Uncovering the balance of forces driving microtubule aster migration in C. elegans zygotes
Uncovering the balance of forces driving microtubule aster migration in C. elegans zygotes
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DOI：
10.1038/s41467-018-03118-x
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发表时间：
2018-03-05
影响因子：
16.6
通讯作者：
Gonczy, P.
中科院分区：
文献类型：
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作者：
De Simone, A.;Spahr, A.;Gonczy, P.
微管紫菀必须精确定位在细胞内。分子马达（如dynein）产生的力是如何在空间和时间上整合，从而实现这种定位的，目前尚不清楚。特别是，紫菀的运动依赖于细胞质粘度引起的阻力，缺乏体内阻力测量，这妨碍了对紫菀定位机制的彻底理解。在这里，我们研究了秀丽隐杆线虫受精卵中母核和原核迁移过程中的这个基本问题，这一过程对于亲本基因组的混合至关重要。使用雌性原核作为体内探针对这些运动进行详细量化，确定雄性-紫苑复合物的阻力系数大约是雌性原核的五倍。对缺乏皮质动力蛋白的胚胎的进一步分析，紫苑和雄性原核之间的联系，或者整个雄性原核，揭示了动力蛋白驱动的力量的平衡，这种平衡精确地定位了秀丽隐杆线虫受精卵中的微管紫苑。
Microtubule asters must be positioned precisely within cells. How forces generated by molecular motors such as dynein are integrated in space and time to enable such positioning remains unclear. In particular, whereas aster movements depend on the drag caused by cytoplasm viscosity, in vivo drag measurements are lacking, precluding a thorough understanding of the mechanisms governing aster positioning. Here, we investigate this fundamental question during the migration of asters and pronuclei in C. elegans zygotes, a process essential for the mixing of parental genomes. Detailed quantification of these movements using the female pronucleus as an in vivo probe establish that the drag coefficient of the male-asters complex is approximately five times that of the female pronucleus. Further analysis of embryos lacking cortical dynein, the connection between asters and male pronucleus, or the male pronucleus altogether, uncovers the balance of dynein-driven forces that accurately position microtubule asters in C. elegans zygotes.