9306848 Burd This Career Advancement Award for Women provides partial support for a sabbatical leave. The goal of the study is to examine cell lineage of and differential gene expression in the olfactory placodes of the frog, Xenopus laevis. Cell lineage experiments consist of injecting dyes into cells in the anterior neural plate, and following the migration of injected cells with a SIT camera and time-lapsed video recordings. Likewise, the source of cells in regenerating olfactory placodes will be determined. Two genes (distal-less and empty spiracles) known to be expressed in mouse olfactory placodes will be characterized in Xenopus placodes. The pattern of expression of these genes will be determined with in situ hybridization and Northern blots. This study will determine factors that regulate differentiation and regeneration of the olfactory placodes. Development of a fertilized egg into a multicellular organism is controlled by an array of genes and tissue interactions that determine the fates of particular cell and tissue types. The goal of this study is to examine developmental expression of genes and the formation and regeneration of the peripheral tissue for the sense of smell, the olfactory epithelium, in the frog. Fluorescent dyes will be injected into cells that are thought to form or reform the olfactory placode, the precursor tissue to the olfactory epithelium. The long-term goal of this study is to determine the molecular and cellular factors that regulate development and regeneration in the developing nervous system, using the peripheral olfactory system as a model. ***
