DiaMot: Motility of diatoms and its contribution to benthic biofilm formation

硅藻是一组高度多样化的微藻，占水生系统的主导地位，占全球初级生产的四分之一。在潮间带沉积物中，它们对底栖生物膜群落有重要贡献，从而在生态系统功能中发挥重要作用。这些生物膜形成细胞通过主动运动在复杂和动态的微生境中茁壮成长。与其他能动生物不同，硅藻缺乏纤毛，鞭毛或由于其刚性硅化细胞壁而改变形状的灵活性，因此代表了一种用于理解细胞运动和表面适应性的新系统。这一建议集中在三个方面，共同提供了第一个完整的行为和机制表征硅藻运动及其在生物膜形成中的作用。为此，我将（1）表征代表性优势底栖硅藻的基线运动;（2）评估轨迹如何随扰动而变化（即，光、硅酸盐可用性、基底形貌、剪切）;以及（3）研究复杂3D基底中的运动模式，用于原位观察个体和群体动态。在这项工作中，我选择了五个具有代表性的硅藻物种（常见的底栖生物膜的重要组成部分），表现出不同的中缝形态和垂直迁移模式。该提案将首次在2D和3D场景中实现硅藻运动的完整表征。独特的是，这项工作将寻求尖端的显微镜和计算机视觉技术来解决个人的行为模式，以提供对运动和生物膜形成的生物力学的新理解。我的项目的结果对于预测生物膜群落中存在的微尺度异质性如何最终影响生态系统的全球调节至关重要。这个奖学金也将促进我的职业发展，并作为科学独立的跳板。

Diatoms are a group of highly diverse microalgae dominating aquatic systems and contributing to a quarter of the global primary production. In intertidal sediments, they contribute significantly to benthic biofilm communities, thereby playing an essential role in ecosystem functioning. These biofilm-forming cells thrive in a complex and dynamic microhabitat through active motility. Unlike other motile organisms, diatoms lack cilia, flagella, or the flexibility to change shape due to their rigid silicified cell walls, and hence represent a novel system for understanding cellular movement and adaptability on surfaces. This proposal focuses on three aspects that together will deliver the first complete behavioural and mechanistic characterisation of diatom motility and its role in biofilm formation.To this end, I will (1) characterize the baseline motility of representative dominant benthic diatoms; (2) evaluate how trajectories change with perturbations (i.e., light, silicate availability, substrate topography, shear); and (3) investigate movement patterns in complex 3D substrates for in situ observation of individual and population dynamics. For this work, I have selected five representative diatom species (important constituents of common benthic biofilms) that exhibit distinct raphe morphology and vertical migration patterns. This proposal will achieve the first complete characterisation of diatom motility in both 2D and 3D scenarios. Uniquely, this work will solicit cutting-edge microscopy and computer vision technology to resolve the behavioural patterns of individuals to provide novel understanding of the biomechanics of motility and biofilm formation. The outcomes of my project are critical to predict how microscale heterogeneity present within biofilm communities can ultimately impact the global regulation of ecosystems. This fellowship will also advance my career development and act as a springboard for scientific independence.