Vertebrate head morphogenesis involves carefully-orchestrated tissue growth and cell movements of the mesoderm and neural crest to form the distinct craniofacial pattern. To better understand structural birth defects, it is important that we characterize the dynamics of these processes and learn how they rely on each other. Here we examine this question during chick head morphogenesis using time-lapse imaging, computational modeling, and experiments. We find that head mesodermal cells in culture move in random directions as individuals and move faster in the presence of neural crest cells. In vivo, mesodermal cells migrate in a directed manner and maintain neighbor relationships; neural crest cells travel through the mesoderm at a faster speed. The mesoderm grows with a non-uniform spatio-temporal profile determined by BrdU labeling during the period of faster and more-directed neural crest collective migration through this domain. We use computer simulations to probe the robustness of neural crest stream formation by varying the spatio-temporal growth profile of the mesoderm. We follow this with experimental manipulations that either stop mesoderm growth or prevent neural crest migration and observe changes in the non-manipulated cell population, implying a dynamic feedback between tissue growth and neural crest cell signaling to confer robustness to the system. Overall, we present a novel descriptive analysis of mesoderm and neural crest cell dynamics that reveals the coordination and co-dependence of these two cell populations during head morphogenesis.

中文翻译：

---

可视化鸡头形态发生过程中的中胚层和神经c细胞动力学。

脊椎动物头部的形态发生涉及精心策划的组织生长以及中胚层和神经c的细胞运动，形成独特的颅面模式。为了更好地理解结构性先天缺陷，重要的是我们刻画这些过程的动力学特征并了解它们如何相互依赖。在这里，我们使用延时成像，计算模型和实验研究了鸡头形态发生过程中的这个问题。我们发现，培养中的头部中胚层细胞会以个体随机的方向移动，并且在存在神经rest细胞的情况下移动速度会更快。在体内，中胚层细胞以定向方式迁移并维持邻居关系。神经c细胞以更快的速度穿过中胚层。中胚层的生长具有不均匀的时空分布，该分布由BrdU标记确定，并通过该域更快，更直接地引导神经c集体迁移。我们使用计算机模拟来通过改变中胚层的时空生长轮廓来探究神经c流形成的鲁棒性。我们通过实验操作来遵循该操作，这些操作要么停止中胚层的生长，要么阻止神经c的迁移，并观察未操纵的细胞群的变化，这暗示着组织生长和神经c细胞信号之间的动态反馈，从而赋予系统鲁棒性。总的来说，我们提出了中胚层和神经c细胞动力学的新颖描述性分析，揭示了头部形态发生过程中这两个细胞群体的协调和相互依赖性。