Postnatal subventricular zone of the neocortex contributes GFAP+ cells to the rostral migratory stream under the control of Sip1.
Developmental Biology(2012)
摘要
The rostral migratory stream (RMS) is composed of neuroblasts migrating from the striatal SVZ to the olfactory bulb through a meshwork of GFAP- expressing astrocytes called the glial tube. So far, the origin of the glial tube astrocytes was attributed to differentiation of Type-B stem cells of the striatal SVZ. The true identity of these cells (Type-B stem cells versus immature/mature astrocytes) is also unclear. By analyzing a neocortex-specific conditional knockout of the transcriptional repressor Sip1 (Smad-interacting protein 1), we have now identified a novel pool of progenitors located within the dorsal SVZ (dSVZ) at early postnatal stages that differentiate into GFAP+ cells of the glial tube. We show that Sip1, expressed in postmitotic cortical neurons, controls the size of this dorsal progenitor pool possibly through cell-extrinsic mechanisms. Lack of Sip1 in the neocortex causes an expansion of this population leading to an increased production of GFAP+ astrocytes/Type-B stem cells in the glial tube, and a denser intercalation of these cells with Dcx+ neuroblasts of the RMS, the consequence of which is not yet clear. Neocortex-specific Sip1 deletion also led to an expansion of Dcx+ and Tbr2+ progenitor populations in the dSVZ. We show that the dSVZ progenitors (possibly remnants of embryonic radial glia) differentiate exclusively into BLBP+ cells which migrate into the RMS and mature into GFAP+ astrocytes/Type-B stem cells at around two weeks of postnatal development. In summary, our work shows that Sip1 controls the generation of GFAP+ cells of the RMS by regulating the size of a novel progenitor pool located in the postnatal dSVZ.
更多查看译文
关键词
Dorsal SVZ,GFAP,Neocortex,Rostral migratory stream,Smad-interacting protein 1
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要