The Future Vocation of Neural Stem Cells: Lineage Commitment in Brain Development and Evolution

Understanding the fate commitment of neural stem cells is critical to identify the regulatory mechanisms in developing brains. Genetic lineage-tracing has provided a powerful strategy to unveil the heterogeneous nature of stem cells and their descendants. However, recent studies have reported controversial data regarding the heterogeneity of neural stem cells in the developing mouse neocortex, which prevents a decisive conclusion on this issue. Here, we review the progress that has been made using lineage-tracing analyses of the developing neocortex and discuss stem cell heterogeneity from the viewpoint of comparative and evolutionary biology.