Phenotyping single-cell motility in microfluidic confinement.
Phenotyping single-cell motility in microfluidic confinement.
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作者：
Bentley SA;Laeverenz-Schlogelhofer H;Anagnostidis V;Cammann J;Mazza MG;Gielen F;Wan KY
生物体的运动轨迹是其行为和生理的动态读数。对于微生物来说，由于它们的体积小和移动快，这可能很难解决。在这里，我们设计了一种新的液滴微流体检测方法，将单个微米大小的藻类封装在封闭的区域内，从而实现对同一细胞的超长高速跟踪。比较两个模式物种-衣藻reinhardtii（淡水，2纤毛），和Pyramimonas章鱼（海洋，8纤毛），我们详细介绍了他们的高度定型，但对比鲜明的游泳行为和环境相互作用。通过测量细胞在三种运动状态（平稳向前游泳、静止、翻滚或兴奋向后游泳）之间转变的速率和概率，我们重建了这种步态切换动态的控制网络。一个简化的模型，细胞漫游循环限制再现所观察到的长期行为和空间通量，包括新的边界循环行为。最后，我们建立了一种检测方法，其中成对的液滴按需融合，一个含有一个被困的细胞，另一个含有一种扰乱细胞兴奋性的化学物质，以揭示neural微生物如何实时适应它们的运动模式。
The movement trajectories of organisms serve as dynamic read-outs of their behaviour and physiology. For microorganisms this can be difficult to resolve due to their small size and fast movement. Here, we devise a novel droplet microfluidics assay to encapsulate single micron-sized algae inside closed arenas, enabling ultralong high-speed tracking of the same cell. Comparing two model species - Chlamydomonas reinhardtii (freshwater, 2 cilia), and Pyramimonas octopus (marine, 8 cilia), we detail their highly-stereotyped yet contrasting swimming behaviours and environmental interactions. By measuring the rates and probabilities with which cells transition between a trio of motility states (smooth-forward swimming, quiescence, tumbling or excitable backward swimming), we reconstruct the control network that underlies this gait switching dynamics. A simplified model of cell-roaming in circular confinement reproduces the observed long-term behaviours and spatial fluxes, including novel boundary circulation behaviour. Finally, we establish an assay in which pairs of droplets are fused on demand, one containing a trapped cell with another containing a chemical that perturbs cellular excitability, to reveal how aneural microorganisms adapt their locomotor patterns in real-time.