Golden J A, Cepko C L
Department of Genetics, Harvard Medical School, Boston, MA, USA.
Development. 1996 Jan;122(1):65-78. doi: 10.1242/dev.122.1.65.
The thalamus, hypothalamus and epithalamus of the vertebrate central nervous system are derived from the embryonic diencephalon. These regions of the nervous system function as major relays between the telencephalon and more caudal regions of the brain. Early in development, the diencephalon morphologically comprises distinct units known as neuromeres or prosomeres. As development proceeds, multiple nuclei, the functional and anatomical units of the diencephalon, derive from the neuromeres. It was of interest to determine whether progenitors in the diencephalon give rise to daughters that cross nuclear or neuromeric boundaries. To this end, a highly complex retroviral library was used to infect diencephalic progenitors. Retrovirally marked clones were found to contain neurons, glia and occasionally radial glia. The majority of clones dispersed in all directions, resulting in sibling cells populating multiple nuclei within the diencephalon. In addition, several distinctive patterns of dispersion were observed. These included clones with siblings distributed bilaterally across the third ventricle, clones that originated in the lateral ventricle, clones that crossed neuromeric boundaries, and clones that crossed major boundaries of the developing nervous system, such as the diencephalon and mesencephalon. These findings demonstrate that progenitor cells in the diencephalon are multipotent and that their daughters can become widely dispersed.
脊椎动物中枢神经系统的丘脑、下丘脑和上丘脑源自胚胎期的间脑。神经系统的这些区域在端脑和脑的更靠尾端区域之间起到主要中继作用。在发育早期，间脑在形态上由称为神经节或原节的不同单元组成。随着发育的进行，间脑的多个核团（间脑的功能和解剖单元）源自神经节。确定间脑的祖细胞是否产生跨越核或神经节边界的子代细胞很有意思。为此，使用了一个高度复杂的逆转录病毒文库来感染间脑祖细胞。发现逆转录病毒标记的克隆包含神经元、神经胶质细胞，偶尔还有放射状胶质细胞。大多数克隆向各个方向分散，导致同胞细胞分布在间脑内的多个核团中。此外，还观察到几种独特的分散模式。这些包括同胞细胞双侧分布在第三脑室两侧的克隆、起源于侧脑室的克隆、跨越神经节边界的克隆以及跨越发育中神经系统主要边界（如间脑和中脑）的克隆。这些发现表明，间脑的祖细胞是多能的，并且它们的子代细胞可以广泛分散。
