Sperm navigation along helical paths in 3D chemoattractant landscapes.
Sperm navigation along helical paths in 3D chemoattractant landscapes.
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DOI：
10.1038/ncomms8985
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发表时间：
2015-08-17
影响因子：
16.6
通讯作者：
Kaupp UB
中科院分区：
文献类型：
--
作者：
Jikeli JF;Alvarez L;Friedrich BM;Wilson LG;Pascal R;Colin R;Pichlo M;Rennhack A;Brenker C;Kaupp UB
精子需要方向感来定位卵子进行受精。它们遵循由卵子或输卵管提供的化学和物理线索的梯度。然而，化学景观中的三维（3D）导航的基本原理是未知的。在这里，使用全息显微镜和光化学技术，我们跟踪海胆精子导航三维化学引诱梯度。精子在两个时间尺度上感知梯度，从而产生两种不同的转向反应。由螺旋游动产生的周期性分量使螺旋逐渐朝向梯度排列。当渐进式路径修正失败，精子偏离轨道时，一个急转弯的动作会让精子回到轨道上。转向的结果从一个'关闭'的Ca 2+反应，标志着化学引诱物刺激减少，从而，在环GMP浓度和膜电压下降。这些发现强调了计算的复杂性，精子样本梯度确定性klinotaxis。我们提供了一个概念和技术框架，在三维化学景观研究microswimmer。精子利用外部线索来寻找卵子，使用不明确的原则。在这里，作者使用全息显微镜和光化学工具来研究精子在光雕刻的化学3D景观中的游泳;他们表明精子将时间刺激模式转化为多种游泳行为，以确定性地在梯度中定向。
Sperm require a sense of direction to locate the egg for fertilization. They follow gradients of chemical and physical cues provided by the egg or the oviduct. However, the principles underlying three-dimensional (3D) navigation in chemical landscapes are unknown. Here using holographic microscopy and optochemical techniques, we track sea urchin sperm navigating in 3D chemoattractant gradients. Sperm sense gradients on two timescales, which produces two different steering responses. A periodic component, resulting from the helical swimming, gradually aligns the helix towards the gradient. When incremental path corrections fail and sperm get off course, a sharp turning manoeuvre puts sperm back on track. Turning results from an ‘off' Ca2+ response signifying a chemoattractant stimulation decrease and, thereby, a drop in cyclic GMP concentration and membrane voltage. These findings highlight the computational sophistication by which sperm sample gradients for deterministic klinotaxis. We provide a conceptual and technical framework for studying microswimmers in 3D chemical landscapes. Sperm use external cues to find the egg using ill-defined principles. Here the authors use holographic microscopy and optochemical tools to study sperm swimming in light-sculpted chemical 3D landscapes; they show that sperm translate the temporal stimulation pattern into multiple swimming behaviours to orient deterministically in a gradient.