Grinblat Y, Sive H
Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA.
Dev Dyn. 2001 Dec;222(4):688-93. doi: 10.1002/dvdy.1221.
Anteroposterior (A/P) patterning of the vertebrate neurectoderm begins early during development. In vitro explant assays have been used to show that an A/P subdivision of the zebrafish neurectoderm is in place by early gastrulation. However, no direct markers of this subdivision had been described. We report isolation of two members of the zic gene family, zic2 and zic3, which mark distinct regions in the developing nervous system. zic3 is expressed in early gastrula embryos in a posterior domain, directly demonstrating that A/P pattern is present in the future neurectoderm by this stage. Analysis of mutants in genes encoding bone morphogenetic proteins (BMPs) shows that dorsal restriction of zic3 expression requires intact BMP function, and that posterior restriction of zic3 expression is regulated independently of BMP signaling. These data show an early subdivision of the A/P axis in the presumptive neurectoderm.
脊椎动物神经外胚层的前后（A/P）模式形成在发育早期就开始了。体外外植体实验已用于表明，斑马鱼神经外胚层的A/P分区在原肠胚形成早期就已形成。然而，尚未描述该分区的直接标记物。我们报告了zic基因家族的两个成员zic2和zic3的分离，它们标记了发育中的神经系统中的不同区域。zic3在原肠胚早期胚胎的后部区域表达，直接证明了在这个阶段未来的神经外胚层中存在A/P模式。对编码骨形态发生蛋白（BMPs）的基因突变体的分析表明，zic3表达的背侧限制需要完整的BMP功能，并且zic3表达的后部限制独立于BMP信号传导进行调节。这些数据表明了预定神经外胚层中A/P轴的早期分区。
