Yun K, Potter S, Rubenstein J L
Nina Ireland Laboratory of Developmental Neurobiology, Department of Psychiatry, LPPI, University of California, San Francisco, Box 0984, San Francisco, CA 94143-0984, USA.
Development. 2001 Jan;128(2):193-205. doi: 10.1242/dev.128.2.193.
The telencephalon has two major subdivisions, the pallium and subpallium. The pallium, which primarily consists of glutamatergic cortical structures, expresses dorsal molecular markers, whereas the subpallium, which primarily consists of the GABAergic basal ganglia, expresses ventral molecular markers. Here, we present evidence that the progenitor and postmitotic cells flanking the pallial/subpallial boundary (PSB) in the embryonic mouse can be subdivided into multiple regions that express unique combinations of transcription factors. The domains that immediately flank the PSB are the ventral pallium (VP) and the dorsal lateral ganglionic eminence (dLGE). The early expression of the Pax6 and Gsh2 homeobox transcription factors overlaps in the region of the dLGE. Analyses of mice that lack functional alleles of either Gsh2 or Pax6 demonstrate that these genes have complementary roles in patterning the primordia flanking the PSB. In the Gsh2 mutants, the dLGE is respecified into a VP-like structure, whereas in the Pax6 mutants the VP is respecified into a dLGE-like structure. The role of Pax6 in dorsalizing the telencephalon is similar to its role in the spinal cord, supporting the hypothesis that some dorsoventral patterning mechanisms are used at all axial levels of the central nervous system.
端脑有两个主要亚区，即大脑皮质和皮质下结构。大脑皮质主要由谷氨酸能皮质结构组成，表达背侧分子标记，而皮质下结构主要由γ-氨基丁酸能基底神经节组成，表达腹侧分子标记。在此，我们提供证据表明，胚胎小鼠中位于大脑皮质/皮质下边界（PSB）两侧的祖细胞和有丝分裂后细胞可细分为多个区域，这些区域表达独特的转录因子组合。紧邻PSB的区域是腹侧大脑皮质（VP）和背外侧神经节隆起（dLGE）。Pax6和Gsh2同源框转录因子在dLGE区域的早期表达重叠。对缺乏Gsh2或Pax6功能等位基因的小鼠的分析表明，这些基因在PSB两侧原基的模式形成中具有互补作用。在Gsh2突变体中，dLGE被重新指定为类似VP的结构，而在Pax6突变体中，VP被重新指定为类似dLGE 的结构。Pax6在使端脑背侧化方面的作用与其在脊髓中的作用相似，这支持了在中枢神经系统所有轴向上都使用一些背腹模式形成机制的假说。
