Morphogenetic and cellular movements that shape the mouse cerebellum; insights from genetic fate mapping.
We used the cerebellum as a model to study the morphogenetic and cellular processes underlying the formation of elaborate brain structures from a simple neural tube, using an inducible genetic fate mapping approach in mouse. We demonstrate how a 90 degrees rotation between embryonic days 9 and 12 converts the rostral-caudal axis of dorsal rhombomere 1 into the medial-lateral axis of the wing-like bilateral cerebellar primordium. With the appropriate use of promoters, we marked specific medial-lateral domains of the cerebellar primordium and derived a positional fate map of the murine cerebellum. We show that the adult medial cerebellum is produced by expansion, rather than fusion, of the thin medial primordium. Furthermore, ventricular-derived cells maintain their original medial-lateral coordinates into the adult, whereas rhombic lip-derived granule cells undergo lateral to medial posterior transverse migrations during foliation. Thus, we show that progressive changes in the axes of the cerebellum underlie its genesis.
Pubmed ID: 15629700 RIS Download
Animals | Body Patterning | Cell Differentiation | Cell Lineage | Cell Movement | Cerebellum | Chimera | Female | Gene Expression Regulation, Developmental | Genetic Markers | Homeodomain Proteins | Integrases | Male | Mice | Mice, Inbred C57BL | Mice, Transgenic | Morphogenesis | Nerve Tissue Proteins | Neurons | Promoter Regions, Genetic | Stem Cells