Beating flagella exhibit a variety of synchronization modes. This synchrony has long been attributed to hydrodynamic coupling between the flagella. However, recent work with flagellated algae indicates that a mechanism internal to the cell, through the contractile fibres connecting the flagella basal bodies, must be at play to actively modulate flagellar synchrony. Exactly how basal coupling mediates flagellar coordination remains unclear. Here, we examine the role of basal coupling in the synchronization of the model biflagellate Chlamydomonas reinhardtii using a series of mathematical models of decreasing levels of complexity. We report that basal coupling is sufficient to achieve inphase, antiphase and bistable synchrony, even in the absence of hydrodynamic coupling and flagellar compliance. These modes can be reached by modulating the activity level of the individual flagella or the strength of the basal coupling. We observe a slip mode when allowing for differential flagellar activity, just as in experiments with live cells. We introduce a dimensionless ratio of flagellar activity to basal coupling that is predictive of the mode of synchrony. This ratio allows us to query biological parameters which are not yet directly measurable experimentally. Our work shows a concrete route for cells to actively control the synchronization of their flagella.

中文翻译：

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细胞内偶联调节双鞭毛同步

跳动鞭毛表现出多种同步模式。这种同步一直归因于鞭毛之间的水动力耦合。然而，最近对鞭毛藻的研究表明，细胞内部的一种机制，通过连接鞭毛基体的收缩纤维，必须发挥作用，积极调节鞭毛同步。基础耦合究竟如何介导鞭毛协调仍不清楚。在这里，我们使用一系列降低复杂性的数学模型来检查基础耦合在模型双鞭毛藻莱茵衣藻同步中的作用。我们报告说，即使没有流体动力耦合和鞭毛顺应性，基础耦合也足以实现同相、反相和双稳态同步。这些模式可以通过调节单个鞭毛的活动水平或基础耦合的强度来实现。当允许差异鞭毛活动时，我们观察到滑动模式，就像在活细胞实验中一样。我们引入了鞭毛活动与基础耦合的无量纲比，它可以预测同步模式。这个比率使我们能够查询尚未通过实验直接测量的生物参数。我们的工作展示了细胞主动控制鞭毛同步的具体途径。我们引入了鞭毛活动与基础耦合的无量纲比，它可以预测同步模式。这个比率使我们能够查询尚未通过实验直接测量的生物参数。我们的工作展示了细胞主动控制鞭毛同步的具体途径。我们引入了鞭毛活动与基础耦合的无量纲比，它可以预测同步模式。这个比率使我们能够查询尚未通过实验直接测量的生物参数。我们的工作展示了细胞主动控制鞭毛同步的具体途径。