A quantitative analysis of forces and mechanics during interkinetic nuclear migration in the developing zebrafish embryo.

动间核迁移(IKNM)描述了从海葵到哺乳动物新皮质等多种发育中生物的假复层上皮细胞中依赖于细胞周期时相的核运动。尽管IKNM期间的核运动被认为与成功的增殖和随后的分化密切相关，但人们对IKNM和发展计划之间的关系知之甚少。最近，在理解不同的蛋白质，特别是细胞骨架元素及其马达如何在单细胞基础上影响IKNM期间的核运动方面取得了一些进展。然而，仍然缺乏的是对这种现象在空间和时间上的认识，考虑到所有的上皮细胞核和其他亚细胞安排。我们的目标是在活体内诱导斑马鱼神经上皮细胞单细胞水平以外的核运动，开发新的跟踪算法，从而获得所有核轨迹的整体图景。这一数据集将有助于理解核运动如何影响组织结构，以及IKNM中核运动的动力学是导致核紧密堆积的原因还是结果。我们将进一步研究IKNM的组织规模组织和导致它的细胞内力之间的联系，主要集中在肌动蛋白和微管细胞骨架上。实验工作的结果将是一种理论方法的先决条件，该方法将IKNM描述为紧密堆积的上皮的一种紧急属性，这是本提案的最终目标。

Interkinetic Nuclear Migration (IKNM) describes cell cycle phase dependent nuclear movements in pseudostratified epithelia in a broad range of developing organisms from the anemone nematostella to the mammalian neocortex. Despite the fact that nuclear movements during IKNM are thought to be intimately tied to successful proliferation and subsequent differentiation, not much is known about the relationship between IKNM and developmental programs. Recently some progress has been made in understanding how distinct proteins, especially cytoskeletal elements and their motors, influence nuclear movement during IKNM on a single cell basis. What is still lacking however is an appreciation of the phenomenon in space and time taking all epithelial nuclei and other subcellular arrangements into consideration. We here aim to elicit nuclear movements beyond the single cell level in zebrafish neuroepithelia in vivo, developing new tracking algorithms that will permit to obtain a holistic picture of all nuclear trajectories. This dataset will help to understand how nuclear movements influence tissue architecture and whether the dynamics of nuclear movement in IKNM are cause or consequence for tight nuclear packing. We will further investigate the links between the tissue scale organization of IKNM and the intracellular forces that lead to it, mainly focusing on the actin and the microtubule cytoskeleton. The outcome of the experimental work will be a prerequisite for a theoretical approach describing IKNM as an emergent property of the tightly packed epithelium, which is the ultimate goal of this proposal.