Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
Dev Cell. 2013 Jun 10;25(5):451-62. doi: 10.1016/j.devcel.2013.05.009.
The vertebrate body is made by progressive addition of new tissue from progenitors at the posterior embryonic end. Axial extension involves different mechanisms that produce internal organs in the trunk but not in the tail. We show that Gdf11 signaling is a major coordinator of the trunk-to-tail transition. Without Gdf11 signaling, the switch from trunk to tail is significantly delayed, and its premature activation brings the hindlimbs and cloaca next to the forelimbs, leaving extremely short trunks. Gdf11 activity includes activation of Isl1 to promote formation of the hindlimbs and cloaca-associated mesoderm as the most posterior derivatives of lateral mesoderm progenitors. Gdf11 also coordinates reallocation of bipotent neuromesodermal progenitors from the anterior primitive streak to the tail bud, in part by reducing the retinoic acid available to the progenitors. Our findings provide a perspective to understand the evolution of the vertebrate body plan.
脊椎动物的身体是由胚胎后端的祖先进化而来的新组织逐渐添加而成的。轴向延伸涉及不同的机制，这些机制产生了躯干内部的器官，但不产生尾部的器官。我们发现 Gdf11 信号是躯干到尾部过渡的主要协调因子。没有 Gdf11 信号，从躯干到尾部的转变会显著延迟，如果过早激活 Gdf11，会导致后肢和泄殖腔靠近前肢，导致极短的躯干。Gdf11 活性包括激活 Isl1，以促进后肢和泄殖腔相关中胚层的形成，作为侧中胚层祖细胞的最末级衍生物。Gdf11 还协调具有双重潜能的神经中胚层祖细胞从原始胚盘前端到尾部芽的重新分配，部分原因是减少了祖细胞可用的视黄酸。我们的研究结果为理解脊椎动物体式的进化提供了一个视角。
