Tfap2 and Sox1/2/3 cooperatively specify ectodermal fates in ascidian embryos
Tfap2 and Sox1/2/3 cooperatively specify ectodermal fates in ascidian embryos
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DOI：
10.1242/dev.142109
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发表时间：
2017-01-01
期刊：
影响因子：
4.6
通讯作者：
Satou, Yutaka
中科院分区：
文献类型：
--
作者：
Imai, Kaoru S.;Hikawa, Hiroki;Satou, Yutaka
表皮和神经组织从动物胚胎的外胚层分化而来。尽管表皮命运被认为是在脊椎动物胚胎中诱导的，但胚胎学证据表明，海鞘胚胎中的表皮命运不需要早期阶段的细胞间相互作用。为了检验这一假设，我们确定了海鞘胚胎中表皮和神经规范的基因调控回路。这些电路始于 Tfap2-r.b 和 Sox1/2/3，它们在合子基因组激活后立即在外胚层谱系中表达。在成纤维细胞生长因子信号传导激活后，Tfap2-r.b 的表达在神经谱系中减少，已知该信号会诱导神经命运，并且仅在表皮谱系中持续存在。 Tfap2-r.b 与 Dlx.b 协同指定表皮命运，Dlx.b 被 Sox1/2/3 激活。该 Sox1/2/3-Dlx.b 电路也是前神经命运规范所必需的。在后神经谱系中，Sox1/2/3 激活 Nodal，这是后神经命运规范所必需的。我们的研究结果支持这样的假设：表皮命运在海鞘胚胎中是自主指定的。
Epidermis and neural tissues differentiate from the ectoderm in animal embryos. Although epidermal fate is thought to be induced in vertebrate embryos, embryological evidence has indicated that no intercellular interactions during early stages are required for epidermal fate in ascidian embryos. To test this hypothesis, we determined the gene regulatory circuits for epidermal and neural specification in the ascidian embryo. These circuits started with Tfap2-r.b and Sox1/2/3, which are expressed in the ectodermal lineage immediately after zygotic genome activation. Tfap2-r.b expression was diminished in the neural lineages upon activation of fibroblast growth factor signaling, which is known to induce neural fate, and sustained only in the epidermal lineage. Tfap2-r.b specified the epidermal fate cooperatively with Dlx.b, which was activated by Sox1/2/3. This Sox1/2/3-Dlx.b circuit was also required for specification of the anterior neural fate. In the posterior neural lineage, Sox1/2/3 activated Nodal, which is required for specification of the posterior neural fate. Our findings support the hypothesis that the epidermal fate is specified autonomously in ascidian embryos.