Wilkinson D G
MRC Laboratory of Eukaryotic Molecular Genetics, National Institute for Medical Research, London, UK.
Perspect Dev Neurobiol. 1993;1(3):117-25.
The finding that pattern formation in the vertebrate hindbrain occurs through a process of segmentation raises the question of the underlying molecular mechanisms. A number of genes have been implicated in this pattern through their segment-restricted expression, and the function and possible regulatory relationships of these are discussed. There is now strong evidence that certain Hox genes are involved in specifying hindbrain segments and neural crest derivatives that contribute to cranial ganglia and the branchial arches. It is likely that retinoic acid receptors either directly or indirectly regulate Hox gene expression in the hindbrain. The zinc finger gene Krox-20 controls the segment-restricted up-regulation of at least one Hox gene, Hox-B2. Studies of the Krox-20 gene reveal a progressive sharpening of its expression domains that reflect cellular interactions leading to segment formation. A receptor tyrosine kinase gene, Sek, has been implicated in such cellular interactions by its rhombomeric expression pattern. In addition, this receptor kinase may be involved in mesoderm segmentation.
脊椎动物后脑的模式形成是通过分段过程实现的这一发现，引发了关于其潜在分子机制的问题。许多基因因其在分段区域的特异性表达而与这种模式相关，本文将讨论这些基因的功能以及可能的调控关系。目前有充分的证据表明，某些Hox基因参与确定后脑节段以及对脑神经节和鳃弓有贡献的神经嵴衍生物。视黄酸受体很可能直接或间接地调节后脑Hox基因的表达。锌指基因Krox-20控制至少一种Hox基因Hox-B2在分段区域的上调表达。对Krox-20基因的研究揭示了其表达域的逐渐细化，这反映了导致节段形成的细胞间相互作用。一种受体酪氨酸激酶基因Sek，因其在菱脑节中的表达模式而与这种细胞间相互作用有关。此外，这种受体激酶可能参与中胚层的分段。
