Similar regulatory logic in Ciona intestinalis for two Wnt pathway modulators, ROR and SFRP-1/5
Similar regulatory logic in Ciona intestinalis for two Wnt pathway modulators, ROR and SFRP-1/5
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DOI：
10.1016/j.ydbio.2009.02.018
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发表时间：
2009-05-15
影响因子：
2.7
通讯作者：
Joly, Jean-Stephane
中科院分区：
文献类型：
--
作者：
Auger, Helene;Lamy, Clement;Joly, Jean-Stephane
无脊椎动物脊索动物玻璃海鞘的外胚层的前后模式首先依赖于关键的合子激活因子，例如 FoxA，然后依赖于对来自底层中内胚层的诱导信号的协调反应。在这里，我们通过观察 Ci-Rora 和 G-Rorb 的顺式调控逻辑来重点关注这些反应的协调机制，它们编码假定的非规范跨膜 Wnt 受体，并沿着肠棒状杆菌染色体 08q 串联存在。我们发现，在卵裂阶段，Ci-Rora 和 Ci-Rorb 基因最初在前外胚层的所有卵裂球中表达（a 线），如 sFRP1/5（Lamy, C.、Rothbacher, U.、Caillol, D.、Lemaire, P., 2006。Ci-FoxA-a 是海鞘前外胚层最早的合子决定簇，直接激活 Ci-sFRP1/5。Development 133, 2835-2844。）。然后我们对顺式调控区进行了功能分析，结果表明这两个基因都具有富含 Ci-FoxA-a 结合位点的元件。我们剖析了这些早期增强子之一，并表明它作为 sFRP1/5 顺式调节元件之一直接被 Ci-FoxA-a 激活。我们还表明，尽管 FoxA 结合位点在基因组中丰富，但在极少数基因的上游发现了这些位点的密集簇，并且对 a 系表达具有很高的预测价值。这些数据表明 FoxA 通过属于各种信号通路的靶基因的转录调节在前部规范中发挥重要作用。 (C) 2009 Elsevier Inc. 保留所有权利。
Anteroposterior patterning of the ectoderm in the invertebrate chordate Ciona intestinalis first relies on key zygotic activators, such as FoxA, and later on the coordinated responses to inducing signals from the underlying mesendoderm. Here, we focus on a mechanism of coordination of these responses by looking at the cis-regulatory logics of Ci-Rora and G-Rorb, which are coding for putative non-canonical transmembrane Wnt receptors, and are present in tandem along the C intestinalis chromosome 08q.We showed that during cleavage stages, both Ci-Rora and Ci-Rorb genes are initially expressed in all blastomeres of the anterior ectoderm (a-line), as sFRP1/5 (Lamy, C., Rothbacher, U., Caillol, D., Lemaire, P., 2006. Ci-FoxA-a is the earliest zygotic determinant of the ascidian anterior ectoderm and directly activates Ci-sFRP1/5. Development 133, 2835-2844.). We then carried out a functional analysis of cis-regulatory regions and showed that both genes have elements enriched in Ci-FoxA-a binding sites. We dissected one of these early enhancers, and showed that it is directly activated by Ci-FoxA-a, as one sFRP1/5 cis-regulatory element. We also showed that although FoxA binding sites are abundant in genomes, dense clusters of these sites are found upstream from very few genes, and have a high predictive value of a-line expression. These data indicate an important role for FoxA in anterior specification, via the transcriptional regulation of target genes belonging to various signalling pathways. (C) 2009 Elsevier Inc. All rights reserved.