SPATIALLY LOCALIZED NEURONAL CELL LINEAGES IN THE DEVELOPING MAMMALIAN FOREBRAIN

The role of cell lineage in the organization of the cerebral cortex an d striatum of the developing rat forebrain was analysed using retrovir al-mediated gene transfer to mark the progeny of individual progenitor s. Injections around the onset of neurogenesis (embryonic day 14) prod uced neuronal- and glial-specific clones in the striatum and cortex. T he majority of the neuronal clones were restricted to either the deep or superficial layers of the cortex and to either the striatal patch o r matrix compartments of the striatum. Moreover, modeling the distribu tions of the neuronal clones in various ways revealed that grouping th e clones into deep vs superficial cortical compartments and patch vs m atrix striatal compartments best accounted for the clone distributions . These results suggest that at the onset of neurogenesis there is a h eterogeneity of neuronal progenitors within the proliferative ventricu lar zone.