Origin and Evolution of Neural Crest Cells in Chordates

1.神经脊是脊椎动物胚胎特有的组织。神经脊细胞出现在神经管的背侧，迁移到身体的不同区域，并分化为各种细胞。因此，神经脊参与形成脊椎动物的身体组织。首先，用一种标记迁移神经脊细胞的单抗HNK-1，研究了七鳃鳗神经冠细胞在最原始脊椎动物体内的迁移和定植模式。(1)在七鳃鳗胚胎的躯干中，神经脊细胞以三种途径迁移：表皮与体节之间的背外侧路径，体节与神经管之间的腹侧路径，以及向背鳍雏形的背侧路径。在腹侧通路中，这些细胞不会向腹侧迁移到脊索以外。这可能与七鳃鳗缺乏交感神经链有关。鳍状突起细胞可分化为间充质细胞，形成d…的一部分。在七鳃鳗胚胎中，感觉细胞存在于神经管中，它们被HNK-1染色。HNK-1免疫反应阳性神经纤维也可见于表皮下，至少部分纤维来自背侧细胞。七鳃鳗的感觉脊神经节很小。背侧细胞可能由“非迁移性神经脊细胞”分化而来。这些观察结果与神经脊和/或安慰剂的起源有关。2.用HNK-1和一些抗细胞外基质分子的抗体研究了神经脊细胞在剑尾胚胎中的迁移和定植模式。(1)在剑尾胚胎的躯干中，神经脊细胞像七鳃鳗胚胎一样被识别出三条迁移途径。腹侧入路的神经脊细胞定植于脊索下方，并分化为交感神经节细胞。(2)HNK-1免疫反应阳性的神经脊细胞出现和迁移时，细胞外物质如纤维连接蛋白和硫酸软骨素等出现和分布。因此，这些物质可能与硬骨中的神经脊细胞迁移密切相关，就像高等脊椎动物一样。较少

1.The neural crest is a characteristic tissue of vertebrate embryos. Neural crest cells appear on the dorsal side of the neural tube, migrate to various regions of the body, and differentiate into a variety of cells. Thus, the neural crest participates in forming the vertebrate body organization. At first, migration and colonization patterns of neural crest cells were studied in the most primitive vertebrate, the lamprey, using a monoclonal antibody, HNK-1, which stains migratory neural crest cells.(1) In the trunk of lamprey embryos, neural crest cells migrate in three routes ; the dorsolateral route between epidermis and somite, the ventral route between somite and neural tube, and the dorsal route towards the dorsal fin rudiment. In the ventral route, these cells do not migrate ventrally beyond the notochord. This may be related to the absence of sympathetic chains in lampreys. The neural crest cells in the fin rudiment may differentiate into mesenchymal cells and form part of the d … More orsal fin.(2) In lamprey embryos, sensory "doral cells" exist in the neural tube and they are stained with HNK-1. HNK-1-immunoreactive nerve fibers are also detected sub-epidermally and at least some of the fibers originate from dorsal cells. Sensory spinal ganglia are very small in lampreys. Dorsal cells may differentiate from "non-migratory neural crest cells". These observations are relevant to the origin of neural crest and/or placode.2.The migration and colonization patterns of neural crest cells were also studied in the swordtail embryo, using HNK-1 and some antibodies against extracellular matrix molecules.(1) In the trunk of swordtail embryos, three migration routes of neural crest cells are recognized, as in lamprey embryos. Neural crest cells in the ventral route colonize the region below the notochord and differentiate into sympathetic ganglion cells.(2) Extracellular materials such as fibronectin and chondroitin sulfate appear and distribute immunohistochemically, as HNK-1 immunoreactive neural crest cells appear and migrate. Thus, these materials may be intimately related to neural crest cell migration in the teleost as in the higher vertebrate. Less