Data from: Multi-scale quantification of tissue behavior during amniote embryo axis elongation

Embryonic axis elongation is a complex multi-tissue morphogenetic process responsible for the formation of the posterior part of the amniote body. How movements and growth are coordinated between the different posterior tissues (e.g. neural tube, axial and paraxial mesoderm, lateral plate, ectoderm, endoderm) to drive axis morphogenesis remain largely unknown. Here, we use quail embryos to quantify cell behavior and tissue movements during elongation. We quantify the tissue-specific contribution to axis elongation by using 3D volumetric techniques, then quantify tissue-specific parameters such as cell density and proliferation. To study cell behavior at a multi-tissue scale we used high-resolution 4D imaging of transgenic quail embryos expressing fluorescent proteins. We developed specific tracking and image analysis techniques to analyze cell motion and compute tissue deformations in 4D. This analysis reveals extensive sliding between tissues during axis extension. Further quantification of tissue tectonics showed patterns of rotations, contractions and expansions, which are coherent with the multi-tissue behavior observed previously. Our approach defines a quantitative and multiscale method to analyze the coordination between tissue behaviors during early vertebrate embryo morphogenetic events.

胚胎轴伸长（Embryonic axis elongation）是一类复杂的多组织形态发生过程，负责构建羊膜动物（amniote）躯体的后部结构。不同后部组织（例如神经管（neural tube）、轴旁中胚层（axial and paraxial mesoderm）、侧板中胚层（lateral plate）、外胚层（ectoderm）、内胚层（endoderm））之间如何协调运动与生长以驱动轴形态发生，目前仍在很大程度上未被阐明。本研究以鹌鹑胚胎为模型，量化轴伸长过程中的细胞行为与组织运动。我们采用三维体绘制技术（3D volumetric techniques）量化各组织对胚胎轴伸长的特异性贡献，并测定细胞密度、增殖活性等组织特异性参数。为在多组织尺度下研究细胞行为，我们对表达荧光蛋白（fluorescent proteins）的转基因鹌鹑胚胎开展高分辨率四维成像（4D imaging）。我们开发了专属的细胞追踪与图像分析技术，用于分析四维尺度下的细胞运动并计算组织形变。该分析揭示了轴伸长过程中组织间存在广泛的滑动现象。进一步的组织构造（tissue tectonics）定量分析显示，组织呈现旋转、收缩与扩张模式，这与此前观测到的多组织行为一致。本研究提出的方法构建了一套定量、多尺度的分析框架，用于解析早期脊椎动物胚胎形态发生事件中各组织行为的协调机制。