Nuclear crowding and nonlinear diffusion during interkinetic nuclear migration in the zebrafish retina.
Nuclear crowding and nonlinear diffusion during interkinetic nuclear migration in the zebrafish retina.
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DOI：
10.7554/elife.58635
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发表时间：
2020-10-06
期刊：
影响因子：
7.7
通讯作者：
Harris WA
中科院分区：
文献类型：
--
作者：
Azizi A;Herrmann A;Wan Y;Buse SJ;Keller PJ;Goldstein RE;Harris WA
在早期神经发育中的一个重要问题是运动间期核迁移过程中神经上皮细胞顶面和基面之间的随机核移动的起源。对核子群的跟踪显示了扩散的证据--平均平方位移随时间线性增长--并表明顶端表面细胞分裂的拥挤推动了基底面的运动。然而，这一假设尚未得到检验，所涉及的力量也没有量化。我们使用长期、快速的光片和双光子成像技术对早期斑马鱼的视网膜发生进行成像，以跟踪组织内的整个细胞核群体。随时间变化的浓度分布表明，当原子核达到紧密堆积时，存在明显的拥挤现象，并可用非线性扩散模型进行定量描述。对包被细胞膜内约束的核运动的考虑表明，细胞内依赖浓度的随机力在大小上与细胞骨架运输中的随机力一致，可以解释观察到的扩散常数的大小。
An important question in early neural development is the origin of stochastic nuclear movement between apical and basal surfaces of neuroepithelia during interkinetic nuclear migration. Tracking of nuclear subpopulations has shown evidence of diffusion - mean squared displacements growing linearly in time - and suggested crowding from cell division at the apical surface drives basalward motion. Yet, this hypothesis has not yet been tested, and the forces involved not quantified. We employ long-term, rapid light-sheet and two-photon imaging of early zebrafish retinogenesis to track entire populations of nuclei within the tissue. The time-varying concentration profiles show clear evidence of crowding as nuclei reach close-packing and are quantitatively described by a nonlinear diffusion model. Considerations of nuclear motion constrained inside the enveloping cell membrane show that concentration-dependent stochastic forces inside cells, compatible in magnitude to those found in cytoskeletal transport, can explain the observed magnitude of the diffusion constant.