Oikonomou Panagiotis, Calvary Lisa, Cirne Helena C, Welch Andreas E, Durel John F, Powell Olivia, Kim Kwantae, Nerurkar Nandan L
Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
Development. 2025 Aug 15;152(16). doi: 10.1242/dev.204561. Epub 2025 Aug 29.
As cross-disciplinary approaches drawing from mechanics have increasingly influenced our understanding of morphogenesis, tools to measure and perturb physical aspects of embryogenesis have expanded as well. However, it remains a challenge to measure mechanical properties and apply exogenous tissue-scale forces in vivo, particularly for epithelia. Exploiting size and accessibility of the chick embryo, we describe a technique to apply and measure exogenous forces in the order of ∼1-100 µN to the endoderm. To demonstrate the utility of this approach, we performed several proof-of-concept experiments, revealing fundamental, yet unexpected, mechanical behaviors in the early embryo. This included heterogeneous single-cell mechanotypes within the endoderm, a complex non-cell autonomous mechanical role for actin, and tight mechanical coupling across germ layers. To illustrate the broader utility of this method, we expanded this approach to the ectoderm as well, where the mechanical behavior of neural plate cells was distinct from that of the endoderm. These findings provide basic insights into the mechanics of embryonic epithelia in vivo in the early avian embryo, and provide a useful tool for future investigations of how morphogenesis is influenced by mechanical factors.
随着源自力学的跨学科方法越来越多地影响我们对形态发生的理解，用于测量和扰动胚胎发生物理方面的工具也在不断扩展。然而，在体内测量力学性质并施加外源性组织尺度的力仍然是一项挑战，尤其是对于上皮组织而言。利用鸡胚的大小和易操作性，我们描述了一种向内胚层施加并测量约1-100微牛顿量级外源性力的技术。为了证明这种方法的实用性，我们进行了几个概念验证实验，揭示了早期胚胎中基本但出乎意料的力学行为。这包括内胚层内异质的单细胞力学类型、肌动蛋白复杂的非细胞自主力学作用以及跨胚层的紧密力学耦合。为了说明这种方法更广泛的实用性，我们还将这种方法扩展到外胚层，其中神经板细胞的力学行为与内胚层不同。这些发现为早期鸡胚体内胚胎上皮组织的力学提供了基本见解，并为未来研究形态发生如何受力学因素影响提供了有用的工具。
