Nishizaki Y, Shimazu K, Kondoh H, Sasaki H
Laboratory of Developmental Biology, Institute for Molecular and Cellular Biology, Osaka University, 1-3 Yamada-oka, Suita, 565-0871, Osaka, Japan.
Mech Dev. 2001 Apr;102(1-2):57-66. doi: 10.1016/s0925-4773(01)00281-7.
The expression of a winged-helix transcription factor, Foxa2/HNF3beta, is essential for development of the node and the notochord. We examined the node/notochord enhancer of mouse Foxa2 for sequence motifs conserved across vertebrate species. We cloned Foxa2 genes from chicken and fish, and identified the respective node/notochord enhancers that were active in transgenic mouse embryos. Comparison of the sequences of the enhancers revealed three evolutionally conserved sequence motifs, CS1, CS2 and CS3. Mutational analysis of the mouse enhancer indicated that CS3 is indispensable for gene expression in the node and the notochord, while CS1 and CS2 are required to augment enhancer activity. These motifs do not correspond to the consensus binding sequences of transcription factors known to be involved in node/notochord development.
翼状螺旋转录因子Foxa2/HNF3β的表达对于节点和脊索的发育至关重要。我们研究了小鼠Foxa2的节点/脊索增强子，以寻找在脊椎动物物种中保守的序列基序。我们从鸡和鱼中克隆了Foxa2基因，并鉴定出在转基因小鼠胚胎中具有活性的各自的节点/脊索增强子。对增强子序列的比较揭示了三个进化上保守的序列基序，即CS1、CS2和CS3。对小鼠增强子的突变分析表明，CS3对于节点和脊索中的基因表达是不可或缺的，而CS1和CS2则是增强增强子活性所必需的。这些基序与已知参与节点/脊索发育的转录因子的共有结合序列不对应。
