The migration of paraxial and lateral plate mesoderm cells emerging from the late primitive streak is controlled by different Wnt signals.
The migration of paraxial and lateral plate mesoderm cells emerging from the late primitive streak is controlled by different Wnt signals.
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DOI：
10.1186/1471-213x-8-63
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发表时间：
2008-06-09
影响因子：
--
通讯作者：
Muensterberg, Andrea
中科院分区：
文献类型：
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作者：
Sweetman, Dylan;Wagstaff, Laura;Cooper, Oliver;Weijer, Cornelis;Muensterberg, Andrea
协调的细胞运动是发育中的胚胎的基本特征。大量的细胞运动发生在脊椎动物原肠胚形成和随后的胚胎体轴延伸过程中。这些是由细胞-细胞信号传导控制的，并且涉及许多途径。在这里，我们使用鸡胚胎的长期视频显微镜来观察中胚层祖细胞在HH期7和10之间从原始条纹（PS）中出现时的迁移路线和运动行为。我们观察到沿着条纹长度的不同细胞运动行为，并确定这与细胞对环境线索的反应有关。通过将胚胎或原始条纹外植体暴露于表达Wnt3a和Wnt5a的细胞颗粒中，细胞的行为发生了改变，而不影响细胞的命运，从而暗示这些配体调节细胞的运动行为。有趣的是，较年轻的胚胎没有反应，这表明Wnt3a和Wnt5a特异性参与后中胚层的产生，与现有的小鼠和斑马鱼突变体一致。为了研究哪些下游成分参与其中，将突变体disheveled （dsh）和prickle1 （pk1）电穿孔到原始条纹中。这些对中胚层祖细胞的行为有不同的影响，表明在羊膜胚胎体轴延伸过程中，多种Wnt通路参与控制细胞迁移。我们认为，当Wnt5a和Wnt3a离开神经期胚胎的原始条纹时，旁轴和外侧中胚层前体的不同行为受到Wnt5a和Wnt3a的相反作用的调节。我们的数据表明，Wnt5a通过刺刺引起细胞从后条纹迁移。在前条纹中，这被Wnt3a拮抗，产生非迁移的内侧中胚层。
Co-ordinated cell movement is a fundamental feature of developing embryos. Massive cell movements occur during vertebrate gastrulation and during the subsequent extension of the embryonic body axis. These are controlled by cell-cell signalling and a number of pathways have been implicated. Here we use long-term video microscopy in chicken embryos to visualize the migration routes and movement behaviour of mesoderm progenitor cells as they emerge from the primitive streak (PS) between HH stages 7 and 10. We observed distinct cell movement behaviours along the length of the streak and determined that this is position dependent with cells responding to environmental cues. The behaviour of cells was altered by exposing embryos or primitive streak explants to cell pellets expressing Wnt3a and Wnt5a, without affecting cell fates, thus implicating these ligands in the regulation of cell movement behaviour. Interestingly younger embryos were not responsive, suggesting that Wnt3a and Wnt5a are specifically involved in the generation of posterior mesoderm, consistent with existing mouse and zebrafish mutants. To investigate which downstream components are involved mutant forms of dishevelled (dsh) and prickle1 (pk1) were electroporated into the primitive streak. These had differential effects on the behaviour of mesoderm progenitors emerging from anterior or posterior regions of the streak, suggesting that multiple Wnt pathways are involved in controlling cell migration during extension of the body axis in amniote embryos. We suggest that the distinct behaviours of paraxial and lateral mesoderm precursors are regulated by the opposing actions of Wnt5a and Wnt3a as they leave the primitive streak in neurula stage embryos. Our data suggests that Wnt5a acts via prickle to cause migration of cells from the posterior streak. In the anterior streak, this is antagonised by Wnt3a to generate non-migratory medial mesoderm.