How nematode sperm crawl.
How nematode sperm crawl.
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发表时间：
2002-01
影响因子：
4
通讯作者：
D. Bottino;A. Mogilner;T. Roberts;M. Stewart;G. Oster
中科院分区：
文献类型：
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作者：
D. Bottino;A. Mogilner;T. Roberts;M. Stewart;G. Oster
猪蛔虫（Ascaris suum）的精子通过板足状突起、粘附和收缩爬行，这一过程类似于其他真核细胞的变形虫运动。然而，线虫精子不是利用肌动蛋白细胞骨架来产生运动，而是使用主要精子蛋白（MSP）。此外，线虫精子缺乏可检测的分子马达或肌动蛋白结合蛋白电池，而肌动蛋白结合蛋白是肌动蛋白运动的特征。蛔虫系统提供了一个简单的“剥离”版本的爬行细胞，用于检查独立于涉及细胞骨架的其他细胞功能的细胞运动的基本机制。在这里，我们提出了蛔虫精子爬行的机械化学分析。我们构建了一个有限元模型，其中(a)局部的纤维聚合和束束产生板形延伸的力，(b)储存在凝胶中的能量由前缘的纤维束形成，随后用于产生收缩，将细胞后部向前拉。该模型再现了爬行精子的主要特征，并提供了一个可以分析变形虫细胞运动的框架。尽管该模型主要涉及线虫精子的运动，但它对基于肌动蛋白的细胞运动机制具有重要意义。
Sperm of the nematode, Ascaris suum, crawl using lamellipodial protrusion, adhesion and retraction, a process analogous to the amoeboid motility of other eukaryotic cells. However, rather than employing an actin cytoskeleton to generate locomotion, nematode sperm use the major sperm protein (MSP). Moreover, nematode sperm lack detectable molecular motors or the battery of actin-binding proteins that characterize actin-based motility. The Ascaris system provides a simple 'stripped down' version of a crawling cell in which to examine the basic mechanism of cell locomotion independently of other cellular functions that involve the cytoskeleton. Here we present a mechanochemical analysis of crawling in Ascaris sperm. We construct a finite element model wherein (a) localized filament polymerization and bundling generate the force for lamellipodial extension and (b) energy stored in the gel formed from the filament bundles at the leading edge is subsequently used to produce the contraction that pulls the rear of the cell forward. The model reproduces the major features of crawling sperm and provides a framework in which amoeboid cell motility can be analyzed. Although the model refers primarily to the locomotion of nematode sperm, it has important implications for the mechanics of actin-based cell motility.