Eomesodermin is a localized maternal determinant required for endoderm induction in zebrafish
Eomesodermin is a localized maternal determinant required for endoderm induction in zebrafish
复制标题
DOI：
10.1016/j.devcel.2005.08.010
复制
发表时间：
2005-10-01
影响因子：
11.8
通讯作者：
Kimelman, D
中科院分区：
文献类型：
--
作者：
Bjornson, CRR;Griffin, KJR;Kimelman, D
在斑马鱼中，内胚层的诱导发生在边缘的卵裂球中，需要卡萨诺瓦(Casanova，Cas)，这是第一个在胚胎中表达的内胚层特异性因子。转录因子Gata5和Bon是在边缘卵裂球中表达CaS的必要条件和充分条件，但Bon和Gata5不能诱导动物极细胞中的CaS表达，这表明CaS的表达需要一个额外的未知因子(S)。在这里，我们证明了CaS的表达依赖于T盒转录因子Eomesodermin(Eomesodermin)，这是一种定位于边缘卵裂球的母性决定因素。EOMES与Bon和Gata5有效地协同作用，甚至在动物的极裂球中也能诱导CA。我们发现eome是内源性内胚层诱导所必需的，它通过cas启动子中的一个重要结合部位发挥作用。Eome、Bon和Gata5之间的直接物理相互作用表明，eome通过促进转录激活复合体在cas启动子上的组装，促进边缘卵裂球内胚层的诱导。
In zebrafish, endoderm induction occurs in marginal blastomeres and requires Casanova (Cas), the first endoderm-specific factor expressed in the embryo. Whereas the transcription factors Gata5 and Bon are necessary and sufficient for cas expression in marginal blastomeres, Bon and Gata5 are unable to induce cas in animal pole cells, suggesting that cas expression requires an additional, unidentified factor(s). Here, we show that cas expression depends upon the T box transcription factor Eomesodermin (Eomes), a maternal determinant that is localized to marginal blastomeres. Eomes synergizes potently with Bon and Gata5 to induce cas, even in animal pole blastomeres. We show that Eomes is required for endogenous endoderm induction, acting via an essential binding site in the cas promoter. Direct physical interactions between Eomes, Bon, and Gata5 suggest that Eomes promotes endoderm induction in marginal blastomeres by facilitating the assembly of a transcriptional activating complex on the cas promoter.