Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
Department of Physics, University of California San Diego, La Jolla, CA 92093, USA.
Sci Adv. 2023 Jan 4;9(1):eabn5429. doi: 10.1126/sciadv.abn5429.
The morphology of gastrulation driving the internalization of the mesoderm and endoderm differs markedly among vertebrate species. It ranges from involution of epithelial sheets of cells through a circular blastopore in amphibians to ingression of mesenchymal cells through a primitive streak in amniotes. By targeting signaling pathways controlling critical cell behaviors in the chick embryo, we generated crescent- and ring-shaped mesendoderm territories in which cells can or cannot ingress. These alterations subvert the formation of the chick primitive streak into the gastrulation modes seen in amphibians, reptiles, and teleost fish. Our experimental manipulations are supported by a theoretical framework linking cellular behaviors to self-organized multicellular flows outlined in detail in the accompanying paper. Together, this suggests that the evolution of gastrulation movements is largely determined by changes in a few critical cell behaviors in the mesendoderm territory across different species and controlled by a relatively small number of signaling pathways.
原肠作用过程中中胚层和内胚层的内化形态在脊椎动物物种间存在显著差异。在两栖动物中，这一过程表现为细胞上皮片的内卷，通过圆形胚孔进行；而在羊膜动物中，则是通过原条中的间质细胞内陷。通过靶向控制鸡胚中关键细胞行为的信号通路，我们生成了新月形和环形中胚内胚层区域，其中细胞可以或不能进行内陷。这些改变颠覆了鸡胚原条的形成，使其进入到在两栖动物、爬行动物和硬骨鱼中观察到的原肠作用模式。我们的实验操作得到了一个理论框架的支持，该框架将细胞行为与伴随论文中详细阐述的自我组织多细胞流联系起来。总的来说，这表明原肠作用运动的进化在很大程度上取决于不同物种中中胚内胚层区域的少数几个关键细胞行为的变化，并由相对较少的信号通路控制。
