Halpern M E, Ho R K, Walker C, Kimmel C B
Institute of Neuroscience, University of Oregon, Eugene 97403.
Cell. 1993 Oct 8;75(1):99-111.
Dorsal mesoderm is thought to provide important signals for axis formation and neural differentiation in vertebrate embryos. We have examined induction and patterning in a zebrafish mutant, no tail, that lacks a derivative of dorsal mesoderm, the notochord. Despite the absence of a differentiated notochord, development of the central nervous system including floor plate appears normal, likely owing to the presence of notochord precursor cells. In contrast, somites are misshapen, and muscle pioneer cells are absent. Wild-type cells transplanted into mutant hosts can autonomously differentiate into notochord and thereby rescue somitic defects, suggesting that interactions between notochord and paraxial mesoderm are necessary for proper somite patterning. Thus, cells derived from dorsal mesoderm may have multiple signaling functions during zebrafish embryogenesis.
背侧中胚层被认为在脊椎动物胚胎中为轴的形成和神经分化提供重要信号。我们研究了斑马鱼突变体“无尾”中的诱导和模式形成，该突变体缺乏背侧中胚层的衍生物——脊索。尽管没有分化的脊索，但包括底板在内的中枢神经系统的发育看起来正常，这可能是由于脊索前体细胞的存在。相比之下，体节形状异常，且肌肉先驱细胞缺失。移植到突变宿主中的野生型细胞可自主分化为脊索，从而挽救体节缺陷，这表明脊索与轴旁中胚层之间的相互作用对于正确的体节模式形成是必要的。因此，源自背侧中胚层的细胞在斑马鱼胚胎发育过程中可能具有多种信号功能。
