Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK; Achucarro Basque Center for Neuroscience, Parque Científico UPV/EHU Edif. Sede, 48940 Leioa, Spain; IKERBASQUE Foundation, María Díaz de Haro 3, 6th Floor, 48013 Bilbao, Spain.
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
Cell Rep. 2018 Jan 2;22(1):96-109. doi: 10.1016/j.celrep.2017.12.032.
Several neuronal populations orchestrate neocortical development during mammalian embryogenesis. These include the glutamatergic subplate-, Cajal-Retzius-, and ventral pallium-derived populations, which coordinate cortical wiring, migration, and proliferation, respectively. These transient populations are primarily derived from other non-cortical pallial sources that migrate to the dorsal pallium. Are these migrations to the dorsal pallium conserved in amniotes or are they specific to mammals? Using in ovo electroporation, we traced the entire lineage of defined chick telencephalic progenitors. We found that several pallial sources that produce tangential migratory neurons in mammals only produced radially migrating neurons in the avian brain. Moreover, ectopic expression of VP-specific mammalian Dbx1 in avian brains altered neurogenesis but did not convert the migration into a mammal-like tangential movement. Together, these data indicate that tangential cellular contributions of glutamatergic neurons originate from outside the dorsal pallium and that pallial Dbx1 expression may underlie the generation of the mammalian neocortex during evolution.
在哺乳动物胚胎发生过程中，有几个神经元群体协调新皮层的发育。这些群体包括谷氨酸能基板、Cajal-Retzius 和腹侧苍白球衍生的群体，它们分别协调皮质布线、迁移和增殖。这些短暂的群体主要来自其他非皮质皮质来源，迁移到背侧皮质。这些向背侧皮质的迁移在羊膜动物中是否保守，还是仅存在于哺乳动物中？通过在鸡胚中进行电穿孔，我们追踪了已定义的鸡端脑祖细胞的整个谱系。我们发现，在哺乳动物中产生切线迁移神经元的几个皮质来源仅在鸟类大脑中产生放射状迁移神经元。此外，在鸟类大脑中异位表达 VP 特异性哺乳动物 Dbx1 改变了神经发生，但并未将迁移转化为类似哺乳动物的切线运动。总之，这些数据表明，谷氨酸能神经元的切线细胞贡献来自背侧皮质之外，并且皮质 Dbx1 表达可能是哺乳动物新皮层在进化过程中产生的基础。
