Generation of Oligodendrocyte Precursor Cells from Mouse Dorsal Spinal Cord Independent of Nkx6 Regulation and Shh Signaling

• Published in: Neuron (Cambridge, Mass.) Mass.), 2005-01, Vol.45 (1), p.41-53
• Main Authors: Cai, Jun, Qi, Yingchuan, Hu, Xuemei, Tan, Min, Liu, Zijing, Zhang, Jianshe, Li, Qun, Sander, Maike, Qiu, Mengsheng
• Format: Article
• Language: English
• Subjects: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation - physiology; DNA-Binding Proteins - metabolism; Epithelial Cells - cytology; Epithelial Cells - metabolism; Gene expression; Gene Expression Regulation, Developmental - genetics; Hedgehog Proteins; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Immunohistochemistry; Mice; Mice, Knockout; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neurogenesis; Neurons; Oligodendrocyte Transcription Factor 2; Oligodendroglia - cytology; Oligodendroglia - metabolism; PAX7 Transcription Factor; Receptors, G-Protein-Coupled - genetics; Rodents; Signal Transduction - genetics; Smoothened Receptor; Spinal cord; Spinal Cord - cytology; Spinal Cord - embryology; Spinal Cord - metabolism; Stem cells; Stem Cells - cytology; Stem Cells - metabolism; Trans-Activators - genetics; Transcription factors; Transcription Factors - metabolism
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2004.12.028

In the developing spinal cord, early progenitor cells of the oligodendrocyte lineage are induced in the motor neuron progenitor (pMN) domain of the ventral neuroepithelium by the ventral midline signal Sonic hedgehog ( Shh). The ventral generation of oligodendrocytes requires Nkx6-regulated expression of the bHLH gene Olig2 in this domain. In the absence of Nkx6 genes or Shh signaling, the initial expression of Olig2 in the pMN domain is completely abolished. In this study, we provide the in vivo evidence for a late phase of Olig gene expression independent of Nkx6 and Shh gene activities and reveal a brief second wave of oligodendrogenesis in the dorsal spinal cord. In addition, we provide genetic evidence that oligodendrogenesis can occur in the absence of hedgehog receptor Smoothened, which is essential for all hedgehog signaling.