Morphogenesis of hierarchically patterned diatom biosilica: theory and experiment

硅藻细胞壁复杂的二氧化硅图案因其遗传编码的可变性和结构复杂性而吸引了生物学家，工程师因其应用潜力而着迷，自然科学家和外行都因其美丽而着迷。然而，我们不了解指导具有规则间隔的肋和纳米孔的生物二氧化硅图案的自组织形成的物理和化学原理，也没有通过今天的材料合成获得类似复杂性的结构。我们的目的是揭示一般原则的生物硅模式形成中心硅藻物种。为了实现这一目标，我们提出了一个物理指导的数学建模和有针对性的遗传扰动实验相结合，以机械地了解层次生物二氧化硅模式如何形成内部的增长隔间。该项目已成为可能，通过最近的进展，实验分析硅藻二氧化硅形态。它建立在Kröger和Friedrich小组之间建立的合作基础上，导致在一个关键硅藻物种中形成分支肋骨模式的模型。我们的目标是一个集成模型的形式相分离反应扩散系统在一个不断增长的二维域，定量占（一）分支肋图案，（二）肋之间的横向连接，和（三）定期定位孔，其中可解释的模型参数的变化占不同的二氧化硅阀模式在三个原型硅藻物种与径向对称。使用硅藻作为模型系统，我们将推进一个一般性的理解如何活细胞的遗传编码的有机机械雕塑无机矿物。

The intricate silica patterns of diatom cell walls have fascinated biologists for their genetically encoded variability and structural intricacy, engineers for their application potential, and natural scientists and laymen alike for their beauty. Yet, we do not understand the physical and chemical principles that guide the self-organized formation of biosilica patterns with regularly spaced ribs and nano-pores, nor are structures of similar complexity accessible through material synthesis today. We aim to reveal general principles of biosilica pattern formation across centric diatom species. To achieve this, we propose a combination of physics-guided mathematical modeling and targeted genetic perturbation experiments to mechanistically understand how hierarchical biosilica patterns form inside a growing compartment. This project has become possible through recent advances in experimental analysis of diatom silica morphogenesis. It builds on an established collaboration between the Kröger and Friedrich groups resulting in a model for the formation of branched rib patterns in a key diatom species. We aim for an integrated model in the form of a phase-separating reaction-diffusion system in a growing two-dimensional domain that quantitatively accounts for (i) branched rib patterns, (ii) transverse connections between ribs, and (iii) regularly positioned pores, where interpretable changes of model parameters account for different silica valve patterns in three prototypical diatom species with radial symmetry. Using diatoms as model system, we will advance a general understanding how the genetically-encoded organic machineries of living cells sculpture inorganic minerals.