title: Granule cells migrate within raphes in the developing cerebellum: an evolutionarily conserved morphogenic event.
abstract: The early phase of granule cell migration in the developing chick cerebellum occurs within ribbons of cells moving through parasagittally arrayed gaps between Purkinje cell clusters. These parasagittal arrays of migrating granule cells, termed "granule cell raphes," also have been reported in rabbit and cat, but recent publications variously report that granule cell raphes are absent or present in rodents. By using Nissl counterstaining and Pax6 immunohistochemistry, we confirm that granule cells do migrate in raphes in the developing mouse cerebellum, and also in the primate cerebellum during a period of development that coincides with Purkinje cell compartmentation. In mouse and primate cerebellum, as in chick cerebellum, granule cell migratory streams occur at the borders of Purkinje cell clusters. GFAP immunostaining of Bergmann glial fibers shows no parasagittally localized pattern of distribution, indicating that the formation of granule cell ribbons is not prepatterned by heterogeneous distribution of radial glia. The conservation of the ribboned pattern of granule cell migration from bird to primate and the timing of this event suggest a possible role for granule cell raphes in parasagittal compartmentation of Purkinje cells. A potential mechanism for such an interaction is discussed.
authors.affiliation: Department of Physiology and Biophysics, University of Washington, Seattle, Washington, 98195, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Karam
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Bothwell
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning / Q000502:physiology*; D064026:Calbindins; D002454:Cell Differentiation / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002525:Cerebellar Cortex / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D005136:Eye Proteins; D005260:Female; D005326:Fetal Proteins / Q000378:metabolism; D005333:Fetus; D005904:Glial Fibrillary Acidic Protein; D018398:Homeodomain Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D008254:Macaca nemestrina / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL / Q000196:embryology* / Q000378:metabolism; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D011247:Pregnancy; D011689:Purkinje Cells / Q000166:cytology / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D036122:Receptor, EphA4; D012097:Repressor Proteins; D064030:S100 Calcium Binding Protein G / Q000378:metabolism
chemical_list: D064026:Calbindins; D005136:Eye Proteins; D005326:Fetal Proteins; D005904:Glial Fibrillary Acidic Protein; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D064030:S100 Calcium Binding Protein G; D020794:Receptor Protein-Tyrosine Kinases; D036122:Receptor, EphA4