Sun T, Pringle N P, Hardy A P, Richardson W D, Smith H K
Department of Biology, University College London, Gower Street, London, WC1E 6BT.
Mol Cell Neurosci. 1998 Nov;12(4-5):228-39. doi: 10.1006/mcne.1998.0711.
Neuroepithelial precursors in the ventral ventricular zone (VZ) of the spinal cord generate motor neurons (MNs) and interneurons, and then a subset of precursors starts to produce oligodendrocyte progenitors (OLPs). We show that OLPs originate in the ventral-most part of the Pax6-positive VZ, which at earlier times generates somatic (Isl2/Lim3-positive) MNs. In Small eye (Pax6-deficient) mice, the origin of OLPs is shifted dorsally and both OLPs and Isl2/Lim3 MNs are delayed. We suggest that somatic MNs and OLPs are generated sequentially from a common set of MN-OL precursors whose position in the VZ is influenced by Pax6. Neuron-glia fate switching might be a preprogrammed property of these precursors or a response to feedback from newly generated neurons. OLs developed normally in explants of Isl1(-/-) spinal cords, which lack MNs, arguing against feedback control and suggesting that the neuron-glia switch is an intrinsic developmental program in a specific subset of neural precursors.
脊髓腹侧脑室区（VZ）的神经上皮前体细胞可生成运动神经元（MNs）和中间神经元，随后一部分前体细胞开始产生少突胶质细胞前体细胞（OLPs）。我们发现，OLPs起源于Pax6阳性VZ的最腹侧部分，该部分在早期产生躯体（Isl2/Lim3阳性）MNs。在小眼（Pax6缺陷）小鼠中，OLPs的起源向背侧偏移，且OLPs和Isl2/Lim3 MNs均出现延迟。我们认为，躯体MNs和OLPs是由一组共同的MN-OL前体细胞依次产生的，这些前体细胞在VZ中的位置受Pax6影响。神经元-胶质细胞命运转换可能是这些前体细胞的预编程特性，或是对新生成神经元反馈的一种反应。OLs在缺乏MNs的Isl1（-/-）脊髓外植体中正常发育，这与反馈控制相悖，并表明神经元-胶质细胞转换是特定神经前体细胞亚群的内在发育程序。
