Orentas D M, Miller R H
Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, 44106-4975, USA.
Dev Biol. 1996 Jul 10;177(1):43-53. doi: 10.1006/dbio.1996.0143.
During spinal cord development, oligodendrocytes originate in a discrete region of the ventral ventricular zone. What regulates this initial localization of oligodendrocyte precursors is unclear. Using a combination of notochord transplantations in vivo and co-culture experiments, we demonstrate that the origin of chick spinal cord oligodendrocytes is dependent on local influences from the notochord. In stage 10-12 dorsal chick spinal cord, Mab O4+ oligodendrocyte precursors were induced both in vivo by isochronic transplantation of an additional notochord adjacent to the dorsal neural tube and in vitro by co-culture of notochord and dorsal neural tube. Heterochronic transplantations demonstrated that the notochord was capable of inducing O4+ cells in adjacent neural tube until stage 12 and that the competence of the dorsal neural tube to respond to this inductive signal declined after stage 10. During normal development the ventral neural tube is competent to develop oligodendrocytes independent of the notochord by stage 10. The induction of oligodendrocytes by the notochord may either reflect a direct interaction or be mediated through other ventrally located cells such as the floor plate. In the majority of experimental animals the appearance of ectopic oligodendrocyte precursors was correlated with local floor plate formation.
在脊髓发育过程中，少突胶质细胞起源于腹侧脑室区的一个离散区域。目前尚不清楚是什么调节了少突胶质细胞前体的这种初始定位。通过体内脊索移植和共培养实验相结合的方法，我们证明了鸡脊髓少突胶质细胞的起源依赖于脊索的局部影响。在第10 - 12阶段的鸡背侧脊髓中，Mab O4 +少突胶质细胞前体在体内通过将额外的脊索等时移植到背侧神经管附近而被诱导，在体外通过脊索与背侧神经管的共培养而被诱导。异时移植表明，脊索能够在第12阶段之前诱导相邻神经管中的O4 +细胞，并且背侧神经管对这种诱导信号的反应能力在第10阶段之后下降。在正常发育过程中，到第10阶段时腹侧神经管能够独立于脊索发育少突胶质细胞。脊索对少突胶质细胞的诱导可能反映了直接相互作用，或者是通过其他位于腹侧的细胞（如底板）介导的。在大多数实验动物中，异位少突胶质细胞前体的出现与局部底板形成相关。
