Lineage-independent mosaic expression and regulation of the Ciona multidom gene in the ancestral notochord
Lineage-independent mosaic expression and regulation of the Ciona multidom gene in the ancestral notochord
复制标题
DOI：
10.1002/dvdy.21213
复制
发表时间：
2007-07-01
影响因子：
2.5
通讯作者：
Di Gregorio, Anna
中科院分区：
文献类型：
--
作者：
Oda-Ishii, Izumi;Di Gregorio, Anna
转录因子Ciona Brachyury（Ci-Bra）在海鞘玻璃海鞘脊索发育中起着重要作用。我们表征了一个假定的Ci-Bra靶基因，我们将其命名为Ci-multidom，并详细分析了其在正常胚胎和Ci-Bra错误表达的胚胎中的表达模式。Ci-multidom编码一种新的蛋白质，含有8个CCP结构域和一个VWFA结构域。我们发现，EGFP-多域融合蛋白优先定位于内质网（ER），并被排除在细胞核之外。原位杂交实验表明，Ci-multidom表达在脊索和前神经边界（ANB）。我们发现AN-B中的表达完全被位于Ci-多结构上游的增强子元件重演。通过错误表达实验，我们提供的证据表明，Ci-Bra控制转录的Ci-multidom在脊索;然而，虽然Ci-Bra是均匀地表达在整个结构，Ci-multidom转录在可检测的水平，仅在脊索细胞的随机子集。表达Ci-multidom的脊索细胞的数量在不同的胚胎中变化，并且与发育阶段、谱系和沿前后轴的沿着位置无关。这些结果表明，尽管其形态简单和不变的细胞谱系，祖先脊索是一个马赛克的细胞中的基因级联下游的Brachyury差异调制。发展动力学236：1806-1819，2007。(c)2007 Wiley-Liss，Inc.
The transcription factor Ciona Brachyury (Ci-Bra) plays an essential role in notochord development in the ascidian Ciona intestinalis. We characterized a putative Ci-Bra target gene, which we named Ci-multidom, and analyzed in detail its expression pattern in normal embryos and in embryos where Ci-Bra was misexpressed. Ci-multidom encodes a novel protein, which contains eight CCP domains and a partial VWFA domain. We show that an EGFP-multidom fusion protein localizes preferentially to the endoplasmic reticulum (ER), and is excluded from the nucleus. In situ hybridization experiments demonstrate that Ci-multidom is expressed in the notochord and in the anterior neural boundary (ANB). We found that the expression in the AN-B is fully recapitulated by an enhancer element located upstream of Ci-multidom. By means of misexpression experiments, we provide evidence that Ci-Bra controls transcription of Ci-multidom in the notochord; however, while Ci-Bra is homogeneously expressed throughout this structure, Ci-multidom is transcribed at detectable levels only in a random subset of notochord cells. The number of notochord cells expressing Ci-multidom varies among different embryos and is independent of developmental stage, lineage, and position along the anterior-posterior axis. These results suggest that despite its morphological simplicity and invariant cell-lineage, the ancestral notochord is a mosaic of cells in which the gene cascade downstream of Brachyury is differentially modulated. Developmental Dynamics 236:1806-1819, 2007. (c) 2007 Wiley-Liss, Inc.