The developing vertebrate hindbrain is subdivided into functional segments called neuromeres. Cells can mix within but not between neuromeres –so-called lineage restriction – a process discovered in Drosophila wing development. Langenberg and Brand now reveal that brain segmentation extends at least as far as the midbrain-hindbrain boundary(mhb) region in zebrafish (see ). The researchers used continuous single cell analysis in a GFP transgenic zebrafish line to trace the movement of nuclei in the developing mhb region and analyzed the final position of each nucleus with an antibody against Otx, a midbrain marker. Their results identify a lineage restriction boundary in the mhb region that is probably established during late gastrulation. Lineage restriction between these regions may serve to constrain the mhb organizer cell population during brain development, conclude the researchers. Such a link has been well studied in flies but poorly characterized in vertebrate brain development.
