Form-function relationships in the development of Bacillus subtilis fruiting bodies

天然分离的内孢子形成模式细菌枯草芽孢杆菌表现出复杂的多细胞特性。与植物类似，枯草芽孢杆菌的一个孢子可以产生一个三维的宏观多细胞结构，产生更多的孢子——一个子实体。不同类型的细胞参与子实体及其亚结构的形成。在这个项目中，我们将研究细胞类型的特定功能如何支持生物膜皱纹的形成（“功能驱动形式”）以及大菌落结构如何影响孢子的产生（“形式驱动功能”）。在细胞类型特异性荧光报告器的帮助下，我们将在整个大菌落水平及其亚结构水平上成像到单个细胞（孢子）。我们将开发基于深度学习的计算机图像分析方法，以量化空间和时间上的细胞状态转换。通过这种方法和其他方法，我们将通过对枯草芽孢杆菌进行有针对性的遗传操作来测试关于子实体形成的不同假设。这将揭示这些遗传因素是否以及如何在多细胞发育过程中促进涌现特性。

Natural isolates of the endospore-forming model bacterium Bacillus subtilis show complex multicellular traits. Similar to plants, out of a spore of B. subtilis a 3D macroscopic multicellular structure can emerge that produces many more spores - a fruiting body. Different cell types partake in the formation of a fruiting body and its substructures. In this project, we will study how cell-type specific functions support the formation of biofilm wrinkles (“function drives form”) and how macrocolony architecture affects the production of spores (“form drives function”). With the help of cell-type specific fluorescent reporters we will image processes at the level of the entire macrocolony and at the level of its substructures down to individual cells (spores). We will develop computer-based image analysis methods based on deep learning in order to quantify cellular state transitions in space and time. With this approach – and other methods - we will test different hypotheses regarding the formation of fruiting bodies by targeted genetic manipulations of B. subtilis. This will reveal whether and how these genetic elements contribute to emergent properties during multicellular development.