Section on Neural Developmental Dynamics
Ajay Chitnis, Section Head
Our goal is to understand mechanisms by which the spatial distribution of early neurons is determined in the spinal cord. In Xenopus and zebrafish embryos, the distribution of these neurons is relatively simple; at the early neural plate stage, they are found in a salt-and-pepper pattern in three longitudinal domains on either side of the midline. Previously, we showed that lateral inhibition mediated by vertebrate homologs of Drosophila neurogenic genes helps to select cells that become neurons within these longitudinal domains in the neural plate. We are continuing to explore the role of neurogenic genes in determining the pattern of neurons by analyzing a zebrafish mutant, mindbomb, which is characterized by an overproduction of neurons within the longitudinal domains. Furthermore, to identify genes that determine how these domains are established, we have identified zebrafish mutants that lack neurons in specific longitudinal domains, as well as mutants with neurons in ectopic domains. Our laboratory is now using a combination of cellular, molecular, and genetic approaches to characterize these mutants.