PDF(Pubmed)
Abstract：
The mechanisms underlying the organization and evolution of the telencephalic pallium are not yet clear.. To address this issue, we first performed comparative analysis of genes critical for the development of the pallium (Emx1/2 and Pax6) and subpallium (Dlx2 and Nkx1/2) among 500 vertebrate species. We found that these genes have no obvious variations in chromosomal duplication/loss, gene locus synteny or Darwinian selection. However, there is an additional fragment of approximately 20 amino acids in mammalian Emx1 and a poly-(Ala)6-7 in Emx2. Lentiviruses expressing mouse or chick Emx2 (m-Emx2 or c-Emx2 Lv) were injected into the ventricle of the chick telencephalon at embryonic Day 3 (E3), and the embryos were allowed to develop to E12-14 or to posthatchling. After transfection with m-Emx2 Lv, the cells expressing Reelin, Vimentin or GABA increased, and neurogenesis of calbindin cells changed towards the mammalian inside-out pattern in the dorsal pallium and mesopallium. In addition, a behavior test for posthatched chicks indicated that the passive avoidance ratio increased significantly. The study suggests that the acquisition of an additional fragment in mammalian Emx2 is associated with the organization and evolution of the mammalian pallium.
摘要：
端脑皮层的组织和演化的潜在机制尚不清楚。.为了解决这个问题，我们首先对500种脊椎动物中的大脑皮层（Emx1/2和Pax6）和亚脑皮层（Dlx2和Nkx1/2）的发育至关重要的基因进行了比较分析。我们发现这些基因在染色体复制/丢失方面没有明显的变异，基因位点合并症或达尔文选择。然而,在哺乳动物Emx1中存在大约20个氨基酸的额外片段,在Emx2中存在聚-(Ala)6-7。在胚胎第3天（E3），将表达小鼠或雏鸡Emx2（m-Emx2或c-Emx2Lv）的慢病毒注射到雏鸡端脑的心室中，并允许胚胎发育到E12-14或后期。用m-Emx2Lv转染后，表达Reelin的细胞，波形蛋白或GABA增加，钙结合蛋白细胞的神经发生在背侧大脑皮层和中皮层中朝着哺乳动物的由内而外的模式变化。此外,对茅草雏鸡的行为测试表明，被动回避比率显着增加。研究表明，在哺乳动物Emx2中获得其他片段与哺乳动物大脑皮层的组织和进化有关。
