Strähle U, Blader P, Ingham P W
ICRF Developmental Biology Unit, Department of Zoology, Oxford, United Kingdom.
Int J Dev Biol. 1996 Oct;40(5):929-40.
We present a description of the expression of the HNF-3 beta homolog axial (axl) in the developing zebrafish up to larva stages and compare it with that of sonic hedgehog (shh). Both genes are expressed in derivatives of all three germ layers in dynamic patterns that show substantial overlap, consistent with mutual regulatory interactions between the two genes. However, we also describe unique sites of expression of both axl and shh indicating that some aspects of their regulation are independent of one another. In no tail (ntl, zebrafish Brachyury) and floating head (flh, zebrafish Xnot1) mutants, both of which affect notochord development, early expression of axl in the organizer is unaffected, excluding a function for these genes in establishment of axl expression. At later stages, ntl and flh mutants show different effects on the expression of both axl and shh in the neuroectoderm of the trunk and tail reflecting their distinct contributions to the development of the midline mesoderm; in contrast to flh and ntl mutations whose effects are restricted to the trunk and tail, mutation of cyclops (cyc) affects axl and shh expression along the entire midline of the neuroectoderm. Endodermal expression of axl and shh is not affected by the mutations showing that development of the endoderm is under distinct control.
我们描述了肝细胞核因子3β同源物轴向（axl）在斑马鱼发育至幼虫阶段的表达情况，并将其与音猬因子（shh）的表达进行比较。这两个基因均在所有三个胚层的衍生物中以动态模式表达，表现出大量重叠，这与两个基因之间的相互调节相互作用一致。然而，我们也描述了axl和shh的独特表达位点，表明它们调控的某些方面彼此独立。在无尾（ntl，斑马鱼Brachyury）和浮头（flh，斑马鱼Xnot1）突变体中，这两种突变体均影响脊索发育，但axl在组织者中的早期表达不受影响，排除了这些基因在axl表达建立中的作用。在后期阶段，ntl和flh突变体对躯干和尾部神经外胚层中axl和shh的表达显示出不同的影响，反映了它们对中线中胚层发育的不同贡献；与flh和ntl突变的影响仅限于躯干和尾部不同，独眼（cyc）突变影响神经外胚层整个中线的axl和shh表达。axl和shh的内胚层表达不受这些突变的影响，表明内胚层的发育受不同的控制。
