A positive-feedback-based mechanism for constriction rate acceleration during cytokinesis in Caenorhabditis elegans.
A positive-feedback-based mechanism for constriction rate acceleration during cytokinesis in Caenorhabditis elegans.
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DOI：
10.7554/elife.36073
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发表时间：
2018-07-02
期刊：
影响因子：
7.7
通讯作者：
Oegema K
中科院分区：
文献类型：
--
作者：
Khaliullin RN;Green RA;Shi LZ;Gomez-Cavazos JS;Berns MW;Desai A;Oegema K
为了确保及时的胞质分裂，赤道肌球蛋白收缩环以相对恒定的速度收缩，尽管其大小逐渐减小。因此，单位长度的收缩速率随着环周长的减小而增加。为了了解这种加速，我们监测了秀丽线虫胚胎第一次细胞质分裂过程中皮质表面和环成分的动态变化。我们发现，在单位长度内，环组分(肌球蛋白、香草素)的数量和收缩速度呈平行的指数动力学增加。皮质血流的定量分析表明，环内的皮质沿垂直于环的轴线受到压缩，在收缩过程中，单位长度的皮质压缩率与环肌球蛋白成比例增加。我们提出，环状肌球蛋白与压缩驱动的皮质流进入环状结构之间的正反馈驱动环状肌球蛋白单位长度的数量指数增加，以维持较高的环状收缩速率，并用解析的数学模型支持这一假设。
To ensure timely cytokinesis, the equatorial actomyosin contractile ring constricts at a relatively constant rate despite its progressively decreasing size. Thus, the per-unit-length constriction rate increases as ring perimeter decreases. To understand this acceleration, we monitored cortical surface and ring component dynamics during the first cytokinesis of the Caenorhabditis elegans embryo. We found that, per unit length, the amount of ring components (myosin, anillin) and the constriction rate increase with parallel exponential kinetics. Quantitative analysis of cortical flow indicated that the cortex within the ring is compressed along the axis perpendicular to the ring, and the per-unit-length rate of cortical compression increases during constriction in proportion to ring myosin. We propose that positive feedback between ring myosin and compression-driven flow of cortex into the ring drives an exponential increase in the per-unit-length amount of ring myosin to maintain a high ring constriction rate and support this proposal with an analytical mathematical model.