title: Delta-like 1 regulates Bergmann glial monolayer formation during cerebellar development.
abstract: BACKGROUND
  Bergmann glia (BG) are unipolar cerebellar astrocytes. The somata of mature BG reside in the Purkinje cell layer and extend radially arranged processes to the pial surface. BG have multiple branched processes, which enwrap the synapses of Purkinje cell dendrites. They migrate from the ventricular zone and align next to the Purkinje cell layer during development. Previously, we reported that Notch1, Notch2, and RBPj genes in the BG play crucial roles in the monolayer formation and morphogenesis of BG. However, it remains to be determined which ligand activates Nocth1 and Notch 2 on BG. Delta-like 1 (Dll1) is a major ligand of Notch receptors that is expressed in the developing cerebellum.
  
  
  RESULTS
  In this study, we used human glial fibrillary acidic protein (hGFAP) promoter-driven Cre-mediated recombination to delete Dll1 in BG. Dll1-conditional mutant mice showed disorganization of Bergmann fibers, ectopic localization of BG in the molecular layer and a reduction in the number of BG.
  
  
  CONCLUSIONS
  These results suggest that Dll1 is required for the formation of the BG layer and its morphological maturation, apparently through a Notch1/2-RBPj dependent signaling pathway.
authors.affiliation: Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hiraoka
authors.forename: Okiru
authors.initials: O
authors.lastname: Komine
authors.forename: Mai
authors.initials: M
authors.lastname: Nagaoka
authors.forename: Ning
authors.initials: N
authors.lastname: Bai
authors.forename: Katsuto
authors.initials: K
authors.lastname: Hozumi
authors.forename: Kohichi
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D002135:Calcium-Binding Proteins; D002452:Cell Count; D002454:Cell Differentiation; D002531:Cerebellum / Q000002:abnormalities / Q000254:growth & development* / Q000378:metabolism*; D017353:Gene Deletion; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein / Q000378:metabolism; D019426:Integrases / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D051379:Mice; D009457:Neuroglia / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D011689:Purkinje Cells / Q000378:metabolism / Q000473:pathology; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D002135:Calcium-Binding Proteins; C512925:Dlk1 protein, mouse; D005904:Glial Fibrillary Acidic Protein; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D036341:Intercellular Signaling Peptides and Proteins; C497571:Rbpj protein, mouse; D051880:Receptors, Notch; C045073:Cre recombinase; D019426:Integrases