Lablaine Armand, Juillot Dimitri, Condon Ciarán, Carballido-López Rut
Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France.
Expression Génétique Microbienne (CNRS, Université de Paris-Cité), Institut de Biologie Physico-Chimique, Paris, France.
Commun Biol. 2025 Jul 30;8(1):1131. doi: 10.1038/s42003-025-08522-w.
Spores of Bacillaceae, ubiquitous in soil, can withstand extreme conditions virtually indefinitely. The spore coat, one of the most sophisticated multiprotein complexes built by bacteria, protects the spore from environmental stresses and predators. In Bacillus subtilis, assembly of the multilayered coat initiates at the forespore pole and is perceived as a stable process that progresses continuously until covering the entire forespore surface. In contrast, in Bacillus cereus, coat formation initiates in the midspore region and extends outward to the spore poles. Using Structured Illumination Microscopy, we monitored B. subtilis coat development in real-time at the single-sporangium level with lateral resolution of 70 nm. We found that late-synthesized proteins from the innermost coat layers first assemble in the midspore region and are subsequently displaced toward the poles. This process is coupled with a unique redistribution of pre-assembled coat material across the forespore surface and influenced by outer coat development, highlighting a dynamic interplay in coat layer co-construction.
芽孢杆菌科的孢子在土壤中无处不在，几乎可以无限期地承受极端条件。芽孢衣是细菌构建的最复杂的多蛋白复合物之一，可保护孢子免受环境压力和捕食者的侵害。在枯草芽孢杆菌中，多层芽孢衣的组装在前芽孢极开始，被视为一个稳定的过程，持续进行直到覆盖整个前芽孢表面。相比之下，在蜡样芽孢杆菌中，芽孢衣的形成在芽孢中部区域开始，并向外延伸至芽孢极。我们使用结构光照显微镜，在单孢子囊水平实时监测枯草芽孢杆菌芽孢衣的发育，横向分辨率为70纳米。我们发现，最内层芽孢衣层的后期合成蛋白首先在芽孢中部区域组装，随后向两极移动。这一过程与预组装的芽孢衣材料在整个前芽孢表面的独特重新分布相关联，并受到外层芽孢衣发育的影响，突出了芽孢衣层共同构建中的动态相互作用。
