. M. J. (e-mail: Email: tmj1@columbia.edu).