The monolayer formation of Bergmann glial cells is regulated by Notch/RBP-J signaling

• DOI: 10.1016/j.ydbio.2007.08.042
• Publication Date: 2007-09-04T12:42:51Z
• Authors: Okiru Komine; Mai Nagaoka; Kei Watase; David H. Gutmann; Kenji Tanigaki; Tasuku Honjo; Freddy Radtke; Toshiki Saito; Shigeru Chiba; Kohichi Tanaka
• Keywords: Mice, Knockout; 0301 basic medicine; Notch; Bergmann glia; RBP-J; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Mice, Transgenic; Cell Biology; Conditional knockout mouse; Monolayer formation; Mice; 03 medical and health sciences; Astrocytes; Cerebellum; Immunoglobulin J Recombination Signal Sequence-Binding Protein; Animals; Receptor, Notch2; Receptor, Notch1; Molecular Biology; Gene Deletion; Developmental Biology; Signal Transduction

The Bergmann glia is a unipolar astrocyte in the cerebellar cortex, displaying a tight association with Purkinje cells. The cell bodies of Bergmann glia are located in a row around Purkinje cell somata; they extend radially arranged Bergmann fibers which enwrap the synapses on the Purkinje cell dendrites. It is well known that Bergmann glial somata migrate from the ventricular zone through the mantle zone, forming an epithelium-like lining in the Purkinje cell layer during development. However, the mechanism of the monolayer formation of Bergmann glia is poorly understood. Several reports have suggested that Notch signaling plays instructive roles in promoting the identities of several types of glial cells, including Bergmann glia. Moreover, Notch receptors are expressed in Bergmann glia during development. Here, we have deleted the Notch1, Notch2 and RBP-J genes in the Bergmann glia by GFAP-driven, Cre-mediated recombination, to study the role of Notch-RBP-J-signaling in the monolayer formation of Bergmann glia. Notch1/2- and RBP-J-conditional mutant mice showed disorganization of Bergmann fibers, irregularities of the Bergmann glial lining and aberrant localization of Bergmann glia in the molecular layer. Thus, Notch-RBP-J signaling plays crucial roles in the monolayer formation and morphogenesis of Bergmann glia.